Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted

Pull I3C updates from Alexandre Belloni:
 "A new driver this cycle, for the AMD AXI I3C controller.

  There are also new features such as IBI wakeup support, SETAASA device
  discovery and ACPI support for the the DAA methods, meaning we can now
  communicate with the SPD devices on DDR5 modules.

  New driver:
   - AMD AXI I3C master controller

  Subsystem:
   - I3C Common Command Code (CCC) handling improvements, especially
     around GET CCCs
   - SETAASA device discovery support
   - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
     well as I2C devices on I3C bus
   - IBI-based wakeup support

  Drivers:
   - dw: SETAASA support
   - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
     controller support, PIO queue management support for HCI v1.2
   - renesas: improve suspend to RAM support, add runtime PM support"

* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
  i3c: dw: reduce do_daa time if there's no client
  i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
  i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
  i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
  i3c: dw: rename "pclk" to "apb" to match dt-binding
  i3c: dw: make struct dw_i3c_cmd smaller
  i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
  i3c: renesas: Don't register devices when ENTDAA times out
  i3c: master: dw-i3c-master: fix OD timing for first broadcast
  i3c: mipi-i3c-hci: Advertise IBI wakeup capability
  i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
  i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
  i3c: master: Reject IBI requests from non-IBI-capable devices
  i3c: master: Add helper to query bus wakeup requirements
  i3c: master: Report wakeup events for IBIs
  i3c: master: Support IBI-based wakeup capability
  i3c: master: Fix potential UAF in i3c_device_match()
  i3c: master: Fix potential UAF in i3c_device_uevent()
  i3c: Make dev->desc locking assumptions explicit
  i3c: master: Fix use-after-free of master->this
  ...

13 files changed, 9270 insertions, 0 deletions

diff --git a/fs/btrfs/tests/btrfs-tests.c b/fs/btrfs/tests/btrfs-tests.c
new file mode 100644
index 000000000..6287d9403
--- /dev/null
+++ b/fs/btrfs/tests/btrfs-tests.c
@@ -0,0 +1,314 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2013 Fusion IO.  All rights reserved.
+ */
+
+#include <linux/fs.h>
+#include <linux/mount.h>
+#include <linux/pseudo_fs.h>
+#include <linux/magic.h>
+#include "btrfs-tests.h"
+#include "../ctree.h"
+#include "../free-space-cache.h"
+#include "../free-space-tree.h"
+#include "../transaction.h"
+#include "../volumes.h"
+#include "../disk-io.h"
+#include "../qgroup.h"
+#include "../block-group.h"
+#include "../fs.h"
+
+static struct vfsmount *test_mnt = NULL;
+
+const char *test_error[] = {
+	[TEST_ALLOC_FS_INFO]	     = "cannot allocate fs_info",
+	[TEST_ALLOC_ROOT]	     = "cannot allocate root",
+	[TEST_ALLOC_EXTENT_BUFFER]   = "cannot extent buffer",
+	[TEST_ALLOC_PATH]	     = "cannot allocate path",
+	[TEST_ALLOC_INODE]	     = "cannot allocate inode",
+	[TEST_ALLOC_BLOCK_GROUP]     = "cannot allocate block group",
+	[TEST_ALLOC_EXTENT_MAP]      = "cannot allocate extent map",
+	[TEST_ALLOC_CHUNK_MAP]       = "cannot allocate chunk map",
+	[TEST_ALLOC_IO_CONTEXT]	     = "cannot allocate io context",
+	[TEST_ALLOC_TRANSACTION]     = "cannot allocate transaction",
+};
+
+static const struct super_operations btrfs_test_super_ops = {
+	.alloc_inode	= btrfs_alloc_inode,
+	.destroy_inode	= btrfs_test_destroy_inode,
+};
+
+
+static int btrfs_test_init_fs_context(struct fs_context *fc)
+{
+	struct pseudo_fs_context *ctx = init_pseudo(fc, BTRFS_TEST_MAGIC);
+	if (!ctx)
+		return -ENOMEM;
+	ctx->ops = &btrfs_test_super_ops;
+	return 0;
+}
+
+static struct file_system_type test_type = {
+	.name		= "btrfs_test_fs",
+	.init_fs_context = btrfs_test_init_fs_context,
+	.kill_sb	= kill_anon_super,
+};
+
+struct inode *btrfs_new_test_inode(void)
+{
+	struct inode *inode;
+
+	inode = new_inode(test_mnt->mnt_sb);
+	if (!inode)
+		return NULL;
+
+	inode->i_mode = S_IFREG;
+	btrfs_set_inode_number(BTRFS_I(inode), BTRFS_FIRST_FREE_OBJECTID);
+	inode_init_owner(&nop_mnt_idmap, inode, NULL, S_IFREG);
+
+	return inode;
+}
+
+static int btrfs_init_test_fs(void)
+{
+	int ret;
+
+	ret = register_filesystem(&test_type);
+	if (ret) {
+		printk(KERN_ERR "btrfs: cannot register test file system\n");
+		return ret;
+	}
+
+	test_mnt = kern_mount(&test_type);
+	if (IS_ERR(test_mnt)) {
+		printk(KERN_ERR "btrfs: cannot mount test file system\n");
+		unregister_filesystem(&test_type);
+		return PTR_ERR(test_mnt);
+	}
+	return 0;
+}
+
+static void btrfs_destroy_test_fs(void)
+{
+	kern_unmount(test_mnt);
+	unregister_filesystem(&test_type);
+}
+
+struct btrfs_device *btrfs_alloc_dummy_device(struct btrfs_fs_info *fs_info)
+{
+	struct btrfs_device *dev;
+
+	dev = kzalloc_obj(*dev);
+	if (!dev)
+		return ERR_PTR(-ENOMEM);
+
+	btrfs_extent_io_tree_init(fs_info, &dev->alloc_state, 0);
+	INIT_LIST_HEAD(&dev->dev_list);
+	list_add(&dev->dev_list, &fs_info->fs_devices->devices);
+
+	return dev;
+}
+
+static void btrfs_free_dummy_device(struct btrfs_device *dev)
+{
+	btrfs_extent_io_tree_release(&dev->alloc_state);
+	kfree(dev);
+}
+
+struct btrfs_fs_info *btrfs_alloc_dummy_fs_info(u32 nodesize, u32 sectorsize)
+{
+	struct btrfs_fs_info *fs_info = kzalloc_obj(struct btrfs_fs_info);
+
+	if (!fs_info)
+		return fs_info;
+	fs_info->fs_devices = kzalloc_obj(struct btrfs_fs_devices);
+	if (!fs_info->fs_devices) {
+		kfree(fs_info);
+		return NULL;
+	}
+	INIT_LIST_HEAD(&fs_info->fs_devices->devices);
+
+	fs_info->super_copy = kzalloc_obj(struct btrfs_super_block);
+	if (!fs_info->super_copy) {
+		kfree(fs_info->fs_devices);
+		kfree(fs_info);
+		return NULL;
+	}
+
+	btrfs_init_fs_info(fs_info);
+
+	fs_info->nodesize = nodesize;
+	fs_info->sectorsize = sectorsize;
+	fs_info->sectorsize_bits = ilog2(sectorsize);
+
+	/* CRC32C csum size. */
+	fs_info->csum_size = 4;
+	fs_info->csums_per_leaf = BTRFS_MAX_ITEM_SIZE(fs_info) /
+		fs_info->csum_size;
+	fs_info->use_bitmap = btrfs_use_bitmap;
+	set_bit(BTRFS_FS_STATE_DUMMY_FS_INFO, &fs_info->fs_state);
+
+	test_mnt->mnt_sb->s_fs_info = fs_info;
+
+	return fs_info;
+}
+
+void btrfs_free_dummy_fs_info(struct btrfs_fs_info *fs_info)
+{
+	struct btrfs_device *dev, *tmp;
+	struct extent_buffer *eb;
+	unsigned long index;
+
+	if (!fs_info)
+		return;
+
+	if (WARN_ON(!btrfs_is_testing(fs_info)))
+		return;
+
+	test_mnt->mnt_sb->s_fs_info = NULL;
+
+	xa_lock_irq(&fs_info->buffer_tree);
+	xa_for_each(&fs_info->buffer_tree, index, eb) {
+		xa_unlock_irq(&fs_info->buffer_tree);
+		free_extent_buffer(eb);
+		xa_lock_irq(&fs_info->buffer_tree);
+	}
+	xa_unlock_irq(&fs_info->buffer_tree);
+
+	btrfs_mapping_tree_free(fs_info);
+	list_for_each_entry_safe(dev, tmp, &fs_info->fs_devices->devices,
+				 dev_list) {
+		btrfs_free_dummy_device(dev);
+	}
+	btrfs_free_qgroup_config(fs_info);
+	btrfs_free_fs_roots(fs_info);
+	kfree(fs_info->super_copy);
+	btrfs_check_leaked_roots(fs_info);
+	btrfs_extent_buffer_leak_debug_check(fs_info);
+	kfree(fs_info->fs_devices);
+	kfree(fs_info);
+}
+
+void btrfs_free_dummy_root(struct btrfs_root *root)
+{
+	if (IS_ERR_OR_NULL(root))
+		return;
+	/* Will be freed by btrfs_free_fs_roots */
+	if (WARN_ON(test_bit(BTRFS_ROOT_IN_RADIX, &root->state)))
+		return;
+	btrfs_global_root_delete(root);
+	btrfs_put_root(root);
+}
+
+struct btrfs_block_group *
+btrfs_alloc_dummy_block_group(struct btrfs_fs_info *fs_info,
+			      unsigned long length)
+{
+	struct btrfs_block_group *cache;
+
+	cache = kzalloc_obj(*cache);
+	if (!cache)
+		return NULL;
+	cache->free_space_ctl = kzalloc_obj(*cache->free_space_ctl);
+	if (!cache->free_space_ctl) {
+		kfree(cache);
+		return NULL;
+	}
+
+	cache->start = 0;
+	cache->length = length;
+	cache->full_stripe_len = fs_info->sectorsize;
+	cache->fs_info = fs_info;
+
+	INIT_LIST_HEAD(&cache->list);
+	INIT_LIST_HEAD(&cache->cluster_list);
+	INIT_LIST_HEAD(&cache->bg_list);
+	btrfs_init_free_space_ctl(cache, cache->free_space_ctl);
+	mutex_init(&cache->free_space_lock);
+
+	return cache;
+}
+
+void btrfs_free_dummy_block_group(struct btrfs_block_group *cache)
+{
+	if (!cache)
+		return;
+	btrfs_remove_free_space_cache(cache);
+	kfree(cache->free_space_ctl);
+	kfree(cache);
+}
+
+void btrfs_init_dummy_transaction(struct btrfs_transaction *trans, struct btrfs_fs_info *fs_info)
+{
+	memset(trans, 0, sizeof(*trans));
+	trans->fs_info = fs_info;
+	xa_init(&trans->delayed_refs.head_refs);
+	xa_init(&trans->delayed_refs.dirty_extents);
+	spin_lock_init(&trans->delayed_refs.lock);
+}
+
+void btrfs_init_dummy_trans(struct btrfs_trans_handle *trans,
+			    struct btrfs_fs_info *fs_info)
+{
+	memset(trans, 0, sizeof(*trans));
+	trans->transid = 1;
+	trans->type = __TRANS_DUMMY;
+	trans->fs_info = fs_info;
+}
+
+int btrfs_run_sanity_tests(void)
+{
+	int ret, i;
+	u32 sectorsize, nodesize;
+	u32 test_sectorsize[] = {
+		PAGE_SIZE,
+	};
+	ret = btrfs_init_test_fs();
+	if (ret)
+		return ret;
+	for (i = 0; i < ARRAY_SIZE(test_sectorsize); i++) {
+		sectorsize = test_sectorsize[i];
+		for (nodesize = sectorsize;
+		     nodesize <= BTRFS_MAX_METADATA_BLOCKSIZE;
+		     nodesize <<= 1) {
+			pr_info("BTRFS: selftest: sectorsize: %u  nodesize: %u\n",
+				sectorsize, nodesize);
+			ret = btrfs_test_free_space_cache(sectorsize, nodesize);
+			if (ret)
+				goto out;
+			ret = btrfs_test_extent_buffer_operations(sectorsize,
+				nodesize);
+			if (ret)
+				goto out;
+			ret = btrfs_test_extent_io(sectorsize, nodesize);
+			if (ret)
+				goto out;
+			ret = btrfs_test_inodes(sectorsize, nodesize);
+			if (ret)
+				goto out;
+			ret = btrfs_test_qgroups(sectorsize, nodesize);
+			if (ret)
+				goto out;
+			ret = btrfs_test_free_space_tree(sectorsize, nodesize);
+			if (ret)
+				goto out;
+			ret = btrfs_test_raid_stripe_tree(sectorsize, nodesize);
+			if (ret)
+				goto out;
+			ret = btrfs_test_delayed_refs(sectorsize, nodesize);
+			if (ret)
+				goto out;
+			ret = btrfs_test_chunk_allocation(sectorsize, nodesize);
+			if (ret)
+				goto out;
+		}
+	}
+	ret = btrfs_test_extent_map();
+	if (ret)
+		goto out;
+	ret = btrfs_test_zoned();
+
+out:
+	btrfs_destroy_test_fs();
+	return ret;
+}
diff --git a/fs/btrfs/tests/btrfs-tests.h b/fs/btrfs/tests/btrfs-tests.h
new file mode 100644
index 000000000..cea58fe84
--- /dev/null
+++ b/fs/btrfs/tests/btrfs-tests.h
@@ -0,0 +1,83 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2013 Fusion IO.  All rights reserved.
+ */
+
+#ifndef BTRFS_TESTS_H
+#define BTRFS_TESTS_H
+
+#include <linux/types.h>
+#include <linux/cleanup.h>
+
+#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
+
+int btrfs_run_sanity_tests(void);
+
+#define test_msg(fmt, ...) pr_info("BTRFS: selftest: " fmt "\n", ##__VA_ARGS__)
+#define test_err(fmt, ...) pr_err("BTRFS: selftest: %s:%d " fmt "\n",	\
+		__FILE__, __LINE__, ##__VA_ARGS__)
+
+#define test_std_err(index)	test_err("%s", test_error[index])
+
+enum {
+	TEST_ALLOC_FS_INFO,
+	TEST_ALLOC_ROOT,
+	TEST_ALLOC_EXTENT_BUFFER,
+	TEST_ALLOC_PATH,
+	TEST_ALLOC_INODE,
+	TEST_ALLOC_BLOCK_GROUP,
+	TEST_ALLOC_EXTENT_MAP,
+	TEST_ALLOC_CHUNK_MAP,
+	TEST_ALLOC_IO_CONTEXT,
+	TEST_ALLOC_TRANSACTION,
+};
+
+extern const char *test_error[];
+
+struct btrfs_root;
+struct btrfs_trans_handle;
+struct btrfs_transaction;
+
+int btrfs_test_extent_buffer_operations(u32 sectorsize, u32 nodesize);
+int btrfs_test_free_space_cache(u32 sectorsize, u32 nodesize);
+int btrfs_test_extent_io(u32 sectorsize, u32 nodesize);
+int btrfs_test_inodes(u32 sectorsize, u32 nodesize);
+int btrfs_test_qgroups(u32 sectorsize, u32 nodesize);
+int btrfs_test_free_space_tree(u32 sectorsize, u32 nodesize);
+int btrfs_test_raid_stripe_tree(u32 sectorsize, u32 nodesize);
+int btrfs_test_extent_map(void);
+int btrfs_test_delayed_refs(u32 sectorsize, u32 nodesize);
+int btrfs_test_chunk_allocation(u32 sectorsize, u32 nodesize);
+struct inode *btrfs_new_test_inode(void);
+struct btrfs_fs_info *btrfs_alloc_dummy_fs_info(u32 nodesize, u32 sectorsize);
+void btrfs_free_dummy_fs_info(struct btrfs_fs_info *fs_info);
+DEFINE_FREE(btrfs_free_dummy_fs_info, struct btrfs_fs_info *,
+	    btrfs_free_dummy_fs_info(_T))
+void btrfs_free_dummy_root(struct btrfs_root *root);
+struct btrfs_block_group *
+btrfs_alloc_dummy_block_group(struct btrfs_fs_info *fs_info, unsigned long length);
+void btrfs_free_dummy_block_group(struct btrfs_block_group *cache);
+DEFINE_FREE(btrfs_free_dummy_block_group, struct btrfs_block_group *,
+	    btrfs_free_dummy_block_group(_T));
+void btrfs_init_dummy_trans(struct btrfs_trans_handle *trans,
+			    struct btrfs_fs_info *fs_info);
+void btrfs_init_dummy_transaction(struct btrfs_transaction *trans, struct btrfs_fs_info *fs_info);
+struct btrfs_device *btrfs_alloc_dummy_device(struct btrfs_fs_info *fs_info);
+
+#ifdef CONFIG_BLK_DEV_ZONED
+int btrfs_test_zoned(void);
+#else
+static inline int btrfs_test_zoned(void)
+{
+	return 0;
+}
+#endif
+
+#else
+static inline int btrfs_run_sanity_tests(void)
+{
+	return 0;
+}
+#endif
+
+#endif
diff --git a/fs/btrfs/tests/chunk-allocation-tests.c b/fs/btrfs/tests/chunk-allocation-tests.c
new file mode 100644
index 000000000..9beb0602f
--- /dev/null
+++ b/fs/btrfs/tests/chunk-allocation-tests.c
@@ -0,0 +1,476 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2026 Meta.  All rights reserved.
+ */
+
+#include <linux/sizes.h>
+#include "btrfs-tests.h"
+#include "../volumes.h"
+#include "../disk-io.h"
+#include "../extent-io-tree.h"
+
+/*
+ * Tests for chunk allocator pending extent internals.
+ * These two functions form the core of searching the chunk allocation pending
+ * extent bitmap and have relatively easily definable semantics, so unit
+ * testing them can help ensure the correctness of chunk allocation.
+ */
+
+/*
+ * Describes the inputs to the system and expected results
+ * when testing btrfs_find_hole_in_pending_extents().
+ */
+struct pending_extent_test_case {
+	const char *name;
+	/* Input range to search. */
+	u64 hole_start;
+	u64 hole_len;
+	/* The size of hole we are searching for. */
+	u64 min_hole_size;
+	/*
+	 * Pending extents to set up (up to 2 for up to 3 holes)
+	 * If len == 0, then it is skipped.
+	 */
+	struct {
+		u64 start;
+		u64 len;
+	} pending_extents[2];
+	/* Expected outputs. */
+	bool expected_found;
+	u64 expected_start;
+	u64 expected_len;
+};
+
+static const struct pending_extent_test_case find_hole_tests[] = {
+	{
+		.name = "no pending extents",
+		.hole_start = 0,
+		.hole_len = 10ULL * SZ_1G,
+		.min_hole_size = SZ_1G,
+		.pending_extents = { },
+		.expected_found = true,
+		.expected_start = 0,
+		.expected_len = 10ULL * SZ_1G,
+	},
+	{
+		.name = "pending extent at start of range",
+		.hole_start = 0,
+		.hole_len = 10ULL * SZ_1G,
+		.min_hole_size = SZ_1G,
+		.pending_extents = {
+			{ .start = 0, .len = SZ_1G },
+		},
+		.expected_found = true,
+		.expected_start = SZ_1G,
+		.expected_len = 9ULL * SZ_1G,
+	},
+	{
+		.name = "pending extent overlapping start of range",
+		.hole_start = SZ_1G,
+		.hole_len = 9ULL * SZ_1G,
+		.min_hole_size = SZ_1G,
+		.pending_extents = {
+			{ .start = 0, .len = SZ_2G },
+		},
+		.expected_found = true,
+		.expected_start = SZ_2G,
+		.expected_len = 8ULL * SZ_1G,
+	},
+	{
+		.name = "two holes; first hole is exactly big enough",
+		.hole_start = 0,
+		.hole_len = 10ULL * SZ_1G,
+		.min_hole_size = SZ_1G,
+		.pending_extents = {
+			{ .start = SZ_1G, .len = SZ_1G },
+		},
+		.expected_found = true,
+		.expected_start = 0,
+		.expected_len = SZ_1G,
+	},
+	{
+		.name = "two holes; first hole is big enough",
+		.hole_start = 0,
+		.hole_len = 10ULL * SZ_1G,
+		.min_hole_size = SZ_1G,
+		.pending_extents = {
+			{ .start = SZ_2G, .len = SZ_1G },
+		},
+		.expected_found = true,
+		.expected_start = 0,
+		.expected_len = SZ_2G,
+	},
+	{
+		.name = "two holes; second hole is big enough",
+		.hole_start = 0,
+		.hole_len = 10ULL * SZ_1G,
+		.min_hole_size = SZ_2G,
+		.pending_extents = {
+			{ .start = SZ_1G, .len = SZ_1G },
+		},
+		.expected_found = true,
+		.expected_start = SZ_2G,
+		.expected_len = 8ULL * SZ_1G,
+	},
+	{
+		.name = "three holes; first hole big enough",
+		.hole_start = 0,
+		.hole_len = 10ULL * SZ_1G,
+		.min_hole_size = SZ_2G,
+		.pending_extents = {
+			{ .start = SZ_2G, .len = SZ_1G },
+			{ .start = 4ULL * SZ_1G, .len = SZ_1G },
+		},
+		.expected_found = true,
+		.expected_start = 0,
+		.expected_len = SZ_2G,
+	},
+	{
+		.name = "three holes; second hole big enough",
+		.hole_start = 0,
+		.hole_len = 10ULL * SZ_1G,
+		.min_hole_size = SZ_2G,
+		.pending_extents = {
+			{ .start = SZ_1G, .len = SZ_1G },
+			{ .start = 5ULL * SZ_1G, .len = SZ_1G },
+		},
+		.expected_found = true,
+		.expected_start = SZ_2G,
+		.expected_len = 3ULL * SZ_1G,
+	},
+	{
+		.name = "three holes; third hole big enough",
+		.hole_start = 0,
+		.hole_len = 10ULL * SZ_1G,
+		.min_hole_size = SZ_2G,
+		.pending_extents = {
+			{ .start = SZ_1G, .len = SZ_1G },
+			{ .start = 3ULL * SZ_1G, .len = 5ULL * SZ_1G },
+		},
+		.expected_found = true,
+		.expected_start = 8ULL * SZ_1G,
+		.expected_len = SZ_2G,
+	},
+	{
+		.name = "three holes; all holes too small",
+		.hole_start = 0,
+		.hole_len = 10ULL * SZ_1G,
+		.min_hole_size = SZ_2G,
+		.pending_extents = {
+			{ .start = SZ_1G, .len = SZ_1G },
+			{ .start = 3ULL * SZ_1G, .len = 6ULL * SZ_1G },
+		},
+		.expected_found = false,
+		.expected_start = 0,
+		.expected_len = SZ_1G,
+	},
+	{
+		.name = "three holes; all holes too small; first biggest",
+		.hole_start = 0,
+		.hole_len = 10ULL * SZ_1G,
+		.min_hole_size = 3ULL * SZ_1G,
+		.pending_extents = {
+			{ .start = SZ_2G, .len = SZ_1G },
+			{ .start = 4ULL * SZ_1G, .len = 5ULL * SZ_1G },
+		},
+		.expected_found = false,
+		.expected_start = 0,
+		.expected_len = SZ_2G,
+	},
+	{
+		.name = "three holes; all holes too small; second biggest",
+		.hole_start = 0,
+		.hole_len = 10ULL * SZ_1G,
+		.min_hole_size = 3ULL * SZ_1G,
+		.pending_extents = {
+			{ .start = SZ_1G, .len = SZ_1G },
+			{ .start = 4ULL * SZ_1G, .len = 5ULL * SZ_1G },
+		},
+		.expected_found = false,
+		.expected_start = SZ_2G,
+		.expected_len = SZ_2G,
+	},
+	{
+		.name = "three holes; all holes too small; third biggest",
+		.hole_start = 0,
+		.hole_len = 10ULL * SZ_1G,
+		.min_hole_size = 3ULL * SZ_1G,
+		.pending_extents = {
+			{ .start = SZ_1G, .len = SZ_1G },
+			{ .start = 3ULL * SZ_1G, .len = 5ULL * SZ_1G },
+		},
+		.expected_found = false,
+		.expected_start = 8ULL * SZ_1G,
+		.expected_len = SZ_2G,
+	},
+	{
+		.name = "hole entirely allocated by pending",
+		.hole_start = 0,
+		.hole_len = 10ULL * SZ_1G,
+		.min_hole_size = SZ_1G,
+		.pending_extents = {
+			{ .start = 0, .len = 10ULL * SZ_1G },
+		},
+		.expected_found = false,
+		.expected_start = 10ULL * SZ_1G,
+		.expected_len = 0,
+	},
+	{
+		.name = "pending extent at end of range",
+		.hole_start = 0,
+		.hole_len = 10ULL * SZ_1G,
+		.min_hole_size = SZ_1G,
+		.pending_extents = {
+			{ .start = 9ULL * SZ_1G, .len = SZ_2G },
+		},
+		.expected_found = true,
+		.expected_start = 0,
+		.expected_len = 9ULL * SZ_1G,
+	},
+	{
+		.name = "zero length input",
+		.hole_start = SZ_1G,
+		.hole_len = 0,
+		.min_hole_size = SZ_1G,
+		.pending_extents = { },
+		.expected_found = false,
+		.expected_start = SZ_1G,
+		.expected_len = 0,
+	},
+};
+
+static int test_find_hole_in_pending(u32 sectorsize, u32 nodesize)
+{
+	struct btrfs_fs_info *fs_info;
+	struct btrfs_device *device;
+	int ret = 0;
+
+	test_msg("running find_hole_in_pending_extents tests");
+
+	fs_info = btrfs_alloc_dummy_fs_info(nodesize, sectorsize);
+	if (!fs_info) {
+		test_std_err(TEST_ALLOC_FS_INFO);
+		return -ENOMEM;
+	}
+
+	device = btrfs_alloc_dummy_device(fs_info);
+	if (IS_ERR(device)) {
+		test_err("failed to allocate dummy device");
+		ret = PTR_ERR(device);
+		goto out_free_fs_info;
+	}
+	device->fs_info = fs_info;
+
+	for (int i = 0; i < ARRAY_SIZE(find_hole_tests); i++) {
+		const struct pending_extent_test_case *test_case = &find_hole_tests[i];
+		u64 hole_start = test_case->hole_start;
+		u64 hole_len = test_case->hole_len;
+		bool found;
+
+		for (int j = 0; j < ARRAY_SIZE(test_case->pending_extents); j++) {
+			u64 start = test_case->pending_extents[j].start;
+			u64 len = test_case->pending_extents[j].len;
+
+			if (!len)
+				continue;
+			btrfs_set_extent_bit(&device->alloc_state,
+					     start, start + len - 1,
+					     CHUNK_ALLOCATED, NULL);
+		}
+
+		mutex_lock(&fs_info->chunk_mutex);
+		found = btrfs_find_hole_in_pending_extents(device, &hole_start, &hole_len,
+							   test_case->min_hole_size);
+		mutex_unlock(&fs_info->chunk_mutex);
+
+		if (found != test_case->expected_found) {
+			test_err("%s: expected found=%d, got found=%d",
+				 test_case->name, test_case->expected_found, found);
+			ret = -EINVAL;
+			goto out_clear_pending_extents;
+		}
+		if (hole_start != test_case->expected_start ||
+		    hole_len != test_case->expected_len) {
+			test_err("%s: expected [%llu, %llu), got [%llu, %llu)",
+				 test_case->name, test_case->expected_start,
+				 test_case->expected_start +
+					 test_case->expected_len,
+				 hole_start, hole_start + hole_len);
+			ret = -EINVAL;
+			goto out_clear_pending_extents;
+		}
+out_clear_pending_extents:
+		btrfs_clear_extent_bit(&device->alloc_state, 0, (u64)-1,
+				       CHUNK_ALLOCATED, NULL);
+		if (ret)
+			break;
+	}
+
+out_free_fs_info:
+	btrfs_free_dummy_fs_info(fs_info);
+	return ret;
+}
+
+/*
+ * Describes the inputs to the system and expected results
+ * when testing btrfs_first_pending_extent().
+ */
+struct first_pending_test_case {
+	const char *name;
+	/* The range to look for a pending extent in. */
+	u64 hole_start;
+	u64 hole_len;
+	/* The pending extent to look for. */
+	struct {
+		u64 start;
+		u64 len;
+	} pending_extent;
+	/* Expected outputs. */
+	bool expected_found;
+	u64 expected_pending_start;
+	u64 expected_pending_end;
+};
+
+static const struct first_pending_test_case first_pending_tests[] = {
+	{
+		.name = "no pending extent",
+		.hole_start = 0,
+		.hole_len = 10ULL * SZ_1G,
+		.pending_extent = { 0, 0 },
+		.expected_found = false,
+	},
+	{
+		.name = "pending extent at search start",
+		.hole_start = SZ_1G,
+		.hole_len = 9ULL * SZ_1G,
+		.pending_extent = { SZ_1G, SZ_1G },
+		.expected_found = true,
+		.expected_pending_start = SZ_1G,
+		.expected_pending_end = SZ_2G - 1,
+	},
+	{
+		.name = "pending extent overlapping search start",
+		.hole_start = SZ_1G,
+		.hole_len = 9ULL * SZ_1G,
+		.pending_extent = { 0, SZ_2G },
+		.expected_found = true,
+		.expected_pending_start = 0,
+		.expected_pending_end = SZ_2G - 1,
+	},
+	{
+		.name = "pending extent inside search range",
+		.hole_start = 0,
+		.hole_len = 10ULL * SZ_1G,
+		.pending_extent = { SZ_2G, SZ_1G },
+		.expected_found = true,
+		.expected_pending_start = SZ_2G,
+		.expected_pending_end = 3ULL * SZ_1G - 1,
+	},
+	{
+		.name = "pending extent outside search range",
+		.hole_start = 0,
+		.hole_len = SZ_1G,
+		.pending_extent = { SZ_2G, SZ_1G },
+		.expected_found = false,
+	},
+	{
+		.name = "pending extent overlapping end of search range",
+		.hole_start = 0,
+		.hole_len = SZ_2G,
+		.pending_extent = { SZ_1G, SZ_2G },
+		.expected_found = true,
+		.expected_pending_start = SZ_1G,
+		.expected_pending_end = 3ULL * SZ_1G - 1,
+	},
+};
+
+static int test_first_pending_extent(u32 sectorsize, u32 nodesize)
+{
+	struct btrfs_fs_info *fs_info;
+	struct btrfs_device *device;
+	int ret = 0;
+
+	test_msg("running first_pending_extent tests");
+
+	fs_info = btrfs_alloc_dummy_fs_info(nodesize, sectorsize);
+	if (!fs_info) {
+		test_std_err(TEST_ALLOC_FS_INFO);
+		return -ENOMEM;
+	}
+
+	device = btrfs_alloc_dummy_device(fs_info);
+	if (IS_ERR(device)) {
+		test_err("failed to allocate dummy device");
+		ret = PTR_ERR(device);
+		goto out_free_fs_info;
+	}
+
+	device->fs_info = fs_info;
+
+	for (int i = 0; i < ARRAY_SIZE(first_pending_tests); i++) {
+		const struct first_pending_test_case *test_case = &first_pending_tests[i];
+		u64 start = test_case->pending_extent.start;
+		u64 len = test_case->pending_extent.len;
+		u64 pending_start, pending_end;
+		bool found;
+
+		if (len) {
+			btrfs_set_extent_bit(&device->alloc_state,
+					     start, start + len - 1,
+					     CHUNK_ALLOCATED, NULL);
+		}
+
+		mutex_lock(&fs_info->chunk_mutex);
+		found = btrfs_first_pending_extent(device, test_case->hole_start,
+						   test_case->hole_len,
+						   &pending_start, &pending_end);
+		mutex_unlock(&fs_info->chunk_mutex);
+
+		if (found != test_case->expected_found) {
+			test_err("%s: expected found=%d, got found=%d",
+				 test_case->name, test_case->expected_found, found);
+			ret = -EINVAL;
+			goto out_clear_pending_extents;
+		}
+		if (!found)
+			goto out_clear_pending_extents;
+
+		if (pending_start != test_case->expected_pending_start ||
+		    pending_end != test_case->expected_pending_end) {
+			test_err("%s: expected pending [%llu, %llu], got [%llu, %llu]",
+				 test_case->name,
+				 test_case->expected_pending_start,
+				 test_case->expected_pending_end,
+				 pending_start, pending_end);
+			ret = -EINVAL;
+			goto out_clear_pending_extents;
+		}
+
+out_clear_pending_extents:
+		btrfs_clear_extent_bit(&device->alloc_state, 0, (u64)-1,
+				       CHUNK_ALLOCATED, NULL);
+		if (ret)
+			break;
+	}
+
+out_free_fs_info:
+	btrfs_free_dummy_fs_info(fs_info);
+	return ret;
+}
+
+int btrfs_test_chunk_allocation(u32 sectorsize, u32 nodesize)
+{
+	int ret;
+
+	test_msg("running chunk allocation tests");
+
+	ret = test_first_pending_extent(sectorsize, nodesize);
+	if (ret)
+		return ret;
+
+	ret = test_find_hole_in_pending(sectorsize, nodesize);
+	if (ret)
+		return ret;
+
+	return 0;
+}
diff --git a/fs/btrfs/tests/delayed-refs-tests.c b/fs/btrfs/tests/delayed-refs-tests.c
new file mode 100644
index 000000000..ccab45d84
--- /dev/null
+++ b/fs/btrfs/tests/delayed-refs-tests.c
@@ -0,0 +1,1016 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/sizes.h>
+#include "btrfs-tests.h"
+#include "../transaction.h"
+#include "../delayed-ref.h"
+#include "../extent-tree.h"
+
+#define FAKE_ROOT_OBJECTID 256
+#define FAKE_BYTENR 0
+#define FAKE_LEVEL 1
+#define FAKE_INO 256
+#define FAKE_FILE_OFFSET 0
+#define FAKE_PARENT SZ_1M
+
+struct ref_head_check {
+	u64 bytenr;
+	u64 num_bytes;
+	int ref_mod;
+	int total_ref_mod;
+	int must_insert;
+};
+
+struct ref_node_check {
+	u64 bytenr;
+	u64 num_bytes;
+	int ref_mod;
+	enum btrfs_delayed_ref_action action;
+	u8 type;
+	u64 parent;
+	u64 root;
+	u64 owner;
+	u64 offset;
+};
+
+static enum btrfs_ref_type ref_type_from_disk_ref_type(u8 type)
+{
+	if ((type == BTRFS_TREE_BLOCK_REF_KEY) ||
+	    (type == BTRFS_SHARED_BLOCK_REF_KEY))
+		return BTRFS_REF_METADATA;
+	return BTRFS_REF_DATA;
+}
+
+static void delete_delayed_ref_head(struct btrfs_trans_handle *trans,
+				    struct btrfs_delayed_ref_head *head)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_delayed_ref_root *delayed_refs =
+		&trans->transaction->delayed_refs;
+
+	spin_lock(&delayed_refs->lock);
+	spin_lock(&head->lock);
+	btrfs_delete_ref_head(fs_info, delayed_refs, head);
+	spin_unlock(&head->lock);
+	spin_unlock(&delayed_refs->lock);
+
+	btrfs_delayed_ref_unlock(head);
+	btrfs_put_delayed_ref_head(head);
+}
+
+static void delete_delayed_ref_node(struct btrfs_delayed_ref_head *head,
+				    struct btrfs_delayed_ref_node *node)
+{
+	rb_erase_cached(&node->ref_node, &head->ref_tree);
+	RB_CLEAR_NODE(&node->ref_node);
+	if (!list_empty(&node->add_list))
+		list_del_init(&node->add_list);
+	btrfs_put_delayed_ref(node);
+}
+
+static int validate_ref_head(struct btrfs_delayed_ref_head *head,
+			     struct ref_head_check *check)
+{
+	if (head->bytenr != check->bytenr) {
+		test_err("invalid bytenr have: %llu want: %llu", head->bytenr,
+			 check->bytenr);
+		return -EINVAL;
+	}
+
+	if (head->num_bytes != check->num_bytes) {
+		test_err("invalid num_bytes have: %llu want: %llu",
+			 head->num_bytes, check->num_bytes);
+		return -EINVAL;
+	}
+
+	if (head->ref_mod != check->ref_mod) {
+		test_err("invalid ref_mod have: %d want: %d", head->ref_mod,
+			 check->ref_mod);
+		return -EINVAL;
+	}
+
+	if (head->total_ref_mod != check->total_ref_mod) {
+		test_err("invalid total_ref_mod have: %d want: %d",
+			 head->total_ref_mod, check->total_ref_mod);
+		return -EINVAL;
+	}
+
+	if (head->must_insert_reserved != check->must_insert) {
+		test_err("invalid must_insert have: %d want: %d",
+			 head->must_insert_reserved, check->must_insert);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int validate_ref_node(struct btrfs_delayed_ref_node *node,
+			     struct ref_node_check *check)
+{
+	if (node->bytenr != check->bytenr) {
+		test_err("invalid bytenr have: %llu want: %llu", node->bytenr,
+			 check->bytenr);
+		return -EINVAL;
+	}
+
+	if (node->num_bytes != check->num_bytes) {
+		test_err("invalid num_bytes have: %llu want: %llu",
+			 node->num_bytes, check->num_bytes);
+		return -EINVAL;
+	}
+
+	if (node->ref_mod != check->ref_mod) {
+		test_err("invalid ref_mod have: %d want: %d", node->ref_mod,
+			 check->ref_mod);
+		return -EINVAL;
+	}
+
+	if (node->action != check->action) {
+		test_err("invalid action have: %d want: %d", node->action,
+			 check->action);
+		return -EINVAL;
+	}
+
+	if (node->parent != check->parent) {
+		test_err("invalid parent have: %llu want: %llu", node->parent,
+			 check->parent);
+		return -EINVAL;
+	}
+
+	if (node->ref_root != check->root) {
+		test_err("invalid root have: %llu want: %llu", node->ref_root,
+			 check->root);
+		return -EINVAL;
+	}
+
+	if (node->type != check->type) {
+		test_err("invalid type have: %d want: %d", node->type,
+			 check->type);
+		return -EINVAL;
+	}
+
+	if (btrfs_delayed_ref_owner(node) != check->owner) {
+		test_err("invalid owner have: %llu want: %llu",
+			 btrfs_delayed_ref_owner(node), check->owner);
+		return -EINVAL;
+	}
+
+	if (btrfs_delayed_ref_offset(node) != check->offset) {
+		test_err("invalid offset have: %llu want: %llu",
+			 btrfs_delayed_ref_offset(node), check->offset);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int simple_test(struct btrfs_trans_handle *trans,
+		       struct ref_head_check *head_check,
+		       struct ref_node_check *node_check)
+{
+	struct btrfs_delayed_ref_root *delayed_refs =
+		&trans->transaction->delayed_refs;
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_delayed_ref_head *head;
+	struct btrfs_delayed_ref_node *node;
+	struct btrfs_ref ref = {
+		.type = ref_type_from_disk_ref_type(node_check->type),
+		.action = node_check->action,
+		.parent = node_check->parent,
+		.ref_root = node_check->root,
+		.bytenr = node_check->bytenr,
+		.num_bytes = fs_info->nodesize,
+	};
+	int ret;
+
+	if (ref.type == BTRFS_REF_METADATA)
+		btrfs_init_tree_ref(&ref, node_check->owner, node_check->root,
+				    false);
+	else
+		btrfs_init_data_ref(&ref, node_check->owner, node_check->offset,
+				    node_check->root, true);
+
+	if (ref.type == BTRFS_REF_METADATA)
+		ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
+	else
+		ret = btrfs_add_delayed_data_ref(trans, &ref, 0);
+	if (ret) {
+		test_err("failed ref action %d", ret);
+		return ret;
+	}
+
+	head = btrfs_select_ref_head(fs_info, delayed_refs);
+	if (IS_ERR_OR_NULL(head)) {
+		if (IS_ERR(head))
+			test_err("failed to select delayed ref head: %ld",
+				 PTR_ERR(head));
+		else
+			test_err("failed to find delayed ref head");
+		return -EINVAL;
+	}
+
+	ret = -EINVAL;
+	if (validate_ref_head(head, head_check))
+		goto out;
+
+	spin_lock(&head->lock);
+	node = btrfs_select_delayed_ref(head);
+	spin_unlock(&head->lock);
+	if (!node) {
+		test_err("failed to select delayed ref");
+		goto out;
+	}
+
+	if (validate_ref_node(node, node_check))
+		goto out;
+	ret = 0;
+out:
+	btrfs_unselect_ref_head(delayed_refs, head);
+	btrfs_destroy_delayed_refs(trans->transaction);
+	return ret;
+}
+
+/*
+ * These are simple tests, make sure that our btrfs_ref's get turned into the
+ * appropriate btrfs_delayed_ref_node based on their settings and action.
+ */
+static int simple_tests(struct btrfs_trans_handle *trans)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct ref_head_check head_check = {
+		.bytenr = FAKE_BYTENR,
+		.num_bytes = fs_info->nodesize,
+		.ref_mod = 1,
+		.total_ref_mod = 1,
+	};
+	struct ref_node_check node_check = {
+		.bytenr = FAKE_BYTENR,
+		.num_bytes = fs_info->nodesize,
+		.ref_mod = 1,
+		.action = BTRFS_ADD_DELAYED_REF,
+		.type = BTRFS_TREE_BLOCK_REF_KEY,
+		.parent = 0,
+		.root = FAKE_ROOT_OBJECTID,
+		.owner = FAKE_LEVEL,
+		.offset = 0,
+	};
+
+	if (simple_test(trans, &head_check, &node_check)) {
+		test_err("single add tree block failed");
+		return -EINVAL;
+	}
+
+	node_check.type = BTRFS_EXTENT_DATA_REF_KEY;
+	node_check.owner = FAKE_INO;
+	node_check.offset = FAKE_FILE_OFFSET;
+
+	if (simple_test(trans, &head_check, &node_check)) {
+		test_err("single add extent data failed");
+		return -EINVAL;
+	}
+
+	node_check.parent = FAKE_PARENT;
+	node_check.type = BTRFS_SHARED_BLOCK_REF_KEY;
+	node_check.owner = FAKE_LEVEL;
+	node_check.offset = 0;
+
+	if (simple_test(trans, &head_check, &node_check)) {
+		test_err("single add shared block failed");
+		return -EINVAL;
+	}
+
+	node_check.type = BTRFS_SHARED_DATA_REF_KEY;
+	node_check.owner = FAKE_INO;
+	node_check.offset = FAKE_FILE_OFFSET;
+
+	if (simple_test(trans, &head_check, &node_check)) {
+		test_err("single add shared data failed");
+		return -EINVAL;
+	}
+
+	head_check.ref_mod = -1;
+	head_check.total_ref_mod = -1;
+	node_check.action = BTRFS_DROP_DELAYED_REF;
+	node_check.type = BTRFS_TREE_BLOCK_REF_KEY;
+	node_check.owner = FAKE_LEVEL;
+	node_check.offset = 0;
+	node_check.parent = 0;
+
+	if (simple_test(trans, &head_check, &node_check)) {
+		test_err("single drop tree block failed");
+		return -EINVAL;
+	}
+
+	node_check.type = BTRFS_EXTENT_DATA_REF_KEY;
+	node_check.owner = FAKE_INO;
+	node_check.offset = FAKE_FILE_OFFSET;
+
+	if (simple_test(trans, &head_check, &node_check)) {
+		test_err("single drop extent data failed");
+		return -EINVAL;
+	}
+
+	node_check.parent = FAKE_PARENT;
+	node_check.type = BTRFS_SHARED_BLOCK_REF_KEY;
+	node_check.owner = FAKE_LEVEL;
+	node_check.offset = 0;
+	if (simple_test(trans, &head_check, &node_check)) {
+		test_err("single drop shared block failed");
+		return -EINVAL;
+	}
+
+	node_check.type = BTRFS_SHARED_DATA_REF_KEY;
+	node_check.owner = FAKE_INO;
+	node_check.offset = FAKE_FILE_OFFSET;
+	if (simple_test(trans, &head_check, &node_check)) {
+		test_err("single drop shared data failed");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/*
+ * Merge tests, validate that we do delayed ref merging properly, the ref counts
+ * all end up properly, and delayed refs are deleted once they're no longer
+ * needed.
+ */
+static int merge_tests(struct btrfs_trans_handle *trans,
+		       enum btrfs_ref_type type)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_delayed_ref_head *head = NULL;
+	struct btrfs_delayed_ref_node *node;
+	struct btrfs_ref ref = {
+		.type = type,
+		.action = BTRFS_ADD_DELAYED_REF,
+		.parent = 0,
+		.ref_root = FAKE_ROOT_OBJECTID,
+		.bytenr = FAKE_BYTENR,
+		.num_bytes = fs_info->nodesize,
+	};
+	struct ref_head_check head_check = {
+		.bytenr = FAKE_BYTENR,
+		.num_bytes = fs_info->nodesize,
+		.ref_mod = 0,
+		.total_ref_mod = 0,
+	};
+	struct ref_node_check node_check = {
+		.bytenr = FAKE_BYTENR,
+		.num_bytes = fs_info->nodesize,
+		.ref_mod = 2,
+		.action = BTRFS_ADD_DELAYED_REF,
+		.parent = 0,
+		.root = FAKE_ROOT_OBJECTID,
+	};
+	int ret;
+
+	/*
+	 * First add a ref and then drop it, make sure we get a head ref with a
+	 * 0 total ref mod and no nodes.
+	 */
+	if (type == BTRFS_REF_METADATA) {
+		node_check.type = BTRFS_TREE_BLOCK_REF_KEY;
+		node_check.owner = FAKE_LEVEL;
+		btrfs_init_tree_ref(&ref, FAKE_LEVEL, FAKE_ROOT_OBJECTID, false);
+	} else {
+		node_check.type = BTRFS_EXTENT_DATA_REF_KEY;
+		node_check.owner = FAKE_INO;
+		node_check.offset = FAKE_FILE_OFFSET;
+		btrfs_init_data_ref(&ref, FAKE_INO, FAKE_FILE_OFFSET,
+				    FAKE_ROOT_OBJECTID, true);
+	}
+
+	if (type == BTRFS_REF_METADATA)
+		ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
+	else
+		ret = btrfs_add_delayed_data_ref(trans, &ref, 0);
+	if (ret) {
+		test_err("failed ref action %d", ret);
+		return ret;
+	}
+
+	ref.action = BTRFS_DROP_DELAYED_REF;
+	if (type == BTRFS_REF_METADATA)
+		ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
+	else
+		ret = btrfs_add_delayed_data_ref(trans, &ref, 0);
+	if (ret) {
+		test_err("failed ref action %d", ret);
+		goto out;
+	}
+
+	head = btrfs_select_ref_head(fs_info, &trans->transaction->delayed_refs);
+	if (IS_ERR_OR_NULL(head)) {
+		if (IS_ERR(head))
+			test_err("failed to select delayed ref head: %ld",
+				 PTR_ERR(head));
+		else
+			test_err("failed to find delayed ref head");
+		goto out;
+	}
+
+	ret = -EINVAL;
+	if (validate_ref_head(head, &head_check)) {
+		test_err("single add and drop failed");
+		goto out;
+	}
+
+	spin_lock(&head->lock);
+	node = btrfs_select_delayed_ref(head);
+	spin_unlock(&head->lock);
+	if (node) {
+		test_err("found node when none should exist");
+		goto out;
+	}
+
+	delete_delayed_ref_head(trans, head);
+	head = NULL;
+
+	/*
+	 * Add a ref, then add another ref, make sure we get a head ref with a
+	 * 2 total ref mod and 1 node.
+	 */
+	ref.action = BTRFS_ADD_DELAYED_REF;
+	if (type == BTRFS_REF_METADATA)
+		ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
+	else
+		ret = btrfs_add_delayed_data_ref(trans, &ref, 0);
+	if (ret) {
+		test_err("failed ref action %d", ret);
+		goto out;
+	}
+
+	if (type == BTRFS_REF_METADATA)
+		ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
+	else
+		ret = btrfs_add_delayed_data_ref(trans, &ref, 0);
+	if (ret) {
+		test_err("failed ref action %d", ret);
+		goto out;
+	}
+
+	head = btrfs_select_ref_head(fs_info, &trans->transaction->delayed_refs);
+	if (IS_ERR_OR_NULL(head)) {
+		if (IS_ERR(head))
+			test_err("failed to select delayed ref head: %ld",
+				 PTR_ERR(head));
+		else
+			test_err("failed to find delayed ref head");
+		goto out;
+	}
+
+	head_check.ref_mod = 2;
+	head_check.total_ref_mod = 2;
+	ret = -EINVAL;
+	if (validate_ref_head(head, &head_check)) {
+		test_err("double add failed");
+		goto out;
+	}
+
+	spin_lock(&head->lock);
+	node = btrfs_select_delayed_ref(head);
+	spin_unlock(&head->lock);
+	if (!node) {
+		test_err("failed to select delayed ref");
+		goto out;
+	}
+
+	if (validate_ref_node(node, &node_check)) {
+		test_err("node check failed");
+		goto out;
+	}
+
+	delete_delayed_ref_node(head, node);
+
+	spin_lock(&head->lock);
+	node = btrfs_select_delayed_ref(head);
+	spin_unlock(&head->lock);
+	if (node) {
+		test_err("found node when none should exist");
+		goto out;
+	}
+	delete_delayed_ref_head(trans, head);
+	head = NULL;
+
+	/* Add two drop refs, make sure they are merged properly. */
+	ref.action = BTRFS_DROP_DELAYED_REF;
+	if (type == BTRFS_REF_METADATA)
+		ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
+	else
+		ret = btrfs_add_delayed_data_ref(trans, &ref, 0);
+	if (ret) {
+		test_err("failed ref action %d", ret);
+		goto out;
+	}
+
+	if (type == BTRFS_REF_METADATA)
+		ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
+	else
+		ret = btrfs_add_delayed_data_ref(trans, &ref, 0);
+	if (ret) {
+		test_err("failed ref action %d", ret);
+		goto out;
+	}
+
+	head = btrfs_select_ref_head(fs_info, &trans->transaction->delayed_refs);
+	if (IS_ERR_OR_NULL(head)) {
+		if (IS_ERR(head))
+			test_err("failed to select delayed ref head: %ld",
+				 PTR_ERR(head));
+		else
+			test_err("failed to find delayed ref head");
+		goto out;
+	}
+
+	head_check.ref_mod = -2;
+	head_check.total_ref_mod = -2;
+	ret = -EINVAL;
+	if (validate_ref_head(head, &head_check)) {
+		test_err("double drop failed");
+		goto out;
+	}
+
+	node_check.action = BTRFS_DROP_DELAYED_REF;
+	spin_lock(&head->lock);
+	node = btrfs_select_delayed_ref(head);
+	spin_unlock(&head->lock);
+	if (!node) {
+		test_err("failed to select delayed ref");
+		goto out;
+	}
+
+	if (validate_ref_node(node, &node_check)) {
+		test_err("node check failed");
+		goto out;
+	}
+
+	delete_delayed_ref_node(head, node);
+
+	spin_lock(&head->lock);
+	node = btrfs_select_delayed_ref(head);
+	spin_unlock(&head->lock);
+	if (node) {
+		test_err("found node when none should exist");
+		goto out;
+	}
+	delete_delayed_ref_head(trans, head);
+	head = NULL;
+
+	/* Add multiple refs, then drop until we go negative again. */
+	ref.action = BTRFS_ADD_DELAYED_REF;
+	for (int i = 0; i < 10; i++) {
+		if (type == BTRFS_REF_METADATA)
+			ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
+		else
+			ret = btrfs_add_delayed_data_ref(trans, &ref, 0);
+		if (ret) {
+			test_err("failed ref action %d", ret);
+			goto out;
+		}
+	}
+
+	ref.action = BTRFS_DROP_DELAYED_REF;
+	for (int i = 0; i < 12; i++) {
+		if (type == BTRFS_REF_METADATA)
+			ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
+		else
+			ret = btrfs_add_delayed_data_ref(trans, &ref, 0);
+		if (ret) {
+			test_err("failed ref action %d", ret);
+			goto out;
+		}
+	}
+
+	head = btrfs_select_ref_head(fs_info, &trans->transaction->delayed_refs);
+	if (IS_ERR_OR_NULL(head)) {
+		if (IS_ERR(head))
+			test_err("failed to select delayed ref head: %ld",
+				 PTR_ERR(head));
+		else
+			test_err("failed to find delayed ref head");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	head_check.ref_mod = -2;
+	head_check.total_ref_mod = -2;
+	ret = -EINVAL;
+	if (validate_ref_head(head, &head_check)) {
+		test_err("double drop failed");
+		goto out;
+	}
+
+	spin_lock(&head->lock);
+	node = btrfs_select_delayed_ref(head);
+	spin_unlock(&head->lock);
+	if (!node) {
+		test_err("failed to select delayed ref");
+		goto out;
+	}
+
+	if (validate_ref_node(node, &node_check)) {
+		test_err("node check failed");
+		goto out;
+	}
+
+	delete_delayed_ref_node(head, node);
+
+	spin_lock(&head->lock);
+	node = btrfs_select_delayed_ref(head);
+	spin_unlock(&head->lock);
+	if (node) {
+		test_err("found node when none should exist");
+		goto out;
+	}
+
+	delete_delayed_ref_head(trans, head);
+	head = NULL;
+
+	/* Drop multiple refs, then add until we go positive again. */
+	ref.action = BTRFS_DROP_DELAYED_REF;
+	for (int i = 0; i < 10; i++) {
+		if (type == BTRFS_REF_METADATA)
+			ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
+		else
+			ret = btrfs_add_delayed_data_ref(trans, &ref, 0);
+		if (ret) {
+			test_err("failed ref action %d", ret);
+			goto out;
+		}
+	}
+
+	ref.action = BTRFS_ADD_DELAYED_REF;
+	for (int i = 0; i < 12; i++) {
+		if (type == BTRFS_REF_METADATA)
+			ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
+		else
+			ret = btrfs_add_delayed_data_ref(trans, &ref, 0);
+		if (ret) {
+			test_err("failed ref action %d", ret);
+			goto out;
+		}
+	}
+
+	head = btrfs_select_ref_head(fs_info, &trans->transaction->delayed_refs);
+	if (IS_ERR_OR_NULL(head)) {
+		if (IS_ERR(head))
+			test_err("failed to select delayed ref head: %ld",
+				 PTR_ERR(head));
+		else
+			test_err("failed to find delayed ref head");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	head_check.ref_mod = 2;
+	head_check.total_ref_mod = 2;
+	ret = -EINVAL;
+	if (validate_ref_head(head, &head_check)) {
+		test_err("add and drop to positive failed");
+		goto out;
+	}
+
+	node_check.action = BTRFS_ADD_DELAYED_REF;
+	spin_lock(&head->lock);
+	node = btrfs_select_delayed_ref(head);
+	spin_unlock(&head->lock);
+	if (!node) {
+		test_err("failed to select delayed ref");
+		goto out;
+	}
+
+	if (validate_ref_node(node, &node_check)) {
+		test_err("node check failed");
+		goto out;
+	}
+
+	delete_delayed_ref_node(head, node);
+
+	spin_lock(&head->lock);
+	node = btrfs_select_delayed_ref(head);
+	spin_unlock(&head->lock);
+	if (node) {
+		test_err("found node when none should exist");
+		goto out;
+	}
+	delete_delayed_ref_head(trans, head);
+	head = NULL;
+
+	/*
+	 * Add a bunch of refs with different roots and parents, then drop them
+	 * all, make sure everything is properly merged.
+	 */
+	ref.action = BTRFS_ADD_DELAYED_REF;
+	for (int i = 0; i < 50; i++) {
+		if (!(i % 2)) {
+			ref.parent = 0;
+			ref.ref_root = FAKE_ROOT_OBJECTID + i;
+		} else {
+			ref.parent = FAKE_PARENT + (i * fs_info->nodesize);
+		}
+		if (type == BTRFS_REF_METADATA)
+			ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
+		else
+			ret = btrfs_add_delayed_data_ref(trans, &ref, 0);
+		if (ret) {
+			test_err("failed ref action %d", ret);
+			goto out;
+		}
+	}
+
+	ref.action = BTRFS_DROP_DELAYED_REF;
+	for (int i = 0; i < 50; i++) {
+		if (!(i % 2)) {
+			ref.parent = 0;
+			ref.ref_root = FAKE_ROOT_OBJECTID + i;
+		} else {
+			ref.parent = FAKE_PARENT + (i * fs_info->nodesize);
+		}
+		if (type == BTRFS_REF_METADATA)
+			ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
+		else
+			ret = btrfs_add_delayed_data_ref(trans, &ref, 0);
+		if (ret) {
+			test_err("failed ref action %d", ret);
+			goto out;
+		}
+	}
+
+	head = btrfs_select_ref_head(fs_info, &trans->transaction->delayed_refs);
+	if (IS_ERR_OR_NULL(head)) {
+		if (IS_ERR(head))
+			test_err("failed to select delayed ref head: %ld",
+				 PTR_ERR(head));
+		else
+			test_err("failed to find delayed ref head");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	head_check.ref_mod = 0;
+	head_check.total_ref_mod = 0;
+	ret = -EINVAL;
+	if (validate_ref_head(head, &head_check)) {
+		test_err("add and drop multiple failed");
+		goto out;
+	}
+
+	spin_lock(&head->lock);
+	node = btrfs_select_delayed_ref(head);
+	spin_unlock(&head->lock);
+	if (node) {
+		test_err("found node when none should exist");
+		goto out;
+	}
+	ret = 0;
+out:
+	if (!IS_ERR_OR_NULL(head))
+		btrfs_unselect_ref_head(&trans->transaction->delayed_refs, head);
+	btrfs_destroy_delayed_refs(trans->transaction);
+	return ret;
+}
+
+/*
+ * Basic test to validate we always get the add operations first followed by any
+ * delete operations.
+ */
+static int select_delayed_refs_test(struct btrfs_trans_handle *trans)
+{
+	struct btrfs_delayed_ref_root *delayed_refs =
+		&trans->transaction->delayed_refs;
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_delayed_ref_head *head = NULL;
+	struct btrfs_delayed_ref_node *node;
+	struct btrfs_ref ref = {
+		.type = BTRFS_REF_METADATA,
+		.action = BTRFS_DROP_DELAYED_REF,
+		.parent = 0,
+		.ref_root = FAKE_ROOT_OBJECTID,
+		.bytenr = FAKE_BYTENR,
+		.num_bytes = fs_info->nodesize,
+	};
+	struct ref_head_check head_check = {
+		.bytenr = FAKE_BYTENR,
+		.num_bytes = fs_info->nodesize,
+		.ref_mod = 0,
+		.total_ref_mod = 0,
+	};
+	struct ref_node_check node_check = {
+		.bytenr = FAKE_BYTENR,
+		.num_bytes = fs_info->nodesize,
+		.ref_mod = 1,
+		.action = BTRFS_ADD_DELAYED_REF,
+		.type = BTRFS_TREE_BLOCK_REF_KEY,
+		.parent = 0,
+		.owner = FAKE_LEVEL,
+		.offset = 0,
+	};
+	int ret;
+
+	/* Add the drop first. */
+	btrfs_init_tree_ref(&ref, FAKE_LEVEL, FAKE_ROOT_OBJECTID, false);
+	ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
+	if (ret) {
+		test_err("failed ref action %d", ret);
+		return ret;
+	}
+
+	/*
+	 * Now add the add, and make it a different root so it's logically later
+	 * in the rb tree.
+	 */
+	ref.action = BTRFS_ADD_DELAYED_REF;
+	ref.ref_root = FAKE_ROOT_OBJECTID + 1;
+	ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
+	if (ret) {
+		test_err("failed ref action %d", ret);
+		goto out;
+	}
+
+	head = btrfs_select_ref_head(fs_info, delayed_refs);
+	if (IS_ERR_OR_NULL(head)) {
+		if (IS_ERR(head))
+			test_err("failed to select delayed ref head: %ld",
+				 PTR_ERR(head));
+		else
+			test_err("failed to find delayed ref head");
+		ret = -EINVAL;
+		head = NULL;
+		goto out;
+	}
+
+	ret = -EINVAL;
+	if (validate_ref_head(head, &head_check)) {
+		test_err("head check failed");
+		goto out;
+	}
+
+	spin_lock(&head->lock);
+	node = btrfs_select_delayed_ref(head);
+	spin_unlock(&head->lock);
+	if (!node) {
+		test_err("failed to select delayed ref");
+		goto out;
+	}
+
+	node_check.root = FAKE_ROOT_OBJECTID + 1;
+	if (validate_ref_node(node, &node_check)) {
+		test_err("node check failed");
+		goto out;
+	}
+	delete_delayed_ref_node(head, node);
+
+	spin_lock(&head->lock);
+	node = btrfs_select_delayed_ref(head);
+	spin_unlock(&head->lock);
+	if (!node) {
+		test_err("failed to select delayed ref");
+		goto out;
+	}
+
+	node_check.action = BTRFS_DROP_DELAYED_REF;
+	node_check.root = FAKE_ROOT_OBJECTID;
+	if (validate_ref_node(node, &node_check)) {
+		test_err("node check failed");
+		goto out;
+	}
+	delete_delayed_ref_node(head, node);
+	delete_delayed_ref_head(trans, head);
+	head = NULL;
+
+	/*
+	 * Now we're going to do the same thing, but we're going to have an add
+	 * that gets deleted because of a merge, and make sure we still have
+	 * another add in place.
+	 */
+	ref.action = BTRFS_DROP_DELAYED_REF;
+	ref.ref_root = FAKE_ROOT_OBJECTID;
+	ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
+	if (ret) {
+		test_err("failed ref action %d", ret);
+		goto out;
+	}
+
+	ref.action = BTRFS_ADD_DELAYED_REF;
+	ref.ref_root = FAKE_ROOT_OBJECTID + 1;
+	ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
+	if (ret) {
+		test_err("failed ref action %d", ret);
+		goto out;
+	}
+
+	ref.action = BTRFS_DROP_DELAYED_REF;
+	ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
+	if (ret) {
+		test_err("failed ref action %d", ret);
+		goto out;
+	}
+
+	ref.action = BTRFS_ADD_DELAYED_REF;
+	ref.ref_root = FAKE_ROOT_OBJECTID + 2;
+	ret = btrfs_add_delayed_tree_ref(trans, &ref, NULL);
+	if (ret) {
+		test_err("failed ref action %d", ret);
+		goto out;
+	}
+
+	head = btrfs_select_ref_head(fs_info, delayed_refs);
+	if (IS_ERR_OR_NULL(head)) {
+		if (IS_ERR(head))
+			test_err("failed to select delayed ref head: %ld",
+				 PTR_ERR(head));
+		else
+			test_err("failed to find delayed ref head");
+		ret = -EINVAL;
+		head = NULL;
+		goto out;
+	}
+
+	ret = -EINVAL;
+	if (validate_ref_head(head, &head_check)) {
+		test_err("head check failed");
+		goto out;
+	}
+
+	spin_lock(&head->lock);
+	node = btrfs_select_delayed_ref(head);
+	spin_unlock(&head->lock);
+	if (!node) {
+		test_err("failed to select delayed ref");
+		goto out;
+	}
+
+	node_check.action = BTRFS_ADD_DELAYED_REF;
+	node_check.root = FAKE_ROOT_OBJECTID + 2;
+	if (validate_ref_node(node, &node_check)) {
+		test_err("node check failed");
+		goto out;
+	}
+	delete_delayed_ref_node(head, node);
+
+	spin_lock(&head->lock);
+	node = btrfs_select_delayed_ref(head);
+	spin_unlock(&head->lock);
+	if (!node) {
+		test_err("failed to select delayed ref");
+		goto out;
+	}
+
+	node_check.action = BTRFS_DROP_DELAYED_REF;
+	node_check.root = FAKE_ROOT_OBJECTID;
+	if (validate_ref_node(node, &node_check)) {
+		test_err("node check failed");
+		goto out;
+	}
+	delete_delayed_ref_node(head, node);
+	ret = 0;
+out:
+	if (head)
+		btrfs_unselect_ref_head(delayed_refs, head);
+	btrfs_destroy_delayed_refs(trans->transaction);
+	return ret;
+}
+
+int btrfs_test_delayed_refs(u32 sectorsize, u32 nodesize)
+{
+	struct btrfs_transaction *transaction;
+	struct btrfs_trans_handle trans;
+	struct btrfs_fs_info *fs_info;
+	int ret;
+
+	test_msg("running delayed refs tests");
+
+	fs_info = btrfs_alloc_dummy_fs_info(nodesize, sectorsize);
+	if (!fs_info) {
+		test_std_err(TEST_ALLOC_FS_INFO);
+		return -ENOMEM;
+	}
+	transaction = kmalloc_obj(*transaction);
+	if (!transaction) {
+		test_std_err(TEST_ALLOC_TRANSACTION);
+		ret = -ENOMEM;
+		goto out_free_fs_info;
+	}
+	btrfs_init_dummy_trans(&trans, fs_info);
+	btrfs_init_dummy_transaction(transaction, fs_info);
+	trans.transaction = transaction;
+
+	ret = simple_tests(&trans);
+	if (!ret) {
+		test_msg("running delayed refs merge tests on metadata refs");
+		ret = merge_tests(&trans, BTRFS_REF_METADATA);
+	}
+
+	if (!ret) {
+		test_msg("running delayed refs merge tests on data refs");
+		ret = merge_tests(&trans, BTRFS_REF_DATA);
+	}
+
+	if (!ret)
+		ret = select_delayed_refs_test(&trans);
+
+	kfree(transaction);
+out_free_fs_info:
+	btrfs_free_dummy_fs_info(fs_info);
+	return ret;
+}
diff --git a/fs/btrfs/tests/extent-buffer-tests.c b/fs/btrfs/tests/extent-buffer-tests.c
new file mode 100644
index 000000000..6a43a64ba
--- /dev/null
+++ b/fs/btrfs/tests/extent-buffer-tests.c
@@ -0,0 +1,223 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2013 Fusion IO.  All rights reserved.
+ */
+
+#include <linux/slab.h>
+#include "btrfs-tests.h"
+#include "../ctree.h"
+#include "../extent_io.h"
+#include "../disk-io.h"
+#include "../accessors.h"
+
+static int test_btrfs_split_item(u32 sectorsize, u32 nodesize)
+{
+	struct btrfs_fs_info *fs_info;
+	struct btrfs_path *path = NULL;
+	struct btrfs_root *root = NULL;
+	struct extent_buffer *eb;
+	char *value = "mary had a little lamb";
+	char *split1 = "mary had a little";
+	char *split2 = " lamb";
+	char *split3 = "mary";
+	char *split4 = " had a little";
+	char buf[32];
+	struct btrfs_key key;
+	u32 value_len = strlen(value);
+	int ret = 0;
+
+	test_msg("running btrfs_split_item tests");
+
+	fs_info = btrfs_alloc_dummy_fs_info(nodesize, sectorsize);
+	if (!fs_info) {
+		test_std_err(TEST_ALLOC_FS_INFO);
+		return -ENOMEM;
+	}
+
+	root = btrfs_alloc_dummy_root(fs_info);
+	if (IS_ERR(root)) {
+		test_std_err(TEST_ALLOC_ROOT);
+		ret = PTR_ERR(root);
+		goto out;
+	}
+
+	path = btrfs_alloc_path();
+	if (!path) {
+		test_std_err(TEST_ALLOC_PATH);
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	eb = alloc_dummy_extent_buffer(fs_info, nodesize);
+	path->nodes[0] = eb;
+	if (!eb) {
+		test_std_err(TEST_ALLOC_EXTENT_BUFFER);
+		ret = -ENOMEM;
+		goto out;
+	}
+	path->slots[0] = 0;
+
+	key.objectid = 0;
+	key.type = BTRFS_EXTENT_CSUM_KEY;
+	key.offset = 0;
+
+	/*
+	 * Passing a NULL trans handle is fine here, we have a dummy root eb
+	 * and the tree is a single node (level 0).
+	 */
+	btrfs_setup_item_for_insert(NULL, root, path, &key, value_len);
+	write_extent_buffer(eb, value, btrfs_item_ptr_offset(eb, 0),
+			    value_len);
+
+	key.offset = 3;
+
+	/*
+	 * Passing NULL trans here should be safe because we have plenty of
+	 * space in this leaf to split the item without having to split the
+	 * leaf.
+	 */
+	ret = btrfs_split_item(NULL, root, path, &key, 17);
+	if (ret) {
+		test_err("split item failed %d", ret);
+		goto out;
+	}
+
+	/*
+	 * Read the first slot, it should have the original key and contain only
+	 * 'mary had a little'
+	 */
+	btrfs_item_key_to_cpu(eb, &key, 0);
+	if (key.objectid != 0 || key.type != BTRFS_EXTENT_CSUM_KEY ||
+	    key.offset != 0) {
+		test_err("invalid key at slot 0");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (btrfs_item_size(eb, 0) != strlen(split1)) {
+		test_err("invalid len in the first split");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	read_extent_buffer(eb, buf, btrfs_item_ptr_offset(eb, 0),
+			   strlen(split1));
+	if (memcmp(buf, split1, strlen(split1))) {
+		test_err(
+"data in the buffer doesn't match what it should in the first split have='%.*s' want '%s'",
+			 (int)strlen(split1), buf, split1);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	btrfs_item_key_to_cpu(eb, &key, 1);
+	if (key.objectid != 0 || key.type != BTRFS_EXTENT_CSUM_KEY ||
+	    key.offset != 3) {
+		test_err("invalid key at slot 1");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (btrfs_item_size(eb, 1) != strlen(split2)) {
+		test_err("invalid len in the second split");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	read_extent_buffer(eb, buf, btrfs_item_ptr_offset(eb, 1),
+			   strlen(split2));
+	if (memcmp(buf, split2, strlen(split2))) {
+		test_err(
+	"data in the buffer doesn't match what it should in the second split");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	key.offset = 1;
+	/* Do it again so we test memmoving the other items in the leaf */
+	ret = btrfs_split_item(NULL, root, path, &key, 4);
+	if (ret) {
+		test_err("second split item failed %d", ret);
+		goto out;
+	}
+
+	btrfs_item_key_to_cpu(eb, &key, 0);
+	if (key.objectid != 0 || key.type != BTRFS_EXTENT_CSUM_KEY ||
+	    key.offset != 0) {
+		test_err("invalid key at slot 0");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (btrfs_item_size(eb, 0) != strlen(split3)) {
+		test_err("invalid len in the first split");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	read_extent_buffer(eb, buf, btrfs_item_ptr_offset(eb, 0),
+			   strlen(split3));
+	if (memcmp(buf, split3, strlen(split3))) {
+		test_err(
+	"data in the buffer doesn't match what it should in the third split");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	btrfs_item_key_to_cpu(eb, &key, 1);
+	if (key.objectid != 0 || key.type != BTRFS_EXTENT_CSUM_KEY ||
+	    key.offset != 1) {
+		test_err("invalid key at slot 1");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (btrfs_item_size(eb, 1) != strlen(split4)) {
+		test_err("invalid len in the second split");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	read_extent_buffer(eb, buf, btrfs_item_ptr_offset(eb, 1),
+			   strlen(split4));
+	if (memcmp(buf, split4, strlen(split4))) {
+		test_err(
+	"data in the buffer doesn't match what it should in the fourth split");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	btrfs_item_key_to_cpu(eb, &key, 2);
+	if (key.objectid != 0 || key.type != BTRFS_EXTENT_CSUM_KEY ||
+	    key.offset != 3) {
+		test_err("invalid key at slot 2");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (btrfs_item_size(eb, 2) != strlen(split2)) {
+		test_err("invalid len in the second split");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	read_extent_buffer(eb, buf, btrfs_item_ptr_offset(eb, 2),
+			   strlen(split2));
+	if (memcmp(buf, split2, strlen(split2))) {
+		test_err(
+	"data in the buffer doesn't match what it should in the last chunk");
+		ret = -EINVAL;
+		goto out;
+	}
+out:
+	btrfs_free_path(path);
+	btrfs_free_dummy_root(root);
+	btrfs_free_dummy_fs_info(fs_info);
+	return ret;
+}
+
+int btrfs_test_extent_buffer_operations(u32 sectorsize, u32 nodesize)
+{
+	test_msg("running extent buffer operation tests");
+	return test_btrfs_split_item(sectorsize, nodesize);
+}
diff --git a/fs/btrfs/tests/extent-io-tests.c b/fs/btrfs/tests/extent-io-tests.c
new file mode 100644
index 000000000..b2aacf846
--- /dev/null
+++ b/fs/btrfs/tests/extent-io-tests.c
@@ -0,0 +1,830 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2013 Fusion IO.  All rights reserved.
+ */
+
+#include <linux/pagemap.h>
+#include <linux/folio_batch.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/sizes.h>
+#include "btrfs-tests.h"
+#include "../ctree.h"
+#include "../extent_io.h"
+#include "../disk-io.h"
+#include "../btrfs_inode.h"
+
+#define PROCESS_UNLOCK		(1U << 0)
+#define PROCESS_RELEASE		(1U << 1)
+#define PROCESS_TEST_LOCKED	(1U << 2)
+
+static noinline int process_page_range(struct inode *inode, u64 start, u64 end,
+				       unsigned long flags)
+{
+	int ret;
+	struct folio_batch fbatch;
+	pgoff_t index = start >> PAGE_SHIFT;
+	pgoff_t end_index = end >> PAGE_SHIFT;
+	int i;
+	int count = 0;
+	int loops = 0;
+
+	folio_batch_init(&fbatch);
+
+	while (index <= end_index) {
+		ret = filemap_get_folios_contig(inode->i_mapping, &index,
+				end_index, &fbatch);
+		for (i = 0; i < ret; i++) {
+			struct folio *folio = fbatch.folios[i];
+
+			if (flags & PROCESS_TEST_LOCKED &&
+			    !folio_test_locked(folio))
+				count++;
+			if (flags & PROCESS_UNLOCK && folio_test_locked(folio))
+				folio_unlock(folio);
+			if (flags & PROCESS_RELEASE)
+				folio_put(folio);
+		}
+		folio_batch_release(&fbatch);
+		cond_resched();
+		loops++;
+		if (loops > 100000) {
+			printk(KERN_ERR
+		"stuck in a loop, start %llu, end %llu, ret %d\n",
+				start, end, ret);
+			break;
+		}
+	}
+
+	return count;
+}
+
+#define STATE_FLAG_STR_LEN			256
+
+#define PRINT_ONE_FLAG(state, dest, cur, name)				\
+({									\
+	if (state->state & EXTENT_##name)				\
+		cur += scnprintf(dest + cur, STATE_FLAG_STR_LEN - cur,	\
+				 "%s" #name, cur == 0 ? "" : "|");	\
+})
+
+static void extent_flag_to_str(const struct extent_state *state, char *dest)
+{
+	int cur = 0;
+
+	dest[0] = 0;
+	PRINT_ONE_FLAG(state, dest, cur, DIRTY);
+	PRINT_ONE_FLAG(state, dest, cur, LOCKED);
+	PRINT_ONE_FLAG(state, dest, cur, DIRTY_LOG1);
+	PRINT_ONE_FLAG(state, dest, cur, DIRTY_LOG2);
+	PRINT_ONE_FLAG(state, dest, cur, DELALLOC);
+	PRINT_ONE_FLAG(state, dest, cur, DEFRAG);
+	PRINT_ONE_FLAG(state, dest, cur, BOUNDARY);
+	PRINT_ONE_FLAG(state, dest, cur, NODATASUM);
+	PRINT_ONE_FLAG(state, dest, cur, CLEAR_META_RESV);
+	PRINT_ONE_FLAG(state, dest, cur, NEED_WAIT);
+	PRINT_ONE_FLAG(state, dest, cur, NORESERVE);
+	PRINT_ONE_FLAG(state, dest, cur, QGROUP_RESERVED);
+	PRINT_ONE_FLAG(state, dest, cur, CLEAR_DATA_RESV);
+}
+
+static void dump_extent_io_tree(const struct extent_io_tree *tree)
+{
+	struct rb_node *node;
+	char flags_str[STATE_FLAG_STR_LEN];
+
+	node = rb_first(&tree->state);
+	test_msg("io tree content:");
+	while (node) {
+		struct extent_state *state;
+
+		state = rb_entry(node, struct extent_state, rb_node);
+		extent_flag_to_str(state, flags_str);
+		test_msg("  start=%llu len=%llu flags=%s", state->start,
+			 state->end + 1 - state->start, flags_str);
+		node = rb_next(node);
+	}
+}
+
+static int test_find_delalloc(u32 sectorsize, u32 nodesize)
+{
+	struct btrfs_fs_info *fs_info;
+	struct btrfs_root *root = NULL;
+	struct inode *inode = NULL;
+	struct extent_io_tree *tmp;
+	struct page *page;
+	struct page *locked_page = NULL;
+	/* In this test we need at least 2 file extents at its maximum size */
+	u64 max_bytes = BTRFS_MAX_EXTENT_SIZE;
+	u64 total_dirty = 2 * max_bytes;
+	u64 start, end, test_start;
+	bool found;
+	int ret = -EINVAL;
+
+	test_msg("running find delalloc tests");
+
+	fs_info = btrfs_alloc_dummy_fs_info(nodesize, sectorsize);
+	if (!fs_info) {
+		test_std_err(TEST_ALLOC_FS_INFO);
+		return -ENOMEM;
+	}
+
+	root = btrfs_alloc_dummy_root(fs_info);
+	if (IS_ERR(root)) {
+		test_std_err(TEST_ALLOC_ROOT);
+		ret = PTR_ERR(root);
+		goto out;
+	}
+
+	inode = btrfs_new_test_inode();
+	if (!inode) {
+		test_std_err(TEST_ALLOC_INODE);
+		ret = -ENOMEM;
+		goto out;
+	}
+	tmp = &BTRFS_I(inode)->io_tree;
+	BTRFS_I(inode)->root = root;
+
+	/*
+	 * Passing NULL as we don't have fs_info but tracepoints are not used
+	 * at this point
+	 */
+	btrfs_extent_io_tree_init(NULL, tmp, IO_TREE_SELFTEST);
+
+	/*
+	 * First go through and create and mark all of our pages dirty, we pin
+	 * everything to make sure our pages don't get evicted and screw up our
+	 * test.
+	 */
+	for (pgoff_t index = 0; index < (total_dirty >> PAGE_SHIFT); index++) {
+		page = find_or_create_page(inode->i_mapping, index, GFP_KERNEL);
+		if (!page) {
+			test_err("failed to allocate test page");
+			ret = -ENOMEM;
+			goto out;
+		}
+		SetPageDirty(page);
+		if (index) {
+			unlock_page(page);
+		} else {
+			get_page(page);
+			locked_page = page;
+		}
+	}
+
+	/* Test this scenario
+	 * |--- delalloc ---|
+	 * |---  search  ---|
+	 */
+	btrfs_set_extent_bit(tmp, 0, sectorsize - 1, EXTENT_DELALLOC, NULL);
+	start = 0;
+	end = start + PAGE_SIZE - 1;
+	found = find_lock_delalloc_range(inode, page_folio(locked_page), &start,
+					 &end);
+	if (!found) {
+		test_err("should have found at least one delalloc");
+		goto out_bits;
+	}
+	if (start != 0 || end != (sectorsize - 1)) {
+		test_err("expected start 0 end %u, got start %llu end %llu",
+			sectorsize - 1, start, end);
+		goto out_bits;
+	}
+	btrfs_unlock_extent(tmp, start, end, NULL);
+	unlock_page(locked_page);
+	put_page(locked_page);
+
+	/*
+	 * Test this scenario
+	 *
+	 * |--- delalloc ---|
+	 *           |--- search ---|
+	 */
+	test_start = SZ_64M;
+	locked_page = find_lock_page(inode->i_mapping,
+				     test_start >> PAGE_SHIFT);
+	if (!locked_page) {
+		test_err("couldn't find the locked page");
+		goto out_bits;
+	}
+	btrfs_set_extent_bit(tmp, sectorsize, max_bytes - 1, EXTENT_DELALLOC, NULL);
+	start = test_start;
+	end = start + PAGE_SIZE - 1;
+	found = find_lock_delalloc_range(inode, page_folio(locked_page), &start,
+					 &end);
+	if (!found) {
+		test_err("couldn't find delalloc in our range");
+		goto out_bits;
+	}
+	if (start != test_start || end != max_bytes - 1) {
+		test_err("expected start %llu end %llu, got start %llu, end %llu",
+				test_start, max_bytes - 1, start, end);
+		goto out_bits;
+	}
+	if (process_page_range(inode, start, end,
+			       PROCESS_TEST_LOCKED | PROCESS_UNLOCK)) {
+		test_err("there were unlocked pages in the range");
+		goto out_bits;
+	}
+	btrfs_unlock_extent(tmp, start, end, NULL);
+	/* locked_page was unlocked above */
+	put_page(locked_page);
+
+	/*
+	 * Test this scenario
+	 * |--- delalloc ---|
+	 *                    |--- search ---|
+	 */
+	test_start = max_bytes + sectorsize;
+	locked_page = find_lock_page(inode->i_mapping, test_start >>
+				     PAGE_SHIFT);
+	if (!locked_page) {
+		test_err("couldn't find the locked page");
+		goto out_bits;
+	}
+	start = test_start;
+	end = start + PAGE_SIZE - 1;
+	found = find_lock_delalloc_range(inode, page_folio(locked_page), &start,
+					 &end);
+	if (found) {
+		test_err("found range when we shouldn't have");
+		goto out_bits;
+	}
+	if (end != test_start + PAGE_SIZE - 1) {
+		test_err("did not return the proper end offset");
+		goto out_bits;
+	}
+
+	/*
+	 * Test this scenario
+	 * [------- delalloc -------|
+	 * [max_bytes]|-- search--|
+	 *
+	 * We are re-using our test_start from above since it works out well.
+	 */
+	btrfs_set_extent_bit(tmp, max_bytes, total_dirty - 1, EXTENT_DELALLOC, NULL);
+	start = test_start;
+	end = start + PAGE_SIZE - 1;
+	found = find_lock_delalloc_range(inode, page_folio(locked_page), &start,
+					 &end);
+	if (!found) {
+		test_err("didn't find our range");
+		goto out_bits;
+	}
+	if (start != test_start || end != total_dirty - 1) {
+		test_err("expected start %llu end %llu, got start %llu end %llu",
+			 test_start, total_dirty - 1, start, end);
+		goto out_bits;
+	}
+	if (process_page_range(inode, start, end,
+			       PROCESS_TEST_LOCKED | PROCESS_UNLOCK)) {
+		test_err("pages in range were not all locked");
+		goto out_bits;
+	}
+	btrfs_unlock_extent(tmp, start, end, NULL);
+
+	/*
+	 * Now to test where we run into a page that is no longer dirty in the
+	 * range we want to find.
+	 */
+	page = find_get_page(inode->i_mapping,
+			     (max_bytes + SZ_1M) >> PAGE_SHIFT);
+	if (!page) {
+		test_err("couldn't find our page");
+		goto out_bits;
+	}
+	ClearPageDirty(page);
+	put_page(page);
+
+	/* We unlocked it in the previous test */
+	lock_page(locked_page);
+	start = test_start;
+	end = start + PAGE_SIZE - 1;
+	/*
+	 * Currently if we fail to find dirty pages in the delalloc range we
+	 * will adjust max_bytes down to PAGE_SIZE and then re-search.  If
+	 * this changes at any point in the future we will need to fix this
+	 * tests expected behavior.
+	 */
+	found = find_lock_delalloc_range(inode, page_folio(locked_page), &start,
+					 &end);
+	if (!found) {
+		test_err("didn't find our range");
+		goto out_bits;
+	}
+	if (start != test_start && end != test_start + PAGE_SIZE - 1) {
+		test_err("expected start %llu end %llu, got start %llu end %llu",
+			 test_start, test_start + PAGE_SIZE - 1, start, end);
+		goto out_bits;
+	}
+	if (process_page_range(inode, start, end, PROCESS_TEST_LOCKED |
+			       PROCESS_UNLOCK)) {
+		test_err("pages in range were not all locked");
+		goto out_bits;
+	}
+	ret = 0;
+out_bits:
+	if (ret)
+		dump_extent_io_tree(tmp);
+	btrfs_clear_extent_bit(tmp, 0, total_dirty - 1, (unsigned)-1, NULL);
+out:
+	if (locked_page)
+		put_page(locked_page);
+	process_page_range(inode, 0, total_dirty - 1,
+			   PROCESS_UNLOCK | PROCESS_RELEASE);
+	iput(inode);
+	btrfs_free_dummy_root(root);
+	btrfs_free_dummy_fs_info(fs_info);
+	return ret;
+}
+
+static int check_eb_bitmap(unsigned long *bitmap, struct extent_buffer *eb)
+{
+	unsigned long i;
+
+	for (i = 0; i < eb->len * BITS_PER_BYTE; i++) {
+		bool bit_set, bit1_set;
+
+		bit_set = test_bit(i, bitmap);
+		bit1_set = extent_buffer_test_bit(eb, 0, i);
+		if (bit1_set != bit_set) {
+			u8 has;
+			u8 expect;
+
+			read_extent_buffer(eb, &has, i / BITS_PER_BYTE, 1);
+			expect = bitmap_get_value8(bitmap, ALIGN(i, BITS_PER_BYTE));
+
+			test_err(
+		"bits do not match, start byte 0 bit %lu, byte %lu has 0x%02x expect 0x%02x",
+				 i, i / BITS_PER_BYTE, has, expect);
+			return -EINVAL;
+		}
+
+		bit1_set = extent_buffer_test_bit(eb, i / BITS_PER_BYTE,
+						  i % BITS_PER_BYTE);
+		if (bit1_set != bit_set) {
+			u8 has;
+			u8 expect;
+
+			read_extent_buffer(eb, &has, i / BITS_PER_BYTE, 1);
+			expect = bitmap_get_value8(bitmap, ALIGN(i, BITS_PER_BYTE));
+
+			test_err(
+		"bits do not match, start byte %lu bit %lu, byte %lu has 0x%02x expect 0x%02x",
+				 i / BITS_PER_BYTE, i % BITS_PER_BYTE,
+				 i / BITS_PER_BYTE, has, expect);
+			return -EINVAL;
+		}
+	}
+	return 0;
+}
+
+static int test_bitmap_set(const char *name, unsigned long *bitmap,
+			   struct extent_buffer *eb,
+			   unsigned long byte_start, unsigned long bit_start,
+			   unsigned long bit_len)
+{
+	int ret;
+
+	bitmap_set(bitmap, byte_start * BITS_PER_BYTE + bit_start, bit_len);
+	extent_buffer_bitmap_set(eb, byte_start, bit_start, bit_len);
+	ret = check_eb_bitmap(bitmap, eb);
+	if (ret < 0)
+		test_err("%s test failed", name);
+	return ret;
+}
+
+static int test_bitmap_clear(const char *name, unsigned long *bitmap,
+			     struct extent_buffer *eb,
+			     unsigned long byte_start, unsigned long bit_start,
+			     unsigned long bit_len)
+{
+	int ret;
+
+	bitmap_clear(bitmap, byte_start * BITS_PER_BYTE + bit_start, bit_len);
+	extent_buffer_bitmap_clear(eb, byte_start, bit_start, bit_len);
+	ret = check_eb_bitmap(bitmap, eb);
+	if (ret < 0)
+		test_err("%s test failed", name);
+	return ret;
+}
+static int __test_eb_bitmaps(unsigned long *bitmap, struct extent_buffer *eb)
+{
+	unsigned long i, j;
+	unsigned long byte_len = eb->len;
+	u32 x;
+	int ret;
+
+	ret = test_bitmap_clear("clear all run 1", bitmap, eb, 0, 0,
+				byte_len * BITS_PER_BYTE);
+	if (ret < 0)
+		return ret;
+
+	ret = test_bitmap_set("set all", bitmap, eb, 0, 0, byte_len * BITS_PER_BYTE);
+	if (ret < 0)
+		return ret;
+
+	ret = test_bitmap_clear("clear all run 2", bitmap, eb, 0, 0,
+				byte_len * BITS_PER_BYTE);
+	if (ret < 0)
+		return ret;
+
+	ret = test_bitmap_set("same byte set", bitmap, eb, 0, 2, 4);
+	if (ret < 0)
+		return ret;
+
+	ret = test_bitmap_clear("same byte partial clear", bitmap, eb, 0, 4, 1);
+	if (ret < 0)
+		return ret;
+
+	ret = test_bitmap_set("cross byte set", bitmap, eb, 2, 4, 8);
+	if (ret < 0)
+		return ret;
+
+	ret = test_bitmap_set("cross multi byte set", bitmap, eb, 4, 4, 24);
+	if (ret < 0)
+		return ret;
+
+	ret = test_bitmap_clear("cross byte clear", bitmap, eb, 2, 6, 4);
+	if (ret < 0)
+		return ret;
+
+	ret = test_bitmap_clear("cross multi byte clear", bitmap, eb, 4, 6, 20);
+	if (ret < 0)
+		return ret;
+
+	/* Straddling pages test */
+	if (byte_len > PAGE_SIZE) {
+		ret = test_bitmap_set("cross page set", bitmap, eb,
+				      PAGE_SIZE - sizeof(long) / 2, 0,
+				      sizeof(long) * BITS_PER_BYTE);
+		if (ret < 0)
+			return ret;
+
+		ret = test_bitmap_set("cross page set all", bitmap, eb, 0, 0,
+				      byte_len * BITS_PER_BYTE);
+		if (ret < 0)
+			return ret;
+
+		ret = test_bitmap_clear("cross page clear", bitmap, eb,
+					PAGE_SIZE - sizeof(long) / 2, 0,
+					sizeof(long) * BITS_PER_BYTE);
+		if (ret < 0)
+			return ret;
+	}
+
+	/*
+	 * Generate a wonky pseudo-random bit pattern for the sake of not using
+	 * something repetitive that could miss some hypothetical off-by-n bug.
+	 */
+	x = 0;
+	ret = test_bitmap_clear("clear all run 3", bitmap, eb, 0, 0,
+				byte_len * BITS_PER_BYTE);
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < byte_len * BITS_PER_BYTE / 32; i++) {
+		x = (0x19660dULL * (u64)x + 0x3c6ef35fULL) & 0xffffffffU;
+		for (j = 0; j < 32; j++) {
+			if (x & (1U << j)) {
+				bitmap_set(bitmap, i * 32 + j, 1);
+				extent_buffer_bitmap_set(eb, 0, i * 32 + j, 1);
+			}
+		}
+	}
+
+	ret = check_eb_bitmap(bitmap, eb);
+	if (ret) {
+		test_err("random bit pattern failed");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int test_eb_bitmaps(u32 sectorsize, u32 nodesize)
+{
+	struct btrfs_fs_info *fs_info;
+	unsigned long AUTO_KFREE(bitmap);
+	struct extent_buffer *eb = NULL;
+	int ret;
+
+	test_msg("running extent buffer bitmap tests");
+
+	fs_info = btrfs_alloc_dummy_fs_info(nodesize, sectorsize);
+	if (!fs_info) {
+		test_std_err(TEST_ALLOC_FS_INFO);
+		return -ENOMEM;
+	}
+
+	bitmap = kmalloc(nodesize, GFP_KERNEL);
+	if (!bitmap) {
+		test_err("couldn't allocate test bitmap");
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	eb = alloc_dummy_extent_buffer(fs_info, 0);
+	if (!eb) {
+		test_std_err(TEST_ALLOC_ROOT);
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	ret = __test_eb_bitmaps(bitmap, eb);
+	if (ret)
+		goto out;
+
+	free_extent_buffer(eb);
+
+	/*
+	 * Test again for case where the tree block is sectorsize aligned but
+	 * not nodesize aligned.
+	 */
+	eb = alloc_dummy_extent_buffer(fs_info, sectorsize);
+	if (!eb) {
+		test_std_err(TEST_ALLOC_ROOT);
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	ret = __test_eb_bitmaps(bitmap, eb);
+out:
+	free_extent_buffer(eb);
+	btrfs_free_dummy_fs_info(fs_info);
+	return ret;
+}
+
+static int test_find_first_clear_extent_bit(void)
+{
+	struct extent_io_tree tree;
+	u64 start, end;
+	int ret = -EINVAL;
+
+	test_msg("running find_first_clear_extent_bit test");
+
+	btrfs_extent_io_tree_init(NULL, &tree, IO_TREE_SELFTEST);
+
+	/* Test correct handling of empty tree */
+	btrfs_find_first_clear_extent_bit(&tree, 0, &start, &end, CHUNK_TRIMMED);
+	if (start != 0 || end != -1) {
+		test_err(
+	"error getting a range from completely empty tree: start %llu end %llu",
+			 start, end);
+		goto out;
+	}
+	/*
+	 * Set 1M-4M alloc/discard and 32M-64M thus leaving a hole between
+	 * 4M-32M
+	 */
+	btrfs_set_extent_bit(&tree, SZ_1M, SZ_4M - 1,
+			     CHUNK_TRIMMED | CHUNK_ALLOCATED, NULL);
+
+	btrfs_find_first_clear_extent_bit(&tree, SZ_512K, &start, &end,
+					  CHUNK_TRIMMED | CHUNK_ALLOCATED);
+
+	if (start != 0 || end != SZ_1M - 1) {
+		test_err("error finding beginning range: start %llu end %llu",
+			 start, end);
+		goto out;
+	}
+
+	/* Now add 32M-64M so that we have a hole between 4M-32M */
+	btrfs_set_extent_bit(&tree, SZ_32M, SZ_64M - 1,
+			     CHUNK_TRIMMED | CHUNK_ALLOCATED, NULL);
+
+	/*
+	 * Request first hole starting at 12M, we should get 4M-32M
+	 */
+	btrfs_find_first_clear_extent_bit(&tree, 12 * SZ_1M, &start, &end,
+					  CHUNK_TRIMMED | CHUNK_ALLOCATED);
+
+	if (start != SZ_4M || end != SZ_32M - 1) {
+		test_err("error finding trimmed range: start %llu end %llu",
+			 start, end);
+		goto out;
+	}
+
+	/*
+	 * Search in the middle of allocated range, should get the next one
+	 * available, which happens to be unallocated -> 4M-32M
+	 */
+	btrfs_find_first_clear_extent_bit(&tree, SZ_2M, &start, &end,
+					  CHUNK_TRIMMED | CHUNK_ALLOCATED);
+
+	if (start != SZ_4M || end != SZ_32M - 1) {
+		test_err("error finding next unalloc range: start %llu end %llu",
+			 start, end);
+		goto out;
+	}
+
+	/*
+	 * Set 64M-72M with CHUNK_ALLOC flag, then search for CHUNK_TRIMMED flag
+	 * being unset in this range, we should get the entry in range 64M-72M
+	 */
+	btrfs_set_extent_bit(&tree, SZ_64M, SZ_64M + SZ_8M - 1, CHUNK_ALLOCATED, NULL);
+	btrfs_find_first_clear_extent_bit(&tree, SZ_64M + SZ_1M, &start, &end,
+					  CHUNK_TRIMMED);
+
+	if (start != SZ_64M || end != SZ_64M + SZ_8M - 1) {
+		test_err("error finding exact range: start %llu end %llu",
+			 start, end);
+		goto out;
+	}
+
+	btrfs_find_first_clear_extent_bit(&tree, SZ_64M - SZ_8M, &start, &end,
+					  CHUNK_TRIMMED);
+
+	/*
+	 * Search in the middle of set range whose immediate neighbour doesn't
+	 * have the bits set so it must be returned
+	 */
+	if (start != SZ_64M || end != SZ_64M + SZ_8M - 1) {
+		test_err("error finding next alloc range: start %llu end %llu",
+			 start, end);
+		goto out;
+	}
+
+	/*
+	 * Search beyond any known range, shall return after last known range
+	 * and end should be -1
+	 */
+	btrfs_find_first_clear_extent_bit(&tree, -1, &start, &end, CHUNK_TRIMMED);
+	if (start != SZ_64M + SZ_8M || end != -1) {
+		test_err(
+		"error handling beyond end of range search: start %llu end %llu",
+			start, end);
+		goto out;
+	}
+
+	ret = 0;
+out:
+	if (ret)
+		dump_extent_io_tree(&tree);
+	btrfs_clear_extent_bit(&tree, 0, (u64)-1, CHUNK_TRIMMED | CHUNK_ALLOCATED, NULL);
+
+	return ret;
+}
+
+static void dump_eb_and_memory_contents(struct extent_buffer *eb, void *memory,
+					const char *test_name)
+{
+	for (int i = 0; i < eb->len; i++) {
+		struct page *page = folio_page(eb->folios[i >> PAGE_SHIFT], 0);
+		void *addr = page_address(page) + offset_in_page(i);
+
+		if (memcmp(addr, memory + i, 1) != 0) {
+			test_err("%s failed", test_name);
+			test_err("eb and memory diffs at byte %u, eb has 0x%02x memory has 0x%02x",
+				 i, *(u8 *)addr, *(u8 *)(memory + i));
+			return;
+		}
+	}
+}
+
+static int verify_eb_and_memory(struct extent_buffer *eb, void *memory,
+				const char *test_name)
+{
+	for (int i = 0; i < (eb->len >> PAGE_SHIFT); i++) {
+		void *eb_addr = folio_address(eb->folios[i]);
+
+		if (memcmp(memory + (i << PAGE_SHIFT), eb_addr, PAGE_SIZE) != 0) {
+			dump_eb_and_memory_contents(eb, memory, test_name);
+			return -EUCLEAN;
+		}
+	}
+	return 0;
+}
+
+/*
+ * Init both memory and extent buffer contents to the same randomly generated
+ * contents.
+ */
+static void init_eb_and_memory(struct extent_buffer *eb, void *memory)
+{
+	get_random_bytes(memory, eb->len);
+	write_extent_buffer(eb, memory, 0, eb->len);
+}
+
+static int test_eb_mem_ops(u32 sectorsize, u32 nodesize)
+{
+	struct btrfs_fs_info *fs_info;
+	struct extent_buffer *eb = NULL;
+	void *memory = NULL;
+	int ret;
+
+	test_msg("running extent buffer memory operation tests");
+
+	fs_info = btrfs_alloc_dummy_fs_info(nodesize, sectorsize);
+	if (!fs_info) {
+		test_std_err(TEST_ALLOC_FS_INFO);
+		return -ENOMEM;
+	}
+
+	memory = kvzalloc(nodesize, GFP_KERNEL);
+	if (!memory) {
+		test_err("failed to allocate memory");
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	eb = alloc_dummy_extent_buffer(fs_info, SZ_1M);
+	if (!eb) {
+		test_std_err(TEST_ALLOC_EXTENT_BUFFER);
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	init_eb_and_memory(eb, memory);
+	ret = verify_eb_and_memory(eb, memory, "full eb write");
+	if (ret < 0)
+		goto out;
+
+	memcpy(memory, memory + 16, 16);
+	memcpy_extent_buffer(eb, 0, 16, 16);
+	ret = verify_eb_and_memory(eb, memory, "same page non-overlapping memcpy 1");
+	if (ret < 0)
+		goto out;
+
+	memcpy(memory, memory + 2048, 16);
+	memcpy_extent_buffer(eb, 0, 2048, 16);
+	ret = verify_eb_and_memory(eb, memory, "same page non-overlapping memcpy 2");
+	if (ret < 0)
+		goto out;
+	memcpy(memory, memory + 2048, 2048);
+	memcpy_extent_buffer(eb, 0, 2048, 2048);
+	ret = verify_eb_and_memory(eb, memory, "same page non-overlapping memcpy 3");
+	if (ret < 0)
+		goto out;
+
+	memmove(memory + 512, memory + 256, 512);
+	memmove_extent_buffer(eb, 512, 256, 512);
+	ret = verify_eb_and_memory(eb, memory, "same page overlapping memcpy 1");
+	if (ret < 0)
+		goto out;
+
+	memmove(memory + 2048, memory + 512, 2048);
+	memmove_extent_buffer(eb, 2048, 512, 2048);
+	ret = verify_eb_and_memory(eb, memory, "same page overlapping memcpy 2");
+	if (ret < 0)
+		goto out;
+	memmove(memory + 512, memory + 2048, 2048);
+	memmove_extent_buffer(eb, 512, 2048, 2048);
+	ret = verify_eb_and_memory(eb, memory, "same page overlapping memcpy 3");
+	if (ret < 0)
+		goto out;
+
+	if (nodesize > PAGE_SIZE) {
+		memcpy(memory, memory + 4096 - 128, 256);
+		memcpy_extent_buffer(eb, 0, 4096 - 128, 256);
+		ret = verify_eb_and_memory(eb, memory, "cross page non-overlapping memcpy 1");
+		if (ret < 0)
+			goto out;
+
+		memcpy(memory + 4096 - 128, memory + 4096 + 128, 256);
+		memcpy_extent_buffer(eb, 4096 - 128, 4096 + 128, 256);
+		ret = verify_eb_and_memory(eb, memory, "cross page non-overlapping memcpy 2");
+		if (ret < 0)
+			goto out;
+
+		memmove(memory + 4096 - 128, memory + 4096 - 64, 256);
+		memmove_extent_buffer(eb, 4096 - 128, 4096 - 64, 256);
+		ret = verify_eb_and_memory(eb, memory, "cross page overlapping memcpy 1");
+		if (ret < 0)
+			goto out;
+
+		memmove(memory + 4096 - 64, memory + 4096 - 128, 256);
+		memmove_extent_buffer(eb, 4096 - 64, 4096 - 128, 256);
+		ret = verify_eb_and_memory(eb, memory, "cross page overlapping memcpy 2");
+		if (ret < 0)
+			goto out;
+	}
+out:
+	free_extent_buffer(eb);
+	kvfree(memory);
+	btrfs_free_dummy_fs_info(fs_info);
+	return ret;
+}
+
+int btrfs_test_extent_io(u32 sectorsize, u32 nodesize)
+{
+	int ret;
+
+	test_msg("running extent I/O tests");
+
+	ret = test_find_delalloc(sectorsize, nodesize);
+	if (ret)
+		goto out;
+
+	ret = test_find_first_clear_extent_bit();
+	if (ret)
+		goto out;
+
+	ret = test_eb_bitmaps(sectorsize, nodesize);
+	if (ret)
+		goto out;
+
+	ret = test_eb_mem_ops(sectorsize, nodesize);
+out:
+	return ret;
+}
diff --git a/fs/btrfs/tests/extent-map-tests.c b/fs/btrfs/tests/extent-map-tests.c
new file mode 100644
index 000000000..811f36d41
--- /dev/null
+++ b/fs/btrfs/tests/extent-map-tests.c
@@ -0,0 +1,1202 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2017 Oracle.  All rights reserved.
+ */
+
+#include <linux/types.h>
+#include "btrfs-tests.h"
+#include "../ctree.h"
+#include "../btrfs_inode.h"
+#include "../volumes.h"
+#include "../disk-io.h"
+#include "../block-group.h"
+
+static int free_extent_map_tree(struct btrfs_inode *inode)
+{
+	struct extent_map_tree *em_tree = &inode->extent_tree;
+	struct extent_map *em;
+	struct rb_node *node;
+	int ret = 0;
+
+	write_lock(&em_tree->lock);
+	while (!RB_EMPTY_ROOT(&em_tree->root)) {
+		node = rb_first(&em_tree->root);
+		em = rb_entry(node, struct extent_map, rb_node);
+		btrfs_remove_extent_mapping(inode, em);
+
+#ifdef CONFIG_BTRFS_DEBUG
+		if (refcount_read(&em->refs) != 1) {
+			ret = -EINVAL;
+			test_err(
+"em leak: em (start %llu len %llu disk_bytenr %llu disk_num_bytes %llu offset %llu) refs %d",
+				 em->start, em->len, em->disk_bytenr,
+				 em->disk_num_bytes, em->offset,
+				 refcount_read(&em->refs));
+
+			refcount_set(&em->refs, 1);
+		}
+#endif
+		btrfs_free_extent_map(em);
+	}
+	write_unlock(&em_tree->lock);
+
+	return ret;
+}
+
+/*
+ * Test scenario:
+ *
+ * Suppose that no extent map has been loaded into memory yet, there is a file
+ * extent [0, 16K), followed by another file extent [16K, 20K), two dio reads
+ * are entering btrfs_get_extent() concurrently, t1 is reading [8K, 16K), t2 is
+ * reading [0, 8K)
+ *
+ *     t1                            t2
+ *  btrfs_get_extent()              btrfs_get_extent()
+ *    -> lookup_extent_mapping()      ->lookup_extent_mapping()
+ *    -> add_extent_mapping(0, 16K)
+ *    -> return em
+ *                                    ->add_extent_mapping(0, 16K)
+ *                                    -> #handle -EEXIST
+ */
+static int test_case_1(struct btrfs_fs_info *fs_info, struct btrfs_inode *inode)
+{
+	struct extent_map_tree *em_tree = &inode->extent_tree;
+	struct extent_map *em;
+	u64 start = 0;
+	u64 len = SZ_8K;
+	int ret;
+	int ret2;
+
+	em = btrfs_alloc_extent_map();
+	if (!em) {
+		test_std_err(TEST_ALLOC_EXTENT_MAP);
+		return -ENOMEM;
+	}
+
+	/* Add [0, 16K) */
+	em->start = 0;
+	em->len = SZ_16K;
+	em->disk_bytenr = 0;
+	em->disk_num_bytes = SZ_16K;
+	em->ram_bytes = SZ_16K;
+	write_lock(&em_tree->lock);
+	ret = btrfs_add_extent_mapping(inode, &em, em->start, em->len);
+	write_unlock(&em_tree->lock);
+	if (ret < 0) {
+		test_err("cannot add extent range [0, 16K)");
+		goto out;
+	}
+	btrfs_free_extent_map(em);
+
+	/* Add [16K, 20K) following [0, 16K)  */
+	em = btrfs_alloc_extent_map();
+	if (!em) {
+		test_std_err(TEST_ALLOC_EXTENT_MAP);
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	em->start = SZ_16K;
+	em->len = SZ_4K;
+	em->disk_bytenr = SZ_32K; /* avoid merging */
+	em->disk_num_bytes = SZ_4K;
+	em->ram_bytes = SZ_4K;
+	write_lock(&em_tree->lock);
+	ret = btrfs_add_extent_mapping(inode, &em, em->start, em->len);
+	write_unlock(&em_tree->lock);
+	if (ret < 0) {
+		test_err("cannot add extent range [16K, 20K)");
+		goto out;
+	}
+	btrfs_free_extent_map(em);
+
+	em = btrfs_alloc_extent_map();
+	if (!em) {
+		test_std_err(TEST_ALLOC_EXTENT_MAP);
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	/* Add [0, 8K), should return [0, 16K) instead. */
+	em->start = start;
+	em->len = len;
+	em->disk_bytenr = start;
+	em->disk_num_bytes = len;
+	em->ram_bytes = len;
+	write_lock(&em_tree->lock);
+	ret = btrfs_add_extent_mapping(inode, &em, em->start, em->len);
+	write_unlock(&em_tree->lock);
+	if (ret) {
+		test_err("case1 [%llu %llu]: ret %d", start, start + len, ret);
+		goto out;
+	}
+	if (!em) {
+		test_err("case1 [%llu %llu]: no extent map returned",
+			 start, start + len);
+		ret = -ENOENT;
+		goto out;
+	}
+	if (em->start != 0 || btrfs_extent_map_end(em) != SZ_16K ||
+	    em->disk_bytenr != 0 || em->disk_num_bytes != SZ_16K) {
+		test_err(
+"case1 [%llu %llu]: ret %d return a wrong em (start %llu len %llu disk_bytenr %llu disk_num_bytes %llu",
+			 start, start + len, ret, em->start, em->len,
+			 em->disk_bytenr, em->disk_num_bytes);
+		ret = -EINVAL;
+	}
+	btrfs_free_extent_map(em);
+out:
+	ret2 = free_extent_map_tree(inode);
+	if (ret == 0)
+		ret = ret2;
+
+	return ret;
+}
+
+/*
+ * Test scenario:
+ *
+ * Reading the inline ending up with EEXIST, ie. read an inline
+ * extent and discard page cache and read it again.
+ */
+static int test_case_2(struct btrfs_fs_info *fs_info, struct btrfs_inode *inode)
+{
+	struct extent_map_tree *em_tree = &inode->extent_tree;
+	struct extent_map *em;
+	int ret;
+	int ret2;
+
+	em = btrfs_alloc_extent_map();
+	if (!em) {
+		test_std_err(TEST_ALLOC_EXTENT_MAP);
+		return -ENOMEM;
+	}
+
+	/*
+	 * Add [0, 1K) which is inlined. And the extent map length must
+	 * be one block.
+	 */
+	em->start = 0;
+	em->len = SZ_4K;
+	em->disk_bytenr = EXTENT_MAP_INLINE;
+	em->disk_num_bytes = 0;
+	em->ram_bytes = SZ_1K;
+	write_lock(&em_tree->lock);
+	ret = btrfs_add_extent_mapping(inode, &em, em->start, em->len);
+	write_unlock(&em_tree->lock);
+	if (ret < 0) {
+		test_err("cannot add extent range [0, 1K)");
+		goto out;
+	}
+	btrfs_free_extent_map(em);
+
+	/* Add [4K, 8K) following [0, 1K)  */
+	em = btrfs_alloc_extent_map();
+	if (!em) {
+		test_std_err(TEST_ALLOC_EXTENT_MAP);
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	em->start = SZ_4K;
+	em->len = SZ_4K;
+	em->disk_bytenr = SZ_4K;
+	em->disk_num_bytes = SZ_4K;
+	em->ram_bytes = SZ_4K;
+	write_lock(&em_tree->lock);
+	ret = btrfs_add_extent_mapping(inode, &em, em->start, em->len);
+	write_unlock(&em_tree->lock);
+	if (ret < 0) {
+		test_err("cannot add extent range [4K, 8K)");
+		goto out;
+	}
+	btrfs_free_extent_map(em);
+
+	em = btrfs_alloc_extent_map();
+	if (!em) {
+		test_std_err(TEST_ALLOC_EXTENT_MAP);
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	/* Add [0, 1K) */
+	em->start = 0;
+	em->len = SZ_4K;
+	em->disk_bytenr = EXTENT_MAP_INLINE;
+	em->disk_num_bytes = 0;
+	em->ram_bytes = SZ_1K;
+	write_lock(&em_tree->lock);
+	ret = btrfs_add_extent_mapping(inode, &em, em->start, em->len);
+	write_unlock(&em_tree->lock);
+	if (ret) {
+		test_err("case2 [0 1K]: ret %d", ret);
+		goto out;
+	}
+	if (!em) {
+		test_err("case2 [0 1K]: no extent map returned");
+		ret = -ENOENT;
+		goto out;
+	}
+	if (em->start != 0 || btrfs_extent_map_end(em) != SZ_4K ||
+	    em->disk_bytenr != EXTENT_MAP_INLINE) {
+		test_err(
+"case2 [0 1K]: ret %d return a wrong em (start %llu len %llu disk_bytenr %llu",
+			 ret, em->start, em->len, em->disk_bytenr);
+		ret = -EINVAL;
+	}
+	btrfs_free_extent_map(em);
+out:
+	ret2 = free_extent_map_tree(inode);
+	if (ret == 0)
+		ret = ret2;
+
+	return ret;
+}
+
+static int __test_case_3(struct btrfs_fs_info *fs_info,
+			 struct btrfs_inode *inode, u64 start)
+{
+	struct extent_map_tree *em_tree = &inode->extent_tree;
+	struct extent_map *em;
+	u64 len = SZ_4K;
+	int ret;
+	int ret2;
+
+	em = btrfs_alloc_extent_map();
+	if (!em) {
+		test_std_err(TEST_ALLOC_EXTENT_MAP);
+		return -ENOMEM;
+	}
+
+	/* Add [4K, 8K) */
+	em->start = SZ_4K;
+	em->len = SZ_4K;
+	em->disk_bytenr = SZ_4K;
+	em->disk_num_bytes = SZ_4K;
+	em->ram_bytes = SZ_4K;
+	write_lock(&em_tree->lock);
+	ret = btrfs_add_extent_mapping(inode, &em, em->start, em->len);
+	write_unlock(&em_tree->lock);
+	if (ret < 0) {
+		test_err("cannot add extent range [4K, 8K)");
+		goto out;
+	}
+	btrfs_free_extent_map(em);
+
+	em = btrfs_alloc_extent_map();
+	if (!em) {
+		test_std_err(TEST_ALLOC_EXTENT_MAP);
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	/* Add [0, 16K) */
+	em->start = 0;
+	em->len = SZ_16K;
+	em->disk_bytenr = 0;
+	em->disk_num_bytes = SZ_16K;
+	em->ram_bytes = SZ_16K;
+	write_lock(&em_tree->lock);
+	ret = btrfs_add_extent_mapping(inode, &em, start, len);
+	write_unlock(&em_tree->lock);
+	if (ret) {
+		test_err("case3 [%llu %llu): ret %d",
+			 start, start + len, ret);
+		goto out;
+	}
+	if (!em) {
+		test_err("case3 [%llu %llu): no extent map returned",
+			 start, start + len);
+		ret = -ENOENT;
+		goto out;
+	}
+	/*
+	 * Since bytes within em are contiguous, em->block_start is identical to
+	 * em->start.
+	 */
+	if (start < em->start || start + len > btrfs_extent_map_end(em) ||
+	    em->start != btrfs_extent_map_block_start(em)) {
+		test_err(
+"case3 [%llu %llu): ret %d em (start %llu len %llu disk_bytenr %llu block_len %llu)",
+			 start, start + len, ret, em->start, em->len,
+			 em->disk_bytenr, em->disk_num_bytes);
+		ret = -EINVAL;
+	}
+	btrfs_free_extent_map(em);
+out:
+	ret2 = free_extent_map_tree(inode);
+	if (ret == 0)
+		ret = ret2;
+
+	return ret;
+}
+
+/*
+ * Test scenario:
+ *
+ * Suppose that no extent map has been loaded into memory yet.
+ * There is a file extent [0, 16K), two jobs are running concurrently
+ * against it, t1 is buffered writing to [4K, 8K) and t2 is doing dio
+ * read from [0, 4K) or [8K, 12K) or [12K, 16K).
+ *
+ * t1 goes ahead of t2 and adds em [4K, 8K) into tree.
+ *
+ *         t1                       t2
+ *  cow_file_range()	     btrfs_get_extent()
+ *                            -> lookup_extent_mapping()
+ *   -> add_extent_mapping()
+ *                            -> add_extent_mapping()
+ */
+static int test_case_3(struct btrfs_fs_info *fs_info, struct btrfs_inode *inode)
+{
+	int ret;
+
+	ret = __test_case_3(fs_info, inode, 0);
+	if (ret)
+		return ret;
+	ret = __test_case_3(fs_info, inode, SZ_8K);
+	if (ret)
+		return ret;
+	ret = __test_case_3(fs_info, inode, (12 * SZ_1K));
+
+	return ret;
+}
+
+static int __test_case_4(struct btrfs_fs_info *fs_info,
+			 struct btrfs_inode *inode, u64 start)
+{
+	struct extent_map_tree *em_tree = &inode->extent_tree;
+	struct extent_map *em;
+	u64 len = SZ_4K;
+	int ret;
+	int ret2;
+
+	em = btrfs_alloc_extent_map();
+	if (!em) {
+		test_std_err(TEST_ALLOC_EXTENT_MAP);
+		return -ENOMEM;
+	}
+
+	/* Add [0K, 8K) */
+	em->start = 0;
+	em->len = SZ_8K;
+	em->disk_bytenr = 0;
+	em->disk_num_bytes = SZ_8K;
+	em->ram_bytes = SZ_8K;
+	write_lock(&em_tree->lock);
+	ret = btrfs_add_extent_mapping(inode, &em, em->start, em->len);
+	write_unlock(&em_tree->lock);
+	if (ret < 0) {
+		test_err("cannot add extent range [0, 8K)");
+		goto out;
+	}
+	btrfs_free_extent_map(em);
+
+	em = btrfs_alloc_extent_map();
+	if (!em) {
+		test_std_err(TEST_ALLOC_EXTENT_MAP);
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	/* Add [8K, 32K) */
+	em->start = SZ_8K;
+	em->len = 24 * SZ_1K;
+	em->disk_bytenr = SZ_16K; /* avoid merging */
+	em->disk_num_bytes = 24 * SZ_1K;
+	em->ram_bytes = 24 * SZ_1K;
+	write_lock(&em_tree->lock);
+	ret = btrfs_add_extent_mapping(inode, &em, em->start, em->len);
+	write_unlock(&em_tree->lock);
+	if (ret < 0) {
+		test_err("cannot add extent range [8K, 32K)");
+		goto out;
+	}
+	btrfs_free_extent_map(em);
+
+	em = btrfs_alloc_extent_map();
+	if (!em) {
+		test_std_err(TEST_ALLOC_EXTENT_MAP);
+		ret = -ENOMEM;
+		goto out;
+	}
+	/* Add [0K, 32K) */
+	em->start = 0;
+	em->len = SZ_32K;
+	em->disk_bytenr = 0;
+	em->disk_num_bytes = SZ_32K;
+	em->ram_bytes = SZ_32K;
+	write_lock(&em_tree->lock);
+	ret = btrfs_add_extent_mapping(inode, &em, start, len);
+	write_unlock(&em_tree->lock);
+	if (ret) {
+		test_err("case4 [%llu %llu): ret %d",
+			 start, start + len, ret);
+		goto out;
+	}
+	if (!em) {
+		test_err("case4 [%llu %llu): no extent map returned",
+			 start, start + len);
+		ret = -ENOENT;
+		goto out;
+	}
+	if (start < em->start || start + len > btrfs_extent_map_end(em)) {
+		test_err(
+"case4 [%llu %llu): ret %d, added wrong em (start %llu len %llu disk_bytenr %llu disk_num_bytes %llu)",
+			 start, start + len, ret, em->start, em->len,
+			 em->disk_bytenr, em->disk_num_bytes);
+		ret = -EINVAL;
+	}
+	btrfs_free_extent_map(em);
+out:
+	ret2 = free_extent_map_tree(inode);
+	if (ret == 0)
+		ret = ret2;
+
+	return ret;
+}
+
+/*
+ * Test scenario:
+ *
+ * Suppose that no extent map has been loaded into memory yet.
+ * There is a file extent [0, 32K), two jobs are running concurrently
+ * against it, t1 is doing dio write to [8K, 32K) and t2 is doing dio
+ * read from [0, 4K) or [4K, 8K).
+ *
+ * t1 goes ahead of t2 and splits em [0, 32K) to em [0K, 8K) and [8K 32K).
+ *
+ *         t1                                t2
+ *  btrfs_get_blocks_direct()	       btrfs_get_blocks_direct()
+ *   -> btrfs_get_extent()              -> btrfs_get_extent()
+ *       -> lookup_extent_mapping()
+ *       -> add_extent_mapping()            -> lookup_extent_mapping()
+ *          # load [0, 32K)
+ *   -> btrfs_new_extent_direct()
+ *       -> btrfs_drop_extent_cache()
+ *          # split [0, 32K)
+ *       -> add_extent_mapping()
+ *          # add [8K, 32K)
+ *                                          -> add_extent_mapping()
+ *                                             # handle -EEXIST when adding
+ *                                             # [0, 32K)
+ */
+static int test_case_4(struct btrfs_fs_info *fs_info, struct btrfs_inode *inode)
+{
+	int ret;
+
+	ret = __test_case_4(fs_info, inode, 0);
+	if (ret)
+		return ret;
+	ret = __test_case_4(fs_info, inode, SZ_4K);
+
+	return ret;
+}
+
+static int add_compressed_extent(struct btrfs_inode *inode,
+				 u64 start, u64 len, u64 block_start)
+{
+	struct extent_map_tree *em_tree = &inode->extent_tree;
+	struct extent_map *em;
+	int ret;
+
+	em = btrfs_alloc_extent_map();
+	if (!em) {
+		test_std_err(TEST_ALLOC_EXTENT_MAP);
+		return -ENOMEM;
+	}
+
+	em->start = start;
+	em->len = len;
+	em->disk_bytenr = block_start;
+	em->disk_num_bytes = SZ_4K;
+	em->ram_bytes = len;
+	em->flags |= EXTENT_FLAG_COMPRESS_ZLIB;
+	write_lock(&em_tree->lock);
+	ret = btrfs_add_extent_mapping(inode, &em, em->start, em->len);
+	write_unlock(&em_tree->lock);
+	btrfs_free_extent_map(em);
+	if (ret < 0) {
+		test_err("cannot add extent map [%llu, %llu)", start, start + len);
+		return ret;
+	}
+
+	return 0;
+}
+
+struct extent_range {
+	u64 start;
+	u64 len;
+};
+
+/* The valid states of the tree after every drop, as described below. */
+struct extent_range valid_ranges[][7] = {
+	{
+	  { .start = 0,			.len = SZ_8K },		/* [0, 8K) */
+	  { .start = SZ_4K * 3,		.len = SZ_4K * 3},	/* [12k, 24k) */
+	  { .start = SZ_4K * 6,		.len = SZ_4K * 3},	/* [24k, 36k) */
+	  { .start = SZ_32K + SZ_4K,	.len = SZ_4K},		/* [36k, 40k) */
+	  { .start = SZ_4K * 10,	.len = SZ_4K * 6},	/* [40k, 64k) */
+	},
+	{
+	  { .start = 0,			.len = SZ_8K },		/* [0, 8K) */
+	  { .start = SZ_4K * 5,		.len = SZ_4K},		/* [20k, 24k) */
+	  { .start = SZ_4K * 6,		.len = SZ_4K * 3},	/* [24k, 36k) */
+	  { .start = SZ_32K + SZ_4K,	.len = SZ_4K},		/* [36k, 40k) */
+	  { .start = SZ_4K * 10,	.len = SZ_4K * 6},	/* [40k, 64k) */
+	},
+	{
+	  { .start = 0,			.len = SZ_8K },		/* [0, 8K) */
+	  { .start = SZ_4K * 5,		.len = SZ_4K},		/* [20k, 24k) */
+	  { .start = SZ_4K * 6,		.len = SZ_4K},		/* [24k, 28k) */
+	  { .start = SZ_32K,		.len = SZ_4K},		/* [32k, 36k) */
+	  { .start = SZ_32K + SZ_4K,	.len = SZ_4K},		/* [36k, 40k) */
+	  { .start = SZ_4K * 10,	.len = SZ_4K * 6},	/* [40k, 64k) */
+	},
+	{
+	  { .start = 0,			.len = SZ_8K},		/* [0, 8K) */
+	  { .start = SZ_4K * 5,		.len = SZ_4K},		/* [20k, 24k) */
+	  { .start = SZ_4K * 6,		.len = SZ_4K},		/* [24k, 28k) */
+	}
+};
+
+static int validate_range(struct extent_map_tree *em_tree, int index)
+{
+	struct rb_node *n;
+	int i;
+
+	for (i = 0, n = rb_first(&em_tree->root);
+	     valid_ranges[index][i].len && n;
+	     i++, n = rb_next(n)) {
+		struct extent_map *entry = rb_entry(n, struct extent_map, rb_node);
+
+		if (entry->start != valid_ranges[index][i].start) {
+			test_err("mapping has start %llu expected %llu",
+				 entry->start, valid_ranges[index][i].start);
+			return -EINVAL;
+		}
+
+		if (entry->len != valid_ranges[index][i].len) {
+			test_err("mapping has len %llu expected %llu",
+				 entry->len, valid_ranges[index][i].len);
+			return -EINVAL;
+		}
+	}
+
+	/*
+	 * We exited because we don't have any more entries in the extent_map
+	 * but we still expect more valid entries.
+	 */
+	if (valid_ranges[index][i].len) {
+		test_err("missing an entry");
+		return -EINVAL;
+	}
+
+	/* We exited the loop but still have entries in the extent map. */
+	if (n) {
+		test_err("we have a left over entry in the extent map we didn't expect");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/*
+ * Test scenario:
+ *
+ * Test the various edge cases of btrfs_drop_extent_map_range, create the
+ * following ranges
+ *
+ * [0, 12k)[12k, 24k)[24k, 36k)[36k, 40k)[40k,64k)
+ *
+ * And then we'll drop:
+ *
+ * [8k, 12k) - test the single front split
+ * [12k, 20k) - test the single back split
+ * [28k, 32k) - test the double split
+ * [32k, 64k) - test whole em dropping
+ *
+ * They'll have the EXTENT_FLAG_COMPRESSED flag set to keep the em tree from
+ * merging the em's.
+ */
+static int test_case_5(struct btrfs_fs_info *fs_info, struct btrfs_inode *inode)
+{
+	u64 start, end;
+	int ret;
+	int ret2;
+
+	test_msg("Running btrfs_drop_extent_map_range tests");
+
+	/* [0, 12k) */
+	ret = add_compressed_extent(inode, 0, SZ_4K * 3, 0);
+	if (ret) {
+		test_err("cannot add extent range [0, 12K)");
+		goto out;
+	}
+
+	/* [12k, 24k) */
+	ret = add_compressed_extent(inode, SZ_4K * 3, SZ_4K * 3, SZ_4K);
+	if (ret) {
+		test_err("cannot add extent range [12k, 24k)");
+		goto out;
+	}
+
+	/* [24k, 36k) */
+	ret = add_compressed_extent(inode, SZ_4K * 6, SZ_4K * 3, SZ_8K);
+	if (ret) {
+		test_err("cannot add extent range [12k, 24k)");
+		goto out;
+	}
+
+	/* [36k, 40k) */
+	ret = add_compressed_extent(inode, SZ_32K + SZ_4K, SZ_4K, SZ_4K * 3);
+	if (ret) {
+		test_err("cannot add extent range [12k, 24k)");
+		goto out;
+	}
+
+	/* [40k, 64k) */
+	ret = add_compressed_extent(inode, SZ_4K * 10, SZ_4K * 6, SZ_16K);
+	if (ret) {
+		test_err("cannot add extent range [12k, 24k)");
+		goto out;
+	}
+
+	/* Drop [8k, 12k) */
+	start = SZ_8K;
+	end = (3 * SZ_4K) - 1;
+	btrfs_drop_extent_map_range(inode, start, end, false);
+	ret = validate_range(&inode->extent_tree, 0);
+	if (ret)
+		goto out;
+
+	/* Drop [12k, 20k) */
+	start = SZ_4K * 3;
+	end = SZ_16K + SZ_4K - 1;
+	btrfs_drop_extent_map_range(inode, start, end, false);
+	ret = validate_range(&inode->extent_tree, 1);
+	if (ret)
+		goto out;
+
+	/* Drop [28k, 32k) */
+	start = SZ_32K - SZ_4K;
+	end = SZ_32K - 1;
+	btrfs_drop_extent_map_range(inode, start, end, false);
+	ret = validate_range(&inode->extent_tree, 2);
+	if (ret)
+		goto out;
+
+	/* Drop [32k, 64k) */
+	start = SZ_32K;
+	end = SZ_64K - 1;
+	btrfs_drop_extent_map_range(inode, start, end, false);
+	ret = validate_range(&inode->extent_tree, 3);
+	if (ret)
+		goto out;
+out:
+	ret2 = free_extent_map_tree(inode);
+	if (ret == 0)
+		ret = ret2;
+
+	return ret;
+}
+
+/*
+ * Test the btrfs_add_extent_mapping helper which will attempt to create an em
+ * for areas between two existing ems.  Validate it doesn't do this when there
+ * are two unmerged em's side by side.
+ */
+static int test_case_6(struct btrfs_fs_info *fs_info, struct btrfs_inode *inode)
+{
+	struct extent_map_tree *em_tree = &inode->extent_tree;
+	struct extent_map *em = NULL;
+	int ret;
+	int ret2;
+
+	ret = add_compressed_extent(inode, 0, SZ_4K, 0);
+	if (ret)
+		goto out;
+
+	ret = add_compressed_extent(inode, SZ_4K, SZ_4K, 0);
+	if (ret)
+		goto out;
+
+	em = btrfs_alloc_extent_map();
+	if (!em) {
+		test_std_err(TEST_ALLOC_EXTENT_MAP);
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	em->start = SZ_4K;
+	em->len = SZ_4K;
+	em->disk_bytenr = SZ_16K;
+	em->disk_num_bytes = SZ_16K;
+	em->ram_bytes = SZ_16K;
+	write_lock(&em_tree->lock);
+	ret = btrfs_add_extent_mapping(inode, &em, 0, SZ_8K);
+	write_unlock(&em_tree->lock);
+
+	if (ret != 0) {
+		test_err("got an error when adding our em: %d", ret);
+		goto out;
+	}
+
+	ret = -EINVAL;
+	if (em->start != 0) {
+		test_err("unexpected em->start at %llu, wanted 0", em->start);
+		goto out;
+	}
+	if (em->len != SZ_4K) {
+		test_err("unexpected em->len %llu, expected 4K", em->len);
+		goto out;
+	}
+	ret = 0;
+out:
+	btrfs_free_extent_map(em);
+	ret2 = free_extent_map_tree(inode);
+	if (ret == 0)
+		ret = ret2;
+
+	return ret;
+}
+
+/*
+ * Regression test for btrfs_drop_extent_map_range.  Calling with skip_pinned ==
+ * true would mess up the start/end calculations and subsequent splits would be
+ * incorrect.
+ */
+static int test_case_7(struct btrfs_fs_info *fs_info, struct btrfs_inode *inode)
+{
+	struct extent_map_tree *em_tree = &inode->extent_tree;
+	struct extent_map *em;
+	int ret;
+	int ret2;
+
+	test_msg("Running btrfs_drop_extent_cache with pinned");
+
+	em = btrfs_alloc_extent_map();
+	if (!em) {
+		test_std_err(TEST_ALLOC_EXTENT_MAP);
+		return -ENOMEM;
+	}
+
+	/* [0, 16K), pinned */
+	em->start = 0;
+	em->len = SZ_16K;
+	em->disk_bytenr = 0;
+	em->disk_num_bytes = SZ_4K;
+	em->ram_bytes = SZ_16K;
+	em->flags |= (EXTENT_FLAG_PINNED | EXTENT_FLAG_COMPRESS_ZLIB);
+	write_lock(&em_tree->lock);
+	ret = btrfs_add_extent_mapping(inode, &em, em->start, em->len);
+	write_unlock(&em_tree->lock);
+	if (ret < 0) {
+		test_err("couldn't add extent map");
+		goto out;
+	}
+	btrfs_free_extent_map(em);
+
+	em = btrfs_alloc_extent_map();
+	if (!em) {
+		test_std_err(TEST_ALLOC_EXTENT_MAP);
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	/* [32K, 48K), not pinned */
+	em->start = SZ_32K;
+	em->len = SZ_16K;
+	em->disk_bytenr = SZ_32K;
+	em->disk_num_bytes = SZ_16K;
+	em->ram_bytes = SZ_16K;
+	write_lock(&em_tree->lock);
+	ret = btrfs_add_extent_mapping(inode, &em, em->start, em->len);
+	write_unlock(&em_tree->lock);
+	if (ret < 0) {
+		test_err("couldn't add extent map");
+		goto out;
+	}
+	btrfs_free_extent_map(em);
+
+	/*
+	 * Drop [0, 36K) This should skip the [0, 4K) extent and then split the
+	 * [32K, 48K) extent.
+	 */
+	btrfs_drop_extent_map_range(inode, 0, (36 * SZ_1K) - 1, true);
+
+	/* Make sure our extent maps look sane. */
+	ret = -EINVAL;
+
+	em = btrfs_lookup_extent_mapping(em_tree, 0, SZ_16K);
+	if (!em) {
+		test_err("didn't find an em at 0 as expected");
+		goto out;
+	}
+
+	if (em->start != 0) {
+		test_err("em->start is %llu, expected 0", em->start);
+		goto out;
+	}
+
+	if (em->len != SZ_16K) {
+		test_err("em->len is %llu, expected 16K", em->len);
+		goto out;
+	}
+
+	btrfs_free_extent_map(em);
+
+	read_lock(&em_tree->lock);
+	em = btrfs_lookup_extent_mapping(em_tree, SZ_16K, SZ_16K);
+	read_unlock(&em_tree->lock);
+	if (em) {
+		test_err("found an em when we weren't expecting one");
+		goto out;
+	}
+
+	read_lock(&em_tree->lock);
+	em = btrfs_lookup_extent_mapping(em_tree, SZ_32K, SZ_16K);
+	read_unlock(&em_tree->lock);
+	if (!em) {
+		test_err("didn't find an em at 32K as expected");
+		goto out;
+	}
+
+	if (em->start != (36 * SZ_1K)) {
+		test_err("em->start is %llu, expected 36K", em->start);
+		goto out;
+	}
+
+	if (em->len != (12 * SZ_1K)) {
+		test_err("em->len is %llu, expected 12K", em->len);
+		goto out;
+	}
+
+	if (btrfs_extent_map_block_start(em) != SZ_32K + SZ_4K) {
+		test_err("em->block_start is %llu, expected 36K",
+			 btrfs_extent_map_block_start(em));
+		goto out;
+	}
+
+	btrfs_free_extent_map(em);
+
+	read_lock(&em_tree->lock);
+	em = btrfs_lookup_extent_mapping(em_tree, 48 * SZ_1K, (u64)-1);
+	read_unlock(&em_tree->lock);
+	if (em) {
+		test_err("found an unexpected em above 48K");
+		goto out;
+	}
+
+	ret = 0;
+out:
+	btrfs_free_extent_map(em);
+	/* Unpin our extent to prevent warning when removing it below. */
+	ret2 = btrfs_unpin_extent_cache(inode, 0, SZ_16K, 0);
+	if (ret == 0)
+		ret = ret2;
+	ret2 = free_extent_map_tree(inode);
+	if (ret == 0)
+		ret = ret2;
+
+	return ret;
+}
+
+/*
+ * Test a regression for compressed extent map adjustment when we attempt to
+ * add an extent map that is partially overlapped by another existing extent
+ * map. The resulting extent map offset was left unchanged despite having
+ * incremented its start offset.
+ */
+static int test_case_8(struct btrfs_fs_info *fs_info, struct btrfs_inode *inode)
+{
+	struct extent_map_tree *em_tree = &inode->extent_tree;
+	struct extent_map *em;
+	int ret;
+	int ret2;
+
+	em = btrfs_alloc_extent_map();
+	if (!em) {
+		test_std_err(TEST_ALLOC_EXTENT_MAP);
+		return -ENOMEM;
+	}
+
+	/* Compressed extent for the file range [120K, 128K). */
+	em->start = SZ_1K * 120;
+	em->len = SZ_8K;
+	em->disk_num_bytes = SZ_4K;
+	em->ram_bytes = SZ_8K;
+	em->flags |= EXTENT_FLAG_COMPRESS_ZLIB;
+	write_lock(&em_tree->lock);
+	ret = btrfs_add_extent_mapping(inode, &em, em->start, em->len);
+	write_unlock(&em_tree->lock);
+	btrfs_free_extent_map(em);
+	if (ret < 0) {
+		test_err("couldn't add extent map for range [120K, 128K)");
+		goto out;
+	}
+
+	em = btrfs_alloc_extent_map();
+	if (!em) {
+		test_std_err(TEST_ALLOC_EXTENT_MAP);
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	/*
+	 * Compressed extent for the file range [108K, 144K), which overlaps
+	 * with the [120K, 128K) we previously inserted.
+	 */
+	em->start = SZ_1K * 108;
+	em->len = SZ_1K * 36;
+	em->disk_num_bytes = SZ_4K;
+	em->ram_bytes = SZ_1K * 36;
+	em->flags |= EXTENT_FLAG_COMPRESS_ZLIB;
+
+	/*
+	 * Try to add the extent map but with a search range of [140K, 144K),
+	 * this should succeed and adjust the extent map to the range
+	 * [128K, 144K), with a length of 16K and an offset of 20K.
+	 *
+	 * This simulates a scenario where in the subvolume tree of an inode we
+	 * have a compressed file extent item for the range [108K, 144K) and we
+	 * have an overlapping compressed extent map for the range [120K, 128K),
+	 * which was created by an encoded write, but its ordered extent was not
+	 * yet completed, so the subvolume tree doesn't have yet the file extent
+	 * item for that range - we only have the extent map in the inode's
+	 * extent map tree.
+	 */
+	write_lock(&em_tree->lock);
+	ret = btrfs_add_extent_mapping(inode, &em, SZ_1K * 140, SZ_4K);
+	write_unlock(&em_tree->lock);
+	btrfs_free_extent_map(em);
+	if (ret < 0) {
+		test_err("couldn't add extent map for range [108K, 144K)");
+		goto out;
+	}
+
+	if (em->start != SZ_128K) {
+		test_err("unexpected extent map start %llu (should be 128K)", em->start);
+		ret = -EINVAL;
+		goto out;
+	}
+	if (em->len != SZ_16K) {
+		test_err("unexpected extent map length %llu (should be 16K)", em->len);
+		ret = -EINVAL;
+		goto out;
+	}
+	if (em->offset != SZ_1K * 20) {
+		test_err("unexpected extent map offset %llu (should be 20K)", em->offset);
+		ret = -EINVAL;
+		goto out;
+	}
+out:
+	ret2 = free_extent_map_tree(inode);
+	if (ret == 0)
+		ret = ret2;
+
+	return ret;
+}
+
+struct rmap_test_vector {
+	u64 raid_type;
+	u64 physical_start;
+	u64 data_stripe_size;
+	u64 num_data_stripes;
+	u64 num_stripes;
+	/* Assume we won't have more than 5 physical stripes */
+	u64 data_stripe_phys_start[5];
+	bool expected_mapped_addr;
+	/* Physical to logical addresses */
+	u64 mapped_logical[5];
+};
+
+static int test_rmap_block(struct btrfs_fs_info *fs_info,
+			   struct rmap_test_vector *test)
+{
+	struct btrfs_chunk_map *map;
+	u64 AUTO_KFREE(logical);
+	int i, out_ndaddrs, out_stripe_len;
+	int ret;
+
+	map = btrfs_alloc_chunk_map(test->num_stripes, GFP_KERNEL);
+	if (!map) {
+		test_std_err(TEST_ALLOC_CHUNK_MAP);
+		return -ENOMEM;
+	}
+
+	/* Start at 4GiB logical address */
+	map->start = SZ_4G;
+	map->chunk_len = test->data_stripe_size * test->num_data_stripes;
+	map->stripe_size = test->data_stripe_size;
+	map->num_stripes = test->num_stripes;
+	map->type = test->raid_type;
+
+	for (i = 0; i < map->num_stripes; i++) {
+		struct btrfs_device *dev = btrfs_alloc_dummy_device(fs_info);
+
+		if (IS_ERR(dev)) {
+			test_err("cannot allocate device");
+			ret = PTR_ERR(dev);
+			goto out;
+		}
+		map->stripes[i].dev = dev;
+		map->stripes[i].physical = test->data_stripe_phys_start[i];
+	}
+
+	ret = btrfs_add_chunk_map(fs_info, map);
+	if (ret) {
+		test_err("error adding chunk map to mapping tree");
+		btrfs_free_chunk_map(map);
+		return ret;
+	}
+
+	ret = btrfs_rmap_block(fs_info, map->start, btrfs_sb_offset(1),
+			       &logical, &out_ndaddrs, &out_stripe_len);
+	if (ret || (out_ndaddrs == 0 && test->expected_mapped_addr)) {
+		test_err("didn't rmap anything but expected %d",
+			 test->expected_mapped_addr);
+		goto out;
+	}
+
+	if (out_stripe_len != BTRFS_STRIPE_LEN) {
+		test_err("calculated stripe length doesn't match");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (out_ndaddrs != test->expected_mapped_addr) {
+		for (i = 0; i < out_ndaddrs; i++)
+			test_msg("mapped %llu", logical[i]);
+		test_err("unexpected number of mapped addresses: %d", out_ndaddrs);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	for (i = 0; i < out_ndaddrs; i++) {
+		if (logical[i] != test->mapped_logical[i]) {
+			test_err("unexpected logical address mapped");
+			ret = -EINVAL;
+			goto out;
+		}
+	}
+
+	ret = 0;
+out:
+	btrfs_remove_chunk_map(fs_info, map);
+	return ret;
+}
+
+int btrfs_test_extent_map(void)
+{
+	struct btrfs_fs_info *fs_info = NULL;
+	struct inode *inode;
+	struct btrfs_root *root = NULL;
+	int ret = 0, i;
+	struct rmap_test_vector rmap_tests[] = {
+		{
+			/*
+			 * Test a chunk with 2 data stripes one of which
+			 * intersects the physical address of the super block
+			 * is correctly recognized.
+			 */
+			.raid_type = BTRFS_BLOCK_GROUP_RAID1,
+			.physical_start = SZ_64M - SZ_4M,
+			.data_stripe_size = SZ_256M,
+			.num_data_stripes = 2,
+			.num_stripes = 2,
+			.data_stripe_phys_start =
+				{SZ_64M - SZ_4M, SZ_64M - SZ_4M + SZ_256M},
+			.expected_mapped_addr = true,
+			.mapped_logical= {SZ_4G + SZ_4M}
+		},
+		{
+			/*
+			 * Test that out-of-range physical addresses are
+			 * ignored
+			 */
+
+			 /* SINGLE chunk type */
+			.raid_type = 0,
+			.physical_start = SZ_4G,
+			.data_stripe_size = SZ_256M,
+			.num_data_stripes = 1,
+			.num_stripes = 1,
+			.data_stripe_phys_start = {SZ_256M},
+			.expected_mapped_addr = false,
+			.mapped_logical = {0}
+		}
+	};
+
+	test_msg("running extent_map tests");
+
+	/*
+	 * Note: the fs_info is not set up completely, we only need
+	 * fs_info::fsid for the tracepoint.
+	 *
+	 * And all the immediate numbers are based on 4K blocksize,
+	 * thus we have to use 4K as sectorsize no matter the page size.
+	 */
+	fs_info = btrfs_alloc_dummy_fs_info(SZ_4K, SZ_4K);
+	if (!fs_info) {
+		test_std_err(TEST_ALLOC_FS_INFO);
+		return -ENOMEM;
+	}
+
+	inode = btrfs_new_test_inode();
+	if (!inode) {
+		test_std_err(TEST_ALLOC_INODE);
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	root = btrfs_alloc_dummy_root(fs_info);
+	if (IS_ERR(root)) {
+		test_std_err(TEST_ALLOC_ROOT);
+		ret = PTR_ERR(root);
+		root = NULL;
+		goto out;
+	}
+
+	BTRFS_I(inode)->root = root;
+
+	ret = test_case_1(fs_info, BTRFS_I(inode));
+	if (ret)
+		goto out;
+	ret = test_case_2(fs_info, BTRFS_I(inode));
+	if (ret)
+		goto out;
+	ret = test_case_3(fs_info, BTRFS_I(inode));
+	if (ret)
+		goto out;
+	ret = test_case_4(fs_info, BTRFS_I(inode));
+	if (ret)
+		goto out;
+	ret = test_case_5(fs_info, BTRFS_I(inode));
+	if (ret)
+		goto out;
+	ret = test_case_6(fs_info, BTRFS_I(inode));
+	if (ret)
+		goto out;
+	ret = test_case_7(fs_info, BTRFS_I(inode));
+	if (ret)
+		goto out;
+	ret = test_case_8(fs_info, BTRFS_I(inode));
+	if (ret)
+		goto out;
+
+	test_msg("running rmap tests");
+	for (i = 0; i < ARRAY_SIZE(rmap_tests); i++) {
+		ret = test_rmap_block(fs_info, &rmap_tests[i]);
+		if (ret)
+			goto out;
+	}
+
+out:
+	iput(inode);
+	btrfs_free_dummy_root(root);
+	btrfs_free_dummy_fs_info(fs_info);
+
+	return ret;
+}
diff --git a/fs/btrfs/tests/free-space-tests.c b/fs/btrfs/tests/free-space-tests.c
new file mode 100644
index 000000000..0425b3b68
--- /dev/null
+++ b/fs/btrfs/tests/free-space-tests.c
@@ -0,0 +1,1059 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2013 Fusion IO.  All rights reserved.
+ */
+
+#include <linux/slab.h>
+#include "btrfs-tests.h"
+#include "../ctree.h"
+#include "../disk-io.h"
+#include "../free-space-cache.h"
+#include "../block-group.h"
+
+#define BITS_PER_BITMAP		(PAGE_SIZE * 8UL)
+
+/*
+ * This test just does basic sanity checking, making sure we can add an extent
+ * entry and remove space from either end and the middle, and make sure we can
+ * remove space that covers adjacent extent entries.
+ */
+static int test_extents(struct btrfs_block_group *cache)
+{
+	int ret = 0;
+
+	test_msg("running extent only tests");
+
+	/* First just make sure we can remove an entire entry */
+	ret = btrfs_add_free_space(cache, 0, SZ_4M);
+	if (ret) {
+		test_err("error adding initial extents %d", ret);
+		return ret;
+	}
+
+	ret = btrfs_remove_free_space(cache, 0, SZ_4M);
+	if (ret) {
+		test_err("error removing extent %d", ret);
+		return ret;
+	}
+
+	if (test_check_exists(cache, 0, SZ_4M)) {
+		test_err("full remove left some lingering space");
+		return -1;
+	}
+
+	/* Ok edge and middle cases now */
+	ret = btrfs_add_free_space(cache, 0, SZ_4M);
+	if (ret) {
+		test_err("error adding half extent %d", ret);
+		return ret;
+	}
+
+	ret = btrfs_remove_free_space(cache, 3 * SZ_1M, SZ_1M);
+	if (ret) {
+		test_err("error removing tail end %d", ret);
+		return ret;
+	}
+
+	ret = btrfs_remove_free_space(cache, 0, SZ_1M);
+	if (ret) {
+		test_err("error removing front end %d", ret);
+		return ret;
+	}
+
+	ret = btrfs_remove_free_space(cache, SZ_2M, 4096);
+	if (ret) {
+		test_err("error removing middle piece %d", ret);
+		return ret;
+	}
+
+	if (test_check_exists(cache, 0, SZ_1M)) {
+		test_err("still have space at the front");
+		return -1;
+	}
+
+	if (test_check_exists(cache, SZ_2M, 4096)) {
+		test_err("still have space in the middle");
+		return -1;
+	}
+
+	if (test_check_exists(cache, 3 * SZ_1M, SZ_1M)) {
+		test_err("still have space at the end");
+		return -1;
+	}
+
+	/* Cleanup */
+	btrfs_remove_free_space_cache(cache);
+
+	return 0;
+}
+
+static int test_bitmaps(struct btrfs_block_group *cache, u32 sectorsize)
+{
+	u64 next_bitmap_offset;
+	int ret;
+
+	test_msg("running bitmap only tests");
+
+	ret = test_add_free_space_entry(cache, 0, SZ_4M, 1);
+	if (ret) {
+		test_err("couldn't create a bitmap entry %d", ret);
+		return ret;
+	}
+
+	ret = btrfs_remove_free_space(cache, 0, SZ_4M);
+	if (ret) {
+		test_err("error removing bitmap full range %d", ret);
+		return ret;
+	}
+
+	if (test_check_exists(cache, 0, SZ_4M)) {
+		test_err("left some space in bitmap");
+		return -1;
+	}
+
+	ret = test_add_free_space_entry(cache, 0, SZ_4M, 1);
+	if (ret) {
+		test_err("couldn't add to our bitmap entry %d", ret);
+		return ret;
+	}
+
+	ret = btrfs_remove_free_space(cache, SZ_1M, SZ_2M);
+	if (ret) {
+		test_err("couldn't remove middle chunk %d", ret);
+		return ret;
+	}
+
+	/*
+	 * The first bitmap we have starts at offset 0 so the next one is just
+	 * at the end of the first bitmap.
+	 */
+	next_bitmap_offset = (u64)(BITS_PER_BITMAP * sectorsize);
+
+	/* Test a bit straddling two bitmaps */
+	ret = test_add_free_space_entry(cache, next_bitmap_offset - SZ_2M,
+					SZ_4M, 1);
+	if (ret) {
+		test_err("couldn't add space that straddles two bitmaps %d",
+				ret);
+		return ret;
+	}
+
+	ret = btrfs_remove_free_space(cache, next_bitmap_offset - SZ_1M, SZ_2M);
+	if (ret) {
+		test_err("couldn't remove overlapping space %d", ret);
+		return ret;
+	}
+
+	if (test_check_exists(cache, next_bitmap_offset - SZ_1M, SZ_2M)) {
+		test_err("left some space when removing overlapping");
+		return -1;
+	}
+
+	btrfs_remove_free_space_cache(cache);
+
+	return 0;
+}
+
+/* This is the high grade jackassery */
+static int test_bitmaps_and_extents(struct btrfs_block_group *cache,
+				    u32 sectorsize)
+{
+	u64 bitmap_offset = (u64)(BITS_PER_BITMAP * sectorsize);
+	int ret;
+
+	test_msg("running bitmap and extent tests");
+
+	/*
+	 * First let's do something simple, an extent at the same offset as the
+	 * bitmap, but the free space completely in the extent and then
+	 * completely in the bitmap.
+	 */
+	ret = test_add_free_space_entry(cache, SZ_4M, SZ_1M, 1);
+	if (ret) {
+		test_err("couldn't create bitmap entry %d", ret);
+		return ret;
+	}
+
+	ret = test_add_free_space_entry(cache, 0, SZ_1M, 0);
+	if (ret) {
+		test_err("couldn't add extent entry %d", ret);
+		return ret;
+	}
+
+	ret = btrfs_remove_free_space(cache, 0, SZ_1M);
+	if (ret) {
+		test_err("couldn't remove extent entry %d", ret);
+		return ret;
+	}
+
+	if (test_check_exists(cache, 0, SZ_1M)) {
+		test_err("left remnants after our remove");
+		return -1;
+	}
+
+	/* Now to add back the extent entry and remove from the bitmap */
+	ret = test_add_free_space_entry(cache, 0, SZ_1M, 0);
+	if (ret) {
+		test_err("couldn't re-add extent entry %d", ret);
+		return ret;
+	}
+
+	ret = btrfs_remove_free_space(cache, SZ_4M, SZ_1M);
+	if (ret) {
+		test_err("couldn't remove from bitmap %d", ret);
+		return ret;
+	}
+
+	if (test_check_exists(cache, SZ_4M, SZ_1M)) {
+		test_err("left remnants in the bitmap");
+		return -1;
+	}
+
+	/*
+	 * Ok so a little more evil, extent entry and bitmap at the same offset,
+	 * removing an overlapping chunk.
+	 */
+	ret = test_add_free_space_entry(cache, SZ_1M, SZ_4M, 1);
+	if (ret) {
+		test_err("couldn't add to a bitmap %d", ret);
+		return ret;
+	}
+
+	ret = btrfs_remove_free_space(cache, SZ_512K, 3 * SZ_1M);
+	if (ret) {
+		test_err("couldn't remove overlapping space %d", ret);
+		return ret;
+	}
+
+	if (test_check_exists(cache, SZ_512K, 3 * SZ_1M)) {
+		test_err("left over pieces after removing overlapping");
+		return -1;
+	}
+
+	btrfs_remove_free_space_cache(cache);
+
+	/* Now with the extent entry offset into the bitmap */
+	ret = test_add_free_space_entry(cache, SZ_4M, SZ_4M, 1);
+	if (ret) {
+		test_err("couldn't add space to the bitmap %d", ret);
+		return ret;
+	}
+
+	ret = test_add_free_space_entry(cache, SZ_2M, SZ_2M, 0);
+	if (ret) {
+		test_err("couldn't add extent to the cache %d", ret);
+		return ret;
+	}
+
+	ret = btrfs_remove_free_space(cache, 3 * SZ_1M, SZ_4M);
+	if (ret) {
+		test_err("problem removing overlapping space %d", ret);
+		return ret;
+	}
+
+	if (test_check_exists(cache, 3 * SZ_1M, SZ_4M)) {
+		test_err("left something behind when removing space");
+		return -1;
+	}
+
+	/*
+	 * This has blown up in the past, the extent entry starts before the
+	 * bitmap entry, but we're trying to remove an offset that falls
+	 * completely within the bitmap range and is in both the extent entry
+	 * and the bitmap entry, looks like this
+	 *
+	 *   [ extent ]
+	 *      [ bitmap ]
+	 *        [ del ]
+	 */
+	btrfs_remove_free_space_cache(cache);
+	ret = test_add_free_space_entry(cache, bitmap_offset + SZ_4M, SZ_4M, 1);
+	if (ret) {
+		test_err("couldn't add bitmap %d", ret);
+		return ret;
+	}
+
+	ret = test_add_free_space_entry(cache, bitmap_offset - SZ_1M,
+					5 * SZ_1M, 0);
+	if (ret) {
+		test_err("couldn't add extent entry %d", ret);
+		return ret;
+	}
+
+	ret = btrfs_remove_free_space(cache, bitmap_offset + SZ_1M, 5 * SZ_1M);
+	if (ret) {
+		test_err("failed to free our space %d", ret);
+		return ret;
+	}
+
+	if (test_check_exists(cache, bitmap_offset + SZ_1M, 5 * SZ_1M)) {
+		test_err("left stuff over");
+		return -1;
+	}
+
+	btrfs_remove_free_space_cache(cache);
+
+	/*
+	 * This blew up before, we have part of the free space in a bitmap and
+	 * then the entirety of the rest of the space in an extent.  This used
+	 * to return -EAGAIN back from btrfs_remove_extent, make sure this
+	 * doesn't happen.
+	 */
+	ret = test_add_free_space_entry(cache, SZ_1M, SZ_2M, 1);
+	if (ret) {
+		test_err("couldn't add bitmap entry %d", ret);
+		return ret;
+	}
+
+	ret = test_add_free_space_entry(cache, 3 * SZ_1M, SZ_1M, 0);
+	if (ret) {
+		test_err("couldn't add extent entry %d", ret);
+		return ret;
+	}
+
+	ret = btrfs_remove_free_space(cache, SZ_1M, 3 * SZ_1M);
+	if (ret) {
+		test_err("error removing bitmap and extent overlapping %d", ret);
+		return ret;
+	}
+
+	btrfs_remove_free_space_cache(cache);
+	return 0;
+}
+
+/* Used by test_steal_space_from_bitmap_to_extent(). */
+static bool test_use_bitmap(struct btrfs_free_space_ctl *ctl,
+			    struct btrfs_free_space *info)
+{
+	return ctl->free_extents > 0;
+}
+
+/* Used by test_steal_space_from_bitmap_to_extent(). */
+static int
+check_num_extents_and_bitmaps(const struct btrfs_block_group *cache,
+			      const int num_extents,
+			      const int num_bitmaps)
+{
+	if (cache->free_space_ctl->free_extents != num_extents) {
+		test_err(
+		"incorrect # of extent entries in the cache: %d, expected %d",
+			 cache->free_space_ctl->free_extents, num_extents);
+		return -EINVAL;
+	}
+	if (cache->free_space_ctl->total_bitmaps != num_bitmaps) {
+		test_err(
+		"incorrect # of extent entries in the cache: %d, expected %d",
+			 cache->free_space_ctl->total_bitmaps, num_bitmaps);
+		return -EINVAL;
+	}
+	return 0;
+}
+
+/* Used by test_steal_space_from_bitmap_to_extent(). */
+static int check_cache_empty(struct btrfs_block_group *cache)
+{
+	u64 offset;
+	u64 max_extent_size;
+
+	/*
+	 * Now lets confirm that there's absolutely no free space left to
+	 * allocate.
+	 */
+	if (cache->free_space_ctl->free_space != 0) {
+		test_err("cache free space is not 0");
+		return -EINVAL;
+	}
+
+	/* And any allocation request, no matter how small, should fail now. */
+	offset = btrfs_find_space_for_alloc(cache, 0, 4096, 0,
+					    &max_extent_size);
+	if (offset != 0) {
+		test_err("space allocation did not fail, returned offset: %llu",
+			 offset);
+		return -EINVAL;
+	}
+
+	/* And no extent nor bitmap entries in the cache anymore. */
+	return check_num_extents_and_bitmaps(cache, 0, 0);
+}
+
+/*
+ * Before we were able to steal free space from a bitmap entry to an extent
+ * entry, we could end up with 2 entries representing a contiguous free space.
+ * One would be an extent entry and the other a bitmap entry. Since in order
+ * to allocate space to a caller we use only 1 entry, we couldn't return that
+ * whole range to the caller if it was requested. This forced the caller to
+ * either assume ENOSPC or perform several smaller space allocations, which
+ * wasn't optimal as they could be spread all over the block group while under
+ * concurrency (extra overhead and fragmentation).
+ *
+ * This stealing approach is beneficial, since we always prefer to allocate
+ * from extent entries, both for clustered and non-clustered allocation
+ * requests.
+ */
+static int
+test_steal_space_from_bitmap_to_extent(struct btrfs_block_group *cache,
+				       u32 sectorsize)
+{
+	int ret;
+	u64 offset;
+	u64 max_extent_size;
+	bool (*orig_use_bitmap)(struct btrfs_free_space_ctl *ctl,
+				struct btrfs_free_space *info);
+
+	test_msg("running space stealing from bitmap to extent tests");
+
+	/*
+	 * For this test, we want to ensure we end up with an extent entry
+	 * immediately adjacent to a bitmap entry, where the bitmap starts
+	 * at an offset where the extent entry ends. We keep adding and
+	 * removing free space to reach into this state, but to get there
+	 * we need to reach a point where marking new free space doesn't
+	 * result in adding new extent entries or merging the new space
+	 * with existing extent entries - the space ends up being marked
+	 * in an existing bitmap that covers the new free space range.
+	 *
+	 * To get there, we need to reach the threshold defined set at
+	 * cache->free_space_ctl->extents_thresh, which currently is
+	 * 256 extents on a x86_64 system at least, and a few other
+	 * conditions (check free_space_cache.c). Instead of making the
+	 * test much longer and complicated, use a "use_bitmap" operation
+	 * that forces use of bitmaps as soon as we have at least 1
+	 * extent entry.
+	 */
+	orig_use_bitmap = cache->fs_info->use_bitmap;
+	cache->fs_info->use_bitmap = test_use_bitmap;
+
+	/*
+	 * Extent entry covering free space range [128Mb - 256Kb, 128Mb - 128Kb[
+	 */
+	ret = test_add_free_space_entry(cache, SZ_128M - SZ_256K, SZ_128K, 0);
+	if (ret) {
+		test_err("couldn't add extent entry %d", ret);
+		return ret;
+	}
+
+	/* Bitmap entry covering free space range [128Mb + 512Kb, 256Mb[ */
+	ret = test_add_free_space_entry(cache, SZ_128M + SZ_512K,
+					SZ_128M - SZ_512K, 1);
+	if (ret) {
+		test_err("couldn't add bitmap entry %d", ret);
+		return ret;
+	}
+
+	ret = check_num_extents_and_bitmaps(cache, 2, 1);
+	if (ret)
+		return ret;
+
+	/*
+	 * Now make only the first 256Kb of the bitmap marked as free, so that
+	 * we end up with only the following ranges marked as free space:
+	 *
+	 * [128Mb - 256Kb, 128Mb - 128Kb[
+	 * [128Mb + 512Kb, 128Mb + 768Kb[
+	 */
+	ret = btrfs_remove_free_space(cache,
+				      SZ_128M + 768 * SZ_1K,
+				      SZ_128M - 768 * SZ_1K);
+	if (ret) {
+		test_err("failed to free part of bitmap space %d", ret);
+		return ret;
+	}
+
+	/* Confirm that only those 2 ranges are marked as free. */
+	if (!test_check_exists(cache, SZ_128M - SZ_256K, SZ_128K)) {
+		test_err("free space range missing");
+		return -ENOENT;
+	}
+	if (!test_check_exists(cache, SZ_128M + SZ_512K, SZ_256K)) {
+		test_err("free space range missing");
+		return -ENOENT;
+	}
+
+	/*
+	 * Confirm that the bitmap range [128Mb + 768Kb, 256Mb[ isn't marked
+	 * as free anymore.
+	 */
+	if (test_check_exists(cache, SZ_128M + 768 * SZ_1K,
+			      SZ_128M - 768 * SZ_1K)) {
+		test_err("bitmap region not removed from space cache");
+		return -EINVAL;
+	}
+
+	/*
+	 * Confirm that the region [128Mb + 256Kb, 128Mb + 512Kb[, which is
+	 * covered by the bitmap, isn't marked as free.
+	 */
+	if (test_check_exists(cache, SZ_128M + SZ_256K, SZ_256K)) {
+		test_err("invalid bitmap region marked as free");
+		return -EINVAL;
+	}
+
+	/*
+	 * Confirm that the region [128Mb, 128Mb + 256Kb[, which is covered
+	 * by the bitmap too, isn't marked as free either.
+	 */
+	if (test_check_exists(cache, SZ_128M, SZ_256K)) {
+		test_err("invalid bitmap region marked as free");
+		return -EINVAL;
+	}
+
+	/*
+	 * Now lets mark the region [128Mb, 128Mb + 512Kb[ as free too. But,
+	 * lets make sure the free space cache marks it as free in the bitmap,
+	 * and doesn't insert a new extent entry to represent this region.
+	 */
+	ret = btrfs_add_free_space(cache, SZ_128M, SZ_512K);
+	if (ret) {
+		test_err("error adding free space: %d", ret);
+		return ret;
+	}
+	/* Confirm the region is marked as free. */
+	if (!test_check_exists(cache, SZ_128M, SZ_512K)) {
+		test_err("bitmap region not marked as free");
+		return -ENOENT;
+	}
+
+	/*
+	 * Confirm that no new extent entries or bitmap entries were added to
+	 * the cache after adding that free space region.
+	 */
+	ret = check_num_extents_and_bitmaps(cache, 2, 1);
+	if (ret)
+		return ret;
+
+	/*
+	 * Now lets add a small free space region to the right of the previous
+	 * one, which is not contiguous with it and is part of the bitmap too.
+	 * The goal is to test that the bitmap entry space stealing doesn't
+	 * steal this space region.
+	 */
+	ret = btrfs_add_free_space(cache, SZ_128M + SZ_16M, sectorsize);
+	if (ret) {
+		test_err("error adding free space: %d", ret);
+		return ret;
+	}
+
+	/*
+	 * Confirm that no new extent entries or bitmap entries were added to
+	 * the cache after adding that free space region.
+	 */
+	ret = check_num_extents_and_bitmaps(cache, 2, 1);
+	if (ret)
+		return ret;
+
+	/*
+	 * Now mark the region [128Mb - 128Kb, 128Mb[ as free too. This will
+	 * expand the range covered by the existing extent entry that represents
+	 * the free space [128Mb - 256Kb, 128Mb - 128Kb[.
+	 */
+	ret = btrfs_add_free_space(cache, SZ_128M - SZ_128K, SZ_128K);
+	if (ret) {
+		test_err("error adding free space: %d", ret);
+		return ret;
+	}
+	/* Confirm the region is marked as free. */
+	if (!test_check_exists(cache, SZ_128M - SZ_128K, SZ_128K)) {
+		test_err("extent region not marked as free");
+		return -ENOENT;
+	}
+
+	/*
+	 * Confirm that our extent entry didn't stole all free space from the
+	 * bitmap, because of the small 4Kb free space region.
+	 */
+	ret = check_num_extents_and_bitmaps(cache, 2, 1);
+	if (ret)
+		return ret;
+
+	/*
+	 * So now we have the range [128Mb - 256Kb, 128Mb + 768Kb[ as free
+	 * space. Without stealing bitmap free space into extent entry space,
+	 * we would have all this free space represented by 2 entries in the
+	 * cache:
+	 *
+	 * extent entry covering range: [128Mb - 256Kb, 128Mb[
+	 * bitmap entry covering range: [128Mb, 128Mb + 768Kb[
+	 *
+	 * Attempting to allocate the whole free space (1Mb) would fail, because
+	 * we can't allocate from multiple entries.
+	 * With the bitmap free space stealing, we get a single extent entry
+	 * that represents the 1Mb free space, and therefore we're able to
+	 * allocate the whole free space at once.
+	 */
+	if (!test_check_exists(cache, SZ_128M - SZ_256K, SZ_1M)) {
+		test_err("expected region not marked as free");
+		return -ENOENT;
+	}
+
+	if (cache->free_space_ctl->free_space != (SZ_1M + sectorsize)) {
+		test_err("cache free space is not 1Mb + %u", sectorsize);
+		return -EINVAL;
+	}
+
+	offset = btrfs_find_space_for_alloc(cache,
+					    0, SZ_1M, 0,
+					    &max_extent_size);
+	if (offset != (SZ_128M - SZ_256K)) {
+		test_err(
+	"failed to allocate 1Mb from space cache, returned offset is: %llu",
+			 offset);
+		return -EINVAL;
+	}
+
+	/*
+	 * All that remains is a sectorsize free space region in a bitmap.
+	 * Confirm.
+	 */
+	ret = check_num_extents_and_bitmaps(cache, 1, 1);
+	if (ret)
+		return ret;
+
+	if (cache->free_space_ctl->free_space != sectorsize) {
+		test_err("cache free space is not %u", sectorsize);
+		return -EINVAL;
+	}
+
+	offset = btrfs_find_space_for_alloc(cache,
+					    0, sectorsize, 0,
+					    &max_extent_size);
+	if (offset != (SZ_128M + SZ_16M)) {
+		test_err("failed to allocate %u, returned offset : %llu",
+			 sectorsize, offset);
+		return -EINVAL;
+	}
+
+	ret = check_cache_empty(cache);
+	if (ret)
+		return ret;
+
+	btrfs_remove_free_space_cache(cache);
+
+	/*
+	 * Now test a similar scenario, but where our extent entry is located
+	 * to the right of the bitmap entry, so that we can check that stealing
+	 * space from a bitmap to the front of an extent entry works.
+	 */
+
+	/*
+	 * Extent entry covering free space range [128Mb + 128Kb, 128Mb + 256Kb[
+	 */
+	ret = test_add_free_space_entry(cache, SZ_128M + SZ_128K, SZ_128K, 0);
+	if (ret) {
+		test_err("couldn't add extent entry %d", ret);
+		return ret;
+	}
+
+	/* Bitmap entry covering free space range [0, 128Mb - 512Kb[ */
+	ret = test_add_free_space_entry(cache, 0, SZ_128M - SZ_512K, 1);
+	if (ret) {
+		test_err("couldn't add bitmap entry %d", ret);
+		return ret;
+	}
+
+	ret = check_num_extents_and_bitmaps(cache, 2, 1);
+	if (ret)
+		return ret;
+
+	/*
+	 * Now make only the last 256Kb of the bitmap marked as free, so that
+	 * we end up with only the following ranges marked as free space:
+	 *
+	 * [128Mb + 128b, 128Mb + 256Kb[
+	 * [128Mb - 768Kb, 128Mb - 512Kb[
+	 */
+	ret = btrfs_remove_free_space(cache, 0, SZ_128M - 768 * SZ_1K);
+	if (ret) {
+		test_err("failed to free part of bitmap space %d", ret);
+		return ret;
+	}
+
+	/* Confirm that only those 2 ranges are marked as free. */
+	if (!test_check_exists(cache, SZ_128M + SZ_128K, SZ_128K)) {
+		test_err("free space range missing");
+		return -ENOENT;
+	}
+	if (!test_check_exists(cache, SZ_128M - 768 * SZ_1K, SZ_256K)) {
+		test_err("free space range missing");
+		return -ENOENT;
+	}
+
+	/*
+	 * Confirm that the bitmap range [0, 128Mb - 768Kb[ isn't marked
+	 * as free anymore.
+	 */
+	if (test_check_exists(cache, 0, SZ_128M - 768 * SZ_1K)) {
+		test_err("bitmap region not removed from space cache");
+		return -EINVAL;
+	}
+
+	/*
+	 * Confirm that the region [128Mb - 512Kb, 128Mb[, which is
+	 * covered by the bitmap, isn't marked as free.
+	 */
+	if (test_check_exists(cache, SZ_128M - SZ_512K, SZ_512K)) {
+		test_err("invalid bitmap region marked as free");
+		return -EINVAL;
+	}
+
+	/*
+	 * Now lets mark the region [128Mb - 512Kb, 128Mb[ as free too. But,
+	 * lets make sure the free space cache marks it as free in the bitmap,
+	 * and doesn't insert a new extent entry to represent this region.
+	 */
+	ret = btrfs_add_free_space(cache, SZ_128M - SZ_512K, SZ_512K);
+	if (ret) {
+		test_err("error adding free space: %d", ret);
+		return ret;
+	}
+	/* Confirm the region is marked as free. */
+	if (!test_check_exists(cache, SZ_128M - SZ_512K, SZ_512K)) {
+		test_err("bitmap region not marked as free");
+		return -ENOENT;
+	}
+
+	/*
+	 * Confirm that no new extent entries or bitmap entries were added to
+	 * the cache after adding that free space region.
+	 */
+	ret = check_num_extents_and_bitmaps(cache, 2, 1);
+	if (ret)
+		return ret;
+
+	/*
+	 * Now lets add a small free space region to the left of the previous
+	 * one, which is not contiguous with it and is part of the bitmap too.
+	 * The goal is to test that the bitmap entry space stealing doesn't
+	 * steal this space region.
+	 */
+	ret = btrfs_add_free_space(cache, SZ_32M, 2 * sectorsize);
+	if (ret) {
+		test_err("error adding free space: %d", ret);
+		return ret;
+	}
+
+	/*
+	 * Now mark the region [128Mb, 128Mb + 128Kb[ as free too. This will
+	 * expand the range covered by the existing extent entry that represents
+	 * the free space [128Mb + 128Kb, 128Mb + 256Kb[.
+	 */
+	ret = btrfs_add_free_space(cache, SZ_128M, SZ_128K);
+	if (ret) {
+		test_err("error adding free space: %d", ret);
+		return ret;
+	}
+	/* Confirm the region is marked as free. */
+	if (!test_check_exists(cache, SZ_128M, SZ_128K)) {
+		test_err("extent region not marked as free");
+		return -ENOENT;
+	}
+
+	/*
+	 * Confirm that our extent entry didn't stole all free space from the
+	 * bitmap, because of the small 2 * sectorsize free space region.
+	 */
+	ret = check_num_extents_and_bitmaps(cache, 2, 1);
+	if (ret)
+		return ret;
+
+	/*
+	 * So now we have the range [128Mb - 768Kb, 128Mb + 256Kb[ as free
+	 * space. Without stealing bitmap free space into extent entry space,
+	 * we would have all this free space represented by 2 entries in the
+	 * cache:
+	 *
+	 * extent entry covering range: [128Mb, 128Mb + 256Kb[
+	 * bitmap entry covering range: [128Mb - 768Kb, 128Mb[
+	 *
+	 * Attempting to allocate the whole free space (1Mb) would fail, because
+	 * we can't allocate from multiple entries.
+	 * With the bitmap free space stealing, we get a single extent entry
+	 * that represents the 1Mb free space, and therefore we're able to
+	 * allocate the whole free space at once.
+	 */
+	if (!test_check_exists(cache, SZ_128M - 768 * SZ_1K, SZ_1M)) {
+		test_err("expected region not marked as free");
+		return -ENOENT;
+	}
+
+	if (cache->free_space_ctl->free_space != (SZ_1M + 2 * sectorsize)) {
+		test_err("cache free space is not 1Mb + %u", 2 * sectorsize);
+		return -EINVAL;
+	}
+
+	offset = btrfs_find_space_for_alloc(cache, 0, SZ_1M, 0,
+					    &max_extent_size);
+	if (offset != (SZ_128M - 768 * SZ_1K)) {
+		test_err(
+	"failed to allocate 1Mb from space cache, returned offset is: %llu",
+			 offset);
+		return -EINVAL;
+	}
+
+	/*
+	 * All that remains is 2 * sectorsize free space region
+	 * in a bitmap. Confirm.
+	 */
+	ret = check_num_extents_and_bitmaps(cache, 1, 1);
+	if (ret)
+		return ret;
+
+	if (cache->free_space_ctl->free_space != 2 * sectorsize) {
+		test_err("cache free space is not %u", 2 * sectorsize);
+		return -EINVAL;
+	}
+
+	offset = btrfs_find_space_for_alloc(cache,
+					    0, 2 * sectorsize, 0,
+					    &max_extent_size);
+	if (offset != SZ_32M) {
+		test_err("failed to allocate %u, offset: %llu",
+			 2 * sectorsize, offset);
+		return -EINVAL;
+	}
+
+	ret = check_cache_empty(cache);
+	if (ret)
+		return ret;
+
+	cache->fs_info->use_bitmap = orig_use_bitmap;
+	btrfs_remove_free_space_cache(cache);
+
+	return 0;
+}
+
+static bool bytes_index_use_bitmap(struct btrfs_free_space_ctl *ctl,
+				   struct btrfs_free_space *info)
+{
+	return true;
+}
+
+static int test_bytes_index(struct btrfs_block_group *cache, u32 sectorsize)
+{
+	bool (*orig_use_bitmap)(struct btrfs_free_space_ctl *ctl,
+				struct btrfs_free_space *info);
+	struct btrfs_free_space_ctl *ctl = cache->free_space_ctl;
+	struct btrfs_free_space *entry;
+	struct rb_node *node;
+	u64 offset, max_extent_size, bytes;
+	int ret, i;
+
+	test_msg("running bytes index tests");
+
+	/* First just validate that it does everything in order. */
+	offset = 0;
+	for (i = 0; i < 10; i++) {
+		bytes = (i + 1) * SZ_1M;
+		ret = test_add_free_space_entry(cache, offset, bytes, 0);
+		if (ret) {
+			test_err("couldn't add extent entry %d\n", ret);
+			return ret;
+		}
+		offset += bytes + sectorsize;
+	}
+
+	for (node = rb_first_cached(&ctl->free_space_bytes), i = 9; node;
+	     node = rb_next(node), i--) {
+		entry = rb_entry(node, struct btrfs_free_space, bytes_index);
+		bytes = (i + 1) * SZ_1M;
+		if (entry->bytes != bytes) {
+			test_err("invalid bytes index order, found %llu expected %llu",
+				 entry->bytes, bytes);
+			return -EINVAL;
+		}
+	}
+
+	/* Now validate bitmaps do the correct thing. */
+	btrfs_remove_free_space_cache(cache);
+	for (i = 0; i < 2; i++) {
+		offset = i * BITS_PER_BITMAP * sectorsize;
+		bytes = (i + 1) * SZ_1M;
+		ret = test_add_free_space_entry(cache, offset, bytes, 1);
+		if (ret) {
+			test_err("couldn't add bitmap entry");
+			return ret;
+		}
+	}
+
+	for (node = rb_first_cached(&ctl->free_space_bytes), i = 1; node;
+	     node = rb_next(node), i--) {
+		entry = rb_entry(node, struct btrfs_free_space, bytes_index);
+		bytes = (i + 1) * SZ_1M;
+		if (entry->bytes != bytes) {
+			test_err("invalid bytes index order, found %llu expected %llu",
+				 entry->bytes, bytes);
+			return -EINVAL;
+		}
+	}
+
+	/* Now validate bitmaps with different ->max_extent_size. */
+	btrfs_remove_free_space_cache(cache);
+	orig_use_bitmap = cache->fs_info->use_bitmap;
+	cache->fs_info->use_bitmap = bytes_index_use_bitmap;
+
+	ret = test_add_free_space_entry(cache, 0, sectorsize, 1);
+	if (ret) {
+		test_err("couldn't add bitmap entry");
+		return ret;
+	}
+
+	offset = BITS_PER_BITMAP * sectorsize;
+	ret = test_add_free_space_entry(cache, offset, sectorsize, 1);
+	if (ret) {
+		test_err("couldn't add bitmap_entry");
+		return ret;
+	}
+
+	/*
+	 * Now set a bunch of sectorsize extents in the first entry so it's
+	 * ->bytes is large.
+	 */
+	for (i = 2; i < 20; i += 2) {
+		offset = sectorsize * i;
+		ret = btrfs_add_free_space(cache, offset, sectorsize);
+		if (ret) {
+			test_err("error populating sparse bitmap %d", ret);
+			return ret;
+		}
+	}
+
+	/*
+	 * Now set a contiguous extent in the second bitmap so its
+	 * ->max_extent_size is larger than the first bitmaps.
+	 */
+	offset = (BITS_PER_BITMAP * sectorsize) + sectorsize;
+	ret = btrfs_add_free_space(cache, offset, sectorsize);
+	if (ret) {
+		test_err("error adding contiguous extent %d", ret);
+		return ret;
+	}
+
+	/*
+	 * Since we don't set ->max_extent_size unless we search everything
+	 * should be indexed on bytes.
+	 */
+	entry = rb_entry(rb_first_cached(&ctl->free_space_bytes),
+			 struct btrfs_free_space, bytes_index);
+	if (entry->bytes != (10 * sectorsize)) {
+		test_err("error, wrong entry in the first slot in bytes_index");
+		return -EINVAL;
+	}
+
+	max_extent_size = 0;
+	offset = btrfs_find_space_for_alloc(cache, cache->start, sectorsize * 3,
+					    0, &max_extent_size);
+	if (offset != 0) {
+		test_err("found space to alloc even though we don't have enough space");
+		return -EINVAL;
+	}
+
+	if (max_extent_size != (2 * sectorsize)) {
+		test_err("got the wrong max_extent size %llu expected %llu",
+			 max_extent_size, (unsigned long long)(2 * sectorsize));
+		return -EINVAL;
+	}
+
+	/*
+	 * The search should have re-arranged the bytes index to use the
+	 * ->max_extent_size, validate it's now what we expect it to be.
+	 */
+	entry = rb_entry(rb_first_cached(&ctl->free_space_bytes),
+			 struct btrfs_free_space, bytes_index);
+	if (entry->bytes != (2 * sectorsize)) {
+		test_err("error, the bytes index wasn't recalculated properly");
+		return -EINVAL;
+	}
+
+	/* Add another sectorsize to re-arrange the tree back to ->bytes. */
+	offset = (BITS_PER_BITMAP * sectorsize) - sectorsize;
+	ret = btrfs_add_free_space(cache, offset, sectorsize);
+	if (ret) {
+		test_err("error adding extent to the sparse entry %d", ret);
+		return ret;
+	}
+
+	entry = rb_entry(rb_first_cached(&ctl->free_space_bytes),
+			 struct btrfs_free_space, bytes_index);
+	if (entry->bytes != (11 * sectorsize)) {
+		test_err("error, wrong entry in the first slot in bytes_index");
+		return -EINVAL;
+	}
+
+	/*
+	 * Now make sure we find our correct entry after searching that will
+	 * result in a re-arranging of the tree.
+	 */
+	max_extent_size = 0;
+	offset = btrfs_find_space_for_alloc(cache, cache->start, sectorsize * 2,
+					    0, &max_extent_size);
+	if (offset != (BITS_PER_BITMAP * sectorsize)) {
+		test_err("error, found %llu instead of %llu for our alloc",
+			 offset,
+			 (unsigned long long)(BITS_PER_BITMAP * sectorsize));
+		return -EINVAL;
+	}
+
+	cache->fs_info->use_bitmap = orig_use_bitmap;
+	btrfs_remove_free_space_cache(cache);
+	return 0;
+}
+
+int btrfs_test_free_space_cache(u32 sectorsize, u32 nodesize)
+{
+	struct btrfs_fs_info *fs_info;
+	struct btrfs_block_group *cache;
+	struct btrfs_root *root = NULL;
+	int ret = -ENOMEM;
+
+	test_msg("running btrfs free space cache tests");
+	fs_info = btrfs_alloc_dummy_fs_info(nodesize, sectorsize);
+	if (!fs_info) {
+		test_std_err(TEST_ALLOC_FS_INFO);
+		return -ENOMEM;
+	}
+
+	/*
+	 * For ppc64 (with 64k page size), bytes per bitmap might be
+	 * larger than 1G.  To make bitmap test available in ppc64,
+	 * alloc dummy block group whose size cross bitmaps.
+	 */
+	cache = btrfs_alloc_dummy_block_group(fs_info,
+				      BITS_PER_BITMAP * sectorsize + PAGE_SIZE);
+	if (!cache) {
+		test_std_err(TEST_ALLOC_BLOCK_GROUP);
+		btrfs_free_dummy_fs_info(fs_info);
+		return 0;
+	}
+
+	root = btrfs_alloc_dummy_root(fs_info);
+	if (IS_ERR(root)) {
+		test_std_err(TEST_ALLOC_ROOT);
+		ret = PTR_ERR(root);
+		goto out;
+	}
+
+	root->root_key.objectid = BTRFS_EXTENT_TREE_OBJECTID;
+	root->root_key.type = BTRFS_ROOT_ITEM_KEY;
+	root->root_key.offset = 0;
+	btrfs_global_root_insert(root);
+
+	ret = test_extents(cache);
+	if (ret)
+		goto out;
+	ret = test_bitmaps(cache, sectorsize);
+	if (ret)
+		goto out;
+	ret = test_bitmaps_and_extents(cache, sectorsize);
+	if (ret)
+		goto out;
+
+	ret = test_steal_space_from_bitmap_to_extent(cache, sectorsize);
+	if (ret)
+		goto out;
+	ret = test_bytes_index(cache, sectorsize);
+out:
+	btrfs_free_dummy_block_group(cache);
+	btrfs_free_dummy_root(root);
+	btrfs_free_dummy_fs_info(fs_info);
+	return ret;
+}
diff --git a/fs/btrfs/tests/free-space-tree-tests.c b/fs/btrfs/tests/free-space-tree-tests.c
new file mode 100644
index 000000000..8dee057f4
--- /dev/null
+++ b/fs/btrfs/tests/free-space-tree-tests.c
@@ -0,0 +1,586 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2015 Facebook.  All rights reserved.
+ */
+
+#include <linux/types.h>
+#include "btrfs-tests.h"
+#include "../ctree.h"
+#include "../disk-io.h"
+#include "../free-space-tree.h"
+#include "../transaction.h"
+#include "../block-group.h"
+#include "../accessors.h"
+
+struct free_space_extent {
+	u64 start;
+	u64 length;
+};
+
+static int __check_free_space_extents(struct btrfs_trans_handle *trans,
+				      struct btrfs_fs_info *fs_info,
+				      struct btrfs_block_group *cache,
+				      struct btrfs_path *path,
+				      const struct free_space_extent * const extents,
+				      unsigned int num_extents)
+{
+	struct btrfs_free_space_info *info;
+	struct btrfs_key key;
+	int prev_bit = 0, bit;
+	u64 extent_start = 0, offset, end;
+	u32 flags, extent_count;
+	unsigned int i;
+	int ret;
+
+	info = btrfs_search_free_space_info(trans, cache, path, 0);
+	if (IS_ERR(info)) {
+		test_err("could not find free space info");
+		ret = PTR_ERR(info);
+		goto out;
+	}
+	flags = btrfs_free_space_flags(path->nodes[0], info);
+	extent_count = btrfs_free_space_extent_count(path->nodes[0], info);
+
+	if (extent_count != num_extents) {
+		test_err("extent count is wrong");
+		ret = -EINVAL;
+		goto out;
+	}
+	if (flags & BTRFS_FREE_SPACE_USING_BITMAPS) {
+		if (path->slots[0] != 0)
+			goto invalid;
+		end = btrfs_block_group_end(cache);
+		i = 0;
+		while (++path->slots[0] < btrfs_header_nritems(path->nodes[0])) {
+			btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
+			if (key.type != BTRFS_FREE_SPACE_BITMAP_KEY)
+				goto invalid;
+			offset = key.objectid;
+			while (offset < key.objectid + key.offset) {
+				bit = btrfs_free_space_test_bit(cache, path, offset);
+				if (prev_bit == 0 && bit == 1) {
+					extent_start = offset;
+				} else if (prev_bit == 1 && bit == 0) {
+					if (i >= num_extents ||
+					    extent_start != extents[i].start ||
+					    offset - extent_start != extents[i].length)
+						goto invalid;
+					i++;
+				}
+				prev_bit = bit;
+				offset += fs_info->sectorsize;
+			}
+		}
+		if (prev_bit == 1) {
+			if (i >= num_extents ||
+			    extent_start != extents[i].start ||
+			    end - extent_start != extents[i].length)
+				goto invalid;
+			i++;
+		}
+		if (i != num_extents)
+			goto invalid;
+	} else {
+		if (btrfs_header_nritems(path->nodes[0]) != num_extents + 1 ||
+		    path->slots[0] != 0)
+			goto invalid;
+		for (i = 0; i < num_extents; i++) {
+			path->slots[0]++;
+			btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
+			if (key.type != BTRFS_FREE_SPACE_EXTENT_KEY ||
+			    key.objectid != extents[i].start ||
+			    key.offset != extents[i].length)
+				goto invalid;
+		}
+	}
+
+	ret = 0;
+out:
+	btrfs_release_path(path);
+	return ret;
+invalid:
+	test_err("free space tree is invalid");
+	ret = -EINVAL;
+	goto out;
+}
+
+static int check_free_space_extents(struct btrfs_trans_handle *trans,
+				    struct btrfs_fs_info *fs_info,
+				    struct btrfs_block_group *cache,
+				    struct btrfs_path *path,
+				    const struct free_space_extent * const extents,
+				    unsigned int num_extents)
+{
+	struct btrfs_free_space_info *info;
+	u32 flags;
+	int ret;
+
+	info = btrfs_search_free_space_info(trans, cache, path, 0);
+	if (IS_ERR(info)) {
+		test_err("could not find free space info");
+		btrfs_release_path(path);
+		return PTR_ERR(info);
+	}
+	flags = btrfs_free_space_flags(path->nodes[0], info);
+	btrfs_release_path(path);
+
+	ret = __check_free_space_extents(trans, fs_info, cache, path, extents,
+					 num_extents);
+	if (ret)
+		return ret;
+
+	/* Flip it to the other format and check that for good measure. */
+	if (flags & BTRFS_FREE_SPACE_USING_BITMAPS) {
+		ret = btrfs_convert_free_space_to_extents(trans, cache, path);
+		if (ret) {
+			test_err("could not convert to extents");
+			return ret;
+		}
+	} else {
+		ret = btrfs_convert_free_space_to_bitmaps(trans, cache, path);
+		if (ret) {
+			test_err("could not convert to bitmaps");
+			return ret;
+		}
+	}
+	return __check_free_space_extents(trans, fs_info, cache, path, extents,
+					  num_extents);
+}
+
+static int test_empty_block_group(struct btrfs_trans_handle *trans,
+				  struct btrfs_fs_info *fs_info,
+				  struct btrfs_block_group *cache,
+				  struct btrfs_path *path,
+				  u32 alignment)
+{
+	const struct free_space_extent extents[] = {
+		{cache->start, cache->length},
+	};
+
+	return check_free_space_extents(trans, fs_info, cache, path,
+					extents, ARRAY_SIZE(extents));
+}
+
+static int test_remove_all(struct btrfs_trans_handle *trans,
+			   struct btrfs_fs_info *fs_info,
+			   struct btrfs_block_group *cache,
+			   struct btrfs_path *path,
+			   u32 alignment)
+{
+	const struct free_space_extent extents[] = {};
+	int ret;
+
+	ret = __btrfs_remove_from_free_space_tree(trans, cache, path,
+						  cache->start, cache->length);
+	if (ret) {
+		test_err("could not remove free space");
+		return ret;
+	}
+
+	return check_free_space_extents(trans, fs_info, cache, path,
+					extents, ARRAY_SIZE(extents));
+}
+
+static int test_remove_beginning(struct btrfs_trans_handle *trans,
+				 struct btrfs_fs_info *fs_info,
+				 struct btrfs_block_group *cache,
+				 struct btrfs_path *path,
+				 u32 alignment)
+{
+	const struct free_space_extent extents[] = {
+		{cache->start + alignment, cache->length - alignment},
+	};
+	int ret;
+
+	ret = __btrfs_remove_from_free_space_tree(trans, cache, path,
+						  cache->start, alignment);
+	if (ret) {
+		test_err("could not remove free space");
+		return ret;
+	}
+
+	return check_free_space_extents(trans, fs_info, cache, path,
+					extents, ARRAY_SIZE(extents));
+
+}
+
+static int test_remove_end(struct btrfs_trans_handle *trans,
+			   struct btrfs_fs_info *fs_info,
+			   struct btrfs_block_group *cache,
+			   struct btrfs_path *path,
+			   u32 alignment)
+{
+	const struct free_space_extent extents[] = {
+		{cache->start, cache->length - alignment},
+	};
+	int ret;
+
+	ret = __btrfs_remove_from_free_space_tree(trans, cache, path,
+				    btrfs_block_group_end(cache) - alignment,
+				    alignment);
+	if (ret) {
+		test_err("could not remove free space");
+		return ret;
+	}
+
+	return check_free_space_extents(trans, fs_info, cache, path,
+					extents, ARRAY_SIZE(extents));
+}
+
+static int test_remove_middle(struct btrfs_trans_handle *trans,
+			      struct btrfs_fs_info *fs_info,
+			      struct btrfs_block_group *cache,
+			      struct btrfs_path *path,
+			      u32 alignment)
+{
+	const struct free_space_extent extents[] = {
+		{cache->start, alignment},
+		{cache->start + 2 * alignment, cache->length - 2 * alignment},
+	};
+	int ret;
+
+	ret = __btrfs_remove_from_free_space_tree(trans, cache, path,
+						  cache->start + alignment,
+						  alignment);
+	if (ret) {
+		test_err("could not remove free space");
+		return ret;
+	}
+
+	return check_free_space_extents(trans, fs_info, cache, path,
+					extents, ARRAY_SIZE(extents));
+}
+
+static int test_merge_left(struct btrfs_trans_handle *trans,
+			   struct btrfs_fs_info *fs_info,
+			   struct btrfs_block_group *cache,
+			   struct btrfs_path *path,
+			   u32 alignment)
+{
+	const struct free_space_extent extents[] = {
+		{cache->start, 2 * alignment},
+	};
+	int ret;
+
+	ret = __btrfs_remove_from_free_space_tree(trans, cache, path,
+						  cache->start, cache->length);
+	if (ret) {
+		test_err("could not remove free space");
+		return ret;
+	}
+
+	ret = __btrfs_add_to_free_space_tree(trans, cache, path, cache->start,
+					     alignment);
+	if (ret) {
+		test_err("could not add free space");
+		return ret;
+	}
+
+	ret = __btrfs_add_to_free_space_tree(trans, cache, path,
+					     cache->start + alignment, alignment);
+	if (ret) {
+		test_err("could not add free space");
+		return ret;
+	}
+
+	return check_free_space_extents(trans, fs_info, cache, path,
+					extents, ARRAY_SIZE(extents));
+}
+
+static int test_merge_right(struct btrfs_trans_handle *trans,
+			   struct btrfs_fs_info *fs_info,
+			   struct btrfs_block_group *cache,
+			   struct btrfs_path *path,
+			   u32 alignment)
+{
+	const struct free_space_extent extents[] = {
+		{cache->start + alignment, 2 * alignment},
+	};
+	int ret;
+
+	ret = __btrfs_remove_from_free_space_tree(trans, cache, path,
+						  cache->start, cache->length);
+	if (ret) {
+		test_err("could not remove free space");
+		return ret;
+	}
+
+	ret = __btrfs_add_to_free_space_tree(trans, cache, path,
+					     cache->start + 2 * alignment,
+					     alignment);
+	if (ret) {
+		test_err("could not add free space");
+		return ret;
+	}
+
+	ret = __btrfs_add_to_free_space_tree(trans, cache, path,
+					     cache->start + alignment, alignment);
+	if (ret) {
+		test_err("could not add free space");
+		return ret;
+	}
+
+	return check_free_space_extents(trans, fs_info, cache, path,
+					extents, ARRAY_SIZE(extents));
+}
+
+static int test_merge_both(struct btrfs_trans_handle *trans,
+			   struct btrfs_fs_info *fs_info,
+			   struct btrfs_block_group *cache,
+			   struct btrfs_path *path,
+			   u32 alignment)
+{
+	const struct free_space_extent extents[] = {
+		{cache->start, 3 * alignment},
+	};
+	int ret;
+
+	ret = __btrfs_remove_from_free_space_tree(trans, cache, path,
+						  cache->start, cache->length);
+	if (ret) {
+		test_err("could not remove free space");
+		return ret;
+	}
+
+	ret = __btrfs_add_to_free_space_tree(trans, cache, path, cache->start,
+					     alignment);
+	if (ret) {
+		test_err("could not add free space");
+		return ret;
+	}
+
+	ret = __btrfs_add_to_free_space_tree(trans, cache, path,
+					     cache->start + 2 * alignment, alignment);
+	if (ret) {
+		test_err("could not add free space");
+		return ret;
+	}
+
+	ret = __btrfs_add_to_free_space_tree(trans, cache, path,
+					     cache->start + alignment, alignment);
+	if (ret) {
+		test_err("could not add free space");
+		return ret;
+	}
+
+	return check_free_space_extents(trans, fs_info, cache, path,
+					extents, ARRAY_SIZE(extents));
+}
+
+static int test_merge_none(struct btrfs_trans_handle *trans,
+			   struct btrfs_fs_info *fs_info,
+			   struct btrfs_block_group *cache,
+			   struct btrfs_path *path,
+			   u32 alignment)
+{
+	const struct free_space_extent extents[] = {
+		{cache->start, alignment},
+		{cache->start + 2 * alignment, alignment},
+		{cache->start + 4 * alignment, alignment},
+	};
+	int ret;
+
+	ret = __btrfs_remove_from_free_space_tree(trans, cache, path,
+						  cache->start, cache->length);
+	if (ret) {
+		test_err("could not remove free space");
+		return ret;
+	}
+
+	ret = __btrfs_add_to_free_space_tree(trans, cache, path, cache->start,
+					     alignment);
+	if (ret) {
+		test_err("could not add free space");
+		return ret;
+	}
+
+	ret = __btrfs_add_to_free_space_tree(trans, cache, path,
+					     cache->start + 4 * alignment, alignment);
+	if (ret) {
+		test_err("could not add free space");
+		return ret;
+	}
+
+	ret = __btrfs_add_to_free_space_tree(trans, cache, path,
+					     cache->start + 2 * alignment, alignment);
+	if (ret) {
+		test_err("could not add free space");
+		return ret;
+	}
+
+	return check_free_space_extents(trans, fs_info, cache, path,
+					extents, ARRAY_SIZE(extents));
+}
+
+typedef int (*test_func_t)(struct btrfs_trans_handle *,
+			   struct btrfs_fs_info *,
+			   struct btrfs_block_group *,
+			   struct btrfs_path *,
+			   u32 alignment);
+
+static int run_test(test_func_t test_func, int bitmaps, u32 sectorsize,
+		    u32 nodesize, u32 alignment)
+{
+	struct btrfs_fs_info *fs_info;
+	struct btrfs_root *root = NULL;
+	struct btrfs_block_group *cache = NULL;
+	struct btrfs_trans_handle trans;
+	struct btrfs_path *path = NULL;
+	int ret;
+
+	fs_info = btrfs_alloc_dummy_fs_info(nodesize, sectorsize);
+	if (!fs_info) {
+		test_std_err(TEST_ALLOC_FS_INFO);
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	root = btrfs_alloc_dummy_root(fs_info);
+	if (IS_ERR(root)) {
+		test_std_err(TEST_ALLOC_ROOT);
+		ret = PTR_ERR(root);
+		goto out;
+	}
+
+	btrfs_set_super_compat_ro_flags(root->fs_info->super_copy,
+					BTRFS_FEATURE_COMPAT_RO_FREE_SPACE_TREE);
+	root->root_key.objectid = BTRFS_FREE_SPACE_TREE_OBJECTID;
+	root->root_key.type = BTRFS_ROOT_ITEM_KEY;
+	root->root_key.offset = 0;
+	btrfs_global_root_insert(root);
+	root->fs_info->tree_root = root;
+
+	root->node = alloc_test_extent_buffer(root->fs_info, nodesize);
+	if (IS_ERR(root->node)) {
+		test_std_err(TEST_ALLOC_EXTENT_BUFFER);
+		ret = PTR_ERR(root->node);
+		goto out;
+	}
+	btrfs_set_header_level(root->node, 0);
+	btrfs_set_header_nritems(root->node, 0);
+	root->alloc_bytenr += 2 * nodesize;
+
+	cache = btrfs_alloc_dummy_block_group(fs_info, 8 * alignment);
+	if (!cache) {
+		test_std_err(TEST_ALLOC_BLOCK_GROUP);
+		ret = -ENOMEM;
+		goto out;
+	}
+	cache->bitmap_low_thresh = 0;
+	cache->bitmap_high_thresh = (u32)-1;
+	set_bit(BLOCK_GROUP_FLAG_NEEDS_FREE_SPACE, &cache->runtime_flags);
+	cache->fs_info = root->fs_info;
+
+	btrfs_init_dummy_trans(&trans, root->fs_info);
+
+	path = btrfs_alloc_path();
+	if (!path) {
+		test_std_err(TEST_ALLOC_ROOT);
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	ret = btrfs_add_block_group_free_space(&trans, cache);
+	if (ret) {
+		test_err("could not add block group free space");
+		goto out;
+	}
+
+	if (bitmaps) {
+		ret = btrfs_convert_free_space_to_bitmaps(&trans, cache, path);
+		if (ret) {
+			test_err("could not convert block group to bitmaps");
+			goto out;
+		}
+	}
+
+	ret = test_func(&trans, root->fs_info, cache, path, alignment);
+	if (ret)
+		goto out;
+
+	ret = btrfs_remove_block_group_free_space(&trans, cache);
+	if (ret) {
+		test_err("could not remove block group free space");
+		goto out;
+	}
+
+	if (btrfs_header_nritems(root->node) != 0) {
+		test_err("free space tree has leftover items");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ret = 0;
+out:
+	btrfs_free_path(path);
+	btrfs_free_dummy_block_group(cache);
+	btrfs_free_dummy_root(root);
+	btrfs_free_dummy_fs_info(fs_info);
+	return ret;
+}
+
+static int run_test_both_formats(test_func_t test_func, u32 sectorsize,
+				 u32 nodesize, u32 alignment)
+{
+	int test_ret = 0;
+	int ret;
+
+	ret = run_test(test_func, 0, sectorsize, nodesize, alignment);
+	if (ret) {
+		test_err(
+	"%ps failed with extents, sectorsize=%u, nodesize=%u, alignment=%u",
+			 test_func, sectorsize, nodesize, alignment);
+		test_ret = ret;
+	}
+
+	ret = run_test(test_func, 1, sectorsize, nodesize, alignment);
+	if (ret) {
+		test_err(
+	"%ps failed with bitmaps, sectorsize=%u, nodesize=%u, alignment=%u",
+			 test_func, sectorsize, nodesize, alignment);
+		test_ret = ret;
+	}
+
+	return test_ret;
+}
+
+int btrfs_test_free_space_tree(u32 sectorsize, u32 nodesize)
+{
+	test_func_t tests[] = {
+		test_empty_block_group,
+		test_remove_all,
+		test_remove_beginning,
+		test_remove_end,
+		test_remove_middle,
+		test_merge_left,
+		test_merge_right,
+		test_merge_both,
+		test_merge_none,
+	};
+	u32 bitmap_alignment;
+	int test_ret = 0;
+	int i;
+
+	/*
+	 * Align some operations to a page to flush out bugs in the extent
+	 * buffer bitmap handling of highmem.
+	 */
+	bitmap_alignment = BTRFS_FREE_SPACE_BITMAP_BITS * PAGE_SIZE;
+
+	test_msg("running free space tree tests");
+	for (i = 0; i < ARRAY_SIZE(tests); i++) {
+		int ret;
+
+		ret = run_test_both_formats(tests[i], sectorsize, nodesize,
+					    sectorsize);
+		if (ret)
+			test_ret = ret;
+
+		ret = run_test_both_formats(tests[i], sectorsize, nodesize,
+					    bitmap_alignment);
+		if (ret)
+			test_ret = ret;
+	}
+
+	return test_ret;
+}
diff --git a/fs/btrfs/tests/inode-tests.c b/fs/btrfs/tests/inode-tests.c
new file mode 100644
index 000000000..b04fbcaf0
--- /dev/null
+++ b/fs/btrfs/tests/inode-tests.c
@@ -0,0 +1,1095 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2013 Fusion IO.  All rights reserved.
+ */
+
+#include <linux/types.h>
+#include "btrfs-tests.h"
+#include "../ctree.h"
+#include "../btrfs_inode.h"
+#include "../disk-io.h"
+#include "../extent_io.h"
+#include "../volumes.h"
+#include "../compression.h"
+#include "../accessors.h"
+
+static void insert_extent(struct btrfs_root *root, u64 start, u64 len,
+			  u64 ram_bytes, u64 offset, u64 disk_bytenr,
+			  u64 disk_len, u32 type, u8 compression, int slot)
+{
+	struct btrfs_path path;
+	struct btrfs_file_extent_item *fi;
+	struct extent_buffer *leaf = root->node;
+	struct btrfs_key key;
+	u32 value_len = sizeof(struct btrfs_file_extent_item);
+
+	if (type == BTRFS_FILE_EXTENT_INLINE)
+		value_len += len;
+	memset(&path, 0, sizeof(path));
+
+	path.nodes[0] = leaf;
+	path.slots[0] = slot;
+
+	key.objectid = BTRFS_FIRST_FREE_OBJECTID;
+	key.type = BTRFS_EXTENT_DATA_KEY;
+	key.offset = start;
+
+	/*
+	 * Passing a NULL trans handle is fine here, we have a dummy root eb
+	 * and the tree is a single node (level 0).
+	 */
+	btrfs_setup_item_for_insert(NULL, root, &path, &key, value_len);
+	fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
+	btrfs_set_file_extent_generation(leaf, fi, 1);
+	btrfs_set_file_extent_type(leaf, fi, type);
+	btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
+	btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_len);
+	btrfs_set_file_extent_offset(leaf, fi, offset);
+	btrfs_set_file_extent_num_bytes(leaf, fi, len);
+	btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
+	btrfs_set_file_extent_compression(leaf, fi, compression);
+	btrfs_set_file_extent_encryption(leaf, fi, 0);
+	btrfs_set_file_extent_other_encoding(leaf, fi, 0);
+}
+
+static void insert_inode_item_key(struct btrfs_root *root)
+{
+	struct btrfs_path path;
+	struct extent_buffer *leaf = root->node;
+	struct btrfs_key key;
+	u32 value_len = 0;
+
+	memset(&path, 0, sizeof(path));
+
+	path.nodes[0] = leaf;
+	path.slots[0] = 0;
+
+	key.objectid = BTRFS_INODE_ITEM_KEY;
+	key.type = BTRFS_INODE_ITEM_KEY;
+	key.offset = 0;
+
+	/*
+	 * Passing a NULL trans handle is fine here, we have a dummy root eb
+	 * and the tree is a single node (level 0).
+	 */
+	btrfs_setup_item_for_insert(NULL, root, &path, &key, value_len);
+}
+
+/*
+ * Build the most complicated map of extents the earth has ever seen.  We want
+ * this so we can test all of the corner cases of btrfs_get_extent.  Here is a
+ * diagram of how the extents will look though this may not be possible we still
+ * want to make sure everything acts normally (the last number is not inclusive)
+ *
+ * The numbers are using 4K fs block size as an example, the real test will scale
+ * all the extent maps (except the inlined one) according to the block size.
+ *
+ * [ 0  - 6 ][ 6 - 4K       ][ 4K - 8K ][ 8K -  12K      ]
+ * [ inline ][ implied hole ][ regular ][ regular1 split ]
+ *
+ * [ 12K - 16K ][ 16K - 24K      ][ 24K - 28K ][ 28K - 32K ][ 32K - 36K         ]
+ * [ hole      ][ regular1 split ][ prealloc  ][ prealloc1 ][ prealloc1 written ]
+ *
+ * [ 36K - 44K ][ 44K - 52K  ][ 52K - 56K   ][ 56K - 60K ][ 60K - 68 K  ]
+ * [ prealloc1 ][ compressed ][ compressed1 ][ regular   ][ compressed1 ]
+ *
+ * [ 68K - 72K ][ 72K - 84K          ][ 84K - 88K ]
+ * [  regular  ][ hole but no extent ][ regular   ]
+ */
+static void setup_file_extents(struct btrfs_root *root, u32 sectorsize)
+{
+	int slot = 0;
+	u64 disk_bytenr = SZ_1M;
+	u64 offset = 0;
+
+	/*
+	 * Start 0, length 6, inlined.
+	 *
+	 * Tree-checker has strict limits on inline extents that they can only
+	 * exist at file offset 0, thus we can only have one inline file extent
+	 * at most.
+	 */
+	insert_extent(root, offset, 6, 6, 0, 0, 0, BTRFS_FILE_EXTENT_INLINE, 0,
+		      slot);
+	slot++;
+	offset = sectorsize;
+
+	/* Start 1 * blocksize, length 1 * blocksize, regular. */
+	insert_extent(root, offset, sectorsize, sectorsize, 0,
+		      disk_bytenr, sectorsize, BTRFS_FILE_EXTENT_REG, 0, slot);
+	slot++;
+
+	/* We don't want the regular em merged with the next one. */
+	disk_bytenr += 2 * sectorsize;
+	offset += sectorsize;
+
+	/*
+	 * Start 2 * blocksize, length 1 * blocksize, regular.
+	 *
+	 * Now for 3 extents that were split from a hole punch so we test
+	 * offsets properly.
+	 */
+	insert_extent(root, offset, sectorsize, 4 * sectorsize, 0, disk_bytenr,
+		      4 * sectorsize, BTRFS_FILE_EXTENT_REG, 0, slot);
+	slot++;
+	offset += sectorsize;
+
+	/* Start 3 * blocksize, length 1 * blocksize, regular, explicit hole. */
+	insert_extent(root, offset, sectorsize, sectorsize, 0, 0, 0,
+		      BTRFS_FILE_EXTENT_REG, 0, slot);
+	slot++;
+	offset += sectorsize;
+
+	/* Start 4 * blocksize, length 2 * blocksize, regular. */
+	insert_extent(root, offset, 2 * sectorsize, 4 * sectorsize,
+		      2 * sectorsize, disk_bytenr, 4 * sectorsize,
+		      BTRFS_FILE_EXTENT_REG, 0, slot);
+	slot++;
+	offset += 2 * sectorsize;
+	disk_bytenr += 4 * sectorsize;
+
+	/* Start 6 * blocksize, length 1 * blocksize, preallocated. */
+	insert_extent(root, offset, sectorsize, sectorsize, 0, disk_bytenr,
+		sectorsize, BTRFS_FILE_EXTENT_PREALLOC, 0, slot);
+	slot++;
+	offset += sectorsize;
+
+	/*
+	 * We want to jack up disk_bytenr a little more so the em stuff doesn't
+	 * merge our records.
+	 */
+	disk_bytenr += 2 * sectorsize;
+
+	/*
+	 * Start 7 * blocksize, length 1 * blocksize, prealloc.
+	 *
+	 * Now for a partially written prealloc extent, basically the same as
+	 * the hole punch example above.  Ram_bytes never changes when you mark
+	 * extents written btw.
+	 */
+	insert_extent(root, offset, sectorsize, 4 * sectorsize, 0, disk_bytenr,
+		      4 * sectorsize, BTRFS_FILE_EXTENT_PREALLOC, 0, slot);
+	slot++;
+	offset += sectorsize;
+
+	/* Start 8 * blocksize, length 1 * blocksize, regular. */
+	insert_extent(root, offset, sectorsize, 4 * sectorsize, sectorsize,
+		      disk_bytenr, 4 * sectorsize, BTRFS_FILE_EXTENT_REG, 0,
+		      slot);
+	slot++;
+	offset += sectorsize;
+
+	/* Start 9 * blocksize, length 2 * blocksize, prealloc. */
+	insert_extent(root, offset, 2 * sectorsize, 4 * sectorsize,
+		      2 * sectorsize, disk_bytenr, 4 * sectorsize,
+		      BTRFS_FILE_EXTENT_PREALLOC, 0, slot);
+	slot++;
+	offset += 2 * sectorsize;
+	disk_bytenr += 4 * sectorsize;
+
+	/* Start 11 * blocksize, length 2 * blocksize, regular. */
+	insert_extent(root, offset, 2 * sectorsize, 2 * sectorsize, 0,
+		      disk_bytenr, sectorsize, BTRFS_FILE_EXTENT_REG,
+		      BTRFS_COMPRESS_ZLIB, slot);
+	slot++;
+	offset += 2 * sectorsize;
+	/* No merges */
+	disk_bytenr += 2 * sectorsize;
+
+	/* Start 13 * blocksize, length 1 * blocksize, regular. */
+	insert_extent(root, offset, sectorsize, 4 * sectorsize, 0, disk_bytenr,
+		      sectorsize, BTRFS_FILE_EXTENT_REG,
+		      BTRFS_COMPRESS_ZLIB, slot);
+	slot++;
+	offset += sectorsize;
+
+	/* Start 14 * blocksize, length 1 * blocksize, regular. */
+	insert_extent(root, offset, sectorsize, sectorsize, 0,
+		      disk_bytenr + sectorsize, sectorsize,
+		      BTRFS_FILE_EXTENT_REG, 0, slot);
+	slot++;
+	offset += sectorsize;
+
+	/* Start 15 * blocksize, length 2 * blocksize, regular. */
+	insert_extent(root, offset, 2 * sectorsize, 4 * sectorsize,
+		      2 * sectorsize, disk_bytenr, sectorsize,
+		      BTRFS_FILE_EXTENT_REG, BTRFS_COMPRESS_ZLIB, slot);
+	slot++;
+	offset += 2 * sectorsize;
+	disk_bytenr += 2 * sectorsize;
+
+	/* Start 17 * blocksize, length 1 * blocksize, regular. */
+	insert_extent(root, offset, sectorsize, sectorsize, 0, disk_bytenr,
+		      sectorsize, BTRFS_FILE_EXTENT_REG, 0, slot);
+	slot++;
+	offset += 4 * sectorsize;
+	disk_bytenr += sectorsize;
+
+	/*
+	 * Start 18 * blocksize, length 3 * blocksize, implied hole (aka no
+	 * file extent item).
+	 *
+	 * Start 21 * blocksize, length 1 * blocksize, regular.
+	 */
+	insert_extent(root, offset, sectorsize, sectorsize, 0, disk_bytenr,
+		      sectorsize, BTRFS_FILE_EXTENT_REG, 0, slot);
+}
+
+static u32 prealloc_only = 0;
+static u32 compressed_only = 0;
+static u32 vacancy_only = 0;
+
+static noinline int test_btrfs_get_extent(u32 sectorsize, u32 nodesize)
+{
+	struct btrfs_fs_info *fs_info = NULL;
+	struct inode *inode = NULL;
+	struct btrfs_root *root = NULL;
+	struct extent_map *em = NULL;
+	u64 orig_start;
+	u64 disk_bytenr;
+	u64 offset;
+	int ret = -ENOMEM;
+
+	test_msg("running btrfs_get_extent tests");
+
+	inode = btrfs_new_test_inode();
+	if (!inode) {
+		test_std_err(TEST_ALLOC_INODE);
+		return ret;
+	}
+
+	fs_info = btrfs_alloc_dummy_fs_info(nodesize, sectorsize);
+	if (!fs_info) {
+		test_std_err(TEST_ALLOC_FS_INFO);
+		goto out;
+	}
+
+	root = btrfs_alloc_dummy_root(fs_info);
+	if (IS_ERR(root)) {
+		test_std_err(TEST_ALLOC_ROOT);
+		goto out;
+	}
+
+	root->node = alloc_dummy_extent_buffer(fs_info, nodesize);
+	if (!root->node) {
+		test_std_err(TEST_ALLOC_ROOT);
+		goto out;
+	}
+
+	btrfs_set_header_nritems(root->node, 0);
+	btrfs_set_header_level(root->node, 0);
+	ret = -EINVAL;
+
+	/* First with no extents */
+	BTRFS_I(inode)->root = root;
+	em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, sectorsize);
+	if (IS_ERR(em)) {
+		em = NULL;
+		test_err("got an error when we shouldn't have");
+		goto out;
+	}
+	if (em->disk_bytenr != EXTENT_MAP_HOLE) {
+		test_err("expected a hole, got %llu", em->disk_bytenr);
+		goto out;
+	}
+	btrfs_free_extent_map(em);
+	btrfs_drop_extent_map_range(BTRFS_I(inode), 0, (u64)-1, false);
+
+	/*
+	 * All of the magic numbers are based on the mapping setup in
+	 * setup_file_extents, so if you change anything there you need to
+	 * update the comment and update the expected values below.
+	 */
+	setup_file_extents(root, sectorsize);
+
+	em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, (u64)-1);
+	if (IS_ERR(em)) {
+		test_err("got an error when we shouldn't have");
+		goto out;
+	}
+	if (em->disk_bytenr != EXTENT_MAP_INLINE) {
+		test_err("expected an inline, got %llu", em->disk_bytenr);
+		goto out;
+	}
+
+	/*
+	 * For inline extent, we always round up the em to sectorsize, as
+	 * they are either:
+	 *
+	 * a) a hidden hole
+	 *    The range will be zeroed at inline extent read time.
+	 *
+	 * b) a file extent with unaligned bytenr
+	 *    Tree checker will reject it.
+	 */
+	if (em->start != 0 || em->len != sectorsize) {
+		test_err(
+	"unexpected extent wanted start 0 len %u, got start %llu len %llu",
+			sectorsize, em->start, em->len);
+		goto out;
+	}
+	if (em->flags != 0) {
+		test_err("unexpected flags set, want 0 have %u", em->flags);
+		goto out;
+	}
+	/*
+	 * We don't test anything else for inline since it doesn't get set
+	 * unless we have a page for it to write into.  Maybe we should change
+	 * this?
+	 */
+	offset = btrfs_extent_map_end(em);
+	btrfs_free_extent_map(em);
+
+	/* Regular extent */
+	em = btrfs_get_extent(BTRFS_I(inode), NULL, offset, sectorsize);
+	if (IS_ERR(em)) {
+		test_err("got an error when we shouldn't have");
+		goto out;
+	}
+	if (em->disk_bytenr >= EXTENT_MAP_LAST_BYTE) {
+		test_err("expected a real extent, got %llu", em->disk_bytenr);
+		goto out;
+	}
+	if (em->start != offset || em->len != sectorsize) {
+		test_err(
+	"unexpected extent wanted start %llu len %u, got start %llu len %llu",
+			offset, sectorsize, em->start, em->len);
+		goto out;
+	}
+	if (em->flags != 0) {
+		test_err("unexpected flags set, want 0 have %u", em->flags);
+		goto out;
+	}
+	if (em->offset != 0) {
+		test_err("wrong offset, want 0, have %llu", em->offset);
+		goto out;
+	}
+	offset = btrfs_extent_map_end(em);
+	btrfs_free_extent_map(em);
+
+	/* The next 3 are split extents */
+	em = btrfs_get_extent(BTRFS_I(inode), NULL, offset, sectorsize);
+	if (IS_ERR(em)) {
+		test_err("got an error when we shouldn't have");
+		goto out;
+	}
+	if (em->disk_bytenr >= EXTENT_MAP_LAST_BYTE) {
+		test_err("expected a real extent, got %llu", em->disk_bytenr);
+		goto out;
+	}
+	if (em->start != offset || em->len != sectorsize) {
+		test_err(
+		"unexpected extent start %llu len %u, got start %llu len %llu",
+			offset, sectorsize, em->start, em->len);
+		goto out;
+	}
+	if (em->flags != 0) {
+		test_err("unexpected flags set, want 0 have %u", em->flags);
+		goto out;
+	}
+	if (em->offset != 0) {
+		test_err("wrong offset, want 0, have %llu", em->offset);
+		goto out;
+	}
+	disk_bytenr = btrfs_extent_map_block_start(em);
+	orig_start = em->start;
+	offset = btrfs_extent_map_end(em);
+	btrfs_free_extent_map(em);
+
+	em = btrfs_get_extent(BTRFS_I(inode), NULL, offset, sectorsize);
+	if (IS_ERR(em)) {
+		test_err("got an error when we shouldn't have");
+		goto out;
+	}
+	if (em->disk_bytenr != EXTENT_MAP_HOLE) {
+		test_err("expected a hole, got %llu", em->disk_bytenr);
+		goto out;
+	}
+	if (em->start != offset || em->len != sectorsize) {
+		test_err(
+	"unexpected extent wanted start %llu len %u, got start %llu len %llu",
+			offset, sectorsize, em->start, em->len);
+		goto out;
+	}
+	if (em->flags != 0) {
+		test_err("unexpected flags set, want 0 have %u", em->flags);
+		goto out;
+	}
+	offset = btrfs_extent_map_end(em);
+	btrfs_free_extent_map(em);
+
+	em = btrfs_get_extent(BTRFS_I(inode), NULL, offset, sectorsize);
+	if (IS_ERR(em)) {
+		test_err("got an error when we shouldn't have");
+		goto out;
+	}
+	if (em->disk_bytenr >= EXTENT_MAP_LAST_BYTE) {
+		test_err("expected a real extent, got %llu", em->disk_bytenr);
+		goto out;
+	}
+	if (em->start != offset || em->len != 2 * sectorsize) {
+		test_err(
+	"unexpected extent wanted start %llu len %u, got start %llu len %llu",
+			offset, 2 * sectorsize, em->start, em->len);
+		goto out;
+	}
+	if (em->flags != 0) {
+		test_err("unexpected flags set, want 0 have %u", em->flags);
+		goto out;
+	}
+	if (em->start - em->offset != orig_start) {
+		test_err("wrong offset, em->start=%llu em->offset=%llu orig_start=%llu",
+			 em->start, em->offset, orig_start);
+		goto out;
+	}
+	disk_bytenr += (em->start - orig_start);
+	if (btrfs_extent_map_block_start(em) != disk_bytenr) {
+		test_err("wrong block start, want %llu, have %llu",
+			 disk_bytenr, btrfs_extent_map_block_start(em));
+		goto out;
+	}
+	offset = btrfs_extent_map_end(em);
+	btrfs_free_extent_map(em);
+
+	/* Prealloc extent */
+	em = btrfs_get_extent(BTRFS_I(inode), NULL, offset, sectorsize);
+	if (IS_ERR(em)) {
+		test_err("got an error when we shouldn't have");
+		goto out;
+	}
+	if (em->disk_bytenr >= EXTENT_MAP_LAST_BYTE) {
+		test_err("expected a real extent, got %llu", em->disk_bytenr);
+		goto out;
+	}
+	if (em->start != offset || em->len != sectorsize) {
+		test_err(
+	"unexpected extent wanted start %llu len %u, got start %llu len %llu",
+			offset, sectorsize, em->start, em->len);
+		goto out;
+	}
+	if (em->flags != prealloc_only) {
+		test_err("unexpected flags set, want %u have %u",
+			 prealloc_only, em->flags);
+		goto out;
+	}
+	if (em->offset != 0) {
+		test_err("wrong offset, want 0, have %llu", em->offset);
+		goto out;
+	}
+	offset = btrfs_extent_map_end(em);
+	btrfs_free_extent_map(em);
+
+	/* The next 3 are a half written prealloc extent */
+	em = btrfs_get_extent(BTRFS_I(inode), NULL, offset, sectorsize);
+	if (IS_ERR(em)) {
+		test_err("got an error when we shouldn't have");
+		goto out;
+	}
+	if (em->disk_bytenr >= EXTENT_MAP_LAST_BYTE) {
+		test_err("expected a real extent, got %llu", em->disk_bytenr);
+		goto out;
+	}
+	if (em->start != offset || em->len != sectorsize) {
+		test_err(
+	"unexpected extent wanted start %llu len %u, got start %llu len %llu",
+			offset, sectorsize, em->start, em->len);
+		goto out;
+	}
+	if (em->flags != prealloc_only) {
+		test_err("unexpected flags set, want %u have %u",
+			 prealloc_only, em->flags);
+		goto out;
+	}
+	if (em->offset != 0) {
+		test_err("wrong offset, want 0, have %llu", em->offset);
+		goto out;
+	}
+	disk_bytenr = btrfs_extent_map_block_start(em);
+	orig_start = em->start;
+	offset = btrfs_extent_map_end(em);
+	btrfs_free_extent_map(em);
+
+	em = btrfs_get_extent(BTRFS_I(inode), NULL, offset, sectorsize);
+	if (IS_ERR(em)) {
+		test_err("got an error when we shouldn't have");
+		goto out;
+	}
+	if (em->disk_bytenr >= EXTENT_MAP_HOLE) {
+		test_err("expected a real extent, got %llu", em->disk_bytenr);
+		goto out;
+	}
+	if (em->start != offset || em->len != sectorsize) {
+		test_err(
+	"unexpected extent wanted start %llu len %u, got start %llu len %llu",
+			offset, sectorsize, em->start, em->len);
+		goto out;
+	}
+	if (em->flags != 0) {
+		test_err("unexpected flags set, want 0 have %u", em->flags);
+		goto out;
+	}
+	if (em->start - em->offset != orig_start) {
+		test_err("unexpected offset, wanted %llu, have %llu",
+			 em->start - orig_start, em->offset);
+		goto out;
+	}
+	if (btrfs_extent_map_block_start(em) != disk_bytenr + em->offset) {
+		test_err("unexpected block start, wanted %llu, have %llu",
+			 disk_bytenr + em->offset, btrfs_extent_map_block_start(em));
+		goto out;
+	}
+	offset = btrfs_extent_map_end(em);
+	btrfs_free_extent_map(em);
+
+	em = btrfs_get_extent(BTRFS_I(inode), NULL, offset, sectorsize);
+	if (IS_ERR(em)) {
+		test_err("got an error when we shouldn't have");
+		goto out;
+	}
+	if (em->disk_bytenr >= EXTENT_MAP_LAST_BYTE) {
+		test_err("expected a real extent, got %llu", em->disk_bytenr);
+		goto out;
+	}
+	if (em->start != offset || em->len != 2 * sectorsize) {
+		test_err(
+	"unexpected extent wanted start %llu len %u, got start %llu len %llu",
+			offset, 2 * sectorsize, em->start, em->len);
+		goto out;
+	}
+	if (em->flags != prealloc_only) {
+		test_err("unexpected flags set, want %u have %u",
+			 prealloc_only, em->flags);
+		goto out;
+	}
+	if (em->start - em->offset != orig_start) {
+		test_err("wrong offset, em->start=%llu em->offset=%llu orig_start=%llu",
+			 em->start, em->offset, orig_start);
+		goto out;
+	}
+	if (btrfs_extent_map_block_start(em) != disk_bytenr + em->offset) {
+		test_err("unexpected block start, wanted %llu, have %llu",
+			 disk_bytenr + em->offset, btrfs_extent_map_block_start(em));
+		goto out;
+	}
+	offset = btrfs_extent_map_end(em);
+	btrfs_free_extent_map(em);
+
+	/* Now for the compressed extent */
+	em = btrfs_get_extent(BTRFS_I(inode), NULL, offset, sectorsize);
+	if (IS_ERR(em)) {
+		test_err("got an error when we shouldn't have");
+		goto out;
+	}
+	if (em->disk_bytenr >= EXTENT_MAP_LAST_BYTE) {
+		test_err("expected a real extent, got %llu", em->disk_bytenr);
+		goto out;
+	}
+	if (em->start != offset || em->len != 2 * sectorsize) {
+		test_err(
+	"unexpected extent wanted start %llu len %u, got start %llu len %llu",
+			offset, 2 * sectorsize, em->start, em->len);
+		goto out;
+	}
+	if (em->flags != compressed_only) {
+		test_err("unexpected flags set, want %u have %u",
+			 compressed_only, em->flags);
+		goto out;
+	}
+	if (em->offset != 0) {
+		test_err("wrong offset, want 0, have %llu", em->offset);
+		goto out;
+	}
+	if (btrfs_extent_map_compression(em) != BTRFS_COMPRESS_ZLIB) {
+		test_err("unexpected compress type, wanted %d, got %d",
+			 BTRFS_COMPRESS_ZLIB, btrfs_extent_map_compression(em));
+		goto out;
+	}
+	offset = btrfs_extent_map_end(em);
+	btrfs_free_extent_map(em);
+
+	/* Split compressed extent */
+	em = btrfs_get_extent(BTRFS_I(inode), NULL, offset, sectorsize);
+	if (IS_ERR(em)) {
+		test_err("got an error when we shouldn't have");
+		goto out;
+	}
+	if (em->disk_bytenr >= EXTENT_MAP_LAST_BYTE) {
+		test_err("expected a real extent, got %llu", em->disk_bytenr);
+		goto out;
+	}
+	if (em->start != offset || em->len != sectorsize) {
+		test_err(
+	"unexpected extent wanted start %llu len %u, got start %llu len %llu",
+			offset, sectorsize, em->start, em->len);
+		goto out;
+	}
+	if (em->flags != compressed_only) {
+		test_err("unexpected flags set, want %u have %u",
+			 compressed_only, em->flags);
+		goto out;
+	}
+	if (em->offset != 0) {
+		test_err("wrong offset, want 0, have %llu", em->offset);
+		goto out;
+	}
+	if (btrfs_extent_map_compression(em) != BTRFS_COMPRESS_ZLIB) {
+		test_err("unexpected compress type, wanted %d, got %d",
+			 BTRFS_COMPRESS_ZLIB, btrfs_extent_map_compression(em));
+		goto out;
+	}
+	disk_bytenr = btrfs_extent_map_block_start(em);
+	orig_start = em->start;
+	offset = btrfs_extent_map_end(em);
+	btrfs_free_extent_map(em);
+
+	em = btrfs_get_extent(BTRFS_I(inode), NULL, offset, sectorsize);
+	if (IS_ERR(em)) {
+		test_err("got an error when we shouldn't have");
+		goto out;
+	}
+	if (em->disk_bytenr >= EXTENT_MAP_LAST_BYTE) {
+		test_err("expected a real extent, got %llu", em->disk_bytenr);
+		goto out;
+	}
+	if (em->start != offset || em->len != sectorsize) {
+		test_err(
+	"unexpected extent wanted start %llu len %u, got start %llu len %llu",
+			offset, sectorsize, em->start, em->len);
+		goto out;
+	}
+	if (em->flags != 0) {
+		test_err("unexpected flags set, want 0 have %u", em->flags);
+		goto out;
+	}
+	if (em->offset != 0) {
+		test_err("wrong offset, want 0, have %llu", em->offset);
+		goto out;
+	}
+	offset = btrfs_extent_map_end(em);
+	btrfs_free_extent_map(em);
+
+	em = btrfs_get_extent(BTRFS_I(inode), NULL, offset, sectorsize);
+	if (IS_ERR(em)) {
+		test_err("got an error when we shouldn't have");
+		goto out;
+	}
+	if (btrfs_extent_map_block_start(em) != disk_bytenr) {
+		test_err("block start does not match, want %llu got %llu",
+			 disk_bytenr, btrfs_extent_map_block_start(em));
+		goto out;
+	}
+	if (em->start != offset || em->len != 2 * sectorsize) {
+		test_err(
+	"unexpected extent wanted start %llu len %u, got start %llu len %llu",
+			offset, 2 * sectorsize, em->start, em->len);
+		goto out;
+	}
+	if (em->flags != compressed_only) {
+		test_err("unexpected flags set, want %u have %u",
+			 compressed_only, em->flags);
+		goto out;
+	}
+	if (em->start - em->offset != orig_start) {
+		test_err("wrong offset, em->start=%llu em->offset=%llu orig_start=%llu",
+			 em->start, em->offset, orig_start);
+		goto out;
+	}
+	if (btrfs_extent_map_compression(em) != BTRFS_COMPRESS_ZLIB) {
+		test_err("unexpected compress type, wanted %d, got %d",
+			 BTRFS_COMPRESS_ZLIB, btrfs_extent_map_compression(em));
+		goto out;
+	}
+	offset = btrfs_extent_map_end(em);
+	btrfs_free_extent_map(em);
+
+	/* A hole between regular extents but no hole extent */
+	em = btrfs_get_extent(BTRFS_I(inode), NULL, offset + 6, sectorsize);
+	if (IS_ERR(em)) {
+		test_err("got an error when we shouldn't have");
+		goto out;
+	}
+	if (em->disk_bytenr >= EXTENT_MAP_LAST_BYTE) {
+		test_err("expected a real extent, got %llu", em->disk_bytenr);
+		goto out;
+	}
+	if (em->start != offset || em->len != sectorsize) {
+		test_err(
+	"unexpected extent wanted start %llu len %u, got start %llu len %llu",
+			offset, sectorsize, em->start, em->len);
+		goto out;
+	}
+	if (em->flags != 0) {
+		test_err("unexpected flags set, want 0 have %u", em->flags);
+		goto out;
+	}
+	if (em->offset != 0) {
+		test_err("wrong offset, want 0, have %llu", em->offset);
+		goto out;
+	}
+	offset = btrfs_extent_map_end(em);
+	btrfs_free_extent_map(em);
+
+	em = btrfs_get_extent(BTRFS_I(inode), NULL, offset, SZ_4M);
+	if (IS_ERR(em)) {
+		test_err("got an error when we shouldn't have");
+		goto out;
+	}
+	if (em->disk_bytenr != EXTENT_MAP_HOLE) {
+		test_err("expected a hole extent, got %llu", em->disk_bytenr);
+		goto out;
+	}
+	/*
+	 * Currently we just return a length that we requested rather than the
+	 * length of the actual hole, if this changes we'll have to change this
+	 * test.
+	 */
+	if (em->start != offset || em->len != 3 * sectorsize) {
+		test_err(
+	"unexpected extent wanted start %llu len %u, got start %llu len %llu",
+			offset, 3 * sectorsize, em->start, em->len);
+		goto out;
+	}
+	if (em->flags != vacancy_only) {
+		test_err("unexpected flags set, want %u have %u",
+			 vacancy_only, em->flags);
+		goto out;
+	}
+	if (em->offset != 0) {
+		test_err("wrong offset, want 0, have %llu", em->offset);
+		goto out;
+	}
+	offset = btrfs_extent_map_end(em);
+	btrfs_free_extent_map(em);
+
+	em = btrfs_get_extent(BTRFS_I(inode), NULL, offset, sectorsize);
+	if (IS_ERR(em)) {
+		test_err("got an error when we shouldn't have");
+		goto out;
+	}
+	if (em->disk_bytenr >= EXTENT_MAP_LAST_BYTE) {
+		test_err("expected a real extent, got %llu", em->disk_bytenr);
+		goto out;
+	}
+	if (em->start != offset || em->len != sectorsize) {
+		test_err(
+	"unexpected extent wanted start %llu len %u, got start %llu len %llu",
+			offset, sectorsize, em->start, em->len);
+		goto out;
+	}
+	if (em->flags != 0) {
+		test_err("unexpected flags set, want 0 have %u", em->flags);
+		goto out;
+	}
+	if (em->offset != 0) {
+		test_err("wrong orig offset, want 0, have %llu", em->offset);
+		goto out;
+	}
+	ret = 0;
+out:
+	if (!IS_ERR(em))
+		btrfs_free_extent_map(em);
+	iput(inode);
+	btrfs_free_dummy_root(root);
+	btrfs_free_dummy_fs_info(fs_info);
+	return ret;
+}
+
+static int test_hole_first(u32 sectorsize, u32 nodesize)
+{
+	struct btrfs_fs_info *fs_info = NULL;
+	struct inode *inode = NULL;
+	struct btrfs_root *root = NULL;
+	struct extent_map *em = NULL;
+	int ret = -ENOMEM;
+
+	test_msg("running hole first btrfs_get_extent test");
+
+	inode = btrfs_new_test_inode();
+	if (!inode) {
+		test_std_err(TEST_ALLOC_INODE);
+		return ret;
+	}
+
+	fs_info = btrfs_alloc_dummy_fs_info(nodesize, sectorsize);
+	if (!fs_info) {
+		test_std_err(TEST_ALLOC_FS_INFO);
+		goto out;
+	}
+
+	root = btrfs_alloc_dummy_root(fs_info);
+	if (IS_ERR(root)) {
+		test_std_err(TEST_ALLOC_ROOT);
+		goto out;
+	}
+
+	root->node = alloc_dummy_extent_buffer(fs_info, nodesize);
+	if (!root->node) {
+		test_std_err(TEST_ALLOC_ROOT);
+		goto out;
+	}
+
+	btrfs_set_header_nritems(root->node, 0);
+	btrfs_set_header_level(root->node, 0);
+	BTRFS_I(inode)->root = root;
+	ret = -EINVAL;
+
+	/*
+	 * Need a blank inode item here just so we don't confuse
+	 * btrfs_get_extent.
+	 */
+	insert_inode_item_key(root);
+	insert_extent(root, sectorsize, sectorsize, sectorsize, 0, sectorsize,
+		      sectorsize, BTRFS_FILE_EXTENT_REG, 0, 1);
+	em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, 2 * sectorsize);
+	if (IS_ERR(em)) {
+		test_err("got an error when we shouldn't have");
+		goto out;
+	}
+	if (em->disk_bytenr != EXTENT_MAP_HOLE) {
+		test_err("expected a hole, got %llu", em->disk_bytenr);
+		goto out;
+	}
+	if (em->start != 0 || em->len != sectorsize) {
+		test_err(
+	"unexpected extent wanted start 0 len %u, got start %llu len %llu",
+			sectorsize, em->start, em->len);
+		goto out;
+	}
+	if (em->flags != vacancy_only) {
+		test_err("wrong flags, wanted %u, have %u", vacancy_only,
+			 em->flags);
+		goto out;
+	}
+	btrfs_free_extent_map(em);
+
+	em = btrfs_get_extent(BTRFS_I(inode), NULL, sectorsize, 2 * sectorsize);
+	if (IS_ERR(em)) {
+		test_err("got an error when we shouldn't have");
+		goto out;
+	}
+	if (btrfs_extent_map_block_start(em) != sectorsize) {
+		test_err("expected a real extent, got %llu",
+			 btrfs_extent_map_block_start(em));
+		goto out;
+	}
+	if (em->start != sectorsize || em->len != sectorsize) {
+		test_err(
+	"unexpected extent wanted start %u len %u, got start %llu len %llu",
+			sectorsize, sectorsize, em->start, em->len);
+		goto out;
+	}
+	if (em->flags != 0) {
+		test_err("unexpected flags set, wanted 0 got %u",
+			 em->flags);
+		goto out;
+	}
+	ret = 0;
+out:
+	if (!IS_ERR(em))
+		btrfs_free_extent_map(em);
+	iput(inode);
+	btrfs_free_dummy_root(root);
+	btrfs_free_dummy_fs_info(fs_info);
+	return ret;
+}
+
+static int test_extent_accounting(u32 sectorsize, u32 nodesize)
+{
+	struct btrfs_fs_info *fs_info = NULL;
+	struct inode *inode = NULL;
+	struct btrfs_root *root = NULL;
+	int ret = -ENOMEM;
+
+	test_msg("running outstanding_extents tests");
+
+	inode = btrfs_new_test_inode();
+	if (!inode) {
+		test_std_err(TEST_ALLOC_INODE);
+		return ret;
+	}
+
+	fs_info = btrfs_alloc_dummy_fs_info(nodesize, sectorsize);
+	if (!fs_info) {
+		test_std_err(TEST_ALLOC_FS_INFO);
+		goto out;
+	}
+
+	root = btrfs_alloc_dummy_root(fs_info);
+	if (IS_ERR(root)) {
+		test_std_err(TEST_ALLOC_ROOT);
+		goto out;
+	}
+
+	BTRFS_I(inode)->root = root;
+
+	/* [BTRFS_MAX_EXTENT_SIZE] */
+	ret = btrfs_set_extent_delalloc(BTRFS_I(inode), 0,
+					BTRFS_MAX_EXTENT_SIZE - 1, 0, NULL);
+	if (ret) {
+		test_err("btrfs_set_extent_delalloc returned %d", ret);
+		goto out;
+	}
+	if (BTRFS_I(inode)->outstanding_extents != 1) {
+		ret = -EINVAL;
+		test_err("miscount, wanted 1, got %u",
+			 BTRFS_I(inode)->outstanding_extents);
+		goto out;
+	}
+
+	/* [BTRFS_MAX_EXTENT_SIZE][sectorsize] */
+	ret = btrfs_set_extent_delalloc(BTRFS_I(inode), BTRFS_MAX_EXTENT_SIZE,
+					BTRFS_MAX_EXTENT_SIZE + sectorsize - 1,
+					0, NULL);
+	if (ret) {
+		test_err("btrfs_set_extent_delalloc returned %d", ret);
+		goto out;
+	}
+	if (BTRFS_I(inode)->outstanding_extents != 2) {
+		ret = -EINVAL;
+		test_err("miscount, wanted 2, got %u",
+			 BTRFS_I(inode)->outstanding_extents);
+		goto out;
+	}
+
+	/* [BTRFS_MAX_EXTENT_SIZE/2][sectorsize HOLE][the rest] */
+	ret = btrfs_clear_extent_bit(&BTRFS_I(inode)->io_tree,
+				     BTRFS_MAX_EXTENT_SIZE >> 1,
+				     (BTRFS_MAX_EXTENT_SIZE >> 1) + sectorsize - 1,
+				     EXTENT_DELALLOC | EXTENT_DELALLOC_NEW, NULL);
+	if (ret) {
+		test_err("clear_extent_bit returned %d", ret);
+		goto out;
+	}
+	if (BTRFS_I(inode)->outstanding_extents != 2) {
+		ret = -EINVAL;
+		test_err("miscount, wanted 2, got %u",
+			 BTRFS_I(inode)->outstanding_extents);
+		goto out;
+	}
+
+	/* [BTRFS_MAX_EXTENT_SIZE][sectorsize] */
+	ret = btrfs_set_extent_delalloc(BTRFS_I(inode), BTRFS_MAX_EXTENT_SIZE >> 1,
+					(BTRFS_MAX_EXTENT_SIZE >> 1)
+					+ sectorsize - 1,
+					0, NULL);
+	if (ret) {
+		test_err("btrfs_set_extent_delalloc returned %d", ret);
+		goto out;
+	}
+	if (BTRFS_I(inode)->outstanding_extents != 2) {
+		ret = -EINVAL;
+		test_err("miscount, wanted 2, got %u",
+			 BTRFS_I(inode)->outstanding_extents);
+		goto out;
+	}
+
+	/*
+	 * [BTRFS_MAX_EXTENT_SIZE+sectorsize][sectorsize HOLE][BTRFS_MAX_EXTENT_SIZE+sectorsize]
+	 */
+	ret = btrfs_set_extent_delalloc(BTRFS_I(inode),
+			BTRFS_MAX_EXTENT_SIZE + 2 * sectorsize,
+			(BTRFS_MAX_EXTENT_SIZE << 1) + 3 * sectorsize - 1,
+			0, NULL);
+	if (ret) {
+		test_err("btrfs_set_extent_delalloc returned %d", ret);
+		goto out;
+	}
+	if (BTRFS_I(inode)->outstanding_extents != 4) {
+		ret = -EINVAL;
+		test_err("miscount, wanted 4, got %u",
+			 BTRFS_I(inode)->outstanding_extents);
+		goto out;
+	}
+
+	/*
+	* [BTRFS_MAX_EXTENT_SIZE+sectorsize][sectorsize][BTRFS_MAX_EXTENT_SIZE+sectorsize]
+	*/
+	ret = btrfs_set_extent_delalloc(BTRFS_I(inode),
+			BTRFS_MAX_EXTENT_SIZE + sectorsize,
+			BTRFS_MAX_EXTENT_SIZE + 2 * sectorsize - 1, 0, NULL);
+	if (ret) {
+		test_err("btrfs_set_extent_delalloc returned %d", ret);
+		goto out;
+	}
+	if (BTRFS_I(inode)->outstanding_extents != 3) {
+		ret = -EINVAL;
+		test_err("miscount, wanted 3, got %u",
+			 BTRFS_I(inode)->outstanding_extents);
+		goto out;
+	}
+
+	/* [BTRFS_MAX_EXTENT_SIZE+4k][4K HOLE][BTRFS_MAX_EXTENT_SIZE+4k] */
+	ret = btrfs_clear_extent_bit(&BTRFS_I(inode)->io_tree,
+				     BTRFS_MAX_EXTENT_SIZE + sectorsize,
+				     BTRFS_MAX_EXTENT_SIZE + 2 * sectorsize - 1,
+				     EXTENT_DELALLOC | EXTENT_DELALLOC_NEW, NULL);
+	if (ret) {
+		test_err("clear_extent_bit returned %d", ret);
+		goto out;
+	}
+	if (BTRFS_I(inode)->outstanding_extents != 4) {
+		ret = -EINVAL;
+		test_err("miscount, wanted 4, got %u",
+			 BTRFS_I(inode)->outstanding_extents);
+		goto out;
+	}
+
+	/*
+	 * Refill the hole again just for good measure, because I thought it
+	 * might fail and I'd rather satisfy my paranoia at this point.
+	 */
+	ret = btrfs_set_extent_delalloc(BTRFS_I(inode),
+			BTRFS_MAX_EXTENT_SIZE + sectorsize,
+			BTRFS_MAX_EXTENT_SIZE + 2 * sectorsize - 1, 0, NULL);
+	if (ret) {
+		test_err("btrfs_set_extent_delalloc returned %d", ret);
+		goto out;
+	}
+	if (BTRFS_I(inode)->outstanding_extents != 3) {
+		ret = -EINVAL;
+		test_err("miscount, wanted 3, got %u",
+			 BTRFS_I(inode)->outstanding_extents);
+		goto out;
+	}
+
+	/* Empty */
+	ret = btrfs_clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, (u64)-1,
+				     EXTENT_DELALLOC | EXTENT_DELALLOC_NEW, NULL);
+	if (ret) {
+		test_err("clear_extent_bit returned %d", ret);
+		goto out;
+	}
+	if (BTRFS_I(inode)->outstanding_extents) {
+		ret = -EINVAL;
+		test_err("miscount, wanted 0, got %u",
+			 BTRFS_I(inode)->outstanding_extents);
+		goto out;
+	}
+	ret = 0;
+out:
+	if (ret)
+		btrfs_clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, (u64)-1,
+				       EXTENT_DELALLOC | EXTENT_DELALLOC_NEW, NULL);
+	iput(inode);
+	btrfs_free_dummy_root(root);
+	btrfs_free_dummy_fs_info(fs_info);
+	return ret;
+}
+
+int btrfs_test_inodes(u32 sectorsize, u32 nodesize)
+{
+	int ret;
+
+	test_msg("running inode tests");
+
+	compressed_only |= EXTENT_FLAG_COMPRESS_ZLIB;
+	prealloc_only |= EXTENT_FLAG_PREALLOC;
+
+	ret = test_btrfs_get_extent(sectorsize, nodesize);
+	if (ret)
+		return ret;
+	ret = test_hole_first(sectorsize, nodesize);
+	if (ret)
+		return ret;
+	return test_extent_accounting(sectorsize, nodesize);
+}
diff --git a/fs/btrfs/tests/qgroup-tests.c b/fs/btrfs/tests/qgroup-tests.c
new file mode 100644
index 000000000..0fcc31bee
--- /dev/null
+++ b/fs/btrfs/tests/qgroup-tests.c
@@ -0,0 +1,550 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2013 Facebook.  All rights reserved.
+ */
+
+#include <linux/types.h>
+#include "btrfs-tests.h"
+#include "../ctree.h"
+#include "../transaction.h"
+#include "../disk-io.h"
+#include "../qgroup.h"
+#include "../backref.h"
+#include "../fs.h"
+#include "../accessors.h"
+
+static int insert_normal_tree_ref(struct btrfs_root *root, u64 bytenr,
+				  u64 num_bytes, u64 parent, u64 root_objectid)
+{
+	struct btrfs_trans_handle trans;
+	struct btrfs_extent_item *item;
+	struct btrfs_extent_inline_ref *iref;
+	struct btrfs_tree_block_info *block_info;
+	BTRFS_PATH_AUTO_FREE(path);
+	struct extent_buffer *leaf;
+	struct btrfs_key ins;
+	u32 size = sizeof(*item) + sizeof(*iref) + sizeof(*block_info);
+	int ret;
+
+	btrfs_init_dummy_trans(&trans, NULL);
+
+	ins.objectid = bytenr;
+	ins.type = BTRFS_EXTENT_ITEM_KEY;
+	ins.offset = num_bytes;
+
+	path = btrfs_alloc_path();
+	if (!path) {
+		test_std_err(TEST_ALLOC_ROOT);
+		return -ENOMEM;
+	}
+
+	ret = btrfs_insert_empty_item(&trans, root, path, &ins, size);
+	if (ret) {
+		test_err("couldn't insert ref %d", ret);
+		return ret;
+	}
+
+	leaf = path->nodes[0];
+	item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
+	btrfs_set_extent_refs(leaf, item, 1);
+	btrfs_set_extent_generation(leaf, item, 1);
+	btrfs_set_extent_flags(leaf, item, BTRFS_EXTENT_FLAG_TREE_BLOCK);
+	block_info = (struct btrfs_tree_block_info *)(item + 1);
+	btrfs_set_tree_block_level(leaf, block_info, 0);
+	iref = (struct btrfs_extent_inline_ref *)(block_info + 1);
+	if (parent > 0) {
+		btrfs_set_extent_inline_ref_type(leaf, iref,
+						 BTRFS_SHARED_BLOCK_REF_KEY);
+		btrfs_set_extent_inline_ref_offset(leaf, iref, parent);
+	} else {
+		btrfs_set_extent_inline_ref_type(leaf, iref, BTRFS_TREE_BLOCK_REF_KEY);
+		btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid);
+	}
+	return 0;
+}
+
+static int add_tree_ref(struct btrfs_root *root, u64 bytenr, u64 num_bytes,
+			u64 parent, u64 root_objectid)
+{
+	struct btrfs_trans_handle trans;
+	struct btrfs_extent_item *item;
+	BTRFS_PATH_AUTO_FREE(path);
+	struct btrfs_key key;
+	u64 refs;
+	int ret;
+
+	btrfs_init_dummy_trans(&trans, NULL);
+
+	key.objectid = bytenr;
+	key.type = BTRFS_EXTENT_ITEM_KEY;
+	key.offset = num_bytes;
+
+	path = btrfs_alloc_path();
+	if (!path) {
+		test_std_err(TEST_ALLOC_ROOT);
+		return -ENOMEM;
+	}
+
+	ret = btrfs_search_slot(&trans, root, &key, path, 0, 1);
+	if (ret) {
+		test_err("couldn't find extent ref");
+		return ret;
+	}
+
+	item = btrfs_item_ptr(path->nodes[0], path->slots[0],
+			      struct btrfs_extent_item);
+	refs = btrfs_extent_refs(path->nodes[0], item);
+	btrfs_set_extent_refs(path->nodes[0], item, refs + 1);
+	btrfs_release_path(path);
+
+	key.objectid = bytenr;
+	if (parent) {
+		key.type = BTRFS_SHARED_BLOCK_REF_KEY;
+		key.offset = parent;
+	} else {
+		key.type = BTRFS_TREE_BLOCK_REF_KEY;
+		key.offset = root_objectid;
+	}
+
+	ret = btrfs_insert_empty_item(&trans, root, path, &key, 0);
+	if (ret)
+		test_err("failed to insert backref");
+	return ret;
+}
+
+static int remove_extent_item(struct btrfs_root *root, u64 bytenr,
+			      u64 num_bytes)
+{
+	struct btrfs_trans_handle trans;
+	struct btrfs_key key;
+	BTRFS_PATH_AUTO_FREE(path);
+	int ret;
+
+	btrfs_init_dummy_trans(&trans, NULL);
+
+	key.objectid = bytenr;
+	key.type = BTRFS_EXTENT_ITEM_KEY;
+	key.offset = num_bytes;
+
+	path = btrfs_alloc_path();
+	if (!path) {
+		test_std_err(TEST_ALLOC_ROOT);
+		return -ENOMEM;
+	}
+
+	ret = btrfs_search_slot(&trans, root, &key, path, -1, 1);
+	if (ret) {
+		test_err("didn't find our key %d", ret);
+		return ret;
+	}
+	btrfs_del_item(&trans, root, path);
+	return 0;
+}
+
+static int remove_extent_ref(struct btrfs_root *root, u64 bytenr,
+			     u64 num_bytes, u64 parent, u64 root_objectid)
+{
+	struct btrfs_trans_handle trans;
+	struct btrfs_extent_item *item;
+	BTRFS_PATH_AUTO_FREE(path);
+	struct btrfs_key key;
+	u64 refs;
+	int ret;
+
+	btrfs_init_dummy_trans(&trans, NULL);
+
+	key.objectid = bytenr;
+	key.type = BTRFS_EXTENT_ITEM_KEY;
+	key.offset = num_bytes;
+
+	path = btrfs_alloc_path();
+	if (!path) {
+		test_std_err(TEST_ALLOC_ROOT);
+		return -ENOMEM;
+	}
+
+	ret = btrfs_search_slot(&trans, root, &key, path, 0, 1);
+	if (ret) {
+		test_err("couldn't find extent ref");
+		return ret;
+	}
+
+	item = btrfs_item_ptr(path->nodes[0], path->slots[0],
+			      struct btrfs_extent_item);
+	refs = btrfs_extent_refs(path->nodes[0], item);
+	btrfs_set_extent_refs(path->nodes[0], item, refs - 1);
+	btrfs_release_path(path);
+
+	key.objectid = bytenr;
+	if (parent) {
+		key.type = BTRFS_SHARED_BLOCK_REF_KEY;
+		key.offset = parent;
+	} else {
+		key.type = BTRFS_TREE_BLOCK_REF_KEY;
+		key.offset = root_objectid;
+	}
+
+	ret = btrfs_search_slot(&trans, root, &key, path, -1, 1);
+	if (ret) {
+		test_err("couldn't find backref %d", ret);
+		return ret;
+	}
+	btrfs_del_item(&trans, root, path);
+	return ret;
+}
+
+static int test_no_shared_qgroup(struct btrfs_root *root,
+		u32 sectorsize, u32 nodesize)
+{
+	struct btrfs_backref_walk_ctx ctx = { 0 };
+	struct btrfs_trans_handle trans;
+	struct btrfs_fs_info *fs_info = root->fs_info;
+	struct ulist *old_roots = NULL;
+	struct ulist *new_roots = NULL;
+	int ret;
+
+	btrfs_init_dummy_trans(&trans, fs_info);
+
+	test_msg("running qgroup add/remove tests");
+	ret = btrfs_create_qgroup(&trans, BTRFS_FS_TREE_OBJECTID);
+	if (ret) {
+		test_err("couldn't create a qgroup %d", ret);
+		return ret;
+	}
+
+	ctx.bytenr = nodesize;
+	ctx.trans = &trans;
+	ctx.fs_info = fs_info;
+
+	/*
+	 * Since the test trans doesn't have the complicated delayed refs,
+	 * we can only call btrfs_qgroup_account_extent() directly to test
+	 * quota.
+	 */
+	ret = btrfs_find_all_roots(&ctx, false);
+	if (ret) {
+		test_err("couldn't find old roots: %d", ret);
+		return ret;
+	}
+	old_roots = ctx.roots;
+	ctx.roots = NULL;
+
+	ret = insert_normal_tree_ref(root, nodesize, nodesize, 0,
+				BTRFS_FS_TREE_OBJECTID);
+	if (ret) {
+		ulist_free(old_roots);
+		return ret;
+	}
+
+	ret = btrfs_find_all_roots(&ctx, false);
+	if (ret) {
+		ulist_free(old_roots);
+		test_err("couldn't find old roots: %d", ret);
+		return ret;
+	}
+	new_roots = ctx.roots;
+	ctx.roots = NULL;
+
+	ret = btrfs_qgroup_account_extent(&trans, nodesize, nodesize, old_roots,
+					  new_roots);
+	if (ret) {
+		test_err("couldn't account space for a qgroup %d", ret);
+		return ret;
+	}
+
+	/* btrfs_qgroup_account_extent() always frees the ulists passed to it. */
+	old_roots = NULL;
+	new_roots = NULL;
+
+	if (btrfs_verify_qgroup_counts(fs_info, BTRFS_FS_TREE_OBJECTID,
+				nodesize, nodesize)) {
+		test_err("qgroup counts didn't match expected values");
+		return -EINVAL;
+	}
+
+	ret = btrfs_find_all_roots(&ctx, false);
+	if (ret) {
+		test_err("couldn't find old roots: %d", ret);
+		return ret;
+	}
+	old_roots = ctx.roots;
+	ctx.roots = NULL;
+
+	ret = remove_extent_item(root, nodesize, nodesize);
+	if (ret) {
+		ulist_free(old_roots);
+		return -EINVAL;
+	}
+
+	ret = btrfs_find_all_roots(&ctx, false);
+	if (ret) {
+		ulist_free(old_roots);
+		test_err("couldn't find old roots: %d", ret);
+		return ret;
+	}
+	new_roots = ctx.roots;
+	ctx.roots = NULL;
+
+	ret = btrfs_qgroup_account_extent(&trans, nodesize, nodesize, old_roots,
+					  new_roots);
+	if (ret) {
+		test_err("couldn't account space for a qgroup %d", ret);
+		return -EINVAL;
+	}
+
+	if (btrfs_verify_qgroup_counts(fs_info, BTRFS_FS_TREE_OBJECTID, 0, 0)) {
+		test_err("qgroup counts didn't match expected values");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/*
+ * Add a ref for two different roots to make sure the shared value comes out
+ * right, also remove one of the roots and make sure the exclusive count is
+ * adjusted properly.
+ */
+static int test_multiple_refs(struct btrfs_root *root,
+		u32 sectorsize, u32 nodesize)
+{
+	struct btrfs_backref_walk_ctx ctx = { 0 };
+	struct btrfs_trans_handle trans;
+	struct btrfs_fs_info *fs_info = root->fs_info;
+	struct ulist *old_roots = NULL;
+	struct ulist *new_roots = NULL;
+	int ret;
+
+	btrfs_init_dummy_trans(&trans, fs_info);
+
+	test_msg("running qgroup multiple refs test");
+
+	/*
+	 * We have BTRFS_FS_TREE_OBJECTID created already from the
+	 * previous test.
+	 */
+	ret = btrfs_create_qgroup(&trans, BTRFS_FIRST_FREE_OBJECTID);
+	if (ret) {
+		test_err("couldn't create a qgroup %d", ret);
+		return ret;
+	}
+
+	ctx.bytenr = nodesize;
+	ctx.trans = &trans;
+	ctx.fs_info = fs_info;
+
+	ret = btrfs_find_all_roots(&ctx, false);
+	if (ret) {
+		test_err("couldn't find old roots: %d", ret);
+		return ret;
+	}
+	old_roots = ctx.roots;
+	ctx.roots = NULL;
+
+	ret = insert_normal_tree_ref(root, nodesize, nodesize, 0,
+				BTRFS_FS_TREE_OBJECTID);
+	if (ret) {
+		ulist_free(old_roots);
+		return ret;
+	}
+
+	ret = btrfs_find_all_roots(&ctx, false);
+	if (ret) {
+		ulist_free(old_roots);
+		test_err("couldn't find old roots: %d", ret);
+		return ret;
+	}
+	new_roots = ctx.roots;
+	ctx.roots = NULL;
+
+	ret = btrfs_qgroup_account_extent(&trans, nodesize, nodesize, old_roots,
+					  new_roots);
+	if (ret) {
+		test_err("couldn't account space for a qgroup %d", ret);
+		return ret;
+	}
+
+	if (btrfs_verify_qgroup_counts(fs_info, BTRFS_FS_TREE_OBJECTID,
+				       nodesize, nodesize)) {
+		test_err("qgroup counts didn't match expected values");
+		return -EINVAL;
+	}
+
+	ret = btrfs_find_all_roots(&ctx, false);
+	if (ret) {
+		test_err("couldn't find old roots: %d", ret);
+		return ret;
+	}
+	old_roots = ctx.roots;
+	ctx.roots = NULL;
+
+	ret = add_tree_ref(root, nodesize, nodesize, 0,
+			BTRFS_FIRST_FREE_OBJECTID);
+	if (ret) {
+		ulist_free(old_roots);
+		return ret;
+	}
+
+	ret = btrfs_find_all_roots(&ctx, false);
+	if (ret) {
+		ulist_free(old_roots);
+		test_err("couldn't find old roots: %d", ret);
+		return ret;
+	}
+	new_roots = ctx.roots;
+	ctx.roots = NULL;
+
+	ret = btrfs_qgroup_account_extent(&trans, nodesize, nodesize, old_roots,
+					  new_roots);
+	if (ret) {
+		test_err("couldn't account space for a qgroup %d", ret);
+		return ret;
+	}
+
+	if (btrfs_verify_qgroup_counts(fs_info, BTRFS_FS_TREE_OBJECTID,
+					nodesize, 0)) {
+		test_err("qgroup counts didn't match expected values");
+		return -EINVAL;
+	}
+
+	if (btrfs_verify_qgroup_counts(fs_info, BTRFS_FIRST_FREE_OBJECTID,
+					nodesize, 0)) {
+		test_err("qgroup counts didn't match expected values");
+		return -EINVAL;
+	}
+
+	ret = btrfs_find_all_roots(&ctx, false);
+	if (ret) {
+		test_err("couldn't find old roots: %d", ret);
+		return ret;
+	}
+	old_roots = ctx.roots;
+	ctx.roots = NULL;
+
+	ret = remove_extent_ref(root, nodesize, nodesize, 0,
+				BTRFS_FIRST_FREE_OBJECTID);
+	if (ret) {
+		ulist_free(old_roots);
+		return ret;
+	}
+
+	ret = btrfs_find_all_roots(&ctx, false);
+	if (ret) {
+		ulist_free(old_roots);
+		test_err("couldn't find old roots: %d", ret);
+		return ret;
+	}
+	new_roots = ctx.roots;
+	ctx.roots = NULL;
+
+	ret = btrfs_qgroup_account_extent(&trans, nodesize, nodesize, old_roots,
+					  new_roots);
+	if (ret) {
+		test_err("couldn't account space for a qgroup %d", ret);
+		return ret;
+	}
+
+	if (btrfs_verify_qgroup_counts(fs_info, BTRFS_FIRST_FREE_OBJECTID,
+					0, 0)) {
+		test_err("qgroup counts didn't match expected values");
+		return -EINVAL;
+	}
+
+	if (btrfs_verify_qgroup_counts(fs_info, BTRFS_FS_TREE_OBJECTID,
+					nodesize, nodesize)) {
+		test_err("qgroup counts didn't match expected values");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+int btrfs_test_qgroups(u32 sectorsize, u32 nodesize)
+{
+	struct btrfs_fs_info *fs_info = NULL;
+	struct btrfs_root *root;
+	struct btrfs_root *tmp_root;
+	int ret = 0;
+
+	fs_info = btrfs_alloc_dummy_fs_info(nodesize, sectorsize);
+	if (!fs_info) {
+		test_std_err(TEST_ALLOC_FS_INFO);
+		return -ENOMEM;
+	}
+
+	root = btrfs_alloc_dummy_root(fs_info);
+	if (IS_ERR(root)) {
+		test_std_err(TEST_ALLOC_ROOT);
+		ret = PTR_ERR(root);
+		goto out;
+	}
+
+	/* We are using this root as our extent root */
+	root->root_key.objectid = BTRFS_EXTENT_TREE_OBJECTID;
+	root->root_key.type = BTRFS_ROOT_ITEM_KEY;
+	root->root_key.offset = 0;
+	btrfs_global_root_insert(root);
+
+	/*
+	 * Some of the paths we test assume we have a filled out fs_info, so we
+	 * just need to add the root in there so we don't panic.
+	 */
+	root->fs_info->tree_root = root;
+	root->fs_info->quota_root = root;
+	set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
+
+	/*
+	 * Can't use bytenr 0, some things freak out
+	 * *cough*backref walking code*cough*
+	 */
+	root->node = alloc_test_extent_buffer(root->fs_info, nodesize);
+	if (IS_ERR(root->node)) {
+		test_err("couldn't allocate dummy buffer");
+		ret = PTR_ERR(root->node);
+		goto out;
+	}
+	btrfs_set_header_level(root->node, 0);
+	btrfs_set_header_nritems(root->node, 0);
+	root->alloc_bytenr += 2 * nodesize;
+
+	tmp_root = btrfs_alloc_dummy_root(fs_info);
+	if (IS_ERR(tmp_root)) {
+		test_std_err(TEST_ALLOC_ROOT);
+		ret = PTR_ERR(tmp_root);
+		goto out;
+	}
+
+	tmp_root->root_key.objectid = BTRFS_FS_TREE_OBJECTID;
+	root->fs_info->fs_root = tmp_root;
+	ret = btrfs_insert_fs_root(root->fs_info, tmp_root);
+	btrfs_put_root(tmp_root);
+	if (ret) {
+		test_err("couldn't insert fs root %d", ret);
+		goto out;
+	}
+
+	tmp_root = btrfs_alloc_dummy_root(fs_info);
+	if (IS_ERR(tmp_root)) {
+		test_std_err(TEST_ALLOC_ROOT);
+		ret = PTR_ERR(tmp_root);
+		goto out;
+	}
+
+	tmp_root->root_key.objectid = BTRFS_FIRST_FREE_OBJECTID;
+	ret = btrfs_insert_fs_root(root->fs_info, tmp_root);
+	btrfs_put_root(tmp_root);
+	if (ret) {
+		test_err("couldn't insert subvolume root %d", ret);
+		goto out;
+	}
+
+	test_msg("running qgroup tests");
+	ret = test_no_shared_qgroup(root, sectorsize, nodesize);
+	if (ret)
+		goto out;
+	ret = test_multiple_refs(root, sectorsize, nodesize);
+out:
+	btrfs_free_dummy_root(root);
+	btrfs_free_dummy_fs_info(fs_info);
+	return ret;
+}
diff --git a/fs/btrfs/tests/raid-stripe-tree-tests.c b/fs/btrfs/tests/raid-stripe-tree-tests.c
new file mode 100644
index 000000000..a7bc58a5c
--- /dev/null
+++ b/fs/btrfs/tests/raid-stripe-tree-tests.c
@@ -0,0 +1,1161 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2024 Western Digital Corporation or its affiliates.
+ */
+
+#include <linux/sizes.h>
+#include "../fs.h"
+#include "../disk-io.h"
+#include "../transaction.h"
+#include "../volumes.h"
+#include "../raid-stripe-tree.h"
+#include "btrfs-tests.h"
+
+#define RST_TEST_NUM_DEVICES	(2)
+#define RST_TEST_RAID1_TYPE	(BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_RAID1)
+
+#define SZ_48K (SZ_32K + SZ_16K)
+
+typedef int (*test_func_t)(struct btrfs_trans_handle *trans);
+
+static struct btrfs_device *btrfs_device_by_devid(struct btrfs_fs_devices *fs_devices,
+						  u64 devid)
+{
+	struct btrfs_device *dev;
+
+	list_for_each_entry(dev, &fs_devices->devices, dev_list) {
+		if (dev->devid == devid)
+			return dev;
+	}
+
+	return NULL;
+}
+
+/*
+ * Test creating a range of three extents and then punch a hole in the middle,
+ * deleting all of the middle extents and partially deleting the "book ends".
+ */
+static int test_punch_hole_3extents(struct btrfs_trans_handle *trans)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_io_context *bioc;
+	struct btrfs_io_stripe io_stripe = { 0 };
+	u64 map_type = RST_TEST_RAID1_TYPE;
+	u64 logical1 = SZ_1M;
+	u64 len1 = SZ_1M;
+	u64 logical2 = logical1 + len1;
+	u64 len2 = SZ_1M;
+	u64 logical3 = logical2 + len2;
+	u64 len3 = SZ_1M;
+	u64 hole_start = logical1 + SZ_256K;
+	u64 hole_len = SZ_2M;
+	int ret;
+
+	bioc = alloc_btrfs_io_context(fs_info, logical1, RST_TEST_NUM_DEVICES);
+	if (!bioc) {
+		test_std_err(TEST_ALLOC_IO_CONTEXT);
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	io_stripe.dev = btrfs_device_by_devid(fs_info->fs_devices, 0);
+
+	/* Prepare for the test, 1st create 3 x 1M extents. */
+	bioc->map_type = map_type;
+	bioc->size = len1;
+
+	for (int i = 0; i < RST_TEST_NUM_DEVICES; i++) {
+		struct btrfs_io_stripe *stripe = &bioc->stripes[i];
+
+		stripe->dev = btrfs_device_by_devid(fs_info->fs_devices, i);
+		if (!stripe->dev) {
+			test_err("cannot find device with devid %d", i);
+			ret = -EINVAL;
+			goto out;
+		}
+
+		stripe->physical = logical1 + i * SZ_1G;
+	}
+
+	ret = btrfs_insert_one_raid_extent(trans, bioc);
+	if (ret) {
+		test_err("inserting RAID extent failed: %d", ret);
+		goto out;
+	}
+
+	bioc->logical = logical2;
+	bioc->size = len2;
+	for (int i = 0; i < RST_TEST_NUM_DEVICES; i++) {
+		struct btrfs_io_stripe *stripe = &bioc->stripes[i];
+
+		stripe->dev = btrfs_device_by_devid(fs_info->fs_devices, i);
+		if (!stripe->dev) {
+			test_err("cannot find device with devid %d", i);
+			ret = -EINVAL;
+			goto out;
+		}
+
+		stripe->physical = logical2 + i * SZ_1G;
+	}
+
+	ret = btrfs_insert_one_raid_extent(trans, bioc);
+	if (ret) {
+		test_err("inserting RAID extent failed: %d", ret);
+		goto out;
+	}
+
+	bioc->logical = logical3;
+	bioc->size = len3;
+	for (int i = 0; i < RST_TEST_NUM_DEVICES; i++) {
+		struct btrfs_io_stripe *stripe = &bioc->stripes[i];
+
+		stripe->dev = btrfs_device_by_devid(fs_info->fs_devices, i);
+		if (!stripe->dev) {
+			test_err("cannot find device with devid %d", i);
+			ret = -EINVAL;
+			goto out;
+		}
+
+		stripe->physical = logical3 + i * SZ_1G;
+	}
+
+	ret = btrfs_insert_one_raid_extent(trans, bioc);
+	if (ret) {
+		test_err("inserting RAID extent failed: %d", ret);
+		goto out;
+	}
+
+	/*
+	 * Delete a range starting at logical1 + 256K and 2M in length. Extent
+	 * 1 is truncated to 256k length, extent 2 is completely dropped and
+	 * extent 3 is moved 256K to the right.
+	 */
+	ret = btrfs_delete_raid_extent(trans, hole_start, hole_len);
+	if (ret) {
+		test_err("deleting RAID extent [%llu, %llu] failed",
+			 hole_start, hole_start + hole_len);
+		goto out;
+	}
+
+	/* Get the first extent and check its size. */
+	ret = btrfs_get_raid_extent_offset(fs_info, logical1, &len1, map_type,
+					   0, &io_stripe);
+	if (ret) {
+		test_err("lookup of RAID extent [%llu, %llu] failed",
+			 logical1, logical1 + len1);
+		goto out;
+	}
+
+	if (io_stripe.physical != logical1) {
+		test_err("invalid physical address, expected %llu, got %llu",
+			 logical1, io_stripe.physical);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (len1 != SZ_256K) {
+		test_err("invalid stripe length, expected %llu, got %llu",
+			 (u64)SZ_256K, len1);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* Get the second extent and check it's absent. */
+	ret = btrfs_get_raid_extent_offset(fs_info, logical2, &len2, map_type,
+					   0, &io_stripe);
+	if (ret != -ENODATA) {
+		test_err("lookup of RAID extent [%llu, %llu] succeeded should fail",
+			 logical2, logical2 + len2);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* Get the third extent and check its size. */
+	logical3 += SZ_256K;
+	ret = btrfs_get_raid_extent_offset(fs_info, logical3, &len3, map_type,
+					   0, &io_stripe);
+	if (ret) {
+		test_err("lookup of RAID extent [%llu, %llu] failed",
+			 logical3, logical3 + len3);
+		goto out;
+	}
+
+	if (io_stripe.physical != logical3) {
+		test_err("invalid physical address, expected %llu, got %llu",
+			 logical3 + SZ_256K, io_stripe.physical);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (len3 != SZ_1M - SZ_256K) {
+		test_err("invalid stripe length, expected %llu, got %llu",
+			 (u64)SZ_1M - SZ_256K, len3);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ret = btrfs_delete_raid_extent(trans, logical1, len1);
+	if (ret) {
+		test_err("deleting RAID extent [%llu, %llu] failed",
+			 logical1, logical1 + len1);
+		goto out;
+	}
+
+	ret = btrfs_delete_raid_extent(trans, logical3, len3);
+	if (ret) {
+		test_err("deleting RAID extent [%llu, %llu] failed",
+			 logical1, logical1 + len1);
+		goto out;
+	}
+
+out:
+	btrfs_put_bioc(bioc);
+	return ret;
+}
+
+static int test_delete_two_extents(struct btrfs_trans_handle *trans)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_io_context *bioc;
+	struct btrfs_io_stripe io_stripe = { 0 };
+	u64 map_type = RST_TEST_RAID1_TYPE;
+	u64 logical1 = SZ_1M;
+	u64 len1 = SZ_1M;
+	u64 logical2 = logical1 + len1;
+	u64 len2 = SZ_1M;
+	u64 logical3 = logical2 + len2;
+	u64 len3 = SZ_1M;
+	int ret;
+
+	bioc = alloc_btrfs_io_context(fs_info, logical1, RST_TEST_NUM_DEVICES);
+	if (!bioc) {
+		test_std_err(TEST_ALLOC_IO_CONTEXT);
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	io_stripe.dev = btrfs_device_by_devid(fs_info->fs_devices, 0);
+
+	/* Prepare for the test, 1st create 3 x 1M extents. */
+	bioc->map_type = map_type;
+	bioc->size = len1;
+
+	for (int i = 0; i < RST_TEST_NUM_DEVICES; i++) {
+		struct btrfs_io_stripe *stripe = &bioc->stripes[i];
+
+		stripe->dev = btrfs_device_by_devid(fs_info->fs_devices, i);
+		if (!stripe->dev) {
+			test_err("cannot find device with devid %d", i);
+			ret = -EINVAL;
+			goto out;
+		}
+
+		stripe->physical = logical1 + i * SZ_1G;
+	}
+
+	ret = btrfs_insert_one_raid_extent(trans, bioc);
+	if (ret) {
+		test_err("inserting RAID extent failed: %d", ret);
+		goto out;
+	}
+
+	bioc->logical = logical2;
+	bioc->size = len2;
+	for (int i = 0; i < RST_TEST_NUM_DEVICES; i++) {
+		struct btrfs_io_stripe *stripe = &bioc->stripes[i];
+
+		stripe->dev = btrfs_device_by_devid(fs_info->fs_devices, i);
+		if (!stripe->dev) {
+			test_err("cannot find device with devid %d", i);
+			ret = -EINVAL;
+			goto out;
+		}
+
+		stripe->physical = logical2 + i * SZ_1G;
+	}
+
+	ret = btrfs_insert_one_raid_extent(trans, bioc);
+	if (ret) {
+		test_err("inserting RAID extent failed: %d", ret);
+		goto out;
+	}
+
+	bioc->logical = logical3;
+	bioc->size = len3;
+	for (int i = 0; i < RST_TEST_NUM_DEVICES; i++) {
+		struct btrfs_io_stripe *stripe = &bioc->stripes[i];
+
+		stripe->dev = btrfs_device_by_devid(fs_info->fs_devices, i);
+		if (!stripe->dev) {
+			test_err("cannot find device with devid %d", i);
+			ret = -EINVAL;
+			goto out;
+		}
+
+		stripe->physical = logical3 + i * SZ_1G;
+	}
+
+	ret = btrfs_insert_one_raid_extent(trans, bioc);
+	if (ret) {
+		test_err("inserting RAID extent failed: %d", ret);
+		goto out;
+	}
+
+	/*
+	 * Delete a range starting at logical1 and 2M in length. Extents 1
+	 * and 2 are dropped and extent 3 is kept as is.
+	 */
+	ret = btrfs_delete_raid_extent(trans, logical1, len1 + len2);
+	if (ret) {
+		test_err("deleting RAID extent [%llu, %llu] failed",
+			 logical1, logical1 + len1 + len2);
+		goto out;
+	}
+
+	ret = btrfs_get_raid_extent_offset(fs_info, logical1, &len1, map_type,
+					   0, &io_stripe);
+	if (ret != -ENODATA) {
+		test_err("lookup of RAID extent [%llu, %llu] succeeded, should fail",
+			 logical1, len1);
+		goto out;
+	}
+
+	ret = btrfs_get_raid_extent_offset(fs_info, logical2, &len2, map_type,
+					   0, &io_stripe);
+	if (ret != -ENODATA) {
+		test_err("lookup of RAID extent [%llu, %llu] succeeded, should fail",
+			 logical2, len2);
+		goto out;
+	}
+
+	ret = btrfs_get_raid_extent_offset(fs_info, logical3, &len3, map_type,
+					   0, &io_stripe);
+	if (ret) {
+		test_err("lookup of RAID extent [%llu, %llu] failed",
+			 logical3, len3);
+		goto out;
+	}
+
+	if (io_stripe.physical != logical3) {
+		test_err("invalid physical address, expected %llu, got %llu",
+			 logical3, io_stripe.physical);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (len3 != SZ_1M) {
+		test_err("invalid stripe length, expected %llu, got %llu",
+			 (u64)SZ_1M, len3);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ret = btrfs_delete_raid_extent(trans, logical3, len3);
+out:
+	btrfs_put_bioc(bioc);
+	return ret;
+}
+
+/* Test punching a hole into a single RAID stripe-extent. */
+static int test_punch_hole(struct btrfs_trans_handle *trans)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_io_context *bioc;
+	struct btrfs_io_stripe io_stripe = { 0 };
+	u64 map_type = RST_TEST_RAID1_TYPE;
+	u64 logical1 = SZ_1M;
+	u64 hole_start = logical1 + SZ_32K;
+	u64 hole_len = SZ_64K;
+	u64 logical2 = hole_start + hole_len;
+	u64 len = SZ_1M;
+	u64 len1 = SZ_32K;
+	u64 len2 = len - len1 - hole_len;
+	int ret;
+
+	bioc = alloc_btrfs_io_context(fs_info, logical1, RST_TEST_NUM_DEVICES);
+	if (!bioc) {
+		test_std_err(TEST_ALLOC_IO_CONTEXT);
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	io_stripe.dev = btrfs_device_by_devid(fs_info->fs_devices, 0);
+	bioc->map_type = map_type;
+	bioc->size = len;
+
+	for (int i = 0; i < RST_TEST_NUM_DEVICES; i++) {
+		struct btrfs_io_stripe *stripe = &bioc->stripes[i];
+
+		stripe->dev = btrfs_device_by_devid(fs_info->fs_devices, i);
+		if (!stripe->dev) {
+			test_err("cannot find device with devid %d", i);
+			ret = -EINVAL;
+			goto out;
+		}
+
+		stripe->physical = logical1 + i * SZ_1G;
+	}
+
+	ret = btrfs_insert_one_raid_extent(trans, bioc);
+	if (ret) {
+		test_err("inserting RAID extent failed: %d", ret);
+		goto out;
+	}
+
+	ret = btrfs_get_raid_extent_offset(fs_info, logical1, &len, map_type, 0,
+					   &io_stripe);
+	if (ret) {
+		test_err("lookup of RAID extent [%llu, %llu] failed", logical1,
+			 logical1 + len);
+		goto out;
+	}
+
+	if (io_stripe.physical != logical1) {
+		test_err("invalid physical address, expected %llu got %llu",
+			 logical1, io_stripe.physical);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (len != SZ_1M) {
+		test_err("invalid stripe length, expected %llu got %llu",
+			 (u64)SZ_1M, len);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ret = btrfs_delete_raid_extent(trans, hole_start, hole_len);
+	if (ret) {
+		test_err("deleting RAID extent [%llu, %llu] failed",
+			 hole_start, hole_start + hole_len);
+		goto out;
+	}
+
+	ret = btrfs_get_raid_extent_offset(fs_info, logical1, &len1, map_type,
+					   0, &io_stripe);
+	if (ret) {
+		test_err("lookup of RAID extent [%llu, %llu] failed",
+			 logical1, logical1 + len1);
+		goto out;
+	}
+
+	if (io_stripe.physical != logical1) {
+		test_err("invalid physical address, expected %llu, got %llu",
+			 logical1, io_stripe.physical);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (len1 != SZ_32K) {
+		test_err("invalid stripe length, expected %llu, got %llu",
+			 (u64)SZ_32K, len1);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ret = btrfs_get_raid_extent_offset(fs_info, logical2, &len2, map_type,
+					   0, &io_stripe);
+	if (ret) {
+		test_err("lookup of RAID extent [%llu, %llu] failed", logical2,
+			 logical2 + len2);
+		goto out;
+	}
+
+	if (io_stripe.physical != logical2) {
+		test_err("invalid physical address, expected %llu, got %llu",
+			 logical2, io_stripe.physical);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (len2 != len - len1 - hole_len) {
+		test_err("invalid length, expected %llu, got %llu",
+			 len - len1 - hole_len, len2);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* Check for the absence of the hole. */
+	ret = btrfs_get_raid_extent_offset(fs_info, hole_start, &hole_len,
+					   map_type, 0, &io_stripe);
+	if (ret != -ENODATA) {
+		ret = -EINVAL;
+		test_err("lookup of RAID extent [%llu, %llu] succeeded, should fail",
+			 hole_start, hole_start + SZ_64K);
+		goto out;
+	}
+
+	ret = btrfs_delete_raid_extent(trans, logical1, len1);
+	if (ret)
+		goto out;
+
+	ret = btrfs_delete_raid_extent(trans, logical2, len2);
+out:
+	btrfs_put_bioc(bioc);
+	return ret;
+}
+
+/*
+ * Test a 1M RST write that spans two adjacent RST items on disk and then
+ * delete a portion starting in the first item and spanning into the second
+ * item. This is similar to test_front_delete(), but spanning multiple items.
+ */
+static int test_front_delete_prev_item(struct btrfs_trans_handle *trans)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_io_context *bioc;
+	struct btrfs_io_stripe io_stripe = { 0 };
+	u64 map_type = RST_TEST_RAID1_TYPE;
+	u64 logical1 = SZ_1M;
+	u64 logical2 = SZ_2M;
+	u64 len = SZ_1M;
+	int ret;
+
+	bioc = alloc_btrfs_io_context(fs_info, logical1, RST_TEST_NUM_DEVICES);
+	if (!bioc) {
+		test_std_err(TEST_ALLOC_IO_CONTEXT);
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	io_stripe.dev = btrfs_device_by_devid(fs_info->fs_devices, 0);
+	bioc->map_type = map_type;
+	bioc->size = len;
+
+	/* Insert RAID extent 1. */
+	for (int i = 0; i < RST_TEST_NUM_DEVICES; i++) {
+		struct btrfs_io_stripe *stripe = &bioc->stripes[i];
+
+		stripe->dev = btrfs_device_by_devid(fs_info->fs_devices, i);
+		if (!stripe->dev) {
+			test_err("cannot find device with devid %d", i);
+			ret = -EINVAL;
+			goto out;
+		}
+
+		stripe->physical = logical1 + i * SZ_1G;
+	}
+
+	ret = btrfs_insert_one_raid_extent(trans, bioc);
+	if (ret) {
+		test_err("inserting RAID extent failed: %d", ret);
+		goto out;
+	}
+
+	bioc->logical = logical2;
+	/* Insert RAID extent 2, directly adjacent to it. */
+	for (int i = 0; i < RST_TEST_NUM_DEVICES; i++) {
+		struct btrfs_io_stripe *stripe = &bioc->stripes[i];
+
+		stripe->dev = btrfs_device_by_devid(fs_info->fs_devices, i);
+		if (!stripe->dev) {
+			test_err("cannot find device with devid %d", i);
+			ret = -EINVAL;
+			goto out;
+		}
+
+		stripe->physical = logical2 + i * SZ_1G;
+	}
+
+	ret = btrfs_insert_one_raid_extent(trans, bioc);
+	if (ret) {
+		test_err("inserting RAID extent failed: %d", ret);
+		goto out;
+	}
+
+	ret = btrfs_delete_raid_extent(trans, logical1 + SZ_512K, SZ_1M);
+	if (ret) {
+		test_err("deleting RAID extent [%llu, %llu] failed",
+			 logical1 + SZ_512K, (u64)SZ_1M);
+		goto out;
+	}
+
+	/* Verify item 1 is truncated to 512K. */
+	ret = btrfs_get_raid_extent_offset(fs_info, logical1, &len, map_type, 0,
+					   &io_stripe);
+	if (ret) {
+		test_err("lookup of RAID extent [%llu, %llu] failed", logical1,
+			 logical1 + len);
+		goto out;
+	}
+
+	if (io_stripe.physical != logical1) {
+		test_err("invalid physical address, expected %llu got %llu",
+			 logical1, io_stripe.physical);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (len != SZ_512K) {
+		test_err("invalid stripe length, expected %llu got %llu",
+			 (u64)SZ_512K, len);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* Verify item 2's start is moved by 512K. */
+	ret = btrfs_get_raid_extent_offset(fs_info, logical2 + SZ_512K, &len,
+					   map_type, 0, &io_stripe);
+	if (ret) {
+		test_err("lookup of RAID extent [%llu, %llu] failed",
+			 logical2 + SZ_512K, logical2 + len);
+		goto out;
+	}
+
+	if (io_stripe.physical != logical2 + SZ_512K) {
+		test_err("invalid physical address, expected %llu got %llu",
+			 logical2 + SZ_512K, io_stripe.physical);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (len != SZ_512K) {
+		test_err("invalid stripe length, expected %llu got %llu",
+			 (u64)SZ_512K, len);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* Verify there's a hole at [1M+512K, 2M+512K] . */
+	len = SZ_1M;
+	ret = btrfs_get_raid_extent_offset(fs_info, logical1 + SZ_512K, &len,
+					   map_type, 0, &io_stripe);
+	if (ret != -ENODATA) {
+		test_err("lookup of RAID [%llu, %llu] succeeded, should fail",
+			 logical1 + SZ_512K, logical1 + SZ_512K + len);
+		goto out;
+	}
+
+	/* Clean up after us. */
+	ret = btrfs_delete_raid_extent(trans, logical1, SZ_512K);
+	if (ret)
+		goto out;
+
+	ret = btrfs_delete_raid_extent(trans, logical2 + SZ_512K, SZ_512K);
+
+out:
+	btrfs_put_bioc(bioc);
+	return ret;
+}
+
+/*
+ * Test a 64K RST write on a 2 disk RAID1 at a logical address of 1M and then
+ * delete the 1st 32K, making the new start address 1M+32K.
+ */
+static int test_front_delete(struct btrfs_trans_handle *trans)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_io_context *bioc;
+	struct btrfs_io_stripe io_stripe = { 0 };
+	u64 map_type = RST_TEST_RAID1_TYPE;
+	u64 logical = SZ_1M;
+	u64 len = SZ_64K;
+	int ret;
+
+	bioc = alloc_btrfs_io_context(fs_info, logical, RST_TEST_NUM_DEVICES);
+	if (!bioc) {
+		test_std_err(TEST_ALLOC_IO_CONTEXT);
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	io_stripe.dev = btrfs_device_by_devid(fs_info->fs_devices, 0);
+	bioc->map_type = map_type;
+	bioc->size = len;
+
+	for (int i = 0; i < RST_TEST_NUM_DEVICES; i++) {
+		struct btrfs_io_stripe *stripe = &bioc->stripes[i];
+
+		stripe->dev = btrfs_device_by_devid(fs_info->fs_devices, i);
+		if (!stripe->dev) {
+			test_err("cannot find device with devid %d", i);
+			ret = -EINVAL;
+			goto out;
+		}
+
+		stripe->physical = logical + i * SZ_1G;
+	}
+
+	ret = btrfs_insert_one_raid_extent(trans, bioc);
+	if (ret) {
+		test_err("inserting RAID extent failed: %d", ret);
+		goto out;
+	}
+
+	ret = btrfs_get_raid_extent_offset(fs_info, logical, &len, map_type, 0, &io_stripe);
+	if (ret) {
+		test_err("lookup of RAID extent [%llu, %llu] failed", logical,
+			 logical + len);
+		goto out;
+	}
+
+	if (io_stripe.physical != logical) {
+		test_err("invalid physical address, expected %llu got %llu",
+			 logical, io_stripe.physical);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (len != SZ_64K) {
+		test_err("invalid stripe length, expected %llu got %llu",
+			 (u64)SZ_64K, len);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ret = btrfs_delete_raid_extent(trans, logical, SZ_16K);
+	if (ret) {
+		test_err("deleting RAID extent [%llu, %llu] failed", logical,
+			 logical + SZ_16K);
+		goto out;
+	}
+
+	len -= SZ_16K;
+	ret = btrfs_get_raid_extent_offset(fs_info, logical + SZ_16K, &len,
+					   map_type, 0, &io_stripe);
+	if (ret) {
+		test_err("lookup of RAID extent [%llu, %llu] failed",
+			 logical + SZ_16K, logical + SZ_64K);
+		goto out;
+	}
+
+	if (io_stripe.physical != logical + SZ_16K) {
+		test_err("invalid physical address, expected %llu, got %llu",
+			 logical + SZ_16K, io_stripe.physical);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (len != SZ_48K) {
+		test_err("invalid stripe length, expected %llu, got %llu",
+			 (u64)SZ_48K, len);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ret = btrfs_get_raid_extent_offset(fs_info, logical, &len, map_type, 0, &io_stripe);
+	if (ret != -ENODATA) {
+		ret = -EINVAL;
+		test_err("lookup of RAID extent [%llu, %llu] succeeded, should fail",
+			 logical, logical + SZ_16K);
+		goto out;
+	}
+
+	ret = btrfs_delete_raid_extent(trans, logical + SZ_16K, SZ_48K);
+out:
+	btrfs_put_bioc(bioc);
+	return ret;
+}
+
+/*
+ * Test a 64K RST write on a 2 disk RAID1 at a logical address of 1M and then
+ * truncate the stripe extent down to 32K.
+ */
+static int test_tail_delete(struct btrfs_trans_handle *trans)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_io_context *bioc;
+	struct btrfs_io_stripe io_stripe = { 0 };
+	u64 map_type = RST_TEST_RAID1_TYPE;
+	u64 logical = SZ_1M;
+	u64 len = SZ_64K;
+	int ret;
+
+	bioc = alloc_btrfs_io_context(fs_info, logical, RST_TEST_NUM_DEVICES);
+	if (!bioc) {
+		test_std_err(TEST_ALLOC_IO_CONTEXT);
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	io_stripe.dev = btrfs_device_by_devid(fs_info->fs_devices, 0);
+	bioc->map_type = map_type;
+	bioc->size = len;
+
+	for (int i = 0; i < RST_TEST_NUM_DEVICES; i++) {
+		struct btrfs_io_stripe *stripe = &bioc->stripes[i];
+
+		stripe->dev = btrfs_device_by_devid(fs_info->fs_devices, i);
+		if (!stripe->dev) {
+			test_err("cannot find device with devid %d", i);
+			ret = -EINVAL;
+			goto out;
+		}
+
+		stripe->physical = logical + i * SZ_1G;
+	}
+
+	ret = btrfs_insert_one_raid_extent(trans, bioc);
+	if (ret) {
+		test_err("inserting RAID extent failed: %d", ret);
+		goto out;
+	}
+
+	io_stripe.dev = btrfs_device_by_devid(fs_info->fs_devices, 0);
+	if (!io_stripe.dev) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ret = btrfs_get_raid_extent_offset(fs_info, logical, &len, map_type, 0, &io_stripe);
+	if (ret) {
+		test_err("lookup of RAID extent [%llu, %llu] failed", logical,
+			 logical + len);
+		goto out;
+	}
+
+	if (io_stripe.physical != logical) {
+		test_err("invalid physical address, expected %llu got %llu",
+			 logical, io_stripe.physical);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (len != SZ_64K) {
+		test_err("invalid stripe length, expected %llu got %llu",
+			 (u64)SZ_64K, len);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ret = btrfs_delete_raid_extent(trans, logical + SZ_48K, SZ_16K);
+	if (ret) {
+		test_err("deleting RAID extent [%llu, %llu] failed",
+			 logical + SZ_48K, logical + SZ_64K);
+		goto out;
+	}
+
+	len = SZ_48K;
+	ret = btrfs_get_raid_extent_offset(fs_info, logical, &len, map_type, 0, &io_stripe);
+	if (ret) {
+		test_err("lookup of RAID extent [%llu, %llu] failed", logical,
+			 logical + len);
+		goto out;
+	}
+
+	if (io_stripe.physical != logical) {
+		test_err("invalid physical address, expected %llu, got %llu",
+			 logical, io_stripe.physical);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (len != SZ_48K) {
+		test_err("invalid stripe length, expected %llu, got %llu",
+			 (u64)SZ_48K, len);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	len = SZ_16K;
+	ret = btrfs_get_raid_extent_offset(fs_info, logical + SZ_48K, &len,
+					   map_type, 0, &io_stripe);
+	if (ret != -ENODATA) {
+		test_err("lookup of RAID extent [%llu, %llu] succeeded should fail",
+			 logical + SZ_48K, logical + SZ_64K);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ret = btrfs_delete_raid_extent(trans, logical, len);
+	if (ret)
+		test_err("deleting RAID extent [%llu, %llu] failed", logical,
+			 logical + len);
+
+out:
+	btrfs_put_bioc(bioc);
+	return ret;
+}
+
+/*
+ * Test a 64K RST write on a 2 disk RAID1 at a logical address of 1M and then
+ * overwrite the whole range giving it new physical address at an offset of 1G.
+ * The intent of this test is to exercise the 'update_raid_extent_item()'
+ * function called be btrfs_insert_one_raid_extent().
+ */
+static int test_create_update_delete(struct btrfs_trans_handle *trans)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_io_context *bioc;
+	struct btrfs_io_stripe io_stripe = { 0 };
+	u64 map_type = RST_TEST_RAID1_TYPE;
+	u64 logical = SZ_1M;
+	u64 len = SZ_64K;
+	int ret;
+
+	bioc = alloc_btrfs_io_context(fs_info, logical, RST_TEST_NUM_DEVICES);
+	if (!bioc) {
+		test_std_err(TEST_ALLOC_IO_CONTEXT);
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	io_stripe.dev = btrfs_device_by_devid(fs_info->fs_devices, 0);
+	bioc->map_type = map_type;
+	bioc->size = len;
+
+	for (int i = 0; i < RST_TEST_NUM_DEVICES; i++) {
+		struct btrfs_io_stripe *stripe = &bioc->stripes[i];
+
+		stripe->dev = btrfs_device_by_devid(fs_info->fs_devices, i);
+		if (!stripe->dev) {
+			test_err("cannot find device with devid %d", i);
+			ret = -EINVAL;
+			goto out;
+		}
+
+		stripe->physical = logical + i * SZ_1G;
+	}
+
+	ret = btrfs_insert_one_raid_extent(trans, bioc);
+	if (ret) {
+		test_err("inserting RAID extent failed: %d", ret);
+		goto out;
+	}
+
+	io_stripe.dev = btrfs_device_by_devid(fs_info->fs_devices, 0);
+	if (!io_stripe.dev) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ret = btrfs_get_raid_extent_offset(fs_info, logical, &len, map_type, 0, &io_stripe);
+	if (ret) {
+		test_err("lookup of RAID extent [%llu, %llu] failed", logical,
+			 logical + len);
+		goto out;
+	}
+
+	if (io_stripe.physical != logical) {
+		test_err("invalid physical address, expected %llu got %llu",
+			 logical, io_stripe.physical);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (len != SZ_64K) {
+		test_err("invalid stripe length, expected %llu got %llu",
+			 (u64)SZ_64K, len);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	for (int i = 0; i < RST_TEST_NUM_DEVICES; i++) {
+		struct btrfs_io_stripe *stripe = &bioc->stripes[i];
+
+		stripe->dev = btrfs_device_by_devid(fs_info->fs_devices, i);
+		if (!stripe->dev) {
+			test_err("cannot find device with devid %d", i);
+			ret = -EINVAL;
+			goto out;
+		}
+
+		stripe->physical = SZ_1G + logical + i * SZ_1G;
+	}
+
+	ret = btrfs_insert_one_raid_extent(trans, bioc);
+	if (ret) {
+		test_err("updating RAID extent failed: %d", ret);
+		goto out;
+	}
+
+	ret = btrfs_get_raid_extent_offset(fs_info, logical, &len, map_type, 0, &io_stripe);
+	if (ret) {
+		test_err("lookup of RAID extent [%llu, %llu] failed", logical,
+			 logical + len);
+		goto out;
+	}
+
+	if (io_stripe.physical != logical + SZ_1G) {
+		test_err("invalid physical address, expected %llu, got %llu",
+			 logical + SZ_1G, io_stripe.physical);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (len != SZ_64K) {
+		test_err("invalid stripe length, expected %llu, got %llu",
+			 (u64)SZ_64K, len);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ret = btrfs_delete_raid_extent(trans, logical, len);
+	if (ret)
+		test_err("deleting RAID extent [%llu, %llu] failed", logical,
+			 logical + len);
+
+out:
+	btrfs_put_bioc(bioc);
+	return ret;
+}
+
+/*
+ * Test a simple 64K RST write on a 2 disk RAID1 at a logical address of 1M.
+ * The "physical" copy on device 0 is at 1M, on device 1 it is at 1G+1M.
+ */
+static int test_simple_create_delete(struct btrfs_trans_handle *trans)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_io_context *bioc;
+	struct btrfs_io_stripe io_stripe = { 0 };
+	u64 map_type = RST_TEST_RAID1_TYPE;
+	u64 logical = SZ_1M;
+	u64 len = SZ_64K;
+	int ret;
+
+	bioc = alloc_btrfs_io_context(fs_info, logical, RST_TEST_NUM_DEVICES);
+	if (!bioc) {
+		test_std_err(TEST_ALLOC_IO_CONTEXT);
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	bioc->map_type = map_type;
+	bioc->size = SZ_64K;
+
+	for (int i = 0; i < RST_TEST_NUM_DEVICES; i++) {
+		struct btrfs_io_stripe *stripe = &bioc->stripes[i];
+
+		stripe->dev = btrfs_device_by_devid(fs_info->fs_devices, i);
+		if (!stripe->dev) {
+			test_err("cannot find device with devid %d", i);
+			ret = -EINVAL;
+			goto out;
+		}
+
+		stripe->physical = logical + i * SZ_1G;
+	}
+
+	ret = btrfs_insert_one_raid_extent(trans, bioc);
+	if (ret) {
+		test_err("inserting RAID extent failed: %d", ret);
+		goto out;
+	}
+
+	io_stripe.dev = btrfs_device_by_devid(fs_info->fs_devices, 0);
+	if (!io_stripe.dev) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ret = btrfs_get_raid_extent_offset(fs_info, logical, &len, map_type, 0, &io_stripe);
+	if (ret)  {
+		test_err("lookup of RAID extent [%llu, %llu] failed", logical,
+			 logical + len);
+		goto out;
+	}
+
+	if (io_stripe.physical != logical) {
+		test_err("invalid physical address, expected %llu got %llu",
+			 logical, io_stripe.physical);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (len != SZ_64K) {
+		test_err("invalid stripe length, expected %llu got %llu",
+			 (u64)SZ_64K, len);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ret = btrfs_delete_raid_extent(trans, logical, len);
+	if (ret)
+		test_err("deleting RAID extent [%llu, %llu] failed", logical,
+			 logical + len);
+
+out:
+	btrfs_put_bioc(bioc);
+	return ret;
+}
+
+static const test_func_t tests[] = {
+	test_simple_create_delete,
+	test_create_update_delete,
+	test_tail_delete,
+	test_front_delete,
+	test_front_delete_prev_item,
+	test_punch_hole,
+	test_punch_hole_3extents,
+	test_delete_two_extents,
+};
+
+static int run_test(test_func_t test, u32 sectorsize, u32 nodesize)
+{
+	struct btrfs_trans_handle trans;
+	struct btrfs_fs_info *fs_info;
+	struct btrfs_root *root = NULL;
+	int ret;
+
+	fs_info = btrfs_alloc_dummy_fs_info(sectorsize, nodesize);
+	if (!fs_info) {
+		test_std_err(TEST_ALLOC_FS_INFO);
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	root = btrfs_alloc_dummy_root(fs_info);
+	if (IS_ERR(root)) {
+		test_std_err(TEST_ALLOC_ROOT);
+		ret = PTR_ERR(root);
+		goto out;
+	}
+	btrfs_set_super_incompat_flags(root->fs_info->super_copy,
+				       BTRFS_FEATURE_INCOMPAT_RAID_STRIPE_TREE);
+	root->root_key.objectid = BTRFS_RAID_STRIPE_TREE_OBJECTID;
+	root->root_key.type = BTRFS_ROOT_ITEM_KEY;
+	root->root_key.offset = 0;
+	fs_info->stripe_root = root;
+	root->fs_info->tree_root = root;
+
+	root->node = alloc_test_extent_buffer(root->fs_info, nodesize);
+	if (IS_ERR(root->node)) {
+		test_std_err(TEST_ALLOC_EXTENT_BUFFER);
+		ret = PTR_ERR(root->node);
+		goto out;
+	}
+	btrfs_set_header_level(root->node, 0);
+	btrfs_set_header_nritems(root->node, 0);
+	root->alloc_bytenr += 2 * nodesize;
+
+	for (int i = 0; i < RST_TEST_NUM_DEVICES; i++) {
+		struct btrfs_device *dev;
+
+		dev = btrfs_alloc_dummy_device(fs_info);
+		if (IS_ERR(dev)) {
+			test_err("cannot allocate device");
+			ret = PTR_ERR(dev);
+			goto out;
+		}
+		dev->devid = i;
+	}
+
+	btrfs_init_dummy_trans(&trans, root->fs_info);
+	ret = test(&trans);
+	if (ret)
+		goto out;
+
+out:
+	btrfs_free_dummy_root(root);
+	btrfs_free_dummy_fs_info(fs_info);
+
+	return ret;
+}
+
+int btrfs_test_raid_stripe_tree(u32 sectorsize, u32 nodesize)
+{
+	int ret = 0;
+
+	test_msg("running raid-stripe-tree tests");
+	for (int i = 0; i < ARRAY_SIZE(tests); i++) {
+		ret = run_test(tests[i], sectorsize, nodesize);
+		if (ret) {
+			test_err("test-case %ps failed with %d\n", tests[i], ret);
+			goto out;
+		}
+	}
+
+out:
+	return ret;
+}
diff --git a/fs/btrfs/tests/zoned-tests.c b/fs/btrfs/tests/zoned-tests.c
new file mode 100644
index 000000000..2bc3b14ba
--- /dev/null
+++ b/fs/btrfs/tests/zoned-tests.c
@@ -0,0 +1,675 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2026 Western Digital.  All rights reserved.
+ */
+
+#include <linux/cleanup.h>
+#include <linux/sizes.h>
+
+#include "btrfs-tests.h"
+#include "../space-info.h"
+#include "../volumes.h"
+#include "../zoned.h"
+
+#define WP_MISSING_DEV				((u64)-1)
+#define WP_CONVENTIONAL				((u64)-2)
+#define ZONE_SIZE				SZ_256M
+
+#define HALF_STRIPE_LEN				(BTRFS_STRIPE_LEN >> 1)
+
+struct load_zone_info_test_vector {
+	u64 raid_type;
+	u64 num_stripes;
+	u64 alloc_offsets[8];
+	u64 last_alloc;
+	u64 bg_length;
+	bool degraded;
+
+	int expected_result;
+	u64 expected_alloc_offset;
+
+	const char *description;
+};
+
+struct zone_info {
+	u64 physical;
+	u64 capacity;
+	u64 alloc_offset;
+};
+
+static int test_load_zone_info(struct btrfs_fs_info *fs_info,
+			       const struct load_zone_info_test_vector *test)
+{
+	struct btrfs_block_group *bg __free(btrfs_free_dummy_block_group) = NULL;
+	struct btrfs_chunk_map *map __free(btrfs_free_chunk_map) = NULL;
+	struct zone_info AUTO_KFREE(zone_info);
+	unsigned long AUTO_KFREE(active);
+	int ret;
+
+	bg = btrfs_alloc_dummy_block_group(fs_info, test->bg_length);
+	if (!bg) {
+		test_std_err(TEST_ALLOC_BLOCK_GROUP);
+		return -ENOMEM;
+	}
+
+	map = btrfs_alloc_chunk_map(test->num_stripes, GFP_KERNEL);
+	if (!map) {
+		test_std_err(TEST_ALLOC_EXTENT_MAP);
+		return -ENOMEM;
+	}
+
+	zone_info = kzalloc_objs(*zone_info, test->num_stripes, GFP_KERNEL);
+	if (!zone_info) {
+		test_err("cannot allocate zone info");
+		return -ENOMEM;
+	}
+
+	active = bitmap_zalloc(test->num_stripes, GFP_KERNEL);
+	if (!zone_info) {
+		test_err("cannot allocate active bitmap");
+		return -ENOMEM;
+	}
+
+	map->type = test->raid_type;
+	map->num_stripes = test->num_stripes;
+	if (test->raid_type == BTRFS_BLOCK_GROUP_RAID10)
+		map->sub_stripes = 2;
+	for (int i = 0; i < test->num_stripes; i++) {
+		zone_info[i].physical = 0;
+		zone_info[i].alloc_offset = test->alloc_offsets[i];
+		zone_info[i].capacity = ZONE_SIZE;
+		if (zone_info[i].alloc_offset && zone_info[i].alloc_offset < ZONE_SIZE)
+			__set_bit(i, active);
+	}
+	if (test->degraded)
+		btrfs_set_opt(fs_info->mount_opt, DEGRADED);
+	else
+		btrfs_clear_opt(fs_info->mount_opt, DEGRADED);
+
+	ret = btrfs_load_block_group_by_raid_type(bg, map, zone_info, active,
+						  test->last_alloc);
+
+	if (ret != test->expected_result) {
+		test_err("unexpected return value: ret %d expected %d", ret,
+			 test->expected_result);
+		return -EINVAL;
+	}
+
+	if (!ret && bg->alloc_offset != test->expected_alloc_offset) {
+		test_err("unexpected alloc_offset: alloc_offset %llu expected %llu",
+			 bg->alloc_offset, test->expected_alloc_offset);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static const struct load_zone_info_test_vector load_zone_info_tests[] = {
+	/* SINGLE */
+	{
+		.description = "SINGLE: load write pointer from sequential zone",
+		.raid_type = 0,
+		.num_stripes = 1,
+		.alloc_offsets = {
+			SZ_1M,
+		},
+		.expected_alloc_offset = SZ_1M,
+	},
+	/*
+	 * SINGLE block group on a conventional zone sets last_alloc outside of
+	 * btrfs_load_block_group_*(). Do not test that case.
+	 */
+
+	/* DUP */
+	/* Normal case */
+	{
+		.description = "DUP: having matching write pointers",
+		.raid_type = BTRFS_BLOCK_GROUP_DUP,
+		.num_stripes = 2,
+		.alloc_offsets = {
+			SZ_1M, SZ_1M,
+		},
+		.expected_alloc_offset = SZ_1M,
+	},
+	/*
+	 * One sequential zone and one conventional zone, having matching
+	 * last_alloc.
+	 */
+	{
+		.description = "DUP: seq zone and conv zone, matching last_alloc",
+		.raid_type = BTRFS_BLOCK_GROUP_DUP,
+		.num_stripes = 2,
+		.alloc_offsets = {
+			SZ_1M, WP_CONVENTIONAL,
+		},
+		.last_alloc = SZ_1M,
+		.expected_alloc_offset = SZ_1M,
+	},
+	/*
+	 * One sequential and one conventional zone, but having smaller
+	 * last_alloc than write pointer.
+	 */
+	{
+		.description = "DUP: seq zone and conv zone, smaller last_alloc",
+		.raid_type = BTRFS_BLOCK_GROUP_DUP,
+		.num_stripes = 2,
+		.alloc_offsets = {
+			SZ_1M, WP_CONVENTIONAL,
+		},
+		.last_alloc = 0,
+		.expected_alloc_offset = SZ_1M,
+	},
+	/* Error case: having different write pointers. */
+	{
+		.description = "DUP: fail: different write pointers",
+		.raid_type = BTRFS_BLOCK_GROUP_DUP,
+		.num_stripes = 2,
+		.alloc_offsets = {
+			SZ_1M, SZ_2M,
+		},
+		.expected_result = -EIO,
+	},
+	/* Error case: partial missing device should not happen on DUP. */
+	{
+		.description = "DUP: fail: missing device",
+		.raid_type = BTRFS_BLOCK_GROUP_DUP,
+		.num_stripes = 2,
+		.alloc_offsets = {
+			SZ_1M, WP_MISSING_DEV,
+		},
+		.expected_result = -EIO,
+	},
+	/*
+	 * Error case: one sequential and one conventional zone, but having larger
+	 * last_alloc than write pointer.
+	 */
+	{
+		.description = "DUP: fail: seq zone and conv zone, larger last_alloc",
+		.raid_type = BTRFS_BLOCK_GROUP_DUP,
+		.num_stripes = 2,
+		.alloc_offsets = {
+			SZ_1M, WP_CONVENTIONAL,
+		},
+		.last_alloc = SZ_2M,
+		.expected_result = -EIO,
+	},
+
+	/* RAID1 */
+	/* Normal case */
+	{
+		.description = "RAID1: having matching write pointers",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID1,
+		.num_stripes = 2,
+		.alloc_offsets = {
+			SZ_1M, SZ_1M,
+		},
+		.expected_alloc_offset = SZ_1M,
+	},
+	/*
+	 * One sequential zone and one conventional zone, having matching
+	 * last_alloc.
+	 */
+	{
+		.description = "RAID1: seq zone and conv zone, matching last_alloc",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID1,
+		.num_stripes = 2,
+		.alloc_offsets = {
+			SZ_1M, WP_CONVENTIONAL,
+		},
+		.last_alloc = SZ_1M,
+		.expected_alloc_offset = SZ_1M,
+	},
+	/*
+	 * One sequential and one conventional zone, but having smaller
+	 * last_alloc than write pointer.
+	 */
+	{
+		.description = "RAID1: seq zone and conv zone, smaller last_alloc",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID1,
+		.num_stripes = 2,
+		.alloc_offsets = {
+			SZ_1M, WP_CONVENTIONAL,
+		},
+		.last_alloc = 0,
+		.expected_alloc_offset = SZ_1M,
+	},
+	/* Partial missing device should be recovered on DEGRADED mount */
+	{
+		.description = "RAID1: fail: missing device on DEGRADED",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID1,
+		.num_stripes = 2,
+		.alloc_offsets = {
+			SZ_1M, WP_MISSING_DEV,
+		},
+		.degraded = true,
+		.expected_alloc_offset = SZ_1M,
+	},
+	/* Error case: having different write pointers. */
+	{
+		.description = "RAID1: fail: different write pointers",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID1,
+		.num_stripes = 2,
+		.alloc_offsets = {
+			SZ_1M, SZ_2M,
+		},
+		.expected_result = -EIO,
+	},
+	/*
+	 * Partial missing device is not allowed on non-DEGRADED mount never happen
+	 * as it is rejected beforehand.
+	 */
+	/*
+	 * Error case: one sequential and one conventional zone, but having larger
+	 * last_alloc than write pointer.
+	 */
+	{
+		.description = "RAID1: fail: seq zone and conv zone, larger last_alloc",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID1,
+		.num_stripes = 2,
+		.alloc_offsets = {
+			SZ_1M, WP_CONVENTIONAL,
+		},
+		.last_alloc = SZ_2M,
+		.expected_result = -EIO,
+	},
+
+	/* RAID0 */
+	/* Normal case */
+	{
+		.description = "RAID0: initial partial write",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID0,
+		.num_stripes = 4,
+		.alloc_offsets = {
+			HALF_STRIPE_LEN, 0, 0, 0,
+		},
+		.expected_alloc_offset = HALF_STRIPE_LEN,
+	},
+	{
+		.description = "RAID0: while in second stripe",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID0,
+		.num_stripes = 4,
+		.alloc_offsets = {
+			BTRFS_STRIPE_LEN * 2, BTRFS_STRIPE_LEN + HALF_STRIPE_LEN,
+			BTRFS_STRIPE_LEN, BTRFS_STRIPE_LEN,
+		},
+		.expected_alloc_offset = BTRFS_STRIPE_LEN * 5 + HALF_STRIPE_LEN,
+	},
+	{
+		.description = "RAID0: one stripe advanced",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID0,
+		.num_stripes = 2,
+		.alloc_offsets = {
+			SZ_1M + BTRFS_STRIPE_LEN, SZ_1M,
+		},
+		.expected_alloc_offset = SZ_2M + BTRFS_STRIPE_LEN,
+	},
+	/* Error case: having different write pointers. */
+	{
+		.description = "RAID0: fail: disordered stripes",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID0,
+		.num_stripes = 4,
+		.alloc_offsets = {
+			BTRFS_STRIPE_LEN, BTRFS_STRIPE_LEN * 2,
+			BTRFS_STRIPE_LEN, BTRFS_STRIPE_LEN,
+		},
+		.expected_result = -EIO,
+	},
+	{
+		.description = "RAID0: fail: far distance",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID0,
+		.num_stripes = 4,
+		.alloc_offsets = {
+			BTRFS_STRIPE_LEN * 3, BTRFS_STRIPE_LEN,
+			BTRFS_STRIPE_LEN, BTRFS_STRIPE_LEN,
+		},
+		.expected_result = -EIO,
+	},
+	{
+		.description = "RAID0: fail: too many partial write",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID0,
+		.num_stripes = 4,
+		.alloc_offsets = {
+			HALF_STRIPE_LEN, HALF_STRIPE_LEN, 0, 0,
+		},
+		.expected_result = -EIO,
+	},
+	/*
+	 * Error case: Partial missing device is not allowed even on non-DEGRADED
+	 * mount.
+	 */
+	{
+		.description = "RAID0: fail: missing device on DEGRADED",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID0,
+		.num_stripes = 2,
+		.alloc_offsets = {
+			SZ_1M, WP_MISSING_DEV,
+		},
+		.degraded = true,
+		.expected_result = -EIO,
+	},
+
+	/*
+	 * One sequential zone and one conventional zone, having matching
+	 * last_alloc.
+	 */
+	{
+		.description = "RAID0: seq zone and conv zone, partially written stripe",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID0,
+		.num_stripes = 2,
+		.alloc_offsets = {
+			SZ_1M, WP_CONVENTIONAL,
+		},
+		.last_alloc = SZ_2M - SZ_4K,
+		.expected_alloc_offset = SZ_2M - SZ_4K,
+	},
+	{
+		.description = "RAID0: conv zone and seq zone, partially written stripe",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID0,
+		.num_stripes = 2,
+		.alloc_offsets = {
+			WP_CONVENTIONAL, SZ_1M,
+		},
+		.last_alloc = SZ_2M + SZ_4K,
+		.expected_alloc_offset = SZ_2M + SZ_4K,
+	},
+	/*
+	 * Error case: one sequential and one conventional zone, but having larger
+	 * last_alloc than write pointer.
+	 */
+	{
+		.description = "RAID0: fail: seq zone and conv zone, larger last_alloc",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID0,
+		.num_stripes = 2,
+		.alloc_offsets = {
+			SZ_1M, WP_CONVENTIONAL,
+		},
+		.last_alloc = SZ_2M + BTRFS_STRIPE_LEN * 2,
+		.expected_result = -EIO,
+	},
+
+	/* RAID0, 4 stripes with seq zones and conv zones. */
+	{
+		.description = "RAID0: stripes [2, 2, ?, ?] last_alloc = 6",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID0,
+		.num_stripes = 4,
+		.alloc_offsets = {
+			BTRFS_STRIPE_LEN * 2, BTRFS_STRIPE_LEN * 2,
+			WP_CONVENTIONAL, WP_CONVENTIONAL,
+		},
+		.last_alloc = BTRFS_STRIPE_LEN * 6,
+		.expected_alloc_offset = BTRFS_STRIPE_LEN * 6,
+	},
+	{
+		.description = "RAID0: stripes [2, 2, ?, ?] last_alloc = 7.5",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID0,
+		.num_stripes = 4,
+		.alloc_offsets = {
+			BTRFS_STRIPE_LEN * 2, BTRFS_STRIPE_LEN * 2,
+			WP_CONVENTIONAL, WP_CONVENTIONAL,
+		},
+		.last_alloc = BTRFS_STRIPE_LEN * 7 + HALF_STRIPE_LEN,
+		.expected_alloc_offset = BTRFS_STRIPE_LEN * 7 + HALF_STRIPE_LEN,
+	},
+	{
+		.description = "RAID0: stripes [3, ?, ?, ?] last_alloc = 1",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID0,
+		.num_stripes = 4,
+		.alloc_offsets = {
+			BTRFS_STRIPE_LEN * 3, WP_CONVENTIONAL,
+			WP_CONVENTIONAL, WP_CONVENTIONAL,
+		},
+		.last_alloc = BTRFS_STRIPE_LEN,
+		.expected_alloc_offset = BTRFS_STRIPE_LEN * 9,
+	},
+	{
+		.description = "RAID0: stripes [2, ?, 1, ?] last_alloc = 5",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID0,
+		.num_stripes = 4,
+		.alloc_offsets = {
+			BTRFS_STRIPE_LEN * 2, WP_CONVENTIONAL,
+			BTRFS_STRIPE_LEN, WP_CONVENTIONAL,
+		},
+		.last_alloc = BTRFS_STRIPE_LEN * 5,
+		.expected_alloc_offset = BTRFS_STRIPE_LEN * 5,
+	},
+	{
+		.description = "RAID0: fail: stripes [2, ?, 1, ?] last_alloc = 7",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID0,
+		.num_stripes = 4,
+		.alloc_offsets = {
+			BTRFS_STRIPE_LEN * 2, WP_CONVENTIONAL,
+			BTRFS_STRIPE_LEN, WP_CONVENTIONAL,
+		},
+		.last_alloc = BTRFS_STRIPE_LEN * 7,
+		.expected_result = -EIO,
+	},
+
+	/* RAID10 */
+	/* Normal case */
+	{
+		.description = "RAID10: initial partial write",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID10,
+		.num_stripes = 4,
+		.alloc_offsets = {
+			HALF_STRIPE_LEN, HALF_STRIPE_LEN, 0, 0,
+		},
+		.expected_alloc_offset = HALF_STRIPE_LEN,
+	},
+	{
+		.description = "RAID10: while in second stripe",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID10,
+		.num_stripes = 8,
+		.alloc_offsets = {
+			BTRFS_STRIPE_LEN * 2, BTRFS_STRIPE_LEN * 2,
+			BTRFS_STRIPE_LEN + HALF_STRIPE_LEN,
+			BTRFS_STRIPE_LEN + HALF_STRIPE_LEN,
+			BTRFS_STRIPE_LEN, BTRFS_STRIPE_LEN,
+			BTRFS_STRIPE_LEN, BTRFS_STRIPE_LEN,
+		},
+		.expected_alloc_offset = BTRFS_STRIPE_LEN * 5 + HALF_STRIPE_LEN,
+	},
+	{
+		.description = "RAID10: one stripe advanced",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID10,
+		.num_stripes = 4,
+		.alloc_offsets = {
+			SZ_1M + BTRFS_STRIPE_LEN, SZ_1M + BTRFS_STRIPE_LEN,
+			SZ_1M, SZ_1M,
+		},
+		.expected_alloc_offset = SZ_2M + BTRFS_STRIPE_LEN,
+	},
+	{
+		.description = "RAID10: one stripe advanced, with conventional zone",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID10,
+		.num_stripes = 4,
+		.alloc_offsets = {
+			SZ_1M + BTRFS_STRIPE_LEN, WP_CONVENTIONAL,
+			WP_CONVENTIONAL, SZ_1M,
+		},
+		.expected_alloc_offset = SZ_2M + BTRFS_STRIPE_LEN,
+	},
+	/* Error case: having different write pointers. */
+	{
+		.description = "RAID10: fail: disordered stripes",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID10,
+		.num_stripes = 8,
+		.alloc_offsets = {
+			BTRFS_STRIPE_LEN, BTRFS_STRIPE_LEN,
+			BTRFS_STRIPE_LEN * 2, BTRFS_STRIPE_LEN * 2,
+			BTRFS_STRIPE_LEN, BTRFS_STRIPE_LEN,
+			BTRFS_STRIPE_LEN, BTRFS_STRIPE_LEN,
+		},
+		.expected_result = -EIO,
+	},
+	{
+		.description = "RAID10: fail: far distance",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID10,
+		.num_stripes = 8,
+		.alloc_offsets = {
+			BTRFS_STRIPE_LEN * 3, BTRFS_STRIPE_LEN * 3,
+			BTRFS_STRIPE_LEN, BTRFS_STRIPE_LEN,
+			BTRFS_STRIPE_LEN, BTRFS_STRIPE_LEN,
+			BTRFS_STRIPE_LEN, BTRFS_STRIPE_LEN,
+		},
+		.expected_result = -EIO,
+	},
+	{
+		.description = "RAID10: fail: too many partial write",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID10,
+		.num_stripes = 8,
+		.alloc_offsets = {
+			HALF_STRIPE_LEN, HALF_STRIPE_LEN,
+			HALF_STRIPE_LEN, HALF_STRIPE_LEN,
+			0, 0, 0, 0,
+		},
+		.expected_result = -EIO,
+	},
+	/*
+	 * Error case: Partial missing device in RAID0 level is not allowed even on
+	 * non-DEGRADED mount.
+	 */
+	{
+		.description = "RAID10: fail: missing device on DEGRADED",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID10,
+		.num_stripes = 4,
+		.alloc_offsets = {
+			SZ_1M, SZ_1M,
+			WP_MISSING_DEV, WP_MISSING_DEV,
+		},
+		.degraded = true,
+		.expected_result = -EIO,
+	},
+
+	/*
+	 * One sequential zone and one conventional zone, having matching
+	 * last_alloc.
+	 */
+	{
+		.description = "RAID10: seq zone and conv zone, partially written stripe",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID10,
+		.num_stripes = 4,
+		.alloc_offsets = {
+			SZ_1M, SZ_1M,
+			WP_CONVENTIONAL, WP_CONVENTIONAL,
+		},
+		.last_alloc = SZ_2M - SZ_4K,
+		.expected_alloc_offset = SZ_2M - SZ_4K,
+	},
+	{
+		.description = "RAID10: conv zone and seq zone, partially written stripe",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID10,
+		.num_stripes = 4,
+		.alloc_offsets = {
+			WP_CONVENTIONAL, WP_CONVENTIONAL,
+			SZ_1M, SZ_1M,
+		},
+		.last_alloc = SZ_2M + SZ_4K,
+		.expected_alloc_offset = SZ_2M + SZ_4K,
+	},
+	/*
+	 * Error case: one sequential and one conventional zone, but having larger
+	 * last_alloc than write pointer.
+	 */
+	{
+		.description = "RAID10: fail: seq zone and conv zone, larger last_alloc",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID10,
+		.num_stripes = 4,
+		.alloc_offsets = {
+			SZ_1M, SZ_1M,
+			WP_CONVENTIONAL, WP_CONVENTIONAL,
+		},
+		.last_alloc = SZ_2M + BTRFS_STRIPE_LEN * 2,
+		.expected_result = -EIO,
+	},
+
+	/* RAID10, 4 stripes with seq zones and conv zones. */
+	{
+		.description = "RAID10: stripes [2, 2, ?, ?] last_alloc = 6",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID10,
+		.num_stripes = 8,
+		.alloc_offsets = {
+			BTRFS_STRIPE_LEN * 2, BTRFS_STRIPE_LEN * 2,
+			BTRFS_STRIPE_LEN * 2, BTRFS_STRIPE_LEN * 2,
+			WP_CONVENTIONAL, WP_CONVENTIONAL,
+			WP_CONVENTIONAL, WP_CONVENTIONAL,
+		},
+		.last_alloc = BTRFS_STRIPE_LEN * 6,
+		.expected_alloc_offset = BTRFS_STRIPE_LEN * 6,
+	},
+	{
+		.description = "RAID10: stripes [2, 2, ?, ?] last_alloc = 7.5",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID10,
+		.num_stripes = 8,
+		.alloc_offsets = {
+			BTRFS_STRIPE_LEN * 2, BTRFS_STRIPE_LEN * 2,
+			BTRFS_STRIPE_LEN * 2, BTRFS_STRIPE_LEN * 2,
+			WP_CONVENTIONAL, WP_CONVENTIONAL,
+			WP_CONVENTIONAL, WP_CONVENTIONAL,
+		},
+		.last_alloc = BTRFS_STRIPE_LEN * 7 + HALF_STRIPE_LEN,
+		.expected_alloc_offset = BTRFS_STRIPE_LEN * 7 + HALF_STRIPE_LEN,
+	},
+	{
+		.description = "RAID10: stripes [3, ?, ?, ?] last_alloc = 1",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID10,
+		.num_stripes = 8,
+		.alloc_offsets = {
+			BTRFS_STRIPE_LEN * 3, BTRFS_STRIPE_LEN * 3,
+			WP_CONVENTIONAL, WP_CONVENTIONAL,
+			WP_CONVENTIONAL, WP_CONVENTIONAL,
+			WP_CONVENTIONAL, WP_CONVENTIONAL,
+		},
+		.last_alloc = BTRFS_STRIPE_LEN,
+		.expected_alloc_offset = BTRFS_STRIPE_LEN * 9,
+	},
+	{
+		.description = "RAID10: stripes [2, ?, 1, ?] last_alloc = 5",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID10,
+		.num_stripes = 8,
+		.alloc_offsets = {
+			BTRFS_STRIPE_LEN * 2, BTRFS_STRIPE_LEN * 2,
+			WP_CONVENTIONAL, WP_CONVENTIONAL,
+			BTRFS_STRIPE_LEN, BTRFS_STRIPE_LEN,
+			WP_CONVENTIONAL, WP_CONVENTIONAL,
+		},
+		.last_alloc = BTRFS_STRIPE_LEN * 5,
+		.expected_alloc_offset = BTRFS_STRIPE_LEN * 5,
+	},
+	{
+		.description = "RAID10: fail: stripes [2, ?, 1, ?] last_alloc = 7",
+		.raid_type = BTRFS_BLOCK_GROUP_RAID10,
+		.num_stripes = 8,
+		.alloc_offsets = {
+			BTRFS_STRIPE_LEN * 2, BTRFS_STRIPE_LEN * 2,
+			WP_CONVENTIONAL, WP_CONVENTIONAL,
+			BTRFS_STRIPE_LEN, BTRFS_STRIPE_LEN,
+			WP_CONVENTIONAL, WP_CONVENTIONAL,
+		},
+		.last_alloc = BTRFS_STRIPE_LEN * 7,
+		.expected_result = -EIO,
+	},
+};
+
+int btrfs_test_zoned(void)
+{
+	struct btrfs_fs_info *fs_info __free(btrfs_free_dummy_fs_info) = NULL;
+	int ret;
+
+	test_msg("running zoned tests (error messages are expected)");
+
+	fs_info = btrfs_alloc_dummy_fs_info(PAGE_SIZE, PAGE_SIZE);
+	if (!fs_info) {
+		test_std_err(TEST_ALLOC_FS_INFO);
+		return -ENOMEM;
+	}
+
+	for (int i = 0; i < ARRAY_SIZE(load_zone_info_tests); i++) {
+		ret = test_load_zone_info(fs_info, &load_zone_info_tests[i]);
+		if (ret) {
+			test_err("test case \"%s\" failed", load_zone_info_tests[i].description);
+			return ret;
+		}
+	}
+
+	return 0;
+}