treewide: refresh kmalloc_obj() conversionsgrafted

This is another run of the Coccinelle script for converting kmalloc()
family of allocations to kmalloc_obj() via the existing rules in
scripts/coccinelle/api/kmalloc_objs.cocci

This catches both the set of kmalloc() uses added since the first
kmalloc_obj() conversions in v7.0 and adds a large group missed in the
first pass due to Coccinelle not interacting well with the cleanup.h
scoped_...() family of macros[1]. I worked around this with spatch's
"--macro-file" argument to a file with all the scoped_...() macros mapped
to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control
flow indicator I could find.

Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc,
riscv, and s390 with no new warnings.

Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1]
Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2]
Signed-off-by: Kees Cook <kees+treewide@kernel.org>

1 files changed, 1371 insertions, 0 deletions

diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
new file mode 100644
index 000000000..b32d4eabe
--- /dev/null
+++ b/fs/btrfs/ordered-data.c
@@ -0,0 +1,1371 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2007 Oracle.  All rights reserved.
+ */
+
+#include <linux/slab.h>
+#include <linux/blkdev.h>
+#include <linux/writeback.h>
+#include <linux/sched/mm.h>
+#include "messages.h"
+#include "misc.h"
+#include "ctree.h"
+#include "transaction.h"
+#include "btrfs_inode.h"
+#include "extent_io.h"
+#include "disk-io.h"
+#include "compression.h"
+#include "delalloc-space.h"
+#include "qgroup.h"
+#include "subpage.h"
+#include "file.h"
+#include "block-group.h"
+
+static struct kmem_cache *btrfs_ordered_extent_cache;
+
+static u64 entry_end(struct btrfs_ordered_extent *entry)
+{
+	if (entry->file_offset + entry->num_bytes < entry->file_offset)
+		return (u64)-1;
+	return entry->file_offset + entry->num_bytes;
+}
+
+/* returns NULL if the insertion worked, or it returns the node it did find
+ * in the tree
+ */
+static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset,
+				   struct rb_node *node)
+{
+	struct rb_node **p = &root->rb_node;
+	struct rb_node *parent = NULL;
+	struct btrfs_ordered_extent *entry;
+
+	while (*p) {
+		parent = *p;
+		entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node);
+
+		if (file_offset < entry->file_offset)
+			p = &(*p)->rb_left;
+		else if (file_offset >= entry_end(entry))
+			p = &(*p)->rb_right;
+		else
+			return parent;
+	}
+
+	rb_link_node(node, parent, p);
+	rb_insert_color(node, root);
+	return NULL;
+}
+
+/*
+ * look for a given offset in the tree, and if it can't be found return the
+ * first lesser offset
+ */
+static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset,
+				     struct rb_node **prev_ret)
+{
+	struct rb_node *n = root->rb_node;
+	struct rb_node *prev = NULL;
+	struct rb_node *test;
+	struct btrfs_ordered_extent *entry;
+	struct btrfs_ordered_extent *prev_entry = NULL;
+
+	while (n) {
+		entry = rb_entry(n, struct btrfs_ordered_extent, rb_node);
+		prev = n;
+		prev_entry = entry;
+
+		if (file_offset < entry->file_offset)
+			n = n->rb_left;
+		else if (file_offset >= entry_end(entry))
+			n = n->rb_right;
+		else
+			return n;
+	}
+	if (!prev_ret)
+		return NULL;
+
+	while (prev && file_offset >= entry_end(prev_entry)) {
+		test = rb_next(prev);
+		if (!test)
+			break;
+		prev_entry = rb_entry(test, struct btrfs_ordered_extent,
+				      rb_node);
+		if (file_offset < entry_end(prev_entry))
+			break;
+
+		prev = test;
+	}
+	if (prev)
+		prev_entry = rb_entry(prev, struct btrfs_ordered_extent,
+				      rb_node);
+	while (prev && file_offset < entry_end(prev_entry)) {
+		test = rb_prev(prev);
+		if (!test)
+			break;
+		prev_entry = rb_entry(test, struct btrfs_ordered_extent,
+				      rb_node);
+		prev = test;
+	}
+	*prev_ret = prev;
+	return NULL;
+}
+
+static int btrfs_range_overlaps(struct btrfs_ordered_extent *entry, u64 file_offset,
+				u64 len)
+{
+	if (file_offset + len <= entry->file_offset ||
+	    entry->file_offset + entry->num_bytes <= file_offset)
+		return 0;
+	return 1;
+}
+
+/*
+ * look find the first ordered struct that has this offset, otherwise
+ * the first one less than this offset
+ */
+static inline struct rb_node *ordered_tree_search(struct btrfs_inode *inode,
+						  u64 file_offset)
+{
+	struct rb_node *prev = NULL;
+	struct rb_node *ret;
+	struct btrfs_ordered_extent *entry;
+
+	if (inode->ordered_tree_last) {
+		entry = rb_entry(inode->ordered_tree_last, struct btrfs_ordered_extent,
+				 rb_node);
+		if (in_range(file_offset, entry->file_offset, entry->num_bytes))
+			return inode->ordered_tree_last;
+	}
+	ret = __tree_search(&inode->ordered_tree, file_offset, &prev);
+	if (!ret)
+		ret = prev;
+	if (ret)
+		inode->ordered_tree_last = ret;
+	return ret;
+}
+
+static struct btrfs_ordered_extent *alloc_ordered_extent(
+			struct btrfs_inode *inode, u64 file_offset, u64 num_bytes,
+			u64 ram_bytes, u64 disk_bytenr, u64 disk_num_bytes,
+			u64 offset, unsigned long flags, int compress_type)
+{
+	struct btrfs_ordered_extent *entry;
+	int ret;
+	u64 qgroup_rsv = 0;
+	const bool is_nocow = (flags &
+	       ((1U << BTRFS_ORDERED_NOCOW) | (1U << BTRFS_ORDERED_PREALLOC)));
+
+	/* Only one type flag can be set. */
+	ASSERT(has_single_bit_set(flags & BTRFS_ORDERED_EXCLUSIVE_FLAGS),
+	       "flags=0x%lx", flags);
+
+	/* DIRECT cannot be set with COMPRESSED nor ENCODED. */
+	if (test_bit(BTRFS_ORDERED_DIRECT, &flags)) {
+		ASSERT(!test_bit(BTRFS_ORDERED_COMPRESSED, &flags));
+		ASSERT(!test_bit(BTRFS_ORDERED_ENCODED, &flags));
+	}
+
+	/* ENCODED must be set with COMPRESSED. */
+	if (test_bit(BTRFS_ORDERED_ENCODED, &flags))
+		ASSERT(test_bit(BTRFS_ORDERED_COMPRESSED, &flags));
+
+	/*
+	 * For a NOCOW write we can free the qgroup reserve right now. For a COW
+	 * one we transfer the reserved space from the inode's iotree into the
+	 * ordered extent by calling btrfs_qgroup_release_data() and tracking
+	 * the qgroup reserved amount in the ordered extent, so that later after
+	 * completing the ordered extent, when running the data delayed ref it
+	 * creates, we free the reserved data with btrfs_qgroup_free_refroot().
+	 */
+	if (is_nocow)
+		ret = btrfs_qgroup_free_data(inode, NULL, file_offset, num_bytes, &qgroup_rsv);
+	else
+		ret = btrfs_qgroup_release_data(inode, file_offset, num_bytes, &qgroup_rsv);
+
+	if (ret < 0)
+		return ERR_PTR(ret);
+
+	entry = kmem_cache_zalloc(btrfs_ordered_extent_cache, GFP_NOFS);
+	if (!entry) {
+		entry = ERR_PTR(-ENOMEM);
+		goto out;
+	}
+
+	entry->file_offset = file_offset;
+	entry->num_bytes = num_bytes;
+	entry->ram_bytes = ram_bytes;
+	entry->disk_bytenr = disk_bytenr;
+	entry->disk_num_bytes = disk_num_bytes;
+	entry->offset = offset;
+	entry->bytes_left = num_bytes;
+	if (WARN_ON_ONCE(!igrab(&inode->vfs_inode))) {
+		kmem_cache_free(btrfs_ordered_extent_cache, entry);
+		entry = ERR_PTR(-ESTALE);
+		goto out;
+	}
+	entry->inode = inode;
+	entry->compress_type = compress_type;
+	entry->truncated_len = (u64)-1;
+	entry->qgroup_rsv = qgroup_rsv;
+	entry->flags = flags;
+	refcount_set(&entry->refs, 1);
+	init_waitqueue_head(&entry->wait);
+	INIT_LIST_HEAD(&entry->csum_list);
+	INIT_LIST_HEAD(&entry->log_list);
+	INIT_LIST_HEAD(&entry->root_extent_list);
+	INIT_LIST_HEAD(&entry->work_list);
+	INIT_LIST_HEAD(&entry->bioc_list);
+	init_completion(&entry->completion);
+
+	/*
+	 * We don't need the count_max_extents here, we can assume that all of
+	 * that work has been done at higher layers, so this is truly the
+	 * smallest the extent is going to get.
+	 */
+	spin_lock(&inode->lock);
+	btrfs_mod_outstanding_extents(inode, 1);
+	spin_unlock(&inode->lock);
+
+out:
+	if (IS_ERR(entry) && !is_nocow)
+		btrfs_qgroup_free_refroot(inode->root->fs_info,
+					  btrfs_root_id(inode->root),
+					  qgroup_rsv, BTRFS_QGROUP_RSV_DATA);
+
+	return entry;
+}
+
+static void insert_ordered_extent(struct btrfs_ordered_extent *entry)
+{
+	struct btrfs_inode *inode = entry->inode;
+	struct btrfs_root *root = inode->root;
+	struct btrfs_fs_info *fs_info = root->fs_info;
+	struct rb_node *node;
+
+	trace_btrfs_ordered_extent_add(inode, entry);
+
+	percpu_counter_add_batch(&fs_info->ordered_bytes, entry->num_bytes,
+				 fs_info->delalloc_batch);
+
+	/* One ref for the tree. */
+	refcount_inc(&entry->refs);
+
+	spin_lock(&inode->ordered_tree_lock);
+	node = tree_insert(&inode->ordered_tree, entry->file_offset,
+			   &entry->rb_node);
+	if (unlikely(node)) {
+		struct btrfs_ordered_extent *exist =
+			rb_entry(node, struct btrfs_ordered_extent, rb_node);
+
+		btrfs_panic(fs_info, -EEXIST,
+"overlapping ordered extents, existing oe file_offset %llu num_bytes %llu flags 0x%lx, new oe file_offset %llu num_bytes %llu flags 0x%lx",
+			    exist->file_offset, exist->num_bytes, exist->flags,
+			    entry->file_offset, entry->num_bytes, entry->flags);
+	}
+	spin_unlock(&inode->ordered_tree_lock);
+
+	spin_lock(&root->ordered_extent_lock);
+	list_add_tail(&entry->root_extent_list,
+		      &root->ordered_extents);
+	root->nr_ordered_extents++;
+	if (root->nr_ordered_extents == 1) {
+		spin_lock(&fs_info->ordered_root_lock);
+		BUG_ON(!list_empty(&root->ordered_root));
+		list_add_tail(&root->ordered_root, &fs_info->ordered_roots);
+		spin_unlock(&fs_info->ordered_root_lock);
+	}
+	spin_unlock(&root->ordered_extent_lock);
+}
+
+/*
+ * Add an ordered extent to the per-inode tree.
+ *
+ * @inode:           Inode that this extent is for.
+ * @file_offset:     Logical offset in file where the extent starts.
+ * @num_bytes:       Logical length of extent in file.
+ * @ram_bytes:       Full length of unencoded data.
+ * @disk_bytenr:     Offset of extent on disk.
+ * @disk_num_bytes:  Size of extent on disk.
+ * @offset:          Offset into unencoded data where file data starts.
+ * @flags:           Flags specifying type of extent (1U << BTRFS_ORDERED_*).
+ * @compress_type:   Compression algorithm used for data.
+ *
+ * Most of these parameters correspond to &struct btrfs_file_extent_item. The
+ * tree is given a single reference on the ordered extent that was inserted, and
+ * the returned pointer is given a second reference.
+ *
+ * Return: the new ordered extent or error pointer.
+ */
+struct btrfs_ordered_extent *btrfs_alloc_ordered_extent(
+			struct btrfs_inode *inode, u64 file_offset,
+			const struct btrfs_file_extent *file_extent, unsigned long flags)
+{
+	struct btrfs_ordered_extent *entry;
+
+	ASSERT((flags & ~BTRFS_ORDERED_TYPE_FLAGS) == 0, "flags=0x%lx", flags);
+
+	/*
+	 * For regular writes, we just use the members in @file_extent.
+	 *
+	 * For NOCOW, we don't really care about the numbers except @start and
+	 * file_extent->num_bytes, as we won't insert a file extent item at all.
+	 *
+	 * For PREALLOC, we do not use ordered extent members, but
+	 * btrfs_mark_extent_written() handles everything.
+	 *
+	 * So here we always pass 0 as offset for NOCOW/PREALLOC ordered extents,
+	 * or btrfs_split_ordered_extent() cannot handle it correctly.
+	 */
+	if (flags & ((1U << BTRFS_ORDERED_NOCOW) | (1U << BTRFS_ORDERED_PREALLOC)))
+		entry = alloc_ordered_extent(inode, file_offset,
+					     file_extent->num_bytes,
+					     file_extent->num_bytes,
+					     file_extent->disk_bytenr + file_extent->offset,
+					     file_extent->num_bytes, 0, flags,
+					     file_extent->compression);
+	else
+		entry = alloc_ordered_extent(inode, file_offset,
+					     file_extent->num_bytes,
+					     file_extent->ram_bytes,
+					     file_extent->disk_bytenr,
+					     file_extent->disk_num_bytes,
+					     file_extent->offset, flags,
+					     file_extent->compression);
+	if (!IS_ERR(entry))
+		insert_ordered_extent(entry);
+	return entry;
+}
+
+/*
+ * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
+ * when an ordered extent is finished.  If the list covers more than one
+ * ordered extent, it is split across multiples.
+ */
+void btrfs_add_ordered_sum(struct btrfs_ordered_extent *entry,
+			   struct btrfs_ordered_sum *sum)
+{
+	struct btrfs_inode *inode = entry->inode;
+
+	spin_lock(&inode->ordered_tree_lock);
+	list_add_tail(&sum->list, &entry->csum_list);
+	spin_unlock(&inode->ordered_tree_lock);
+}
+
+void btrfs_mark_ordered_extent_error(struct btrfs_ordered_extent *ordered)
+{
+	if (!test_and_set_bit(BTRFS_ORDERED_IOERR, &ordered->flags))
+		mapping_set_error(ordered->inode->vfs_inode.i_mapping, -EIO);
+}
+
+void btrfs_mark_ordered_extent_truncated(struct btrfs_ordered_extent *ordered,
+					 u64 truncate_len)
+{
+	struct btrfs_inode *inode = ordered->inode;
+
+	ASSERT(truncate_len <= ordered->num_bytes);
+	spin_lock(&inode->ordered_tree_lock);
+	set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
+	ordered->truncated_len = min(ordered->truncated_len, truncate_len);
+	spin_unlock(&inode->ordered_tree_lock);
+}
+
+static void finish_ordered_fn(struct btrfs_work *work)
+{
+	struct btrfs_ordered_extent *ordered_extent;
+
+	ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
+	btrfs_finish_ordered_io(ordered_extent);
+}
+
+static bool can_finish_ordered_extent(struct btrfs_ordered_extent *ordered,
+				      u64 file_offset, u64 len, bool uptodate)
+{
+	struct btrfs_inode *inode = ordered->inode;
+	struct btrfs_fs_info *fs_info = inode->root->fs_info;
+
+	lockdep_assert_held(&inode->ordered_tree_lock);
+
+	/* Now we're fine to update the accounting. */
+	if (WARN_ON_ONCE(len > ordered->bytes_left)) {
+		btrfs_crit(fs_info,
+"bad ordered extent accounting, root=%llu ino=%llu OE offset=%llu OE len=%llu to_dec=%llu left=%llu",
+			   btrfs_root_id(inode->root), btrfs_ino(inode),
+			   ordered->file_offset, ordered->num_bytes,
+			   len, ordered->bytes_left);
+		ordered->bytes_left = 0;
+	} else {
+		ordered->bytes_left -= len;
+	}
+
+	if (!uptodate)
+		btrfs_mark_ordered_extent_error(ordered);
+
+	if (ordered->bytes_left)
+		return false;
+
+	/*
+	 * All the IO of the ordered extent is finished, we need to queue
+	 * the finish_func to be executed.
+	 */
+	set_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags);
+	cond_wake_up(&ordered->wait);
+	refcount_inc(&ordered->refs);
+	trace_btrfs_ordered_extent_mark_finished(inode, ordered);
+	return true;
+}
+
+static void btrfs_queue_ordered_fn(struct btrfs_ordered_extent *ordered)
+{
+	struct btrfs_inode *inode = ordered->inode;
+	struct btrfs_fs_info *fs_info = inode->root->fs_info;
+	struct btrfs_workqueue *wq = btrfs_is_free_space_inode(inode) ?
+		fs_info->endio_freespace_worker : fs_info->endio_write_workers;
+
+	btrfs_init_work(&ordered->work, finish_ordered_fn, NULL);
+	btrfs_queue_work(wq, &ordered->work);
+}
+
+void btrfs_finish_ordered_extent(struct btrfs_ordered_extent *ordered,
+				 u64 file_offset, u64 len, bool uptodate)
+{
+	struct btrfs_inode *inode = ordered->inode;
+	bool ret;
+
+	trace_btrfs_finish_ordered_extent(inode, file_offset, len, uptodate);
+
+	spin_lock(&inode->ordered_tree_lock);
+	ret = can_finish_ordered_extent(ordered, file_offset, len,
+					uptodate);
+	spin_unlock(&inode->ordered_tree_lock);
+
+	/*
+	 * If this is a COW write it means we created new extent maps for the
+	 * range and they point to unwritten locations if we got an error either
+	 * before submitting a bio or during IO.
+	 *
+	 * We have marked the ordered extent with BTRFS_ORDERED_IOERR, and we
+	 * are queuing its completion below. During completion, at
+	 * btrfs_finish_one_ordered(), we will drop the extent maps for the
+	 * unwritten extents.
+	 *
+	 * However because completion runs in a work queue we can end up having
+	 * a fast fsync running before that. In the case of direct IO, once we
+	 * unlock the inode the fsync might start, and we queue the completion
+	 * before unlocking the inode. In the case of buffered IO when writeback
+	 * finishes (end_bbio_data_write()) we queue the completion, so if the
+	 * writeback was triggered by a fast fsync, the fsync might start
+	 * logging before ordered extent completion runs in the work queue.
+	 *
+	 * The fast fsync will log file extent items based on the extent maps it
+	 * finds, so if by the time it collects extent maps the ordered extent
+	 * completion didn't happen yet, it will log file extent items that
+	 * point to unwritten extents, resulting in a corruption if a crash
+	 * happens and the log tree is replayed. Note that a fast fsync does not
+	 * wait for completion of ordered extents in order to reduce latency.
+	 *
+	 * Set a flag in the inode so that the next fast fsync will wait for
+	 * ordered extents to complete before starting to log.
+	 */
+	if (!uptodate && !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags))
+		set_bit(BTRFS_INODE_COW_WRITE_ERROR, &inode->runtime_flags);
+
+	if (ret)
+		btrfs_queue_ordered_fn(ordered);
+}
+
+/*
+ * Mark all ordered extents io inside the specified range finished.
+ *
+ * @folio:	 The involved folio for the operation.
+ *		 For uncompressed buffered IO, the folio status also needs to be
+ *		 updated to indicate whether the pending ordered io is finished.
+ *		 Can be NULL for direct IO and compressed write.
+ *		 For these cases, callers are ensured they won't execute the
+ *		 endio function twice.
+ *
+ * This function is called for endio, thus the range must have ordered
+ * extent(s) covering it.
+ */
+void btrfs_mark_ordered_io_finished(struct btrfs_inode *inode,
+				    u64 file_offset, u64 num_bytes, bool uptodate)
+{
+	struct rb_node *node;
+	struct btrfs_ordered_extent *entry = NULL;
+	u64 cur = file_offset;
+	const u64 end = file_offset + num_bytes;
+
+	trace_btrfs_writepage_end_io_hook(inode, file_offset, end - 1, uptodate);
+
+	spin_lock(&inode->ordered_tree_lock);
+	while (cur < end) {
+		u64 entry_end;
+		u64 this_end;
+		u64 len;
+
+		node = ordered_tree_search(inode, cur);
+		/* No ordered extents at all */
+		if (!node)
+			break;
+
+		entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
+		entry_end = entry->file_offset + entry->num_bytes;
+		/*
+		 * |<-- OE --->|  |
+		 *		  cur
+		 * Go to next OE.
+		 */
+		if (cur >= entry_end) {
+			node = rb_next(node);
+			/* No more ordered extents, exit */
+			if (!node)
+				break;
+			entry = rb_entry(node, struct btrfs_ordered_extent,
+					 rb_node);
+
+			/* Go to next ordered extent and continue */
+			cur = entry->file_offset;
+			continue;
+		}
+		/*
+		 * |	|<--- OE --->|
+		 * cur
+		 * Go to the start of OE.
+		 */
+		if (cur < entry->file_offset) {
+			cur = entry->file_offset;
+			continue;
+		}
+
+		/*
+		 * Now we are definitely inside one ordered extent.
+		 *
+		 * |<--- OE --->|
+		 *	|
+		 *	cur
+		 */
+		this_end = min(entry_end, end);
+		len = this_end - cur;
+		ASSERT(len < U32_MAX);
+
+		if (can_finish_ordered_extent(entry, cur, len, uptodate)) {
+			spin_unlock(&inode->ordered_tree_lock);
+			btrfs_queue_ordered_fn(entry);
+			spin_lock(&inode->ordered_tree_lock);
+		}
+		cur += len;
+	}
+	spin_unlock(&inode->ordered_tree_lock);
+}
+
+/*
+ * Finish IO for one ordered extent across a given range.  The range can only
+ * contain one ordered extent.
+ *
+ * @cached:	 The cached ordered extent. If not NULL, we can skip the tree
+ *               search and use the ordered extent directly.
+ * 		 Will be also used to store the finished ordered extent.
+ * @file_offset: File offset for the finished IO
+ * @io_size:	 Length of the finish IO range
+ *
+ * Return true if the ordered extent is finished in the range, and update
+ * @cached.
+ * Return false otherwise.
+ *
+ * NOTE: The range can NOT cross multiple ordered extents.
+ * Thus caller should ensure the range doesn't cross ordered extents.
+ */
+bool btrfs_dec_test_ordered_pending(struct btrfs_inode *inode,
+				    struct btrfs_ordered_extent **cached,
+				    u64 file_offset, u64 io_size)
+{
+	struct rb_node *node;
+	struct btrfs_ordered_extent *entry = NULL;
+	bool finished = false;
+
+	spin_lock(&inode->ordered_tree_lock);
+	if (cached && *cached) {
+		entry = *cached;
+		goto have_entry;
+	}
+
+	node = ordered_tree_search(inode, file_offset);
+	if (!node)
+		goto out;
+
+	entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
+have_entry:
+	if (!in_range(file_offset, entry->file_offset, entry->num_bytes))
+		goto out;
+
+	if (io_size > entry->bytes_left)
+		btrfs_crit(inode->root->fs_info,
+			   "bad ordered accounting left %llu size %llu",
+		       entry->bytes_left, io_size);
+
+	entry->bytes_left -= io_size;
+
+	if (entry->bytes_left == 0) {
+		/*
+		 * Ensure only one caller can set the flag and finished_ret
+		 * accordingly
+		 */
+		finished = !test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
+		/* test_and_set_bit implies a barrier */
+		cond_wake_up_nomb(&entry->wait);
+	}
+out:
+	if (finished && cached && entry) {
+		*cached = entry;
+		refcount_inc(&entry->refs);
+		trace_btrfs_ordered_extent_dec_test_pending(inode, entry);
+	}
+	spin_unlock(&inode->ordered_tree_lock);
+	return finished;
+}
+
+/*
+ * used to drop a reference on an ordered extent.  This will free
+ * the extent if the last reference is dropped
+ */
+void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
+{
+	trace_btrfs_ordered_extent_put(entry->inode, entry);
+
+	if (refcount_dec_and_test(&entry->refs)) {
+		struct btrfs_ordered_sum *sum;
+		struct btrfs_ordered_sum *tmp;
+
+		ASSERT(list_empty(&entry->root_extent_list));
+		ASSERT(list_empty(&entry->log_list));
+		ASSERT(RB_EMPTY_NODE(&entry->rb_node));
+		btrfs_add_delayed_iput(entry->inode);
+		list_for_each_entry_safe(sum, tmp, &entry->csum_list, list)
+			kvfree(sum);
+		kmem_cache_free(btrfs_ordered_extent_cache, entry);
+	}
+}
+
+/*
+ * remove an ordered extent from the tree.  No references are dropped
+ * and waiters are woken up.
+ */
+void btrfs_remove_ordered_extent(struct btrfs_ordered_extent *entry)
+{
+	struct btrfs_inode *btrfs_inode = entry->inode;
+	struct btrfs_root *root = btrfs_inode->root;
+	struct btrfs_fs_info *fs_info = root->fs_info;
+	struct rb_node *node;
+	bool pending;
+	bool freespace_inode;
+
+	/*
+	 * If this is a free space inode the thread has not acquired the ordered
+	 * extents lockdep map.
+	 */
+	freespace_inode = btrfs_is_free_space_inode(btrfs_inode);
+
+	btrfs_lockdep_acquire(fs_info, btrfs_trans_pending_ordered);
+	/* This is paired with alloc_ordered_extent(). */
+	spin_lock(&btrfs_inode->lock);
+	btrfs_mod_outstanding_extents(btrfs_inode, -1);
+	spin_unlock(&btrfs_inode->lock);
+	if (root != fs_info->tree_root) {
+		u64 release;
+
+		if (test_bit(BTRFS_ORDERED_ENCODED, &entry->flags))
+			release = entry->disk_num_bytes;
+		else
+			release = entry->num_bytes;
+		btrfs_delalloc_release_metadata(btrfs_inode, release,
+						test_bit(BTRFS_ORDERED_IOERR,
+							 &entry->flags));
+	}
+
+	percpu_counter_add_batch(&fs_info->ordered_bytes, -entry->num_bytes,
+				 fs_info->delalloc_batch);
+
+	spin_lock(&btrfs_inode->ordered_tree_lock);
+	node = &entry->rb_node;
+	rb_erase(node, &btrfs_inode->ordered_tree);
+	RB_CLEAR_NODE(node);
+	if (btrfs_inode->ordered_tree_last == node)
+		btrfs_inode->ordered_tree_last = NULL;
+	set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
+	pending = test_and_clear_bit(BTRFS_ORDERED_PENDING, &entry->flags);
+	spin_unlock(&btrfs_inode->ordered_tree_lock);
+
+	/*
+	 * The current running transaction is waiting on us, we need to let it
+	 * know that we're complete and wake it up.
+	 */
+	if (pending) {
+		struct btrfs_transaction *trans;
+
+		/*
+		 * The checks for trans are just a formality, it should be set,
+		 * but if it isn't we don't want to deref/assert under the spin
+		 * lock, so be nice and check if trans is set, but ASSERT() so
+		 * if it isn't set a developer will notice.
+		 */
+		spin_lock(&fs_info->trans_lock);
+		trans = fs_info->running_transaction;
+		if (trans)
+			refcount_inc(&trans->use_count);
+		spin_unlock(&fs_info->trans_lock);
+
+		ASSERT(trans || BTRFS_FS_ERROR(fs_info));
+		if (trans) {
+			if (atomic_dec_and_test(&trans->pending_ordered))
+				wake_up(&trans->pending_wait);
+			btrfs_put_transaction(trans);
+		}
+	}
+
+	btrfs_lockdep_release(fs_info, btrfs_trans_pending_ordered);
+
+	spin_lock(&root->ordered_extent_lock);
+	list_del_init(&entry->root_extent_list);
+	root->nr_ordered_extents--;
+
+	trace_btrfs_ordered_extent_remove(btrfs_inode, entry);
+
+	if (!root->nr_ordered_extents) {
+		spin_lock(&fs_info->ordered_root_lock);
+		BUG_ON(list_empty(&root->ordered_root));
+		list_del_init(&root->ordered_root);
+		spin_unlock(&fs_info->ordered_root_lock);
+	}
+	spin_unlock(&root->ordered_extent_lock);
+	wake_up(&entry->wait);
+	if (!freespace_inode)
+		btrfs_lockdep_release(fs_info, btrfs_ordered_extent);
+}
+
+static void btrfs_run_ordered_extent_work(struct btrfs_work *work)
+{
+	struct btrfs_ordered_extent *ordered;
+
+	ordered = container_of(work, struct btrfs_ordered_extent, flush_work);
+	btrfs_start_ordered_extent(ordered);
+	complete(&ordered->completion);
+}
+
+/*
+ * Wait for all the ordered extents in a root. Use @bg as range or do whole
+ * range if it's NULL.
+ */
+u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
+			       const struct btrfs_block_group *bg)
+{
+	struct btrfs_fs_info *fs_info = root->fs_info;
+	LIST_HEAD(splice);
+	LIST_HEAD(skipped);
+	LIST_HEAD(works);
+	struct btrfs_ordered_extent *ordered, *next;
+	u64 count = 0;
+	u64 range_start, range_len;
+	u64 range_end;
+
+	if (bg) {
+		range_start = bg->start;
+		range_len = bg->length;
+	} else {
+		range_start = 0;
+		range_len = U64_MAX;
+	}
+	range_end = range_start + range_len;
+
+	mutex_lock(&root->ordered_extent_mutex);
+	spin_lock(&root->ordered_extent_lock);
+	list_splice_init(&root->ordered_extents, &splice);
+	while (!list_empty(&splice) && nr) {
+		ordered = list_first_entry(&splice, struct btrfs_ordered_extent,
+					   root_extent_list);
+
+		if (range_end <= ordered->disk_bytenr ||
+		    ordered->disk_bytenr + ordered->disk_num_bytes <= range_start) {
+			list_move_tail(&ordered->root_extent_list, &skipped);
+			cond_resched_lock(&root->ordered_extent_lock);
+			continue;
+		}
+
+		list_move_tail(&ordered->root_extent_list,
+			       &root->ordered_extents);
+		refcount_inc(&ordered->refs);
+		spin_unlock(&root->ordered_extent_lock);
+
+		btrfs_init_work(&ordered->flush_work,
+				btrfs_run_ordered_extent_work, NULL);
+		list_add_tail(&ordered->work_list, &works);
+		btrfs_queue_work(fs_info->flush_workers, &ordered->flush_work);
+
+		cond_resched();
+		if (nr != U64_MAX)
+			nr--;
+		count++;
+		spin_lock(&root->ordered_extent_lock);
+	}
+	list_splice_tail(&skipped, &root->ordered_extents);
+	list_splice_tail(&splice, &root->ordered_extents);
+	spin_unlock(&root->ordered_extent_lock);
+
+	list_for_each_entry_safe(ordered, next, &works, work_list) {
+		list_del_init(&ordered->work_list);
+		wait_for_completion(&ordered->completion);
+		btrfs_put_ordered_extent(ordered);
+		cond_resched();
+	}
+	mutex_unlock(&root->ordered_extent_mutex);
+
+	return count;
+}
+
+/*
+ * Wait for @nr ordered extents that intersect the @bg, or the whole range of
+ * the filesystem if @bg is NULL.
+ */
+void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
+			      const struct btrfs_block_group *bg)
+{
+	struct btrfs_root *root;
+	LIST_HEAD(splice);
+	u64 done;
+
+	mutex_lock(&fs_info->ordered_operations_mutex);
+	spin_lock(&fs_info->ordered_root_lock);
+	list_splice_init(&fs_info->ordered_roots, &splice);
+	while (!list_empty(&splice) && nr) {
+		root = list_first_entry(&splice, struct btrfs_root,
+					ordered_root);
+		root = btrfs_grab_root(root);
+		BUG_ON(!root);
+		list_move_tail(&root->ordered_root,
+			       &fs_info->ordered_roots);
+		spin_unlock(&fs_info->ordered_root_lock);
+
+		done = btrfs_wait_ordered_extents(root, nr, bg);
+		btrfs_put_root(root);
+
+		if (nr != U64_MAX)
+			nr -= done;
+
+		spin_lock(&fs_info->ordered_root_lock);
+	}
+	list_splice_tail(&splice, &fs_info->ordered_roots);
+	spin_unlock(&fs_info->ordered_root_lock);
+	mutex_unlock(&fs_info->ordered_operations_mutex);
+}
+
+/*
+ * Start IO and wait for a given ordered extent to finish.
+ *
+ * Wait on page writeback for all the pages in the extent but not in
+ * [@nowriteback_start, @nowriteback_start + @nowriteback_len) and the
+ * IO completion code to insert metadata into the btree corresponding to the extent.
+ */
+void btrfs_start_ordered_extent_nowriteback(struct btrfs_ordered_extent *entry,
+					    u64 nowriteback_start, u32 nowriteback_len)
+{
+	u64 start = entry->file_offset;
+	u64 end = start + entry->num_bytes - 1;
+	struct btrfs_inode *inode = entry->inode;
+	bool freespace_inode;
+
+	trace_btrfs_ordered_extent_start(inode, entry);
+
+	/*
+	 * If this is a free space inode do not take the ordered extents lockdep
+	 * map.
+	 */
+	freespace_inode = btrfs_is_free_space_inode(inode);
+
+	/*
+	 * pages in the range can be dirty, clean or writeback.  We
+	 * start IO on any dirty ones so the wait doesn't stall waiting
+	 * for the flusher thread to find them
+	 */
+	if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags)) {
+		if (!nowriteback_len) {
+			filemap_fdatawrite_range(inode->vfs_inode.i_mapping, start, end);
+		} else {
+			if (start < nowriteback_start)
+				filemap_fdatawrite_range(inode->vfs_inode.i_mapping, start,
+							 nowriteback_start - 1);
+			if (nowriteback_start + nowriteback_len < end)
+				filemap_fdatawrite_range(inode->vfs_inode.i_mapping,
+							 nowriteback_start + nowriteback_len,
+							 end);
+		}
+	}
+
+	if (!freespace_inode)
+		btrfs_might_wait_for_event(inode->root->fs_info, btrfs_ordered_extent);
+	wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE, &entry->flags));
+}
+
+/*
+ * Used to wait on ordered extents across a large range of bytes.
+ */
+int btrfs_wait_ordered_range(struct btrfs_inode *inode, u64 start, u64 len)
+{
+	int ret = 0;
+	int ret_wb = 0;
+	u64 end;
+	u64 orig_end;
+	struct btrfs_ordered_extent *ordered;
+
+	if (start + len < start) {
+		orig_end = OFFSET_MAX;
+	} else {
+		orig_end = start + len - 1;
+		if (orig_end > OFFSET_MAX)
+			orig_end = OFFSET_MAX;
+	}
+
+	/* start IO across the range first to instantiate any delalloc
+	 * extents
+	 */
+	ret = btrfs_fdatawrite_range(inode, start, orig_end);
+	if (ret)
+		return ret;
+
+	/*
+	 * If we have a writeback error don't return immediately. Wait first
+	 * for any ordered extents that haven't completed yet. This is to make
+	 * sure no one can dirty the same page ranges and call writepages()
+	 * before the ordered extents complete - to avoid failures (-EEXIST)
+	 * when adding the new ordered extents to the ordered tree.
+	 */
+	ret_wb = filemap_fdatawait_range(inode->vfs_inode.i_mapping, start, orig_end);
+
+	end = orig_end;
+	while (1) {
+		ordered = btrfs_lookup_first_ordered_extent(inode, end);
+		if (!ordered)
+			break;
+		if (ordered->file_offset > orig_end) {
+			btrfs_put_ordered_extent(ordered);
+			break;
+		}
+		if (ordered->file_offset + ordered->num_bytes <= start) {
+			btrfs_put_ordered_extent(ordered);
+			break;
+		}
+		btrfs_start_ordered_extent(ordered);
+		end = ordered->file_offset;
+		/*
+		 * If the ordered extent had an error save the error but don't
+		 * exit without waiting first for all other ordered extents in
+		 * the range to complete.
+		 */
+		if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags))
+			ret = -EIO;
+		btrfs_put_ordered_extent(ordered);
+		if (end == 0 || end == start)
+			break;
+		end--;
+	}
+	return ret_wb ? ret_wb : ret;
+}
+
+/*
+ * find an ordered extent corresponding to file_offset.  return NULL if
+ * nothing is found, otherwise take a reference on the extent and return it
+ */
+struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct btrfs_inode *inode,
+							 u64 file_offset)
+{
+	struct rb_node *node;
+	struct btrfs_ordered_extent *entry = NULL;
+
+	spin_lock(&inode->ordered_tree_lock);
+	node = ordered_tree_search(inode, file_offset);
+	if (!node)
+		goto out;
+
+	entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
+	if (!in_range(file_offset, entry->file_offset, entry->num_bytes))
+		entry = NULL;
+	if (entry) {
+		refcount_inc(&entry->refs);
+		trace_btrfs_ordered_extent_lookup(inode, entry);
+	}
+out:
+	spin_unlock(&inode->ordered_tree_lock);
+	return entry;
+}
+
+/* Since the DIO code tries to lock a wide area we need to look for any ordered
+ * extents that exist in the range, rather than just the start of the range.
+ */
+struct btrfs_ordered_extent *btrfs_lookup_ordered_range(
+		struct btrfs_inode *inode, u64 file_offset, u64 len)
+{
+	struct rb_node *node;
+	struct btrfs_ordered_extent *entry = NULL;
+
+	spin_lock(&inode->ordered_tree_lock);
+	node = ordered_tree_search(inode, file_offset);
+	if (!node) {
+		node = ordered_tree_search(inode, file_offset + len);
+		if (!node)
+			goto out;
+	}
+
+	while (1) {
+		entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
+		if (btrfs_range_overlaps(entry, file_offset, len))
+			break;
+
+		if (entry->file_offset >= file_offset + len) {
+			entry = NULL;
+			break;
+		}
+		entry = NULL;
+		node = rb_next(node);
+		if (!node)
+			break;
+	}
+out:
+	if (entry) {
+		refcount_inc(&entry->refs);
+		trace_btrfs_ordered_extent_lookup_range(inode, entry);
+	}
+	spin_unlock(&inode->ordered_tree_lock);
+	return entry;
+}
+
+/*
+ * Adds all ordered extents to the given list. The list ends up sorted by the
+ * file_offset of the ordered extents.
+ */
+void btrfs_get_ordered_extents_for_logging(struct btrfs_inode *inode,
+					   struct list_head *list)
+{
+	struct rb_node *n;
+
+	btrfs_assert_inode_locked(inode);
+
+	spin_lock(&inode->ordered_tree_lock);
+	for (n = rb_first(&inode->ordered_tree); n; n = rb_next(n)) {
+		struct btrfs_ordered_extent *ordered;
+
+		ordered = rb_entry(n, struct btrfs_ordered_extent, rb_node);
+
+		if (test_bit(BTRFS_ORDERED_LOGGED, &ordered->flags))
+			continue;
+
+		ASSERT(list_empty(&ordered->log_list));
+		list_add_tail(&ordered->log_list, list);
+		refcount_inc(&ordered->refs);
+		trace_btrfs_ordered_extent_lookup_for_logging(inode, ordered);
+	}
+	spin_unlock(&inode->ordered_tree_lock);
+}
+
+/*
+ * lookup and return any extent before 'file_offset'.  NULL is returned
+ * if none is found
+ */
+struct btrfs_ordered_extent *
+btrfs_lookup_first_ordered_extent(struct btrfs_inode *inode, u64 file_offset)
+{
+	struct rb_node *node;
+	struct btrfs_ordered_extent *entry = NULL;
+
+	spin_lock(&inode->ordered_tree_lock);
+	node = ordered_tree_search(inode, file_offset);
+	if (!node)
+		goto out;
+
+	entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
+	refcount_inc(&entry->refs);
+	trace_btrfs_ordered_extent_lookup_first(inode, entry);
+out:
+	spin_unlock(&inode->ordered_tree_lock);
+	return entry;
+}
+
+/*
+ * Lookup the first ordered extent that overlaps the range
+ * [@file_offset, @file_offset + @len).
+ *
+ * The difference between this and btrfs_lookup_first_ordered_extent() is
+ * that this one won't return any ordered extent that does not overlap the range.
+ * And the difference against btrfs_lookup_ordered_extent() is, this function
+ * ensures the first ordered extent gets returned.
+ */
+struct btrfs_ordered_extent *btrfs_lookup_first_ordered_range(
+			struct btrfs_inode *inode, u64 file_offset, u64 len)
+{
+	struct rb_node *node;
+	struct rb_node *cur;
+	struct rb_node *prev;
+	struct rb_node *next;
+	struct btrfs_ordered_extent *entry = NULL;
+
+	spin_lock(&inode->ordered_tree_lock);
+	node = inode->ordered_tree.rb_node;
+	/*
+	 * Here we don't want to use tree_search() which will use tree->last
+	 * and screw up the search order.
+	 * And __tree_search() can't return the adjacent ordered extents
+	 * either, thus here we do our own search.
+	 */
+	while (node) {
+		entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
+
+		if (file_offset < entry->file_offset) {
+			node = node->rb_left;
+		} else if (file_offset >= entry_end(entry)) {
+			node = node->rb_right;
+		} else {
+			/*
+			 * Direct hit, got an ordered extent that starts at
+			 * @file_offset
+			 */
+			goto out;
+		}
+	}
+	if (!entry) {
+		/* Empty tree */
+		goto out;
+	}
+
+	cur = &entry->rb_node;
+	/* We got an entry around @file_offset, check adjacent entries */
+	if (entry->file_offset < file_offset) {
+		prev = cur;
+		next = rb_next(cur);
+	} else {
+		prev = rb_prev(cur);
+		next = cur;
+	}
+	if (prev) {
+		entry = rb_entry(prev, struct btrfs_ordered_extent, rb_node);
+		if (btrfs_range_overlaps(entry, file_offset, len))
+			goto out;
+	}
+	if (next) {
+		entry = rb_entry(next, struct btrfs_ordered_extent, rb_node);
+		if (btrfs_range_overlaps(entry, file_offset, len))
+			goto out;
+	}
+	/* No ordered extent in the range */
+	entry = NULL;
+out:
+	if (entry) {
+		refcount_inc(&entry->refs);
+		trace_btrfs_ordered_extent_lookup_first_range(inode, entry);
+	}
+
+	spin_unlock(&inode->ordered_tree_lock);
+	return entry;
+}
+
+/*
+ * Lock the passed range and ensures all pending ordered extents in it are run
+ * to completion.
+ *
+ * @inode:        Inode whose ordered tree is to be searched
+ * @start:        Beginning of range to flush
+ * @end:          Last byte of range to lock
+ * @cached_state: If passed, will return the extent state responsible for the
+ *                locked range. It's the caller's responsibility to free the
+ *                cached state.
+ *
+ * Always return with the given range locked, ensuring after it's called no
+ * order extent can be pending.
+ */
+void btrfs_lock_and_flush_ordered_range(struct btrfs_inode *inode, u64 start,
+					u64 end,
+					struct extent_state **cached_state)
+{
+	struct btrfs_ordered_extent *ordered;
+	struct extent_state *cache = NULL;
+	struct extent_state **cachedp = &cache;
+
+	if (cached_state)
+		cachedp = cached_state;
+
+	while (1) {
+		btrfs_lock_extent(&inode->io_tree, start, end, cachedp);
+		ordered = btrfs_lookup_ordered_range(inode, start,
+						     end - start + 1);
+		if (!ordered) {
+			/*
+			 * If no external cached_state has been passed then
+			 * decrement the extra ref taken for cachedp since we
+			 * aren't exposing it outside of this function
+			 */
+			if (!cached_state)
+				refcount_dec(&cache->refs);
+			break;
+		}
+		btrfs_unlock_extent(&inode->io_tree, start, end, cachedp);
+		btrfs_start_ordered_extent(ordered);
+		btrfs_put_ordered_extent(ordered);
+	}
+}
+
+/*
+ * Lock the passed range and ensure all pending ordered extents in it are run
+ * to completion in nowait mode.
+ *
+ * Return true if btrfs_lock_ordered_range does not return any extents,
+ * otherwise false.
+ */
+bool btrfs_try_lock_ordered_range(struct btrfs_inode *inode, u64 start, u64 end,
+				  struct extent_state **cached_state)
+{
+	struct btrfs_ordered_extent *ordered;
+
+	if (!btrfs_try_lock_extent(&inode->io_tree, start, end, cached_state))
+		return false;
+
+	ordered = btrfs_lookup_ordered_range(inode, start, end - start + 1);
+	if (!ordered)
+		return true;
+
+	btrfs_put_ordered_extent(ordered);
+	btrfs_unlock_extent(&inode->io_tree, start, end, cached_state);
+
+	return false;
+}
+
+/* Split out a new ordered extent for this first @len bytes of @ordered. */
+struct btrfs_ordered_extent *btrfs_split_ordered_extent(
+			struct btrfs_ordered_extent *ordered, u64 len)
+{
+	struct btrfs_inode *inode = ordered->inode;
+	struct btrfs_root *root = inode->root;
+	struct btrfs_fs_info *fs_info = root->fs_info;
+	u64 file_offset = ordered->file_offset;
+	u64 disk_bytenr = ordered->disk_bytenr;
+	unsigned long flags = ordered->flags;
+	struct btrfs_ordered_sum *sum, *tmpsum;
+	struct btrfs_ordered_extent *new;
+	struct rb_node *node;
+	u64 offset = 0;
+
+	trace_btrfs_ordered_extent_split(inode, ordered);
+
+	ASSERT(!(flags & (1U << BTRFS_ORDERED_COMPRESSED)), "flags=0x%lx", flags);
+
+	/*
+	 * The entire bio must be covered by the ordered extent, but we can't
+	 * reduce the original extent to a zero length either.
+	 */
+	if (WARN_ON_ONCE(len >= ordered->num_bytes))
+		return ERR_PTR(-EINVAL);
+	/*
+	 * If our ordered extent had an error there's no point in continuing.
+	 * The error may have come from a transaction abort done either by this
+	 * task or some other concurrent task, and the transaction abort path
+	 * iterates over all existing ordered extents and sets the flag
+	 * BTRFS_ORDERED_IOERR on them.
+	 */
+	if (unlikely(flags & (1U << BTRFS_ORDERED_IOERR))) {
+		const int fs_error = BTRFS_FS_ERROR(fs_info);
+
+		return fs_error ? ERR_PTR(fs_error) : ERR_PTR(-EIO);
+	}
+	/* We cannot split partially completed ordered extents. */
+	if (ordered->bytes_left) {
+		ASSERT(!(flags & ~BTRFS_ORDERED_TYPE_FLAGS), "flags=0x%lx", flags);
+		if (WARN_ON_ONCE(ordered->bytes_left != ordered->disk_num_bytes))
+			return ERR_PTR(-EINVAL);
+	}
+	/* We cannot split a compressed ordered extent. */
+	if (WARN_ON_ONCE(ordered->disk_num_bytes != ordered->num_bytes))
+		return ERR_PTR(-EINVAL);
+
+	new = alloc_ordered_extent(inode, file_offset, len, len, disk_bytenr,
+				   len, 0, flags, ordered->compress_type);
+	if (IS_ERR(new))
+		return new;
+
+	/* One ref for the tree. */
+	refcount_inc(&new->refs);
+
+	/*
+	 * Take the root's ordered_extent_lock to avoid a race with
+	 * btrfs_wait_ordered_extents() when updating the disk_bytenr and
+	 * disk_num_bytes fields of the ordered extent below.
+	 *
+	 * There's no concern about a previous caller of
+	 * btrfs_wait_ordered_extents() getting the trimmed ordered extent
+	 * before we insert the new one, because even if it gets the ordered
+	 * extent before it's trimmed and the new one inserted, right before it
+	 * uses it or during its use, the ordered extent might have been
+	 * trimmed in the meanwhile, and it missed the new ordered extent.
+	 * There's no way around this and it's harmless for current use cases,
+	 * so we take the root's ordered_extent_lock to fix that race during
+	 * trimming and silence tools like KCSAN.
+	 */
+	spin_lock_irq(&root->ordered_extent_lock);
+	spin_lock(&inode->ordered_tree_lock);
+
+	/*
+	 * We don't have overlapping ordered extents (that would imply double
+	 * allocation of extents) and we checked above that the split length
+	 * does not cross the ordered extent's num_bytes field, so there's
+	 * no need to remove it and re-insert it in the tree.
+	 */
+	ordered->file_offset += len;
+	ordered->disk_bytenr += len;
+	ordered->num_bytes -= len;
+	ordered->disk_num_bytes -= len;
+	ordered->ram_bytes -= len;
+
+	if (test_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags)) {
+		ASSERT(ordered->bytes_left == 0, "ordered->bytes_left=%llu",
+		       ordered->bytes_left);
+		new->bytes_left = 0;
+	} else {
+		ordered->bytes_left -= len;
+	}
+
+	if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags)) {
+		if (ordered->truncated_len > len) {
+			ordered->truncated_len -= len;
+		} else {
+			new->truncated_len = ordered->truncated_len;
+			ordered->truncated_len = 0;
+		}
+	}
+
+	list_for_each_entry_safe(sum, tmpsum, &ordered->csum_list, list) {
+		if (offset == len)
+			break;
+		list_move_tail(&sum->list, &new->csum_list);
+		offset += sum->len;
+	}
+
+	node = tree_insert(&inode->ordered_tree, new->file_offset, &new->rb_node);
+	if (unlikely(node))
+		btrfs_panic(fs_info, -EEXIST,
+			"inconsistency in ordered tree at offset %llu after split",
+			new->file_offset);
+	spin_unlock(&inode->ordered_tree_lock);
+
+	list_add_tail(&new->root_extent_list, &root->ordered_extents);
+	root->nr_ordered_extents++;
+	spin_unlock_irq(&root->ordered_extent_lock);
+	return new;
+}
+
+int __init ordered_data_init(void)
+{
+	btrfs_ordered_extent_cache = KMEM_CACHE(btrfs_ordered_extent, 0);
+	if (!btrfs_ordered_extent_cache)
+		return -ENOMEM;
+
+	return 0;
+}
+
+void __cold ordered_data_exit(void)
+{
+	kmem_cache_destroy(btrfs_ordered_extent_cache);
+}