Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 1072 insertions, 0 deletions

diff --git a/fs/btrfs/bio.c b/fs/btrfs/bio.c
new file mode 100644
index 000000000..cc0bd0304
--- /dev/null
+++ b/fs/btrfs/bio.c
@@ -0,0 +1,1072 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2007 Oracle.  All rights reserved.
+ * Copyright (C) 2022 Christoph Hellwig.
+ */
+
+#include <linux/blk_types.h>
+#include <linux/bio.h>
+#include "bio.h"
+#include "ctree.h"
+#include "volumes.h"
+#include "raid56.h"
+#include "async-thread.h"
+#include "dev-replace.h"
+#include "zoned.h"
+#include "file-item.h"
+#include "raid-stripe-tree.h"
+
+static struct bio_set btrfs_bioset;
+static struct bio_set btrfs_clone_bioset;
+static struct bio_set btrfs_repair_bioset;
+static mempool_t btrfs_failed_bio_pool;
+
+struct btrfs_failed_bio {
+	struct btrfs_bio *bbio;
+	int num_copies;
+	atomic_t repair_count;
+};
+
+/* Is this a data path I/O that needs storage layer checksum and repair? */
+static inline bool is_data_bbio(const struct btrfs_bio *bbio)
+{
+	return bbio->inode && is_data_inode(bbio->inode);
+}
+
+static bool bbio_has_ordered_extent(const struct btrfs_bio *bbio)
+{
+	return is_data_bbio(bbio) && btrfs_op(&bbio->bio) == BTRFS_MAP_WRITE;
+}
+
+/*
+ * Initialize a btrfs_bio structure.  This skips the embedded bio itself as it
+ * is already initialized by the block layer.
+ */
+void btrfs_bio_init(struct btrfs_bio *bbio, struct btrfs_inode *inode, u64 file_offset,
+		    btrfs_bio_end_io_t end_io, void *private)
+{
+	/* @inode parameter is mandatory. */
+	ASSERT(inode);
+
+	memset(bbio, 0, offsetof(struct btrfs_bio, bio));
+	bbio->inode = inode;
+	bbio->end_io = end_io;
+	bbio->private = private;
+	bbio->file_offset = file_offset;
+	atomic_set(&bbio->pending_ios, 1);
+	WRITE_ONCE(bbio->status, BLK_STS_OK);
+}
+
+/*
+ * Allocate a btrfs_bio structure.  The btrfs_bio is the main I/O container for
+ * btrfs, and is used for all I/O submitted through btrfs_submit_bbio().
+ *
+ * Just like the underlying bio_alloc_bioset it will not fail as it is backed by
+ * a mempool.
+ */
+struct btrfs_bio *btrfs_bio_alloc(unsigned int nr_vecs, blk_opf_t opf,
+				  struct btrfs_inode *inode, u64 file_offset,
+				  btrfs_bio_end_io_t end_io, void *private)
+{
+	struct btrfs_bio *bbio;
+	struct bio *bio;
+
+	bio = bio_alloc_bioset(NULL, nr_vecs, opf, GFP_NOFS, &btrfs_bioset);
+	bbio = btrfs_bio(bio);
+	btrfs_bio_init(bbio, inode, file_offset, end_io, private);
+	return bbio;
+}
+
+static struct btrfs_bio *btrfs_split_bio(struct btrfs_fs_info *fs_info,
+					 struct btrfs_bio *orig_bbio,
+					 u64 map_length)
+{
+	struct btrfs_bio *bbio;
+	struct bio *bio;
+
+	bio = bio_split(&orig_bbio->bio, map_length >> SECTOR_SHIFT, GFP_NOFS,
+			&btrfs_clone_bioset);
+	if (IS_ERR(bio))
+		return ERR_CAST(bio);
+
+	bbio = btrfs_bio(bio);
+	btrfs_bio_init(bbio, orig_bbio->inode, orig_bbio->file_offset, NULL, orig_bbio);
+	orig_bbio->file_offset += map_length;
+	if (bbio_has_ordered_extent(bbio)) {
+		refcount_inc(&orig_bbio->ordered->refs);
+		bbio->ordered = orig_bbio->ordered;
+		bbio->orig_logical = orig_bbio->orig_logical;
+		orig_bbio->orig_logical += map_length;
+	}
+
+	bbio->csum_search_commit_root = orig_bbio->csum_search_commit_root;
+	bbio->can_use_append = orig_bbio->can_use_append;
+	bbio->is_scrub = orig_bbio->is_scrub;
+	bbio->is_remap = orig_bbio->is_remap;
+	bbio->async_csum = orig_bbio->async_csum;
+
+	atomic_inc(&orig_bbio->pending_ios);
+	return bbio;
+}
+
+void btrfs_bio_end_io(struct btrfs_bio *bbio, blk_status_t status)
+{
+	/* Make sure we're already in task context. */
+	ASSERT(in_task());
+
+	if (bbio->async_csum)
+		wait_for_completion(&bbio->csum_done);
+
+	bbio->bio.bi_status = status;
+	if (bbio->bio.bi_pool == &btrfs_clone_bioset) {
+		struct btrfs_bio *orig_bbio = bbio->private;
+
+		/* Free bio that was never submitted to the underlying device. */
+		if (bbio_has_ordered_extent(bbio))
+			btrfs_put_ordered_extent(bbio->ordered);
+		bio_put(&bbio->bio);
+
+		bbio = orig_bbio;
+	}
+
+	/*
+	 * At this point, bbio always points to the original btrfs_bio. Save
+	 * the first error in it.
+	 */
+	if (status != BLK_STS_OK)
+		cmpxchg(&bbio->status, BLK_STS_OK, status);
+
+	if (atomic_dec_and_test(&bbio->pending_ios)) {
+		/* Load split bio's error which might be set above. */
+		if (status == BLK_STS_OK)
+			bbio->bio.bi_status = READ_ONCE(bbio->status);
+
+		if (bbio_has_ordered_extent(bbio)) {
+			struct btrfs_ordered_extent *ordered = bbio->ordered;
+
+			bbio->end_io(bbio);
+			btrfs_put_ordered_extent(ordered);
+		} else {
+			bbio->end_io(bbio);
+		}
+	}
+}
+
+static int next_repair_mirror(const struct btrfs_failed_bio *fbio, int cur_mirror)
+{
+	if (cur_mirror == fbio->num_copies)
+		return cur_mirror + 1 - fbio->num_copies;
+	return cur_mirror + 1;
+}
+
+static int prev_repair_mirror(const struct btrfs_failed_bio *fbio, int cur_mirror)
+{
+	if (cur_mirror == 1)
+		return fbio->num_copies;
+	return cur_mirror - 1;
+}
+
+static void btrfs_repair_done(struct btrfs_failed_bio *fbio)
+{
+	if (atomic_dec_and_test(&fbio->repair_count)) {
+		btrfs_bio_end_io(fbio->bbio, fbio->bbio->bio.bi_status);
+		mempool_free(fbio, &btrfs_failed_bio_pool);
+	}
+}
+
+static void btrfs_end_repair_bio(struct btrfs_bio *repair_bbio,
+				 struct btrfs_device *dev)
+{
+	struct btrfs_failed_bio *fbio = repair_bbio->private;
+	struct btrfs_inode *inode = repair_bbio->inode;
+	struct btrfs_fs_info *fs_info = inode->root->fs_info;
+	/*
+	 * We can not move forward the saved_iter, as it will be later
+	 * utilized by repair_bbio again.
+	 */
+	struct bvec_iter saved_iter = repair_bbio->saved_iter;
+	const u32 step = min(fs_info->sectorsize, PAGE_SIZE);
+	const u64 logical = repair_bbio->saved_iter.bi_sector << SECTOR_SHIFT;
+	const u32 nr_steps = repair_bbio->saved_iter.bi_size / step;
+	int mirror = repair_bbio->mirror_num;
+	phys_addr_t paddrs[BTRFS_MAX_BLOCKSIZE / PAGE_SIZE];
+	phys_addr_t paddr;
+	unsigned int slot = 0;
+
+	/* Repair bbio should be eaxctly one block sized. */
+	ASSERT(repair_bbio->saved_iter.bi_size == fs_info->sectorsize);
+
+	btrfs_bio_for_each_block(paddr, &repair_bbio->bio, &saved_iter, step) {
+		ASSERT(slot < nr_steps);
+		paddrs[slot] = paddr;
+		slot++;
+	}
+
+	if (repair_bbio->bio.bi_status ||
+	    !btrfs_data_csum_ok(repair_bbio, dev, 0, paddrs)) {
+		bio_reset(&repair_bbio->bio, NULL, REQ_OP_READ);
+		repair_bbio->bio.bi_iter = repair_bbio->saved_iter;
+
+		mirror = next_repair_mirror(fbio, mirror);
+		if (mirror == fbio->bbio->mirror_num) {
+			btrfs_debug(fs_info, "no mirror left");
+			fbio->bbio->bio.bi_status = BLK_STS_IOERR;
+			goto done;
+		}
+
+		btrfs_submit_bbio(repair_bbio, mirror);
+		return;
+	}
+
+	do {
+		mirror = prev_repair_mirror(fbio, mirror);
+		btrfs_repair_io_failure(fs_info, btrfs_ino(inode),
+				  repair_bbio->file_offset, fs_info->sectorsize,
+				  logical, paddrs, step, mirror);
+	} while (mirror != fbio->bbio->mirror_num);
+
+done:
+	btrfs_repair_done(fbio);
+	bio_put(&repair_bbio->bio);
+}
+
+/*
+ * Try to kick off a repair read to the next available mirror for a bad sector.
+ *
+ * This primarily tries to recover good data to serve the actual read request,
+ * but also tries to write the good data back to the bad mirror(s) when a
+ * read succeeded to restore the redundancy.
+ */
+static struct btrfs_failed_bio *repair_one_sector(struct btrfs_bio *failed_bbio,
+						  u32 bio_offset,
+						  phys_addr_t paddrs[],
+						  struct btrfs_failed_bio *fbio)
+{
+	struct btrfs_inode *inode = failed_bbio->inode;
+	struct btrfs_fs_info *fs_info = inode->root->fs_info;
+	const u32 sectorsize = fs_info->sectorsize;
+	const u32 step = min(fs_info->sectorsize, PAGE_SIZE);
+	const u32 nr_steps = sectorsize / step;
+	/*
+	 * For bs > ps cases, the saved_iter can be partially moved forward.
+	 * In that case we should round it down to the block boundary.
+	 */
+	const u64 logical = round_down(failed_bbio->saved_iter.bi_sector << SECTOR_SHIFT,
+				       sectorsize);
+	struct btrfs_bio *repair_bbio;
+	struct bio *repair_bio;
+	int num_copies;
+	int mirror;
+
+	btrfs_debug(fs_info, "repair read error: read error at %llu",
+		    failed_bbio->file_offset + bio_offset);
+
+	num_copies = btrfs_num_copies(fs_info, logical, sectorsize);
+	if (num_copies == 1) {
+		btrfs_debug(fs_info, "no copy to repair from");
+		failed_bbio->bio.bi_status = BLK_STS_IOERR;
+		return fbio;
+	}
+
+	if (!fbio) {
+		fbio = mempool_alloc(&btrfs_failed_bio_pool, GFP_NOFS);
+		fbio->bbio = failed_bbio;
+		fbio->num_copies = num_copies;
+		atomic_set(&fbio->repair_count, 1);
+	}
+
+	atomic_inc(&fbio->repair_count);
+
+	repair_bio = bio_alloc_bioset(NULL, nr_steps, REQ_OP_READ, GFP_NOFS,
+				      &btrfs_repair_bioset);
+	repair_bio->bi_iter.bi_sector = logical >> SECTOR_SHIFT;
+	for (int i = 0; i < nr_steps; i++) {
+		int ret;
+
+		ASSERT(offset_in_page(paddrs[i]) + step <= PAGE_SIZE);
+
+		ret = bio_add_page(repair_bio, phys_to_page(paddrs[i]), step,
+				   offset_in_page(paddrs[i]));
+		ASSERT(ret == step);
+	}
+
+	repair_bbio = btrfs_bio(repair_bio);
+	btrfs_bio_init(repair_bbio, failed_bbio->inode, failed_bbio->file_offset + bio_offset,
+		       NULL, fbio);
+
+	mirror = next_repair_mirror(fbio, failed_bbio->mirror_num);
+	btrfs_debug(fs_info, "submitting repair read to mirror %d", mirror);
+	btrfs_submit_bbio(repair_bbio, mirror);
+	return fbio;
+}
+
+static void btrfs_check_read_bio(struct btrfs_bio *bbio, struct btrfs_device *dev)
+{
+	struct btrfs_inode *inode = bbio->inode;
+	struct btrfs_fs_info *fs_info = inode->root->fs_info;
+	const u32 sectorsize = fs_info->sectorsize;
+	const u32 step = min(sectorsize, PAGE_SIZE);
+	const u32 nr_steps = sectorsize / step;
+	struct bvec_iter *iter = &bbio->saved_iter;
+	blk_status_t status = bbio->bio.bi_status;
+	struct btrfs_failed_bio *fbio = NULL;
+	phys_addr_t paddrs[BTRFS_MAX_BLOCKSIZE / PAGE_SIZE];
+	phys_addr_t paddr;
+	u32 offset = 0;
+
+	/* Read-repair requires the inode field to be set by the submitter. */
+	ASSERT(inode);
+
+	/*
+	 * Hand off repair bios to the repair code as there is no upper level
+	 * submitter for them.
+	 */
+	if (bbio->bio.bi_pool == &btrfs_repair_bioset) {
+		btrfs_end_repair_bio(bbio, dev);
+		return;
+	}
+
+	/* Clear the I/O error. A failed repair will reset it. */
+	bbio->bio.bi_status = BLK_STS_OK;
+
+	btrfs_bio_for_each_block(paddr, &bbio->bio, iter, step) {
+		paddrs[(offset / step) % nr_steps] = paddr;
+		offset += step;
+
+		if (IS_ALIGNED(offset, sectorsize)) {
+			if (status ||
+			    !btrfs_data_csum_ok(bbio, dev, offset - sectorsize, paddrs))
+				fbio = repair_one_sector(bbio, offset - sectorsize,
+							 paddrs, fbio);
+		}
+	}
+	if (bbio->csum != bbio->csum_inline)
+		kvfree(bbio->csum);
+
+	if (fbio)
+		btrfs_repair_done(fbio);
+	else
+		btrfs_bio_end_io(bbio, bbio->bio.bi_status);
+}
+
+static void btrfs_log_dev_io_error(const struct bio *bio, struct btrfs_device *dev)
+{
+	blk_status_t sts = bio->bi_status;
+
+	if (!dev || !dev->bdev)
+		return;
+	if (unlikely(sts == BLK_STS_OK))
+		return;
+	if (unlikely(sts != BLK_STS_IOERR && sts != BLK_STS_TARGET &&
+		     sts != BLK_STS_MEDIUM && sts != BLK_STS_PROTECTION)) {
+		btrfs_warn_rl(dev->fs_info, "bdev %s unexpected block io error: %d",
+			      btrfs_dev_name(dev), sts);
+		return;
+	}
+	if (btrfs_op(bio) == BTRFS_MAP_WRITE)
+		btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_WRITE_ERRS);
+	else if (!(bio->bi_opf & REQ_RAHEAD))
+		btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_READ_ERRS);
+	if (bio->bi_opf & REQ_PREFLUSH)
+		btrfs_dev_stat_inc_and_print(dev, BTRFS_DEV_STAT_FLUSH_ERRS);
+}
+
+static struct workqueue_struct *btrfs_end_io_wq(const struct btrfs_fs_info *fs_info,
+						const struct bio *bio)
+{
+	if (bio->bi_opf & REQ_META)
+		return fs_info->endio_meta_workers;
+	return fs_info->endio_workers;
+}
+
+static void simple_end_io_work(struct work_struct *work)
+{
+	struct btrfs_bio *bbio = container_of(work, struct btrfs_bio, end_io_work);
+	struct bio *bio = &bbio->bio;
+
+	if (bio_op(bio) == REQ_OP_READ) {
+		/* Metadata reads are checked and repaired by the submitter. */
+		if (is_data_bbio(bbio))
+			return btrfs_check_read_bio(bbio, bbio->bio.bi_private);
+		return btrfs_bio_end_io(bbio, bbio->bio.bi_status);
+	}
+	if (bio_is_zone_append(bio) && !bio->bi_status)
+		btrfs_record_physical_zoned(bbio);
+	btrfs_bio_end_io(bbio, bbio->bio.bi_status);
+}
+
+static void btrfs_simple_end_io(struct bio *bio)
+{
+	struct btrfs_bio *bbio = btrfs_bio(bio);
+	struct btrfs_device *dev = bio->bi_private;
+	struct btrfs_fs_info *fs_info = bbio->inode->root->fs_info;
+
+	btrfs_bio_counter_dec(fs_info);
+
+	if (bio->bi_status)
+		btrfs_log_dev_io_error(bio, dev);
+
+	INIT_WORK(&bbio->end_io_work, simple_end_io_work);
+	queue_work(btrfs_end_io_wq(fs_info, bio), &bbio->end_io_work);
+}
+
+static void btrfs_raid56_end_io(struct bio *bio)
+{
+	struct btrfs_io_context *bioc = bio->bi_private;
+	struct btrfs_bio *bbio = btrfs_bio(bio);
+
+	/* RAID56 endio is always handled in workqueue. */
+	ASSERT(in_task());
+
+	btrfs_bio_counter_dec(bioc->fs_info);
+	bbio->mirror_num = bioc->mirror_num;
+	if (bio_op(bio) == REQ_OP_READ && is_data_bbio(bbio))
+		btrfs_check_read_bio(bbio, NULL);
+	else
+		btrfs_bio_end_io(bbio, bbio->bio.bi_status);
+
+	btrfs_put_bioc(bioc);
+}
+
+static void orig_write_end_io_work(struct work_struct *work)
+{
+	struct btrfs_bio *bbio = container_of(work, struct btrfs_bio, end_io_work);
+	struct bio *bio = &bbio->bio;
+	struct btrfs_io_stripe *stripe = bio->bi_private;
+	struct btrfs_io_context *bioc = stripe->bioc;
+
+	btrfs_bio_counter_dec(bioc->fs_info);
+
+	if (bio->bi_status) {
+		atomic_inc(&bioc->error);
+		btrfs_log_dev_io_error(bio, stripe->dev);
+	}
+
+	/*
+	 * Only send an error to the higher layers if it is beyond the tolerance
+	 * threshold.
+	 */
+	if (atomic_read(&bioc->error) > bioc->max_errors)
+		bio->bi_status = BLK_STS_IOERR;
+	else
+		bio->bi_status = BLK_STS_OK;
+
+	if (bio_is_zone_append(bio) && !bio->bi_status)
+		stripe->physical = bio->bi_iter.bi_sector << SECTOR_SHIFT;
+
+	btrfs_bio_end_io(bbio, bbio->bio.bi_status);
+	btrfs_put_bioc(bioc);
+}
+
+static void btrfs_orig_write_end_io(struct bio *bio)
+{
+	struct btrfs_bio *bbio = btrfs_bio(bio);
+
+	INIT_WORK(&bbio->end_io_work, orig_write_end_io_work);
+	queue_work(btrfs_end_io_wq(bbio->inode->root->fs_info, bio), &bbio->end_io_work);
+}
+
+static void clone_write_end_io_work(struct work_struct *work)
+{
+	struct btrfs_bio *bbio = container_of(work, struct btrfs_bio, end_io_work);
+	struct bio *bio = &bbio->bio;
+	struct btrfs_io_stripe *stripe = bio->bi_private;
+
+	if (bio->bi_status) {
+		atomic_inc(&stripe->bioc->error);
+		btrfs_log_dev_io_error(bio, stripe->dev);
+	} else if (bio_is_zone_append(bio)) {
+		stripe->physical = bio->bi_iter.bi_sector << SECTOR_SHIFT;
+	}
+
+	/* Pass on control to the original bio this one was cloned from */
+	bio_endio(stripe->bioc->orig_bio);
+	bio_put(bio);
+}
+
+static void btrfs_clone_write_end_io(struct bio *bio)
+{
+	struct btrfs_bio *bbio = btrfs_bio(bio);
+
+	INIT_WORK(&bbio->end_io_work, clone_write_end_io_work);
+	queue_work(btrfs_end_io_wq(bbio->inode->root->fs_info, bio), &bbio->end_io_work);
+}
+
+static void btrfs_submit_dev_bio(struct btrfs_device *dev, struct bio *bio)
+{
+	u64 physical = bio->bi_iter.bi_sector << SECTOR_SHIFT;
+
+	if (!dev || !dev->bdev ||
+	    test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state) ||
+	    (btrfs_op(bio) == BTRFS_MAP_WRITE &&
+	     !test_bit(BTRFS_DEV_STATE_WRITEABLE, &dev->dev_state))) {
+		bio_io_error(bio);
+		return;
+	}
+
+	bio_set_dev(bio, dev->bdev);
+
+	/*
+	 * For zone append writing, bi_sector must point the beginning of the
+	 * zone
+	 */
+	if (btrfs_bio(bio)->can_use_append && btrfs_dev_is_sequential(dev, physical)) {
+		u64 zone_start = round_down(physical, dev->fs_info->zone_size);
+
+		ASSERT(btrfs_dev_is_sequential(dev, physical));
+		bio->bi_iter.bi_sector = zone_start >> SECTOR_SHIFT;
+		bio->bi_opf &= ~REQ_OP_WRITE;
+		bio->bi_opf |= REQ_OP_ZONE_APPEND;
+	}
+	btrfs_debug(dev->fs_info,
+	"%s: rw %d 0x%x, sector=%llu, dev=%lu (%s id %llu), size=%u",
+		__func__, bio_op(bio), bio->bi_opf, bio->bi_iter.bi_sector,
+		(unsigned long)dev->bdev->bd_dev, btrfs_dev_name(dev),
+		dev->devid, bio->bi_iter.bi_size);
+
+	/*
+	 * Track reads if tracking is enabled; ignore I/O operations before the
+	 * filesystem is fully initialized.
+	 */
+	if (dev->fs_devices->collect_fs_stats && bio_op(bio) == REQ_OP_READ && dev->fs_info)
+		percpu_counter_add(&dev->fs_info->stats_read_blocks,
+				   bio->bi_iter.bi_size >> dev->fs_info->sectorsize_bits);
+
+	if (bio->bi_opf & REQ_BTRFS_CGROUP_PUNT)
+		blkcg_punt_bio_submit(bio);
+	else
+		submit_bio(bio);
+}
+
+static void btrfs_submit_mirrored_bio(struct btrfs_io_context *bioc, int dev_nr)
+{
+	struct bio *orig_bio = bioc->orig_bio, *bio;
+	struct btrfs_bio *orig_bbio = btrfs_bio(orig_bio);
+
+	ASSERT(bio_op(orig_bio) != REQ_OP_READ);
+
+	/* Reuse the bio embedded into the btrfs_bio for the last mirror */
+	if (dev_nr == bioc->num_stripes - 1) {
+		bio = orig_bio;
+		bio->bi_end_io = btrfs_orig_write_end_io;
+	} else {
+		/* We need to use endio_work to run end_io in task context. */
+		bio = bio_alloc_clone(NULL, orig_bio, GFP_NOFS, &btrfs_bioset);
+		bio_inc_remaining(orig_bio);
+		btrfs_bio_init(btrfs_bio(bio), orig_bbio->inode,
+			       orig_bbio->file_offset, NULL, NULL);
+		bio->bi_end_io = btrfs_clone_write_end_io;
+	}
+
+	bio->bi_private = &bioc->stripes[dev_nr];
+	bio->bi_iter.bi_sector = bioc->stripes[dev_nr].physical >> SECTOR_SHIFT;
+	bioc->stripes[dev_nr].bioc = bioc;
+	bioc->size = bio->bi_iter.bi_size;
+	btrfs_submit_dev_bio(bioc->stripes[dev_nr].dev, bio);
+}
+
+static void btrfs_submit_bio(struct bio *bio, struct btrfs_io_context *bioc,
+			     struct btrfs_io_stripe *smap, int mirror_num)
+{
+	if (!bioc) {
+		/* Single mirror read/write fast path. */
+		btrfs_bio(bio)->mirror_num = mirror_num;
+		bio->bi_iter.bi_sector = smap->physical >> SECTOR_SHIFT;
+		if (bio_op(bio) != REQ_OP_READ)
+			btrfs_bio(bio)->orig_physical = smap->physical;
+		bio->bi_private = smap->dev;
+		bio->bi_end_io = btrfs_simple_end_io;
+		btrfs_submit_dev_bio(smap->dev, bio);
+	} else if (bioc->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
+		/* Parity RAID write or read recovery. */
+		bio->bi_private = bioc;
+		bio->bi_end_io = btrfs_raid56_end_io;
+		if (bio_op(bio) == REQ_OP_READ)
+			raid56_parity_recover(bio, bioc, mirror_num);
+		else
+			raid56_parity_write(bio, bioc);
+	} else {
+		/* Write to multiple mirrors. */
+		int total_devs = bioc->num_stripes;
+
+		bioc->orig_bio = bio;
+		for (int dev_nr = 0; dev_nr < total_devs; dev_nr++)
+			btrfs_submit_mirrored_bio(bioc, dev_nr);
+	}
+}
+
+static int btrfs_bio_csum(struct btrfs_bio *bbio)
+{
+	if (bbio->bio.bi_opf & REQ_META)
+		return btree_csum_one_bio(bbio);
+#ifdef CONFIG_BTRFS_EXPERIMENTAL
+	return btrfs_csum_one_bio(bbio, true);
+#else
+	return btrfs_csum_one_bio(bbio, false);
+#endif
+}
+
+/*
+ * Async submit bios are used to offload expensive checksumming onto the worker
+ * threads.
+ */
+struct async_submit_bio {
+	struct btrfs_bio *bbio;
+	struct btrfs_io_context *bioc;
+	struct btrfs_io_stripe smap;
+	int mirror_num;
+	struct btrfs_work work;
+};
+
+/*
+ * In order to insert checksums into the metadata in large chunks, we wait
+ * until bio submission time.   All the pages in the bio are checksummed and
+ * sums are attached onto the ordered extent record.
+ *
+ * At IO completion time the csums attached on the ordered extent record are
+ * inserted into the btree.
+ */
+static void run_one_async_start(struct btrfs_work *work)
+{
+	struct async_submit_bio *async =
+		container_of(work, struct async_submit_bio, work);
+	int ret;
+
+	ret = btrfs_bio_csum(async->bbio);
+	if (ret)
+		async->bbio->bio.bi_status = errno_to_blk_status(ret);
+}
+
+/*
+ * In order to insert checksums into the metadata in large chunks, we wait
+ * until bio submission time.   All the pages in the bio are checksummed and
+ * sums are attached onto the ordered extent record.
+ *
+ * At IO completion time the csums attached on the ordered extent record are
+ * inserted into the tree.
+ *
+ * If called with @do_free == true, then it will free the work struct.
+ */
+static void run_one_async_done(struct btrfs_work *work, bool do_free)
+{
+	struct async_submit_bio *async =
+		container_of(work, struct async_submit_bio, work);
+	struct bio *bio = &async->bbio->bio;
+
+	if (do_free) {
+		kfree(container_of(work, struct async_submit_bio, work));
+		return;
+	}
+
+	/* If an error occurred we just want to clean up the bio and move on. */
+	if (bio->bi_status) {
+		btrfs_bio_end_io(async->bbio, bio->bi_status);
+		return;
+	}
+
+	/*
+	 * All of the bios that pass through here are from async helpers.
+	 * Use REQ_BTRFS_CGROUP_PUNT to issue them from the owning cgroup's
+	 * context.  This changes nothing when cgroups aren't in use.
+	 */
+	bio->bi_opf |= REQ_BTRFS_CGROUP_PUNT;
+	btrfs_submit_bio(bio, async->bioc, &async->smap, async->mirror_num);
+}
+
+static bool should_async_write(struct btrfs_bio *bbio)
+{
+	struct btrfs_fs_info *fs_info = bbio->inode->root->fs_info;
+	bool auto_csum_mode = true;
+
+#ifdef CONFIG_BTRFS_EXPERIMENTAL
+	/*
+	 * Write bios will calculate checksum and submit bio at the same time.
+	 * Unless explicitly required don't offload serial csum calculate and bio
+	 * submit into a workqueue.
+	 */
+	return false;
+#endif
+
+	/* Submit synchronously if the checksum implementation is fast. */
+	if (auto_csum_mode && test_bit(BTRFS_FS_CSUM_IMPL_FAST, &fs_info->flags))
+		return false;
+
+	/*
+	 * Try to defer the submission to a workqueue to parallelize the
+	 * checksum calculation unless the I/O is issued synchronously.
+	 */
+	if (op_is_sync(bbio->bio.bi_opf))
+		return false;
+
+	/* Zoned devices require I/O to be submitted in order. */
+	if ((bbio->bio.bi_opf & REQ_META) && btrfs_is_zoned(fs_info))
+		return false;
+
+	return true;
+}
+
+/*
+ * Submit bio to an async queue.
+ *
+ * Return true if the work has been successfully submitted, else false.
+ */
+static bool btrfs_wq_submit_bio(struct btrfs_bio *bbio,
+				struct btrfs_io_context *bioc,
+				struct btrfs_io_stripe *smap, int mirror_num)
+{
+	struct btrfs_fs_info *fs_info = bbio->inode->root->fs_info;
+	struct async_submit_bio *async;
+
+	async = kmalloc_obj(*async, GFP_NOFS);
+	if (!async)
+		return false;
+
+	async->bbio = bbio;
+	async->bioc = bioc;
+	async->smap = *smap;
+	async->mirror_num = mirror_num;
+
+	btrfs_init_work(&async->work, run_one_async_start, run_one_async_done);
+	btrfs_queue_work(fs_info->workers, &async->work);
+	return true;
+}
+
+static u64 btrfs_append_map_length(struct btrfs_bio *bbio, u64 map_length)
+{
+	struct btrfs_fs_info *fs_info = bbio->inode->root->fs_info;
+	unsigned int nr_segs;
+	int sector_offset;
+
+	map_length = min(map_length, fs_info->max_zone_append_size);
+	sector_offset = bio_split_rw_at(&bbio->bio, &fs_info->limits,
+					&nr_segs, map_length);
+	if (sector_offset) {
+		/*
+		 * bio_split_rw_at() could split at a size smaller than our
+		 * sectorsize and thus cause unaligned I/Os.  Fix that by
+		 * always rounding down to the nearest boundary.
+		 */
+		return ALIGN_DOWN(sector_offset << SECTOR_SHIFT, fs_info->sectorsize);
+	}
+	return map_length;
+}
+
+static bool btrfs_submit_chunk(struct btrfs_bio *bbio, int mirror_num)
+{
+	struct btrfs_inode *inode = bbio->inode;
+	struct btrfs_fs_info *fs_info = inode->root->fs_info;
+	struct bio *bio = &bbio->bio;
+	u64 logical = bio->bi_iter.bi_sector << SECTOR_SHIFT;
+	u64 length = bio->bi_iter.bi_size;
+	u64 map_length = length;
+	struct btrfs_io_context *bioc = NULL;
+	struct btrfs_io_stripe smap;
+	blk_status_t status;
+	int ret;
+
+	if (bbio->is_scrub || btrfs_is_data_reloc_root(inode->root))
+		smap.rst_search_commit_root = true;
+	else
+		smap.rst_search_commit_root = false;
+
+	btrfs_bio_counter_inc_blocked(fs_info);
+	ret = btrfs_map_block(fs_info, btrfs_op(bio), logical, &map_length,
+			      &bioc, &smap, &mirror_num);
+	if (ret) {
+		status = errno_to_blk_status(ret);
+		btrfs_bio_counter_dec(fs_info);
+		goto end_bbio;
+	}
+
+	/*
+	 * For fscrypt writes we will get the encrypted bio after we've remapped
+	 * our bio to the physical disk location, so we need to save the
+	 * original bytenr so we know what we're checksumming.
+	 */
+	if (bio_op(bio) == REQ_OP_WRITE && is_data_bbio(bbio))
+		bbio->orig_logical = logical;
+
+	bbio->can_use_append = btrfs_use_zone_append(bbio);
+
+	map_length = min(map_length, length);
+	if (bbio->can_use_append)
+		map_length = btrfs_append_map_length(bbio, map_length);
+
+	if (map_length < length) {
+		struct btrfs_bio *split;
+
+		split = btrfs_split_bio(fs_info, bbio, map_length);
+		if (IS_ERR(split)) {
+			status = errno_to_blk_status(PTR_ERR(split));
+			btrfs_bio_counter_dec(fs_info);
+			goto end_bbio;
+		}
+		bbio = split;
+		bio = &bbio->bio;
+	}
+
+	/*
+	 * Save the iter for the end_io handler and preload the checksums for
+	 * data reads.
+	 */
+	if (bio_op(bio) == REQ_OP_READ && is_data_bbio(bbio)) {
+		bbio->saved_iter = bio->bi_iter;
+		ret = btrfs_lookup_bio_sums(bbio);
+		status = errno_to_blk_status(ret);
+		if (status)
+			goto fail;
+	}
+
+	if (btrfs_op(bio) == BTRFS_MAP_WRITE) {
+		if (is_data_bbio(bbio) && bioc && bioc->use_rst) {
+			/*
+			 * No locking for the list update, as we only add to
+			 * the list in the I/O submission path, and list
+			 * iteration only happens in the completion path, which
+			 * can't happen until after the last submission.
+			 */
+			btrfs_get_bioc(bioc);
+			list_add_tail(&bioc->rst_ordered_entry, &bbio->ordered->bioc_list);
+		}
+
+		/*
+		 * Csum items for reloc roots have already been cloned at this
+		 * point, so they are handled as part of the no-checksum case.
+		 */
+		if (!(inode->flags & BTRFS_INODE_NODATASUM) &&
+		    !test_bit(BTRFS_FS_STATE_NO_DATA_CSUMS, &fs_info->fs_state) &&
+		    !btrfs_is_data_reloc_root(inode->root) && !bbio->is_remap) {
+			if (should_async_write(bbio) &&
+			    btrfs_wq_submit_bio(bbio, bioc, &smap, mirror_num))
+				goto done;
+
+			ret = btrfs_bio_csum(bbio);
+			status = errno_to_blk_status(ret);
+			if (status)
+				goto fail;
+		} else if (bbio->can_use_append ||
+			   (btrfs_is_zoned(fs_info) && inode->flags & BTRFS_INODE_NODATASUM)) {
+			ret = btrfs_alloc_dummy_sum(bbio);
+			status = errno_to_blk_status(ret);
+			if (status)
+				goto fail;
+		}
+	}
+
+	btrfs_submit_bio(bio, bioc, &smap, mirror_num);
+done:
+	return map_length == length;
+
+fail:
+	btrfs_bio_counter_dec(fs_info);
+	/*
+	 * We have split the original bbio, now we have to end both the current
+	 * @bbio and remaining one, as the remaining one will never be submitted.
+	 */
+	if (map_length < length) {
+		struct btrfs_bio *remaining = bbio->private;
+
+		ASSERT(bbio->bio.bi_pool == &btrfs_clone_bioset);
+		ASSERT(remaining);
+
+		btrfs_bio_end_io(remaining, status);
+	}
+end_bbio:
+	btrfs_bio_end_io(bbio, status);
+	/* Do not submit another chunk */
+	return true;
+}
+
+static void assert_bbio_alignment(struct btrfs_bio *bbio)
+{
+#ifdef CONFIG_BTRFS_ASSERT
+	struct btrfs_fs_info *fs_info = bbio->inode->root->fs_info;
+	struct bio_vec bvec;
+	struct bvec_iter iter;
+	const u32 blocksize = fs_info->sectorsize;
+	const u32 alignment = min(blocksize, PAGE_SIZE);
+	const u64 logical = bbio->bio.bi_iter.bi_sector << SECTOR_SHIFT;
+	const u32 length = bbio->bio.bi_iter.bi_size;
+
+	/* The logical and length should still be aligned to blocksize. */
+	ASSERT(IS_ALIGNED(logical, blocksize) && IS_ALIGNED(length, blocksize) &&
+	       length != 0, "root=%llu inode=%llu logical=%llu length=%u",
+	       btrfs_root_id(bbio->inode->root),
+	       btrfs_ino(bbio->inode), logical, length);
+
+	bio_for_each_bvec(bvec, &bbio->bio, iter)
+		ASSERT(IS_ALIGNED(bvec.bv_offset, alignment) &&
+		       IS_ALIGNED(bvec.bv_len, alignment),
+		"root=%llu inode=%llu logical=%llu length=%u index=%u bv_offset=%u bv_len=%u",
+		btrfs_root_id(bbio->inode->root),
+		btrfs_ino(bbio->inode), logical, length, iter.bi_idx,
+		bvec.bv_offset, bvec.bv_len);
+#endif
+}
+
+void btrfs_submit_bbio(struct btrfs_bio *bbio, int mirror_num)
+{
+	/* If bbio->inode is not populated, its file_offset must be 0. */
+	ASSERT(bbio->inode || bbio->file_offset == 0);
+
+	assert_bbio_alignment(bbio);
+
+	while (!btrfs_submit_chunk(bbio, mirror_num))
+		;
+}
+
+/*
+ * Submit a repair write.
+ *
+ * This bypasses btrfs_submit_bbio() deliberately, as that writes all copies in a
+ * RAID setup.  Here we only want to write the one bad copy, so we do the
+ * mapping ourselves and submit the bio directly.
+ *
+ * The I/O is issued synchronously to block the repair read completion from
+ * freeing the bio.
+ *
+ * @ino:	Offending inode number
+ * @fileoff:	File offset inside the inode
+ * @length:	Length of the repair write
+ * @logical:	Logical address of the range
+ * @paddrs:	Physical address array of the content
+ * @step:	Length of for each paddrs
+ * @mirror_num: Mirror number to write to. Must not be zero
+ */
+int btrfs_repair_io_failure(struct btrfs_fs_info *fs_info, u64 ino, u64 fileoff,
+			    u32 length, u64 logical, const phys_addr_t paddrs[],
+			    unsigned int step, int mirror_num)
+{
+	const u32 nr_steps = DIV_ROUND_UP_POW2(length, step);
+	struct btrfs_io_stripe smap = { 0 };
+	struct bio *bio = NULL;
+	int ret = 0;
+
+	BUG_ON(!mirror_num);
+
+	/* Basic alignment checks. */
+	ASSERT(IS_ALIGNED(logical, fs_info->sectorsize));
+	ASSERT(IS_ALIGNED(length, fs_info->sectorsize));
+	ASSERT(IS_ALIGNED(fileoff, fs_info->sectorsize));
+	/* Either it's a single data or metadata block. */
+	ASSERT(length <= BTRFS_MAX_BLOCKSIZE);
+	ASSERT(step <= length);
+	ASSERT(is_power_of_2(step));
+
+	/*
+	 * The fs either mounted RO or hit critical errors, no need
+	 * to continue repairing.
+	 */
+	if (unlikely(sb_rdonly(fs_info->sb)))
+		return 0;
+
+	if (btrfs_repair_one_zone(fs_info, logical))
+		return 0;
+
+	/*
+	 * Avoid races with device replace and make sure our bioc has devices
+	 * associated to its stripes that don't go away while we are doing the
+	 * read repair operation.
+	 */
+	btrfs_bio_counter_inc_blocked(fs_info);
+	ret = btrfs_map_repair_block(fs_info, &smap, logical, length, mirror_num);
+	if (ret < 0)
+		goto out_counter_dec;
+
+	if (unlikely(!smap.dev->bdev ||
+		     !test_bit(BTRFS_DEV_STATE_WRITEABLE, &smap.dev->dev_state))) {
+		ret = -EIO;
+		goto out_counter_dec;
+	}
+
+	bio = bio_alloc(smap.dev->bdev, nr_steps, REQ_OP_WRITE | REQ_SYNC, GFP_NOFS);
+	bio->bi_iter.bi_sector = smap.physical >> SECTOR_SHIFT;
+	for (int i = 0; i < nr_steps; i++) {
+		ret = bio_add_page(bio, phys_to_page(paddrs[i]), step, offset_in_page(paddrs[i]));
+		/* We should have allocated enough slots to contain all the different pages. */
+		ASSERT(ret == step);
+	}
+	ret = submit_bio_wait(bio);
+	bio_put(bio);
+	if (ret) {
+		/* try to remap that extent elsewhere? */
+		btrfs_dev_stat_inc_and_print(smap.dev, BTRFS_DEV_STAT_WRITE_ERRS);
+		goto out_counter_dec;
+	}
+
+	btrfs_info_rl(fs_info,
+		"read error corrected: ino %llu off %llu (dev %s sector %llu)",
+			     ino, fileoff, btrfs_dev_name(smap.dev),
+			     smap.physical >> SECTOR_SHIFT);
+	ret = 0;
+
+out_counter_dec:
+	btrfs_bio_counter_dec(fs_info);
+	return ret;
+}
+
+/*
+ * Submit a btrfs_bio based repair write.
+ *
+ * If @dev_replace is true, the write would be submitted to dev-replace target.
+ */
+void btrfs_submit_repair_write(struct btrfs_bio *bbio, int mirror_num, bool dev_replace)
+{
+	struct btrfs_fs_info *fs_info = bbio->inode->root->fs_info;
+	u64 logical = bbio->bio.bi_iter.bi_sector << SECTOR_SHIFT;
+	u64 length = bbio->bio.bi_iter.bi_size;
+	struct btrfs_io_stripe smap = { 0 };
+	int ret;
+
+	ASSERT(mirror_num > 0);
+	ASSERT(btrfs_op(&bbio->bio) == BTRFS_MAP_WRITE);
+	ASSERT(!is_data_inode(bbio->inode));
+	ASSERT(bbio->is_scrub);
+
+	btrfs_bio_counter_inc_blocked(fs_info);
+	ret = btrfs_map_repair_block(fs_info, &smap, logical, length, mirror_num);
+	if (ret < 0)
+		goto fail;
+
+	if (dev_replace) {
+		ASSERT(smap.dev == fs_info->dev_replace.srcdev);
+		smap.dev = fs_info->dev_replace.tgtdev;
+	}
+	btrfs_submit_bio(&bbio->bio, NULL, &smap, mirror_num);
+	return;
+
+fail:
+	btrfs_bio_counter_dec(fs_info);
+	btrfs_bio_end_io(bbio, errno_to_blk_status(ret));
+}
+
+int __init btrfs_bioset_init(void)
+{
+	if (bioset_init(&btrfs_bioset, BIO_POOL_SIZE,
+			offsetof(struct btrfs_bio, bio),
+			BIOSET_NEED_BVECS))
+		return -ENOMEM;
+	if (bioset_init(&btrfs_clone_bioset, BIO_POOL_SIZE,
+			offsetof(struct btrfs_bio, bio), 0))
+		goto out;
+	if (bioset_init(&btrfs_repair_bioset, BIO_POOL_SIZE,
+			offsetof(struct btrfs_bio, bio),
+			BIOSET_NEED_BVECS))
+		goto out;
+	if (mempool_init_kmalloc_pool(&btrfs_failed_bio_pool, BIO_POOL_SIZE,
+				      sizeof(struct btrfs_failed_bio)))
+		goto out;
+	return 0;
+
+out:
+	btrfs_bioset_exit();
+	return -ENOMEM;
+}
+
+void __cold btrfs_bioset_exit(void)
+{
+	mempool_exit(&btrfs_failed_bio_pool);
+	bioset_exit(&btrfs_repair_bioset);
+	bioset_exit(&btrfs_clone_bioset);
+	bioset_exit(&btrfs_bioset);
+}