Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 872 insertions, 0 deletions

diff --git a/fs/btrfs/bio.c b/fs/btrfs/bio.c
new file mode 100644
index 0000000000..12b12443ef
--- /dev/null
+++ b/fs/btrfs/bio.c
@@ -0,0 +1,872 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2007 Oracle.  All rights reserved.
+ * Copyright (C) 2022 Christoph Hellwig.
+ */
+
+#include <linux/bio.h>
+#include "bio.h"
+#include "ctree.h"
+#include "volumes.h"
+#include "raid56.h"
+#include "async-thread.h"
+#include "check-integrity.h"
+#include "dev-replace.h"
+#include "rcu-string.h"
+#include "zoned.h"
+#include "file-item.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(struct btrfs_bio *bbio)
+{
+	return bbio->inode && is_data_inode(&bbio->inode->vfs_inode);
+}
+
+static bool bbio_has_ordered_extent(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_fs_info *fs_info,
+		    btrfs_bio_end_io_t end_io, void *private)
+{
+	memset(bbio, 0, offsetof(struct btrfs_bio, bio));
+	bbio->fs_info = fs_info;
+	bbio->end_io = end_io;
+	bbio->private = private;
+	atomic_set(&bbio->pending_ios, 1);
+}
+
+/*
+ * 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_bio.
+ *
+ * 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_fs_info *fs_info,
+				  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, fs_info, 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, bool use_append)
+{
+	struct btrfs_bio *bbio;
+	struct bio *bio;
+
+	if (use_append) {
+		unsigned int nr_segs;
+
+		bio = bio_split_rw(&orig_bbio->bio, &fs_info->limits, &nr_segs,
+				   &btrfs_clone_bioset, map_length);
+	} else {
+		bio = bio_split(&orig_bbio->bio, map_length >> SECTOR_SHIFT,
+				GFP_NOFS, &btrfs_clone_bioset);
+	}
+	bbio = btrfs_bio(bio);
+	btrfs_bio_init(bbio, fs_info, NULL, orig_bbio);
+	bbio->inode = orig_bbio->inode;
+	bbio->file_offset = orig_bbio->file_offset;
+	orig_bbio->file_offset += map_length;
+	if (bbio_has_ordered_extent(bbio)) {
+		refcount_inc(&orig_bbio->ordered->refs);
+		bbio->ordered = orig_bbio->ordered;
+	}
+	atomic_inc(&orig_bbio->pending_ios);
+	return bbio;
+}
+
+/* Free a bio that was never submitted to the underlying device. */
+static void btrfs_cleanup_bio(struct btrfs_bio *bbio)
+{
+	if (bbio_has_ordered_extent(bbio))
+		btrfs_put_ordered_extent(bbio->ordered);
+	bio_put(&bbio->bio);
+}
+
+static void __btrfs_bio_end_io(struct btrfs_bio *bbio)
+{
+	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);
+	}
+}
+
+void btrfs_bio_end_io(struct btrfs_bio *bbio, blk_status_t status)
+{
+	bbio->bio.bi_status = status;
+	__btrfs_bio_end_io(bbio);
+}
+
+static void btrfs_orig_write_end_io(struct bio *bio);
+
+static void btrfs_bbio_propagate_error(struct btrfs_bio *bbio,
+				       struct btrfs_bio *orig_bbio)
+{
+	/*
+	 * For writes we tolerate nr_mirrors - 1 write failures, so we can't
+	 * just blindly propagate a write failure here.  Instead increment the
+	 * error count in the original I/O context so that it is guaranteed to
+	 * be larger than the error tolerance.
+	 */
+	if (bbio->bio.bi_end_io == &btrfs_orig_write_end_io) {
+		struct btrfs_io_stripe *orig_stripe = orig_bbio->bio.bi_private;
+		struct btrfs_io_context *orig_bioc = orig_stripe->bioc;
+
+		atomic_add(orig_bioc->max_errors, &orig_bioc->error);
+	} else {
+		orig_bbio->bio.bi_status = bbio->bio.bi_status;
+	}
+}
+
+static void btrfs_orig_bbio_end_io(struct btrfs_bio *bbio)
+{
+	if (bbio->bio.bi_pool == &btrfs_clone_bioset) {
+		struct btrfs_bio *orig_bbio = bbio->private;
+
+		if (bbio->bio.bi_status)
+			btrfs_bbio_propagate_error(bbio, orig_bbio);
+		btrfs_cleanup_bio(bbio);
+		bbio = orig_bbio;
+	}
+
+	if (atomic_dec_and_test(&bbio->pending_ios))
+		__btrfs_bio_end_io(bbio);
+}
+
+static int next_repair_mirror(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(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_orig_bbio_end_io(fbio->bbio);
+		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;
+	struct bio_vec *bv = bio_first_bvec_all(&repair_bbio->bio);
+	int mirror = repair_bbio->mirror_num;
+
+	if (repair_bbio->bio.bi_status ||
+	    !btrfs_data_csum_ok(repair_bbio, dev, 0, bv)) {
+		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_bio(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,
+				  repair_bbio->saved_iter.bi_sector << SECTOR_SHIFT,
+				  bv->bv_page, bv->bv_offset, 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,
+						  struct bio_vec *bv,
+						  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 u64 logical = (failed_bbio->saved_iter.bi_sector << SECTOR_SHIFT);
+	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, 1, REQ_OP_READ, GFP_NOFS,
+				      &btrfs_repair_bioset);
+	repair_bio->bi_iter.bi_sector = failed_bbio->saved_iter.bi_sector;
+	__bio_add_page(repair_bio, bv->bv_page, bv->bv_len, bv->bv_offset);
+
+	repair_bbio = btrfs_bio(repair_bio);
+	btrfs_bio_init(repair_bbio, fs_info, NULL, fbio);
+	repair_bbio->inode = failed_bbio->inode;
+	repair_bbio->file_offset = failed_bbio->file_offset + bio_offset;
+
+	mirror = next_repair_mirror(fbio, failed_bbio->mirror_num);
+	btrfs_debug(fs_info, "submitting repair read to mirror %d", mirror);
+	btrfs_submit_bio(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;
+	u32 sectorsize = fs_info->sectorsize;
+	struct bvec_iter *iter = &bbio->saved_iter;
+	blk_status_t status = bbio->bio.bi_status;
+	struct btrfs_failed_bio *fbio = NULL;
+	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;
+
+	while (iter->bi_size) {
+		struct bio_vec bv = bio_iter_iovec(&bbio->bio, *iter);
+
+		bv.bv_len = min(bv.bv_len, sectorsize);
+		if (status || !btrfs_data_csum_ok(bbio, dev, offset, &bv))
+			fbio = repair_one_sector(bbio, offset, &bv, fbio);
+
+		bio_advance_iter_single(&bbio->bio, iter, sectorsize);
+		offset += sectorsize;
+	}
+
+	if (bbio->csum != bbio->csum_inline)
+		kfree(bbio->csum);
+
+	if (fbio)
+		btrfs_repair_done(fbio);
+	else
+		btrfs_orig_bbio_end_io(bbio);
+}
+
+static void btrfs_log_dev_io_error(struct bio *bio, struct btrfs_device *dev)
+{
+	if (!dev || !dev->bdev)
+		return;
+	if (bio->bi_status != BLK_STS_IOERR && bio->bi_status != BLK_STS_TARGET)
+		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(struct btrfs_fs_info *fs_info,
+						struct bio *bio)
+{
+	if (bio->bi_opf & REQ_META)
+		return fs_info->endio_meta_workers;
+	return fs_info->endio_workers;
+}
+
+static void btrfs_end_bio_work(struct work_struct *work)
+{
+	struct btrfs_bio *bbio = container_of(work, struct btrfs_bio, end_io_work);
+
+	/* Metadata reads are checked and repaired by the submitter. */
+	if (is_data_bbio(bbio))
+		btrfs_check_read_bio(bbio, bbio->bio.bi_private);
+	else
+		btrfs_orig_bbio_end_io(bbio);
+}
+
+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->fs_info;
+
+	btrfs_bio_counter_dec(fs_info);
+
+	if (bio->bi_status)
+		btrfs_log_dev_io_error(bio, dev);
+
+	if (bio_op(bio) == REQ_OP_READ) {
+		INIT_WORK(&bbio->end_io_work, btrfs_end_bio_work);
+		queue_work(btrfs_end_io_wq(fs_info, bio), &bbio->end_io_work);
+	} else {
+		if (bio_op(bio) == REQ_OP_ZONE_APPEND && !bio->bi_status)
+			btrfs_record_physical_zoned(bbio);
+		btrfs_orig_bbio_end_io(bbio);
+	}
+}
+
+static void btrfs_raid56_end_io(struct bio *bio)
+{
+	struct btrfs_io_context *bioc = bio->bi_private;
+	struct btrfs_bio *bbio = btrfs_bio(bio);
+
+	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_orig_bbio_end_io(bbio);
+
+	btrfs_put_bioc(bioc);
+}
+
+static void btrfs_orig_write_end_io(struct bio *bio)
+{
+	struct btrfs_io_stripe *stripe = bio->bi_private;
+	struct btrfs_io_context *bioc = stripe->bioc;
+	struct btrfs_bio *bbio = btrfs_bio(bio);
+
+	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;
+
+	btrfs_orig_bbio_end_io(bbio);
+	btrfs_put_bioc(bioc);
+}
+
+static void btrfs_clone_write_end_io(struct bio *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);
+	}
+
+	/* Pass on control to the original bio this one was cloned from */
+	bio_endio(stripe->bioc->orig_bio);
+	bio_put(bio);
+}
+
+static void btrfs_submit_dev_bio(struct btrfs_device *dev, struct bio *bio)
+{
+	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 (bio_op(bio) == REQ_OP_ZONE_APPEND) {
+		u64 physical = bio->bi_iter.bi_sector << SECTOR_SHIFT;
+		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;
+	}
+	btrfs_debug_in_rcu(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);
+
+	btrfsic_check_bio(bio);
+
+	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;
+
+	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 {
+		bio = bio_alloc_clone(NULL, orig_bio, GFP_NOFS, &fs_bio_set);
+		bio_inc_remaining(orig_bio);
+		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;
+	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 blk_status_t btrfs_bio_csum(struct btrfs_bio *bbio)
+{
+	if (bbio->bio.bi_opf & REQ_META)
+		return btree_csum_one_bio(bbio);
+	return btrfs_csum_one_bio(bbio);
+}
+
+/*
+ * 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);
+	blk_status_t ret;
+
+	ret = btrfs_bio_csum(async->bbio);
+	if (ret)
+		async->bbio->bio.bi_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.
+ */
+static void run_one_async_done(struct btrfs_work *work)
+{
+	struct async_submit_bio *async =
+		container_of(work, struct async_submit_bio, work);
+	struct bio *bio = &async->bbio->bio;
+
+	/* If an error occurred we just want to clean up the bio and move on. */
+	if (bio->bi_status) {
+		btrfs_orig_bbio_end_io(async->bbio);
+		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 void run_one_async_free(struct btrfs_work *work)
+{
+	kfree(container_of(work, struct async_submit_bio, work));
+}
+
+static bool should_async_write(struct btrfs_bio *bbio)
+{
+	/* Submit synchronously if the checksum implementation is fast. */
+	if (test_bit(BTRFS_FS_CSUM_IMPL_FAST, &bbio->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(bbio->fs_info))
+		return false;
+
+	return true;
+}
+
+/*
+ * Submit bio to an async queue.
+ *
+ * Return true if the work has been succesfuly 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->fs_info;
+	struct async_submit_bio *async;
+
+	async = kmalloc(sizeof(*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,
+			run_one_async_free);
+	btrfs_queue_work(fs_info->workers, &async->work);
+	return true;
+}
+
+static bool btrfs_submit_chunk(struct btrfs_bio *bbio, int mirror_num)
+{
+	struct btrfs_inode *inode = bbio->inode;
+	struct btrfs_fs_info *fs_info = bbio->fs_info;
+	struct btrfs_bio *orig_bbio = bbio;
+	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;
+	bool use_append = btrfs_use_zone_append(bbio);
+	struct btrfs_io_context *bioc = NULL;
+	struct btrfs_io_stripe smap;
+	blk_status_t ret;
+	int error;
+
+	btrfs_bio_counter_inc_blocked(fs_info);
+	error = btrfs_map_block(fs_info, btrfs_op(bio), logical, &map_length,
+				&bioc, &smap, &mirror_num, 1);
+	if (error) {
+		ret = errno_to_blk_status(error);
+		goto fail;
+	}
+
+	map_length = min(map_length, length);
+	if (use_append)
+		map_length = min(map_length, fs_info->max_zone_append_size);
+
+	if (map_length < length) {
+		bbio = btrfs_split_bio(fs_info, bbio, map_length, use_append);
+		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);
+		if (ret)
+			goto fail_put_bio;
+	}
+
+	if (btrfs_op(bio) == BTRFS_MAP_WRITE) {
+		if (use_append) {
+			bio->bi_opf &= ~REQ_OP_WRITE;
+			bio->bi_opf |= REQ_OP_ZONE_APPEND;
+		}
+
+		/*
+		 * 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 && !(inode->flags & BTRFS_INODE_NODATASUM) &&
+		    !test_bit(BTRFS_FS_STATE_NO_CSUMS, &fs_info->fs_state) &&
+		    !btrfs_is_data_reloc_root(inode->root)) {
+			if (should_async_write(bbio) &&
+			    btrfs_wq_submit_bio(bbio, bioc, &smap, mirror_num))
+				goto done;
+
+			ret = btrfs_bio_csum(bbio);
+			if (ret)
+				goto fail_put_bio;
+		} else if (use_append) {
+			ret = btrfs_alloc_dummy_sum(bbio);
+			if (ret)
+				goto fail_put_bio;
+		}
+	}
+
+	__btrfs_submit_bio(bio, bioc, &smap, mirror_num);
+done:
+	return map_length == length;
+
+fail_put_bio:
+	if (map_length < length)
+		btrfs_cleanup_bio(bbio);
+fail:
+	btrfs_bio_counter_dec(fs_info);
+	btrfs_bio_end_io(orig_bbio, ret);
+	/* Do not submit another chunk */
+	return true;
+}
+
+void btrfs_submit_bio(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);
+
+	while (!btrfs_submit_chunk(bbio, mirror_num))
+		;
+}
+
+/*
+ * Submit a repair write.
+ *
+ * This bypasses btrfs_submit_bio 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.
+ */
+int btrfs_repair_io_failure(struct btrfs_fs_info *fs_info, u64 ino, u64 start,
+			    u64 length, u64 logical, struct page *page,
+			    unsigned int pg_offset, int mirror_num)
+{
+	struct btrfs_io_stripe smap = { 0 };
+	struct bio_vec bvec;
+	struct bio bio;
+	int ret = 0;
+
+	ASSERT(!(fs_info->sb->s_flags & SB_RDONLY));
+	BUG_ON(!mirror_num);
+
+	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 (!smap.dev->bdev ||
+	    !test_bit(BTRFS_DEV_STATE_WRITEABLE, &smap.dev->dev_state)) {
+		ret = -EIO;
+		goto out_counter_dec;
+	}
+
+	bio_init(&bio, smap.dev->bdev, &bvec, 1, REQ_OP_WRITE | REQ_SYNC);
+	bio.bi_iter.bi_sector = smap.physical >> SECTOR_SHIFT;
+	__bio_add_page(&bio, page, length, pg_offset);
+
+	btrfsic_check_bio(&bio);
+	ret = submit_bio_wait(&bio);
+	if (ret) {
+		/* try to remap that extent elsewhere? */
+		btrfs_dev_stat_inc_and_print(smap.dev, BTRFS_DEV_STAT_WRITE_ERRS);
+		goto out_bio_uninit;
+	}
+
+	btrfs_info_rl_in_rcu(fs_info,
+		"read error corrected: ino %llu off %llu (dev %s sector %llu)",
+			     ino, start, btrfs_dev_name(smap.dev),
+			     smap.physical >> SECTOR_SHIFT);
+	ret = 0;
+
+out_bio_uninit:
+	bio_uninit(&bio);
+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->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(fs_info);
+	ASSERT(mirror_num > 0);
+	ASSERT(btrfs_op(&bbio->bio) == BTRFS_MAP_WRITE);
+	ASSERT(!bbio->inode);
+
+	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_free_bioset;
+	if (bioset_init(&btrfs_repair_bioset, BIO_POOL_SIZE,
+			offsetof(struct btrfs_bio, bio),
+			BIOSET_NEED_BVECS))
+		goto out_free_clone_bioset;
+	if (mempool_init_kmalloc_pool(&btrfs_failed_bio_pool, BIO_POOL_SIZE,
+				      sizeof(struct btrfs_failed_bio)))
+		goto out_free_repair_bioset;
+	return 0;
+
+out_free_repair_bioset:
+	bioset_exit(&btrfs_repair_bioset);
+out_free_clone_bioset:
+	bioset_exit(&btrfs_clone_bioset);
+out_free_bioset:
+	bioset_exit(&btrfs_bioset);
+	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);
+}