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btrfs: limit write bios to a single ordered extent

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Currently buffered writeback bios are allowed to span multiple
ordered_extents, although that basically never actually happens since
commit 4a445b7b61 ("btrfs: don't merge pages into bio if their page
offset is not contiguous").

Supporting bios than span ordered_extents complicates the file
checksumming code, and prevents us from adding an ordered_extent pointer
to the btrfs_bio structure.  Use the existing code to limit a bio to
single ordered_extent for zoned device writes for all writes.

This allows to remove the REQ_BTRFS_ONE_ORDERED flags, and the
handling of multiple ordered_extents in btrfs_csum_one_bio.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Christoph Hellwig 2023-05-31 09:53:55 +02:00 committed by David Sterba
parent c731cd0b6d
commit a39da514eb
5 changed files with 2 additions and 55 deletions
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3
fs/btrfs/bio.c
View File

@ -457,9 +457,6 @@ static void btrfs_submit_mirrored_bio(struct btrfs_io_context *bioc, int dev_nr)
static void __btrfs_submit_bio(struct bio *bio, struct btrfs_io_context *bioc,
struct btrfs_io_stripe *smap, int mirror_num)
{
/* Do not leak our private flag into the block layer. */
bio->bi_opf &= ~REQ_BTRFS_ONE_ORDERED;
if (!bioc) {
/* Single mirror read/write fast path. */
btrfs_bio(bio)->mirror_num = mirror_num;

3
fs/btrfs/bio.h
View File

@ -102,9 +102,6 @@ static inline void btrfs_bio_end_io(struct btrfs_bio *bbio, blk_status_t status)
bbio->end_io(bbio);
}
/* Bio only refers to one ordered extent. */
#define REQ_BTRFS_ONE_ORDERED REQ_DRV
/* Submit using blkcg_punt_bio_submit. */
#define REQ_BTRFS_CGROUP_PUNT REQ_FS_PRIVATE

2
fs/btrfs/compression.c
View File

@ -293,8 +293,6 @@ void btrfs_submit_compressed_write(struct btrfs_inode *inode, u64 start,
ASSERT(IS_ALIGNED(start, fs_info->sectorsize) &&
IS_ALIGNED(len, fs_info->sectorsize));
write_flags |= REQ_BTRFS_ONE_ORDERED;
cb = alloc_compressed_bio(inode, start, REQ_OP_WRITE | write_flags,
end_compressed_bio_write);
cb->start = start;

11
fs/btrfs/extent_io.c
View File

@ -826,13 +826,8 @@ static void alloc_new_bio(struct btrfs_inode *inode,
bio_ctrl->bbio = bbio;
bio_ctrl->len_to_oe_boundary = U32_MAX;
/*
* Limit the extent to the ordered boundary for Zone Append.
* Compressed bios aren't submitted directly, so it doesn't apply to
* them.
*/
if (bio_ctrl->compress_type == BTRFS_COMPRESS_NONE &&
btrfs_use_zone_append(bbio)) {
/* Limit data write bios to the ordered boundary. */
if (bio_ctrl->wbc) {
struct btrfs_ordered_extent *ordered;
ordered = btrfs_lookup_ordered_extent(inode, file_offset);
@ -842,9 +837,7 @@ static void alloc_new_bio(struct btrfs_inode *inode,
ordered->disk_num_bytes - file_offset);
btrfs_put_ordered_extent(ordered);
}
}
if (bio_ctrl->wbc) {
/*
* Pick the last added device to support cgroup writeback. For
* multi-device file systems this means blk-cgroup policies have

38
fs/btrfs/file-item.c
View File

@ -733,8 +733,6 @@ blk_status_t btrfs_csum_one_bio(struct btrfs_bio *bbio)
struct bio_vec bvec;
int index;
unsigned int blockcount;
unsigned long total_bytes = 0;
unsigned long this_sum_bytes = 0;
int i;
unsigned nofs_flag;
@ -776,34 +774,6 @@ blk_status_t btrfs_csum_one_bio(struct btrfs_bio *bbio)
- 1);
for (i = 0; i < blockcount; i++) {
if (!(bio->bi_opf & REQ_BTRFS_ONE_ORDERED) &&
!in_range(offset, ordered->file_offset,
ordered->num_bytes)) {
unsigned long bytes_left;
sums->len = this_sum_bytes;
this_sum_bytes = 0;
btrfs_add_ordered_sum(ordered, sums);
btrfs_put_ordered_extent(ordered);
bytes_left = bio->bi_iter.bi_size - total_bytes;
nofs_flag = memalloc_nofs_save();
sums = kvzalloc(btrfs_ordered_sum_size(fs_info,
bytes_left), GFP_KERNEL);
memalloc_nofs_restore(nofs_flag);
if (!sums)
return BLK_STS_RESOURCE;
sums->len = bytes_left;
ordered = btrfs_lookup_ordered_extent(inode,
offset);
ASSERT(ordered); /* Logic error */
sums->logical = (bio->bi_iter.bi_sector << SECTOR_SHIFT)
+ total_bytes;
index = 0;
}
data = bvec_kmap_local(&bvec);
crypto_shash_digest(shash,
data + (i * fs_info->sectorsize),
@ -812,18 +782,10 @@ blk_status_t btrfs_csum_one_bio(struct btrfs_bio *bbio)
kunmap_local(data);
index += fs_info->csum_size;
offset += fs_info->sectorsize;
this_sum_bytes += fs_info->sectorsize;
total_bytes += fs_info->sectorsize;
}
}
this_sum_bytes = 0;
/*
* The ->sums assignment is for zoned writes, where a bio never spans
* ordered extents and is only done unconditionally because that's cheaper
* than a branch.
*/
bbio->sums = sums;
btrfs_add_ordered_sum(ordered, sums);
btrfs_put_ordered_extent(ordered);