diff options
| author | Liu Bo <bo.li.liu@oracle.com> | 2017-05-15 17:43:31 -0700 |
|---|---|---|
| committer | Liu Bo <bo.li.liu@oracle.com> | 2017-05-16 10:46:28 -0700 |
| commit | 27c64a373254bb720818ef0b736ff6e91ce2c24b (patch) | |
| tree | 0197bf9e84f733555380768322a8ac8251c9b77c /fs | |
| parent | 44772c342a67314ba128af24b89b9002ae4442cb (diff) | |
Btrfs: new helper btrfs_bio_clone_partial
This adds a new helper btrfs_bio_clone_partial, it'll allocate a cloned
bio that only owns a part of the original bio's data.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/extent_io.c | 18 | ||||
| -rw-r--r-- | fs/btrfs/extent_io.h | 2 |
2 files changed, 20 insertions, 0 deletions
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 0d4aea4cdddb..90815c7c21b2 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -2726,6 +2726,24 @@ struct bio *btrfs_io_bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs) return bio; } +struct bio *btrfs_bio_clone_partial(struct bio *orig, gfp_t gfp_mask, + int offset, int size) +{ + struct bio *bio; + struct btrfs_io_bio *btrfs_bio; + + /* this will fail when it's backed by a bioset */ + bio = bio_clone_fast(orig, gfp_mask, btrfs_bioset); + ASSERT(bio); + + btrfs_bio = btrfs_io_bio(bio); + btrfs_bio->csum = NULL; + btrfs_bio->csum_allocated = NULL; + btrfs_bio->end_io = NULL; + + bio_trim(bio, offset >> 9, size >> 9); + return bio; +} static int __must_check submit_one_bio(struct bio *bio, int mirror_num, unsigned long bio_flags) diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h index 3e4fad4a909d..b2235b577cca 100644 --- a/fs/btrfs/extent_io.h +++ b/fs/btrfs/extent_io.h @@ -460,6 +460,8 @@ btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs, gfp_t gfp_flags); struct bio *btrfs_io_bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs); struct bio *btrfs_bio_clone(struct bio *bio, gfp_t gfp_mask); +struct bio *btrfs_bio_clone_partial(struct bio *orig, gfp_t gfp_mask, + int offset, int size); struct btrfs_fs_info; struct btrfs_inode; |