diff options
| author | Liu Bo | 2017-05-15 17:43:31 -0700 |
|---|---|---|
| committer | David Sterba | 2017-06-19 18:25:58 +0200 |
| commit | 2f8e9140426dff6091b7a40d441befc791882658 (patch) | |
| tree | b7f6b66a9fc9f20b1d6eb3d1aa855c3103b23a75 /fs | |
| parent | 015c1bd9f162a00934dd71859f36b12d03c8e771 (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>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.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 292e458b2a9d..db2bbf92b4bc 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -2720,6 +2720,24 @@ 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 never 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 1383afdf1eeb..3df018549ce4 100644 --- a/fs/btrfs/extent_io.h +++ b/fs/btrfs/extent_io.h @@ -467,6 +467,8 @@ 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; |