diff options
| author |   Ming Lei <ming.lei@redhat.com> | 2018-09-05 15:45:54 -0600 |
|---|---|---|
| committer |   Jens Axboe <axboe@kernel.dk> | 2018-09-06 15:12:24 -0600 |
| commit | 7759eb23fd9808a2e4498cf36a798ed65cde78ae (patch) | |
| tree | 5ff1a0f21a48ee3f1c4eae4c2dbc7dd084e59792 /include/linux/bio.h | |
| parent | drbd: Convert from ahash to shash (diff) | |
| download | wireguard-linux-7759eb23fd9808a2e4498cf36a798ed65cde78ae.tar.xz wireguard-linux-7759eb23fd9808a2e4498cf36a798ed65cde78ae.zip | |
block: remove bio_rewind_iter()
It is pointed that bio_rewind_iter() is one very bad API[1]:
1) bio size may not be restored after rewinding
2) it causes some bogus change, such as 5151842b9d8732 (block: reset
bi_iter.bi_done after splitting bio)
3) rewinding really makes things complicated wrt. bio splitting
4) unnecessary updating of .bi_done in fast path
[1] https://marc.info/?t=153549924200005&r=1&w=2
So this patch takes Kent's suggestion to restore one bio into its original
state via saving bio iterator(struct bvec_iter) in bio_integrity_prep(),
given now bio_rewind_iter() is only used by bio integrity code.
Cc: Dmitry Monakhov <dmonakhov@openvz.org>
Cc: Hannes Reinecke <hare@suse.com>
Suggested-by: Kent Overstreet <kent.overstreet@gmail.com>
Acked-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'include/linux/bio.h')
| -rw-r--r-- | include/linux/bio.h | 22 |
1 files changed, 4 insertions, 18 deletions
diff --git a/include/linux/bio.h b/include/linux/bio.h index 51371740d2a8..14b4fa266357 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -170,27 +170,11 @@ static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter, { iter->bi_sector += bytes >> 9; - if (bio_no_advance_iter(bio)) { + if (bio_no_advance_iter(bio)) iter->bi_size -= bytes; - iter->bi_done += bytes; - } else { + else bvec_iter_advance(bio->bi_io_vec, iter, bytes); /* TODO: It is reasonable to complete bio with error here. */ - } -} - -static inline bool bio_rewind_iter(struct bio *bio, struct bvec_iter *iter, - unsigned int bytes) -{ - iter->bi_sector -= bytes >> 9; - - if (bio_no_advance_iter(bio)) { - iter->bi_size += bytes; - iter->bi_done -= bytes; - return true; - } - - return bvec_iter_rewind(bio->bi_io_vec, iter, bytes); } #define __bio_for_each_segment(bvl, bio, iter, start) \ @@ -353,6 +337,8 @@ struct bio_integrity_payload { unsigned short bip_max_vcnt; /* integrity bio_vec slots */ unsigned short bip_flags; /* control flags */ + struct bvec_iter bio_iter; /* for rewinding parent bio */ + struct work_struct bip_work; /* I/O completion */ struct bio_vec *bip_vec; |