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author | Kent Overstreet <kmo@daterainc.com> | 2013-11-23 18:34:15 -0800 |
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committer | Kent Overstreet <kmo@daterainc.com> | 2013-11-23 22:33:56 -0800 |
commit | 196d38bccfcfa32faed8c561868336fdfa0fe8e4 (patch) | |
tree | 9dee2bc174436072c9e90ffebbe71f47fde63aaf /include/linux | |
parent | e90abc8ec323c1fd2a25600097ef7ae1e91f39b0 (diff) | |
download | linux-stable-196d38bccfcfa32faed8c561868336fdfa0fe8e4.tar.gz linux-stable-196d38bccfcfa32faed8c561868336fdfa0fe8e4.tar.bz2 linux-stable-196d38bccfcfa32faed8c561868336fdfa0fe8e4.zip |
block: Generic bio chaining
This adds a generic mechanism for chaining bio completions. This is
going to be used for a bio_split() replacement, and it turns out to be
very useful in a fair amount of driver code - a fair number of drivers
were implementing this in their own roundabout ways, often painfully.
Note that this means it's no longer to call bio_endio() more than once
on the same bio! This can cause problems for drivers that save/restore
bi_end_io. Arguably they shouldn't be saving/restoring bi_end_io at all
- in all but the simplest cases they'd be better off just cloning the
bio, and immutable biovecs is making bio cloning cheaper. But for now,
we add a bio_endio_nodec() for these cases.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'include/linux')
-rw-r--r-- | include/linux/bio.h | 2 | ||||
-rw-r--r-- | include/linux/blk_types.h | 2 |
2 files changed, 4 insertions, 0 deletions
diff --git a/include/linux/bio.h b/include/linux/bio.h index 0c32a45a419c..64f5169c224b 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -356,6 +356,7 @@ static inline struct bio *bio_clone_kmalloc(struct bio *bio, gfp_t gfp_mask) } extern void bio_endio(struct bio *, int); +extern void bio_endio_nodec(struct bio *, int); struct request_queue; extern int bio_phys_segments(struct request_queue *, struct bio *); @@ -364,6 +365,7 @@ extern void bio_advance(struct bio *, unsigned); extern void bio_init(struct bio *); extern void bio_reset(struct bio *); +void bio_chain(struct bio *, struct bio *); extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int); extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *, diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index d369f8f6af79..bbc3a6c88fce 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -65,6 +65,8 @@ struct bio { unsigned int bi_seg_front_size; unsigned int bi_seg_back_size; + atomic_t bi_remaining; + bio_end_io_t *bi_end_io; void *bi_private; |