diff options
| author | NeilBrown <neilb@suse.com> | 2017-03-15 06:05:13 +0300 |
|---|---|---|
| committer | Shaohua Li <shli@fb.com> | 2017-03-23 05:16:30 +0300 |
| commit | 016c76ac76e4c678b01a75a602dc6be0282f5b29 (patch) | |
| tree | ed943bdfc80ab4ff7aa3228023f6f0dc0c0992fa /drivers/md/raid5.h | |
| parent | bd83d0a28c68bacba88a3193a1bd6a083bb8d9f5 (diff) | |
| download | linux-016c76ac76e4c678b01a75a602dc6be0282f5b29.tar.xz | |
md/raid5: use bio_inc_remaining() instead of repurposing bi_phys_segments as a counter
md/raid5 needs to keep track of how many stripe_heads are processing a
bio so that it can delay calling bio_endio() until all stripe_heads
have completed. It currently uses 16 bits of ->bi_phys_segments for
this purpose.
16 bits is only enough for 256M requests, and it is possible for a
single bio to be larger than this, which causes problems. Also, the
bio struct contains a larger counter, __bi_remaining, which has a
purpose very similar to the purpose of our counter. So stop using
->bi_phys_segments, and instead use __bi_remaining.
This means we don't need to initialize the counter, as our caller
initializes it to '1'. It also means we can call bio_endio() directly
as it tests this counter internally.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Diffstat (limited to 'drivers/md/raid5.h')
| -rw-r--r-- | drivers/md/raid5.h | 17 |
1 files changed, 1 insertions, 16 deletions
diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h index fd5c21cde77f..7d74fb3f2ec6 100644 --- a/drivers/md/raid5.h +++ b/drivers/md/raid5.h @@ -488,8 +488,7 @@ static inline struct bio *r5_next_bio(struct bio *bio, sector_t sector) } /* - * We maintain a biased count of active stripes in the bottom 16 bits of - * bi_phys_segments, and a count of processed stripes in the upper 16 bits + * We maintain a count of processed stripes in the upper 16 bits */ static inline int raid5_bi_processed_stripes(struct bio *bio) { @@ -498,20 +497,6 @@ static inline int raid5_bi_processed_stripes(struct bio *bio) return (atomic_read(segments) >> 16) & 0xffff; } -static inline int raid5_dec_bi_active_stripes(struct bio *bio) -{ - atomic_t *segments = (atomic_t *)&bio->bi_phys_segments; - - return atomic_sub_return(1, segments) & 0xffff; -} - -static inline void raid5_inc_bi_active_stripes(struct bio *bio) -{ - atomic_t *segments = (atomic_t *)&bio->bi_phys_segments; - - atomic_inc(segments); -} - static inline void raid5_set_bi_processed_stripes(struct bio *bio, unsigned int cnt) { |