diff options
Diffstat (limited to 'drivers/md/raid5.c')
| -rw-r--r-- | drivers/md/raid5.c | 62 |
1 files changed, 32 insertions, 30 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 8480346..6ef1eeb 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -99,34 +99,40 @@ 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 */ -static inline int raid5_bi_phys_segments(struct bio *bio) +static inline int raid5_bi_processed_stripes(struct bio *bio) { - return bio->bi_phys_segments & 0xffff; + atomic_t *segments = (atomic_t *)&bio->bi_phys_segments; + return (atomic_read(segments) >> 16) & 0xffff; } -static inline int raid5_bi_hw_segments(struct bio *bio) +static inline int raid5_dec_bi_active_stripes(struct bio *bio) { - return (bio->bi_phys_segments >> 16) & 0xffff; + atomic_t *segments = (atomic_t *)&bio->bi_phys_segments; + return atomic_sub_return(1, segments) & 0xffff; } -static inline int raid5_dec_bi_phys_segments(struct bio *bio) +static inline void raid5_inc_bi_active_stripes(struct bio *bio) { - --bio->bi_phys_segments; - return raid5_bi_phys_segments(bio); + atomic_t *segments = (atomic_t *)&bio->bi_phys_segments; + atomic_inc(segments); } -static inline int raid5_dec_bi_hw_segments(struct bio *bio) +static inline void raid5_set_bi_processed_stripes(struct bio *bio, + unsigned int cnt) { - unsigned short val = raid5_bi_hw_segments(bio); + atomic_t *segments = (atomic_t *)&bio->bi_phys_segments; + int old, new; - --val; - bio->bi_phys_segments = (val << 16) | raid5_bi_phys_segments(bio); - return val; + do { + old = atomic_read(segments); + new = (old & 0xffff) | (cnt << 16); + } while (atomic_cmpxchg(segments, old, new) != old); } -static inline void raid5_set_bi_hw_segments(struct bio *bio, unsigned int cnt) +static inline void raid5_set_bi_stripes(struct bio *bio, unsigned int cnt) { - bio->bi_phys_segments = raid5_bi_phys_segments(bio) | (cnt << 16); + atomic_t *segments = (atomic_t *)&bio->bi_phys_segments; + atomic_set(segments, cnt); } /* Find first data disk in a raid6 stripe */ @@ -781,7 +787,7 @@ static void ops_complete_biofill(void *stripe_head_ref) while (rbi && rbi->bi_sector < dev->sector + STRIPE_SECTORS) { rbi2 = r5_next_bio(rbi, dev->sector); - if (!raid5_dec_bi_phys_segments(rbi)) { + if (!raid5_dec_bi_active_stripes(rbi)) { rbi->bi_next = return_bi; return_bi = rbi; } @@ -2367,7 +2373,7 @@ static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, in if (*bip) bi->bi_next = *bip; *bip = bi; - bi->bi_phys_segments++; + raid5_inc_bi_active_stripes(bi); if (forwrite) { /* check if page is covered */ @@ -2464,7 +2470,7 @@ handle_failed_stripe(struct r5conf *conf, struct stripe_head *sh, sh->dev[i].sector + STRIPE_SECTORS) { struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector); clear_bit(BIO_UPTODATE, &bi->bi_flags); - if (!raid5_dec_bi_phys_segments(bi)) { + if (!raid5_dec_bi_active_stripes(bi)) { md_write_end(conf->mddev); bi->bi_next = *return_bi; *return_bi = bi; @@ -2479,7 +2485,7 @@ handle_failed_stripe(struct r5conf *conf, struct stripe_head *sh, sh->dev[i].sector + STRIPE_SECTORS) { struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector); clear_bit(BIO_UPTODATE, &bi->bi_flags); - if (!raid5_dec_bi_phys_segments(bi)) { + if (!raid5_dec_bi_active_stripes(bi)) { md_write_end(conf->mddev); bi->bi_next = *return_bi; *return_bi = bi; @@ -2503,7 +2509,7 @@ handle_failed_stripe(struct r5conf *conf, struct stripe_head *sh, struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector); clear_bit(BIO_UPTODATE, &bi->bi_flags); - if (!raid5_dec_bi_phys_segments(bi)) { + if (!raid5_dec_bi_active_stripes(bi)) { bi->bi_next = *return_bi; *return_bi = bi; } @@ -2722,7 +2728,7 @@ static void handle_stripe_clean_event(struct r5conf *conf, while (wbi && wbi->bi_sector < dev->sector + STRIPE_SECTORS) { wbi2 = r5_next_bio(wbi, dev->sector); - if (!raid5_dec_bi_phys_segments(wbi)) { + if (!raid5_dec_bi_active_stripes(wbi)) { md_write_end(conf->mddev); wbi->bi_next = *return_bi; *return_bi = wbi; @@ -3798,7 +3804,7 @@ static struct bio *remove_bio_from_retry(struct r5conf *conf) * this sets the active strip count to 1 and the processed * strip count to zero (upper 8 bits) */ - bi->bi_phys_segments = 1; /* biased count of active stripes */ + raid5_set_bi_stripes(bi, 1); /* biased count of active stripes */ } return bi; @@ -4133,9 +4139,7 @@ static void make_request(struct mddev *mddev, struct bio * bi) } } - spin_lock_irq(&conf->device_lock); - remaining = raid5_dec_bi_phys_segments(bi); - spin_unlock_irq(&conf->device_lock); + remaining = raid5_dec_bi_active_stripes(bi); if (remaining == 0) { if ( rw == WRITE ) @@ -4491,7 +4495,7 @@ static int retry_aligned_read(struct r5conf *conf, struct bio *raid_bio) sector += STRIPE_SECTORS, scnt++) { - if (scnt < raid5_bi_hw_segments(raid_bio)) + if (scnt < raid5_bi_processed_stripes(raid_bio)) /* already done this stripe */ continue; @@ -4499,14 +4503,14 @@ static int retry_aligned_read(struct r5conf *conf, struct bio *raid_bio) if (!sh) { /* failed to get a stripe - must wait */ - raid5_set_bi_hw_segments(raid_bio, scnt); + raid5_set_bi_processed_stripes(raid_bio, scnt); conf->retry_read_aligned = raid_bio; return handled; } if (!add_stripe_bio(sh, raid_bio, dd_idx, 0)) { release_stripe(sh); - raid5_set_bi_hw_segments(raid_bio, scnt); + raid5_set_bi_processed_stripes(raid_bio, scnt); conf->retry_read_aligned = raid_bio; return handled; } @@ -4515,9 +4519,7 @@ static int retry_aligned_read(struct r5conf *conf, struct bio *raid_bio) release_stripe(sh); handled++; } - spin_lock_irq(&conf->device_lock); - remaining = raid5_dec_bi_phys_segments(raid_bio); - spin_unlock_irq(&conf->device_lock); + remaining = raid5_dec_bi_active_stripes(raid_bio); if (remaining == 0) bio_endio(raid_bio, 0); if (atomic_dec_and_test(&conf->active_aligned_reads)) |