diff options
| -rw-r--r-- | drivers/md/raid5.c | 52 |
1 files changed, 40 insertions, 12 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 025228a22522..200dc64fa3dc 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -843,7 +843,8 @@ static bool stripe_can_batch(struct stripe_head *sh) } /* we only do back search */ -static void stripe_add_to_batch_list(struct r5conf *conf, struct stripe_head *sh) +static void stripe_add_to_batch_list(struct r5conf *conf, + struct stripe_head *sh, struct stripe_head *last_sh) { struct stripe_head *head; sector_t head_sector, tmp_sec; @@ -856,15 +857,20 @@ static void stripe_add_to_batch_list(struct r5conf *conf, struct stripe_head *sh return; head_sector = sh->sector - RAID5_STRIPE_SECTORS(conf); - hash = stripe_hash_locks_hash(conf, head_sector); - spin_lock_irq(conf->hash_locks + hash); - head = find_get_stripe(conf, head_sector, conf->generation, hash); - spin_unlock_irq(conf->hash_locks + hash); - - if (!head) - return; - if (!stripe_can_batch(head)) - goto out; + if (last_sh && head_sector == last_sh->sector) { + head = last_sh; + atomic_inc(&head->count); + } else { + hash = stripe_hash_locks_hash(conf, head_sector); + spin_lock_irq(conf->hash_locks + hash); + head = find_get_stripe(conf, head_sector, conf->generation, + hash); + spin_unlock_irq(conf->hash_locks + hash); + if (!head) + return; + if (!stripe_can_batch(head)) + goto out; + } lock_two_stripes(head, sh); /* clear_batch_ready clear the flag */ @@ -5795,6 +5801,8 @@ enum stripe_result { }; struct stripe_request_ctx { + /* a reference to the last stripe_head for batching */ + struct stripe_head *batch_last; /* the request had REQ_PREFLUSH, cleared after the first stripe_head */ bool do_flush; }; @@ -5889,8 +5897,13 @@ static enum stripe_result make_stripe_request(struct mddev *mddev, goto out_release; } - if (stripe_can_batch(sh)) - stripe_add_to_batch_list(conf, sh); + if (stripe_can_batch(sh)) { + stripe_add_to_batch_list(conf, sh, ctx->batch_last); + if (ctx->batch_last) + raid5_release_stripe(ctx->batch_last); + atomic_inc(&sh->count); + ctx->batch_last = sh; + } if (ctx->do_flush) { set_bit(STRIPE_R5C_PREFLUSH, &sh->state); @@ -5985,6 +5998,18 @@ static bool raid5_make_request(struct mddev *mddev, struct bio * bi) continue; if (res == STRIPE_SCHEDULE_AND_RETRY) { + /* + * Must release the reference to batch_last before + * scheduling and waiting for work to be done, + * otherwise the batch_last stripe head could prevent + * raid5_activate_delayed() from making progress + * and thus deadlocking. + */ + if (ctx.batch_last) { + raid5_release_stripe(ctx.batch_last); + ctx.batch_last = NULL; + } + schedule(); prepare_to_wait(&conf->wait_for_overlap, &w, TASK_UNINTERRUPTIBLE); @@ -5996,6 +6021,9 @@ static bool raid5_make_request(struct mddev *mddev, struct bio * bi) finish_wait(&conf->wait_for_overlap, &w); + if (ctx.batch_last) + raid5_release_stripe(ctx.batch_last); + if (rw == WRITE) md_write_end(mddev); bio_endio(bi); |