From: NeilBrown 1/ When aligned requests fail (read error) they need to be retried via the normal method (stripe cache). As we cannot be sure that we can process a single read in one go (we may not be able to allocate all the stripes needed) we store a bio-being-retried and a list of bioes-that-still-need-to-be-retried. When find a bio that needs to be retried, we should add it to the list, not to single-bio... 2/ We were never incrementing 'scnt' when resubmitting failed aligned requests. Signed-off-by: Neil Brown Signed-off-by: Andrew Morton --- drivers/md/raid5.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff -puN drivers/md/raid5.c~md-allow-reads-that-have-bypassed-the-cache-to-be-retried-on-failure-misc-fixes-for-error-handling-of-aligned-reads drivers/md/raid5.c --- a/drivers/md/raid5.c~md-allow-reads-that-have-bypassed-the-cache-to-be-retried-on-failure-misc-fixes-for-error-handling-of-aligned-reads +++ a/drivers/md/raid5.c @@ -2656,8 +2656,8 @@ static void add_bio_to_retry(struct bio spin_lock_irqsave(&conf->device_lock, flags); - bi->bi_next = conf->retry_read_aligned; - conf->retry_read_aligned = bi; + bi->bi_next = conf->retry_read_aligned_list; + conf->retry_read_aligned_list = bi; spin_unlock_irqrestore(&conf->device_lock, flags); md_wakeup_thread(conf->mddev->thread); @@ -3154,7 +3154,8 @@ static int retry_aligned_read(raid5_con conf); last_sector = raid_bio->bi_sector + (raid_bio->bi_size>>9); - for (; logical_sector < last_sector; logical_sector += STRIPE_SECTORS) { + for (; logical_sector < last_sector; + logical_sector += STRIPE_SECTORS, scnt++) { if (scnt < raid_bio->bi_hw_segments) /* already done this stripe */ _