From 37c61ff31e9b5e3fcf3cc6579f5c68f6ad40c4b1 Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Sat, 19 Oct 2013 14:50:28 +0800 Subject: raid5: set bio bi_vcnt 0 for discard request SCSI layer will add new payload for discard request. If two bios are merged to one, the second bio has bi_vcnt 1 which is set in raid5. This will confuse SCSI and cause oops. Suitable for backport to 3.7+ Cc: stable@vger.kernel.org (v3.7+) Reported-by: Jes Sorensen Signed-off-by: Shaohua Li Signed-off-by: NeilBrown Acked-by: Martin K. Petersen --- drivers/md/raid5.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'drivers/md/raid5.c') diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 7ff4f252ca1a..302d7cd2076c 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -778,6 +778,12 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s) bi->bi_io_vec[0].bv_len = STRIPE_SIZE; bi->bi_io_vec[0].bv_offset = 0; bi->bi_size = STRIPE_SIZE; + /* + * If this is discard request, set bi_vcnt 0. We don't + * want to confuse SCSI because SCSI will replace payload + */ + if (rw & REQ_DISCARD) + bi->bi_vcnt = 0; if (rrdev) set_bit(R5_DOUBLE_LOCKED, &sh->dev[i].flags); @@ -816,6 +822,12 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s) rbi->bi_io_vec[0].bv_len = STRIPE_SIZE; rbi->bi_io_vec[0].bv_offset = 0; rbi->bi_size = STRIPE_SIZE; + /* + * If this is discard request, set bi_vcnt 0. We don't + * want to confuse SCSI because SCSI will replace payload + */ + if (rw & REQ_DISCARD) + rbi->bi_vcnt = 0; if (conf->mddev->gendisk) trace_block_bio_remap(bdev_get_queue(rbi->bi_bdev), rbi, disk_devt(conf->mddev->gendisk), -- cgit v1.2.3 From d47648fcf0611812286f68131b40251c6fa54f5e Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Sat, 19 Oct 2013 14:51:42 +0800 Subject: raid5: avoid finding "discard" stripe SCSI discard will damage discard stripe bio setting, eg, some fields are changed. If the stripe is reused very soon, we have wrong bios setting. We remove discard stripe from hash list, so next time the strip will be fully initialized. Suitable for backport to 3.7+. Cc: (3.7+) Signed-off-by: Shaohua Li Signed-off-by: NeilBrown --- drivers/md/raid5.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'drivers/md/raid5.c') diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 302d7cd2076c..f8b906843926 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -2922,6 +2922,14 @@ static void handle_stripe_clean_event(struct r5conf *conf, } /* now that discard is done we can proceed with any sync */ clear_bit(STRIPE_DISCARD, &sh->state); + /* + * SCSI discard will change some bio fields and the stripe has + * no updated data, so remove it from hash list and the stripe + * will be reinitialized + */ + spin_lock_irq(&conf->device_lock); + remove_hash(sh); + spin_unlock_irq(&conf->device_lock); if (test_bit(STRIPE_SYNC_REQUESTED, &sh->state)) set_bit(STRIPE_HANDLE, &sh->state); -- cgit v1.2.3