This is a note to let you know that I've just added the patch titled
blk-mq: NVMe 512B/4K+T10 DIF/DIX format returns I/O error on dd with split op
to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: blk-mq-nvme-512b-4k-t10-dif-dix-format-returns-i-o-error-on-dd-with-split-op.patch and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From foo@baz Mon Apr 9 17:09:24 CEST 2018
From: Wen Xiong wenxiong@linux.vnet.ibm.com Date: Wed, 10 May 2017 08:54:11 -0500 Subject: blk-mq: NVMe 512B/4K+T10 DIF/DIX format returns I/O error on dd with split op
From: Wen Xiong wenxiong@linux.vnet.ibm.com
[ Upstream commit f36ea50ca0043e7b1204feaf1d2ba6bd68c08d36 ]
When formatting NVMe to 512B/4K + T10 DIf/DIX, dd with split op returns "Input/output error". Looks block layer split the bio after calling bio_integrity_prep(bio). This patch fixes the issue.
Below is how we debug this issue: (1)format nvme to 4K block # size with type 2 DIF (2)dd with block size bigger than 1024k. oflag=direct dd: error writing '/dev/nvme0n1': Input/output error
We added some debug code in nvme device driver. It showed us the first op and the second op have the same bi and pi address. This is not correct.
1st op: nvme0n1 Op:Wr slba 0x505 length 0x100, PI ctrl=0x1400, dsmgmt=0x0, AT=0x0 & RT=0x505 Guard 0x00b1, AT 0x0000, RT physical 0x00000505 RT virtual 0x00002828
2nd op: nvme0n1 Op:Wr slba 0x605 length 0x1, PI ctrl=0x1400, dsmgmt=0x0, AT=0x0 & RT=0x605 ==> This op fails and subsequent 5 retires.. Guard 0x00b1, AT 0x0000, RT physical 0x00000605 RT virtual 0x00002828
With the fix, It showed us both of the first op and the second op have correct bi and pi address.
1st op: nvme2n1 Op:Wr slba 0x505 length 0x100, PI ctrl=0x1400, dsmgmt=0x0, AT=0x0 & RT=0x505 Guard 0x5ccb, AT 0x0000, RT physical 0x00000505 RT virtual 0x00002828 2nd op: nvme2n1 Op:Wr slba 0x605 length 0x1, PI ctrl=0x1400, dsmgmt=0x0, AT=0x0 & RT=0x605 Guard 0xab4c, AT 0x0000, RT physical 0x00000605 RT virtual 0x00003028
Signed-off-by: Wen Xiong wenxiong@linux.vnet.ibm.com Signed-off-by: Jens Axboe axboe@fb.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- block/blk-mq.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1265,13 +1265,13 @@ static blk_qc_t blk_mq_make_request(stru
blk_queue_bounce(q, &bio);
+ blk_queue_split(q, &bio, q->bio_split); + if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) { bio_io_error(bio); return BLK_QC_T_NONE; }
- blk_queue_split(q, &bio, q->bio_split); - if (!is_flush_fua && !blk_queue_nomerges(q) && blk_attempt_plug_merge(q, bio, &request_count, &same_queue_rq)) return BLK_QC_T_NONE;
Patches currently in stable-queue which might be from wenxiong@linux.vnet.ibm.com are
queue-4.9/blk-mq-nvme-512b-4k-t10-dif-dix-format-returns-i-o-error-on-dd-with-split-op.patch