path: root/0002-blk-mq-fix-corruption-with-direct-issue.patch
diff options
Diffstat (limited to '0002-blk-mq-fix-corruption-with-direct-issue.patch')
1 files changed, 0 insertions, 60 deletions
diff --git a/0002-blk-mq-fix-corruption-with-direct-issue.patch b/0002-blk-mq-fix-corruption-with-direct-issue.patch
deleted file mode 100644
index 5ca4828bc1f..00000000000
--- a/0002-blk-mq-fix-corruption-with-direct-issue.patch
+++ /dev/null
@@ -1,60 +0,0 @@
-From 144c54b5c08cc1afc060281a79a9892e898337c6 Mon Sep 17 00:00:00 2001
-From: Jens Axboe <>
-Date: Tue, 4 Dec 2018 15:47:46 -0700
-Subject: [PATCH 2/2] blk-mq: fix corruption with direct issue
-If we attempt a direct issue to a SCSI device, and it returns BUSY, then
-we queue the request up normally. However, the SCSI layer may have
-already setup SG tables etc for this particular command. If we later
-merge with this request, then the old tables are no longer valid. Once
-we issue the IO, we only read/write the original part of the request,
-not the new state of it.
-This causes data corruption, and is most often noticed with the file
-system complaining about the just read data being invalid:
-[ 235.934465] EXT4-fs error (device sda1): ext4_iget:4831: inode #7142: comm dpkg-query: bad extra_isize 24937 (inode size 256)
-because most of it is garbage...
-This doesn't happen from the normal issue path, as we will simply defer
-the request to the hardware queue dispatch list if we fail. Once it's on
-the dispatch list, we never merge with it.
-Fix this from the direct issue path by flagging the request as
-REQ_NOMERGE so we don't change the size of it before issue.
-See also:
-Fixes: 6ce3dd6eec1 ("blk-mq: issue directly if hw queue isn't busy in case of 'none'")
-Signed-off-by: Jens Axboe <>
-Tested-by: Guenter Roeck <>
-Reviewed-by: Christoph Hellwig <>
- block/blk-mq.c | 9 +++++++++
- 1 file changed, 9 insertions(+)
-diff --git a/block/blk-mq.c b/block/blk-mq.c
-index e3c39ea8e17b..66d64a13c50a 100644
---- a/block/blk-mq.c
-+++ b/block/blk-mq.c
-@@ -1698,6 +1698,15 @@ static blk_status_t __blk_mq_issue_directly(struct blk_mq_hw_ctx *hctx,
- break;
-+ /*
-+ * If direct dispatch fails, we cannot allow any merging on
-+ * this IO. Drivers (like SCSI) may have set up permanent state
-+ * for this request, like SG tables and mappings, and if we
-+ * merge to it later on then we'll still only do IO to the
-+ * original part.
-+ */
-+ rq->cmd_flags |= REQ_NOMERGE;
- blk_mq_update_dispatch_busy(hctx, true);
- __blk_mq_requeue_request(rq);
- break;