diff options
Diffstat (limited to '0002-blk-mq-fix-corruption-with-direct-issue.patch')
| -rw-r--r-- | 0002-blk-mq-fix-corruption-with-direct-issue.patch | 60 |
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 5ca4828bc1f9..000000000000 --- 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 <axboe@kernel.dk> -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 If we later -merge with this request, then the old tables are no longer valid.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: - https://bugzilla.kernel.org/show_bug.cgi?id=201685 - -Fixes: 6ce3dd6eec1 ("blk-mq: issue directly if hw queue isn't busy in case of 'none'") -Signed-off-by: Jens Axboe <axboe@kernel.dk> -Tested-by: Guenter Roeck <linux@roeck-us.net> -Reviewed-by: Christoph Hellwig <hch@lst.de> ---- - 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; - case BLK_STS_RESOURCE: - case BLK_STS_DEV_RESOURCE: -+ /* -+ * 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; --- -2.20.0.rc2.7.g965798d1f2 - |