Messages in this thread Patch in this message | | | From | Namjae Jeon <> | Subject | [PATCH] block: fix max discard sectors limit | Date | Wed, 24 Apr 2013 22:55:20 +0900 |
| |
From: James Bottomley <JBottomley@Parallels.com>
linux-v3.8-rc1 and later support for plug for blkdev_issue_discard with commit 0cfbcafcae8b7364b5fa96c2b26ccde7a3a296a9 (block: add plug for blkdev_issue_discard )
For example, 1) DISCARD rq-1 with size size 4GB 2) DISCARD rq-2 with size size 1GB
If these 2 discard requests get merged, final request size will be 5GB.
In this case, request's __data_len field may overflow as it can store max 4GB(unsigned int).
This issue was observed while doing mkfs.f2fs on 5GB SD card: https://lkml.org/lkml/2013/4/1/292
Info: sector size = 512 Info: total sectors = 11370496 (in 512bytes) Info: zone aligned segment0 blkaddr: 512 [ 257.789764] blk_update_request: bio idx 0 >= vcnt 0
mkfs process gets stuck in D state and I see the following in the dmesg:
[ 257.789733] __end_that: dev mmcblk0: type=1, flags=122c8081 [ 257.789764] sector 4194304, nr/cnr 2981888/4294959104 [ 257.789764] bio df3840c0, biotail df3848c0, buffer (null), len 1526726656 [ 257.789764] blk_update_request: bio idx 0 >= vcnt 0 [ 257.794921] request botched: dev mmcblk0: type=1, flags=122c8081 [ 257.794921] sector 4194304, nr/cnr 2981888/4294959104 [ 257.794921] bio df3840c0, biotail df3848c0, buffer (null), len 1526726656
This patch fixes this issue.
Reported-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com> Tested-by: Max Filippov <jcmvbkbc@gmail.com> Cc: <stable@vger.kernel.org> --- include/linux/blkdev.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 07aa5f6..ff636bd 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -844,7 +844,7 @@ static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q, unsigned int cmd_flags) { if (unlikely(cmd_flags & REQ_DISCARD)) - return q->limits.max_discard_sectors; + return min(q->limits.max_discard_sectors, UINT_MAX >> 9); if (unlikely(cmd_flags & REQ_WRITE_SAME)) return q->limits.max_write_same_sectors; -- 1.7.9.5
| |