On Wed, Apr 24 2013, Namjae Jeon wrote: > From: James Bottomley <JBottomley@xxxxxxxxxxxxx> > > 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@xxxxxxxxx> > Signed-off-by: Namjae Jeon <namjae.jeon@xxxxxxxxxxx> > Signed-off-by: James Bottomley <JBottomley@xxxxxxxxxxxxx> > Tested-by: Max Filippov <jcmvbkbc@xxxxxxxxx> > Cc: <stable@xxxxxxxxxxxxxxx> Thanks! One minor nit - I don't think James signed off on the patch when he sent it in. James? -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html