https://bugzilla.kernel.org/show_bug.cgi?id=43292 --- Comment #14 from Jan Kara <jack@xxxxxxx> 2012-06-01 15:24:37 --- OK, something strange is going on. The block trace ends like: 253,2 0 3716 19.264276270 751 Q R 485490688 + 8 [nfsd] 9,0 0 3699 19.264279134 751 A R 527540608 + 8 <- (253,2) 485490688 9,0 0 3700 19.264280391 751 Q R 527540608 + 8 [nfsd] 8,32 0 14793 19.264283254 751 A R 527540672 + 8 <- (8,33) 527540608 8,32 0 14794 19.264284162 751 Q R 527540672 + 8 [nfsd] 8,32 0 14795 19.264286537 751 G R 527540672 + 8 [nfsd] 8,32 0 14796 19.264288073 751 P N [nfsd] 8,32 0 14797 19.264290727 751 I R 527540672 + 8 [nfsd] 8,32 0 14798 19.264292264 751 U N [nfsd] 1 8,32 0 14799 19.264293940 751 D R 527540672 + 8 [nfsd] We see request to read 8 sectors starting at 485490688 has been issued to /dev/dm-2. I've checked that against dumpe2fs output and indeed that is a block bitmap for group 1852. That request has gone through md-0 to sdc where it has been dispatched to the disk driver for processing. All is well but for some reason the read never completed which is why nfsd hangs. So this doesn't look like a problem in the filesystem or block layer but rather somewhere in the driver or hardware. Can you check what happens if you just run dd if=/dev/dm-2 of=/dev/null bs=512 count=8 skip=485490688 Does the command finish? And what if you run it after nfsd has hung? If it does finish in both cases, can you gather the blktrace of hanging once more like before so that I can check whether we hang waiting for the same block the second time as well? Thanks! -- Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are watching the assignee of the bug. -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
