On Mon, Nov 24, 2014 at 08:32:21AM +0000, Tuomas Räsänen wrote: > Hi > > We have been experiencing quite regular umount failures on our NFS > servers which are exporting EXT4 /home via exportfs. > > Servers are running kernels from mainline 3.10-series. > > Both the reproduction steps and symptoms are almost indentical to what > was reported in https://lkml.org/lkml/2013/8/11/26 by Toralf Förster. > > The steps to reproduce: > 1. export EXT4 /home via exportfs > 2. let clients work on /home > 3. shutdown clients > 4. service nfs-kernel-server stop > 5. umount /home > > Umount causes the following BUG trace: > > [685206.207459] Call Trace: > [685206.208356] [<ffffffff811a2482>] generic_shutdown_super+0x62/0xf0 > [685206.209264] [<ffffffff811a2540>] kill_block_super+0x30/0x80 > [685206.210179] [<ffffffff811a2dcd>] deactivate_locked_super+0x4d/0x80 > [685206.211115] [<ffffffff811a344e>] deactivate_super+0x4e/0x70 > [685206.212039] [<ffffffff811beed6>] mntput_no_expire+0x106/0x160 > [685206.212964] [<ffffffff811c07e9>] SyS_umount+0xa9/0xf0 > [685206.213895] [<ffffffff8170fc6f>] tracesys+0xe1/0xe6 > [685206.214838] Code: 81 49 8b 57 78 48 81 c6 20 03 00 00 89 04 24 31 c0 e8 c5 3f 49 00 4d 8b 3f 4d 39 fe 75 c4 4c 39 b3 00 02 00 00 0f 84 97 fe ff ff <0f> 0b 66 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 > [685206.216885] RIP [<ffffffff81259782>] ext4_put_super+0x342/0x350 > [685206.217913] RSP <ffff8807d3f7fe28> > > The trace is preceded by dumped orphan list info. > > The most annoying thing is that in practice, it happens when the server > is rebooted normally, causing the reboot to stall (services have alredy > been shutdown at this point so the remote connection is closed as well). > > I tried the following patch (which landed on mainline in 3.11): > > commit bf7bd3e98be5c74813bee6ad496139fb0a011b3b > Author: J. Bruce Fields <bfields@xxxxxxxxxx> > Date: Thu Aug 15 16:55:26 2013 -0400 > > nfsd4: fix leak of inode reference on delegation failure > > The patch didn't apply cleanly on top of 3.10.58 but I think I got the > few conflicts right and it seems to have fixed the issue. > > Is there any particular reason why the patch has not been included in > 3.10 stable -series? Probably not. Could you send your fixed-up version to stable@xxxxxxxxxxxxxxx, with a cc: to me and to linux-nfs@xxxxxxxxxxxxxxx? You could also add to the changelog a note about the conflicts you had to fix up, if that looks like it would e helpful. --b. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
