On Tue, Sep 28, 2010 at 11:30:55AM +0800, Ian Kent wrote: > On Mon, 2010-09-27 at 07:55 +0200, Sebastian Hetze wrote: > > Hi *, > > > > we are suffering from some sort of race condition that causes > > automount to hang: > > > > [351841.568061] INFO: task automount:22055 blocked for more than 120 > > seconds. > > [351841.568689] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables > > this message. > > [351841.569717] automount D b983e7f6 0 22055 1 0x00000000 > > [351841.570252] e0ca7ef4 00000082 f3c38000 b983e7f6 00013fde eaed6000 > > f63af880 f5037c00 > > [351841.571308] c0863320 c0863320 f30de480 f30de718 c5589320 00000002 > > b9841648 00013fde > > [351841.572316] f30de718 f72ceff4 f72ceff0 ffffffff e0ca7f20 c059fd3e > > e0ca7f14 f30de480 > > [351841.573364] Call Trace: > > [351841.573686] [<c059fd3e>] __mutex_lock_slowpath+0xbe/0x120 > > [351841.574130] [<c059fc60>] mutex_lock+0x20/0x40 > > [351841.574496] [<c0202732>] do_rmdir+0x52/0xe0 > > [351841.574878] [<c04b67ad>] ? sys_socketcall+0x1cd/0x2a0 > > [351841.575266] [<c0202820>] sys_rmdir+0x10/0x20 > > [351841.575781] [<c010968c>] syscall_call+0x7/0xb > > This is only half the story. > > I think you'll find another process that is waiting on the expire via > autofs4_revalidate() and holds the mutex that the above process is > waiting on.
Actually, there is another blocked process: [351961.584408] INFO: task install:22804 blocked for more than 120 seconds. [351961.584913] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [351961.585545] install D e268c4fc 0 22804 22798 0x00000000 [351961.586100] f442fed8 00000086 c02000b1 e268c4fc 00013fec f442fee8 e04efc00 00000000 [351961.587180] c0863320 c0863320 f3a19920 f3a19bb8 c55a9320 00000004 f442ff30 c1010000 [351961.588255] f3a19bb8 f72ceff4 f72ceff0 ffffffff f442ff04 c059fd3e f547be58 f3a19920 [351961.589550] Call Trace: [351961.589864] [<c02000b1>] ? path_to_nameidata+0x31/0x50 [351961.590286] [<c059fd3e>] __mutex_lock_slowpath+0xbe/0x120 [351961.590793] [<c059fc60>] mutex_lock+0x20/0x40 [351961.591140] [<c01ffc4f>] lookup_create+0x1f/0xa0 [351961.591569] [<c020287c>] sys_mkdirat+0x4c/0x100 [351961.591996] [<c020e48a>] ? mntput_no_expire+0x1a/0xd0 [351961.592427] [<c0202950>] sys_mkdir+0x20/0x30 [351961.592912] [<c010968c>] syscall_call+0x7/0xb > > This is a known problem and has been present for years and cannot be > resolved using the current automount framwork. > > I don't know why we're suddenly seeing people get caught by it recently > but we are. > > Assuming you are seeing the problem I think you are you should be able > to work around it by using the "browse" option on your autofs mounts. > This should work OK as long as your maps are not too large. > We will try this option. Thanx for your explanation. Can you point me to an kernel bug report number that I can trace for further development on that subject? Best regards, Sebastian _______________________________________________ autofs mailing list [email protected] http://linux.kernel.org/mailman/listinfo/autofs
