Re: autofs4 hang in 2.6.37-rc1

[Ian Kent]

On Sun, 2010-11-14 at 16:15 +0100, Arnd Bergmann wrote:
> On Sunday 14 November 2010 14:51:04 Avi Kivity wrote:
> > automount     S ffff88012a28a680     0   399      1 0x00000000
> >   ffff88012a07bd08 0000000000000082 0000000000000000 0000000000000000
> >   ffff88012a07a010 ffff88012a07bfd8 0000000000011800 ffff88012693c260
> >   ffff88012693c5d0 ffff88012693c5c8 0000000000011800 0000000000011800
> > Call Trace:
> >   [<ffffffff81056197>] ? prepare_to_wait+0x67/0x74
> >   [<ffffffff811b23eb>] autofs4_wait+0x5a4/0x6d5
> >   [<ffffffff81055f25>] ? autoremove_wake_function+0x0/0x34
> >   [<ffffffff811b2ba5>] autofs4_do_expire_multi+0x5b/0xa3
> >   [<ffffffff811b2c39>] autofs4_expire_multi+0x4c/0x54
> >   [<ffffffff811b1750>] autofs4_root_ioctl_unlocked+0x23e/0x252
> >   [<ffffffff811b1808>] autofs4_root_ioctl+0x39/0x53
> >   [<ffffffff810f5e5c>] do_vfs_ioctl+0x557/0x5bb
> >   [<ffffffff810ca644>] ? remove_vma+0x6e/0x76
> >   [<ffffffff810cb6a2>] ? do_munmap+0x31c/0x33e
> >   [<ffffffff810f5f02>] sys_ioctl+0x42/0x65
> >   [<ffffffff81002b42>] system_call_fastpath+0x16/0x1b
> > 
> > 
> > Shouldn't we drop autofs4_ioctl_mutex while we wait?
> 
> If the ioctl can sleep for multiple seconds, the mutex should
> indeed be dropped, and that would be safe because we used to
> do the same with the BKL.
> 
> The question is why this would sleep for more than 120 seconds.

umount against a server that isn't responding can easily take more than
2 minutes.
 
Ian

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/