Date: Sat, 13 Nov 2010 03:27:07 +0100 From: Martin Matuska <mm@FreeBSD.org> To: Andriy Gapon <avg@freebsd.org> Cc: freebsd-fs@freebsd.org, freebsd-stable@freebsd.org Subject: Re: 8.1-STABLE: problem with unmounting ZFS snapshots Message-ID: <4CDDF77B.90708@FreeBSD.org> In-Reply-To: <4CDD4EB4.40004@freebsd.org> References: <D9ABDE54892A4D9285FE7FFA6E1B1B69@vosz.local> <4CDD2F5F.2000902@freebsd.org> <FD7FC6ED159249338A04BE125941D146@vosz.local> <4CDD4EB4.40004@freebsd.org>
next in thread | previous in thread | raw e-mail | index | archive | help
Yes, this is indeed a leak introduced by importing onnv revision 9214 and it exists in perforce as well - very easy to reproduce. # mount -t zfs test@t1 /mnt # umount /mnt (-> hang) http://bugs.opensolaris.org/bugdatabase/view_bug.do?bug_id=6604992 http://bugs.opensolaris.org/bugdatabase/view_bug.do?bug_id=6810367 This is not compatible with mounting snapshots outside mounted ZFS and I was not able to reproduce the errors defined in 6604992 and 6810367 (they are Solaris-specific). I suggest we comment out this code (from head, later MFC and p4 as well). Patch (should work with HEAD and 8-STABLE): http://people.freebsd.org/~mm/patches/zfs/zfs_vfsops.c.patch Dňa 12.11.2010 15:27, Andriy Gapon wrote / napísal(a): > on 12/11/2010 16:00 Alexander Zagrebin said the following: >> Thanks for your reply! >> >>>> 2. the umount is waiting for disk >>>> #ps | egrep 'PID|umount' >>>> PID TT STAT TIME COMMAND >>>> 958 0 D+ 0:00,04 umount /mnt >>>> # procstat -t 958 >>>> PID TID COMM TDNAME CPU PRI >>> STATE WCHAN >>>> 958 100731 umount - 3 133 >>> sleep mntref >>> >>> procstat -kk <pid> >> >> $ ps a | grep umount >> 86874 2- D 0:00,06 umount /mnt >> 90433 3 S+ 0:00,01 grep umount >> >> $ sudo procstat -kk 86874 >> PID TID COMM TDNAME KSTACK >> 86874 100731 umount - mi_switch+0x176 >> sleepq_wait+0x42 _sleep+0x317 vfs_mount_destroy+0x5a dounmount+0x4d4 >> unmount+0x38b syscall+0x1cf Xfast_syscall+0xe2 >> > > > Looks like possible mnt_ref leak. > I think that something like that was fixed some not long time ago. > Perhaps you either don't have the fix or there is another leak. > What revision do you have? > > Perhaps Martin has an insight here. >
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?4CDDF77B.90708>