[Linux-cluster] Can't mount snapshot LUN with new infrastructure

[Kenji Wakamiya]

Hello,

I have a three node GFS1 cluster that is based on OpenAIS and CentOS 5,
and am using NetApp's iSCSI LUN as a block device.

Now I want to mount that LUN's snapshot LUN with lock_nolock on any
member of the three nodes, with having mounted original LUN.

With old version of CMAN (not OpenAIS), the same thing worked well.
But I've got the following error with new infrastructure:

# mount -t gfs
/dev/isda on /web type gfs (rw,hostdata=jid=2:id=131074:first=0,acl)
# mount -t gfs -o lockproto=lock_nolock /dev/isdb /testsnap
/sbin/mount.gfs: error 17 mounting /dev/isdb on /testsnap

/var/log/mssages:
Jun 22 17:10:46 node17 kernel: kobject_add failed for cluster3:gfstest with -EEXIST, don't try to register things with the same name in the same directory.
Jun 22 17:10:46 node17 kernel:  [<c04dc1e0>] kobject_add+0x147/0x16d
Jun 22 17:10:46 node17 kernel:  [<c04dc2ec>] kobject_register+0x19/0x30
Jun 22 17:10:46 node17 kernel:  [<f8c599ca>] fill_super+0x3df/0x5c9 [gfs]
Jun 22 17:10:46 node17 kernel:  [<c04708f6>] get_sb_bdev+0xc6/0x110
Jun 22 17:10:46 node17 kernel:  [<c0453f2e>] __alloc_pages+0x57/0x27e
Jun 22 17:10:46 node17 kernel:  [<f8c58d15>] gfs_get_sb+0x12/0x16 [gfs]
Jun 22 17:10:46 node17 kernel:  [<f8c595eb>] fill_super+0x0/0x5c9 [gfs]
Jun 22 17:10:46 node17 kernel:  [<c04703bb>] vfs_kern_mount+0x7d/0xf2
Jun 22 17:10:46 node17 kernel:  [<c0470462>] do_kern_mount+0x25/0x36
Jun 22 17:10:46 node17 kernel:  [<c0482eb4>] do_mount+0x5d6/0x646
Jun 22 17:10:46 node17 kernel:  [<c044f86c>] find_get_pages_tag+0x30/0x6e
Jun 22 17:10:46 node17 kernel:  [<c0455887>] pagevec_lookup_tag+0x1b/0x22
Jun 22 17:10:46 node17 kernel:  [<c0453c5d>] get_page_from_freelist+0x96/0x310
Jun 22 17:10:46 node17 kernel:  [<c0453e6d>] get_page_from_freelist+0x2a6/0x310
Jun 22 17:10:46 node17 kernel:  [<c0453c5d>] get_page_from_freelist+0x96/0x310
Jun 22 17:10:46 node17 kernel:  [<c0481dc5>] copy_mount_options+0x26/0x109
Jun 22 17:10:46 node17 kernel:  [<c0482f91>] sys_mount+0x6d/0xa5
Jun 22 17:10:46 node17 kernel:  [<c0403eff>] syscall_call+0x7/0xb
Jun 22 17:10:46 node17 kernel:  =======================

Now I have /sys/fs/gfs/cluster3:gfstest/.  So I suspect that a
conflict between two LUN's lock table names is occurring in sysfs.

Is there any good solution?

Thanks,
Kenji