Bug 458182 - cat /sys/kernel/debug/gfs2/X/glocks causes panic
cat /sys/kernel/debug/gfs2/X/glocks causes panic
Product: Red Hat Enterprise Linux 5
Classification: Red Hat
Component: kernel (Show other bugs)
All Linux
medium Severity high
: rc
: ---
Assigned To: Steve Whitehouse
Cluster QE
: Regression
Depends On:
  Show dependency treegraph
Reported: 2008-08-06 17:30 EDT by Nate Straz
Modified: 2009-05-27 23:36 EDT (History)
5 users (show)

See Also:
Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of:
Last Closed: 2008-08-07 10:24:26 EDT
Type: ---
Regression: ---
Mount Type: ---
Documentation: ---
Verified Versions:
Category: ---
oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

Attachments (Terms of Use)

  None (edit)
Description Nate Straz 2008-08-06 17:30:52 EDT
Description of problem:

When I cat the glocks debugfs file for a mounted GFS2 file system I hit the following panic.

[root@morph-01 morph-cluster:brawl0]# cat glocks  > /tmp/glocks
BUG: unable to handle kernel paging request at virtual address 8136bd30
 printing eip:
*pde = 00000000
Oops: 0000 [#1]
last sysfs file: /fs/gfs2/morph-cluster:brawl0/lock_module/block
Modules linked in: lock_dlm(U) gfs2(U) dlm configfs autofs4 hidp rfcomm l2cap bluetooth sunrpc ipv6 xfrm_nalgo crypto_api dm_multipath video sbs backlight i2c_ec button battery asus_acpi ac lp i2c_i801 parport_pc ide_cd parport e1000 e7xxx_edac cdrom intel_rng edac_mc i2c_core floppy sg pcspkr dm_snapshot dm_zero dm_mirror dm_mod qla2xxx scsi_transport_fc ata_piix libata sd_mod scsi_mod ext3 jbd uhci_hcd ohci_hcd ehci_hcd
CPU:    1
EIP:    0060:[<c04e5eb6>]    Tainted: G      VLI
EFLAGS: 00010297   (2.6.18-98.el5 #1) 
EIP is at vsnprintf+0x2aa/0x45d
eax: 8136bd30   ebx: ffffffff   ecx: 8136bd30   edx: fffffffe
esi: f6a7684b   edi: f55e8db4   ebp: ffffffff   esp: f55e8d38
ds: 007b   es: 007b   ss: 0068
Process cat (pid: 3187, ti=f55e8000 task=f6ba9000 task.ti=f55e8000)
Stack: 095897f3 f6a7680c 00498089 0000000a ffffffff ffffffff 00000000 f8da6252 
       f6a7680c f64e7c40 f8da6228 f8da621f c04e60df f55e8d90 f8d8f7f0 f55e8d90 
       f8da621f c3131ed0 0000328c f8d8fa3f f64e7c40 f8da6228 f8da621f f8da621f 
Call Trace:
 [<c04e60df>] vsprintf+0xd/0xf
 [<f8d8f7f0>] gfs2_print_dbg+0x28/0x4f [gfs2]
 [<f8d8fa3f>] __dump_glock+0x228/0x39f [gfs2]
 [<c0472b05>] __find_get_block_slow+0xfb/0x105
 [<c0488a46>] mntput_no_expire+0x11/0x6a
 [<c047e7d5>] link_path_walk+0xb3/0xbd
 [<c0459aab>] get_page_from_freelist+0x96/0x333
 [<c04059bf>] apic_timer_interrupt+0x1f/0x24
 [<c0609b9c>] _read_lock+0x4/0xc
 [<f8d8fbcd>] dump_glock+0x17/0x1f [gfs2]
 [<c048c2c4>] seq_read+0xe7/0x273
 [<c048c1dd>] seq_read+0x0/0x273
 [<c0471734>] vfs_read+0x9f/0x141
 [<c0471b82>] sys_read+0x3c/0x63
 [<c0404eff>] syscall_call+0x7/0xb
Code: 74 24 10 73 03 c6 06 20 4d 46 85 ed 7f f1 e9 a1 00 00 00 8b 0f b8 12 84 63 c0 8b 54 24 14 81 f9 ff 0f 00 00 0f 46 c8 89 c8 eb 06 <80> 38 00 74 07 40 4a 83 fa ff 75 f4 29 c8 f6 44 24 18 10 89 c3 
EIP: [<c04e5eb6>] vsnprintf+0x2aa/0x45d SS:ESP 0068:f55e8d38
 <0>Kernel panic - not syncing: Fatal exception

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
1. mount -t gfs2 /dev/foo /mnt/foo
2. cat /sys/kernel/debug/gfs2/*/glocks
3. panic
Actual results:

Expected results:

Additional info:
Comment 1 Nate Straz 2008-08-06 17:52:30 EDT
I retested with the gfs2.ko from kernel-2.6.18-101.el5 and I was not able to hit the panic.  Loading the gfs2.ko from kmod-gfs2-1.98-1.1.el5.abhi.12 caused the bug to come back.
Comment 2 Steve Whitehouse 2008-08-07 04:06:42 EDT
Is this missing bz #456334? If so please retest with that patch applied.
Comment 3 Nate Straz 2008-08-07 10:24:26 EDT
Marking this a closed against the latest kernel.  With the -101.el5 kernel I was not able to panic the system by simply mounting the file system and reading the glocks file.

Note You need to log in before you can comment on or make changes to this bug.