[Ocfs2-devel] [Question] deadlock on chmod when running discontigous block group multiple node testing

[Eric Ren]

Hi Junxiao,

> Hi Eric,
>
> On 10/11/2016 10:42 AM, Eric Ren wrote:
>> Hi Junxiao,
>>
>> As the subject, the testing hung there on a kernel without your patches:
>>
>> "ocfs2: revert using ocfs2_acl_chmod to avoid inode cluster lock hang"
>> and
>> "ocfs2: fix posix_acl_create deadlock"
>>
>> The stack trace is:
>> ```
>> ocfs2cts1:~ # pstree -pl 24133
>> discontig_runne(24133)───activate_discon(21156)───mpirun(15146)─┬─fillup_contig_b(15149)───sudo(15231)───chmod(15232)
>>
>> ocfs2cts1:~ # pgrep -a chmod
>> 15232 /bin/chmod -R 777 /mnt/ocfs2
>>
>> ocfs2cts1:~ # cat /proc/15232/stack
>> [<ffffffffa05377ef>] __ocfs2_cluster_lock.isra.39+0x1bf/0x620 [ocfs2]
>> [<ffffffffa053856d>] ocfs2_inode_lock_full_nested+0x12d/0x840 [ocfs2]
>> [<ffffffffa0538dbb>] ocfs2_inode_lock_atime+0xcb/0x170 [ocfs2]
>> [<ffffffffa0531e61>] ocfs2_readdir+0x41/0x1b0 [ocfs2]
>> [<ffffffff8120d03c>] iterate_dir+0x9c/0x110
>> [<ffffffff8120d453>] SyS_getdents+0x83/0xf0
>> [<ffffffff815e126e>] entry_SYSCALL_64_fastpath+0x12/0x6d
>> [<ffffffffffffffff>] 0xffffffffffffffff
>> ```
>>
>> Do you think this issue can be fixed by your patches?
> Looks not. Those two patches are to fix recursive locking deadlock. But
> from above call trace, there is no recursive lock.
Sorry, the call trace on another node was missing.  Here it is:

ocfs2cts2:~ # pstree -lp
sshd(4292)─┬─sshd(4745)───sshd(4753)───bash(4754)───orted(4781)───fillup_contig_b(4782)───sudo(4864)───chmod(4865)

ocfs2cts2:~ # cat /proc/4865/stack
[<ffffffffa053e7ef>] __ocfs2_cluster_lock.isra.39+0x1bf/0x620 [ocfs2]
[<ffffffffa053f56d>] ocfs2_inode_lock_full_nested+0x12d/0x840 [ocfs2]
[<ffffffffa059c860>] ocfs2_iop_get_acl+0x40/0xf0 [ocfs2]
[<ffffffff812044e6>] generic_permission+0x166/0x1c0
[<ffffffffa0542aca>] ocfs2_permission+0xaa/0xd0 [ocfs2]
[<ffffffff81204596>] __inode_permission+0x56/0xb0
[<ffffffff812068fa>] link_path_walk+0x29a/0x560
[<ffffffff81206cbf>] path_lookupat+0x7f/0x110
[<ffffffff8120929c>] filename_lookup+0x9c/0x150
[<ffffffff811f96c3>] SyS_fchmodat+0x33/0x90
[<ffffffff815e126e>] entry_SYSCALL_64_fastpath+0x12/0x6d
[<ffffffffffffffff>] 0xffffffffffffffff

Thanks,
Eric


>
> Thanks,
> Junxiao.
>> I will try your patches later, but I am little worried the possibility
>> of reproduction may not be 100%.
>> So ask you to confirm;-)
>>
>> Eric
>