[Ocfs2-devel] kernel BUG in function ocfs2_truncate_file

[Junxiao Bi]

On 03/31/2016 10:56 AM, Gang He wrote:
> Hello Joseph and Junxiao,
> 
> Did you encounter this issue in the past? I doubt this is possible a race condition bug (rather than data inconsistency).
Never saw this. fsck report any corruption?

Thanks,
Junxiao.
> 
> Thanks
> Gang
> 
> 
>>>>
>> Hello Guys,
>>
>> I got a bug, which reported a kernel BUG in function ocfs2_truncate_file,
>> Base on my initial analysis, this bug looks like a race condition problem.
>> Unfortunately, there was no kernel crash dump caught, just got some kernel 
>> log as below,
>>
>> kernel BUG at /usr/src/packages/BUILD/ocfs2-1.6/default/ocfs2/file.c:466!
>> Oct 21 13:02:19 uii316 [ 1766.831230] Supported: Yes
>> Oct 21 13:02:19 uii316 [ 1766.831234]
>> Oct 21 13:02:19 uii316 [ 1766.831238] Pid: 7134, comm: saposcol Not tainted 
>> 3.0.101-0.47.67-default #1
>> Oct 21 13:02:19 uii316 HP ProLiant BL460c G1
>> Oct 21 13:02:19 uii316
>> Oct 21 13:02:19 uii316 [ 1766.831247] RIP: 0010:[<ffffffffa0744b95>]
>> Oct 21 13:02:19 uii316 [<ffffffffa0744b95>] ocfs2_truncate_file+0xa5/0x490 
>> [ocfs2]
>> Oct 21 13:02:19 uii316 [ 1766.831312] RSP: 0018:ffff880f39d79b68  EFLAGS: 
>> 00010296
>> Oct 21 13:02:19 uii316 [ 1766.831321] RAX: 000000000000008f RBX: 
>> ffff880f39c5e240 RCX: 00000000000039fd
>> Oct 21 13:02:19 uii316 [ 1766.831326] RDX: 0000000000000000 RSI: 
>> 0000000000000007 RDI: 0000000000000246
>> Oct 21 13:02:19 uii316 [ 1766.831331] RBP: 1000000000000000 R08: 
>> ffffffff81da0ac0 R09: 0000000000000000
>> Oct 21 13:02:19 uii316 [ 1766.831336] R10: 0000000000000003 R11: 
>> 00000000ffffffff R12: ffff880f3949bc78
>> Oct 21 13:02:19 uii316 [ 1766.831342] R13: ffff880f39c5e888 R14: 
>> ffff880f3d481000 R15: 00000000000e43bc
>> Oct 21 13:02:19 uii316 [ 1766.831347] FS:  00007f11cda9d720(0000) 
>> GS:ffff880fefd40000(0000) knlGS:0000000000000000
>> Oct 21 13:02:19 uii316 [ 1766.831353] CS:  0010 DS: 0000 ES: 0000 CR0: 
>> 0000000080050033
>> Oct 21 13:02:19 uii316 [ 1766.831358] CR2: 00007f11cdad4000 CR3: 
>> 0000000f39d35000 CR4: 00000000000007e0
>> Oct 21 13:02:19 uii316 [ 1766.831363] DR0: 0000000000000000 DR1: 
>> 0000000000000000 DR2: 0000000000000000
>> Oct 21 13:02:19 uii316 [ 1766.831368] DR3: 0000000000000000 DR6: 
>> 00000000ffff0ff0 DR7: 0000000000000400
>> Oct 21 13:02:19 uii316 [ 1766.831374] Process saposcol (pid: 7134, 
>> threadinfo ffff880f39d78000, task ffff880f39c5e240)
>> Oct 21 13:02:19 uii316 [ 1766.831379] Stack:
>> Oct 21 13:02:19 uii316 [ 1766.831383]  000000000002433c
>> Oct 21 13:02:19 uii316 00000000000e43bc
>> Oct 21 13:02:19 uii316 00000000000eab40
>> Oct 21 13:02:19 uii316 ffff880f00000001
>> Oct 21 13:02:19 uii316
>> Oct 21 13:02:19 uii316 [ 1766.831397]  ffff880f394956e0
>> Oct 21 13:02:19 uii316 ffff880f8e0d1000
>> Oct 21 13:02:19 uii316 ffff880f3949b800
>> Oct 21 13:02:19 uii316 0000000000000000
>> Oct 21 13:02:19 uii316
>> Oct 21 13:02:19 uii316 [ 1766.831410]  ffff880f39454980
>> Oct 21 13:02:19 uii316 0000000000000001
>> Oct 21 13:02:19 uii316 000000000002433c
>> Oct 21 13:02:19 uii316 0000000000000008
>> Oct 21 13:02:19 uii316
>> Oct 21 13:02:19 uii316 [ 1766.831423] Call Trace:
>> Oct 21 13:02:19 uii316 [ 1766.831492]  [<ffffffffa074742e>] 
>> ocfs2_setattr+0x26e/0xa90 [ocfs2]
>> Oct 21 13:02:19 uii316 [ 1766.831522]  [<ffffffff81178faf>] 
>> notify_change+0x19f/0x2f0
>> Oct 21 13:02:19 uii316 [ 1766.831534]  [<ffffffff8115d517>] 
>> do_truncate+0x57/0x80
>> Oct 21 13:02:19 uii316 [ 1766.831544]  [<ffffffff8116c053>] 
>> do_last+0x603/0x800
>> Oct 21 13:02:19 uii316 [ 1766.831551]  [<ffffffff8116ceb9>] 
>> path_openat+0xd9/0x420
>> Oct 21 13:02:19 uii316 [ 1766.831558]  [<ffffffff8116d33c>] 
>> do_filp_open+0x4c/0xc0
>> Oct 21 13:02:19 uii316 [ 1766.831566]  [<ffffffff8115de5f>] 
>> do_sys_open+0x17f/0x250
>> Oct 21 13:02:19 uii316 [ 1766.831575]  [<ffffffff8146e1f2>] 
>> system_call_fastpath+0x16/0x1b
>> Oct 21 13:02:19 uii316 [ 1766.831588]  [<00007f11ccb07080>] 0x7f11ccb0707f
>> Oct 21 13:02:19 uii316 [ 1766.831592] Code:
>>
>>  The source code in question is as below,
>>  444 static int ocfs2_truncate_file(struct inode *inode,
>>  445                                struct buffer_head *di_bh,
>>  446                                u64 new_i_size)
>>  447 {
>>  448         int status = 0;
>>  449         struct ocfs2_dinode *fe = NULL;
>>  450         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
>>  451
>>  452         /* We trust di_bh because it comes from ocfs2_inode_lock(), 
>> which
>>  453          * already validated it */
>>  454         fe = (struct ocfs2_dinode *) di_bh->b_data;
>>  455
>>  456         trace_ocfs2_truncate_file((unsigned long 
>> long)OCFS2_I(inode)->ip_blkno,
>>  457                                   (unsigned long 
>> long)le64_to_cpu(fe->i_size),
>>  458                                   (unsigned long long)new_i_size);
>>  459
>>  460         mlog_bug_on_msg(le64_to_cpu(fe->i_size) != i_size_read(inode),    
>>  <<= here
>>  461                         "Inode %llu, inode i_size = %lld != di "
>>  462                         "i_size = %llu, i_flags = 0x%x\n",
>>  463                         (unsigned long long)OCFS2_I(inode)->ip_blkno,
>>  464                         i_size_read(inode),
>>  465                         (unsigned long long)le64_to_cpu(fe->i_size),
>>  466                         le32_to_cpu(fe->i_flags));
>>  467
>>
>> If your encountered the similar issue in the past, please let me know, to 
>> see if there is any patch/discussion for this bug.
>>
>> Thanks a lot.
>> Gang
>>
>>  
>>
>>
>> _______________________________________________
>> Ocfs2-devel mailing list
>> Ocfs2-devel at oss.oracle.com 
>> https://oss.oracle.com/mailman/listinfo/ocfs2-devel