[Ocfs2-devel] [PATCH] ocfs2: fix ocfs2 read inode data panic in ocfs2_iget

[sunny.s.zhang]

在 2019年03月25日 09:31, Joseph Qi 写道:
>
> On 19/3/25 09:26, Shuning Zhang wrote:
>> In some cases, the function ocfs2_iget read the data of inode, which has
>> been deleted for some reason. That will make the system panic. So We
>> should judge whether this inode has been deleted, and tell the caller
>> that the inode is a bad inode.
>>
>> [283465.542049] OCFS2: ERROR (device sdp): ocfs2_validate_inode_block:
>> Invalid dinode #580640: OCFS2_VALID_FL not set
>>
> Looks like it is a filesystem corruption bug.
> So we'd better find where it is introduced and try to fix it there.
Thank you for reviewing
In that case, the ocfs2 was used as rear end of NFS(V3), which is 
stateless as we know.  NFS can't protect parent
directory from being deleted, when child is being accessed.  We can find 
the description at Documentation/filesystems/nfs/Exporting.
I have reproduced this issue by adding some delay codes.  This issue can 
be reproduced in the production environment in case of heavy load .
Of course this is a defect of NFS(V3),  But I think ocfs2 should have 
some fault tolerance. ocfs2 should not panic, if it try to get a 
nonexistent inode.

Thanks,
Sunny
> Thanks,
> Joseph
>
>> [283465.545490] Kernel panic - not syncing: OCFS2: (device sdp): panic forced
>> after error
>>
>> [283465.546889] CPU: 5 PID: 12416 Comm: nfsd Tainted: G        W
>> 4.1.12-124.18.6.el6uek.bug28762940v3.x86_64 #2
>> [283465.548382] Hardware name: VMware, Inc. VMware Virtual Platform/440BX
>> Desktop Reference Platform, BIOS 6.00 09/21/2015
>> [283465.549657]  0000000000000000 ffff8800a56fb7b8 ffffffff816e839c
>> ffffffffa0514758
>> [283465.550392]  000000000008dc20 ffff8800a56fb838 ffffffff816e62d3
>> 0000000000000008
>> [283465.551056]  ffff880000000010 ffff8800a56fb848 ffff8800a56fb7e8
>> ffff88005df9f000
>> [283465.551710] Call Trace:
>> [283465.552516]  [<ffffffff816e839c>] dump_stack+0x63/0x81
>> [283465.553291]  [<ffffffff816e62d3>] panic+0xcb/0x21b
>> [283465.554037]  [<ffffffffa04e66b0>] ocfs2_handle_error+0xf0/0xf0 [ocfs2]
>> [283465.554882]  [<ffffffffa04e7737>] __ocfs2_error+0x67/0x70 [ocfs2]
>> [283465.555768]  [<ffffffffa049c0f9>] ocfs2_validate_inode_block+0x229/0x230
>> [ocfs2]
>> [283465.556683]  [<ffffffffa047bcbc>] ocfs2_read_blocks+0x46c/0x7b0 [ocfs2]
>> [283465.557408]  [<ffffffffa049bed0>] ? ocfs2_inode_cache_io_unlock+0x20/0x20
>> [ocfs2]
>> [283465.557973]  [<ffffffffa049f0eb>] ocfs2_read_inode_block_full+0x3b/0x60
>> [ocfs2]
>> [283465.558525]  [<ffffffffa049f5ba>] ocfs2_iget+0x4aa/0x880 [ocfs2]
>> [283465.559082]  [<ffffffffa049146e>] ocfs2_get_parent+0x9e/0x220 [ocfs2]
>> [283465.559622]  [<ffffffff81297c05>] reconnect_path+0xb5/0x300
>> [283465.560156]  [<ffffffff81297f46>] exportfs_decode_fh+0xf6/0x2b0
>> [283465.560708]  [<ffffffffa062faf0>] ? nfsd_proc_getattr+0xa0/0xa0 [nfsd]
>> [283465.561262]  [<ffffffff810a8196>] ? prepare_creds+0x26/0x110
>> [283465.561932]  [<ffffffffa0630860>] fh_verify+0x350/0x660 [nfsd]
>> [283465.562862]  [<ffffffffa0637804>] ? nfsd_cache_lookup+0x44/0x630 [nfsd]
>> [283465.563697]  [<ffffffffa063a8b9>] nfsd3_proc_getattr+0x69/0xf0 [nfsd]
>> [283465.564510]  [<ffffffffa062cf60>] nfsd_dispatch+0xe0/0x290 [nfsd]
>> [283465.565358]  [<ffffffffa05eb892>] ? svc_tcp_adjust_wspace+0x12/0x30
>> [sunrpc]
>> [283465.566272]  [<ffffffffa05ea652>] svc_process_common+0x412/0x6a0 [sunrpc]
>> [283465.567155]  [<ffffffffa05eaa03>] svc_process+0x123/0x210 [sunrpc]
>> [283465.568020]  [<ffffffffa062c90f>] nfsd+0xff/0x170 [nfsd]
>> [283465.568962]  [<ffffffffa062c810>] ? nfsd_destroy+0x80/0x80 [nfsd]
>> [283465.570112]  [<ffffffff810a622b>] kthread+0xcb/0xf0
>> [283465.571099]  [<ffffffff810a6160>] ? kthread_create_on_node+0x180/0x180
>> [283465.572114]  [<ffffffff816f11b8>] ret_from_fork+0x58/0x90
>> [283465.573156]  [<ffffffff810a6160>] ? kthread_create_on_node+0x180/0x180
>> ---
>>   fs/ocfs2/inode.c |   22 ++++++++++++++++++++++
>>   1 files changed, 22 insertions(+), 0 deletions(-)
>>
>> diff --git a/fs/ocfs2/inode.c b/fs/ocfs2/inode.c
>> index b254416..a7f8160 100644
>> --- a/fs/ocfs2/inode.c
>> +++ b/fs/ocfs2/inode.c
>> @@ -513,6 +513,16 @@ static int ocfs2_read_locked_inode(struct inode *inode,
>>   	status = -EINVAL;
>>   	fe = (struct ocfs2_dinode *) bh->b_data;
>>   
>> +	/*
>> +	 * In some cases, this inode has been deleted, but the data of
>> +	 * inode is read directly. So We should judge whether this inode
>> +	 * has been deleted.
>> +	 * */
>> +	if (unlikely(fe->i_dtime != 0)) {
>> +		mlog(ML_NOTICE, "The inode %llu has been deleted\n",
>> +		     le64_to_cpu(fe->i_blkno));
>> +	        goto bail;
>> +	}
>>   	/*
>>   	 * This is a code bug. Right now the caller needs to
>>   	 * understand whether it is asking for a system file inode or
>> @@ -1331,6 +1341,18 @@ int ocfs2_validate_inode_block(struct super_block *sb,
>>   
>>   	BUG_ON(!buffer_uptodate(bh));
>>   
>> +	/*
>> +	 * In some cases, this inode has been deleted, but the data of
>> +	 * inode is read directly. This is not a data corruption.So
>> +	 * We should judge whether this inode has been deleted.
>> +	 * */
>> +	if (unlikely(di->i_dtime != 0)) {
>> +		rc = -EINVAL;
>> +		mlog(ML_NOTICE, "The inode %llu has been deleted\n",
>> +		     le64_to_cpu(di->i_blkno));
>> +	        goto bail;
>> +	}
>> +
>>   	/*
>>   	 * If the ecc fails, we return the error but otherwise
>>   	 * leave the filesystem running.  We know any error is
>>