Re: [PATCH] Don't reset di_format in xfs_ifree()

From: Lachlan McIlroy <lachlan@sgi.com>
To: Eric Sandeen <sandeen@sandeen.net>
Cc: xfs-oss <xfs@oss.sgi.com>
Subject: Re: [PATCH] Don't reset di_format in xfs_ifree()
Date: Wed, 11 Feb 2009 14:13:15 +1100	[thread overview]
Message-ID: <4992424B.3030608@sgi.com> (raw)
In-Reply-To: <4992362F.1020307@sandeen.net>

Eric Sandeen wrote:
> Lachlan McIlroy wrote:
>> I hit a panic while flushing a reclaimed inode that is fairly
>> reproducible under load.
> 
> With what testcase?
Initially with fsstress but then I wrote the extent.c program I
attached to the next patch I posted.

> 
> Thanks,
> -Eric
> 
>> In xfs_iflush_fork() we're led to believe that there are extents
>> on this inode but there aren't any.  Actually the inode was a
>> directory.  I added some debugging to xfs_ifree() and found
>> that di_format was XFS_DINODE_FMT_LOCAL and got reset to
>> XFS_DINODE_FMT_EXTENTS and this has confused the code in
>> xfs_iflush_fork().
>>
>> [<ffffffffa0047de7>] xfs_iext_get_ext+0x6c/0xca [xfs]
>> [<ffffffffa004a3d4>] xfs_iflush_fork+0x1b0/0x3c6 [xfs]
>> [<ffffffffa004aa3f>] xfs_iflush_int+0x455/0x5a1 [xfs]
>> [<ffffffffa004b0da>] xfs_iflush+0x229/0x2d6 [xfs]
>> [<ffffffffa007283c>] xfs_reclaim_inode+0xd8/0x10f [xfs]
>> [<ffffffffa0072976>] xfs_reclaim_inodes_ag+0x103/0x13e [xfs]
>> [<ffffffffa00729f3>] xfs_reclaim_inodes+0x42/0x60 [xfs]
>> [<ffffffffa0072d1b>] xfs_sync_worker+0x30/0x8a [xfs]
>> [<ffffffffa0073416>] xfssyncd+0x14e/0x1a2 [xfs]
>> [<ffffffffa00732c8>] ? xfssyncd+0x0/0x1a2 [xfs]
>> [<ffffffff8104fc70>] kthread+0x49/0x79
>>
>> I made this change and it passes the load test and XFSQA too.  I'm
>> not sure if this is indicative of a bigger problem though.
>>
>> Index: xfs-fix/fs/xfs/xfs_inode.c
>> ===================================================================
>> --- xfs-fix.orig/fs/xfs/xfs_inode.c
>> +++ xfs-fix/fs/xfs/xfs_inode.c
>> @@ -2165,8 +2165,6 @@ xfs_ifree(
>>   	ip->i_d.di_forkoff = 0;		/* mark the attr fork not in use */
>>   	ip->i_df.if_ext_max =
>>   		XFS_IFORK_DSIZE(ip) / (uint)sizeof(xfs_bmbt_rec_t);
>> -	ip->i_d.di_format = XFS_DINODE_FMT_EXTENTS;
>> -	ip->i_d.di_aformat = XFS_DINODE_FMT_EXTENTS;
>>   	/*
>>   	 * Bump the generation count so no one will be confused
>>   	 * by reincarnations of this inode.
>>
>> _______________________________________________
>> xfs mailing list
>> xfs@oss.sgi.com
>> http://oss.sgi.com/mailman/listinfo/xfs
>>
> 

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