[Cluster-devel] [GFS2 PATCH] inode size inconsistency

[Cluster-devel] [GFS2 PATCH] inode size inconsistency

[Wendy Cheng]

This should have been part of the NFS patch #1 but somehow I missed it 
when packaging the patches. It is not a critical issue as the others (I 
hope). RHEL 5.1 31.el5 kernel runs fine without this change.

Our truncate code is chopped into two parts, one for vfs inode changes 
(in vmtruncate()) and one of gfs inode (in gfs2_truncatei()). These two 
operatons are, unfortunately, not atomic. So it could happens that 
vmtruncate() succeeds (inode->i_size is changed) but gfs2_truncatei 
fails (say kernel temporarily out of memory). This would leave gfs inode 
i_di.di_size out of sync with vfs inode i_size. It will later confuse 
gfs2_commit_write() if a write is issued. Last time I checked, it will 
cause file corruption.

-- Wendy

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[Cluster-devel] [GFS2 PATCH] inode size inconsistency

[Steven Whitehouse]

Hi,

Now in the -nmw git tree. Thanks,

Steve.

On Wed, 2007-06-27 at 11:00 -0400, Wendy Cheng wrote:
> This should have been part of the NFS patch #1 but somehow I missed it 
> when packaging the patches. It is not a critical issue as the others (I 
> hope). RHEL 5.1 31.el5 kernel runs fine without this change.
> 
> Our truncate code is chopped into two parts, one for vfs inode changes 
> (in vmtruncate()) and one of gfs inode (in gfs2_truncatei()). These two 
> operatons are, unfortunately, not atomic. So it could happens that 
> vmtruncate() succeeds (inode->i_size is changed) but gfs2_truncatei 
> fails (say kernel temporarily out of memory). This would leave gfs inode 
> i_di.di_size out of sync with vfs inode i_size. It will later confuse 
> gfs2_commit_write() if a write is issued. Last time I checked, it will 
> cause file corruption.
> 
> -- Wendy
>