Re: [PATCH] ext3: truncate block allocated on a failed ext3_write_begin

["Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>]

On Thu, Aug 28, 2008 at 12:56:28PM -0500, Eric Sandeen wrote:
> Aneesh Kumar K.V wrote:
> > For blocksize < pagesize we need to remove blocks that
> > got allocte in block_wirte_begin if we fail with ENOSPC
> > for later blocks. block_write_begin internally does
> > this if it allocated page locally. This make sure
> > we don't have blocks outisde inode.i_size during
> > ENOSPC
> 
> I think this is good; here's an easy testcase:
> 
> # dd if=/dev/zero of=fsfile bs=1k count=2048
> # mkfs.ext3 -F fsfile
> # mkdir mnt
> # mount -o loop fsfile mnt/
> # dd if=/dev/zero of=mnt/1kfile bs=1k count=1
> # cd mnt/
> # dd if=/dev/zero of=bigfile bs=4k
> # cd ..
> # umount mnt
> # e2fsck -f fsfile
> e2fsck 1.39 (29-May-2006)
> Pass 1: Checking inodes, blocks, and sizes
> Inode 13, i_size is 974848, should be 976896.  Fix<y>?
> ...
> 
> can you test with that, unless you already have a testcase you've used?

I tested the above and it works fine. The problem appeared during
fsstress run and I used fsstress to debug and fix.


> 
> Assuming it fixes it (it should) you can add:
> 
> Acked-by: Eric Sandeen <sandeen@redhat.com>
> 

-aneesh