linux-kernel - Re: [PATCH]: initialize parts of udf inode earlier in create

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Date:	Mon, 07 Aug 2006 17:45:03 -0500
From:	Eric Sandeen <sandeen@...deen.net>
To:	dan@...enterprises.com
CC:	linux-kernel@...r.kernel.org, bfennema@...con.csc.calpoly.edu
Subject: Re: [PATCH]: initialize parts of udf inode earlier in create

dan@...enterprises.com wrote:
> I ran into the same issue today, but when listing a directory with
> invalid/corrupt entries:

...

> The following patch to udf_alloc_inode() should take care of both (and
> other similar) cases, but I've only tested it with udf_lookup().
> 
> Dan
> 
> --
> 
> Signed-off-by: Dan Bastone <dan@...enterprises.com>
> 
> --- linux-2.6.17.7/fs/udf/super.c.orig
> +++ linux-2.6.17.7/fs/udf/super.c
> @@ -116,6 +116,13 @@
>         ei = (struct udf_inode_info *)kmem_cache_alloc(udf_inode_cachep,
>         SLAB_KERNEL);
>         if (!ei)
>                 return NULL;
> +
> +       ei->i_unique = 0;
> +       ei->i_lenExtents = 0;
> +       ei->i_next_alloc_block = 0;
> +       ei->i_next_alloc_goal = 0;
> +       ei->i_strat4096 = 0;
> +
>         return &ei->vfs_inode;
>  }

That looks fine to me, but I wonder if there's a cleaner way, rather 
than sprinkling these initializations in the code.  If __udf_read_inode 
fails, then it calls mark_bad_inode; maybe the code should check for 
that before trying to discard prealloced blocks?  I don't really know 
enough about all the UDF codepaths (by far!) to know for sure what the 
best solution is, here.

I do notice that for example ext2_put_inode() checks for bad_inode 
before calling ext2_discard_prealloc.  And it looks like the udf code 
may have a little ext2 history in it :)

-Eric

(hm, just realized that my original patch in this thread isn't strictly 
necessary for the reasons I originally proposed; udf_clear_inode checks 
for MS_RDONLY before discarding the prealloc, and my first UDF patch set 
the MS_RDONLY flag on these read-only-marked filesystems... ah well)
-
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