On Wed, Apr 02, 2008 at 04:25:11PM +1000, Barry Naujok wrote:
> The next step for case-insensitive support is to avoid polution of
> the dentry cache with entries pointing to the same inode, but with
> names that only differ in case.
>
> To perform this, we will need to pass the actual filename that
> matched backup to the XFS/VFS interface and make sure the dentry
> cache only contains entries with the actual case-sensitive name.
>
> But, before we can do this, it was found that the directory lookup
> code with multiple leaves was shared with code adding a name to
> that directory. Most of xfs_dir2_leafn_lookup_int() could be broken
> into two functions determined by if (args->addname) { } else { }.
>
> For the following patch, only the lookup case needs to handle the
> various xfs_nameops, with case-insensitive match handling in
> addition to returning the actual name.
>
> So, this patch separates xfs_dir2_leafn_lookup_int() into
> xfs_dir2_leafn_lookup_for_addname() and xfs_dir2_leafn_lookup_for_entry().
>
> xfs_dir2_leafn_lookup_for_addname() iterates through the data blocks looking
> for a suitable empty space to insert the name while
> xfs_dir2_leafn_lookup_for_entry() uses the xfs_nameops to find the entry.
>
> xfs_dir2_leafn_lookup_for_entry() path also retains the data block where
> the first case-insensitive match occured as in the next patch which will
> return the name, the name is obtained from that block.
>
> Signed-off-by: Barry Naujok <bnaujok@xxxxxxx>
>
> ---
> fs/xfs/xfs_dir2_node.c | 373 +++++++++++++++++++++++++++++--------------------
> 1 file changed, 225 insertions(+), 148 deletions(-)
>
> Index: kern_ci/fs/xfs/xfs_dir2_node.c
> ===================================================================
> --- kern_ci.orig/fs/xfs/xfs_dir2_node.c
> +++ kern_ci/fs/xfs/xfs_dir2_node.c
> @@ -387,12 +387,11 @@ xfs_dir2_leafn_lasthash(
> }
>
> /*
> - * Look up a leaf entry in a node-format leaf block.
> - * If this is an addname then the extrablk in state is a freespace block,
> - * otherwise it's a data block.
> + * Look up a leaf entry for space to add a name in a node-format leaf block.
> + * The extrablk in state is a freespace block.
> */
> -int
> -xfs_dir2_leafn_lookup_int(
> +static int
STATIC
(and for the other new function)
> +xfs_dir2_leafn_lookup_for_addname(
> xfs_dabuf_t *bp, /* leaf buffer */
> xfs_da_args_t *args, /* operation arguments */
> int *indexp, /* out: leaf entry index */
....
> @@ -1785,6 +1857,11 @@ xfs_dir2_node_lookup(
> if (error)
> rval = error;
> /*
> + * If case-insensitive match was found in a leaf, return EEXIST.
> + */
> + else if (rval == ENOENT && args->cmpresult == XFS_CMP_CASE)
> + rval = EEXIST;
Can you put the comment inside the if branch?
if (error) {
rval = error;
} else if (rval == ENOENT && args->cmpresult == XFS_CMP_CASE) {
/* found a case-insensitive match in a leaf */
rval = EEXIST;
}
I think Josef got the others...
Cheers,
Dave.
--
Dave Chinner
Principal Engineer
SGI Australian Software Group
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