Re: [PATCH v2 7/7] f2fs: Enable negative dentries on case-insensitive lookup

Eric Biggers
2023-07-14T05:49:29Z

On Fri, Apr 21, 2023 at 08:03:10PM -0400, Gabriel Krisman Bertazi wrote:
> From: Gabriel Krisman Bertazi <krisman@collabora.com>
>
> Instead of invalidating negative dentries during case-insensitive
> lookups, mark them as such and let them be added to the dcache.
> d_ci_revalidate is able to properly filter them out if necessary based
> on the dentry casefold flag.
>
> Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
> ---
> fs/f2fs/namei.c | 23 ++---------------------
> 1 file changed, 2 insertions(+), 21 deletions(-)
>
> diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
> index 11fc4c8036a9..57ca7ea86509 100644
> --- a/fs/f2fs/namei.c
> +++ b/fs/f2fs/namei.c
> @@ -564,17 +564,8 @@ static struct dentry *f2fs_lookup(struct inode *dir, struct dentry *dentry,
> goto out_iput;
> }
> out_splice:
> -#if IS_ENABLED(CONFIG_UNICODE)
> - if (!inode && IS_CASEFOLDED(dir)) {
> - /* Eventually we want to call d_add_ci(dentry, NULL)
> - * for negative dentries in the encoding case as
> - * well. For now, prevent the negative dentry
> - * from being cached.
> - */
> - trace_f2fs_lookup_end(dir, dentry, ino, err);
> - return NULL;
> - }
> -#endif
> + if (IS_ENABLED(CONFIG_UNICODE) && IS_CASEFOLDED(dir))
> + d_set_casefold_lookup(dentry);

I wonder if a more consistent place for the above code would be earlier in
f2fs_lookup(), next to the call to generic_set_encrypted_ci_d_ops()? That's
where the dentry_operations are set. It's also next to f2fs_prepare_lookup()
which is where DCACHE_NOKEY_NAME gets set if needed.

- Eric