[PATCH v2 6/7] ext4: Enable negative dentries on case-insensitive lookup

Gabriel Krisman Bertazi
2023-04-22T00:03:48Z

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/ext4/namei.c | 34 +++-------------------------------
1 file changed, 3 insertions(+), 31 deletions(-)

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index a5010b5b8a8c..35f87f7141fe 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1850,16 +1850,9 @@ static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsi
}
}

-#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.
- */
- return NULL;
- }
-#endif
+ if (IS_ENABLED(CONFIG_UNICODE) && IS_CASEFOLDED(dir))
+ d_set_casefold_lookup(dentry);
+
return d_splice_alias(inode, dentry);
}

@@ -3185,17 +3178,6 @@ static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
ext4_fc_track_unlink(handle, dentry);
retval = ext4_mark_inode_dirty(handle, dir);

-#if IS_ENABLED(CONFIG_UNICODE)
- /* VFS negative dentries are incompatible with Encoding and
- * Case-insensitiveness. Eventually we'll want avoid
- * invalidating the dentries here, alongside with returning the
- * negative dentries at ext4_lookup(), when it is better
- * supported by the VFS for the CI case.
- */
- if (IS_CASEFOLDED(dir))
- d_invalidate(dentry);
-#endif
-
end_rmdir:
brelse(bh);
if (handle)
@@ -3296,16 +3278,6 @@ static int ext4_unlink(struct inode *dir, struct dentry *dentry)
goto out_trace;

retval = __ext4_unlink(dir, &dentry->d_name, d_inode(dentry), dentry);
-#if IS_ENABLED(CONFIG_UNICODE)
- /* VFS negative dentries are incompatible with Encoding and
- * Case-insensitiveness. Eventually we'll want avoid
- * invalidating the dentries here, alongside with returning the
- * negative dentries at ext4_lookup(), when it is better
- * supported by the VFS for the CI case.
- */
- if (IS_CASEFOLDED(dir))
- d_invalidate(dentry);
-#endif

out_trace:
trace_ext4_unlink_exit(dentry, retval);
--
2.40.0