linux-ext4 - [PATCH RFC 7/7] f2fs: Enable negative dentries on case-insensitive lookup

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Message-Id: <20220601204437.676872-8-krisman@collabora.com>
Date:   Wed,  1 Jun 2022 16:44:37 -0400
From:   Gabriel Krisman Bertazi <krisman@...labora.com>
To:     viro@...iv.linux.org.uk, tytso@....edu, jaegeuk@...nel.org
Cc:     ebiggers@...nel.org, linux-fsdevel@...r.kernel.org,
        linux-ext4@...r.kernel.org, linux-f2fs-devel@...ts.sourceforge.net,
        Gabriel Krisman Bertazi <krisman@...labora.com>,
        kernel@...labora.com
Subject: [PATCH RFC 7/7] f2fs: Enable negative dentries on case-insensitive lookup

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@...labora.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 5ed79b29999f..6e970a6c3623 100644
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -562,17 +562,8 @@ 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);
 	new = d_splice_alias(inode, dentry);
 	err = PTR_ERR_OR_ZERO(new);
 	trace_f2fs_lookup_end(dir, dentry, ino, !new ? -ENOENT : err);
@@ -623,16 +614,6 @@ static int f2fs_unlink(struct inode *dir, struct dentry *dentry)
 		goto fail;
 	}
 	f2fs_delete_entry(de, page, dir, inode);
-#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 f2fs_lookup(), when it is better
-	 * supported by the VFS for the CI case.
-	 */
-	if (IS_CASEFOLDED(dir))
-		d_invalidate(dentry);
-#endif
 	f2fs_unlock_op(sbi);
 
 	if (IS_DIRSYNC(dir))
-- 
2.36.1