linux-kernel - [PATCH] fs/ntfs3: update mode in xattr when ACL can be reduced to mode

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Message-ID: <20251113152054.7663-1-almaz.alexandrovich@paragon-software.com>
Date: Thu, 13 Nov 2025 16:20:54 +0100
From: Konstantin Komarov <almaz.alexandrovich@...agon-software.com>
To: <ntfs3@...ts.linux.dev>
CC: <linux-kernel@...r.kernel.org>, <linux-fsdevel@...r.kernel.org>,
	Konstantin Komarov <almaz.alexandrovich@...agon-software.com>
Subject: [PATCH] fs/ntfs3: update mode in xattr when ACL can be reduced to mode

If a file's ACL can be reduced to standard mode bits, update mode
accordingly, persist the change, and update the cached ACL. This keeps
mode and ACL consistent and avoids redundant xattrs.

Signed-off-by: Konstantin Komarov <almaz.alexandrovich@...agon-software.com>
---
 fs/ntfs3/xattr.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/fs/ntfs3/xattr.c b/fs/ntfs3/xattr.c
index e519e21596a7..c93df55e98d0 100644
--- a/fs/ntfs3/xattr.c
+++ b/fs/ntfs3/xattr.c
@@ -654,12 +654,22 @@ static noinline int ntfs_set_acl_ex(struct mnt_idmap *idmap,
 	err = ntfs_set_ea(inode, name, name_len, value, size, flags, 0, NULL);
 	if (err == -ENODATA && !size)
 		err = 0; /* Removing non existed xattr. */
-	if (!err) {
-		set_cached_acl(inode, type, acl);
+	if (err)
+		goto out;
+
+	if (inode->i_mode != mode) {
+		umode_t old_mode = inode->i_mode;
+		inode->i_mode = mode;
+		err = ntfs_save_wsl_perm(inode, NULL);
+		if (err) {
+			inode->i_mode = old_mode;
+			goto out;
+		}
 		inode->i_mode = mode;
-		inode_set_ctime_current(inode);
-		mark_inode_dirty(inode);
 	}
+	set_cached_acl(inode, type, acl);
+	inode_set_ctime_current(inode);
+	mark_inode_dirty(inode);
 
 out:
 	kfree(value);
-- 
2.43.0