From: Christian Brauner <brauner@kernel.org>
Date: Mon, 27 Jul 2026 15:15:57 +0000 (+0200)
Subject: fat: Propagate inode buffer write errors from fat_sync_inode_metadata()
X-Git-Url: http://git.ipfire.org/gitweb/index.cgi?a=commitdiff_plain;h=a50587bbf30b04c1c643ecff1efd27acf6b933ec;p=thirdparty%2Flinux.git

fat: Propagate inode buffer write errors from fat_sync_inode_metadata()

fat_sync_inode_metadata() ignores the result of writing the buffer
containing the inode's directory entry. Before commit 525da4f40a7c
("fat: Fix missed inode writeback during fsync(2)") a write error was
propagated to fsync(2) via __fat_write_inode() -> sync_dirty_buffer(),
now fsync(2) reports success even though the inode's directory entry
could not be written. Check buffer_write_io_error() after
sync_dirty_buffer() like the other ->sync_inode_metadata
implementations do.

Fixes: 525da4f40a7c ("fat: Fix missed inode writeback during fsync(2)")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
---

diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index e3bb7b4713f2..ef1f826179cd 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -646,8 +646,13 @@ static int fat_sync_inode_metadata(struct inode *inode,
 	 * Buffer present? We leave buffer_dirty check for sync_dirty_buffer()
 	 * for proper synchronization with ongoing IO.
 	 */
-	if (bh && buffer_uptodate(bh))
+	if (bh && buffer_uptodate(bh)) {
 		sync_dirty_buffer(bh);
+		if (buffer_write_io_error(bh)) {
+			brelse(bh);
+			return -EIO;
+		}
+	}
 	brelse(bh);
 	return mmb_sync(&MSDOS_I(inode)->i_metadata_bhs);
 }