ext4: on a remount, only log the ro or r/w state when it has changed

A user complained that a message such as:

EXT4-fs (nvme0n1p3): re-mounted UUID ro. Quota mode: none.

implied that the file system was previously mounted read/write and was
now remounted read-only, when it could have been some other mount
state that had changed by the "mount -o remount" operation.  Fix this
by only logging "ro"or "r/w" when it has changed.

https://bugzilla.kernel.org/show_bug.cgi?id=219132

Signed-off-by: Nicolas Bretz <bretznic@gmail.com>
Link: https://patch.msgid.link/20250319171011.8372-1-bretznic@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Author: nicbretz

fs/ext4/super.c

@@ -6780,6 +6780,7 @@ static int ext4_reconfigure(struct fs_context *fc)
 {
 	struct super_block *sb = fc->root->d_sb;
 	int ret;
+	bool old_ro = sb_rdonly(sb);
 
 	fc->s_fs_info = EXT4_SB(sb);
 
@@ -6791,9 +6792,9 @@ static int ext4_reconfigure(struct fs_context *fc)
 	if (ret < 0)
 		return ret;
 
-	ext4_msg(sb, KERN_INFO, "re-mounted %pU %s. Quota mode: %s.",
-		 &sb->s_uuid, sb_rdonly(sb) ? "ro" : "r/w",
-		 ext4_quota_mode(sb));
+	ext4_msg(sb, KERN_INFO, "re-mounted %pU%s.",
+		 &sb->s_uuid,
+		 (old_ro != sb_rdonly(sb)) ? (sb_rdonly(sb) ? " ro" : " r/w") : "");
 
 	return 0;
 }