proc: fix mount -t proc -o AAA

The proc_parse_options() call from proc_mount() runs only once at boot time. So on any later mount attempt, any mount options are ignored because ->s_root is already initialized. As a consequence, "mount -o <options>" will ignore the options. The only way to change mount options is "mount -o remount,<options>". To fix this, parse the mount options unconditionally. Signed-off-by: Vasiliy Kulikov <[email protected]> Reported-by: Arkadiusz Miskiewicz <[email protected]> Tested-by: Arkadiusz Miskiewicz <[email protected]> Cc: Alexey Dobriyan <[email protected]> Cc: Al Viro <[email protected]> Cc: Valdis Kletnieks <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
rtvt123 · Apr 5, 2012 · 99663be · 99663be
1 parent 10bdfb5
commit 99663be
Showing 1 changed file with 5 additions and 4 deletions.
diff --git a/fs/proc/root.c b/fs/proc/root.c
@@ -115,12 +115,13 @@ static struct dentry *proc_mount(struct file_system_type *fs_type,
 	if (IS_ERR(sb))
 		return ERR_CAST(sb);
 
+	if (!proc_parse_options(options, ns)) {
+		deactivate_locked_super(sb);
+		return ERR_PTR(-EINVAL);
+	}
+
 	if (!sb->s_root) {
 		sb->s_flags = flags;
-		if (!proc_parse_options(options, ns)) {
-			deactivate_locked_super(sb);
-			return ERR_PTR(-EINVAL);
-		}
 		err = proc_fill_super(sb);
 		if (err) {
 			deactivate_locked_super(sb);