fs: simplify error handling

Rely on cleanup helper and simplify error handling

Link: https://lore.kernel.org/r/20240607-vfs-listmount-reverse-v1-3-7877a2bfa5e5@kernel.org
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/fs/namespace.c b/fs/namespace.c
index 57311ecbdf5aa9556cd328dfc1346a47993cfb19..98671cd8951199eb7063dc287f346875bc986675 100644 (file)
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -5050,7 +5050,7 @@ static struct mount *listmnt_next(struct mount *curr)
 static ssize_t do_listmount(u64 mnt_parent_id, u64 last_mnt_id, u64 *mnt_ids,
                            size_t nr_mnt_ids)
 {
-       struct path root;
+       struct path root __free(path_put) = {};
        struct mnt_namespace *ns = current->nsproxy->mnt_ns;
        struct path orig;
        struct mount *r, *first;
@@ -5063,10 +5063,8 @@ static ssize_t do_listmount(u64 mnt_parent_id, u64 last_mnt_id, u64 *mnt_ids,
                orig = root;
        } else {
                orig.mnt = lookup_mnt_in_ns(mnt_parent_id, ns);
-               if (!orig.mnt) {
-                       ret = -ENOENT;
-                       goto err;
-               }
+               if (!orig.mnt)
+                       return -ENOENT;
                orig.dentry = orig.mnt->mnt_root;
        }
 
@@ -5075,14 +5073,12 @@ static ssize_t do_listmount(u64 mnt_parent_id, u64 last_mnt_id, u64 *mnt_ids,
         * mounts to show users.
         */
        if (!is_path_reachable(real_mount(orig.mnt), orig.dentry, &root) &&
-           !ns_capable_noaudit(&init_user_ns, CAP_SYS_ADMIN)) {
-               ret = -EPERM;
-               goto err;
-       }
+           !ns_capable_noaudit(&init_user_ns, CAP_SYS_ADMIN))
+               return -EPERM;
 
        ret = security_sb_statfs(orig.dentry);
        if (ret)
-               goto err;
+               return ret;
 
        if (!last_mnt_id)
                first = node_to_mount(rb_first(&ns->mounts));
@@ -5099,8 +5095,6 @@ static ssize_t do_listmount(u64 mnt_parent_id, u64 last_mnt_id, u64 *mnt_ids,
                nr_mnt_ids--;
                ret++;
        }
-err:
-       path_put(&root);
        return ret;
 }