diff options
| author | Al Viro <viro@zeniv.linux.org.uk> | 2025-08-20 03:23:12 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2025-09-15 21:26:05 -0400 |
| commit | 25423edc787842d17520b3f9df4d0a58a6a663b1 (patch) | |
| tree | edcb63f6345d6a5373d02bc889be1dc3c350bec1 /fs/namespace.c | |
| parent | ed8ba4aad78887d88231c1c66c0ddf9fe12aaad1 (diff) | |
| download | random-25423edc787842d17520b3f9df4d0a58a6a663b1.tar.gz | |
new helper: topmost_overmount()
Returns the final (topmost) mount in the chain of overmounts
starting at given mount. Same locking rules as for any mount
tree traversal - either the spinlock side of mount_lock, or
rcu + sample the seqcount side of mount_lock before the call
and recheck afterwards.
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/namespace.c')
| -rw-r--r-- | fs/namespace.c | 9 |
1 files changed, 3 insertions, 6 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index b48bfb46b351d1..b6983adaa73b7a 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -2696,10 +2696,9 @@ static int attach_recursive_mnt(struct mount *source_mnt, child->mnt_mountpoint); commit_tree(child); if (q) { + struct mount *r = topmost_overmount(child); struct mountpoint *mp = root.mp; - struct mount *r = child; - while (unlikely(r->overmount)) - r = r->overmount; + if (unlikely(shorter) && child != source_mnt) mp = shorter; mnt_change_mountpoint(r, mp, q); @@ -6168,9 +6167,7 @@ bool current_chrooted(void) guard(mount_locked_reader)(); - root = current->nsproxy->mnt_ns->root; - while (unlikely(root->overmount)) - root = root->overmount; + root = topmost_overmount(current->nsproxy->mnt_ns->root); return fs_root.mnt != &root->mnt || !path_mounted(&fs_root); } |