diff options
| author | Al Viro <viro@zeniv.linux.org.uk> | 2025-07-02 22:30:32 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-08-20 18:30:20 +0200 |
| commit | afa5ceab9d234ba8db805024fd8009b368d5a90d (patch) | |
| tree | 0a10d3cd3d6e7e06b5a09d659c6a3afa3d035e72 | |
| parent | 01e20eb22d1daa4b2d32898adaaf8cad42113f95 (diff) | |
better lockdep annotations for simple_recursive_removal()
[ Upstream commit 2a8061ee5e41034eb14170ec4517b5583dbeff9f ]
We want a class that nests outside of I_MUTEX_NORMAL (for the sake of
callbacks that might want to lock the victim) and inside I_MUTEX_PARENT
(so that a variant of that could be used with parent of the victim
held locked by the caller).
In reality, simple_recursive_removal()
* never holds two locks at once
* holds the lock on parent of dentry passed to callback
* is used only on the trees with fixed topology, so the depths
are not changing.
So the locking order is actually fine.
AFAICS, the best solution is to assign I_MUTEX_CHILD to the locks
grabbed by that thing.
Reported-by: syzbot+169de184e9defe7fe709@syzkaller.appspotmail.com
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | fs/libfs.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/libfs.c b/fs/libfs.c index 3cb49463a849..874324167849 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -608,7 +608,7 @@ void simple_recursive_removal(struct dentry *dentry, struct dentry *victim = NULL, *child; struct inode *inode = this->d_inode; - inode_lock(inode); + inode_lock_nested(inode, I_MUTEX_CHILD); if (d_is_dir(this)) inode->i_flags |= S_DEAD; while ((child = find_next_child(this, victim)) == NULL) { @@ -620,7 +620,7 @@ void simple_recursive_removal(struct dentry *dentry, victim = this; this = this->d_parent; inode = this->d_inode; - inode_lock(inode); + inode_lock_nested(inode, I_MUTEX_CHILD); if (simple_positive(victim)) { d_invalidate(victim); // avoid lost mounts if (d_is_dir(victim)) |