Merge tag 'vfs-6.10-rc7.fixes.2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull vfs fixes from Christian Brauner:
 "VFS:

   - Improve handling of deep ancestor chains in is_subdir()

   - Release locks cleanly when fctnl_setlk() races with close().

     When setting a file lock fails the VFS tries to cleanup the already
     created lock. The helper used for this calls back into the LSM
     layer which may cause it to fail, leaving the stale lock accessible
     via /proc/locks.

  AFS:

   - Fix a comma/semicolon typo"

* tag 'vfs-6.10-rc7.fixes.2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  afs: Convert comma to semicolon
  fs: better handle deep ancestor chains in is_subdir()
  filelock: Remove locks reliably when fcntl/close race is detected

Author: torvalds

fs/afs/inode.c

@@ -512,7 +512,7 @@ static int afs_iget5_set_root(struct inode *inode, void *opaque)
 	struct afs_vnode *vnode = AFS_FS_I(inode);
 
 	vnode->volume		= as->volume;
-	vnode->fid.vid		= as->volume->vid,
+	vnode->fid.vid		= as->volume->vid;
 	vnode->fid.vnode	= 1;
 	vnode->fid.unique	= 1;
 	inode->i_ino		= 1;
@@ -545,7 +545,7 @@ struct inode *afs_root_iget(struct super_block *sb, struct key *key)
 	BUG_ON(!(inode->i_state & I_NEW));
 
 	vnode = AFS_FS_I(inode);
-	vnode->cb_v_check = atomic_read(&as->volume->cb_v_break),
+	vnode->cb_v_check = atomic_read(&as->volume->cb_v_break);
 	afs_set_netfs_context(vnode);
 
 	op = afs_alloc_operation(key, as->volume);

fs/dcache.c

@@ -3029,28 +3029,25 @@ EXPORT_SYMBOL(d_splice_alias);
 
 bool is_subdir(struct dentry *new_dentry, struct dentry *old_dentry)
 {
-	bool result;
+	bool subdir;
 	unsigned seq;
 
 	if (new_dentry == old_dentry)
 		return true;
 
-	do {
-		/* for restarting inner loop in case of seq retry */
-		seq = read_seqbegin(&rename_lock);
-		/*
-		 * Need rcu_readlock to protect against the d_parent trashing
-		 * due to d_move
-		 */
-		rcu_read_lock();
-		if (d_ancestor(old_dentry, new_dentry))
-			result = true;
-		else
-			result = false;
-		rcu_read_unlock();
-	} while (read_seqretry(&rename_lock, seq));
-
-	return result;
+	/* Access d_parent under rcu as d_move() may change it. */
+	rcu_read_lock();
+	seq = read_seqbegin(&rename_lock);
+	subdir = d_ancestor(old_dentry, new_dentry);
+	 /* Try lockless once... */
+	if (read_seqretry(&rename_lock, seq)) {
+		/* ...else acquire lock for progress even on deep chains. */
+		read_seqlock_excl(&rename_lock);
+		subdir = d_ancestor(old_dentry, new_dentry);
+		read_sequnlock_excl(&rename_lock);
+	}
+	rcu_read_unlock();
+	return subdir;
 }
 EXPORT_SYMBOL(is_subdir);
 

fs/locks.c

@@ -2448,8 +2448,9 @@ int fcntl_setlk(unsigned int fd, struct file *filp, unsigned int cmd,
 	error = do_lock_file_wait(filp, cmd, file_lock);
 
 	/*
-	 * Attempt to detect a close/fcntl race and recover by releasing the
-	 * lock that was just acquired. There is no need to do that when we're
+	 * Detect close/fcntl races and recover by zapping all POSIX locks
+	 * associated with this file and our files_struct, just like on
+	 * filp_flush(). There is no need to do that when we're
 	 * unlocking though, or for OFD locks.
 	 */
 	if (!error && file_lock->c.flc_type != F_UNLCK &&
@@ -2464,9 +2465,7 @@ int fcntl_setlk(unsigned int fd, struct file *filp, unsigned int cmd,
 		f = files_lookup_fd_locked(files, fd);
 		spin_unlock(&files->file_lock);
 		if (f != filp) {
-			file_lock->c.flc_type = F_UNLCK;
-			error = do_lock_file_wait(filp, cmd, file_lock);
-			WARN_ON_ONCE(error);
+			locks_remove_posix(filp, files);
 			error = -EBADF;
 		}
 	}