return p;
}
- inode_lock_nested(p1->d_inode, I_MUTEX_PARENT);
- inode_lock_nested(p2->d_inode, I_MUTEX_PARENT2);
+ lock_two_inodes(p1->d_inode, p2->d_inode,
+ I_MUTEX_PARENT, I_MUTEX_PARENT2);
return NULL;
}
EXPORT_SYMBOL(lock_rename);
* sb->s_vfs_rename_mutex. We might be more accurate, but that's another
* story.
* c) we have to lock _four_ objects - parents and victim (if it exists),
- * and source (if it is not a directory).
+ * and source.
* And that - after we got ->i_mutex on parents (until then we don't know
* whether the target exists). Solution: try to be smart with locking
* order for inodes. We rely on the fact that tree topology may change
take_dentry_name_snapshot(&old_name, old_dentry);
dget(new_dentry);
- if (!is_dir || (flags & RENAME_EXCHANGE))
- lock_two_nondirectories(source, target);
- else if (target)
- inode_lock(target);
+ /*
+ * Lock all moved children. Moved directories may need to change parent
+ * pointer so they need the lock to prevent against concurrent
+ * directory changes moving parent pointer. For regular files we've
+ * historically always done this. The lockdep locking subclasses are
+ * somewhat arbitrary but RENAME_EXCHANGE in particular can swap
+ * regular files and directories so it's difficult to tell which
+ * subclasses to use.
+ */
+ lock_two_inodes(source, target, I_MUTEX_NORMAL, I_MUTEX_NONDIR2);
error = -EPERM;
if (IS_SWAPFILE(source) || (target && IS_SWAPFILE(target)))
d_exchange(old_dentry, new_dentry);
}
out:
- if (!is_dir || (flags & RENAME_EXCHANGE))
- unlock_two_nondirectories(source, target);
- else if (target)
+ inode_unlock(source);
+ if (target)
inode_unlock(target);
dput(new_dentry);
if (!error) {