Merge tag 'pull-rename' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull rename updates from Al Viro:
 "Fix directory locking scheme on rename

  This was broken in 6.5; we really can't lock two unrelated directories
  without holding ->s_vfs_rename_mutex first and in case of same-parent
  rename of a subdirectory 6.5 ends up doing just that"

* tag 'pull-rename' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  rename(): avoid a deadlock in the case of parents having no common ancestor
  kill lock_two_inodes()
  rename(): fix the locking of subdirectories
  f2fs: Avoid reading renamed directory if parent does not change
  ext4: don't access the source subdirectory content on same-directory rename
  ext2: Avoid reading renamed directory if parent does not change
  udf_rename(): only access the child content on cross-directory rename
  ocfs2: Avoid touching renamed directory if parent does not change
  reiserfs: Avoid touching renamed directory if parent does not change

1 files changed, 6 insertions, 43 deletions

diff --git a/fs/inode.c b/fs/inode.c
index d23362a671dd..91048c4c9c9e 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1089,48 +1089,6 @@ void discard_new_inode(struct inode *inode)
 EXPORT_SYMBOL(discard_new_inode);
 
 /**
- * lock_two_inodes - lock two inodes (may be regular files but also dirs)
- *
- * Lock any non-NULL argument. The caller must make sure that if he is passing
- * in two directories, one is not ancestor of the other.  Zero, one or two
- * objects may be locked by this function.
- *
- * @inode1: first inode to lock
- * @inode2: second inode to lock
- * @subclass1: inode lock subclass for the first lock obtained
- * @subclass2: inode lock subclass for the second lock obtained
- */
-void lock_two_inodes(struct inode *inode1, struct inode *inode2,
-		     unsigned subclass1, unsigned subclass2)
-{
-	if (!inode1 || !inode2) {
-		/*
-		 * Make sure @subclass1 will be used for the acquired lock.
-		 * This is not strictly necessary (no current caller cares) but
-		 * let's keep things consistent.
-		 */
-		if (!inode1)
-			swap(inode1, inode2);
-		goto lock;
-	}
-
-	/*
-	 * If one object is directory and the other is not, we must make sure
-	 * to lock directory first as the other object may be its child.
-	 */
-	if (S_ISDIR(inode2->i_mode) == S_ISDIR(inode1->i_mode)) {
-		if (inode1 > inode2)
-			swap(inode1, inode2);
-	} else if (!S_ISDIR(inode1->i_mode))
-		swap(inode1, inode2);
-lock:
-	if (inode1)
-		inode_lock_nested(inode1, subclass1);
-	if (inode2 && inode2 != inode1)
-		inode_lock_nested(inode2, subclass2);
-}
-
-/**
  * lock_two_nondirectories - take two i_mutexes on non-directory objects
  *
  * Lock any non-NULL argument. Passed objects must not be directories.
@@ -1145,7 +1103,12 @@ void lock_two_nondirectories(struct inode *inode1, struct inode *inode2)
 		WARN_ON_ONCE(S_ISDIR(inode1->i_mode));
 	if (inode2)
 		WARN_ON_ONCE(S_ISDIR(inode2->i_mode));
-	lock_two_inodes(inode1, inode2, I_MUTEX_NORMAL, I_MUTEX_NONDIR2);
+	if (inode1 > inode2)
+		swap(inode1, inode2);
+	if (inode1)
+		inode_lock(inode1);
+	if (inode2 && inode2 != inode1)
+		inode_lock_nested(inode2, I_MUTEX_NONDIR2);
 }
 EXPORT_SYMBOL(lock_two_nondirectories);