dcache: d_splice_alias should ignore DCACHE_DISCONNECTED
Any IS_ROOT() alias should be safe to use; there's nothing special about
DCACHE_DISCONNECTED dentries.
Note that this is in fact useful for filesystems such as btrfs which can
legimately encounter a directory with a preexisting IS_ROOT alias on a
lookup that crosses into a subvolume. (Those aliases are currently
marked DCACHE_DISCONNECTED--but not really for any good reason, and
we'll change that soon.)
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/dcache.c b/fs/dcache.c
index a191eeb..3ed09536 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -2649,9 +2649,9 @@
* @inode: the inode which may have a disconnected dentry
* @dentry: a negative dentry which we want to point to the inode.
*
- * If inode is a directory and has a 'disconnected' dentry (i.e. IS_ROOT and
- * DCACHE_DISCONNECTED), then d_move that in place of the given dentry
- * and return it, else simply d_add the inode to the dentry and return NULL.
+ * If inode is a directory and has an IS_ROOT alias, then d_move that in
+ * place of the given dentry and return it, else simply d_add the inode
+ * to the dentry and return NULL.
*
* If a non-IS_ROOT directory is found, the filesystem is corrupt, and
* we should error out: directories can't have multiple aliases.
@@ -2678,7 +2678,7 @@
spin_lock(&inode->i_lock);
new = __d_find_any_alias(inode);
if (new) {
- if (!IS_ROOT(new) || !(new->d_flags & DCACHE_DISCONNECTED)) {
+ if (!IS_ROOT(new)) {
spin_unlock(&inode->i_lock);
dput(new);
return ERR_PTR(-EIO);