[PATCH] inotify: check for NULL inode in inotify_d_instantiate

The spufs file system creates files in a directory before instantiating the
directory itself, which causes a NULL pointer access in
inotify_d_instantiate since c32ccd8.

I'd like to keep this behavior since it means that the user will not have
access to files in the directory before I know that I succeed in creating
everything in it.  This patch adds a simple check for the inode to keep
that working.

Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Acked-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/inotify.c

@@ -538,7 +538,7 @@ void inotify_d_instantiate(struct dentry *entry, struct inode *inode)
 	WARN_ON(entry->d_flags & DCACHE_INOTIFY_PARENT_WATCHED);
 	spin_lock(&entry->d_lock);
 	parent = entry->d_parent;
-	if (inotify_inode_watched(parent->d_inode))
+	if (parent->d_inode && inotify_inode_watched(parent->d_inode))
 		entry->d_flags |= DCACHE_INOTIFY_PARENT_WATCHED;
 	spin_unlock(&entry->d_lock);
 }