[POWERPC] spufs: Fix error handling in spufs_fill_dir()

The error path in spufs_fill_dir() is broken. If d_alloc_name() or
spufs_new_file() fails, spufs_prune_dir() is getting called. At this time
dir->inode is not set and a NULL pointer is dereferenced by mutex_lock().
This bugfix replaces spufs_prune_dir() with a shorter version that does
not touch dir->inode but simply removes all children.

Signed-off-by: Sebastian Siewior <bigeasy@linux.vnet.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Acked-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 15 insertions, 2 deletions

diff --git a/arch/powerpc/platforms/cell/spufs/inode.c b/arch/powerpc/platforms/cell/spufs/inode.c
index 083568139771..9807206e0219 100644
--- a/arch/powerpc/platforms/cell/spufs/inode.c
+++ b/arch/powerpc/platforms/cell/spufs/inode.c
@@ -177,7 +177,7 @@ static int spufs_rmdir(struct inode *parent, struct dentry *dir)
 static int spufs_fill_dir(struct dentry *dir, struct tree_descr *files,
                           int mode, struct spu_context *ctx)
 {
-        struct dentry *dentry;
+        struct dentry *dentry, *tmp;
         int ret;
 
         while (files->name && files->name[0]) {
@@ -193,7 +193,20 @@ static int spufs_fill_dir(struct dentry *dir, struct tree_descr *files,
         }
         return 0;
 out:
-        spufs_prune_dir(dir);
+        /*
+         * remove all children from dir. dir->inode is not set so don't
+         * just simply use spufs_prune_dir() and panic afterwards :)
+         * dput() looks like it will do the right thing:
+         * - dec parent's ref counter
+         * - remove child from parent's child list
+         * - free child's inode if possible
+         * - free child
+         */
+        list_for_each_entry_safe(dentry, tmp, &dir->d_subdirs, d_u.d_child) {
+                dput(dentry);
+        }
+
+        shrink_dcache_parent(dir);
         return ret;
 }