Merge tag 'fscache-fixes-20141013' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull fs-cache fixes from David Howells:
 "Two fixes for bugs in CacheFiles and a cleanup in FS-Cache"

* tag 'fscache-fixes-20141013' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  fs/fscache/object-list.c: use __seq_open_private()
  CacheFiles: Fix incorrect test for in-memory object collision
  CacheFiles: Handle object being killed before being set up

3 files changed, 23 insertions, 28 deletions

diff --git a/fs/cachefiles/interface.c b/fs/cachefiles/interface.c
index 584743d456c3..1c7293c3a93a 100644
--- a/fs/cachefiles/interface.c
+++ b/fs/cachefiles/interface.c
@@ -268,20 +268,27 @@ static void cachefiles_drop_object(struct fscache_object *_object)
         ASSERT((atomic_read(&object->usage) & 0xffff0000) != 0x6b6b0000);
 #endif
 
-        /* delete retired objects */
-        if (test_bit(FSCACHE_OBJECT_RETIRED, &object->fscache.flags) &&
-            _object != cache->cache.fsdef
-            ) {
-                _debug("- retire object OBJ%x", object->fscache.debug_id);
-                cachefiles_begin_secure(cache, &saved_cred);
-                cachefiles_delete_object(cache, object);
-                cachefiles_end_secure(cache, saved_cred);
-        }
+        /* We need to tidy the object up if we did in fact manage to open it.
+         * It's possible for us to get here before the object is fully
+         * initialised if the parent goes away or the object gets retired
+         * before we set it up.
+         */
+        if (object->dentry) {
+                /* delete retired objects */
+                if (test_bit(FSCACHE_OBJECT_RETIRED, &object->fscache.flags) &&
+                    _object != cache->cache.fsdef
+                    ) {
+                        _debug("- retire object OBJ%x", object->fscache.debug_id);
+                        cachefiles_begin_secure(cache, &saved_cred);
+                        cachefiles_delete_object(cache, object);
+                        cachefiles_end_secure(cache, saved_cred);
+                }
 
-        /* close the filesystem stuff attached to the object */
-        if (object->backer != object->dentry)
-                dput(object->backer);
-        object->backer = NULL;
+                /* close the filesystem stuff attached to the object */
+                if (object->backer != object->dentry)
+                        dput(object->backer);
+                object->backer = NULL;
+        }
 
         /* note that the object is now inactive */
         if (test_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags)) {
diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c
index dad7d9542a24..e12f189d539b 100644
--- a/fs/cachefiles/namei.c
+++ b/fs/cachefiles/namei.c
@@ -189,7 +189,7 @@ try_again:
         /* an old object from a previous incarnation is hogging the slot - we
          * need to wait for it to be destroyed */
 wait_for_old_object:
-        if (fscache_object_is_live(&object->fscache)) {
+        if (fscache_object_is_live(&xobject->fscache)) {
                 pr_err("\n");
                 pr_err("Error: Unexpected object collision\n");
                 cachefiles_printk_object(object, xobject);
diff --git a/fs/fscache/object-list.c b/fs/fscache/object-list.c
index b8179ca6bf9d..51dde817e1f2 100644
--- a/fs/fscache/object-list.c
+++ b/fs/fscache/object-list.c
@@ -380,26 +380,14 @@ no_config:
 static int fscache_objlist_open(struct inode *inode, struct file *file)
 {
         struct fscache_objlist_data *data;
-        struct seq_file *m;
-        int ret;
 
-        ret = seq_open(file, &fscache_objlist_ops);
-        if (ret < 0)
-                return ret;
-
-        m = file->private_data;
-
-        /* buffer for key extraction */
-        data = kmalloc(sizeof(struct fscache_objlist_data), GFP_KERNEL);
-        if (!data) {
-                seq_release(inode, file);
+        data = __seq_open_private(file, &fscache_objlist_ops, sizeof(*data));
+        if (!data)
                 return -ENOMEM;
-        }
 
         /* get the configuration key */
         fscache_objlist_config(data);
 
-        m->private = data;
         return 0;
 }