Btrfs: deal with NULL srv_rsv in the delalloc inode reservation code

[pandora-kernel.git] / fs / btrfs / xattr.c

diff --git a/fs/btrfs/xattr.c b/fs/btrfs/xattr.c
index 5366fe4..a76e41c 100644 (file)
--- a/fs/btrfs/xattr.c
+++ b/fs/btrfs/xattr.c
@@ -102,48 +102,82 @@ static int do_setxattr(struct btrfs_trans_handle *trans,
        if (!path)
                return -ENOMEM;
 
-       /* first lets see if we already have this xattr */
-       di = btrfs_lookup_xattr(trans, root, path, btrfs_ino(inode), name,
-                               strlen(name), -1);
-       if (IS_ERR(di)) {
-               ret = PTR_ERR(di);
-               goto out;
-       }
-
-       /* ok we already have this xattr, lets remove it */
-       if (di) {
-               /* if we want create only exit */
-               if (flags & XATTR_CREATE) {
-                       ret = -EEXIST;
+       if (flags & XATTR_REPLACE) {
+               di = btrfs_lookup_xattr(trans, root, path, btrfs_ino(inode), name,
+                                       name_len, -1);
+               if (IS_ERR(di)) {
+                       ret = PTR_ERR(di);
+                       goto out;
+               } else if (!di) {
+                       ret = -ENODATA;
                        goto out;
                }
-
                ret = btrfs_delete_one_dir_name(trans, root, path, di);
-               BUG_ON(ret);
+               if (ret)
+                       goto out;
                btrfs_release_path(path);
 
-               /* if we don't have a value then we are removing the xattr */
+               /*
+                * remove the attribute
+                */
                if (!value)
                        goto out;
-       } else {
+       }
+
+again:
+       ret = btrfs_insert_xattr_item(trans, root, path, btrfs_ino(inode),
+                                     name, name_len, value, size);
+       /*
+        * If we're setting an xattr to a new value but the new value is say
+        * exactly BTRFS_MAX_XATTR_SIZE, we could end up with EOVERFLOW getting
+        * back from split_leaf.  This is because it thinks we'll be extending
+        * the existing item size, but we're asking for enough space to add the
+        * item itself.  So if we get EOVERFLOW just set ret to EEXIST and let
+        * the rest of the function figure it out.
+        */
+       if (ret == -EOVERFLOW)
+               ret = -EEXIST;
+
+       if (ret == -EEXIST) {
+               if (flags & XATTR_CREATE)
+                       goto out;
+               /*
+                * We can't use the path we already have since we won't have the
+                * proper locking for a delete, so release the path and
+                * re-lookup to delete the thing.
+                */
                btrfs_release_path(path);
+               di = btrfs_lookup_xattr(trans, root, path, btrfs_ino(inode),
+                                       name, name_len, -1);
+               if (IS_ERR(di)) {
+                       ret = PTR_ERR(di);
+                       goto out;
+               } else if (!di) {
+                       /* Shouldn't happen but just in case... */
+                       btrfs_release_path(path);
+                       goto again;
+               }
 
-               if (flags & XATTR_REPLACE) {
-                       /* we couldn't find the attr to replace */
-                       ret = -ENODATA;
+               ret = btrfs_delete_one_dir_name(trans, root, path, di);
+               if (ret)
                        goto out;
+
+               /*
+                * We have a value to set, so go back and try to insert it now.
+                */
+               if (value) {
+                       btrfs_release_path(path);
+                       goto again;
                }
        }
-
-       /* ok we have to create a completely new xattr */
-       ret = btrfs_insert_xattr_item(trans, root, path, btrfs_ino(inode),
-                                     name, name_len, value, size);
-       BUG_ON(ret);
 out:
        btrfs_free_path(path);
        return ret;
 }
 
+/*
+ * @value: "" makes the attribute to empty, NULL removes it
+ */
 int __btrfs_setxattr(struct btrfs_trans_handle *trans,
                     struct inode *inode, const char *name,
                     const void *value, size_t size, int flags)