Btrfs: cleanup xattr code

Andrew's review of the xattr code revealed some minor issues that this patch
addresses.  Just an error return fix, got rid of a useless statement and
commented one of the trickier parts of __btrfs_getxattr.

Signed-off-by: Josef Bacik <jbacik@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --git a/fs/btrfs/xattr.c b/fs/btrfs/xattr.c
index 7f332e2..b4fa5f4 100644 (file)
--- a/fs/btrfs/xattr.c
+++ b/fs/btrfs/xattr.c
@@ -45,9 +45,12 @@ ssize_t __btrfs_getxattr(struct inode *inode, const char *name,
        /* lookup the xattr by name */
        di = btrfs_lookup_xattr(NULL, root, path, inode->i_ino, name,
                                strlen(name), 0);
-       if (!di || IS_ERR(di)) {
+       if (!di) {
                ret = -ENODATA;
                goto out;
+       } else if (IS_ERR(di)) {
+               ret = PTR_ERR(di);
+               goto out;
        }
 
        leaf = path->nodes[0];
@@ -62,6 +65,14 @@ ssize_t __btrfs_getxattr(struct inode *inode, const char *name,
                ret = -ERANGE;
                goto out;
        }
+
+       /*
+        * The way things are packed into the leaf is like this
+        * |struct btrfs_dir_item|name|data|
+        * where name is the xattr name, so security.foo, and data is the
+        * content of the xattr.  data_ptr points to the location in memory
+        * where the data starts in the in memory leaf
+        */
        data_ptr = (unsigned long)((char *)(di + 1) +
                                   btrfs_dir_name_len(leaf, di));
        read_extent_buffer(leaf, buffer, data_ptr,
@@ -176,7 +187,6 @@ ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
        ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
        if (ret < 0)
                goto err;
-       ret = 0;
        advance = 0;
        while (1) {
                leaf = path->nodes[0];