Btrfs: Remove special cases for "." and ".."

Date: Sun, 17 Aug 2008 15:14:48 +0100
We never get asked by the VFS to lookup either of them, and we can
handle the readdir() case a lot more simply, too.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 0da1ae4..4520a0e 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1702,42 +1702,9 @@ static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
        struct btrfs_root *root = BTRFS_I(dir)->root;
        int ret = 0;
 
-       if (namelen == 1 && strcmp(name, ".") == 0) {
-               location->objectid = dir->i_ino;
-               location->type = BTRFS_INODE_ITEM_KEY;
-               location->offset = 0;
-               return 0;
-       }
        path = btrfs_alloc_path();
        BUG_ON(!path);
 
-       if (namelen == 2 && strcmp(name, "..") == 0) {
-               struct btrfs_key key;
-               struct extent_buffer *leaf;
-               int slot;
-
-               key.objectid = dir->i_ino;
-               key.offset = (u64)-1;
-               btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
-               if (ret < 0 || path->slots[0] == 0)
-                       goto out_err;
-               ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
-               BUG_ON(ret == 0);
-               ret = 0;
-               leaf = path->nodes[0];
-               slot = path->slots[0] - 1;
-
-               btrfs_item_key_to_cpu(leaf, &key, slot);
-               if (key.objectid != dir->i_ino ||
-                   key.type != BTRFS_INODE_REF_KEY) {
-                       goto out_err;
-               }
-               location->objectid = key.offset;
-               location->type = BTRFS_INODE_ITEM_KEY;
-               location->offset = 0;
-               goto out;
-       }
-
        di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
                                    namelen, 0);
        if (IS_ERR(di))
@@ -1960,29 +1927,14 @@ static int btrfs_real_readdir(struct file *filp, void *dirent,
 
        /* special case for .., just use the back ref */
        if (filp->f_pos == 1) {
-               btrfs_set_key_type(&key, BTRFS_INODE_REF_KEY);
-               key.offset = (u64)-1;
-               ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
-               if (ret < 0 || path->slots[0] == 0) {
-                       btrfs_release_path(root, path);
-                       goto read_dir_items;
-               }
-               BUG_ON(ret == 0);
-               leaf = path->nodes[0];
-               slot = path->slots[0] - 1;
-               btrfs_item_key_to_cpu(leaf, &found_key, slot);
-               btrfs_release_path(root, path);
-               if (found_key.objectid != key.objectid ||
-                   found_key.type != BTRFS_INODE_REF_KEY)
-                       goto read_dir_items;
+               u64 pino = parent_ino(filp->f_path.dentry);
                over = filldir(dirent, "..", 2,
-                              2, found_key.offset, DT_DIR);
+                              2, pino, DT_DIR);
                if (over)
                        goto nopos;
                filp->f_pos = 2;
        }
 
-read_dir_items:
        btrfs_set_key_type(&key, key_type);
        key.offset = filp->f_pos;