xattr support for btrfs

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

1 files changed, 94 insertions, 6 deletions

diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c
index 514a1dc337a8..ddbe12ae0d63 100644
--- a/fs/btrfs/dir-item.c
+++ b/fs/btrfs/dir-item.c
@@ -43,8 +43,6 @@ static struct btrfs_dir_item *insert_with_overflow(struct btrfs_trans_handle
                         return ERR_PTR(-EEXIST);
                 ret = btrfs_extend_item(trans, root, path, data_size);
                 WARN_ON(ret > 0);
-                if (ret)
-                        return ERR_PTR(ret);
         }
         if (ret < 0)
                 return ERR_PTR(ret);
@@ -57,6 +55,57 @@ static struct btrfs_dir_item *insert_with_overflow(struct btrfs_trans_handle
         return (struct btrfs_dir_item *)ptr;
 }
 
+int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
+                            struct btrfs_root *root, const char *name,
+                            u16 name_len, const void *data, u16 data_len,
+                            u64 dir)
+{
+        int ret = 0;
+        struct btrfs_path *path;
+        struct btrfs_dir_item *dir_item;
+        unsigned long name_ptr, data_ptr;
+        struct btrfs_key key, location;
+        struct btrfs_disk_key disk_key;
+        struct extent_buffer *leaf;
+        u32 data_size;
+
+        key.objectid = dir;
+        btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY);
+        ret = btrfs_name_hash(name, name_len, &key.offset);
+        BUG_ON(ret);
+        path = btrfs_alloc_path();
+        if (!path)
+                return -ENOMEM;
+
+        data_size = sizeof(*dir_item) + name_len + data_len;
+        dir_item = insert_with_overflow(trans, root, path, &key, data_size,
+                                        name, name_len);
+        /*
+         * FIXME: at some point we should handle xattr's that are larger than
+         * what we can fit in our leaf.  We set location to NULL b/c we arent
+         * pointing at anything else, that will change if we store the xattr
+         * data in a separate inode.
+         */
+        BUG_ON(IS_ERR(dir_item));
+        memset(&location, 0, sizeof(location));
+
+        leaf = path->nodes[0];
+        btrfs_cpu_key_to_disk(&disk_key, &location);
+        btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
+        btrfs_set_dir_type(leaf, dir_item, BTRFS_FT_XATTR);
+        btrfs_set_dir_name_len(leaf, dir_item, name_len);
+        btrfs_set_dir_data_len(leaf, dir_item, data_len);
+        name_ptr = (unsigned long)(dir_item + 1);
+        data_ptr = (unsigned long)((char *)name_ptr + name_len);
+
+        write_extent_buffer(leaf, name, name_ptr, name_len);
+        write_extent_buffer(leaf, data, data_ptr, data_len);
+        btrfs_mark_buffer_dirty(path->nodes[0]);
+
+        btrfs_free_path(path);
+        return ret;
+}
+
 int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
                           *root, const char *name, int name_len, u64 dir,
                           struct btrfs_key *location, u8 type)
@@ -90,7 +139,7 @@ int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
         btrfs_cpu_key_to_disk(&disk_key, location);
         btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
         btrfs_set_dir_type(leaf, dir_item, type);
-        btrfs_set_dir_flags(leaf, dir_item, 0);
+        btrfs_set_dir_data_len(leaf, dir_item, 0);
         btrfs_set_dir_name_len(leaf, dir_item, name_len);
         name_ptr = (unsigned long)(dir_item + 1);
 
@@ -117,7 +166,7 @@ second_insert:
         btrfs_cpu_key_to_disk(&disk_key, location);
         btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
         btrfs_set_dir_type(leaf, dir_item, type);
-        btrfs_set_dir_flags(leaf, dir_item, 0);
+        btrfs_set_dir_data_len(leaf, dir_item, 0);
         btrfs_set_dir_name_len(leaf, dir_item, name_len);
         name_ptr = (unsigned long)(dir_item + 1);
         write_extent_buffer(leaf, name, name_ptr, name_len);
@@ -194,6 +243,43 @@ btrfs_lookup_dir_index_item(struct btrfs_trans_handle *trans,
         return btrfs_match_dir_item_name(root, path, name, name_len);
 }
 
+struct btrfs_dir_item *btrfs_lookup_xattr(struct btrfs_trans_handle *trans,
+                                          struct btrfs_root *root,
+                                          struct btrfs_path *path, u64 dir,
+                                          const char *name, u16 name_len,
+                                          int mod)
+{
+        int ret;
+        struct btrfs_key key;
+        int ins_len = mod < 0 ? -1 : 0;
+        int cow = mod != 0;
+        struct btrfs_key found_key;
+        struct extent_buffer *leaf;
+
+        key.objectid = dir;
+        btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY);
+        ret = btrfs_name_hash(name, name_len, &key.offset);
+        BUG_ON(ret);
+        ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
+        if (ret < 0)
+                return ERR_PTR(ret);
+        if (ret > 0) {
+                if (path->slots[0] == 0)
+                        return NULL;
+                path->slots[0]--;
+        }
+
+        leaf = path->nodes[0];
+        btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+
+        if (found_key.objectid != dir ||
+            btrfs_key_type(&found_key) != BTRFS_XATTR_ITEM_KEY ||
+            found_key.offset != key.offset)
+                return NULL;
+
+        return btrfs_match_dir_item_name(root, path, name, name_len);
+}
+
 struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_root *root,
                               struct btrfs_path *path,
                               const char *name, int name_len)
@@ -210,7 +296,8 @@ struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_root *root,
         total_len = btrfs_item_size_nr(leaf, path->slots[0]);
         while(cur < total_len) {
                 this_len = sizeof(*dir_item) +
-                        btrfs_dir_name_len(leaf, dir_item);
+                        btrfs_dir_name_len(leaf, dir_item) +
+                        btrfs_dir_data_len(leaf, dir_item);
                 name_ptr = (unsigned long)(dir_item + 1);
 
                 if (btrfs_dir_name_len(leaf, dir_item) == name_len &&
@@ -236,7 +323,8 @@ int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
         int ret = 0;
 
         leaf = path->nodes[0];
-        sub_item_len = sizeof(*di) + btrfs_dir_name_len(leaf, di);
+        sub_item_len = sizeof(*di) + btrfs_dir_name_len(leaf, di) +
+                btrfs_dir_data_len(leaf, di);
         item_len = btrfs_item_size_nr(leaf, path->slots[0]);
         if (sub_item_len == item_len) {
                 ret = btrfs_del_item(trans, root, path);