btrfs-progs: free-space-cache: Use DIV_ROUND_UP() to replace open code
[platform/upstream/btrfs-progs.git] / dir-item.c
index 2a888e9..0b7250c 100644 (file)
-#include <stdio.h>
-#include <stdlib.h>
-#include "kerncompat.h"
-#include "radix-tree.h"
+/*
+ * Copyright (C) 2007 Oracle.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/limits.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "hash.h"
+#include "transaction.h"
+
+static struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_root *root,
+                             struct btrfs_path *path,
+                             const char *name, int name_len);
+
+static struct btrfs_dir_item *insert_with_overflow(struct btrfs_trans_handle
+                                                  *trans,
+                                                  struct btrfs_root *root,
+                                                  struct btrfs_path *path,
+                                                  struct btrfs_key *cpu_key,
+                                                  u32 data_size,
+                                                  const char *name,
+                                                  int name_len)
+{
+       int ret;
+       char *ptr;
+       struct btrfs_item *item;
+       struct extent_buffer *leaf;
 
-int btrfs_insert_dir_item(struct btrfs_root *root, char *name, int name_len,
-                         u64 dir, u64 objectid, u8 type)
+       ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
+       if (ret == -EEXIST) {
+               struct btrfs_dir_item *di;
+               di = btrfs_match_dir_item_name(root, path, name, name_len);
+               if (di)
+                       return ERR_PTR(-EEXIST);
+               ret = btrfs_extend_item(root, path, data_size);
+               WARN_ON(ret > 0);
+       }
+       if (ret < 0)
+               return ERR_PTR(ret);
+       WARN_ON(ret > 0);
+       leaf = path->nodes[0];
+       item = btrfs_item_nr(path->slots[0]);
+       ptr = btrfs_item_ptr(leaf, path->slots[0], char);
+       BUG_ON(data_size > btrfs_item_size(leaf, item));
+       ptr += btrfs_item_size(leaf, item) - data_size;
+       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_path *path;
        struct btrfs_dir_item *dir_item;
-       char *name_ptr;
-       struct btrfs_key key;
+       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;
-       key.flags = 0;
-       ret = btrfs_name_hash(name, name_len, &key.offset);
-       BUG_ON(ret);
-       btrfs_init_path(&path);
-       data_size = sizeof(*dir_item) + name_len;
-       ret = btrfs_insert_empty_item(root, &path, &key, data_size);
-       if (ret)
-               goto out;
+       key.type = BTRFS_XATTR_ITEM_KEY;
+       key.offset = btrfs_name_hash(name, name_len);
+       path = btrfs_alloc_path();
+       if (!path)
+               return -ENOMEM;
 
-       dir_item = btrfs_item_ptr(&path.nodes[0]->leaf, path.slots[0],
-                                 struct btrfs_dir_item);
-       btrfs_set_dir_objectid(dir_item, objectid);
-       btrfs_set_dir_type(dir_item, type);
-       btrfs_set_dir_flags(dir_item, 0);
-       name_ptr = (char *)(dir_item + 1);
-       memcpy(name_ptr, name, name_len);
-out:
-       btrfs_release_path(root, &path);
+       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 aren't
+        * 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_del_dir_item(struct btrfs_root *root, u64 dir, char *name,
-                      int name_len)
+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, u64 index)
 {
        int ret = 0;
-       struct btrfs_path path;
+       int ret2 = 0;
+       struct btrfs_path *path;
+       struct btrfs_dir_item *dir_item;
+       struct extent_buffer *leaf;
+       unsigned long name_ptr;
        struct btrfs_key key;
+       struct btrfs_disk_key disk_key;
+       u32 data_size;
 
        key.objectid = dir;
-       key.flags = 0;
-       ret = btrfs_name_hash(name, name_len, &key.offset);
-       BUG_ON(ret);
-       btrfs_init_path(&path);
-       ret = btrfs_search_slot(root, &key, &path, 0, 1);
-       if (ret)
+       key.type = BTRFS_DIR_ITEM_KEY;
+       key.offset = btrfs_name_hash(name, name_len);
+       path = btrfs_alloc_path();
+       if (!path)
+               return -ENOMEM;
+       data_size = sizeof(*dir_item) + name_len;
+       dir_item = insert_with_overflow(trans, root, path, &key, data_size,
+                                       name, name_len);
+       if (IS_ERR(dir_item)) {
+               ret = PTR_ERR(dir_item);
+
+               /* Continue to insert item if existed */
+               if (ret == -EEXIST) {
+                       ret = 0;
+                       goto insert;
+               } else {
+                       goto out;
+               }
+       }
+
+       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, type);
+       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);
+       btrfs_mark_buffer_dirty(leaf);
+
+insert:
+       /* FIXME, use some real flag for selecting the extra index */
+       if (root == root->fs_info->tree_root) {
+               ret = 0;
                goto out;
-       ret = btrfs_del_item(root, &path);
+       }
+       btrfs_release_path(path);
+
+       key.type = BTRFS_DIR_INDEX_KEY;
+       key.offset = index;
+       dir_item = insert_with_overflow(trans, root, path, &key, data_size,
+                                       name, name_len);
+       if (IS_ERR(dir_item)) {
+               ret2 = PTR_ERR(dir_item);
+               if (ret2 == -EEXIST)
+                       ret = 0;
+               goto out;
+       }
+       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, type);
+       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);
+       btrfs_mark_buffer_dirty(leaf);
 out:
-       btrfs_release_path(root, &path);
-       return ret;
+       btrfs_free_path(path);
+       if (ret)
+               return ret;
+       if (ret2)
+               return ret2;
+       return 0;
 }
 
-int btrfs_lookup_dir_item(struct btrfs_root *root, u64 dir, char *name,
-                         int name_len, u64 *objectid)
+struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
+                                            struct btrfs_root *root,
+                                            struct btrfs_path *path, u64 dir,
+                                            const char *name, int name_len,
+                                            int mod)
 {
-       int ret = 0;
-       struct btrfs_path path;
-       struct btrfs_dir_item *dir_item;
-       char *name_ptr;
+       int ret;
        struct btrfs_key key;
-       u32 item_len;
-       struct btrfs_item *item;
+       int ins_len = mod < 0 ? -1 : 0;
+       int cow = mod != 0;
+       struct btrfs_key found_key;
+       struct extent_buffer *leaf;
 
        key.objectid = dir;
-       key.flags = 0;
-       ret = btrfs_name_hash(name, name_len, &key.offset);
-       BUG_ON(ret);
-       btrfs_init_path(&path);
-       ret = btrfs_search_slot(root, &key, &path, 0, 0);
-       if (ret)
-               goto out;
+       key.type = BTRFS_DIR_ITEM_KEY;
 
-       dir_item = btrfs_item_ptr(&path.nodes[0]->leaf, path.slots[0],
-                                 struct btrfs_dir_item);
+       key.offset = btrfs_name_hash(name, name_len);
 
-       item = path.nodes[0]->leaf.items + path.slots[0];
-       item_len = btrfs_item_size(item);
-       if (item_len != name_len + sizeof(struct btrfs_dir_item)) {
-               BUG();
-               ret = 1;
-               goto out;
+       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]--;
        }
-       name_ptr = (char *)(dir_item + 1);
-       if (memcmp(name_ptr, name, name_len)) {
-               BUG();
-               ret = 1;
-               goto out;
+
+       leaf = path->nodes[0];
+       btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+
+       if (found_key.objectid != dir ||
+           found_key.type != BTRFS_DIR_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_lookup_dir_index(struct btrfs_trans_handle *trans,
+                                             struct btrfs_root *root,
+                                             struct btrfs_path *path, u64 dir,
+                                             const char *name, int name_len,
+                                             u64 index, int mod)
+{
+       int ret;
+       struct btrfs_key key;
+       int ins_len = mod < 0 ? -1 : 0;
+       int cow = mod != 0;
+
+       key.objectid = dir;
+       key.type = BTRFS_DIR_INDEX_KEY;
+       key.offset = index;
+
+       ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
+       if (ret < 0)
+               return ERR_PTR(ret);
+       if (ret > 0)
+               return ERR_PTR(-ENOENT);
+
+       return btrfs_match_dir_item_name(root, path, name, name_len);
+}
+
+/*
+ * given a pointer into a directory item, delete it.  This
+ * handles items that have more than one entry in them.
+ */
+int btrfs_delete_one_dir_name(struct btrfs_trans_handle *trans,
+                             struct btrfs_root *root,
+                             struct btrfs_path *path,
+                             struct btrfs_dir_item *di)
+{
+
+       struct extent_buffer *leaf;
+       u32 sub_item_len;
+       u32 item_len;
+       int ret = 0;
+
+       leaf = path->nodes[0];
+       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);
+       } else {
+               unsigned long ptr = (unsigned long)di;
+               unsigned long start;
+
+               start = btrfs_item_ptr_offset(leaf, path->slots[0]);
+               memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
+                       item_len - (ptr + sub_item_len - start));
+               btrfs_truncate_item(root, path, item_len - sub_item_len, 1);
        }
-       *objectid = btrfs_dir_objectid(dir_item);
-out:
-       btrfs_release_path(root, &path);
        return ret;
 }
+
+static int verify_dir_item(struct btrfs_root *root,
+                   struct extent_buffer *leaf,
+                   struct btrfs_dir_item *dir_item)
+{
+       u16 namelen = BTRFS_NAME_LEN;
+       u8 type = btrfs_dir_type(leaf, dir_item);
+
+       if (type >= BTRFS_FT_MAX) {
+               fprintf(stderr, "invalid dir item type: %d\n",
+                      (int)type);
+               return 1;
+       }
+
+       if (type == BTRFS_FT_XATTR)
+               namelen = XATTR_NAME_MAX;
+
+       if (btrfs_dir_name_len(leaf, dir_item) > namelen) {
+               fprintf(stderr, "invalid dir item name len: %u\n",
+                      (unsigned)btrfs_dir_data_len(leaf, dir_item));
+               return 1;
+       }
+
+       /* BTRFS_MAX_XATTR_SIZE is the same for all dir items */
+       if ((btrfs_dir_data_len(leaf, dir_item) +
+            btrfs_dir_name_len(leaf, dir_item)) >
+                       BTRFS_MAX_XATTR_SIZE(root->fs_info)) {
+               fprintf(stderr, "invalid dir item name + data len: %u + %u\n",
+                      (unsigned)btrfs_dir_name_len(leaf, dir_item),
+                      (unsigned)btrfs_dir_data_len(leaf, dir_item));
+               return 1;
+       }
+
+       return 0;
+}
+
+static struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_root *root,
+                             struct btrfs_path *path,
+                             const char *name, int name_len)
+{
+       struct btrfs_dir_item *dir_item;
+       unsigned long name_ptr;
+       u32 total_len;
+       u32 cur = 0;
+       u32 this_len;
+       struct extent_buffer *leaf;
+
+       leaf = path->nodes[0];
+       dir_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dir_item);
+       total_len = btrfs_item_size_nr(leaf, path->slots[0]);
+       if (verify_dir_item(root, leaf, dir_item))
+               return NULL;
+
+       while(cur < total_len) {
+               this_len = sizeof(*dir_item) +
+                       btrfs_dir_name_len(leaf, dir_item) +
+                       btrfs_dir_data_len(leaf, dir_item);
+               if (this_len > (total_len - cur)) {
+                       fprintf(stderr, "invalid dir item size\n");
+                       return NULL;
+               }
+
+               name_ptr = (unsigned long)(dir_item + 1);
+
+               if (btrfs_dir_name_len(leaf, dir_item) == name_len &&
+                   memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0)
+                       return dir_item;
+
+               cur += this_len;
+               dir_item = (struct btrfs_dir_item *)((char *)dir_item +
+                                                    this_len);
+       }
+       return NULL;
+}