btrfs-progs: ctree: Add extra level check for read_node_slot()
[platform/upstream/btrfs-progs.git] / dir-item.c
index a3cb278..0b7250c 100644 (file)
  * Boston, MA 021110-1307, USA.
  */
 
-#include <stdio.h>
-#include <stdlib.h>
-#include "kerncompat.h"
-#include "radix-tree.h"
+#include <linux/limits.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "hash.h"
 #include "transaction.h"
 
-static struct btrfs_dir_item *insert_with_overflow(struct
-                                                  btrfs_trans_handle *trans,
+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,
@@ -37,173 +38,325 @@ static struct btrfs_dir_item *insert_with_overflow(struct
        int ret;
        char *ptr;
        struct btrfs_item *item;
-       struct btrfs_leaf *leaf;
+       struct extent_buffer *leaf;
+
        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 NULL;
-               ret = btrfs_extend_item(trans, root, path, data_size);
+                       return ERR_PTR(-EEXIST);
+               ret = btrfs_extend_item(root, path, data_size);
+               WARN_ON(ret > 0);
        }
-       BUG_ON(ret > 0);
-       if (ret)
-               return NULL;
-       leaf = &path->nodes[0]->leaf;
-       item = leaf->items + path->slots[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(item));
-       ptr += btrfs_item_size(item) - data_size;
+       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_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;
+       key.type = BTRFS_XATTR_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 + 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_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root
-                         *root, char *name, int name_len, u64 dir,
-                         struct btrfs_key *location, u8 type)
+                         *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;
-       char *name_ptr;
+       struct extent_buffer *leaf;
+       unsigned long name_ptr;
        struct btrfs_key key;
+       struct btrfs_disk_key disk_key;
        u32 data_size;
 
        key.objectid = dir;
-       btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
-       if (name_len == 1 && *name == '.')
-               key.offset = 1;
-       else if (name_len == 2 && name[0] == '.' && name[1] == '.')
-               key.offset = 2;
-       else
-               ret = btrfs_name_hash(name, name_len, &key.offset);
-       BUG_ON(ret);
-       btrfs_init_path(&path);
+       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,
+       dir_item = insert_with_overflow(trans, root, path, &key, data_size,
                                        name, name_len);
-       if (!dir_item) {
-               ret = -1;
-               goto out;
+       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;
+               }
        }
-       btrfs_cpu_key_to_disk(&dir_item->location, location);
-       btrfs_set_dir_type(dir_item, type);
-       btrfs_set_dir_name_len(dir_item, name_len);
-       btrfs_set_dir_data_len(dir_item, 0);
-       name_ptr = (char *)(dir_item + 1);
-       memcpy(name_ptr, name, name_len);
 
+       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)
+       if (root == root->fs_info->tree_root) {
+               ret = 0;
                goto out;
+       }
+       btrfs_release_path(path);
 
-       btrfs_release_path(root, &path);
-       btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
-       key.offset = location->objectid;
-       dir_item = insert_with_overflow(trans, root, &path, &key, data_size,
+       key.type = BTRFS_DIR_INDEX_KEY;
+       key.offset = index;
+       dir_item = insert_with_overflow(trans, root, path, &key, data_size,
                                        name, name_len);
-       if (!dir_item) {
-               ret = -1;
+       if (IS_ERR(dir_item)) {
+               ret2 = PTR_ERR(dir_item);
+               if (ret2 == -EEXIST)
+                       ret = 0;
                goto out;
        }
-       btrfs_cpu_key_to_disk(&dir_item->location, location);
-       btrfs_set_dir_type(dir_item, type);
-       btrfs_set_dir_name_len(dir_item, name_len);
-       btrfs_set_dir_data_len(dir_item, 0);
-       name_ptr = (char *)(dir_item + 1);
-       memcpy(name_ptr, name, name_len);
+       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;
 }
+
 struct btrfs_dir_item *btrfs_lookup_dir_item(struct btrfs_trans_handle *trans,
-                                             struct btrfs_root *root,
-                                             struct btrfs_path *path, u64 dir,
-                                             char *name, int name_len, int mod)
+                                            struct btrfs_root *root,
+                                            struct btrfs_path *path, u64 dir,
+                                            const char *name, int 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 btrfs_leaf *leaf;
+       struct extent_buffer *leaf;
+
        key.objectid = dir;
-       btrfs_set_key_type(&key, BTRFS_DIR_ITEM_KEY);
-       ret = btrfs_name_hash(name, name_len, &key.offset);
-       BUG_ON(ret);
+       key.type = BTRFS_DIR_ITEM_KEY;
+
+       key.offset = btrfs_name_hash(name, name_len);
+
        ret = btrfs_search_slot(trans, root, &key, path, ins_len, cow);
        if (ret < 0)
-               return NULL;
+               return ERR_PTR(ret);
        if (ret > 0) {
                if (path->slots[0] == 0)
                        return NULL;
                path->slots[0]--;
        }
 
-       leaf = &path->nodes[0]->leaf;
-       btrfs_disk_key_to_cpu(&found_key, &leaf->items[path->slots[0]].key);
+       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_DIR_ITEM_KEY ||
+           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_match_dir_item_name(struct btrfs_root *root,
-                             struct btrfs_path *path,
-                             const char *name, int 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)
 {
-       u32 cur = 0;
-       u32 this_len;
-       u32 total_len;
-       char *name_ptr;
-       struct btrfs_leaf *leaf;
-       struct btrfs_dir_item *dir_item;
+       int ret;
+       struct btrfs_key key;
+       int ins_len = mod < 0 ? -1 : 0;
+       int cow = mod != 0;
 
-       leaf = &path->nodes[0]->leaf;
-       dir_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dir_item);
-       total_len = btrfs_item_size(leaf->items + path->slots[0]);
-       while(cur < total_len) {
-               this_len = sizeof(*dir_item) + btrfs_dir_name_len(dir_item) +
-                          btrfs_dir_data_len(dir_item);
-               name_ptr = (char *)(dir_item + 1);
+       key.objectid = dir;
+       key.type = BTRFS_DIR_INDEX_KEY;
+       key.offset = index;
 
-               if (btrfs_dir_name_len(dir_item) == name_len &&
-                   memcmp(name, name_ptr, name_len) == 0)
-                       return dir_item;
+       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);
 
-               cur += this_len;
-               dir_item = (struct btrfs_dir_item *)((char *)dir_item +
-                                                    this_len);
-       }
-       return NULL;
+       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 btrfs_leaf *leaf;
+       struct extent_buffer *leaf;
        u32 sub_item_len;
        u32 item_len;
        int ret = 0;
 
-       leaf = &path->nodes[0]->leaf;
-       sub_item_len = sizeof(*di) + btrfs_dir_name_len(di) +
-                      btrfs_dir_data_len(di);
-       item_len = btrfs_item_size(leaf->items + path->slots[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 {
-               char *ptr = (char *)di;
-               char *start = btrfs_item_ptr(leaf, path->slots[0], char);
-               memmove(ptr, ptr + sub_item_len,
+               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));
-               ret = btrfs_truncate_item(trans, root, path,
-                                         item_len - sub_item_len, 1);
+               btrfs_truncate_item(root, path, item_len - sub_item_len, 1);
        }
+       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;
+}