btrfs-progs: tests: Test if mkfs.btrfs --rootdir can handle ng symlink
[platform/upstream/btrfs-progs.git] / inode-item.c
index 7caeb11..1cc1066 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 "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
+#include "hash.h"
+
+static int find_name_in_backref(struct btrfs_path *path, const char * name,
+                        int name_len, struct btrfs_inode_ref **ref_ret)
+{
+       struct extent_buffer *leaf;
+       struct btrfs_inode_ref *ref;
+       unsigned long ptr;
+       unsigned long name_ptr;
+       u32 item_size;
+       u32 cur_offset = 0;
+       int len;
+
+       leaf = path->nodes[0];
+       item_size = btrfs_item_size_nr(leaf, path->slots[0]);
+       ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
+       while (cur_offset < item_size) {
+               ref = (struct btrfs_inode_ref *)(ptr + cur_offset);
+               len = btrfs_inode_ref_name_len(leaf, ref);
+               name_ptr = (unsigned long)(ref + 1);
+               cur_offset += len + sizeof(*ref);
+               if (len != name_len)
+                       continue;
+               if (memcmp_extent_buffer(leaf, name, name_ptr, name_len) == 0) {
+                       *ref_ret = ref;
+                       return 1;
+               }
+       }
+       return 0;
+}
+
+int btrfs_insert_inode_ref(struct btrfs_trans_handle *trans,
+                          struct btrfs_root *root,
+                          const char *name, int name_len,
+                          u64 inode_objectid, u64 ref_objectid, u64 index)
+{
+       struct btrfs_path *path;
+       struct btrfs_key key;
+       struct btrfs_inode_ref *ref;
+       unsigned long ptr;
+       int ret;
+       int ins_len = name_len + sizeof(*ref);
+
+       key.objectid = inode_objectid;
+       key.offset = ref_objectid;
+       key.type = BTRFS_INODE_REF_KEY;
+
+       path = btrfs_alloc_path();
+       if (!path)
+               return -ENOMEM;
+
+       ret = btrfs_insert_empty_item(trans, root, path, &key,
+                                     ins_len);
+       if (ret == -EEXIST) {
+               u32 old_size;
+
+               if (find_name_in_backref(path, name, name_len, &ref))
+                       goto out;
+
+               old_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
+               ret = btrfs_extend_item(root, path, ins_len);
+               BUG_ON(ret);
+               ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
+                                    struct btrfs_inode_ref);
+               ref = (struct btrfs_inode_ref *)((unsigned long)ref + old_size);
+               btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
+               btrfs_set_inode_ref_index(path->nodes[0], ref, index);
+               ptr = (unsigned long)(ref + 1);
+               ret = 0;
+       } else if (ret < 0) {
+               if (ret == -EOVERFLOW)
+                       ret = -EMLINK;
+               goto out;
+       } else {
+               ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
+                                    struct btrfs_inode_ref);
+               btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
+               btrfs_set_inode_ref_index(path->nodes[0], ref, index);
+               ptr = (unsigned long)(ref + 1);
+       }
+       write_extent_buffer(path->nodes[0], name, ptr, name_len);
+       btrfs_mark_buffer_dirty(path->nodes[0]);
+
+out:
+       btrfs_free_path(path);
+
+       if (ret == -EMLINK) {
+               if (btrfs_fs_incompat(root->fs_info, EXTENDED_IREF))
+                       ret = btrfs_insert_inode_extref(trans, root, name,
+                                                       name_len,
+                                                       inode_objectid,
+                                                       ref_objectid, index);
+       }
+       return ret;
+}
+
+int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
+                      *root, struct btrfs_path *path,
+                      struct btrfs_key *location, int mod)
+{
+       int ins_len = mod < 0 ? -1 : 0;
+       int cow = mod != 0;
+       int ret;
+       int slot;
+       struct extent_buffer *leaf;
+       struct btrfs_key found_key;
+
+       ret = btrfs_search_slot(trans, root, location, path, ins_len, cow);
+       if (ret > 0 && location->type == BTRFS_ROOT_ITEM_KEY &&
+           location->offset == (u64)-1 && path->slots[0] != 0) {
+               slot = path->slots[0] - 1;
+               leaf = path->nodes[0];
+               btrfs_item_key_to_cpu(leaf, &found_key, slot);
+               if (found_key.objectid == location->objectid &&
+                   found_key.type == location->type) {
+                       path->slots[0]--;
+                       return 0;
+               }
+       }
+       return ret;
+}
 
 int btrfs_insert_inode(struct btrfs_trans_handle *trans, struct btrfs_root
                       *root, u64 objectid, struct btrfs_inode_item
                       *inode_item)
 {
-       struct btrfs_path path;
-       struct btrfs_key key;
        int ret;
+       struct btrfs_key key;
+
        key.objectid = objectid;
-       key.flags = 0;
-       btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
+       key.type = BTRFS_INODE_ITEM_KEY;
        key.offset = 0;
 
-       btrfs_init_path(&path);
        ret = btrfs_insert_item(trans, root, &key, inode_item,
                                sizeof(*inode_item));
-       btrfs_release_path(root, &path);
        return ret;
 }
 
-int btrfs_lookup_inode(struct btrfs_trans_handle *trans, struct btrfs_root
-                      *root, struct btrfs_path *path, u64 objectid, int mod)
+struct btrfs_inode_ref *btrfs_lookup_inode_ref(struct btrfs_trans_handle *trans,
+               struct btrfs_root *root, struct btrfs_path *path,
+               const char *name, int namelen, u64 ino, u64 parent_ino,
+               int ins_len)
 {
        struct btrfs_key key;
-       int ins_len = mod < 0 ? -1 : 0;
-       int cow = mod != 0;
+       struct btrfs_inode_ref *ret_inode_ref = NULL;
+       int ret = 0;
 
-       key.objectid = objectid;
-       key.flags = 0;
-       btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
-       key.offset = 0;
-       return btrfs_search_slot(trans, root, &key, path, ins_len, cow);
+       key.objectid = ino;
+       key.type = BTRFS_INODE_REF_KEY;
+       key.offset = parent_ino;
+
+       ret = btrfs_search_slot(trans, root, &key, path, ins_len,
+                               ins_len ? 1 : 0);
+       if (ret)
+               goto out;
+
+       find_name_in_backref(path, name, namelen, &ret_inode_ref);
+out:
+       if (ret < 0)
+               return ERR_PTR(ret);
+       else
+               return ret_inode_ref;
+}
+
+static int btrfs_find_name_in_ext_backref(struct btrfs_path *path,
+               u64 parent_ino, const char *name, int namelen,
+               struct btrfs_inode_extref **extref_ret)
+{
+       struct extent_buffer *node;
+       struct btrfs_inode_extref *extref;
+       unsigned long ptr;
+       unsigned long name_ptr;
+       u32 item_size;
+       u32 cur_offset = 0;
+       int ref_name_len;
+       int slot;
+
+       node = path->nodes[0];
+       slot = path->slots[0];
+       item_size = btrfs_item_size_nr(node, slot);
+       ptr = btrfs_item_ptr_offset(node, slot);
+
+       /*
+        * Search all extended backrefs in this item. We're only looking
+        * through any collisions so most of the time this is just going to
+        * compare against one buffer. If all is well, we'll return success and
+        * the inode ref object.
+        */
+       while (cur_offset < item_size) {
+               extref = (struct btrfs_inode_extref *) (ptr + cur_offset);
+               name_ptr = (unsigned long)(&extref->name);
+               ref_name_len = btrfs_inode_extref_name_len(node, extref);
+
+               if (ref_name_len == namelen &&
+                   btrfs_inode_extref_parent(node, extref) == parent_ino &&
+                   (memcmp_extent_buffer(node, name, name_ptr, namelen) == 0))
+               {
+                       if (extref_ret)
+                               *extref_ret = extref;
+                       return 1;
+               }
+
+               cur_offset += ref_name_len + sizeof(*extref);
+       }
+
+       return 0;
+}
+
+struct btrfs_inode_extref *btrfs_lookup_inode_extref(struct btrfs_trans_handle
+               *trans, struct btrfs_path *path, struct btrfs_root *root,
+               u64 ino, u64 parent_ino, u64 index, const char *name,
+               int namelen, int ins_len)
+{
+       struct btrfs_key key;
+       struct btrfs_inode_extref *extref;
+       int ret = 0;
+
+       key.objectid = ino;
+       key.type = BTRFS_INODE_EXTREF_KEY;
+       key.offset = btrfs_extref_hash(parent_ino, name, namelen);
+
+       ret = btrfs_search_slot(trans, root, &key, path, ins_len,
+                       ins_len ? 1 : 0);
+       if (ret < 0)
+               return ERR_PTR(ret);
+       if (ret > 0)
+               return NULL;
+       if (!btrfs_find_name_in_ext_backref(path, parent_ino, name,
+                                           namelen, &extref))
+               return NULL;
+
+       return extref;
+}
+
+int btrfs_del_inode_extref(struct btrfs_trans_handle *trans,
+                          struct btrfs_root *root,
+                          const char *name, int name_len,
+                          u64 inode_objectid, u64 ref_objectid,
+                          u64 *index)
+{
+       struct btrfs_path *path;
+       struct btrfs_key key;
+       struct btrfs_inode_extref *extref;
+       struct extent_buffer *leaf;
+       int ret;
+       int del_len = name_len + sizeof(*extref);
+       unsigned long ptr;
+       unsigned long item_start;
+       u32 item_size;
+
+       key.objectid = inode_objectid;
+       key.type = BTRFS_INODE_EXTREF_KEY;
+       key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
+
+       path = btrfs_alloc_path();
+       if (!path)
+               return -ENOMEM;
+
+       ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+       if (ret > 0)
+               ret = -ENOENT;
+       if (ret < 0)
+               goto out;
+
+       /*
+        * Sanity check - did we find the right item for this name?  This
+        * should always succeed so error here will make the FS readonly.
+        */
+       if (!btrfs_find_name_in_ext_backref(path, ref_objectid,
+                                           name, name_len, &extref)) {
+               ret = -ENOENT;
+               goto out;
+       }
+
+       leaf = path->nodes[0];
+       item_size = btrfs_item_size_nr(leaf, path->slots[0]);
+       if (index)
+               *index = btrfs_inode_extref_index(leaf, extref);
+
+       if (del_len == item_size) {
+               /*
+                * Common case only one ref in the item, remove the whole item.
+                */
+               ret = btrfs_del_item(trans, root, path);
+               goto out;
+       }
+
+       ptr = (unsigned long)extref;
+       item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
+
+       memmove_extent_buffer(leaf, ptr, ptr + del_len,
+                             item_size - (ptr + del_len - item_start));
+
+       btrfs_truncate_item(root, path, item_size - del_len, 1);
+
+out:
+       btrfs_free_path(path);
+
+       return ret;
+}
+
+/*
+ * btrfs_insert_inode_extref() - Inserts an extended inode ref into a tree.
+ *
+ * The caller must have checked against BTRFS_LINK_MAX already.
+ */
+int btrfs_insert_inode_extref(struct btrfs_trans_handle *trans,
+                             struct btrfs_root *root,
+                             const char *name, int name_len,
+                             u64 inode_objectid, u64 ref_objectid, u64 index)
+{
+       struct btrfs_inode_extref *extref;
+       int ret;
+       int ins_len = name_len + sizeof(*extref);
+       unsigned long ptr;
+       struct btrfs_path *path;
+       struct btrfs_key key;
+       struct extent_buffer *leaf;
+       struct btrfs_item *item;
+
+       key.objectid = inode_objectid;
+       key.type = BTRFS_INODE_EXTREF_KEY;
+       key.offset = btrfs_extref_hash(ref_objectid, name, name_len);
+
+       path = btrfs_alloc_path();
+       if (!path)
+               return -ENOMEM;
+
+       ret = btrfs_insert_empty_item(trans, root, path, &key,
+                                     ins_len);
+       if (ret == -EEXIST) {
+               if (btrfs_find_name_in_ext_backref(path, ref_objectid,
+                                                  name, name_len, NULL))
+                       goto out;
+
+               btrfs_extend_item(root, path, ins_len);
+               ret = 0;
+       }
+
+       if (ret < 0)
+               goto out;
+
+       leaf = path->nodes[0];
+       item = btrfs_item_nr(path->slots[0]);
+       ptr = (unsigned long)btrfs_item_ptr(leaf, path->slots[0], char);
+       ptr += btrfs_item_size(leaf, item) - ins_len;
+       extref = (struct btrfs_inode_extref *)ptr;
+
+       btrfs_set_inode_extref_name_len(path->nodes[0], extref, name_len);
+       btrfs_set_inode_extref_index(path->nodes[0], extref, index);
+       btrfs_set_inode_extref_parent(path->nodes[0], extref, ref_objectid);
+
+       ptr = (unsigned long)&extref->name;
+       write_extent_buffer(path->nodes[0], name, ptr, name_len);
+       btrfs_mark_buffer_dirty(path->nodes[0]);
+
+out:
+       btrfs_free_path(path);
+
+       return ret;
+}
+
+int btrfs_del_inode_ref(struct btrfs_trans_handle *trans,
+                       struct btrfs_root *root, const char *name, int name_len,
+                       u64 ino, u64 parent_ino, u64 *index)
+{
+       struct btrfs_path *path;
+       struct btrfs_key key;
+       struct btrfs_inode_ref *ref;
+       struct extent_buffer *leaf;
+       unsigned long ptr;
+       unsigned long item_start;
+       u32 item_size;
+       u32 sub_item_len;
+       int ret;
+       int search_ext_refs = 0;
+       int del_len = name_len + sizeof(*ref);
+
+       key.objectid = ino;
+       key.offset = parent_ino;
+       key.type = BTRFS_INODE_REF_KEY;
+
+       path = btrfs_alloc_path();
+       if (!path)
+               return -ENOMEM;
+
+       ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+       if (ret > 0) {
+               ret = -ENOENT;
+               search_ext_refs = 1;
+               goto out;
+       } else if (ret < 0) {
+               goto out;
+       }
+       if (!find_name_in_backref(path, name, name_len, &ref)) {
+               ret = -ENOENT;
+               search_ext_refs = 1;
+               goto out;
+       }
+       leaf = path->nodes[0];
+       item_size = btrfs_item_size_nr(leaf, path->slots[0]);
+
+       if (index)
+               *index = btrfs_inode_ref_index(leaf, ref);
+
+       if (del_len == item_size) {
+               ret = btrfs_del_item(trans, root, path);
+               goto out;
+       }
+       ptr = (unsigned long)ref;
+       sub_item_len = name_len + sizeof(*ref);
+       item_start = btrfs_item_ptr_offset(leaf, path->slots[0]);
+       memmove_extent_buffer(leaf, ptr, ptr + sub_item_len,
+                             item_size - (ptr + sub_item_len - item_start));
+       btrfs_truncate_item(root, path, item_size - sub_item_len, 1);
+       btrfs_mark_buffer_dirty(path->nodes[0]);
+out:
+       btrfs_free_path(path);
+
+       if (search_ext_refs &&
+           btrfs_fs_incompat(root->fs_info, EXTENDED_IREF)) {
+               /*
+                * No refs were found, or we could not find the name in our ref
+                * array. Find and remove the extended inode ref then.
+                */
+               return btrfs_del_inode_extref(trans, root, name, name_len,
+                                             ino, parent_ino, index);
+       }
+
+       return ret;
 }