Merge branch 'master' of ssh://mason@master.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable

1 files changed, 277 insertions, 0 deletions

diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c
new file mode 100644
index 000000000000..eb7f7655e9d5
--- /dev/null
+++ b/fs/btrfs/root-tree.c
@@ -0,0 +1,277 @@
+/*
+ * 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 "transaction.h"
+#include "disk-io.h"
+#include "print-tree.h"
+
+/*
+ *  search forward for a root, starting with objectid 'search_start'
+ *  if a root key is found, the objectid we find is filled into 'found_objectid'
+ *  and 0 is returned.  < 0 is returned on error, 1 if there is nothing
+ *  left in the tree.
+ */
+int btrfs_search_root(struct btrfs_root *root, u64 search_start,
+                      u64 *found_objectid)
+{
+        struct btrfs_path *path;
+        struct btrfs_key search_key;
+        int ret;
+
+        root = root->fs_info->tree_root;
+        search_key.objectid = search_start;
+        search_key.type = (u8)-1;
+        search_key.offset = (u64)-1;
+
+        path = btrfs_alloc_path();
+        BUG_ON(!path);
+again:
+        ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
+        if (ret < 0)
+                goto out;
+        if (ret == 0) {
+                ret = 1;
+                goto out;
+        }
+        if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
+                ret = btrfs_next_leaf(root, path);
+                if (ret)
+                        goto out;
+        }
+        btrfs_item_key_to_cpu(path->nodes[0], &search_key, path->slots[0]);
+        if (search_key.type != BTRFS_ROOT_ITEM_KEY) {
+                search_key.offset++;
+                btrfs_release_path(root, path);
+                goto again;
+        }
+        ret = 0;
+        *found_objectid = search_key.objectid;
+
+out:
+        btrfs_free_path(path);
+        return ret;
+}
+
+/*
+ * lookup the root with the highest offset for a given objectid.  The key we do
+ * find is copied into 'key'.  If we find something return 0, otherwise 1, < 0
+ * on error.
+ */
+int btrfs_find_last_root(struct btrfs_root *root, u64 objectid,
+                        struct btrfs_root_item *item, struct btrfs_key *key)
+{
+        struct btrfs_path *path;
+        struct btrfs_key search_key;
+        struct btrfs_key found_key;
+        struct extent_buffer *l;
+        int ret;
+        int slot;
+
+        search_key.objectid = objectid;
+        search_key.type = (u8)-1;
+        search_key.offset = (u64)-1;
+
+        path = btrfs_alloc_path();
+        BUG_ON(!path);
+        ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
+        if (ret < 0)
+                goto out;
+
+        BUG_ON(ret == 0);
+        l = path->nodes[0];
+        BUG_ON(path->slots[0] == 0);
+        slot = path->slots[0] - 1;
+        btrfs_item_key_to_cpu(l, &found_key, slot);
+        if (found_key.objectid != objectid) {
+                ret = 1;
+                goto out;
+        }
+        read_extent_buffer(l, item, btrfs_item_ptr_offset(l, slot),
+                           sizeof(*item));
+        memcpy(key, &found_key, sizeof(found_key));
+        ret = 0;
+out:
+        btrfs_free_path(path);
+        return ret;
+}
+
+/*
+ * copy the data in 'item' into the btree
+ */
+int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root
+                      *root, struct btrfs_key *key, struct btrfs_root_item
+                      *item)
+{
+        struct btrfs_path *path;
+        struct extent_buffer *l;
+        int ret;
+        int slot;
+        unsigned long ptr;
+
+        path = btrfs_alloc_path();
+        BUG_ON(!path);
+        ret = btrfs_search_slot(trans, root, key, path, 0, 1);
+        if (ret < 0)
+                goto out;
+
+        if (ret != 0) {
+                btrfs_print_leaf(root, path->nodes[0]);
+                printk("unable to update root key %Lu %u %Lu\n",
+                       key->objectid, key->type, key->offset);
+                BUG_ON(1);
+        }
+
+        l = path->nodes[0];
+        slot = path->slots[0];
+        ptr = btrfs_item_ptr_offset(l, slot);
+        write_extent_buffer(l, item, ptr, sizeof(*item));
+        btrfs_mark_buffer_dirty(path->nodes[0]);
+out:
+        btrfs_release_path(root, path);
+        btrfs_free_path(path);
+        return ret;
+}
+
+int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root
+                      *root, struct btrfs_key *key, struct btrfs_root_item
+                      *item)
+{
+        int ret;
+        ret = btrfs_insert_item(trans, root, key, item, sizeof(*item));
+        return ret;
+}
+
+/*
+ * at mount time we want to find all the old transaction snapshots that were in
+ * the process of being deleted if we crashed.  This is any root item with an offset
+ * lower than the latest root.  They need to be queued for deletion to finish
+ * what was happening when we crashed.
+ */
+int btrfs_find_dead_roots(struct btrfs_root *root, u64 objectid,
+                          struct btrfs_root *latest)
+{
+        struct btrfs_root *dead_root;
+        struct btrfs_item *item;
+        struct btrfs_root_item *ri;
+        struct btrfs_key key;
+        struct btrfs_key found_key;
+        struct btrfs_path *path;
+        int ret;
+        u32 nritems;
+        struct extent_buffer *leaf;
+        int slot;
+
+        key.objectid = objectid;
+        btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
+        key.offset = 0;
+        path = btrfs_alloc_path();
+        if (!path)
+                return -ENOMEM;
+
+again:
+        ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+        if (ret < 0)
+                goto err;
+        while(1) {
+                leaf = path->nodes[0];
+                nritems = btrfs_header_nritems(leaf);
+                slot = path->slots[0];
+                if (slot >= nritems) {
+                        ret = btrfs_next_leaf(root, path);
+                        if (ret)
+                                break;
+                        leaf = path->nodes[0];
+                        nritems = btrfs_header_nritems(leaf);
+                        slot = path->slots[0];
+                }
+                item = btrfs_item_nr(leaf, slot);
+                btrfs_item_key_to_cpu(leaf, &key, slot);
+                if (btrfs_key_type(&key) != BTRFS_ROOT_ITEM_KEY)
+                        goto next;
+
+                if (key.objectid < objectid)
+                        goto next;
+
+                if (key.objectid > objectid)
+                        break;
+
+                ri = btrfs_item_ptr(leaf, slot, struct btrfs_root_item);
+                if (btrfs_disk_root_refs(leaf, ri) != 0)
+                        goto next;
+
+                memcpy(&found_key, &key, sizeof(key));
+                key.offset++;
+                btrfs_release_path(root, path);
+                dead_root =
+                        btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
+                                                    &found_key);
+                if (IS_ERR(dead_root)) {
+                        ret = PTR_ERR(dead_root);
+                        goto err;
+                }
+
+                if (objectid == BTRFS_TREE_RELOC_OBJECTID)
+                        ret = btrfs_add_dead_reloc_root(dead_root);
+                else
+                        ret = btrfs_add_dead_root(dead_root, latest);
+                if (ret)
+                        goto err;
+                goto again;
+next:
+                slot++;
+                path->slots[0]++;
+        }
+        ret = 0;
+err:
+        btrfs_free_path(path);
+        return ret;
+}
+
+/* drop the root item for 'key' from 'root' */
+int btrfs_del_root(struct btrfs_trans_handle *trans, struct btrfs_root *root,
+                   struct btrfs_key *key)
+{
+        struct btrfs_path *path;
+        int ret;
+        u32 refs;
+        struct btrfs_root_item *ri;
+        struct extent_buffer *leaf;
+
+        path = btrfs_alloc_path();
+        BUG_ON(!path);
+        ret = btrfs_search_slot(trans, root, key, path, -1, 1);
+        if (ret < 0)
+                goto out;
+        if (ret) {
+btrfs_print_leaf(root, path->nodes[0]);
+printk("failed to del %Lu %u %Lu\n", key->objectid, key->type, key->offset);
+
+        }
+        BUG_ON(ret != 0);
+        leaf = path->nodes[0];
+        ri = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_item);
+
+        refs = btrfs_disk_root_refs(leaf, ri);
+        BUG_ON(refs != 0);
+        ret = btrfs_del_item(trans, root, path);
+out:
+        btrfs_release_path(root, path);
+        btrfs_free_path(path);
+        return ret;
+}