* Boston, MA 021110-1307, USA.
*/
-#include <linux/module.h>
#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_leaf *l;
+ struct btrfs_key found_key;
+ struct extent_buffer *l;
int ret;
int slot;
search_key.objectid = objectid;
- search_key.flags = (u32)-1;
+ search_key.type = BTRFS_ROOT_ITEM_KEY;
search_key.offset = (u64)-1;
path = btrfs_alloc_path();
ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
if (ret < 0)
goto out;
+
BUG_ON(ret == 0);
- l = btrfs_buffer_leaf(path->nodes[0]);
+ l = path->nodes[0];
BUG_ON(path->slots[0] == 0);
slot = path->slots[0] - 1;
- if (btrfs_disk_key_objectid(&l->items[slot].key) != objectid) {
+ btrfs_item_key_to_cpu(l, &found_key, slot);
+ if (found_key.objectid != objectid) {
ret = 1;
goto out;
}
- memcpy(item, btrfs_item_ptr(l, slot, struct btrfs_root_item),
- sizeof(*item));
- btrfs_disk_key_to_cpu(key, &l->items[slot].key);
-printk("find last finds key %Lu %u %Lu slot %d search for obj %Lu\n", key->objectid, key->flags, key->offset, slot, objectid);
+ read_extent_buffer(l, item, btrfs_item_ptr_offset(l, slot),
+ sizeof(*item));
+ memcpy(key, &found_key, sizeof(found_key));
ret = 0;
out:
- btrfs_release_path(root, path);
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 btrfs_leaf *l;
+ struct extent_buffer *l;
int ret;
int slot;
- struct btrfs_root_item *update_item;
+ 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;
- BUG_ON(ret != 0);
- l = btrfs_buffer_leaf(path->nodes[0]);
+
+ if (ret != 0) {
+ btrfs_print_leaf(root, path->nodes[0]);
+ printk(KERN_CRIT "unable to update root key %llu %u %llu\n",
+ (unsigned long long)key->objectid, key->type,
+ (unsigned long long)key->offset);
+ BUG_ON(1);
+ }
+
+ l = path->nodes[0];
slot = path->slots[0];
- update_item = btrfs_item_ptr(l, slot, struct btrfs_root_item);
- btrfs_memcpy(root, l, update_item, item, sizeof(*item));
+ 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);
return ret;
}
-int btrfs_find_dead_roots(struct btrfs_root *root)
+/*
+ * 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 btrfs_leaf *leaf;
+ struct extent_buffer *leaf;
int slot;
- key.objectid = 0;
- key.flags = 0;
+ 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 = btrfs_buffer_leaf(path->nodes[0]);
- nritems = btrfs_header_nritems(&leaf->header);
+ 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 = btrfs_buffer_leaf(path->nodes[0]);
- nritems = btrfs_header_nritems(&leaf->header);
+ leaf = path->nodes[0];
+ nritems = btrfs_header_nritems(leaf);
slot = path->slots[0];
}
- item = leaf->items + slot;
- btrfs_disk_key_to_cpu(&key, &item->key);
+ 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_root_refs(ri) != 0)
+ if (btrfs_disk_root_refs(leaf, ri) != 0)
goto next;
- dead_root = btrfs_read_fs_root_no_radix(root->fs_info, &key);
- if (IS_ERR(root)) {
- ret = PTR_ERR(root);
+
+ 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;
}
-printk("found dead root %Lu %u %Lu\n", key.objectid, key.flags, key.offset);
- ret = btrfs_add_dead_root(dead_root,
- &root->fs_info->dead_roots);
+
+ 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]++;
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)
{
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;
+
BUG_ON(ret != 0);
- ri = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
- path->slots[0], struct btrfs_root_item);
+ leaf = path->nodes[0];
+ ri = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_item);
- refs = btrfs_root_refs(ri);
+ refs = btrfs_disk_root_refs(leaf, ri);
BUG_ON(refs != 0);
ret = btrfs_del_item(trans, root, path);
out:
btrfs_free_path(path);
return ret;
}
+
+#if 0 /* this will get used when snapshot deletion is implemented */
+int btrfs_del_root_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *tree_root,
+ u64 root_id, u8 type, u64 ref_id)
+{
+ struct btrfs_key key;
+ int ret;
+ struct btrfs_path *path;
+
+ path = btrfs_alloc_path();
+
+ key.objectid = root_id;
+ key.type = type;
+ key.offset = ref_id;
+
+ ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1);
+ BUG_ON(ret);
+
+ ret = btrfs_del_item(trans, tree_root, path);
+ BUG_ON(ret);
+
+ btrfs_free_path(path);
+ return ret;
+}
+#endif
+
+int btrfs_find_root_ref(struct btrfs_root *tree_root,
+ struct btrfs_path *path,
+ u64 root_id, u64 ref_id)
+{
+ struct btrfs_key key;
+ int ret;
+
+ key.objectid = root_id;
+ key.type = BTRFS_ROOT_REF_KEY;
+ key.offset = ref_id;
+
+ ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0);
+ return ret;
+}
+
+
+/*
+ * add a btrfs_root_ref item. type is either BTRFS_ROOT_REF_KEY
+ * or BTRFS_ROOT_BACKREF_KEY.
+ *
+ * The dirid, sequence, name and name_len refer to the directory entry
+ * that is referencing the root.
+ *
+ * For a forward ref, the root_id is the id of the tree referencing
+ * the root and ref_id is the id of the subvol or snapshot.
+ *
+ * For a back ref the root_id is the id of the subvol or snapshot and
+ * ref_id is the id of the tree referencing it.
+ */
+int btrfs_add_root_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *tree_root,
+ u64 root_id, u8 type, u64 ref_id,
+ u64 dirid, u64 sequence,
+ const char *name, int name_len)
+{
+ struct btrfs_key key;
+ int ret;
+ struct btrfs_path *path;
+ struct btrfs_root_ref *ref;
+ struct extent_buffer *leaf;
+ unsigned long ptr;
+
+
+ path = btrfs_alloc_path();
+
+ key.objectid = root_id;
+ key.type = type;
+ key.offset = ref_id;
+
+ ret = btrfs_insert_empty_item(trans, tree_root, path, &key,
+ sizeof(*ref) + name_len);
+ BUG_ON(ret);
+
+ leaf = path->nodes[0];
+ ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
+ btrfs_set_root_ref_dirid(leaf, ref, dirid);
+ btrfs_set_root_ref_sequence(leaf, ref, sequence);
+ btrfs_set_root_ref_name_len(leaf, ref, name_len);
+ ptr = (unsigned long)(ref + 1);
+ write_extent_buffer(leaf, name, ptr, name_len);
+ btrfs_mark_buffer_dirty(leaf);
+
+ btrfs_free_path(path);
+ return ret;
+}
git.openpandora.org / pandora-kernel.git / blobdiff