Today this is much too simple, it just allocates the highest inode + 1.
Longer term something similar to the caching in extent-tree.c needs to
be done.
Signed-off-by: Chris Mason <chris.mason@xxxxxxxxxx>
diff --git a/fs/btrfs/inode-map.c b/fs/btrfs/inode-map.c
new file mode 100644
index 0000000..2aa7987
--- /dev/null
+++ b/fs/btrfs/inode-map.c
@@ -0,0 +1,144 @@
+/*
+ * 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"
+
+int btrfs_find_highest_inode(struct btrfs_root *root, u64 *objectid)
+{
+ struct btrfs_path *path;
+ int ret;
+ struct extent_buffer *l;
+ struct btrfs_key search_key;
+ struct btrfs_key found_key;
+ int slot;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+
+ search_key.objectid = BTRFS_LAST_FREE_OBJECTID;
+ search_key.type = -1;
+ search_key.offset = (u64)-1;
+ ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
+ if (ret < 0)
+ goto error;
+ BUG_ON(ret == 0);
+ if (path->slots[0] > 0) {
+ slot = path->slots[0] - 1;
+ l = path->nodes[0];
+ btrfs_item_key_to_cpu(l, &found_key, slot);
+ *objectid = found_key.objectid;
+ } else {
+ *objectid = BTRFS_FIRST_FREE_OBJECTID;
+ }
+ ret = 0;
+error:
+ btrfs_free_path(path);
+ return ret;
+}
+
+/*
+ * walks the btree of allocated inodes and find a hole.
+ */
+int btrfs_find_free_objectid(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 dirid, u64 *objectid)
+{
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ int ret;
+ int slot = 0;
+ u64 last_ino = 0;
+ int start_found;
+ struct extent_buffer *l;
+ struct btrfs_key search_key;
+ u64 search_start = dirid;
+
+ mutex_lock(&root->objectid_mutex);
+ if (root->last_inode_alloc >= BTRFS_FIRST_FREE_OBJECTID &&
+ root->last_inode_alloc < BTRFS_LAST_FREE_OBJECTID) {
+ *objectid = ++root->last_inode_alloc;
+ mutex_unlock(&root->objectid_mutex);
+ return 0;
+ }
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ search_start = max(search_start, BTRFS_FIRST_FREE_OBJECTID);
+ search_key.objectid = search_start;
+ search_key.type = 0;
+ search_key.offset = 0;
+
+ btrfs_init_path(path);
+ start_found = 0;
+ ret = btrfs_search_slot(trans, root, &search_key, path, 0, 0);
+ if (ret < 0)
+ goto error;
+
+ while (1) {
+ l = path->nodes[0];
+ slot = path->slots[0];
+ if (slot >= btrfs_header_nritems(l)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret == 0)
+ continue;
+ if (ret < 0)
+ goto error;
+ if (!start_found) {
+ *objectid = search_start;
+ start_found = 1;
+ goto found;
+ }
+ *objectid = last_ino > search_start ?
+ last_ino : search_start;
+ goto found;
+ }
+ btrfs_item_key_to_cpu(l, &key, slot);
+ if (key.objectid >= search_start) {
+ if (start_found) {
+ if (last_ino < search_start)
+ last_ino = search_start;
+ if (key.objectid > last_ino) {
+ *objectid = last_ino;
+ goto found;
+ }
+ } else if (key.objectid > search_start) {
+ *objectid = search_start;
+ goto found;
+ }
+ }
+ if (key.objectid >= BTRFS_LAST_FREE_OBJECTID)
+ break;
+
+ start_found = 1;
+ last_ino = key.objectid + 1;
+ path->slots[0]++;
+ }
+ BUG_ON(1);
+found:
+ btrfs_release_path(root, path);
+ btrfs_free_path(path);
+ BUG_ON(*objectid < search_start);
+ mutex_unlock(&root->objectid_mutex);
+ return 0;
+error:
+ btrfs_release_path(root, path);
+ btrfs_free_path(path);
+ mutex_unlock(&root->objectid_mutex);
+ return ret;
+}
--
1.6.0.2
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