Btrfs: Add inode map, and the start of file extent items
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/inode-map.c b/fs/btrfs/inode-map.c
new file mode 100644
index 0000000..f412b33
--- /dev/null
+++ b/fs/btrfs/inode-map.c
@@ -0,0 +1,136 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include "kerncompat.h"
+#include "radix-tree.h"
+#include "ctree.h"
+#include "disk-io.h"
+#include "transaction.h"
+
+/*
+ * walks the btree of allocated inodes and find a hole.
+ */
+int btrfs_find_free_objectid(struct btrfs_trans_handle *trans,
+ struct btrfs_root *fs_root,
+ u64 dirid, u64 *objectid)
+{
+ struct btrfs_path path;
+ struct btrfs_key key;
+ int ret;
+ u64 hole_size = 0;
+ int slot = 0;
+ u64 last_ino;
+ int start_found;
+ struct btrfs_leaf *l;
+ struct btrfs_root *root = fs_root->fs_info->inode_root;
+ struct btrfs_key search_key;
+ u64 search_start = dirid;
+
+ if (fs_root->fs_info->last_inode_alloc_dirid == dirid)
+ search_start = fs_root->fs_info->last_inode_alloc;
+
+ search_key.objectid = search_start;
+ search_key.flags = 0;
+ btrfs_set_key_type(&search_key, BTRFS_INODE_MAP_ITEM_KEY);
+ 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;
+
+ if (path.slots[0] > 0)
+ path.slots[0]--;
+
+ while (1) {
+ l = &path.nodes[0]->leaf;
+ slot = path.slots[0];
+ if (slot >= btrfs_header_nritems(&l->header)) {
+ 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_disk_key_to_cpu(&key, &l->items[slot].key);
+ if (key.objectid >= search_start) {
+ if (start_found) {
+ if (last_ino < search_start)
+ last_ino = search_start;
+ hole_size = key.objectid - last_ino;
+ if (hole_size > 0) {
+ *objectid = last_ino;
+ goto found;
+ }
+ }
+ }
+ start_found = 1;
+ last_ino = key.objectid + 1;
+ path.slots[0]++;
+ }
+ // FIXME -ENOSPC
+found:
+ root->fs_info->last_inode_alloc = *objectid;
+ root->fs_info->last_inode_alloc_dirid = dirid;
+ btrfs_release_path(root, &path);
+ BUG_ON(*objectid < search_start);
+ return 0;
+error:
+ btrfs_release_path(root, &path);
+ return ret;
+}
+
+int btrfs_insert_inode_map(struct btrfs_trans_handle *trans,
+ struct btrfs_root *fs_root,
+ u64 objectid, struct btrfs_key *location)
+{
+ int ret = 0;
+ struct btrfs_path path;
+ struct btrfs_inode_map_item *inode_item;
+ struct btrfs_key key;
+ struct btrfs_root *inode_root = fs_root->fs_info->inode_root;
+
+ key.objectid = objectid;
+ key.flags = 0;
+ btrfs_set_key_type(&key, BTRFS_INODE_MAP_ITEM_KEY);
+ key.offset = 0;
+ btrfs_init_path(&path);
+ ret = btrfs_insert_empty_item(trans, inode_root, &path, &key,
+ sizeof(struct btrfs_inode_map_item));
+ if (ret)
+ goto out;
+
+ inode_item = btrfs_item_ptr(&path.nodes[0]->leaf, path.slots[0],
+ struct btrfs_inode_map_item);
+ btrfs_cpu_key_to_disk(&inode_item->key, location);
+out:
+ btrfs_release_path(inode_root, &path);
+ return ret;
+}
+
+int btrfs_lookup_inode_map(struct btrfs_trans_handle *trans,
+ struct btrfs_root *fs_root, struct btrfs_path *path,
+ u64 objectid, int mod)
+{
+ int ret;
+ struct btrfs_key key;
+ int ins_len = mod < 0 ? -1 : 0;
+ int cow = mod != 0;
+ struct btrfs_root *inode_root = fs_root->fs_info->inode_root;
+
+ key.objectid = objectid;
+ key.flags = 0;
+ key.offset = 0;
+ btrfs_set_key_type(&key, BTRFS_INODE_MAP_ITEM_KEY);
+ ret = btrfs_search_slot(trans, inode_root, &key, path, ins_len, cow);
+ return ret;
+}
+