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#include <linux/module.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 = 0;
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_start = max(search_start, BTRFS_FIRST_FREE_OBJECTID);
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 = btrfs_buffer_leaf(path.nodes[0]);
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(btrfs_buffer_leaf(path.nodes[0]),
path.slots[0], struct btrfs_inode_map_item);
btrfs_cpu_key_to_disk(&inode_item->key, location);
mark_buffer_dirty(path.nodes[0]);
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;
}
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