135 lines
3.4 KiB
C
135 lines
3.4 KiB
C
#include <linux/module.h>
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#include "ctree.h"
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#include "disk-io.h"
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#include "transaction.h"
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/*
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* walks the btree of allocated inodes and find a hole.
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*/
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int btrfs_find_free_objectid(struct btrfs_trans_handle *trans,
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struct btrfs_root *fs_root,
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u64 dirid, u64 *objectid)
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{
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struct btrfs_path path;
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struct btrfs_key key;
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int ret;
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u64 hole_size = 0;
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int slot = 0;
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u64 last_ino = 0;
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int start_found;
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struct btrfs_leaf *l;
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struct btrfs_root *root = fs_root->fs_info->inode_root;
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struct btrfs_key search_key;
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u64 search_start = dirid;
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if (fs_root->fs_info->last_inode_alloc_dirid == dirid)
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search_start = fs_root->fs_info->last_inode_alloc;
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search_start = max(search_start, BTRFS_FIRST_FREE_OBJECTID);
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search_key.objectid = search_start;
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search_key.flags = 0;
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btrfs_set_key_type(&search_key, BTRFS_INODE_MAP_ITEM_KEY);
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search_key.offset = 0;
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btrfs_init_path(&path);
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start_found = 0;
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ret = btrfs_search_slot(trans, root, &search_key, &path, 0, 0);
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if (ret < 0)
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goto error;
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if (path.slots[0] > 0)
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path.slots[0]--;
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while (1) {
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l = btrfs_buffer_leaf(path.nodes[0]);
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slot = path.slots[0];
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if (slot >= btrfs_header_nritems(&l->header)) {
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ret = btrfs_next_leaf(root, &path);
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if (ret == 0)
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continue;
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if (ret < 0)
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goto error;
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if (!start_found) {
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*objectid = search_start;
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start_found = 1;
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goto found;
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}
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*objectid = last_ino > search_start ?
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last_ino : search_start;
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goto found;
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}
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btrfs_disk_key_to_cpu(&key, &l->items[slot].key);
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if (key.objectid >= search_start) {
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if (start_found) {
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if (last_ino < search_start)
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last_ino = search_start;
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hole_size = key.objectid - last_ino;
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if (hole_size > 0) {
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*objectid = last_ino;
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goto found;
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}
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}
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}
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start_found = 1;
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last_ino = key.objectid + 1;
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path.slots[0]++;
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}
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// FIXME -ENOSPC
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found:
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root->fs_info->last_inode_alloc = *objectid;
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root->fs_info->last_inode_alloc_dirid = dirid;
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btrfs_release_path(root, &path);
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BUG_ON(*objectid < search_start);
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return 0;
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error:
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btrfs_release_path(root, &path);
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return ret;
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}
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int btrfs_insert_inode_map(struct btrfs_trans_handle *trans,
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struct btrfs_root *fs_root,
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u64 objectid, struct btrfs_key *location)
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{
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int ret = 0;
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struct btrfs_path path;
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struct btrfs_inode_map_item *inode_item;
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struct btrfs_key key;
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struct btrfs_root *inode_root = fs_root->fs_info->inode_root;
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key.objectid = objectid;
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key.flags = 0;
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btrfs_set_key_type(&key, BTRFS_INODE_MAP_ITEM_KEY);
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key.offset = 0;
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btrfs_init_path(&path);
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ret = btrfs_insert_empty_item(trans, inode_root, &path, &key,
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sizeof(struct btrfs_inode_map_item));
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if (ret)
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goto out;
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inode_item = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]),
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path.slots[0], struct btrfs_inode_map_item);
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btrfs_cpu_key_to_disk(&inode_item->key, location);
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mark_buffer_dirty(path.nodes[0]);
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out:
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btrfs_release_path(inode_root, &path);
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return ret;
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}
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int btrfs_lookup_inode_map(struct btrfs_trans_handle *trans,
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struct btrfs_root *fs_root, struct btrfs_path *path,
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u64 objectid, int mod)
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{
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int ret;
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struct btrfs_key key;
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int ins_len = mod < 0 ? -1 : 0;
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int cow = mod != 0;
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struct btrfs_root *inode_root = fs_root->fs_info->inode_root;
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key.objectid = objectid;
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key.flags = 0;
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key.offset = 0;
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btrfs_set_key_type(&key, BTRFS_INODE_MAP_ITEM_KEY);
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ret = btrfs_search_slot(trans, inode_root, &key, path, ins_len, cow);
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return ret;
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}
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