131 строка
3.6 KiB
C
131 строка
3.6 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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int btrfs_alloc_file_extent(struct btrfs_trans_handle *trans,
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struct btrfs_root *root,
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u64 objectid, u64 offset,
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u64 num_blocks, u64 hint_block,
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u64 *result)
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{
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struct btrfs_key ins;
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int ret = 0;
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struct btrfs_file_extent_item *item;
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struct btrfs_key file_key;
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struct btrfs_path *path;
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path = btrfs_alloc_path();
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BUG_ON(!path);
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btrfs_init_path(path);
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ret = btrfs_alloc_extent(trans, root, num_blocks, hint_block,
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(u64)-1, &ins);
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BUG_ON(ret);
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file_key.objectid = objectid;
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file_key.offset = offset;
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file_key.flags = 0;
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btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
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ret = btrfs_insert_empty_item(trans, root, path, &file_key,
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sizeof(*item));
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BUG_ON(ret);
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item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
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struct btrfs_file_extent_item);
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btrfs_set_file_extent_disk_blocknr(item, ins.objectid);
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btrfs_set_file_extent_disk_num_blocks(item, ins.offset);
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btrfs_set_file_extent_offset(item, 0);
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btrfs_set_file_extent_num_blocks(item, ins.offset);
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btrfs_set_file_extent_generation(item, trans->transid);
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btrfs_mark_buffer_dirty(path->nodes[0]);
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*result = ins.objectid;
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btrfs_release_path(root, path);
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btrfs_free_path(path);
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return 0;
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}
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int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
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struct btrfs_root *root,
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struct btrfs_path *path, u64 objectid,
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u64 offset, int mod)
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{
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int ret;
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struct btrfs_key file_key;
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int ins_len = mod < 0 ? -1 : 0;
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int cow = mod != 0;
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file_key.objectid = objectid;
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file_key.offset = offset;
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file_key.flags = 0;
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btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
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ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
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return ret;
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}
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int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
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struct btrfs_root *root,
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u64 objectid, u64 offset,
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char *data, size_t len)
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{
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int ret;
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struct btrfs_key file_key;
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struct btrfs_path *path;
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struct btrfs_csum_item *item;
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path = btrfs_alloc_path();
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BUG_ON(!path);
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btrfs_init_path(path);
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file_key.objectid = objectid;
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file_key.offset = offset;
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file_key.flags = 0;
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btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
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ret = btrfs_insert_empty_item(trans, root, path, &file_key,
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BTRFS_CSUM_SIZE);
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if (ret != 0 && ret != -EEXIST)
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goto fail;
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item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
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struct btrfs_csum_item);
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ret = 0;
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ret = btrfs_csum_data(root, data, len, item->csum);
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btrfs_mark_buffer_dirty(path->nodes[0]);
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fail:
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btrfs_release_path(root, path);
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btrfs_free_path(path);
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return ret;
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}
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int btrfs_csum_verify_file_block(struct btrfs_root *root,
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u64 objectid, u64 offset,
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char *data, size_t len)
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{
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int ret;
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struct btrfs_key file_key;
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struct btrfs_path *path;
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struct btrfs_csum_item *item;
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char result[BTRFS_CSUM_SIZE];
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path = btrfs_alloc_path();
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BUG_ON(!path);
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btrfs_init_path(path);
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file_key.objectid = objectid;
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file_key.offset = offset;
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file_key.flags = 0;
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btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
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mutex_lock(&root->fs_info->fs_mutex);
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ret = btrfs_search_slot(NULL, root, &file_key, path, 0, 0);
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if (ret)
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goto fail;
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item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
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struct btrfs_csum_item);
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ret = 0;
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ret = btrfs_csum_data(root, data, len, result);
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WARN_ON(ret);
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if (memcmp(result, item->csum, BTRFS_CSUM_SIZE))
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ret = 1;
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fail:
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btrfs_release_path(root, path);
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btrfs_free_path(path);
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mutex_unlock(&root->fs_info->fs_mutex);
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return ret;
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}
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