#include <linux/module.h>
#include "ctree.h"
+#include "disk-io.h"
#include "transaction.h"
+#include "print-tree.h"
-int btrfs_create_file(struct btrfs_trans_handle *trans,
- struct btrfs_root *root, u64 dirid, u64 *objectid)
+#define MAX_CSUM_ITEMS(r) ((((BTRFS_LEAF_DATA_SIZE(r) - \
+ sizeof(struct btrfs_item) * 2) / \
+ BTRFS_CRC32_SIZE) - 1))
+int btrfs_insert_file_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 objectid, u64 pos,
+ u64 offset, u64 disk_num_blocks,
+ u64 num_blocks)
{
+ int ret = 0;
+ struct btrfs_file_extent_item *item;
+ struct btrfs_key file_key;
+ struct btrfs_path *path;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ btrfs_init_path(path);
+ file_key.objectid = objectid;
+ file_key.offset = pos;
+ file_key.flags = 0;
+ btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
+
+ ret = btrfs_insert_empty_item(trans, root, path, &file_key,
+ sizeof(*item));
+ BUG_ON(ret);
+ item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
+ struct btrfs_file_extent_item);
+ btrfs_set_file_extent_disk_blocknr(item, offset);
+ btrfs_set_file_extent_disk_num_blocks(item, disk_num_blocks);
+ btrfs_set_file_extent_offset(item, 0);
+ btrfs_set_file_extent_num_blocks(item, num_blocks);
+ btrfs_set_file_extent_generation(item, trans->transid);
+ btrfs_set_file_extent_type(item, BTRFS_FILE_EXTENT_REG);
+ btrfs_mark_buffer_dirty(path->nodes[0]);
+
+ btrfs_release_path(root, path);
+ btrfs_free_path(path);
return 0;
}
+
+struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ u64 objectid, u64 offset,
+ int cow)
+{
+ int ret;
+ struct btrfs_key file_key;
+ struct btrfs_key found_key;
+ struct btrfs_csum_item *item;
+ struct btrfs_leaf *leaf;
+ u64 csum_offset = 0;
+ int csums_in_item;
+
+ file_key.objectid = objectid;
+ file_key.offset = offset;
+ file_key.flags = 0;
+ btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
+ ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
+ if (ret < 0)
+ goto fail;
+ leaf = btrfs_buffer_leaf(path->nodes[0]);
+ if (ret > 0) {
+ ret = 1;
+ if (path->slots[0] == 0)
+ goto fail;
+ path->slots[0]--;
+ btrfs_disk_key_to_cpu(&found_key,
+ &leaf->items[path->slots[0]].key);
+ if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
+ found_key.objectid != objectid) {
+ goto fail;
+ }
+ csum_offset = (offset - found_key.offset) >>
+ root->fs_info->sb->s_blocksize_bits;
+ csums_in_item = btrfs_item_size(leaf->items + path->slots[0]);
+ csums_in_item /= BTRFS_CRC32_SIZE;
+
+ if (csum_offset >= csums_in_item) {
+ ret = -EFBIG;
+ goto fail;
+ }
+ }
+ item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
+ item = (struct btrfs_csum_item *)((unsigned char *)item +
+ csum_offset * BTRFS_CRC32_SIZE);
+ return item;
+fail:
+ if (ret > 0)
+ ret = -ENOENT;
+ return ERR_PTR(ret);
+}
+
+
+int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, u64 objectid,
+ u64 offset, int mod)
+{
+ int ret;
+ struct btrfs_key file_key;
+ int ins_len = mod < 0 ? -1 : 0;
+ int cow = mod != 0;
+
+ file_key.objectid = objectid;
+ file_key.offset = offset;
+ file_key.flags = 0;
+ btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
+ ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
+ return ret;
+}
+
+int btrfs_csum_file_block(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 objectid, u64 offset,
+ char *data, size_t len)
+{
+ int ret;
+ struct btrfs_key file_key;
+ struct btrfs_key found_key;
+ struct btrfs_path *path;
+ struct btrfs_csum_item *item;
+ struct btrfs_leaf *leaf;
+ u64 csum_offset;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+
+ file_key.objectid = objectid;
+ file_key.offset = offset;
+ file_key.flags = 0;
+ btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
+
+ item = btrfs_lookup_csum(trans, root, path, objectid, offset, 1);
+ if (!IS_ERR(item))
+ goto found;
+ ret = PTR_ERR(item);
+ if (ret == -EFBIG) {
+ u32 item_size;
+ /* we found one, but it isn't big enough yet */
+ leaf = btrfs_buffer_leaf(path->nodes[0]);
+ item_size = btrfs_item_size(leaf->items + path->slots[0]);
+ if ((item_size / BTRFS_CRC32_SIZE) >= MAX_CSUM_ITEMS(root)) {
+ /* already at max size, make a new one */
+ goto insert;
+ }
+ } else {
+ /* we didn't find a csum item, insert one */
+ goto insert;
+ }
+
+ /*
+ * at this point, we know the tree has an item, but it isn't big
+ * enough yet to put our csum in. Grow it
+ */
+ btrfs_release_path(root, path);
+ ret = btrfs_search_slot(trans, root, &file_key, path,
+ BTRFS_CRC32_SIZE, 1);
+ if (ret < 0)
+ goto fail;
+ if (ret == 0) {
+ BUG();
+ }
+ if (path->slots[0] == 0) {
+ goto insert;
+ }
+ path->slots[0]--;
+ leaf = btrfs_buffer_leaf(path->nodes[0]);
+ btrfs_disk_key_to_cpu(&found_key, &leaf->items[path->slots[0]].key);
+ csum_offset = (offset - found_key.offset) >>
+ root->fs_info->sb->s_blocksize_bits;
+ if (btrfs_key_type(&found_key) != BTRFS_CSUM_ITEM_KEY ||
+ found_key.objectid != objectid ||
+ csum_offset >= MAX_CSUM_ITEMS(root)) {
+ goto insert;
+ }
+ if (csum_offset >= btrfs_item_size(leaf->items + path->slots[0]) /
+ BTRFS_CRC32_SIZE) {
+ u32 diff = (csum_offset + 1) * BTRFS_CRC32_SIZE;
+ diff = diff - btrfs_item_size(leaf->items + path->slots[0]);
+ if (diff != BTRFS_CRC32_SIZE)
+ goto insert;
+ ret = btrfs_extend_item(trans, root, path, diff);
+ BUG_ON(ret);
+ goto csum;
+ }
+
+insert:
+ btrfs_release_path(root, path);
+ csum_offset = 0;
+ ret = btrfs_insert_empty_item(trans, root, path, &file_key,
+ BTRFS_CRC32_SIZE);
+ if (ret != 0) {
+ WARN_ON(1);
+ goto fail;
+ }
+csum:
+ item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
+ struct btrfs_csum_item);
+ ret = 0;
+ item = (struct btrfs_csum_item *)((unsigned char *)item +
+ csum_offset * BTRFS_CRC32_SIZE);
+found:
+ btrfs_check_bounds(&item->csum, BTRFS_CRC32_SIZE,
+ path->nodes[0]->b_data,
+ root->fs_info->sb->s_blocksize);
+ ret = btrfs_csum_data(root, data, len, &item->csum);
+ btrfs_mark_buffer_dirty(path->nodes[0]);
+fail:
+ btrfs_release_path(root, path);
+ btrfs_free_path(path);
+ return ret;
+}
+
+int btrfs_csum_truncate(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct btrfs_path *path,
+ u64 isize)
+{
+ struct btrfs_key key;
+ struct btrfs_leaf *leaf = btrfs_buffer_leaf(path->nodes[0]);
+ int slot = path->slots[0];
+ int ret;
+ u32 new_item_size;
+ u64 new_item_span;
+ u64 blocks;
+
+ btrfs_disk_key_to_cpu(&key, &leaf->items[slot].key);
+ if (isize <= key.offset)
+ return 0;
+ new_item_span = isize - key.offset;
+ blocks = (new_item_span + root->blocksize - 1) >>
+ root->fs_info->sb->s_blocksize_bits;
+ new_item_size = blocks * BTRFS_CRC32_SIZE;
+ if (new_item_size >= btrfs_item_size(leaf->items + slot))
+ return 0;
+ ret = btrfs_truncate_item(trans, root, path, new_item_size);
+ BUG_ON(ret);
+ return ret;
+}
+
+int btrfs_csum_verify_file_block(struct btrfs_root *root,
+ u64 objectid, u64 offset,
+ char *data, size_t len)
+{
+ int ret;
+ struct btrfs_key file_key;
+ struct btrfs_path *path;
+ struct btrfs_csum_item *item;
+ char result[BTRFS_CRC32_SIZE];
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ btrfs_init_path(path);
+ file_key.objectid = objectid;
+ file_key.offset = offset;
+ file_key.flags = 0;
+ btrfs_set_key_type(&file_key, BTRFS_CSUM_ITEM_KEY);
+ mutex_lock(&root->fs_info->fs_mutex);
+
+ item = btrfs_lookup_csum(NULL, root, path, objectid, offset, 0);
+ if (IS_ERR(item)) {
+ ret = PTR_ERR(item);
+ /* a csum that isn't present is a preallocated region. */
+ if (ret == -ENOENT || ret == -EFBIG)
+ ret = -ENOENT;
+ goto fail;
+ }
+
+ ret = btrfs_csum_data(root, data, len, result);
+ WARN_ON(ret);
+ if (memcmp(result, &item->csum, BTRFS_CRC32_SIZE))
+ ret = 1;
+fail:
+ btrfs_release_path(root, path);
+ btrfs_free_path(path);
+ mutex_unlock(&root->fs_info->fs_mutex);
+ return ret;
+}
+
projects / mv-sheeva.git / blobdiff