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| author | Chris Mason | 2007-03-29 21:15:27 +0200 |
|---|---|---|
| committer | David Woodhouse | 2007-03-29 21:15:27 +0200 |
| commit | f254e52c1ce550fdaa0d31f5e068f0d67c2485d4 (patch) | |
| tree | 1232b7e16b6f0b1b1b150c5df396452cac5e3853 /fs/btrfs/file-item.c | |
| parent | btrfs_file_write -- first pass (diff) | |
| download | kernel-qcow2-linux-f254e52c1ce550fdaa0d31f5e068f0d67c2485d4.tar.gz kernel-qcow2-linux-f254e52c1ce550fdaa0d31f5e068f0d67c2485d4.tar.xz kernel-qcow2-linux-f254e52c1ce550fdaa0d31f5e068f0d67c2485d4.zip | |
Btrfs: verify csums on read
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs/btrfs/file-item.c')
| -rw-r--r-- | fs/btrfs/file-item.c | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c index 5230a44cb19b..2d2c23ca7cbf 100644 --- a/fs/btrfs/file-item.c +++ b/fs/btrfs/file-item.c @@ -57,3 +57,63 @@ int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans, 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_path path; + struct btrfs_csum_item *item; + + 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); + ret = btrfs_insert_empty_item(trans, root, &path, &file_key, + BTRFS_CSUM_SIZE); + if (ret != 0 && ret != -EEXIST) + goto fail; + item = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]), path.slots[0], + struct btrfs_csum_item); + ret = 0; + ret = btrfs_csum_data(root, data, len, item->csum); + mark_buffer_dirty(path.nodes[0]); +fail: + btrfs_release_path(root, &path); + 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_CSUM_SIZE]; + + 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); + ret = btrfs_search_slot(NULL, root, &file_key, &path, 0, 0); + if (ret) + goto fail; + item = btrfs_item_ptr(btrfs_buffer_leaf(path.nodes[0]), path.slots[0], + struct btrfs_csum_item); + ret = 0; + ret = btrfs_csum_data(root, data, len, result); + WARN_ON(ret); + if (memcmp(result, item->csum, BTRFS_CSUM_SIZE)) + ret = 1; +fail: + btrfs_release_path(root, &path); + return ret; +} + |