From: Chris Mason Date: Wed, 28 Mar 2007 23:44:27 +0000 (-0400) Subject: Btrfs: sha256 csums on metadata X-Git-Url: http://git.mmlx.us/?a=commitdiff_plain;h=87cbda5c1f54aba67b1e318a4a4824c9e9f16324;p=linux-edison.git Btrfs: sha256 csums on metadata Signed-off-by: Chris Mason --- diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index b2ebed756c1..6ff87f44c5d 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -51,11 +51,11 @@ struct btrfs_key { * every tree block (leaf or node) starts with this header. */ struct btrfs_header { + __le32 csum[8]; u8 fsid[16]; /* FS specific uuid */ __le64 blocknr; /* which block this node is supposed to live in */ __le64 generation; __le64 parentid; /* objectid of the tree root */ - __le32 csum; __le32 ham; __le16 nritems; __le16 flags; @@ -75,9 +75,10 @@ struct buffer_head; * it currently lacks any block count etc etc */ struct btrfs_super_block { + __le32 csum[8]; + /* the first 3 fields must match struct btrfs_header */ u8 fsid[16]; /* FS specific uuid */ __le64 blocknr; /* this block number */ - __le32 csum; __le64 magic; __le32 blocksize; __le64 generation; @@ -217,6 +218,7 @@ struct btrfs_inode_map_item { struct btrfs_disk_key key; } __attribute__ ((__packed__)); +struct crypto_hash; struct btrfs_fs_info { struct btrfs_root *fs_root; struct btrfs_root *extent_root; @@ -236,6 +238,8 @@ struct btrfs_fs_info { struct inode *btree_inode; struct mutex trans_mutex; struct mutex fs_mutex; + struct crypto_hash *hash_tfm; + spinlock_t hash_lock; }; /* diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 970103f2cac..2afb7922b06 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1,6 +1,8 @@ #include #include #include +#include +#include #include "ctree.h" #include "disk-io.h" #include "transaction.h" @@ -126,8 +128,51 @@ static int btree_get_block(struct inode *inode, sector_t iblock, return 0; } +static int csum_tree_block(struct btrfs_root * root, struct buffer_head *bh, + int verify) +{ + struct btrfs_node *node = btrfs_buffer_node(bh); + struct scatterlist sg; + struct crypto_hash *tfm = root->fs_info->hash_tfm; + struct hash_desc desc; + int ret; + char result[32]; + + desc.tfm = tfm; + desc.flags = 0; + sg_init_one(&sg, bh->b_data + 32, bh->b_size - 32); + spin_lock(&root->fs_info->hash_lock); + ret = crypto_hash_digest(&desc, &sg, bh->b_size - 32, result); + spin_unlock(&root->fs_info->hash_lock); + if (ret) { + printk("sha256 digest failed\n"); + } + if (verify) { + if (memcmp(node->header.csum, result, sizeof(result))) + printk("csum verify failed on %Lu\n", bh->b_blocknr); + return -EINVAL; + } else + memcpy(node->header.csum, result, sizeof(node->header.csum)); + return 0; +} + static int btree_writepage(struct page *page, struct writeback_control *wbc) { + struct buffer_head *bh; + struct btrfs_root *root = btrfs_sb(page->mapping->host->i_sb); + struct buffer_head *head; + + if (!page_has_buffers(page)) { + create_empty_buffers(page, root->fs_info->sb->s_blocksize, + (1 << BH_Dirty)|(1 << BH_Uptodate)); + } + head = page_buffers(page); + bh = head; + do { + if (buffer_dirty(bh)) + csum_tree_block(root, bh, 0); + bh = bh->b_this_page; + } while (bh != head); return block_write_full_page(page, btree_get_block, wbc); } @@ -157,6 +202,7 @@ struct buffer_head *read_tree_block(struct btrfs_root *root, u64 blocknr) wait_on_buffer(bh); if (!buffer_uptodate(bh)) goto fail; + csum_tree_block(root, bh, 1); } else { unlock_buffer(bh); } @@ -233,8 +279,9 @@ struct btrfs_root *open_ctree(struct super_block *sb, GFP_NOFS); int ret; - if (!btrfs_super_root(disk_super)) + if (!btrfs_super_root(disk_super)) { return NULL; + } init_bit_radix(&fs_info->pinned_radix); init_bit_radix(&fs_info->pending_del_radix); sb_set_blocksize(sb, sb_buffer->b_size); @@ -252,6 +299,12 @@ struct btrfs_root *open_ctree(struct super_block *sb, fs_info->btree_inode->i_size = sb->s_bdev->bd_inode->i_size; fs_info->btree_inode->i_mapping->a_ops = &btree_aops; mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS); + fs_info->hash_tfm = crypto_alloc_hash("sha256", 0, CRYPTO_ALG_ASYNC); + if (!fs_info->hash_tfm) { + printk("failed to allocate sha256 hash\n"); + return NULL; + } + spin_lock_init(&fs_info->hash_lock); mutex_init(&fs_info->trans_mutex); mutex_init(&fs_info->fs_mutex); @@ -262,9 +315,10 @@ struct btrfs_root *open_ctree(struct super_block *sb, fs_info->sb_buffer = read_tree_block(tree_root, sb_buffer->b_blocknr); - if (!fs_info->sb_buffer) + if (!fs_info->sb_buffer) { +printk("failed2\n"); return NULL; - + } brelse(sb_buffer); sb_buffer = NULL; disk_super = (struct btrfs_super_block *)fs_info->sb_buffer->b_data; @@ -300,6 +354,7 @@ int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root root->fs_info->tree_root->node->b_blocknr); lock_buffer(bh); clear_buffer_dirty(bh); + csum_tree_block(root, bh, 0); bh->b_end_io = end_buffer_write_sync; get_bh(bh); submit_bh(WRITE, bh); @@ -338,6 +393,7 @@ int close_ctree(struct btrfs_root *root) root->fs_info->tree_root->node); btrfs_block_release(root, root->commit_root); btrfs_block_release(root, root->fs_info->sb_buffer); + crypto_free_hash(root->fs_info->hash_tfm); iput(root->fs_info->btree_inode); kfree(root->fs_info->extent_root); kfree(root->fs_info->inode_root); diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 8f07f462236..151c1002d74 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -473,13 +473,13 @@ static int btrfs_fill_super(struct super_block * sb, void * data, int silent) } disk_super = (struct btrfs_super_block *)bh->b_data; root = open_ctree(sb, bh, disk_super); - sb->s_fs_info = root; - disk_super = root->fs_info->disk_super; if (!root) { printk("btrfs: open_ctree failed\n"); return -EIO; } + sb->s_fs_info = root; + disk_super = root->fs_info->disk_super; printk("read in super total blocks %Lu root %Lu\n", btrfs_super_total_blocks(disk_super), btrfs_super_root_dir(disk_super));