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Btrfs: sha256 csums on metadata 

Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason 2007-03-28 19:44:27 -04:00 committed by David Woodhouse
parent d98237b3ed
commit 87cbda5c1f
3 changed files with 67 additions and 7 deletions
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8
fs/btrfs/ctree.h
View File

@ -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;
};
/*

62
fs/btrfs/disk-io.c
View File

@ -1,6 +1,8 @@
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/blkdev.h>
#include <linux/crypto.h>
#include <linux/scatterlist.h>
#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);

4
fs/btrfs/super.c
View File

@ -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));