Btrfs: switch to crc32c instead of sha256
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 92a6078..d8caeba 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -30,6 +30,8 @@
/* 32 bytes in various csum fields */
#define BTRFS_CSUM_SIZE 32
+/* four bytes for CRC32 */
+#define BTRFS_CRC32_SIZE 4
/*
* the key defines the order in the tree, and so it also defines (optimal)
@@ -235,7 +237,7 @@
} __attribute__ ((__packed__));
struct btrfs_csum_item {
- u8 csum[BTRFS_CSUM_SIZE];
+ u8 csum;
} __attribute__ ((__packed__));
struct btrfs_device_item {
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 2dbf422..678456d 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -196,14 +196,14 @@
ret = crypto_hash_digest(&desc, &sg, 1, result);
spin_unlock(&root->fs_info->hash_lock);
if (ret) {
- printk("sha256 digest failed\n");
+ printk("digest failed\n");
}
return ret;
}
static int csum_tree_block(struct btrfs_root *root, struct buffer_head *bh,
int verify)
{
- char result[BTRFS_CSUM_SIZE];
+ char result[BTRFS_CRC32_SIZE];
int ret;
struct btrfs_node *node;
@@ -212,14 +212,14 @@
if (ret)
return ret;
if (verify) {
- if (memcmp(bh->b_data, result, BTRFS_CSUM_SIZE)) {
+ if (memcmp(bh->b_data, result, BTRFS_CRC32_SIZE)) {
printk("checksum verify failed on %Lu\n",
bh_blocknr(bh));
return 1;
}
} else {
node = btrfs_buffer_node(bh);
- memcpy(node->header.csum, result, BTRFS_CSUM_SIZE);
+ memcpy(node->header.csum, result, BTRFS_CRC32_SIZE);
}
return 0;
}
@@ -576,10 +576,10 @@
sizeof(struct btrfs_key));
insert_inode_hash(fs_info->btree_inode);
mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
- fs_info->hash_tfm = crypto_alloc_hash("sha256", 0, CRYPTO_ALG_ASYNC);
+ fs_info->hash_tfm = crypto_alloc_hash("crc32c", 0, CRYPTO_ALG_ASYNC);
spin_lock_init(&fs_info->hash_lock);
if (!fs_info->hash_tfm || IS_ERR(fs_info->hash_tfm)) {
- printk("failed to allocate sha256 hash\n");
+ printk("failed to allocate digest hash\n");
return NULL;
}
mutex_init(&fs_info->trans_mutex);
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 10e4cf0..a66709e 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -4,8 +4,8 @@
#include "transaction.h"
#define MAX_CSUM_ITEMS(r) ((((BTRFS_LEAF_DATA_SIZE(r) - \
- sizeof(struct btrfs_item) * 2) / \
- sizeof(struct btrfs_csum_item)) - 1))
+ 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,
@@ -78,7 +78,7 @@
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 /= sizeof(struct btrfs_csum_item);
+ csums_in_item /= BTRFS_CRC32_SIZE;
if (csum_offset >= csums_in_item) {
ret = -EFBIG;
@@ -86,7 +86,8 @@
}
}
item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
- item += csum_offset;
+ item = (struct btrfs_csum_item *)((unsigned char *)item +
+ csum_offset * BTRFS_CRC32_SIZE);
return item;
fail:
if (ret > 0)
@@ -143,8 +144,7 @@
/* 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 / sizeof(struct btrfs_csum_item)) >=
- MAX_CSUM_ITEMS(root)) {
+ if ((item_size / BTRFS_CRC32_SIZE) >= MAX_CSUM_ITEMS(root)) {
/* already at max size, make a new one */
goto insert;
}
@@ -159,7 +159,7 @@
*/
btrfs_release_path(root, path);
ret = btrfs_search_slot(trans, root, &file_key, path,
- sizeof(struct btrfs_csum_item), 1);
+ BTRFS_CRC32_SIZE, 1);
if (ret < 0)
goto fail;
if (ret == 0) {
@@ -180,10 +180,10 @@
goto insert;
}
if (csum_offset >= btrfs_item_size(leaf->items + path->slots[0]) /
- sizeof(struct btrfs_csum_item)) {
- u32 diff = (csum_offset + 1) * sizeof(struct btrfs_csum_item);
+ BTRFS_CRC32_SIZE) {
+ u32 diff = (csum_offset + 1) * BTRFS_CRC32_SIZE;
diff = diff - btrfs_item_size(leaf->items + path->slots[0]);
- WARN_ON(diff != sizeof(struct btrfs_csum_item));
+ WARN_ON(diff != BTRFS_CRC32_SIZE);
ret = btrfs_extend_item(trans, root, path, diff);
BUG_ON(ret);
goto csum;
@@ -193,7 +193,7 @@
btrfs_release_path(root, path);
csum_offset = 0;
ret = btrfs_insert_empty_item(trans, root, path, &file_key,
- sizeof(struct btrfs_csum_item));
+ BTRFS_CRC32_SIZE);
if (ret != 0) {
printk("at insert for %Lu %u %Lu ret is %d\n", file_key.objectid, file_key.flags, file_key.offset, ret);
WARN_ON(1);
@@ -203,10 +203,13 @@
item = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]), path->slots[0],
struct btrfs_csum_item);
ret = 0;
- item += csum_offset;
+ item = (struct btrfs_csum_item *)((unsigned char *)item +
+ csum_offset * BTRFS_CRC32_SIZE);
found:
- btrfs_check_bounds(item->csum, BTRFS_CSUM_SIZE, path->nodes[0]->b_data, root->fs_info->sb->s_blocksize);
- ret = btrfs_csum_data(root, data, len, item->csum);
+ 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);
@@ -222,7 +225,7 @@
struct btrfs_key file_key;
struct btrfs_path *path;
struct btrfs_csum_item *item;
- char result[BTRFS_CSUM_SIZE];
+ char result[BTRFS_CRC32_SIZE];
path = btrfs_alloc_path();
BUG_ON(!path);
@@ -244,7 +247,7 @@
ret = btrfs_csum_data(root, data, len, result);
WARN_ON(ret);
- if (memcmp(result, item->csum, BTRFS_CSUM_SIZE))
+ if (memcmp(result, &item->csum, BTRFS_CRC32_SIZE))
ret = 1;
fail:
btrfs_release_path(root, path);