Now that we have already checked for a valid checksum type before calling
btrfs_check_super_csum(), it can be simplified even further.
While at it get rid of the implicit size assumption of the resulting
checksum as well.
This is a preparation for changing all checksum functionality to use the
crypto layer later.
Signed-off-by: Johannes Thumshirn <jthumsh...@suse.de>
Reviewed-by: Nikolay Borisov <nbori...@suse.com>
---
Changes to v1:
- Check for disk_sb->csum instead of raw buffer (Nikolay)
---
fs/btrfs/disk-io.c | 43 +++++++++++++++++--------------------------
1 file changed, 17 insertions(+), 26 deletions(-)
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index b11091612074..a2b29b875ea4 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -375,30 +375,20 @@ static int btrfs_check_super_csum(struct btrfs_fs_info
*fs_info,
{
struct btrfs_super_block *disk_sb =
(struct btrfs_super_block *)raw_disk_sb;
- u16 csum_type = btrfs_super_csum_type(disk_sb);
-
- if (!btrfs_supported_super_csum(csum_type)) {
- btrfs_err(fs_info, "unsupported checksum algorithm %u",
- csum_type);
- return 1;
- }
-
- if (csum_type == BTRFS_CSUM_TYPE_CRC32) {
- u32 crc = ~(u32)0;
- char result[sizeof(crc)];
+ u32 crc = ~(u32)0;
+ char result[BTRFS_CSUM_SIZE];
- /*
- * The super_block structure does not span the whole
- * BTRFS_SUPER_INFO_SIZE range, we expect that the unused space
- * is filled with zeros and is included in the checksum.
- */
- crc = btrfs_csum_data(raw_disk_sb + BTRFS_CSUM_SIZE,
- crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
- btrfs_csum_final(crc, result);
+ /*
+ * The super_block structure does not span the whole
+ * BTRFS_SUPER_INFO_SIZE range, we expect that the unused space
+ * is filled with zeros and is included in the checksum.
+ */
+ crc = btrfs_csum_data(raw_disk_sb + BTRFS_CSUM_SIZE,
+ crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
+ btrfs_csum_final(crc, result);
- if (memcmp(raw_disk_sb, result, sizeof(result)))
- return 1;
- }
+ if (memcmp(disk_sb->csum, result, btrfs_super_csum_size(disk_sb)))
+ return 1;
return 0;
}
@@ -2616,6 +2606,7 @@ int open_ctree(struct super_block *sb,
u32 stripesize;
u64 generation;
u64 features;
+ u16 csum_type;
struct btrfs_key location;
struct buffer_head *bh;
struct btrfs_super_block *disk_super;
@@ -2821,11 +2812,11 @@ int open_ctree(struct super_block *sb,
goto fail_alloc;
}
- if (!btrfs_supported_super_csum(btrfs_super_csum_type(
- (struct btrfs_super_block *) bh->b_data))) {
+ csum_type = btrfs_super_csum_type((struct btrfs_super_block *)
+ bh->b_data);
+ if (!btrfs_supported_super_csum(csum_type)) {
btrfs_err(fs_info, "unsupported checksum algorithm: %u",
- btrfs_super_csum_type((struct btrfs_super_block *)
- bh->b_data));
+ csum_type);
err = -EINVAL;
brelse(bh);
goto fail_alloc;
--
2.16.4
