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btrfs: Simplify btrfs_check_super_csum() and get rid of size assumptions

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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.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Johannes Thumshirn
2019-06-03 16:58:55 +02:00
committed by David Sterba
parent 8dc3f22c8b
commit 51bce6c9b9
1 changed files with 16 additions and 26 deletions
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42
fs/btrfs/disk-io.c
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@@ -371,30 +371,20 @@ static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
{ {
struct btrfs_super_block *disk_sb = struct btrfs_super_block *disk_sb =
(struct btrfs_super_block *)raw_disk_sb; (struct btrfs_super_block *)raw_disk_sb;
u16 csum_type = btrfs_super_csum_type(disk_sb); u32 crc = ~(u32)0;
char result[BTRFS_CSUM_SIZE];
if (!btrfs_supported_super_csum(csum_type)) { /*
btrfs_err(fs_info, "unsupported checksum algorithm %u", * The super_block structure does not span the whole
csum_type); * 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(disk_sb->csum, result, btrfs_super_csum_size(disk_sb)))
return 1; return 1;
}
if (csum_type == BTRFS_CSUM_TYPE_CRC32) {
u32 crc = ~(u32)0;
char result[sizeof(crc)];
/*
* 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;
}
return 0; return 0;
} }
@@ -2611,6 +2601,7 @@ int open_ctree(struct super_block *sb,
u32 stripesize; u32 stripesize;
u64 generation; u64 generation;
u64 features; u64 features;
u16 csum_type;
struct btrfs_key location; struct btrfs_key location;
struct buffer_head *bh; struct buffer_head *bh;
struct btrfs_super_block *disk_super; struct btrfs_super_block *disk_super;
@@ -2820,11 +2811,10 @@ int open_ctree(struct super_block *sb,
* Verify the type first, if that or the the checksum value are * Verify the type first, if that or the the checksum value are
* corrupted, we'll find out * corrupted, we'll find out
*/ */
if (!btrfs_supported_super_csum(btrfs_super_csum_type( csum_type = btrfs_super_csum_type((struct btrfs_super_block *)bh->b_data);
(struct btrfs_super_block *) bh->b_data))) { if (!btrfs_supported_super_csum(csum_type)) {
btrfs_err(fs_info, "unsupported checksum algorithm: %u", btrfs_err(fs_info, "unsupported checksum algorithm: %u",
btrfs_super_csum_type((struct btrfs_super_block *) csum_type);
bh->b_data));
err = -EINVAL; err = -EINVAL;
brelse(bh); brelse(bh);
goto fail_alloc; goto fail_alloc;