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btrfs: scrub: simplify superblock checksum calculation

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BTRFS_SUPER_INFO_SIZE is 4096, and fits to a page on all supported
architectures, so we can calculate the checksum in one go.

Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
David Sterba 2020-05-29 15:40:36 +02:00
parent b04852520e
commit 83cf6d5eae
1 changed files with 4 additions and 27 deletions
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31
fs/btrfs/scrub.c
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@ -1907,15 +1907,8 @@ static int scrub_checksum_super(struct scrub_block *sblock)
u8 on_disk_csum[BTRFS_CSUM_SIZE];
struct page *page;
char *kaddr;
u64 mapped_size;
void *p;
int fail_gen = 0;
int fail_cor = 0;
u64 len;
int index;
shash->tfm = fs_info->csum_shash;
crypto_shash_init(shash);
BUG_ON(sblock->page_count < 1);
page = sblock->pagev[0]->page;
@ -1932,27 +1925,11 @@ static int scrub_checksum_super(struct scrub_block *sblock)
if (!scrub_check_fsid(s->fsid, sblock->pagev[0]))
++fail_cor;
len = BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE;
mapped_size = PAGE_SIZE - BTRFS_CSUM_SIZE;
p = kaddr + BTRFS_CSUM_SIZE;
index = 0;
for (;;) {
u64 l = min_t(u64, len, mapped_size);
shash->tfm = fs_info->csum_shash;
crypto_shash_init(shash);
crypto_shash_digest(shash, kaddr + BTRFS_CSUM_SIZE,
BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE, calculated_csum);
crypto_shash_update(shash, p, l);
len -= l;
if (len == 0)
break;
index++;
BUG_ON(index >= sblock->page_count);
BUG_ON(!sblock->pagev[index]->page);
page = sblock->pagev[index]->page;
kaddr = page_address(page);
mapped_size = PAGE_SIZE;
p = kaddr;
}
crypto_shash_final(shash, calculated_csum);
if (memcmp(calculated_csum, on_disk_csum, sctx->csum_size))
++fail_cor;