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btrfs: scrub: simplify tree block checksum calculation 

Use a simpler iteration over tree block pages, same what csum_tree_block
does: first page always exists, loop over the rest.

Signed-off-by: David Sterba <dsterba@suse.com>
zero-sugar-mainline-defconfig
David Sterba 2020-05-29 15:54:41 +02:00
parent d41ebef200
commit 521e102227
1 changed files with 9 additions and 24 deletions
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33
fs/btrfs/scrub.c
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@ -1814,15 +1814,10 @@ static int scrub_checksum_tree_block(struct scrub_block *sblock)
SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
u8 calculated_csum[BTRFS_CSUM_SIZE];
u8 on_disk_csum[BTRFS_CSUM_SIZE];
const int num_pages = sctx->fs_info->nodesize >> PAGE_SHIFT;
int i;
struct page *page;
char *kaddr;
u64 mapped_size;
void *p;
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;
@ -1850,24 +1845,14 @@ static int scrub_checksum_tree_block(struct scrub_block *sblock)
BTRFS_UUID_SIZE))
sblock->header_error = 1;
len = sctx->fs_info->nodesize - 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_update(shash, kaddr + BTRFS_CSUM_SIZE,
PAGE_SIZE - BTRFS_CSUM_SIZE);
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;
for (i = 1; i < num_pages; i++) {
kaddr = page_address(sblock->pagev[i]->page);
crypto_shash_update(shash, kaddr, PAGE_SIZE);
}
crypto_shash_final(shash, calculated_csum);