for (i = 0; i < cb->nr_pages; i++) {
                page = cb->compressed_pages[i];
 
-               crypto_shash_init(shash);
                kaddr = kmap_atomic(page);
-               crypto_shash_update(shash, kaddr, PAGE_SIZE);
+               crypto_shash_digest(shash, kaddr, PAGE_SIZE, csum);
                kunmap_atomic(kaddr);
-               crypto_shash_final(shash, (u8 *)&csum);
 
                if (memcmp(&csum, cb_sum, csum_size)) {
                        btrfs_print_data_csum_error(inode, disk_start,
 
        SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
 
        shash->tfm = fs_info->csum_shash;
-       crypto_shash_init(shash);
 
        /*
         * 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.
         */
-       crypto_shash_update(shash, raw_disk_sb + BTRFS_CSUM_SIZE,
-                           BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
-       crypto_shash_final(shash, result);
+       crypto_shash_digest(shash, raw_disk_sb + BTRFS_CSUM_SIZE,
+                           BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE, result);
 
        if (memcmp(disk_sb->csum, result, btrfs_super_csum_size(disk_sb)))
                return 1;
 
                btrfs_set_super_bytenr(sb, bytenr);
 
-               crypto_shash_init(shash);
-               crypto_shash_update(shash, (const char *)sb + BTRFS_CSUM_SIZE,
-                                   BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE);
-               crypto_shash_final(shash, sb->csum);
+               crypto_shash_digest(shash, (const char *)sb + BTRFS_CSUM_SIZE,
+                                   BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE,
+                                   sb->csum);
 
                page = find_or_create_page(mapping, bytenr >> PAGE_SHIFT,
                                           GFP_NOFS);
 
                                index = 0;
                        }
 
-                       crypto_shash_init(shash);
                        data = kmap_atomic(bvec.bv_page);
-                       crypto_shash_update(shash, data + bvec.bv_offset
+                       crypto_shash_digest(shash, data + bvec.bv_offset
                                            + (i * fs_info->sectorsize),
-                                           fs_info->sectorsize);
+                                           fs_info->sectorsize,
+                                           sums->sums + index);
                        kunmap_atomic(data);
-                       crypto_shash_final(shash, (char *)(sums->sums + index));
                        index += csum_size;
                        offset += fs_info->sectorsize;
                        this_sum_bytes += fs_info->sectorsize;
 
        kaddr = kmap_atomic(page);
        shash->tfm = fs_info->csum_shash;
 
-       crypto_shash_init(shash);
-       crypto_shash_update(shash, kaddr + pgoff, len);
-       crypto_shash_final(shash, csum);
+       crypto_shash_digest(shash, kaddr + pgoff, len, csum);
 
        if (memcmp(csum, csum_expected, csum_size))
                goto zeroit;