From b4e967be431cf37f56cd1993592943007d7ab03b Mon Sep 17 00:00:00 2001
From: David Sterba <dsterba@suse.com>
Date: Tue, 8 Oct 2019 18:41:33 +0200
Subject: btrfs: add member for a specific checksum driver
Currently all the checksum algorithms generate a fixed size digest size
and we use it. The on-disk format can hold up to BTRFS_CSUM_SIZE bytes
and BLAKE2b produces digest of 512 bits by default. We can't do that and
will use the blake2b-256, this needs to be passed to the crypto API.
Separate that from the base algorithm name and add a member to request
specific driver, in this case with the digest size.
The only place that uses the driver name is the crypto API setup.
Signed-off-by: David Sterba <dsterba@suse.com>
---
fs/btrfs/ctree.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
(limited to 'fs/btrfs/ctree.c')
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index c1561097e5a3..c211216b4524 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -32,6 +32,7 @@ static void del_ptr(struct btrfs_root *root, struct btrfs_path *path,
static const struct btrfs_csums {
u16 size;
const char *name;
+ const char *driver;
} btrfs_csums[] = {
[BTRFS_CSUM_TYPE_CRC32] = { .size = 4, .name = "crc32c" },
[BTRFS_CSUM_TYPE_XXHASH] = { .size = 8, .name = "xxhash64" },
@@ -53,6 +54,17 @@ const char *btrfs_super_csum_name(u16 csum_type)
return btrfs_csums[csum_type].name;
}
+/*
+ * Return driver name if defined, otherwise the name that's also a valid driver
+ * name
+ */
+const char *btrfs_super_csum_driver(u16 csum_type)
+{
+ /* csum type is validated at mount time */
+ return btrfs_csums[csum_type].driver ?:
+ btrfs_csums[csum_type].name;
+}
+
size_t __const btrfs_get_num_csums(void)
{
return ARRAY_SIZE(btrfs_csums);
--
cgit