Now that we everything in place, we can add SHA-256 as another checksum
algorithm.
SHA-256 was taken as it was the cryptographically strongest algorithm that
can fit into the 32 Bytes we have left.
Signed-off-by: Johannes Thumshirn <jthumshirn@xxxxxxx>
---
fs/btrfs/btrfs_inode.h | 3 +++
fs/btrfs/ctree.h | 4 ++--
fs/btrfs/disk-io.c | 2 ++
include/uapi/linux/btrfs_tree.h | 1 +
4 files changed, 8 insertions(+), 2 deletions(-)
diff --git a/fs/btrfs/btrfs_inode.h b/fs/btrfs/btrfs_inode.h
index e79fd9129075..fccc372ef719 100644
--- a/fs/btrfs/btrfs_inode.h
+++ b/fs/btrfs/btrfs_inode.h
@@ -346,6 +346,9 @@ static inline void btrfs_csum_format(struct btrfs_super_block *sb,
case BTRFS_CSUM_TYPE_CRC32:
snprintf(cbuf, size, "0x%08x", *(u32 *)csum);
break;
+ case BTRFS_CSUM_TYPE_SHA256:
+ memcpy(cbuf, csum, size);
+ break;
default: /* can't happen - csum type is validated at mount time */
break;
}
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 8733c55ed686..d60138208dd4 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -72,8 +72,8 @@ struct btrfs_ref;
#define BTRFS_LINK_MAX 65535U
/* four bytes for CRC32 */
-static const int btrfs_csum_sizes[] = { 4 };
-static char *btrfs_csum_names[] = { "crc32c" };
+static const int btrfs_csum_sizes[] = { 4, 32 };
+static char *btrfs_csum_names[] = { "crc32c", "sha256" };
#define BTRFS_EMPTY_DIR_SIZE 0
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 2be8f05be1e6..bdcffa0d6b13 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -390,6 +390,8 @@ static bool btrfs_supported_super_csum(struct btrfs_super_block *sb)
switch (btrfs_super_csum_type(sb)) {
case BTRFS_CSUM_TYPE_CRC32:
return true;
+ case BTRFS_CSUM_TYPE_SHA256:
+ return true;
default:
return false;
}
diff --git a/include/uapi/linux/btrfs_tree.h b/include/uapi/linux/btrfs_tree.h
index 421239b98db2..3667ab4bc215 100644
--- a/include/uapi/linux/btrfs_tree.h
+++ b/include/uapi/linux/btrfs_tree.h
@@ -301,6 +301,7 @@
/* csum types */
#define BTRFS_CSUM_TYPE_CRC32 0
+#define BTRFS_CSUM_TYPE_SHA256 1
/*
* flags definitions for directory entry item type
--
2.16.4
