btrfs: resurrect btrfs_crc32c()

Commit 9678c54388b6 ("btrfs: Remove custom crc32c init code") removed
the btrfs_crc32c() function, because it was a duplicate of the crc32c()
library function we already have in the kernel.

Resurrect it as a shim wrapper over crc32c() to make following
transformations of the checksumming code in btrfs easier.

Also provide a btrfs_crc32_final() to ease following transformations.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 1baa8cc39571..3691cd177ead 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -19,6 +19,7 @@
 #include <linux/kobject.h>
 #include <trace/events/btrfs.h>
 #include <asm/kmap_types.h>
+#include <asm/unaligned.h>
 #include <linux/pagemap.h>
 #include <linux/btrfs.h>
 #include <linux/btrfs_tree.h>
@@ -2644,6 +2645,16 @@ BTRFS_SETGET_STACK_FUNCS(stack_dev_replace_cursor_right,
 	((unsigned long)(BTRFS_LEAF_DATA_OFFSET + \
 	btrfs_item_offset_nr(leaf, slot)))
 
+static inline u32 btrfs_crc32c(u32 crc, const void *address, unsigned length)
+{
+	return crc32c(crc, address, length);
+}
+
+static inline void btrfs_crc32c_final(u32 crc, u8 *result)
+{
+	put_unaligned_le32(~crc, result);
+}
+
 static inline u64 btrfs_name_hash(const char *name, int len)
 {
        return crc32c((u32)~1, name, len);