1 files changed, 7 insertions, 9 deletions

diff --git a/fs/btrfs/hash.c b/fs/btrfs/hash.c
index 64f15bb30a81..aae520b2aee5 100644
--- a/fs/btrfs/hash.c
+++ b/fs/btrfs/hash.c
@@ -31,18 +31,16 @@ void btrfs_hash_exit(void)
 
 u32 btrfs_crc32c(u32 crc, const void *address, unsigned int length)
 {
-        struct {
-                struct shash_desc shash;
-                char ctx[crypto_shash_descsize(tfm)];
-        } desc;
+        SHASH_DESC_ON_STACK(shash, tfm);
+        u32 *ctx = (u32 *)shash_desc_ctx(shash);
         int err;
 
-        desc.shash.tfm = tfm;
-        desc.shash.flags = 0;
-        *(u32 *)desc.ctx = crc;
+        shash->tfm = tfm;
+        shash->flags = 0;
+        *ctx = crc;
 
-        err = crypto_shash_update(&desc.shash, address, length);
+        err = crypto_shash_update(shash, address, length);
         BUG_ON(err);
 
-        return *(u32 *)desc.ctx;
+        return *ctx;
 }