bcachefs: convert __bch2_encrypt_bio() to darray

like the previous patch, kill use of bare arrays; the encryption code
likes to work in big batches, so this is a small performance
improvement.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

diff --git a/fs/bcachefs/checksum.c b/fs/bcachefs/checksum.c
index 6e6cc1d04b1c6ccee4720560f61ff3cf59a16961..398177eb9c66e42cb43914542b5a82d3db5289da 100644 (file)
--- a/fs/bcachefs/checksum.c
+++ b/fs/bcachefs/checksum.c
@@ -337,39 +337,42 @@ int __bch2_encrypt_bio(struct bch_fs *c, unsigned type,
 {
        struct bio_vec bv;
        struct bvec_iter iter;
-       struct scatterlist sgl[16], *sg = sgl;
-       size_t bytes = 0;
+       DARRAY_PREALLOCATED(struct scatterlist, 4) sgl;
+       size_t sgl_len = 0;
        int ret = 0;
 
        if (!bch2_csum_type_is_encryption(type))
                return 0;
 
-       sg_init_table(sgl, ARRAY_SIZE(sgl));
+       darray_init(&sgl);
 
        bio_for_each_segment(bv, bio, iter) {
-               if (sg == sgl + ARRAY_SIZE(sgl)) {
-                       sg_mark_end(sg - 1);
-
-                       ret = do_encrypt_sg(c->chacha20, nonce, sgl, bytes);
+               struct scatterlist sg = {
+                       .page_link      = (unsigned long) bv.bv_page,
+                       .offset         = bv.bv_offset,
+                       .length         = bv.bv_len,
+               };
+
+               if (darray_push(&sgl, sg)) {
+                       sg_mark_end(&darray_last(sgl));
+                       ret = do_encrypt_sg(c->chacha20, nonce, sgl.data, sgl_len);
                        if (ret)
-                               return ret;
+                               goto err;
 
-                       nonce = nonce_add(nonce, bytes);
-                       bytes = 0;
+                       nonce = nonce_add(nonce, sgl_len);
+                       sgl_len = 0;
+                       sgl.nr = 0;
 
-                       sg_init_table(sgl, ARRAY_SIZE(sgl));
-                       sg = sgl;
+                       BUG_ON(darray_push(&sgl, sg));
                }
 
-               sg_set_page(sg++, bv.bv_page, bv.bv_len, bv.bv_offset);
-               bytes += bv.bv_len;
-       }
-
-       if (sg != sgl) {
-               sg_mark_end(sg - 1);
-               return do_encrypt_sg(c->chacha20, nonce, sgl, bytes);
+               sgl_len += sg.length;
        }
 
+       sg_mark_end(&darray_last(sgl));
+       ret = do_encrypt_sg(c->chacha20, nonce, sgl.data, sgl_len);
+err:
+       darray_exit(&sgl);
        return ret;
 }