... incidentally, using pointer instead of index in an array
(the only change here) trims half-kilobyte of .text...
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
lib/iov_iter.c | 33 ++++++++++++++++++++-------------
1 file changed, 20 insertions(+), 13 deletions(-)
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 19c103e9ef7d..af9525c21c77 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -37,14 +37,23 @@
n = wanted - n; \
}
-#define iterate_bvec(i, n, __v, __bi, skip, STEP) { \
- struct bvec_iter __start; \
- __start.bi_size = n; \
- __start.bi_bvec_done = skip; \
- __start.bi_idx = 0; \
- for_each_bvec(__v, i->bvec, __bi, __start) { \
- (void)(STEP); \
- } \
+#define iterate_bvec(i, n, __v, p, skip, STEP) { \
+ size_t wanted = n; \
+ while (n) { \
+ unsigned offset = p->bv_offset + skip; \
+ __v.bv_offset = offset % PAGE_SIZE; \
+ __v.bv_page = p->bv_page + offset / PAGE_SIZE; \
+ __v.bv_len = min(min(n, p->bv_len - skip), \
+ (size_t)(PAGE_SIZE - offset % PAGE_SIZE)); \
+ (void)(STEP); \
+ skip += __v.bv_len; \
+ if (skip == p->bv_len) { \
+ skip = 0; \
+ p++; \
+ } \
+ n -= __v.bv_len; \
+ } \
+ n = wanted - n; \
}
#define iterate_xarray(i, n, __v, skip, STEP) { \
@@ -98,11 +107,9 @@
} else if (iov_iter_is_bvec(i)) { \
const struct bio_vec *bvec = i->bvec; \
struct bio_vec v; \
- struct bvec_iter __bi; \
- iterate_bvec(i, n, v, __bi, skip, (B)) \
- i->bvec = __bvec_iter_bvec(i->bvec, __bi); \
- i->nr_segs -= i->bvec - bvec; \
- skip = __bi.bi_bvec_done; \
+ iterate_bvec(i, n, v, bvec, skip, (B)) \
+ i->nr_segs -= bvec - i->bvec; \
+ i->bvec = bvec; \
} else if (iov_iter_is_kvec(i)) { \
const struct kvec *kvec = i->kvec; \
struct kvec v; \
--
2.11.0
