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| author | Al Viro <viro@zeniv.linux.org.uk> | 2021-04-26 20:19:14 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2021-06-10 11:45:17 -0400 |
| commit | 7491a2bf64e3a4f1699deba97728cd9f8856bdf3 (patch) | |
| tree | 8c90a59ad52e394f46539e1b5ddea7e9d90c7330 /lib/iov_iter.c | |
| parent | 5c67aa90cd5c59912ee71cff879e8f1ab237ad88 (diff) | |
iterate_bvec(): expand bvec.h macro forest, massage a bit
... incidentally, using pointer instead of index in an array
(the only change here) trims half-kilobyte of .text...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'lib/iov_iter.c')
| -rw-r--r-- | lib/iov_iter.c | 33 |
1 files changed, 20 insertions, 13 deletions
diff --git a/lib/iov_iter.c b/lib/iov_iter.c index fc071d7b4528..58d53deb62b8 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; \ |