openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

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>
This commit is contained in:
Al Viro 2021-04-26 20:19:14 -04:00
parent 5c67aa90cd
commit 7491a2bf64
1 changed files with 20 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

33
lib/iov_iter.c
View File

@ -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; \