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| author | Al Viro <viro@zeniv.linux.org.uk> | 2021-04-25 23:57:42 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2021-06-10 11:45:16 -0400 |
| commit | 5c67aa90cd5c59912ee71cff879e8f1ab237ad88 (patch) | |
| tree | 35bd0d1b879a3ee9113372a5397143ab82209a25 /lib | |
| parent | 7a1bcb5d255d4fd8b9725c3cf7ee0880a6369d2f (diff) | |
| download | linux-5c67aa90cd5c59912ee71cff879e8f1ab237ad88.tar.gz linux-5c67aa90cd5c59912ee71cff879e8f1ab237ad88.tar.bz2 linux-5c67aa90cd5c59912ee71cff879e8f1ab237ad88.zip | |
iov_iter: unify iterate_iovec and iterate_kvec
The differences between iterate_iovec and iterate_kvec are minor:
* kvec callback is treated as if it returned 0
* initialization of __p is with i->iov and i->kvec resp.
which is trivially dealt with.
No code generation changes - compiler is quite capable of turning
left = ((void)(STEP), 0);
__v.iov_len -= left;
(with no accesses to left downstream) and
(void)(STEP);
into the same code.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/iov_iter.c | 28 |
1 files changed, 5 insertions, 23 deletions
diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 2098059da64c..fc071d7b4528 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -16,10 +16,10 @@ #define PIPE_PARANOIA /* for now */ +/* covers iovec and kvec alike */ #define iterate_iovec(i, n, __v, __p, skip, STEP) { \ size_t left; \ size_t wanted = n; \ - __p = i->iov; \ do { \ __v.iov_len = min(n, __p->iov_len - skip); \ if (likely(__v.iov_len)) { \ @@ -37,25 +37,6 @@ n = wanted - n; \ } -#define iterate_kvec(i, n, __v, __p, skip, STEP) { \ - size_t wanted = n; \ - __p = i->kvec; \ - do { \ - __v.iov_len = min(n, __p->iov_len - skip); \ - if (likely(__v.iov_len)) { \ - __v.iov_base = __p->iov_base + skip; \ - (void)(STEP); \ - skip += __v.iov_len; \ - n -= __v.iov_len; \ - if (skip < __p->iov_len) \ - break; \ - } \ - __p++; \ - skip = 0; \ - } while (n); \ - n = wanted - n; \ -} - #define iterate_bvec(i, n, __v, __bi, skip, STEP) { \ struct bvec_iter __start; \ __start.bi_size = n; \ @@ -109,7 +90,7 @@ if (likely(n)) { \ size_t skip = i->iov_offset; \ if (likely(iter_is_iovec(i))) { \ - const struct iovec *iov; \ + const struct iovec *iov = i->iov; \ struct iovec v; \ iterate_iovec(i, n, v, iov, skip, (I)) \ i->nr_segs -= iov - i->iov; \ @@ -123,9 +104,10 @@ i->nr_segs -= i->bvec - bvec; \ skip = __bi.bi_bvec_done; \ } else if (iov_iter_is_kvec(i)) { \ - const struct kvec *kvec; \ + const struct kvec *kvec = i->kvec; \ struct kvec v; \ - iterate_kvec(i, n, v, kvec, skip, (K)) \ + iterate_iovec(i, n, v, kvec, skip, \ + ((void)(K),0)) \ i->nr_segs -= kvec - i->kvec; \ i->kvec = kvec; \ } else if (iov_iter_is_xarray(i)) { \ |