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| author | Al Viro <viro@zeniv.linux.org.uk> | 2022-06-21 22:55:19 +0300 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2022-07-07 00:11:11 +0300 |
| commit | dda8e5d17c170415a3c10f68365f3a2800a6e68f (patch) | |
| tree | 8319d24eb4ee46c1c0148b706efdbebd0fbb3d3a /lib | |
| parent | 599a0bdd72f0a7ed5f55faef0ecdcd36cb1bc287 (diff) | |
| download | linux-dda8e5d17c170415a3c10f68365f3a2800a6e68f.tar.xz | |
iov_iter: first_{iovec,bvec}_segment() - simplify a bit
We return length + offset in page via *size. Don't bother - the caller
can do that arithmetics just as well; just report the length to it.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/iov_iter.c | 32 |
1 files changed, 16 insertions, 16 deletions
diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 1b5e96ddddf3..45dccecae946 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -1308,7 +1308,7 @@ static unsigned long first_iovec_segment(const struct iov_iter *i, continue; if (len > maxsize) len = maxsize; - len += (*start = addr % PAGE_SIZE); + *start = addr % PAGE_SIZE; *size = len; return addr & PAGE_MASK; } @@ -1328,7 +1328,7 @@ static struct page *first_bvec_segment(const struct iov_iter *i, len = maxsize; skip += i->bvec->bv_offset; page = i->bvec->bv_page + skip / PAGE_SIZE; - len += (*start = skip % PAGE_SIZE); + *start = skip % PAGE_SIZE; *size = len; return page; } @@ -1357,24 +1357,24 @@ ssize_t iov_iter_get_pages(struct iov_iter *i, gup_flags |= FOLL_NOFAULT; addr = first_iovec_segment(i, &len, start, maxsize); - if (len > maxpages * PAGE_SIZE) - len = maxpages * PAGE_SIZE; - n = DIV_ROUND_UP(len, PAGE_SIZE); + n = DIV_ROUND_UP(len + *start, PAGE_SIZE); + if (n > maxpages) + n = maxpages; res = get_user_pages_fast(addr, n, gup_flags, pages); if (unlikely(res <= 0)) return res; - return (res == n ? len : res * PAGE_SIZE) - *start; + return min_t(size_t, len, res * PAGE_SIZE - *start); } if (iov_iter_is_bvec(i)) { struct page *page; page = first_bvec_segment(i, &len, start, maxsize); - if (len > maxpages * PAGE_SIZE) - len = maxpages * PAGE_SIZE; - n = DIV_ROUND_UP(len, PAGE_SIZE); - while (n--) + n = DIV_ROUND_UP(len + *start, PAGE_SIZE); + if (n > maxpages) + n = maxpages; + for (int k = 0; k < n; k++) get_page(*pages++ = page++); - return len - *start; + return min_t(size_t, len, n * PAGE_SIZE - *start); } if (iov_iter_is_pipe(i)) return pipe_get_pages(i, pages, maxsize, maxpages, start); @@ -1489,7 +1489,7 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, gup_flags |= FOLL_NOFAULT; addr = first_iovec_segment(i, &len, start, maxsize); - n = DIV_ROUND_UP(len, PAGE_SIZE); + n = DIV_ROUND_UP(len + *start, PAGE_SIZE); p = get_pages_array(n); if (!p) return -ENOMEM; @@ -1500,19 +1500,19 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, return res; } *pages = p; - return (res == n ? len : res * PAGE_SIZE) - *start; + return min_t(size_t, len, res * PAGE_SIZE - *start); } if (iov_iter_is_bvec(i)) { struct page *page; page = first_bvec_segment(i, &len, start, maxsize); - n = DIV_ROUND_UP(len, PAGE_SIZE); + n = DIV_ROUND_UP(len + *start, PAGE_SIZE); *pages = p = get_pages_array(n); if (!p) return -ENOMEM; - while (n--) + for (int k = 0; k < n; k++) get_page(*p++ = page++); - return len - *start; + return min_t(size_t, len, n * PAGE_SIZE - *start); } if (iov_iter_is_pipe(i)) return pipe_get_pages_alloc(i, pages, maxsize, start); |