| Message ID | 20220622041552.737754-31-viro@zeniv.linux.org.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [01/44] 9p: handling Rerror without copy_from_iter_full() | expand |
On Wed, 2022-06-22 at 05:15 +0100, Al Viro wrote: > 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> > --- > lib/iov_iter.c | 22 +++++++++++----------- > 1 file changed, 11 insertions(+), 11 deletions(-) > > diff --git a/lib/iov_iter.c b/lib/iov_iter.c > index 9ef671b101dc..0bed684d91d0 100644 > --- a/lib/iov_iter.c > +++ b/lib/iov_iter.c > @@ -1310,7 +1310,7 @@ static unsigned long found_ubuf_segment(unsigned long addr, > size_t len, > size_t *size, size_t *start) > { > - len += (*start = addr % PAGE_SIZE); > + *start = addr % PAGE_SIZE; > *size = len; > return addr & PAGE_MASK; > } > @@ -1354,7 +1354,7 @@ 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; > } > @@ -1383,9 +1383,9 @@ static ssize_t __iov_iter_get_pages_alloc(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; > if (!*pages) { > *pages = get_pages_array(n); > if (!*pages) > @@ -1394,25 +1394,25 @@ static ssize_t __iov_iter_get_pages_alloc(struct iov_iter *i, > 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 **p; > 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); > + n = DIV_ROUND_UP(len + *start, PAGE_SIZE); > + if (n > maxpages) > + n = maxpages; > p = *pages; > if (!p) { > *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(i, pages, maxsize, maxpages, start); Reviewed-by: Jeff Layton <jlayton@kernel.org>
diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 9ef671b101dc..0bed684d91d0 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -1310,7 +1310,7 @@ static unsigned long found_ubuf_segment(unsigned long addr, size_t len, size_t *size, size_t *start) { - len += (*start = addr % PAGE_SIZE); + *start = addr % PAGE_SIZE; *size = len; return addr & PAGE_MASK; } @@ -1354,7 +1354,7 @@ 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; } @@ -1383,9 +1383,9 @@ static ssize_t __iov_iter_get_pages_alloc(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; if (!*pages) { *pages = get_pages_array(n); if (!*pages) @@ -1394,25 +1394,25 @@ static ssize_t __iov_iter_get_pages_alloc(struct iov_iter *i, 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 **p; 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); + n = DIV_ROUND_UP(len + *start, PAGE_SIZE); + if (n > maxpages) + n = maxpages; p = *pages; if (!p) { *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(i, pages, maxsize, maxpages, start);
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> --- lib/iov_iter.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-)