From 4b179e9a9c7c98550747b76405626dd59968f078 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 4 May 2021 17:50:07 -0400 Subject: [PATCH] iterate_xarray(): only of the first iteration we might get offset != 0 recalculating offset on each iteration is pointless - on all subsequent passes through the loop it will be zero anyway. Signed-off-by: Al Viro --- lib/iov_iter.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 48a55de..d5f750c 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -70,9 +70,9 @@ __label__ __out; \ size_t __off = 0; \ struct page *head = NULL; \ - size_t offset; \ loff_t start = i->xarray_start + i->iov_offset; \ - pgoff_t index = start >> PAGE_SHIFT; \ + unsigned offset = start % PAGE_SIZE; \ + pgoff_t index = start / PAGE_SIZE; \ int j; \ \ XA_STATE(xas, i->xarray, index); \ @@ -89,7 +89,6 @@ for (j = (head->index < index) ? index - head->index : 0; \ j < thp_nr_pages(head); j++) { \ void *kaddr = kmap_local_page(head + j); \ - offset = (start + __off) % PAGE_SIZE; \ base = kaddr + offset; \ len = PAGE_SIZE - offset; \ len = min(n, len); \ @@ -100,6 +99,7 @@ n -= len; \ if (left || n == 0) \ goto __out; \ + offset = 0; \ } \ } \ __out: \ -- 2.7.4