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authorAl Viro <viro@zeniv.linux.org.uk>2014-11-27 14:09:46 -0500
committerAl Viro <viro@zeniv.linux.org.uk>2014-11-27 18:44:11 -0500
commite0f2dc4061e6238905001e8ec6c88b15c2e3b950 (patch)
tree7fa4f2829d8ae5e26099679cb649f911bf8b16ff /mm/iov_iter.c
parent7ce2a91e51288f308bfe5ea7e5743517c15c8e25 (diff)
iov_iter.c: convert iov_iter_npages() to iterate_all_kinds
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'mm/iov_iter.c')
-rw-r--r--mm/iov_iter.c73
1 files changed, 19 insertions, 54 deletions
diff --git a/mm/iov_iter.c b/mm/iov_iter.c
index e91bf0accc47..bc666e79b5bd 100644
--- a/mm/iov_iter.c
+++ b/mm/iov_iter.c
@@ -493,32 +493,6 @@ static ssize_t get_pages_alloc_iovec(struct iov_iter *i,
return (res == n ? len : res * PAGE_SIZE) - *start;
}
-static int iov_iter_npages_iovec(const struct iov_iter *i, int maxpages)
-{
- size_t offset = i->iov_offset;
- size_t size = i->count;
- const struct iovec *iov = i->iov;
- int npages = 0;
- int n;
-
- for (n = 0; size && n < i->nr_segs; n++, iov++) {
- unsigned long addr = (unsigned long)iov->iov_base + offset;
- size_t len = iov->iov_len - offset;
- offset = 0;
- if (unlikely(!len)) /* empty segment */
- continue;
- if (len > size)
- len = size;
- npages += (addr + len + PAGE_SIZE - 1) / PAGE_SIZE
- - addr / PAGE_SIZE;
- if (npages >= maxpages) /* don't bother going further */
- return maxpages;
- size -= len;
- offset = 0;
- }
- return min(npages, maxpages);
-}
-
static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len)
{
char *from = kmap_atomic(page);
@@ -715,30 +689,6 @@ static ssize_t get_pages_alloc_bvec(struct iov_iter *i,
return len;
}
-static int iov_iter_npages_bvec(const struct iov_iter *i, int maxpages)
-{
- size_t offset = i->iov_offset;
- size_t size = i->count;
- const struct bio_vec *bvec = i->bvec;
- int npages = 0;
- int n;
-
- for (n = 0; size && n < i->nr_segs; n++, bvec++) {
- size_t len = bvec->bv_len - offset;
- offset = 0;
- if (unlikely(!len)) /* empty segment */
- continue;
- if (len > size)
- len = size;
- npages++;
- if (npages >= maxpages) /* don't bother going further */
- return maxpages;
- size -= len;
- offset = 0;
- }
- return min(npages, maxpages);
-}
-
size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
struct iov_iter *i)
{
@@ -862,9 +812,24 @@ EXPORT_SYMBOL(iov_iter_get_pages_alloc);
int iov_iter_npages(const struct iov_iter *i, int maxpages)
{
- if (i->type & ITER_BVEC)
- return iov_iter_npages_bvec(i, maxpages);
- else
- return iov_iter_npages_iovec(i, maxpages);
+ size_t size = i->count;
+ int npages = 0;
+
+ if (!size)
+ return 0;
+
+ iterate_all_kinds(i, size, v, ({
+ unsigned long p = (unsigned long)v.iov_base;
+ npages += DIV_ROUND_UP(p + v.iov_len, PAGE_SIZE)
+ - p / PAGE_SIZE;
+ if (npages >= maxpages)
+ return maxpages;
+ 0;}),({
+ npages++;
+ if (npages >= maxpages)
+ return maxpages;
+ })
+ )
+ return npages;
}
EXPORT_SYMBOL(iov_iter_npages);