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Subject[PATCH 21/29] iov_iter: Split iov_iter_get_pages()
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Split iov_iter_get_pages() by type.

Signed-off-by: David Howells <dhowells@redhat.com>
---

lib/iov_iter.c | 46 +++++++++++++++++++++++++++++-----------------
1 file changed, 29 insertions(+), 17 deletions(-)

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 5744ddec854f..a2de201b947f 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -1611,6 +1611,8 @@ static ssize_t pipe_get_pages(struct iov_iter *i,
unsigned int iter_head, npages;
size_t capacity;

+ if (maxsize > i->count)
+ maxsize = i->count;
if (!maxsize)
return 0;

@@ -1625,19 +1627,14 @@ static ssize_t pipe_get_pages(struct iov_iter *i,
return __pipe_get_pages(i, min(maxsize, capacity), pages, iter_head, start);
}

-static ssize_t xxx_get_pages(struct iov_iter *i,
+static ssize_t iovec_get_pages(struct iov_iter *i,
struct page **pages, size_t maxsize, unsigned maxpages,
size_t *start)
{
if (maxsize > i->count)
maxsize = i->count;

- if (unlikely(iov_iter_is_pipe(i)))
- return pipe_get_pages(i, pages, maxsize, maxpages, start);
- if (unlikely(iov_iter_is_discard(i)))
- return -EFAULT;
-
- iterate_all_kinds(i, maxsize, v, ({
+ iterate_over_iovec(i, maxsize, v, ({
unsigned long addr = (unsigned long)v.iov_base;
size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1));
int n;
@@ -1653,18 +1650,33 @@ static ssize_t xxx_get_pages(struct iov_iter *i,
if (unlikely(res < 0))
return res;
return (res == n ? len : res * PAGE_SIZE) - *start;
- 0;}),({
+ 0;}));
+ return 0;
+}
+
+static ssize_t bvec_get_pages(struct iov_iter *i,
+ struct page **pages, size_t maxsize, unsigned maxpages,
+ size_t *start)
+{
+ if (maxsize > i->count)
+ maxsize = i->count;
+
+ iterate_over_bvec(i, maxsize, v, ({
/* can't be more than PAGE_SIZE */
*start = v.bv_offset;
get_page(*pages = v.bv_page);
return v.bv_len;
- }),({
- return -EFAULT;
- })
- )
+ }));
return 0;
}

+static ssize_t no_get_pages(struct iov_iter *i,
+ struct page **pages, size_t maxsize, unsigned maxpages,
+ size_t *start)
+{
+ return -EFAULT;
+}
+
static struct page **get_pages_array(size_t n)
{
return kvmalloc_array(n, sizeof(struct page *), GFP_KERNEL);
@@ -2179,7 +2191,7 @@ static const struct iov_iter_ops iovec_iter_ops = {
.zero = iovec_zero,
.alignment = iovec_alignment,
.gap_alignment = iovec_gap_alignment,
- .get_pages = xxx_get_pages,
+ .get_pages = iovec_get_pages,
.get_pages_alloc = xxx_get_pages_alloc,
.npages = xxx_npages,
.dup_iter = xxx_dup_iter,
@@ -2213,7 +2225,7 @@ static const struct iov_iter_ops kvec_iter_ops = {
.zero = kvec_zero,
.alignment = kvec_alignment,
.gap_alignment = kvec_gap_alignment,
- .get_pages = xxx_get_pages,
+ .get_pages = no_get_pages,
.get_pages_alloc = xxx_get_pages_alloc,
.npages = xxx_npages,
.dup_iter = xxx_dup_iter,
@@ -2247,7 +2259,7 @@ static const struct iov_iter_ops bvec_iter_ops = {
.zero = bvec_zero,
.alignment = bvec_alignment,
.gap_alignment = bvec_gap_alignment,
- .get_pages = xxx_get_pages,
+ .get_pages = bvec_get_pages,
.get_pages_alloc = xxx_get_pages_alloc,
.npages = xxx_npages,
.dup_iter = xxx_dup_iter,
@@ -2281,7 +2293,7 @@ static const struct iov_iter_ops pipe_iter_ops = {
.zero = pipe_zero,
.alignment = pipe_alignment,
.gap_alignment = no_gap_alignment,
- .get_pages = xxx_get_pages,
+ .get_pages = pipe_get_pages,
.get_pages_alloc = xxx_get_pages_alloc,
.npages = xxx_npages,
.dup_iter = xxx_dup_iter,
@@ -2315,7 +2327,7 @@ static const struct iov_iter_ops discard_iter_ops = {
.zero = discard_zero,
.alignment = no_alignment,
.gap_alignment = no_gap_alignment,
- .get_pages = xxx_get_pages,
+ .get_pages = no_get_pages,
.get_pages_alloc = xxx_get_pages_alloc,
.npages = xxx_npages,
.dup_iter = xxx_dup_iter,

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