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Subject[PATCH 22/29] iov_iter: Split iov_iter_get_pages_alloc()
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Split iov_iter_get_pages_alloc() by type.

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

lib/iov_iter.c | 48 +++++++++++++++++++++++++++++++-----------------
1 file changed, 31 insertions(+), 17 deletions(-)

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index a2de201b947f..a038bfbbbd53 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -1690,6 +1690,8 @@ static ssize_t pipe_get_pages_alloc(struct iov_iter *i,
unsigned int iter_head, npages;
ssize_t n;

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

@@ -1715,7 +1717,7 @@ static ssize_t pipe_get_pages_alloc(struct iov_iter *i,
return n;
}

-static ssize_t xxx_get_pages_alloc(struct iov_iter *i,
+static ssize_t iovec_get_pages_alloc(struct iov_iter *i,
struct page ***pages, size_t maxsize,
size_t *start)
{
@@ -1724,12 +1726,7 @@ static ssize_t xxx_get_pages_alloc(struct iov_iter *i,
if (maxsize > i->count)
maxsize = i->count;

- if (unlikely(iov_iter_is_pipe(i)))
- return pipe_get_pages_alloc(i, pages, maxsize, 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;
@@ -1748,7 +1745,20 @@ static ssize_t xxx_get_pages_alloc(struct iov_iter *i,
}
*pages = p;
return (res == n ? len : res * PAGE_SIZE) - *start;
- 0;}),({
+ 0;}));
+ return 0;
+}
+
+static ssize_t bvec_get_pages_alloc(struct iov_iter *i,
+ struct page ***pages, size_t maxsize,
+ size_t *start)
+{
+ struct page **p;
+
+ if (maxsize > i->count)
+ maxsize = i->count;
+
+ iterate_over_bvec(i, maxsize, v, ({
/* can't be more than PAGE_SIZE */
*start = v.bv_offset;
*pages = p = get_pages_array(1);
@@ -1756,13 +1766,17 @@ static ssize_t xxx_get_pages_alloc(struct iov_iter *i,
return -ENOMEM;
get_page(*p = v.bv_page);
return v.bv_len;
- }),({
- return -EFAULT;
- })
- )
+ }));
return 0;
}

+static ssize_t no_get_pages_alloc(struct iov_iter *i,
+ struct page ***pages, size_t maxsize,
+ size_t *start)
+{
+ return -EFAULT;
+}
+
static size_t xxx_csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum,
struct iov_iter *i)
{
@@ -2192,7 +2206,7 @@ static const struct iov_iter_ops iovec_iter_ops = {
.alignment = iovec_alignment,
.gap_alignment = iovec_gap_alignment,
.get_pages = iovec_get_pages,
- .get_pages_alloc = xxx_get_pages_alloc,
+ .get_pages_alloc = iovec_get_pages_alloc,
.npages = xxx_npages,
.dup_iter = xxx_dup_iter,
.for_each_range = xxx_for_each_range,
@@ -2226,7 +2240,7 @@ static const struct iov_iter_ops kvec_iter_ops = {
.alignment = kvec_alignment,
.gap_alignment = kvec_gap_alignment,
.get_pages = no_get_pages,
- .get_pages_alloc = xxx_get_pages_alloc,
+ .get_pages_alloc = no_get_pages_alloc,
.npages = xxx_npages,
.dup_iter = xxx_dup_iter,
.for_each_range = xxx_for_each_range,
@@ -2260,7 +2274,7 @@ static const struct iov_iter_ops bvec_iter_ops = {
.alignment = bvec_alignment,
.gap_alignment = bvec_gap_alignment,
.get_pages = bvec_get_pages,
- .get_pages_alloc = xxx_get_pages_alloc,
+ .get_pages_alloc = bvec_get_pages_alloc,
.npages = xxx_npages,
.dup_iter = xxx_dup_iter,
.for_each_range = xxx_for_each_range,
@@ -2294,7 +2308,7 @@ static const struct iov_iter_ops pipe_iter_ops = {
.alignment = pipe_alignment,
.gap_alignment = no_gap_alignment,
.get_pages = pipe_get_pages,
- .get_pages_alloc = xxx_get_pages_alloc,
+ .get_pages_alloc = pipe_get_pages_alloc,
.npages = xxx_npages,
.dup_iter = xxx_dup_iter,
.for_each_range = xxx_for_each_range,
@@ -2328,7 +2342,7 @@ static const struct iov_iter_ops discard_iter_ops = {
.alignment = no_alignment,
.gap_alignment = no_gap_alignment,
.get_pages = no_get_pages,
- .get_pages_alloc = xxx_get_pages_alloc,
+ .get_pages_alloc = no_get_pages_alloc,
.npages = xxx_npages,
.dup_iter = xxx_dup_iter,
.for_each_range = xxx_for_each_range,

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