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Subject[PATCH 07/29] iov_iter: Split copy_from_iter()
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Split copy_from_iter() by type.

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

lib/iov_iter.c | 50 ++++++++++++++++++++++++++++++++------------------
1 file changed, 32 insertions(+), 18 deletions(-)

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 7c1d92f7d020..5b18dfe0dcc7 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -863,22 +863,36 @@ static size_t kvec_copy_mc_to_iter(const void *addr, size_t bytes, struct iov_it
}
#endif /* CONFIG_ARCH_HAS_COPY_MC */

-static size_t xxx_copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
+static size_t iovec_copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
{
char *to = addr;
- if (unlikely(iov_iter_is_pipe(i))) {
- WARN_ON(1);
- return 0;
- }
- if (iter_is_iovec(i))
- might_fault();
- iterate_and_advance(i, bytes, v,
- copyin((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len),
+ might_fault();
+ iterate_and_advance_iovec(i, bytes, v,
+ copyin((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len));
+
+ return bytes;
+}
+
+static size_t bvec_copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
+{
+ char *to = addr;
+ iterate_and_advance_bvec(i, bytes, v,
memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page,
- v.bv_offset, v.bv_len),
- memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len)
- )
+ v.bv_offset, v.bv_len));
+ return bytes;
+}
+
+static size_t kvec_copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
+{
+ char *to = addr;
+ iterate_and_advance_kvec(i, bytes, v,
+ memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len));
+ return bytes;
+}

+static size_t no_copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
+{
+ WARN_ON(1);
return bytes;
}

@@ -1037,7 +1051,7 @@ static size_t xxx_copy_page_from_iter(struct page *page, size_t offset, size_t b
}
if (iov_iter_type(i) & (ITER_BVEC|ITER_KVEC)) {
void *kaddr = kmap_atomic(page);
- size_t wanted = xxx_copy_from_iter(kaddr + offset, bytes, i);
+ size_t wanted = copy_from_iter(kaddr + offset, bytes, i);
kunmap_atomic(kaddr);
return wanted;
} else
@@ -1943,7 +1957,7 @@ static const struct iov_iter_ops iovec_iter_ops = {
.copy_page_to_iter = iovec_copy_page_to_iter,
.copy_page_from_iter = xxx_copy_page_from_iter,
.copy_to_iter = iovec_copy_to_iter,
- .copy_from_iter = xxx_copy_from_iter,
+ .copy_from_iter = iovec_copy_from_iter,
.copy_from_iter_full = xxx_copy_from_iter_full,
.copy_from_iter_nocache = xxx_copy_from_iter_nocache,
.copy_from_iter_full_nocache = xxx_copy_from_iter_full_nocache,
@@ -1977,7 +1991,7 @@ static const struct iov_iter_ops kvec_iter_ops = {
.copy_page_to_iter = bkvec_copy_page_to_iter,
.copy_page_from_iter = xxx_copy_page_from_iter,
.copy_to_iter = kvec_copy_to_iter,
- .copy_from_iter = xxx_copy_from_iter,
+ .copy_from_iter = kvec_copy_from_iter,
.copy_from_iter_full = xxx_copy_from_iter_full,
.copy_from_iter_nocache = xxx_copy_from_iter_nocache,
.copy_from_iter_full_nocache = xxx_copy_from_iter_full_nocache,
@@ -2011,7 +2025,7 @@ static const struct iov_iter_ops bvec_iter_ops = {
.copy_page_to_iter = bkvec_copy_page_to_iter,
.copy_page_from_iter = xxx_copy_page_from_iter,
.copy_to_iter = bvec_copy_to_iter,
- .copy_from_iter = xxx_copy_from_iter,
+ .copy_from_iter = bvec_copy_from_iter,
.copy_from_iter_full = xxx_copy_from_iter_full,
.copy_from_iter_nocache = xxx_copy_from_iter_nocache,
.copy_from_iter_full_nocache = xxx_copy_from_iter_full_nocache,
@@ -2045,7 +2059,7 @@ static const struct iov_iter_ops pipe_iter_ops = {
.copy_page_to_iter = pipe_copy_page_to_iter,
.copy_page_from_iter = xxx_copy_page_from_iter,
.copy_to_iter = pipe_copy_to_iter,
- .copy_from_iter = xxx_copy_from_iter,
+ .copy_from_iter = no_copy_from_iter,
.copy_from_iter_full = xxx_copy_from_iter_full,
.copy_from_iter_nocache = xxx_copy_from_iter_nocache,
.copy_from_iter_full_nocache = xxx_copy_from_iter_full_nocache,
@@ -2079,7 +2093,7 @@ static const struct iov_iter_ops discard_iter_ops = {
.copy_page_to_iter = discard_copy_page_to_iter,
.copy_page_from_iter = xxx_copy_page_from_iter,
.copy_to_iter = discard_copy_to_iter,
- .copy_from_iter = xxx_copy_from_iter,
+ .copy_from_iter = no_copy_from_iter,
.copy_from_iter_full = xxx_copy_from_iter_full,
.copy_from_iter_nocache = xxx_copy_from_iter_nocache,
.copy_from_iter_full_nocache = xxx_copy_from_iter_full_nocache,

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