Split copy_page_from_iter() by type.

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

 lib/iov_iter.c |   39 +++++++++++++++++++++------------------
 1 file changed, 21 insertions(+), 18 deletions(-)

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 544e532e3e9f..54029aeab3ec 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -344,7 +344,7 @@ static size_t iovec_copy_page_to_iter(struct page *page, 
size_t offset, size_t b
        return wanted - bytes;
 }
 
-static size_t copy_page_from_iter_iovec(struct page *page, size_t offset, 
size_t bytes,
+static size_t iovec_copy_page_from_iter(struct page *page, size_t offset, 
size_t bytes,
                         struct iov_iter *i)
 {
        size_t skip, copy, left, wanted;
@@ -352,6 +352,8 @@ static size_t copy_page_from_iter_iovec(struct page *page, 
size_t offset, size_t
        char __user *buf;
        void *kaddr, *to;
 
+       if (unlikely(!page_copy_sane(page, offset, bytes)))
+               return 0;
        if (unlikely(bytes > i->count))
                bytes = i->count;
 
@@ -1120,22 +1122,23 @@ static size_t discard_copy_page_to_iter(struct page 
*page, size_t offset, size_t
        return bytes;
 }
 
-static size_t xxx_copy_page_from_iter(struct page *page, size_t offset, size_t 
bytes,
+static size_t bkvec_copy_page_from_iter(struct page *page, size_t offset, 
size_t bytes,
                         struct iov_iter *i)
 {
-       if (unlikely(!page_copy_sane(page, offset, bytes)))
-               return 0;
-       if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) {
-               WARN_ON(1);
-               return 0;
-       }
-       if (iov_iter_type(i) & (ITER_BVEC|ITER_KVEC)) {
+       size_t wanted = 0;
+       if (likely(page_copy_sane(page, offset, bytes))) {
                void *kaddr = kmap_atomic(page);
-               size_t wanted = copy_from_iter(kaddr + offset, bytes, i);
+               wanted = copy_from_iter(kaddr + offset, bytes, i);
                kunmap_atomic(kaddr);
-               return wanted;
-       } else
-               return copy_page_from_iter_iovec(page, offset, bytes, i);
+       }
+       return wanted;
+}
+
+static size_t no_copy_page_from_iter(struct page *page, size_t offset, size_t 
bytes,
+                                    struct iov_iter *i)
+{
+       WARN_ON(1);
+       return 0;
 }
 
 static size_t pipe_zero(size_t bytes, struct iov_iter *i)
@@ -2035,7 +2038,7 @@ static const struct iov_iter_ops iovec_iter_ops = {
        .fault_in_readable              = iovec_fault_in_readable,
        .single_seg_count               = xxx_single_seg_count,
        .copy_page_to_iter              = iovec_copy_page_to_iter,
-       .copy_page_from_iter            = xxx_copy_page_from_iter,
+       .copy_page_from_iter            = iovec_copy_page_from_iter,
        .copy_to_iter                   = iovec_copy_to_iter,
        .copy_from_iter                 = iovec_copy_from_iter,
        .copy_from_iter_full            = iovec_copy_from_iter_full,
@@ -2069,7 +2072,7 @@ static const struct iov_iter_ops kvec_iter_ops = {
        .fault_in_readable              = no_fault_in_readable,
        .single_seg_count               = xxx_single_seg_count,
        .copy_page_to_iter              = bkvec_copy_page_to_iter,
-       .copy_page_from_iter            = xxx_copy_page_from_iter,
+       .copy_page_from_iter            = bkvec_copy_page_from_iter,
        .copy_to_iter                   = kvec_copy_to_iter,
        .copy_from_iter                 = kvec_copy_from_iter,
        .copy_from_iter_full            = kvec_copy_from_iter_full,
@@ -2103,7 +2106,7 @@ static const struct iov_iter_ops bvec_iter_ops = {
        .fault_in_readable              = no_fault_in_readable,
        .single_seg_count               = xxx_single_seg_count,
        .copy_page_to_iter              = bkvec_copy_page_to_iter,
-       .copy_page_from_iter            = xxx_copy_page_from_iter,
+       .copy_page_from_iter            = bkvec_copy_page_from_iter,
        .copy_to_iter                   = bvec_copy_to_iter,
        .copy_from_iter                 = bvec_copy_from_iter,
        .copy_from_iter_full            = bvec_copy_from_iter_full,
@@ -2137,7 +2140,7 @@ static const struct iov_iter_ops pipe_iter_ops = {
        .fault_in_readable              = no_fault_in_readable,
        .single_seg_count               = xxx_single_seg_count,
        .copy_page_to_iter              = pipe_copy_page_to_iter,
-       .copy_page_from_iter            = xxx_copy_page_from_iter,
+       .copy_page_from_iter            = no_copy_page_from_iter,
        .copy_to_iter                   = pipe_copy_to_iter,
        .copy_from_iter                 = no_copy_from_iter,
        .copy_from_iter_full            = no_copy_from_iter_full,
@@ -2171,7 +2174,7 @@ static const struct iov_iter_ops discard_iter_ops = {
        .fault_in_readable              = no_fault_in_readable,
        .single_seg_count               = xxx_single_seg_count,
        .copy_page_to_iter              = discard_copy_page_to_iter,
-       .copy_page_from_iter            = xxx_copy_page_from_iter,
+       .copy_page_from_iter            = no_copy_page_from_iter,
        .copy_to_iter                   = discard_copy_to_iter,
        .copy_from_iter                 = no_copy_from_iter,
        .copy_from_iter_full            = no_copy_from_iter_full,


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