[PATCH 05/29] iov_iter: Split copy_to_iter()

[David Howells]

Split copy_to_iter() by type.

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

 lib/iov_iter.c |   47 +++++++++++++++++++++++++++++++----------------
 1 file changed, 31 insertions(+), 16 deletions(-)

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index a221e7771201..0865e0b6eee9 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -634,7 +634,7 @@ static size_t push_pipe(struct iov_iter *i, size_t size,
        return size - left;
 }
 
-static size_t copy_pipe_to_iter(const void *addr, size_t bytes,
+static size_t pipe_copy_to_iter(const void *addr, size_t bytes,
                                struct iov_iter *i)
 {
        struct pipe_inode_info *pipe = i->pipe;
@@ -703,20 +703,35 @@ static size_t csum_and_copy_to_pipe_iter(const void 
*addr, size_t bytes,
        return bytes;
 }
 
-static size_t xxx_copy_to_iter(const void *addr, size_t bytes, struct iov_iter 
*i)
+static size_t iovec_copy_to_iter(const void *addr, size_t bytes, struct 
iov_iter *i)
 {
        const char *from = addr;
-       if (unlikely(iov_iter_is_pipe(i)))
-               return copy_pipe_to_iter(addr, bytes, i);
-       if (iter_is_iovec(i))
-               might_fault();
-       iterate_and_advance(i, bytes, v,
-               copyout(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len),
+       might_fault();
+       iterate_and_advance_iovec(i, bytes, v,
+               copyout(v.iov_base, (from += v.iov_len) - v.iov_len, 
v.iov_len));
+       return bytes;
+}
+
+static size_t bvec_copy_to_iter(const void *addr, size_t bytes, struct 
iov_iter *i)
+{
+       const char *from = addr;
+       iterate_and_advance_bvec(i, bytes, v,
                memcpy_to_page(v.bv_page, v.bv_offset,
-                              (from += v.bv_len) - v.bv_len, v.bv_len),
-               memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len)
-       )
+                              (from += v.bv_len) - v.bv_len, v.bv_len));
+       return bytes;
+}
 
+static size_t kvec_copy_to_iter(const void *addr, size_t bytes, struct 
iov_iter *i)
+{
+       const char *from = addr;
+       iterate_and_advance_kvec(i, bytes, v,
+               memcpy(v.iov_base, (from += v.iov_len) - v.iov_len, v.iov_len));
+       return bytes;
+}
+
+static size_t discard_copy_to_iter(const void *addr, size_t bytes, struct 
iov_iter *i)
+{
+       iterate_and_advance_discard(i, bytes);
        return bytes;
 }
 
@@ -1915,7 +1930,7 @@ static const struct iov_iter_ops iovec_iter_ops = {
        .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_to_iter                   = xxx_copy_to_iter,
+       .copy_to_iter                   = iovec_copy_to_iter,
        .copy_from_iter                 = xxx_copy_from_iter,
        .copy_from_iter_full            = xxx_copy_from_iter_full,
        .copy_from_iter_nocache         = xxx_copy_from_iter_nocache,
@@ -1949,7 +1964,7 @@ static const struct iov_iter_ops kvec_iter_ops = {
        .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_to_iter                   = xxx_copy_to_iter,
+       .copy_to_iter                   = kvec_copy_to_iter,
        .copy_from_iter                 = xxx_copy_from_iter,
        .copy_from_iter_full            = xxx_copy_from_iter_full,
        .copy_from_iter_nocache         = xxx_copy_from_iter_nocache,
@@ -1983,7 +1998,7 @@ static const struct iov_iter_ops bvec_iter_ops = {
        .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_to_iter                   = xxx_copy_to_iter,
+       .copy_to_iter                   = bvec_copy_to_iter,
        .copy_from_iter                 = xxx_copy_from_iter,
        .copy_from_iter_full            = xxx_copy_from_iter_full,
        .copy_from_iter_nocache         = xxx_copy_from_iter_nocache,
@@ -2017,7 +2032,7 @@ static const struct iov_iter_ops pipe_iter_ops = {
        .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_to_iter                   = xxx_copy_to_iter,
+       .copy_to_iter                   = pipe_copy_to_iter,
        .copy_from_iter                 = xxx_copy_from_iter,
        .copy_from_iter_full            = xxx_copy_from_iter_full,
        .copy_from_iter_nocache         = xxx_copy_from_iter_nocache,
@@ -2051,7 +2066,7 @@ static const struct iov_iter_ops discard_iter_ops = {
        .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_to_iter                   = xxx_copy_to_iter,
+       .copy_to_iter                   = discard_copy_to_iter,
        .copy_from_iter                 = xxx_copy_from_iter,
        .copy_from_iter_full            = xxx_copy_from_iter_full,
        .copy_from_iter_nocache         = xxx_copy_from_iter_nocache,