[PATCH 07/29] iov_iter: Split copy_from_iter()

[David Howells]

Split copy_from_iter() by type.

Signed-off-by: David Howells <dhowe...@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,