Split copy_from_user_atomic() by type.

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

 lib/iov_iter.c |   53 ++++++++++++++++++++++++++++++++++++++++-------------
 1 file changed, 40 insertions(+), 13 deletions(-)

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 9a167f53ecff..a626d41fef72 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -1195,7 +1195,7 @@ static size_t discard_zero(size_t bytes, struct iov_iter 
*i)
        return bytes;
 }
 
-static size_t xxx_copy_from_user_atomic(struct page *page,
+static size_t iovec_copy_from_user_atomic(struct page *page,
                struct iov_iter *i, unsigned long offset, size_t bytes)
 {
        char *kaddr = kmap_atomic(page), *p = kaddr + offset;
@@ -1203,21 +1203,48 @@ static size_t xxx_copy_from_user_atomic(struct page 
*page,
                kunmap_atomic(kaddr);
                return 0;
        }
-       if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) {
+       iterate_over_iovec(i, bytes, v,
+               copyin((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len));
+       kunmap_atomic(kaddr);
+       return bytes;
+}
+
+static size_t bvec_copy_from_user_atomic(struct page *page,
+               struct iov_iter *i, unsigned long offset, size_t bytes)
+{
+       char *kaddr = kmap_atomic(page), *p = kaddr + offset;
+       if (unlikely(!page_copy_sane(page, offset, bytes))) {
                kunmap_atomic(kaddr);
-               WARN_ON(1);
                return 0;
        }
-       iterate_all_kinds(i, bytes, v,
-               copyin((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len),
+       iterate_over_bvec(i, bytes, v,
                memcpy_from_page((p += v.bv_len) - v.bv_len, v.bv_page,
-                                v.bv_offset, v.bv_len),
-               memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len)
-       )
+                                v.bv_offset, v.bv_len));
        kunmap_atomic(kaddr);
        return bytes;
 }
 
+static size_t kvec_copy_from_user_atomic(struct page *page,
+               struct iov_iter *i, unsigned long offset, size_t bytes)
+{
+       char *kaddr = kmap_atomic(page), *p = kaddr + offset;
+       if (unlikely(!page_copy_sane(page, offset, bytes))) {
+               kunmap_atomic(kaddr);
+               return 0;
+       }
+       iterate_over_kvec(i, bytes, v,
+               memcpy((p += v.iov_len) - v.iov_len, v.iov_base, v.iov_len));
+       kunmap_atomic(kaddr);
+       return bytes;
+}
+
+static size_t no_copy_from_user_atomic(struct page *page,
+               struct iov_iter *i, unsigned long offset, size_t bytes)
+{
+       WARN_ON(1);
+       return 0;
+}
+
 static inline void pipe_truncate(struct iov_iter *i)
 {
        struct pipe_inode_info *pipe = i->pipe;
@@ -2046,7 +2073,7 @@ static int xxx_for_each_range(struct iov_iter *i, size_t 
bytes,
 
 static const struct iov_iter_ops iovec_iter_ops = {
        .type                           = ITER_IOVEC,
-       .copy_from_user_atomic          = xxx_copy_from_user_atomic,
+       .copy_from_user_atomic          = iovec_copy_from_user_atomic,
        .advance                        = xxx_advance,
        .revert                         = xxx_revert,
        .fault_in_readable              = iovec_fault_in_readable,
@@ -2080,7 +2107,7 @@ static const struct iov_iter_ops iovec_iter_ops = {
 
 static const struct iov_iter_ops kvec_iter_ops = {
        .type                           = ITER_KVEC,
-       .copy_from_user_atomic          = xxx_copy_from_user_atomic,
+       .copy_from_user_atomic          = kvec_copy_from_user_atomic,
        .advance                        = xxx_advance,
        .revert                         = xxx_revert,
        .fault_in_readable              = no_fault_in_readable,
@@ -2114,7 +2141,7 @@ static const struct iov_iter_ops kvec_iter_ops = {
 
 static const struct iov_iter_ops bvec_iter_ops = {
        .type                           = ITER_BVEC,
-       .copy_from_user_atomic          = xxx_copy_from_user_atomic,
+       .copy_from_user_atomic          = bvec_copy_from_user_atomic,
        .advance                        = xxx_advance,
        .revert                         = xxx_revert,
        .fault_in_readable              = no_fault_in_readable,
@@ -2148,7 +2175,7 @@ static const struct iov_iter_ops bvec_iter_ops = {
 
 static const struct iov_iter_ops pipe_iter_ops = {
        .type                           = ITER_PIPE,
-       .copy_from_user_atomic          = xxx_copy_from_user_atomic,
+       .copy_from_user_atomic          = no_copy_from_user_atomic,
        .advance                        = xxx_advance,
        .revert                         = xxx_revert,
        .fault_in_readable              = no_fault_in_readable,
@@ -2182,7 +2209,7 @@ static const struct iov_iter_ops pipe_iter_ops = {
 
 static const struct iov_iter_ops discard_iter_ops = {
        .type                           = ITER_DISCARD,
-       .copy_from_user_atomic          = xxx_copy_from_user_atomic,
+       .copy_from_user_atomic          = no_copy_from_user_atomic,
        .advance                        = xxx_advance,
        .revert                         = xxx_revert,
        .fault_in_readable              = no_fault_in_readable,


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