From: Al Viro <v...@zeniv.linux.org.uk>
Signed-off-by: Al Viro <v...@zeniv.linux.org.uk>
---
mm/iov_iter.c | 98 ++++++++---------------------------------------------------
1 file changed, 12 insertions(+), 86 deletions(-)
diff --git a/mm/iov_iter.c b/mm/iov_iter.c
index 3214b9b..39ad713 100644
--- a/mm/iov_iter.c
+++ b/mm/iov_iter.c
@@ -349,50 +349,6 @@ done:
return wanted - bytes;
}
-static size_t zero_iovec(size_t bytes, struct iov_iter *i)
-{
- size_t skip, copy, left, wanted;
- const struct iovec *iov;
- char __user *buf;
-
- if (unlikely(bytes > i->count))
- bytes = i->count;
-
- if (unlikely(!bytes))
- return 0;
-
- wanted = bytes;
- iov = i->iov;
- skip = i->iov_offset;
- buf = iov->iov_base + skip;
- copy = min(bytes, iov->iov_len - skip);
-
- left = __clear_user(buf, copy);
- copy -= left;
- skip += copy;
- bytes -= copy;
-
- while (unlikely(!left && bytes)) {
- iov++;
- buf = iov->iov_base;
- copy = min(bytes, iov->iov_len);
- left = __clear_user(buf, copy);
- copy -= left;
- skip = copy;
- bytes -= copy;
- }
-
- if (skip == iov->iov_len) {
- iov++;
- skip = 0;
- }
- i->count -= wanted - bytes;
- i->nr_segs -= iov - i->iov;
- i->iov = iov;
- i->iov_offset = skip;
- return wanted - bytes;
-}
-
/*
* Fault in the first iovec of the given iov_iter, to a maximum length
* of bytes. Returns 0 on success, or non-zero if the memory could not be
@@ -548,43 +504,6 @@ static size_t copy_page_from_iter_bvec(struct page *page,
size_t offset,
return wanted;
}
-static size_t zero_bvec(size_t bytes, struct iov_iter *i)
-{
- size_t skip, copy, wanted;
- const struct bio_vec *bvec;
-
- if (unlikely(bytes > i->count))
- bytes = i->count;
-
- if (unlikely(!bytes))
- return 0;
-
- wanted = bytes;
- bvec = i->bvec;
- skip = i->iov_offset;
- copy = min_t(size_t, bytes, bvec->bv_len - skip);
-
- memzero_page(bvec->bv_page, skip + bvec->bv_offset, copy);
- skip += copy;
- bytes -= copy;
- while (bytes) {
- bvec++;
- copy = min(bytes, (size_t)bvec->bv_len);
- memzero_page(bvec->bv_page, bvec->bv_offset, copy);
- skip = copy;
- bytes -= copy;
- }
- if (skip == bvec->bv_len) {
- bvec++;
- skip = 0;
- }
- i->count -= wanted - bytes;
- i->nr_segs -= bvec - i->bvec;
- i->bvec = bvec;
- i->iov_offset = skip;
- return wanted - bytes;
-}
-
size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
struct iov_iter *i)
{
@@ -625,11 +544,18 @@ EXPORT_SYMBOL(copy_from_iter);
size_t iov_iter_zero(size_t bytes, struct iov_iter *i)
{
- if (i->type & ITER_BVEC) {
- return zero_bvec(bytes, i);
- } else {
- return zero_iovec(bytes, i);
- }
+ if (unlikely(bytes > i->count))
+ bytes = i->count;
+
+ if (unlikely(!bytes))
+ return 0;
+
+ iterate_and_advance(i, bytes, v,
+ __clear_user(v.iov_base, v.iov_len),
+ memzero_page(v.bv_page, v.bv_offset, v.bv_len)
+ )
+
+ return bytes;
}
EXPORT_SYMBOL(iov_iter_zero);
--
2.1.3
--
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