[PATCH 07/25] iov_iter.c: get rid of bvec_copy_page_{to,from}_iter()
From: Al Viro <viro@ZenIV.linux.org.uk>
Date: 2014-12-09 22:57:34
Also in:
lkml
Subsystem:
memory management, the rest · Maintainers:
Andrew Morton, Linus Torvalds
From: Al Viro <viro@zeniv.linux.org.uk>
Just have copy_page_{to,from}_iter() fall back to kmap_atomic +
copy_{to,from}_iter() + kunmap_atomic() in ITER_BVEC case. As
the matter of fact, that's what we want to do for any iov_iter
kind that isn't blocking - e.g. ITER_KVEC will also go that way
once we recognize it on iov_iter.c primitives level
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
mm/iov_iter.c | 60 ++++++++++++++++++++++++-----------------------------------
1 file changed, 24 insertions(+), 36 deletions(-)
diff --git a/mm/iov_iter.c b/mm/iov_iter.c
index 39ad713..17b7144 100644
--- a/mm/iov_iter.c
+++ b/mm/iov_iter.c@@ -486,30 +486,33 @@ static size_t copy_from_iter_bvec(void *to, size_t bytes, struct iov_iter *i) return wanted; } -static size_t copy_page_to_iter_bvec(struct page *page, size_t offset, - size_t bytes, struct iov_iter *i) +size_t copy_to_iter(void *addr, size_t bytes, struct iov_iter *i) { - void *kaddr = kmap_atomic(page); - size_t wanted = copy_to_iter_bvec(kaddr + offset, bytes, i); - kunmap_atomic(kaddr); - return wanted; + if (i->type & ITER_BVEC) + return copy_to_iter_bvec(addr, bytes, i); + else + return copy_to_iter_iovec(addr, bytes, i); } +EXPORT_SYMBOL(copy_to_iter); -static size_t copy_page_from_iter_bvec(struct page *page, size_t offset, - size_t bytes, struct iov_iter *i) +size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) { - void *kaddr = kmap_atomic(page); - size_t wanted = copy_from_iter_bvec(kaddr + offset, bytes, i); - kunmap_atomic(kaddr); - return wanted; + if (i->type & ITER_BVEC) + return copy_from_iter_bvec(addr, bytes, i); + else + return copy_from_iter_iovec(addr, bytes, i); } +EXPORT_SYMBOL(copy_from_iter); size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, struct iov_iter *i) { - if (i->type & ITER_BVEC) - return copy_page_to_iter_bvec(page, offset, bytes, i); - else + if (i->type & (ITER_BVEC|ITER_KVEC)) { + void *kaddr = kmap_atomic(page); + size_t wanted = copy_to_iter(kaddr + offset, bytes, i); + kunmap_atomic(kaddr); + return wanted; + } else return copy_page_to_iter_iovec(page, offset, bytes, i); } EXPORT_SYMBOL(copy_page_to_iter);
@@ -517,31 +520,16 @@ EXPORT_SYMBOL(copy_page_to_iter); size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, struct iov_iter *i) { - if (i->type & ITER_BVEC) - return copy_page_from_iter_bvec(page, offset, bytes, i); - else + if (i->type & ITER_BVEC) { + void *kaddr = kmap_atomic(page); + size_t wanted = copy_from_iter(kaddr + offset, bytes, i); + kunmap_atomic(kaddr); + return wanted; + } else return copy_page_from_iter_iovec(page, offset, bytes, i); } EXPORT_SYMBOL(copy_page_from_iter); -size_t copy_to_iter(void *addr, size_t bytes, struct iov_iter *i) -{ - if (i->type & ITER_BVEC) - return copy_to_iter_bvec(addr, bytes, i); - else - return copy_to_iter_iovec(addr, bytes, i); -} -EXPORT_SYMBOL(copy_to_iter); - -size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) -{ - if (i->type & ITER_BVEC) - return copy_from_iter_bvec(addr, bytes, i); - else - return copy_from_iter_iovec(addr, bytes, i); -} -EXPORT_SYMBOL(copy_from_iter); - size_t iov_iter_zero(size_t bytes, struct iov_iter *i) { if (unlikely(bytes > i->count))
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2.1.3