Commit 4b6c132b authored by Al Viro's avatar Al Viro
Browse files

iov_iter: switch ..._full() variants of primitives to use of iov_iter_revert() 



Use corresponding plain variants, revert on short copy.  That's the way it
should've been done from the very beginning, except that we didn't have
iov_iter_revert() back then...

[fixed another braino caught by Qian Cai <quic_qiancai@quicinc.com>]

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 3b3fc051

include/linux/uio.h

+21 −11
Original line number Diff line number Diff line
@@ -132,9 +132,7 @@ size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, 


size_t _copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i);

size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i);

bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i);

size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i);

bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i);



static __always_inline __must_check

size_t copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
@@ -157,10 +155,11 @@ size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) 
static __always_inline __must_check

bool copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i)

{

	if (unlikely(!check_copy_size(addr, bytes, false)))

	size_t copied = copy_from_iter(addr, bytes, i);

	if (likely(copied == bytes))

		return true;

	iov_iter_revert(i, copied);

	return false;

	else

		return _copy_from_iter_full(addr, bytes, i);

}



static __always_inline __must_check
@@ -175,10 +174,11 @@ size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i) 
static __always_inline __must_check

bool copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i)

{

	if (unlikely(!check_copy_size(addr, bytes, false)))

	size_t copied = copy_from_iter_nocache(addr, bytes, i);

	if (likely(copied == bytes))

		return true;

	iov_iter_revert(i, copied);

	return false;

	else

		return _copy_from_iter_full_nocache(addr, bytes, i);

}



#ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
@@ -278,7 +278,17 @@ struct csum_state { 


size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *csstate, struct iov_iter *i);

size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i);

bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i);



static __always_inline __must_check

bool csum_and_copy_from_iter_full(void *addr, size_t bytes,

				  __wsum *csum, struct iov_iter *i)

{

	size_t copied = csum_and_copy_from_iter(addr, bytes, csum, i);

	if (likely(copied == bytes))

		return true;

	iov_iter_revert(i, copied);

	return false;

}

size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp,

		struct iov_iter *i);

lib/iov_iter.c

+0 −104
Original line number Diff line number Diff line
@@ -819,35 +819,6 @@ size_t _copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) 
}

EXPORT_SYMBOL(_copy_from_iter);



bool _copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i)

{

	char *to = addr;

	if (unlikely(iov_iter_is_pipe(i))) {

		WARN_ON(1);

		return false;

	}

	if (unlikely(i->count < bytes))

		return false;



	if (iter_is_iovec(i))

		might_fault();

	iterate_all_kinds(i, bytes, v, ({

		if (copyin((to += v.iov_len) - v.iov_len,

				      v.iov_base, v.iov_len))

			return false;

		0;}),

		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),

		memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page,

				 v.bv_offset, v.bv_len)

	)



	iov_iter_advance(i, bytes);

	return true;

}

EXPORT_SYMBOL(_copy_from_iter_full);



size_t _copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i)

{

	char *to = addr;
@@ -907,32 +878,6 @@ size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i) 
EXPORT_SYMBOL_GPL(_copy_from_iter_flushcache);

#endif



bool _copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i)

{

	char *to = addr;

	if (unlikely(iov_iter_is_pipe(i))) {

		WARN_ON(1);

		return false;

	}

	if (unlikely(i->count < bytes))

		return false;

	iterate_all_kinds(i, bytes, v, ({

		if (__copy_from_user_inatomic_nocache((to += v.iov_len) - v.iov_len,

					     v.iov_base, v.iov_len))

			return false;

		0;}),

		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),

		memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page,

				 v.bv_offset, v.bv_len)

	)



	iov_iter_advance(i, bytes);

	return true;

}

EXPORT_SYMBOL(_copy_from_iter_full_nocache);



static inline bool page_copy_sane(struct page *page, size_t offset, size_t n)

{

	struct page *head;
@@ -1740,55 +1685,6 @@ size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, 
}

EXPORT_SYMBOL(csum_and_copy_from_iter);



bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum,

			       struct iov_iter *i)

{

	char *to = addr;

	__wsum sum, next;

	size_t off = 0;

	sum = *csum;

	if (unlikely(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) {

		WARN_ON(1);

		return false;

	}

	if (unlikely(i->count < bytes))

		return false;

	iterate_all_kinds(i, bytes, v, ({

		next = csum_and_copy_from_user(v.iov_base,

					       (to += v.iov_len) - v.iov_len,

					       v.iov_len);

		if (!next)

			return false;

		sum = csum_block_add(sum, next, off);

		off += v.iov_len;

		0;

	}), ({

		char *p = kmap_atomic(v.bv_page);

		sum = csum_and_memcpy((to += v.bv_len) - v.bv_len,

				      p + v.bv_offset, v.bv_len,

				      sum, off);

		kunmap_atomic(p);

		off += v.bv_len;

	}),({

		sum = csum_and_memcpy((to += v.iov_len) - v.iov_len,

				      v.iov_base, v.iov_len,

				      sum, off);

		off += v.iov_len;

	}), ({

		char *p = kmap_atomic(v.bv_page);

		sum = csum_and_memcpy((to += v.bv_len) - v.bv_len,

				      p + v.bv_offset, v.bv_len,

				      sum, off);

		kunmap_atomic(p);

		off += v.bv_len;

	})

	)

	*csum = sum;

	iov_iter_advance(i, bytes);

	return true;

}

EXPORT_SYMBOL(csum_and_copy_from_iter_full);



size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *_csstate,

			     struct iov_iter *i)

{