Commit a6e4ec7b authored by Al Viro's avatar Al Viro
Browse files

pull handling of ->iov_offset into iterate_{iovec,bvec,xarray} 



fewer arguments (by one, but still...) for iterate_...() macros

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 7baa5099

lib/iov_iter.c

+14 −12
Original line number Diff line number Diff line
@@ -17,8 +17,9 @@ 
#define PIPE_PARANOIA /* for now */



/* covers iovec and kvec alike */

#define iterate_iovec(i, n, base, len, off, __p, skip, STEP) {	\

#define iterate_iovec(i, n, base, len, off, __p, STEP) {	\

	size_t off = 0;						\

	size_t skip = i->iov_offset;				\

	do {							\

		len = min(n, __p->iov_len - skip);		\

		if (likely(len)) {				\
@@ -33,18 +34,20 @@ 
		__p++;						\

		skip = 0;					\

	} while (n);						\

	i->iov_offset = skip;					\

	n = off;						\

}



#define iterate_bvec(i, n, base, len, off, p, skip, STEP) {	\

#define iterate_bvec(i, n, base, len, off, p, STEP) {		\

	size_t off = 0;						\

	unsigned skip = i->iov_offset;				\

	while (n) {						\

		unsigned offset = p->bv_offset + skip;		\

		unsigned left;					\

		void *kaddr = kmap_local_page(p->bv_page +	\

					offset / PAGE_SIZE);	\

		base = kaddr + offset % PAGE_SIZE;		\

		len = min(min(n, p->bv_len - skip),		\

		len = min(min(n, (size_t)(p->bv_len - skip)),	\

		     (size_t)(PAGE_SIZE - offset % PAGE_SIZE));	\

		left = (STEP);					\

		kunmap_local(kaddr);				\
@@ -59,15 +62,16 @@ 
		if (left)					\

			break;					\

	}							\

	i->iov_offset = skip;					\

	n = off;						\

}



#define iterate_xarray(i, n, base, len, __off, skip, STEP) {	\

#define iterate_xarray(i, n, base, len, __off, STEP) {		\

	__label__ __out;					\

	size_t __off = 0;					\

	struct page *head = NULL;				\

	size_t offset;						\

	loff_t start = i->xarray_start + skip;			\

	loff_t start = i->xarray_start + i->iov_offset;		\

	pgoff_t index = start >> PAGE_SHIFT;			\

	int j;							\

								\
@@ -100,7 +104,7 @@ 
	}							\

__out:								\

	rcu_read_unlock();					\

	skip += __off;						\

	i->iov_offset += __off;						\

	n = __off;						\

}
@@ -108,13 +112,12 @@ __out: \ 
	if (unlikely(i->count < n))				\

		n = i->count;					\

	if (likely(n)) {					\

		size_t skip = i->iov_offset;			\

		if (likely(iter_is_iovec(i))) {			\

			const struct iovec *iov = i->iov;	\

			void __user *base;			\

			size_t len;				\

			iterate_iovec(i, n, base, len, off,	\

						iov, skip, (I))	\

						iov, (I))	\

			i->nr_segs -= iov - i->iov;		\

			i->iov = iov;				\

		} else if (iov_iter_is_bvec(i)) {		\
@@ -122,7 +125,7 @@ __out: \ 
			void *base;				\

			size_t len;				\

			iterate_bvec(i, n, base, len, off,	\

					bvec, skip, (K))	\

						bvec, (K))	\

			i->nr_segs -= bvec - i->bvec;		\

			i->bvec = bvec;				\

		} else if (iov_iter_is_kvec(i)) {		\
@@ -130,17 +133,16 @@ __out: \ 
			void *base;				\

			size_t len;				\

			iterate_iovec(i, n, base, len, off,	\

					kvec, skip, (K))	\

						kvec, (K))	\

			i->nr_segs -= kvec - i->kvec;		\

			i->kvec = kvec;				\

		} else if (iov_iter_is_xarray(i)) {		\

			void *base;				\

			size_t len;				\

			iterate_xarray(i, n, base, len, off,	\

						skip, (K))	\

							(K))	\

		}						\

		i->count -= n;					\

		i->iov_offset = skip;				\

	}							\

}

#define iterate_and_advance(i, n, base, len, off, I, K) \