iov_iter.c: convert iov_iter_get_pages_alloc() to iterate_all_kinds (1b17f1f2) · Commits · e / devices / android_kernel_oneplus_sm7250

mm/iov_iter.c

+45 −62

Original line number	Diff line number	Diff line
		@@ -428,43 +428,6 @@ void iov_iter_init(struct iov_iter *i, int direction,
		}
		EXPORT_SYMBOL(iov_iter_init);

		static ssize_t get_pages_alloc_iovec(struct iov_iter *i,
		struct page ***pages, size_t maxsize,
		size_t *start)
		{
		size_t offset = i->iov_offset;
		const struct iovec *iov = i->iov;
		size_t len;
		unsigned long addr;
		void *p;
		int n;
		int res;

		len = iov->iov_len - offset;
		if (len > i->count)
		len = i->count;
		if (len > maxsize)
		len = maxsize;
		addr = (unsigned long)iov->iov_base + offset;
		len += *start = addr & (PAGE_SIZE - 1);
		addr &= ~(PAGE_SIZE - 1);
		n = (len + PAGE_SIZE - 1) / PAGE_SIZE;

		p = kmalloc(n * sizeof(struct page *), GFP_KERNEL);
		if (!p)
		p = vmalloc(n * sizeof(struct page *));
		if (!p)
		return -ENOMEM;

		res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, p);
		if (unlikely(res < 0)) {
		kvfree(p);
		return res;
		}
		*pages = p;
		return (res == n ? len : res * PAGE_SIZE) - *start;
		}

		static void memcpy_from_page(char to, struct page page, size_t offset, size_t len)
		{
		char *from = kmap_atomic(page);
		@@ -622,27 +585,6 @@ static size_t zero_bvec(size_t bytes, struct iov_iter *i)
		return wanted - bytes;
		}

		static ssize_t get_pages_alloc_bvec(struct iov_iter *i,
		struct page ***pages, size_t maxsize,
		size_t *start)
		{
		const struct bio_vec *bvec = i->bvec;
		size_t len = bvec->bv_len - i->iov_offset;
		if (len > i->count)
		len = i->count;
		if (len > maxsize)
		len = maxsize;
		*start = bvec->bv_offset + i->iov_offset;

		pages = kmalloc(sizeof(struct page ), GFP_KERNEL);
		if (!*pages)
		return -ENOMEM;

		get_page(**pages = bvec->bv_page);

		return len;
		}

		size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
		struct iov_iter *i)
		{
		@@ -777,14 +719,55 @@ ssize_t iov_iter_get_pages(struct iov_iter *i,
		}
		EXPORT_SYMBOL(iov_iter_get_pages);

		static struct page **get_pages_array(size_t n)
		{
		struct page *p = kmalloc(n sizeof(struct page *), GFP_KERNEL);
		if (!p)
		p = vmalloc(n * sizeof(struct page *));
		return p;
		}

		ssize_t iov_iter_get_pages_alloc(struct iov_iter *i,
		struct page ***pages, size_t maxsize,
		size_t *start)
		{
		if (i->type & ITER_BVEC)
		return get_pages_alloc_bvec(i, pages, maxsize, start);
		else
		return get_pages_alloc_iovec(i, pages, maxsize, start);
		struct page **p;

		if (maxsize > i->count)
		maxsize = i->count;

		if (!maxsize)
		return 0;

		iterate_all_kinds(i, maxsize, v, ({
		unsigned long addr = (unsigned long)v.iov_base;
		size_t len = v.iov_len + (*start = addr & (PAGE_SIZE - 1));
		int n;
		int res;

		addr &= ~(PAGE_SIZE - 1);
		n = DIV_ROUND_UP(len, PAGE_SIZE);
		p = get_pages_array(n);
		if (!p)
		return -ENOMEM;
		res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, p);
		if (unlikely(res < 0)) {
		kvfree(p);
		return res;
		}
		*pages = p;
		return (res == n ? len : res * PAGE_SIZE) - *start;
		0;}),({
		/* can't be more than PAGE_SIZE */
		*start = v.bv_offset;
		*pages = p = get_pages_array(1);
		if (!p)
		return -ENOMEM;
		get_page(*p = v.bv_page);
		return v.bv_len;
		})
		)
		return 0;
		}
		EXPORT_SYMBOL(iov_iter_get_pages_alloc);