vhost/scsi: switch to iov_iter_get_pages() (2f240c4a) · Commits · 戴 / test

drivers/vhost/scsi.c

+20 −48

Original line number	Diff line number	Diff line
		@@ -210,12 +210,6 @@ static struct workqueue_struct *vhost_scsi_workqueue;
		static DEFINE_MUTEX(vhost_scsi_mutex);
		static LIST_HEAD(vhost_scsi_list);

		static int iov_num_pages(void __user *iov_base, size_t iov_len)
		{
		return (PAGE_ALIGN((unsigned long)iov_base + iov_len) -
		((unsigned long)iov_base & PAGE_MASK)) >> PAGE_SHIFT;
		}

		static void vhost_scsi_done_inflight(struct kref *kref)
		{
		struct vhost_scsi_inflight *inflight;
		@@ -618,48 +612,31 @@ vhost_scsi_get_tag(struct vhost_virtqueue vq, struct vhost_scsi_tpg tpg,
		*/
		static int
		vhost_scsi_map_to_sgl(struct vhost_scsi_cmd *cmd,
		void __user *ptr,
		size_t len,
		struct iov_iter *iter,
		struct scatterlist *sgl,
		bool write)
		{
		unsigned int npages = 0, offset, nbytes;
		unsigned int pages_nr = iov_num_pages(ptr, len);
		struct scatterlist *sg = sgl;
		struct page **pages = cmd->tvc_upages;
		int ret, i;

		if (pages_nr > VHOST_SCSI_PREALLOC_UPAGES) {
		pr_err("vhost_scsi_map_to_sgl() pages_nr: %u greater than"
		" preallocated VHOST_SCSI_PREALLOC_UPAGES: %u\n",
		pages_nr, VHOST_SCSI_PREALLOC_UPAGES);
		return -ENOBUFS;
		}
		struct scatterlist *sg = sgl;
		ssize_t bytes;
		size_t offset;
		unsigned int npages = 0;

		ret = get_user_pages_fast((unsigned long)ptr, pages_nr, write, pages);
		bytes = iov_iter_get_pages(iter, pages, LONG_MAX,
		VHOST_SCSI_PREALLOC_UPAGES, &offset);
		/* No pages were pinned */
		if (ret < 0)
		goto out;
		/* Less pages pinned than wanted */
		if (ret != pages_nr) {
		for (i = 0; i < ret; i++)
		put_page(pages[i]);
		ret = -EFAULT;
		goto out;
		}
		if (bytes <= 0)
		return bytes < 0 ? bytes : -EFAULT;

		while (len > 0) {
		offset = (uintptr_t)ptr & ~PAGE_MASK;
		nbytes = min_t(unsigned int, PAGE_SIZE - offset, len);
		sg_set_page(sg, pages[npages], nbytes, offset);
		ptr += nbytes;
		len -= nbytes;
		sg++;
		npages++;
		}
		iov_iter_advance(iter, bytes);

		out:
		return ret;
		while (bytes) {
		unsigned n = min_t(unsigned, PAGE_SIZE - offset, bytes);
		sg_set_page(sg++, pages[npages++], n, offset);
		bytes -= n;
		offset = 0;
		}
		return npages;
		}

		static int
		@@ -687,15 +664,11 @@ vhost_scsi_iov_to_sgl(struct vhost_scsi_cmd *cmd, bool write,
		struct iov_iter *iter,
		struct scatterlist *sg, int sg_count)
		{
		size_t off = iter->iov_offset;
		struct scatterlist *p = sg;
		int i, ret;

		for (i = 0; i < iter->nr_segs; i++) {
		void __user *base = iter->iov[i].iov_base + off;
		size_t len = iter->iov[i].iov_len - off;
		int ret;

		ret = vhost_scsi_map_to_sgl(cmd, base, len, sg, write);
		while (iov_iter_count(iter)) {
		ret = vhost_scsi_map_to_sgl(cmd, iter, sg, write);
		if (ret < 0) {
		while (p < sg) {
		struct page *page = sg_page(p++);
		@@ -705,7 +678,6 @@ vhost_scsi_iov_to_sgl(struct vhost_scsi_cmd *cmd, bool write,
		return ret;
		}
		sg += ret;
		off = 0;
		}
		return 0;
		}

Admin message