Merge branch 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

[linux-block.git] / drivers / vhost / scsi.c

diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index 1bc9be829fb45ccbabf7eb8c252823b1fc1541f2..71517b3c55582266becd3f0aa2639664c96f5148 100644 (file)
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -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
@@ -687,24 +664,20 @@ 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;
-       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;
+       struct scatterlist *p = sg;
+       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) {
-                       for (i = 0; i < sg_count; i++) {
-                               struct page *page = sg_page(&sg[i]);
+                       while (p < sg) {
+                               struct page *page = sg_page(p++);
                                if (page)
                                        put_page(page);
                        }
                        return ret;
                }
                sg += ret;
-               off = 0;
        }
        return 0;
 }