On Fri, Jan 30, 2015 at 08:12:28AM +0000, Nicholas A. Bellinger wrote:
> From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
>
> This patch changes vhost_scsi_map_to_sgl() parameters to accept virtio
> iovec ptr + len when determing pages_nr.
>
> This is currently done with iov_num_pages() -> PAGE_ALIGN, so allow
> the same parameters as well.
>
> Cc: Michael S. Tsirkin <mst@xxxxxxxxxx>
> Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
> ---
> drivers/vhost/scsi.c | 37 +++++++++++++++----------------------
> 1 file changed, 15 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
> index 9c5ac23..049e603 100644
> --- a/drivers/vhost/scsi.c
> +++ b/drivers/vhost/scsi.c
> @@ -220,10 +220,10 @@ static struct workqueue_struct *tcm_vhost_workqueue;
> static DEFINE_MUTEX(tcm_vhost_mutex);
> static LIST_HEAD(tcm_vhost_list);
>
> -static int iov_num_pages(struct iovec *iov)
> +static int iov_num_pages(void __user *iov_base, size_t iov_len)
> {
> - return (PAGE_ALIGN((unsigned long)iov->iov_base + iov->iov_len) -
> - ((unsigned long)iov->iov_base & PAGE_MASK)) >> PAGE_SHIFT;
> + return (PAGE_ALIGN((unsigned long)iov_base + iov_len) -
> + ((unsigned long)iov_base & PAGE_MASK)) >> PAGE_SHIFT;
> }
>
> static void tcm_vhost_done_inflight(struct kref *kref)
> @@ -777,25 +777,18 @@ vhost_scsi_get_tag(struct vhost_virtqueue *vq, struct tcm_vhost_tpg *tpg,
> * Returns the number of scatterlist entries used or -errno on error.
> */
> static int
> -vhost_scsi_map_to_sgl(struct tcm_vhost_cmd *tv_cmd,
> +vhost_scsi_map_to_sgl(struct tcm_vhost_cmd *cmd,
> + void __user *ptr,
> + size_t len,
> struct scatterlist *sgl,
> - unsigned int sgl_count,
> - struct iovec *iov,
> - struct page **pages,
> bool write)
> {
> - unsigned int npages = 0, pages_nr, offset, nbytes;
> + unsigned int npages = 0, offset, nbytes;
> + unsigned int pages_nr = iov_num_pages(ptr, len);
> struct scatterlist *sg = sgl;
> - void __user *ptr = iov->iov_base;
> - size_t len = iov->iov_len;
> + struct page **pages = cmd->tvc_upages;
> int ret, i;
>
> - pages_nr = iov_num_pages(iov);
> - if (pages_nr > sgl_count) {
> - pr_err("vhost_scsi_map_to_sgl() pages_nr: %u greater than"
> - " sgl_count: %u\n", pages_nr, sgl_count);
> - return -ENOBUFS;
> - }
> if (pages_nr > TCM_VHOST_PREALLOC_UPAGES) {
> pr_err("vhost_scsi_map_to_sgl() pages_nr: %u greater than"
> " preallocated TCM_VHOST_PREALLOC_UPAGES: %u\n",
> @@ -840,7 +833,7 @@ vhost_scsi_map_iov_to_sgl(struct tcm_vhost_cmd *cmd,
> int ret, i;
>
> for (i = 0; i < niov; i++)
> - sgl_count += iov_num_pages(&iov[i]);
> + sgl_count += iov_num_pages(iov[i].iov_base, iov[i].iov_len);
>
A helper function for this loop seems in order as well?
> if (sgl_count > TCM_VHOST_PREALLOC_SGLS) {
> pr_err("vhost_scsi_map_iov_to_sgl() sgl_count: %u greater than"
> @@ -856,8 +849,8 @@ vhost_scsi_map_iov_to_sgl(struct tcm_vhost_cmd *cmd,
> pr_debug("Mapping iovec %p for %u pages\n", &iov[0], sgl_count);
>
> for (i = 0; i < niov; i++) {
> - ret = vhost_scsi_map_to_sgl(cmd, sg, sgl_count, &iov[i],
> - cmd->tvc_upages, write);
> + ret = vhost_scsi_map_to_sgl(cmd, iov[i].iov_base, iov[i].iov_len,
> + sg, write);
> if (ret < 0) {
> for (i = 0; i < cmd->tvc_sgl_count; i++) {
> struct page *page = sg_page(&cmd->tvc_sgl[i]);
> @@ -884,7 +877,7 @@ vhost_scsi_map_iov_to_prot(struct tcm_vhost_cmd *cmd,
> int ret, i;
>
> for (i = 0; i < niov; i++)
> - prot_sgl_count += iov_num_pages(&iov[i]);
> + prot_sgl_count += iov_num_pages(iov[i].iov_base, iov[i].iov_len);
>
> if (prot_sgl_count > TCM_VHOST_PREALLOC_PROT_SGLS) {
> pr_err("vhost_scsi_map_iov_to_prot() sgl_count: %u greater than"
> @@ -899,8 +892,8 @@ vhost_scsi_map_iov_to_prot(struct tcm_vhost_cmd *cmd,
> cmd->tvc_prot_sgl_count = prot_sgl_count;
>
> for (i = 0; i < niov; i++) {
> - ret = vhost_scsi_map_to_sgl(cmd, prot_sg, prot_sgl_count, &iov[i],
> - cmd->tvc_upages, write);
> + ret = vhost_scsi_map_to_sgl(cmd, iov[i].iov_base, iov[i].iov_len,
> + prot_sg, write);
> if (ret < 0) {
> for (i = 0; i < cmd->tvc_prot_sgl_count; i++) {
> struct page *page = sg_page(&cmd->tvc_prot_sgl[i]);
> --
> 1.9.1
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