diff mbox

[4/8] vhost/scsi: Change vhost_scsi_map_to_sgl to accept iov ptr + len

Message ID 1422605552-24797-5-git-send-email-nab@daterainc.com (mailing list archive)
State New, archived
Headers show

Commit Message

Nicholas A. Bellinger Jan. 30, 2015, 8:12 a.m. UTC 
From: Nicholas Bellinger <nab@linux-iscsi.org>

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@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
---
 drivers/vhost/scsi.c | 37 +++++++++++++++----------------------
 1 file changed, 15 insertions(+), 22 deletions(-)

Comments

Michael S. Tsirkin Jan. 30, 2015, 10:51 a.m. UTC | #1 
On Fri, Jan 30, 2015 at 08:12:28AM +0000, Nicholas A. Bellinger wrote:
> From: Nicholas Bellinger <nab@linux-iscsi.org>
> 
> 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@redhat.com>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
> ---
>  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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Nicholas A. Bellinger Feb. 1, 2015, 7:24 a.m. UTC | #2 
On Fri, 2015-01-30 at 12:51 +0200, Michael S. Tsirkin wrote:
> On Fri, Jan 30, 2015 at 08:12:28AM +0000, Nicholas A. Bellinger wrote:
> > From: Nicholas Bellinger <nab@linux-iscsi.org>
> > 
> > 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@redhat.com>
> > Cc: Paolo Bonzini <pbonzini@redhat.com>
> > Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
> > ---
> >  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?
> 

I didn't bother with this, as it's only used by the legacy !ANY_LAYOUT
related code-path.

Also, I don't see a reason at this point to keep the !ANY_LAYOUT bits
around for >= v3.20 code, so for -v2 I'll just drop the legacy code
(including the above) all together.

Thank you,

--nab

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diff mbox

Patch

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);
 
 	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]);