diff mbox series

[v3,1/4] net: introduce helper sendpages_ok()

Message ID 20240606161219.2745817-2-ofir.gal@volumez.com
State Superseded
Headers show
Series [v3,1/4] net: introduce helper sendpages_ok() | expand

Commit Message

Ofir Gal June 6, 2024, 4:12 p.m. UTC 
Network drivers are using sendpage_ok() to check the first page of an
iterator in order to disable MSG_SPLICE_PAGES. The iterator can
represent list of contiguous pages.

When MSG_SPLICE_PAGES is enabled skb_splice_from_iter() is being used,
it requires all pages in the iterator to be sendable. Therefore it needs
to check that each page is sendable.

The patch introduces a helper sendpages_ok(), it returns true if all the
contiguous pages are sendable.

Drivers who want to send contiguous pages with MSG_SPLICE_PAGES may use
this helper to check whether the page list is OK. If the helper does not
return true, the driver should remove MSG_SPLICE_PAGES flag.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ofir Gal <ofir.gal@volumez.com>
---
 include/linux/net.h | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

Comments

Sagi Grimberg June 10, 2024, 10:05 a.m. UTC | #1 
On 06/06/2024 19:12, Ofir Gal wrote:
> Network drivers are using sendpage_ok() to check the first page of an
> iterator in order to disable MSG_SPLICE_PAGES. The iterator can
> represent list of contiguous pages.
>
> When MSG_SPLICE_PAGES is enabled skb_splice_from_iter() is being used,
> it requires all pages in the iterator to be sendable. Therefore it needs
> to check that each page is sendable.
>
> The patch introduces a helper sendpages_ok(), it returns true if all the
> contiguous pages are sendable.
>
> Drivers who want to send contiguous pages with MSG_SPLICE_PAGES may use
> this helper to check whether the page list is OK. If the helper does not
> return true, the driver should remove MSG_SPLICE_PAGES flag.
>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> Signed-off-by: Ofir Gal <ofir.gal@volumez.com>
> ---
>   include/linux/net.h | 22 ++++++++++++++++++++++
>   1 file changed, 22 insertions(+)
>
> diff --git a/include/linux/net.h b/include/linux/net.h
> index 688320b79fcc..421a6b5b9ad1 100644
> --- a/include/linux/net.h
> +++ b/include/linux/net.h
> @@ -322,6 +322,28 @@ static inline bool sendpage_ok(struct page *page)
>   	return !PageSlab(page) && page_count(page) >= 1;
>   }
>   
> +/*
> + * Check sendpage_ok on contiguous pages.
> + */
> +static inline bool sendpages_ok(struct page *page, size_t len, size_t offset)
> +{
> +	struct page *p;
> +	size_t count;
> +
> +	p = page + (offset >> PAGE_SHIFT);
> +
> +	count = 0;

Assignment can move to the declaration.

> +	while (count < len) {
> +		if (!sendpage_ok(p))
> +			return false;
> +
> +		p++;
> +		count += PAGE_SIZE;
> +	}
> +
> +	return true;
> +}
> +
>   int kernel_sendmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
>   		   size_t num, size_t len);
>   int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg,

Other than that,

Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Ofir Gal June 11, 2024, 6:33 a.m. UTC | #2 
On 10/06/2024 13:05, Sagi Grimberg wrote:
>
>
> On 06/06/2024 19:12, Ofir Gal wrote:
>> Network drivers are using sendpage_ok() to check the first page of an
>> iterator in order to disable MSG_SPLICE_PAGES. The iterator can
>> represent list of contiguous pages.
>>
>> When MSG_SPLICE_PAGES is enabled skb_splice_from_iter() is being used,
>> it requires all pages in the iterator to be sendable. Therefore it needs
>> to check that each page is sendable.
>>
>> The patch introduces a helper sendpages_ok(), it returns true if all the
>> contiguous pages are sendable.
>>
>> Drivers who want to send contiguous pages with MSG_SPLICE_PAGES may use
>> this helper to check whether the page list is OK. If the helper does not
>> return true, the driver should remove MSG_SPLICE_PAGES flag.
>>
>> Reviewed-by: Christoph Hellwig <hch@lst.de>
>> Signed-off-by: Ofir Gal <ofir.gal@volumez.com>
>> ---
>>   include/linux/net.h | 22 ++++++++++++++++++++++
>>   1 file changed, 22 insertions(+)
>>
>> diff --git a/include/linux/net.h b/include/linux/net.h
>> index 688320b79fcc..421a6b5b9ad1 100644
>> --- a/include/linux/net.h
>> +++ b/include/linux/net.h
>> @@ -322,6 +322,28 @@ static inline bool sendpage_ok(struct page *page)
>>       return !PageSlab(page) && page_count(page) >= 1;
>>   }
>>   +/*
>> + * Check sendpage_ok on contiguous pages.
>> + */
>> +static inline bool sendpages_ok(struct page *page, size_t len, size_t offset)
>> +{
>> +    struct page *p;
>> +    size_t count;
>> +
>> +    p = page + (offset >> PAGE_SHIFT);
>> +
>> +    count = 0;
>
> Assignment can move to the declaration.
Applying to v4.

>
>
>> +    while (count < len) {
>> +        if (!sendpage_ok(p))
>> +            return false;
>> +
>> +        p++;
>> +        count += PAGE_SIZE;
>> +    }
>> +
>> +    return true;
>> +}
>> +
>>   int kernel_sendmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
>>              size_t num, size_t len);
>>   int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg,
>
> Other than that,
>
> Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Thanks for the review.
diff mbox series

Patch

diff --git a/include/linux/net.h b/include/linux/net.h
index 688320b79fcc..421a6b5b9ad1 100644
--- a/include/linux/net.h
+++ b/include/linux/net.h
@@ -322,6 +322,28 @@  static inline bool sendpage_ok(struct page *page)
 	return !PageSlab(page) && page_count(page) >= 1;
 }
 
+/*
+ * Check sendpage_ok on contiguous pages.
+ */
+static inline bool sendpages_ok(struct page *page, size_t len, size_t offset)
+{
+	struct page *p;
+	size_t count;
+
+	p = page + (offset >> PAGE_SHIFT);
+
+	count = 0;
+	while (count < len) {
+		if (!sendpage_ok(p))
+			return false;
+
+		p++;
+		count += PAGE_SIZE;
+	}
+
+	return true;
+}
+
 int kernel_sendmsg(struct socket *sock, struct msghdr *msg, struct kvec *vec,
 		   size_t num, size_t len);
 int kernel_sendmsg_locked(struct sock *sk, struct msghdr *msg,