* [PATCH v1] SUNRPC: Fix NFS READs that start at non-page-aligned offsets
@ 2021-02-01 0:53 Chuck Lever
2021-02-01 6:14 ` A. Duvnjak
0 siblings, 1 reply; 2+ messages in thread
From: Chuck Lever @ 2021-02-01 0:53 UTC (permalink / raw)
To: linux-nfs; +Cc: avian
Anj Duvnjak reports that the Kodi.tv NFS client is not able to read
video files from a v5.10.11 Linux NFS server.
The new sendpage-based TCP sendto logic was not attentive to non-
zero page_base values. nfsd_splice_read() sets that field when a
READ payload starts in the middle of a page.
The Linux NFS client rarely emits an NFS READ that is not page-
aligned. All of my testing so far has been with Linux clients, so I
missed this one.
Reported-by: A. Duvnjak <avian@extremenerds.net>
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=211471
Fixes: 4a85a6a3320b ("SUNRPC: Handle TCP socket sends with kernel_sendpage() again")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
net/sunrpc/svcsock.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index c9766d07eb81..5a809c64dc7b 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -1113,14 +1113,15 @@ static int svc_tcp_sendmsg(struct socket *sock, struct msghdr *msg,
unsigned int offset, len, remaining;
struct bio_vec *bvec;
- bvec = xdr->bvec;
- offset = xdr->page_base;
+ bvec = xdr->bvec + (xdr->page_base >> PAGE_SHIFT);
+ offset = offset_in_page(xdr->page_base);
remaining = xdr->page_len;
flags = MSG_MORE | MSG_SENDPAGE_NOTLAST;
while (remaining > 0) {
if (remaining <= PAGE_SIZE && tail->iov_len == 0)
flags = 0;
- len = min(remaining, bvec->bv_len);
+
+ len = min(remaining, bvec->bv_len - offset);
ret = kernel_sendpage(sock, bvec->bv_page,
bvec->bv_offset + offset,
len, flags);
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v1] SUNRPC: Fix NFS READs that start at non-page-aligned offsets
2021-02-01 0:53 [PATCH v1] SUNRPC: Fix NFS READs that start at non-page-aligned offsets Chuck Lever
@ 2021-02-01 6:14 ` A. Duvnjak
0 siblings, 0 replies; 2+ messages in thread
From: A. Duvnjak @ 2021-02-01 6:14 UTC (permalink / raw)
To: Chuck Lever; +Cc: linux-nfs
I tried this patch on 5.10.12 (which would normally produce streaming errors). So far it works well. Have tried it in the three situations that would previously cause issues - Kodi on Windows, Kodi on Mac, and the Windows 10 NFS client with VLC. All check out fine.
> On 1 Feb 2021, at 11:53 am, Chuck Lever <chuck.lever@oracle.com> wrote:
>
> Anj Duvnjak reports that the Kodi.tv NFS client is not able to read
> video files from a v5.10.11 Linux NFS server.
>
> The new sendpage-based TCP sendto logic was not attentive to non-
> zero page_base values. nfsd_splice_read() sets that field when a
> READ payload starts in the middle of a page.
>
> The Linux NFS client rarely emits an NFS READ that is not page-
> aligned. All of my testing so far has been with Linux clients, so I
> missed this one.
>
> Reported-by: A. Duvnjak <avian@extremenerds.net>
> BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=211471
> Fixes: 4a85a6a3320b ("SUNRPC: Handle TCP socket sends with kernel_sendpage() again")
> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
> ---
> net/sunrpc/svcsock.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
> index c9766d07eb81..5a809c64dc7b 100644
> --- a/net/sunrpc/svcsock.c
> +++ b/net/sunrpc/svcsock.c
> @@ -1113,14 +1113,15 @@ static int svc_tcp_sendmsg(struct socket *sock, struct msghdr *msg,
> unsigned int offset, len, remaining;
> struct bio_vec *bvec;
>
> - bvec = xdr->bvec;
> - offset = xdr->page_base;
> + bvec = xdr->bvec + (xdr->page_base >> PAGE_SHIFT);
> + offset = offset_in_page(xdr->page_base);
> remaining = xdr->page_len;
> flags = MSG_MORE | MSG_SENDPAGE_NOTLAST;
> while (remaining > 0) {
> if (remaining <= PAGE_SIZE && tail->iov_len == 0)
> flags = 0;
> - len = min(remaining, bvec->bv_len);
> +
> + len = min(remaining, bvec->bv_len - offset);
> ret = kernel_sendpage(sock, bvec->bv_page,
> bvec->bv_offset + offset,
> len, flags);
>
>
^ permalink raw reply [flat|nested] 2+ messages in thread
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