6.5-stable review patch. If anyone has any objections, please let me know.
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From: Chuck Lever chuck.lever@oracle.com
[ Upstream commit f16ff1cafbf1e65cc706af912df90bcc15d39a6c ]
Jeff confirmed his original fix addressed his pynfs test failure, but this same bug also impacted qemu: accessing qcow2 virtual disks using direct I/O was failing. Jeff's fix missed that you have to shorten the bio_vec element by the same amount as you increased the page offset.
Reported-by: Maxim Levitsky mlevitsk@redhat.com Fixes: c96e2a695e00 ("sunrpc: set the bv_offset of first bvec in svc_tcp_sendmsg") Tested-by: Maxim Levitsky mlevitsk@redhat.com Reviewed-by: Jeff Layton jlayton@kernel.org Signed-off-by: Chuck Lever chuck.lever@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/sunrpc/svcsock.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c index 2eb8df44f894d..589020ed909dc 100644 --- a/net/sunrpc/svcsock.c +++ b/net/sunrpc/svcsock.c @@ -1244,8 +1244,10 @@ static int svc_tcp_sendmsg(struct socket *sock, struct xdr_buf *xdr, if (ret != head->iov_len) goto out;
- if (xdr_buf_pagecount(xdr)) + if (xdr_buf_pagecount(xdr)) { xdr->bvec[0].bv_offset = offset_in_page(xdr->page_base); + xdr->bvec[0].bv_len -= offset_in_page(xdr->page_base); + }
msg.msg_flags = MSG_SPLICE_PAGES; iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, xdr->bvec,