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authorJ. Bruce Fields <bfields@redhat.com>2019-02-20 20:54:50 +0300
committerJ. Bruce Fields <bfields@redhat.com>2019-02-21 18:17:36 +0300
commitb7e5034cbecf5a65b7bfdc2b20a8378039577706 (patch)
treec870f31de77d6108b2b58b57ff0b1863853c39fc /net/sunrpc
parent8820bcaa5bd73db2e28caae98f080a04cb6e2abb (diff)
downloadlinux-b7e5034cbecf5a65b7bfdc2b20a8378039577706.tar.xz
svcrpc: fix UDP on servers with lots of threads
James Pearson found that an NFS server stopped responding to UDP requests if started with more than 1017 threads. sv_max_mesg is about 2^20, so that is probably where the calculation performed by svc_sock_setbufsize(svsk->sk_sock, (serv->sv_nrthreads+3) * serv->sv_max_mesg, (serv->sv_nrthreads+3) * serv->sv_max_mesg); starts to overflow an int. Reported-by: James Pearson <jcpearson@gmail.com> Tested-by: James Pearson <jcpearson@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Diffstat (limited to 'net/sunrpc')
-rw-r--r--net/sunrpc/svcsock.c20
1 files changed, 10 insertions, 10 deletions
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index a6a060925e5d..43590a968b73 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -349,12 +349,16 @@ static ssize_t svc_recvfrom(struct svc_rqst *rqstp, struct kvec *iov,
/*
* Set socket snd and rcv buffer lengths
*/
-static void svc_sock_setbufsize(struct socket *sock, unsigned int snd,
- unsigned int rcv)
+static void svc_sock_setbufsize(struct svc_sock *svsk, unsigned int nreqs)
{
+ unsigned int max_mesg = svsk->sk_xprt.xpt_server->sv_max_mesg;
+ struct socket *sock = svsk->sk_sock;
+
+ nreqs = min(nreqs, INT_MAX / 2 / max_mesg);
+
lock_sock(sock->sk);
- sock->sk->sk_sndbuf = snd * 2;
- sock->sk->sk_rcvbuf = rcv * 2;
+ sock->sk->sk_sndbuf = nreqs * max_mesg * 2;
+ sock->sk->sk_rcvbuf = nreqs * max_mesg * 2;
sock->sk->sk_write_space(sock->sk);
release_sock(sock->sk);
}
@@ -516,9 +520,7 @@ static int svc_udp_recvfrom(struct svc_rqst *rqstp)
* provides an upper bound on the number of threads
* which will access the socket.
*/
- svc_sock_setbufsize(svsk->sk_sock,
- (serv->sv_nrthreads+3) * serv->sv_max_mesg,
- (serv->sv_nrthreads+3) * serv->sv_max_mesg);
+ svc_sock_setbufsize(svsk, serv->sv_nrthreads + 3);
clear_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);
skb = NULL;
@@ -681,9 +683,7 @@ static void svc_udp_init(struct svc_sock *svsk, struct svc_serv *serv)
* receive and respond to one request.
* svc_udp_recvfrom will re-adjust if necessary
*/
- svc_sock_setbufsize(svsk->sk_sock,
- 3 * svsk->sk_xprt.xpt_server->sv_max_mesg,
- 3 * svsk->sk_xprt.xpt_server->sv_max_mesg);
+ svc_sock_setbufsize(svsk, 3);
/* data might have come in before data_ready set up */
set_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags);