diff options
| author | J. Bruce Fields <bfields@redhat.com> | 2019-02-20 12:54:50 -0500 |
|---|---|---|
| committer | J. Bruce Fields <bfields@redhat.com> | 2019-02-21 10:17:36 -0500 |
| commit | b7e5034cbecf5a65b7bfdc2b20a8378039577706 (patch) | |
| tree | c870f31de77d6108b2b58b57ff0b1863853c39fc /net/sunrpc/svcsock.c | |
| parent | 8820bcaa5bd73db2e28caae98f080a04cb6e2abb (diff) | |
| download | lwn-b7e5034cbecf5a65b7bfdc2b20a8378039577706.tar.gz lwn-b7e5034cbecf5a65b7bfdc2b20a8378039577706.zip | |
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/svcsock.c')
| -rw-r--r-- | net/sunrpc/svcsock.c | 20 |
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); |