From: Jeff Layton jlayton@kernel.org
[ Upstream commit 64e6304169f1e1f078e7f0798033f80a7fb0ea46 ]
It's not safe to call nfsd_put once nfsd_last_thread has been called, as that function will zero out the nn->nfsd_serv pointer.
Drop the nfsd_put helper altogether and open-code the svc_put in its callers instead. That allows us to not be reliant on the value of that pointer when handling an error.
Fixes: 2a501f55cd64 ("nfsd: call nfsd_last_thread() before final nfsd_put()") Reported-by: Zhi Li yieli@redhat.com Cc: NeilBrown neilb@suse.de Signed-off-by: Jeffrey Layton jlayton@redhat.com Signed-off-by: Chuck Lever chuck.lever@oracle.com --- fs/nfsd/nfsctl.c | 31 +++++++++++++++++-------------- fs/nfsd/nfsd.h | 7 ------- 2 files changed, 17 insertions(+), 21 deletions(-)
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c index a906d0257e3a..2feaa49fb9fe 100644 --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -709,6 +709,7 @@ static ssize_t __write_ports_addfd(char *buf, struct net *net, const struct cred char *mesg = buf; int fd, err; struct nfsd_net *nn = net_generic(net, nfsd_net_id); + struct svc_serv *serv;
err = get_int(&mesg, &fd); if (err != 0 || fd < 0) @@ -718,15 +719,15 @@ static ssize_t __write_ports_addfd(char *buf, struct net *net, const struct cred if (err != 0) return err;
- err = svc_addsock(nn->nfsd_serv, net, fd, buf, SIMPLE_TRANSACTION_LIMIT, cred); + serv = nn->nfsd_serv; + err = svc_addsock(serv, net, fd, buf, SIMPLE_TRANSACTION_LIMIT, cred);
- if (err < 0 && !nn->nfsd_serv->sv_nrthreads && !nn->keep_active) + if (err < 0 && !serv->sv_nrthreads && !nn->keep_active) nfsd_last_thread(net); - else if (err >= 0 && - !nn->nfsd_serv->sv_nrthreads && !xchg(&nn->keep_active, 1)) - svc_get(nn->nfsd_serv); + else if (err >= 0 && !serv->sv_nrthreads && !xchg(&nn->keep_active, 1)) + svc_get(serv);
- nfsd_put(net); + svc_put(serv); return err; }
@@ -740,6 +741,7 @@ static ssize_t __write_ports_addxprt(char *buf, struct net *net, const struct cr struct svc_xprt *xprt; int port, err; struct nfsd_net *nn = net_generic(net, nfsd_net_id); + struct svc_serv *serv;
if (sscanf(buf, "%15s %5u", transport, &port) != 2) return -EINVAL; @@ -751,32 +753,33 @@ static ssize_t __write_ports_addxprt(char *buf, struct net *net, const struct cr if (err != 0) return err;
- err = svc_xprt_create(nn->nfsd_serv, transport, net, + serv = nn->nfsd_serv; + err = svc_xprt_create(serv, transport, net, PF_INET, port, SVC_SOCK_ANONYMOUS, cred); if (err < 0) goto out_err;
- err = svc_xprt_create(nn->nfsd_serv, transport, net, + err = svc_xprt_create(serv, transport, net, PF_INET6, port, SVC_SOCK_ANONYMOUS, cred); if (err < 0 && err != -EAFNOSUPPORT) goto out_close;
- if (!nn->nfsd_serv->sv_nrthreads && !xchg(&nn->keep_active, 1)) - svc_get(nn->nfsd_serv); + if (!serv->sv_nrthreads && !xchg(&nn->keep_active, 1)) + svc_get(serv);
- nfsd_put(net); + svc_put(serv); return 0; out_close: - xprt = svc_find_xprt(nn->nfsd_serv, transport, net, PF_INET, port); + xprt = svc_find_xprt(serv, transport, net, PF_INET, port); if (xprt != NULL) { svc_xprt_close(xprt); svc_xprt_put(xprt); } out_err: - if (!nn->nfsd_serv->sv_nrthreads && !nn->keep_active) + if (!serv->sv_nrthreads && !nn->keep_active) nfsd_last_thread(net);
- nfsd_put(net); + svc_put(serv); return err; }
diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h index 781781b88cca..996f3f62335b 100644 --- a/fs/nfsd/nfsd.h +++ b/fs/nfsd/nfsd.h @@ -97,13 +97,6 @@ int nfsd_pool_stats_open(struct inode *, struct file *); int nfsd_pool_stats_release(struct inode *, struct file *); void nfsd_shutdown_threads(struct net *net);
-static inline void nfsd_put(struct net *net) -{ - struct nfsd_net *nn = net_generic(net, nfsd_net_id); - - svc_put(nn->nfsd_serv); -} - bool i_am_nfsd(void);
struct nfsdfs_client {