Skip to contentSkip to conversation

FAILED: patch "[PATCH] nfsd: call nfsd_last_thread() before final nfsd_put()" failed to apply to 6.1-stable tree

PATCH [email protected] 1 participant 1 message Dec 28, 2023

Subsystems (2)
Stable branch NFS server
lore
Share & tools
lore

[email protected]

author maintainer
#0 lore raw

The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 2a501f55cd641eb4d3c16a2eab0d678693fac663
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2023122826-siding-ocean-a757@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..

Possible dependencies:

2a501f55cd64 ("nfsd: call nfsd_last_thread() before final nfsd_put()") 9f28a971ee9f ("nfsd: separate nfsd_last_thread() from nfsd_put()")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 2a501f55cd641eb4d3c16a2eab0d678693fac663 Mon Sep 17 00:00:00 2001
From: NeilBrown <[email protected]>
Date: Fri, 15 Dec 2023 11:56:31 +1100
Subject: [PATCH] nfsd: call nfsd_last_thread() before final nfsd_put()

If write_ports_addfd or write_ports_addxprt fail, they call nfsd_put() without calling nfsd_last_thread(). This leaves nn->nfsd_serv pointing to a structure that has been freed.

So remove 'static' from nfsd_last_thread() and call it when the nfsd_serv is about to be destroyed.

Fixes ec52361df99b ("SUNRPC: stop using ->sv_nrthreads as a refcount")
Signed-off-by NeilBrown <[email protected]>
Reviewed-by Jeff Layton <[email protected]>
Cc <[email protected]>
Signed-off-by Chuck Lever <[email protected]>
fs/nfsd/nfsctl.c +7 -2
index 739ed5bf71cd..79efb1075f38 100644
@@ -705,8 +705,10 @@ static ssize_t __write_ports_addfd(char *buf, struct net *net, const struct cred
 
 	err = svc_addsock(nn->nfsd_serv, net, fd, buf, SIMPLE_TRANSACTION_LIMIT, cred);
 
-	if (err >= 0 &&
-	    !nn->nfsd_serv->sv_nrthreads && !xchg(&nn->keep_active, 1))
+	if (err < 0 && !nn->nfsd_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);
 
 	nfsd_put(net);

@@ -757,6 +759,9 @@ static ssize_t __write_ports_addxprt(char *buf, struct net *net, const struct cr
 		svc_xprt_put(xprt);
 	}
 out_err:
+	if (!nn->nfsd_serv->sv_nrthreads && !nn->keep_active)
+		nfsd_last_thread(net);
+
 	nfsd_put(net);
 	return err;
 }
fs/nfsd/nfsd.h +1 -0
index f5ff42f41ee7..3286ffacbc56 100644
@@ -155,6 +155,7 @@ int nfsd_vers(struct nfsd_net *nn, int vers, enum vers_op change);
 int nfsd_minorversion(struct nfsd_net *nn, u32 minorversion, enum vers_op change);
 void nfsd_reset_versions(struct nfsd_net *nn);
 int nfsd_create_serv(struct net *net);
+void nfsd_last_thread(struct net *net);
 
 extern int nfsd_max_blksize;
fs/nfsd/nfssvc.c +1 -1
index fe61d9bbcc1f..d6939e23ffcf 100644
@@ -542,7 +542,7 @@ static struct notifier_block nfsd_inet6addr_notifier = {
 /* Only used under nfsd_mutex, so this atomic may be overkill: */
 static atomic_t nfsd_notifier_refcount = ATOMIC_INIT(0);
 
-static void nfsd_last_thread(struct net *net)
+void nfsd_last_thread(struct net *net)
 {
 	struct nfsd_net *nn = net_generic(net, nfsd_net_id);
 	struct svc_serv *serv = nn->nfsd_serv;