Patch "nfsd: register pernet ops last, unregister first" has been added to the 5.11-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    nfsd: register pernet ops last, unregister first

to the 5.11-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     nfsd-register-pernet-ops-last-unregister-first.patch
and it can be found in the queue-5.11 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 015ddec9bba4852c2e92e3a9e46d60a019a19f3c
Author: J. Bruce Fields <bfields@xxxxxxxxxx>
Date:   Wed Feb 3 11:42:13 2021 -0500

    nfsd: register pernet ops last, unregister first
    
    [ Upstream commit bd5ae9288d6451bd346a1b4a59d4fe7e62ba29b7 ]
    
    These pernet operations may depend on stuff set up or torn down in the
    module init/exit functions.  And they may be called at any time in
    between.  So it makes more sense for them to be the last to be
    registered in the init function, and the first to be unregistered in the
    exit function.
    
    In particular, without this, the drc slab is being destroyed before all
    the per-net drcs are shut down, resulting in an "Objects remaining in
    nfsd_drc on __kmem_cache_shutdown()" warning in exit_nfsd.
    
    Reported-by: Zhi Li <yieli@xxxxxxxxxx>
    Fixes: 3ba75830ce17 "nfsd4: drc containerization"
    Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
    Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index f6d5d783f4a45..0759e589ab52b 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -1522,12 +1522,9 @@ static int __init init_nfsd(void)
 	int retval;
 	printk(KERN_INFO "Installing knfsd (copyright (C) 1996 okir@xxxxxxxxxxxx).\n");
 
-	retval = register_pernet_subsys(&nfsd_net_ops);
-	if (retval < 0)
-		return retval;
 	retval = register_cld_notifier();
 	if (retval)
-		goto out_unregister_pernet;
+		return retval;
 	retval = nfsd4_init_slabs();
 	if (retval)
 		goto out_unregister_notifier;
@@ -1544,9 +1541,14 @@ static int __init init_nfsd(void)
 		goto out_free_lockd;
 	retval = register_filesystem(&nfsd_fs_type);
 	if (retval)
+		goto out_free_exports;
+	retval = register_pernet_subsys(&nfsd_net_ops);
+	if (retval < 0)
 		goto out_free_all;
 	return 0;
 out_free_all:
+	unregister_pernet_subsys(&nfsd_net_ops);
+out_free_exports:
 	remove_proc_entry("fs/nfs/exports", NULL);
 	remove_proc_entry("fs/nfs", NULL);
 out_free_lockd:
@@ -1559,13 +1561,12 @@ static int __init init_nfsd(void)
 	nfsd4_free_slabs();
 out_unregister_notifier:
 	unregister_cld_notifier();
-out_unregister_pernet:
-	unregister_pernet_subsys(&nfsd_net_ops);
 	return retval;
 }
 
 static void __exit exit_nfsd(void)
 {
+	unregister_pernet_subsys(&nfsd_net_ops);
 	nfsd_drc_slab_free();
 	remove_proc_entry("fs/nfs/exports", NULL);
 	remove_proc_entry("fs/nfs", NULL);
@@ -1575,7 +1576,6 @@ static void __exit exit_nfsd(void)
 	nfsd4_exit_pnfs();
 	unregister_filesystem(&nfsd_fs_type);
 	unregister_cld_notifier();
-	unregister_pernet_subsys(&nfsd_net_ops);
 }
 
 MODULE_AUTHOR("Olaf Kirch <okir@xxxxxxxxxxxx>");