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authorGiuseppe Cantavenera <giuseppe.cantavenera.ext@nokia.com>2015-04-20 18:00:08 +0200
committerJ. Bruce Fields <bfields@redhat.com>2015-04-21 16:16:03 -0400
commitbb7ffbf29e76b89a86ca4c3ee0d4690641f2f772 (patch)
treecafb6c6eae841ad534e3a92964624f0b663224a2
parent135dd002c23054aaa056ea3162c1e0356905c195 (diff)
downloadlinux-bb7ffbf29e76b89a86ca4c3ee0d4690641f2f772.tar.bz2
nfsd: fix nsfd startup race triggering BUG_ON
nfsd triggered a BUG_ON in net_generic(...) when rpc_pipefs_event(...) in fs/nfsd/nfs4recover.c was called before assigning ntfsd_net_id. The following was observed on a MIPS 32-core processor: kernel: Call Trace: kernel: [<ffffffffc00bc5e4>] rpc_pipefs_event+0x7c/0x158 [nfsd] kernel: [<ffffffff8017a2a0>] notifier_call_chain+0x70/0xb8 kernel: [<ffffffff8017a4e4>] __blocking_notifier_call_chain+0x4c/0x70 kernel: [<ffffffff8053aff8>] rpc_fill_super+0xf8/0x1a0 kernel: [<ffffffff8022204c>] mount_ns+0xb4/0xf0 kernel: [<ffffffff80222b48>] mount_fs+0x50/0x1f8 kernel: [<ffffffff8023dc00>] vfs_kern_mount+0x58/0xf0 kernel: [<ffffffff802404ac>] do_mount+0x27c/0xa28 kernel: [<ffffffff80240cf0>] SyS_mount+0x98/0xe8 kernel: [<ffffffff80135d24>] handle_sys64+0x44/0x68 kernel: kernel: Code: 0040f809 00000000 2e020001 <00020336> 3c12c00d 3c02801a de100000 6442eb98 0040f809 kernel: ---[ end trace 7471374335809536 ]--- Fixed this behaviour by calling register_pernet_subsys(&nfsd_net_ops) before registering rpc_pipefs_event(...) with the notifier chain. Signed-off-by: Giuseppe Cantavenera <giuseppe.cantavenera.ext@nokia.com> Signed-off-by: Lorenzo Restelli <lorenzo.restelli.ext@nokia.com> Reviewed-by: Kinlong Mee <kinglongmee@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com>
-rw-r--r--fs/nfsd/nfsctl.c16
1 files changed, 8 insertions, 8 deletions
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index aa47d75ddb26..9690cb4dd588 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -1250,15 +1250,15 @@ static int __init init_nfsd(void)
int retval;
printk(KERN_INFO "Installing knfsd (copyright (C) 1996 okir@monad.swb.de).\n");
- retval = register_cld_notifier();
- if (retval)
- return retval;
retval = register_pernet_subsys(&nfsd_net_ops);
if (retval < 0)
- goto out_unregister_notifier;
- retval = nfsd4_init_slabs();
+ return retval;
+ retval = register_cld_notifier();
if (retval)
goto out_unregister_pernet;
+ retval = nfsd4_init_slabs();
+ if (retval)
+ goto out_unregister_notifier;
retval = nfsd4_init_pnfs();
if (retval)
goto out_free_slabs;
@@ -1290,10 +1290,10 @@ out_exit_pnfs:
nfsd4_exit_pnfs();
out_free_slabs:
nfsd4_free_slabs();
-out_unregister_pernet:
- unregister_pernet_subsys(&nfsd_net_ops);
out_unregister_notifier:
unregister_cld_notifier();
+out_unregister_pernet:
+ unregister_pernet_subsys(&nfsd_net_ops);
return retval;
}
@@ -1308,8 +1308,8 @@ static void __exit exit_nfsd(void)
nfsd4_exit_pnfs();
nfsd_fault_inject_cleanup();
unregister_filesystem(&nfsd_fs_type);
- unregister_pernet_subsys(&nfsd_net_ops);
unregister_cld_notifier();
+ unregister_pernet_subsys(&nfsd_net_ops);
}
MODULE_AUTHOR("Olaf Kirch <okir@monad.swb.de>");