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| author | Giuseppe Cantavenera <giuseppe.cantavenera.ext@nokia.com> | 2015-04-20 18:00:08 +0200 |
|---|---|---|
| committer | Zefan Li <lizefan@huawei.com> | 2015-09-18 09:20:31 +0800 |
| commit | c15158153494485de5baba3ee7c1b2e6ce946a76 (patch) | |
| tree | d102899739646c50522eded71ddde7bb4bebb35e | |
| parent | 4897576f6dd988ccdf4a0923e0e626fdc6e5f690 (diff) | |
| download | lwn-c15158153494485de5baba3ee7c1b2e6ce946a76.tar.gz lwn-c15158153494485de5baba3ee7c1b2e6ce946a76.zip | |
nfsd: fix nsfd startup race triggering BUG_ON
commit bb7ffbf29e76b89a86ca4c3ee0d4690641f2f772 upstream.
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>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li <lizefan@huawei.com>
| -rw-r--r-- | fs/nfsd/nfsctl.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c index 4db777d3dc05..c8bc7ea199f5 100644 --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -1163,15 +1163,15 @@ 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; nfs4_state_init(); retval = nfsd_fault_inject_init(); /* nfsd fault injection controls */ if (retval) @@ -1209,10 +1209,10 @@ out_free_stat: nfsd_fault_inject_cleanup(); 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; } @@ -1228,8 +1228,8 @@ static void __exit exit_nfsd(void) nfsd4_free_slabs(); 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>"); |