diff mbox

kernel 3.8.4 : kernel BUG at fs/locks.c:2093! part #2

Message ID 20130326144640.GB3353@fieldses.org (mailing list archive)
State New, archived
Headers show

Commit Message

J. Bruce Fields March 26, 2013, 2:46 p.m. UTC 
On Mon, Mar 25, 2013 at 06:01:43PM -0400, bfields wrote:
> On Sun, Mar 24, 2013 at 06:02:39PM +0100, Toralf Förster wrote:
> > The following bug was triggered twice under a stable 3.8.4 kernel if I export a NFS (v4) directory
> > and mount it within a user mode linux (running at the same system) and run within that UML trinity
> > (16 UML trinity processes at a 4-core host CPU) with victim files+directories within that NFS directory.
> > 
> > I could not trigger that bug at the host kernel if I run trinity within UML without victim files
> > - therefore the issue seems to be tied to NFS. The syslog messages are :
> 
> Thanks!
> 
> fs/locks.c:2093 says that we did the final fput of a file that still had
> posix locks held on it.
> 
> I can't see how that would happen, but admittedly the nfsd4 code here is
> much too complicated for its own good.
> 
> If it were possible it would be useful to know what lead up to this.  A
> network trace (tcpdump -s0 -wtmp.pcap, then send me tmp.pcap) would be
> useful for that, but I fear it's probably too huge by the time you hit
> the bug.
> 
> (The following warning ("rcu_sched self-detected stall") looks like the
> result of BUGing while holding file_lock_lock.  That BUG should probably
> be downgraded to a WARN_ON_ONCE.)

Can you run with test patches?

This just makes nfsd's fput calls synchronous so that we see in the
backtrace who called them.

(But assuming it does turn out to be one of these callers, we may then
need some more printk's in the nfsd code...).

--b.

commit 27a3395a72e1d9be121f5493e7a330d60b3d1de3
Author: J. Bruce Fields <bfields@redhat.com>
Date:   Tue Mar 26 09:37:07 2013 -0400

    nfsd4: convert fput to fput_sync for debugging purposes
    
    Just a temporary hack to get backtraces out of __fput failures.
    
    Also, demote a BUG to a WARN_ON_ONCE.
    
    Signed-off-by: J. Bruce Fields <bfields@redhat.com>

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Comments

Al Viro March 26, 2013, 5:37 p.m. UTC | #1 
On Tue, Mar 26, 2013 at 10:46:40AM -0400, J. Bruce Fields wrote:
> > fs/locks.c:2093 says that we did the final fput of a file that still had
> > posix locks held on it.
> > 
> > I can't see how that would happen, but admittedly the nfsd4 code here is
> > much too complicated for its own good.
> > 
> > If it were possible it would be useful to know what lead up to this.  A
> > network trace (tcpdump -s0 -wtmp.pcap, then send me tmp.pcap) would be
> > useful for that, but I fear it's probably too huge by the time you hit
> > the bug.
> > 
> > (The following warning ("rcu_sched self-detected stall") looks like the
> > result of BUGing while holding file_lock_lock.  That BUG should probably
> > be downgraded to a WARN_ON_ONCE.)
> 
> Can you run with test patches?
> 
> This just makes nfsd's fput calls synchronous so that we see in the
> backtrace who called them.
> 
> (But assuming it does turn out to be one of these callers, we may then
> need some more printk's in the nfsd code...).

Might also be a good idea to dump the offending struct file_lock, while
we are at it...
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Toralf Förster March 26, 2013, 5:46 p.m. UTC | #2 
On 03/26/2013 03:46 PM, J. Bruce Fields wrote:
> Can you run with test patches?
> 
> This just makes nfsd's fput calls synchronous so that we see in the
> backtrace who called them.

Well - the patched 3.8.4 host kernel now survives the stress test of the UML system.
What I get at the host is now :

2013-03-26T18:32:17.487+01:00 n22 kernel: ------------[ cut here ]------------
2013-03-26T18:32:17.487+01:00 n22 kernel: WARNING: at mm/page_alloc.c:2376 __alloc_pages_nodemask+0x262/0x7c0()
2013-03-26T18:32:17.487+01:00 n22 kernel: Hardware name: 4180F65
2013-03-26T18:32:17.487+01:00 n22 kernel: Modules linked in: md5 nfsd auth_rpcgss ipt_MASQUERADE xt_owner xt_multiport ipt_REJECT xt_tcpudp xt_recent xt_conntrack nf_conntrack_ftp xt_limit xt_LOG iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_filter ip_tables x_tables af_packet pppoe pppox ppp_generic slhc bridge stp llc tun msr snd_hda_codec_conexant snd_hda_intel uvcvideo i915 usblp snd_hda_codec sdhci_pci snd_pcm cfbfillrect videobuf2_vmalloc arc4 iwldvm cfbimgblt i2c_algo_bit cfbcopyarea intel_agp videobuf2_memops sdhci coretemp videobuf2_core mac80211 snd_page_alloc kvm_intel acpi_cpufreq fbcon mperf bitblit softcursor font intel_gtt videodev mmc_core snd_timer kvm drm_kms_helper thinkpad_acpi drm nvram agpgart fb snd i2c_i801 video i2c_core tpm_tis soundcore processor 8250_pci 8250_core iwlwifi thermal battery cfg80211 fbdev ac tpm rfkill psmouse serial_core e1000e evdev thermal_sys button tpm_bios wmi hwmon aesni_intel ablk_helper cryptd lr
w aes_i586 xts gf128mul cbc sha256_generic fuse nfs lockd sunrpc dm_crypt dm_mod hid_monterey hid_microsoft hid_logitech hid_ezkey hid_cypress hid_chicony hid_cherry hid_belkin hid_apple hid_a4tech hid_generic usbhid hid sr_mod cdrom sg [last unloaded: microcode]
2013-03-26T18:32:17.487+01:00 n22 kernel: Pid: 6614, comm: nfsd Not tainted 3.8.4 #9
2013-03-26T18:32:17.487+01:00 n22 kernel: Call Trace:
2013-03-26T18:32:17.487+01:00 n22 kernel: [<c1033ba2>] warn_slowpath_common+0x72/0xa0
2013-03-26T18:32:17.487+01:00 n22 kernel: [<c10db802>] ? __alloc_pages_nodemask+0x262/0x7c0
2013-03-26T18:32:17.487+01:00 n22 kernel: [<c10db802>] ? __alloc_pages_nodemask+0x262/0x7c0
2013-03-26T18:32:17.487+01:00 n22 kernel: [<c1033bf2>] warn_slowpath_null+0x22/0x30
2013-03-26T18:32:17.487+01:00 n22 kernel: [<c10db802>] __alloc_pages_nodemask+0x262/0x7c0
2013-03-26T18:32:17.487+01:00 n22 kernel: [<c1069758>] ? dequeue_task_fair+0x258/0x6f0
2013-03-26T18:32:17.487+01:00 n22 kernel: [<c13a8803>] ? inet_recvmsg+0x73/0x90
2013-03-26T18:32:17.487+01:00 n22 kernel: [<c10dbd7c>] __get_free_pages+0x1c/0x30
2013-03-26T18:32:17.487+01:00 n22 kernel: [<c110e0f9>] kmalloc_order_trace+0x29/0xb0
2013-03-26T18:32:17.487+01:00 n22 kernel: [<f857e480>] ? ip_map_request+0xd0/0xd0 [sunrpc]
2013-03-26T18:32:17.487+01:00 n22 kernel: [<f85824d6>] ? cache_revisit_request+0x26/0xd0 [sunrpc]
2013-03-26T18:32:17.487+01:00 n22 kernel: [<c110f149>] __kmalloc+0x1b9/0x1e0
2013-03-26T18:32:17.487+01:00 n22 kernel: [<f85835bf>] ? cache_check+0x22f/0x340 [sunrpc]
2013-03-26T18:32:17.487+01:00 n22 kernel: [<f90a0b1c>] nfs4_acl_new+0x1c/0x30 [nfsd]
2013-03-26T18:32:17.488+01:00 n22 kernel: [<f9095482>] nfsd4_decode_fattr+0x302/0x6c0 [nfsd]
2013-03-26T18:32:17.488+01:00 n22 kernel: [<c110f068>] ? __kmalloc+0xd8/0x1e0
2013-03-26T18:32:17.488+01:00 n22 kernel: [<f9095871>] nfsd4_decode_setattr+0x31/0x40 [nfsd]
2013-03-26T18:32:17.488+01:00 n22 kernel: [<f909804d>] nfs4svc_decode_compoundargs+0x23d/0x280 [nfsd]
2013-03-26T18:32:17.488+01:00 n22 kernel: [<f9097e10>] ? nfsd4_release_compoundargs+0x70/0x70 [nfsd]
2013-03-26T18:32:17.488+01:00 n22 kernel: [<f9081b3f>] nfsd_dispatch+0x3f/0x1b0 [nfsd]
2013-03-26T18:32:17.488+01:00 n22 kernel: [<f857b8a8>] svc_process+0x3f8/0x6d0 [sunrpc]
2013-03-26T18:32:17.488+01:00 n22 kernel: [<f8586d5e>] ? svc_xprt_received+0x3e/0x80 [sunrpc]
2013-03-26T18:32:17.488+01:00 n22 kernel: [<f85879e1>] ? svc_recv+0x2d1/0x3c0 [sunrpc]
2013-03-26T18:32:17.488+01:00 n22 kernel: [<f908165d>] nfsd+0xad/0x110 [nfsd]
2013-03-26T18:32:17.488+01:00 n22 kernel: [<f90815b0>] ? nfsd_destroy+0x70/0x70 [nfsd]
2013-03-26T18:32:17.488+01:00 n22 kernel: [<c1053b94>] kthread+0x94/0xa0
2013-03-26T18:32:17.488+01:00 n22 kernel: [<c13d0f77>] ret_from_kernel_thread+0x1b/0x28
2013-03-26T18:32:17.488+01:00 n22 kernel: [<c1053b00>] ? flush_kthread_work+0xd0/0xd0
2013-03-26T18:32:17.488+01:00 n22 kernel: ---[ end trace 82b96ff8bcd5453f ]---
Toralf Förster March 27, 2013, 9:35 p.m. UTC | #3 
On 03/26/2013 03:46 PM, J. Bruce Fields wrote:
> Can you run with test patches?

applied - today I got a warning instead a bug at the host kernel (3.8.4):


2013-03-27T22:28:43.480+01:00 n22 kernel: ------------[ cut here ]------------
2013-03-27T22:28:43.480+01:00 n22 kernel: WARNING: at fs/locks.c:2093 locks_remove_flock+0xe5/0x110()
2013-03-27T22:28:43.480+01:00 n22 kernel: Hardware name: 4180F65
2013-03-27T22:28:43.480+01:00 n22 kernel: Modules linked in: loop md5 nfsd auth_rpcgss ipt_MASQUERADE xt_owner xt_multiport ipt_REJECT xt_tcpudp xt_recent xt_conntrack nf_conntrack_ftp xt_limit xt_LOG iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_filter ip_tables x_tables af_packet pppoe pppox ppp_generic slhc bridge stp llc tun msr i915 cfbfillrect cfbimgblt i2c_algo_bit cfbcopyarea intel_agp intel_gtt sdhci_pci fbcon bitblit softcursor font drm_kms_helper sdhci usblp drm arc4 mmc_core iwldvm mac80211 uvcvideo videobuf2_vmalloc snd_hda_codec_conexant videobuf2_memops videobuf2_core coretemp videodev acpi_cpufreq iwlwifi mperf cfg80211 snd_hda_intel agpgart fb fbdev i2c_i801 thinkpad_acpi processor video thermal ac snd_hda_codec snd_pcm snd_page_alloc 8250_pci i2c_core kvm_intel snd_timer nvram snd soundcore 8250_core e1000e serial_core button tpm_tis tpm kvm rfkill tpm_bios psmouse thermal_sys battery wmi evdev hwmon aesni_intel ablk_helper cryp
td lrw aes_i586 xts gf128mul cbc sha256_generic fuse nfs lockd sunrpc dm_crypt dm_mod hid_monterey hid_microsoft hid_logitech hid_ezkey hid_cypress hid_chicony hid_cherry hid_belkin hid_apple hid_a4tech hid_generic usbhid hid sr_mod cdrom sg [last unloaded: microcode]
2013-03-27T22:28:43.480+01:00 n22 kernel: Pid: 7442, comm: nfsd Not tainted 3.8.4 #13
2013-03-27T22:28:43.480+01:00 n22 kernel: Call Trace:
2013-03-27T22:28:43.480+01:00 n22 kernel: [<c1033ba2>] warn_slowpath_common+0x72/0xa0
2013-03-27T22:28:43.480+01:00 n22 kernel: [<c1160885>] ? locks_remove_flock+0xe5/0x110
2013-03-27T22:28:43.480+01:00 n22 kernel: [<c1160885>] ? locks_remove_flock+0xe5/0x110
2013-03-27T22:28:43.480+01:00 n22 kernel: [<c1033bf2>] warn_slowpath_null+0x22/0x30
2013-03-27T22:28:43.480+01:00 n22 kernel: [<c1160885>] locks_remove_flock+0xe5/0x110
2013-03-27T22:28:43.480+01:00 n22 kernel: [<c110eb53>] ? kmem_cache_alloc+0x73/0x140
2013-03-27T22:28:43.480+01:00 n22 kernel: [<c111e719>] __fput+0x79/0x1f0
2013-03-27T22:28:43.480+01:00 n22 kernel: [<c111ed1b>] __fput_sync+0x4b/0x60
2013-03-27T22:28:43.480+01:00 n22 kernel: [<f8bb8b17>] __nfs4_file_put_access+0x57/0x80 [nfsd]
2013-03-27T22:28:43.480+01:00 n22 kernel: [<f8bb8b73>] nfs4_file_put_access+0x33/0x40 [nfsd]
2013-03-27T22:28:43.480+01:00 n22 kernel: [<f8bbd4f6>] nfsd4_open_downgrade+0x1b6/0x210 [nfsd]
2013-03-27T22:28:43.480+01:00 n22 kernel: [<f8bbd340>] ? nfsd4_open_confirm+0x130/0x130 [nfsd]
2013-03-27T22:28:43.480+01:00 n22 kernel: [<f8baf94b>] nfsd4_proc_compound+0x41b/0x530 [nfsd]
2013-03-27T22:28:43.480+01:00 n22 kernel: [<f8bbf180>] ? nfsd4_set_lockstateid+0x50/0x50 [nfsd]
2013-03-27T22:28:43.481+01:00 n22 kernel: [<f8ba1ba0>] nfsd_dispatch+0xa0/0x1b0 [nfsd]
2013-03-27T22:28:43.481+01:00 n22 kernel: [<f857b8a8>] svc_process+0x3f8/0x6d0 [sunrpc]
2013-03-27T22:28:43.481+01:00 n22 kernel: [<f8586d5e>] ? svc_xprt_received+0x3e/0x80 [sunrpc]
2013-03-27T22:28:43.481+01:00 n22 kernel: [<f85879e1>] ? svc_recv+0x2d1/0x3c0 [sunrpc]
2013-03-27T22:28:43.481+01:00 n22 kernel: [<f8ba165d>] nfsd+0xad/0x110 [nfsd]
2013-03-27T22:28:43.481+01:00 n22 kernel: [<f8ba15b0>] ? nfsd_destroy+0x70/0x70 [nfsd]
2013-03-27T22:28:43.481+01:00 n22 kernel: [<c1053b94>] kthread+0x94/0xa0
2013-03-27T22:28:43.481+01:00 n22 kernel: [<c13d0f77>] ret_from_kernel_thread+0x1b/0x28
2013-03-27T22:28:43.481+01:00 n22 kernel: [<c1053b00>] ? flush_kthread_work+0xd0/0xd0
2013-03-27T22:28:43.481+01:00 n22 kernel: ---[ end trace 66f6fe36b0d13e8f ]---


The UML kernel was 3.9.0-rc4-00144-ga8c4528, and the trinity command just :
$> trinity --children 2 --victims /mnt/nfs/n22/victims -x mremap
J. Bruce Fields March 27, 2013, 9:57 p.m. UTC | #4 
On Wed, Mar 27, 2013 at 10:35:12PM +0100, Toralf Förster wrote:
> On 03/26/2013 03:46 PM, J. Bruce Fields wrote:
> > Can you run with test patches?
> 
> applied - today I got a warning instead a bug at the host kernel (3.8.4):

Excellent!  Thanks, I think I see the bug now....

--b.

> 2013-03-27T22:28:43.480+01:00 n22 kernel: ------------[ cut here ]------------
> 2013-03-27T22:28:43.480+01:00 n22 kernel: WARNING: at fs/locks.c:2093 locks_remove_flock+0xe5/0x110()
> 2013-03-27T22:28:43.480+01:00 n22 kernel: Hardware name: 4180F65
> 2013-03-27T22:28:43.480+01:00 n22 kernel: Modules linked in: loop md5 nfsd auth_rpcgss ipt_MASQUERADE xt_owner xt_multiport ipt_REJECT xt_tcpudp xt_recent xt_conntrack nf_conntrack_ftp xt_limit xt_LOG iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_filter ip_tables x_tables af_packet pppoe pppox ppp_generic slhc bridge stp llc tun msr i915 cfbfillrect cfbimgblt i2c_algo_bit cfbcopyarea intel_agp intel_gtt sdhci_pci fbcon bitblit softcursor font drm_kms_helper sdhci usblp drm arc4 mmc_core iwldvm mac80211 uvcvideo videobuf2_vmalloc snd_hda_codec_conexant videobuf2_memops videobuf2_core coretemp videodev acpi_cpufreq iwlwifi mperf cfg80211 snd_hda_intel agpgart fb fbdev i2c_i801 thinkpad_acpi processor video thermal ac snd_hda_codec snd_pcm snd_page_alloc 8250_pci i2c_core kvm_intel snd_timer nvram snd soundcore 8250_core e1000e serial_core button tpm_tis tpm kvm rfkill tpm_bios psmouse thermal_sys battery wmi evdev hwmon aesni_intel ablk_helper cryp
> td lrw aes_i586 xts gf128mul cbc sha256_generic fuse nfs lockd sunrpc dm_crypt dm_mod hid_monterey hid_microsoft hid_logitech hid_ezkey hid_cypress hid_chicony hid_cherry hid_belkin hid_apple hid_a4tech hid_generic usbhid hid sr_mod cdrom sg [last unloaded: microcode]
> 2013-03-27T22:28:43.480+01:00 n22 kernel: Pid: 7442, comm: nfsd Not tainted 3.8.4 #13
> 2013-03-27T22:28:43.480+01:00 n22 kernel: Call Trace:
> 2013-03-27T22:28:43.480+01:00 n22 kernel: [<c1033ba2>] warn_slowpath_common+0x72/0xa0
> 2013-03-27T22:28:43.480+01:00 n22 kernel: [<c1160885>] ? locks_remove_flock+0xe5/0x110
> 2013-03-27T22:28:43.480+01:00 n22 kernel: [<c1160885>] ? locks_remove_flock+0xe5/0x110
> 2013-03-27T22:28:43.480+01:00 n22 kernel: [<c1033bf2>] warn_slowpath_null+0x22/0x30
> 2013-03-27T22:28:43.480+01:00 n22 kernel: [<c1160885>] locks_remove_flock+0xe5/0x110
> 2013-03-27T22:28:43.480+01:00 n22 kernel: [<c110eb53>] ? kmem_cache_alloc+0x73/0x140
> 2013-03-27T22:28:43.480+01:00 n22 kernel: [<c111e719>] __fput+0x79/0x1f0
> 2013-03-27T22:28:43.480+01:00 n22 kernel: [<c111ed1b>] __fput_sync+0x4b/0x60
> 2013-03-27T22:28:43.480+01:00 n22 kernel: [<f8bb8b17>] __nfs4_file_put_access+0x57/0x80 [nfsd]
> 2013-03-27T22:28:43.480+01:00 n22 kernel: [<f8bb8b73>] nfs4_file_put_access+0x33/0x40 [nfsd]
> 2013-03-27T22:28:43.480+01:00 n22 kernel: [<f8bbd4f6>] nfsd4_open_downgrade+0x1b6/0x210 [nfsd]
> 2013-03-27T22:28:43.480+01:00 n22 kernel: [<f8bbd340>] ? nfsd4_open_confirm+0x130/0x130 [nfsd]
> 2013-03-27T22:28:43.480+01:00 n22 kernel: [<f8baf94b>] nfsd4_proc_compound+0x41b/0x530 [nfsd]
> 2013-03-27T22:28:43.480+01:00 n22 kernel: [<f8bbf180>] ? nfsd4_set_lockstateid+0x50/0x50 [nfsd]
> 2013-03-27T22:28:43.481+01:00 n22 kernel: [<f8ba1ba0>] nfsd_dispatch+0xa0/0x1b0 [nfsd]
> 2013-03-27T22:28:43.481+01:00 n22 kernel: [<f857b8a8>] svc_process+0x3f8/0x6d0 [sunrpc]
> 2013-03-27T22:28:43.481+01:00 n22 kernel: [<f8586d5e>] ? svc_xprt_received+0x3e/0x80 [sunrpc]
> 2013-03-27T22:28:43.481+01:00 n22 kernel: [<f85879e1>] ? svc_recv+0x2d1/0x3c0 [sunrpc]
> 2013-03-27T22:28:43.481+01:00 n22 kernel: [<f8ba165d>] nfsd+0xad/0x110 [nfsd]
> 2013-03-27T22:28:43.481+01:00 n22 kernel: [<f8ba15b0>] ? nfsd_destroy+0x70/0x70 [nfsd]
> 2013-03-27T22:28:43.481+01:00 n22 kernel: [<c1053b94>] kthread+0x94/0xa0
> 2013-03-27T22:28:43.481+01:00 n22 kernel: [<c13d0f77>] ret_from_kernel_thread+0x1b/0x28
> 2013-03-27T22:28:43.481+01:00 n22 kernel: [<c1053b00>] ? flush_kthread_work+0xd0/0xd0
> 2013-03-27T22:28:43.481+01:00 n22 kernel: ---[ end trace 66f6fe36b0d13e8f ]---
> 
> 
> The UML kernel was 3.9.0-rc4-00144-ga8c4528, and the trinity command just :
> $> trinity --children 2 --victims /mnt/nfs/n22/victims -x mremap
> 
> -- 
> MfG/Sincerely
> Toralf Förster
> pgp finger print: 7B1A 07F4 EC82 0F90 D4C2 8936 872A E508 7DB6 9DA3
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diff mbox

Patch

diff --git a/fs/file_table.c b/fs/file_table.c
index de9e965..79cb999 100644
--- a/fs/file_table.c
+++ b/fs/file_table.c
@@ -337,6 +337,8 @@  void __fput_sync(struct file *file)
 	}
 }
 
+EXPORT_SYMBOL(__fput_sync);
+
 EXPORT_SYMBOL(fput);
 
 void put_filp(struct file *file)
diff --git a/fs/locks.c b/fs/locks.c
index a94e331..c962161 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -2090,7 +2090,7 @@  void locks_remove_flock(struct file *filp)
 				continue;
 			}
 			/* What? */
-			BUG();
+			WARN_ON_ONCE(1);
  		}
 		before = &fl->fl_next;
 	}
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 9d1c5db..c01c60c 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -951,7 +951,7 @@  nfsd4_write(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 			     write->wr_offset, rqstp->rq_vec, nvecs,
 			     &cnt, &write->wr_how_written);
 	if (filp)
-		fput(filp);
+		__fput_sync(filp);
 
 	write->wr_bytes_written = cnt;
 
@@ -1325,7 +1325,7 @@  encode_op:
 		}
 		/* XXX Ugh, we need to get rid of this kind of special case: */
 		if (op->opnum == OP_READ && op->u.read.rd_filp)
-			fput(op->u.read.rd_filp);
+			__fput_sync(op->u.read.rd_filp);
 
 		nfsd4_increment_op_stats(op->opnum);
 	}
diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
index ba6fdd4..dfdf54c 100644
--- a/fs/nfsd/nfs4recover.c
+++ b/fs/nfsd/nfs4recover.c
@@ -546,7 +546,7 @@  nfsd4_shutdown_recdir(struct nfsd_net *nn)
 {
 	if (!nn->rec_file)
 		return;
-	fput(nn->rec_file);
+	__fput_sync(nn->rec_file);
 	nn->rec_file = NULL;
 }
 
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index a8309c6..0f38b39 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -201,7 +201,7 @@  static void nfs4_file_get_access(struct nfs4_file *fp, int oflag)
 static void nfs4_file_put_fd(struct nfs4_file *fp, int oflag)
 {
 	if (fp->fi_fds[oflag]) {
-		fput(fp->fi_fds[oflag]);
+		__fput_sync(fp->fi_fds[oflag]);
 		fp->fi_fds[oflag] = NULL;
 	}
 }
@@ -353,7 +353,7 @@  static void nfs4_put_deleg_lease(struct nfs4_file *fp)
 	if (atomic_dec_and_test(&fp->fi_delegees)) {
 		vfs_setlease(fp->fi_deleg_file, F_UNLCK, &fp->fi_lease);
 		fp->fi_lease = NULL;
-		fput(fp->fi_deleg_file);
+		__fput_sync(fp->fi_deleg_file);
 		fp->fi_deleg_file = NULL;
 	}
 }
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index d586117..76bb67c 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -826,7 +826,7 @@  out:
 void
 nfsd_close(struct file *filp)
 {
-	fput(filp);
+	__fput_sync(filp);
 }
 
 /*