Hi Tigran,
On Mon, 2018-03-05 at 23:26 +0100, Mkrtchyan, Tigran wrote:
> Hi Trond et al.
>
> looks like I can always reproduce the following ops with a simple cp:
>
> [10722.729463] nfs4flexfilelayout_init: NFSv4 Flexfile Layout Driver
> Registering...
> [10736.187403] ------------[ cut here ]------------
> [10736.187405] Kernel BUG at 00000000f71645f7 [verbose debug info
> unavailable]
> [10736.187417] ------------[ cut here ]------------
> [10736.187432] refcount_t hit zero at
> pnfs_layout_remove_lseg+0x46/0x90 [nfsv4] in kworker/1:0[16409],
> uid/euid: 0/0
> [10736.187436] WARNING: CPU: 1 PID: 16409 at kernel/panic.c:657
> refcount_error_report+0x94/0x9e
> [10736.187436] Modules linked in: nfs_layout_flexfiles
> rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace
> fscache xt_nat veth ipt_MASQUERADE nf_nat_masquerade_ipv4 xt_addrtype
> br_netfilter overlay tun rfcomm fuse ccm nf_conntrack_netbios_ns
> nf_conntrack_broadcast xt_CT ip6t_rpfilter ip6t_REJECT nf_reject_ipv6
> xt_conntrack xt_multiport ip_set nfnetlink ebtable_nat ebtable_broute
> bridge stp llc ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6
> nf_nat_ipv6 ip6table_mangle ip6table_raw ip6table_security
> iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat
> nf_conntrack libcrc32c iptable_mangle iptable_raw iptable_security
> ebtable_filter ebtables ip6table_filter ip6_tables cmac binfmt_misc
> bnep sunrpc vfat fat arc4 snd_soc_skl snd_hda_codec_hdmi
> snd_soc_skl_ipc snd_hda_ext_core snd_soc_sst_dsp
> [10736.187463] snd_soc_sst_ipc snd_soc_acpi uvcvideo snd_soc_core
> videobuf2_vmalloc btusb btrtl intel_rapl btbcm btintel
> videobuf2_memops x86_pkg_temp_thermal intel_powerclamp videobuf2_v4l2
> bluetooth snd_hda_codec_realtek videobuf2_core iwlmvm
> snd_hda_codec_generic coretemp videodev kvm_intel snd_compress
> snd_pcm_dmaengine ac97_bus mac80211 media snd_hda_intel kvm
> snd_hda_codec iTCO_wdt iTCO_vendor_support iwlwifi mei_wdt dell_wmi
> ecdh_generic wmi_bmof dell_smbios_wmi dell_laptop sparse_keymap
> snd_hda_core dell_wmi_descriptor ppdev dell_smbios_smm dell_smbios
> dcdbas snd_hwdep irqbypass crct10dif_pclmul dell_smm_hwmon
> crc32_pclmul snd_seq cfg80211 snd_seq_device ghash_clmulni_intel
> snd_pcm intel_cstate intel_uncore i2c_i801 intel_rapl_perf snd_timer
> joydev rtsx_pci_ms memstick snd mei_me soundcore
> [10736.187491] mei processor_thermal_device shpchp
> intel_soc_dts_iosf intel_pch_thermal wmi parport_pc parport dell_rbtn
> int3400_thermal acpi_thermal_rel acpi_pad int3403_thermal rfkill
> int340x_thermal_zone i915 rtsx_pci_sdmmc mmc_core i2c_algo_bit
> drm_kms_helper drm e1000e crc32c_intel serio_raw rtsx_pci ptp
> pps_core video
> [10736.187504] CPU: 1 PID: 16409 Comm: kworker/1:0 Tainted:
> G W 4.15.6-300.fc27.x86_64 #1
> [10736.187505] Hardware name: Dell Inc. Latitude E7470/0T6HHJ, BIOS
> 1.6.3 06/15/2016
> [10736.187518] Workqueue: nfsiod rpc_async_release [sunrpc]
> [10736.187520] RIP: 0010:refcount_error_report+0x94/0x9e
> [10736.187521] RSP: 0018:ffffa5c6d196fac0 EFLAGS: 00010282
> [10736.187522] RAX: 0000000000000000 RBX: ffffffff93088273 RCX:
> 0000000000000006
> [10736.187523] RDX: 0000000000000007 RSI: 0000000000000082 RDI:
> ffff9a780dc968f0
> [10736.187523] RBP: ffffa5c6d196fc08 R08: 0000000000000651 R09:
> 0000000000000004
> [10736.187524] R10: ffffffff93206a80 R11: 0000000000000001 R12:
> ffff9a776fe63f80
> [10736.187525] R13: 0000000000000000 R14: ffffffff930795b5 R15:
> 0000000000000004
> [10736.187526] FS: 0000000000000000(0000) GS:ffff9a780dc80000(0000)
> knlGS:0000000000000000
> [10736.187527] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [10736.187528] CR2: 000000000000000c CR3: 000000036120a005 CR4:
> 00000000003606e0
> [10736.187529] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
> 0000000000000000
> [10736.187529] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:
> 0000000000000400
> [10736.187530] Call Trace:
> [10736.187534] ex_handler_refcount+0x4e/0x80
> [10736.187536] fixup_exception+0x33/0x40
> [10736.187538] do_trap+0x83/0x140
> [10736.187540] do_error_trap+0x9d/0x120
> [10736.187550] ? nfs42_proc_clone+0x2c7/0x309 [nfsv4]
> [10736.187552] ? __update_load_avg_se.isra.30+0x1b6/0x1c0
> [10736.187553] ? __update_load_avg_se.isra.30+0x1b6/0x1c0
> [10736.187555] ? update_load_avg+0x558/0x6b0
> [10736.187557] invalid_op+0x51/0x70
> [10736.187566] RIP: 0010:pnfs_layout_remove_lseg+0x46/0x90 [nfsv4]
> [10736.187566] RSP: 0018:ffffa5c6d196fcb8 EFLAGS: 00010246
> [10736.187567] RAX: ffff9a765cc07f28 RBX: ffff9a757fe5f000 RCX:
> ffff9a765cc07f00
> [10736.187568] RDX: ffff9a765cc07f28 RSI: ffff9a757fe5f000 RDI:
> ffff9a757fe5f000
> [10736.187569] RBP: ffff9a765cc07f00 R08: 0000000000000004 R09:
> 0fb19d5a01000000
> [10736.187570] R10: ffffa5c6d196fda8 R11: ffffffffc10e3470 R12:
> ffff9a765cc07f01
> [10736.187570] R13: ffff9a756cc2d8c0 R14: 0000000000000000 R15:
> ffff9a765cc07f00
> [10736.187579] ? pnfs_layout_remove_lseg+0x1d/0x90 [nfsv4]
> [10736.187585] pnfs_lseg_dec_and_remove_zero+0x37/0x70 [nfsv4]
> [10736.187593] mark_lseg_invalid+0x29/0x50 [nfsv4]
> [10736.187600] pnfs_roc+0x1ad/0x310 [nfsv4]
> [10736.187606] ? nfs4_do_close+0x1c9/0x2e0 [nfsv4]
> [10736.187611] nfs4_do_close+0x1c9/0x2e0 [nfsv4]
> [10736.187620] __put_nfs_open_context+0x7c/0x100 [nfs]
> [10736.187627] nfs_commitdata_release+0x15/0x30 [nfs]
> [10736.187634] rpc_free_task+0x2d/0x70 [sunrpc]
> [10736.187637] process_one_work+0x175/0x390
> [10736.187640] worker_thread+0x2e/0x380
> [10736.187641] ? process_one_work+0x390/0x390
> [10736.187644] kthread+0x113/0x130
> [10736.187645] ? kthread_create_worker_on_cpu+0x70/0x70
> [10736.187647] ? kthread_create_worker_on_cpu+0x70/0x70
> [10736.187648] ret_from_fork+0x35/0x40
> [10736.187649] Code: 48 8b 95 80 00 00 00 41 55 49 8d 8c 24 48 07 00
> 00 45 8b 84 24 68 05 00 00 41 89 c1 48 89 de 48 c7 c7 c0 c7 08 93 e8
> 4c fa ff ff <0f> 0b 58 5b 5d 41 5c 41 5d c3 0f 1f 44 00 00 55 48 89
> e5 41 56
> [10736.187673] ---[ end trace ae865330f8bfd4f0 ]---
> [10736.187699] ------------[ cut here ]------------
> [10736.187700] Kernel BUG at 00000000c11ed4b1 [verbose debug info
> unavailable]
>
>
> If I downgrade my kernel to any of 4.14 - ops is gone. The 4.16-rc4
> panics as well.
> Let me know if you need more info or testing.
Does the following patch fix it?
8<--------------------------------------------------------
>From a5c81f5040a9e986eafb728719dfab2d588fe2d0 Mon Sep 17 00:00:00 2001
From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Date: Wed, 7 Mar 2018 14:49:06 -0500
Subject: [PATCH] pNFS: Prevent the layout header refcount going to zero in
pnfs_roc()
Ensure that we hold a reference to the layout header when processing
the pNFS return-on-close so that the refcount value does not inadvertently
go to zero.
Reported-by: Tigran Mkrtchyan <tigran.mkrtchyan@xxxxxxx>
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # v4.10+
---
fs/nfs/pnfs.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index c13e826614b5..ee723aa153a3 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -292,8 +292,11 @@ pnfs_detach_layout_hdr(struct pnfs_layout_hdr *lo)
void
pnfs_put_layout_hdr(struct pnfs_layout_hdr *lo)
{
- struct inode *inode = lo->plh_inode;
+ struct inode *inode;
+ if (!lo)
+ return;
+ inode = lo->plh_inode;
pnfs_layoutreturn_before_put_layout_hdr(lo);
if (refcount_dec_and_lock(&lo->plh_refcount, &inode->i_lock)) {
@@ -1241,10 +1244,12 @@ bool pnfs_roc(struct inode *ino,
spin_lock(&ino->i_lock);
lo = nfsi->layout;
if (!lo || !pnfs_layout_is_valid(lo) ||
- test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags))
+ test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
+ lo = NULL;
goto out_noroc;
+ }
+ pnfs_get_layout_hdr(lo);
if (test_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags)) {
- pnfs_get_layout_hdr(lo);
spin_unlock(&ino->i_lock);
wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN,
TASK_UNINTERRUPTIBLE);
@@ -1312,10 +1317,12 @@ bool pnfs_roc(struct inode *ino,
struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
if (ld->prepare_layoutreturn)
ld->prepare_layoutreturn(args);
+ pnfs_put_layout_hdr(lo);
return true;
}
if (layoutreturn)
pnfs_send_layoutreturn(lo, &stateid, iomode, true);
+ pnfs_put_layout_hdr(lo);
return false;
}
--
2.14.3
--
Trond Myklebust
Linux NFS client maintainer, PrimaryData
trond.myklebust@xxxxxxxxxxxxxxx
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