<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"> <head> <meta http-equiv="Content-Type" content="text/html; charset=gb2312"> <meta name="Generator" content="Microsoft Word 15 (filtered medium)"> <style></style> </head> <body lang="ZH-CN" link="#0563C1" vlink="#954F72" style="text-justify-trim:punctuation"> <div class="WordSection1"> Hi,<o:p></o:p> <o:p> </o:p> We got feedback from customer that cvm(cloud virtual machine) crashed when using kubelet updating container-service in ubuntu xenial. Logs show as follow. <o:p></o:p> We find a patch (commit 33c35aa4817864e056fd772230b0c6b552e36ea2) in linux mainline, which can indeed fix this bug. But ubuntu-xenial.git has not merged it yet. <o:p></o:p> <o:p> </o:p> Do you guys have a plan for merging?<o:p></o:p> <o:p> </o:p> ----------------------panic log-----------------------------<o:p></o:p> [2018-02-02 10:21:48][4397731.721563] BUG: unable to handle kernel paging request at 000000010000005c<o:p></o:p> [2018-02-02 10:40:50][4397731.722666] IP: css_clear_dir+0x5/0x70<o:p></o:p> [2018-02-02 10:40:50][4397731.723261] PGD a12b067 <o:p></o:p> [2018-02-02 10:40:50][4397731.723261] PUD 0 <o:p></o:p> [2018-02-02 10:40:50][4397731.723628] <o:p> </o:p> [2018-02-02 10:40:50][4397731.724004] Oops: 0000 [#1] SMP<o:p></o:p> [2018-02-02 10:40:50][4397731.724004] Modules linked in: xt_statistic nf_conntrack_netlink ebt_ip ebtable_filter ebtables veth xt_set ip_set_hash_net ip_set nfnetlink xt_nat xt_recent xt_mark ipt_REJ[2018-02-02 10:40:50]ECT nf_reject_ipv4 xt_tcpudp xt_comment ipt_MASQUERADE nf_nat_masquerade_ipv4 xfrm_user xfrm_algo iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 xt_addrtype iptable_fil[2018-02-02 10:40:50]ter ip_tables xt_conntrack x_tables nf_nat nf_conntrack br_netfilter bridge stp llc aufs ppdev sb_edac edac_core crct10dif_pclmul crc32_pclmul ghash_clmulni_intel joydev input_le[2018-02-02 10:40:50]ds serio_raw parport_pc parport i2c_piix4 mac_hid ib_iser rdma_cm iw_cm ib_cm ib_core configfs iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi autofs4 btrfs raid10 raid456 a[2018-02-02 10:40:50]sync_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath<o:p></o:p> [2018-02-02 10:40:50][4397731.724004] linear cirrus ttm drm_kms_helper syscopyarea sysfillrect sysimgblt aesni_intel fb_sys_fops aes_x86_64 crypto_simd cryptd glue_helper psmouse virtio_blk virtio_n[2018-02-02 10:40:50]et drm pata_acpi floppy<o:p></o:p> [2018-02-02 10:40:50][4397731.724004] CPU: 0 PID: 23347 Comm: kubelet Not tainted 4.10.0-32-generic #36~16.04.1-Ubuntu<o:p></o:p> [2018-02-02 10:40:50][4397731.724004] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011<o:p></o:p> [2018-02-02 10:40:50][4397731.724004] task: ffff92abde590000 task.stack: ffffbaa94165c000<o:p></o:p> [2018-02-02 10:40:50][4397731.724004] RIP: 0010:css_clear_dir+0x5/0x70<o:p></o:p> [2018-02-02 10:40:50][4397731.724004] RSP: 0018:ffffbaa94165fe10 EFLAGS: 00010206<o:p></o:p> [2018-02-02 10:40:50][4397731.724004] RAX: 000047fd40005d7b RBX: 00000000ffffffe8 RCX: ffff92abffc0fcec<o:p></o:p> [2018-02-02 10:40:50][4397731.724004] RDX: ffffffff9b070800 RSI: 0000000000000206 RDI: 00000000ffffffe8<o:p></o:p> [2018-02-02 10:40:50][4397731.724004] RBP: ffffbaa94165fe20 R08: 00000000c8b18701 R09: 0000000180220017<o:p></o:p> [2018-02-02 10:40:50][4397731.724004] R10: ffff92abc8b187f8 R11: ffff92abf7751d00 R12: ffff92abd5601000<o:p></o:p> [2018-02-02 10:40:50][4397731.724004] R13: 0000000000000000 R14: ffff92abd5601150 R15: 0000000000000000<o:p></o:p> [2018-02-02 10:40:50][4397731.724004] FS: 00007f6f92ffd700(0000) GS:ffff92abffc00000(0000) knlGS:0000000000000000<o:p></o:p> [2018-02-02 10:40:50][4397731.724004] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033<o:p></o:p> [2018-02-02 10:40:50][4397731.724004] CR2: 000000010000005c CR3: 00000000280cb000 CR4: 00000000000406f0<o:p></o:p> [2018-02-02 10:40:50][4397731.724004] Call Trace:<o:p></o:p> [2018-02-02 10:40:50][4397731.724004] ? kill_css+0x12/0x60<o:p></o:p> [2018-02-02 10:40:50][4397731.724004] cgroup_destroy_locked+0xa5/0xf0<o:p></o:p> [2018-02-02 10:40:50][4397731.724004] cgroup_rmdir+0x2c/0x90<o:p></o:p> [2018-02-02 10:40:50][4397731.724004] kernfs_iop_rmdir+0x4d/0x80<o:p></o:p> [2018-02-02 10:40:50][4397731.724004] vfs_rmdir+0xb4/0x130<o:p></o:p> [2018-02-02 10:40:50][4397731.724004] do_rmdir+0x1c7/0x1e0<o:p></o:p> [2018-02-02 10:40:50][4397731.724004] SyS_unlinkat+0x22/0x30<o:p></o:p> [2018-02-02 10:40:50][4397731.724004] entry_SYSCALL_64_fastpath+0x1e/0xad<o:p></o:p> [2018-02-02 10:40:50][4397731.724004] RIP: 0033:0x481bd4<o:p></o:p> [2018-02-02 10:40:50][4397731.724004] RSP: 002b:000000c422893af0 EFLAGS: 00000246 ORIG_RAX: 0000000000000107<o:p></o:p> [2018-02-02 10:40:50][4397731.724004] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000481bd4<o:p></o:p> [2018-02-02 10:40:50][4397731.724004] RDX: 0000000000000200 RSI: 000000c421c7ef00 RDI: ffffffffffffff9c<o:p></o:p> [2018-02-02 10:40:50][4397731.724004] RBP: 000000c422893bc0 R08: 0000000000000000 R09: 0000000000000000<o:p></o:p> [2018-02-02 10:40:50][4397731.724004] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000000ce<o:p></o:p> [2018-02-02 10:40:50][4397731.724004] R13: 00000000ffffffee R14: 0000000000001740 R15: 0000000000000055<o:p></o:p> [2018-02-02 10:40:50][4397731.724004] Code: fd ff ff 85 c0 41 89 c6 0f 84 5b fd ff ff eb 83 4d 89 fc e9 0f ff ff ff e8 d9 37 f6 ff 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 <8b> 47 74 a8 08 74 5d 55 [2018-02-02 10:40:50]83 e0 f7 48 89 e5 41 55 41 54 53 89 47 <o:p></o:p> [2018-02-02 10:40:50][4397731.724004] RIP: css_clear_dir+0x5/0x70 RSP: ffffbaa94165fe10<o:p></o:p> [2018-02-02 10:40:50][4397731.724004] CR2: 000000010000005c<o:p></o:p> <o:p> </o:p> <o:p> </o:p> ----------------------patch in linux.git----------------------------<o:p></o:p> commit 33c35aa4817864e056fd772230b0c6b552e36ea2<o:p></o:p> Author: Waiman Long <<a href="mailto:longman@redhat.com">longman@redhat.com</a>><o:p></o:p> Date: Mon May 15 09:34:06 2017 -0400<o:p></o:p> <o:p> </o:p> cgroup: Prevent kill_css() from being called more than once<o:p></o:p> <o:p></o:p> The kill_css() function may be called more than once under the condition<o:p></o:p> that the css was killed but not physically removed yet followed by the<o:p></o:p> removal of the cgroup that is hosting the css. This patch prevents any<o:p></o:p> harmm from being done when that happens.<o:p></o:p> <o:p></o:p> Signed-off-by: Waiman Long <<a href="mailto:longman@redhat.com">longman@redhat.com</a>><o:p></o:p> Signed-off-by: Tejun Heo <<a href="mailto:tj@kernel.org">tj@kernel.org</a>><o:p></o:p> Cc: <a href="mailto:stable@vger.kernel.org"> stable@vger.kernel.org</a> # v4.5+<o:p></o:p> <o:p> </o:p> diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c<o:p></o:p> index c3c9a0e1b3c9..8d4e85eae42c 100644<o:p></o:p> --- a/kernel/cgroup/cgroup.c<o:p></o:p> +++ b/kernel/cgroup/cgroup.c<o:p></o:p> @@ -4265,6 +4265,11 @@ static void kill_css(struct cgroup_subsys_state *css)<o:p></o:p> {<o:p></o:p> lockdep_assert_held(&cgroup_mutex);<o:p></o:p> <o:p> </o:p> + if (css->flags & CSS_DYING)<o:p></o:p> + return;<o:p></o:p> +<o:p></o:p> + css->flags |= CSS_DYING;<o:p></o:p> +<o:p></o:p> /*<o:p></o:p> * This must happen before css is disassociated with its cgroup.<o:p></o:p> * See seq_css() for details.<o:p></o:p> <o:p> </o:p> </div> </body> </html>