From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933697AbdA0LJT (ORCPT ); Fri, 27 Jan 2017 06:09:19 -0500 Received: from mx2.suse.de ([195.135.220.15]:35089 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933773AbdA0LJM (ORCPT ); Fri, 27 Jan 2017 06:09:12 -0500 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Eric Ren , Mark Fasheh , Joel Becker , Junxiao Bi , Andrew Morton , Linus Torvalds , Jiri Slaby Subject: [PATCH 3.12 148/235] ocfs2: fix crash caused by stale lvb with fsdlm plugin Date: Fri, 27 Jan 2017 11:54:41 +0100 Message-Id: <762f213c7c123ace3488d0752dabc2930f92e3a2.1485514374.git.jslaby@suse.cz> X-Mailer: git-send-email 2.11.0 In-Reply-To: <5b46dc789ca2be4046e4e40a131858d386cac741.1485514374.git.jslaby@suse.cz> References: <5b46dc789ca2be4046e4e40a131858d386cac741.1485514374.git.jslaby@suse.cz> MIME-Version: 1.0 In-Reply-To: References: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric Ren 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit e7ee2c089e94067d68475990bdeed211c8852917 upstream. The crash happens rather often when we reset some cluster nodes while nodes contend fiercely to do truncate and append. The crash backtrace is below: dlm: C21CBDA5E0774F4BA5A9D4F317717495: dlm_recover_grant 1 locks on 971 resources dlm: C21CBDA5E0774F4BA5A9D4F317717495: dlm_recover 9 generation 5 done: 4 ms ocfs2: Begin replay journal (node 318952601, slot 2) on device (253,18) ocfs2: End replay journal (node 318952601, slot 2) on device (253,18) ocfs2: Beginning quota recovery on device (253,18) for slot 2 ocfs2: Finishing quota recovery on device (253,18) for slot 2 (truncate,30154,1):ocfs2_truncate_file:470 ERROR: bug expression: le64_to_cpu(fe->i_size) != i_size_read(inode) (truncate,30154,1):ocfs2_truncate_file:470 ERROR: Inode 290321, inode i_size = 732 != di i_size = 937, i_flags = 0x1 ------------[ cut here ]------------ kernel BUG at /usr/src/linux/fs/ocfs2/file.c:470! invalid opcode: 0000 [#1] SMP Modules linked in: ocfs2_stack_user(OEN) ocfs2(OEN) ocfs2_nodemanager ocfs2_stackglue(OEN) quota_tree dlm(OEN) configfs fuse sd_mod iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi af_packet iscsi_ibft iscsi_boot_sysfs softdog xfs libcrc32c ppdev parport_pc pcspkr parport joydev virtio_balloon virtio_net i2c_piix4 acpi_cpufreq button processor ext4 crc16 jbd2 mbcache ata_generic cirrus virtio_blk ata_piix drm_kms_helper ahci syscopyarea libahci sysfillrect sysimgblt fb_sys_fops ttm floppy libata drm virtio_pci virtio_ring uhci_hcd virtio ehci_hcd usbcore serio_raw usb_common sg dm_multipath dm_mod scsi_dh_rdac scsi_dh_emc scsi_dh_alua scsi_mod autofs4 Supported: No, Unsupported modules are loaded CPU: 1 PID: 30154 Comm: truncate Tainted: G OE N 4.4.21-69-default #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.1-0-g4adadbd-20151112_172657-sheep25 04/01/2014 task: ffff88004ff6d240 ti: ffff880074e68000 task.ti: ffff880074e68000 RIP: 0010:[] [] ocfs2_truncate_file+0x640/0x6c0 [ocfs2] RSP: 0018:ffff880074e6bd50 EFLAGS: 00010282 RAX: 0000000000000074 RBX: 000000000000029e RCX: 0000000000000000 RDX: 0000000000000001 RSI: 0000000000000246 RDI: 0000000000000246 RBP: ffff880074e6bda8 R08: 000000003675dc7a R09: ffffffff82013414 R10: 0000000000034c50 R11: 0000000000000000 R12: ffff88003aab3448 R13: 00000000000002dc R14: 0000000000046e11 R15: 0000000000000020 FS: 00007f839f965700(0000) GS:ffff88007fc80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 00007f839f97e000 CR3: 0000000036723000 CR4: 00000000000006e0 Call Trace: ocfs2_setattr+0x698/0xa90 [ocfs2] notify_change+0x1ae/0x380 do_truncate+0x5e/0x90 do_sys_ftruncate.constprop.11+0x108/0x160 entry_SYSCALL_64_fastpath+0x12/0x6d Code: 24 28 ba d6 01 00 00 48 c7 c6 30 43 62 a0 8b 41 2c 89 44 24 08 48 8b 41 20 48 c7 c1 78 a3 62 a0 48 89 04 24 31 c0 e8 a0 97 f9 ff <0f> 0b 3d 00 fe ff ff 0f 84 ab fd ff ff 83 f8 fc 0f 84 a2 fd ff RIP [] ocfs2_truncate_file+0x640/0x6c0 [ocfs2] It's because ocfs2_inode_lock() get us stale LVB in which the i_size is not equal to the disk i_size. We mistakenly trust the LVB because the underlaying fsdlm dlm_lock() doesn't set lkb_sbflags with DLM_SBF_VALNOTVALID properly for us. But, why? The current code tries to downconvert lock without DLM_LKF_VALBLK flag to tell o2cb don't update RSB's LVB if it's a PR->NULL conversion, even if the lock resource type needs LVB. This is not the right way for fsdlm. The fsdlm plugin behaves different on DLM_LKF_VALBLK, it depends on DLM_LKF_VALBLK to decide if we care about the LVB in the LKB. If DLM_LKF_VALBLK is not set, fsdlm will skip recovering RSB's LVB from this lkb and set the right DLM_SBF_VALNOTVALID appropriately when node failure happens. The following diagram briefly illustrates how this crash happens: RSB1 is inode metadata lock resource with LOCK_TYPE_USES_LVB; The 1st round: Node1 Node2 RSB1: PR RSB1(master): NULL->EX ocfs2_downconvert_lock(PR->NULL, set_lvb==0) ocfs2_dlm_lock(no DLM_LKF_VALBLK) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - dlm_lock(no DLM_LKF_VALBLK) convert_lock(overwrite lkb->lkb_exflags with no DLM_LKF_VALBLK) RSB1: NULL RSB1: EX reset Node2 dlm_recover_rsbs() recover_lvb() /* The LVB is not trustable if the node with EX fails and * no lock >= PR is left. We should set RSB_VALNOTVALID for RSB1. */ if(!(kb_exflags & DLM_LKF_VALBLK)) /* This means we miss the chance to return; * to invalid the LVB here. */ The 2nd round: Node 1 Node2 RSB1(become master from recovery) ocfs2_setattr() ocfs2_inode_lock(NULL->EX) /* dlm_lock() return the stale lvb without setting DLM_SBF_VALNOTVALID */ ocfs2_meta_lvb_is_trustable() return 1 /* so we don't refresh inode from disk */ ocfs2_truncate_file() mlog_bug_on_msg(disk isize != i_size_read(inode)) /* crash! */ The fix is quite straightforward. We keep to set DLM_LKF_VALBLK flag for dlm_lock() if the lock resource type needs LVB and the fsdlm plugin is uesed. Link: http://lkml.kernel.org/r/1481275846-6604-1-git-send-email-zren@suse.com Signed-off-by: Eric Ren Reviewed-by: Joseph Qi Cc: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Jiri Slaby --- fs/ocfs2/dlmglue.c | 10 ++++++++++ fs/ocfs2/stackglue.c | 6 ++++++ fs/ocfs2/stackglue.h | 3 +++ 3 files changed, 19 insertions(+) diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c index 416a2ab68ac1..9c93df0f241d 100644 --- a/fs/ocfs2/dlmglue.c +++ b/fs/ocfs2/dlmglue.c @@ -3302,6 +3302,16 @@ static int ocfs2_downconvert_lock(struct ocfs2_super *osb, mlog(ML_BASTS, "lockres %s, level %d => %d\n", lockres->l_name, lockres->l_level, new_level); + /* + * On DLM_LKF_VALBLK, fsdlm behaves differently with o2cb. It always + * expects DLM_LKF_VALBLK being set if the LKB has LVB, so that + * we can recover correctly from node failure. Otherwise, we may get + * invalid LVB in LKB, but without DLM_SBF_VALNOTVALID being set. + */ + if (!ocfs2_is_o2cb_active() && + lockres->l_ops->flags & LOCK_TYPE_USES_LVB) + lvb = 1; + if (lvb) dlm_flags |= DLM_LKF_VALBLK; diff --git a/fs/ocfs2/stackglue.c b/fs/ocfs2/stackglue.c index 39abf89697ed..88610b3cbc04 100644 --- a/fs/ocfs2/stackglue.c +++ b/fs/ocfs2/stackglue.c @@ -48,6 +48,12 @@ static char ocfs2_hb_ctl_path[OCFS2_MAX_HB_CTL_PATH] = "/sbin/ocfs2_hb_ctl"; */ static struct ocfs2_stack_plugin *active_stack; +inline int ocfs2_is_o2cb_active(void) +{ + return !strcmp(active_stack->sp_name, OCFS2_STACK_PLUGIN_O2CB); +} +EXPORT_SYMBOL_GPL(ocfs2_is_o2cb_active); + static struct ocfs2_stack_plugin *ocfs2_stack_lookup(const char *name) { struct ocfs2_stack_plugin *p; diff --git a/fs/ocfs2/stackglue.h b/fs/ocfs2/stackglue.h index 1ec56fdb8d0d..fa49d8a1dc7b 100644 --- a/fs/ocfs2/stackglue.h +++ b/fs/ocfs2/stackglue.h @@ -289,4 +289,7 @@ void ocfs2_stack_glue_set_max_proto_version(struct ocfs2_protocol_version *max_p int ocfs2_stack_glue_register(struct ocfs2_stack_plugin *plugin); void ocfs2_stack_glue_unregister(struct ocfs2_stack_plugin *plugin); +/* In ocfs2_downconvert_lock(), we need to know which stack we are using */ +int ocfs2_is_o2cb_active(void); + #endif /* STACKGLUE_H */ -- 2.11.0