From: Yi Li yilikernel@gmail.com Subject: ocfs2: fix panic due to ocfs2_wq is null

mount.ocfs2 failed when reading ocfs2 filesystem superblock encounters an error. ocfs2_initialize_super() returns before allocating ocfs2_wq. ocfs2_dismount_volume() triggers the following panic.

Oct 15 16:09:27 cnwarekv-205120 kernel: On-disk corruption discovered.Please run fsck.ocfs2 once the filesystem is unmounted. Oct 15 16:09:27 cnwarekv-205120 kernel: (mount.ocfs2,22804,44): ocfs2_read_locked_inode:537 ERROR: status = -30 Oct 15 16:09:27 cnwarekv-205120 kernel: (mount.ocfs2,22804,44): ocfs2_init_global_system_inodes:458 ERROR: status = -30 Oct 15 16:09:27 cnwarekv-205120 kernel: (mount.ocfs2,22804,44): ocfs2_init_global_system_inodes:491 ERROR: status = -30 Oct 15 16:09:27 cnwarekv-205120 kernel: (mount.ocfs2,22804,44): ocfs2_initialize_super:2313 ERROR: status = -30 Oct 15 16:09:27 cnwarekv-205120 kernel: (mount.ocfs2,22804,44): ocfs2_fill_super:1033 ERROR: status = -30 ------------[ cut here ]------------ Oops: 0002 [#1] SMP NOPTI Modules linked in: ocfs2 rpcsec_gss_krb5 auth_rpcgss nfsv4 nfs fscache lockd grace ocfs2_dlmfs ocfs2_stack_o2cb ocfs2_dlm ocfs2_nodemanager ocfs2_stackglue configfs sunrpc ipt_REJECT nf_reject_ipv4 nf_conntrack_ipv4 nf_defrag_ipv4 iptable_filter ip_tables ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables ib_ipoib rdma_ucm ib_ucm ib_uverbs ib_umad rdma_cm ib_cm iw_cm ib_sa ib_mad ib_core ib_addr ipv6 ovmapi ppdev parport_pc parport fb_sys_fops sysimgblt sysfillrect syscopyarea acpi_cpufreq pcspkr i2c_piix4 i2c_core sg ext4 jbd2 mbcache2 sr_mod cdrom CPU: 1 PID: 11753 Comm: mount.ocfs2 Tainted: G E 4.14.148-200.ckv.x86_64 #1 Hardware name: Sugon H320-G30/35N16-US, BIOS 0SSDX017 12/21/2018 task: ffff967af0520000 task.stack: ffffa5f05484000 RIP: 0010:mutex_lock+0x19/0x20 Call Trace: flush_workqueue+0x81/0x460 ocfs2_shutdown_local_alloc+0x47/0x440 [ocfs2] ocfs2_dismount_volume+0x84/0x400 [ocfs2] ocfs2_fill_super+0xa4/0x1270 [ocfs2] ? ocfs2_initialize_super.isa.211+0xf20/0xf20 [ocfs2] mount_bdev+0x17f/0x1c0 mount_fs+0x3a/0x160

Link: http://lkml.kernel.org/r/1571139611-24107-1-git-send-email-yili@winhong.com Signed-off-by: Yi Li yilikernel@gmail.com Reviewed-by: Joseph Qi joseph.qi@linux.alibaba.com Cc: Mark Fasheh mark@fasheh.com Cc: Joel Becker jlbec@evilplan.org Cc: Junxiao Bi junxiao.bi@oracle.com Cc: Changwei Ge gechangwei@live.cn Cc: Gang He ghe@suse.com Cc: Jun Piao piaojun@huawei.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

fs/ocfs2/journal.c | 3 ++- fs/ocfs2/localalloc.c | 3 ++- 2 files changed, 4 insertions(+), 2 deletions(-)

--- a/fs/ocfs2/journal.c~ocfs2-fix-panic-due-to-ocfs2_wq-is-null +++ a/fs/ocfs2/journal.c @@ -217,7 +217,8 @@ void ocfs2_recovery_exit(struct ocfs2_su /* At this point, we know that no more recovery threads can be * launched, so wait for any recovery completion work to * complete. */ - flush_workqueue(osb->ocfs2_wq); + if (osb->ocfs2_wq) + flush_workqueue(osb->ocfs2_wq);

/* * Now that recovery is shut down, and the osb is about to be --- a/fs/ocfs2/localalloc.c~ocfs2-fix-panic-due-to-ocfs2_wq-is-null +++ a/fs/ocfs2/localalloc.c @@ -377,7 +377,8 @@ void ocfs2_shutdown_local_alloc(struct o struct ocfs2_dinode *alloc = NULL;

cancel_delayed_work(&osb->la_enable_wq); - flush_workqueue(osb->ocfs2_wq); + if (osb->ocfs2_wq) + flush_workqueue(osb->ocfs2_wq);

if (osb->local_alloc_state == OCFS2_LA_UNUSED) goto out; _