Re: [PATCH v2] ocfs2: fix panic due to ocfs2_wq is null

[Joseph Qi <joseph.qi@linux.alibaba.com>]

On 19/10/15 19:29, Yi Li wrote:
> From: Yi Li <yilikernel@gmail.com>
> 
> mount.ocfs2 failed when read ocfs2 filesystem super error.
> the func ocfs2_initialize_super will return before allocate ocfs2_wq.
> ocfs2_dismount_volume will triggered 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
> 
> Signed-off-by: Yi Li <yilikernel@gmail.com>

Cc: stable@vger.kernel.org

Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
> ---
>  fs/ocfs2/journal.c    | 3 ++-
>  fs/ocfs2/localalloc.c | 3 ++-
>  2 files changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
> index 930e3d3..699a560 100644
> --- a/fs/ocfs2/journal.c
> +++ b/fs/ocfs2/journal.c
> @@ -217,7 +217,8 @@ void ocfs2_recovery_exit(struct ocfs2_super *osb)
>  	/* 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
> diff --git a/fs/ocfs2/localalloc.c b/fs/ocfs2/localalloc.c
> index 158e5af..720e9f9 100644
> --- a/fs/ocfs2/localalloc.c
> +++ b/fs/ocfs2/localalloc.c
> @@ -377,7 +377,8 @@ void ocfs2_shutdown_local_alloc(struct ocfs2_super *osb)
>  	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;
>