[Ocfs2-devel] [PATCH] ocfs2: limit printk when journal is aborted

[Joseph Qi <joseph.qi@huawei.com>]

On 2014/4/18 5:01, Mark Fasheh wrote:
> On Thu, Apr 17, 2014 at 07:08:42PM +0800, Joseph Qi wrote:
>>
>> Once JBD2_ABORT is set, ocfs2_commit_cache will fail in
>> ocfs2_commit_thread. Then it will get into a loop with mass logs. This
>> will meaninglessly consume a larger number of resource and may lead to
>> system hung at last.
>> So limit printk in this case.
>>
>> Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
>> ---
>>  fs/ocfs2/journal.c | 12 ++++++++++--
>>  1 file changed, 10 insertions(+), 2 deletions(-)
>>
>> diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
>> index 44fc3e5..cfefbd1 100644
>> --- a/fs/ocfs2/journal.c
>> +++ b/fs/ocfs2/journal.c
>> @@ -30,6 +30,7 @@
>>  #include <linux/kthread.h>
>>  #include <linux/time.h>
>>  #include <linux/random.h>
>> +#include <linux/delay.h>
>>  
>>  #include <cluster/masklog.h>
>>  
>> @@ -2191,8 +2192,15 @@ static int ocfs2_commit_thread(void *arg)
>>  					 || kthread_should_stop());
>>  
>>  		status = ocfs2_commit_cache(osb);
>> -		if (status < 0)
>> -			mlog_errno(status);
>> +		if (status < 0) {
>> +			static unsigned long abort_warn_time;
>> +
>> +			/* Warn about this once per minute */
>> +			if (printk_timed_ratelimit(&abort_warn_time, 60*HZ))
>> +				mlog(ML_ERROR, "status = %d, journal is "
>> +						"already aborted.\n", status);
>> +			msleep_interruptible(1000);
>> +		}
> 
> Why the msleep? ocfs2_commit_thread will wait on the checkpoint_event queue
> right after this anyway - is there a problem with it waiting on that?
> 
Since jbd2 is already aborted, commit cache is meaningless.

> Generally I really don't like peppering msleep() into the code where we
> might need to sleep - there is often a more elegant solution available.
> 
> Thanks,
> 	--Mark
> 
> --
> Mark Fasheh
> 
>