Hi Zhonghua, >From you describe, the issue is reproducible. I suggest you to trigger a core dump when you find the threads meet a dead lock, the crash dump is most convincing. Then, you can use crash command to list the related threads/backtraces/lock variables in the patch description. it is easy to let the people know where we meet this dead-lock when code review, and it is easy to let the users find your patch to fix this bug in the future.
Thanks Gang >>> > Hi Guozhonghua, > > It seems that deadlock could be reproduced easily, right? Sharing the > lock with VFS-layer probably is risky, and introducing a new lock for > "quota_recovery" sounds good. Could you post a patch to fix this > problem? > > thanks, > Jun > > On 2018/1/13 11:04, Guozhonghua wrote: >> >>> Message: 1 >>> Date: Fri, 12 Jan 2018 06:15:01 +0000 >>> From: Shichangkuo <shi.chang...@h3c.com> >>> Subject: Re: [Ocfs2-devel] [Ocfs2-dev] BUG: deadlock with umount and >>> ocfs2 workqueue triggered by ocfs2rec thread >>> To: Joseph Qi <jiangqi...@gmail.com>, "z...@suse.com" <z...@suse.com>, >>> "j...@suse.cz" <j...@suse.cz> >>> Cc: "ocfs2-devel@oss.oracle.com" <ocfs2-devel@oss.oracle.com> >>> Message-ID: >>> <d1e4d02760513d4b90dc3b40ff32af35e22ec...@h3cmlb14-ex.srv.huawe >>> i-3com.com> >>> >>> Content-Type: text/plain; charset="gb2312" >>> >>> Hi Joseph >>> Thanks for replying. >>> Umount will flush the ocfs2 workqueue in function >>> ocfs2_truncate_log_shutdown and journal recovery is one work of ocfs2 wq. >>> >>> Thanks >>> Changkuo >>> >> >> Umount >> mngput >> cleanup_mnt >> deactivate_super: down_write the rw_semaphore: >> down_write(&s->s_umount) >> deactivate_locked_super >> kill_sb: kill_block_super >> generic_shutdown_super >> put_super : ocfs2_put_supe >> ocfs2_dismount_volume >> ocfs2_truncate_log_shutdown >> >> flush_workqueue(osb->ocfs2_wq); >> >> ocfs2_finish_quota_recovery >> >> down_read(&sb->s_umount); >> Here >> retry down_read rw_semaphore; down read while holding write? Try > rw_semaphore twice, dead lock ? >> The flush work queue of ocfs2_wq will >> be > blocked, so as the umount ops. >> >> Thanks. >> >> >> _______________________________________________ >> Ocfs2-devel mailing list >> Ocfs2-devel@oss.oracle.com >> https://oss.oracle.com/mailman/listinfo/ocfs2-devel >> > > _______________________________________________ > Ocfs2-devel mailing list > Ocfs2-devel@oss.oracle.com > https://oss.oracle.com/mailman/listinfo/ocfs2-devel _______________________________________________ Ocfs2-devel mailing list Ocfs2-devel@oss.oracle.com https://oss.oracle.com/mailman/listinfo/ocfs2-devel
