Hi Srini, On 01/08/2014 07:29 PM, Srinivas Eeda wrote: > Hi Goldwyn, > > On 01/08/2014 04:12 PM, Goldwyn Rodrigues wrote: >> Hi, >> >> >From the comments in fs/ocfs2/inode.h:90 it seems, this was used in >> legacy ocfs2 systems when a node received unlink votes. Since unlink >> votes has been done away with and replaced with open locks, is this >> flag still required? If yes, why? > My understanding is that unlink voting protocol was heavy. So the > following was done to address it. > > To do an unlink, dentry has to be removed. In order to do that the node > has to get EX lock on the dentry which means all other nodes have to > downconvert. In general EX lock on dentry is acquired only in unlink and > I assume rename case. So all nodes which down convert the lock mark > their inode OCFS2_INODE_MAYBE_ORPHANED. The only problem with this is > that dentry on a node can get purged because of memory pressure which > marks inode as OCFS2_INODE_MAYBE_ORPHANED even when no unlink was done > on this inode. >
I think you are getting confused between dentry_lock (dentry_lockres) and open lock (ip_open_lockres). AFAICS, dentry locks are used to control the remote dentries. > >> >From my ongoing investigation of unlink() times, it seems this flag is >> causing the delay with releasing the open locks while downconverting >> dentry locks. The flag is set _everytime_ a dentry downconvert is >> performed even if the file is not scheduled to be deleted. If not, we >> can be smartly evict the inodes which are *not* to be deleted >> (i_nlink>0) by not offloading to ocfs2_wq. This way open lock will >> release faster speeding up unlink on the deleting node. >> >> > Are you referring to the delay caused by ocfs2_drop_dentry_lock queueing > dentry locks to dentry_lock_list ?. If that's the case, have you tried > removing following patches which introduced that behavior ? I think that > quota's deadlock bug might have to be addressed differently ? > > ea455f8ab68338ba69f5d3362b342c115bea8e13 Yes, that should make some difference. Let me try that. However, I was suggesting we do not set the OCFS2_INODE_MAYBE_ORPHANED flag in ocfs2_dentry_convert_worker as well, but I am not sure of the consequences and that is the reason I asked why it is used. > eb90e46458b08bc7c1c96420ca0eb4263dc1d6e5 > bb44bf820481e19381ec549118e4ee0b89d56191 I did not find these gits. Which tree are you referring to? > > The above patches were leaving orphan files around which was causing a > big problem to some applications that removes lot of files which inturn > caused intermittent hangs > -- Goldwyn _______________________________________________ Ocfs2-devel mailing list Ocfs2-devel@oss.oracle.com https://oss.oracle.com/mailman/listinfo/ocfs2-devel
