----- Original Message ----- > From: "Soumya Koduri" <skoduri@xxxxxxxxxx> > To: "Zhitao Li" <zhitaoli1201@xxxxxxxxxxx>, "Gluster Devel" <gluster-devel@xxxxxxxxxxx> > Cc: "Zhitao Li" <zhitaoli1201@xxxxxxx>, 1318078301@xxxxxx, "Poornima Gurusiddaiah" <pgurusid@xxxxxxxxxx> > Sent: Monday, March 20, 2017 2:21:12 PM > Subject: Re: What does xdata mean? "gfid-req"? > > > > On 03/18/2017 06:51 PM, Zhitao Li wrote: > > Hello, everyone, > > > > > > I am investigating the difference between stat and lookup operations in > > GlusterFs now. In the translator named "md_cache", stat operation will > > hit the cache generally, while lookup operation will miss the cache. > > > > > > The reason is that for lookup operation, md_cache will check whether the > > xdata is satisfied. In my case, lookup will include xdata "gfid-req" > > filled by fuse-bridge. However, in md_cache, this check never pass > > because the load flag of mdc_key "gfid-req" is always 0. > > Client(in this case fuse-bridge) generates gfid and sets it as xdata > 'gfid-req' key during the first lookup so as to let server heal the > file/dir with the missing gfid (if any) with the newly generated one. > > I guess md-cache ignores the LOOKUP fop with this xdata key set as it > implies that its the first lookup done by the client. Even if it doesn't > filter it out, the file/dir entry will not be present in the > cache then. Subsequent LOOKUPs should be served from md-cache. Poornima > (cc'ed) shall be able to clarify the actual reason. Yes, gfid-req will be set only on the first lookup. If not then that definitely needs to be looked at. > > Thanks, > Soumya > > > > > > > Could anyone tell me why "gfid-req" is filled by > > fuse-bridge.c(fuse_getattr: nodeid==1->lookup)? What does it mean? And > > how xdata is used? > > > > > > If no xdata, what would happen? > > > > Thank you! > > > > > > Best regards, > > Zhitao Li > > > > Sent from Outlook <http://aka.ms/weboutlook> > > > > > > _______________________________________________ > > Gluster-devel mailing list > > Gluster-devel@xxxxxxxxxxx > > http://lists.gluster.org/mailman/listinfo/gluster-devel > > > _______________________________________________ Gluster-devel mailing list Gluster-devel@xxxxxxxxxxx http://lists.gluster.org/mailman/listinfo/gluster-devel
