On 11/16/2016 07:38 PM, jin deng wrote:
Thank you so much.Soumya,you make me more clear about the logic of the code. I used to wonder the code was to handle the last resolve case.However i followed the "nfs3_fh_resolve_entry_hard" and I thought it would get the ret == -2 case and went into the "nfs3_lookup_op" branch,and finally call the "nfs3_call_resume".Seems has no chance to call "nfs3_fh_resolve_entry_lookup_cbk" because it was a LOOKUP operation.Am i wrong again? :-)
You are right :)...for LOOKUP fop, we go to "nfs3_call_resume" which is nfs3_lookup_resume and the callback is "nfs3svc_lookup_cbk" where in we are not updating cs->stbuf. But we seem to be constructing lookup reply (nfs3_lookup_reply) using 'buf' directly returned for the child entry instead of using cs->stbuf. Maybe that's the reason it was working well till now. FYI - there was an issue in the lookup logic code path which we fixed as part of http://review.gluster.org/14911 . I will not be surprised if there are any more lurking around :)
Thanks, Soumya
2016-11-16 21:45 GMT+08:00 Soumya Koduri <skoduri@xxxxxxxxxx <mailto:skoduri@xxxxxxxxxx>>: On 11/16/2016 06:38 PM, Pranith Kumar Karampuri wrote: Added people who know nfs code. On Wed, Nov 16, 2016 at 6:21 PM, jin deng <cheneydeng88@xxxxxxxxx <mailto:cheneydeng88@xxxxxxxxx> <mailto:cheneydeng88@xxxxxxxxx <mailto:cheneydeng88@xxxxxxxxx>>> wrote: Hi all, I'm reading the code of 3.6.9 version and got a question.And I'm not very familiar with the code,so I have to confirm it(I checked the master branch,it's same with 3.6.9). The question is about the 'lookup' operation of NFS.And i'm with this code flow: nfs3_lookup (nfs3.c) ==> nfs3_fh_resolve_and_resume ==> nfs3_fh_resolve_root ==> nfs3_fh_resolve_resume ==> nfs3_fh_resolve_entry ==> nfs3_fh_resolve_entry_hard. Now enter the "nfs_entry_loc_fill" and return with -1 which means the "parent" not found,so we have to do hard resolve about the parent. After doing a hard resolve,we get into the callback "nfs3_fh_resolve_inode_lookup_cbk".And the callback has the following code: >>> memcpy (&cs->stbuf, buf, sizeof(*buf)); >>> memcpy (&cs->postparent, buf, sizeof(*postparent)) This must had been done (and required) in case if this was the last entry(/inode) to be looked up I think we've just done a parent resolve,how could we assign the parent result into the "stbuf" and "postparent".The later two should be the information of the child file/directory.Do i made a misunderstand? In case if it was not the last entry we fall through below code in "nfs3_fh_resolve_inode_lookup_cbk" - if (cs->resolventry) nfs3_fh_resolve_entry_hard (cs); Callback is "nfs3_fh_resolve_entry_lookup_cbk()" where in cs->stbuf and cs->postparent get overridden with the values corresponding to the child entry. Thanks, Soumya Thanks advance for your help. _______________________________________________ Gluster-users mailing list Gluster-users@xxxxxxxxxxx <mailto:Gluster-users@xxxxxxxxxxx> <mailto:Gluster-users@xxxxxxxxxxx <mailto:Gluster-users@xxxxxxxxxxx>> http://www.gluster.org/mailman/listinfo/gluster-users <http://www.gluster.org/mailman/listinfo/gluster-users> <http://www.gluster.org/mailman/listinfo/gluster-users <http://www.gluster.org/mailman/listinfo/gluster-users>> -- Pranith
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