https://jira.whamcloud.com This file is an XML representation of an issue en-us 9.4.14 940014 05-12-2023 https://jira.whamcloud.com/browse/LU-6578 Lustre <div class="preformatted panel" style="border-width: 1px;"><div class="preformattedContent panelContent"> <pre>int mdc_intent_getattr_async(struct obd_export *exp, struct md_enqueue_info *minfo, struct ldlm_enqueue_info *einfo) { struct md_op_data *op_data = &amp;minfo-&gt;mi_data; struct lookup_intent *it = &amp;minfo-&gt;mi_it; struct ptlrpc_request *req; struct mdc_getattr_args *ga; struct obd_device *obddev = class_exp2obd(exp); struct ldlm_res_id res_id; /*XXX: Both MDS_INODELOCK_LOOKUP and MDS_INODELOCK_UPDATE are needed * for statahead currently. Consider CMD in future, such two bits * maybe managed by different MDS, should be adjusted then. */ ldlm_policy_data_t policy = { .l_inodebits = { MDS_INODELOCK_LOOKUP | MDS_INODELOCK_UPDATE } }; int rc = 0; __u64 flags = LDLM_FL_HAS_INTENT; ENTRY; </pre> </div></div> LU-6578

inodebit locks for remote entries.

Bug Blocker Resolved Fixed Lai Siyao Di Wang dne2 Wed, 6 May 2015 23:01:10 +0000 Fri, 9 Sep 2016 19:30:34 +0000 Wed, 23 Sep 2015 13:06:34 +0000 Lustre 2.7.0 Lustre 2.5.3 Lustre 2.8.0 Lustre 2.8.0 0 6 <p>Di, what is needed to fix this? Can you please add a description, and maybe Lai can work on it?</p> <p>lmv_intent_getattr_async needs to be fixed to handle such cross-MDT object. So </p> <p>1. If the parent and child are in the same MDT. then lmv_intent_getattr_async --&gt; mdc_intent_getattr_async can get both LOOKUP| UPDATE lock.<br/> 2. if they are in different MDTs, it needs to get LOOKUP lock on the parent MDT, and UPDATE lock on the child MDT. that said lmv_intent_getattr_async should know parent FID, name, and child FID, i.e. these information should be input into the lmv_intent_getattr_async().</p> <p>After some thoughts, I think this may not be necessary, or at least not urgent to support remote entries for statahead now. Because it needs send two RPCs to fetch two locks from different MDT, and furthermore the UPDATE lock may need to be fetched after LOOKUP lock is fetched (to verify it's the same fid), all these is hard to implement asynchronously.</p> <p>IMHO if statahead doesn't fetch attributes from remote entry, it won't cause any issue, because lookup() will find UPDATE lock is not there, and then it will fetch it synchronously. And directories with many remote entries should be rare case? if so, statahead failure should be rare too.</p> <p>Hmm, this is actually a bug more than an optimization. For remote entry, the LOOCK lock is actually granted by parent MDT, instead of child MDT. And in this function, it sends both LOOKUP and UPDATE lock to the child MDT, and the MDT has no way to know if the FID has local or remote entry, then it might grant both LOCKS, which is wrong of course. So in lmv_intent_getattr_async, it should tell if the name entry is remote entry, then enqueue lookup lock on the parent MDT, and update lock on the child MDT. Or only enqueue update lock on the child MDT. (or maybe skip remote entry, if you think implement this is complicate.) </p> <p>Lai Siyao (lai.siyao@intel.com) uploaded a new patch: <a href="http://review.whamcloud.com/15767" class="external-link" target="_blank" rel="nofollow noopener">http://review.whamcloud.com/15767</a><br/> Subject: <a href="https://jira.whamcloud.com/browse/LU-6578" title="inodebit locks for remote entries." class="issue-link" data-issue-key="LU-6578"><del>LU-6578</del></a> statahead: drop support for remote entry<br/> Project: fs/lustre-release<br/> Branch: master<br/> Current Patch Set: 1<br/> Commit: c1bf57c81dbe18629169436f674e8c44a90d0403</p> <p>Oleg Drokin (oleg.drokin@intel.com) merged in patch <a href="http://review.whamcloud.com/15767/" class="external-link" target="_blank" rel="nofollow noopener">http://review.whamcloud.com/15767/</a><br/> Subject: <a href="https://jira.whamcloud.com/browse/LU-6578" title="inodebit locks for remote entries." class="issue-link" data-issue-key="LU-6578"><del>LU-6578</del></a> statahead: drop support for remote entry<br/> Project: fs/lustre-release<br/> Branch: master<br/> Current Patch Set: <br/> Commit: c0944cc831183a3af9adc7d41cca222b636eec2f</p> <p>Landed for 2.8</p> Related LU-6829 Development Rank 1|hzxcp3: Rank (Obsolete) 9223372036854775807 Severity