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-7357 Lustre <p>Currently DNE2 doesn't handle layout locks to revoke the layout if it is changed. When performing an migration on a striped directory the layout lock needs to be invalidated so the client can refresh the layout.</p> LU-7357

Add layout lock for striped directories.

Improvement Major Resolved Won't Do Lai Siyao James A Simmons dne2 dne3 Thu, 29 Oct 2015 20:44:24 +0000 Tue, 30 Nov 2021 11:11:41 +0000 Tue, 30 Nov 2021 11:11:41 +0000 Lustre 2.8.0 0 9 <p>So I am not really sure what does it have to do with layout lock?</p> <p>Unlink invalidates an update lock to flush client readdir cache and that should be enough.</p> <p>Can you please elaborate here about what it is you are trying to achieve?</p> <p>All the details are in the patch : <a href="http://review.whamcloud.com/#/c/10110" class="external-link" target="_blank" rel="nofollow noopener">http://review.whamcloud.com/#/c/10110</a>. The patch needs a rebase.</p> <p>Di </p> <p>This appears to have been your patch originally</p> <p>Peter</p> <p>This will be needed when we implement directory restriping.</p> <p>Lai, is there actually a need for a separate layout bit for directory migration? Oleg thinks we can use the UPDATE bit to cancel the directory cache. Will the client get a new directory layout after that?</p> <p>Directory migration will migrate directory to a new fid, so the inode is different after migration. But there is one place that directory layout may change: after all sub files migration the parent directory will be shrunk to contain new layout only.</p> <p>But I don't see the benefit of introducing this bit, because it can't eleminate race: client can't hold ibit lock, its layout can be stale at any moment with or without this bit lock. But this race is not serious, because <a href="https://review.whamcloud.com/#/c/31504/" class="external-link" target="_blank" rel="nofollow noopener">https://review.whamcloud.com/#/c/31504/</a> adds rules to access migrating directory, operations through old layout may fail, but they won't corrupt the directory.</p> <p>Directory layout will be updated after each lookup, getattr, setattr, setdirstripe and open, I'd say it's protected by UPDATE bit, but it's used by MDT to serialize operations, client won't clear its directory layout upon UPDATE bit revoke, because it needs layout information to access directory (just like fid), and I think we've kept it up-to-date already.</p> <p>Now directory layout is protected by LOOKUP lock, since directory layout is revoked only by directory migration/shrink and LFSCK layout recreate, put it under LOOKUP lock won't cause too many lock revoke.</p> <p>Lai, with the changes in patch <a href="https://review.whamcloud.com/45370" class="external-link" target="_blank" rel="nofollow noopener">https://review.whamcloud.com/45370</a> "<tt><a href="https://jira.whamcloud.com/browse/LU-14448" title="lod_get_default_lov_striping() may crash for uninitialized .llc_pool" class="issue-link" data-issue-key="LU-14448"><del>LU-14448</del></a> lod: verify LOV early in lod_get_default_striping</tt>" and patch <a href="https://review.whamcloud.com/45237" class="external-link" target="_blank" rel="nofollow noopener">https://review.whamcloud.com/45237</a> "<tt><a href="https://jira.whamcloud.com/browse/LU-15070" title="client does not inherit default directory layout if changed" class="issue-link" data-issue-key="LU-15070"><del>LU-15070</del></a> llite: update default LMV upon any change</tt>" is there anything left to be done here? </p> <p>If not, then the patch <a href="https://review.whamcloud.com/10110" class="external-link" target="_blank" rel="nofollow noopener">https://review.whamcloud.com/10110</a> "<tt><a href="https://jira.whamcloud.com/browse/LU-7357" title="Add layout lock for striped directories." class="issue-link" data-issue-key="LU-7357"><del>LU-7357</del></a> lmv: add layout lock to striped directory</tt>" could be abandoned and this ticket closed.</p> <p>Andreas, yes, <a href="https://review.whamcloud.com/10110" class="external-link" target="_blank" rel="nofollow noopener">https://review.whamcloud.com/10110</a> can be abandoned and this can be closed.</p> Blocker LU-4684 Duplicate Related LU-6831 LU-14448 LU-15070 LU-8230 Development End date Thu, 2 Jun 2016 20:44:24 +0000 Rank 1|hzxrtz: Rank (Obsolete) 9223372036854775807 Start date Thu, 29 Oct 2015 20:44:24 +0000