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-12460 Lustre <p>Neil Brown discovered during the linux lustre client work a potential read lock condition involving lli_trunc_sem. If you mmap a lustre file, then read into that mapped memory from the file they can shared the same mmap_sem which does is okay since they are down_read() calls. The read lock can happen if truncate is called in between memory mapping the file and reading into the that mapped memory from the file.</p> Any lustre client LU-12460

lli_trunc_sem can lead to a readlock

Bug Major Resolved Fixed Neil Brown James A Simmons Thu, 20 Jun 2019 01:47:08 +0000 Fri, 3 Dec 2021 19:03:05 +0000 Thu, 23 Jan 2020 13:10:44 +0000 Lustre 2.13.0 Lustre 2.12.2 Lustre 2.14.0 0 5 <p>James Simmons (uja.ornl@yahoo.com) uploaded a new patch: <a href="https://review.whamcloud.com/35271" class="external-link" target="_blank" rel="nofollow noopener">https://review.whamcloud.com/35271</a><br/> Subject: <a href="https://jira.whamcloud.com/browse/LU-12460" title="lli_trunc_sem can lead to a readlock" class="issue-link" data-issue-key="LU-12460"><del>LU-12460</del></a> llite: replace lli_trunc_sem<br/> Project: fs/lustre-release<br/> Branch: master<br/> Current Patch Set: 1<br/> Commit: a234469c691056b1eb81ae0a22ab9f105cffa8a9</p> <p>James, your bug description doesn't quite make sense. Is there supposed to be a write lock somewhere in there?</p> <p>I haven't looked at the CLIO code in a while, but we used to have a check for the source pages coming from mmapped memory of the target file, or vice versa.</p> <p>Yeah the details were lacking at the time I opened the ticket. It was based on what was in the patch. As the discussion continues this ticket description can be updated.</p> <p>James,</p> <p>I asked this in Gerrit but didn't see a response - Has this patch been on a mailing list and I missed it?  Or is this the first appearance of it?  If it's been on a mailing list, which one?</p> <p>Patrick Farrell (pfarrell@whamcloud.com) uploaded a new patch: <a href="https://review.whamcloud.com/35283" class="external-link" target="_blank" rel="nofollow noopener">https://review.whamcloud.com/35283</a><br/> Subject: <a href="https://jira.whamcloud.com/browse/LU-12460" title="lli_trunc_sem can lead to a readlock" class="issue-link" data-issue-key="LU-12460"><del>LU-12460</del></a> llite: replace lli_trunc_sem<br/> Project: fs/lustre-release<br/> Branch: master<br/> Current Patch Set: 1<br/> Commit: e0561ca36a6062d423a447070eda688d0194b2cf</p> <p>Patrick,</p> <p> that patch has been in my lustre-testing branch for a while, but I hadn't posted it because I really want there to be a better way - so I was procrastinating.</p> <p>James did post it to the list on 20th May with a bunch of patches which were patches from my lustre-testing which he had modified to varying extents (I've merged the changes I liked into my lustre-testing).</p> <p>You might  remember discussing your "ll_fault fixes" patch that was in the series and I had questions about it.  It was patch 1 of the series.  This patch was patch  3 (of 29).</p> <p>Right, thank you - Obviously, I did not read through the full series......</p> <p>Oleg Drokin (green@whamcloud.com) merged in patch <a href="https://review.whamcloud.com/35271/" class="external-link" target="_blank" rel="nofollow noopener">https://review.whamcloud.com/35271/</a><br/> Subject: <a href="https://jira.whamcloud.com/browse/LU-12460" title="lli_trunc_sem can lead to a readlock" class="issue-link" data-issue-key="LU-12460"><del>LU-12460</del></a> llite: replace lli_trunc_sem<br/> Project: fs/lustre-release<br/> Branch: master<br/> Current Patch Set: <br/> Commit: e5914a61ac7705f5768c9c75094a456dafefb04f</p> <p>Landed for 2.14</p> Related LU-12511 Development Rank 1|i00iin: Rank (Obsolete) 9223372036854775807 Severity