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-13528 Lustre <p>This issue was created by maloo for S Buisson &lt;sbuisson@ddn.com&gt;</p> <p>This issue relates to the following test suite run: <a href="https://testing.whamcloud.com/test_sets/2be4adce-b792-4432-8f8b-6caba6148d68" class="external-link" target="_blank" rel="nofollow noopener">https://testing.whamcloud.com/test_sets/2be4adce-b792-4432-8f8b-6caba6148d68</a></p> <p>test_69 failed with the following error:</p> <div class="preformatted panel" style="border-width: 1px;"><div class="preformattedContent panelContent"> <pre>read succeeded, expect -ENOENT </pre> </div></div> <p>This error occurs only on aarch64 platforms. It seems the fail_loc value set on server side has no effect.</p> <p>VVVVVVV DO NOT REMOVE LINES BELOW, Added by Maloo for auto-association VVVVVVV<br/> sanity test_69 - read succeeded, expect -ENOENT</p> LU-13528

sanity test_69: read succeeded, expect -ENOENT

Bug Minor Resolved Fixed Sebastien Buisson Maloo Thu, 7 May 2020 07:23:18 +0000 Wed, 27 May 2020 14:54:35 +0000 Wed, 27 May 2020 14:54:35 +0000 Lustre 2.14.0 0 3 <p>After further investigation, it appears that a bug with the Lustre code on aarch64 platforms turns the <tt>O_DIRECT</tt> IO into a regular IO, hence bypassing the expected fail_loc behavior in sanity test_69.</p> <p>The bug stems from the fact that the <tt>MAX_DIO_SIZE</tt> value is truncated to its lower 32 bits.<br/> Its definition is:</p> <div class="preformatted panel" style="border-width: 1px;"><div class="preformattedContent panelContent"> <pre>#define MAX_DIO_SIZE ((MAX_MALLOC / sizeof(struct brw_page) * PAGE_SIZE) &amp; \ ~(DT_MAX_BRW_SIZE - 1)) </pre> </div></div> <p>On 4kB <tt>PAGE_SIZE</tt> platforms, it goes unnoticed as the value fits into 32 bits. But on 64kB <tt>PAGE_SIZE</tt> platforms, this value can go up to 1365GB.</p> <p>This problem, in combination with the fact that patch <a href="https://review.whamcloud.com/36144" class="external-link" target="_blank" rel="nofollow noopener">https://review.whamcloud.com/36144</a> increased the size of struct brw_page to 32 bytes, makes 1024GB (64 bits) truncated to 0 (lower 32 bits). The consequence is that <tt>ll_direct_IO_impl()</tt> triggers a direct IO of 0 bytes, which in turn makes llite issue a normal, buffered IO.</p> <p>Sebastien Buisson (sbuisson@ddn.com) uploaded a new patch: <a href="https://review.whamcloud.com/38526" class="external-link" target="_blank" rel="nofollow noopener">https://review.whamcloud.com/38526</a><br/> Subject: <a href="https://jira.whamcloud.com/browse/LU-13528" title="sanity test_69: read succeeded, expect -ENOENT" class="issue-link" data-issue-key="LU-13528"><del>LU-13528</del></a> llite: prevent MAX_DIO_SIZE 32-bit truncation<br/> Project: fs/lustre-release<br/> Branch: master<br/> Current Patch Set: 1<br/> Commit: 0e0984dcdd4a1f0b3c0b619793c31131704519be</p> <p>Oleg Drokin (green@whamcloud.com) merged in patch <a href="https://review.whamcloud.com/38526/" class="external-link" target="_blank" rel="nofollow noopener">https://review.whamcloud.com/38526/</a><br/> Subject: <a href="https://jira.whamcloud.com/browse/LU-13528" title="sanity test_69: read succeeded, expect -ENOENT" class="issue-link" data-issue-key="LU-13528"><del>LU-13528</del></a> llite: prevent MAX_DIO_SIZE 32-bit truncation<br/> Project: fs/lustre-release<br/> Branch: master<br/> Current Patch Set: <br/> Commit: 8cfd5be8b04bdaaa4a0c794392cc2e6835e103eb</p> <p>Landed for 2.14</p> Development Rank 1|i00zov: Rank (Obsolete) 9223372036854775807 Severity