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-3831 Lustre <p>ll_readdir calls touch_atime() which is wrong because it ignores<br/> whether O_NOATIME is set in f_flags. On RHEL 6, this is moreover unnecessary as vfs_readdir() calls file_accessed() (which does check for O_NOATIME) after invoking f_op-&gt;readdir().</p> LU-3831

ll_readdir() ignores O_NOATIME

Bug Major Resolved Fixed John Hammond John Hammond llite patch Fri, 23 Aug 2013 15:30:59 +0000 Mon, 6 Apr 2015 07:59:43 +0000 Sun, 9 Mar 2014 01:38:17 +0000 Lustre 2.5.0 Lustre 2.6.0 0 8 <p>There is likely a historical reason for this (i.e. it wasn't done in some 2.4.9 kernel), but was moved into the VFS and nobody noticed. Sounds like this call can just be deleted.</p> <p>It is also worthwhile to check if the MDS code handles "-o noatime" or "-o relatime" properly or not. It might be that the MDS writes the atime sent from the client even if it is mounted with "-o noatime".</p> <p>O_NOATIME is broken in several places. I'm preparing to report that issue but didn't want to forget this one. Will investigate '-o noatime' after this. Not sure about how it's handled on-disk but I feel confident that from the client POV it will appear to be broken.</p> <p>Despite ll_readdir() ignoring O_NATIME, directory access timestamps are not updated from userspace's POV.</p> <div class="preformatted panel" style="border-width: 1px;"><div class="preformattedContent panelContent"> <pre># mkdir /mnt/lustre/d0 # stat /mnt/lustre/d0 File: `/mnt/lustre/d0' Size: 4096 Blocks: 8 IO Block: 4096 directory Device: 2c54f966h/743766374d Inode: 144115205255725058 Links: 2 Access: (0755/drwxr-xr-x) Uid: ( 0/ root) Gid: ( 0/ root) Access: 2013-08-23 13:51:06.000000000 -0500 Modify: 2013-08-23 13:51:06.000000000 -0500 Change: 2013-08-23 13:51:06.000000000 -0500 # /bin/ls /mnt/lustre/d0 # stat /mnt/lustre/d0 File: `/mnt/lustre/d0' Size: 4096 Blocks: 8 IO Block: 4096 directory Device: 2c54f966h/743766374d Inode: 144115205255725058 Links: 2 Access: (0755/drwxr-xr-x) Uid: ( 0/ root) Gid: ( 0/ root) Access: 2013-08-23 13:51:06.000000000 -0500 Modify: 2013-08-23 13:51:06.000000000 -0500 Change: 2013-08-23 13:51:06.000000000 -0500 # date Fri Aug 23 13:52:10 CDT 2013 # /bin/ls /mnt/lustre/d0 # stat /mnt/lustre/d0 File: `/mnt/lustre/d0' Size: 4096 Blocks: 8 IO Block: 4096 directory Device: 2c54f966h/743766374d Inode: 144115205255725058 Links: 2 Access: (0755/drwxr-xr-x) Uid: ( 0/ root) Gid: ( 0/ root) Access: 2013-08-23 13:51:06.000000000 -0500 Modify: 2013-08-23 13:51:06.000000000 -0500 Change: 2013-08-23 13:51:06.000000000 -0500 </pre> </div></div> <p>Patch: <a href="http://review.whamcloud.com/#/c/8664/" class="external-link" target="_blank" rel="nofollow noopener">http://review.whamcloud.com/#/c/8664/</a></p> <p>I used the recently added file_is_noatime() to honor O_NOATIME before calling touch_atime in ll_readdir()</p> <p>Patch landed to master. Thanks Swapnil.</p> <p>Faccini Bruno (bruno.faccini@intel.com) uploaded a new patch: <a href="http://review.whamcloud.com/13687" class="external-link" target="_blank" rel="nofollow noopener">http://review.whamcloud.com/13687</a><br/> Subject: <a href="https://jira.whamcloud.com/browse/LU-3831" title="ll_readdir() ignores O_NOATIME" class="issue-link" data-issue-key="LU-3831"><del>LU-3831</del></a> llite: Remove touch_atime() call in ll_readdir()<br/> Project: fs/lustre-release<br/> Branch: b2_5<br/> Current Patch Set: 1<br/> Commit: e6105f668ec9135f1c888399329f4d8fd5b68cde</p> <p>b2_5 patch version/back-port is at <a href="http://review.whamcloud.com/13687/" class="external-link" target="_blank" rel="nofollow noopener">http://review.whamcloud.com/13687/</a>.</p> Duplicate LU-3315 LU-4632 Development Rank 1|hzvz3z: Rank (Obsolete) 9899 Severity