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-3344 Lustre <p>The open_by_handle_at() and name_to_handle() functions were added to Linux 2.6.38, and allow opening files by a file handle instead of path traversal. This may be useful for HPC applications to reduce loading on the metadata server from repeated path traversal.</p> <p>There is some chance this feature already works on Lustre, due to the re-use of the NFS exportfs_encode_fh() and exportfs_decode_fh() functions. This code needs a regression test in Lustre to verify it is working correctly, along with documentation in the user manual.</p> LU-3344

Add open_by_handle() syscall for Lustre clients

New Feature Minor Resolved Fixed Jian Yu Andreas Dilger patch Wed, 15 May 2013 10:09:58 +0000 Fri, 5 Jun 2015 00:31:03 +0000 Sun, 2 Feb 2014 16:06:59 +0000 Lustre 2.6.0 0 11 <p>Working on this. We are hit by a Null pointer dereference in ll_revalidate_nd (llite/dcache.c) in an NFS mounted Lustre file system. <a href="https://jira.hpdd.intel.com/browse/LU-3483" class="external-link" target="_blank" rel="nofollow noopener">https://jira.hpdd.intel.com/browse/LU-3483</a></p> <p>Status : Work In Progress</p> <p>Here is the initial patch for sanity tests to check 'name_to_handle_at' and 'open_by_handle_at' syscalls.<br/> <a href="http://review.whamcloud.com/#/c/7129/" class="external-link" target="_blank" rel="nofollow noopener">http://review.whamcloud.com/#/c/7129/</a></p> <p>Currently the patch is incomplete because 'name_to_handle_at' and 'open_by_handle_at' are updated in glibc 2.14. Current Glibc version is 2.12. So for now we are calling the syscalls with syscall numbers directly.</p> <p>Please note that the above patch (<a href="http://review.whamcloud.com/#/c/7129/" class="external-link" target="_blank" rel="nofollow noopener">http://review.whamcloud.com/#/c/7129/</a>) is abandoned.</p> <p>I have added a new patch here (<a href="http://review.whamcloud.com/#/c/7247/" class="external-link" target="_blank" rel="nofollow noopener">http://review.whamcloud.com/#/c/7247/</a>)<br/> As mentioned in the previous comment, these syscalls are supported in glibc &gt;= 2.14<br/> So currently this test is run only on FC18 clients which have 2.16 glibc and skipped otherwise.</p> <p>While testing these syscalls on FC18 client, I hit this (<a href="https://jira.hpdd.intel.com/browse/LU-3717" class="external-link" target="_blank" rel="nofollow noopener">https://jira.hpdd.intel.com/browse/LU-3717</a>) panic in ll_enocde_fh()</p> <p>As noted in the ticket description the syscalls and the structure file_handle were added in Linux kernel 2.6.39</p> <p>I have added a config time check which checks whether file_handle, name_to_handle_at() and open_by_handle_at() can be resolved.<br/> I expect this patch (<a href="http://review.whamcloud.com/#/c/7247/5" class="external-link" target="_blank" rel="nofollow noopener">http://review.whamcloud.com/#/c/7247/5</a>) to solve the build errors on targets where these syscalls aren't supported.</p> <p>Bobbie</p> <p>Could you please review and take care of this patch?</p> <p>Thanks</p> <p>Peter</p> <p>Yu, Jian will take over ensuring that this patch lands</p> <p>I updated the patch. Even tho I was testing with a 3.11 kernel I couldn't get this to work but then I realized the kernel has to be configured with CONFIG_FHANDLE so I updated the autoconf test to handle this case. I also removed the FC18 condition for the sanity test since this is not the case for me.</p> <p>Patch <a href="http://review.whamcloud.com/#/c/7247" class="external-link" target="_blank" rel="nofollow noopener">http://review.whamcloud.com/#/c/7247</a> has been updated and tested.</p> <p><span class="error">&#91;root@spoon46 tests&#93;</span># ./check_fhandle_syscalls temp-file /lustre/barry<br/> fh_bytes: 32<br/> fh_type: 151<br/> fh_data: 0 4 0 0 2 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0<br/> check_fhandle_syscalls test Passed!</p> <p>The last patch <a href="http://review.whamcloud.com/#/c/7247" class="external-link" target="_blank" rel="nofollow noopener">http://review.whamcloud.com/#/c/7247</a> has been merged. This ticket can be closed.</p> <p>Fixed in 2.6</p> Related LU-3717 Development Rank 1|hzvr1j: Rank (Obsolete) 8271