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-4945 Lustre <p>I found this problem when I tried to run racer with MDSCOUNT=4</p> <p>LustreError: 8391:0:(pack_generic.c:815:lustre_msg_string()) can't unpack short string in msg ffffc90017980658 buffer<span class="error">&#91;5&#93;</span> len 3: strlen 0<br/> LustreError: 8391:0:(layout.c:2060:__req_capsule_get()) @@@ Wrong buffer for field `name' (5 of 6) in format `LDLM_INTENT_GETATTR': 3 vs. 0 (client)<br/> req@ffff8802055e9800 x1466142079352512/t0(0) o101-&gt;203a5d79-0163-0009-b60a-805a18baffe6@0@lo:0/0 lens 576/3384 e 0 to 0 dl 1398222210 ref 1 fl Interpret:/0/0 rc 0/0</p> LU-4945

req_capsule_get: Wrong buffer for field `name' (5 of 6) in format `LDLM_INTENT_GETATTR': 3 vs. 0 (client)

Bug Critical Closed Fixed Di Wang Di Wang Wed, 23 Apr 2014 19:40:45 +0000 Thu, 1 May 2014 22:31:07 +0000 Thu, 1 May 2014 22:31:07 +0000 Lustre 2.6.0 Lustre 2.6.0 0 5 <p>Di, how serious is this bug, and what problem would be visible to the client?</p> <p>Is the source of this bug obvious, and could Lai create the patch?</p> <p>Andreas: this bug is pretty serious to me, which seems related with the new readdir change. I am investigating it right now, no obvious clue yet. Thanks. </p> <p>Hmm, it turns out using the dir_ent pointer to locate next entry is not very safe without holding ldlm lock. </p> <div class="preformatted panel" style="border-width: 1px;"><div class="preformattedContent panelContent"> <pre>mdc_read_entry() { .... /* If op_data-&gt;op_ent != NULL(see ll_dir_entry_next), try to get * next ent directly */ if (likely(op_data-&gt;op_ent != NULL)) { ent = lu_dirent_next(op_data-&gt;op_ent); if (likely(ent != NULL)) GOTO(out, rc); } else { ..... </pre> </div></div> <p>So we either find a new way to resolve the hash conflict or hold the ldlm lock during iteration. I will cook a patch.</p> <p>This is a good excuse/opportunity to kill all the uses of LOGL0() to pack names:</p> <div class="preformatted panel" style="border-width: 1px;"><div class="preformattedContent panelContent"> <pre>+static void mdc_pack_name(struct ptlrpc_request *req, + const struct req_msg_field *field, + const char *name, size_t name_len) +{ + char *buf; + size_t buf_size; + + buf = req_capsule_client_get(&amp;req-&gt;rq_pill, field); + buf_size = req_capsule_get_size(&amp;req-&gt;rq_pill, field, RCL_CLIENT); + + LASSERT(buf != NULL &amp;&amp; + buf_size == name_len + 1 &amp;&amp; + name != NULL &amp;&amp; + name_len != 0 &amp;&amp; + strnlen(name, name_len) == name_len &amp;&amp; + name[name_len] == '\0'); + + strlcpy(buf, name, buf_size); + + LASSERT(strlen(buf) == name_len); +} + ... - tmp = req_capsule_client_get(&amp;req-&gt;rq_pill, &amp;RMF_NAME); - LOGL0(op_data-&gt;op_name, op_data-&gt;op_namelen, tmp); + mdc_pack_name(req, &amp;RMF_NAME, op_data-&gt;op_name, op_data-&gt;op_namelen); </pre> </div></div> <p><a href="http://review.whamcloud.com/#/c/10109/" class="external-link" target="_blank" rel="nofollow noopener">http://review.whamcloud.com/#/c/10109/</a></p> <p>Sorry, John, I did not include your changes into this patch. I will try to add it later.</p> <p>Changes merged into <a href="http://review.whamcloud.com/#/c/9191/" class="external-link" target="_blank" rel="nofollow noopener">http://review.whamcloud.com/#/c/9191/</a></p> <p>Fix was merged into <a href="http://review.whamcloud.com/9191" class="external-link" target="_blank" rel="nofollow noopener">http://review.whamcloud.com/9191</a> under <a href="https://jira.whamcloud.com/browse/LU-4603" title="NFS reexport leads to problems of &quot;ls&quot;" class="issue-link" data-issue-key="LU-4603"><del>LU-4603</del></a>.</p> <p>The patch is already merged to the fix of <a href="https://jira.whamcloud.com/browse/LU-4603" title="NFS reexport leads to problems of &quot;ls&quot;" class="issue-link" data-issue-key="LU-4603"><del>LU-4603</del></a>. I will close this for now.</p> <p>John: Sorry, Could you please create a new ticket for your suggestion? Thanks.</p> <p>Done.</p> Related LU-4603 LU-3531 Development Epic/Theme dne Rank 1|hzwkuv: Rank (Obsolete) 13685 Severity