<div dir="ltr"><div dir="ltr"><br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, Apr 15, 2019 at 12:52 PM Zhou, Cynthia (NSB - CN/Hangzhou) <<a href="mailto:cynthia.zhou@nokia-sbell.com">cynthia.zhou@nokia-sbell.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US">Hi,<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US">The reason why I move event_handled to the end of socket_event_poll_in is because if event_handled is called before rpc_transport_pollin_destroy, it allowed another round
of event_dispatch_epoll_handler happen before rpc_transport_pollin_destroy, in this way, when the latter poll in goes to rpc_transport_pollin_destroy , there is a chance that the pollin->iobref has already been destroyed by the first one(there is no lock
destroy for iobref->lock in iobref_destroy by the way). That may cause stuck in “LOCK (&iobref->lock);”<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US">I find the one of recent patch<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:8pt;font-family:"Courier New"" lang="EN-US">SHA-1: f747d55a7fd364e2b9a74fe40360ab3cb7b11537<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:8pt;font-family:"Courier New"" lang="EN-US"><u></u> <u></u></span></p>
<p class="MsoNormal"><b><span style="font-size:8pt;font-family:"Courier New"" lang="EN-US">* socket: fix issue on concurrent handle of a socket<u></u><u></u></span></b></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US">I think the point is to avoid the concurrent handling of the same socket at the same time, but after my test with this patch this problem also exists, so I think event_handled
is still called too early to allow concurrent handling of the same socket happen, </span></p></div></div></blockquote><div><br></div><div>But concurrent handling is required for performance. So, we cannot serialize it.</div><div> <br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div lang="ZH-CN"><div class="gmail-m_2023506530592226367WordSection1"><p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US">and after move it to the end of socket_event_poll this glusterd stuck issue disappeared.</span></p></div></div></blockquote><div><br></div><div>Ideally there shouldn't be a single instance of datastructure that should be shared between two instances of pollin handling. My initial code-reading didn't find any issues with the way iobref is handled even when there is concurrent reading when the previous message was still not notified. I'll continue to investigate how objects are shared across two instances of pollin. Will post if I find anything interesting.<br></div><div> <br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div lang="ZH-CN"><div class="gmail-m_2023506530592226367WordSection1"><p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US">cynthia<u></u><u></u></span></p>
<p class="MsoNormal"><b><span style="font-size:11pt;font-family:"Calibri",sans-serif" lang="EN-US">From:</span></b><span style="font-size:11pt;font-family:"Calibri",sans-serif" lang="EN-US"> Raghavendra Gowdappa <<a href="mailto:rgowdapp@redhat.com" target="_blank">rgowdapp@redhat.com</a>>
<br>
<b>Sent:</b> Monday, April 15, 2019 2:36 PM<br>
<b>To:</b> Zhou, Cynthia (NSB - CN/Hangzhou) <<a href="mailto:cynthia.zhou@nokia-sbell.com" target="_blank">cynthia.zhou@nokia-sbell.com</a>><br>
<b>Cc:</b> <a href="mailto:gluster-devel@gluster.org" target="_blank">gluster-devel@gluster.org</a><br>
<b>Subject:</b> Re: glusterd stuck for glusterfs with version 3.12.15<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US">On Mon, Apr 15, 2019 at 11:08 AM Zhou, Cynthia (NSB - CN/Hangzhou) <<a href="mailto:cynthia.zhou@nokia-sbell.com" target="_blank">cynthia.zhou@nokia-sbell.com</a>> wrote:<u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US">Ok, thanks for your comment!</span><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US"> </span><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US">cynthia</span><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US"> </span><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><b><span style="font-size:11pt;font-family:"Calibri",sans-serif" lang="EN-US">From:</span></b><span style="font-size:11pt;font-family:"Calibri",sans-serif" lang="EN-US"> Raghavendra
Gowdappa <<a href="mailto:rgowdapp@redhat.com" target="_blank">rgowdapp@redhat.com</a>>
<br>
<b>Sent:</b> Monday, April 15, 2019 11:52 AM<br>
<b>To:</b> Zhou, Cynthia (NSB - CN/Hangzhou) <<a href="mailto:cynthia.zhou@nokia-sbell.com" target="_blank">cynthia.zhou@nokia-sbell.com</a>><br>
<b>Cc:</b> <a href="mailto:gluster-devel@gluster.org" target="_blank">gluster-devel@gluster.org</a><br>
<b>Subject:</b> Re: glusterd stuck for glusterfs with version 3.12.15</span><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US"> <u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US">Cynthia,<u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US"> <u></u><u></u></span></p>
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<div>
<p class="MsoNormal"><span lang="EN-US">On Mon, Apr 15, 2019 at 8:10 AM Zhou, Cynthia (NSB - CN/Hangzhou) <<a href="mailto:cynthia.zhou@nokia-sbell.com" target="_blank">cynthia.zhou@nokia-sbell.com</a>>
wrote:<u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US">Hi,</span><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US">I made a patch and according to my test, this glusterd stuck issue disappear with my patch. Only need to move event_handled
to the end of socket_event_poll_in function.</span><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US"> </span><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US">--- a/rpc/rpc-transport/socket/src/socket.c
</span><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US">+++ b/rpc/rpc-transport/socket/src/socket.c</span><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US">@@ -2305,9 +2305,9 @@ socket_event_poll_in (rpc_transport_t *this, gf_boolean_t notify_handled)</span><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US"> }</span><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US"> </span><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US">- if (notify_handled && (ret != -1))</span><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US">- event_handled (ctx->event_pool, priv->sock, priv->idx,</span><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US">- priv->gen);</span><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US">@@ -2330,6 +2327,9 @@ socket_event_poll_in (rpc_transport_t *this, gf_boolean_t notify_handled)</span><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US"> }</span><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US"> pthread_mutex_unlock (&priv->notify.lock);</span><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US"> }</span><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US">+ if (notify_handled && (ret != -1))</span><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US">+ event_handled (ctx->event_pool, priv->sock, priv->idx,</span><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US">+ priv->gen);</span><span lang="EN-US"><u></u><u></u></span></p>
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</blockquote>
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<p class="MsoNormal"><span lang="EN-US"> <u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US">Thanks for this tip. Though this helps in fixing the hang, this change has performance impact. Moving event_handled to end of poll_in means, socket will be added
back for polling of new events only _after_ the rpc is msg is processed by higher layers (like EC) and higher layers can have significant latency for processing the msg. Which means, socket will be out of polling for longer periods of time which decreases
the throughput (number of msgs read per second) affecting performance. However, this experiment definitely indicates there is a codepath where event_handled is not called (and hence causing the hang). I'll go through this codepath again.<u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US">Can you check whether patch [1] fixes the issue you are seeing?<u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US">[1] <a href="https://review.gluster.org/#/c/glusterfs/+/22566" target="_blank">
https://review.gluster.org/#/c/glusterfs/+/22566</a><u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US"><u></u> <u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US"> <u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US">Thanks for that experiment :).<u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US"> <u></u><u></u></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US"> return ret;</span><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US">}</span><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US"> </span><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US">cynthia</span><span lang="EN-US"><u></u><u></u></span></p>
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<p class="MsoNormal"><b><span style="font-size:11pt;font-family:"Calibri",sans-serif" lang="EN-US">From:</span></b><span style="font-size:11pt;font-family:"Calibri",sans-serif" lang="EN-US"> Zhou,
Cynthia (NSB - CN/Hangzhou) <br>
<b>Sent:</b> Tuesday, April 09, 2019 3:57 PM<br>
<b>To:</b> 'Raghavendra Gowdappa' <<a href="mailto:rgowdapp@redhat.com" target="_blank">rgowdapp@redhat.com</a>><br>
<b>Cc:</b> <a href="mailto:gluster-devel@gluster.org" target="_blank">gluster-devel@gluster.org</a><br>
<b>Subject:</b> RE: glusterd stuck for glusterfs with version 3.12.15</span><span lang="EN-US"><u></u><u></u></span></p>
</div>
</div>
<p class="MsoNormal"><span lang="EN-US"> <u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US">Can you figure out some possible reason why iobref is corrupted, is it possible that thread 8 has called poll in
and iobref has been relased, but the lock within it is not properly released (as I can not find any free lock operation in iobref_destroy), then thread 9 called
</span><span lang="EN-US">rpc_transport_pollin_destroy again, and so stuck on this lock<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">Also, there should not be two thread handling the same socket at the same time, although there has been a patch claimed to tackle this issue.<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US"> <u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">cynthia<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian" lang="EN-US"> </span><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><b><span style="font-size:11pt;font-family:"Calibri",sans-serif" lang="EN-US">From:</span></b><span style="font-size:11pt;font-family:"Calibri",sans-serif" lang="EN-US"> Raghavendra
Gowdappa <<a href="mailto:rgowdapp@redhat.com" target="_blank">rgowdapp@redhat.com</a>>
<br>
<b>Sent:</b> Tuesday, April 09, 2019 3:52 PM<br>
<b>To:</b> Zhou, Cynthia (NSB - CN/Hangzhou) <<a href="mailto:cynthia.zhou@nokia-sbell.com" target="_blank">cynthia.zhou@nokia-sbell.com</a>><br>
<b>Cc:</b> <a href="mailto:gluster-devel@gluster.org" target="_blank">gluster-devel@gluster.org</a><br>
<b>Subject:</b> Re: glusterd stuck for glusterfs with version 3.12.15</span><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US"> <u></u><u></u></span></p>
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<div>
<p class="MsoNormal"><span lang="EN-US"> <u></u><u></u></span></p>
</div>
<p class="MsoNormal"><span lang="EN-US"> <u></u><u></u></span></p>
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<div>
<p class="MsoNormal"><span lang="EN-US">On Mon, Apr 8, 2019 at 7:42 AM Zhou, Cynthia (NSB - CN/Hangzhou) <<a href="mailto:cynthia.zhou@nokia-sbell.com" target="_blank">cynthia.zhou@nokia-sbell.com</a>>
wrote:<u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US">Hi glusterfs experts,<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">Good day!<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">In my test env, sometimes glusterd stuck issue happened, and it is not responding to any gluster commands, when I checked this issue I find that glusterd thread
9 and thread 8 is dealing with the same socket, I thought following patch should be able to solve this issue, however after I merged this patch this issue still exist. When I looked into this code, it seems socket_event_poll_in called event_handled before
rpc_transport_pollin_destroy, I think this gives the chance for another poll for the exactly the same socket. And caused this glusterd stuck issue, also, I find there is no LOCK_DESTROY(&iobref->lock)<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">In iobref_destroy, I think it is better to add destroy lock.<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">Following is the gdb info when this issue happened, I would like to know your opinion on this issue, thanks!<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US"> <u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:8pt;font-family:"Courier New"" lang="EN-US">SHA-1: f747d55a7fd364e2b9a74fe40360ab3cb7b11537</span><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:8pt;font-family:"Courier New"" lang="EN-US"> </span><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><b><span style="font-size:8pt;font-family:"Courier New"" lang="EN-US">* socket: fix issue on concurrent handle of a socket</span></b><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><b><span style="font-size:8pt;font-family:"Courier New"" lang="EN-US"> </span></b><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><b><span style="font-size:8pt;font-family:"Courier New"" lang="EN-US"> </span></b><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><b><span style="font-size:8pt;font-family:"Courier New"" lang="EN-US"> </span></b><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><b><span style="font-size:8pt;font-family:"Courier New"" lang="EN-US">GDB INFO:</span></b><span lang="EN-US"><u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">Thread 8 is blocked on pthread_cond_wait, and thread 9 is blocked in iobref_unref, I think
<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">Thread 9 (Thread 0x7f9edf7fe700 (LWP 1933)):<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">#0 0x00007f9ee9fd785c in __lll_lock_wait () from /lib64/libpthread.so.0<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">#1 0x00007f9ee9fda657 in __lll_lock_elision () from /lib64/libpthread.so.0<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">#2 0x00007f9eeb24cae6 in iobref_unref (iobref=0x7f9ed00063b0) at iobuf.c:944<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">#3 0x00007f9eeafd2f29 in rpc_transport_pollin_destroy (pollin=0x7f9ed00452d0) at rpc-transport.c:123<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">#4 0x00007f9ee4fbf319 in socket_event_poll_in (this=0x7f9ed0049cc0, notify_handled=_gf_true) at socket.c:2322<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">#5 0x00007f9ee4fbf932 in socket_event_handler (<b><span style="color:red">fd=36</span>,<span style="color:red"> idx=27, gen=4, data=0x7f9ed0049cc0, poll_in=1,
poll_out=0, poll_err=0</span></b>) at socket.c:2471<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">#6 0x00007f9eeb2825d4 in event_dispatch_epoll_handler (event_pool=0x17feb00, event=0x7f9edf7fde84) at event-epoll.c:583<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">#7 0x00007f9eeb2828ab in event_dispatch_epoll_worker (data=0x180d0c0) at event-epoll.c:659<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">#8 0x00007f9ee9fce5da in start_thread () from /lib64/libpthread.so.0<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">#9 0x00007f9ee98a4eaf in clone () from /lib64/libc.so.6<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US"> <u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">Thread 8 (Thread 0x7f9edffff700 (LWP 1932)):<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">#0 0x00007f9ee9fd785c in __lll_lock_wait () from /lib64/libpthread.so.0<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">#1 0x00007f9ee9fd2b42 in __pthread_mutex_cond_lock () from /lib64/libpthread.so.0<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">#2 0x00007f9ee9fd44a8 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">#3 0x00007f9ee4fbadab in socket_event_poll_err (this=0x7f9ed0049cc0, gen=4, idx=27) at socket.c:1201<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">#4 0x00007f9ee4fbf99c in socket_event_handler (<b><span style="color:red">fd=36, idx=27, gen=4, data=0x7f9ed0049cc0, poll_in=1, poll_out=0, poll_err=0</span></b>)
at socket.c:2480<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">#5 0x00007f9eeb2825d4 in event_dispatch_epoll_handler (event_pool=0x17feb00, event=0x7f9edfffee84) at event-epoll.c:583<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">#6 0x00007f9eeb2828ab in event_dispatch_epoll_worker (data=0x180cf20) at event-epoll.c:659<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">#7 0x00007f9ee9fce5da in start_thread () from /lib64/libpthread.so.0<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">#8 0x00007f9ee98a4eaf in clone () from /lib64/libc.so.6<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US"> <u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">(gdb) thread 9<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">[Switching to thread 9 (Thread 0x7f9edf7fe700 (LWP 1933))]<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">#0 0x00007f9ee9fd785c in __lll_lock_wait () from /lib64/libpthread.so.0<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">(gdb) bt<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">#0 0x00007f9ee9fd785c in __lll_lock_wait () from /lib64/libpthread.so.0<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">#1 0x00007f9ee9fda657 in __lll_lock_elision () from /lib64/libpthread.so.0<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">#2 0x00007f9eeb24cae6 in iobref_unref (iobref=0x7f9ed00063b0) at iobuf.c:944<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">#3 0x00007f9eeafd2f29 in rpc_transport_pollin_destroy (pollin=0x7f9ed00452d0) at rpc-transport.c:123<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">#4 0x00007f9ee4fbf319 in socket_event_poll_in (this=0x7f9ed0049cc0, notify_handled=_gf_true) at socket.c:2322<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">#5 0x00007f9ee4fbf932 in socket_event_handler (fd=36, idx=27, gen=4, data=0x7f9ed0049cc0, poll_in=1, poll_out=0, poll_err=0) at socket.c:2471<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">#6 0x00007f9eeb2825d4 in event_dispatch_epoll_handler (event_pool=0x17feb00, event=0x7f9edf7fde84) at event-epoll.c:583<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">#7 0x00007f9eeb2828ab in event_dispatch_epoll_worker (data=0x180d0c0) at event-epoll.c:659<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">#8 0x00007f9ee9fce5da in start_thread () from /lib64/libpthread.so.0<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">#9 0x00007f9ee98a4eaf in clone () from /lib64/libc.so.6<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">(gdb) frame 2<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">#2 0x00007f9eeb24cae6 in iobref_unref (iobref=0x7f9ed00063b0) at iobuf.c:944<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">944 iobuf.c: No such file or directory.<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">(gdb) print *iobref<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">$1 = {lock = {spinlock = 2, mutex = {__data = {__lock = 2, __count = 222, __owner = -2120437760, __nusers = 1, __kind = 8960, __spins = 512,
<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US"> __elision = 0, __list = {__prev = 0x4000, __next = 0x7f9ed00063b000}},
<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US"> __size = "\002\000\000\000\336\000\000\000\000\260\234\201\001\000\000\000\000#\000\000\000\002\000\000\000@\000\000\000\000\000\000\000\260c\000</span>О<span lang="EN-US">\177",
__align = 953482739714}}, ref = -256, iobrefs = 0xffffffffffffffff, alloced = -1, used = -1}<u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US"> <u></u><u></u></span></p>
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<div>
<p class="MsoNormal"><span lang="EN-US">looks like the iobref is corrupted here. It seems to be a use-after-free issue. We need to dig into why a freed iobref is being accessed here.<u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US"> <u></u><u></u></span></p>
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<p class="MsoNormal"><span lang="EN-US">(gdb) quit<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-US">A debugging session is active.<u></u><u></u></span></p>
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