[Gluster-devel] glusterfsd crash when using quota without io-threads

Kinglong Mee kinglongmee at gmail.com
Tue Jun 13 00:28:04 UTC 2017


Hi Sanoj,

What's your opinion about this problem?

thanks,
Kinglong Mee

On 6/9/2017 17:20, Kinglong Mee wrote:
> Hi Sanoj,
> 
> On 6/9/2017 15:48, Sanoj Unnikrishnan wrote:
>> I have not used valgrind before, so I may be wrong here.
>>
>> I think the valgrind_stack_deregister should have been after GF_FREE_STACK.
>> That may explain the instance of invalid_write during stack_destroy calls in after.log.
> 
> No. I move it, but the instance of invalid_write also exist.
> 
>>
>> There seems to be numerous issues reported in before.log (I am assuming, you did not have the valgrind_stack_register call in it), 
> 
> Yes, the before.log is test without any code change(but without io-threads).
> 
>> From http://valgrind.org/docs/manual/manual-core.html <http://valgrind.org/docs/manual/manual-core.html>, looks like valgrind detects client switching stack only If a memory of > 2MB change in Stack pointer register. 
> 
> I test with a larger max-stackframe as, 
> valgrind  --leak-check=full --max-stackframe=242293216 
> 
>> Is it possible that since marker is only using 16k, the stack pointer could have been in less than 2MB offset from current Stack Pointer?
> 
> Maybe.
> But with io-threads (with adding valgrind_stack_deregister), the valgrind only show some
> "Invalid read/write" about __gf_mem_invalidate.
> The only reason here I think is the stack size (16K) of marker using.
> 
> I have not used makecontext/swapcontext before, am i right?
> 1. without swapconext, the stack maybe (just an example)
>    --> io_stats-> quota-> marker-> io-threads ->.....
> 
> 2. with swapcontext, 
>    --> io_stats-> quota-> marker
>                swithto new stack -> io-threads
> 
> After switchto new stack, the new stack size is 16K,
> Does it enough without io-threads?
> 
> I don't know what's the behave of io-threads, does it call all sub-xlator using the 16K ? or others?
> 
>> It seems unlikely to me since we are allocating the stack from heap.
>>
>> Did you try a run with the valgrind instrumentation, without changing stack size ?
> 
> OK.
> The following valgrind-without-stack-change.log is test with adding valgrind_stack_deregister
> (and without io-threads).
> 
> thanks,
> Kinglong Mee
> 
>> None of this explains the crash though.. We had seen a memory overrun crash in same code path on netbsd earlier but did not follow up then.
>> Will look further into it.
>>
>>
>>
>> On Thu, Jun 8, 2017 at 4:51 PM, Kinglong Mee <kinglongmee at gmail.com <mailto:kinglongmee at gmail.com>> wrote:
>>
>>     Maybe it's my fault, I found valgrind can't parse context switch(makecontext/swapcontext) by default.
>>     So, I test with the following patch (tells valgrind new stack by VALGRIND_STACK_DEREGISTER).
>>     With it, only some "Invalid read/write" by __gf_mem_invalidate, Does it right ??
>>     So, there is only one problem, if without io-threads, the stack size is small for marker.
>>     Am I right?
>>
>>     Ps:
>>     valgrind-before.log is the log without the following patch, the valgrind-after.log is with the patch.
>>
>>     ==35656== Invalid write of size 8
>>     ==35656==    at 0x4E8FFD4: __gf_mem_invalidate (mem-pool.c:278)
>>     ==35656==    by 0x4E90313: __gf_free (mem-pool.c:334)
>>     ==35656==    by 0x4EA4E5B: synctask_destroy (syncop.c:394)
>>     ==35656==    by 0x4EA4EDF: synctask_done (syncop.c:412)
>>     ==35656==    by 0x4EA58B3: synctask_switchto (syncop.c:673)
>>     ==35656==    by 0x4EA596B: syncenv_processor (syncop.c:704)
>>     ==35656==    by 0x60B2DC4: start_thread (in /usr/lib64/libpthread-2.17.so <http://libpthread-2.17.so>)
>>     ==35656==    by 0x67A873C: clone (in /usr/lib64/libc-2.17.so <http://libc-2.17.so>)
>>     ==35656==  Address 0x1b104931 is 2,068,017 bytes inside a block of size 2,097,224 alloc'd
>>     ==35656==    at 0x4C29975: calloc (vg_replace_malloc.c:711)
>>     ==35656==    by 0x4E8FA5E: __gf_calloc (mem-pool.c:117)
>>     ==35656==    by 0x4EA52F5: synctask_create (syncop.c:500)
>>     ==35656==    by 0x4EA55AE: synctask_new1 (syncop.c:576)
>>     ==35656==    by 0x143AE0D7: mq_synctask1 (marker-quota.c:1078)
>>     ==35656==    by 0x143AE199: mq_synctask (marker-quota.c:1097)
>>     ==35656==    by 0x143AE6F6: _mq_create_xattrs_txn (marker-quota.c:1236)
>>     ==35656==    by 0x143AE82D: mq_create_xattrs_txn (marker-quota.c:1253)
>>     ==35656==    by 0x143B0DCB: mq_inspect_directory_xattr (marker-quota.c:2027)
>>     ==35656==    by 0x143B13A8: mq_xattr_state (marker-quota.c:2117)
>>     ==35656==    by 0x143A6E80: marker_lookup_cbk (marker.c:2961)
>>     ==35656==    by 0x141811E0: up_lookup_cbk (upcall.c:753)
>>
>>     ----------------------- valgrind ------------------------------------------
>>
>>     Don't forget install valgrind-devel.
>>
>>     diff --git a/libglusterfs/src/syncop.c b/libglusterfs/src/syncop.c
>>     index 00a9b57..97b1de1 100644
>>     --- a/libglusterfs/src/syncop.c
>>     +++ b/libglusterfs/src/syncop.c
>>     @@ -10,6 +10,7 @@
>>
>>      #include "syncop.h"
>>      #include "libglusterfs-messages.h"
>>     +#include <valgrind/valgrind.h>
>>
>>      int
>>      syncopctx_setfsuid (void *uid)
>>     @@ -388,6 +389,8 @@ synctask_destroy (struct synctask *task)
>>              if (!task)
>>                      return;
>>
>>     +VALGRIND_STACK_DEREGISTER(task->valgrind_ret);
>>     +
>>              GF_FREE (task->stack);
>>
>>              if (task->opframe)
>>     @@ -509,6 +512,8 @@ synctask_create (struct syncenv *env, size_t stacksize, sync
>>
>>              newtask->ctx.uc_stack.ss_sp   = newtask->stack;
>>
>>     +       newtask->valgrind_ret = VALGRIND_STACK_REGISTER(newtask->stack, newtask-
>>     +
>>              makecontext (&newtask->ctx, (void (*)(void)) synctask_wrap, 2, newtask)
>>
>>              newtask->state = SYNCTASK_INIT;
>>     diff --git a/libglusterfs/src/syncop.h b/libglusterfs/src/syncop.h
>>     index c2387e6..247325b 100644
>>     --- a/libglusterfs/src/syncop.h
>>     +++ b/libglusterfs/src/syncop.h
>>     @@ -63,6 +63,7 @@ struct synctask {
>>              int                 woken;
>>              int                 slept;
>>              int                 ret;
>>     +       int                 valgrind_ret;
>>
>>              uid_t               uid;
>>              gid_t               gid;
>>     diff --git a/xlators/features/marker/src/marker-quota.c b/xlators/features/marke
>>     index 902b8e5..f3d2507 100644
>>     --- a/xlators/features/marker/src/marker-quota.c
>>     +++ b/xlators/features/marker/src/marker-quota.c
>>     @@ -1075,7 +1075,7 @@ mq_synctask1 (xlator_t *this, synctask_fn_t task, gf_boole
>>              }
>>
>>              if (spawn) {
>>     -                ret = synctask_new1 (this->ctx->env, 1024 * 16, task,
>>     +                ret = synctask_new1 (this->ctx->env, 0, task,
>>                                            mq_synctask_cleanup, NULL, args);
>>                      if (ret) {
>>                              gf_log (this->name, GF_LOG_ERROR, "Failed to spawn "
>>
>>
>>     On 6/8/2017 19:02, Sanoj Unnikrishnan wrote:
>>     > I would still be worried about the Invalid read/write. IMO whether an illegal access causes a crash depends on whether the page is currently mapped.
>>     > So, it could so happen that there is a use after free / use outside of bounds happening in the code  and  it turns out that this location gets mapped in a different (unmapped) page when IO threads is not loaded.
>>     >
>>     > Could you please share the valgrind logs as well.
>>     >
>>     > On Wed, Jun 7, 2017 at 8:22 PM, Kinglong Mee <kinglongmee at gmail.com <mailto:kinglongmee at gmail.com> <mailto:kinglongmee at gmail.com <mailto:kinglongmee at gmail.com>>> wrote:
>>     >
>>     >     After deleting io-threads from the vols, quota operates (list/set/modify) lets glusterfsd crash.
>>     >     I use it at CentOS 7 (CentOS Linux release 7.3.1611) with glusterfs 3.8.12.
>>     >     It seems the stack corrupt, when testing with the following diff, glusterfsd runs correctly.
>>     >
>>     >     There are two questions as,
>>     >     1. When using valgrind, it shows there are many "Invalid read/write" when with io-threads.
>>     >        Why glusterfsd runs correctly with io-threads? but crash without io-threads?
>>     >
>>     >     2. With the following diff, valgrind also shows many "Invalid read/write" when without io-threads?
>>     >        but no any crash.
>>     >
>>     >     Any comments are welcome.
>>     >
>>     >     Revert http://review.gluster.org/11499 <http://review.gluster.org/11499> <http://review.gluster.org/11499 <http://review.gluster.org/11499>> seems better than the diff.
>>     >
>>     >     diff --git a/xlators/features/marker/src/marker-quota.c b/xlators/features/marke
>>     >     index 902b8e5..f3d2507 100644
>>     >     --- a/xlators/features/marker/src/marker-quota.c
>>     >     +++ b/xlators/features/marker/src/marker-quota.c
>>     >     @@ -1075,7 +1075,7 @@ mq_synctask1 (xlator_t *this, synctask_fn_t task, gf_boole
>>     >              }
>>     >
>>     >              if (spawn) {
>>     >     -                ret = synctask_new1 (this->ctx->env, 1024 * 16, task,
>>     >     +                ret = synctask_new1 (this->ctx->env, 0, task,
>>     >                                            mq_synctask_cleanup, NULL, args);
>>     >                      if (ret) {
>>     >                              gf_log (this->name, GF_LOG_ERROR, "Failed to spawn "
>>     >
>>     >     -----------------------------------test steps ----------------------------------
>>     >     1. gluster volume create gvtest node1:/test/ node2:/test/
>>     >     2. gluster volume start gvtest
>>     >     3. gluster volume quota enable gvtest
>>     >
>>     >     4. "deletes io-threads from all vols"
>>     >     5. reboot node1 and node2.
>>     >     6. sh quota-set.sh
>>     >
>>     >     # cat quota-set.sh
>>     >     gluster volume quota gvtest list
>>     >     gluster volume quota gvtest limit-usage / 10GB
>>     >     gluster volume quota gvtest limit-usage /1234 1GB
>>     >     gluster volume quota gvtest limit-usage /hello 1GB
>>     >     gluster volume quota gvtest limit-usage /test 1GB
>>     >     gluster volume quota gvtest limit-usage /xyz 1GB
>>     >     gluster volume quota gvtest list
>>     >     gluster volume quota gvtest remove /hello
>>     >     gluster volume quota gvtest remove /test
>>     >     gluster volume quota gvtest list
>>     >     gluster volume quota gvtest limit-usage /test 1GB
>>     >     gluster volume quota gvtest remove /xyz
>>     >     gluster volume quota gvtest list
>>     >
>>     >     -----------------------glusterfsd crash without the diff--------------------------------
>>     >
>>     >     /usr/local/lib/libglusterfs.so.0(_gf_msg_backtrace_nomem+0xf5)[0x7f6e1e950af1]
>>     >     /usr/local/lib/libglusterfs.so.0(gf_print_trace+0x21f)[0x7f6e1e956943]
>>     >     /usr/local/sbin/glusterfsd(glusterfsd_print_trace+0x1f)[0x409c83]
>>     >     /lib64/libc.so.6(+0x35250)[0x7f6e1d025250]
>>     >     /lib64/libc.so.6(gsignal+0x37)[0x7f6e1d0251d7]
>>     >     /lib64/libc.so.6(abort+0x148)[0x7f6e1d0268c8]
>>     >     /lib64/libc.so.6(+0x74f07)[0x7f6e1d064f07]
>>     >     /lib64/libc.so.6(+0x7baf5)[0x7f6e1d06baf5]
>>     >     /lib64/libc.so.6(+0x7c3e6)[0x7f6e1d06c3e6]
>>     >     /usr/local/lib/libglusterfs.so.0(__gf_free+0x311)[0x7f6e1e981327]
>>     >     /usr/local/lib/libglusterfs.so.0(synctask_destroy+0x82)[0x7f6e1e995c20]
>>     >     /usr/local/lib/libglusterfs.so.0(synctask_done+0x25)[0x7f6e1e995c47]
>>     >     /usr/local/lib/libglusterfs.so.0(synctask_switchto+0xcf)[0x7f6e1e996585]
>>     >     /usr/local/lib/libglusterfs.so.0(syncenv_processor+0x60)[0x7f6e1e99663d]
>>     >     /lib64/libpthread.so.0(+0x7dc5)[0x7f6e1d7a2dc5]
>>     >     /lib64/libc.so.6(clone+0x6d)[0x7f6e1d0e773d]
>>     >
>>     >     or
>>     >
>>     >     package-string: glusterfs 3.8.12
>>     >     /usr/local/lib/libglusterfs.so.0(_gf_msg_backtrace_nomem+0xf5)[0x7fa15e623af1]
>>     >     /usr/local/lib/libglusterfs.so.0(gf_print_trace+0x21f)[0x7fa15e629943]
>>     >     /usr/local/sbin/glusterfsd(glusterfsd_print_trace+0x1f)[0x409c83]
>>     >     /lib64/libc.so.6(+0x35250)[0x7fa15ccf8250]
>>     >     /lib64/libc.so.6(gsignal+0x37)[0x7fa15ccf81d7]
>>     >     /lib64/libc.so.6(abort+0x148)[0x7fa15ccf98c8]
>>     >     /lib64/libc.so.6(+0x74f07)[0x7fa15cd37f07]
>>     >     /lib64/libc.so.6(+0x7dd4d)[0x7fa15cd40d4d]
>>     >     /lib64/libc.so.6(__libc_calloc+0xb4)[0x7fa15cd43a14]
>>     >     /usr/local/lib/libglusterfs.so.0(__gf_calloc+0xa7)[0x7fa15e653a5f]
>>     >     /usr/local/lib/libglusterfs.so.0(iobref_new+0x2b)[0x7fa15e65875a]
>>     >     /usr/local/lib/glusterfs/3.8.12/rpc-transport/socket.so(+0xa98c)[0x7fa153a8398c]
>>     >     /usr/local/lib/glusterfs/3.8.12/rpc-transport/socket.so(+0xacbc)[0x7fa153a83cbc]
>>     >     /usr/local/lib/glusterfs/3.8.12/rpc-transport/socket.so(+0xad10)[0x7fa153a83d10]
>>     >     /usr/local/lib/glusterfs/3.8.12/rpc-transport/socket.so(+0xb2a7)[0x7fa153a842a7]
>>     >     /usr/local/lib/libglusterfs.so.0(+0x97ea9)[0x7fa15e68eea9]
>>     >     /usr/local/lib/libglusterfs.so.0(+0x982c6)[0x7fa15e68f2c6]
>>     >     /lib64/libpthread.so.0(+0x7dc5)[0x7fa15d475dc5]
>>     >     /lib64/libc.so.6(clone+0x6d)[0x7fa15cdba73d]
>>     >
>>     >     _______________________________________________
>>     >     Gluster-devel mailing list
>>     >     Gluster-devel at gluster.org <mailto:Gluster-devel at gluster.org> <mailto:Gluster-devel at gluster.org <mailto:Gluster-devel at gluster.org>>
>>     >     http://lists.gluster.org/mailman/listinfo/gluster-devel <http://lists.gluster.org/mailman/listinfo/gluster-devel> <http://lists.gluster.org/mailman/listinfo/gluster-devel <http://lists.gluster.org/mailman/listinfo/gluster-devel>>
>>     >
>>     >
>>
>>
> 


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