On 01/11/2016 07:03 AM, Jens Rosenboom wrote:
2016-01-11 12:09 GMT+01:00 Jens Rosenboom <j.rosenboom@xxxxxxxx>:
2016-01-08 12:15 GMT+01:00 Jens Rosenboom <j.rosenboom@xxxxxxxx>:
When running fio-2.3 with the rbd engine, the tests themselves run
fine, but instead of the results being printed, I get:
fio: mutex.c:163: fio_mutex_down: Assertion `mutex->magic ==
0x4d555445U' failed.
The command I am using is
fio --ioengine=rbd --clientname=admin --pool=test --rbdname=test1
--rw=randwrite --runtime=10 --ramp_time=None --numjobs=1 --direct=1
--bs=1048576B --iodepth=64 --name=test1
If I instead use another engine, everything is fine, e.g.:
fio --ioengine=libaio --filename=/dev/sdb1 --rw=randwrite --runtime=10
--ramp_time=None --numjobs=1 --direct=1 --bs=1048576B --iodepth=64
--name=test1
Going back to fio-2.2.13 makes the error go away and running a git
bisect leads to the commit mentioned in the subject as the culprit,
the error turns into a Segmentation Fault at that point, though.
Accidentally I found out that I can also reproduce the bug with libaio if I set
LD_PRELOAD=../jemalloc/lib/libjemalloc.so
compiled from https://github.com/jemalloc/jemalloc.git (tested with
3.6.0 and 4.0.4)
So it seems there is some use-after-free issue in this commit. I'll
try to dig into this a bit more when I get the time, but I won't be
sad if someone else is faster. ;)
In the standalone case, sk_out_key is used uninitialized, which may
happen to work fine until some other library also uses a pthread_key,
like it seems both librbd and libjemalloc do.
Attached is a patch that fixes this.
Thanks for reporting this! I merged a cleaner fix, we can just set up
the key earlier and not have to worry about server vs non-server. Can
you check if current -git works for you?
--
Jens Axboe
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