Description of problem:

While testing two of my geo-rep patches [1] and [2] I see the geo-rep mount process crashed. I was running the modified upstream geo-rep regression test suite to run on replica 3 (6*3) volume. Geo-rep client process crashed as below. Note that the geo-rep mount are aux-gfid-mount.

I looked into the traceback, it's during dht attr heal and the gfid is null in both loc and loc->inode. I didn't have much context on afr/dht, so could debug it further.

(gdb) 
#0  0x00007f260e71b765 in raise () from /lib64/libc.so.6
#1  0x00007f260e71d36a in abort () from /lib64/libc.so.6
#2  0x00007f260e713f97 in __assert_fail_base () from /lib64/libc.so.6
#3  0x00007f260e714042 in __assert_fail () from /lib64/libc.so.6
#4  0x00007f2602149ec2 in client_pre_inodelk (this=0x7f25fc00ef20, req=0x7f25e4217670, loc=0x7f25e400a298, cmd=6, flock=0x7f25e400a4b8, volume=0x7f25fc0132b0 "slave-replicate-1", xdata=0x0)
    at client-common.c:841
#5  0x00007f2602138b24 in client3_3_inodelk (frame=0x7f25e4015290, this=0x7f25fc00ef20, data=0x7f25e4217760) at client-rpc-fops.c:5307
#6  0x00007f260210d9d9 in client_inodelk (frame=0x7f25e4015290, this=0x7f25fc00ef20, volume=0x7f25fc0132b0 "slave-replicate-1", loc=0x7f25e400a298, cmd=6, lock=0x7f25e400a4b8, xdata=0x0)
    at client.c:1679
#7  0x00007f2601ea4444 in afr_nonblocking_inodelk (frame=0x7f25e400f680, this=0x7f25fc015230) at afr-lk-common.c:1093
#8  0x00007f2601e9d149 in afr_lock (frame=0x7f25e400f680, this=0x7f25fc015230) at afr-transaction.c:1652
#9  0x00007f2601e9eb84 in afr_transaction_start (local=0x7f25e4009e60, this=0x7f25fc015230) at afr-transaction.c:2333
#10 0x00007f2601e9eec0 in afr_transaction (frame=0x7f25e400f680, this=0x7f25fc015230, type=AFR_METADATA_TRANSACTION) at afr-transaction.c:2402
#11 0x00007f2601e875d7 in afr_setattr (frame=0x7f25e400ece0, this=0x7f25fc015230, loc=0x7f25e4008e58, buf=0x7f25e4008f58, valid=7, xdata=0x0) at afr-inode-write.c:895
#12 0x00007f261011681d in syncop_setattr (subvol=0x7f25fc015230, loc=0x7f25e4008e58, iatt=0x7f25e4008f58, valid=7, preop=0x0, postop=0x0, xdata_in=0x0, xdata_out=0x0) at syncop.c:1811
#13 0x00007f2601bc0448 in dht_dir_attr_heal (data=0x7f25e4007c60) at dht-selfheal.c:2497
#14 0x00007f261010f894 in synctask_wrap () at syncop.c:375
#15 0x00007f260e72fb60 in ?? () from /lib64/libc.so.6
#16 0x0000000000000000 in ?? ()
(gdb) f 4
#4  0x00007f2602149ec2 in client_pre_inodelk (this=0x7f25fc00ef20, req=0x7f25e4217670, loc=0x7f25e400a298, cmd=6, flock=0x7f25e400a4b8, volume=0x7f25fc0132b0 "slave-replicate-1", xdata=0x0)
    at client-common.c:841
841	        GF_ASSERT_AND_GOTO_WITH_ERROR (this->name,
(gdb) p *loc
$1 = {path = 0x7f25e40102f0 "/.gfid/00000000-0000-0000-0000-", '0' <repeats 11 times>, "1/rsnapshot_symlinkbug", name = 0x7f25e401031c "rsnapshot_symlinkbug", inode = 0x7f25ec030d30, 
  parent = 0x7f25fc078870, gfid = '\000' <repeats 15 times>, pargfid = '\000' <repeats 15 times>, "\001"}
(gdb) p *loc->inode
$2 = {table = 0x7f25fc078770, gfid = '\000' <repeats 15 times>, lock = {spinlock = 0, mutex = {__data = {__lock = 0, __count = 0, __owner = 0, __nusers = 0, __kind = 0, __spins = 0, 
        __elision = 0, __list = {__prev = 0x0, __next = 0x0}}, __size = '\000' <repeats 39 times>, __align = 0}}, nlookup = 0, fd_count = 0, active_fd_count = 0, ref = 3, 
  ia_type = IA_INVAL, fd_list = {next = 0x7f25ec030d88, prev = 0x7f25ec030d88}, dentry_list = {next = 0x7f25ec030d98, prev = 0x7f25ec030d98}, hash = {next = 0x7f25ec030da8, 
    prev = 0x7f25ec030da8}, list = {next = 0x7f25ec03aa98, prev = 0x7f25fc0787d0}, _ctx = 0x7f25ec032580}
(gdb) 
$3 = {table = 0x7f25fc078770, gfid = '\000' <repeats 15 times>, lock = {spinlock = 0, mutex = {__data = {__lock = 0, __count = 0, __owner = 0, __nusers = 0, __kind = 0, __spins = 0, 
        __elision = 0, __list = {__prev = 0x0, __next = 0x0}}, __size = '\000' <repeats 39 times>, __align = 0}}, nlookup = 0, fd_count = 0, active_fd_count = 0, ref = 3, 
  ia_type = IA_INVAL, fd_list = {next = 0x7f25ec030d88, prev = 0x7f25ec030d88}, dentry_list = {next = 0x7f25ec030d98, prev = 0x7f25ec030d98}, hash = {next = 0x7f25ec030da8, 
    prev = 0x7f25ec030da8}, list = {next = 0x7f25ec03aa98, prev = 0x7f25fc0787d0}, _ctx = 0x7f25ec032580}

Version-Release number of selected component (if applicable):

3.4 source install:
Had two patches [1] and [2] on top of
 commit  8c9028b560b1f0fd816e7d2a9e0bec70cc526c1a


How reproducible:
Rarely, I have hit only once.

Steps to Reproduce:
1.  Run upstream regression test suite modifying the volume type of both master and slave to 6*3
   # prove -v tests/00-geo-rep/georep-basic-dr-rsync.t


Actual results:
mount process crashed 


[1]  https://code.engineering.redhat.com/gerrit/143400
[2]  https://code.engineering.redhat.com/gerrit/143826

Expected results:
No crash should be seen

Additional info:
The mount is done by geo-rep worker process and it's a gfid-acces fuse mount.
Fust mount mounted with option "-o aux-gfid-mount".