"dog vdi object location" PANIC when "node < x"

[Saeki Masaki]

This problem is similar to the report already as below , but occurrence conditions may slightly different.

https://bugs.launchpad.net/sheepdog-project/+bug/1389125

How to reproduce:

# sheep -v
Sheepdog daemon version 0.9.0_101_g821dc61_dirty

# dog cluster format -c 4
Number of copies (4) is larger than number of nodes (3).
Are you sure you want to continue? [yes/no]: yes
using backend plain store

# dog node list
  Id Host:Port V-Nodes Zone
   0 172.16.2.103:7000 128 0
   1 172.16.2.103:7001 128 1
   2 172.16.2.103:7002 128 2

# dog vdi create test 1M

# dog vdi list
  Name Id Size Used Shared Creation time VDI id Copies Tag Block Size Shift
  test 0 1.0 MB 0.0 MB 0.0 MB 2015-03-02 15:59 7c2b25 4 22

# dog vdi object location test
Looking for the inode object 0x7c2b25 with 3 nodes

172.16.2.103:7000 has the object
172.16.2.103:7001 has the object
172.16.2.103:7002 has the object

According to sheepdog algorithm, the object should be located at:
PANIC: can't find a valid vnode
dog exits unexpectedly (Aborted).
dog.c:375: crash_handler
/lib64/libpthread.so.0(+0xf70f) [0x7f4bc90bd70f]
/lib64/libc.so.6(gsignal+0x34) [0x7f4bc8b44624]
/lib64/libc.so.6(abort+0x174) [0x7f4bc8b45e04]
sheep.h:80: oid_to_vnodes
vdi.c:1172: vdi_object_location
common.c:280: do_generic_subcommand
dog.c:576: main
/lib64/libc.so.6(__libc_start_main+0xfc) [0x7f4bc8b30d5c]
dog() [0x403238]
[root@dfs1103 sheepdog-0302]# sheep -v
Sheepdog daemon version 0.9.0_101_g821dc61_dirty

[Saeki Masaki (saeki-masaki)]

I tested in my reproduce environment with version below.

# sheep -v
Sheepdog daemon version 0.9.0_106_gb08ee11_dirty.

it works good to me.