rbd: set a default value for options in `nbd map`

Since `vm` does not contain an `options` item and
`vm.at("options").value()` will throw an exception.

root@s222:/ceph-dev/build# rbd nbd map img1
rbd: 'nbd map' command is deprecated, use 'device map -t nbd' instead
terminate called after throwing an instance of 'std::out_of_range'
  what():  map::at
*** Caught signal (Aborted) **
 in thread 7f0e5e046400 thread_name:rbd
 ceph version 12.0.3-11022-ga09b319 (a09b319a5e984185bd56064e52f2e8ec3da49b73) mimic (dev)
 1: (()+0x1afb00) [0x55a07d677b00]
 2: (()+0x10340) [0x7f0e545a0340]
 3: (gsignal()+0x39) [0x7f0e531b0cc9]
 4: (abort()+0x148) [0x7f0e531b40d8]
 5: (__gnu_cxx::__verbose_terminate_handler()+0x125) [0x7f0e53ac8415]
 6: (()+0x6a206) [0x7f0e53ac6206]
 7: (()+0x6a251) [0x7f0e53ac6251]
 8: (()+0x6a493) [0x7f0e53ac6493]
 9: (std::__throw_out_of_range(char const*)+0x3f) [0x7f0e53aeac3f]
 10: (rbd::action::nbd::execute_map_deprecated(boost::program_options::variables_map const&,
     std::vector<std::string, std::allocator<std::string> > const&)+0xa35) [0x55a07d5f6a15]
 11: (rbd::Shell::execute(int, char const**)+0xb5b) [0x55a07d581adb]
 12: (main()+0x15) [0x55a07d546615]
 13: (__libc_start_main()+0xf5) [0x7f0e5319bec5]
 14: (()+0xa141f) [0x55a07d56941f]
2018-02-22 13:43:59.212 7f0e5e046400 -1 *** Caught signal (Aborted) **
 in thread 7f0e5e046400 thread_name:rbd

Signed-off-by: songweibin <song.weibin@zte.com.cn>

diff --git a/src/tools/rbd/action/Nbd.cc b/src/tools/rbd/action/Nbd.cc
index de64b5e89fc8a13da152f72754943ea0a427f019..93012cf68b2cec4b73ded3cc9b39867925f12922 100644 (file)
--- a/src/tools/rbd/action/Nbd.cc
+++ b/src/tools/rbd/action/Nbd.cc
@@ -221,7 +221,8 @@ int execute_map_deprecated(const po::variables_map &vm_deprecated,
   options.add_options()
     ("read-only", po::bool_switch(), "")
     ("exclusive", po::bool_switch(), "")
-    ("options,o", po::value<std::vector<std::string>>(), "");
+    ("options,o", po::value<std::vector<std::string>>()
+                  ->default_value(std::vector<std::string>(), ""), "");
 
   po::variables_map vm;
   po::store(po::command_line_parser({}).options(options).run(), vm);