[ceph-client:testing 13/14] fs/ceph/snap.c:438:14: warning: variable '_realm' is uninitialized when used here

[kernel test robot <lkp@intel.com>]

tree:   https://github.com/ceph/ceph-client.git testing
head:   91e59cfc6ca1a2bf594f60474996c71047edd1e5
commit: 7c7e63bc9910b15ffd1f791838ff0a919058f97c [13/14] ceph: eliminate the recursion when rebuilding the snap context
config: hexagon-randconfig-r005-20220216 (https://download.01.org/0day-ci/archive/20220217/202202170318.82LIXBXX-lkp@intel.com/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 0e628a783b935c70c80815db6c061ec84f884af5)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/ceph/ceph-client/commit/7c7e63bc9910b15ffd1f791838ff0a919058f97c
        git remote add ceph-client https://github.com/ceph/ceph-client.git
        git fetch --no-tags ceph-client testing
        git checkout 7c7e63bc9910b15ffd1f791838ff0a919058f97c
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash fs/ceph/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> fs/ceph/snap.c:438:14: warning: variable '_realm' is uninitialized when used here [-Wuninitialized]
                           list_del(&_realm->rebuild_item);
                                     ^~~~~~
   fs/ceph/snap.c:430:33: note: initialize the variable '_realm' to silence this warning
                   struct ceph_snap_realm *_realm, *child;
                                                 ^
                                                  = NULL
   1 warning generated.


vim +/_realm +438 fs/ceph/snap.c

   417	
   418	/*
   419	 * rebuild snap context for the given realm and all of its children.
   420	 */
   421	static void rebuild_snap_realms(struct ceph_snap_realm *realm,
   422					struct list_head *dirty_realms)
   423	{
   424		LIST_HEAD(realm_queue);
   425		int last = 0;
   426	
   427		list_add_tail(&realm->rebuild_item, &realm_queue);
   428	
   429		while (!list_empty(&realm_queue)) {
   430			struct ceph_snap_realm *_realm, *child;
   431	
   432			/*
   433			 * If the last building failed dues to memory
   434			 * issue, just empty the realm_queue and return
   435			 * to avoid infinite loop.
   436			 */
   437			if (last < 0) {
 > 438				list_del(&_realm->rebuild_item);
   439				continue;
   440			}
   441	
   442			_realm = list_first_entry(&realm_queue,
   443						  struct ceph_snap_realm,
   444						  rebuild_item);
   445			last = build_snap_context(_realm, &realm_queue, dirty_realms);
   446			dout("rebuild_snap_realms %llx %p, %s\n", _realm->ino, _realm,
   447			     last > 0 ? "is deferred" : !last ? "succeeded" : "failed");
   448	
   449			list_for_each_entry(child, &_realm->children, child_item)
   450				list_add_tail(&child->rebuild_item, &realm_queue);
   451	
   452			/* last == 1 means need to build parent first */
   453			if (last <= 0)
   454				list_del(&_realm->rebuild_item);
   455		}
   456	}
   457	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org