[koverstreet-bcachefs:trace_sched_wakeup_backtrace 57/332] fs/bcachefs/snapshots/snapshot.c:378:7: warning: variable 'lock_dropped' set but not used

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

tree:   https://github.com/koverstreet/bcachefs trace_sched_wakeup_backtrace
head:   9e7cbd4ad9c7a7ba461dbba9185628c006e200cd
commit: 54998105f6ef5d0c64d7986fd6f670d2b4f3bef4 [57/332] bcachefs: Drop locks for printbuf allocation in snapshot_get_print()
config: xtensa-randconfig-r073-20260913 (https://download.01.org/0day-ci/archive/20260913/202609130706.MIJr23Rk-lkp@intel.com/config)
compiler: xtensa-linux-gcc (GCC) 10.5.0
smatch: v0.5.0-9187-g5189e3fb
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260913/202609130706.MIJr23Rk-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202609130706.MIJr23Rk-lkp@intel.com/

All warnings (new ones prefixed by >>):

   fs/bcachefs/snapshots/snapshot.c: In function 'snapshot_get_print':
>> fs/bcachefs/snapshots/snapshot.c:378:7: warning: variable 'lock_dropped' set but not used [-Wunused-but-set-variable]
     378 |  bool lock_dropped = false;
         |       ^~~~~~~~~~~~


vim +/lock_dropped +378 fs/bcachefs/snapshots/snapshot.c

   330	
   331	static int snapshot_get_print(struct printbuf *out, struct btree_trans *trans, u32 id)
   332	{
   333		prt_printf(out, "%u \t", id);
   334	
   335		struct bch_snapshot s;
   336		int ret = bch2_snapshot_lookup(trans, id, &s);
   337		if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
   338			return ret;
   339	
   340		if (ret) {
   341			prt_str(out, bch2_err_str(ret));
   342		} else {
   343			if (BCH_SNAPSHOT_DELETED(&s))
   344				prt_str(out, "deleted ");
   345			if (BCH_SNAPSHOT_NO_KEYS(&s))
   346				prt_str(out, "no_keys ");
   347			if (BCH_SNAPSHOT_WILL_DELETE(&s))
   348				prt_str(out, "will_delete ");
   349			if (BCH_SNAPSHOT_SUBVOL(&s))
   350				prt_printf(out, "subvol %u", le32_to_cpu(s.subvol));
   351	
   352			prt_tab(out);
   353	
   354			if (s.subvol) {
   355				struct bch_subvolume subvol;
   356				ret = bch2_subvolume_get(trans, le32_to_cpu(s.subvol), false, &subvol);
   357				if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
   358					return ret;
   359	
   360				if (ret)
   361					prt_str(out, bch2_err_str(ret));
   362				else
   363					try(bch2_inum_to_path(trans, (subvol_inum)
   364						{ le32_to_cpu(s.subvol), le64_to_cpu(subvol.inode) }, out));
   365			}
   366	
   367			prt_tab(out);
   368	
   369			u64 v[1] = { 0 };
   370			try(bch2_fs_accounting_read_key2(trans, v, snapshot, id));
   371	
   372			prt_human_readable_u64(out, v[0] << 9);
   373			prt_tab_rjust(out);
   374		}
   375	
   376		prt_newline(out);
   377	
 > 378		bool lock_dropped = false;
   379		allocate_dropping_locks_norelock(trans, lock_dropped,
   380				!bch2_printbuf_make_room_gfp(out, 1024, _gfp));
   381		return 0;
   382	}
   383	

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