Re: [PATCH] nfs: Implement delayed data server destruction with hold cache

Re: [PATCH] nfs: Implement delayed data server destruction with hold cache

[kernel test robot]

Hi Gaurav,

kernel test robot noticed the following build warnings:

[auto build test WARNING on trondmy-nfs/linux-next]
[also build test WARNING on linus/master v6.18-rc6 next-20251119]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Gaurav-Gangalwar/nfs-Implement-delayed-data-server-destruction-with-hold-cache/20251118-190020
base:   git://git.linux-nfs.org/projects/trondmy/linux-nfs.git linux-next
patch link:    https://lore.kernel.org/r/20251118105752.52098-1-gaurav.gangalwar%40gmail.com
patch subject: [PATCH] nfs: Implement delayed data server destruction with hold cache
config: arm-lpc32xx_defconfig (https://download.01.org/0day-ci/archive/20251119/202511191852.nGdrhdUC-lkp@intel.com/config)
compiler: clang version 17.0.6 (https://github.com/llvm/llvm-project 6009708b4367171ccdbf4b5905cb6a803753fe18)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251119/202511191852.nGdrhdUC-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/202511191852.nGdrhdUC-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> fs/nfs/pnfs_nfs.c:753:6: warning: variable 'active_count' set but not used [-Wunused-but-set-variable]
     753 |         int active_count = 0, hold_count = 0, expired_count = 0;
         |             ^
>> fs/nfs/pnfs_nfs.c:753:24: warning: variable 'hold_count' set but not used [-Wunused-but-set-variable]
     753 |         int active_count = 0, hold_count = 0, expired_count = 0;
         |                               ^
>> fs/nfs/pnfs_nfs.c:753:40: warning: variable 'expired_count' set but not used [-Wunused-but-set-variable]
     753 |         int active_count = 0, hold_count = 0, expired_count = 0;
         |                                               ^
   3 warnings generated.


vim +/active_count +753 fs/nfs/pnfs_nfs.c

   741	
   742	/*
   743	 * Periodic cleanup task to check hold cache and destroy expired DS entries
   744	 */
   745	void nfs4_pnfs_ds_cleanup_work(struct work_struct *work)
   746	{
   747		struct nfs_net *nn = container_of(work, struct nfs_net,
   748						  nfs4_data_server_cleanup_work.work);
   749		struct nfs4_pnfs_ds *ds, *tmp;
   750		LIST_HEAD(destroy_list);
   751		unsigned long grace_period = nfs4_pnfs_ds_grace_period * HZ;
   752		unsigned long now = jiffies;
 > 753		int active_count = 0, hold_count = 0, expired_count = 0;
   754	
   755		dprintk("NFS: DS cleanup work started for namespace (jiffies=%lu)\n", now);
   756	
   757		spin_lock(&nn->nfs4_data_server_lock);
   758	
   759		/* Count entries in active cache */
   760		list_for_each_entry(ds, &nn->nfs4_data_server_cache, ds_node)
   761			active_count++;
   762	
   763		/* Process hold cache */
   764		list_for_each_entry_safe(ds, tmp, &nn->nfs4_data_server_hold_cache, ds_node) {
   765			unsigned long time_since_last_access = now - ds->ds_last_access;
   766	
   767			hold_count++;
   768			if (time_since_last_access >= grace_period) {
   769				/* Grace period expired, move to destroy list */
   770				dprintk("NFS: DS cleanup task destroying expired DS: %s (idle for %lu seconds)\n",
   771					ds->ds_remotestr, time_since_last_access / HZ);
   772				list_move(&ds->ds_node, &destroy_list);
   773				expired_count++;
   774			} else {
   775				dprintk("NFS: DS %s in hold cache (idle for %lu seconds, %lu seconds remaining)\n",
   776					ds->ds_remotestr, time_since_last_access / HZ,
   777					(grace_period - time_since_last_access) / HZ);
   778			}
   779		}
   780	
   781		spin_unlock(&nn->nfs4_data_server_lock);
   782	
   783		dprintk("NFS: DS cleanup work: active_cache=%d, hold_cache=%d, expired=%d\n",
   784			active_count, hold_count, expired_count);
   785	
   786		/* Destroy DS entries outside of lock */
   787		list_for_each_entry_safe(ds, tmp, &destroy_list, ds_node) {
   788			list_del_init(&ds->ds_node);
   789			destroy_ds(ds);
   790		}
   791	
   792		/* Reschedule cleanup task */
   793		dprintk("NFS: DS cleanup work completed, rescheduling in %u seconds\n",
   794			nfs4_pnfs_ds_cleanup_interval);
   795		schedule_delayed_work(&nn->nfs4_data_server_cleanup_work,
   796				      nfs4_pnfs_ds_cleanup_interval * HZ);
   797	}
   798	EXPORT_SYMBOL_GPL(nfs4_pnfs_ds_cleanup_work);
   799	

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