tree:   https://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse.git for-next
head:   a8c6f1876b08d29557ccfe7ddec3a925d135a81c
commit: 4a24f7819533856715baeeea35fae41d7e0893e0 [8/9] fuse: wait for writepages in syncfs
config: i386-randconfig-s002-20210831 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce:
        # apt-get install sparse
        # sparse version: v0.6.3-348-gf0e6938b-dirty
        # https://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse.git/commit/?id=4a24f7819533856715baeeea35fae41d7e0893e0
        git remote add fuse https://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse.git
        git fetch --no-tags fuse for-next
        git checkout 4a24f7819533856715baeeea35fae41d7e0893e0
        # save the attached .config to linux build tree
        make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=i386 SHELL=/bin/bash fs/fuse/

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


sparse warnings: (new ones prefixed by >>)
>> fs/fuse/inode.c:544:9: sparse: sparse: incompatible types in comparison expression (different address spaces):
>> fs/fuse/inode.c:544:9: sparse:    struct fuse_sync_bucket [noderef] __rcu *
>> fs/fuse/inode.c:544:9: sparse:    struct fuse_sync_bucket *
--
>> fs/fuse/file.c:1890:31: sparse: sparse: incompatible types in comparison expression (different address spaces):
>> fs/fuse/file.c:1890:31: sparse:    struct fuse_sync_bucket [noderef] __rcu *
>> fs/fuse/file.c:1890:31: sparse:    struct fuse_sync_bucket *

vim +544 fs/fuse/inode.c

   521	
   522	static void fuse_sync_fs_writes(struct fuse_conn *fc)
   523	{
   524		struct fuse_sync_bucket *bucket, *new_bucket;
   525		int count;
   526	
   527		new_bucket = fuse_sync_bucket_alloc();
   528		spin_lock(&fc->lock);
   529		bucket = fc->curr_bucket;
   530		count = atomic_read(&bucket->count);
   531		WARN_ON(count < 1);
   532		/* No outstanding writes? */
   533		if (count == 1) {
   534			spin_unlock(&fc->lock);
   535			kfree(new_bucket);
   536			return;
   537		}
   538	
   539		/*
   540		 * Completion of new bucket depends on completion of this bucket, so add
   541		 * one more count.
   542		 */
   543		atomic_inc(&new_bucket->count);
 > 544		rcu_assign_pointer(fc->curr_bucket, new_bucket);
   545		spin_unlock(&fc->lock);
   546		/*
   547		 * Drop initial active count.  At this point if all writes in this and
   548		 * ancestor buckets complete, the count will go to zero and this task
   549		 * will be woken up.
   550		 */
   551		atomic_dec(&bucket->count);
   552	
   553		wait_event(bucket->waitq, atomic_read(&bucket->count) == 0);
   554	
   555		/* Drop temp count on descendant bucket */
   556		fuse_sync_bucket_dec(new_bucket);
   557		kfree_rcu(bucket, rcu);
   558	}
   559	

---
0-DAY CI Kernel Test Service, Intel Corporation
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