[fuse:for-next 8/9] fs/fuse/inode.c:544:9: sparse: sparse: incompatible types in comparison expression (different address spaces):

From: kernel test robot
Date: Tue Aug 31 2021 - 16:21:25 EST


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@xxxxxxxxx>


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
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx

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