[snitzer:nfs-localio-for-6.11 13/29] fs/nfs/flexfilelayout/flexfilelayout.c:199:24: sparse: sparse: incorrect type in initializer (different address spaces)

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

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/snitzer/linux.git nfs-localio-for-6.11
head:   1dadc081b646bfa3fca1c0e117e0be8f4de62509
commit: 51267937be8090c58d3741df1005db6b633bfc1e [13/29] pnfs/flexfiles: Enable localio for flexfiles I/O
config: arc-randconfig-r133-20240607 (https://download.01.org/0day-ci/archive/20240607/202406071836.IOK5vz73-lkp@intel.com/config)
compiler: arc-elf-gcc (GCC) 13.2.0
reproduce: (https://download.01.org/0day-ci/archive/20240607/202406071836.IOK5vz73-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/202406071836.IOK5vz73-lkp@intel.com/

sparse warnings: (new ones prefixed by >>)
>> fs/nfs/flexfilelayout/flexfilelayout.c:199:24: sparse: sparse: incorrect type in initializer (different address spaces) @@     expected struct file [noderef] __rcu *_n_ @@     got struct file *[assigned] new @@
   fs/nfs/flexfilelayout/flexfilelayout.c:199:24: sparse:     expected struct file [noderef] __rcu *_n_
   fs/nfs/flexfilelayout/flexfilelayout.c:199:24: sparse:     got struct file *[assigned] new
>> fs/nfs/flexfilelayout/flexfilelayout.c:199:22: sparse: sparse: incorrect type in assignment (different address spaces) @@     expected struct file *[assigned] filp @@     got struct file [noderef] __rcu *[assigned] _prev_ @@
   fs/nfs/flexfilelayout/flexfilelayout.c:199:22: sparse:     expected struct file *[assigned] filp
   fs/nfs/flexfilelayout/flexfilelayout.c:199:22: sparse:     got struct file [noderef] __rcu *[assigned] _prev_
>> fs/nfs/flexfilelayout/flexfilelayout.c:205:30: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected struct file [noderef] __rcu **f @@     got struct file ** @@
   fs/nfs/flexfilelayout/flexfilelayout.c:205:30: sparse:     expected struct file [noderef] __rcu **f
   fs/nfs/flexfilelayout/flexfilelayout.c:205:30: sparse:     got struct file **
   fs/nfs/flexfilelayout/flexfilelayout.c:336:38: sparse: sparse: self-comparison always evaluates to false
   fs/nfs/flexfilelayout/flexfilelayout.c:339:62: sparse: sparse: self-comparison always evaluates to false

vim +199 fs/nfs/flexfilelayout/flexfilelayout.c

   165	
   166	static struct file *
   167	ff_local_open_fh(struct pnfs_layout_segment *lseg,
   168			 u32 ds_idx,
   169			 struct nfs_client *clp,
   170			 const struct cred *cred,
   171			 struct nfs_fh *fh,
   172			 fmode_t mode)
   173	{
   174		struct nfs4_ff_layout_mirror *mirror = FF_LAYOUT_COMP(lseg, ds_idx);
   175		struct file *filp, *new, __rcu **pfile;
   176	
   177		if (!nfs_server_is_local(clp))
   178			return NULL;
   179		if (mode & FMODE_WRITE) {
   180			/*
   181			 * Always request read and write access since this corresponds
   182			 * to a rw layout.
   183			 */
   184			mode |= FMODE_READ;
   185			pfile = &mirror->rw_file;
   186		} else
   187			pfile = &mirror->ro_file;
   188	
   189		new = NULL;
   190		rcu_read_lock();
   191		filp = rcu_dereference(*pfile);
   192		if (!filp) {
   193			rcu_read_unlock();
   194			new = nfs_local_open_fh(clp, cred, fh, mode);
   195			if (IS_ERR(new))
   196				return NULL;
   197			rcu_read_lock();
   198			/* try to swap in the pointer */
 > 199			filp = cmpxchg(pfile, NULL, new);
   200			if (!filp) {
   201				filp = new;
   202				new = NULL;
   203			}
   204		}
 > 205		filp = get_file_rcu(&filp);
   206		rcu_read_unlock();
   207		if (new)
   208			fput(new);
   209		return filp;
   210	}
   211	

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