[mszeredi-fuse:extent-map-v2 22/28] fs/fuse/iomode.c:231:11: warning: variable 'err' is used uninitialized whenever 'if' condition is false

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

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse.git extent-map-v2
head:   5c4fbaa4906d18f12935a5920c3b789b827a1b01
commit: ba6831ba66ccaf841f3cda3e6fc8dca0d8689cf1 [22/28] fuse: add helpers for EIO return value with kernel message
config: sparc64-randconfig-r2307-20261001 (https://download.01.org/0day-ci/archive/20261002/202610020858.9R8H2Vqa-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
sparse: v0.6.5-rc1
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20261002/202610020858.9R8H2Vqa-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/202610020858.9R8H2Vqa-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> fs/fuse/iomode.c:231:11: warning: variable 'err' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
     231 |         else if (!fuse_file_cached_io_open(inode, ff))
         |                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   fs/fuse/iomode.c:234:9: note: uninitialized use occurs here
     234 |         return err;
         |                ^~~
   fs/fuse/iomode.c:231:7: note: remove the 'if' if its condition is always true
     231 |         else if (!fuse_file_cached_io_open(inode, ff))
         |              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     232 |                 err = fuse_EIO("conflicting passthrough open");
   fs/fuse/iomode.c:193:9: note: initialize the variable 'err' to silence this warning
     193 |         int err;
         |                ^
         |                 = 0
   1 warning generated.


vim +231 fs/fuse/iomode.c

   187	
   188	/* Request access to submit new io to inode via open file */
   189	int fuse_file_io_open(struct file *file, struct inode *inode)
   190	{
   191		struct fuse_file *ff = file->private_data;
   192		struct fuse_inode *fi = get_fuse_inode(inode);
   193		int err;
   194	
   195		/*
   196		 * io modes are not relevant with virtiofs DAX and with server that does not
   197		 * implement open.
   198		 */
   199		if (FUSE_IS_VDAX(inode) || !ff->args)
   200			return 0;
   201	
   202		/*
   203		 * Server is expected to use FOPEN_PASSTHROUGH for all opens of an inode
   204		 * which is already open for passthrough.  Using incorrect open mode is
   205		 * a server mistake, which results in user visible failure of open()
   206		 * with EIO error.
   207		 */
   208		if (fuse_inode_backing(fi) && !(ff->open_flags & FOPEN_PASSTHROUGH))
   209			return fuse_EIO("FOPEN_PASSTHROUGH expected");
   210	
   211		/*
   212		 * FOPEN_PARALLEL_DIRECT_WRITES requires FOPEN_DIRECT_IO.
   213		 */
   214		if (!(ff->open_flags & FOPEN_DIRECT_IO))
   215			ff->open_flags &= ~FOPEN_PARALLEL_DIRECT_WRITES;
   216	
   217		/*
   218		 * First passthrough file open denies caching inode io mode.
   219		 * First caching file open enters caching inode io mode.
   220		 *
   221		 * Note that if user opens a file open with O_DIRECT, but server did
   222		 * not specify FOPEN_DIRECT_IO, a later fcntl() could remove O_DIRECT,
   223		 * so we put the inode in caching mode to prevent parallel dio.
   224		 */
   225		if ((ff->open_flags & FOPEN_DIRECT_IO) &&
   226		    !(ff->open_flags & FOPEN_PASSTHROUGH))
   227			return 0;
   228	
   229		if (ff->open_flags & FOPEN_PASSTHROUGH)
   230			err = fuse_file_passthrough_open(inode, file);
 > 231		else if (!fuse_file_cached_io_open(inode, ff))
   232			err = fuse_EIO("conflicting passthrough open");
   233	
   234		return err;
   235	}
   236	

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