[dhowells-fs:netfs-lib 25/34] fs/netfs/io.c:871:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is true

[dhowells-fs:netfs-lib 25/34] fs/netfs/io.c:871:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is true

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git netfs-lib
head:   8b08a7e2d3217f7054808246fc559c867f54a524
commit: 051a41b875d04f931d3416d7b15e4cd3f6ba4edb [25/34] netfs: Implement DIO write support
config: x86_64-rhel-8.3-rust (https://download.01.org/0day-ci/archive/20231002/202310022348.lsNkvm7R-lkp@intel.com/config)
compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git ae42196bc493ffe877a7e3dff8be32035dea4d07)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231002/202310022348.lsNkvm7R-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/202310022348.lsNkvm7R-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> fs/netfs/io.c:871:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
           if (len2 && !netfs_rmw_read_one(rreq, start2, len2))
               ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   fs/netfs/io.c:898:9: note: uninitialized use occurs here
           return ret;
                  ^~~
   fs/netfs/io.c:871:2: note: remove the 'if' if its condition is always false
           if (len2 && !netfs_rmw_read_one(rreq, start2, len2))
           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   fs/netfs/io.c:869:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
           if (len1 && !netfs_rmw_read_one(rreq, start1, len1))
               ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   fs/netfs/io.c:898:9: note: uninitialized use occurs here
           return ret;
                  ^~~
   fs/netfs/io.c:869:2: note: remove the 'if' if its condition is always false
           if (len1 && !netfs_rmw_read_one(rreq, start1, len1))
           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   fs/netfs/io.c:849:13: note: initialize the variable 'ret' to silence this warning
           ssize_t ret;
                      ^
                       = 0
   2 warnings generated.


vim +871 fs/netfs/io.c

   837	
   838	/*
   839	 * Begin the process of reading in one or two chunks of data for use by
   840	 * unbuffered write to perform an RMW cycle.  We don't read directly into the
   841	 * write buffer as this may get called to redo the read in the case that a
   842	 * conditional write fails due to conflicting 3rd-party modifications.
   843	 */
   844	ssize_t netfs_rmw_read(struct netfs_io_request *wreq, struct file *file,
   845			       unsigned long long start1, size_t len1,
   846			       unsigned long long start2, size_t len2)
   847	{
   848		struct netfs_io_request *rreq;
   849		ssize_t ret;
   850	
   851		_enter("RMW:R=%x %llx-%llx %llx-%llx",
   852		       rreq->debug_id, start1, start1 + len1 - 1, start2, start2 + len2 - 1);
   853	
   854		rreq = netfs_alloc_request(wreq->mapping, file,
   855					   start1, start2 - start1 + len2, NETFS_RMW_READ);
   856		if (IS_ERR(rreq))
   857			return PTR_ERR(rreq);
   858	
   859		INIT_WORK(&rreq->work, netfs_rreq_work);
   860	
   861		rreq->iter = wreq->io_iter;
   862		__set_bit(NETFS_RREQ_CRYPT_IN_PLACE, &rreq->flags);
   863		__set_bit(NETFS_RREQ_USE_BOUNCE_BUFFER, &rreq->flags);
   864	
   865		/* Chop the reads into slices according to what the netfs wants and
   866		 * submit each one.
   867		 */
   868		atomic_set(&rreq->nr_outstanding, 1);
   869		if (len1 && !netfs_rmw_read_one(rreq, start1, len1))
   870			goto out;
 > 871		if (len2 && !netfs_rmw_read_one(rreq, start2, len2))

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