Re: [PATCH v3 08/12] xfs: Iomap SW-based atomic write support

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

Hi John,

kernel test robot noticed the following build warnings:

[auto build test WARNING on xfs-linux/for-next]
[also build test WARNING on tytso-ext4/dev linus/master v6.14-rc4]
[cannot apply to brauner-vfs/vfs.all next-20250228]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/John-Garry/xfs-Pass-flags-to-xfs_reflink_allocate_cow/20250228-021818
base:   https://git.kernel.org/pub/scm/fs/xfs/xfs-linux.git for-next
patch link:    https://lore.kernel.org/r/20250227180813.1553404-9-john.g.garry%40oracle.com
patch subject: [PATCH v3 08/12] xfs: Iomap SW-based atomic write support
config: hexagon-randconfig-001-20250302 (https://download.01.org/0day-ci/archive/20250302/202503020355.fr9QWxQJ-lkp@intel.com/config)
compiler: clang version 21.0.0git (https://github.com/llvm/llvm-project 14170b16028c087ca154878f5ed93d3089a965c6)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250302/202503020355.fr9QWxQJ-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/202503020355.fr9QWxQJ-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> fs/xfs/xfs_iomap.c:1029:8: warning: variable 'iomap_flags' set but not used [-Wunused-but-set-variable]
    1029 |         u16                     iomap_flags = 0;
         |                                 ^
   1 warning generated.


vim +/iomap_flags +1029 fs/xfs/xfs_iomap.c

  1011	
  1012	static int
  1013	xfs_atomic_write_sw_iomap_begin(
  1014		struct inode		*inode,
  1015		loff_t			offset,
  1016		loff_t			length,
  1017		unsigned		flags,
  1018		struct iomap		*iomap,
  1019		struct iomap		*srcmap)
  1020	{
  1021		struct xfs_inode	*ip = XFS_I(inode);
  1022		struct xfs_mount	*mp = ip->i_mount;
  1023		struct xfs_bmbt_irec	imap, cmap;
  1024		xfs_fileoff_t		offset_fsb = XFS_B_TO_FSBT(mp, offset);
  1025		xfs_fileoff_t		end_fsb = xfs_iomap_end_fsb(mp, offset, length);
  1026		int			nimaps = 1, error;
  1027		unsigned int		reflink_flags;
  1028		bool			shared = false;
> 1029		u16			iomap_flags = 0;
  1030		unsigned int		lockmode = XFS_ILOCK_EXCL;
  1031		u64			seq;
  1032	
  1033		if (xfs_is_shutdown(mp))
  1034			return -EIO;
  1035	
  1036		reflink_flags = XFS_REFLINK_CONVERT | XFS_REFLINK_ATOMIC_SW;
  1037	
  1038		/*
  1039		 * Set IOMAP_F_DIRTY similar to xfs_atomic_write_iomap_begin()
  1040		 */
  1041		if (offset + length > i_size_read(inode))
  1042			iomap_flags |= IOMAP_F_DIRTY;
  1043	
  1044		error = xfs_ilock_for_iomap(ip, flags, &lockmode);
  1045		if (error)
  1046			return error;
  1047	
  1048		error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, &imap,
  1049				&nimaps, 0);
  1050		if (error)
  1051			goto out_unlock;
  1052	
  1053		error = xfs_reflink_allocate_cow(ip, &imap, &cmap, &shared,
  1054				&lockmode, reflink_flags);
  1055		/*
  1056		 * Don't check @shared. For atomic writes, we should error when
  1057		 * we don't get a COW mapping
  1058		 */
  1059		if (error)
  1060			goto out_unlock;
  1061	
  1062		end_fsb = imap.br_startoff + imap.br_blockcount;
  1063	
  1064		length = XFS_FSB_TO_B(mp, cmap.br_startoff + cmap.br_blockcount);
  1065		trace_xfs_iomap_found(ip, offset, length - offset, XFS_COW_FORK, &cmap);
  1066		if (imap.br_startblock != HOLESTARTBLOCK) {
  1067			seq = xfs_iomap_inode_sequence(ip, 0);
  1068			error = xfs_bmbt_to_iomap(ip, srcmap, &imap, flags, 0, seq);
  1069			if (error)
  1070				goto out_unlock;
  1071		}
  1072		seq = xfs_iomap_inode_sequence(ip, IOMAP_F_SHARED);
  1073		xfs_iunlock(ip, lockmode);
  1074		return xfs_bmbt_to_iomap(ip, iomap, &cmap, flags, IOMAP_F_SHARED, seq);
  1075	
  1076	out_unlock:
  1077		if (lockmode)
  1078			xfs_iunlock(ip, lockmode);
  1079		return error;
  1080	}
  1081	

-- 
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