[openeuler:openEuler-1.0-LTS 8359/23883] fs/gfs2/bmap.c:960:31: warning: 'lblock' may be used uninitialized - Kernel

29 Oct 2024


      Hi Andreas,
FYI, the error/warning still remains.
tree:   https://gitee.com/openeuler/kernel.git openEuler-1.0-LTS
head:   27399521743732e65e7635fa93bd0cca53981c9e
commit: 484798bc8218ce6a0f8269675897b870a12c49e2 [8359/23883] gfs2: gfs2_walk_metadata fix
config: x86_64-buildonly-randconfig-001-20241029 (https://download.01.org/0day-ci/archive/20241029/202410290938.ovb4D3kI-lkp@i...)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241029/202410290938.ovb4D3kI-lkp@i...)
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/202410290938.ovb4D3kI-lkp@intel.com/
Note: it may well be a FALSE warning. FWIW you are at least aware of it now.
http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings
All warnings (new ones prefixed by >>):
fs/gfs2/bmap.c: In function 'gfs2_iomap_alloc':
   fs/gfs2/bmap.c:748:28: warning: this statement may fall through [-Wimplicit-fallthrough=]
     748 |                         if (n == 0)
         |                            ^
   fs/gfs2/bmap.c:751:17: note: here
     751 |                 case ALLOC_GROW_DEPTH:
         |                 ^~~~
   fs/gfs2/bmap.c:759:28: warning: this statement may fall through [-Wimplicit-fallthrough=]
     759 |                         if (n == 0)
         |                            ^
   fs/gfs2/bmap.c:762:17: note: here
     762 |                 case ALLOC_DATA:
         |                 ^~~~
   fs/gfs2/bmap.c: In function 'gfs2_iomap_get':
...
...
fs/gfs2/bmap.c:960:31: warning: 'lblock' may be used uninitialized [-Wmaybe-uninitialized]
960 |                         ret = gfs2_hole_size(inode, lblock, len, mp, iomap);
         |                               ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   fs/gfs2/bmap.c:851:18: note: 'lblock' was declared here
     851 |         sector_t lblock;
         |                  ^~~~~~
   fs/gfs2/bmap.c:960:31: warning: 'len' may be used uninitialized [-Wmaybe-uninitialized]
     960 |                         ret = gfs2_hole_size(inode, lblock, len, mp, iomap);
         |                               ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   fs/gfs2/bmap.c:855:13: note: 'len' was declared here
     855 |         u64 len;
         |             ^~~
   fs/gfs2/bmap.c:959:32: warning: 'height' may be used uninitialized [-Wmaybe-uninitialized]
     959 |                 if (pos < size && height == ip->i_height)
         |                     ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
   fs/gfs2/bmap.c:857:12: note: 'height' was declared here
     857 |         u8 height;
         |            ^~~~~~
   fs/gfs2/bmap.c:1290: warning: Function parameter or member 'inode' not described in 'gfs2_block_zero_range'
   fs/gfs2/bmap.c:1290: warning: Function parameter or member 'from' not described in 'gfs2_block_zero_range'
   fs/gfs2/bmap.c:1290: warning: Function parameter or member 'length' not described in 'gfs2_block_zero_range'
   fs/gfs2/bmap.c:1493: warning: Function parameter or member 'rd_gh' not described in 'sweep_bh_for_rgrps'
   fs/gfs2/bmap.c:1493: warning: Excess function parameter 'rg_gh' description in 'sweep_bh_for_rgrps'
   fs/gfs2/bmap.c:1661: warning: Function parameter or member 'sdp' not described in 'find_nonnull_ptr'
   fs/gfs2/bmap.c:1661: warning: Function parameter or member 'end_list' not described in 'find_nonnull_ptr'
   fs/gfs2/bmap.c:1661: warning: Function parameter or member 'end_aligned' not described in 'find_nonnull_ptr'
vim +/lblock +960 fs/gfs2/bmap.c
7ee66c03e40a57 Christoph Hellwig   2018-06-01  831  
3974320ca6aa68 Bob Peterson        2017-02-16  832  /**
628e366df11c0a Andreas Gruenbacher 2018-06-04  833   * gfs2_iomap_get - Map blocks from an inode to disk blocks
3974320ca6aa68 Bob Peterson        2017-02-16  834   * @inode: The inode
3974320ca6aa68 Bob Peterson        2017-02-16  835   * @pos: Starting position in bytes
3974320ca6aa68 Bob Peterson        2017-02-16  836   * @length: Length to map, in bytes
3974320ca6aa68 Bob Peterson        2017-02-16  837   * @flags: iomap flags
3974320ca6aa68 Bob Peterson        2017-02-16  838   * @iomap: The iomap structure
628e366df11c0a Andreas Gruenbacher 2018-06-04  839   * @mp: The metapath
3974320ca6aa68 Bob Peterson        2017-02-16  840   *
3974320ca6aa68 Bob Peterson        2017-02-16  841   * Returns: errno
3974320ca6aa68 Bob Peterson        2017-02-16  842   */
628e366df11c0a Andreas Gruenbacher 2018-06-04  843  static int gfs2_iomap_get(struct inode *inode, loff_t pos, loff_t length,
628e366df11c0a Andreas Gruenbacher 2018-06-04  844  			  unsigned flags, struct iomap *iomap,
628e366df11c0a Andreas Gruenbacher 2018-06-04  845  			  struct metapath *mp)
b3b94faa5fe596 David Teigland      2006-01-16  846  {
feaa7bba026c18 Steven Whitehouse   2006-06-14  847  	struct gfs2_inode *ip = GFS2_I(inode);
feaa7bba026c18 Steven Whitehouse   2006-06-14  848  	struct gfs2_sbd *sdp = GFS2_SB(inode);
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  849  	loff_t size = i_size_read(inode);
9b8c81d1de4994 Steven Whitehouse   2008-02-22  850  	__be64 *ptr;
3974320ca6aa68 Bob Peterson        2017-02-16  851  	sector_t lblock;
628e366df11c0a Andreas Gruenbacher 2018-06-04  852  	sector_t lblock_stop;
628e366df11c0a Andreas Gruenbacher 2018-06-04  853  	int ret;
9b8c81d1de4994 Steven Whitehouse   2008-02-22  854  	int eob;
628e366df11c0a Andreas Gruenbacher 2018-06-04  855  	u64 len;
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  856  	struct buffer_head *dibh = NULL, *bh;
9b8c81d1de4994 Steven Whitehouse   2008-02-22  857  	u8 height;
7276b3b0c77101 Steven Whitehouse   2006-09-21  858  
628e366df11c0a Andreas Gruenbacher 2018-06-04  859  	if (!length)
628e366df11c0a Andreas Gruenbacher 2018-06-04  860  		return -EINVAL;
b3b94faa5fe596 David Teigland      2006-01-16  861  
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  862  	down_read(&ip->i_rw_mutex);
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  863  
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  864  	ret = gfs2_meta_inode_buffer(ip, &dibh);
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  865  	if (ret)
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  866  		goto unlock;
38084377af4fc8 Andreas Gruenbacher 2018-11-11  867  	mp->mp_bh[0] = dibh;
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  868  
49edd5bf429c40 Andreas Gruenbacher 2018-02-06  869  	if (gfs2_is_stuffed(ip)) {
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  870  		if (flags & IOMAP_WRITE) {
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  871  			loff_t max_size = gfs2_max_stuffed_size(ip);
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  872  
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  873  			if (pos + length > max_size)
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  874  				goto unstuff;
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  875  			iomap->length = max_size;
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  876  		} else {
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  877  			if (pos >= size) {
49edd5bf429c40 Andreas Gruenbacher 2018-02-06  878  				if (flags & IOMAP_REPORT) {
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  879  					ret = -ENOENT;
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  880  					goto unlock;
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  881  				} else {
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  882  					/* report a hole */
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  883  					iomap->offset = pos;
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  884  					iomap->length = length;
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  885  					goto do_alloc;
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  886  				}
3974320ca6aa68 Bob Peterson        2017-02-16  887  			}
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  888  			iomap->length = size;
49edd5bf429c40 Andreas Gruenbacher 2018-02-06  889  		}
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  890  		iomap->addr = (ip->i_no_addr << inode->i_blkbits) +
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  891  			      sizeof(struct gfs2_dinode);
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  892  		iomap->type = IOMAP_INLINE;
64bc06bb32ee9c Andreas Gruenbacher 2018-06-24  893  		iomap->inline_data = dibh->b_data + sizeof(struct gfs2_dinode);
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  894  		goto out;
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  895  	}
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  896  
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  897  unstuff:
3974320ca6aa68 Bob Peterson        2017-02-16  898  	lblock = pos >> inode->i_blkbits;
3974320ca6aa68 Bob Peterson        2017-02-16  899  	iomap->offset = lblock << inode->i_blkbits;
628e366df11c0a Andreas Gruenbacher 2018-06-04  900  	lblock_stop = (pos + length - 1) >> inode->i_blkbits;
628e366df11c0a Andreas Gruenbacher 2018-06-04  901  	len = lblock_stop - lblock + 1;
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  902  	iomap->length = len << inode->i_blkbits;
20cdc1931ee8e0 Andreas Gruenbacher 2017-09-22  903  
9b8c81d1de4994 Steven Whitehouse   2008-02-22  904  	height = ip->i_height;
9a38662ba4e268 Andreas Gruenbacher 2018-04-16  905  	while ((lblock + 1) * sdp->sd_sb.sb_bsize > sdp->sd_heightsize[height])
ecc30c79157103 Steven Whitehouse   2008-01-28  906  		height++;
628e366df11c0a Andreas Gruenbacher 2018-06-04  907  	find_metapath(sdp, lblock, mp, height);
9b8c81d1de4994 Steven Whitehouse   2008-02-22  908  	if (height > ip->i_height || gfs2_is_stuffed(ip))
9b8c81d1de4994 Steven Whitehouse   2008-02-22  909  		goto do_alloc;
3974320ca6aa68 Bob Peterson        2017-02-16  910  
628e366df11c0a Andreas Gruenbacher 2018-06-04  911  	ret = lookup_metapath(ip, mp);
e8b43fe0c1e035 Andreas Gruenbacher 2017-12-08  912  	if (ret)
628e366df11c0a Andreas Gruenbacher 2018-06-04  913  		goto unlock;
3974320ca6aa68 Bob Peterson        2017-02-16  914  
628e366df11c0a Andreas Gruenbacher 2018-06-04  915  	if (mp->mp_aheight != ip->i_height)
9b8c81d1de4994 Steven Whitehouse   2008-02-22  916  		goto do_alloc;
3974320ca6aa68 Bob Peterson        2017-02-16  917  
628e366df11c0a Andreas Gruenbacher 2018-06-04  918  	ptr = metapointer(ip->i_height - 1, mp);
9b8c81d1de4994 Steven Whitehouse   2008-02-22  919  	if (*ptr == 0)
9b8c81d1de4994 Steven Whitehouse   2008-02-22  920  		goto do_alloc;
3974320ca6aa68 Bob Peterson        2017-02-16  921  
628e366df11c0a Andreas Gruenbacher 2018-06-04  922  	bh = mp->mp_bh[ip->i_height - 1];
bcfe94139a45fa Andreas Gruenbacher 2018-05-11  923  	len = gfs2_extent_length(bh, ptr, len, &eob);
3974320ca6aa68 Bob Peterson        2017-02-16  924  
628e366df11c0a Andreas Gruenbacher 2018-06-04  925  	iomap->addr = be64_to_cpu(*ptr) << inode->i_blkbits;
628e366df11c0a Andreas Gruenbacher 2018-06-04  926  	iomap->length = len << inode->i_blkbits;
628e366df11c0a Andreas Gruenbacher 2018-06-04  927  	iomap->type = IOMAP_MAPPED;
0ed91eca1130e6 Andreas Gruenbacher 2018-07-25  928  	iomap->flags |= IOMAP_F_MERGED;
9b8c81d1de4994 Steven Whitehouse   2008-02-22  929  	if (eob)
7ee66c03e40a57 Christoph Hellwig   2018-06-01  930  		iomap->flags |= IOMAP_F_GFS2_BOUNDARY;
3974320ca6aa68 Bob Peterson        2017-02-16  931  
3974320ca6aa68 Bob Peterson        2017-02-16  932  out:
628e366df11c0a Andreas Gruenbacher 2018-06-04  933  	iomap->bdev = inode->i_sb->s_bdev;
628e366df11c0a Andreas Gruenbacher 2018-06-04  934  unlock:
628e366df11c0a Andreas Gruenbacher 2018-06-04  935  	up_read(&ip->i_rw_mutex);
9b8c81d1de4994 Steven Whitehouse   2008-02-22  936  	return ret;
9b8c81d1de4994 Steven Whitehouse   2008-02-22  937  
9b8c81d1de4994 Steven Whitehouse   2008-02-22  938  do_alloc:
628e366df11c0a Andreas Gruenbacher 2018-06-04  939  	iomap->addr = IOMAP_NULL_ADDR;
628e366df11c0a Andreas Gruenbacher 2018-06-04  940  	iomap->type = IOMAP_HOLE;
628e366df11c0a Andreas Gruenbacher 2018-06-04  941  	if (flags & IOMAP_REPORT) {
49edd5bf429c40 Andreas Gruenbacher 2018-02-06  942  		if (pos >= size)
3974320ca6aa68 Bob Peterson        2017-02-16  943  			ret = -ENOENT;
628e366df11c0a Andreas Gruenbacher 2018-06-04  944  		else if (height == ip->i_height)
628e366df11c0a Andreas Gruenbacher 2018-06-04  945  			ret = gfs2_hole_size(inode, lblock, len, mp, iomap);
49edd5bf429c40 Andreas Gruenbacher 2018-02-06  946  		else
49edd5bf429c40 Andreas Gruenbacher 2018-02-06  947  			iomap->length = size - pos;
64bc06bb32ee9c Andreas Gruenbacher 2018-06-24  948  	} else if (flags & IOMAP_WRITE) {
64bc06bb32ee9c Andreas Gruenbacher 2018-06-24  949  		u64 alloc_size;
64bc06bb32ee9c Andreas Gruenbacher 2018-06-24  950  
967bcc91b04493 Andreas Gruenbacher 2018-06-19  951  		if (flags & IOMAP_DIRECT)
967bcc91b04493 Andreas Gruenbacher 2018-06-19  952  			goto out;  /* (see gfs2_file_direct_write) */
967bcc91b04493 Andreas Gruenbacher 2018-06-19  953  
64bc06bb32ee9c Andreas Gruenbacher 2018-06-24  954  		len = gfs2_alloc_size(inode, mp, len);
64bc06bb32ee9c Andreas Gruenbacher 2018-06-24  955  		alloc_size = len << inode->i_blkbits;
64bc06bb32ee9c Andreas Gruenbacher 2018-06-24  956  		if (alloc_size < iomap->length)
64bc06bb32ee9c Andreas Gruenbacher 2018-06-24  957  			iomap->length = alloc_size;
64bc06bb32ee9c Andreas Gruenbacher 2018-06-24  958  	} else {
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24  959  		if (pos < size && height == ip->i_height)
d505a96a3b16f4 Andreas Gruenbacher 2018-06-24 @960  			ret = gfs2_hole_size(inode, lblock, len, mp, iomap);
3974320ca6aa68 Bob Peterson        2017-02-16  961  	}
628e366df11c0a Andreas Gruenbacher 2018-06-04  962  	goto out;
628e366df11c0a Andreas Gruenbacher 2018-06-04  963  }
628e366df11c0a Andreas Gruenbacher 2018-06-04  964
:::::: The code at line 960 was first introduced by commit
:::::: d505a96a3b16f46455035dc0296bc2da6014e163 gfs2: Further iomap cleanups
:::::: TO: Andreas Gruenbacher agruenba@redhat.com
:::::: CC: Andreas Gruenbacher agruenba@redhat.com
-- 
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