[next:master 6096/6547] fs/nilfs2/btree.c:1611 nilfs_btree_seek_key() warn: impossible condition '(start > (~0)) => (0-u64max > u64max)'

[next:master 6096/6547] fs/nilfs2/btree.c:1611 nilfs_btree_seek_key() warn: impossible condition '(start > (~0)) => (0-u64max > u64max)'

[Dan Carpenter]

[ I suppose this is intentional but this is the first time
  NILFS_BTREE_KEY_MAX has been used since it was introduced in 2009 so
  it's strange. - dan ]

tree:   git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head:   50d4d7167355e3ffa6e0a759e88cd277e58a5cb9
commit: 6c302a8684cd06a7ec985fb23f31fa8f3f210eef [6096/6547] nilfs2: add bmap function to seek a valid key

fs/nilfs2/btree.c:1611 nilfs_btree_seek_key() warn: impossible condition '(start > (~0)) => (0-u64max > u64max)'

git remote add next git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
git remote update next
git checkout 6c302a8684cd06a7ec985fb23f31fa8f3f210eef
vim +1611 fs/nilfs2/btree.c

17c76b01 Koji Sato       2009-04-06  1595  		goto out;
2e0c2c73 Ryusuke Konishi 2009-08-15  1596  	nilfs_btree_commit_delete(btree, path, level, dat);
be667377 Ryusuke Konishi 2011-03-05  1597  	nilfs_inode_sub_blocks(btree->b_inode, stats.bs_nblocks);
17c76b01 Koji Sato       2009-04-06  1598  
17c76b01 Koji Sato       2009-04-06  1599  out:
6d28f7ea Ryusuke Konishi 2009-08-15  1600  	nilfs_btree_free_path(path);
17c76b01 Koji Sato       2009-04-06  1601  	return ret;
17c76b01 Koji Sato       2009-04-06  1602  }
17c76b01 Koji Sato       2009-04-06  1603  
6c302a86 Ryusuke Konishi 2015-03-20  1604  static int nilfs_btree_seek_key(const struct nilfs_bmap *btree, __u64 start,
6c302a86 Ryusuke Konishi 2015-03-20  1605  				__u64 *keyp)
6c302a86 Ryusuke Konishi 2015-03-20  1606  {
6c302a86 Ryusuke Konishi 2015-03-20  1607  	struct nilfs_btree_path *path;
6c302a86 Ryusuke Konishi 2015-03-20  1608  	const int minlevel = NILFS_BTREE_LEVEL_NODE_MIN;
6c302a86 Ryusuke Konishi 2015-03-20  1609  	int ret;
6c302a86 Ryusuke Konishi 2015-03-20  1610  
6c302a86 Ryusuke Konishi 2015-03-20 @1611  	if (start > NILFS_BTREE_KEY_MAX)
6c302a86 Ryusuke Konishi 2015-03-20  1612  		return -ENOENT;
6c302a86 Ryusuke Konishi 2015-03-20  1613  
6c302a86 Ryusuke Konishi 2015-03-20  1614  	path = nilfs_btree_alloc_path();
6c302a86 Ryusuke Konishi 2015-03-20  1615  	if (!path)
6c302a86 Ryusuke Konishi 2015-03-20  1616  		return -ENOMEM;
6c302a86 Ryusuke Konishi 2015-03-20  1617  
6c302a86 Ryusuke Konishi 2015-03-20  1618  	ret = nilfs_btree_do_lookup(btree, path, start, NULL, minlevel, 0);
6c302a86 Ryusuke Konishi 2015-03-20  1619  	if (!ret)

---
0-DAY kernel test infrastructure                Open Source Technology Center
http://lists.01.org/mailman/listinfo/kbuild                 Intel Corporation

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Re: [next:master 6096/6547] fs/nilfs2/btree.c:1611 nilfs_btree_seek_key() warn: impossible condition '(start > (~0)) => (0-u64max > u64max)'

[Ryusuke Konishi]

Hi,

On 2015/03/24 17:48, Dan Carpenter wrote:
> [ I suppose this is intentional but this is the first time
>    NILFS_BTREE_KEY_MAX has been used since it was introduced in 2009 so
>    it's strange. - dan ]
>
> tree:   git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> head:   50d4d7167355e3ffa6e0a759e88cd277e58a5cb9
> commit: 6c302a8684cd06a7ec985fb23f31fa8f3f210eef [6096/6547] nilfs2: add bmap function to seek a valid key
>
> fs/nilfs2/btree.c:1611 nilfs_btree_seek_key() warn: impossible condition '(start > (~0)) => (0-u64max > u64max)'
>
<snip>
> 6c302a86 Ryusuke Konishi 2015-03-20  1604  static int nilfs_btree_seek_key(const struct nilfs_bmap *btree, __u64 start,
> 6c302a86 Ryusuke Konishi 2015-03-20  1605  				__u64 *keyp)
> 6c302a86 Ryusuke Konishi 2015-03-20  1606  {
> 6c302a86 Ryusuke Konishi 2015-03-20  1607  	struct nilfs_btree_path *path;
> 6c302a86 Ryusuke Konishi 2015-03-20  1608  	const int minlevel = NILFS_BTREE_LEVEL_NODE_MIN;
> 6c302a86 Ryusuke Konishi 2015-03-20  1609  	int ret;
> 6c302a86 Ryusuke Konishi 2015-03-20  1610
> 6c302a86 Ryusuke Konishi 2015-03-20 @1611  	if (start > NILFS_BTREE_KEY_MAX)
> 6c302a86 Ryusuke Konishi 2015-03-20  1612  		return -ENOENT;

Thanks.  This check is actually meaningless.
Will fix it.

Regards,
Ryusuke Konishi


> 6c302a86 Ryusuke Konishi 2015-03-20  1613
> 6c302a86 Ryusuke Konishi 2015-03-20  1614  	path = nilfs_btree_alloc_path();
> 6c302a86 Ryusuke Konishi 2015-03-20  1615  	if (!path)
> 6c302a86 Ryusuke Konishi 2015-03-20  1616  		return -ENOMEM;
> 6c302a86 Ryusuke Konishi 2015-03-20  1617
> 6c302a86 Ryusuke Konishi 2015-03-20  1618  	ret = nilfs_btree_do_lookup(btree, path, start, NULL, minlevel, 0);
> 6c302a86 Ryusuke Konishi 2015-03-20  1619  	if (!ret)
>
> ---
> 0-DAY kernel test infrastructure                Open Source Technology Center
> http://lists.01.org/mailman/listinfo/kbuild                 Intel Corporation

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