passing positive numbers to ERR_PTR()

passing positive numbers to ERR_PTR()

[Dan Carpenter]

Hi Jan,

Smatch complains when you pass positive numbers to ERR_PTR().  There
is a warning triggered in iref_to_path().

fs/btrfs/backref.c +920 iref_to_path()
   918  
   919          if (ret)
   920                  return ERR_PTR(ret);
                                       ^^^
"ret" can be either a negative error code, zero, or one here.

   921  

I looked at the code, but couldn't tell if it was intentional or not.
It really is pretty unusual to do that, so maybe there should be a
comment or something.

regards,
dan carpenter

[PATCH] Btrfs: avoid positive number with ERR_PTR

[Jan Schmidt]

inode_ref_info() returns 1 when the element wasn't found and < 0 on error,
just like btrfs_search_slot(). In iref_to_path() it's an error when the
inode ref can't be found, thus we return ERR_PTR(ret) in that case. In order
to avoid ERR_PTR(1), we now set ret to -ENOENT in that case.

Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
---
On 08.02.2012 10:18, Dan Carpenter wrote:
> I looked at the code, but couldn't tell if it was intentional or not.

It wasn't :-)

Thank you,
-Jan
---
 fs/btrfs/backref.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---

diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index 633c701..98f6bf10 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -892,6 +892,8 @@ static char *iref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path,
 		if (eb != eb_in)
 			free_extent_buffer(eb);
 		ret = inode_ref_info(parent, 0, fs_root, path, &found_key);
+		if (ret > 0)
+			ret = -ENOENT;
 		if (ret)
 			break;
 		next_inum = found_key.offset;
-- 
1.7.3.4