[PATCH 3.16 088/148] fuse: verify nlink

[Ben Hutchings]

3.16.82-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Miklos Szeredi <mszeredi@xxxxxxxxxx>

commit c634da718db9b2fac201df2ae1b1b095344ce5eb upstream.

When adding a new hard link, make sure that i_nlink doesn't overflow.

Fixes: ac45d61357e8 ("fuse: fix nlink after unlink")
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 fs/fuse/dir.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -890,7 +890,8 @@ static int fuse_link(struct dentry *entr
 
 		spin_lock(&fc->lock);
 		fi->attr_version = ++fc->attr_version;
-		inc_nlink(inode);
+		if (likely(inode->i_nlink < UINT_MAX))
+			inc_nlink(inode);
 		spin_unlock(&fc->lock);
 		fuse_invalidate_attr(inode);
 		fuse_update_ctime(inode);