[bug report] ubifs: Fix unlink code wrt. double hash lookups

[Richard Weinberger]

Dan,

Am 17.07.2017 um 20:04 schrieb Dan Carpenter:
> Hello Richard Weinberger,
> 
> The patch 781f675e2d7e: "ubifs: Fix unlink code wrt. double hash
> lookups" from May 17, 2017, leads to the following static checker
> warning:
> 
> 	fs/ubifs/tnc.c:1893 search_dh_cookie()
> 	error: uninitialized symbol 'err'.
> 
> fs/ubifs/tnc.c
>   1883  static int search_dh_cookie(struct ubifs_info *c, const union ubifs_key *key,
>   1884                              struct ubifs_dent_node *dent, uint32_t cookie,
>   1885                              struct ubifs_znode **zn, int *n)
>   1886  {
>   1887          int err;
>                 ^^^^^^^
> 
> This used to be initialized with:
> 
> 	err = ubifs_lookup_level0(c, &start_key, &znode, &n);
> 
>   1888          struct ubifs_znode *znode = *zn;
>   1889          struct ubifs_zbranch *zbr;
>   1890          union ubifs_key *dkey;
>   1891  
>   1892          for (;;) {
>   1893                  if (!err) {
>                             ^^^^
> Uninitialized.
> 
>   1894                          err = tnc_next(c, &znode, n);
>   1895                          if (err)
>   1896                                  goto out;
>   1897                  }
>   1898  
>   1899                  zbr = &znode->zbranch[*n];
>   1900                  dkey = &zbr->key;
>   1901  
>   1902                  if (key_inum(c, dkey) != key_inum(c, key) ||
>   1903                      key_type(c, dkey) != key_type(c, key)) {
>   1904                          err = -ENOENT;
>   1905                          goto out;
>   1906                  }
>   1907  
>   1908                  err = tnc_read_hashed_node(c, zbr, dent);
>   1909                  if (err)
>   1910                          goto out;
>   1911  
>   1912                  if (key_hash(c, key) == key_hash(c, dkey) &&
>   1913                      le32_to_cpu(dent->cookie) == cookie) {
>   1914                          *zn = znode;
>   1915                          goto out;
>   1916                  }
>   1917          }
>   1918  
>   1919  out:
>   1920  
>   1921          return err;
>   1922  }
>

Sorry, Colin was faster. :-)
http://patchwork.ozlabs.org/patch/789586/

Thanks,
//richard