releases/3.18.51/gfs2-avoid-uninitialized-variable-warning.patch

   1 From 67893f12e5374bbcaaffbc6e570acbc2714ea884 Mon Sep 17 00:00:00 2001
   2 From: Arnd Bergmann <arnd@arndb.de>
   3 Date: Tue, 26 Jan 2016 13:08:10 -0500
   4 Subject: gfs2: avoid uninitialized variable warning
   5
   6 From: Arnd Bergmann <arnd@arndb.de>
   7
   8 commit 67893f12e5374bbcaaffbc6e570acbc2714ea884 upstream.
   9
  10 We get a bogus warning about a potential uninitialized variable
  11 use in gfs2, because the compiler does not figure out that we
  12 never use the leaf number if get_leaf_nr() returns an error:
  13
  14 fs/gfs2/dir.c: In function 'get_first_leaf':
  15 fs/gfs2/dir.c:802:9: warning: 'leaf_no' may be used uninitialized in this function [-Wmaybe-uninitialized]
  16 fs/gfs2/dir.c: In function 'dir_split_leaf':
  17 fs/gfs2/dir.c:1021:8: warning: 'leaf_no' may be used uninitialized in this function [-Wmaybe-uninitialized]
  18
  19 Changing the 'if (!error)' to 'if (!IS_ERR_VALUE(error))' is
  20 sufficient to let gcc understand that this is exactly the same
  21 condition as in IS_ERR() so it can optimize the code path enough
  22 to understand it.
  23
  24 Signed-off-by: Arnd Bergmann <arnd@arndb.de>
  25 Signed-off-by: Bob Peterson <rpeterso@redhat.com>
  26 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  27
  28 ---
  29  fs/gfs2/dir.c |    4 ++--
  30  1 file changed, 2 insertions(+), 2 deletions(-)
  31
  32 --- a/fs/gfs2/dir.c
  33 +++ b/fs/gfs2/dir.c
  34 @@ -764,7 +764,7 @@ static int get_first_leaf(struct gfs2_in
  35         int error;
  36
  37         error = get_leaf_nr(dip, index, &leaf_no);
  38 -       if (!error)
  39 +       if (!IS_ERR_VALUE(error))
  40                 error = get_leaf(dip, leaf_no, bh_out);
  41
  42         return error;
  43 @@ -980,7 +980,7 @@ static int dir_split_leaf(struct inode *
  44
  45         index = name->hash >> (32 - dip->i_depth);
  46         error = get_leaf_nr(dip, index, &leaf_no);
  47 -       if (error)
  48 +       if (IS_ERR_VALUE(error))
  49                 return error;
  50
  51         /*  Get the old leaf block  */