gfs2: avoid uninitialized variable warning

commit 67893f12e5374bbcaaffbc6e570acbc2714ea884 upstream.

We get a bogus warning about a potential uninitialized variable
use in gfs2, because the compiler does not figure out that we
never use the leaf number if get_leaf_nr() returns an error:

fs/gfs2/dir.c: In function 'get_first_leaf':
fs/gfs2/dir.c:802:9: warning: 'leaf_no' may be used uninitialized in this function [-Wmaybe-uninitialized]
fs/gfs2/dir.c: In function 'dir_split_leaf':
fs/gfs2/dir.c:1021:8: warning: 'leaf_no' may be used uninitialized in this function [-Wmaybe-uninitialized]

Changing the 'if (!error)' to 'if (!IS_ERR_VALUE(error))' is
sufficient to let gcc understand that this is exactly the same
condition as in IS_ERR() so it can optimize the code path enough
to understand it.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>

diff --git a/fs/gfs2/dir.c b/fs/gfs2/dir.c
index 2e5fc268d3242678c8a8e348141679a8fc94b530..bdef6fef651cc294918923aeb0dd189d2cfb35d9 100644 (file)
--- a/fs/gfs2/dir.c
+++ b/fs/gfs2/dir.c
@@ -763,7 +763,7 @@ static int get_first_leaf(struct gfs2_inode *dip, u32 index,
        int error;
 
        error = get_leaf_nr(dip, index, &leaf_no);
-       if (!error)
+       if (!IS_ERR_VALUE(error))
                error = get_leaf(dip, leaf_no, bh_out);
 
        return error;
@@ -974,7 +974,7 @@ static int dir_split_leaf(struct inode *inode, const struct qstr *name)
 
        index = name->hash >> (32 - dip->i_depth);
        error = get_leaf_nr(dip, index, &leaf_no);
-       if (error)
+       if (IS_ERR_VALUE(error))
                return error;
 
        /*  Get the old leaf block  */