gfs2: avoid uninitialized variable warning

[ Upstream commit 67893f12e5374bbcaaffbc6e570acbc2714ea884 ]

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: Sasha Levin <alexander.levin@verizon.com>

diff --git a/fs/gfs2/dir.c b/fs/gfs2/dir.c
index 487527b42d94a381d329d8be5ae4459cafabe15b..e4aab588d822648a4a36ef5266c62730a8c86090 100644 (file)
--- a/fs/gfs2/dir.c
+++ b/fs/gfs2/dir.c
@@ -755,7 +755,7 @@ 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;
@@ -971,7 +971,7 @@ 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  */