Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 07/17] gfs2: avoid uninitialized variable warning | Date | Fri, 28 Apr 2017 10:30:20 +0200 |
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4.4-stable review patch. If anyone has any objections, please let me know.
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From: Arnd Bergmann <arnd@arndb.de>
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- fs/gfs2/dir.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/fs/gfs2/dir.c +++ b/fs/gfs2/dir.c @@ -760,7 +760,7 @@ static int get_first_leaf(struct gfs2_in 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; @@ -976,7 +976,7 @@ static int dir_split_leaf(struct inode * 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 */
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