| Message ID | 1453735996-1958733-2-git-send-email-arnd@arndb.de |
|---|---|
| State | Accepted |
| Commit | 67893f12e5374bbcaaffbc6e570acbc2714ea884 |
| Headers | show |
----- Original Message ----- > 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> > --- > fs/gfs2/dir.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/fs/gfs2/dir.c b/fs/gfs2/dir.c > index 6a92592304fb..d4014af4f064 100644 > --- a/fs/gfs2/dir.c > +++ b/fs/gfs2/dir.c > @@ -798,7 +798,7 @@ 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; > @@ -1014,7 +1014,7 @@ 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 */ > -- > 2.7.0 > > Hi, Thanks. This is now applied to the for-next branch of the linux-gfs2 tree: https://git.kernel.org/cgit/linux/kernel/git/gfs2/linux-gfs2.git/commit/fs/gfs2?h=for-next&id=07cfdc3071432a07713e4d007c2811e0224490b0 Regards, Bob Peterson Red Hat File Systems
diff --git a/fs/gfs2/dir.c b/fs/gfs2/dir.c index 6a92592304fb..d4014af4f064 100644 --- a/fs/gfs2/dir.c +++ b/fs/gfs2/dir.c @@ -798,7 +798,7 @@ 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; @@ -1014,7 +1014,7 @@ 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 */
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> --- fs/gfs2/dir.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) -- 2.7.0