[PATCH 5.1 091/121] ovl: fix bogus -Wmaybe-unitialized warning

From: Greg Kroah-Hartman
Date: Mon Jun 24 2019 - 06:16:52 EST


[ Upstream commit 1dac6f5b0ed2601be21bb4e27a44b0c3e667b7f4 ]

gcc gets a bit confused by the logic in ovl_setup_trap() and
can't figure out whether the local 'trap' variable in the caller
was initialized or not:

fs/overlayfs/super.c: In function 'ovl_fill_super':
fs/overlayfs/super.c:1333:4: error: 'trap' may be used uninitialized in this function [-Werror=maybe-uninitialized]
iput(trap);
^~~~~~~~~~
fs/overlayfs/super.c:1312:17: note: 'trap' was declared here

Reword slightly to make it easier for the compiler to understand.

Fixes: 146d62e5a586 ("ovl: detect overlapping layers")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/overlayfs/super.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index fa5060f59b88..9780617c69ee 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -996,8 +996,8 @@ static int ovl_setup_trap(struct super_block *sb, struct dentry *dir,
int err;

trap = ovl_get_trap_inode(sb, dir);
- err = PTR_ERR(trap);
- if (IS_ERR(trap)) {
+ err = PTR_ERR_OR_ZERO(trap);
+ if (err) {
if (err == -ELOOP)
pr_err("overlayfs: conflicting %s path\n", name);
return err;
--
2.20.1