This is a note to let you know that I've just added the patch titled
btrfs: initialize location to fix -Wmaybe-uninitialized in btrfs_lookup_dentry()
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
btrfs-initialize-location-to-fix-wmaybe-uninitialize.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 0bf399dec5a3469d7d7b20c1ff99ac7371b70b56
Author: David Sterba <dsterba@xxxxxxxx>
Date: Mon Jul 29 21:59:24 2024 +0200
btrfs: initialize location to fix -Wmaybe-uninitialized in btrfs_lookup_dentry()
[ Upstream commit b8e947e9f64cac9df85a07672b658df5b2bcff07 ]
Some arch + compiler combinations report a potentially unused variable
location in btrfs_lookup_dentry(). This is a false alert as the variable
is passed by value and always valid or there's an error. The compilers
cannot probably reason about that although btrfs_inode_by_name() is in
the same file.
> + /kisskb/src/fs/btrfs/inode.c: error: 'location.objectid' may be used
+uninitialized in this function [-Werror=maybe-uninitialized]: => 5603:9
> + /kisskb/src/fs/btrfs/inode.c: error: 'location.type' may be used
+uninitialized in this function [-Werror=maybe-uninitialized]: => 5674:5
m68k-gcc8/m68k-allmodconfig
mips-gcc8/mips-allmodconfig
powerpc-gcc5/powerpc-all{mod,yes}config
powerpc-gcc5/ppc64_defconfig
Initialize it to zero, this should fix the warnings and won't change the
behaviour as btrfs_inode_by_name() accepts only a root or inode item
types, otherwise returns an error.
Reported-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Tested-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/linux-btrfs/bd4e9928-17b3-9257-8ba7-6b7f9bbb639a@xxxxxxxxxxxxxx/
Reviewed-by: Qu Wenruo <wqu@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index d2a988bf9c89..cd72409ccc94 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -6087,7 +6087,7 @@ struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
struct inode *inode;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_root *sub_root = root;
- struct btrfs_key location;
+ struct btrfs_key location = { 0 };
u8 di_type = 0;
int index;
int ret = 0;
