Commit 0af0b963 authored by Hongbo Li's avatar Hongbo Li Committed by Kent Overstreet
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bcachefs: eliminate the uninitialized compilation warning in bch2_reconstruct_snapshots 



When compiling the bcachefs-tools, the following compilation warning
is reported:
    libbcachefs/snapshot.c: In function ‘bch2_reconstruct_snapshots’:
    libbcachefs/snapshot.c:915:19: warning: ‘tree_id’ may be used uninitialized in this function [-Wmaybe-uninitialized]
      915 |  snapshot->v.tree = cpu_to_le32(tree_id);
    libbcachefs/snapshot.c:903:6: note: ‘tree_id’ was declared here
      903 |  u32 tree_id;
       |      ^~~~~~~

This is a false alert, because @tree_id is changed in
bch2_snapshot_tree_create after it returns 0. And if this function
returns other value, @tree_id wouldn't be used. Thus there should
be nothing wrong in logical.

Although the report itself is a false alert, we can still make it more
explicit by setting the initial value of @tree_id to 0 (an invalid
tree ID).

Fixes: a292be3b ("bcachefs: Reconstruct missing snapshot nodes")
Signed-off-by: default avatarHongbo Li <lihongbo22@huawei.com>
Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
parent 56522d72

fs/bcachefs/snapshot.c

+2 −1
Original line number Diff line number Diff line
@@ -900,7 +900,8 @@ static int check_snapshot_exists(struct btree_trans *trans, u32 id) 
	if (bch2_snapshot_equiv(c, id))

		return 0;



	u32 tree_id;

	/* 0 is an invalid tree ID */

	u32 tree_id = 0;

	int ret = bch2_snapshot_tree_create(trans, id, 0, &tree_id);

	if (ret)

		return ret;