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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Filipe Manana <fdmanana@suse.com>,
        Marcos Paulo de Souza <mpdesouza@suse.com>,
        David Sterba <dsterba@suse.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.4 148/260] btrfs: tree-log: check btrfs_lookup_data_extent return value
Date:   Mon, 20 Sep 2021 18:42:46 +0200
Message-Id: <20210920163936.142825719@linuxfoundation.org>
In-Reply-To: <20210920163931.123590023@linuxfoundation.org>
References: <20210920163931.123590023@linuxfoundation.org>
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From: Marcos Paulo de Souza <mpdesouza@suse.com>

[ Upstream commit 3736127a3aa805602b7a2ad60ec9cfce68065fbb ]

Function btrfs_lookup_data_extent calls btrfs_search_slot to verify if
the EXTENT_ITEM exists in the extent tree. btrfs_search_slot can return
values bellow zero if an error happened.

Function replay_one_extent currently checks if the search found
something (0 returned) and increments the reference, and if not, it
seems to evaluate as 'not found'.

Fix the condition by checking if the value was bellow zero and return
early.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/btrfs/tree-log.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 5412361d0c27..8ea4b3da85d1 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -719,7 +719,9 @@ static noinline int replay_one_extent(struct btrfs_trans_handle *trans,
 			 */
 			ret = btrfs_lookup_data_extent(fs_info, ins.objectid,
 						ins.offset);
-			if (ret == 0) {
+			if (ret < 0) {
+				goto out;
+			} else if (ret == 0) {
 				btrfs_init_generic_ref(&ref,
 						BTRFS_ADD_DELAYED_REF,
 						ins.objectid, ins.offset, 0);
-- 
2.30.2