jbd2: fix block tag checksum verification brokenness

[firefly-linux-kernel-4.4.55.git] / fs / jbd2 / recovery.c

diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c
index 626846bac32f8a5f2c01d4e3f39db9332642a25c..d4851464b57e5ab4aac7e5851f457c796c244795 100644 (file)
--- a/fs/jbd2/recovery.c
+++ b/fs/jbd2/recovery.c
@@ -399,18 +399,17 @@ static int jbd2_commit_block_csum_verify(journal_t *j, void *buf)
 static int jbd2_block_tag_csum_verify(journal_t *j, journal_block_tag_t *tag,
                                      void *buf, __u32 sequence)
 {
-       __u32 provided, calculated;
+       __u32 csum32;
 
        if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
                return 1;
 
        sequence = cpu_to_be32(sequence);
-       calculated = jbd2_chksum(j, j->j_csum_seed, (__u8 *)&sequence,
-                                sizeof(sequence));
-       calculated = jbd2_chksum(j, calculated, buf, j->j_blocksize);
-       provided = be32_to_cpu(tag->t_checksum);
+       csum32 = jbd2_chksum(j, j->j_csum_seed, (__u8 *)&sequence,
+                            sizeof(sequence));
+       csum32 = jbd2_chksum(j, csum32, buf, j->j_blocksize);
 
-       return provided == cpu_to_be32(calculated);
+       return tag->t_checksum == cpu_to_be16(csum32);
 }
 
 static int do_one_pass(journal_t *journal,