e2fsck: check commit block checksum during recovery

When recovering a journal with checksum v2, verify the commit block
checksum.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/e2fsck/recovery.c b/e2fsck/recovery.c
index 208e1cb..897a3ff 100644 (file)
--- a/e2fsck/recovery.c
+++ b/e2fsck/recovery.c
@@ -373,6 +373,26 @@ static int calc_chksums(journal_t *journal, struct buffer_head *bh,
        return 0;
 }
 
+static int jbd2_commit_block_csum_verify(journal_t *j, void *buf)
+{
+       struct commit_header *h;
+       __u32 provided, calculated;
+
+       if (!JFS_HAS_INCOMPAT_FEATURE(j, JFS_FEATURE_INCOMPAT_CSUM_V2))
+               return 1;
+
+       h = buf;
+       provided = h->h_chksum[0];
+       h->h_chksum[0] = 0;
+       calculated = ext2fs_crc32c_le(~0, j->j_superblock->s_uuid,
+                                     sizeof(j->j_superblock->s_uuid));
+       calculated = ext2fs_crc32c_le(calculated, buf, j->j_blocksize);
+       h->h_chksum[0] = provided;
+
+       provided = ext2fs_be32_to_cpu(provided);
+       return provided == calculated;
+}
+
 static int do_one_pass(journal_t *journal,
                        struct recovery_info *info, enum passtype pass)
 {
@@ -695,6 +715,19 @@ static int do_one_pass(journal_t *journal,
                                }
                                crc32_sum = ~0;
                        }
+                       if (pass == PASS_SCAN &&
+                           !jbd2_commit_block_csum_verify(journal,
+                                                          bh->b_data)) {
+                               info->end_transaction = next_commit_ID;
+
+                               if (!JFS_HAS_INCOMPAT_FEATURE(journal,
+                                    JFS_FEATURE_INCOMPAT_ASYNC_COMMIT)) {
+                                       journal->j_failed_commit =
+                                               next_commit_ID;
+                                       brelse(bh);
+                                       break;
+                               }
+                       }
                        brelse(bh);
                        next_commit_ID++;
                        continue;