Merge tag 'dm-3.5-changes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/agk...

[linux-2.6-microblaze.git] / fs / jbd2 / journal.c

diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index f04ab6c..e9a3c4c 100644 (file)
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -106,6 +106,34 @@ int jbd2_verify_csum_type(journal_t *j, journal_superblock_t *sb)
        return sb->s_checksum_type == JBD2_CRC32C_CHKSUM;
 }
 
+static __u32 jbd2_superblock_csum(journal_t *j, journal_superblock_t *sb)
+{
+       __u32 csum, old_csum;
+
+       old_csum = sb->s_checksum;
+       sb->s_checksum = 0;
+       csum = jbd2_chksum(j, ~0, (char *)sb, sizeof(journal_superblock_t));
+       sb->s_checksum = old_csum;
+
+       return cpu_to_be32(csum);
+}
+
+int jbd2_superblock_csum_verify(journal_t *j, journal_superblock_t *sb)
+{
+       if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+               return 1;
+
+       return sb->s_checksum == jbd2_superblock_csum(j, sb);
+}
+
+void jbd2_superblock_csum_set(journal_t *j, journal_superblock_t *sb)
+{
+       if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+               return;
+
+       sb->s_checksum = jbd2_superblock_csum(j, sb);
+}
+
 /*
  * Helper function used to manage commit timeouts
  */
@@ -1357,6 +1385,7 @@ static void jbd2_journal_update_sb_errno(journal_t *journal)
        jbd_debug(1, "JBD2: updating superblock error (errno %d)\n",
                  journal->j_errno);
        sb->s_errno    = cpu_to_be32(journal->j_errno);
+       jbd2_superblock_csum_set(journal, sb);
        read_unlock(&journal->j_state_lock);
 
        jbd2_write_superblock(journal, WRITE_SYNC);
@@ -1449,6 +1478,17 @@ static int journal_get_superblock(journal_t *journal)
                }
        }
 
+       /* Check superblock checksum */
+       if (!jbd2_superblock_csum_verify(journal, sb)) {
+               printk(KERN_ERR "JBD: journal checksum error\n");
+               goto out;
+       }
+
+       /* Precompute checksum seed for all metadata */
+       if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+               journal->j_csum_seed = jbd2_chksum(journal, ~0, sb->s_uuid,
+                                                  sizeof(sb->s_uuid));
+
        set_buffer_verified(bh);
 
        return 0;
@@ -1732,6 +1772,13 @@ int jbd2_journal_set_features (journal_t *journal, unsigned long compat,
                                return 0;
                        }
                }
+
+               /* Precompute checksum seed for all metadata */
+               if (JBD2_HAS_INCOMPAT_FEATURE(journal,
+                                             JBD2_FEATURE_INCOMPAT_CSUM_V2))
+                       journal->j_csum_seed = jbd2_chksum(journal, ~0,
+                                                          sb->s_uuid,
+                                                          sizeof(sb->s_uuid));
        }
 
        /* If enabling v1 checksums, downgrade superblock */
@@ -2050,10 +2097,16 @@ int jbd2_journal_blocks_per_page(struct inode *inode)
  */
 size_t journal_tag_bytes(journal_t *journal)
 {
+       journal_block_tag_t tag;
+       size_t x = 0;
+
+       if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+               x += sizeof(tag.t_checksum);
+
        if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT))
-               return JBD2_TAG_SIZE64;
+               return x + JBD2_TAG_SIZE64;
        else
-               return JBD2_TAG_SIZE32;
+               return x + JBD2_TAG_SIZE32;
 }
 
 /*