diff options
| -rw-r--r-- | fs/jbd2/journal.c | 47 | ||||
| -rw-r--r-- | include/linux/jbd2.h | 3 |
2 files changed, 50 insertions, 0 deletions
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index f04ab6c4b428..9072f03d30b5 100644 --- 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 */ diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h index 71e77dddebf1..a9632bc55d97 100644 --- a/include/linux/jbd2.h +++ b/include/linux/jbd2.h @@ -969,6 +969,9 @@ struct journal_s /* Reference to checksum algorithm driver via cryptoapi */ struct crypto_shash *j_chksum_driver; + + /* Precomputed journal UUID checksum for seeding other checksums */ + __u32 j_csum_seed; }; /* |