jbd2: If a journal checksum error is detected, propagate the error to ext4

If a journal checksum error is detected, the ext4 filesystem will call
ext4_error(), and the mount will either continue, become a read-only
mount, or cause a kernel panic based on the superblock flags
indicating the user's preference of what to do in case of filesystem
corruption being detected.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

3 files changed, 30 insertions, 7 deletions

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 09d9359c8055..d01a32e8b50a 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2189,6 +2189,29 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
                 if (ext4_load_journal(sb, es, journal_devnum))
                         goto failed_mount3;
+                if (!(sb->s_flags & MS_RDONLY) &&
+                    EXT4_SB(sb)->s_journal->j_failed_commit) {
+                        printk(KERN_CRIT "EXT4-fs error (device %s): "
+                               "ext4_fill_super: Journal transaction "
+                               "%u is corrupt\n", sb->s_id, 
+                               EXT4_SB(sb)->s_journal->j_failed_commit);
+                        if (test_opt (sb, ERRORS_RO)) {
+                                printk (KERN_CRIT
+                                        "Mounting filesystem read-only\n");
+                                sb->s_flags |= MS_RDONLY;
+                                EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
+                                es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
+                        }
+                        if (test_opt(sb, ERRORS_PANIC)) {
+                                EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
+                                es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
+                                ext4_commit_super(sb, es, 1);
+                                printk(KERN_CRIT
+                                       "EXT4-fs (device %s): mount failed\n",
+                                      sb->s_id);
+                                goto failed_mount4;
+                        }
+                }
         } else if (journal_inum) {
                 if (ext4_create_journal(sb, es, journal_inum))
                         goto failed_mount3;
diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c
index 7199db52b2fd..058f50f65b76 100644
--- a/fs/jbd2/recovery.c
+++ b/fs/jbd2/recovery.c
@@ -611,9 +611,8 @@ static int do_one_pass(journal_t *journal,
                                 chksum_err = chksum_seen = 0;
 
                                 if (info->end_transaction) {
-                                        printk(KERN_ERR "JBD: Transaction %u "
-                                                "found to be corrupt.\n",
-                                                next_commit_ID - 1);
+                                        journal->j_failed_commit =
+                                                info->end_transaction;
                                         brelse(bh);
                                         break;
                                 }
@@ -644,10 +643,8 @@ static int do_one_pass(journal_t *journal,
 
                                         if (!JBD2_HAS_INCOMPAT_FEATURE(journal,
                                            JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)){
-                                                printk(KERN_ERR
-                                                       "JBD: Transaction %u "
-                                                       "found to be corrupt.\n",
-                                                       next_commit_ID);
+                                                journal->j_failed_commit =
+                                                        next_commit_ID;
                                                 brelse(bh);
                                                 break;
                                         }
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index 05e2b307161a..d147f0f90360 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -919,6 +919,9 @@ struct journal_s
         struct proc_dir_entry   *j_proc_entry;
         struct transaction_stats_s j_stats;
 
+        /* Failed journal commit ID */
+        unsigned int            j_failed_commit;
+
         /*
          * An opaque pointer to fs-private information.  ext3 puts its
          * superblock pointer here