jbd2: fix journal checksum feature flag handling

Clear all three journal checksum feature flags before turning on
whichever journal checksum options we want.  Rearrange the error
checking so that newer flags get complained about first.

Reported-by: TR Reardon <thomas_reardon@hotmail.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

2 files changed, 14 insertions, 13 deletions

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 2766b8eba121..fb219b95f8d2 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3237,6 +3237,10 @@ static int set_journal_csum_feature_set(struct super_block *sb)
                 incompat = 0;
         }
 
+        jbd2_journal_clear_features(sbi->s_journal,
+                        JBD2_FEATURE_COMPAT_CHECKSUM, 0,
+                        JBD2_FEATURE_INCOMPAT_CSUM_V3 |
+                        JBD2_FEATURE_INCOMPAT_CSUM_V2);
         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
                 ret = jbd2_journal_set_features(sbi->s_journal,
                                 compat, 0,
@@ -3249,11 +3253,8 @@ static int set_journal_csum_feature_set(struct super_block *sb)
                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
         } else {
-                jbd2_journal_clear_features(sbi->s_journal,
-                                JBD2_FEATURE_COMPAT_CHECKSUM, 0,
-                                JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
-                                JBD2_FEATURE_INCOMPAT_CSUM_V3 |
-                                JBD2_FEATURE_INCOMPAT_CSUM_V2);
+                jbd2_journal_clear_features(sbi->s_journal, 0, 0,
+                                JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
         }
 
         return ret;
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 415041c4c40c..e4dc74713a43 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -1522,14 +1522,6 @@ static int journal_get_superblock(journal_t *journal)
                 goto out;
         }
 
-        if (jbd2_journal_has_csum_v2or3(journal) &&
-            JBD2_HAS_COMPAT_FEATURE(journal, JBD2_FEATURE_COMPAT_CHECKSUM)) {
-                /* Can't have checksum v1 and v2 on at the same time! */
-                printk(KERN_ERR "JBD2: Can't enable checksumming v1 and v2 "
-                       "at the same time!\n");
-                goto out;
-        }
-
         if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2) &&
             JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V3)) {
                 /* Can't have checksum v2 and v3 at the same time! */
@@ -1538,6 +1530,14 @@ static int journal_get_superblock(journal_t *journal)
                 goto out;
         }
 
+        if (jbd2_journal_has_csum_v2or3(journal) &&
+            JBD2_HAS_COMPAT_FEATURE(journal, JBD2_FEATURE_COMPAT_CHECKSUM)) {
+                /* Can't have checksum v1 and v2 on at the same time! */
+                printk(KERN_ERR "JBD2: Can't enable checksumming v1 and v2/3 "
+                       "at the same time!\n");
+                goto out;
+        }
+
         if (!jbd2_verify_csum_type(journal, sb)) {
                 printk(KERN_ERR "JBD2: Unknown checksum type\n");
                 goto out;