jbd2: enable journal clients to enable v2 checksumming

Add in the necessary code so that journal clients can enable the new
journal checksumming features.

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

1 files changed, 42 insertions, 13 deletions

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 88c2054fb938..8dfb42e380ea 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3013,6 +3013,44 @@ static void ext4_destroy_lazyinit_thread(void)
         kthread_stop(ext4_lazyinit_task);
 }
 
+static int set_journal_csum_feature_set(struct super_block *sb)
+{
+        int ret = 1;
+        int compat, incompat;
+        struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+        if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
+                                       EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
+                /* journal checksum v2 */
+                compat = 0;
+                incompat = JBD2_FEATURE_INCOMPAT_CSUM_V2;
+        } else {
+                /* journal checksum v1 */
+                compat = JBD2_FEATURE_COMPAT_CHECKSUM;
+                incompat = 0;
+        }
+
+        if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
+                ret = jbd2_journal_set_features(sbi->s_journal,
+                                compat, 0,
+                                JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT |
+                                incompat);
+        } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
+                ret = jbd2_journal_set_features(sbi->s_journal,
+                                compat, 0,
+                                incompat);
+                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_V2);
+        }
+
+        return ret;
+}
+
 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 {
         char *orig_data = kstrdup(data, GFP_KERNEL);
@@ -3610,19 +3648,10 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
                 goto failed_mount_wq;
         }
 
-        if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
-                jbd2_journal_set_features(sbi->s_journal,
-                                JBD2_FEATURE_COMPAT_CHECKSUM, 0,
-                                JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
-        } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
-                jbd2_journal_set_features(sbi->s_journal,
-                                JBD2_FEATURE_COMPAT_CHECKSUM, 0, 0);
-                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);
+        if (!set_journal_csum_feature_set(sb)) {
+                ext4_msg(sb, KERN_ERR, "Failed to set journal checksum "
+                         "feature set");
+                goto failed_mount_wq;
         }
 
         /* We have now updated the journal if required, so we can