jbd2: clean up feature test macros with predicate functions

Create separate predicate functions to test/set/clear feature flags,
thereby replacing the wordy old macros.  Furthermore, clean out the
places where we open-coded feature tests.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 474c178..eb8a754 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -1523,8 +1523,8 @@
 		goto out;
 	}
 
-	if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2) &&
-	    JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V3)) {
+	if (jbd2_has_feature_csum2(journal) &&
+	    jbd2_has_feature_csum3(journal)) {
 		/* Can't have checksum v2 and v3 at the same time! */
 		printk(KERN_ERR "JBD2: Can't enable checksumming v2 and v3 "
 		       "at the same time!\n");
@@ -1532,7 +1532,7 @@
 	}
 
 	if (jbd2_journal_has_csum_v2or3_feature(journal) &&
-	    JBD2_HAS_COMPAT_FEATURE(journal, JBD2_FEATURE_COMPAT_CHECKSUM)) {
+	    jbd2_has_feature_checksum(journal)) {
 		/* 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");
@@ -2198,15 +2198,15 @@
 {
 	size_t sz;
 
-	if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V3))
+	if (jbd2_has_feature_csum3(journal))
 		return sizeof(journal_block_tag3_t);
 
 	sz = sizeof(journal_block_tag_t);
 
-	if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+	if (jbd2_has_feature_csum2(journal))
 		sz += sizeof(__u16);
 
-	if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT))
+	if (jbd2_has_feature_64bit(journal))
 		return sz;
 	else
 		return sz - sizeof(__u32);