tune2fs: Cleanup feature handling to avoid merge conflicts

Use a more abstract set of feature tests to avoid merge conflicts as
we add support for new features in the maint, master, next, and pu git
branches.

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

1 files changed, 26 insertions, 29 deletions

diff --git a/misc/tune2fs.c b/misc/tune2fs.c
index ad1d6461..ee7af4b1 100644
--- a/misc/tune2fs.c
+++ b/misc/tune2fs.c
@@ -301,25 +301,23 @@ static void update_mntopts(ext2_filsys fs, char *mntopts)
  */
 static void update_feature_set(ext2_filsys fs, char *features)
 {
-	int sparse, old_sparse, filetype, old_filetype;
-	int journal, old_journal, dxdir, old_dxdir;
 	struct ext2_super_block *sb= fs->super;
 	__u32	old_compat, old_incompat, old_ro_compat;
+	__u32		old_features[3];
 	int		type_err;
 	unsigned int	mask_err;
 
-	old_compat = sb->s_feature_compat;
-	old_ro_compat = sb->s_feature_ro_compat;
-	old_incompat = sb->s_feature_incompat;
+#define FEATURE_ON(type, mask) (!(old_features[(type)] & (mask)) && \
+				((&sb->s_feature_compat)[(type)] & (mask)))
+#define FEATURE_OFF(type, mask) ((old_features[(type)] & (mask)) && \
+				 !((&sb->s_feature_compat)[(type)] & (mask)))
+#define FEATURE_CHANGED(type, mask) ((mask) & \
+		     (old_features[(type)] ^ (&sb->s_feature_compat)[(type)]))
+
+	old_features[E2P_FEATURE_COMPAT] = sb->s_feature_compat;
+	old_features[E2P_FEATURE_INCOMPAT] = sb->s_feature_incompat;
+	old_features[E2P_FEATURE_RO_INCOMPAT] = sb->s_feature_ro_compat;
 
-	old_sparse = sb->s_feature_ro_compat &
-		EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER;
-	old_filetype = sb->s_feature_incompat &
-		EXT2_FEATURE_INCOMPAT_FILETYPE;
-	old_journal = sb->s_feature_compat &
-		EXT3_FEATURE_COMPAT_HAS_JOURNAL;
-	old_dxdir = sb->s_feature_compat &
-		EXT2_FEATURE_COMPAT_DIR_INDEX;
 	if (e2p_edit_feature2(features, &sb->s_feature_compat,
 			      ok_features, clear_ok_features,
 			      &type_err, &mask_err)) {
@@ -339,15 +337,8 @@ static void update_feature_set(ext2_filsys fs, char *features)
 				e2p_feature2string(type_err, mask_err));
 		exit(1);
 	}
-	sparse = sb->s_feature_ro_compat &
-		EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER;
-	filetype = sb->s_feature_incompat &
-		EXT2_FEATURE_INCOMPAT_FILETYPE;
-	journal = sb->s_feature_compat &
-		EXT3_FEATURE_COMPAT_HAS_JOURNAL;
-	dxdir = sb->s_feature_compat &
-		EXT2_FEATURE_COMPAT_DIR_INDEX;
-	if (old_journal && !journal) {
+
+	if (FEATURE_OFF(E2P_FEATURE_COMPAT, EXT3_FEATURE_COMPAT_HAS_JOURNAL)) {
 		if ((mount_flags & EXT2_MF_MOUNTED) &&
 		    !(mount_flags & EXT2_MF_READONLY)) {
 			fputs(_("The has_journal flag may only be "
@@ -370,7 +361,8 @@ static void update_feature_set(ext2_filsys fs, char *features)
 			remove_journal_device(fs);
 		}
 	}
-	if (journal && !old_journal) {
+
+	if (FEATURE_ON(E2P_FEATURE_COMPAT, EXT3_FEATURE_COMPAT_HAS_JOURNAL)) {
 		/*
 		 * If adding a journal flag, let the create journal
 		 * code below handle creating setting the flag and
@@ -381,7 +373,8 @@ static void update_feature_set(ext2_filsys fs, char *features)
 			journal_size = -1;
 		sb->s_feature_compat &= ~EXT3_FEATURE_COMPAT_HAS_JOURNAL;
 	}
-	if (dxdir && !old_dxdir) {
+
+	if (FEATURE_ON(E2P_FEATURE_COMPAT, EXT2_FEATURE_COMPAT_DIR_INDEX)) {
 		if (!sb->s_def_hash_version)
 			sb->s_def_hash_version = EXT2_HASH_TEA;
 		if (uuid_is_null((unsigned char *) sb->s_hash_seed))
@@ -392,14 +385,18 @@ static void update_feature_set(ext2_filsys fs, char *features)
 	    (sb->s_feature_compat || sb->s_feature_ro_compat ||
 	     sb->s_feature_incompat))
 		ext2fs_update_dynamic_rev(fs);
-	if ((sparse != old_sparse) ||
-	    (filetype != old_filetype)) {
+
+	if (FEATURE_CHANGED(E2P_FEATURE_RO_INCOMPAT,
+			    EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER) ||
+	    FEATURE_CHANGED(E2P_FEATURE_INCOMPAT,
+			    EXT2_FEATURE_INCOMPAT_FILETYPE)) {
 		sb->s_state &= ~EXT2_VALID_FS;
 		printf("\n%s\n", _(please_fsck));
 	}
-	if ((old_compat != sb->s_feature_compat) ||
-	    (old_ro_compat != sb->s_feature_ro_compat) ||
-	    (old_incompat != sb->s_feature_incompat))
+
+	if ((old_features[E2P_FEATURE_COMPAT] != sb->s_feature_compat) ||
+	    (old_features[E2P_FEATURE_INCOMPAT] != sb->s_feature_incompat) ||
+	    (old_features[E2P_FEATURE_RO_INCOMPAT] != sb->s_feature_ro_compat))
 		ext2fs_mark_super_dirty(fs);
 }