UBIFS: harmonize znode flag helpers

We have 3 znode flags: cow, obsolete, dirty. For the last flag we have a
'ubifs_zn_dirty()' helper function, but for the other 2 flags we use
'test_bit()' directly.

This patch makes the situation more consistent and introduces helpers for the
other 2 flags: 'ubifs_zn_cow()' and 'ubifs_zn_obsolete()'.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
diff --git a/fs/ubifs/commit.c b/fs/ubifs/commit.c
index 8ab03d1..637e076 100644
--- a/fs/ubifs/commit.c
+++ b/fs/ubifs/commit.c
@@ -78,7 +78,7 @@
 	 * If the root TNC node is dirty, we definitely have something to
 	 * commit.
 	 */
-	if (c->zroot.znode && test_bit(DIRTY_ZNODE, &c->zroot.znode->flags))
+	if (c->zroot.znode && ubifs_zn_dirty(c->zroot.znode))
 		return 0;
 
 	/*
diff --git a/fs/ubifs/misc.h b/fs/ubifs/misc.h
index 0b5296a..160cd90 100644
--- a/fs/ubifs/misc.h
+++ b/fs/ubifs/misc.h
@@ -39,6 +39,29 @@
 }
 
 /**
+ * ubifs_zn_obsolete - check if znode is obsolete.
+ * @znode: znode to check
+ *
+ * This helper function returns %1 if @znode is obsolete and %0 otherwise.
+ */
+static inline int ubifs_zn_obsolete(const struct ubifs_znode *znode)
+{
+	return !!test_bit(OBSOLETE_ZNODE, &znode->flags);
+}
+
+/**
+ * ubifs_zn_cow - check if znode has to be copied on write.
+ * @znode: znode to check
+ *
+ * This helper function returns %1 if @znode is has COW flag set and %0
+ * otherwise.
+ */
+static inline int ubifs_zn_cow(const struct ubifs_znode *znode)
+{
+	return !!test_bit(COW_ZNODE, &znode->flags);
+}
+
+/**
  * ubifs_wake_up_bgt - wake up background thread.
  * @c: UBIFS file-system description object
  */
diff --git a/fs/ubifs/tnc.c b/fs/ubifs/tnc.c
index 48b6ee6..b32a537 100644
--- a/fs/ubifs/tnc.c
+++ b/fs/ubifs/tnc.c
@@ -223,7 +223,7 @@
 	__set_bit(DIRTY_ZNODE, &zn->flags);
 	__clear_bit(COW_ZNODE, &zn->flags);
 
-	ubifs_assert(!test_bit(OBSOLETE_ZNODE, &znode->flags));
+	ubifs_assert(!ubifs_zn_obsolete(znode));
 	__set_bit(OBSOLETE_ZNODE, &znode->flags);
 
 	if (znode->level != 0) {
@@ -271,7 +271,7 @@
 	struct ubifs_znode *zn;
 	int err;
 
-	if (!test_bit(COW_ZNODE, &znode->flags)) {
+	if (!ubifs_zn_cow(znode)) {
 		/* znode is not being committed */
 		if (!test_and_set_bit(DIRTY_ZNODE, &znode->flags)) {
 			atomic_long_inc(&c->dirty_zn_cnt);
@@ -2423,7 +2423,7 @@
 	 */
 
 	do {
-		ubifs_assert(!test_bit(OBSOLETE_ZNODE, &znode->flags));
+		ubifs_assert(!ubifs_zn_obsolete(znode));
 		ubifs_assert(ubifs_zn_dirty(znode));
 
 		zp = znode->parent;
@@ -2479,9 +2479,8 @@
 			c->zroot.offs = zbr->offs;
 			c->zroot.len = zbr->len;
 			c->zroot.znode = znode;
-			ubifs_assert(!test_bit(OBSOLETE_ZNODE,
-				     &zp->flags));
-			ubifs_assert(test_bit(DIRTY_ZNODE, &zp->flags));
+			ubifs_assert(!ubifs_zn_obsolete(zp));
+			ubifs_assert(ubifs_zn_dirty(zp));
 			atomic_long_dec(&c->dirty_zn_cnt);
 
 			if (zp->cnext) {
@@ -2865,7 +2864,7 @@
 		struct ubifs_znode *znode = cnext;
 
 		cnext = cnext->cnext;
-		if (test_bit(OBSOLETE_ZNODE, &znode->flags))
+		if (ubifs_zn_obsolete(znode))
 			kfree(znode);
 	} while (cnext && cnext != c->cnext);
 }
diff --git a/fs/ubifs/tnc_commit.c b/fs/ubifs/tnc_commit.c
index 8315387..f50c3e5 100644
--- a/fs/ubifs/tnc_commit.c
+++ b/fs/ubifs/tnc_commit.c
@@ -87,7 +87,7 @@
 	atomic_long_dec(&c->dirty_zn_cnt);
 
 	ubifs_assert(ubifs_zn_dirty(znode));
-	ubifs_assert(test_bit(COW_ZNODE, &znode->flags));
+	ubifs_assert(ubifs_zn_cow(znode));
 
 	__clear_bit(DIRTY_ZNODE, &znode->flags);
 	__clear_bit(COW_ZNODE, &znode->flags);
@@ -639,7 +639,7 @@
 	}
 	cnt += 1;
 	while (1) {
-		ubifs_assert(!test_bit(COW_ZNODE, &znode->flags));
+		ubifs_assert(!ubifs_zn_cow(znode));
 		__set_bit(COW_ZNODE, &znode->flags);
 		znode->alt = 0;
 		cnext = find_next_dirty(znode);
@@ -888,7 +888,7 @@
 		cnext = znode->cnext;
 
 		ubifs_assert(ubifs_zn_dirty(znode));
-		ubifs_assert(test_bit(COW_ZNODE, &znode->flags));
+		ubifs_assert(ubifs_zn_cow(znode));
 
 		/*
 		 * It is important that other threads should see %DIRTY_ZNODE
@@ -983,7 +983,7 @@
 	do {
 		znode = cnext;
 		cnext = znode->cnext;
-		if (test_bit(OBSOLETE_ZNODE, &znode->flags))
+		if (ubifs_zn_obsolete(znode))
 			kfree(znode);
 		else {
 			znode->cnext = NULL;