f2fs: use inner macro and function to clean up codes

In this patch we use below inner macro and function to clean up codes.
1. ADDRS_PER_PAGE
2. SM_I
3. f2fs_readonly

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/file.c

@@ -272,8 +272,7 @@ static loff_t f2fs_seek_block(struct file *file, loff_t offset, int whence)
 			}
 		}
 
-		end_offset = IS_INODE(dn.node_page) ?
-			ADDRS_PER_INODE(F2FS_I(inode)) : ADDRS_PER_BLOCK;
+		end_offset = ADDRS_PER_PAGE(dn.node_page, F2FS_I(inode));
 
 		/* find data/hole in dnode block */
 		for (; dn.ofs_in_node < end_offset;

fs/f2fs/segment.c

@@ -272,13 +272,13 @@ int create_flush_cmd_control(struct f2fs_sb_info *sbi)
 		return -ENOMEM;
 	spin_lock_init(&fcc->issue_lock);
 	init_waitqueue_head(&fcc->flush_wait_queue);
-	sbi->sm_info->cmd_control_info = fcc;
+	SM_I(sbi)->cmd_control_info = fcc;
 	fcc->f2fs_issue_flush = kthread_run(issue_flush_thread, sbi,
 				"f2fs_flush-%u:%u", MAJOR(dev), MINOR(dev));
 	if (IS_ERR(fcc->f2fs_issue_flush)) {
 		err = PTR_ERR(fcc->f2fs_issue_flush);
 		kfree(fcc);
-		sbi->sm_info->cmd_control_info = NULL;
+		SM_I(sbi)->cmd_control_info = NULL;
 		return err;
 	}
 
@@ -287,13 +287,12 @@ int create_flush_cmd_control(struct f2fs_sb_info *sbi)
 
 void destroy_flush_cmd_control(struct f2fs_sb_info *sbi)
 {
-	struct flush_cmd_control *fcc =
-				sbi->sm_info->cmd_control_info;
+	struct flush_cmd_control *fcc = SM_I(sbi)->cmd_control_info;
 
 	if (fcc && fcc->f2fs_issue_flush)
 		kthread_stop(fcc->f2fs_issue_flush);
 	kfree(fcc);
-	sbi->sm_info->cmd_control_info = NULL;
+	SM_I(sbi)->cmd_control_info = NULL;
 }
 
 static void __locate_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno,

fs/f2fs/super.c

@@ -615,7 +615,7 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
 	 * Previous and new state of filesystem is RO,
 	 * so skip checking GC and FLUSH_MERGE conditions.
 	 */
-	if ((sb->s_flags & MS_RDONLY) && (*flags & MS_RDONLY))
+	if (f2fs_readonly(sb) && (*flags & MS_RDONLY))
 		goto skip;
 
 	/*
@@ -642,8 +642,7 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
 	 */
 	if ((*flags & MS_RDONLY) || !test_opt(sbi, FLUSH_MERGE)) {
 		destroy_flush_cmd_control(sbi);
-	} else if (test_opt(sbi, FLUSH_MERGE) &&
-					!sbi->sm_info->cmd_control_info) {
+	} else if (test_opt(sbi, FLUSH_MERGE) && !SM_I(sbi)->cmd_control_info) {
 		err = create_flush_cmd_control(sbi);
 		if (err)
 			goto restore_gc;
@@ -1082,7 +1081,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 	 * If filesystem is not mounted as read-only then
 	 * do start the gc_thread.
 	 */
-	if (!(sb->s_flags & MS_RDONLY)) {
+	if (!f2fs_readonly(sb)) {
 		/* After POR, we can run background GC thread.*/
 		err = start_gc_thread(sbi);
 		if (err)