jbd2: revert "jbd2: add COW fields to struct jbd2_journal_handle"

This reverts commit 93737456d68ddcb86232f669b83da673dd12e351.

The cow-snapshots effort is no longer active, so remove these extra
fields to shrink down the handle structure.

Signed-off-by: "Theodore Ts'o" <[e-mail]>
Reviewed-by: Jan Kara <[e-mail]>

include/linux/jbd2.h

···
 	int			h_err;
 
 	/* Flags [no locking] */
-	unsigned int	h_sync:1;	/* sync-on-close */
-	unsigned int	h_jdata:1;	/* force data journaling */
-	unsigned int	h_aborted:1;	/* fatal error on handle */
-	unsigned int	h_cowing:1;	/* COWing block to snapshot */
-
-	/* Number of buffers requested by user:
-	 * (before adding the COW credits factor) */
-	unsigned int	h_base_credits:14;
-
-	/* Number of buffers the user is allowed to dirty:
-	 * (counts only buffers dirtied when !h_cowing) */
-	unsigned int	h_user_credits:14;
-
+	unsigned int	h_sync:		1;	/* sync-on-close */
+	unsigned int	h_jdata:	1;	/* force data journaling */
+	unsigned int	h_aborted:	1;	/* fatal error on handle */
 
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 	struct lockdep_map	h_lockdep_map;
-#endif
-
-#ifdef CONFIG_JBD2_DEBUG
-	/* COW debugging counters: */
-	unsigned int h_cow_moved; /* blocks moved to snapshot */
-	unsigned int h_cow_copied; /* blocks copied to snapshot */
-	unsigned int h_cow_ok_jh; /* blocks already COWed during current
-				     transaction */
-	unsigned int h_cow_ok_bitmap; /* blocks not set in COW bitmap */
-	unsigned int h_cow_ok_mapped;/* blocks already mapped in snapshot */
-	unsigned int h_cow_bitmaps; /* COW bitmaps created */
-	unsigned int h_cow_excluded; /* blocks set in exclude bitmap */
 #endif
 };