xfs: turn ic_state into an enum

ic_state really is a set of different states, even if the values are
encoded as non-conflicting bits and we sometimes use logical and
operations to check for them.  Switch all comparisms to check for
exact values (and use switch statements in a few places to make it
more clear) and turn the values into an implicitly enumerated enum
type.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

fs/xfs/xfs_log_cil.c

@@ -847,7 +847,7 @@ xlog_cil_push(
 		goto out_abort;
 
 	spin_lock(&commit_iclog->ic_callback_lock);
-	if (commit_iclog->ic_state & XLOG_STATE_IOERROR) {
+	if (commit_iclog->ic_state == XLOG_STATE_IOERROR) {
 		spin_unlock(&commit_iclog->ic_callback_lock);
 		goto out_abort;
 	}

fs/xfs/xfs_log_priv.h

@@ -40,15 +40,16 @@ static inline uint xlog_get_client_id(__be32 i)
 /*
  * In core log state
  */
-#define XLOG_STATE_ACTIVE    0x0001 /* Current IC log being written to */
-#define XLOG_STATE_WANT_SYNC 0x0002 /* Want to sync this iclog; no more writes */
-#define XLOG_STATE_SYNCING   0x0004 /* This IC log is syncing */
-#define XLOG_STATE_DONE_SYNC 0x0008 /* Done syncing to disk */
-#define XLOG_STATE_DO_CALLBACK \
-			     0x0010 /* Process callback functions */
-#define XLOG_STATE_CALLBACK  0x0020 /* Callback functions now */
-#define XLOG_STATE_DIRTY     0x0040 /* Dirty IC log, not ready for ACTIVE status*/
-#define XLOG_STATE_IOERROR   0x0080 /* IO error happened in sync'ing log */
+enum xlog_iclog_state {
+	XLOG_STATE_ACTIVE,	/* Current IC log being written to */
+	XLOG_STATE_WANT_SYNC,	/* Want to sync this iclog; no more writes */
+	XLOG_STATE_SYNCING,	/* This IC log is syncing */
+	XLOG_STATE_DONE_SYNC,	/* Done syncing to disk */
+	XLOG_STATE_DO_CALLBACK,	/* Process callback functions */
+	XLOG_STATE_CALLBACK,	/* Callback functions now */
+	XLOG_STATE_DIRTY,	/* Dirty IC log, not ready for ACTIVE status */
+	XLOG_STATE_IOERROR,	/* IO error happened in sync'ing log */
+};
 
 /*
  * Flags to log ticket
@@ -202,7 +203,7 @@ typedef struct xlog_in_core {
 	struct xlog		*ic_log;
 	u32			ic_size;
 	u32			ic_offset;
-	unsigned short		ic_state;
+	enum xlog_iclog_state	ic_state;
 	char			*ic_datap;	/* pointer to iclog data */
 
 	/* Callback structures need their own cacheline */