[PATCH 2/2] rbd: convert to using flags field

[Alex Elder <elder@dreamhost.com>]

To allow having more than just read-only as Boolean state associated
with an rbd_device, replace the "read_only" field with a more
general "flags" field.  The non-atomic versions of bit operations
are fine for our purposes.

Signed-off-by: Alex Elder <elder@dreamhost.com>
---
  drivers/block/rbd.c |   14 ++++++++++----
  1 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index e7b443a..da38804 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -176,7 +176,8 @@ struct rbd_device {
  	char                    snap_name[RBD_MAX_SNAP_NAME_LEN];
  	u32 cur_snap;	/* index+1 of current snapshot within snap context
  			   0 - for the head */
-	int read_only;
+
+	unsigned long		flags;

  	struct list_head	node;

@@ -187,19 +188,24 @@ struct rbd_device {
  	struct device		dev;
  };

+/* Bit position definitions for the rbd_device->flags */
+enum {
+	RBD_DEV_FLAG_READ_ONLY,
+};
+
  static inline bool rbd_dev_is_readonly(struct rbd_device *rbd_dev)
  {
-	return rbd_dev->read_only;
+	return test_bit(RBD_DEV_FLAG_READ_ONLY, &rbd_dev->flags);
  }

  static inline void rbd_dev_set_readonly(struct rbd_device *rbd_dev)
  {
-	rbd_dev->read_only = true;
+	__set_bit(RBD_DEV_FLAG_READ_ONLY, &rbd_dev->flags);
  }

  static inline void rbd_dev_clear_readonly(struct rbd_device *rbd_dev)
  {
-	rbd_dev->read_only = false;
+	__clear_bit(RBD_DEV_FLAG_READ_ONLY, &rbd_dev->flags);
  }

  static DEFINE_MUTEX(ctl_mutex);	  /* Serialize 
open/close/setup/teardown */
-- 
1.7.5.4