[PATCH v4 14/16] dax: convert to bitmask for flags

From: Dan Williams
Date: Thu Jun 29 2017 - 14:01:47 EST


In preparation for adding more flags, convert the existing flag to a
bit-flag.

Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
drivers/dax/super.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/dax/super.c b/drivers/dax/super.c
index 9e0160b950d7..8bf71195921b 100644
--- a/drivers/dax/super.c
+++ b/drivers/dax/super.c
@@ -116,13 +116,18 @@ int __bdev_dax_supported(struct super_block *sb, int blocksize)
EXPORT_SYMBOL_GPL(__bdev_dax_supported);
#endif

+enum dax_device_flags {
+ /* !alive + rcu grace period == no new operations / mappings */
+ DAXDEV_ALIVE,
+};
+
/**
* struct dax_device - anchor object for dax services
* @inode: core vfs
* @cdev: optional character interface for "device dax"
* @host: optional name for lookups where the device path is not available
* @private: dax driver private data
- * @alive: !alive + rcu grace period == no new operations / mappings
+ * @flags: state and boolean properties
*/
struct dax_device {
struct hlist_node list;
@@ -130,7 +135,7 @@ struct dax_device {
struct cdev cdev;
const char *host;
void *private;
- bool alive;
+ unsigned long flags;
const struct dax_operations *ops;
};

@@ -197,7 +202,7 @@ EXPORT_SYMBOL_GPL(dax_flush);
bool dax_alive(struct dax_device *dax_dev)
{
lockdep_assert_held(&dax_srcu);
- return dax_dev->alive;
+ return test_bit(DAXDEV_ALIVE, &dax_dev->flags);
}
EXPORT_SYMBOL_GPL(dax_alive);

@@ -217,7 +222,7 @@ void kill_dax(struct dax_device *dax_dev)
if (!dax_dev)
return;

- dax_dev->alive = false;
+ clear_bit(DAXDEV_ALIVE, &dax_dev->flags);

synchronize_srcu(&dax_srcu);

@@ -257,7 +262,7 @@ static void dax_destroy_inode(struct inode *inode)
{
struct dax_device *dax_dev = to_dax_dev(inode);

- WARN_ONCE(dax_dev->alive,
+ WARN_ONCE(test_bit(DAXDEV_ALIVE, &dax_dev->flags),
"kill_dax() must be called before final iput()\n");
call_rcu(&inode->i_rcu, dax_i_callback);
}
@@ -309,7 +314,7 @@ static struct dax_device *dax_dev_get(dev_t devt)

dax_dev = to_dax_dev(inode);
if (inode->i_state & I_NEW) {
- dax_dev->alive = true;
+ set_bit(DAXDEV_ALIVE, &dax_dev->flags);
inode->i_cdev = &dax_dev->cdev;
inode->i_mode = S_IFCHR;
inode->i_flags = S_DAX;