[PATCH v2 4/5] xen/blkback: move persistent grants flags to bool

Juergen Gross
2018-08-08T14:25:27Z

The struct persistent_gnt flags member is meant to be a bitfield of
different flags. There is only PERSISTENT_GNT_ACTIVE flag left, so
convert it to a bool named "active".

Signed-off-by: Juergen Gross <jgross@suse.com>
---
drivers/block/xen-blkback/blkback.c | 13 ++++++-------
drivers/block/xen-blkback/common.h | 7 +------
2 files changed, 7 insertions(+), 13 deletions(-)

diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index f341ac84b853..2483931a3e01 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -255,8 +255,7 @@ static int add_persistent_gnt(struct xen_blkif_ring *ring,
}
}

- bitmap_zero(persistent_gnt->flags, PERSISTENT_GNT_FLAGS_SIZE);
- set_bit(PERSISTENT_GNT_ACTIVE, persistent_gnt->flags);
+ persistent_gnt->active = true;
/* Add new node and rebalance tree. */
rb_link_node(&(persistent_gnt->node), parent, new);
rb_insert_color(&(persistent_gnt->node), &ring->persistent_gnts);
@@ -280,11 +279,11 @@ static struct persistent_gnt *get_persistent_gnt(struct xen_blkif_ring *ring,
else if (gref > data->gnt)
node = node->rb_right;
else {
- if(test_bit(PERSISTENT_GNT_ACTIVE, data->flags)) {
+ if (data->active) {
pr_alert_ratelimited("requesting a grant already in use\n");
return NULL;
}
- set_bit(PERSISTENT_GNT_ACTIVE, data->flags);
+ data->active = true;
atomic_inc(&ring->persistent_gnt_in_use);
return data;
}
@@ -295,10 +294,10 @@ static struct persistent_gnt *get_persistent_gnt(struct xen_blkif_ring *ring,
static void put_persistent_gnt(struct xen_blkif_ring *ring,
struct persistent_gnt *persistent_gnt)
{
- if(!test_bit(PERSISTENT_GNT_ACTIVE, persistent_gnt->flags))
+ if (!persistent_gnt->active)
pr_alert_ratelimited("freeing a grant already unused\n");
persistent_gnt->last_used = jiffies;
- clear_bit(PERSISTENT_GNT_ACTIVE, persistent_gnt->flags);
+ persistent_gnt->active = false;
atomic_dec(&ring->persistent_gnt_in_use);
}

@@ -429,7 +428,7 @@ static void purge_persistent_gnt(struct xen_blkif_ring *ring)
BUG_ON(persistent_gnt->handle ==
BLKBACK_INVALID_HANDLE);

- if (test_bit(PERSISTENT_GNT_ACTIVE, persistent_gnt->flags))
+ if (persistent_gnt->active)
continue;
if (!scan_used && !persistent_gnt_timeout(persistent_gnt))
continue;
diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen-blkback/common.h
index 7bff72db3b7e..2339b8d39c5e 100644
--- a/drivers/block/xen-blkback/common.h
+++ b/drivers/block/xen-blkback/common.h
@@ -233,11 +233,6 @@ struct xen_vbd {

struct backend_info;

-/* Number of available flags */
-#define PERSISTENT_GNT_FLAGS_SIZE 1
-/* This persistent grant is currently in use */
-#define PERSISTENT_GNT_ACTIVE 0
-
/* Number of requests that we can fit in a ring */
#define XEN_BLKIF_REQS_PER_PAGE 32

@@ -246,7 +241,7 @@ struct persistent_gnt {
grant_ref_t gnt;
grant_handle_t handle;
unsigned long last_used;
- DECLARE_BITMAP(flags, PERSISTENT_GNT_FLAGS_SIZE);
+ bool active;
struct rb_node node;
struct list_head remove_node;
};
--
2.13.7