[PATCH 090/118] drbd: Use and idr data structure to map volume numbers to mdev pointers

Philipp Reisner
2011-08-25T15:10:04Z

drivers/block/drbd/drbd_int.h | 4 +++-
drivers/block/drbd/drbd_main.c | 12 +++++++++++-
2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index 9bd156a..4ececc3 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -40,6 +40,7 @@
#include <linux/major.h>
#include <linux/blkdev.h>
#include <linux/genhd.h>
+#include <linux/idr.h>
#include <net/tcp.h>
#include <linux/lru_cache.h>
#include <linux/prefetch.h>
@@ -915,8 +916,9 @@ struct drbd_tconn { /* is a resource from the config file */
char *name; /* Resource name */
struct list_head all_tconn; /* List of all drbd_tconn, prot by global_state_lock */
struct drbd_conf *volume0; /* TODO: Remove me again */
- unsigned long flags;
+ struct idr volumes; /* <tconn, vnr> to mdev mapping */

+ unsigned long flags;
struct net_conf *net_conf; /* protected by get_net_conf() and put_net_conf() */
atomic_t net_cnt; /* Users of net_conf */
wait_queue_head_t net_cnt_wait;
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index ca40f0a..d7421b6 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -2195,6 +2195,7 @@ struct drbd_tconn *drbd_new_tconn(char *name)

atomic_set(&tconn->net_cnt, 0);
init_waitqueue_head(&tconn->net_cnt_wait);
+ idr_init(&tconn->volumes);

write_lock_irq(&global_state_lock);
list_add(&tconn->all_tconn, &drbd_tconns);
@@ -2214,6 +2215,7 @@ void drbd_free_tconn(struct drbd_tconn *tconn)
write_lock_irq(&global_state_lock);
list_del(&tconn->all_tconn);
write_unlock_irq(&global_state_lock);
+ idr_destroy(&tconn->volumes);

kfree(tconn->name);
kfree(tconn->int_dig_out);
@@ -2228,6 +2230,7 @@ struct drbd_conf *drbd_new_device(unsigned int minor)
struct gendisk *disk;
struct request_queue *q;
char conn_name[9]; /* drbd1234N */
+ int vnr;

/* GFP_KERNEL, we are outside of all write-out paths */
mdev = kzalloc(sizeof(struct drbd_conf), GFP_KERNEL);
@@ -2237,7 +2240,14 @@ struct drbd_conf *drbd_new_device(unsigned int minor)
mdev->tconn = drbd_new_tconn(conn_name);
if (!mdev->tconn)
goto out_no_tconn;
-
+ if (!idr_pre_get(&mdev->tconn->volumes, GFP_KERNEL))
+ goto out_no_cpumask;
+ if (idr_get_new(&mdev->tconn->volumes, mdev, &vnr))
+ goto out_no_cpumask;
+ if (vnr != 0) {
+ dev_err(DEV, "vnr = %d\n", vnr);
+ goto out_no_cpumask;
+ }
if (!zalloc_cpumask_var(&mdev->cpu_mask, GFP_KERNEL))
goto out_no_cpumask;

--
1.7.4.1