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Message-Id: <1317386906-19260-5-git-send-email-philipp.reisner@linbit.com>
Date: Fri, 30 Sep 2011 14:48:19 +0200
From: Philipp Reisner <philipp.reisner@...bit.com>
To: linux-kernel@...r.kernel.org, Jens Axboe <axboe@...nel.dk>
Cc: drbd-dev@...ts.linbit.com
Subject: [PATCH 04/11] drbd: Converted drbd_cfg_mutex into drbd_cfg_rwsem
Signed-off-by: Philipp Reisner <philipp.reisner@...bit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@...bit.com>
---
drivers/block/drbd/drbd_int.h | 4 +++-
drivers/block/drbd/drbd_main.c | 10 +++++-----
drivers/block/drbd/drbd_nl.c | 27 ++++++++++++++++-----------
3 files changed, 24 insertions(+), 17 deletions(-)
diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index c49dc08..7896a64 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -171,7 +171,9 @@ drbd_insert_fault(struct drbd_conf *mdev, unsigned int type) {
extern struct ratelimit_state drbd_ratelimit_state;
extern struct idr minors;
extern struct list_head drbd_tconns;
-extern struct mutex drbd_cfg_mutex;
+extern struct rw_semaphore drbd_cfg_rwsem;
+/* drbd_cfg_rwsem protects: drbd_tconns list,
+ note: non sleeping iterations over the idrs are protoected by RCU */
/* on the wire */
enum drbd_packet {
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index c4c0bc5..d48efb4 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -120,7 +120,7 @@ module_param_string(usermode_helper, usermode_helper, sizeof(usermode_helper), 0
*/
struct idr minors;
struct list_head drbd_tconns; /* list of struct drbd_tconn */
-DEFINE_MUTEX(drbd_cfg_mutex);
+DECLARE_RWSEM(drbd_cfg_rwsem);
struct kmem_cache *drbd_request_cache;
struct kmem_cache *drbd_ee_cache; /* peer requests */
@@ -2321,14 +2321,14 @@ struct drbd_tconn *conn_by_name(const char *name)
if (!name || !name[0])
return NULL;
- mutex_lock(&drbd_cfg_mutex);
+ down_read(&drbd_cfg_rwsem);
list_for_each_entry(tconn, &drbd_tconns, all_tconn) {
if (!strcmp(tconn->name, name))
goto found;
}
tconn = NULL;
found:
- mutex_unlock(&drbd_cfg_mutex);
+ up_read(&drbd_cfg_rwsem);
return tconn;
}
@@ -2395,9 +2395,9 @@ struct drbd_tconn *drbd_new_tconn(const char *name)
DRBD_ON_NO_DATA_DEF, /* on_no_data */
};
- mutex_lock(&drbd_cfg_mutex);
+ down_write(&drbd_cfg_rwsem);
list_add_tail(&tconn->all_tconn, &drbd_tconns);
- mutex_unlock(&drbd_cfg_mutex);
+ up_write(&drbd_cfg_rwsem);
return tconn;
diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index fc918d0..5667536 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -1959,7 +1959,7 @@ int drbd_adm_connect(struct sk_buff *skb, struct genl_info *info)
new_my_addr = (struct sockaddr *)&new_conf->my_addr;
new_peer_addr = (struct sockaddr *)&new_conf->peer_addr;
- /* No need to take drbd_cfg_mutex here. All reconfiguration is
+ /* No need to take drbd_cfg_rwsem here. All reconfiguration is
* strictly serialized on genl_lock(). We are protected against
* concurrent reconfiguration/addition/deletion */
list_for_each_entry(oconn, &drbd_tconns, all_tconn) {
@@ -2635,7 +2635,7 @@ int drbd_adm_get_status_all(struct sk_buff *skb, struct netlink_callback *cb)
*/
/* synchronize with drbd_new_tconn/drbd_free_tconn */
- mutex_lock(&drbd_cfg_mutex);
+ down_read(&drbd_cfg_rwsem);
next_tconn:
/* revalidate iterator position */
list_for_each_entry(tmp, &drbd_tconns, all_tconn) {
@@ -2698,7 +2698,7 @@ next_tconn:
}
out:
- mutex_unlock(&drbd_cfg_mutex);
+ up_read(&drbd_cfg_rwsem);
/* where to start the next iteration */
cb->args[0] = (long)pos;
cb->args[1] = (pos == tconn) ? volume + 1 : 0;
@@ -2949,9 +2949,9 @@ int drbd_adm_delete_minor(struct sk_buff *skb, struct genl_info *info)
if (retcode != NO_ERROR)
goto out;
- mutex_lock(&drbd_cfg_mutex);
+ down_write(&drbd_cfg_rwsem);
retcode = adm_delete_minor(adm_ctx.mdev);
- mutex_unlock(&drbd_cfg_mutex);
+ up_write(&drbd_cfg_rwsem);
/* if this was the last volume of this connection,
* this will terminate all threads */
if (retcode == NO_ERROR)
@@ -2979,7 +2979,7 @@ int drbd_adm_down(struct sk_buff *skb, struct genl_info *info)
goto out;
}
- mutex_lock(&drbd_cfg_mutex);
+ down_read(&drbd_cfg_rwsem);
/* demote */
idr_for_each_entry(&adm_ctx.tconn->volumes, mdev, i) {
retcode = drbd_set_role(mdev, R_SECONDARY, 0);
@@ -3006,14 +3006,17 @@ int drbd_adm_down(struct sk_buff *skb, struct genl_info *info)
goto out_unlock;
}
}
+ up_read(&drbd_cfg_rwsem);
/* delete volumes */
+ down_write(&drbd_cfg_rwsem);
idr_for_each_entry(&adm_ctx.tconn->volumes, mdev, i) {
retcode = adm_delete_minor(mdev);
if (retcode != NO_ERROR) {
/* "can not happen" */
drbd_msg_put_info("failed to delete volume");
- goto out_unlock;
+ up_write(&drbd_cfg_rwsem);
+ goto out;
}
}
@@ -3028,10 +3031,12 @@ int drbd_adm_down(struct sk_buff *skb, struct genl_info *info)
/* "can not happen" */
retcode = ERR_CONN_IN_USE;
drbd_msg_put_info("failed to delete connection");
- goto out_unlock;
}
+
+ up_write(&drbd_cfg_rwsem);
+ goto out;
out_unlock:
- mutex_unlock(&drbd_cfg_mutex);
+ up_read(&drbd_cfg_rwsem);
out:
drbd_adm_finish(info, retcode);
return 0;
@@ -3047,14 +3052,14 @@ int drbd_adm_delete_connection(struct sk_buff *skb, struct genl_info *info)
if (retcode != NO_ERROR)
goto out;
- mutex_lock(&drbd_cfg_mutex);
+ down_write(&drbd_cfg_rwsem);
if (conn_lowest_minor(adm_ctx.tconn) < 0) {
drbd_free_tconn(adm_ctx.tconn);
retcode = NO_ERROR;
} else {
retcode = ERR_CONN_IN_USE;
}
- mutex_unlock(&drbd_cfg_mutex);
+ up_write(&drbd_cfg_rwsem);
out:
drbd_adm_finish(info, retcode);
--
1.7.4.1
--
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