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OpenCloudOS-Kernel
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drbd: protect all idr accesses that might sleep with drbd_cfg_rwsem 

With this commit the locking for all accesses to IDRs is complete:

 * Non sleeping read accesses are protected by RCU
 * sleeping read accesses are protocted by a read lock on drbd_cfg_rwsem
 * accesses that add anything are protected by a write lock
 * accesses that remove an object are protoected by a write lock
   and a call to synchronize_rcu() after it is removed from the IDR
   and before the object is actually free()ed.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
This commit is contained in:
Philipp Reisner 2011-04-13 14:46:05 -07:00
parent ef35626284
commit d3fcb4908d
6 changed files with 22 additions and 3 deletions
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2
drivers/block/drbd/drbd_int.h
View File

@ -172,7 +172,7 @@ extern struct ratelimit_state drbd_ratelimit_state;
extern struct idr minors;
extern struct list_head drbd_tconns;
extern struct rw_semaphore drbd_cfg_rwsem;
/* drbd_cfg_rwsem protects: drbd_tconns list,
/* drbd_cfg_rwsem protects: drbd_tconns list, minors idr, tconn->volumes idr
note: non sleeping iterations over the idrs are protoected by RCU */
/* on the wire */

2
drivers/block/drbd/drbd_main.c
View File

@ -2266,8 +2266,10 @@ static void drbd_cleanup(void)
drbd_genl_unregister();
down_write(&drbd_cfg_rwsem);
idr_for_each_entry(&minors, mdev, i)
drbd_delete_device(mdev);
up_write(&drbd_cfg_rwsem);
drbd_destroy_mempools();
unregister_blkdev(DRBD_MAJOR, "drbd");

4
drivers/block/drbd/drbd_nl.c
View File

@ -328,8 +328,10 @@ static void conn_md_sync(struct drbd_tconn *tconn)
struct drbd_conf *mdev;
int vnr;
down_read(&drbd_cfg_rwsem);
idr_for_each_entry(&tconn->volumes, mdev, vnr)
drbd_md_sync(mdev);
up_read(&drbd_cfg_rwsem);
}
int conn_khelper(struct drbd_tconn *tconn, char *cmd)
@ -2865,7 +2867,9 @@ int drbd_adm_add_minor(struct sk_buff *skb, struct genl_info *info)
goto out;
}
down_write(&drbd_cfg_rwsem);
retcode = conn_new_minor(adm_ctx.tconn, dh->minor, adm_ctx.volume);
up_write(&drbd_cfg_rwsem);
out:
drbd_adm_finish(info, retcode);
return 0;

2
drivers/block/drbd/drbd_proc.c
View File

@ -227,6 +227,7 @@ static int drbd_seq_show(struct seq_file *seq, void *v)
oos .. known out-of-sync kB
*/
down_read(&drbd_cfg_rwsem);
idr_for_each_entry(&minors, mdev, i) {
if (prev_i != i - 1)
seq_printf(seq, "\n");
@ -293,6 +294,7 @@ static int drbd_seq_show(struct seq_file *seq, void *v)
}
}
}
up_read(&drbd_cfg_rwsem);
return 0;
}

13
drivers/block/drbd/drbd_receiver.c
View File

@ -964,7 +964,10 @@ retry:
if (drbd_send_protocol(tconn) == -EOPNOTSUPP)
return -1;
return !idr_for_each(&tconn->volumes, drbd_connected, tconn);
down_read(&drbd_cfg_rwsem);
h = !idr_for_each(&tconn->volumes, drbd_connected, tconn);
up_read(&drbd_cfg_rwsem);
return h;
out_release_sockets:
if (tconn->data.socket) {
@ -4084,7 +4087,9 @@ static void drbd_disconnect(struct drbd_tconn *tconn)
drbd_thread_stop(&tconn->asender);
drbd_free_sock(tconn);
down_read(&drbd_cfg_rwsem);
idr_for_each(&tconn->volumes, drbd_disconnected, tconn);
up_read(&drbd_cfg_rwsem);
conn_info(tconn, "Connection closed\n");
if (conn_highest_role(tconn) == R_PRIMARY && conn_highest_pdsk(tconn) >= D_UNKNOWN)
@ -4821,10 +4826,14 @@ static int tconn_finish_peer_reqs(struct drbd_tconn *tconn)
do {
clear_bit(SIGNAL_ASENDER, &tconn->flags);
flush_signals(current);
down_read(&drbd_cfg_rwsem);
idr_for_each_entry(&tconn->volumes, mdev, i) {
if (drbd_finish_peer_reqs(mdev))
if (drbd_finish_peer_reqs(mdev)) {
up_read(&drbd_cfg_rwsem);
return 1; /* error */
}
}
up_read(&drbd_cfg_rwsem);
set_bit(SIGNAL_ASENDER, &tconn->flags);
spin_lock_irq(&tconn->req_lock);

2
drivers/block/drbd/drbd_worker.c
View File

@ -1731,12 +1731,14 @@ int drbd_worker(struct drbd_thread *thi)
spin_unlock_irq(&tconn->data.work.q_lock);
drbd_thread_stop(&tconn->receiver);
down_read(&drbd_cfg_rwsem);
idr_for_each_entry(&tconn->volumes, mdev, vnr) {
D_ASSERT(mdev->state.disk == D_DISKLESS && mdev->state.conn == C_STANDALONE);
/* _drbd_set_state only uses stop_nowait.
* wait here for the exiting receiver. */
drbd_mdev_cleanup(mdev);
}
up_read(&drbd_cfg_rwsem);
clear_bit(OBJECT_DYING, &tconn->flags);
clear_bit(CONFIG_PENDING, &tconn->flags);
wake_up(&tconn->ping_wait);