From d3fcb4908d8cce7f29cff16bbef3b08933148003 Mon Sep 17 00:00:00 2001 From: Philipp Reisner Date: Wed, 13 Apr 2011 14:46:05 -0700 Subject: [PATCH] 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 Signed-off-by: Lars Ellenberg --- drivers/block/drbd/drbd_int.h | 2 +- drivers/block/drbd/drbd_main.c | 2 ++ drivers/block/drbd/drbd_nl.c | 4 ++++ drivers/block/drbd/drbd_proc.c | 2 ++ drivers/block/drbd/drbd_receiver.c | 13 +++++++++++-- drivers/block/drbd/drbd_worker.c | 2 ++ 6 files changed, 22 insertions(+), 3 deletions(-) diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h index 7896a648d4ad..2119d9b02eba 100644 --- a/drivers/block/drbd/drbd_int.h +++ b/drivers/block/drbd/drbd_int.h @@ -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 */ diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c index 86fd4c829005..f298f9c2dbd7 100644 --- a/drivers/block/drbd/drbd_main.c +++ b/drivers/block/drbd/drbd_main.c @@ -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"); diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c index 424dcb30ee1c..dbaffcaf8e1b 100644 --- a/drivers/block/drbd/drbd_nl.c +++ b/drivers/block/drbd/drbd_nl.c @@ -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; diff --git a/drivers/block/drbd/drbd_proc.c b/drivers/block/drbd/drbd_proc.c index a4dbdbc52c15..4025d0883bad 100644 --- a/drivers/block/drbd/drbd_proc.c +++ b/drivers/block/drbd/drbd_proc.c @@ -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; } diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c index 2b0b0ab90f21..fd3859407a05 100644 --- a/drivers/block/drbd/drbd_receiver.c +++ b/drivers/block/drbd/drbd_receiver.c @@ -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); diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c index 410900eb2fff..02cdff2b0814 100644 --- a/drivers/block/drbd/drbd_worker.c +++ b/drivers/block/drbd/drbd_worker.c @@ -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);