drbd: rcu_read_[un]lock() for all idr accesses that do not sleep

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 563427b..5abbdaf 100644 (file)
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -453,8 +453,10 @@ void tl_clear(struct drbd_tconn *tconn)
        }
 
        /* ensure bit indicating barrier is required is clear */
+       rcu_read_lock();
        idr_for_each_entry(&tconn->volumes, mdev, vnr)
                clear_bit(CREATE_BARRIER, &mdev->flags);
+       rcu_read_unlock();
 
        spin_unlock_irq(&tconn->req_lock);
 }
@@ -634,13 +636,15 @@ char *drbd_task_to_thread_name(struct drbd_tconn *tconn, struct task_struct *tas
 
 int conn_lowest_minor(struct drbd_tconn *tconn)
 {
-       int vnr = 0;
        struct drbd_conf *mdev;
+       int vnr = 0, m;
 
+       rcu_read_lock();
        mdev = idr_get_next(&tconn->volumes, &vnr);
-       if (!mdev)
-               return -1;
-       return mdev_to_minor(mdev);
+       m = mdev ? mdev_to_minor(mdev) : -1;
+       rcu_read_unlock();
+
+       return m;
 }
 
 #ifdef CONFIG_SMP

diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index f08fb6f..60c171b 100644 (file)
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -372,12 +372,14 @@ static enum drbd_fencing_p highest_fencing_policy(struct drbd_tconn *tconn)
        struct drbd_conf *mdev;
        int vnr;
 
+       rcu_read_lock();
        idr_for_each_entry(&tconn->volumes, mdev, vnr) {
                if (get_ldev_if_state(mdev, D_CONSISTENT)) {
                        fp = max_t(enum drbd_fencing_p, fp, mdev->ldev->dc.fencing);
                        put_ldev(mdev);
                }
        }
+       rcu_read_unlock();
 
        return fp;
 }
@@ -1624,29 +1626,41 @@ out:
 static bool conn_resync_running(struct drbd_tconn *tconn)
 {
        struct drbd_conf *mdev;
+       bool rv = false;
        int vnr;
 
+       rcu_read_lock();
        idr_for_each_entry(&tconn->volumes, mdev, vnr) {
                if (mdev->state.conn == C_SYNC_SOURCE ||
                    mdev->state.conn == C_SYNC_TARGET ||
                    mdev->state.conn == C_PAUSED_SYNC_S ||
-                   mdev->state.conn == C_PAUSED_SYNC_T)
-                       return true;
+                   mdev->state.conn == C_PAUSED_SYNC_T) {
+                       rv = true;
+                       break;
+               }
        }
-       return false;
+       rcu_read_unlock();
+
+       return rv;
 }
 
 static bool conn_ov_running(struct drbd_tconn *tconn)
 {
        struct drbd_conf *mdev;
+       bool rv = false;
        int vnr;
 
+       rcu_read_lock();
        idr_for_each_entry(&tconn->volumes, mdev, vnr) {
                if (mdev->state.conn == C_VERIFY_S ||
-                   mdev->state.conn == C_VERIFY_T)
-                       return true;
+                   mdev->state.conn == C_VERIFY_T) {
+                       rv = true;
+                       break;
+               }
        }
-       return false;
+       rcu_read_unlock();
+
+       return rv;
 }
 
 int drbd_adm_net_opts(struct sk_buff *skb, struct genl_info *info)
@@ -1858,26 +1872,28 @@ int drbd_adm_connect(struct sk_buff *skb, struct genl_info *info)
                goto fail;
        }
 
+       rcu_read_lock();
        idr_for_each_entry(&tconn->volumes, mdev, i) {
                if (get_ldev(mdev)) {
                        enum drbd_fencing_p fp = mdev->ldev->dc.fencing;
                        put_ldev(mdev);
                        if (new_conf->wire_protocol == DRBD_PROT_A && fp == FP_STONITH) {
                                retcode = ERR_STONITH_AND_PROT_A;
-                               goto fail;
+                               goto fail_rcu_unlock;
                        }
                }
                if (mdev->state.role == R_PRIMARY && new_conf->want_lose) {
                        retcode = ERR_DISCARD;
-                       goto fail;
+                       goto fail_rcu_unlock;
                }
                if (!mdev->bitmap) {
                        if(drbd_bm_init(mdev)) {
                                retcode = ERR_NOMEM;
-                               goto fail;
+                               goto fail_rcu_unlock;
                        }
                }
        }
+       rcu_read_unlock();
 
        if (new_conf->on_congestion != OC_BLOCK && new_conf->wire_protocol != DRBD_PROT_A) {
                retcode = ERR_CONG_NOT_PROTO_A;
@@ -1991,15 +2007,19 @@ int drbd_adm_connect(struct sk_buff *skb, struct genl_info *info)
        retcode = _conn_request_state(tconn, NS(conn, C_UNCONNECTED), CS_VERBOSE);
        spin_unlock_irq(&tconn->req_lock);
 
+       rcu_read_lock();
        idr_for_each_entry(&tconn->volumes, mdev, i) {
                mdev->send_cnt = 0;
                mdev->recv_cnt = 0;
                kobject_uevent(&disk_to_dev(mdev->vdisk)->kobj, KOBJ_CHANGE);
        }
+       rcu_read_unlock();
        conn_reconfig_done(tconn);
        drbd_adm_finish(info, retcode);
        return 0;
 
+fail_rcu_unlock:
+       rcu_read_unlock();
 fail:
        kfree(int_dig_in);
        kfree(int_dig_vv);
@@ -2562,8 +2582,6 @@ 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);
-       /* synchronize with drbd_delete_device */
-       rcu_read_lock();
 next_tconn:
        /* revalidate iterator position */
        list_for_each_entry(tmp, &drbd_tconns, all_tconn) {
@@ -2624,7 +2642,6 @@ next_tconn:
         }
 
 out:
-       rcu_read_unlock();
        mutex_unlock(&drbd_cfg_mutex);
        /* where to start the next iteration */
         cb->args[0] = (long)pos;

diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 7e635b2..2b0b0ab 100644 (file)
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -4828,11 +4828,13 @@ static int tconn_finish_peer_reqs(struct drbd_tconn *tconn)
                set_bit(SIGNAL_ASENDER, &tconn->flags);
 
                spin_lock_irq(&tconn->req_lock);
+               rcu_read_lock();
                idr_for_each_entry(&tconn->volumes, mdev, i) {
                        not_empty = !list_empty(&mdev->done_ee);
                        if (not_empty)
                                break;
                }
+               rcu_read_unlock();
                spin_unlock_irq(&tconn->req_lock);
        } while (not_empty);
 

diff --git a/drivers/block/drbd/drbd_state.c b/drivers/block/drbd/drbd_state.c
index c479577..52ebd9a 100644 (file)
--- a/drivers/block/drbd/drbd_state.c
+++ b/drivers/block/drbd/drbd_state.c
@@ -55,15 +55,21 @@ static inline bool is_susp(union drbd_state s)
 bool conn_all_vols_unconf(struct drbd_tconn *tconn)
 {
        struct drbd_conf *mdev;
+       bool rv = true;
        int vnr;
 
+       rcu_read_lock();
        idr_for_each_entry(&tconn->volumes, mdev, vnr) {
                if (mdev->state.disk != D_DISKLESS ||
                    mdev->state.conn != C_STANDALONE ||
-                   mdev->state.role != R_SECONDARY)
-                       return false;
+                   mdev->state.role != R_SECONDARY) {
+                       rv = false;
+                       break;
+               }
        }
-       return true;
+       rcu_read_unlock();
+
+       return rv;
 }
 
 /* Unfortunately the states where not correctly ordered, when
@@ -91,8 +97,10 @@ enum drbd_role conn_highest_role(struct drbd_tconn *tconn)
        struct drbd_conf *mdev;
        int vnr;
 
+       rcu_read_lock();
        idr_for_each_entry(&tconn->volumes, mdev, vnr)
                role = max_role(role, mdev->state.role);
+       rcu_read_unlock();
 
        return role;
 }
@@ -103,8 +111,10 @@ enum drbd_role conn_highest_peer(struct drbd_tconn *tconn)
        struct drbd_conf *mdev;
        int vnr;
 
+       rcu_read_lock();
        idr_for_each_entry(&tconn->volumes, mdev, vnr)
                peer = max_role(peer, mdev->state.peer);
+       rcu_read_unlock();
 
        return peer;
 }
@@ -115,8 +125,10 @@ enum drbd_disk_state conn_highest_disk(struct drbd_tconn *tconn)
        struct drbd_conf *mdev;
        int vnr;
 
+       rcu_read_lock();
        idr_for_each_entry(&tconn->volumes, mdev, vnr)
                ds = max_t(enum drbd_disk_state, ds, mdev->state.disk);
+       rcu_read_unlock();
 
        return ds;
 }
@@ -127,8 +139,10 @@ enum drbd_disk_state conn_lowest_disk(struct drbd_tconn *tconn)
        struct drbd_conf *mdev;
        int vnr;
 
+       rcu_read_lock();
        idr_for_each_entry(&tconn->volumes, mdev, vnr)
                ds = min_t(enum drbd_disk_state, ds, mdev->state.disk);
+       rcu_read_unlock();
 
        return ds;
 }
@@ -139,8 +153,10 @@ enum drbd_disk_state conn_highest_pdsk(struct drbd_tconn *tconn)
        struct drbd_conf *mdev;
        int vnr;
 
+       rcu_read_lock();
        idr_for_each_entry(&tconn->volumes, mdev, vnr)
                ds = max_t(enum drbd_disk_state, ds, mdev->state.pdsk);
+       rcu_read_unlock();
 
        return ds;
 }
@@ -151,8 +167,10 @@ enum drbd_conns conn_lowest_conn(struct drbd_tconn *tconn)
        struct drbd_conf *mdev;
        int vnr;
 
+       rcu_read_lock();
        idr_for_each_entry(&tconn->volumes, mdev, vnr)
                conn = min_t(enum drbd_conns, conn, mdev->state.conn);
+       rcu_read_unlock();
 
        return conn;
 }
@@ -1406,12 +1424,14 @@ static int w_after_conn_state_ch(struct drbd_work *w, int unused)
                /* case1: The outdate peer handler is successful: */
                if (ns_max.pdsk <= D_OUTDATED) {
                        tl_clear(tconn);
+                       rcu_read_lock();
                        idr_for_each_entry(&tconn->volumes, mdev, vnr) {
                                if (test_bit(NEW_CUR_UUID, &mdev->flags)) {
                                        drbd_uuid_new_current(mdev);
                                        clear_bit(NEW_CUR_UUID, &mdev->flags);
                                }
                        }
+                       rcu_read_unlock();
                        conn_request_state(tconn,
                                           (union drbd_state) { { .susp_fen = 1 } },
                                           (union drbd_state) { { .susp_fen = 0 } },
@@ -1419,8 +1439,10 @@ static int w_after_conn_state_ch(struct drbd_work *w, int unused)
                }
                /* case2: The connection was established again: */
                if (ns_min.conn >= C_CONNECTED) {
+                       rcu_read_lock();
                        idr_for_each_entry(&tconn->volumes, mdev, vnr)
                                clear_bit(NEW_CUR_UUID, &mdev->flags);
+                       rcu_read_unlock();
                        spin_lock_irq(&tconn->req_lock);
                        _tl_restart(tconn, RESEND);
                        _conn_request_state(tconn,
@@ -1445,6 +1467,7 @@ void conn_old_common_state(struct drbd_tconn *tconn, union drbd_state *pcs, enum
        struct drbd_conf *mdev;
        int vnr, first_vol = 1;
 
+       rcu_read_lock();
        idr_for_each_entry(&tconn->volumes, mdev, vnr) {
                os = mdev->state;
 
@@ -1469,6 +1492,7 @@ void conn_old_common_state(struct drbd_tconn *tconn, union drbd_state *pcs, enum
                if (cs.pdsk != os.pdsk)
                        flags &= ~CS_DC_PDSK;
        }
+       rcu_read_unlock();
 
        *pf |= CS_DC_MASK;
        *pf &= flags;
@@ -1484,6 +1508,7 @@ conn_is_valid_transition(struct drbd_tconn *tconn, union drbd_state mask, union
        struct drbd_conf *mdev;
        int vnr;
 
+       rcu_read_lock();
        idr_for_each_entry(&tconn->volumes, mdev, vnr) {
                os = drbd_read_state(mdev);
                ns = sanitize_state(mdev, apply_mask_val(os, mask, val), NULL);
@@ -1509,6 +1534,7 @@ conn_is_valid_transition(struct drbd_tconn *tconn, union drbd_state mask, union
                if (rv < SS_SUCCESS)
                        break;
        }
+       rcu_read_unlock();
 
        if (rv < SS_SUCCESS && flags & CS_VERBOSE)
                print_st_err(mdev, os, ns, rv);
@@ -1534,6 +1560,7 @@ conn_set_state(struct drbd_tconn *tconn, union drbd_state mask, union drbd_state
        if (mask.conn == C_MASK)
                tconn->cstate = val.conn;
 
+       rcu_read_lock();
        idr_for_each_entry(&tconn->volumes, mdev, vnr) {
                os = drbd_read_state(mdev);
                ns = apply_mask_val(os, mask, val);
@@ -1559,6 +1586,7 @@ conn_set_state(struct drbd_tconn *tconn, union drbd_state mask, union drbd_state
                ns_min.disk = min_t(enum drbd_disk_state, ns.disk, ns_min.disk);
                ns_min.pdsk = min_t(enum drbd_disk_state, ns.pdsk, ns_min.pdsk);
        }
+       rcu_read_unlock();
 
        ns_min.susp = ns_max.susp = tconn->susp;
        ns_min.susp_nod = ns_max.susp_nod = tconn->susp_nod;

diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c
index ef35bbd..410900e 100644 (file)
--- a/drivers/block/drbd/drbd_worker.c
+++ b/drivers/block/drbd/drbd_worker.c
@@ -1348,6 +1348,7 @@ static int _drbd_pause_after(struct drbd_conf *mdev)
        struct drbd_conf *odev;
        int i, rv = 0;
 
+       rcu_read_lock();
        idr_for_each_entry(&minors, odev, i) {
                if (odev->state.conn == C_STANDALONE && odev->state.disk == D_DISKLESS)
                        continue;
@@ -1355,6 +1356,7 @@ static int _drbd_pause_after(struct drbd_conf *mdev)
                        rv |= (__drbd_set_state(_NS(odev, aftr_isp, 1), CS_HARD, NULL)
                               != SS_NOTHING_TO_DO);
        }
+       rcu_read_unlock();
 
        return rv;
 }
@@ -1370,6 +1372,7 @@ static int _drbd_resume_next(struct drbd_conf *mdev)
        struct drbd_conf *odev;
        int i, rv = 0;
 
+       rcu_read_lock();
        idr_for_each_entry(&minors, odev, i) {
                if (odev->state.conn == C_STANDALONE && odev->state.disk == D_DISKLESS)
                        continue;
@@ -1380,6 +1383,7 @@ static int _drbd_resume_next(struct drbd_conf *mdev)
                                       != SS_NOTHING_TO_DO) ;
                }
        }
+       rcu_read_unlock();
        return rv;
 }