[PATCH 09/16] drbd: Reworked the unconfiguring and thread stopping code

From: Philipp Reisner
Date: Wed Aug 31 2011 - 11:13:09 EST


* Moved CONFIG_PENDING and DEVICE_DYING from mdev to tconn.
* Renamed drbd_reconfig_start() and drbd_reconfig_done() to
conn_reconfig_start() and conn_reconfig_done().

Signed-off-by: Philipp Reisner <philipp.reisner@xxxxxxxxxx>
Signed-off-by: Lars Ellenberg <lars.ellenberg@xxxxxxxxxx>
---
drivers/block/drbd/drbd_int.h | 18 +++++++----
drivers/block/drbd/drbd_nl.c | 40 ++++++++++++--------------
drivers/block/drbd/drbd_receiver.c | 6 ++--
drivers/block/drbd/drbd_state.c | 54 ++++++++++++++++++++++-------------
drivers/block/drbd/drbd_state.h | 1 +
drivers/block/drbd/drbd_worker.c | 31 ++++++++------------
6 files changed, 80 insertions(+), 70 deletions(-)

diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index e065985..d53fb0f 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -787,12 +787,6 @@ enum {
GO_DISKLESS, /* Disk is being detached, on io-error or admin request. */
WAS_IO_ERROR, /* Local disk failed returned IO error */
RESYNC_AFTER_NEG, /* Resync after online grow after the attach&negotiate finished. */
- CONFIG_PENDING, /* serialization of (re)configuration requests.
- * if set, also prevents the device from dying */
- DEVICE_DYING, /* device became unconfigured,
- * but worker thread is still handling the cleanup.
- * reconfiguring (nl_disk_conf, nl_net_conf) is dissalowed,
- * while this is set. */
RESIZE_PENDING, /* Size change detected locally, waiting for the response from
* the peer, if it changed there as well. */
CONN_DRY_RUN, /* Expect disconnect after resync handshake. */
@@ -921,6 +915,12 @@ enum {
GOT_PING_ACK, /* set when we receive a ping_ack packet, ping_wait gets woken */
CONN_WD_ST_CHG_OKAY,
CONN_WD_ST_CHG_FAIL,
+ CONFIG_PENDING, /* serialization of (re)configuration requests.
+ * if set, also prevents the device from dying */
+ OBJECT_DYING, /* device became unconfigured,
+ * but worker thread is still handling the cleanup.
+ * reconfiguring (nl_disk_conf, nl_net_conf) is dissalowed,
+ * while this is set. */
};

struct drbd_tconn { /* is a resource from the config file */
@@ -1574,7 +1574,11 @@ extern void _drbd_wait_ee_list_empty(struct drbd_conf *mdev,
struct list_head *head);
extern void drbd_set_recv_tcq(struct drbd_conf *mdev, int tcq_enabled);
extern void _drbd_clear_done_ee(struct drbd_conf *mdev, struct list_head *to_be_freed);
-extern void drbd_flush_workqueue(struct drbd_conf *mdev);
+extern void conn_flush_workqueue(struct drbd_tconn *tconn);
+static inline void drbd_flush_workqueue(struct drbd_conf *mdev)
+{
+ conn_flush_workqueue(mdev->tconn);
+}

/* yes, there is kernel_setsockopt, but only since 2.6.18. we don't need to
* mess with get_fs/set_fs, we know we are KERNEL_DS always. */
diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index 0168587..8cdfb46 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -871,29 +871,27 @@ void drbd_reconsider_max_bio_size(struct drbd_conf *mdev)
* or start a new one. Flush any pending work, there may still be an
* after_state_change queued.
*/
-static void drbd_reconfig_start(struct drbd_conf *mdev)
+static void conn_reconfig_start(struct drbd_tconn *tconn)
{
- wait_event(mdev->state_wait, !test_and_set_bit(CONFIG_PENDING, &mdev->flags));
- wait_event(mdev->state_wait, !test_bit(DEVICE_DYING, &mdev->flags));
- drbd_thread_start(&mdev->tconn->worker);
- drbd_flush_workqueue(mdev);
+ wait_event(tconn->ping_wait, !test_and_set_bit(CONFIG_PENDING, &tconn->flags));
+ wait_event(tconn->ping_wait, !test_bit(OBJECT_DYING, &tconn->flags));
+ drbd_thread_start(&tconn->worker);
+ conn_flush_workqueue(tconn);
}

/* if still unconfigured, stops worker again.
* if configured now, clears CONFIG_PENDING.
* wakes potential waiters */
-static void drbd_reconfig_done(struct drbd_conf *mdev)
+static void conn_reconfig_done(struct drbd_tconn *tconn)
{
- spin_lock_irq(&mdev->tconn->req_lock);
- if (mdev->state.disk == D_DISKLESS &&
- mdev->state.conn == C_STANDALONE &&
- mdev->state.role == R_SECONDARY) {
- set_bit(DEVICE_DYING, &mdev->flags);
- drbd_thread_stop_nowait(&mdev->tconn->worker);
+ spin_lock_irq(&tconn->req_lock);
+ if (conn_all_vols_unconf(tconn)) {
+ set_bit(OBJECT_DYING, &tconn->flags);
+ drbd_thread_stop_nowait(&tconn->worker);
} else
- clear_bit(CONFIG_PENDING, &mdev->flags);
- spin_unlock_irq(&mdev->tconn->req_lock);
- wake_up(&mdev->state_wait);
+ clear_bit(CONFIG_PENDING, &tconn->flags);
+ spin_unlock_irq(&tconn->req_lock);
+ wake_up(&tconn->ping_wait);
}

/* Make sure IO is suspended before calling this function(). */
@@ -933,7 +931,7 @@ static int drbd_nl_disk_conf(struct drbd_conf *mdev, struct drbd_nl_cfg_req *nlp
enum drbd_state_rv rv;
int cp_discovered = 0;

- drbd_reconfig_start(mdev);
+ conn_reconfig_start(mdev->tconn);

/* if you want to reconfigure, please tear down first */
if (mdev->state.disk > D_DISKLESS) {
@@ -1279,7 +1277,7 @@ static int drbd_nl_disk_conf(struct drbd_conf *mdev, struct drbd_nl_cfg_req *nlp
kobject_uevent(&disk_to_dev(mdev->vdisk)->kobj, KOBJ_CHANGE);
put_ldev(mdev);
reply->ret_code = retcode;
- drbd_reconfig_done(mdev);
+ conn_reconfig_done(mdev->tconn);
return 0;

force_diskless_dec:
@@ -1300,7 +1298,7 @@ static int drbd_nl_disk_conf(struct drbd_conf *mdev, struct drbd_nl_cfg_req *nlp
lc_destroy(resync_lru);

reply->ret_code = retcode;
- drbd_reconfig_done(mdev);
+ conn_reconfig_done(mdev->tconn);
return 0;
}

@@ -1344,7 +1342,7 @@ static int drbd_nl_net_conf(struct drbd_conf *mdev, struct drbd_nl_cfg_req *nlp,
void *int_dig_vv = NULL;
struct sockaddr *new_my_addr, *new_peer_addr, *taken_addr;

- drbd_reconfig_start(mdev);
+ conn_reconfig_start(mdev->tconn);

if (mdev->state.conn > C_STANDALONE) {
retcode = ERR_NET_CONFIGURED;
@@ -1530,7 +1528,7 @@ static int drbd_nl_net_conf(struct drbd_conf *mdev, struct drbd_nl_cfg_req *nlp,

kobject_uevent(&disk_to_dev(mdev->vdisk)->kobj, KOBJ_CHANGE);
reply->ret_code = retcode;
- drbd_reconfig_done(mdev);
+ conn_reconfig_done(mdev->tconn);
return 0;

fail:
@@ -1543,7 +1541,7 @@ fail:
kfree(new_conf);

reply->ret_code = retcode;
- drbd_reconfig_done(mdev);
+ conn_reconfig_done(mdev->tconn);
return 0;
}

diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 88552e1..b58dc16 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -3935,14 +3935,14 @@ static void drbdd(struct drbd_tconn *tconn)
}
}

-void drbd_flush_workqueue(struct drbd_conf *mdev)
+void conn_flush_workqueue(struct drbd_tconn *tconn)
{
struct drbd_wq_barrier barr;

barr.w.cb = w_prev_work_done;
- barr.w.mdev = mdev;
+ barr.w.tconn = tconn;
init_completion(&barr.done);
- drbd_queue_work(&mdev->tconn->data.work, &barr.w);
+ drbd_queue_work(&tconn->data.work, &barr.w);
wait_for_completion(&barr.done);
}

diff --git a/drivers/block/drbd/drbd_state.c b/drivers/block/drbd/drbd_state.c
index 61c65f5..febefcc 100644
--- a/drivers/block/drbd/drbd_state.c
+++ b/drivers/block/drbd/drbd_state.c
@@ -41,13 +41,29 @@ extern void _tl_restart(struct drbd_conf *mdev, enum drbd_req_event what);
static int w_after_state_ch(struct drbd_work *w, int unused);
static void after_state_ch(struct drbd_conf *mdev, union drbd_state os,
union drbd_state ns, enum chg_state_flags flags);
-static void after_all_state_ch(struct drbd_tconn *tconn, union drbd_state ns);
+static void after_all_state_ch(struct drbd_tconn *tconn);
static enum drbd_state_rv is_valid_state(struct drbd_conf *, union drbd_state);
static enum drbd_state_rv is_valid_soft_transition(union drbd_state, union drbd_state);
static enum drbd_state_rv is_valid_transition(union drbd_state os, union drbd_state ns);
static union drbd_state sanitize_state(struct drbd_conf *mdev, union drbd_state ns,
const char **warn_sync_abort);

+int conn_all_vols_unconf(struct drbd_tconn *tconn)
+{
+ struct drbd_conf *mdev;
+ int minor, uncfg = 1;
+
+ idr_for_each_entry(&tconn->volumes, mdev, minor) {
+ uncfg &= (mdev->state.disk == D_DISKLESS &&
+ mdev->state.conn == C_STANDALONE &&
+ mdev->state.role == R_SECONDARY);
+ if (!uncfg)
+ break;
+ }
+
+ return uncfg;
+}
+
/**
* cl_wide_st_chg() - true if the state change is a cluster wide one
* @mdev: DRBD device.
@@ -744,20 +760,6 @@ __drbd_set_state(struct drbd_conf *mdev, union drbd_state ns,

print_state_change(mdev, os, ns, flags);

- /* solve the race between becoming unconfigured,
- * worker doing the cleanup, and
- * admin reconfiguring us:
- * on (re)configure, first set CONFIG_PENDING,
- * then wait for a potentially exiting worker,
- * start the worker, and schedule one no_op.
- * then proceed with configuration.
- */
- if (ns.disk == D_DISKLESS &&
- ns.conn == C_STANDALONE &&
- ns.role == R_SECONDARY &&
- !test_and_set_bit(CONFIG_PENDING, &mdev->flags))
- set_bit(DEVICE_DYING, &mdev->flags);
-
/* if we are going -> D_FAILED or D_DISKLESS, grab one extra reference
* on the ldev here, to be sure the transition -> D_DISKLESS resp.
* drbd_ldev_destroy() won't happen before our corresponding
@@ -768,6 +770,18 @@ __drbd_set_state(struct drbd_conf *mdev, union drbd_state ns,

mdev->state = ns;

+ /* solve the race between becoming unconfigured,
+ * worker doing the cleanup, and
+ * admin reconfiguring us:
+ * on (re)configure, first set CONFIG_PENDING,
+ * then wait for a potentially exiting worker,
+ * start the worker, and schedule one no_op.
+ * then proceed with configuration.
+ */
+ if(conn_all_vols_unconf(mdev->tconn) &&
+ !test_and_set_bit(CONFIG_PENDING, &mdev->tconn->flags))
+ set_bit(OBJECT_DYING, &mdev->tconn->flags);
+
if (os.disk == D_ATTACHING && ns.disk >= D_NEGOTIATING)
drbd_print_uuids(mdev, "attached to UUIDs");

@@ -1236,7 +1250,7 @@ static void after_state_ch(struct drbd_conf *mdev, union drbd_state os,
resume_next_sg(mdev);
}

- after_all_state_ch(mdev->tconn, ns);
+ after_all_state_ch(mdev->tconn);

drbd_md_sync(mdev);
}
@@ -1248,10 +1262,10 @@ struct after_conn_state_chg_work {
enum chg_state_flags flags;
};

-static void after_all_state_ch(struct drbd_tconn *tconn, union drbd_state ns)
+static void after_all_state_ch(struct drbd_tconn *tconn)
{
- if (ns.disk == D_DISKLESS && ns.conn == C_STANDALONE && ns.role == R_SECONDARY) {
- /* if (test_bit(DEVICE_DYING, &mdev->flags)) TODO: DEVICE_DYING functionality */
+ if (conn_all_vols_unconf(tconn) &&
+ test_bit(OBJECT_DYING, &tconn->flags)) {
drbd_thread_stop_nowait(&tconn->worker);
}
}
@@ -1271,7 +1285,7 @@ static int w_after_conn_state_ch(struct drbd_work *w, int unused)
drbd_thread_start(&tconn->receiver);

//conn_err(tconn, STATE_FMT, STATE_ARGS("nms", nms));
- after_all_state_ch(tconn, nms);
+ after_all_state_ch(tconn);

return 1;
}
diff --git a/drivers/block/drbd/drbd_state.h b/drivers/block/drbd/drbd_state.h
index 5fdbdf0..d9536cd 100644
--- a/drivers/block/drbd/drbd_state.h
+++ b/drivers/block/drbd/drbd_state.h
@@ -91,6 +91,7 @@ conn_request_state(struct drbd_tconn *tconn, union drbd_state mask, union drbd_s
enum chg_state_flags flags);

extern void drbd_resume_al(struct drbd_conf *mdev);
+extern int conn_all_vols_unconf(struct drbd_tconn *tconn);

/**
* drbd_request_state() - Reqest a state change
diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c
index 8ee5c4f..5cb5ffc 100644
--- a/drivers/block/drbd/drbd_worker.c
+++ b/drivers/block/drbd/drbd_worker.c
@@ -1643,29 +1643,13 @@ void drbd_start_resync(struct drbd_conf *mdev, enum drbd_conns side)
mutex_unlock(mdev->state_mutex);
}

-static int _worker_dying(int vnr, void *p, void *data)
-{
- struct drbd_conf *mdev = (struct drbd_conf *)p;
-
- 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_thread_stop(&mdev->tconn->receiver);
- drbd_mdev_cleanup(mdev);
-
- clear_bit(DEVICE_DYING, &mdev->flags);
- clear_bit(CONFIG_PENDING, &mdev->flags);
- wake_up(&mdev->state_wait);
-
- return 0;
-}
-
int drbd_worker(struct drbd_thread *thi)
{
struct drbd_tconn *tconn = thi->tconn;
struct drbd_work *w = NULL;
+ struct drbd_conf *mdev;
LIST_HEAD(work_list);
- int intr = 0;
+ int minor, intr = 0;

while (get_t_state(thi) == RUNNING) {
drbd_thread_current_set_cpu(thi);
@@ -1749,7 +1733,16 @@ int drbd_worker(struct drbd_thread *thi)
*/
spin_unlock_irq(&tconn->data.work.q_lock);

- idr_for_each(&tconn->volumes, _worker_dying, NULL);
+ drbd_thread_stop(&tconn->receiver);
+ idr_for_each_entry(&tconn->volumes, mdev, minor) {
+ 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);
+ }
+ clear_bit(OBJECT_DYING, &tconn->flags);
+ clear_bit(CONFIG_PENDING, &tconn->flags);
+ wake_up(&tconn->ping_wait);

return 0;
}
--
1.7.4.1

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