[PATCH 111/118] drbd: Removed drbd_state_lock() and drbd_state_unlock()

Philipp Reisner
2011-08-25T15:12:42Z

The lock they constructed is only taken when the state_mutex
was already taken. It is superficial.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
---
drivers/block/drbd/drbd_int.h | 18 ------------------
drivers/block/drbd/drbd_receiver.c | 5 +++--
drivers/block/drbd/drbd_state.c | 4 ----
drivers/block/drbd/drbd_worker.c | 10 +++++-----
4 files changed, 8 insertions(+), 29 deletions(-)

diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index 0ea0b15..d5e45c2 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -763,7 +763,6 @@ enum {
UNPLUG_REMOTE, /* sending a "UnplugRemote" could help */
MD_DIRTY, /* current uuids and flags not yet on disk */
USE_DEGR_WFC_T, /* degr-wfc-timeout instead of wfc-timeout. */
- CLUSTER_ST_CHANGE, /* Cluster wide state change going on... */
CL_ST_CHG_SUCCESS,
CL_ST_CHG_FAIL,
CRASHED_PRIMARY, /* This node was a crashed primary.
@@ -1663,23 +1662,6 @@ static inline int drbd_ee_has_active_page(struct drbd_peer_request *peer_req)
return 0;
}

-
-
-
-
-
-static inline void drbd_state_lock(struct drbd_conf *mdev)
-{
- wait_event(mdev->misc_wait,
- !test_and_set_bit(CLUSTER_ST_CHANGE, &mdev->flags));
-}
-
-static inline void drbd_state_unlock(struct drbd_conf *mdev)
-{
- clear_bit(CLUSTER_ST_CHANGE, &mdev->flags);
- wake_up(&mdev->misc_wait);
-}
-
static inline enum drbd_state_rv
_drbd_set_state(struct drbd_conf *mdev, union drbd_state ns,
enum chg_state_flags flags, struct completion *done)
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index f755134..6a30180 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -3170,7 +3170,8 @@ static int receive_uuids(struct drbd_conf *mdev, enum drbd_packet cmd,
ongoing cluster wide state change is finished. That is important if
we are primary and are detaching from our disk. We need to see the
new disk state... */
- wait_event(mdev->misc_wait, !test_bit(CLUSTER_ST_CHANGE, &mdev->flags));
+ mutex_lock(&mdev->state_mutex);
+ mutex_unlock(&mdev->state_mutex);
if (mdev->state.conn >= C_CONNECTED && mdev->state.disk < D_INCONSISTENT)
updated_uuids |= drbd_set_ed_uuid(mdev, p_uuid[UI_CURRENT]);

@@ -3221,7 +3222,7 @@ static int receive_req_state(struct drbd_conf *mdev, enum drbd_packet cmd,
val.i = be32_to_cpu(p->val);

if (test_bit(DISCARD_CONCURRENT, &mdev->tconn->flags) &&
- test_bit(CLUSTER_ST_CHANGE, &mdev->flags)) {
+ mutex_is_locked(&mdev->state_mutex)) {
drbd_send_sr_reply(mdev, SS_CONCURRENT_ST_CHG);
return true;
}
diff --git a/drivers/block/drbd/drbd_state.c b/drivers/block/drbd/drbd_state.c
index 405ed12..bb05d67 100644
--- a/drivers/block/drbd/drbd_state.c
+++ b/drivers/block/drbd/drbd_state.c
@@ -184,9 +184,7 @@ drbd_req_state(struct drbd_conf *mdev, union drbd_state mask,
goto abort;
}

- drbd_state_lock(mdev);
if (!drbd_send_state_req(mdev, mask, val)) {
- drbd_state_unlock(mdev);
rv = SS_CW_FAILED_BY_PEER;
if (f & CS_VERBOSE)
print_st_err(mdev, os, ns, rv);
@@ -197,7 +195,6 @@ drbd_req_state(struct drbd_conf *mdev, union drbd_state mask,
(rv = _req_st_cond(mdev, mask, val)));

if (rv < SS_SUCCESS) {
- drbd_state_unlock(mdev);
if (f & CS_VERBOSE)
print_st_err(mdev, os, ns, rv);
goto abort;
@@ -205,7 +202,6 @@ drbd_req_state(struct drbd_conf *mdev, union drbd_state mask,
spin_lock_irqsave(&mdev->tconn->req_lock, flags);
ns = apply_mask_val(mdev->state, mask, val);
rv = _drbd_set_state(mdev, ns, f, &done);
- drbd_state_unlock(mdev);
} else {
rv = _drbd_set_state(mdev, ns, f, &done);
}
diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c
index eee017d..e844871 100644
--- a/drivers/block/drbd/drbd_worker.c
+++ b/drivers/block/drbd/drbd_worker.c
@@ -1536,21 +1536,21 @@ void drbd_start_resync(struct drbd_conf *mdev, enum drbd_conns side)
}

if (current == mdev->tconn->worker.task) {
- /* The worker should not sleep waiting for drbd_state_lock(),
+ /* The worker should not sleep waiting for state_mutex,
that can take long */
- if (test_and_set_bit(CLUSTER_ST_CHANGE, &mdev->flags)) {
+ if (!mutex_trylock(&mdev->state_mutex)) {
set_bit(B_RS_H_DONE, &mdev->flags);
mdev->start_resync_timer.expires = jiffies + HZ/5;
add_timer(&mdev->start_resync_timer);
return;
}
} else {
- drbd_state_lock(mdev);
+ mutex_lock(&mdev->state_mutex);
}
clear_bit(B_RS_H_DONE, &mdev->flags);

if (!get_ldev_if_state(mdev, D_NEGOTIATING)) {
- drbd_state_unlock(mdev);
+ mutex_unlock(&mdev->state_mutex);
return;
}

@@ -1639,7 +1639,7 @@ void drbd_start_resync(struct drbd_conf *mdev, enum drbd_conns side)
drbd_md_sync(mdev);
}
put_ldev(mdev);
- drbd_state_unlock(mdev);
+ mutex_unlock(&mdev->state_mutex);
}

static int _worker_dying(int vnr, void *p, void *data)
--
1.7.4.1