dlm: send reply before bast

When the lock master processes a successful operation (request,
convert, cancel, or unlock), it will process the effects of the
change before sending the reply for the operation.  The "effects"
of the operation are:

- blocking callbacks (basts) for any newly granted locks
- waiting or converting locks that can now be granted

The cast is queued on the local node when the reply from the lock
master is received.  This means that a lock holder can receive a
bast for a lock mode that is doesn't yet know has been granted.

Signed-off-by: David Teigland <teigland@redhat.com>
This commit is contained in:
David Teigland 2010-02-24 11:59:23 -06:00
parent 7fe2b3190b
commit cf6620acc0

View file

@ -2280,20 +2280,30 @@ static int do_request(struct dlm_rsb *r, struct dlm_lkb *lkb)
if (can_be_queued(lkb)) {
error = -EINPROGRESS;
add_lkb(r, lkb, DLM_LKSTS_WAITING);
send_blocking_asts(r, lkb);
add_timeout(lkb);
goto out;
}
error = -EAGAIN;
if (force_blocking_asts(lkb))
send_blocking_asts_all(r, lkb);
queue_cast(r, lkb, -EAGAIN);
out:
return error;
}
static void do_request_effects(struct dlm_rsb *r, struct dlm_lkb *lkb,
int error)
{
switch (error) {
case -EAGAIN:
if (force_blocking_asts(lkb))
send_blocking_asts_all(r, lkb);
break;
case -EINPROGRESS:
send_blocking_asts(r, lkb);
break;
}
}
static int do_convert(struct dlm_rsb *r, struct dlm_lkb *lkb)
{
int error = 0;
@ -2304,7 +2314,6 @@ static int do_convert(struct dlm_rsb *r, struct dlm_lkb *lkb)
if (can_be_granted(r, lkb, 1, &deadlk)) {
grant_lock(r, lkb);
queue_cast(r, lkb, 0);
grant_pending_locks(r);
goto out;
}
@ -2334,7 +2343,6 @@ static int do_convert(struct dlm_rsb *r, struct dlm_lkb *lkb)
if (_can_be_granted(r, lkb, 1)) {
grant_lock(r, lkb);
queue_cast(r, lkb, 0);
grant_pending_locks(r);
goto out;
}
/* else fall through and move to convert queue */
@ -2344,28 +2352,47 @@ static int do_convert(struct dlm_rsb *r, struct dlm_lkb *lkb)
error = -EINPROGRESS;
del_lkb(r, lkb);
add_lkb(r, lkb, DLM_LKSTS_CONVERT);
send_blocking_asts(r, lkb);
add_timeout(lkb);
goto out;
}
error = -EAGAIN;
if (force_blocking_asts(lkb))
send_blocking_asts_all(r, lkb);
queue_cast(r, lkb, -EAGAIN);
out:
return error;
}
static void do_convert_effects(struct dlm_rsb *r, struct dlm_lkb *lkb,
int error)
{
switch (error) {
case 0:
grant_pending_locks(r);
/* grant_pending_locks also sends basts */
break;
case -EAGAIN:
if (force_blocking_asts(lkb))
send_blocking_asts_all(r, lkb);
break;
case -EINPROGRESS:
send_blocking_asts(r, lkb);
break;
}
}
static int do_unlock(struct dlm_rsb *r, struct dlm_lkb *lkb)
{
remove_lock(r, lkb);
queue_cast(r, lkb, -DLM_EUNLOCK);
grant_pending_locks(r);
return -DLM_EUNLOCK;
}
static void do_unlock_effects(struct dlm_rsb *r, struct dlm_lkb *lkb,
int error)
{
grant_pending_locks(r);
}
/* returns: 0 did nothing, -DLM_ECANCEL canceled lock */
static int do_cancel(struct dlm_rsb *r, struct dlm_lkb *lkb)
@ -2375,12 +2402,18 @@ static int do_cancel(struct dlm_rsb *r, struct dlm_lkb *lkb)
error = revert_lock(r, lkb);
if (error) {
queue_cast(r, lkb, -DLM_ECANCEL);
grant_pending_locks(r);
return -DLM_ECANCEL;
}
return 0;
}
static void do_cancel_effects(struct dlm_rsb *r, struct dlm_lkb *lkb,
int error)
{
if (error)
grant_pending_locks(r);
}
/*
* Four stage 3 varieties:
* _request_lock(), _convert_lock(), _unlock_lock(), _cancel_lock()
@ -2402,11 +2435,15 @@ static int _request_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
goto out;
}
if (is_remote(r))
if (is_remote(r)) {
/* receive_request() calls do_request() on remote node */
error = send_request(r, lkb);
else
} else {
error = do_request(r, lkb);
/* for remote locks the request_reply is sent
between do_request and do_request_effects */
do_request_effects(r, lkb, error);
}
out:
return error;
}
@ -2417,11 +2454,15 @@ static int _convert_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
{
int error;
if (is_remote(r))
if (is_remote(r)) {
/* receive_convert() calls do_convert() on remote node */
error = send_convert(r, lkb);
else
} else {
error = do_convert(r, lkb);
/* for remote locks the convert_reply is sent
between do_convert and do_convert_effects */
do_convert_effects(r, lkb, error);
}
return error;
}
@ -2432,11 +2473,15 @@ static int _unlock_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
{
int error;
if (is_remote(r))
if (is_remote(r)) {
/* receive_unlock() calls do_unlock() on remote node */
error = send_unlock(r, lkb);
else
} else {
error = do_unlock(r, lkb);
/* for remote locks the unlock_reply is sent
between do_unlock and do_unlock_effects */
do_unlock_effects(r, lkb, error);
}
return error;
}
@ -2447,11 +2492,15 @@ static int _cancel_lock(struct dlm_rsb *r, struct dlm_lkb *lkb)
{
int error;
if (is_remote(r))
if (is_remote(r)) {
/* receive_cancel() calls do_cancel() on remote node */
error = send_cancel(r, lkb);
else
} else {
error = do_cancel(r, lkb);
/* for remote locks the cancel_reply is sent
between do_cancel and do_cancel_effects */
do_cancel_effects(r, lkb, error);
}
return error;
}
@ -3191,6 +3240,7 @@ static void receive_request(struct dlm_ls *ls, struct dlm_message *ms)
attach_lkb(r, lkb);
error = do_request(r, lkb);
send_request_reply(r, lkb, error);
do_request_effects(r, lkb, error);
unlock_rsb(r);
put_rsb(r);
@ -3226,15 +3276,19 @@ static void receive_convert(struct dlm_ls *ls, struct dlm_message *ms)
goto out;
receive_flags(lkb, ms);
error = receive_convert_args(ls, lkb, ms);
if (error)
goto out_reply;
if (error) {
send_convert_reply(r, lkb, error);
goto out;
}
reply = !down_conversion(lkb);
error = do_convert(r, lkb);
out_reply:
if (reply)
send_convert_reply(r, lkb, error);
do_convert_effects(r, lkb, error);
out:
unlock_rsb(r);
put_rsb(r);
@ -3266,13 +3320,16 @@ static void receive_unlock(struct dlm_ls *ls, struct dlm_message *ms)
goto out;
receive_flags(lkb, ms);
error = receive_unlock_args(ls, lkb, ms);
if (error)
goto out_reply;
if (error) {
send_unlock_reply(r, lkb, error);
goto out;
}
error = do_unlock(r, lkb);
out_reply:
send_unlock_reply(r, lkb, error);
do_unlock_effects(r, lkb, error);
out:
unlock_rsb(r);
put_rsb(r);
@ -3307,6 +3364,7 @@ static void receive_cancel(struct dlm_ls *ls, struct dlm_message *ms)
error = do_cancel(r, lkb);
send_cancel_reply(r, lkb, error);
do_cancel_effects(r, lkb, error);
out:
unlock_rsb(r);
put_rsb(r);