From cf6620acc0f6fac57968aafef79ab372bdcf6157 Mon Sep 17 00:00:00 2001 From: David Teigland Date: Wed, 24 Feb 2010 11:59:23 -0600 Subject: 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 --- fs/dlm/lock.c | 110 ++++++++++++++++++++++++++++++++++++++++++++-------------- 1 file changed, 84 insertions(+), 26 deletions(-) diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c index e08ea93432b..d0e43a3da88 100644 --- a/fs/dlm/lock.c +++ b/fs/dlm/lock.c @@ -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); -- cgit v1.2.3