From 43279e5376017c40b4be9af5bc79cbb4ef6f53d7 Mon Sep 17 00:00:00 2001 From: David Teigland Date: Wed, 28 Jan 2009 14:37:54 -0600 Subject: dlm: clear defunct cancel state When a conversion completes successfully and finds that a cancel of the convert is still in progress (which is now a moot point), preemptively clear the state associated with outstanding cancel. That state could cause a subsequent conversion to be ignored. Also, improve the consistency and content of error and debug messages in this area. Signed-off-by: David Teigland --- fs/dlm/lock.c | 53 +++++++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 45 insertions(+), 8 deletions(-) (limited to 'fs/dlm/lock.c') diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c index 01e7d39c5fb..8cb92046a58 100644 --- a/fs/dlm/lock.c +++ b/fs/dlm/lock.c @@ -835,7 +835,7 @@ static int add_to_waiters(struct dlm_lkb *lkb, int mstype) lkb->lkb_wait_count++; hold_lkb(lkb); - log_debug(ls, "add overlap %x cur %d new %d count %d flags %x", + log_debug(ls, "addwait %x cur %d overlap %d count %d f %x", lkb->lkb_id, lkb->lkb_wait_type, mstype, lkb->lkb_wait_count, lkb->lkb_flags); goto out; @@ -851,7 +851,7 @@ static int add_to_waiters(struct dlm_lkb *lkb, int mstype) list_add(&lkb->lkb_wait_reply, &ls->ls_waiters); out: if (error) - log_error(ls, "add_to_waiters %x error %d flags %x %d %d %s", + log_error(ls, "addwait error %x %d flags %x %d %d %s", lkb->lkb_id, error, lkb->lkb_flags, mstype, lkb->lkb_wait_type, lkb->lkb_resource->res_name); mutex_unlock(&ls->ls_waiters_mutex); @@ -863,23 +863,55 @@ static int add_to_waiters(struct dlm_lkb *lkb, int mstype) request reply on the requestqueue) between dlm_recover_waiters_pre() which set RESEND and dlm_recover_waiters_post() */ -static int _remove_from_waiters(struct dlm_lkb *lkb, int mstype) +static int _remove_from_waiters(struct dlm_lkb *lkb, int mstype, + struct dlm_message *ms) { struct dlm_ls *ls = lkb->lkb_resource->res_ls; int overlap_done = 0; if (is_overlap_unlock(lkb) && (mstype == DLM_MSG_UNLOCK_REPLY)) { + log_debug(ls, "remwait %x unlock_reply overlap", lkb->lkb_id); lkb->lkb_flags &= ~DLM_IFL_OVERLAP_UNLOCK; overlap_done = 1; goto out_del; } if (is_overlap_cancel(lkb) && (mstype == DLM_MSG_CANCEL_REPLY)) { + log_debug(ls, "remwait %x cancel_reply overlap", lkb->lkb_id); lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL; overlap_done = 1; goto out_del; } + /* Cancel state was preemptively cleared by a successful convert, + see next comment, nothing to do. */ + + if ((mstype == DLM_MSG_CANCEL_REPLY) && + (lkb->lkb_wait_type != DLM_MSG_CANCEL)) { + log_debug(ls, "remwait %x cancel_reply wait_type %d", + lkb->lkb_id, lkb->lkb_wait_type); + return -1; + } + + /* Remove for the convert reply, and premptively remove for the + cancel reply. A convert has been granted while there's still + an outstanding cancel on it (the cancel is moot and the result + in the cancel reply should be 0). We preempt the cancel reply + because the app gets the convert result and then can follow up + with another op, like convert. This subsequent op would see the + lingering state of the cancel and fail with -EBUSY. */ + + if ((mstype == DLM_MSG_CONVERT_REPLY) && + (lkb->lkb_wait_type == DLM_MSG_CONVERT) && + is_overlap_cancel(lkb) && ms && !ms->m_result) { + log_debug(ls, "remwait %x convert_reply zap overlap_cancel", + lkb->lkb_id); + lkb->lkb_wait_type = 0; + lkb->lkb_flags &= ~DLM_IFL_OVERLAP_CANCEL; + lkb->lkb_wait_count--; + goto out_del; + } + /* N.B. type of reply may not always correspond to type of original msg due to lookup->request optimization, verify others? */ @@ -888,8 +920,8 @@ static int _remove_from_waiters(struct dlm_lkb *lkb, int mstype) goto out_del; } - log_error(ls, "remove_from_waiters lkid %x flags %x types %d %d", - lkb->lkb_id, lkb->lkb_flags, mstype, lkb->lkb_wait_type); + log_error(ls, "remwait error %x reply %d flags %x no wait_type", + lkb->lkb_id, mstype, lkb->lkb_flags); return -1; out_del: @@ -899,7 +931,7 @@ static int _remove_from_waiters(struct dlm_lkb *lkb, int mstype) this would happen */ if (overlap_done && lkb->lkb_wait_type) { - log_error(ls, "remove_from_waiters %x reply %d give up on %d", + log_error(ls, "remwait error %x reply %d wait_type %d overlap", lkb->lkb_id, mstype, lkb->lkb_wait_type); lkb->lkb_wait_count--; lkb->lkb_wait_type = 0; @@ -921,7 +953,7 @@ static int remove_from_waiters(struct dlm_lkb *lkb, int mstype) int error; mutex_lock(&ls->ls_waiters_mutex); - error = _remove_from_waiters(lkb, mstype); + error = _remove_from_waiters(lkb, mstype, NULL); mutex_unlock(&ls->ls_waiters_mutex); return error; } @@ -936,7 +968,7 @@ static int remove_from_waiters_ms(struct dlm_lkb *lkb, struct dlm_message *ms) if (ms != &ls->ls_stub_ms) mutex_lock(&ls->ls_waiters_mutex); - error = _remove_from_waiters(lkb, ms->m_type); + error = _remove_from_waiters(lkb, ms->m_type, ms); if (ms != &ls->ls_stub_ms) mutex_unlock(&ls->ls_waiters_mutex); return error; @@ -2083,6 +2115,11 @@ static int validate_lock_args(struct dlm_ls *ls, struct dlm_lkb *lkb, lkb->lkb_timeout_cs = args->timeout; rv = 0; out: + if (rv) + log_debug(ls, "validate_lock_args %d %x %x %x %d %d %s", + rv, lkb->lkb_id, lkb->lkb_flags, args->flags, + lkb->lkb_status, lkb->lkb_wait_type, + lkb->lkb_resource->res_name); return rv; } -- cgit v1.2.3-18-g5258 From a536e38125fe5da8ed49690f30c30a8f651cf1f5 Mon Sep 17 00:00:00 2001 From: David Teigland Date: Fri, 27 Feb 2009 15:23:28 -0600 Subject: dlm: ignore cancel on granted lock Return immediately from dlm_unlock(CANCEL) if the lock is granted and not being converted; there's nothing to cancel. Signed-off-by: David Teigland --- fs/dlm/lock.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'fs/dlm/lock.c') diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c index 8cb92046a58..205ec95b347 100644 --- a/fs/dlm/lock.c +++ b/fs/dlm/lock.c @@ -2186,6 +2186,13 @@ static int validate_unlock_args(struct dlm_lkb *lkb, struct dlm_args *args) goto out; } + /* there's nothing to cancel */ + if (lkb->lkb_status == DLM_LKSTS_GRANTED && + !lkb->lkb_wait_type) { + rv = -EBUSY; + goto out; + } + switch (lkb->lkb_wait_type) { case DLM_MSG_LOOKUP: case DLM_MSG_REQUEST: -- cgit v1.2.3-18-g5258