diff options
| -rw-r--r-- | fs/dlm/lock.c | 69 |
1 files changed, 55 insertions, 14 deletions
diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c index b455919c1998..2082daf083d8 100644 --- a/fs/dlm/lock.c +++ b/fs/dlm/lock.c @@ -1670,9 +1670,10 @@ static int can_be_granted(struct dlm_rsb *r, struct dlm_lkb *lkb, int now, with a deadlk here, we'd have to generate something like grant_lock with the deadlk error.) */ -/* returns the highest requested mode of all blocked conversions */ +/* Returns the highest requested mode of all blocked conversions; sets + cw if there's a blocked conversion to DLM_LOCK_CW. */ -static int grant_pending_convert(struct dlm_rsb *r, int high) +static int grant_pending_convert(struct dlm_rsb *r, int high, int *cw) { struct dlm_lkb *lkb, *s; int hi, demoted, quit, grant_restart, demote_restart; @@ -1709,6 +1710,9 @@ static int grant_pending_convert(struct dlm_rsb *r, int high) } hi = max_t(int, lkb->lkb_rqmode, hi); + + if (cw && lkb->lkb_rqmode == DLM_LOCK_CW) + *cw = 1; } if (grant_restart) @@ -1721,29 +1725,52 @@ static int grant_pending_convert(struct dlm_rsb *r, int high) return max_t(int, high, hi); } -static int grant_pending_wait(struct dlm_rsb *r, int high) +static int grant_pending_wait(struct dlm_rsb *r, int high, int *cw) { struct dlm_lkb *lkb, *s; list_for_each_entry_safe(lkb, s, &r->res_waitqueue, lkb_statequeue) { if (can_be_granted(r, lkb, 0, NULL)) grant_lock_pending(r, lkb); - else + else { high = max_t(int, lkb->lkb_rqmode, high); + if (lkb->lkb_rqmode == DLM_LOCK_CW) + *cw = 1; + } } return high; } +/* cw of 1 means there's a lock with a rqmode of DLM_LOCK_CW that's blocked + on either the convert or waiting queue. + high is the largest rqmode of all locks blocked on the convert or + waiting queue. */ + +static int lock_requires_bast(struct dlm_lkb *gr, int high, int cw) +{ + if (gr->lkb_grmode == DLM_LOCK_PR && cw) { + if (gr->lkb_highbast < DLM_LOCK_EX) + return 1; + return 0; + } + + if (gr->lkb_highbast < high && + !__dlm_compat_matrix[gr->lkb_grmode+1][high+1]) + return 1; + return 0; +} + static void grant_pending_locks(struct dlm_rsb *r) { struct dlm_lkb *lkb, *s; int high = DLM_LOCK_IV; + int cw = 0; DLM_ASSERT(is_master(r), dlm_dump_rsb(r);); - high = grant_pending_convert(r, high); - high = grant_pending_wait(r, high); + high = grant_pending_convert(r, high, &cw); + high = grant_pending_wait(r, high, &cw); if (high == DLM_LOCK_IV) return; @@ -1751,27 +1778,41 @@ static void grant_pending_locks(struct dlm_rsb *r) /* * If there are locks left on the wait/convert queue then send blocking * ASTs to granted locks based on the largest requested mode (high) - * found above. FIXME: highbast < high comparison not valid for PR/CW. + * found above. */ list_for_each_entry_safe(lkb, s, &r->res_grantqueue, lkb_statequeue) { - if (lkb->lkb_bastaddr && (lkb->lkb_highbast < high) && - !__dlm_compat_matrix[lkb->lkb_grmode+1][high+1]) { - queue_bast(r, lkb, high); + if (lkb->lkb_bastaddr && lock_requires_bast(lkb, high, cw)) { + if (cw && high == DLM_LOCK_PR) + queue_bast(r, lkb, DLM_LOCK_CW); + else + queue_bast(r, lkb, high); lkb->lkb_highbast = high; } } } +static int modes_require_bast(struct dlm_lkb *gr, struct dlm_lkb *rq) +{ + if ((gr->lkb_grmode == DLM_LOCK_PR && rq->lkb_rqmode == DLM_LOCK_CW) || + (gr->lkb_grmode == DLM_LOCK_CW && rq->lkb_rqmode == DLM_LOCK_PR)) { + if (gr->lkb_highbast < DLM_LOCK_EX) + return 1; + return 0; + } + + if (gr->lkb_highbast < rq->lkb_rqmode && !modes_compat(gr, rq)) + return 1; + return 0; +} + static void send_bast_queue(struct dlm_rsb *r, struct list_head *head, struct dlm_lkb *lkb) { struct dlm_lkb *gr; list_for_each_entry(gr, head, lkb_statequeue) { - if (gr->lkb_bastaddr && - gr->lkb_highbast < lkb->lkb_rqmode && - !modes_compat(gr, lkb)) { + if (gr->lkb_bastaddr && modes_require_bast(gr, lkb)) { queue_bast(r, gr, lkb->lkb_rqmode); gr->lkb_highbast = lkb->lkb_rqmode; } @@ -2235,7 +2276,7 @@ static int do_convert(struct dlm_rsb *r, struct dlm_lkb *lkb) before we try again to grant this one. */ if (is_demoted(lkb)) { - grant_pending_convert(r, DLM_LOCK_IV); + grant_pending_convert(r, DLM_LOCK_IV, NULL); if (_can_be_granted(r, lkb, 1)) { grant_lock(r, lkb); queue_cast(r, lkb, 0); |