diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c index c7c6cf9e8685..04e3f15aa0cc 100644 --- a/fs/dlm/lock.c +++ b/fs/dlm/lock.c @@ -2279,10 +2279,14 @@ static int conversion_deadlock_detect(struct dlm_rsb *r, struct dlm_lkb *lkb2) * immediate request, it is 0 if called later, after the lock has been * queued. * + * recover is 1 if dlm_recover_grant() is trying to grant conversions + * after recovery. + * * References are from chapter 6 of "VAXcluster Principles" by Roy Davis */ -static int _can_be_granted(struct dlm_rsb *r, struct dlm_lkb *lkb, int now) +static int _can_be_granted(struct dlm_rsb *r, struct dlm_lkb *lkb, int now, + int recover) { int8_t conv = (lkb->lkb_grmode != DLM_LOCK_IV); @@ -2314,7 +2318,7 @@ static int _can_be_granted(struct dlm_rsb *r, struct dlm_lkb *lkb, int now) */ if (queue_conflict(&r->res_grantqueue, lkb)) - goto out; + return 0; /* * 6-3: By default, a conversion request is immediately granted if the @@ -2323,7 +2327,24 @@ static int _can_be_granted(struct dlm_rsb *r, struct dlm_lkb *lkb, int now) */ if (queue_conflict(&r->res_convertqueue, lkb)) - goto out; + return 0; + + /* + * The RECOVER_GRANT flag means dlm_recover_grant() is granting + * locks for a recovered rsb, on which lkb's have been rebuilt. + * The lkb's may have been rebuilt on the queues in a different + * order than they were in on the previous master. So, granting + * queued conversions in order after recovery doesn't make sense + * since the order hasn't been preserved anyway. The new order + * could also have created a new "in place" conversion deadlock. + * (e.g. old, failed master held granted EX, with PR->EX, NL->EX. + * After recovery, there would be no granted locks, and possibly + * NL->EX, PR->EX, an in-place conversion deadlock.) So, after + * recovery, grant conversions without considering order. + */ + + if (conv && recover) + return 1; /* * 6-5: But the default algorithm for deciding whether to grant or @@ -2360,7 +2381,7 @@ static int _can_be_granted(struct dlm_rsb *r, struct dlm_lkb *lkb, int now) if (list_empty(&r->res_convertqueue)) return 1; else - goto out; + return 0; } /* @@ -2406,12 +2427,12 @@ static int _can_be_granted(struct dlm_rsb *r, struct dlm_lkb *lkb, int now) if (!now && !conv && list_empty(&r->res_convertqueue) && first_in_list(lkb, &r->res_waitqueue)) return 1; - out: + return 0; } static int can_be_granted(struct dlm_rsb *r, struct dlm_lkb *lkb, int now, - int *err) + int recover, int *err) { int rv; int8_t alt = 0, rqmode = lkb->lkb_rqmode; @@ -2420,7 +2441,7 @@ static int can_be_granted(struct dlm_rsb *r, struct dlm_lkb *lkb, int now, if (err) *err = 0; - rv = _can_be_granted(r, lkb, now); + rv = _can_be_granted(r, lkb, now, recover); if (rv) goto out; @@ -2461,7 +2482,7 @@ static int can_be_granted(struct dlm_rsb *r, struct dlm_lkb *lkb, int now, if (alt) { lkb->lkb_rqmode = alt; - rv = _can_be_granted(r, lkb, now); + rv = _can_be_granted(r, lkb, now, 0); if (rv) lkb->lkb_sbflags |= DLM_SBF_ALTMODE; else @@ -2485,6 +2506,7 @@ static int grant_pending_convert(struct dlm_rsb *r, int high, int *cw, unsigned int *count) { struct dlm_lkb *lkb, *s; + int recover = rsb_flag(r, RSB_RECOVER_GRANT); int hi, demoted, quit, grant_restart, demote_restart; int deadlk; @@ -2498,7 +2520,7 @@ static int grant_pending_convert(struct dlm_rsb *r, int high, int *cw, demoted = is_demoted(lkb); deadlk = 0; - if (can_be_granted(r, lkb, 0, &deadlk)) { + if (can_be_granted(r, lkb, 0, recover, &deadlk)) { grant_lock_pending(r, lkb); grant_restart = 1; if (count) @@ -2542,7 +2564,7 @@ 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)) { + if (can_be_granted(r, lkb, 0, 0, NULL)) { grant_lock_pending(r, lkb); if (count) (*count)++; @@ -3042,7 +3064,7 @@ static int do_request(struct dlm_rsb *r, struct dlm_lkb *lkb) { int error = 0; - if (can_be_granted(r, lkb, 1, NULL)) { + if (can_be_granted(r, lkb, 1, 0, NULL)) { grant_lock(r, lkb); queue_cast(r, lkb, 0); goto out; @@ -3082,7 +3104,7 @@ static int do_convert(struct dlm_rsb *r, struct dlm_lkb *lkb) /* changing an existing lock may allow others to be granted */ - if (can_be_granted(r, lkb, 1, &deadlk)) { + if (can_be_granted(r, lkb, 1, 0, &deadlk)) { grant_lock(r, lkb); queue_cast(r, lkb, 0); goto out; @@ -3108,7 +3130,7 @@ static int do_convert(struct dlm_rsb *r, struct dlm_lkb *lkb) if (is_demoted(lkb)) { grant_pending_convert(r, DLM_LOCK_IV, NULL, NULL); - if (_can_be_granted(r, lkb, 1)) { + if (_can_be_granted(r, lkb, 1, 0)) { grant_lock(r, lkb); queue_cast(r, lkb, 0); goto out; @@ -5373,9 +5395,10 @@ static struct dlm_rsb *find_grant_rsb(struct dlm_ls *ls, int bucket) if (!rsb_flag(r, RSB_RECOVER_GRANT)) continue; - rsb_clear_flag(r, RSB_RECOVER_GRANT); - if (!is_master(r)) + if (!is_master(r)) { + rsb_clear_flag(r, RSB_RECOVER_GRANT); continue; + } hold_rsb(r); spin_unlock(&ls->ls_rsbtbl[bucket].lock); return r; @@ -5420,7 +5443,9 @@ void dlm_recover_grant(struct dlm_ls *ls) rsb_count++; count = 0; lock_rsb(r); + /* the RECOVER_GRANT flag is checked in the grant path */ grant_pending_locks(r, &count); + rsb_clear_flag(r, RSB_RECOVER_GRANT); lkb_count += count; confirm_master(r, 0); unlock_rsb(r); diff --git a/fs/dlm/recover.c b/fs/dlm/recover.c index 12702cc533b3..4a7a76e42fc3 100644 --- a/fs/dlm/recover.c +++ b/fs/dlm/recover.c @@ -804,6 +804,7 @@ static void recover_lvb(struct dlm_rsb *r) static void recover_conversion(struct dlm_rsb *r) { + struct dlm_ls *ls = r->res_ls; struct dlm_lkb *lkb; int grmode = -1; @@ -818,10 +819,15 @@ static void recover_conversion(struct dlm_rsb *r) list_for_each_entry(lkb, &r->res_convertqueue, lkb_statequeue) { if (lkb->lkb_grmode != DLM_LOCK_IV) continue; - if (grmode == -1) + if (grmode == -1) { + log_debug(ls, "recover_conversion %x set gr to rq %d", + lkb->lkb_id, lkb->lkb_rqmode); lkb->lkb_grmode = lkb->lkb_rqmode; - else + } else { + log_debug(ls, "recover_conversion %x set gr %d", + lkb->lkb_id, grmode); lkb->lkb_grmode = grmode; + } } }