summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
Diffstat
-rw-r--r--fs/dlm/lock.c55
-rw-r--r--fs/dlm/recover.c10
2 files changed, 48 insertions, 17 deletions
diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c
index c7c6cf9..04e3f15 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 12702cc..4a7a76e 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;
+ }
}
}
OpenPOWER on IntegriCloud