summaryrefslogtreecommitdiffstats
path: root/fs/dlm/lock.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/dlm/lock.c')
-rw-r--r--fs/dlm/lock.c69
1 files changed, 55 insertions, 14 deletions
diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c
index b455919..2082daf 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);
OpenPOWER on IntegriCloud