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-rw-r--r--fs/dlm/lock.c82
1 files changed, 80 insertions, 2 deletions
diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c
index eac54d2..d8d6e72 100644
--- a/fs/dlm/lock.c
+++ b/fs/dlm/lock.c
@@ -224,6 +224,16 @@ static inline int is_demoted(struct dlm_lkb *lkb)
return (lkb->lkb_sbflags & DLM_SBF_DEMOTED);
}
+static inline int is_altmode(struct dlm_lkb *lkb)
+{
+ return (lkb->lkb_sbflags & DLM_SBF_ALTMODE);
+}
+
+static inline int is_granted(struct dlm_lkb *lkb)
+{
+ return (lkb->lkb_status == DLM_LKSTS_GRANTED);
+}
+
static inline int is_remote(struct dlm_rsb *r)
{
DLM_ASSERT(r->res_nodeid >= 0, dlm_print_rsb(r););
@@ -1191,6 +1201,50 @@ static void grant_lock_pending(struct dlm_rsb *r, struct dlm_lkb *lkb)
queue_cast(r, lkb, 0);
}
+/* The special CONVDEADLK, ALTPR and ALTCW flags allow the master to
+ change the granted/requested modes. We're munging things accordingly in
+ the process copy.
+ CONVDEADLK: our grmode may have been forced down to NL to resolve a
+ conversion deadlock
+ ALTPR/ALTCW: our rqmode may have been changed to PR or CW to become
+ compatible with other granted locks */
+
+static void munge_demoted(struct dlm_lkb *lkb, struct dlm_message *ms)
+{
+ if (ms->m_type != DLM_MSG_CONVERT_REPLY) {
+ log_print("munge_demoted %x invalid reply type %d",
+ lkb->lkb_id, ms->m_type);
+ return;
+ }
+
+ if (lkb->lkb_rqmode == DLM_LOCK_IV || lkb->lkb_grmode == DLM_LOCK_IV) {
+ log_print("munge_demoted %x invalid modes gr %d rq %d",
+ lkb->lkb_id, lkb->lkb_grmode, lkb->lkb_rqmode);
+ return;
+ }
+
+ lkb->lkb_grmode = DLM_LOCK_NL;
+}
+
+static void munge_altmode(struct dlm_lkb *lkb, struct dlm_message *ms)
+{
+ if (ms->m_type != DLM_MSG_REQUEST_REPLY &&
+ ms->m_type != DLM_MSG_GRANT) {
+ log_print("munge_altmode %x invalid reply type %d",
+ lkb->lkb_id, ms->m_type);
+ return;
+ }
+
+ if (lkb->lkb_exflags & DLM_LKF_ALTPR)
+ lkb->lkb_rqmode = DLM_LOCK_PR;
+ else if (lkb->lkb_exflags & DLM_LKF_ALTCW)
+ lkb->lkb_rqmode = DLM_LOCK_CW;
+ else {
+ log_print("munge_altmode invalid exflags %x", lkb->lkb_exflags);
+ dlm_print_lkb(lkb);
+ }
+}
+
static inline int first_in_list(struct dlm_lkb *lkb, struct list_head *head)
{
struct dlm_lkb *first = list_entry(head->next, struct dlm_lkb,
@@ -1965,9 +2019,24 @@ static int do_convert(struct dlm_rsb *r, struct dlm_lkb *lkb)
goto out;
}
- if (can_be_queued(lkb)) {
- if (is_demoted(lkb))
+ /* is_demoted() means the can_be_granted() above set the grmode
+ to NL, and left us on the granted queue. This auto-demotion
+ (due to CONVDEADLK) might mean other locks, and/or this lock, are
+ now grantable. We have to try to grant other converting locks
+ before we try again to grant this one. */
+
+ if (is_demoted(lkb)) {
+ grant_pending_convert(r, DLM_LOCK_IV);
+ if (_can_be_granted(r, lkb, 1)) {
+ grant_lock(r, lkb);
+ queue_cast(r, lkb, 0);
grant_pending_locks(r);
+ goto out;
+ }
+ /* else fall through and move to convert queue */
+ }
+
+ if (can_be_queued(lkb)) {
error = -EINPROGRESS;
del_lkb(r, lkb);
add_lkb(r, lkb, DLM_LKSTS_CONVERT);
@@ -2908,6 +2977,8 @@ static void receive_grant(struct dlm_ls *ls, struct dlm_message *ms)
lock_rsb(r);
receive_flags_reply(lkb, ms);
+ if (is_altmode(lkb))
+ munge_altmode(lkb, ms);
grant_lock_pc(r, lkb, ms);
queue_cast(r, lkb, 0);
@@ -3038,6 +3109,8 @@ static void receive_request_reply(struct dlm_ls *ls, struct dlm_message *ms)
/* request was queued or granted on remote master */
receive_flags_reply(lkb, ms);
lkb->lkb_remid = ms->m_lkid;
+ if (is_altmode(lkb))
+ munge_altmode(lkb, ms);
if (result)
add_lkb(r, lkb, DLM_LKSTS_WAITING);
else {
@@ -3101,6 +3174,9 @@ static void __receive_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb,
case -EINPROGRESS:
/* convert was queued on remote master */
+ receive_flags_reply(lkb, ms);
+ if (is_demoted(lkb))
+ munge_demoted(lkb, ms);
del_lkb(r, lkb);
add_lkb(r, lkb, DLM_LKSTS_CONVERT);
break;
@@ -3108,6 +3184,8 @@ static void __receive_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb,
case 0:
/* convert was granted on remote master */
receive_flags_reply(lkb, ms);
+ if (is_demoted(lkb))
+ munge_demoted(lkb, ms);
grant_lock_pc(r, lkb, ms);
queue_cast(r, lkb, 0);
break;
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