diff options
| -rw-r--r-- | fs/dlm/lock.c | 82 |
1 files changed, 80 insertions, 2 deletions
diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c index eac54d230fdc..d8d6e729f96b 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; |