diff options
Diffstat (limited to 'fs/gfs2/locking/dlm/thread.c')
-rw-r--r-- | fs/gfs2/locking/dlm/thread.c | 331 |
1 files changed, 12 insertions, 319 deletions
diff --git a/fs/gfs2/locking/dlm/thread.c b/fs/gfs2/locking/dlm/thread.c index e53db6f..38823ef 100644 --- a/fs/gfs2/locking/dlm/thread.c +++ b/fs/gfs2/locking/dlm/thread.c @@ -9,367 +9,60 @@ #include "lock_dlm.h" -/* A lock placed on this queue is re-submitted to DLM as soon as the lock_dlm - thread gets to it. */ - -static void queue_submit(struct gdlm_lock *lp) -{ - struct gdlm_ls *ls = lp->ls; - - spin_lock(&ls->async_lock); - list_add_tail(&lp->delay_list, &ls->submit); - spin_unlock(&ls->async_lock); - wake_up(&ls->thread_wait); -} - -static void process_blocking(struct gdlm_lock *lp, int bast_mode) -{ - struct gdlm_ls *ls = lp->ls; - unsigned int cb = 0; - - switch (gdlm_make_lmstate(bast_mode)) { - case LM_ST_EXCLUSIVE: - cb = LM_CB_NEED_E; - break; - case LM_ST_DEFERRED: - cb = LM_CB_NEED_D; - break; - case LM_ST_SHARED: - cb = LM_CB_NEED_S; - break; - default: - gdlm_assert(0, "unknown bast mode %u", lp->bast_mode); - } - - ls->fscb(ls->sdp, cb, &lp->lockname); -} - -static void wake_up_ast(struct gdlm_lock *lp) -{ - clear_bit(LFL_AST_WAIT, &lp->flags); - smp_mb__after_clear_bit(); - wake_up_bit(&lp->flags, LFL_AST_WAIT); -} - -static void process_complete(struct gdlm_lock *lp) -{ - struct gdlm_ls *ls = lp->ls; - struct lm_async_cb acb; - s16 prev_mode = lp->cur; - - memset(&acb, 0, sizeof(acb)); - - if (lp->lksb.sb_status == -DLM_ECANCEL) { - log_info("complete dlm cancel %x,%llx flags %lx", - lp->lockname.ln_type, - (unsigned long long)lp->lockname.ln_number, - lp->flags); - - lp->req = lp->cur; - acb.lc_ret |= LM_OUT_CANCELED; - if (lp->cur == DLM_LOCK_IV) - lp->lksb.sb_lkid = 0; - goto out; - } - - if (test_and_clear_bit(LFL_DLM_UNLOCK, &lp->flags)) { - if (lp->lksb.sb_status != -DLM_EUNLOCK) { - log_info("unlock sb_status %d %x,%llx flags %lx", - lp->lksb.sb_status, lp->lockname.ln_type, - (unsigned long long)lp->lockname.ln_number, - lp->flags); - return; - } - - lp->cur = DLM_LOCK_IV; - lp->req = DLM_LOCK_IV; - lp->lksb.sb_lkid = 0; - - if (test_and_clear_bit(LFL_UNLOCK_DELETE, &lp->flags)) { - gdlm_delete_lp(lp); - return; - } - goto out; - } - - if (lp->lksb.sb_flags & DLM_SBF_VALNOTVALID) - memset(lp->lksb.sb_lvbptr, 0, GDLM_LVB_SIZE); - - if (lp->lksb.sb_flags & DLM_SBF_ALTMODE) { - if (lp->req == DLM_LOCK_PR) - lp->req = DLM_LOCK_CW; - else if (lp->req == DLM_LOCK_CW) - lp->req = DLM_LOCK_PR; - } - - /* - * A canceled lock request. The lock was just taken off the delayed - * list and was never even submitted to dlm. - */ - - if (test_and_clear_bit(LFL_CANCEL, &lp->flags)) { - log_info("complete internal cancel %x,%llx", - lp->lockname.ln_type, - (unsigned long long)lp->lockname.ln_number); - lp->req = lp->cur; - acb.lc_ret |= LM_OUT_CANCELED; - goto out; - } - - /* - * An error occured. - */ - - if (lp->lksb.sb_status) { - /* a "normal" error */ - if ((lp->lksb.sb_status == -EAGAIN) && - (lp->lkf & DLM_LKF_NOQUEUE)) { - lp->req = lp->cur; - if (lp->cur == DLM_LOCK_IV) - lp->lksb.sb_lkid = 0; - goto out; - } - - /* this could only happen with cancels I think */ - log_info("ast sb_status %d %x,%llx flags %lx", - lp->lksb.sb_status, lp->lockname.ln_type, - (unsigned long long)lp->lockname.ln_number, - lp->flags); - if (lp->lksb.sb_status == -EDEADLOCK && - lp->ls->fsflags & LM_MFLAG_CONV_NODROP) { - lp->req = lp->cur; - acb.lc_ret |= LM_OUT_CONV_DEADLK; - if (lp->cur == DLM_LOCK_IV) - lp->lksb.sb_lkid = 0; - goto out; - } else - return; - } - - /* - * This is an AST for an EX->EX conversion for sync_lvb from GFS. - */ - - if (test_and_clear_bit(LFL_SYNC_LVB, &lp->flags)) { - wake_up_ast(lp); - return; - } - - /* - * A lock has been demoted to NL because it initially completed during - * BLOCK_LOCKS. Now it must be requested in the originally requested - * mode. - */ - - if (test_and_clear_bit(LFL_REREQUEST, &lp->flags)) { - gdlm_assert(lp->req == DLM_LOCK_NL, "%x,%llx", - lp->lockname.ln_type, - (unsigned long long)lp->lockname.ln_number); - gdlm_assert(lp->prev_req > DLM_LOCK_NL, "%x,%llx", - lp->lockname.ln_type, - (unsigned long long)lp->lockname.ln_number); - - lp->cur = DLM_LOCK_NL; - lp->req = lp->prev_req; - lp->prev_req = DLM_LOCK_IV; - lp->lkf &= ~DLM_LKF_CONVDEADLK; - - set_bit(LFL_NOCACHE, &lp->flags); - - if (test_bit(DFL_BLOCK_LOCKS, &ls->flags) && - !test_bit(LFL_NOBLOCK, &lp->flags)) - gdlm_queue_delayed(lp); - else - queue_submit(lp); - return; - } - - /* - * A request is granted during dlm recovery. It may be granted - * because the locks of a failed node were cleared. In that case, - * there may be inconsistent data beneath this lock and we must wait - * for recovery to complete to use it. When gfs recovery is done this - * granted lock will be converted to NL and then reacquired in this - * granted state. - */ - - if (test_bit(DFL_BLOCK_LOCKS, &ls->flags) && - !test_bit(LFL_NOBLOCK, &lp->flags) && - lp->req != DLM_LOCK_NL) { - - lp->cur = lp->req; - lp->prev_req = lp->req; - lp->req = DLM_LOCK_NL; - lp->lkf |= DLM_LKF_CONVERT; - lp->lkf &= ~DLM_LKF_CONVDEADLK; - - log_debug("rereq %x,%llx id %x %d,%d", - lp->lockname.ln_type, - (unsigned long long)lp->lockname.ln_number, - lp->lksb.sb_lkid, lp->cur, lp->req); - - set_bit(LFL_REREQUEST, &lp->flags); - queue_submit(lp); - return; - } - - /* - * DLM demoted the lock to NL before it was granted so GFS must be - * told it cannot cache data for this lock. - */ - - if (lp->lksb.sb_flags & DLM_SBF_DEMOTED) - set_bit(LFL_NOCACHE, &lp->flags); - -out: - /* - * This is an internal lock_dlm lock - */ - - if (test_bit(LFL_INLOCK, &lp->flags)) { - clear_bit(LFL_NOBLOCK, &lp->flags); - lp->cur = lp->req; - wake_up_ast(lp); - return; - } - - /* - * Normal completion of a lock request. Tell GFS it now has the lock. - */ - - clear_bit(LFL_NOBLOCK, &lp->flags); - lp->cur = lp->req; - - acb.lc_name = lp->lockname; - acb.lc_ret |= gdlm_make_lmstate(lp->cur); - - if (!test_and_clear_bit(LFL_NOCACHE, &lp->flags) && - (lp->cur > DLM_LOCK_NL) && (prev_mode > DLM_LOCK_NL)) - acb.lc_ret |= LM_OUT_CACHEABLE; - - ls->fscb(ls->sdp, LM_CB_ASYNC, &acb); -} - -static inline int no_work(struct gdlm_ls *ls, int blocking) +static inline int no_work(struct gdlm_ls *ls) { int ret; spin_lock(&ls->async_lock); - ret = list_empty(&ls->complete) && list_empty(&ls->submit); - if (ret && blocking) - ret = list_empty(&ls->blocking); + ret = list_empty(&ls->submit); spin_unlock(&ls->async_lock); return ret; } -static inline int check_drop(struct gdlm_ls *ls) -{ - if (!ls->drop_locks_count) - return 0; - - if (time_after(jiffies, ls->drop_time + ls->drop_locks_period * HZ)) { - ls->drop_time = jiffies; - if (ls->all_locks_count >= ls->drop_locks_count) - return 1; - } - return 0; -} - -static int gdlm_thread(void *data, int blist) +static int gdlm_thread(void *data) { struct gdlm_ls *ls = (struct gdlm_ls *) data; struct gdlm_lock *lp = NULL; - uint8_t complete, blocking, submit, drop; - - /* Only thread1 is allowed to do blocking callbacks since gfs - may wait for a completion callback within a blocking cb. */ while (!kthread_should_stop()) { wait_event_interruptible(ls->thread_wait, - !no_work(ls, blist) || kthread_should_stop()); - - complete = blocking = submit = drop = 0; + !no_work(ls) || kthread_should_stop()); spin_lock(&ls->async_lock); - if (blist && !list_empty(&ls->blocking)) { - lp = list_entry(ls->blocking.next, struct gdlm_lock, - blist); - list_del_init(&lp->blist); - blocking = lp->bast_mode; - lp->bast_mode = 0; - } else if (!list_empty(&ls->complete)) { - lp = list_entry(ls->complete.next, struct gdlm_lock, - clist); - list_del_init(&lp->clist); - complete = 1; - } else if (!list_empty(&ls->submit)) { + if (!list_empty(&ls->submit)) { lp = list_entry(ls->submit.next, struct gdlm_lock, delay_list); list_del_init(&lp->delay_list); - submit = 1; + spin_unlock(&ls->async_lock); + gdlm_do_lock(lp); + spin_lock(&ls->async_lock); } - - drop = check_drop(ls); spin_unlock(&ls->async_lock); - - if (complete) - process_complete(lp); - - else if (blocking) - process_blocking(lp, blocking); - - else if (submit) - gdlm_do_lock(lp); - - if (drop) - ls->fscb(ls->sdp, LM_CB_DROPLOCKS, NULL); - - schedule(); } return 0; } -static int gdlm_thread1(void *data) -{ - return gdlm_thread(data, 1); -} - -static int gdlm_thread2(void *data) -{ - return gdlm_thread(data, 0); -} - int gdlm_init_threads(struct gdlm_ls *ls) { struct task_struct *p; int error; - p = kthread_run(gdlm_thread1, ls, "lock_dlm1"); - error = IS_ERR(p); - if (error) { - log_error("can't start lock_dlm1 thread %d", error); - return error; - } - ls->thread1 = p; - - p = kthread_run(gdlm_thread2, ls, "lock_dlm2"); + p = kthread_run(gdlm_thread, ls, "lock_dlm"); error = IS_ERR(p); if (error) { - log_error("can't start lock_dlm2 thread %d", error); - kthread_stop(ls->thread1); + log_error("can't start lock_dlm thread %d", error); return error; } - ls->thread2 = p; + ls->thread = p; return 0; } void gdlm_release_threads(struct gdlm_ls *ls) { - kthread_stop(ls->thread1); - kthread_stop(ls->thread2); + kthread_stop(ls->thread); } |