Merge branch 'linus' into core/softlockup

Conflicts:

	kernel/softlockup.c

Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 274 insertions, 94 deletions

diff --git a/fs/gfs2/locking/dlm/lock.c b/fs/gfs2/locking/dlm/lock.c
index cf7ea8abec8..2482c904750 100644
--- a/fs/gfs2/locking/dlm/lock.c
+++ b/fs/gfs2/locking/dlm/lock.c
@@ -11,46 +11,60 @@
 
 static char junk_lvb[GDLM_LVB_SIZE];
 
-static void queue_complete(struct gdlm_lock *lp)
+
+/* convert dlm lock-mode to gfs lock-state */
+
+static s16 gdlm_make_lmstate(s16 dlmmode)
 {
-	struct gdlm_ls *ls = lp->ls;
+	switch (dlmmode) {
+	case DLM_LOCK_IV:
+	case DLM_LOCK_NL:
+		return LM_ST_UNLOCKED;
+	case DLM_LOCK_EX:
+		return LM_ST_EXCLUSIVE;
+	case DLM_LOCK_CW:
+		return LM_ST_DEFERRED;
+	case DLM_LOCK_PR:
+		return LM_ST_SHARED;
+	}
+	gdlm_assert(0, "unknown DLM mode %d", dlmmode);
+	return -1;
+}
 
-	clear_bit(LFL_ACTIVE, &lp->flags);
+/* 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->clist, &ls->complete);
+	list_add_tail(&lp->delay_list, &ls->submit);
 	spin_unlock(&ls->async_lock);
 	wake_up(&ls->thread_wait);
 }
 
-static inline void gdlm_ast(void *astarg)
+static void wake_up_ast(struct gdlm_lock *lp)
 {
-	queue_complete(astarg);
+	clear_bit(LFL_AST_WAIT, &lp->flags);
+	smp_mb__after_clear_bit();
+	wake_up_bit(&lp->flags, LFL_AST_WAIT);
 }
 
-static inline void gdlm_bast(void *astarg, int mode)
+static void gdlm_delete_lp(struct gdlm_lock *lp)
 {
-	struct gdlm_lock *lp = astarg;
 	struct gdlm_ls *ls = lp->ls;
 
-	if (!mode) {
-		printk(KERN_INFO "lock_dlm: bast mode zero %x,%llx\n",
-			lp->lockname.ln_type,
-			(unsigned long long)lp->lockname.ln_number);
-		return;
-	}
-
 	spin_lock(&ls->async_lock);
-	if (!lp->bast_mode) {
-		list_add_tail(&lp->blist, &ls->blocking);
-		lp->bast_mode = mode;
-	} else if (lp->bast_mode < mode)
-		lp->bast_mode = mode;
+	if (!list_empty(&lp->delay_list))
+		list_del_init(&lp->delay_list);
+	ls->all_locks_count--;
 	spin_unlock(&ls->async_lock);
-	wake_up(&ls->thread_wait);
+
+	kfree(lp);
 }
 
-void gdlm_queue_delayed(struct gdlm_lock *lp)
+static void gdlm_queue_delayed(struct gdlm_lock *lp)
 {
 	struct gdlm_ls *ls = lp->ls;
 
@@ -59,6 +73,236 @@ void gdlm_queue_delayed(struct gdlm_lock *lp)
 	spin_unlock(&ls->async_lock);
 }
 
+static void process_complete(struct gdlm_lock *lp)
+{
+	struct gdlm_ls *ls = lp->ls;
+	struct lm_async_cb acb;
+
+	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);
+		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);
+
+	ls->fscb(ls->sdp, LM_CB_ASYNC, &acb);
+}
+
+static void gdlm_ast(void *astarg)
+{
+	struct gdlm_lock *lp = astarg;
+	clear_bit(LFL_ACTIVE, &lp->flags);
+	process_complete(lp);
+}
+
+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", bast_mode);
+	}
+
+	ls->fscb(ls->sdp, cb, &lp->lockname);
+}
+
+
+static void gdlm_bast(void *astarg, int mode)
+{
+	struct gdlm_lock *lp = astarg;
+
+	if (!mode) {
+		printk(KERN_INFO "lock_dlm: bast mode zero %x,%llx\n",
+			lp->lockname.ln_type,
+			(unsigned long long)lp->lockname.ln_number);
+		return;
+	}
+
+	process_blocking(lp, mode);
+}
+
 /* convert gfs lock-state to dlm lock-mode */
 
 static s16 make_mode(s16 lmstate)
@@ -77,24 +321,6 @@ static s16 make_mode(s16 lmstate)
 	return -1;
 }
 
-/* convert dlm lock-mode to gfs lock-state */
-
-s16 gdlm_make_lmstate(s16 dlmmode)
-{
-	switch (dlmmode) {
-	case DLM_LOCK_IV:
-	case DLM_LOCK_NL:
-		return LM_ST_UNLOCKED;
-	case DLM_LOCK_EX:
-		return LM_ST_EXCLUSIVE;
-	case DLM_LOCK_CW:
-		return LM_ST_DEFERRED;
-	case DLM_LOCK_PR:
-		return LM_ST_SHARED;
-	}
-	gdlm_assert(0, "unknown DLM mode %d", dlmmode);
-	return -1;
-}
 
 /* verify agreement with GFS on the current lock state, NB: DLM_LOCK_NL and
    DLM_LOCK_IV are both considered LM_ST_UNLOCKED by GFS. */
@@ -134,14 +360,6 @@ static inline unsigned int make_flags(struct gdlm_lock *lp,
 
 	if (lp->lksb.sb_lkid != 0) {
 		lkf |= DLM_LKF_CONVERT;
-
-		/* Conversion deadlock avoidance by DLM */
-
-		if (!(lp->ls->fsflags & LM_MFLAG_CONV_NODROP) &&
-		    !test_bit(LFL_FORCE_PROMOTE, &lp->flags) &&
-		    !(lkf & DLM_LKF_NOQUEUE) &&
-		    cur > DLM_LOCK_NL && req > DLM_LOCK_NL && cur != req)
-			lkf |= DLM_LKF_CONVDEADLK;
 	}
 
 	if (lp->lvb)
@@ -173,14 +391,9 @@ static int gdlm_create_lp(struct gdlm_ls *ls, struct lm_lockname *name,
 	make_strname(name, &lp->strname);
 	lp->ls = ls;
 	lp->cur = DLM_LOCK_IV;
-	lp->lvb = NULL;
-	lp->hold_null = NULL;
-	INIT_LIST_HEAD(&lp->clist);
-	INIT_LIST_HEAD(&lp->blist);
 	INIT_LIST_HEAD(&lp->delay_list);
 
 	spin_lock(&ls->async_lock);
-	list_add(&lp->all_list, &ls->all_locks);
 	ls->all_locks_count++;
 	spin_unlock(&ls->async_lock);
 
@@ -188,26 +401,6 @@ static int gdlm_create_lp(struct gdlm_ls *ls, struct lm_lockname *name,
 	return 0;
 }
 
-void gdlm_delete_lp(struct gdlm_lock *lp)
-{
-	struct gdlm_ls *ls = lp->ls;
-
-	spin_lock(&ls->async_lock);
-	if (!list_empty(&lp->clist))
-		list_del_init(&lp->clist);
-	if (!list_empty(&lp->blist))
-		list_del_init(&lp->blist);
-	if (!list_empty(&lp->delay_list))
-		list_del_init(&lp->delay_list);
-	gdlm_assert(!list_empty(&lp->all_list), "%x,%llx", lp->lockname.ln_type,
-		    (unsigned long long)lp->lockname.ln_number);
-	list_del_init(&lp->all_list);
-	ls->all_locks_count--;
-	spin_unlock(&ls->async_lock);
-
-	kfree(lp);
-}
-
 int gdlm_get_lock(void *lockspace, struct lm_lockname *name,
 		  void **lockp)
 {
@@ -261,7 +454,7 @@ unsigned int gdlm_do_lock(struct gdlm_lock *lp)
 
 	if ((error == -EAGAIN) && (lp->lkf & DLM_LKF_NOQUEUE)) {
 		lp->lksb.sb_status = -EAGAIN;
-		queue_complete(lp);
+		gdlm_ast(lp);
 		error = 0;
 	}
 
@@ -308,6 +501,12 @@ unsigned int gdlm_lock(void *lock, unsigned int cur_state,
 {
 	struct gdlm_lock *lp = lock;
 
+	if (req_state == LM_ST_UNLOCKED)
+		return gdlm_unlock(lock, cur_state);
+
+	if (req_state == LM_ST_UNLOCKED)
+		return gdlm_unlock(lock, cur_state);
+
 	clear_bit(LFL_DLM_CANCEL, &lp->flags);
 	if (flags & LM_FLAG_NOEXP)
 		set_bit(LFL_NOBLOCK, &lp->flags);
@@ -351,7 +550,7 @@ void gdlm_cancel(void *lock)
 	if (delay_list) {
 		set_bit(LFL_CANCEL, &lp->flags);
 		set_bit(LFL_ACTIVE, &lp->flags);
-		queue_complete(lp);
+		gdlm_ast(lp);
 		return;
 	}
 
@@ -507,22 +706,3 @@ void gdlm_submit_delayed(struct gdlm_ls *ls)
 	wake_up(&ls->thread_wait);
 }
 
-int gdlm_release_all_locks(struct gdlm_ls *ls)
-{
-	struct gdlm_lock *lp, *safe;
-	int count = 0;
-
-	spin_lock(&ls->async_lock);
-	list_for_each_entry_safe(lp, safe, &ls->all_locks, all_list) {
-		list_del_init(&lp->all_list);
-
-		if (lp->lvb && lp->lvb != junk_lvb)
-			kfree(lp->lvb);
-		kfree(lp);
-		count++;
-	}
-	spin_unlock(&ls->async_lock);
-
-	return count;
-}
-