Merge branch 'perf/core' into perf/uprobes

Merge in latest upstream (and the latest perf development tree),
to prepare for tooling changes, and also to pick up v3.4 MM
changes that the uprobes code needs to take care of.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 264 insertions, 351 deletions

diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index e2cc3568c29..6db1fef38bf 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -67,15 +67,10 @@ STATIC void xlog_state_switch_iclogs(xlog_t		*log,
 				     int		eventual_size);
 STATIC void xlog_state_want_sync(xlog_t	*log, xlog_in_core_t *iclog);
 
-/* local functions to manipulate grant head */
-STATIC int  xlog_grant_log_space(xlog_t		*log,
-				 xlog_ticket_t	*xtic);
 STATIC void xlog_grant_push_ail(struct log	*log,
 				int		need_bytes);
 STATIC void xlog_regrant_reserve_log_space(xlog_t	 *log,
 					   xlog_ticket_t *ticket);
-STATIC int xlog_regrant_write_log_space(xlog_t		*log,
-					 xlog_ticket_t  *ticket);
 STATIC void xlog_ungrant_log_space(xlog_t	 *log,
 				   xlog_ticket_t *ticket);
 
@@ -150,78 +145,93 @@ xlog_grant_add_space(
 	} while (head_val != old);
 }
 
-STATIC bool
-xlog_reserveq_wake(
-	struct log		*log,
-	int			*free_bytes)
+STATIC void
+xlog_grant_head_init(
+	struct xlog_grant_head	*head)
+{
+	xlog_assign_grant_head(&head->grant, 1, 0);
+	INIT_LIST_HEAD(&head->waiters);
+	spin_lock_init(&head->lock);
+}
+
+STATIC void
+xlog_grant_head_wake_all(
+	struct xlog_grant_head	*head)
 {
 	struct xlog_ticket	*tic;
-	int			need_bytes;
 
-	list_for_each_entry(tic, &log->l_reserveq, t_queue) {
+	spin_lock(&head->lock);
+	list_for_each_entry(tic, &head->waiters, t_queue)
+		wake_up_process(tic->t_task);
+	spin_unlock(&head->lock);
+}
+
+static inline int
+xlog_ticket_reservation(
+	struct log		*log,
+	struct xlog_grant_head	*head,
+	struct xlog_ticket	*tic)
+{
+	if (head == &log->l_write_head) {
+		ASSERT(tic->t_flags & XLOG_TIC_PERM_RESERV);
+		return tic->t_unit_res;
+	} else {
 		if (tic->t_flags & XLOG_TIC_PERM_RESERV)
-			need_bytes = tic->t_unit_res * tic->t_cnt;
+			return tic->t_unit_res * tic->t_cnt;
 		else
-			need_bytes = tic->t_unit_res;
-
-		if (*free_bytes < need_bytes)
-			return false;
-		*free_bytes -= need_bytes;
-
-		trace_xfs_log_grant_wake_up(log, tic);
-		wake_up(&tic->t_wait);
+			return tic->t_unit_res;
 	}
-
-	return true;
 }
 
 STATIC bool
-xlog_writeq_wake(
+xlog_grant_head_wake(
 	struct log		*log,
+	struct xlog_grant_head	*head,
 	int			*free_bytes)
 {
 	struct xlog_ticket	*tic;
 	int			need_bytes;
 
-	list_for_each_entry(tic, &log->l_writeq, t_queue) {
-		ASSERT(tic->t_flags & XLOG_TIC_PERM_RESERV);
-
-		need_bytes = tic->t_unit_res;
-
+	list_for_each_entry(tic, &head->waiters, t_queue) {
+		need_bytes = xlog_ticket_reservation(log, head, tic);
 		if (*free_bytes < need_bytes)
 			return false;
-		*free_bytes -= need_bytes;
 
-		trace_xfs_log_regrant_write_wake_up(log, tic);
-		wake_up(&tic->t_wait);
+		*free_bytes -= need_bytes;
+		trace_xfs_log_grant_wake_up(log, tic);
+		wake_up_process(tic->t_task);
 	}
 
 	return true;
 }
 
 STATIC int
-xlog_reserveq_wait(
+xlog_grant_head_wait(
 	struct log		*log,
+	struct xlog_grant_head	*head,
 	struct xlog_ticket	*tic,
 	int			need_bytes)
 {
-	list_add_tail(&tic->t_queue, &log->l_reserveq);
+	list_add_tail(&tic->t_queue, &head->waiters);
 
 	do {
 		if (XLOG_FORCED_SHUTDOWN(log))
 			goto shutdown;
 		xlog_grant_push_ail(log, need_bytes);
 
+		__set_current_state(TASK_UNINTERRUPTIBLE);
+		spin_unlock(&head->lock);
+
 		XFS_STATS_INC(xs_sleep_logspace);
-		trace_xfs_log_grant_sleep(log, tic);
 
-		xlog_wait(&tic->t_wait, &log->l_grant_reserve_lock);
+		trace_xfs_log_grant_sleep(log, tic);
+		schedule();
 		trace_xfs_log_grant_wake(log, tic);
 
-		spin_lock(&log->l_grant_reserve_lock);
+		spin_lock(&head->lock);
 		if (XLOG_FORCED_SHUTDOWN(log))
 			goto shutdown;
-	} while (xlog_space_left(log, &log->l_grant_reserve_head) < need_bytes);
+	} while (xlog_space_left(log, &head->grant) < need_bytes);
 
 	list_del_init(&tic->t_queue);
 	return 0;
@@ -230,35 +240,58 @@ shutdown:
 	return XFS_ERROR(EIO);
 }
 
+/*
+ * Atomically get the log space required for a log ticket.
+ *
+ * Once a ticket gets put onto head->waiters, it will only return after the
+ * needed reservation is satisfied.
+ *
+ * This function is structured so that it has a lock free fast path. This is
+ * necessary because every new transaction reservation will come through this
+ * path. Hence any lock will be globally hot if we take it unconditionally on
+ * every pass.
+ *
+ * As tickets are only ever moved on and off head->waiters under head->lock, we
+ * only need to take that lock if we are going to add the ticket to the queue
+ * and sleep. We can avoid taking the lock if the ticket was never added to
+ * head->waiters because the t_queue list head will be empty and we hold the
+ * only reference to it so it can safely be checked unlocked.
+ */
 STATIC int
-xlog_writeq_wait(
+xlog_grant_head_check(
 	struct log		*log,
+	struct xlog_grant_head	*head,
 	struct xlog_ticket	*tic,
-	int			need_bytes)
+	int			*need_bytes)
 {
-	list_add_tail(&tic->t_queue, &log->l_writeq);
-
-	do {
-		if (XLOG_FORCED_SHUTDOWN(log))
-			goto shutdown;
-		xlog_grant_push_ail(log, need_bytes);
-
-		XFS_STATS_INC(xs_sleep_logspace);
-		trace_xfs_log_regrant_write_sleep(log, tic);
+	int			free_bytes;
+	int			error = 0;
 
-		xlog_wait(&tic->t_wait, &log->l_grant_write_lock);
-		trace_xfs_log_regrant_write_wake(log, tic);
+	ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
 
-		spin_lock(&log->l_grant_write_lock);
-		if (XLOG_FORCED_SHUTDOWN(log))
-			goto shutdown;
-	} while (xlog_space_left(log, &log->l_grant_write_head) < need_bytes);
+	/*
+	 * If there are other waiters on the queue then give them a chance at
+	 * logspace before us.  Wake up the first waiters, if we do not wake
+	 * up all the waiters then go to sleep waiting for more free space,
+	 * otherwise try to get some space for this transaction.
+	 */
+	*need_bytes = xlog_ticket_reservation(log, head, tic);
+	free_bytes = xlog_space_left(log, &head->grant);
+	if (!list_empty_careful(&head->waiters)) {
+		spin_lock(&head->lock);
+		if (!xlog_grant_head_wake(log, head, &free_bytes) ||
+		    free_bytes < *need_bytes) {
+			error = xlog_grant_head_wait(log, head, tic,
+						     *need_bytes);
+		}
+		spin_unlock(&head->lock);
+	} else if (free_bytes < *need_bytes) {
+		spin_lock(&head->lock);
+		error = xlog_grant_head_wait(log, head, tic, *need_bytes);
+		spin_unlock(&head->lock);
+	}
 
-	list_del_init(&tic->t_queue);
-	return 0;
-shutdown:
-	list_del_init(&tic->t_queue);
-	return XFS_ERROR(EIO);
+	return error;
 }
 
 static void
@@ -286,6 +319,128 @@ xlog_tic_add_region(xlog_ticket_t *tic, uint len, uint type)
 }
 
 /*
+ * Replenish the byte reservation required by moving the grant write head.
+ */
+int
+xfs_log_regrant(
+	struct xfs_mount	*mp,
+	struct xlog_ticket	*tic)
+{
+	struct log		*log = mp->m_log;
+	int			need_bytes;
+	int			error = 0;
+
+	if (XLOG_FORCED_SHUTDOWN(log))
+		return XFS_ERROR(EIO);
+
+	XFS_STATS_INC(xs_try_logspace);
+
+	/*
+	 * This is a new transaction on the ticket, so we need to change the
+	 * transaction ID so that the next transaction has a different TID in
+	 * the log. Just add one to the existing tid so that we can see chains
+	 * of rolling transactions in the log easily.
+	 */
+	tic->t_tid++;
+
+	xlog_grant_push_ail(log, tic->t_unit_res);
+
+	tic->t_curr_res = tic->t_unit_res;
+	xlog_tic_reset_res(tic);
+
+	if (tic->t_cnt > 0)
+		return 0;
+
+	trace_xfs_log_regrant(log, tic);
+
+	error = xlog_grant_head_check(log, &log->l_write_head, tic,
+				      &need_bytes);
+	if (error)
+		goto out_error;
+
+	xlog_grant_add_space(log, &log->l_write_head.grant, need_bytes);
+	trace_xfs_log_regrant_exit(log, tic);
+	xlog_verify_grant_tail(log);
+	return 0;
+
+out_error:
+	/*
+	 * If we are failing, make sure the ticket doesn't have any current
+	 * reservations.  We don't want to add this back when the ticket/
+	 * transaction gets cancelled.
+	 */
+	tic->t_curr_res = 0;
+	tic->t_cnt = 0;	/* ungrant will give back unit_res * t_cnt. */
+	return error;
+}
+
+/*
+ * Reserve log space and return a ticket corresponding the reservation.
+ *
+ * Each reservation is going to reserve extra space for a log record header.
+ * When writes happen to the on-disk log, we don't subtract the length of the
+ * log record header from any reservation.  By wasting space in each
+ * reservation, we prevent over allocation problems.
+ */
+int
+xfs_log_reserve(
+	struct xfs_mount	*mp,
+	int		 	unit_bytes,
+	int		 	cnt,
+	struct xlog_ticket	**ticp,
+	__uint8_t	 	client,
+	bool			permanent,
+	uint		 	t_type)
+{
+	struct log		*log = mp->m_log;
+	struct xlog_ticket	*tic;
+	int			need_bytes;
+	int			error = 0;
+
+	ASSERT(client == XFS_TRANSACTION || client == XFS_LOG);
+
+	if (XLOG_FORCED_SHUTDOWN(log))
+		return XFS_ERROR(EIO);
+
+	XFS_STATS_INC(xs_try_logspace);
+
+	ASSERT(*ticp == NULL);
+	tic = xlog_ticket_alloc(log, unit_bytes, cnt, client, permanent,
+				KM_SLEEP | KM_MAYFAIL);
+	if (!tic)
+		return XFS_ERROR(ENOMEM);
+
+	tic->t_trans_type = t_type;
+	*ticp = tic;
+
+	xlog_grant_push_ail(log, tic->t_unit_res * tic->t_cnt);
+
+	trace_xfs_log_reserve(log, tic);
+
+	error = xlog_grant_head_check(log, &log->l_reserve_head, tic,
+				      &need_bytes);
+	if (error)
+		goto out_error;
+
+	xlog_grant_add_space(log, &log->l_reserve_head.grant, need_bytes);
+	xlog_grant_add_space(log, &log->l_write_head.grant, need_bytes);
+	trace_xfs_log_reserve_exit(log, tic);
+	xlog_verify_grant_tail(log);
+	return 0;
+
+out_error:
+	/*
+	 * If we are failing, make sure the ticket doesn't have any current
+	 * reservations.  We don't want to add this back when the ticket/
+	 * transaction gets cancelled.
+	 */
+	tic->t_curr_res = 0;
+	tic->t_cnt = 0;	/* ungrant will give back unit_res * t_cnt. */
+	return error;
+}
+
+
+/*
  * NOTES:
  *
  *	1. currblock field gets updated at startup and after in-core logs
@@ -395,88 +550,6 @@ xfs_log_release_iclog(
 }
 
 /*
- *  1. Reserve an amount of on-disk log space and return a ticket corresponding
- *	to the reservation.
- *  2. Potentially, push buffers at tail of log to disk.
- *
- * Each reservation is going to reserve extra space for a log record header.
- * When writes happen to the on-disk log, we don't subtract the length of the
- * log record header from any reservation.  By wasting space in each
- * reservation, we prevent over allocation problems.
- */
-int
-xfs_log_reserve(
-	struct xfs_mount	*mp,
-	int		 	unit_bytes,
-	int		 	cnt,
-	struct xlog_ticket	**ticket,
-	__uint8_t	 	client,
-	uint		 	flags,
-	uint		 	t_type)
-{
-	struct log		*log = mp->m_log;
-	struct xlog_ticket	*internal_ticket;
-	int			retval = 0;
-
-	ASSERT(client == XFS_TRANSACTION || client == XFS_LOG);
-
-	if (XLOG_FORCED_SHUTDOWN(log))
-		return XFS_ERROR(EIO);
-
-	XFS_STATS_INC(xs_try_logspace);
-
-
-	if (*ticket != NULL) {
-		ASSERT(flags & XFS_LOG_PERM_RESERV);
-		internal_ticket = *ticket;
-
-		/*
-		 * this is a new transaction on the ticket, so we need to
-		 * change the transaction ID so that the next transaction has a
-		 * different TID in the log. Just add one to the existing tid
-		 * so that we can see chains of rolling transactions in the log
-		 * easily.
-		 */
-		internal_ticket->t_tid++;
-
-		trace_xfs_log_reserve(log, internal_ticket);
-
-		xlog_grant_push_ail(log, internal_ticket->t_unit_res);
-		retval = xlog_regrant_write_log_space(log, internal_ticket);
-	} else {
-		/* may sleep if need to allocate more tickets */
-		internal_ticket = xlog_ticket_alloc(log, unit_bytes, cnt,
-						  client, flags,
-						  KM_SLEEP|KM_MAYFAIL);
-		if (!internal_ticket)
-			return XFS_ERROR(ENOMEM);
-		internal_ticket->t_trans_type = t_type;
-		*ticket = internal_ticket;
-
-		trace_xfs_log_reserve(log, internal_ticket);
-
-		xlog_grant_push_ail(log,
-				    (internal_ticket->t_unit_res *
-				     internal_ticket->t_cnt));
-		retval = xlog_grant_log_space(log, internal_ticket);
-	}
-
-	if (unlikely(retval)) {
-		/*
-		 * If we are failing, make sure the ticket doesn't have any
-		 * current reservations.  We don't want to add this back
-		 * when the ticket/ transaction gets cancelled.
-		 */
-		internal_ticket->t_curr_res = 0;
-		/* ungrant will give back unit_res * t_cnt. */
-		internal_ticket->t_cnt = 0;
-	}
-
-	return retval;
-}
-
-
-/*
  * Mount a log filesystem
  *
  * mp		- ubiquitous xfs mount point structure
@@ -653,8 +726,9 @@ xfs_log_unmount_write(xfs_mount_t *mp)
 				.lv_iovecp = &reg,
 			};
 
-			/* remove inited flag */
+			/* remove inited flag, and account for space used */
 			tic->t_flags = 0;
+			tic->t_curr_res -= sizeof(magic);
 			error = xlog_write(log, &vec, tic, &lsn,
 					   NULL, XLOG_UNMOUNT_TRANS);
 			/*
@@ -760,64 +834,35 @@ xfs_log_item_init(
 	INIT_LIST_HEAD(&item->li_cil);
 }
 
+/*
+ * Wake up processes waiting for log space after we have moved the log tail.
+ */
 void
-xfs_log_move_tail(xfs_mount_t	*mp,
-		  xfs_lsn_t	tail_lsn)
+xfs_log_space_wake(
+	struct xfs_mount	*mp)
 {
-	xlog_ticket_t	*tic;
-	xlog_t		*log = mp->m_log;
-	int		need_bytes, free_bytes;
+	struct log		*log = mp->m_log;
+	int			free_bytes;
 
 	if (XLOG_FORCED_SHUTDOWN(log))
 		return;
 
-	if (tail_lsn == 0)
-		tail_lsn = atomic64_read(&log->l_last_sync_lsn);
-
-	/* tail_lsn == 1 implies that we weren't passed a valid value.  */
-	if (tail_lsn != 1)
-		atomic64_set(&log->l_tail_lsn, tail_lsn);
-
-	if (!list_empty_careful(&log->l_writeq)) {
-#ifdef DEBUG
-		if (log->l_flags & XLOG_ACTIVE_RECOVERY)
-			panic("Recovery problem");
-#endif
-		spin_lock(&log->l_grant_write_lock);
-		free_bytes = xlog_space_left(log, &log->l_grant_write_head);
-		list_for_each_entry(tic, &log->l_writeq, t_queue) {
-			ASSERT(tic->t_flags & XLOG_TIC_PERM_RESERV);
+	if (!list_empty_careful(&log->l_write_head.waiters)) {
+		ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
 
-			if (free_bytes < tic->t_unit_res && tail_lsn != 1)
-				break;
-			tail_lsn = 0;
-			free_bytes -= tic->t_unit_res;
-			trace_xfs_log_regrant_write_wake_up(log, tic);
-			wake_up(&tic->t_wait);
-		}
-		spin_unlock(&log->l_grant_write_lock);
+		spin_lock(&log->l_write_head.lock);
+		free_bytes = xlog_space_left(log, &log->l_write_head.grant);
+		xlog_grant_head_wake(log, &log->l_write_head, &free_bytes);
+		spin_unlock(&log->l_write_head.lock);
 	}
 
-	if (!list_empty_careful(&log->l_reserveq)) {
-#ifdef DEBUG
-		if (log->l_flags & XLOG_ACTIVE_RECOVERY)
-			panic("Recovery problem");
-#endif
-		spin_lock(&log->l_grant_reserve_lock);
-		free_bytes = xlog_space_left(log, &log->l_grant_reserve_head);
-		list_for_each_entry(tic, &log->l_reserveq, t_queue) {
-			if (tic->t_flags & XLOG_TIC_PERM_RESERV)
-				need_bytes = tic->t_unit_res*tic->t_cnt;
-			else
-				need_bytes = tic->t_unit_res;
-			if (free_bytes < need_bytes && tail_lsn != 1)
-				break;
-			tail_lsn = 0;
-			free_bytes -= need_bytes;
-			trace_xfs_log_grant_wake_up(log, tic);
-			wake_up(&tic->t_wait);
-		}
-		spin_unlock(&log->l_grant_reserve_lock);
+	if (!list_empty_careful(&log->l_reserve_head.waiters)) {
+		ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
+
+		spin_lock(&log->l_reserve_head.lock);
+		free_bytes = xlog_space_left(log, &log->l_reserve_head.grant);
+		xlog_grant_head_wake(log, &log->l_reserve_head, &free_bytes);
+		spin_unlock(&log->l_reserve_head.lock);
 	}
 }
 
@@ -867,21 +912,7 @@ xfs_log_need_covered(xfs_mount_t *mp)
 	return needed;
 }
 
-/******************************************************************************
- *
- *	local routines
- *
- ******************************************************************************
- */
-
-/* xfs_trans_tail_ail returns 0 when there is nothing in the list.
- * The log manager must keep track of the last LR which was committed
- * to disk.  The lsn of this LR will become the new tail_lsn whenever
- * xfs_trans_tail_ail returns 0.  If we don't do this, we run into
- * the situation where stuff could be written into the log but nothing
- * was ever in the AIL when asked.  Eventually, we panic since the
- * tail hits the head.
- *
+/*
  * We may be holding the log iclog lock upon entering this routine.
  */
 xfs_lsn_t
@@ -891,10 +922,17 @@ xlog_assign_tail_lsn(
 	xfs_lsn_t		tail_lsn;
 	struct log		*log = mp->m_log;
 
+	/*
+	 * To make sure we always have a valid LSN for the log tail we keep
+	 * track of the last LSN which was committed in log->l_last_sync_lsn,
+	 * and use that when the AIL was empty and xfs_ail_min_lsn returns 0.
+	 *
+	 * If the AIL has been emptied we also need to wake any process
+	 * waiting for this condition.
+	 */
 	tail_lsn = xfs_ail_min_lsn(mp->m_ail);
 	if (!tail_lsn)
 		tail_lsn = atomic64_read(&log->l_last_sync_lsn);
-
 	atomic64_set(&log->l_tail_lsn, tail_lsn);
 	return tail_lsn;
 }
@@ -1100,12 +1138,9 @@ xlog_alloc_log(xfs_mount_t	*mp,
 	xlog_assign_atomic_lsn(&log->l_tail_lsn, 1, 0);
 	xlog_assign_atomic_lsn(&log->l_last_sync_lsn, 1, 0);
 	log->l_curr_cycle  = 1;	    /* 0 is bad since this is initial value */
-	xlog_assign_grant_head(&log->l_grant_reserve_head, 1, 0);
-	xlog_assign_grant_head(&log->l_grant_write_head, 1, 0);
-	INIT_LIST_HEAD(&log->l_reserveq);
-	INIT_LIST_HEAD(&log->l_writeq);
-	spin_lock_init(&log->l_grant_reserve_lock);
-	spin_lock_init(&log->l_grant_write_lock);
+
+	xlog_grant_head_init(&log->l_reserve_head);
+	xlog_grant_head_init(&log->l_write_head);
 
 	error = EFSCORRUPTED;
 	if (xfs_sb_version_hassector(&mp->m_sb)) {
@@ -1280,7 +1315,7 @@ xlog_grant_push_ail(
 
 	ASSERT(BTOBB(need_bytes) < log->l_logBBsize);
 
-	free_bytes = xlog_space_left(log, &log->l_grant_reserve_head);
+	free_bytes = xlog_space_left(log, &log->l_reserve_head.grant);
 	free_blocks = BTOBBT(free_bytes);
 
 	/*
@@ -1412,8 +1447,8 @@ xlog_sync(xlog_t		*log,
 		 roundoff < BBTOB(1)));
 
 	/* move grant heads by roundoff in sync */
-	xlog_grant_add_space(log, &log->l_grant_reserve_head, roundoff);
-	xlog_grant_add_space(log, &log->l_grant_write_head, roundoff);
+	xlog_grant_add_space(log, &log->l_reserve_head.grant, roundoff);
+	xlog_grant_add_space(log, &log->l_write_head.grant, roundoff);
 
 	/* put cycle number in every block */
 	xlog_pack_data(log, iclog, roundoff); 
@@ -2566,119 +2601,6 @@ restart:
 	return 0;
 }	/* xlog_state_get_iclog_space */
 
-/*
- * Atomically get the log space required for a log ticket.
- *
- * Once a ticket gets put onto the reserveq, it will only return after the
- * needed reservation is satisfied.
- *
- * This function is structured so that it has a lock free fast path. This is
- * necessary because every new transaction reservation will come through this
- * path. Hence any lock will be globally hot if we take it unconditionally on
- * every pass.
- *
- * As tickets are only ever moved on and off the reserveq under the
- * l_grant_reserve_lock, we only need to take that lock if we are going to add
- * the ticket to the queue and sleep. We can avoid taking the lock if the ticket
- * was never added to the reserveq because the t_queue list head will be empty
- * and we hold the only reference to it so it can safely be checked unlocked.
- */
-STATIC int
-xlog_grant_log_space(
-	struct log		*log,
-	struct xlog_ticket	*tic)
-{
-	int			free_bytes, need_bytes;
-	int			error = 0;
-
-	ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
-
-	trace_xfs_log_grant_enter(log, tic);
-
-	/*
-	 * If there are other waiters on the queue then give them a chance at
-	 * logspace before us.  Wake up the first waiters, if we do not wake
-	 * up all the waiters then go to sleep waiting for more free space,
-	 * otherwise try to get some space for this transaction.
-	 */
-	need_bytes = tic->t_unit_res;
-	if (tic->t_flags & XFS_LOG_PERM_RESERV)
-		need_bytes *= tic->t_ocnt;
-	free_bytes = xlog_space_left(log, &log->l_grant_reserve_head);
-	if (!list_empty_careful(&log->l_reserveq)) {
-		spin_lock(&log->l_grant_reserve_lock);
-		if (!xlog_reserveq_wake(log, &free_bytes) ||
-		    free_bytes < need_bytes)
-			error = xlog_reserveq_wait(log, tic, need_bytes);
-		spin_unlock(&log->l_grant_reserve_lock);
-	} else if (free_bytes < need_bytes) {
-		spin_lock(&log->l_grant_reserve_lock);
-		error = xlog_reserveq_wait(log, tic, need_bytes);
-		spin_unlock(&log->l_grant_reserve_lock);
-	}
-	if (error)
-		return error;
-
-	xlog_grant_add_space(log, &log->l_grant_reserve_head, need_bytes);
-	xlog_grant_add_space(log, &log->l_grant_write_head, need_bytes);
-	trace_xfs_log_grant_exit(log, tic);
-	xlog_verify_grant_tail(log);
-	return 0;
-}
-
-/*
- * Replenish the byte reservation required by moving the grant write head.
- *
- * Similar to xlog_grant_log_space, the function is structured to have a lock
- * free fast path.
- */
-STATIC int
-xlog_regrant_write_log_space(
-	struct log		*log,
-	struct xlog_ticket	*tic)
-{
-	int			free_bytes, need_bytes;
-	int			error = 0;
-
-	tic->t_curr_res = tic->t_unit_res;
-	xlog_tic_reset_res(tic);
-
-	if (tic->t_cnt > 0)
-		return 0;
-
-	ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
-
-	trace_xfs_log_regrant_write_enter(log, tic);
-
-	/*
-	 * If there are other waiters on the queue then give them a chance at
-	 * logspace before us.  Wake up the first waiters, if we do not wake
-	 * up all the waiters then go to sleep waiting for more free space,
-	 * otherwise try to get some space for this transaction.
-	 */
-	need_bytes = tic->t_unit_res;
-	free_bytes = xlog_space_left(log, &log->l_grant_write_head);
-	if (!list_empty_careful(&log->l_writeq)) {
-		spin_lock(&log->l_grant_write_lock);
-		if (!xlog_writeq_wake(log, &free_bytes) ||
-		    free_bytes < need_bytes)
-			error = xlog_writeq_wait(log, tic, need_bytes);
-		spin_unlock(&log->l_grant_write_lock);
-	} else if (free_bytes < need_bytes) {
-		spin_lock(&log->l_grant_write_lock);
-		error = xlog_writeq_wait(log, tic, need_bytes);
-		spin_unlock(&log->l_grant_write_lock);
-	}
-
-	if (error)
-		return error;
-
-	xlog_grant_add_space(log, &log->l_grant_write_head, need_bytes);
-	trace_xfs_log_regrant_write_exit(log, tic);
-	xlog_verify_grant_tail(log);
-	return 0;
-}
-
 /* The first cnt-1 times through here we don't need to
  * move the grant write head because the permanent
  * reservation has reserved cnt times the unit amount.
@@ -2695,9 +2617,9 @@ xlog_regrant_reserve_log_space(xlog_t	     *log,
 	if (ticket->t_cnt > 0)
 		ticket->t_cnt--;
 
-	xlog_grant_sub_space(log, &log->l_grant_reserve_head,
+	xlog_grant_sub_space(log, &log->l_reserve_head.grant,
 					ticket->t_curr_res);
-	xlog_grant_sub_space(log, &log->l_grant_write_head,
+	xlog_grant_sub_space(log, &log->l_write_head.grant,
 					ticket->t_curr_res);
 	ticket->t_curr_res = ticket->t_unit_res;
 	xlog_tic_reset_res(ticket);
@@ -2708,7 +2630,7 @@ xlog_regrant_reserve_log_space(xlog_t	     *log,
 	if (ticket->t_cnt > 0)
 		return;
 
-	xlog_grant_add_space(log, &log->l_grant_reserve_head,
+	xlog_grant_add_space(log, &log->l_reserve_head.grant,
 					ticket->t_unit_res);
 
 	trace_xfs_log_regrant_reserve_exit(log, ticket);
@@ -2754,14 +2676,13 @@ xlog_ungrant_log_space(xlog_t	     *log,
 		bytes += ticket->t_unit_res*ticket->t_cnt;
 	}
 
-	xlog_grant_sub_space(log, &log->l_grant_reserve_head, bytes);
-	xlog_grant_sub_space(log, &log->l_grant_write_head, bytes);
+	xlog_grant_sub_space(log, &log->l_reserve_head.grant, bytes);
+	xlog_grant_sub_space(log, &log->l_write_head.grant, bytes);
 
 	trace_xfs_log_ungrant_exit(log, ticket);
 
-	xfs_log_move_tail(log->l_mp, 1);
-}	/* xlog_ungrant_log_space */
-
+	xfs_log_space_wake(log->l_mp);
+}
 
 /*
  * Flush iclog to disk if this is the last reference to the given iclog and
@@ -3219,7 +3140,7 @@ xlog_ticket_alloc(
 	int		unit_bytes,
 	int		cnt,
 	char		client,
-	uint		xflags,
+	bool		permanent,
 	int		alloc_flags)
 {
 	struct xlog_ticket *tic;
@@ -3313,6 +3234,7 @@ xlog_ticket_alloc(
         }
 
 	atomic_set(&tic->t_ref, 1);
+	tic->t_task		= current;
 	INIT_LIST_HEAD(&tic->t_queue);
 	tic->t_unit_res		= unit_bytes;
 	tic->t_curr_res		= unit_bytes;
@@ -3322,9 +3244,8 @@ xlog_ticket_alloc(
 	tic->t_clientid		= client;
 	tic->t_flags		= XLOG_TIC_INITED;
 	tic->t_trans_type	= 0;
-	if (xflags & XFS_LOG_PERM_RESERV)
+	if (permanent)
 		tic->t_flags |= XLOG_TIC_PERM_RESERV;
-	init_waitqueue_head(&tic->t_wait);
 
 	xlog_tic_reset_res(tic);
 
@@ -3380,7 +3301,7 @@ xlog_verify_grant_tail(
 	int		tail_cycle, tail_blocks;
 	int		cycle, space;
 
-	xlog_crack_grant_head(&log->l_grant_write_head, &cycle, &space);
+	xlog_crack_grant_head(&log->l_write_head.grant, &cycle, &space);
 	xlog_crack_atomic_lsn(&log->l_tail_lsn, &tail_cycle, &tail_blocks);
 	if (tail_cycle != cycle) {
 		if (cycle - 1 != tail_cycle &&
@@ -3582,7 +3503,6 @@ xfs_log_force_umount(
 	struct xfs_mount	*mp,
 	int			logerror)
 {
-	xlog_ticket_t	*tic;
 	xlog_t		*log;
 	int		retval;
 
@@ -3650,15 +3570,8 @@ xfs_log_force_umount(
 	 * we don't enqueue anything once the SHUTDOWN flag is set, and this
 	 * action is protected by the grant locks.
 	 */
-	spin_lock(&log->l_grant_reserve_lock);
-	list_for_each_entry(tic, &log->l_reserveq, t_queue)
-		wake_up(&tic->t_wait);
-	spin_unlock(&log->l_grant_reserve_lock);
-
-	spin_lock(&log->l_grant_write_lock);
-	list_for_each_entry(tic, &log->l_writeq, t_queue)
-		wake_up(&tic->t_wait);
-	spin_unlock(&log->l_grant_write_lock);
+	xlog_grant_head_wake_all(&log->l_reserve_head);
+	xlog_grant_head_wake_all(&log->l_write_head);
 
 	if (!(log->l_iclog->ic_state & XLOG_STATE_IOERROR)) {
 		ASSERT(!logerror);