Commit a69ed03c authored by Dave Chinner's avatar Dave Chinner Committed by Dave Chinner
Browse files

xfs: combine grant heads into a single 64 bit integer 



Prepare for switching the grant heads to atomic variables by
combining the two 32 bit values that make up the grant head into a
single 64 bit variable.  Provide wrapper functions to combine and
split the grant heads appropriately for calculations and use them as
necessary.

Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
parent 663e496a

fs/xfs/linux-2.6/xfs_trace.h

+6 −4
Original line number Diff line number Diff line
@@ -786,10 +786,12 @@ DECLARE_EVENT_CLASS(xfs_loggrant_class, 
		__entry->flags = tic->t_flags;

		__entry->reserveq = list_empty(&log->l_reserveq);

		__entry->writeq = list_empty(&log->l_writeq);

		__entry->grant_reserve_cycle = log->l_grant_reserve_cycle;

		__entry->grant_reserve_bytes = log->l_grant_reserve_bytes;

		__entry->grant_write_cycle = log->l_grant_write_cycle;

		__entry->grant_write_bytes = log->l_grant_write_bytes;

		xlog_crack_grant_head(&log->l_grant_reserve_head,

				&__entry->grant_reserve_cycle,

				&__entry->grant_reserve_bytes);

		xlog_crack_grant_head(&log->l_grant_write_head,

				&__entry->grant_write_cycle,

				&__entry->grant_write_bytes);

		__entry->curr_cycle = log->l_curr_cycle;

		__entry->curr_block = log->l_curr_block;

		__entry->tail_lsn = log->l_tail_lsn;

fs/xfs/xfs_log.c

+87 −79
Original line number Diff line number Diff line
@@ -47,7 +47,7 @@ STATIC xlog_t * xlog_alloc_log(xfs_mount_t *mp, 
				xfs_buftarg_t	*log_target,

				xfs_daddr_t	blk_offset,

				int		num_bblks);

STATIC int	 xlog_space_left(xlog_t *log, int cycle, int bytes);

STATIC int	 xlog_space_left(struct log *log, int64_t *head);

STATIC int	 xlog_sync(xlog_t *log, xlog_in_core_t *iclog);

STATIC void	 xlog_dealloc_log(xlog_t *log);
@@ -100,32 +100,44 @@ STATIC int xlog_iclogs_empty(xlog_t *log); 
static void

xlog_grant_sub_space(

	struct log	*log,

	int		*cycle,

	int		*space,

	int64_t		*head,

	int		bytes)

{

	*space -= bytes;

	if (*space < 0) {

		*space += log->l_logsize;

		(*cycle)--;

	int		cycle, space;



	xlog_crack_grant_head(head, &cycle, &space);



	space -= bytes;

	if (space < 0) {

		space += log->l_logsize;

		cycle--;

	}



	xlog_assign_grant_head(head, cycle, space);

}



static void

xlog_grant_add_space(

	struct log	*log,

	int		*cycle,

	int		*space,

	int64_t		*head,

	int		bytes)

{

	int tmp = log->l_logsize - *space;

	int		tmp;

	int		cycle, space;



	xlog_crack_grant_head(head, &cycle, &space);



	tmp = log->l_logsize - space;

	if (tmp > bytes)

		*space += bytes;

		space += bytes;

	else {

		*space = bytes - tmp;

		(*cycle)++;

		space = bytes - tmp;

		cycle++;

	}



	xlog_assign_grant_head(head, cycle, space);

}



static void

xlog_tic_reset_res(xlog_ticket_t *tic)

{
@@ -654,7 +666,7 @@ xfs_log_move_tail(xfs_mount_t *mp, 
{

	xlog_ticket_t	*tic;

	xlog_t		*log = mp->m_log;

	int		need_bytes, free_bytes, cycle, bytes;

	int		need_bytes, free_bytes;



	if (XLOG_FORCED_SHUTDOWN(log))

		return;
@@ -680,9 +692,7 @@ xfs_log_move_tail(xfs_mount_t *mp, 
		if (log->l_flags & XLOG_ACTIVE_RECOVERY)

			panic("Recovery problem");

#endif

		cycle = log->l_grant_write_cycle;

		bytes = log->l_grant_write_bytes;

		free_bytes = xlog_space_left(log, cycle, bytes);

		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);
@@ -699,9 +709,7 @@ xfs_log_move_tail(xfs_mount_t *mp, 
		if (log->l_flags & XLOG_ACTIVE_RECOVERY)

			panic("Recovery problem");

#endif

		cycle = log->l_grant_reserve_cycle;

		bytes = log->l_grant_reserve_bytes;

		free_bytes = xlog_space_left(log, cycle, bytes);

		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;
@@ -814,21 +822,26 @@ xlog_assign_tail_lsn(xfs_mount_t *mp) 
 * result is that we return the size of the log as the amount of space left.

 */

STATIC int

xlog_space_left(xlog_t *log, int cycle, int bytes)

xlog_space_left(

	struct log	*log,

	int64_t		*head)

{

	int		free_bytes;

	int		tail_bytes;

	int		tail_cycle;

	int		head_cycle;

	int		head_bytes;



	xlog_crack_grant_head(head, &head_cycle, &head_bytes);

	tail_bytes = BBTOB(BLOCK_LSN(log->l_tail_lsn));

	tail_cycle = CYCLE_LSN(log->l_tail_lsn);

	if ((tail_cycle == cycle) && (bytes >= tail_bytes)) {

		free_bytes = log->l_logsize - (bytes - tail_bytes);

	} else if ((tail_cycle + 1) < cycle) {

	if (tail_cycle == head_cycle && head_bytes >= tail_bytes)

		free_bytes = log->l_logsize - (head_bytes - tail_bytes);

	else if (tail_cycle + 1 < head_cycle)

		return 0;

	} else if (tail_cycle < cycle) {

		ASSERT(tail_cycle == (cycle - 1));

		free_bytes = tail_bytes - bytes;

	else if (tail_cycle < head_cycle) {

		ASSERT(tail_cycle == (head_cycle - 1));

		free_bytes = tail_bytes - head_bytes;

	} else {

		/*

		 * The reservation head is behind the tail.
@@ -839,12 +852,12 @@ xlog_space_left(xlog_t *log, int cycle, int bytes) 
			"xlog_space_left: head behind tail\n"

			"  tail_cycle = %d, tail_bytes = %d\n"

			"  GH   cycle = %d, GH   bytes = %d",

			tail_cycle, tail_bytes, cycle, bytes);

			tail_cycle, tail_bytes, head_cycle, head_bytes);

		ASSERT(0);

		free_bytes = log->l_logsize;

	}

	return free_bytes;

}	/* xlog_space_left */

}





/*
@@ -1001,8 +1014,8 @@ xlog_alloc_log(xfs_mount_t *mp, 
	/* log->l_tail_lsn = 0x100000000LL; cycle = 1; current block = 0 */

	log->l_last_sync_lsn = log->l_tail_lsn;

	log->l_curr_cycle  = 1;	    /* 0 is bad since this is initial value */

	log->l_grant_reserve_cycle = 1;

	log->l_grant_write_cycle = 1;

	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);
@@ -1190,9 +1203,7 @@ xlog_grant_push_ail(xfs_mount_t *mp, 
    ASSERT(BTOBB(need_bytes) < log->l_logBBsize);



    spin_lock(&log->l_grant_lock);

    free_bytes = xlog_space_left(log,

				 log->l_grant_reserve_cycle,

				 log->l_grant_reserve_bytes);

    free_bytes = xlog_space_left(log, &log->l_grant_reserve_head);

    tail_lsn = log->l_tail_lsn;

    free_blocks = BTOBBT(free_bytes);
@@ -1325,10 +1336,8 @@ xlog_sync(xlog_t *log, 


	/* move grant heads by roundoff in sync */

	spin_lock(&log->l_grant_lock);

	xlog_grant_add_space(log, &log->l_grant_reserve_cycle,

				&log->l_grant_reserve_bytes, roundoff);

	xlog_grant_add_space(log, &log->l_grant_write_cycle,

				&log->l_grant_write_bytes, roundoff);

	xlog_grant_add_space(log, &log->l_grant_reserve_head, roundoff);

	xlog_grant_add_space(log, &log->l_grant_write_head, roundoff);

	spin_unlock(&log->l_grant_lock);



	/* put cycle number in every block */
@@ -2531,8 +2540,7 @@ redo: 
	if (XLOG_FORCED_SHUTDOWN(log))

		goto error_return;



	free_bytes = xlog_space_left(log, log->l_grant_reserve_cycle,

				     log->l_grant_reserve_bytes);

	free_bytes = xlog_space_left(log, &log->l_grant_reserve_head);

	if (free_bytes < need_bytes) {

		if (list_empty(&tic->t_queue))

			list_add_tail(&tic->t_queue, &log->l_reserveq);
@@ -2558,10 +2566,8 @@ redo: 
	list_del_init(&tic->t_queue);



	/* we've got enough space */

	xlog_grant_add_space(log, &log->l_grant_reserve_cycle,

				&log->l_grant_reserve_bytes, need_bytes);

	xlog_grant_add_space(log, &log->l_grant_write_cycle,

				&log->l_grant_write_bytes, need_bytes);

	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_head(log, 1);

	xlog_verify_grant_tail(log);
@@ -2622,8 +2628,7 @@ xlog_regrant_write_log_space(xlog_t *log, 
	need_bytes = tic->t_unit_res;

	if (!list_empty(&log->l_writeq)) {

		struct xlog_ticket *ntic;

		free_bytes = xlog_space_left(log, log->l_grant_write_cycle,

					     log->l_grant_write_bytes);

		free_bytes = xlog_space_left(log, &log->l_grant_write_head);

		list_for_each_entry(ntic, &log->l_writeq, t_queue) {

			ASSERT(ntic->t_flags & XLOG_TIC_PERM_RESERV);
@@ -2662,8 +2667,7 @@ redo: 
	if (XLOG_FORCED_SHUTDOWN(log))

		goto error_return;



	free_bytes = xlog_space_left(log, log->l_grant_write_cycle,

				     log->l_grant_write_bytes);

	free_bytes = xlog_space_left(log, &log->l_grant_write_head);

	if (free_bytes < need_bytes) {

		if (list_empty(&tic->t_queue))

			list_add_tail(&tic->t_queue, &log->l_writeq);
@@ -2688,8 +2692,7 @@ redo: 
	list_del_init(&tic->t_queue);



	/* we've got enough space */

	xlog_grant_add_space(log, &log->l_grant_write_cycle,

				&log->l_grant_write_bytes, need_bytes);

	xlog_grant_add_space(log, &log->l_grant_write_head, need_bytes);

	trace_xfs_log_regrant_write_exit(log, tic);

	xlog_verify_grant_head(log, 1);

	xlog_verify_grant_tail(log);
@@ -2730,11 +2733,9 @@ xlog_regrant_reserve_log_space(xlog_t *log, 
		ticket->t_cnt--;



	spin_lock(&log->l_grant_lock);

	xlog_grant_sub_space(log, &log->l_grant_reserve_cycle,

				&log->l_grant_reserve_bytes,

	xlog_grant_sub_space(log, &log->l_grant_reserve_head,

					ticket->t_curr_res);

	xlog_grant_sub_space(log, &log->l_grant_write_cycle,

				&log->l_grant_write_bytes,

	xlog_grant_sub_space(log, &log->l_grant_write_head,

					ticket->t_curr_res);

	ticket->t_curr_res = ticket->t_unit_res;

	xlog_tic_reset_res(ticket);
@@ -2749,8 +2750,7 @@ xlog_regrant_reserve_log_space(xlog_t *log, 
		return;

	}



	xlog_grant_add_space(log, &log->l_grant_reserve_cycle,

				&log->l_grant_reserve_bytes,

	xlog_grant_add_space(log, &log->l_grant_reserve_head,

					ticket->t_unit_res);



	trace_xfs_log_regrant_reserve_exit(log, ticket);
@@ -2799,10 +2799,8 @@ xlog_ungrant_log_space(xlog_t *log, 
		bytes += ticket->t_unit_res*ticket->t_cnt;

	}



	xlog_grant_sub_space(log, &log->l_grant_reserve_cycle,

				&log->l_grant_reserve_bytes, bytes);

	xlog_grant_sub_space(log, &log->l_grant_write_cycle,

				&log->l_grant_write_bytes, bytes);

	xlog_grant_sub_space(log, &log->l_grant_reserve_head, bytes);

	xlog_grant_sub_space(log, &log->l_grant_write_head, bytes);



	trace_xfs_log_ungrant_exit(log, ticket);
@@ -3430,22 +3428,31 @@ xlog_verify_dest_ptr( 
STATIC void

xlog_verify_grant_head(xlog_t *log, int equals)

{

    if (log->l_grant_reserve_cycle == log->l_grant_write_cycle) {

	int	reserve_cycle, reserve_space;

	int	write_cycle, write_space;



	xlog_crack_grant_head(&log->l_grant_reserve_head,

					&reserve_cycle, &reserve_space);

	xlog_crack_grant_head(&log->l_grant_write_head,

					&write_cycle, &write_space);



	if (reserve_cycle == write_cycle) {

		if (equals)

	    ASSERT(log->l_grant_reserve_bytes >= log->l_grant_write_bytes);

			ASSERT(reserve_space >= write_space);

		else

	    ASSERT(log->l_grant_reserve_bytes > log->l_grant_write_bytes);

			ASSERT(reserve_space > write_space);

	} else {

	ASSERT(log->l_grant_reserve_cycle-1 == log->l_grant_write_cycle);

	ASSERT(log->l_grant_write_bytes >= log->l_grant_reserve_bytes);

		ASSERT(reserve_cycle - 1 == write_cycle);

		ASSERT(write_space >= reserve_space);

	}

}

}	/* xlog_verify_grant_head */



STATIC void

xlog_verify_grant_tail(

	struct log	*log)

{

	xfs_lsn_t	tail_lsn = log->l_tail_lsn;

	int		cycle, space;



	/*

	 * Check to make sure the grant write head didn't just over lap the
@@ -3453,9 +3460,10 @@ xlog_verify_grant_tail( 
	 * Otherwise, make sure that the cycles differ by exactly one and

	 * check the byte count.

	 */

	if (CYCLE_LSN(tail_lsn) != log->l_grant_write_cycle) {

		ASSERT(log->l_grant_write_cycle - 1 == CYCLE_LSN(tail_lsn));

		ASSERT(log->l_grant_write_bytes <= BBTOB(BLOCK_LSN(tail_lsn)));

	xlog_crack_grant_head(&log->l_grant_write_head, &cycle, &space);

	if (CYCLE_LSN(tail_lsn) != cycle) {

		ASSERT(cycle - 1 == CYCLE_LSN(tail_lsn));

		ASSERT(space <= BBTOB(BLOCK_LSN(tail_lsn)));

	}

}

fs/xfs/xfs_log_priv.h

+22 −4
Original line number Diff line number Diff line
@@ -518,10 +518,8 @@ typedef struct log { 
	spinlock_t		l_grant_lock ____cacheline_aligned_in_smp;

	struct list_head	l_reserveq;

	struct list_head	l_writeq;

	int			l_grant_reserve_cycle;

	int			l_grant_reserve_bytes;

	int			l_grant_write_cycle;

	int			l_grant_write_bytes;

	int64_t			l_grant_reserve_head;

	int64_t			l_grant_write_head;



	/* The following field are used for debugging; need to hold icloglock */

#ifdef DEBUG
@@ -560,6 +558,26 @@ int xlog_write(struct log *log, struct xfs_log_vec *log_vector, 
				struct xlog_ticket *tic, xfs_lsn_t *start_lsn,

				xlog_in_core_t **commit_iclog, uint flags);



/*

 * When we crack the grrant head, we sample it first so that the value will not

 * change while we are cracking it into the component values. This means we

 * will always get consistent component values to work from.

 */

static inline void

xlog_crack_grant_head(int64_t *head, int *cycle, int *space)

{

	int64_t	val = *head;



	*cycle = val >> 32;

	*space = val & 0xffffffff;

}



static inline void

xlog_assign_grant_head(int64_t *head, int cycle, int space)

{

	*head = ((int64_t)cycle << 32) | space;

}



/*

 * Committed Item List interfaces

 */

fs/xfs/xfs_log_recover.c

+4 −4
Original line number Diff line number Diff line
@@ -938,10 +938,10 @@ xlog_find_tail( 
		log->l_curr_cycle++;

	log->l_tail_lsn = be64_to_cpu(rhead->h_tail_lsn);

	log->l_last_sync_lsn = be64_to_cpu(rhead->h_lsn);

	log->l_grant_reserve_cycle = log->l_curr_cycle;

	log->l_grant_reserve_bytes = BBTOB(log->l_curr_block);

	log->l_grant_write_cycle = log->l_curr_cycle;

	log->l_grant_write_bytes = BBTOB(log->l_curr_block);

	xlog_assign_grant_head(&log->l_grant_reserve_head, log->l_curr_cycle,

					BBTOB(log->l_curr_block));

	xlog_assign_grant_head(&log->l_grant_write_head, log->l_curr_cycle,

					BBTOB(log->l_curr_block));



	/*

	 * Look for unmount record.  If we find it, then we know there

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