Commit 663e496a authored by Dave Chinner's avatar Dave Chinner Committed by Dave Chinner
Browse files

xfs: rework log grant space calculations 



The log grant space calculations are repeated for both write and
reserve grant heads. To make it simpler to convert the calculations
toa different algorithm, factor them so both the gratn heads use the
same calculation functions. Once this is done we can drop the
wrappers that are used in only a couple of place to update both
grant heads at once as they don't provide any particular value.

Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
parent 3f336c6f

fs/xfs/xfs_log.c

+48 −47
Original line number Diff line number Diff line
@@ -98,53 +98,34 @@ STATIC void xlog_verify_tail_lsn(xlog_t *log, xlog_in_core_t *iclog, 
STATIC int	xlog_iclogs_empty(xlog_t *log);



static void

xlog_grant_sub_space(struct log *log, int bytes)

{

	log->l_grant_write_bytes -= bytes;

	if (log->l_grant_write_bytes < 0) {

		log->l_grant_write_bytes += log->l_logsize;

		log->l_grant_write_cycle--;

	}



	log->l_grant_reserve_bytes -= bytes;

	if ((log)->l_grant_reserve_bytes < 0) {

		log->l_grant_reserve_bytes += log->l_logsize;

		log->l_grant_reserve_cycle--;

	}



}



static void

xlog_grant_add_space_write(struct log *log, int bytes)

xlog_grant_sub_space(

	struct log	*log,

	int		*cycle,

	int		*space,

	int		bytes)

{

	int tmp = log->l_logsize - log->l_grant_write_bytes;

	if (tmp > bytes)

		log->l_grant_write_bytes += bytes;

	else {

		log->l_grant_write_cycle++;

		log->l_grant_write_bytes = bytes - tmp;

	*space -= bytes;

	if (*space < 0) {

		*space += log->l_logsize;

		(*cycle)--;

	}

}



static void

xlog_grant_add_space_reserve(struct log *log, int bytes)

xlog_grant_add_space(

	struct log	*log,

	int		*cycle,

	int		*space,

	int		bytes)

{

	int tmp = log->l_logsize - log->l_grant_reserve_bytes;

	int tmp = log->l_logsize - *space;

	if (tmp > bytes)

		log->l_grant_reserve_bytes += bytes;

		*space += bytes;

	else {

		log->l_grant_reserve_cycle++;

		log->l_grant_reserve_bytes = bytes - tmp;

	}

		*space = bytes - tmp;

		(*cycle)++;

	}



static inline void

xlog_grant_add_space(struct log *log, int bytes)

{

	xlog_grant_add_space_write(log, bytes);

	xlog_grant_add_space_reserve(log, bytes);

}



static void

xlog_tic_reset_res(xlog_ticket_t *tic)

{
@@ -1344,7 +1325,10 @@ xlog_sync(xlog_t *log, 


	/* move grant heads by roundoff in sync */

	spin_lock(&log->l_grant_lock);

	xlog_grant_add_space(log, roundoff);

	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);

	spin_unlock(&log->l_grant_lock);



	/* put cycle number in every block */
@@ -2574,7 +2558,10 @@ redo: 
	list_del_init(&tic->t_queue);



	/* we've got enough space */

	xlog_grant_add_space(log, need_bytes);

	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);

	trace_xfs_log_grant_exit(log, tic);

	xlog_verify_grant_head(log, 1);

	xlog_verify_grant_tail(log);
@@ -2701,7 +2688,8 @@ redo: 
	list_del_init(&tic->t_queue);



	/* we've got enough space */

	xlog_grant_add_space_write(log, need_bytes);

	xlog_grant_add_space(log, &log->l_grant_write_cycle,

				&log->l_grant_write_bytes, need_bytes);

	trace_xfs_log_regrant_write_exit(log, tic);

	xlog_verify_grant_head(log, 1);

	xlog_verify_grant_tail(log);
@@ -2742,7 +2730,12 @@ xlog_regrant_reserve_log_space(xlog_t *log, 
		ticket->t_cnt--;



	spin_lock(&log->l_grant_lock);

	xlog_grant_sub_space(log, ticket->t_curr_res);

	xlog_grant_sub_space(log, &log->l_grant_reserve_cycle,

				&log->l_grant_reserve_bytes,

				ticket->t_curr_res);

	xlog_grant_sub_space(log, &log->l_grant_write_cycle,

				&log->l_grant_write_bytes,

				ticket->t_curr_res);

	ticket->t_curr_res = ticket->t_unit_res;

	xlog_tic_reset_res(ticket);
@@ -2756,7 +2749,9 @@ xlog_regrant_reserve_log_space(xlog_t *log, 
		return;

	}



	xlog_grant_add_space_reserve(log, ticket->t_unit_res);

	xlog_grant_add_space(log, &log->l_grant_reserve_cycle,

				&log->l_grant_reserve_bytes,

				ticket->t_unit_res);



	trace_xfs_log_regrant_reserve_exit(log, ticket);
@@ -2785,24 +2780,30 @@ STATIC void 
xlog_ungrant_log_space(xlog_t	     *log,

		       xlog_ticket_t *ticket)

{

	int	bytes;



	if (ticket->t_cnt > 0)

		ticket->t_cnt--;



	spin_lock(&log->l_grant_lock);

	trace_xfs_log_ungrant_enter(log, ticket);



	xlog_grant_sub_space(log, ticket->t_curr_res);



	trace_xfs_log_ungrant_sub(log, ticket);



	/* If this is a permanent reservation ticket, we may be able to free

	/*

	 * If this is a permanent reservation ticket, we may be able to free

	 * up more space based on the remaining count.

	 */

	bytes = ticket->t_curr_res;

	if (ticket->t_cnt > 0) {

		ASSERT(ticket->t_flags & XLOG_TIC_PERM_RESERV);

		xlog_grant_sub_space(log, ticket->t_unit_res*ticket->t_cnt);

		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);



	trace_xfs_log_ungrant_exit(log, ticket);



	xlog_verify_grant_head(log, 1);

CRA Git | Maintained and supported by SUSTech CRA and CCSE