Commit d3a3a086 authored by John Garry's avatar John Garry Committed by Jens Axboe
Browse files

blk-throttle: Only use seq_printf() in tg_prfill_limit() 



Currently tg_prfill_limit() uses a combination of snprintf() and strcpy()
to generate the values parts of the limits string, before passing them as
arguments to seq_printf().

Convert to use only a sequence of seq_printf() calls per argument, which is
simpler.

Suggested-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJohn Garry <john.g.garry@oracle.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240327094020.3505514-1-john.g.garry@oracle.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent a46c2702

block/blk-throttle.c

+26 −25
Original line number Diff line number Diff line
@@ -1494,11 +1494,8 @@ static u64 tg_prfill_limit(struct seq_file *sf, struct blkg_policy_data *pd, 
{

	struct throtl_grp *tg = pd_to_tg(pd);

	const char *dname = blkg_dev_name(pd->blkg);

	char bufs[4][21] = { "max", "max", "max", "max" };

	u64 bps_dft;

	unsigned int iops_dft;

	char idle_time[26] = "";

	char latency_time[26] = "";



	if (!dname)

		return 0;
@@ -1520,35 +1517,39 @@ static u64 tg_prfill_limit(struct seq_file *sf, struct blkg_policy_data *pd, 
	      tg->latency_target_conf == DFL_LATENCY_TARGET)))

		return 0;



	if (tg->bps_conf[READ][off] != U64_MAX)

		snprintf(bufs[0], sizeof(bufs[0]), "%llu",

			tg->bps_conf[READ][off]);

	if (tg->bps_conf[WRITE][off] != U64_MAX)

		snprintf(bufs[1], sizeof(bufs[1]), "%llu",

			tg->bps_conf[WRITE][off]);

	if (tg->iops_conf[READ][off] != UINT_MAX)

		snprintf(bufs[2], sizeof(bufs[2]), "%u",

			tg->iops_conf[READ][off]);

	if (tg->iops_conf[WRITE][off] != UINT_MAX)

		snprintf(bufs[3], sizeof(bufs[3]), "%u",

			tg->iops_conf[WRITE][off]);

	seq_printf(sf, "%s", dname);

	if (tg->bps_conf[READ][off] == U64_MAX)

		seq_printf(sf, " rbps=max");

	else

		seq_printf(sf, " rbps=%llu", tg->bps_conf[READ][off]);



	if (tg->bps_conf[WRITE][off] == U64_MAX)

		seq_printf(sf, " wbps=max");

	else

		seq_printf(sf, " wbps=%llu", tg->bps_conf[WRITE][off]);



	if (tg->iops_conf[READ][off] == UINT_MAX)

		seq_printf(sf, " riops=max");

	else

		seq_printf(sf, " riops=%u", tg->iops_conf[READ][off]);



	if (tg->iops_conf[WRITE][off] == UINT_MAX)

		seq_printf(sf, " wiops=max");

	else

		seq_printf(sf, " wiops=%u", tg->iops_conf[WRITE][off]);



	if (off == LIMIT_LOW) {

		if (tg->idletime_threshold_conf == ULONG_MAX)

			strcpy(idle_time, " idle=max");

			seq_printf(sf, " idle=max");

		else

			snprintf(idle_time, sizeof(idle_time), " idle=%lu",

				tg->idletime_threshold_conf);

			seq_printf(sf, " idle=%lu", tg->idletime_threshold_conf);



		if (tg->latency_target_conf == ULONG_MAX)

			strcpy(latency_time, " latency=max");

			seq_printf(sf, " latency=max");

		else

			snprintf(latency_time, sizeof(latency_time),

				" latency=%lu", tg->latency_target_conf);

			seq_printf(sf, " latency=%lu", tg->latency_target_conf);

	}



	seq_printf(sf, "%s rbps=%s wbps=%s riops=%s wiops=%s%s%s\n",

		   dname, bufs[0], bufs[1], bufs[2], bufs[3], idle_time,

		   latency_time);

	seq_printf(sf, "\n");

	return 0;

}