Commit 49cb5168 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

blk-cgroup: refactor blkcg_print_stat 



Factor out a helper to deal with a single blkcg_gq to make the code a
little bit easier to follow.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Acked-by: default avatarTejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20210810152623.1796144-1-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 3973e15f

block/blk-cgroup.c

+74 −74
Original line number Diff line number Diff line
@@ -870,36 +870,23 @@ static void blkcg_fill_root_iostats(void) 
	}

}



static int blkcg_print_stat(struct seq_file *sf, void *v)

static void blkcg_print_one_stat(struct blkcg_gq *blkg, struct seq_file *s)

{

	struct blkcg *blkcg = css_to_blkcg(seq_css(sf));

	struct blkcg_gq *blkg;



	if (!seq_css(sf)->parent)

		blkcg_fill_root_iostats();

	else

		cgroup_rstat_flush(blkcg->css.cgroup);



	rcu_read_lock();



	hlist_for_each_entry_rcu(blkg, &blkcg->blkg_list, blkcg_node) {

	struct blkg_iostat_set *bis = &blkg->iostat;

		const char *dname;

		char *buf;

	u64 rbytes, wbytes, rios, wios, dbytes, dios;

		size_t size = seq_get_buf(sf, &buf), off = 0;

		int i;

	bool has_stats = false;

	const char *dname;

	unsigned seq;



		spin_lock_irq(&blkg->q->queue_lock);

	char *buf;

	size_t size = seq_get_buf(s, &buf), off = 0;

	int i;



	if (!blkg->online)

			goto skip;

		return;



	dname = blkg_dev_name(blkg);

	if (!dname)

			goto skip;

		return;



	/*

	 * Hooray string manipulation, count is the size written NOT
@@ -930,10 +917,9 @@ static int blkcg_print_stat(struct seq_file *sf, void *v) 


	if (blkcg_debug_stats && atomic_read(&blkg->use_delay)) {

		has_stats = true;

			off += scnprintf(buf+off, size-off,

					 " use_delay=%d delay_nsec=%llu",

		off += scnprintf(buf+off, size-off, " use_delay=%d delay_nsec=%llu",

			atomic_read(&blkg->use_delay),

					(unsigned long long)atomic64_read(&blkg->delay_nsec));

			atomic64_read(&blkg->delay_nsec));

	}



	for (i = 0; i < BLKCG_MAX_POLS; i++) {
@@ -952,15 +938,29 @@ static int blkcg_print_stat(struct seq_file *sf, void *v) 
	if (has_stats) {

		if (off < size - 1) {

			off += scnprintf(buf+off, size-off, "\n");

				seq_commit(sf, off);

			seq_commit(s, off);

		} else {

				seq_commit(sf, -1);

			seq_commit(s, -1);

		}

	}

	skip:

		spin_unlock_irq(&blkg->q->queue_lock);

}



static int blkcg_print_stat(struct seq_file *sf, void *v)

{

	struct blkcg *blkcg = css_to_blkcg(seq_css(sf));

	struct blkcg_gq *blkg;



	if (!seq_css(sf)->parent)

		blkcg_fill_root_iostats();

	else

		cgroup_rstat_flush(blkcg->css.cgroup);



	rcu_read_lock();

	hlist_for_each_entry_rcu(blkg, &blkcg->blkg_list, blkcg_node) {

		spin_lock_irq(&blkg->q->queue_lock);

		blkcg_print_one_stat(blkg, sf);

		spin_unlock_irq(&blkg->q->queue_lock);

	}

	rcu_read_unlock();

	return 0;

}