Commit d7e3621a authored by Omar Sandoval's avatar Omar Sandoval Committed by Jens Axboe
Browse files

blk-mq: add tags and sched_tags bitmaps to debugfs 



These can be used to debug issues like tag leaks and stuck requests.

Reviewed-by: default avatarHannes Reinecke <hare@suse.com>
Signed-off-by: default avatarOmar Sandoval <osandov@fb.com>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent d96b37c0

block/blk-mq-debugfs.c

+50 −0
Original line number Diff line number Diff line
@@ -197,6 +197,30 @@ static const struct file_operations hctx_tags_fops = { 
	.release	= single_release,

};



static int hctx_tags_bitmap_show(struct seq_file *m, void *v)

{

	struct blk_mq_hw_ctx *hctx = m->private;

	struct request_queue *q = hctx->queue;



	mutex_lock(&q->sysfs_lock);

	if (hctx->tags)

		sbitmap_bitmap_show(&hctx->tags->bitmap_tags.sb, m);

	mutex_unlock(&q->sysfs_lock);

	return 0;

}



static int hctx_tags_bitmap_open(struct inode *inode, struct file *file)

{

	return single_open(file, hctx_tags_bitmap_show, inode->i_private);

}



static const struct file_operations hctx_tags_bitmap_fops = {

	.open		= hctx_tags_bitmap_open,

	.read		= seq_read,

	.llseek		= seq_lseek,

	.release	= single_release,

};



static int hctx_sched_tags_show(struct seq_file *m, void *v)

{

	struct blk_mq_hw_ctx *hctx = m->private;
@@ -222,6 +246,30 @@ static const struct file_operations hctx_sched_tags_fops = { 
	.release	= single_release,

};



static int hctx_sched_tags_bitmap_show(struct seq_file *m, void *v)

{

	struct blk_mq_hw_ctx *hctx = m->private;

	struct request_queue *q = hctx->queue;



	mutex_lock(&q->sysfs_lock);

	if (hctx->sched_tags)

		sbitmap_bitmap_show(&hctx->sched_tags->bitmap_tags.sb, m);

	mutex_unlock(&q->sysfs_lock);

	return 0;

}



static int hctx_sched_tags_bitmap_open(struct inode *inode, struct file *file)

{

	return single_open(file, hctx_sched_tags_bitmap_show, inode->i_private);

}



static const struct file_operations hctx_sched_tags_bitmap_fops = {

	.open		= hctx_sched_tags_bitmap_open,

	.read		= seq_read,

	.llseek		= seq_lseek,

	.release	= single_release,

};



static void *ctx_rq_list_start(struct seq_file *m, loff_t *pos)

{

	struct blk_mq_ctx *ctx = m->private;
@@ -269,7 +317,9 @@ static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = { 
	{"dispatch", 0400, &hctx_dispatch_fops},

	{"ctx_map", 0400, &hctx_ctx_map_fops},

	{"tags", 0400, &hctx_tags_fops},

	{"tags_bitmap", 0400, &hctx_tags_bitmap_fops},

	{"sched_tags", 0400, &hctx_sched_tags_fops},

	{"sched_tags_bitmap", 0400, &hctx_sched_tags_bitmap_fops},

};



static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {