[PATCH] cfq-iosched: kill show_status sysfs entry

This is a debug entry that isn't of much use to the generic user or on a
production system. Additionally it can also easy overflow the sysfs
PAGE_SIZE limitation, if you have many processes doing io. So kill the
entry.
Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/block/cfq-iosched.c

@@ -1688,55 +1688,6 @@ cfq_read_key_type(struct cfq_data *cfqd, char *page)
 	return len;
 }
 
-static ssize_t
-cfq_status_show(struct cfq_data *cfqd, char *page)
-{
-	struct list_head *entry;
-	struct cfq_queue *cfqq;
-	ssize_t len;
-	int i = 0, queues;
-
-	len = sprintf(page, "Busy queues: %u\n", cfqd->busy_queues);
-	len += sprintf(page+len, "key type: %s\n",
-				cfq_key_types[cfqd->key_type]);
-	len += sprintf(page+len, "last sector: %Lu\n",
-				(unsigned long long)cfqd->last_sector);
-	len += sprintf(page+len, "max time in iosched: %lu\n",
-				max_elapsed_dispatch);
-	len += sprintf(page+len, "max completion time: %lu\n", max_elapsed_crq);
-
-	len += sprintf(page+len, "Busy queue list:\n");
-	spin_lock_irq(cfqd->queue->queue_lock);
-	list_for_each(entry, &cfqd->rr_list) {
-		i++;
-		cfqq = list_entry_cfqq(entry);
-		len += sprintf(page+len, "  cfqq: key=%lu alloc=%d/%d, "
-			"queued=%d/%d, last_fifo=%lu, service_used=%lu\n",
-			cfqq->key, cfqq->allocated[0], cfqq->allocated[1],
-			cfqq->queued[0], cfqq->queued[1],
-			cfqq->last_fifo_expire, cfqq->service_used);
-	}
-	len += sprintf(page+len, "  busy queues total: %d\n", i);
-	queues = i;
-
-	len += sprintf(page+len, "Empty queue list:\n");
-	i = 0;
-	list_for_each(entry, &cfqd->empty_list) {
-		i++;
-		cfqq = list_entry_cfqq(entry);
-		len += sprintf(page+len, "  cfqq: key=%lu alloc=%d/%d, "
-			"queued=%d/%d, last_fifo=%lu, service_used=%lu\n",
-			cfqq->key, cfqq->allocated[0], cfqq->allocated[1],
-			cfqq->queued[0], cfqq->queued[1],
-			cfqq->last_fifo_expire, cfqq->service_used);
-	}
-	len += sprintf(page+len, "  empty queues total: %d\n", i);
-	queues += i;
-	len += sprintf(page+len, "Total queues: %d\n", queues);
-	spin_unlock_irq(cfqd->queue->queue_lock);
-	return len;
-}
-
 #define SHOW_FUNCTION(__FUNC, __VAR, __CONV)				\
 static ssize_t __FUNC(struct cfq_data *cfqd, char *page)		\
 {									\
@@ -1824,10 +1775,6 @@ static struct cfq_fs_entry cfq_clear_elapsed_entry = {
 	.attr = {.name = "clear_elapsed", .mode = S_IWUSR },
 	.store = cfq_clear_elapsed,
 };
-static struct cfq_fs_entry cfq_misc_entry = {
-	.attr = {.name = "show_status", .mode = S_IRUGO },
-	.show = cfq_status_show,
-};
 static struct cfq_fs_entry cfq_key_type_entry = {
 	.attr = {.name = "key_type", .mode = S_IRUGO | S_IWUSR },
 	.show = cfq_read_key_type,
@@ -1845,7 +1792,6 @@ static struct attribute *default_attrs[] = {
 	&cfq_back_max_entry.attr,
 	&cfq_back_penalty_entry.attr,
 	&cfq_clear_elapsed_entry.attr,
-	&cfq_misc_entry.attr,
 	NULL,
 };