[PATCH 13/15] block: don't allow writing to the poll queue attribute

Christoph Hellwig
2021-05-12T13:16:57Z

The poll attribute is a historic artefact from before when we had
explicit poll queues that require driver specific configuration.
Just print a warning when writing to the attribute.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
block/blk-sysfs.c | 23 ++++-------------------
1 file changed, 4 insertions(+), 19 deletions(-)

diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index f89e2fc3963b..f78e73ca6091 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -428,26 +428,11 @@ static ssize_t queue_poll_show(struct request_queue *q, char *page)
static ssize_t queue_poll_store(struct request_queue *q, const char *page,
size_t count)
{
- unsigned long poll_on;
- ssize_t ret;
-
- if (!q->tag_set || q->tag_set->nr_maps <= HCTX_TYPE_POLL ||
- !q->tag_set->map[HCTX_TYPE_POLL].nr_queues)
+ if (!test_bit(QUEUE_FLAG_POLL, &q->queue_flags))
return -EINVAL;
-
- ret = queue_var_store(&poll_on, page, count);
- if (ret < 0)
- return ret;
-
- if (poll_on) {
- blk_queue_flag_set(QUEUE_FLAG_POLL, q);
- } else {
- blk_mq_freeze_queue(q);
- blk_queue_flag_clear(QUEUE_FLAG_POLL, q);
- blk_mq_unfreeze_queue(q);
- }
-
- return ret;
+ pr_info_ratelimited("writes to the poll attribute are ignored.\n");
+ pr_info_ratelimited("please use driver specific parameters instead.\n");
+ return count;
}

static ssize_t queue_io_timeout_show(struct request_queue *q, char *page)
--
2.30.2