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| author | Ming Lei <ming.lei@redhat.com> | 2018-12-18 12:15:29 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2018-12-17 21:35:07 -0700 |
| commit | cd19181bf9ad4b7f40f2a4e0355d052109c76529 (patch) | |
| tree | 30896b4375d72ec6097eedfebaf193b368d9db0e /block/blk-sysfs.c | |
| parent | 3c94d83cb352627f221d971b05f163c17527de74 (diff) | |
| download | lwn-cd19181bf9ad4b7f40f2a4e0355d052109c76529.tar.gz lwn-cd19181bf9ad4b7f40f2a4e0355d052109c76529.zip | |
blk-mq: enable IO poll if .nr_queues of type poll > 0
The queue mapping of type poll only exists when set->map[HCTX_TYPE_POLL].nr_queues
is bigger than zero, so enhance the constraint by checking .nr_queues of type poll
before enabling IO poll.
Otherwise IO race & timeout can be observed when running block/007.
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-sysfs.c')
| -rw-r--r-- | block/blk-sysfs.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index bb7c642ffefa..0619c8922893 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -402,7 +402,8 @@ static ssize_t queue_poll_store(struct request_queue *q, const char *page, unsigned long poll_on; ssize_t ret; - if (!q->tag_set || q->tag_set->nr_maps <= HCTX_TYPE_POLL) + if (!q->tag_set || q->tag_set->nr_maps <= HCTX_TYPE_POLL || + !q->tag_set->map[HCTX_TYPE_POLL].nr_queues) return -EINVAL; ret = queue_var_store(&poll_on, page, count); |