From a7a7dabb5dd72d2875bc3ce56f94ea5ceb259d5b Mon Sep 17 00:00:00 2001
From: Ming Lei <ming.lei@redhat.com>
Date: Wed, 9 Aug 2023 10:04:40 +0800
Subject: [PATCH] nvme: core: don't hold rcu read lock in
nvme_ns_chr_uring_cmd_iopoll
Now nvme_ns_chr_uring_cmd_iopoll() has switched to request based io
polling, and the associated NS is guaranteed to be live in case of
io polling, so request is guaranteed to be valid because blk-mq uses
pre-allocated request pool.
Remove the rcu read lock in nvme_ns_chr_uring_cmd_iopoll(), which
isn't needed any more after switching to request based io polling.
Fix "BUG: sleeping function called from invalid context" because
set_page_dirty_lock() from blk_rq_unmap_user() may sleep.
Fixes: 585079b6e425 ("nvme: wire up async polling for io passthrough commands")
Reported-by: Guangwu Zhang <guazhang@redhat.com>
Cc: Kanchan Joshi <joshi.k@samsung.com>
Cc: Anuj Gupta <anuj20.g@samsung.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Guangwu Zhang <guazhang@redhat.com>
Link: https://lore.kernel.org/r/20230809020440.174682-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
drivers/nvme/host/ioctl.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c
index 5c3250f36ce77..d39f3219358b9 100644
--- a/drivers/nvme/host/ioctl.c
+++ b/drivers/nvme/host/ioctl.c
@@ -786,11 +786,9 @@ int nvme_ns_chr_uring_cmd_iopoll(struct io_uring_cmd *ioucmd,
if (!(ioucmd->flags & IORING_URING_CMD_POLLED))
return 0;
- rcu_read_lock();
req = READ_ONCE(ioucmd->cookie);
if (req && blk_rq_is_poll(req))
ret = blk_rq_poll(req, iob, poll_flags);
- rcu_read_unlock();
return ret;
}
#ifdef CONFIG_NVME_MULTIPATH
--
GitLab