From: Ming Lei Date: Wed, 9 Aug 2023 02:04:40 +0000 (+0800) Subject: nvme: core: don't hold rcu read lock in nvme_ns_chr_uring_cmd_iopoll X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=a7a7dabb5dd72d2875bc3ce56f94ea5ceb259d5b;p=tomoyo%2Ftomoyo-test1.git 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 Cc: Kanchan Joshi Cc: Anuj Gupta Signed-off-by: Ming Lei Tested-by: Guangwu Zhang Link: https://lore.kernel.org/r/20230809020440.174682-1-ming.lei@redhat.com Signed-off-by: Jens Axboe --- diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c index 5c3250f36ce7..d39f3219358b 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