This is a note to let you know that I've just added the patch titled
nvme: core: don't hold rcu read lock in nvme_ns_chr_uring_cmd_iopoll
to the 6.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
nvme-core-don-t-hold-rcu-read-lock-in-nvme_ns_chr_ur.patch
and it can be found in the queue-6.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit f577575976f4800ac8750de557748de91d328e78
Author: Ming Lei <ming.lei@xxxxxxxxxx>
Date: Wed Aug 9 10:04:40 2023 +0800
nvme: core: don't hold rcu read lock in nvme_ns_chr_uring_cmd_iopoll
[ Upstream commit a7a7dabb5dd72d2875bc3ce56f94ea5ceb259d5b ]
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@xxxxxxxxxx>
Cc: Kanchan Joshi <joshi.k@xxxxxxxxxxx>
Cc: Anuj Gupta <anuj20.g@xxxxxxxxxxx>
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
Tested-by: Guangwu Zhang <guazhang@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230809020440.174682-1-ming.lei@xxxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c
index f15e7330b75ac..642f0310da278 100644
--- a/drivers/nvme/host/ioctl.c
+++ b/drivers/nvme/host/ioctl.c
@@ -787,14 +787,12 @@ int nvme_ns_chr_uring_cmd_iopoll(struct io_uring_cmd *ioucmd,
struct nvme_ns *ns;
struct request_queue *q;
- rcu_read_lock();
bio = READ_ONCE(ioucmd->cookie);
ns = container_of(file_inode(ioucmd->file)->i_cdev,
struct nvme_ns, cdev);
q = ns->queue;
if (test_bit(QUEUE_FLAG_POLL, &q->queue_flags) && bio && bio->bi_bdev)
ret = bio_poll(bio, iob, poll_flags);
- rcu_read_unlock();
return ret;
}
#ifdef CONFIG_NVME_MULTIPATH
