nvme: release namespace SRCU protection before performing controller ioctls

Holding the SRCU critical section protecting the namespace list can
cause deadlocks when using the per-namespace admin passthrough ioctl to
delete as namespace.  Release it earlier when performing per-controller
ioctls to avoid that.

Reported-by: Kenneth Heitke <kenneth.heitke@intel.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
This commit is contained in:
Christoph Hellwig 2019-05-17 11:47:36 +02:00 committed by Keith Busch
parent 90ec611adc
commit 5fb4aac756

View file

@ -1394,14 +1394,31 @@ static int nvme_ioctl(struct block_device *bdev, fmode_t mode,
if (unlikely(!ns))
return -EWOULDBLOCK;
/*
* Handle ioctls that apply to the controller instead of the namespace
* seperately and drop the ns SRCU reference early. This avoids a
* deadlock when deleting namespaces using the passthrough interface.
*/
if (cmd == NVME_IOCTL_ADMIN_CMD || is_sed_ioctl(cmd)) {
struct nvme_ctrl *ctrl = ns->ctrl;
nvme_get_ctrl(ns->ctrl);
nvme_put_ns_from_disk(head, srcu_idx);
if (cmd == NVME_IOCTL_ADMIN_CMD)
ret = nvme_user_cmd(ctrl, NULL, argp);
else
ret = sed_ioctl(ctrl->opal_dev, cmd, argp);
nvme_put_ctrl(ctrl);
return ret;
}
switch (cmd) {
case NVME_IOCTL_ID:
force_successful_syscall_return();
ret = ns->head->ns_id;
break;
case NVME_IOCTL_ADMIN_CMD:
ret = nvme_user_cmd(ns->ctrl, NULL, argp);
break;
case NVME_IOCTL_IO_CMD:
ret = nvme_user_cmd(ns->ctrl, ns, argp);
break;
@ -1411,8 +1428,6 @@ static int nvme_ioctl(struct block_device *bdev, fmode_t mode,
default:
if (ns->ndev)
ret = nvme_nvm_ioctl(ns, cmd, arg);
else if (is_sed_ioctl(cmd))
ret = sed_ioctl(ns->ctrl->opal_dev, cmd, argp);
else
ret = -ENOTTY;
}