From: Christoph Hellwig <hch@xxxxxx>
[ Upstream commit 5fb4aac756acacf260b9ebd88747251effa3a2f2 ]
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@xxxxxxxxx>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@xxxxxxx>
Reviewed-by: Keith Busch <keith.busch@xxxxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/nvme/host/core.c | 25 ++++++++++++++++++++-----
1 file changed, 20 insertions(+), 5 deletions(-)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 8b77e6a05f4b..23c90382a515 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -1395,14 +1395,31 @@ 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;
@@ -1412,8 +1429,6 @@ 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;
}
--
2.20.1
