From: Nick Bowler <nbowler@draconx.ca>

Date: Wed, 20 Jul 2022 23:57:35 -0400

Subject: nvme: define compat_ioctl again to unbreak 32-bit userspace.

Patch-mainline: v6.0-rc1

Git-commit: a25d4261582cf00dad884c194d21084836663d3d

References: git-fixes

Commit 89b3d6e60550 ("nvme: simplify the compat ioctl handling") removed

the initialization of compat_ioctl from the nvme block_device_operations

structures.

Presumably the expectation was that 32-bit ioctls would be directed

through the regular handler but this is not the case: failing to assign

.compat_ioctl actually means that the compat case is disabled entirely,

and any attempt to submit nvme ioctls from 32-bit userspace fails

outright with -ENOTTY.

For example:

  % smartctl -x /dev/nvme0n1

  [...]

  Read NVMe Identify Controller failed: NVME_IOCTL_ADMIN_CMD: Inappropriate ioctl for device

The blkdev_compat_ptr_ioctl helper can be used to direct compat calls

through the main ioctl handler and makes things work again.

Fixes: 89b3d6e60550 ("nvme: simplify the compat ioctl handling")

Signed-off-by: Nick Bowler <nbowler@draconx.ca>

Reviewed-by: Guixin Liu <kanie@linux.alibaba.com>

Signed-off-by: Christoph Hellwig <hch@lst.de>

Signed-off-by: Jens Axboe <axboe@kernel.dk>

Acked-by: Daniel Wagner <dwagner@suse.de>

---

 drivers/nvme/host/core.c      |    1 +

 drivers/nvme/host/multipath.c |    1 +

 2 files changed, 2 insertions(+)

--- a/drivers/nvme/host/core.c

+++ b/drivers/nvme/host/core.c

@@ -2094,6 +2094,7 @@ static int nvme_report_zones(struct gend

 static const struct block_device_operations nvme_bdev_ops = {

 	.owner		= THIS_MODULE,

 	.ioctl		= nvme_ioctl,

+	.compat_ioctl	= blkdev_compat_ptr_ioctl,

 	.open		= nvme_open,

 	.release	= nvme_release,

 	.getgeo		= nvme_getgeo,

--- a/drivers/nvme/host/multipath.c

+++ b/drivers/nvme/host/multipath.c

@@ -425,6 +425,7 @@ const struct block_device_operations nvm

 	.open		= nvme_ns_head_open,

 	.release	= nvme_ns_head_release,

 	.ioctl		= nvme_ns_head_ioctl,

+	.compat_ioctl	= blkdev_compat_ptr_ioctl,

 	.getgeo		= nvme_getgeo,

 	.report_zones	= nvme_ns_head_report_zones,

 	.pr_ops		= &nvme_pr_ops,