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
Direct .compat_ioctl to the main ioctl handlers in order to make things
work again.
Fixes: 89b3d6e60550 ("nvme: simplify the compat ioctl handling")
Signed-off-by: Nick Bowler <[email protected]>
---
drivers/nvme/host/core.c | 1 +
drivers/nvme/host/multipath.c | 1 +
2 files changed, 2 insertions(+)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index a2862a56fadc..30e105dbc178 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2093,6 +2093,7 @@ static int nvme_report_zones(struct gendisk *disk, sector_t sector,
static const struct block_device_operations nvme_bdev_ops = {
.owner = THIS_MODULE,
.ioctl = nvme_ioctl,
+ .compat_ioctl = nvme_ioctl,
.open = nvme_open,
.release = nvme_release,
.getgeo = nvme_getgeo,
diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index d464fdf978fb..0f38a5feec22 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -408,6 +408,7 @@ const struct block_device_operations nvme_ns_head_ops = {
.open = nvme_ns_head_open,
.release = nvme_ns_head_release,
.ioctl = nvme_ns_head_ioctl,
+ .compat_ioctl = nvme_ns_head_ioctl,
.getgeo = nvme_getgeo,
.report_zones = nvme_ns_head_report_zones,
.pr_ops = &nvme_pr_ops,
--
2.35.1
Hi Nick,
Should this in the brace of "#ifdef CONFIG_COMPAT" and "#endif"?
best regards,
Guixin Liu
在 2022/7/20 09:55, Nick Bowler 写道:
> 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
>
> Direct .compat_ioctl to the main ioctl handlers in order to make things
> work again.
>
> Fixes: 89b3d6e60550 ("nvme: simplify the compat ioctl handling")
> Signed-off-by: Nick Bowler <[email protected]>
> ---
> drivers/nvme/host/core.c | 1 +
> drivers/nvme/host/multipath.c | 1 +
> 2 files changed, 2 insertions(+)
>
> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> index a2862a56fadc..30e105dbc178 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -2093,6 +2093,7 @@ static int nvme_report_zones(struct gendisk *disk, sector_t sector,
> static const struct block_device_operations nvme_bdev_ops = {
> .owner = THIS_MODULE,
> .ioctl = nvme_ioctl,
> + .compat_ioctl = nvme_ioctl,
> .open = nvme_open,
> .release = nvme_release,
> .getgeo = nvme_getgeo,
> diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
> index d464fdf978fb..0f38a5feec22 100644
> --- a/drivers/nvme/host/multipath.c
> +++ b/drivers/nvme/host/multipath.c
> @@ -408,6 +408,7 @@ const struct block_device_operations nvme_ns_head_ops = {
> .open = nvme_ns_head_open,
> .release = nvme_ns_head_release,
> .ioctl = nvme_ns_head_ioctl,
> + .compat_ioctl = nvme_ns_head_ioctl,
> .getgeo = nvme_getgeo,
> .report_zones = nvme_ns_head_report_zones,
> .pr_ops = &nvme_pr_ops,
On Tue, Jul 19, 2022 at 09:55:38PM -0400, Nick Bowler wrote:
> 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.
I don't think wiring up the native version is the right thing to do,
this needs to be blkdev_compat_ptr_ioctl, just like we use
compat_ptr_ioctl for the character device nodes.
On 2022-07-20, Christoph Hellwig <[email protected]> wrote:
> On Tue, Jul 19, 2022 at 09:55:38PM -0400, Nick Bowler wrote:
>> 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.
>
> I don't think wiring up the native version is the right thing to do,
> this needs to be blkdev_compat_ptr_ioctl, just like we use
> compat_ptr_ioctl for the character device nodes.
OK, I will try that.
Thanks,
Nick
On 2022-07-19, Guixin Liu <[email protected]> wrote:
> 在 2022/7/20 09:55, Nick Bowler 写道:
[...]
>> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
>> index a2862a56fadc..30e105dbc178 100644
>> --- a/drivers/nvme/host/core.c
>> +++ b/drivers/nvme/host/core.c
>> @@ -2093,6 +2093,7 @@ static int nvme_report_zones(struct gendisk *disk,
>> sector_t sector,
>> static const struct block_device_operations nvme_bdev_ops = {
>> .owner = THIS_MODULE,
>> .ioctl = nvme_ioctl,
>> + .compat_ioctl = nvme_ioctl,
>> .open = nvme_open,
>> .release = nvme_release,
>> .getgeo = nvme_getgeo,
[...]
> Should this in the brace of "#ifdef CONFIG_COMPAT" and "#endif"?
I think it doesn't make any significant difference either way -- the
.compat_ioctl member is always present in the block_device_operations
structure. Unconditional assignment thus seems more sensible to me.
v2 uses blkdev_compat_ptr_ioctl which expands to NULL for !CONFIG_COMPAT.
Thanks,
Nick