nvme: Mark external NVMe devices as removable

[PATCH] nvme: Mark external NVMe devices as removable

Posted by Kai-Heng Feng 4 years, 5 months ago

Commit c037b6c818c3 ("PCI: Add sysfs "removable" attribute") can mark
entire Thunderbolt hierarchy as removable, if system firmware provides
correct attribute.

So apply GENHD_FL_REMOVABLE for NVMe if removable bit is set, to make
userspace daemon like Udisks knows it can be automount.

Cc: Rajat Jain <rajatja@google.com>
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
 drivers/nvme/host/core.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 1af8a4513708a..1c3b04883965f 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -3851,6 +3851,9 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid,
 	ns->disk = disk;
 	ns->queue = disk->queue;
 
+	if (dev_is_removable(ctrl->dev))
+		ns->disk->flags |= GENHD_FL_REMOVABLE;
+
 	if (ctrl->opts && ctrl->opts->data_digest)
 		blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, ns->queue);
 
-- 
2.33.1

Re: [PATCH] nvme: Mark external NVMe devices as removable

Posted by Christoph Hellwig 4 years, 5 months ago

On Wed, Jan 12, 2022 at 09:31:54AM +0800, Kai-Heng Feng wrote:
> Commit c037b6c818c3 ("PCI: Add sysfs "removable" attribute") can mark
> entire Thunderbolt hierarchy as removable, if system firmware provides
> correct attribute.
> 
> So apply GENHD_FL_REMOVABLE for NVMe if removable bit is set, to make
> userspace daemon like Udisks knows it can be automount.

GENHD_FL_REMOVABLE means removable media as in floppies or CD-ROMs,
which does not apply to NVMe at all.

Re: [PATCH] nvme: Mark external NVMe devices as removable

Posted by Kai-Heng Feng 4 years, 5 months ago

On Wed, Jan 12, 2022 at 3:17 PM Christoph Hellwig <hch@lst.de> wrote:
>
> On Wed, Jan 12, 2022 at 09:31:54AM +0800, Kai-Heng Feng wrote:
> > Commit c037b6c818c3 ("PCI: Add sysfs "removable" attribute") can mark
> > entire Thunderbolt hierarchy as removable, if system firmware provides
> > correct attribute.
> >
> > So apply GENHD_FL_REMOVABLE for NVMe if removable bit is set, to make
> > userspace daemon like Udisks knows it can be automount.
>
> GENHD_FL_REMOVABLE means removable media as in floppies or CD-ROMs,
> which does not apply to NVMe at all.

USB thumb drives also use this flag, so I am not sure why it's not
applicable to NVMe?

Kai-Heng

Re: [PATCH] nvme: Mark external NVMe devices as removable

Posted by Christoph Hellwig 4 years, 5 months ago

On Wed, Jan 12, 2022 at 08:50:33PM +0800, Kai-Heng Feng wrote:
> USB thumb drives also use this flag, so I am not sure why it's not
> applicable to NVMe?

They shouldn't report this flag and might need fixing.

Re: [PATCH] nvme: Mark external NVMe devices as removable

Posted by Kai-Heng Feng 4 years, 5 months ago

On Wed, Jan 12, 2022 at 10:03 PM Christoph Hellwig <hch@lst.de> wrote:
>
> On Wed, Jan 12, 2022 at 08:50:33PM +0800, Kai-Heng Feng wrote:
> > USB thumb drives also use this flag, so I am not sure why it's not
> > applicable to NVMe?
>
> They shouldn't report this flag and might need fixing.

So what should we do? Introduce a different flag but with identical
usage for external USB and NVMe storages?

Kai-Heng

Re: [PATCH] nvme: Mark external NVMe devices as removable

Posted by Keith Busch 4 years, 5 months ago

On Thu, Jan 13, 2022 at 02:39:02PM +0800, Kai-Heng Feng wrote:
> On Wed, Jan 12, 2022 at 10:03 PM Christoph Hellwig <hch@lst.de> wrote:
> >
> > On Wed, Jan 12, 2022 at 08:50:33PM +0800, Kai-Heng Feng wrote:
> > > USB thumb drives also use this flag, so I am not sure why it's not
> > > applicable to NVMe?
> >
> > They shouldn't report this flag and might need fixing.
> 
> So what should we do? Introduce a different flag but with identical
> usage for external USB and NVMe storages?

What's the user visible result with this flag set? Does some rule
automatically mount a 'removable' block device's filesystem partitions
to something like /media/?

Re: [PATCH] nvme: Mark external NVMe devices as removable

Posted by Kai-Heng Feng 4 years, 5 months ago

On Fri, Jan 14, 2022 at 12:12 AM Keith Busch <kbusch@kernel.org> wrote:
>
> On Thu, Jan 13, 2022 at 02:39:02PM +0800, Kai-Heng Feng wrote:
> > On Wed, Jan 12, 2022 at 10:03 PM Christoph Hellwig <hch@lst.de> wrote:
> > >
> > > On Wed, Jan 12, 2022 at 08:50:33PM +0800, Kai-Heng Feng wrote:
> > > > USB thumb drives also use this flag, so I am not sure why it's not
> > > > applicable to NVMe?
> > >
> > > They shouldn't report this flag and might need fixing.
> >
> > So what should we do? Introduce a different flag but with identical
> > usage for external USB and NVMe storages?
>
> What's the user visible result with this flag set? Does some rule
> automatically mount a 'removable' block device's filesystem partitions
> to something like /media/?

Udisks uses 'removable' to flag its 'HintAuto' attribute, and GNOME
Shell will automount the disk based on 'HintAuto'.

Kai-Heng