On Mon, 2007-12-17 at 09:43 +1100, Neil Brown wrote:

On Saturday December 15, kay.sievers@vrfy.org wrote:

quoted

On Dec 14, 2007 7:26 AM, NeilBrown [off-list ref] wrote:

quoted

Given an fd on a block device, returns a string like

        /block/sda/sda1

which can be used to find related information in /sys.

....

quoted

As pointed out to when you came up with the idea, we can't do this. A devpath
is a path to the device and will not necessarily start with "/block" for block
devices. It may start with "/devices" and can be much longer than
BDEVNAME_SIZE*2  + 10.

When you say "will not necessarily" can I take that to mean that it
currently does, but it might (will) change??

It's in -mm. The devpath for all block devices, like for all other
devices, will start with /devices/* if !SYSFS_DEPRECATED.

In that case can we have the patch as it stands and when the path to
block devices in /sys changes, the ioctl can be changed at the same
time to match?

No, you have to use kobject_get_path() to get the path to the object.
This will also handle devices where the name contains '/' which needs to
be translated to '!', which is broken in this patch.

Or are you saying that as the kernel is today, some block devices
appear under /devices/..., in which case could you please give an
example?

We expect the next kernel to have it.

Btw: BLKGETNAME should probably be renamed to something which contains
DEVPATH, to make clear that it's a path to, and not the name of the
device.

Kay