[PATCH 5.15] dm init: add dm-mod.waitfor to wait for asynchronously probed block devices

[Greg KH]

On Thu, Jul 13, 2023 at 01:58:37PM +0800, Mark-PK Tsai wrote:
> From: Peter Korsgaard <peter at korsgaard.com>
> 
> Just calling wait_for_device_probe() is not enough to ensure that
> asynchronously probed block devices are available (E.G. mmc, usb), so
> add a "dm-mod.waitfor=<device1>[,..,<deviceN>]" parameter to get
> dm-init to explicitly wait for specific block devices before
> initializing the tables with logic similar to the rootwait logic that
> was introduced with commit  cc1ed7542c8c ("init: wait for
> asynchronously scanned block devices").
> 
> E.G. with dm-verity on mmc using:
> dm-mod.waitfor="PARTLABEL=hash-a,PARTLABEL=root-a"
> 
> [    0.671671] device-mapper: init: waiting for all devices to be available before creating mapped devices
> [    0.671679] device-mapper: init: waiting for device PARTLABEL=hash-a ...
> [    0.710695] mmc0: new HS200 MMC card at address 0001
> [    0.711158] mmcblk0: mmc0:0001 004GA0 3.69 GiB
> [    0.715954] mmcblk0boot0: mmc0:0001 004GA0 partition 1 2.00 MiB
> [    0.722085] mmcblk0boot1: mmc0:0001 004GA0 partition 2 2.00 MiB
> [    0.728093] mmcblk0rpmb: mmc0:0001 004GA0 partition 3 512 KiB, chardev (249:0)
> [    0.738274]  mmcblk0: p1 p2 p3 p4 p5 p6 p7
> [    0.751282] device-mapper: init: waiting for device PARTLABEL=root-a ...
> [    0.751306] device-mapper: init: all devices available
> [    0.751683] device-mapper: verity: sha256 using implementation "sha256-generic"
> [    0.759344] device-mapper: ioctl: dm-0 (vroot) is ready
> [    0.766540] VFS: Mounted root (squashfs filesystem) readonly on device 254:0.
> 
> Signed-off-by: Peter Korsgaard <peter at korsgaard.com>
> Signed-off-by: Mike Snitzer <snitzer at kernel.org>
> Cc: stable at vger.kernel.org
> Signed-off-by: Mark-PK Tsai <mark-pk.tsai at mediatek.com>
> ---
>  .../admin-guide/device-mapper/dm-init.rst     |  8 +++++++
>  drivers/md/dm-init.c                          | 22 ++++++++++++++++++-
>  2 files changed, 29 insertions(+), 1 deletion(-)

What is the git commit id of this change in Linus's tree?

thanks,

greg k-h