WSL2-Linux-Kernel/Documentation/admin-guide/device-mapper
Peter Korsgaard 866bf37b7c dm init: add dm-mod.waitfor to wait for asynchronously probed block devices
commit 035641b01e upstream.

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  cc1ed7542c ("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@korsgaard.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Cc: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-07-23 13:47:51 +02:00
..
cache-policies.rst
cache.rst
delay.rst
dm-clone.rst
dm-crypt.rst dm crypt: support using trusted keys 2021-02-03 10:13:00 -05:00
dm-dust.rst
dm-ebs.rst
dm-flakey.rst
dm-ima.rst dm ima: update dm documentation for ima measurement support 2021-08-20 16:07:37 -04:00
dm-init.rst dm init: add dm-mod.waitfor to wait for asynchronously probed block devices 2023-07-23 13:47:51 +02:00
dm-integrity.rst - Fix DM integrity's HMAC support to provide enhanced security of 2021-02-22 10:22:54 -08:00
dm-io.rst
dm-log.rst
dm-queue-length.rst
dm-raid.rst
dm-service-time.rst
dm-uevent.rst
dm-zoned.rst
era.rst
index.rst dm: add documentation for IMA measurement support 2021-08-10 13:34:23 -04:00
kcopyd.rst
linear.rst
log-writes.rst
persistent-data.rst
snapshot.rst
statistics.rst
striped.rst
switch.rst
thin-provisioning.rst
unstriped.rst
verity.rst
writecache.rst dm writecache: count number of blocks discarded, not number of discard bios 2022-08-17 14:23:13 +02:00
zero.rst