Chromium Code Reviews
Help | Chromium Project | Sign in

Issue 3026039: [RFC] CHROMIUM: Two patches for comments: EFI GUID boot for dm-verity (Closed)

Can't Edit
Can't Publish+Mail
Start Review
3 years, 8 months ago by Will Drewry
2 years, 11 months ago
CC:, Mandeep Singh Baines, vb, Olof Johansson
Base URL:



[RFC] CHROMIUM: Two patches for comments: EFI GUID boot for dm-verity

I wanted to get these out for a first round of comments. I'll break them
up into at least two patches. The one that is most critical are the
changes to efi.c and efi.h. Do you think they will fly?

At least the dm-verity bits can be a feature of dm-verity, though I modeled
the functions so that dm itself could offer them up.

CHROMIUM: dm-verity: add efi guid-based support

Adds GUID-based device specification _and_ backing device waiting to
dm-verity itself. (We could then pull out the dm= patch if we wanted to.)

CHROMIUM: dm-verity: add dev_wait to device loading

The dm_verity.dev_wait=1 code path allows a boot-time dm-verity target to delay start . Since this is likely meant for boot path use, dm-verity must open the device with blkdev_get instead of just using bdget() and hoping that someone else has opened it (and therefore populated bd_disk, for example).

CHROMIUM: efi: define and export find_efi_partition

At present, there is no way to find a given EFI partition by its unique GUID.
The partition_type_guids are used for device setup during partition scanning
(e.g., md_autodetect) but the EFI/GPT partition table remains opaque.

The new function, find_efi_partition, will traverse a given disk
looking for a matching unique_partition_guid. On match, the partition
index is returned.

An example of use is in dm-verity. It allows the device mapper
target to pick a backing device using its unique GUID.

TEST=manual use at boot-time and from the command line with dmsetup

Boot time use is on a x86 platform with a slow-to-register usb device.

Patch Set 1 #

Patch Set 2 : fix log spam #

Patch Set 3 : make dm_verity.dev_wait=1 work (bd_disk == NULL fix) #

Patch Set 4 : don't probe so frequently #

Patch Set 5 : fix desc. dont always wait #

Unified diffs Side-by-side diffs Delta from patch set Stats (+291 lines, -5 lines) Lint Patch
M drivers/md/dm-verity.c View 1 2 3 4 5 chunks +227 lines, -5 lines 0 comments 147 errors Download
M fs/partitions/efi.c View 1 2 1 chunk +59 lines, -0 lines 0 comments 41 errors Download
M include/linux/efi.h View 1 chunk +5 lines, -0 lines 0 comments 0 errors Download
Trybot results:


Total messages: 2
Will Drewry
3 years, 8 months ago #1
Will Drewry
3 years, 8 months ago #2

Sign in to reply to this message.

Powered by Google App Engine
RSS Feeds Recent Issues | This issue
This is Rietveld 1280:2d3e6564b7b6