[RFC PATCH v2 0/4] mtd: ubi: Enable accessing RO filesystems in UBI vols
Sam Edwards
cfsworks at gmail.com
Fri Oct 6 01:08:27 CEST 2023
Hi list,
This is the second version of my RFC patchset to treat static UBI volumes as DM
block devices, allowing users to access read-only filesystems (SquashFS, EROFS)
contained within such volumes.
This is a rebased and updated version, as requested by Heiko.
Previously, we have agreed on a syntax, which my downstream is now starting to
use:
=> ls ubi 0:rootfs /boot
=> ls ubi 0:2 /boot
This is still not yet ready for mainline inclusion, because the actual UBI DM
access is happening in disk/part.c, which is not "clean" with the way the
DM/legacy switching is currently plumbed. I'm still looking for guidance on how
to name/implement block functions for looking up a *subvolume* block device by
type+parentidx+{name,ID}.
Changes v1->v2:
- Rebased onto next post-2023.10's release.
- Fix NULL dereference caused by passing NULL to `blk_create_device`
- Parse UBI index/volume numbers with `dectoul` instead of `hextoul`, to match
Linux's behavior of treating these numbers as decimal.
- Do not treat a valid decimal number as a volume name, even if the volume ID
doesn't exist, to match Linux's behavior of always treating decimal numbers
as volume IDs.
Cheers,
Sam
Sam Edwards (4):
mtd: ubi: register UBI attachments as DM devices
mtd: ubi: bind block device driver for static volumes
disk: part: fall-through if "ubi" requested but ubifs not mounted
HACK: enable access to `ubi 0:volname` block devices
cmd/ubi.c | 11 +++
disk/part.c | 69 +++++++++++--
drivers/mtd/ubi/Makefile | 1 +
drivers/mtd/ubi/ubi-uclass.c | 185 +++++++++++++++++++++++++++++++++++
include/dm/uclass-id.h | 1 +
include/ubi_uboot.h | 5 +
6 files changed, 264 insertions(+), 8 deletions(-)
create mode 100644 drivers/mtd/ubi/ubi-uclass.c
--
2.41.0
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