[PATCH -next v3] ubi: Fix failure attaching when vid_hdr offset equals to (sub)page size

[Nicolas Schichan]

> Following process will make ubi attaching failed since commit
> 1b42b1a36fc946 ("ubi: ensure that VID header offset ... size"):
>
> ID="0xec,0xa1,0x00,0x15" # 128M 128KB 2KB
> modprobe nandsim id_bytes=$ID
> flash_eraseall /dev/mtd0
> modprobe ubi mtd="0,2048"  # set vid_hdr offset as 2048 (one page)
> (dmesg):
>   ubi0 error: ubi_attach_mtd_dev [ubi]: VID header offset 2048 too large.
>   UBI error: cannot attach mtd0
>   UBI error: cannot initialize UBI, error -22
>
> Rework original solution, the key point is making sure
> 'vid_hdr_shift + UBI_VID_HDR_SIZE < ubi->vid_hdr_alsize',
> so we should check vid_hdr_shift rather not vid_hdr_offset.
> Then, ubi still support (sub)page aligined VID header offset.
>
> Fixes: 1b42b1a36fc946 ("ubi: ensure that VID header offset ... size")
> Signed-off-by: Zhihao Cheng <chengzhihao1 at huawei.com>
> ---
>  v2->v3: Use printing format '%zu' for UBI_VID_HDR_SIZE.
>  drivers/mtd/ubi/build.c | 21 +++++++++++++++------
>  1 file changed, 15 insertions(+), 6 deletions(-)

[...]

Hello,

Having had the problem, and found this patch as a fix, feel free to
add my:

Tested-by: Nicolas Schichan <nschichan at freebox.fr>

-- 
Nicolas Schichan