在 2024/5/20 18:22, Pintu Agarwal 写道:
Hi,
In Linux Kernel 5.15 is there a way to detect in runtime, if UBI
volume (squashfs based, ubiblock, dynamic) is empty or not ?
There is a way to get the empty state of UBI volume by ioctl
UBI_IOCEBUNMAP, for example:
fd = open(UBI_VOLUME, O_EXCL)
check_volume_empty [1]
close(fd)
[1]
https://www.linux-mtd.infradead.org/?p=mtd-utils.git;a=blob;f=ubifs-utils/mkfs.ubifs/mkfs.ubifs.c;h=42a47f839e115567de58e8cdfcc50c4202fc7af1;hb=refs/heads/master#l2804
Based on this we need to make some decisions at runtime.
Currently, we are using a crude way to detect volume empty by reading
the first 1K block using the "dd" command and checking if the contents
are all FF.
Is this good enough, or is there some other better way ?
Thanks.
Pintu
.
