mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-02-18 14:23:35 -05:00
When attempting to use an archive file, such as APEX on android, as a file-backed mount source, it fails because EROFS image within the archive file does not start at offset 0. As a result, a loop or a dm device is still needed to attach the image file at an appropriate offset first. Similarly, if an EROFS image within a block device does not start at offset 0, it cannot be mounted directly either. To address this issue, this patch adds a new mount option `fsoffset=x' to accept a start offset for the primary device. The offset should be aligned to the block size. EROFS will add this offset before performing read requests. Signed-off-by: Sheng Yong <shengyong1@xiaomi.com> Signed-off-by: Wang Shuai <wangshuai12@xiaomi.com> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> Link: https://lore.kernel.org/r/20250517090544.2687651-1-shengyong1@xiaomi.com [ Gao Xiang: minor update on documentation and the error message. ] Reviewed-by: Hongbo Li <lihongbo22@huawei.com> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>