Hi Icenowy,
Yes, I can see that mount_block_root() calls ksys_mount(), however it handles 0,
EACCES and EINVAL error code..., but as manual of mount(2) said that there are
lots of error number it can return, so I suggest we'd better fix below error
handling.
int err = do_mount_root(name, p, flags, root_mount_data);
switch (err) {
case 0:
goto out;
case -EACCES:
case -EINVAL:
continue;
}
In another point, I agreed that we should not just return -EFSCORRUPTED for all
failure cases of sanity_check_raw_super(), EINVAL should be returned correctly
if the filesystem magic number is not f2fs' one, and EFSCORRUPTED for the other
cases.
Thanks,
On 2019/7/24 21:06, Icenowy Zheng wrote:
> The kernel mount_block_root() function expects -EACESS or -EINVAL for a
> unmountable filesystem when trying to mount the root with different
> filesystem types.
>
> However, in 5.3-rc1 the behavior when F2FS code cannot find valid block
> changed to return -EFSCORRUPTED(-EUCLEAN), and this error code makes
> mount_block_root() fail when trying to probe F2FS. As invalid
> superblocks mean the filesystem cannot be recognized as F2FS (it might
> be another FS), returning -EINVAL seems more reasonable, and other
> filesystems also do this.
>
> Change back the return value to -EINVAL when no valid superblocks are
> found.
>
> Fixes: 10f966bbf521 ("f2fs: use generic EFSBADCRC/EFSCORRUPTED")
> Signed-off-by: Icenowy Zheng <icen...@aosc.io>
> ---
> This commit fixes a regression introduced in v5.3-rc1, which leads to
> btrfs / cannot be mounted if no initrd is used and both f2fs and btrfs
> are built-in.
>
> fs/f2fs/super.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index 6de6cda44031..949309b9f1b8 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -2873,7 +2873,7 @@ static int read_raw_super_block(struct f2fs_sb_info
> *sbi,
> if (sanity_check_raw_super(sbi, bh)) {
> f2fs_err(sbi, "Can't find valid F2FS filesystem in %dth
> superblock",
> block + 1);
> - err = -EFSCORRUPTED;
> + err = -EINVAL;
> brelse(bh);
> continue;
> }
>
