Re: [PATCH 4/4] btrfs: introduce new "rescue=ignoresuperflags" mount option

[Qu Wenruo <quwenruo.btrfs@gmx.com>]

在 2024/6/13 05:12, David Sterba 写道:
> On Tue, Jun 11, 2024 at 02:51:38PM +0930, Qu Wenruo wrote:
>> This new mount option would allow the kernel to skip the super flags
>> check, it's mostly to allow the kernel to do a rescue mount of an
>> interrupted checksum conversion.
>
> This is for future-proofing but the current known super flags should be
> at least defined in the kernel code

That's already done in this patch:

https://lore.kernel.org/linux-btrfs/57b836631f9c5dcb24ace616bdb76a37b8d084b2.1717818761.git.wqu@suse.com/T/#u

> and with a warning or info message.
> BTRFS_SUPER_FLAG_CHANGING_FSID and _V2.

I can add some extra warning messages, but currently we do not do any
messages for rescue mount options at all, since user is definitely aware
of some problems then go with rescue.
(And rescue has to be paired with ro, which should already rejected the
mount once when tried without ro, thus the end user definitely knows
what they are doing)

Thus I'm more or less fine without any error messages for now.

Thanks,
Qu
>
> Same comment as for the imetacsum, missing sysfs.c entry.
>