Re: [PATCH v1] xfs: Fail remount with noattr2 on a v5 xfs with CONFIG_XFS_SUPPORT_V4=y

[Christoph Hellwig <hch@infradead.org>]

Hi Nirjhar,

sorry for the delay, I dropped the ball while on vacation.

On Wed, Apr 16, 2025 at 01:05:46PM +0530, Nirjhar Roy (IBM) wrote:
> 
> Yes, we need a second pass and I think that is already being done by
> xfs_finish_flags() in xfs_fs_fill_super(). However, in xfs_fs_reconfigure(),
> we still need a check to make a transition from /* attr2 -> noattr2 */ and
> /* noattr2 -> attr2 */ (only if it is permitted to) and update
> mp->m_features accordingly, just like it is being done for inode32 <->
> inode64, right?

Yes.

> Also, in your previous reply[1], you did suggest moving the
> crc+noattr2 check to xfs_fs_validate_params() - Are you suggesting to add
> another optional (NULLable) parameter "new_mp" to xfs_fs_validate_params()
> and then moving the check to xfs_fs_validate_params()?

No, let's skip that.

But we really should share the code for the validation.  So while a lot
of the checks in xfs_finish_flags are uselss in remount, it might still
be a good idea to just use that for the option validation so that we
don't miss checks in remount.