Re: [PATCH v2 14/14] fs: xfs: Support setting FMODE_CAN_ATOMIC_WRITE

[John Garry]

On 06/03/2024 21:33, Dave Chinner wrote:
> > +static bool xfs_file_open_can_atomicwrite(
> > +	struct inode		*inode,
> > +	struct file		*file)
> > +{
> > +	struct xfs_inode	*ip = XFS_I(inode);
> > +	struct xfs_buftarg	*target = xfs_inode_buftarg(ip);
> > +
> > +	if (!(file->f_flags & O_DIRECT))
> > +		return false;
> > +
> > +	if (!xfs_inode_atomicwrites(ip))
> > +		return false;
> > +
> > +	if (!bdev_can_atomic_write(target->bt_bdev))
> > +		return false;
> Again, this is static blockdev information - the inode atomic write
> flag should not be set if the bdev cannot do atomic writes. It
> should be checked at mount time

ok

> - the filesystem probably should
> only mount read-only if it is configured to allow atomic writes and
> the underlying blockdev does not support atomic writes...

Let me know if you really would like to see that change also. It does 
seem a bit drastic, considering we can just disallow atomic writes.

Thanks,
John