Re: [PATCH] Rearrange i_flags to be consistent with FS_IOC_GETFLAGS

[David Howells <dhowells@redhat.com>]

Dave Chinner <david@fromorbit.com> wrote:

> I'd prefer generic flags are not dependent on fixed values from a
> specific filesystem several layers down the storage stack.

They're not so dependent.  They're based on the FS_IOC_[GS]ETFLAGS ioctl which
even XFS translates its flags for.  These ioctl flags must now remain
invariant.  Whilst they might have originated as Ext2/3/4 flags, they're now
independent of that.

> Also, if the problem you are trying to solve is overhead of calculating the
> flags for stat() on RISC architectures, then I'd argue that XFS is just as
> important target for such an optimisation because it is widely used in small
> ARM and MIPS based NAS appliances....

This can be argued one way or another, however aligning i_flags with something
would probably be an improvement somewhere.  Most of what I deal with is Ext3/4
based, and BTRFS-based is likely to become important too.

David