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

David Howells
2010-07-06T23:45:46Z

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