[PATCH 0/3] xfsdump: more projid32bit fixes

[Eric Sandeen]

I recently sent a patch for 32-bit project IDs for xfsdump, to properly
restore the top 16 bits, which otherwise get lost.  This forced a new
dump format version 4 (we were currently at 3).

One thing missing is that we should not restore a dump with 32-bit
project IDs onto a filesystem w/o that format; the restore will fail
to restore the top 16 bits (but otherwise it returns success; attribute
setting failures are not fatal (!?))

Also, 32-bit project ID is a bit uncommon; bumping the format (and making
older restore incompatible) is a bit draconian.

3 patches here:

1/3: extend fs info call to get fs flags as well
2/3: default back to V3 and go to V4 only if the projid32 flag is set
3/3: fail restore if the target XFS fs doesn't have projid32 set

I have to say, I'm not super happy with this.  I have nagging fear
of feature-flag-itis, and I'm not sure how extensible this is as newer
versions may appear.  But anyway, here's a place to start.

(p.s. anybody have wkendall's new email?)  ;)