On 10/12/12 4:32 PM, Eric Sandeen wrote: > 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?) ;) I spoke with Bill, and he actually didn't feel that a new version was needed for the projid32 fix. I'd like to get some discussion here, and reach an agreement. *NOT* bumping the version simplifies a whole lot of things. Here's what I'd said to Bill: >> If we restore old dumps w/ new xfsdump, nothing special is needed; >> 0 gets restored for the top 16 bits (vs. garbage, which WOULD be >> bad). >> >> So bumping the version really only prevents old restore from >> restoring newer dumps. >> >> If I *didn't* bump the version, then old restore would work, and >> would simply not restore the top 16 bits - just like an old >> dump+restore option did. And Bill replied: > Had a look at xfsdump, and I agree, there's no need to bump the format > version. Nice of someone to leave some zeroed pad bytes next to the > project id. so what are people's thoughts? Moving to a new version has complexity & compatibility consequences... Thanks, -Eric > _______________________________________________ > xfs mailing list > xfs@xxxxxxxxxxx > http://oss.sgi.com/mailman/listinfo/xfs > _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
