Make md(4) support GEOM::ident.
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Authored by trasz on Sep 5 2017, 12:16 PM.

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kib
mav
avg

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rS324275: Make md(4) support GEOM::ident for vnode-backed disks. It's based

Summary

Make md(4) support GEOM::ident. For swap- and malloc-backed disks
it's random; for vnode-backed ones it's based on backing file device
and inode numbers.

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rS FreeBSD src repository - subversion

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Event Timeline

trasz created this revision.Sep 5 2017, 12:16 PM

Herald added a subscriber: imp. · View Herald TranscriptSep 5 2017, 12:16 PM

trasz added reviewers: kib, mav, avg.Sep 5 2017, 12:16 PM

kib added inline comments.Sep 5 2017, 12:24 PM

sys/dev/md/md.c
1300 ↗	(On Diff #32670)	This allows duplicated idents. What is the purpose of the field ?
1419 ↗	(On Diff #32670)	Did you build-tested this on 32bit arches ?

trasz added inline comments.Sep 7 2017, 3:16 PM

sys/dev/md/md.c
1300 ↗	(On Diff #32670)	You mean, 32 bits are not enough to guarantee uniqueness? As for the purpose - in this case (generally: in cases other than vnode) it doesn't serve any purpose. Perhaps I should just remove it for cases other than vnode?
1419 ↗	(On Diff #32670)	Not yet.

kib added inline comments.Sep 7 2017, 3:43 PM

sys/dev/md/md.c
1300 ↗	(On Diff #32670)	I mean that two arc4random() call makes no guarantee about uniqueness of the result. You add some feature and do not explain its purpose, more, you state that in some cases the feature has no purpose.

I don't see a point in reporting random ident strings. Those are normally useful to make things persistent, but random is not a way for that. May be I'd see it more useful to have it user-configurable.

Get rid of random idents; they don't serve any purpose.

Harbormaster completed remote builds in B11430: Diff 32794.Sep 8 2017, 10:44 AM

trasz marked 3 inline comments as done.Sep 12 2017, 2:55 PM

Fix tinderbox.

Harbormaster completed remote builds in B11560: Diff 33060.Sep 14 2017, 11:37 AM

trasz marked 2 inline comments as done.Sep 14 2017, 11:38 AM

Closed by commit rS324275: Make md(4) support GEOM::ident for vnode-backed disks. It's based (authored by trasz). · Explain WhyOct 4 2017, 12:23 PM

This revision was automatically updated to reflect the committed changes.