From: cinap_lenrek@gmx.de
To: 9fans@9fans.net
Subject: Re: [9fans] Disk backup?
Date: Mon, 25 Mar 2013 08:19:45 +0100 [thread overview]
Message-ID: <b554ab3d58d82e0786362357907ebace@rei2.9hal> (raw)
In-Reply-To: <CCCB7481-E1C0-4DA7-8A4E-1F2331F265F1@ar.aichi-u.ac.jp>
the block bitmap on a fakeworm is at the end of the sub
device/partition. see fworm.c:
int
fwormread(Device *d, Off b, void *c)
{
Iobuf *p;
Device *fdev;
Devsize l;
if(chatty > 1)
fprint(2, "fworm read %lld\n", (Wideoff)b);
fdev = FDEV(d);
l = devsize(fdev);
l -= l/(BUFSIZE*8) + 1;
if(b >= l)
panic("fworm: rbounds %lld", (Wideoff)b);
l += b/(BUFSIZE*8);
p = getbuf(fdev, l, Brd|Bres);
if(!p || checktag(p, Tvirgo, l))
panic("fworm: checktag %lld", (Wideoff)l);
l = b % (BUFSIZE*8);
if(!(p->iobuf[l/8] & (1<<(l%8)))) {
putbuf(p);
fprint(2, "fworm: read %lld\n", (Wideoff)b);
return 1;
}
putbuf(p);
return devread(fdev, b, c);
}
the block tags do not really matter for the backup. you use the
fakeworm only as a backend for the cw device so you can just
copy all the blocks that got ther bit set in the bitmap compared
to the backup.
--
cinap
next prev parent reply other threads:[~2013-03-25 7:19 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-24 22:10 trebol
2013-03-25 0:33 ` erik quanstrom
2013-03-25 2:04 ` trebol
2013-03-25 3:14 ` arisawa
2013-03-25 4:36 ` cinap_lenrek
2013-03-25 5:46 ` arisawa
2013-03-25 7:19 ` cinap_lenrek [this message]
2013-03-25 7:32 ` arisawa
2013-03-25 13:43 ` erik quanstrom
2013-03-25 15:03 ` erik quanstrom
2013-03-26 7:27 ` arisawa
2013-03-26 13:19 ` erik quanstrom
2013-03-26 18:34 ` cinap_lenrek
2013-03-26 18:56 ` erik quanstrom
2013-03-26 19:07 ` cinap_lenrek
2013-03-26 19:10 ` erik quanstrom
2013-03-26 19:15 ` erik quanstrom
2013-03-26 19:23 ` cinap_lenrek
2013-03-26 7:07 ` arisawa
2013-03-26 12:52 ` erik quanstrom
2013-03-26 23:22 ` trebol
2013-03-28 7:51 ` arisawa
2013-03-28 13:17 ` erik quanstrom
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