I recently made a few changes to vnd(4) to make it stricter by better
emulating physical disks and their requirements (e.g., raw disk I/O
must be done with whole sectors). However, it turns out that a lot of
the release scripts depended on the more lenient behavior vnd(4) used
to exhibit.
It's too late in the release cycle to attempt to fix up the offending
scripts and tools, so we need to revert vnd(4). The diff below
reverts these behavioral changes I made to vnd(4):
1. Allow disk reads and writes of less than a complete sector at a
time. (This is currently needed for at least sgivol(8), and was
previously needed for some of the dd commands in socppc's
scripts.)
2. In physio(), don't panic if (*strategy)() didn't do a whole
sector worth of I/O. (This is needed because of #1.)
3. Don't flush the disklabel cache when all of the partitions have
been closed. (This is currently needed for at least
readsgilabel(), because it re-spoofs a bad disklabel on >512-byte
sector disks.)
4. Don't complain if the user tries to modify a vnd(4) partition's
offset or size while it's open. (I don't believe this is
actually necessary with #3, but I think it's better to revert
anyway just to avoid further surprises.)
Anyway, expect this diff to be used for building releases. If you
have other uses for vnd(4), then please test this now and report
problems sooner rather than later.
Thanks.
Index: kern/kern_physio.c
===================================================================
RCS file: /home/mdempsky/anoncvs/cvs/src/sys/kern/kern_physio.c,v
retrieving revision 1.38
diff -u -p -r1.38 kern_physio.c
--- kern/kern_physio.c 7 Jul 2011 16:50:15 -0000 1.38
+++ kern/kern_physio.c 16 Jul 2011 17:37:01 -0000
@@ -199,8 +199,6 @@ physio(void (*strategy)(struct buf *), d
panic("done < 0; strategy broken");
if (done > todo)
panic("done > todo; strategy broken");
- if ((done % DEV_BSIZE) != 0)
- panic("(done % DEV_BSIZE) != 0; strategy
broken");
#endif
iovp->iov_len -= done;
iovp->iov_base = (caddr_t)iovp->iov_base + done;
Index: dev/vnd.c
===================================================================
RCS file: /home/mdempsky/anoncvs/cvs/src/sys/dev/vnd.c,v
retrieving revision 1.146
diff -u -p -r1.146 vnd.c
--- dev/vnd.c 8 Jul 2011 20:10:34 -0000 1.146
+++ dev/vnd.c 16 Jul 2011 22:50:03 -0000
@@ -255,8 +255,10 @@ vndclose(dev_t dev, int flags, int mode,
disk_closepart(&sc->sc_dk, part, mode);
+#if 0
if (sc->sc_dk.dk_openmask == 0)
sc->sc_flags &= ~VNF_HAVELABEL;
+#endif
disk_unlock(&sc->sc_dk);
return (0);
@@ -269,6 +271,7 @@ vndstrategy(struct buf *bp)
struct vnd_softc *sc;
struct partition *p;
off_t off;
+ long origbcount;
int s;
DNPRINTF(VDB_FOLLOW, "vndstrategy(%p): unit %d\n", bp, unit);
@@ -284,8 +287,31 @@ vndstrategy(struct buf *bp)
goto bad;
}
- if (bounds_check_with_label(bp, sc->sc_dk.dk_label) == -1)
+ /*
+ * Many of the distrib scripts assume they can issue arbitrary
+ * sized requests to raw vnd devices irrespective of the
+ * emulated disk geometry.
+ *
+ * To continue supporting this, round the block count up to a
+ * multiple of d_secsize for bounds_check_with_label(), and
+ * then restore afterwards.
+ *
+ * We only do this for non-encrypted vnd, because encryption
+ * requires operating on blocks at a time.
+ */
+ origbcount = bp->b_bcount;
+ if (sc->sc_keyctx == NULL) {
+ u_int32_t secsize = sc->sc_dk.dk_label->d_secsize;
+ bp->b_bcount = ((origbcount + secsize - 1) & ~(secsize - 1));
+ }
+
+ if (bounds_check_with_label(bp, sc->sc_dk.dk_label) == -1) {
+ bp->b_resid = bp->b_bcount = origbcount;
goto done;
+ }
+
+ if (origbcount < bp->b_bcount)
+ bp->b_bcount = origbcount;
p = &sc->sc_dk.dk_label->d_partitions[DISKPART(bp->b_dev)];
off = DL_GETPOFFSET(p) * sc->sc_dk.dk_label->d_secsize +
@@ -570,7 +596,7 @@ vndioctl(dev_t dev, u_long cmd, caddr_t
return (error);
error = setdisklabel(sc->sc_dk.dk_label,
- (struct disklabel *)addr, sc->sc_dk.dk_openmask);
+ (struct disklabel *)addr, /* sc->sc_dk.dk_openmask */ 0);
if (error == 0) {
if (cmd == DIOCWDINFO)
error = writedisklabel(DISKLABELDEV(dev),
