Date: Sun, 24 Jan 2016 12:28:03 -0500 From: Allan Jude <allanjude@freebsd.org> To: Shawn Webb <shawn.webb@hardenedbsd.org> Cc: svn-src-all@freebsd.org Subject: Re: svn commit: r294329 - in head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs: . sys Message-ID: <56A509A3.6020808@freebsd.org> In-Reply-To: <20160124141333.GA19117@mutt-hardenedbsd> References: <201601191700.u0JH0P6k061610@repo.freebsd.org> <20160124141333.GA19117@mutt-hardenedbsd>
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This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --PDOfdeqgWrXeiIOK81NRqW2O3lFNSTAum Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable On 2016-01-24 09:13, Shawn Webb wrote: > On Tue, Jan 19, 2016 at 05:00:25PM +0000, Alan Somers wrote: >> Author: asomers >> Date: Tue Jan 19 17:00:25 2016 >> New Revision: 294329 >> URL: https://svnweb.freebsd.org/changeset/base/294329 >> >> Log: >> Disallow zvol-backed ZFS pools >> =20 >> Using zvols as backing devices for ZFS pools is fraught with panics = and >> deadlocks. For example, attempting to online a missing device in the= >> presence of a zvol can cause a panic when vdev_geom tastes the zvol.= Better >> to completely disable vdev_geom from ever opening a zvol. The soluti= on >> relies on setting a thread-local variable during vdev_geom_open, and= >> returning EOPNOTSUPP during zvol_open if that thread-local variable = is set. >> =20 >> Remove the check for MUTEX_HELD(&zfsdev_state_lock) in zvol_open. It= s intent >> was to prevent a recursive mutex acquisition panic. However, the new= check >> for the thread-local variable also fixes that problem. >> =20 >> Also, fix a panic in vdev_geom_taste_orphan. For an unknown reason, = this >> function was set to panic. But it can occur that a device disappears= during >> tasting, and it causes no problems to ignore this departure. >> =20 >> Reviewed by: delphij >> MFC after: 1 week >> Relnotes: yes >> Sponsored by: Spectra Logic Corp >> Differential Revision: https://reviews.freebsd.org/D4986 >=20 > I've just been bit by this pretty hard. I have a bhyve VM that's backed= > by a zvol. The VM is running root-on-zfs. I wrote some experimental cod= e > that's now preventing the VM from booting (kernel panic due to userland= > change). Since I can't import the pool, I have no way of fixing the > problem. >=20 > I'm probably just going to go revert this commit locally on my box so I= > can get some work done. >=20 > Thanks, >=20 Alan is working on making it a sysctl, so you can turn the old behaviour back on. You might want to test that patch: https://reviews.freebsd.org/D4998 --=20 Allan Jude --PDOfdeqgWrXeiIOK81NRqW2O3lFNSTAum Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (MingW32) iQIcBAEBAgAGBQJWpQmjAAoJEBmVNT4SmAt+Q1cP/i3Egvv98EjH070rTkz4ybGA 5xxaTwx0CY0oBH/AT1biFfsBjX/TRd2WvA1+dhdihmByuxFKebwF7Q82Kr5PwkMY V9rFLoJpTEoTFrUtifHXkCxPKbZJm6MuTRFf3fPDoLaw+DJgUFuvEtiQvozrZ6M0 ShE26cz1JCoqjL0jf6SB4b3cS6K2NGvsHnI7J3MNfkDHT9dBe0am2ccdsNS6+W+7 brRTRJ2s4ClTGNJQR81wpEAFYr+X+CCDDEq8FNau6rDwjb1QsbifbbptAm2R8kpa a1c9aTdS0J+S8xp80R1uZVYBwh27mRaoWMwc5OR9+W2kGa7ssZFDDyKcjlNi6F6k jpx1GkIxmmBh0O2+k7gRY263nVtpH1F8XncutJAItAsunLPaPk5kcZjXSqxO3DKY 0QxkQTjyWnyQjXf6DJgFTAgasgombNMNNZ7f7AivGtNh94QA/u1b798pjRLOqFl6 DHufCdNmiK08ECg56UrA+pZ/BEFbAwq2aMOPxf2Yaw8lZRJsW4Kt7gqrpMfRDLjw 1BCBOaph/7PCPFMLzXBQpwoAN9kjDHO9LtGRTWiPNl7LjUxUf/WTPFmKZbJtyxLu wOzPFwXYHz2YLTQ/TyhEfdN2sWxJsnA9O5fkXrvVK4knaFNFOLTjynsHCCcG8wfx 8eG4Mblxbb08AllnvuEz =0MNG -----END PGP SIGNATURE----- --PDOfdeqgWrXeiIOK81NRqW2O3lFNSTAum--
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