Date: Sun, 24 Jan 2016 09:13:33 -0500 From: Shawn Webb <shawn.webb@hardenedbsd.org> To: Alan Somers <asomers@FreeBSD.org> Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r294329 - in head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs: . sys Message-ID: <20160124141333.GA19117@mutt-hardenedbsd> In-Reply-To: <201601191700.u0JH0P6k061610@repo.freebsd.org> References: <201601191700.u0JH0P6k061610@repo.freebsd.org>
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--2oS5YaxWCcQjTEyO Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable 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 >=20 > 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. B= etter > to completely disable vdev_geom from ever opening a zvol. The solution > 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. Its i= ntent > was to prevent a recursive mutex acquisition panic. However, the new ch= eck > 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 du= ring > 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 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 code 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. I'm probably just going to go revert this commit locally on my box so I can get some work done. Thanks, --=20 Shawn Webb HardenedBSD GPG Key ID: 0x6A84658F52456EEE GPG Key Fingerprint: 2ABA B6BD EF6A F486 BE89 3D9E 6A84 658F 5245 6EEE --2oS5YaxWCcQjTEyO Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCAAGBQJWpNwKAAoJEGqEZY9SRW7u0MUP/i7mAOrXGAWq9LUGWbZ2Khiq CIfq9DUKtwDvfEMSqk8tpvyMyqXll68BcFcZBT7lPOOX4DUhkKyYsvhllzu9Yq/a UHA+tXO/64WEXwTCMKBp3pPARr/wD7BRHturAQMgfsBmjWS3LbNXlle3fSMDfq5f X83wsvmU7AbYfmLS3twr9dP4kgp+LFcgGLC8zLHE7HkESXq/rEblLxrTUJCkdZuZ kT79/PkHrr0E8nhyOojCadLHfg1V0toc4Gj03ADHi17G3Bh5P8AZyniZa6fOdXtO Moc8+yMqqAmwh7J/R1QxNtGATs8oEhjgz+55jRUFVml+qlExC7aXh0PrOHSPkPc7 6890Z3HFSahDYbIfBQcku/O41i4DTOticyaAJ82O2Gc8VI4SZLagziai8RIGyETR qhqxJP3jP+g3KoF+QIQu72Ea6p/ww67Edweq80oHfSYsKKSRMP/lFrulIc4E1eP9 QHORBECiFnRvU0FQCNSuSeQ9W0IA5/Rl0Du7NNjaGpd+xsNlHKrjy50FmzgG/GWu HItpdZzQ6QhBbno2mr8AcyL4XoTi9sEWXHeKOWLx9VWqiYCfUKgkFAKh4VoJ+79r LbtMDbjDYstdnSTL7LUerRSz7iSPs/jI4Esoku4LZoCbV22ao0YiXWysR6BwSl0a L8pQ/dPnyR8VtAn7QnAb =1JIc -----END PGP SIGNATURE----- --2oS5YaxWCcQjTEyO--
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