Date: Tue, 22 Nov 2005 23:40:35 +0100 From: =?UTF-8?B?VsOhY2xhdiBIYWlzbWFu?= <V.Haisman@sh.cvut.cz> To: Doug White <dwhite@gumbysoft.com> Cc: freebsd-stable@freebsd.org Subject: Re: Mount related panic with FreeBSD 6? Message-ID: <43839E63.9070707@sh.cvut.cz> In-Reply-To: <20051122142927.Y24336@carver.gumbysoft.com> References: <dlpolp$9t$1@sea.gmane.org> <20051122142927.Y24336@carver.gumbysoft.com>
index | next in thread | previous in thread | raw e-mail
[-- Attachment #1 --] Doug White wrote: > On Sun, 20 Nov 2005, [UTF-8] Václav Haisman wrote: > > >>Hi, >>I got this panic on freshly installed FreeBSD 6. I did this df -h and >>noticed that /mnt/oldroot/home is somewhat mangled. The /mnt/oldroot is >>root of FreeBSD 4.11 system. I successfully copied some settings and all >>user accounts from that /mnt/oldroot/home earlier today. This is what I >>did before the panic: > > > [...] > > I discovered this by accident with a CDROM the other day. In 6.0 you can > overlay read-only mounts (i.e., mount the same R/O FS on top of itself) > but unmounting it will cause GEOM to tear down the underlying device while > leaving the first mount behind. Next access to the mountpoint will panic > the system. > > You can't mount a read/write mount on top of itself, or a r/o mount on a > r/w mount -- you get an error. A quick discussion with phk points to a > faulty or missing access check in GEOM. I'm not familiar with the VFS > operations required to mount a filesystem, though, so I'm not sure where > to look to put in the fix. > > In the interim, be careful not to mount a read-only FS multiple times. > Thanks, I will remember this. Though it really was not my intention to mount it twice. I did so because I got confused by the mangled `/mnt/oldroot/hom' name in the df output and thought it was not mounted. Vaclav Haisman [-- Attachment #2 --] -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (MingW32) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iQEVAwUBQ4Oeam56zbtzMDG0AQKjWAf9F5M6GEbVa1c7SrRbTIr2jOUU9GnSovOb fV+AZgWXlZvDqnpZTFNY94rCtpTSLfFEHgYT/8yV4ryT7wwKs3ngb/yyHePRfJ7L kRmdzHycZeww14RWYYUNAl4ZqXb4Lk1e18vXpyM55Y5zhO1fx0TfDe3j9OzibzuT e/GScUx1XqlEjNq2B9i3wEBpKCuf8VQ55nMlBZ2DA8GhbXKmg0CMrvsdAwe94h4t jFq9ZviaPatdl04SdKSyyVGBcJRurvjawS6xOGZDFkVInviTsiOdgEJqBnQ049Gs NAEdGRvlDCeg00MaNL0Pg1jyeUm2DqyYAx9gVflqvyQtEjxJK3xUfg== =TeUQ -----END PGP SIGNATURE-----help
Want to link to this message? Use this
URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?43839E63.9070707>