lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Message-Id: <004901c86925$7e3d1d60$41a8400a@bsd.tnes.nec.co.jp> Date: Thu, 7 Feb 2008 10:05:12 +0900 From: "Takashi Sato" <t-sato@...jp.nec.com> To: "Theodore Tso" <tytso@....EDU> Cc: <linux-ext4@...r.kernel.org>, <linux-fsdevel@...r.kernel.org>, <linux-kernel@...r.kernel.org> Subject: Re: [RFC] ext3 freeze feature Hi, > What you *could* do is to start putting processes to sleep if they > attempt to write to the frozen filesystem, and then detect the > deadlock case where the process holding the file descriptor used to > freeze the filesystem gets frozen because it attempted to write to the > filesystem --- at which point it gets some kind of signal (which > defaults to killing the process), and the filesystem is unfrozen and > as part of the unfreeze you wake up all of the processes that were put > to sleep for touching the frozen filesystem. > > The other approach would be to say, "oh well, the freeze ioctl is > inherently dangerous, and root is allowed to himself in the foot, so > who cares". :-) Currently the XFS freezer doesn't solve a deadlock automatically and we rely on administrators for ensuring that the freezer will not access the filesystem. And even if the wrong freezer causes a deadlock, it can be solved by other unfreeze process(unfreeze command). So I don't think the freezer itself needs to solve the deadlock. I think the timeout is effective for a unexpected deadlock and the timeout extending feature is very useful as Dmitri proposed. Cheers, Takashi - To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists