From: Al Viro Subject: Re: [PATCH 00/27 v6] Fix filesystem freezing deadlocks Date: Sat, 9 Jun 2012 07:29:52 +0100 Message-ID: <20120609062952.GY30000@ZenIV.linux.org.uk> References: <1338589841-9568-1-git-send-email-jack@suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, dchinner-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, Alex Elder , Anton Altaparmakov , Ben Myers , Chris Mason , cluster-devel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, "David S. Miller" , fuse-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, "J. Bruce Fields" , Joel Becker , KONISHI Ryusuke , linux-btrfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-ext4-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-nilfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-ntfs-dev-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, Mark Fasheh , Miklos Szeredi , ocfs2-devel-N0ozoZBvEnrZJqsBc5GL+g@public.gmane.org, OGAWA Hirofumi , Steven Whitehouse , Theodore Ts'o , xfs-VZNHf3L845pBDgjK7y7TUQ@public.gmane.org To: Jan Kara Return-path: Content-Disposition: inline In-Reply-To: <1338589841-9568-1-git-send-email-jack-AlSwsSmVLrQ@public.gmane.org> Sender: linux-nilfs-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-ext4.vger.kernel.org On Sat, Jun 02, 2012 at 12:30:14AM +0200, Jan Kara wrote: > Hello, > > here is the sixth iteration of my patches to improve filesystem freezing. > The change since last iteration is that filesystem can be frozen with open but > unlinked files. After some thinking, I've decided that the best way to handle > this is to block removal inside ->evict_inode() of each filesystem and use > fs-internal level of freeze protection for that (usually I've instrumented > filesystem's transaction system to use freeze protection). Handling > inside VFS would be less work but the only level of freeze protection that > has a chance of not causing deadlocks is the one used for page faults and even > there it's not clear lock ordering would be correct wrt some fs-specific locks. > I've converted ext2, ext4, btrfs, xfs, nilfs2, ocfs2, gfs2 and also checked > that ext3, reiserfs, jfs should work as well (they have their internal freeze > protection mechanisms, possibly they could be replaced by a generic one but > given these are mostly aging filesystems, it's not a real priority IHMO). > So finally I'm not aware of any pending issue with this patch set so if you > have some concern, please speak up! Could you rebase on top of e.g. -rc2 and repost? -- To unsubscribe from this list: send the line "unsubscribe linux-nilfs" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html