On 10/28/12 12:08 PM, Andreas Dilger wrote: > On 2012-10-27, at 15:34, Eric Sandeen <sandeen@xxxxxxxxxx <mailto:sandeen@xxxxxxxxxx>> wrote: >> I've been testing with a hacked up devicemapper target which creates >> a "dirty" snapshot which requires a replay; saves the actual power >> drop & restore cycle, and I could repro the journal_checksum bug >> right off. > > Are you using dm-flakey, or something home grown? I've heard about dm-flakey, but haven't looked into the details to know whether it is actually useful for such testing. I just changed DM to not quiesce the fs by hardcoding do_lockfs to "0" in dm_suspend(). >> XFS has an ioctl to make this easy in regression testing, and several >> tests in xfstests do cover xfs journal recovery. We need >> to add such a thing to ext4. Not being able to programatically >> test recovery is a problem. > > We have a patch that we used for testing Lustre (and in turn ext4) > recovery which sits in the block layer and discards writes after a > trigger is hit. The trigger can be triggered programmatically inside > the Lustre code, or via ioctl from userspace. > > http://git.whamcloud.com/?p=fs/lustre-release.git;a=blob;f=lustre/kernel_patches/patches/dev_read_only-2.6.32-rhel6.patch > <http://git.whamcloud.com/?p=fs/lustre-release.git;a=blob;f=lustre/kernel_patches/patches/dev_read_only-2.6.32-rhel6.patch;h=8c79b40b939fccbdb5c3bc4501ee433e23cc7831;hb=HEAD> > > > I'd been thinking of moving our testing over to dm-flakey once we get to a new enough kernel (2.6.38+) and/or when it gets back-ported to RHEL6, since this is the last patch to the core kernel that we need for Lustre. XFS has XFS_IOC_GOINGDOWN to force recovery on the next mount, and several xfstests to exercise it. -Eric > Cheers, Andreas -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
