On 7/19/13 11:32 AM, Markus Trippelsdorf wrote: > On 2013.07.19 at 11:02 -0500, Eric Sandeen wrote: >> On 7/19/13 7:51 AM, Markus Trippelsdorf wrote: >>> On 2013.07.19 at 14:41 +0200, Stefan Ring wrote: >>>>> I've bisected this issue to the following commit: >>>>> >>>>> commit cca9f93a52d2ead50b5da59ca83d5f469ee4be5f >>>>> Author: Dave Chinner <dchinner@xxxxxxxxxx> >>>>> Date: Thu Jun 27 16:04:49 2013 +1000 >>>>> >>>>> xfs: don't do IO when creating an new inode >>>>> >>>>> Reverting this commit on top of the Linus tree "solves" all problems for >>>>> me. IOW I no longer loose my KDE and LibreOffice config files during a >>>>> crash. Log recovery now works fine and xfs_repair shows no issues. >>>>> >>>>> So users of 3.11.0-rc1 beware. Only run this version if you have >>>>> up-to-date backups handy. >> >> Are you certain about that bisection point? All that does is >> say: When we allocate a new inode, assign it a random generation >> number, rather than reading it from disk & incrementing the >> older generation number, AFAICS. So it simply avoids a read IO. > > Yes, I'm sure. > As I wrote above I also double-checked by reverting the commit on top of > the current Linus tree. > >> I wonder if simply changing IO patterns on the SSD changes how >> it's doing caching & destaging <handwave>. > > No. The corruption also happens on my conventional (spinning) drives. > >>>> What I miss in this thread is a distinction between filesystem >>>> corruption on the one hand and a few zeroed files on the other. The >>>> latter may be a nuisance, but it is expected behavior, while the >>>> former should never happen, period, if I'm not mistaken. >>> >>> Well, it is natural that fs developers at first try to blame userspace. >> >> I disagree with that, we just need to be clear about your scenarios, >> and what integrity guarantees should apply. >> >>> Unfortunately it turned out that in this case there is filesystem >>> corruption. (Fortunately this normally happens only very rarely on rc1 >>> kernels). >> >> Corruption is when you get back data that you did not write, >> or metadata which is inconsistent or unreadable even after a proper >> log replay. >> >> Corruption is _not_ unsynced, buffered data that was lost on a >> crash or poweroff. >> >> But I might not have followed the thread properly, and I might >> misunderstand your situation. >> >> When you experience this lost file [data] scenario, was it after an >> orderly reboot, or after a crash and/or system reset? > > To reproduce this issue simply boot into your desktop and then hit > sysrq-c and reboot. Ok, a crash, so at a minimum, some buffered data loss is 100% expected. > After log replay without error messages, the > filesystem is in an inconsistent state What exactly do you mean by inconsistent state? Sorry to be pedantic here. > and many small config files are > lost. Written how long ago? Were they fsynced? I suppose you are unsure about that, if they're app-written. > There are also undeletable files. What happens when you try to delete them? > You need to run xfs_repair > manually to bring the filesystem back to normal. And what is the repair output? Can you show an exact sequence of events, capturing all relevant output from repair and/or dmesg, etc, just so we see exactly what you see? Thanks, -Eric > When cca9f93a52d is reverted, you don't loose your config files and the > filesystem is OK after log replay. xfs_repair reports no issues at all. > _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
