On Sat, Jun 9, 2018 at 6:22 AM, Simon Kaiser <[email protected]> wrote: > Hi all, > > I'm having trouble with my btrfs volume on a Samsung SSD 840 pro. On > startup I immediately get the error > > BTRFS critical (device sda5): corrupt leaf: root=1 block=73263579136 > slot=105, unaligned key offset for csum item, have 1271496708 should be > aligned to 4096 > > I used to make regular backups, but slacked off recently. Fixing the > filesystem isn't essential in any way, but would save me quite some time > on config tinkering and weeding out vacation photos. The second of > which I don't enjoy at all... > > On similar issues faulty RAM seemed to be the most prominent cause. I > added a third memory module quite recently which could have caused this, > but I couldn't run memtest long enough yet to verify. > > Here's the trimmed dmesg output (full output at > https://pastebin.com/7XF9i09K) > > [ 4.062748] BTRFS critical (device sda5): corrupt leaf: root=1 > block=73263579136 slot=105, unaligned key offset for csum item, have > 1271496708 should be aligned to 4096 > [ 4.063806] BTRFS info (device sda5): no csum found for inode 7810710 > start 0 > [ 4.064260] BTRFS warning (device sda5): csum failed root 257 ino 7810710 > off 109201939968 csum 0x5307fa6f expected csum 0x00000000 mirror 1 > [ 4.075834] BTRFS info (device sdb3): use lzo compression, level 0 > [ 4.075836] BTRFS info (device sdb3): enabling auto defrag > [ 4.075837] BTRFS info (device sdb3): disk space caching is enabled
What are your mount options? I suggest removing the suspected bad ram first, and then boot off alternate media: btrfs insp dump-s -f <dev> Try to mount with -o ro, and if that doesn't work try -o ro,norecovery. Read only mount is more tolerant of problems than rw mount. If either work, then update your backups while you have a chance. It's easier to backup from ro mount than it is to use 'btrfs restore' If neither -o ro nor -o ro,norecovery work try: -o usebackuproot There might be some recent changes data loss using that option. But if you're using the discard mount option, it probably will fail. If -o ro does not work, but -o ro,norecovery did work, it's a candidate for 'btrfs rescue zero-log' again there might be some recent change data loss if you zero the log. btrfs check --repair is a last resort so I don't recommend it until you've got a backup some other way. -- Chris Murphy -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
