On 2018年06月10日 09:56, Qu Wenruo wrote: > > > On 2018年06月09日 20:22, Simon Kaiser 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 > > Tree-checker detects something. > > And indeed the bytenr is not even aligned to 512. > So definitely a corruption. > >> >> 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. > > Indeed, the corrupted bytenr is 0x4bc98004. > Looks pretty like a bit flip in the 3rd lowest bit. > > It can be fixed by manually patching the corrupted leaf to get rid of > the bitflip. > I could provide a special branch of btrfs-progs to fix it easily. > > But before that, it's better to do a scrub to see if there is other > similar problems, so I could fix them all.
Since there is no other csum error exposed by btrfs check/scrub, the fix for this particular csum item key bit flip can be fetched here: https://github.com/adam900710/btrfs-progs/tree/dirty_fix The usage will be (after the normal compile procedure) $ ./btrfs-corrupt-block -X <device> It needs to be executed offline (the <device> must be unmounted). Thanks, Qu > > Thanks, > Qu > >> >> 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 >> >> `brfs inspect-internal dump-tree -b 73263579136 /dev/sda5` (trimmed, >> full output at https://pastebin.com/dqBJ3b6D) >> >> btrfs-progs v4.16.1 >> leaf 73263579136 items 194 free space 4089 generation 530006 owner CSUM_TREE >> leaf 73263579136 flags 0x1(WRITTEN) backref revision 1 >> fs uuid 95b4974b-a798-44b3-99aa-a4eef990aeeb >> chunk uuid 9c8f46c3-ba51-4175-857c-8041543fa813 >> item 0 key (EXTENT_CSUM EXTENT_CSUM 1268850688) itemoff 16263 itemsize >> 20 >> range start 1268850688 end 1268871168 length 20480 >> item 1 key (EXTENT_CSUM EXTENT_CSUM 1268871168) itemoff 16259 itemsize 4 >> range start 1268871168 end 1268875264 length 4096 >> item 2 key (EXTENT_CSUM EXTENT_CSUM 1268875264) itemoff 16255 itemsize 4 >> range start 1268875264 end 1268879360 length 4096 >> item 3 key (EXTENT_CSUM EXTENT_CSUM 1268879360) itemoff 16239 itemsize >> 16 >> range start 1268879360 end 1268895744 length 16384 >> item 4 key (EXTENT_CSUM EXTENT_CSUM 1268895744) itemoff 16235 itemsize 4 >> range start 1268895744 end 1268899840 length 4096 >> item 5 key (EXTENT_CSUM EXTENT_CSUM 1268899840) itemoff 16223 itemsize >> 12 >> range start 1268899840 end 1268912128 length 12288 >> [...] >> item 100 key (EXTENT_CSUM EXTENT_CSUM 1271410688) itemoff 13827 >> itemsize 8 >> range start 1271410688 end 1271418880 length 8192 >> item 101 key (EXTENT_CSUM EXTENT_CSUM 1271418880) itemoff 13811 >> itemsize 16 >> range start 1271418880 end 1271435264 length 16384 >> item 102 key (EXTENT_CSUM EXTENT_CSUM 1271435264) itemoff 13807 >> itemsize 4 >> range start 1271435264 end 1271439360 length 4096 >> item 103 key (EXTENT_CSUM EXTENT_CSUM 1271439360) itemoff 13771 >> itemsize 36 >> range start 1271439360 end 1271476224 length 36864 >> item 104 key (EXTENT_CSUM EXTENT_CSUM 1271488512) itemoff 13763 >> itemsize 8 >> range start 1271488512 end 1271496704 length 8192 >> item 105 key (EXTENT_CSUM EXTENT_CSUM 1271496708) itemoff 13403 >> itemsize 360 >> range start 1271496708 end 1271865348 length 368640 >> item 106 key (EXTENT_CSUM EXTENT_CSUM 1271873536) itemoff 13399 >> itemsize 4 >> range start 1271873536 end 1271877632 length 4096 >> item 107 key (EXTENT_CSUM EXTENT_CSUM 1271877632) itemoff 13379 >> itemsize 20 >> range start 1271877632 end 1271898112 length 20480 >> item 108 key (EXTENT_CSUM EXTENT_CSUM 1271898112) itemoff 13375 >> itemsize 4 >> range start 1271898112 end 1271902208 length 4096 >> item 109 key (EXTENT_CSUM EXTENT_CSUM 1271918592) itemoff 13363 >> itemsize 12 >> range start 1271918592 end 1271930880 length 12288 >> item 110 key (EXTENT_CSUM EXTENT_CSUM 1271930880) itemoff 13351 >> itemsize 12 >> range start 1271930880 end 1271943168 length 12288 >> [...] >> >> `uname -a` >> >> Linux hostname 4.16.12-1-ARCH #1 SMP PREEMPT Fri May 25 23:30:31 UTC 2018 >> x86_64 GNU/Linux >> >> `btrfs fi show` >> >> Label: 'arch' uuid: 95b4974b-a798-44b3-99aa-a4eef990aeeb >> Total devices 1 FS bytes used 78.10GiB >> devid 1 size 100.00GiB used 94.05GiB path /dev/sda5 >> >> `btrfs fi df` >> >> Data, single: total=90.01GiB, used=76.32GiB >> System, single: total=32.00MiB, used=16.00KiB >> Metadata, single: total=4.01GiB, used=1.78GiB >> GlobalReserve, single: total=512.00MiB, used=0.00B >> >> Is there any chance this can be fixed? Your help would be greatly >> apperciated! >> >> Yours, >> Simon >> -- >> 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 >> >
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