On 2020/8/1 下午2:58, Qu Wenruo wrote:
> 
> 
> On 2020/8/1 下午2:51, Justin Brown wrote:
>> Hello,
>>
>> I've run into a strange problem that I haven't seen before, and I need
>> some help. I started getting generic "input/output" errors on a couple
>> of files, and when I looked deeper, the kernel logs are full of
>> messages like:
>>
>>     sd 5:0:0:0: [sdf] tag#29 access beyond end of device
> 
> We had a new fix for trim. But according to your kernel message, it
> doesn't look like the case.
> 
> (No obvious tag showing it's trim/discard)
> 
>>
>> I've never seen anything like this before with any FS, so I figured it
>> was worth asking before I consider running the standard btrfs tools.
>> (I briefly started a scrub, but it was going crazy with uncorrectable
>> errors, so I cancelled it.)
>>
>> Here's my system info:
>>
>> Fedora 32, kernel 5.7.7-200.fc32.x86_64
>> btrfs-progs v5.7
>>
>> /etc/fstab entry:
>> LABEL=media /var/media btrfs subvol=media,discard 0 2
>>
>> btrfs fi show /var/media/
>> Label: 'media' uuid: 51eef0c7-2977-4037-b271-3270ea22c7d9
>> Total devices 6 FS bytes used 4.68TiB
>> devid 1 size 1.82TiB used 963.00GiB path /dev/sdf1
>> devid 2 size 1.82TiB used 962.00GiB path /dev/sde1
>> devid 4 size 1.82TiB used 963.00GiB path /dev/sdg1
>> devid 6 size 1.82TiB used 962.03GiB path /dev/sda1
>> devid 7 size 7.28TiB used 967.03GiB path /dev/sdb1
>> devid 8 size 7.28TiB used 967.03GiB path /dev/sdd1
>>
>> btrfs fi df /var/media/
>> Data, RAID5: total=4.69TiB, used=4.68TiB
>> System, RAID1C3: total=32.00MiB, used=304.00KiB
>> Metadata, RAID1C3: total=6.00GiB, used=4.94GiB
>> GlobalReserve, single: total=512.00MiB, used=0.00B
>>
>> I can only mount -o degraded now. Here are the logs when mounting:
>>
>> Aug 01 01:15:26 spaceman.fandingo.org sudo[275572]: justin : TTY=pts/0
>> ; PWD=/home/justin ; USER=root ; COMMAND=/usr/bin/mount -t btrfs -o
>> degraded /dev/sda1 /var/media/
>> Aug 01 01:15:26 spaceman.fandingo.org kernel: sd 5:0:0:0: [sdf] tag#30
>> access beyond end of device
>> Aug 01 01:15:26 spaceman.fandingo.org kernel: blk_update_request: I/O
>> error, dev sdf, sector 2176 op 0x0:(READ) flags 0x0 phys_seg 1 prio
>> class 0
> 
> OK, it's read, not DISCARD, thus a completely different problem.
> 
> 
>> Aug 01 01:15:26 spaceman.fandingo.org kernel: Buffer I/O error on dev
>> sdf1, logical block 16, async page read
>> Aug 01 01:15:26 spaceman.fandingo.org kernel: BTRFS info (device
>> sde1): allowing degraded mounts
>> Aug 01 01:15:26 spaceman.fandingo.org kernel: BTRFS info (device
>> sde1): disk space caching is enabled
>> Aug 01 01:15:26 spaceman.fandingo.org kernel: BTRFS warning (device
>> sde1): devid 1 uuid cb05aae6-6c03-49d3-b46d-bf51a0eb8cd0 is missing
>> Aug 01 01:15:26 spaceman.fandingo.org kernel: BTRFS info (device
>> sde1): bdev /dev/sdf1 errs: wr 4458026, rd 14571, flush 0, corrupt 0,
>> gen 0
>>
>> It seems like only relatively recently written files are encountering
>> I/O errors. If I `cat` one of the problematic files when the FS is
>> mounted normally, I see a ton of this:
>>
>> Aug 01 01:13:49 spaceman.fandingo.org kernel: sd 5:0:0:0: [sdf] tag#26
>> access beyond end of device
>> Aug 01 01:13:49 spaceman.fandingo.org kernel: sd 5:0:0:0: [sdf] tag#27
>> access beyond end of device
>> Aug 01 01:13:49 spaceman.fandingo.org kernel: sd 5:0:0:0: [sdf] tag#28
>> access beyond end of device
>> Aug 01 01:13:49 spaceman.fandingo.org kernel: sd 5:0:0:0: [sdf] tag#29
>> access beyond end of device
>> Aug 01 01:13:49 spaceman.fandingo.org kernel: sd 5:0:0:0: [sdf] tag#30
>> access beyond end of device
>> Aug 01 01:13:49 spaceman.fandingo.org kernel: sd 5:0:0:0: [sdf] tag#0
>> access beyond end of device
>> Aug 01 01:13:49 spaceman.fandingo.org kernel: sd 5:0:0:0: [sdf] tag#1
>> access beyond end of device
>> Aug 01 01:13:49 spaceman.fandingo.org kernel: sd 5:0:0:0: [sdf] tag#13
>> access beyond end of device
>> Aug 01 01:13:49 spaceman.fandingo.org kernel: sd 5:0:0:0: [sdf] tag#2
>> access beyond end of device
>>
>> Now that I'm remounted in -o degraded, I'm getting more comprehensible
>> warnings, but it still results in I/O read failures:
>>
>> Aug 01 01:31:53 spaceman.fandingo.org kernel: BTRFS warning (device
>> sde1): csum failed root 2820 ino 747435 off 99942400 csum 0x8941f998
>> expected csum 0xbe3f80a4 mirror 2
>> Aug 01 01:31:53 spaceman.fandingo.org kernel: BTRFS warning (device
>> sde1): csum failed root 2820 ino 747435 off 99946496 csum 0x8941f998
>> expected csum 0x9c36a6b4 mirror 2
>> Aug 01 01:31:53 spaceman.fandingo.org kernel: BTRFS warning (device
>> sde1): csum failed root 2820 ino 747435 off 99950592 csum 0x8941f998
>> expected csum 0x44d30ca2 mirror 2
>> Aug 01 01:31:53 spaceman.fandingo.org kernel: BTRFS warning (device
>> sde1): csum failed root 2820 ino 747435 off 99958784 csum 0x8941f998
>> expected csum 0xc0f08acc mirror 2
>> Aug 01 01:31:53 spaceman.fandingo.org kernel: BTRFS warning (device
>> sde1): csum failed root 2820 ino 747435 off 99954688 csum 0x8941f998
>> expected csum 0xcb11db59 mirror 2
>> Aug 01 01:31:53 spaceman.fandingo.org kernel: BTRFS warning (device
>> sde1): csum failed root 2820 ino 747435 off 99962880 csum 0x8941f998
>> expected csum 0x8a4ee0aa mirror 2
>> Aug 01 01:31:53 spaceman.fandingo.org kernel: BTRFS warning (device
>> sde1): csum failed root 2820 ino 747435 off 99971072 csum 0x8941f998
>> expected csum 0xdfb79e85 mirror 2
>> Aug 01 01:31:53 spaceman.fandingo.org kernel: BTRFS warning (device
>> sde1): csum failed root 2820 ino 747435 off 99966976 csum 0x8941f998
>> expected csum 0xc14921a0 mirror 2
>> Aug 01 01:31:53 spaceman.fandingo.org kernel: BTRFS warning (device
>> sde1): csum failed root 2820 ino 747435 off 99975168 csum 0x8941f998
>> expected csum 0xf2fe8774 mirror 2
>> Aug 01 01:31:53 spaceman.fandingo.org kernel: BTRFS warning (device
>> sde1): csum failed root 2820 ino 747435 off 99979264 csum 0x8941f998
>> expected csum 0xae1cafd6 mirror 2
>>
>> Why trying to research this problem, I came across a Github issue
>> https://github.com/kdave/btrfs-progs/issues/282 and a patch from Qu
>> from yesterday ([PATCH] btrfs: trim: fix underflow in trim length to
>> prevent access beyond device boundary). I do use the discard mount
>> option, and I have a weekly fstrim.timer enabled. I did replace 2x2TB
>> drives with the 2x8TB drives about 1 month ago, which involved a
>> conversion to -d raid5 -m raid1c3, which I suppose could hit the same
>> code paths that resize2fs would?
> 
> The problem doesn't look like a trim one, but more likely some device
> boundary bug.
> 
> Would you please provide the following info?
> - btrfs ins dump-tree -t chunk /dev/sde1
>   This contains the device info and chunk tree dump. Doesn't contain
>   any confidential info.
>   We can use this info to determine if there is some chunk really beyond
>   device boundary.
>   I guess some chunks are already beyond device boundary by somehow.

And `lsblk -b` output.

It may be possible that device size in btrfs doesn't match with the real
device...
> 
> Thanks,
> Qu
> 
>>
>> Any advice on how to proceed would be greatly appreciated.
>>
>> Thanks,
>> Justin
>>
>