Re: Leaf corruption due to csum range

[Filipe Manana <fdmanana@gmail.com>]

On Tue, May 11, 2021 at 7:19 PM Philipp Fent <fent@in.tum.de> wrote:
>
> Thanks for the explanation! I wasn't aware of these ioctls.
>
> > strace would be clear to me, which I'm more familiar with (or even
> better, bpftrace).
>
> I've attached an strace output that decompresses to about 200MB
> logfiles. I can't make heads or tails of it, but I hope it helps.
> I have never used bpftrace, do you have any pointers where I could start?

There's some documentation and examples on their github.

>
> > I just remembered that 5.13-rc1 includes a fix for races between mmap
> writes and fsync that could fix that
>
> I tried 5.13-rc1, but I'm running into the same csum range issue:
>
>
>
> Linux version 5.13.0-rc1-1-mainline (linux-mainline@archlinux) (gcc
> (GCC) 10.2.0, GNU ld (GNU Binutils) 2.36.1) #1 SMP PREEMPT Tue, 11 May
> 2021 15:34:19 +0000
> ...
> BTRFS critical (device sda): corrupt leaf: root=18446744073709551610
> block=507430633472 slot=5, csum end range (293918547968) goes beyond the
> start range (293918416896) of the next csum item
> BTRFS info (device sda): leaf 507430633472 gen 18451 total ptrs 11 free
> space 5016 owner 18446744073709551610
>         item 0 key (18446744073709551606 128 293837238272) itemoff 15923
> itemsize 360
>         item 1 key (18446744073709551606 128 293838544896) itemoff 15863
> itemsize 60
>         item 2 key (18446744073709551606 128 293838675968) itemoff 15563
> itemsize 300
>         item 3 key (18446744073709551606 128 293839527936) itemoff 15503
> itemsize 60
>         item 4 key (18446744073709551606 128 293872295936) itemoff 15263
> itemsize 240
>         item 5 key (18446744073709551606 128 293913763840) itemoff 10591
> itemsize 4672
>         item 6 key (18446744073709551606 128 293918416896) itemoff 8351
> itemsize 2240
>         item 7 key (18446744073709551606 128 293947658240) itemoff 8347
> itemsize 4
>         item 8 key (18446744073709551606 128 293965193216) itemoff 8287
> itemsize 60
>         item 9 key (18446744073709551606 128 293965848576) itemoff 8227
> itemsize 60
>         item 10 key (18446744073709551606 128 293966176256) itemoff 5291
> itemsize 2936
> BTRFS error (device sda): block=507430633472 write time tree block
> corruption detected
> BTRFS critical (device sda): corrupt leaf: root=18446744073709551610
> block=507447197696 slot=0, csum end range (320352133120) goes beyond the
> start range (320352116736) of the next csum item
> BTRFS info (device sda): leaf 507447197696 gen 18451 total ptrs 3 free
> space 116 owner 18446744073709551610
>         item 0 key (18446744073709551606 128 320336326656) itemoff 847
> itemsize 15436
>         item 1 key (18446744073709551606 128 320352116736) itemoff 831
> itemsize 16
>         item 2 key (18446744073709551606 128 320352247808) itemoff 191
> itemsize 640
> BTRFS error (device sda): block=507447197696 write time tree block
> corruption detected
> BTRFS: error (device sda) in btrfs_sync_log:3136: errno=-5 IO failure
> BTRFS info (device sda): forced readonly

Ok, then it's something else.

When I run you reproducer I get an error:

$ ./runMssql.sh
Starting MSSQL docker container...
9943b714ed210a2937d5fce27ec110981b471e6e9f2c619629cb66501621ebb5
Loading TPC-H schema...
Sqlcmd: Error: Microsoft ODBC Driver 17 for SQL Server : Login failed
for user 'sa'..

dbgen.sh ran successfully before.

Any idea?

>
>
>
> Curiously, the second leaf range overshot by only 16KB....
> Let me know, if I can try anything else.



-- 
Filipe David Manana,

“Whether you think you can, or you think you can't — you're right.”