Re: [ASSERT failure] transaction reservations changes bad?

Jeff Liu
2013-03-12T08:08:40Z

Hi Dave,

On 03/12/2013 02:25 PM, Dave Chinner wrote:
> On Tue, Mar 12, 2013 at 05:20:02PM +1100, Dave Chinner wrote:
>> Folks,
>>
>> I just got this ASSERT failure running xfstests on a 3.1.8 xfsprogs
>> and a 3.9-rc1 kernel running test 297:
>
> FYI, it's 100% reproducable here with:
>
> # sudo MKFS_OPTIONS="-b size=512" ./check 297
>
> (reproduced on multiple VMs now with the same command line)
>
> Cheers,
>
> Dave.
>
>>
>> [ 2593.733005] XFS: Assertion failed: BTOBB(need_bytes) < log->l_logBBsize, file: fs/xfs/xfs_log.c, line: 1451
>> [ 2593.736988] ------------[ cut here ]------------
>> [ 2593.738177] kernel BUG at fs/xfs/xfs_message.c:100!
>> [ 2593.739192] invalid opcode: 0000 [#1] SMP
>> [ 2593.740081] Modules linked in:
>> [ 2593.740786] CPU 0
>> [ 2593.741221] Pid: 1385, comm: mkdir Not tainted 3.8.0-dgc+ #472 Bochs Bochs
>> [ 2593.742630] RIP: 0010:[<ffffffff8146a1f2>] [<ffffffff8146a1f2>] assfail+0x22/0x30
>> [ 2593.744173] RSP: 0018:ffff880038c23c98 EFLAGS: 00010292
>> [ 2593.745234] RAX: 000000000000005f RBX: ffff88003cfec800 RCX: 0000000000005251
>> [ 2593.746635] RDX: 0000000000005151 RSI: 0000000000000096 RDI: 0000000000000246
>> [ 2593.748048] RBP: ffff880038c23c98 R08: 000000000000000a R09: 0000000000000889
>> [ 2593.749471] R10: 0000000000000000 R11: 0000000000000888 R12: 0000000000000dcb
>> [ 2593.750862] R13: ffff88003cfec800 R14: 0000000000000003 R15: 0000000000000001
>> [ 2593.752276] FS: 00007f0e64cb97a0(0000) GS:ffff88003fc00000(0000) knlGS:0000000000000000
>> [ 2593.753895] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
>> [ 2593.755039] CR2: 000000000066c004 CR3: 000000003cf26000 CR4: 00000000000006f0
>> [ 2593.756472] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>> [ 2593.757877] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
>> [ 2593.759285] Process mkdir (pid: 1385, threadinfo ffff880038c22000, task ffff88003cb483c0)
>> [ 2593.760914] Stack:
>> [ 2593.761345] ffff880038c23cb8 ffffffff814c9a11 ffff88002fa170a8 ffff880007ac7420
>> [ 2593.762881] ffff880038c23d18 ffffffff814cb608 0000000000000000 000111b838c23fd8
>> [ 2593.764429] ffff880038c23fd8 ffff8800055733d0 ffff880005573000 0000000000000000
>> [ 2593.765964] Call Trace:
>> [ 2593.766449] [<ffffffff814c9a11>] xlog_grant_push_ail+0x41/0xf0
>> [ 2593.767577] [<ffffffff814cb608>] xfs_log_reserve+0xe8/0x270
>> [ 2593.768676] [<ffffffff814c740e>] xfs_trans_reserve+0x2ee/0x300
>> [ 2593.769832] [<ffffffff814c6ec7>] ? _xfs_trans_alloc+0x37/0xa0
>> [ 2593.770950] [<ffffffff8146ed05>] xfs_create+0x185/0x660
>> [ 2593.771975] [<ffffffff8118cadd>] ? lookup_real+0x1d/0x60
>> [ 2593.773028] [<ffffffff814678c6>] xfs_vn_mknod+0xa6/0x1b0
>> [ 2593.774093] [<ffffffff814679e6>] xfs_vn_mkdir+0x16/0x20
>> [ 2593.775112] [<ffffffff81190ece>] vfs_mkdir+0x9e/0xf0
>> [ 2593.776092] [<ffffffff81192862>] sys_mkdirat+0x62/0xe0
>> [ 2593.777111] [<ffffffff811928f9>] sys_mkdir+0x19/0x20
>> [ 2593.778084] [<ffffffff81be0f99>] system_call_fastpath+0x16/0x1b
>> [ 2593.779233] Code: e8 f4 fb ff ff 0f 0b 66 90 0f 1f 44 00 00 55 48 89 f1 41 89 d0 48 89 e5 48 89 fa 48 c7 c6 40 f9 f2 81 31 ff 31 c0 e8 1e fc ff ff <0f> 0b 66 66 66
>> [ 2593.784186] RIP [<ffffffff8146a1f2>] assfail+0x22/0x30
>> [ 2593.785224] RSP <ffff880038c23c98>
>> [ 2593.786366] ---[ end trace bf0cb9ec29b256a6 ]---
>>
>> This implies that the permanent transaction reservation ended up
>> larger than the log itself:
>>
>> $ sudo xfs_info /mnt/scratch/
>> [sudo] password for dave:
>> meta-data=/dev/vdb isize=256 agcount=16, agsize=1441792 blks
>> = sectsz=512 attr=2
>> data = bsize=512 blocks=23068672, imaxpct=25
>> = sunit=512 swidth=6144 blks
>> naming =version 2 bsize=4096 ascii-ci=0
>> log =internal bsize=512 blocks=2560, version=2
>> = sectsz=512 sunit=512 blks, lazy-count=1
>> realtime =none extsz=4096 blocks=0, rtextents=0
>>
>> Can someone please check that the before/after mkdir transaction
>> reservation sizes are unchanged for such a configuration?
I just did a quick verification.

# mkfs.xfs -V
mkfs.xfs version 3.1.8

# uname -a
Linux koala 3.9.0-rc1 #80 SMP Tue Mar 12 15:06:39 CST 2013 x86_64 x86_64 x86_64 GNU/Linux

# mkfs.xfs -f -b size=512 /dev/sda6
meta-data=/dev/sda6 isize=256 agcount=4, agsize=5242880 blks
= sectsz=512 attr=2, projid32bit=0
data = bsize=512 blocks=20971520, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0
log =internal log bsize=512 blocks=20480, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0

The reservation size does not changed, both are 70072 bytes:

[ 230.905092] xfs_calc_mkdir_reservation: res=70072 bytes.

However, I can always reproducing this issue with '"MKFS_OPTIONS=-b size=512" ./check 297' as well.

Thanks,
-Jeff