[Devel] [PATCH VZ9 v2 0/6] ploop BAT optimizations

Denis V. Lunev den at virtuozzo.com
Wed Oct 9 17:35:13 MSK 2024


On 10/9/24 16:33, Denis V. Lunev wrote:
> On 10/9/24 14:17, Andrey Zhadchenko wrote:
>> With this patchset, we start to check if the upcoming requests for ploop
>> have REQ_FUA flag.
>> If the flag is present:
>>   - IO submits immediately, completion waits for BAT update
>>   - BAT updates submit immediately
>>   - set IOCB_DSYNC for writes and BAT updates
>>   - BAT update does not trigger flush
>> If the flag is absent:
>>   - IO completion does not wait for BAT update
>>   - all BAT updates are periodically submitted in a batch
>>   - BAT update does not trigger flush
>>
>> New parameter with metadata submit delay can be specified when setting
>> up ploop table
>>
>> v2 changes:
>> - drop flush after BAT updates even for FUA requests
>> - set IOCB_DSYNC flag on writes triggered by FUA
>> - complete all accumulated metadata on FLUSH requests
>> - support REQ_PREFLUSH flag
>>
>> Andrey Zhadchenko (3):
>>    dm-ploop: do not flush BAT writes if request was not FUA
>>    dm-ploop: do not wait for BAT update for non-FUA requests
>>    dm-ploop: add delay for metadata writeback
>>
>>
>> *** BLURB HERE ***
>>
>> Andrey Zhadchenko (6):
>>    dm-ploop: do not flush after metadata writes
>>    dm-ploop: set IOCB_DSYNC on all FUA requests
>>    dm-ploop: do not wait for BAT update for non-FUA requests
>>    dm-ploop: add delay for metadata writeback
>>    dm-ploop: submit all postponed metadata on REQ_OP_FLUSH
>>    dm-ploop: handle REQ_PREFLUSH
>>
>>   drivers/md/dm-ploop-bat.c    |   1 +
>>   drivers/md/dm-ploop-map.c    | 154 +++++++++++++++++++++++++++--------
>>   drivers/md/dm-ploop-target.c |  13 +++
>>   drivers/md/dm-ploop.h        |   9 ++
>>   4 files changed, 143 insertions(+), 34 deletions(-)
>>
> these patches do not work at all over 32 GB ramdisk
>
> dev007 /mnt/ramdisk # ploop init -s 8G /mnt/ramdisk/root.hds
> Creating delta /mnt/ramdisk/root.hds bs=2048 size=16777216 sectors v2
> Adding snapshot {5fbaabe3-6958-40ff-92a7-860e329aab41}
> Storing /mnt/ramdisk/DiskDescriptor.xml
> Opening delta /mnt/ramdisk/root.hds
> Opening delta /mnt/ramdisk/root.hds
> Adding delta dev=/dev/mapper/ploop30904 img=/mnt/ramdisk/root.hds (rw)
> Update inuse state /mnt/ramdisk/root.hds state=1953459801
> Opening delta /mnt/ramdisk/root.hds
> Running: partprobe /dev/mapper/ploop30904
> Set untrusted /dev/mapper/ploop30904
> Running: parted -s /dev/mapper/ploop30904 mklabel gpt
> Running: sgdisk -n 1:2048:16775167 /dev/mapper/ploop30904
> Warning: The kernel is still using the old partition table.
> The new table will be used at the next reboot or after you
> run partprobe(8) or kpartx(8)
> The operation has completed successfully.
> Running: partprobe /dev/mapper/ploop30904
> Running: mkfs.xfs -b size=4096 /dev/mapper/ploop30904p1
> meta-data=/dev/mapper/ploop30904p1 isize=512    agcount=4, 
> agsize=524160 blks
>          =                       sectsz=512   attr=2, projid32bit=1
>          =                       crc=1        finobt=1, sparse=1, 
> rmapbt=0
>          =                       reflink=1    bigtime=1 inobtcount=1 
> nrext64=0
> data     =                       bsize=4096   blocks=2096640, imaxpct=25
>          =                       sunit=0      swidth=0 blks
> naming   =version 2              bsize=4096   ascii-ci=0, ftype=1
> log      =internal log           bsize=4096   blocks=16384, version=2
>          =                       sectsz=512   sunit=0 blks, lazy-count=1
> realtime =none                   extsz=4096   blocks=0, rtextents=0
> Discarding blocks...Done.
> Metadata CRC error detected at 0x561dffbd10f0, xfs_agf block 0x1/0x200
> Metadata CRC error detected at 0x561dffbd10f0, xfs_agf block 
> 0x3ffc01/0x200
> Metadata CRC error detected at 0x561dffbd10f0, xfs_agf block 
> 0x7ff801/0x200
> Metadata CRC error detected at 0x561dffbd10f0, xfs_agf block 
> 0xbff401/0x200
> Metadata CRC error detected at 0x561dffbee040, xfs_agi block 0x2/0x200
> Metadata CRC error detected at 0x561dffbee040, xfs_agi block 
> 0x3ffc02/0x200
> Metadata CRC error detected at 0x561dffbee040, xfs_agi block 
> 0x7ff802/0x200
> Metadata CRC error detected at 0x561dffbee040, xfs_agi block 
> 0xbff402/0x200
> mkfs.xfs: Inode allocation failed [28 - No space left on device]
> Error in run_prg_rc (util.c:309): Command mkfs.xfs -b size=4096 
> /dev/mapper/ploop30904p1  exited with code 1
> Umount /dev/mapper/ploop30904
> DM command: remove /dev/mapper/ploop30904p1
> DM message: /dev/mapper/ploop30904 get_img_name 0
> Opening delta /mnt/ramdisk/root.hds
> DM command: suspend /dev/mapper/ploop30904
> DM command: resume /dev/mapper/ploop30904
> Unmounting device /dev/mapper/ploop30904
> DM command: resume /dev/mapper/ploop30904
> DM command: remove /dev/mapper/ploop30904
> Clear inuse state
> Dropping image /mnt/ramdisk/root.hds
> dev007 /mnt/ramdisk #
>
> rmmod after that has been hanged.
>
> Den
[  351.210027] 
=============================================================================
[  351.210348] BUG ploop-pio (Tainted: G            E  X  ------- --- ): 
Objects remaining in ploop-pio on __kmem_cache_shutdown()
[  351.210620] 
-----------------------------------------------------------------------------

[  351.210886] Slab 0x00000000afe69346 objects=36 used=3 
fp=0x0000000028f0e0af 
flags=0x17ffffc0010200(slab|head|node=0|zone=2|lastcpupid=0x1fffff)
[  351.211192] CPU: 2 PID: 15519 Comm: rmmod ve: / Kdump: loaded 
Tainted: G            E  X  -------  ---  5.14.0-427.37.1.ovz9.78.1 #6 
ovz9.78.1
[  351.211564] Hardware name: Supermicro SYS-5019C-L/X11SCL-IF, BIOS 1.5 
10/05/2020
[  351.211878] Call Trace:
[  351.212146]  <TASK>
[  351.212452]  dump_stack_lvl+0x34/0x48
[  351.212732]  slab_err+0xa2/0x110
[  351.213006]  __kmem_cache_shutdown+0x16a/0x310
[  351.213305]  kmem_cache_destroy+0x51/0x160
[  351.213583]  dm_ploop_exit+0x24/0x20d [ploop]
[  351.213867]  __do_sys_delete_module.constprop.0+0x175/0x280
[  351.214148]  ? syscall_trace_enter.constprop.0+0x126/0x1a0
[  351.214428]  do_syscall_64+0x59/0x90
[  351.214703]  ? __rseq_handle_notify_resume+0x26/0xb0
[  351.214980]  ? exit_to_user_mode_loop+0xd0/0x130
[  351.215257]  ? exit_to_user_mode_prepare+0xb6/0x100
[  351.215553]  ? syscall_exit_to_user_mode+0x22/0x40
[  351.215830]  ? do_syscall_64+0x69/0x90
[  351.216105]  ? exc_page_fault+0x62/0x150
[  351.216414]  entry_SYSCALL_64_after_hwframe+0x72/0xdc
[  351.216693] RIP: 0033:0x7f72bc83f5ab
[  351.216988] Code: 73 01 c3 48 8b 0d 75 a8 1b 00 f7 d8 64 89 01 48 83 
c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 b0 00 00 00 0f 
05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 45 a8 1b 00 f7 d8 64 89 01 48
[  351.217391] RSP: 002b:00007fff49e1e798 EFLAGS: 00000206 ORIG_RAX: 
00000000000000b0
[  351.217707] RAX: ffffffffffffffda RBX: 00005580d76568f0 RCX: 
00007f72bc83f5ab
[  351.217991] RDX: 000000000000000a RSI: 0000000000000800 RDI: 
00005580d7656958
[  351.218313] RBP: 0000000000000000 R08: 0000000000000000 R09: 
0000000000000000
[  351.218596] R10: 00007f72bc99eac0 R11: 0000000000000206 R12: 
00007fff49e1e9f0
[  351.218881] R13: 00007fff49e1f070 R14: 00005580d76562a0 R15: 
00005580d76568f0
[  351.219166]  </TASK>
[  351.219453] Disabling lock debugging due to kernel taint
[  351.219453] Disabling lock debugging due to kernel taint
[  351.219732] Kernel panic - not syncing: panic_on_warn set ...
[  351.220012] CPU: 2 PID: 15519 Comm: rmmod ve: / Kdump: loaded 
Tainted: G    B       E  X  -------  ---  5.14.0-427.37.1.ovz9.78.1 #6 
ovz9.78.1
[  351.220345] Hardware name: Supermicro SYS-5019C-L/X11SCL-IF, BIOS 1.5 
10/05/2020
[  351.220677] Call Trace:
[  351.220945]  <TASK>
[  351.221230]  dump_stack_lvl+0x34/0x48
[  351.221523]  panic+0x107/0x2f7
[  351.221796]  slab_err.cold+0xc/0xc
[  351.222073]  __kmem_cache_shutdown+0x16a/0x310
[  351.222368]  kmem_cache_destroy+0x51/0x160
[  351.222643]  dm_ploop_exit+0x24/0x20d [ploop]
[  351.222921]  __do_sys_delete_module.constprop.0+0x175/0x280
[  351.223216]  ? syscall_trace_enter.constprop.0+0x126/0x1a0
[  351.223519]  do_syscall_64+0x59/0x90
[  351.223793]  ? __rseq_handle_notify_resume+0x26/0xb0
[  351.224070]  ? exit_to_user_mode_loop+0xd0/0x130
[  351.224345]  ? exit_to_user_mode_prepare+0xb6/0x100
[  351.224622]  ? syscall_exit_to_user_mode+0x22/0x40
[  351.224897]  ? do_syscall_64+0x69/0x90
[  351.225170]  ? exc_page_fault+0x62/0x150
[  351.225460]  entry_SYSCALL_64_after_hwframe+0x72/0xdc
[  351.225737] RIP: 0033:0x7f72bc83f5ab
[  351.226011] Code: 73 01 c3 48 8b 0d 75 a8 1b 00 f7 d8 64 89 01 48 83 
c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 b0 00 00 00 0f 
05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 45 a8 1b 00 f7 d8 64 89 01 48
[  351.226394] RSP: 002b:00007fff49e1e798 EFLAGS: 00000206 ORIG_RAX: 
00000000000000b0
[  351.226709] RAX: ffffffffffffffda RBX: 00005580d76568f0 RCX: 
00007f72bc83f5ab
[  351.226995] RDX: 000000000000000a RSI: 0000000000000800 RDI: 
00005580d7656958
[  351.227316] RBP: 0000000000000000 R08: 0000000000000000 R09: 
0000000000000000
[  351.227601] R10: 00007f72bc99eac0 R11: 0000000000000206 R12: 
00007fff49e1e9f0
[  351.227887] R13: 00007fff49e1f070 R14: 00005580d76562a0 R15: 
00005580d76568f0
[  351.228171]  </TASK>



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