Re: [PATCH V4 0/2] Some bugfix for xfs fsmap

[Chandan Babu R <chandanbabu@kernel.org>]

On Tue, Aug 20, 2024 at 03:51:23 PM +0800, Zizhi Wo wrote:
> 在 2024/8/20 13:53, Chandan Babu R 写道:
>> On Mon, Aug 19, 2024 at 08:53:18 AM +0800, Zizhi Wo wrote:
>>> Changes since V3[1]:
>>>   - For the first patch, simply place the modification logic in the
>>>     xfs_fsmap_owner_to_rmap() function.
>>>   - For the second patch, more detailed comments were added and related
>>>     changes were made to the initialization of the end_daddr field.
>>>
>>> This patch set contains two patches to repair fsmap. Although they are both
>>> problems of missing query intervals, the root causes of the two are
>>> inconsistent, so two patches are proposed.
>>>
>>> Patch 1: The fix addresses the interval omission issue caused by the
>>> incorrect setting of "rm_owner" in the high_key during rmap queries. In
>>> this scenario, fsmap finds the record on the rmapbt, but due to the
>>> incorrect setting of the "rm_owner", the key of the record is larger than
>>> the high_key, causing the query result to be incorrect. This issue is
>>> resolved by fixing the "rm_owner" setup logic.
>>>
>>> Patch 2: The fix addresses the interval omission issue caused by bit
>>> shifting during gap queries in fsmap. In this scenario, fsmap does not
>>> find the record on the rmapbt, so it needs to locate it by the gap of the
>>> info->next_daddr and high_key address. However, due to the shift, the two
>>> are reduced to 0, so the query error is caused. The issue is resolved by
>>> introducing the "end_daddr" field in the xfs_getfsmap_info structure to
>>> store the high_key at the sector granularity.
>>>
>>> [1] https://lore.kernel.org/all/20240812011505.1414130-1-wozizhi@huawei.com/
>>>
>> The two patches in this series cause xfs_scrub to execute
>> indefinitely
>> immediately after xfs/556 is executed.
>> The fstest configuration used is provided below,
>> FSTYP=xfs
>> TEST_DIR=/media/test
>> SCRATCH_MNT=/media/scratch
>> TEST_DEV=/dev/loop16
>> TEST_LOGDEV=/dev/loop13
>> TEST_RTDEV=/dev/loop12
>> TEST_FS_MOUNT_OPTS="-o rtdev=/dev/loop12 -o logdev=/dev/loop13"
>> SCRATCH_DEV_POOL="/dev/loop5 /dev/loop6 /dev/loop7 /dev/loop8
>> /dev/loop9 /dev/loop10 /dev/loop11"
>> MKFS_OPTIONS="-f -m reflink=0,rmapbt=0, -d rtinherit=1 -lsize=1g"
>> SCRATCH_LOGDEV=/dev/loop15
>> SCRATCH_RTDEV=/dev/loop14
>> USE_EXTERNAL=yes
>> 
>
> Sorry, running xfs/556 with this configuration was successful in my
> environment, and my mkfs.xfs version is 6.8.0:
>
> xfs/556
> FSTYP         -- xfs (debug)
> PLATFORM      -- Linux/x86_64 fedora 6.11.0-rc3-00015-g1a9f212eb19f #42
> SMP PREEMPT_DYNAMIC Fri Aug 16 10:19:47 CST 2024
> VMIP          -- 192.168.240.11
> MKFS_OPTIONS  -- -f -f -m reflink=0,rmapbt=0 -d rtinherit=1 -l size=1g
> /dev/vde
> MOUNT_OPTIONS -- /dev/vde /tmp/scratch
>
> xfs/556 4s ...  5s
> Ran: xfs/556
> Passed all 1 tests
>
> I am not sure if it is because of the specific user mode tools or other
> environment configuration differences caused?
>

My Linux kernel is based on v6.11-rc4. The sources can be found at
https://github.com/chandanr/linux/commits/xfs-6.11-fixesC-without-jump-label-fixes/.

Please note that I have reverted commits modifying kernel/jump_label.c. This
is to work around
https://lore.kernel.org/linux-xfs/20240730033849.GH6352@frogsfrogsfrogs/.

Also, I am running xfsprogs v6.9.0. The sources can be found at
https://git.kernel.org/pub/scm/fs/xfs/xfsprogs-dev.git/log/?qt=range&q=v6.9.0

-- 
Chandan