Re: [PATCH] common/populate: decrease the step of rm file

[xuyang <xuyang2018.jy@cn.fujitsu.com>]

On 2019/4/4 6:43, Darrick J. Wong wrote:
> On Thu, Mar 28, 2019 at 03:48:59PM +0800, Yang Xu wrote:
>>   Now that we have allocated 2*4096*64/16(32768) inodes after "Inode btree",
>>   but the step of rm file is too large to create enough free inodes in agi.
>>   So the freecount is not enough large to make free_level gt 1 and call
>>   _scratch__populate on xfs will report the following failure(such as xfs/083):
>>
>> Failed to create fino of sufficient height!
>>
>> By decreasing the step of rm file, xfs/083 will pass.
> Hmm, what are MOUNT_OPTS and MKFS_OPTIONS when this happens?  Are you
> running on top of some kind of RAID or 4k sector disk or something?
    The mkfs and mount option as below:
    MKFS_OPTIONS  -- -f -bsize=4096 /dev/sda11
    MOUNT_OPTIONS -- -o context=system_u:object_r:root_t:s0 /dev/sda11 /mnt/xfstests/scratch

    I run this case on anordinary  disk, in xfs/083.full, the disk information as below:
    meta-data=/dev/sda11             isize=512    agcount=4, agsize=1310720 blks
             =                       sectsz=512   attr=2, projid32bit=1
             =                       crc=1        finobt=1, sparse=1, rmapbt=0
             =                       reflink=1
    data     =                       bsize=4096   blocks=5242880, imaxpct=25
             =                       sunit=0      swidth=0 blks
    naming   =version 2              bsize=4096   ascii-ci=0, ftype=1
    log      =internal log           bsize=4096   blocks=2560, version=2
             =                       sectsz=512   sunit=0 blks, lazy-count=1
    realtime =none                   extsz=4096   blocks=0, rtextents=0
    + populate fs image
    MOUNT_OPTIONS =  -o usrquota,grpquota,prjquota

    fdisk -l /dev/sda
    Disk /dev/sda: 298.1 GiB, 320072933376 bytes, 625142448 sectors
    Units: sectors of 1 * 512 = 512 bytes
    Sector size (logical/physical): 512 bytes / 512 bytes
    I/O size (minimum/optimal): 512 bytes / 512 bytes
    Disklabel type: dos
    Disk identifier: 0x00039ec7

    /dev/sda11      553664512 595607551  41943040    20G 83 Linux


> I think this patch looks ok but I'm puzzled for why a step of
> $(ino_per_rec + 1) isn't enough.
>
> --D

   Hi Darrick

   Sorry, I am not aware that the count mechanism of agi_free_level. IMO, agi_free_count achives a
    threshold that current free inode btree level can notstore free inode information(I want to search the threshold in kernel,but fail).
   Then, free_level will add.

   on my machine, I decrease the step. When the value of step is 2,4,8,16, the free count becomes larger
   and the free_level turns into 2.

   a step of $(ino_per_rec + 1) isn't enough. It maynot fill up current agi_free_level because it doesn't create enough free inodes
  (allocat,free,not unused inodes).

   Thanks,
   Yang Xu

>> Signed-off-by: Yang Xu<xuyang2018.jy@cn.fujitsu.com>
>> ---
>>   common/populate | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/common/populate b/common/populate
>> index 4fa118f0..7403dec3 100644
>> --- a/common/populate
>> +++ b/common/populate
>> @@ -271,7 +271,7 @@ _scratch_xfs_populate() {
>>   		touch "${dir}/${f}"
>>   	done
>>
>> -	seq 0 "$((ino_per_rec + 1))" "${nr}" | while read f; do
>> +	seq 0 2 "${nr}" | while read f; do
>>   		rm -f "${dir}/${f}"
>>   	done
>>
>> -- 
>> 2.18.1
>>
>>
>>
>
>