On 02/10/2012 06:25 AM, Dave Chinner wrote:
> On Thu, Feb 09, 2012 at 10:27:05PM +0800, Jeff Liu wrote:
>> Strange, I also tried to build XFS with 2k which shown as following:
>> $ sudo mkfs.xfs -b size=2k -n size=2k -f /dev/sda7
>> $ xfs_info /dev/sda7
>> meta-data=/dev/sda7 isize=256 agcount=4, agsize=1418736 blks
>> = sectsz=512 attr=2
>> data = bsize=2048 blocks=5674944, imaxpct=25
>> = sunit=0 swidth=0 blks
>> naming =version 2 bsize=2048 ascii-ci=0
>> log =internal bsize=2048 blocks=5120, version=2
> The block size for data, metadata, directories and the log is 2k,
> just like you asked.
Sorry, I mislead you.
Yes, the block size for data and metadata, etc are ok for me, but the
allocate unit at "struct stat.st_blksize" is 4k, It should match
File system magic#: 0x58465342
Allocation unit: 4096 bytes
File system supports the default behavior.
$ stat --print "%o\n" /xfs/seek_test
>> = sectsz=512 sunit=0 blks, lazy-count=1
>> realtime =none extsz=4096 blocks=0, rtextents=0
> For the non-existent realtime device, the default is an extent size
> of 4k. However, extent size for the real time device is separate
> from the data/log device block size - it's more like the bigalloc
> ext4 functionality in that it defines the default extent allocation
> size and alignment for the RT device.
Thanks for those patiently explaining!