XFS: possible memory allocation deadlock in kmem_alloc

[Dave Chinner]

On Tue, May 31, 2016 at 10:43:36AM +0800, 陈宗志 wrote:
> I have fint the way to change the extent size hint
> mkfs.xfs -r extsize=40960 /dev/sda1

Ah, no, that isn't the extsize I'm refering to. That's for realtime
device configuration at mkfs, not a per-inode extent size hint.

When you create the image file do this:

$ xfs_io -f -c "extsize 1m" /path/to/new/vm_image
$ qemu-image create -f qcow2 /path/to/new/vm_image 10g
$ xfs_io -c extsize /path/to/new/vm_image
[1048576] /path/to/new/vm_image
$

And now the qcow2 image file will have extents allocated in
multiples of 1MB.

Cheers,

Dave.
-- 
Dave Chinner
david at fromorbit.com