Re: fiemap is broken for sparse file in ext4?

From: Greg Freemyer
Date: Fri Jun 11 2010 - 12:46:51 EST

On Fri, Jun 11, 2010 at 11:46 AM, Eric Sandeen <sandeen@xxxxxxxxxx> wrote:
> Tao Ma wrote:
>>> What are you using to call fiemap?  Here it seems to be working:
>> I just wrote a simple test program by calling ioctl. It is attached.
>> btw, you need to call it immediately after dd so that we have a chance
>> that ext4 don't have time to allocate extents. ;)
> OK I take it back, I do see it.  *cough* too many different filesystems
> on this box ... ;)
> Yes, it does look like a bug.
> -Eric

I'm not clear how this is supposed to work.

Is this just a userspace bug in that FIEMAP_FLAG_SYNC is needed in the
fiemap call, or is there a kernel bug as well?

If fiemap is called with the FIEMAP_FLAG_SYNC flag is there currently a problem?

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