Messages in this thread | | | Date | Fri, 11 Jun 2010 11:56:11 -0500 | From | Eric Sandeen <> | Subject | Re: fiemap is broken for sparse file in ext4? |
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Greg Freemyer wrote: > On Fri, Jun 11, 2010 at 11:46 AM, Eric Sandeen <sandeen@redhat.com> 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?
The flag is optional, though maybe filefrag should use it.
Without it, we should get the proper logical offset and a delalloc-flagged extent returned
> If fiemap is called with the FIEMAP_FLAG_SYNC flag is there currently a problem?
yep, we should get one delalloc extent in the results and we don't.
-Eric
> Thanks > Greg
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