Re: [PATCH 2/4 v3] fiemap: add EXTENT_DATA_COMPRESSED flag

[David Sterba <dsterba@suse.cz>]

On Thu, Jul 17, 2014 at 12:07:57AM -0600, Andreas Dilger wrote:
> any progress on this patch series?

I'm sorry I got distracted at the end of year and did not finish the
series.

> I never saw an updated version of this patch series after the last round of
> reviews, but it would be great to move it forward.  I have filefrag patches
> in my e2fsprogs tree waiting for an updated version of your patch.
> 
> I recall the main changes were:
> - add FIEMAP_EXTENT_PHYS_LENGTH flag to indicate if fe_phys_length was valid

fe_phys_length will be always valid, so other the flags are set only if it's
not equal to the logical length.

> - rename fe_length to fe_logi_length and #define fe_length fe_logi_length
> - always fill in fe_phys_length (= fe_logi_length for uncompressed files)
>   and set FIEMAP_EXTENT_PHYS_LENGTH whether the extent is compressed or not

This is my understanding and contradicts the first point.

> - add WARN_ONCE() in fiemap_fill_next_extent() as described below
>
> I don't know if there was any clear statement about whether there should be
> separate FIEMAP_EXTENT_PHYS_LENGTH and FIEMAP_EXTENT_DATA_COMPRESSED flags,
> or if the latter should be implicit?  Probably makes sense to have separate
> flags.  It should be fine to use:
>
> #define FIEMAP_EXTENT_PHYS_LENGTH	0x00000010
> 
> since this flag was never used.

I've kept only FIEMAP_EXTENT_DATA_COMPRESSED, I don't see a need for
FIEMAP_EXTENT_PHYS_LENGTH and this would be yet another flag because the
FIEMAP_EXTENT_DATA_ENCODED is also implied.

I'll send V4, we can discuss the PHYS_LENGTH flag then.