Re: [PATCH 0/4 for 5.15 stable] btrfs: some directory fixes for stable 5.15

[Eugeniu Rosca <erosca@de.adit-jv.com>]

Hello Filipe,

On Sat, Jan 27, 2024 at 06:02:55PM +0000, Filipe Manana wrote:
> On Fri, Jan 26, 2024 at 6:55 PM Eugeniu Rosca <erosca@de.adit-jv.com> wrote:

[..]

> > PS: Could you help me out how (and if at all possible) to preserve the
> > Author date of the original patch when downloading and applying the
> > 'raw' file provided by https:// lore.kernel.org/
> 
> If I understand you correctly, you applied the diff of patches
> directly with the "patch" command.

Nope. I download the 'raw' patch [0] (assumed to be in mbox format?),
then apply it via 'git am'. This workflow should preserve such patch
metadata like commit description, Author's name/date, etc.

> To get kernel patches and apply them easily, use the b4 tool available at:
> 
> git://git.kernel.org/pub/scm/utils/b4/b4.git

Thanks for sharing. This reminds me of patchwork/pwclient.

I've reapplied the patches using 'b4' and Author's Date of the stable
commits is still altered compared to the vanilla/mainline commits.

For example:
 - Author's date of vanilla [2]: 2023-08-13 12:34:08 +0100 
 - Author's date of stable [1]:  2024-01-25 11:59:35 +0000 

This likely means that the Author's date is amended during
porting/cherry-picking. Of course, this is not a major issue,
but some of us may assume that most of patch metadata (including
Author's date) is preserved on backporting (as best practice).

PS: We can likely skip it, since a number of other patches seem to
alter the Author's date on 5.15 stable tree (~600 out of 21k+ commits).

[1] https:// lore.kernel.org/stable/f1e33797054fcea8b61d88878e67b8c007b5d5f5.1706183427.git.fdmanana@suse.com/raw
[2] https:// git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=9b378f6ad48cfa

Thanks,
Eugeniu