lkml.org 
[lkml]   [2020]   [Dec]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRE: [PATCH v14 06/10] fs/ntfs3: Add compression
Date
From: Konstantin Komarov
> Sent: Friday, December 11, 2020 7:28 PM
> To: 'Eric Biggers' <ebiggers@kernel.org>
> Cc: linux-fsdevel@vger.kernel.org; viro@zeniv.linux.org.uk; linux-kernel@vger.kernel.org; pali@kernel.org; dsterba@suse.cz;
> aaptel@suse.com; willy@infradead.org; rdunlap@infradead.org; joe@perches.com; mark@harmstone.com; nborisov@suse.com;
> linux-ntfs-dev@lists.sourceforge.net; anton@tuxera.com; dan.carpenter@oracle.com; hch@lst.de
> Subject: RE: [PATCH v14 06/10] fs/ntfs3: Add compression
>
> From: Eric Biggers <ebiggers@kernel.org>
> Sent: Friday, December 4, 2020 9:39 PM
> > To: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
> > Cc: linux-fsdevel@vger.kernel.org; viro@zeniv.linux.org.uk; linux-kernel@vger.kernel.org; pali@kernel.org; dsterba@suse.cz;
> > aaptel@suse.com; willy@infradead.org; rdunlap@infradead.org; joe@perches.com; mark@harmstone.com; nborisov@suse.com;
> > linux-ntfs-dev@lists.sourceforge.net; anton@tuxera.com; dan.carpenter@oracle.com; hch@lst.de
> > Subject: Re: [PATCH v14 06/10] fs/ntfs3: Add compression
> >
> > On Fri, Dec 04, 2020 at 06:45:56PM +0300, Konstantin Komarov wrote:
> > > This adds compression
> > >
> > > Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
> > > ---
> > > fs/ntfs3/lib/common_defs.h | 196 +++++++++++
> > > fs/ntfs3/lib/decompress_common.c | 314 +++++++++++++++++
> > > fs/ntfs3/lib/decompress_common.h | 558 +++++++++++++++++++++++++++++++
> > > fs/ntfs3/lib/lzx_common.c | 204 +++++++++++
> > > fs/ntfs3/lib/lzx_common.h | 31 ++
> > > fs/ntfs3/lib/lzx_constants.h | 113 +++++++
> > > fs/ntfs3/lib/lzx_decompress.c | 553 ++++++++++++++++++++++++++++++
> > > fs/ntfs3/lib/xpress_constants.h | 23 ++
> > > fs/ntfs3/lib/xpress_decompress.c | 165 +++++++++
> > > fs/ntfs3/lznt.c | 452 +++++++++++++++++++++++++
> > > 10 files changed, 2609 insertions(+)
> > > create mode 100644 fs/ntfs3/lib/common_defs.h
> > > create mode 100644 fs/ntfs3/lib/decompress_common.c
> > > create mode 100644 fs/ntfs3/lib/decompress_common.h
> > > create mode 100644 fs/ntfs3/lib/lzx_common.c
> > > create mode 100644 fs/ntfs3/lib/lzx_common.h
> > > create mode 100644 fs/ntfs3/lib/lzx_constants.h
> > > create mode 100644 fs/ntfs3/lib/lzx_decompress.c
> > > create mode 100644 fs/ntfs3/lib/xpress_constants.h
> > > create mode 100644 fs/ntfs3/lib/xpress_decompress.c
> > > create mode 100644 fs/ntfs3/lznt.c
> >
> > This really could use a much better commit message. Including mentioning where
> > the LZX and XPRESS decompression code came from
> > (https://github.com/ebiggers/ntfs-3g-system-compression).
> >
>
> Hi Eric! Fixed in V15!
>
> > Also note you've marked the files as "SPDX-License-Identifier: GPL-2.0",
> > but they really are "SPDX-License-Identifier: GPL-2.0-or-later".
> >
>
> Thanks, fixed as well.
>
> > Also I still think you should consider using the simpler version from
> > ntfs-3g-system-compression commit 3ddd227ee8e3, which I had originally intended
> > to be included in NTFS-3G itself. That version was fewer lines of code and
> > fewer files, as it was simplified for decompression-only. The latest version
> > (the one you're using) is shared with a project that also implements compression
> > (so that I can more easily maintain both projects), so it's more complex than
> > needed for decompression-only support. But in the kernel context it may make
> > sense to go with a simpler version. There are a few performance optimizations
> > you'd miss by going with the older version, but they weren't too significant,
> > and probably you don't need to squeeze out every bit of performance possible
> > when reading XPRESS and LZX-compressed files in this context?
> >
> > - Eric
>
> We used the newest code initially. Looking at the commit you've pointed out, but it will
> take some time as needs to pass full set of tests with new code. On the differences you've
> mentioned between the first and latest code in ntfs-3g system compression: we've removed
> the optimizations (needed to go into kernel), also the reparse points stuff is being parsed by
> ntfs3 driver itself. Given this, doesn't seems there are many differences remain.
> Also, we'll follow your recommendations, if you highly recommend to stick to the commit
> you've mentioned (but at this moment it seems "newer=better" formula still valid).
>
> Thanks!

Hi Eric! The code in V16 is now based on the initial ntfs-3g plugin code, just as you suggested.

Best regards.

\
 
 \ /
  Last update: 2020-12-25 15:32    [W:0.049 / U:0.136 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site