2021-07-12 15:43:43

by Jan Kara

Subject: [PATCH 1/9] ext2fs: Drop HAS_SNAPSHOT feature

It has never been implemented and is dead for quite some time and
unused AFAICT.

Signed-off-by: Jan Kara <[email protected]>
---
lib/ext2fs/ext2_fs.h | 2 --
1 file changed, 2 deletions(-)

diff --git a/lib/ext2fs/ext2_fs.h b/lib/ext2fs/ext2_fs.h
index e92a045205a9..6f1d5db4b482 100644
--- a/lib/ext2fs/ext2_fs.h
+++ b/lib/ext2fs/ext2_fs.h
@@ -825,7 +825,6 @@ struct ext2_super_block {
#define EXT4_FEATURE_RO_COMPAT_GDT_CSUM 0x0010
#define EXT4_FEATURE_RO_COMPAT_DIR_NLINK 0x0020
#define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE 0x0040
-#define EXT4_FEATURE_RO_COMPAT_HAS_SNAPSHOT 0x0080
#define EXT4_FEATURE_RO_COMPAT_QUOTA 0x0100
#define EXT4_FEATURE_RO_COMPAT_BIGALLOC 0x0200
/*
@@ -926,7 +925,6 @@ EXT4_FEATURE_RO_COMPAT_FUNCS(huge_file, 4, HUGE_FILE)
EXT4_FEATURE_RO_COMPAT_FUNCS(gdt_csum, 4, GDT_CSUM)
EXT4_FEATURE_RO_COMPAT_FUNCS(dir_nlink, 4, DIR_NLINK)
EXT4_FEATURE_RO_COMPAT_FUNCS(extra_isize, 4, EXTRA_ISIZE)
-EXT4_FEATURE_RO_COMPAT_FUNCS(has_snapshot, 4, HAS_SNAPSHOT)
EXT4_FEATURE_RO_COMPAT_FUNCS(quota, 4, QUOTA)
EXT4_FEATURE_RO_COMPAT_FUNCS(bigalloc, 4, BIGALLOC)
EXT4_FEATURE_RO_COMPAT_FUNCS(metadata_csum, 4, METADATA_CSUM)
--
2.26.2

2021-07-12 18:20:56

by Andreas Dilger

Subject: Re: [PATCH 1/9] ext2fs: Drop HAS_SNAPSHOT feature

NAK.

We are working on a snapshot implementation for ext4, it is
just taking a lot longer that I thought it would to complete.

There isn't any shortage of these feature bits, so no reason to re-use them.

Cheers, Andreas

> On Jul 12, 2021, at 09:43, Jan Kara <[email protected]> wrote:
>
> It has never been implemented and is dead for quite some time and
> unused AFAICT.
>
> Signed-off-by: Jan Kara <[email protected]>
> ---
> lib/ext2fs/ext2_fs.h | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/lib/ext2fs/ext2_fs.h b/lib/ext2fs/ext2_fs.h
> index e92a045205a9..6f1d5db4b482 100644
> --- a/lib/ext2fs/ext2_fs.h
> +++ b/lib/ext2fs/ext2_fs.h
> @@ -825,7 +825,6 @@ struct ext2_super_block {
> #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM 0x0010
> #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK 0x0020
> #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE 0x0040
> -#define EXT4_FEATURE_RO_COMPAT_HAS_SNAPSHOT 0x0080
> #define EXT4_FEATURE_RO_COMPAT_QUOTA 0x0100
> #define EXT4_FEATURE_RO_COMPAT_BIGALLOC 0x0200
> /*
> @@ -926,7 +925,6 @@ EXT4_FEATURE_RO_COMPAT_FUNCS(huge_file, 4, HUGE_FILE)
> EXT4_FEATURE_RO_COMPAT_FUNCS(gdt_csum, 4, GDT_CSUM)
> EXT4_FEATURE_RO_COMPAT_FUNCS(dir_nlink, 4, DIR_NLINK)
> EXT4_FEATURE_RO_COMPAT_FUNCS(extra_isize, 4, EXTRA_ISIZE)
> -EXT4_FEATURE_RO_COMPAT_FUNCS(has_snapshot, 4, HAS_SNAPSHOT)
> EXT4_FEATURE_RO_COMPAT_FUNCS(quota, 4, QUOTA)
> EXT4_FEATURE_RO_COMPAT_FUNCS(bigalloc, 4, BIGALLOC)
> EXT4_FEATURE_RO_COMPAT_FUNCS(metadata_csum, 4, METADATA_CSUM)
> --
> 2.26.2
>

2021-07-13 08:13:01

by Jan Kara

Subject: Re: [PATCH 1/9] ext2fs: Drop HAS_SNAPSHOT feature

Hello,

On Mon 12-07-21 12:20:03, Andreas Dilger wrote:
> NAK.
>
> We are working on a snapshot implementation for ext4, it is
> just taking a lot longer that I thought it would to complete.
>
> There isn't any shortage of these feature bits, so no reason to re-use them.

Sure. I thought this feature bit was a leftover from experimental ext4
snapshot feature Amir Goldstein was playing with some 10-15 years ago and
which never completed. If there's somebody working on this, I'll allocate a
different bit.

Honza

>
> Cheers, Andreas
>
> > On Jul 12, 2021, at 09:43, Jan Kara <[email protected]> wrote:
> >
> > It has never been implemented and is dead for quite some time and
> > unused AFAICT.
> >
> > Signed-off-by: Jan Kara <[email protected]>
> > ---
> > lib/ext2fs/ext2_fs.h | 2 --
> > 1 file changed, 2 deletions(-)
> >
> > diff --git a/lib/ext2fs/ext2_fs.h b/lib/ext2fs/ext2_fs.h
> > index e92a045205a9..6f1d5db4b482 100644
> > --- a/lib/ext2fs/ext2_fs.h
> > +++ b/lib/ext2fs/ext2_fs.h
> > @@ -825,7 +825,6 @@ struct ext2_super_block {
> > #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM 0x0010
> > #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK 0x0020
> > #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE 0x0040
> > -#define EXT4_FEATURE_RO_COMPAT_HAS_SNAPSHOT 0x0080
> > #define EXT4_FEATURE_RO_COMPAT_QUOTA 0x0100
> > #define EXT4_FEATURE_RO_COMPAT_BIGALLOC 0x0200
> > /*
> > @@ -926,7 +925,6 @@ EXT4_FEATURE_RO_COMPAT_FUNCS(huge_file, 4, HUGE_FILE)
> > EXT4_FEATURE_RO_COMPAT_FUNCS(gdt_csum, 4, GDT_CSUM)
> > EXT4_FEATURE_RO_COMPAT_FUNCS(dir_nlink, 4, DIR_NLINK)
> > EXT4_FEATURE_RO_COMPAT_FUNCS(extra_isize, 4, EXTRA_ISIZE)
> > -EXT4_FEATURE_RO_COMPAT_FUNCS(has_snapshot, 4, HAS_SNAPSHOT)
> > EXT4_FEATURE_RO_COMPAT_FUNCS(quota, 4, QUOTA)
> > EXT4_FEATURE_RO_COMPAT_FUNCS(bigalloc, 4, BIGALLOC)
> > EXT4_FEATURE_RO_COMPAT_FUNCS(metadata_csum, 4, METADATA_CSUM)
> > --
> > 2.26.2
> >
--
Jan Kara <[email protected]>
SUSE Labs, CR