On Wed, May 20, 2020 at 01:02:42PM -0700, Ira Weiny wrote:
> On Wed, May 20, 2020 at 01:26:44PM -0600, Andreas Dilger wrote:
> > On May 19, 2020, at 11:57 PM, ira.weiny@xxxxxxxxx wrote:
> > >
> > > From: Ira Weiny <ira.weiny@xxxxxxxxx>
> > >
> > > Add a flag to preserve FS_XFLAG_DAX in the ext4 inode.
> > >
> > > Set the flag to be user visible and changeable. Set the flag to be
> > > inherited. Allow applications to change the flag at any time with the
> > > exception of if VERITY or ENCRYPT is set.
> > >
> > > Disallow setting VERITY or ENCRYPT if DAX is set.
> > >
> > > Finally, on regular files, flag the inode to not be cached to facilitate
> > > changing S_DAX on the next creation of the inode.
> > >
> > > Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx>
> > >
> > > ---
> > > diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
> > > index 6235440e4c39..467c30a789b6 100644
> > > --- a/fs/ext4/ext4.h
> > > +++ b/fs/ext4/ext4.h
> > > @@ -415,13 +415,16 @@ struct flex_groups {
> > > #define EXT4_VERITY_FL 0x00100000 /* Verity protected inode */
> > > #define EXT4_EA_INODE_FL 0x00200000 /* Inode used for large EA */
> > > /* 0x00400000 was formerly EXT4_EOFBLOCKS_FL */
> > > +
> > > +#define EXT4_DAX_FL 0x01000000 /* Inode is DAX */
> > > +
> > > #define EXT4_INLINE_DATA_FL 0x10000000 /* Inode has inline data. */
> > > #define EXT4_PROJINHERIT_FL 0x20000000 /* Create with parents projid */
> > > #define EXT4_CASEFOLD_FL 0x40000000 /* Casefolded file */
> > > #define EXT4_RESERVED_FL 0x80000000 /* reserved for ext4 lib */
> >
> > Hi Ira,
> > This flag value conflicts with the reserved flag in e2fsprogs for snapshots:
> >
> > #define EXT4_SNAPFILE_FL 0x01000000 /* Inode is a snapshot */
>
> Sure NP but is that new? I'm building off of 5.7-rc4.
>
> Just curious if I completely missed something.
Yeah, you missed that ... for some reason the kernel ext4 driver is
missing flags that are in e2fsprogs. (huh??)
I would say you could probably just take over the flag because the 2010s
called and they don't want next3 back. I guess that leaves 0x02000000
as the sole unclaimed bit, but this seriously needs some cleaning.
--D
> >
> > Please change EXT4_DAX_FL and FS_DAX_FL to use 0x02000000, which is not used
> > for anything in either case.
>
> NP, thanks!
> Ira
>
> >
> > Cheers, Andreas
> >
> >
> > > diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h
> > > index 379a612f8f1d..7c5f6eb51e2d 100644
> > > --- a/include/uapi/linux/fs.h
> > > +++ b/include/uapi/linux/fs.h
> > > @@ -262,6 +262,7 @@ struct fsxattr {
> > > #define FS_EA_INODE_FL 0x00200000 /* Inode used for large EA */
> > > #define FS_EOFBLOCKS_FL 0x00400000 /* Reserved for ext4 */
> > > #define FS_NOCOW_FL 0x00800000 /* Do not cow file */
> > > +#define FS_DAX_FL 0x01000000 /* Inode is DAX */
> > > #define FS_INLINE_DATA_FL 0x10000000 /* Reserved for ext4 */
> > > #define FS_PROJINHERIT_FL 0x20000000 /* Create with parents projid */
> > > #define FS_CASEFOLD_FL 0x40000000 /* Folder is case insensitive */
> > > --
> > > 2.25.1
> > >
> >
> >
> > Cheers, Andreas
> >
> >
> >
> >
> >
>
>
