On Fri, Dec 09, 2016 at 10:41:34AM -0800, Liu Bo wrote:
> On Fri, Dec 09, 2016 at 03:47:20PM +1100, Dave Chinner wrote:
> > On Wed, Dec 07, 2016 at 01:45:05PM -0800, Liu Bo wrote:
> > > Signed-off-by: Liu Bo <bo.li.liu@xxxxxxxxxx>
> > > ---
> > > fs/btrfs/ctree.h | 1 +
> > > fs/btrfs/super.c | 40 +++++++++++++++++++++++++++++++++++++++-
> > > 2 files changed, 40 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
> > > index 0b8ce2b..e54c6e6 100644
> > > --- a/fs/btrfs/ctree.h
> > > +++ b/fs/btrfs/ctree.h
> > > @@ -1317,6 +1317,7 @@ static inline u32 BTRFS_MAX_XATTR_SIZE(const struct btrfs_root *root)
> > > #define BTRFS_MOUNT_FRAGMENT_METADATA (1 << 25)
> > > #define BTRFS_MOUNT_FREE_SPACE_TREE (1 << 26)
> > > #define BTRFS_MOUNT_NOLOGREPLAY (1 << 27)
> > > +#define BTRFS_MOUNT_DAX (1 << 28)
> > >
> > > #define BTRFS_DEFAULT_COMMIT_INTERVAL (30)
> > > #define BTRFS_DEFAULT_MAX_INLINE (2048)
> > > diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
> > > index 74ed5aa..9b18f3d 100644
> > > --- a/fs/btrfs/super.c
> > > +++ b/fs/btrfs/super.c
> > > @@ -323,7 +323,7 @@ enum {
> > > Opt_commit_interval, Opt_barrier, Opt_nodefrag, Opt_nodiscard,
> > > Opt_noenospc_debug, Opt_noflushoncommit, Opt_acl, Opt_datacow,
> > > Opt_datasum, Opt_treelog, Opt_noinode_cache, Opt_usebackuproot,
> > > - Opt_nologreplay, Opt_norecovery,
> > > + Opt_nologreplay, Opt_norecovery, Opt_dax,
> >
> > Can we please not create more filesystems with a DAX mount option?
> > This was only even an enabler, and not meant to be a permanent
> > thing. The permanent functionality for DAX is supposed to be
> > per-inode inheritable DAX flags - not mount options - so that
> > applications can choose on a per file basis to enable/disable DAX
> > access as they see fit.
> >
> > This also enables the filesystem to reject the attempt to turn on
> > DAX if the set of contexts for the file are not DAX compatible....
>
> Sounds good, I'll try to update it to use inode DAX flag directly.
xfs_io already has chattr/lsattr support (+/-x) for the FS_XFLAG_DAX
flag in FS_IOC_FS{GS}ETXATTR, and you can have a look at the XFS
code in xfs_ioctl.c for the operations that are needed to
dynamically change the S_DAX flag on an inode (e.g
xfs_ioctl_setattr_dax_invalidate())
Cheers,
Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx
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