On Wed, Apr 08, 2020 at 09:59:09AM +1000, Dave Chinner wrote: > On Tue, Apr 07, 2020 at 11:29:54AM -0700, ira.weiny@xxxxxxxxx wrote: > > From: Ira Weiny <ira.weiny@xxxxxxxxx> > > > > As agreed upon[1]. We make the dax mount option a tri-state. '-o dax' > > continues to operate the same. We add 'always', 'never', and 'iflag' > > (default). > > > > [1] https://lore.kernel.org/lkml/20200405061945.GA94792@xxxxxxxxxxxxxxxxxxxxxxxxx/ > > > > Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx> > > > > --- > > Changes from v5: > > New Patch > > --- > > fs/xfs/xfs_iops.c | 2 +- > > fs/xfs/xfs_mount.h | 26 +++++++++++++++++++++++++- > > fs/xfs/xfs_super.c | 34 +++++++++++++++++++++++++++++----- > > 3 files changed, 55 insertions(+), 7 deletions(-) > > > > diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c > > index 81f2f93caec0..1ec4a36917bd 100644 > > --- a/fs/xfs/xfs_iops.c > > +++ b/fs/xfs/xfs_iops.c > > @@ -1248,7 +1248,7 @@ xfs_inode_supports_dax( > > return false; > > > > /* DAX mount option or DAX iflag must be set. */ > > - if (!(mp->m_flags & XFS_MOUNT_DAX) && > > + if (xfs_mount_dax_mode(mp) != XFS_DAX_ALWAYS && > > !(ip->i_d.di_flags2 & XFS_DIFLAG2_DAX)) > > return false; > > > > diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h > > index 88ab09ed29e7..ce027ee06692 100644 > > --- a/fs/xfs/xfs_mount.h > > +++ b/fs/xfs/xfs_mount.h > > @@ -233,7 +233,31 @@ typedef struct xfs_mount { > > allocator */ > > #define XFS_MOUNT_NOATTR2 (1ULL << 25) /* disable use of attr2 format */ > > > > -#define XFS_MOUNT_DAX (1ULL << 62) /* TEST ONLY! */ > > +/* DAX flag is a 2 bit field representing a tri-state for dax > > + * iflag, always, never > > + * We reserve/document the 2 bits using dax field/field2 > > + */ > > +#define XFS_DAX_FIELD_MASK 0x3ULL > > +#define XFS_DAX_FIELD_SHIFT 62 > > +#define XFS_MOUNT_DAX_FIELD (1ULL << 62) > > +#define XFS_MOUNT_DAX_FIELD2 (1ULL << 63) > > + > > +enum { > > + XFS_DAX_IFLAG = 0, > > + XFS_DAX_ALWAYS = 1, > > + XFS_DAX_NEVER = 2, > > +}; > > + > > +static inline void xfs_mount_set_dax(struct xfs_mount *mp, u32 val) > > +{ > > + mp->m_flags &= ~(XFS_DAX_FIELD_MASK << XFS_DAX_FIELD_SHIFT); > > + mp->m_flags |= ((val & XFS_DAX_FIELD_MASK) << XFS_DAX_FIELD_SHIFT); > > +} > > + > > +static inline u32 xfs_mount_dax_mode(struct xfs_mount *mp) > > +{ > > + return (mp->m_flags >> XFS_DAX_FIELD_SHIFT) & XFS_DAX_FIELD_MASK; > > +} > > This is overly complex. Just use 2 flags: LOL... I was afraid someone would say that. At first I used 2 flags with fsparam_string, but then I realized Darrick suggested fsparam_enum: "It would be handy if we could have a single fsparam_enum for figuring out the dax mount options." -- https://lore.kernel.org/lkml/20200403183746.GQ80283@magnolia/ So I changed it... Darrick? Ira > > #define XFS_MOUNT_DAX_ALWAYS (1ULL << 26) > #define XFS_MOUNT_DAX_NEVER (1ULL << 27) > > and if no mount flag is set, we use the inode flag.... > > > @@ -59,7 +66,7 @@ enum { > > Opt_filestreams, Opt_quota, Opt_noquota, Opt_usrquota, Opt_grpquota, > > Opt_prjquota, Opt_uquota, Opt_gquota, Opt_pquota, > > Opt_uqnoenforce, Opt_gqnoenforce, Opt_pqnoenforce, Opt_qnoenforce, > > - Opt_discard, Opt_nodiscard, Opt_dax, > > + Opt_discard, Opt_nodiscard, Opt_dax, Opt_dax_enum, > > }; > > > > static const struct fs_parameter_spec xfs_fs_parameters[] = { > > @@ -103,6 +110,7 @@ static const struct fs_parameter_spec xfs_fs_parameters[] = { > > fsparam_flag("discard", Opt_discard), > > fsparam_flag("nodiscard", Opt_nodiscard), > > fsparam_flag("dax", Opt_dax), > > + fsparam_enum("dax", Opt_dax_enum, dax_param_enums), > > {} > > }; > > > > @@ -129,7 +137,6 @@ xfs_fs_show_options( > > { XFS_MOUNT_GRPID, ",grpid" }, > > { XFS_MOUNT_DISCARD, ",discard" }, > > { XFS_MOUNT_LARGEIO, ",largeio" }, > > - { XFS_MOUNT_DAX, ",dax" }, > + { XFS_MOUNT_DAX_ALWAYS, ",dax=always" }, > + { XFS_MOUNT_DAX_NEVER, ",dax=never" }, > > > { 0, NULL } > > }; > > struct xfs_mount *mp = XFS_M(root->d_sb); > > @@ -185,6 +192,20 @@ xfs_fs_show_options( > > if (!(mp->m_qflags & XFS_ALL_QUOTA_ACCT)) > > seq_puts(m, ",noquota"); > > > > + switch (xfs_mount_dax_mode(mp)) { > > + case XFS_DAX_IFLAG: > > + seq_puts(m, ",dax=iflag"); > > + break; > > + case XFS_DAX_ALWAYS: > > + seq_puts(m, ",dax=always"); > > + break; > > + case XFS_DAX_NEVER: > > + seq_puts(m, ",dax=never"); > > + break; > > + default: > > + break; > > + } > > if (!(mp->m_flags & (XFS_MOUNT_DAX_ALWAYS | XFS_MOUNT_DAX_NEVER)) > seq_puts(m, ",dax=iflag"); > > > + > > return 0; > > } > > > > @@ -1244,7 +1265,10 @@ xfs_fc_parse_param( > > return 0; > > #ifdef CONFIG_FS_DAX > > case Opt_dax: > > - mp->m_flags |= XFS_MOUNT_DAX; > > + xfs_mount_set_dax(mp, XFS_DAX_ALWAYS); > > + return 0; > > + case Opt_dax_enum: > > + xfs_mount_set_dax(mp, result.uint_32); > > return 0; > > #endif > > default: > > @@ -1437,7 +1461,7 @@ xfs_fc_fill_super( > > if (XFS_SB_VERSION_NUM(&mp->m_sb) == XFS_SB_VERSION_5) > > sb->s_flags |= SB_I_VERSION; > > > > - if (mp->m_flags & XFS_MOUNT_DAX) { > > + if (xfs_mount_dax_mode(mp) == XFS_DAX_ALWAYS) { > > if (mp->m_flags & XFS_MOUNT_DAX_ALWAYS) { > > > bool rtdev_is_dax = false, datadev_is_dax; > > > > xfs_warn(mp, > > @@ -1451,7 +1475,7 @@ xfs_fc_fill_super( > > if (!rtdev_is_dax && !datadev_is_dax) { > > xfs_alert(mp, > > "DAX unsupported by block device. Turning off DAX."); > > - mp->m_flags &= ~XFS_MOUNT_DAX; > > + xfs_mount_set_dax(mp, XFS_DAX_NEVER); > > } > > if (xfs_sb_version_hasreflink(&mp->m_sb)) { > > xfs_alert(mp, > > -- > > 2.25.1 > > > > > > -- > Dave Chinner > david@xxxxxxxxxxxxx
