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; +} /* * Max and min values for mount-option defined I/O diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c index 2094386af8ac..d2fd465eeed5 100644 --- a/fs/xfs/xfs_super.c +++ b/fs/xfs/xfs_super.c @@ -47,6 +47,13 @@ static struct kset *xfs_kset; /* top-level xfs sysfs dir */ static struct xfs_kobj xfs_dbg_kobj; /* global debug sysfs attrs */ #endif +static const struct constant_table dax_param_enums[] = { + {"iflag", XFS_DAX_IFLAG }, + {"always", XFS_DAX_ALWAYS }, + {"never", XFS_DAX_NEVER }, + {} +}; + /* * Table driven mount option parser. */ @@ -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" }, { 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; + } + 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) { 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
