[PATCH V11 06/11] fs/xfs: Make DAX mount option a tri-state

ira.weiny
2020-04-28T00:22:25Z

From: Ira Weiny <ira.weiny@intel.com>

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 'inode'
(default).

[1] https://lore.kernel.org/lkml/20200405061945.GA94792@iweiny-DESK2.sc.intel.com/

Signed-off-by: Ira Weiny <ira.weiny@intel.com>

---
Changes from V10:
Move show options to xfs_info_set array

Changes from V9:
Fix indentation in xfs_mount_set_dax_mode()
Do not report dax=inode

Changes from v8:
Move NEVER bit to 27
Use xfs signature style
use xfs_dax_mode enum

Changes from v7:
Change to XFS_MOUNT_DAX_NEVER

Changes from v6:
Use 2 flag bits rather than a field.
change iflag to inode

Changes from v5:
New Patch
---
fs/xfs/xfs_mount.h | 1 +
fs/xfs/xfs_super.c | 46 ++++++++++++++++++++++++++++++++++++++++++----
2 files changed, 43 insertions(+), 4 deletions(-)

diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index f6123fb0113c..37bfb50db809 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -238,6 +238,7 @@ typedef struct xfs_mount {
allocator */
#define XFS_MOUNT_NOATTR2 (1ULL << 25) /* disable use of attr2 format */
#define XFS_MOUNT_DAX_ALWAYS (1ULL << 26)
+#define XFS_MOUNT_DAX_NEVER (1ULL << 27)

/*
* 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 ce169d1c7474..e80bd2c4c279 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -47,6 +47,39 @@ static struct kset *xfs_kset; /* top-level xfs sysfs dir */
static struct xfs_kobj xfs_dbg_kobj; /* global debug sysfs attrs */
#endif

+enum xfs_dax_mode {
+ XFS_DAX_INODE = 0,
+ XFS_DAX_ALWAYS = 1,
+ XFS_DAX_NEVER = 2,
+};
+
+static void
+xfs_mount_set_dax_mode(
+ struct xfs_mount *mp,
+ enum xfs_dax_mode mode)
+{
+ switch (mode) {
+ case XFS_DAX_INODE:
+ mp->m_flags &= ~(XFS_MOUNT_DAX_ALWAYS | XFS_MOUNT_DAX_NEVER);
+ break;
+ case XFS_DAX_ALWAYS:
+ mp->m_flags |= XFS_MOUNT_DAX_ALWAYS;
+ mp->m_flags &= ~XFS_MOUNT_DAX_NEVER;
+ break;
+ case XFS_DAX_NEVER:
+ mp->m_flags |= XFS_MOUNT_DAX_NEVER;
+ mp->m_flags &= ~XFS_MOUNT_DAX_ALWAYS;
+ break;
+ }
+}
+
+static const struct constant_table dax_param_enums[] = {
+ {"inode", XFS_DAX_INODE },
+ {"always", XFS_DAX_ALWAYS },
+ {"never", XFS_DAX_NEVER },
+ {}
+};
+
/*
* Table driven mount option parser.
*/
@@ -59,7 +92,7 @@ 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 +136,7 @@ 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 +163,8 @@ xfs_fs_show_options(
{ XFS_MOUNT_GRPID, ",grpid" },
{ XFS_MOUNT_DISCARD, ",discard" },
{ XFS_MOUNT_LARGEIO, ",largeio" },
- { XFS_MOUNT_DAX_ALWAYS, ",dax" },
+ { XFS_MOUNT_DAX_ALWAYS, ",dax=always" },
+ { XFS_MOUNT_DAX_NEVER, ",dax=never" },
{ 0, NULL }
};
struct xfs_mount *mp = XFS_M(root->d_sb);
@@ -1261,7 +1296,10 @@ xfs_fc_parse_param(
return 0;
#ifdef CONFIG_FS_DAX
case Opt_dax:
- mp->m_flags |= XFS_MOUNT_DAX_ALWAYS;
+ xfs_mount_set_dax_mode(mp, XFS_DAX_ALWAYS);
+ return 0;
+ case Opt_dax_enum:
+ xfs_mount_set_dax_mode(mp, result.uint_32);
return 0;
#endif
default:
@@ -1468,7 +1506,7 @@ 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_ALWAYS;
+ xfs_mount_set_dax_mode(mp, XFS_DAX_NEVER);
}
if (xfs_sb_version_hasreflink(&mp->m_sb)) {
xfs_alert(mp,
--
2.25.1