[PATCH V5 10/12] fs/xfs: Allow toggle of effective DAX flag

ira.weiny
2020-02-27T05:33:14Z

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

Now that locking of the inode aops is in place we can allow a DAX state
change.

Use the new xfs_inode_enable_dax() to set IS_DAX() as needed and update
the aops vector after the enabled state change.

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

---
Changes from v4:
Adjust for open coding of the aops lock

Changes from V3:
Remove static branch stuff.
Fix bugs found by Jeff by using xfs_inode_enable_dax()
Condition xfs_ioctl_setattr_dax_invalidate() on CONFIG_FS_DAX

Changes from V2:
Add in lock_dax_state_static_key static branch enabling.
Rebase updates
---
fs/xfs/xfs_inode.h | 2 ++
fs/xfs/xfs_ioctl.c | 20 +++++++++++++++++---
fs/xfs/xfs_iops.c | 17 ++++++++++++-----
3 files changed, 31 insertions(+), 8 deletions(-)

diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
index 492e53992fa9..7d4968915dec 100644
--- a/fs/xfs/xfs_inode.h
+++ b/fs/xfs/xfs_inode.h
@@ -466,6 +466,8 @@ int xfs_break_layouts(struct inode *inode, uint *iolock,
/* from xfs_iops.c */
extern void xfs_setup_inode(struct xfs_inode *ip);
extern void xfs_setup_iops(struct xfs_inode *ip);
+extern void xfs_setup_a_ops(struct xfs_inode *ip);
+extern bool xfs_inode_enable_dax(struct xfs_inode *ip);

/*
* When setting up a newly allocated inode, we need to call
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index 40ae791cfb41..38e91de44a6f 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -1123,12 +1123,11 @@ xfs_diflags_to_linux(
inode->i_flags |= S_NOATIME;
else
inode->i_flags &= ~S_NOATIME;
-#if 0 /* disabled until the flag switching races are sorted out */
- if (xflags & FS_XFLAG_DAX)
+
+ if (xfs_inode_enable_dax(ip))
inode->i_flags |= S_DAX;
else
inode->i_flags &= ~S_DAX;
-#endif
}

static int
@@ -1183,6 +1182,7 @@ xfs_ioctl_setattr_xflags(
* so that the cache invalidation is atomic with respect to the DAX flag
* manipulation.
*/
+#if defined(CONFIG_FS_DAX)
static int
xfs_ioctl_setattr_dax_invalidate(
struct xfs_inode *ip,
@@ -1233,6 +1233,16 @@ xfs_ioctl_setattr_dax_invalidate(
return error;

}
+#else /* !CONFIG_FS_DAX */
+static int
+xfs_ioctl_setattr_dax_invalidate(
+ struct xfs_inode *ip,
+ struct fsxattr *fa,
+ int *join_flags)
+{
+ return 0;
+}
+#endif

/*
* Set up the transaction structure for the setattr operation, checking that we
@@ -1524,6 +1534,8 @@ xfs_ioctl_setattr(
else
ip->i_d.di_cowextsize = 0;

+ xfs_setup_a_ops(ip);
+
code = xfs_trans_commit(tp);

/*
@@ -1639,6 +1651,8 @@ xfs_ioc_setxflags(
goto out_drop_write;
}

+ xfs_setup_a_ops(ip);
+
error = xfs_trans_commit(tp);
out_drop_write:
mnt_drop_write_file(filp);
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index ff711efc5247..8f023be39705 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -1259,7 +1259,7 @@ xfs_inode_supports_dax(
return xfs_inode_buftarg(ip)->bt_daxdev != NULL;
}

-STATIC bool
+bool
xfs_inode_enable_dax(
struct xfs_inode *ip)
{
@@ -1355,6 +1355,16 @@ xfs_setup_inode(
}
}

+void xfs_setup_a_ops(struct xfs_inode *ip)
+{
+ struct inode *inode = &ip->i_vnode;
+
+ if (IS_DAX(inode))
+ inode->i_mapping->a_ops = &xfs_dax_aops;
+ else
+ inode->i_mapping->a_ops = &xfs_address_space_operations;
+}
+
void
xfs_setup_iops(
struct xfs_inode *ip)
@@ -1365,10 +1375,7 @@ xfs_setup_iops(
case S_IFREG:
inode->i_op = &xfs_inode_operations;
inode->i_fop = &xfs_file_operations;
- if (IS_DAX(inode))
- inode->i_mapping->a_ops = &xfs_dax_aops;
- else
- inode->i_mapping->a_ops = &xfs_address_space_operations;
+ xfs_setup_a_ops(ip);
break;
case S_IFDIR:
if (xfs_sb_version_hasasciici(&XFS_M(inode->i_sb)->m_sb))
--
2.21.0