[PATCH v3 12/12] fs/xfs: Allow toggle of effective DAX flag

ira.weiny
2020-02-08T19:35:04Z

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

Now that locking of the inode is in place we can allow a DAX state
change while under the new lock.

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

---
Changes from V2:
Add in lock_dax_state_static_key static branch enabling.

fs/xfs/xfs_inode.h | 1 +
fs/xfs/xfs_ioctl.c | 15 ++++++++++++---
fs/xfs/xfs_iops.c | 15 +++++++++++----
fs/xfs/xfs_super.c | 16 +++++++++-------
4 files changed, 33 insertions(+), 14 deletions(-)

diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
index 25fe20740bf7..0064f8eef41d 100644
--- a/fs/xfs/xfs_inode.h
+++ b/fs/xfs/xfs_inode.h
@@ -469,6 +469,7 @@ 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);

/*
* 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 0134c9e65efb..0736cf45223d 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)
inode->i_flags |= S_DAX;
else
inode->i_flags &= ~S_DAX;
-#endif
+
}

static int
@@ -1194,6 +1193,10 @@ xfs_ioctl_setattr_dax_invalidate(

*join_flags = 0;

+#if !defined(CONFIG_FS_DAX)
+ return -EINVAL;
+#endif
+
/* If the DAX state is not changing, we have nothing to do here. */
if ((fa->fsx_xflags & FS_XFLAG_DAX) &&
(ip->i_d.di_flags2 & XFS_DIFLAG2_DAX))
@@ -1205,7 +1208,7 @@ xfs_ioctl_setattr_dax_invalidate(
if (S_ISDIR(inode->i_mode))
return 0;

- flags = XFS_MMAPLOCK_EXCL | XFS_IOLOCK_EXCL;
+ flags = XFS_MMAPLOCK_EXCL | XFS_IOLOCK_EXCL | XFS_DAX_EXCL;

/* lock, flush and invalidate mapping in preparation for flag change */
xfs_ilock(ip, flags);
@@ -1526,6 +1529,9 @@ xfs_ioctl_setattr(
else
ip->i_d.di_cowextsize = 0;

+ if (join_flags & XFS_DAX_EXCL)
+ xfs_setup_a_ops(ip);
+
code = xfs_trans_commit(tp);

/*
@@ -1635,6 +1641,9 @@ xfs_ioc_setxflags(
goto out_drop_write;
}

+ if (join_flags & XFS_DAX_EXCL)
+ 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 eebec159d873..15ef51c7f0b3 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -1366,6 +1366,16 @@ 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)
@@ -1376,10 +1386,7 @@ 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))
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 2094386af8ac..af57fe07b56d 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -1332,6 +1332,7 @@ xfs_fc_fill_super(
struct xfs_mount *mp = sb->s_fs_info;
struct inode *root;
int flags = 0, error;
+ bool rtdev_is_dax = false, datadev_is_dax;

mp->m_super = sb;

@@ -1437,17 +1438,18 @@ 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) {
- bool rtdev_is_dax = false, datadev_is_dax;
+ datadev_is_dax = bdev_dax_supported(mp->m_ddev_targp->bt_bdev,
+ sb->s_blocksize);
+ if (mp->m_rtdev_targp)
+ rtdev_is_dax = bdev_dax_supported(mp->m_rtdev_targp->bt_bdev,
+ sb->s_blocksize);
+ if (rtdev_is_dax || datadev_is_dax)
+ enable_dax_state_static_branch();

+ if (mp->m_flags & XFS_MOUNT_DAX) {
xfs_warn(mp,
"DAX enabled. Warning: EXPERIMENTAL, use at your own risk");

- datadev_is_dax = bdev_dax_supported(mp->m_ddev_targp->bt_bdev,
- sb->s_blocksize);
- if (mp->m_rtdev_targp)
- rtdev_is_dax = bdev_dax_supported(
- mp->m_rtdev_targp->bt_bdev, sb->s_blocksize);
if (!rtdev_is_dax && !datadev_is_dax) {
xfs_alert(mp,
"DAX unsupported by block device. Turning off DAX.");
--
2.21.0