[PATCH 109/119] xfs: don't mix reflink and DAX mode for now

["Darrick J. Wong" <darrick.wong@xxxxxxxxxx>]

Since we don't have a strategy for handling both DAX and reflink,
for now we'll just prohibit both being set at the same time.

Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
 fs/xfs/libxfs/xfs_inode_buf.c |    4 ++++
 fs/xfs/xfs_file.c             |    4 ++++
 fs/xfs/xfs_ioctl.c            |    4 ++++
 fs/xfs/xfs_iops.c             |    1 +
 4 files changed, 13 insertions(+)


diff --git a/fs/xfs/libxfs/xfs_inode_buf.c b/fs/xfs/libxfs/xfs_inode_buf.c
index c4cbd2b..3f7053a 100644
--- a/fs/xfs/libxfs/xfs_inode_buf.c
+++ b/fs/xfs/libxfs/xfs_inode_buf.c
@@ -412,6 +412,10 @@ xfs_dinode_verify(
        if ((flags2 & XFS_DIFLAG2_REFLINK) && (flags & XFS_DIFLAG_REALTIME))
                return false;
 
+       /* don't let reflink and dax mix */
+       if ((flags2 & XFS_DIFLAG2_REFLINK) && (flags2 & XFS_DIFLAG2_DAX))
+               return false;
+
        return true;
 }
 
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index ad6a467..e8e93f8 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -1126,6 +1126,10 @@ xfs_file_share_range(
        if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode))
                return -EINVAL;
 
+       /* Don't share DAX file data for now. */
+       if (IS_DAX(inode_in) || IS_DAX(inode_out))
+               return -EINVAL;
+
        /* Are we going all the way to the end? */
        isize = i_size_read(inode_in);
        if (isize == 0)
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index f103b15..aa9645c 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -1035,6 +1035,10 @@ xfs_ioctl_setattr_xflags(
        if ((fa->fsx_xflags & FS_XFLAG_REALTIME) && xfs_is_reflink_inode(ip))
                return -EINVAL;
 
+       /* Don't allow us to set DAX mode for a reflinked file for now. */
+       if ((fa->fsx_xflags & FS_XFLAG_DAX) && xfs_is_reflink_inode(ip))
+               return -EINVAL;
+
        /*
         * Can't modify an immutable/append-only file unless
         * we have appropriate permission.
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index 0fa86bd..95073db 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -1217,6 +1217,7 @@ xfs_diflags_to_iflags(
                inode->i_flags |= S_NOATIME;
        if (S_ISREG(inode->i_mode) &&
            ip->i_mount->m_sb.sb_blocksize == PAGE_SIZE &&
+           !xfs_is_reflink_inode(ip) &&
            (ip->i_mount->m_flags & XFS_MOUNT_DAX ||
             ip->i_d.di_flags2 & XFS_DIFLAG2_DAX))
                inode->i_flags |= S_DAX;