device-dax: Add missing address_space_operations

With address_space_operations missing for device dax, namely the
.set_page_dirty, we hit a kernel warning when running destructive
ndctl unit test: make TESTS=device-dax check

WARNING: CPU: 3 PID: 7380 at fs/buffer.c:581 __set_page_dirty+0xb1/0xc0

Setting address_space_operations to noop_set_page_dirty and
noop_invalidatepage for device dax to prevent fallback to
__set_page_dirty_buffers() and block_invalidatepage() respectively.

Fixes: 2232c6382a ("device-dax: Enable page_mapping()")
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Reported-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/drivers/dax/device.c b/drivers/dax/device.c
index bbe4d72ca105b001e36b1d09d382ee9e3a89ee7c..948806e57cee33f74024adb442f398579319b89d 100644 (file)
--- a/drivers/dax/device.c
+++ b/drivers/dax/device.c
@@ -535,6 +535,11 @@ static unsigned long dax_get_unmapped_area(struct file *filp,
        return current->mm->get_unmapped_area(filp, addr, len, pgoff, flags);
 }
 
+static const struct address_space_operations dev_dax_aops = {
+       .set_page_dirty         = noop_set_page_dirty,
+       .invalidatepage         = noop_invalidatepage,
+};
+
 static int dax_open(struct inode *inode, struct file *filp)
 {
        struct dax_device *dax_dev = inode_dax(inode);
@@ -544,6 +549,7 @@ static int dax_open(struct inode *inode, struct file *filp)
        dev_dbg(&dev_dax->dev, "trace\n");
        inode->i_mapping = __dax_inode->i_mapping;
        inode->i_mapping->host = __dax_inode;
+       inode->i_mapping->a_ops = &dev_dax_aops;
        filp->f_mapping = inode->i_mapping;
        filp->f_wb_err = filemap_sample_wb_err(filp->f_mapping);
        filp->private_data = dev_dax;