--- zzzz-none-000/linux-3.10.107/fs/ext2/file.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/fs/ext2/file.c	2021-02-04 17:41:59.000000000 +0000
@@ -20,11 +20,126 @@
 
 #include <linux/time.h>
 #include <linux/pagemap.h>
+#include <linux/dax.h>
 #include <linux/quotaops.h>
 #include "ext2.h"
 #include "xattr.h"
 #include "acl.h"
 
+#ifdef CONFIG_FS_DAX
+/*
+ * The lock ordering for ext2 DAX fault paths is:
+ *
+ * mmap_sem (MM)
+ *   sb_start_pagefault (vfs, freeze)
+ *     ext2_inode_info->dax_sem
+ *       address_space->i_mmap_rwsem or page_lock (mutually exclusive in DAX)
+ *         ext2_inode_info->truncate_mutex
+ *
+ * The default page_lock and i_size verification done by non-DAX fault paths
+ * is sufficient because ext2 doesn't support hole punching.
+ */
+static int ext2_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+	struct inode *inode = file_inode(vma->vm_file);
+	struct ext2_inode_info *ei = EXT2_I(inode);
+	int ret;
+
+	if (vmf->flags & FAULT_FLAG_WRITE) {
+		sb_start_pagefault(inode->i_sb);
+		file_update_time(vma->vm_file);
+	}
+	down_read(&ei->dax_sem);
+
+	ret = __dax_fault(vma, vmf, ext2_get_block, NULL);
+
+	up_read(&ei->dax_sem);
+	if (vmf->flags & FAULT_FLAG_WRITE)
+		sb_end_pagefault(inode->i_sb);
+	return ret;
+}
+
+static int ext2_dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr,
+						pmd_t *pmd, unsigned int flags)
+{
+	struct inode *inode = file_inode(vma->vm_file);
+	struct ext2_inode_info *ei = EXT2_I(inode);
+	int ret;
+
+	if (flags & FAULT_FLAG_WRITE) {
+		sb_start_pagefault(inode->i_sb);
+		file_update_time(vma->vm_file);
+	}
+	down_read(&ei->dax_sem);
+
+	ret = __dax_pmd_fault(vma, addr, pmd, flags, ext2_get_block, NULL);
+
+	up_read(&ei->dax_sem);
+	if (flags & FAULT_FLAG_WRITE)
+		sb_end_pagefault(inode->i_sb);
+	return ret;
+}
+
+static int ext2_dax_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+	struct inode *inode = file_inode(vma->vm_file);
+	struct ext2_inode_info *ei = EXT2_I(inode);
+	int ret;
+
+	sb_start_pagefault(inode->i_sb);
+	file_update_time(vma->vm_file);
+	down_read(&ei->dax_sem);
+
+	ret = __dax_mkwrite(vma, vmf, ext2_get_block, NULL);
+
+	up_read(&ei->dax_sem);
+	sb_end_pagefault(inode->i_sb);
+	return ret;
+}
+
+static int ext2_dax_pfn_mkwrite(struct vm_area_struct *vma,
+		struct vm_fault *vmf)
+{
+	struct inode *inode = file_inode(vma->vm_file);
+	struct ext2_inode_info *ei = EXT2_I(inode);
+	int ret = VM_FAULT_NOPAGE;
+	loff_t size;
+
+	sb_start_pagefault(inode->i_sb);
+	file_update_time(vma->vm_file);
+	down_read(&ei->dax_sem);
+
+	/* check that the faulting page hasn't raced with truncate */
+	size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
+	if (vmf->pgoff >= size)
+		ret = VM_FAULT_SIGBUS;
+
+	up_read(&ei->dax_sem);
+	sb_end_pagefault(inode->i_sb);
+	return ret;
+}
+
+static const struct vm_operations_struct ext2_dax_vm_ops = {
+	.fault		= ext2_dax_fault,
+	.pmd_fault	= ext2_dax_pmd_fault,
+	.page_mkwrite	= ext2_dax_mkwrite,
+	.pfn_mkwrite	= ext2_dax_pfn_mkwrite,
+};
+
+static int ext2_file_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	if (!IS_DAX(file_inode(file)))
+		return generic_file_mmap(file, vma);
+
+	file_accessed(file);
+	vma->vm_ops = &ext2_dax_vm_ops;
+	vma->vm_flags |= VM_MIXEDMAP | VM_HUGEPAGE;
+	return 0;
+}
+#else
+#define ext2_file_mmap	generic_file_mmap
+#endif
+
 /*
  * Called when filp is released. This happens when all file descriptors
  * for a single struct file are closed. Note that different open() calls
@@ -62,38 +177,20 @@
  */
 const struct file_operations ext2_file_operations = {
 	.llseek		= generic_file_llseek,
-	.read		= do_sync_read,
-	.write		= do_sync_write,
-	.aio_read	= generic_file_aio_read,
-	.aio_write	= generic_file_aio_write,
+	.read_iter	= generic_file_read_iter,
+	.write_iter	= generic_file_write_iter,
 	.unlocked_ioctl = ext2_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= ext2_compat_ioctl,
 #endif
-	.mmap		= generic_file_mmap,
+	.mmap		= ext2_file_mmap,
 	.open		= dquot_file_open,
 	.release	= ext2_release_file,
 	.fsync		= ext2_fsync,
 	.splice_read	= generic_file_splice_read,
-	.splice_write	= generic_file_splice_write,
+	.splice_write	= iter_file_splice_write,
 };
 
-#ifdef CONFIG_EXT2_FS_XIP
-const struct file_operations ext2_xip_file_operations = {
-	.llseek		= generic_file_llseek,
-	.read		= xip_file_read,
-	.write		= xip_file_write,
-	.unlocked_ioctl = ext2_ioctl,
-#ifdef CONFIG_COMPAT
-	.compat_ioctl	= ext2_compat_ioctl,
-#endif
-	.mmap		= xip_file_mmap,
-	.open		= dquot_file_open,
-	.release	= ext2_release_file,
-	.fsync		= ext2_fsync,
-};
-#endif
-
 const struct inode_operations ext2_file_inode_operations = {
 #ifdef CONFIG_EXT2_FS_XATTR
 	.setxattr	= generic_setxattr,
@@ -103,5 +200,6 @@
 #endif
 	.setattr	= ext2_setattr,
 	.get_acl	= ext2_get_acl,
+	.set_acl	= ext2_set_acl,
 	.fiemap		= ext2_fiemap,
 };