vfs: plumb remap flags through the vfs dedupe functions

Plumb a remap_flags argument through the vfs_dedupe_file_range_one
functions so that dedupe can take advantage of it.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

diff --git a/fs/read_write.c b/fs/read_write.c
index 0d1ac1b..ea30666 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -2010,10 +2010,12 @@ EXPORT_SYMBOL(vfs_dedupe_file_range_compare);
 
 loff_t vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos,
 				 struct file *dst_file, loff_t dst_pos,
-				 loff_t len)
+				 loff_t len, unsigned int remap_flags)
 {
 	loff_t ret;
 
+	WARN_ON_ONCE(remap_flags & ~(REMAP_FILE_DEDUP));
+
 	ret = mnt_want_write_file(dst_file);
 	if (ret)
 		return ret;
@@ -2044,7 +2046,7 @@ loff_t vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos,
 	}
 
 	ret = dst_file->f_op->remap_file_range(src_file, src_pos, dst_file,
-			dst_pos, len, REMAP_FILE_DEDUP);
+			dst_pos, len, remap_flags | REMAP_FILE_DEDUP);
 out_drop_write:
 	mnt_drop_write_file(dst_file);
 
@@ -2112,7 +2114,8 @@ int vfs_dedupe_file_range(struct file *file, struct file_dedupe_range *same)
 		}
 
 		deduped = vfs_dedupe_file_range_one(file, off, dst_file,
-						    info->dest_offset, len);
+						    info->dest_offset, len,
+						    0);
 		if (deduped == -EBADE)
 			info->status = FILE_DEDUPE_RANGE_DIFFERS;
 		else if (deduped < 0)