2 files changed, 20 insertions, 1 deletions

diff --git a/fs/open.c b/fs/open.c
index 4a923a547d10..c4465b2f8441 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -232,7 +232,12 @@ int do_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
 
         /* Return error if mode is not supported */
         if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
-                     FALLOC_FL_COLLAPSE_RANGE))
+                     FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE))
+                return -EOPNOTSUPP;
+
+        /* Punch hole and zero range are mutually exclusive */
+        if ((mode & (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE)) ==
+            (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE))
                 return -EOPNOTSUPP;
 
         /* Punch hole must have keep size set */
diff --git a/include/uapi/linux/falloc.h b/include/uapi/linux/falloc.h
index 5ff562ddac0b..d1197ae3723c 100644
--- a/include/uapi/linux/falloc.h
+++ b/include/uapi/linux/falloc.h
@@ -27,4 +27,18 @@
  */
 #define FALLOC_FL_COLLAPSE_RANGE        0x08
 
+/*
+ * FALLOC_FL_ZERO_RANGE is used to convert a range of file to zeros preferably
+ * without issuing data IO. Blocks should be preallocated for the regions that
+ * span holes in the file, and the entire range is preferable converted to
+ * unwritten extents - even though file system may choose to zero out the
+ * extent or do whatever which will result in reading zeros from the range
+ * while the range remains allocated for the file.
+ *
+ * This can be also used to preallocate blocks past EOF in the same way as
+ * with fallocate. Flag FALLOC_FL_KEEP_SIZE should cause the inode
+ * size to remain the same.
+ */
+#define FALLOC_FL_ZERO_RANGE            0x10
+
 #endif /* _UAPI_FALLOC_H_ */