3 files changed, 29 insertions, 2 deletions

diff --git a/fs/open.c b/fs/open.c
index 33f9cbf2610b..b724cc0e0228 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -231,8 +231,7 @@ int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
                 return -EINVAL;
 
         /* Return error if mode is not supported */
-        if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
-                     FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE))
+        if (mode & ~FALLOC_FL_SUPPORTED_MASK)
                 return -EOPNOTSUPP;
 
         /* Punch hole and zero range are mutually exclusive */
@@ -250,6 +249,11 @@ int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
             (mode & ~FALLOC_FL_COLLAPSE_RANGE))
                 return -EINVAL;
 
+        /* Insert range should only be used exclusively. */
+        if ((mode & FALLOC_FL_INSERT_RANGE) &&
+            (mode & ~FALLOC_FL_INSERT_RANGE))
+                return -EINVAL;
+
         if (!(file->f_mode & FMODE_WRITE))
                 return -EBADF;
 
diff --git a/include/linux/falloc.h b/include/linux/falloc.h
index 31591686ac2d..996111000a8c 100644
--- a/include/linux/falloc.h
+++ b/include/linux/falloc.h
@@ -21,4 +21,10 @@ struct space_resv {
 #define FS_IOC_RESVSP           _IOW('X', 40, struct space_resv)
 #define FS_IOC_RESVSP64         _IOW('X', 42, struct space_resv)
 
+#define FALLOC_FL_SUPPORTED_MASK        (FALLOC_FL_KEEP_SIZE |          \
+                                         FALLOC_FL_PUNCH_HOLE |         \
+                                         FALLOC_FL_COLLAPSE_RANGE |     \
+                                         FALLOC_FL_ZERO_RANGE |         \
+                                         FALLOC_FL_INSERT_RANGE)
+
 #endif /* _FALLOC_H_ */
diff --git a/include/uapi/linux/falloc.h b/include/uapi/linux/falloc.h
index d1197ae3723c..3e445a760f14 100644
--- a/include/uapi/linux/falloc.h
+++ b/include/uapi/linux/falloc.h
@@ -41,4 +41,21 @@
  */
 #define FALLOC_FL_ZERO_RANGE            0x10
 
+/*
+ * FALLOC_FL_INSERT_RANGE is use to insert space within the file size without
+ * overwriting any existing data. The contents of the file beyond offset are
+ * shifted towards right by len bytes to create a hole.  As such, this
+ * operation will increase the size of the file by len bytes.
+ *
+ * Different filesystems may implement different limitations on the granularity
+ * of the operation. Most will limit operations to filesystem block size
+ * boundaries, but this boundary may be larger or smaller depending on
+ * the filesystem and/or the configuration of the filesystem or file.
+ *
+ * Attempting to insert space using this flag at OR beyond the end of
+ * the file is considered an illegal operation - just use ftruncate(2) or
+ * fallocate(2) with mode 0 for such type of operations.
+ */
+#define FALLOC_FL_INSERT_RANGE          0x20
+
 #endif /* _UAPI_FALLOC_H_ */