1 files changed, 6 insertions, 0 deletions

diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 751ce21dea7b..2970022faa63 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -398,6 +398,12 @@ void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size);
 #define dm_array_too_big(fixed, obj, num) \
         ((num) > (UINT_MAX - (fixed)) / (obj))
 
+/*
+ * Sector offset taken relative to the start of the target instead of
+ * relative to the start of the device.
+ */
+#define dm_target_offset(ti, sector) ((sector) - (ti)->begin)
+
 static inline sector_t to_sector(unsigned long n)
 {
         return (n >> SECTOR_SHIFT);