iomap: add IOMAP_REPORT
This allows the file system to tell a FIEMAP from a read operation, and thus
avoids the need to report flags that aren't actually used in the read path.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index e63e288..7892f55 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -19,11 +19,15 @@ struct vm_fault;
#define IOMAP_UNWRITTEN 0x04 /* blocks allocated @blkno in unwritten state */
/*
- * Flags for iomap mappings:
+ * Flags for all iomap mappings:
*/
-#define IOMAP_F_MERGED 0x01 /* contains multiple blocks/extents */
-#define IOMAP_F_SHARED 0x02 /* block shared with another file */
-#define IOMAP_F_NEW 0x04 /* blocks have been newly allocated */
+#define IOMAP_F_NEW 0x01 /* blocks have been newly allocated */
+
+/*
+ * Flags that only need to be reported for IOMAP_REPORT requests:
+ */
+#define IOMAP_F_MERGED 0x10 /* contains multiple blocks/extents */
+#define IOMAP_F_SHARED 0x20 /* block shared with another file */
/*
* Magic value for blkno:
@@ -42,8 +46,9 @@ struct iomap {
/*
* Flags for iomap_begin / iomap_end. No flag implies a read.
*/
-#define IOMAP_WRITE (1 << 0)
-#define IOMAP_ZERO (1 << 1)
+#define IOMAP_WRITE (1 << 0) /* writing, must allocate blocks */
+#define IOMAP_ZERO (1 << 1) /* zeroing operation, may skip holes */
+#define IOMAP_REPORT (1 << 2) /* report extent status, e.g. FIEMAP */
struct iomap_ops {
/*
