[PATCH] [v2] blkdev: always export SECTOR_SHIFT

[Arnd Bergmann <arnd@arndb.de>]

When CONFIG_BLOCK is disabled, SECTOR_SHIFT is unknown, and this leads
to a failure in the testing infrastructure added from commit c93a0368aaa2
("kbuild: do not create wrappers for header-test-y"):

In file included from <built-in>:3:
include/linux/iomap.h:76:48: error: use of undeclared identifier 'SECTOR_SHIFT'
        return (iomap->addr + pos - iomap->offset) >> SECTOR_SHIFT;

If we want to keep build testing all headers, the macro needs to
either be defined, or not used. Move it out of the #ifdef
section to ensure it is visible.

Fixes: db074436f421 ("iomap: move the direct IO code into a separate file")
Link: https://lore.kernel.org/lkml/20190718125509.775525-1-arnd@arndb.de/T/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
The discussion about the build testing is still going on, but I promised
to send this version anyway for reference. I see no other header-test
failures in randconfig builds with this patch.
---
 include/linux/blkdev.h | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 0ec4f975437e..9c22d8bc6bf9 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -5,6 +5,19 @@
 #include <linux/sched.h>
 #include <linux/sched/clock.h>
 
+/*
+ * The basic unit of block I/O is a sector. It is used in a number of contexts
+ * in Linux (blk, bio, genhd). The size of one sector is 512 = 2**9
+ * bytes. Variables of type sector_t represent an offset or size that is a
+ * multiple of 512 bytes. Hence these two constants.
+ */
+#ifndef SECTOR_SHIFT
+#define SECTOR_SHIFT 9
+#endif
+#ifndef SECTOR_SIZE
+#define SECTOR_SIZE (1 << SECTOR_SHIFT)
+#endif
+
 #ifdef CONFIG_BLOCK
 
 #include <linux/major.h>
@@ -889,19 +902,6 @@ static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
 	return bdev->bd_disk->queue;	/* this is never NULL */
 }
 
-/*
- * The basic unit of block I/O is a sector. It is used in a number of contexts
- * in Linux (blk, bio, genhd). The size of one sector is 512 = 2**9
- * bytes. Variables of type sector_t represent an offset or size that is a
- * multiple of 512 bytes. Hence these two constants.
- */
-#ifndef SECTOR_SHIFT
-#define SECTOR_SHIFT 9
-#endif
-#ifndef SECTOR_SIZE
-#define SECTOR_SIZE (1 << SECTOR_SHIFT)
-#endif
-
 /*
  * blk_rq_pos()			: the current sector
  * blk_rq_bytes()		: bytes left in the entire request
-- 
2.20.0