3.16.43-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
commit 10fbd36e362a0f367e34a7cd876a81295d8fc5ca upstream.
rq_data_dir() returns either READ or WRITE (0 == READ, 1 == WRITE), not
a boolean value.
Now, admittedly the "!= 0" doesn't really change the value (0 stays as
zero, 1 stays as one), but it's not only redundant, it confuses gcc, and
causes gcc to warn about the construct
switch (rq_data_dir(req)) {
case READ:
...
case WRITE:
...
that we have in a few drivers.
Now, the gcc warning is silly and stupid (it seems to warn not about the
switch value having a different type from the case statements, but about
_any_ boolean switch value), but in this case the code itself is silly
and stupid too, so let's just change it, and get rid of warnings like
this:
drivers/block/hd.c: In function ‘hd_request’:
drivers/block/hd.c:630:11: warning: switch condition has boolean value [-Wswitch-bool]
switch (rq_data_dir(req)) {
The odd '!= 0' came in when "cmd_flags" got turned into a "u64" in
commit 5953316dbf90 ("block: make rq->cmd_flags be 64-bit") and is
presumably because the old code (that just did a logical 'and' with 1)
would then end up making the type of rq_data_dir() be u64 too.
But if we want to retain the old regular integer type, let's just cast
the result to 'int' rather than use that rather odd '!= 0'.
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
---
include/linux/blkdev.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -620,7 +620,7 @@ static inline void queue_flag_clear(unsi
#define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)
-#define rq_data_dir(rq) (((rq)->cmd_flags & 1) != 0)
+#define rq_data_dir(rq) ((int)((rq)->cmd_flags & 1))
/*
* Driver can handle struct request, if it either has an old style