[PATCH] block: fix a warning when blkdev.h is included for !CONFIG_BLOCK builds

[PATCH] block: fix a warning when blkdev.h is included for !CONFIG_BLOCK builds

[Christoph Hellwig]

disk_start_io_acct and disk_end_io_acct need at least a struct gendisk
forward declaration, but for weird historic reasons much of blkdev.h
is stubbed out for CONFIG_BLOCK=n.  Fix this by stubbing more out for
now, but eventually this header will need a massive cleanup.

Fixes: 956d510ee78 ("block: add disk/bio-based accounting helpers")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 include/linux/blkdev.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 6f7ff0fa8fcf8..8fd900998b4e2 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1892,12 +1892,12 @@ static inline void blk_wake_io_task(struct task_struct *waiter)
 		wake_up_process(waiter);
 }
 
+#ifdef CONFIG_BLOCK
 unsigned long disk_start_io_acct(struct gendisk *disk, unsigned int sectors,
 		unsigned int op);
 void disk_end_io_acct(struct gendisk *disk, unsigned int op,
 		unsigned long start_time);
 
-#ifdef CONFIG_BLOCK
 /**
  * bio_start_io_acct - start I/O accounting for bio based drivers
  * @bio:	bio to start account for
-- 
2.26.2

Re: [PATCH] block: fix a warning when blkdev.h is included for !CONFIG_BLOCK builds

[Jens Axboe]

On 5/28/20 7:41 AM, Christoph Hellwig wrote:
> disk_start_io_acct and disk_end_io_acct need at least a struct gendisk
> forward declaration, but for weird historic reasons much of blkdev.h
> is stubbed out for CONFIG_BLOCK=n.  Fix this by stubbing more out for
> now, but eventually this header will need a massive cleanup.

Applied, thanks.

-- 
Jens Axboe