在 16/7/1 上午9:51, wangyijing 写道:

Hi Coly, thanks to your review and comments.

Commit 77b5a08427e875 ("bcache: don't embed 'return' statements in closure macros")
remove the return in continue_at(), so I think we should update the document info
about continue_at().

Thanks!
Yijing.

Hi Yijing,

The original version of continue_at() returns to caller function inside
the macro, Jens thinks this macro breaks code execution flow implicitly,
so he moves 'return' out of continue_at() and to follow continue_at() at
the location where continue_at() is referenced.

So as I suggested, the original author means the code should return to
the calling function.

But YES, I agree that the comments should be updated, because there is
no 'return' inside macro continue_at(). We should explicitly point out
that there should be a 'return' immediately following macro continue_at().

Thanks.

Coly

在 2016/6/29 18:16, Coly Li 写道:

quoted

在 16/6/22 上午10:12, Yijing Wang 写道:

quoted

There is no return in continue_at(), update the documentation.

There are 2 modification of this patch. The first one is about a typo,
it is correct.

But I doubt your second modification is proper. The line removed in your
patch is,

quoted

- * continue_at() also, critically, is a macro that returns the

calling function.

quoted

- * There's good reason for this.
- *

I think this is exactly what original author wants to say. It does not
mean return a value, it means return to the calling function. And the
bellowed lines explains the reason.

quoted

Signed-off-by: Yijing Wang <redacted>
---
 drivers/md/bcache/closure.c |    2 +-
 drivers/md/bcache/closure.h |    3 ---
 2 files changed, 1 insertions(+), 4 deletions(-)

diff --git a/drivers/md/bcache/closure.c b/drivers/md/bcache/closure.c
index 9eaf1d6..864e673 100644
--- a/drivers/md/bcache/closure.c
+++ b/drivers/md/bcache/closure.c

@@ -112,7 +112,7 @@ bool closure_wait(struct closure_waitlist *waitlist, struct closure *cl)
 EXPORT_SYMBOL(closure_wait);
 
 /**
- * closure_sync - sleep until a closure a closure has nothing left to wait on
+ * closure_sync - sleep until a closure has nothing left to wait on

Yes, this modification is good.

quoted

  *
  * Sleeps until the refcount hits 1 - the thread that's running the closure owns
  * the last refcount.

diff --git a/drivers/md/bcache/closure.h b/drivers/md/bcache/closure.h
index 782cc2c..f51188d 100644
--- a/drivers/md/bcache/closure.h
+++ b/drivers/md/bcache/closure.h

@@ -31,9 +31,6 @@
  * passing it, as you might expect, the function to run when nothing is pending
  * and the workqueue to run that function out of.
  *
- * continue_at() also, critically, is a macro that returns the calling function.
- * There's good reason for this.
- *
  * To use safely closures asynchronously, they must always have a refcount while
  * they are running owned by the thread that is running them. Otherwise, suppose
  * you submit some bios and wish to have a function run when they all complete:

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