linux-kernel - [PATCH] docs: kref: Clarify the use of two kref

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Date:   Thu, 13 Feb 2020 18:23:11 +0530
From:   Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>
To:     corbet@....net
Cc:     linux-doc@...r.kernel.org, linux-kernel@...r.kernel.org,
        Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>
Subject: [PATCH] docs: kref: Clarify the use of two kref_put() in example code

Eventhough the current documentation explains that the reference count
gets incremented by both kref_init() and kref_get(), it is often
misunderstood that only one instance of kref_put() is needed in the
example code. So let's clarify that a bit.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>
---
 Documentation/kref.txt | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Documentation/kref.txt b/Documentation/kref.txt
index 3af384156d7e..c61eea6f1bf2 100644
--- a/Documentation/kref.txt
+++ b/Documentation/kref.txt
@@ -128,6 +128,10 @@ since we already have a valid pointer that we own a refcount for.  The
 put needs no lock because nothing tries to get the data without
 already holding a pointer.
 
+In the above example, kref_put() will be called 2 times in both success
+and error paths. This is necessary because the reference count got
+incremented 2 times by kref_init() and kref_get().
+
 Note that the "before" in rule 1 is very important.  You should never
 do something like::
 
-- 
2.17.1