linux-kernel - [Bcache v15 01/16] Revert "rw_semaphore: remove up/down_read_non

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 23 Jul 2012 16:50:44 -0700
From:	Kent Overstreet <koverstreet@...gle.com>
To:	linux-bcache@...r.kernel.org, linux-kernel@...r.kernel.org,
	dm-devel@...hat.com
Cc:	Kent Overstreet <koverstreet@...gle.com>, tj@...nel.org,
	vgoyal@...hat.com, joe@...ches.com
Subject: [Bcache v15 01/16] Revert "rw_semaphore: remove up/down_read_non_owner"

This reverts commit 11b80f459adaf91a712f95e7734a17655a36bf30.

Signed-off-by: Kent Overstreet <koverstreet@...gle.com>
---
 include/linux/rwsem.h |   10 ++++++++++
 kernel/rwsem.c        |   16 ++++++++++++++++
 2 files changed, 26 insertions(+), 0 deletions(-)

diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h
index 54bd7cd..ddfe46d 100644
--- a/include/linux/rwsem.h
+++ b/include/linux/rwsem.h
@@ -125,9 +125,19 @@ extern void downgrade_write(struct rw_semaphore *sem);
  */
 extern void down_read_nested(struct rw_semaphore *sem, int subclass);
 extern void down_write_nested(struct rw_semaphore *sem, int subclass);
+/*
+ * Take/release a lock when not the owner will release it.
+ *
+ * [ This API should be avoided as much as possible - the
+ *   proper abstraction for this case is completions. ]
+ */
+extern void down_read_non_owner(struct rw_semaphore *sem);
+extern void up_read_non_owner(struct rw_semaphore *sem);
 #else
 # define down_read_nested(sem, subclass)		down_read(sem)
 # define down_write_nested(sem, subclass)	down_write(sem)
+# define down_read_non_owner(sem)		down_read(sem)
+# define up_read_non_owner(sem)			up_read(sem)
 #endif
 
 #endif /* _LINUX_RWSEM_H */
diff --git a/kernel/rwsem.c b/kernel/rwsem.c
index 6850f53..78b7915 100644
--- a/kernel/rwsem.c
+++ b/kernel/rwsem.c
@@ -116,6 +116,15 @@ void down_read_nested(struct rw_semaphore *sem, int subclass)
 
 EXPORT_SYMBOL(down_read_nested);
 
+void down_read_non_owner(struct rw_semaphore *sem)
+{
+	might_sleep();
+
+	__down_read(sem);
+}
+
+EXPORT_SYMBOL(down_read_non_owner);
+
 void down_write_nested(struct rw_semaphore *sem, int subclass)
 {
 	might_sleep();
@@ -126,6 +135,13 @@ void down_write_nested(struct rw_semaphore *sem, int subclass)
 
 EXPORT_SYMBOL(down_write_nested);
 
+void up_read_non_owner(struct rw_semaphore *sem)
+{
+	__up_read(sem);
+}
+
+EXPORT_SYMBOL(up_read_non_owner);
+
 #endif
 
 
-- 
1.7.7.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/