Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755746Ab2EJDNJ (ORCPT ); Wed, 9 May 2012 23:13:09 -0400 Received: from mail-qa0-f46.google.com ([209.85.216.46]:36796 "EHLO mail-qa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755256Ab2EJDIy (ORCPT ); Wed, 9 May 2012 23:08:54 -0400 Date: Wed, 9 May 2012 23:08:49 -0400 From: Kent Overstreet To: linux-bcache@vger.kernel.org, linux-kernel@vger.kernel.org, dm-devel@redhat.com Cc: tejun@google.com, agk@redhat.com Subject: [Bcache v13 03/16] Revert "rw_semaphore: remove up/down_read_non_owner" Message-ID: <3f51ec3e69b8f471e2d1cc539f01504e2b903fed.1336619038.git.koverstreet@google.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2169 Lines: 74 This reverts commit 11b80f459adaf91a712f95e7734a17655a36bf30. Signed-off-by: Kent Overstreet --- 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 63d4065..5f0dc75 100644 --- a/include/linux/rwsem.h +++ b/include/linux/rwsem.h @@ -126,9 +126,19 @@ 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 b152f74..66de558 100644 --- a/kernel/rwsem.c +++ b/kernel/rwsem.c @@ -117,6 +117,15 @@ 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(); @@ -127,6 +136,13 @@ 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 -- 1.7.9.rc2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/