From mboxrd@z Thu Jan 1 00:00:00 1970 From: Li Zefan Subject: [PATCH 1/5] btrfs: Fix bugs in zlib workspace Date: Mon, 25 Oct 2010 15:11:43 +0800 Message-ID: <4CC52DAF.2030203@cn.fujitsu.com> References: <4CC52D9A.3030709@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 To: linux-btrfs@vger.kernel.org Return-path: In-Reply-To: <4CC52D9A.3030709@cn.fujitsu.com> List-ID: - Fix a race that can result in alloc_workspace > cpus. - Fix to check num_workspace after wakeup. Signed-off-by: Li Zefan --- fs/btrfs/zlib.c | 7 +++++-- 1 files changed, 5 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/zlib.c b/fs/btrfs/zlib.c index b9cd544..e5b8b22 100644 --- a/fs/btrfs/zlib.c +++ b/fs/btrfs/zlib.c @@ -75,16 +75,19 @@ again: return workspace; } - spin_unlock(&workspace_lock); if (atomic_read(&alloc_workspace) > cpus) { DEFINE_WAIT(wait); + + spin_unlock(&workspace_lock); prepare_to_wait(&workspace_wait, &wait, TASK_UNINTERRUPTIBLE); - if (atomic_read(&alloc_workspace) > cpus) + if (atomic_read(&alloc_workspace) > cpus && !num_workspace) schedule(); finish_wait(&workspace_wait, &wait); goto again; } atomic_inc(&alloc_workspace); + spin_unlock(&workspace_lock); + workspace = kzalloc(sizeof(*workspace), GFP_NOFS); if (!workspace) { ret = -ENOMEM; -- 1.7.0.1