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From: Li Zefan <lizf@cn.fujitsu.com>
To: linux-btrfs@vger.kernel.org
Subject: [PATCH 1/5] btrfs: Fix bugs in zlib workspace
Date: Mon, 25 Oct 2010 15:11:43 +0800	[thread overview]
Message-ID: <4CC52DAF.2030203@cn.fujitsu.com> (raw)
In-Reply-To: <4CC52D9A.3030709@cn.fujitsu.com>

- Fix a race that can result in alloc_workspace > cpus.
- Fix to check num_workspace after wakeup.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
---
 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


  reply	other threads:[~2010-10-25  7:11 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-10-25  7:11 [PATCH 0/5] btrfs: Add lzo compression support Li Zefan
2010-10-25  7:11 ` Li Zefan [this message]
2010-10-25  7:12 ` [PATCH 2/5] btrfs: Allow to add new compression algorithm Li Zefan
2010-10-25  7:12 ` [PATCH 3/5] btrfs: Add lzo compression support Li Zefan
2010-10-25  7:12 ` [PATCH 4/5] btrfs: Allow to specify compress method when defrag Li Zefan
2010-10-25  7:13 ` [PATCH 5/5] btrfs: Extract duplicate decompress code Li Zefan
2010-10-26  2:13 ` [PATCH 0/5] btrfs: Add lzo compression support Chris Mason
2010-10-26  2:34   ` Li Zefan
2010-11-15 18:55     ` Mitch Harder
2010-11-16  0:57       ` Li Zefan
2010-11-16 18:51         ` Mitch Harder

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