Commit 8844355d authored by Li Zefan's avatar Li Zefan
Browse files

btrfs: Fix bugs in zlib workspace 



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

Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
parent 83a50de9

fs/btrfs/zlib.c

+5 −2
Original line number Diff line number Diff line
@@ -75,16 +75,19 @@ static struct workspace *find_zlib_workspace(void) 
		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;