cpuset: remove unneeded NODEMASK_ALLOC() in cpuset_sprintf_memlist() (9303e0c4) · Commits · 戴 / test

It's not necessary to copy cpuset->mems_allowed to a buffer allocated by NODEMASK_ALLOC(). Just pass it to nodelist_scnprintf(). As spotted by Paul, a side effect is we fix a bug that the function can return -ENOMEM but the caller doesn't expect negative return value. Therefore change the return value of cpuset_sprintf_cpulist() and cpuset_sprintf_memlist() from int to size_t. Signed-off-by:

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

Paul Menage <menage@google.com> Acked-by:

David Rientjes <rientjes@google.com> Cc: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

kernel/cpuset.c

+8 −16

Original line number	Diff line number	Diff line
		@@ -1610,34 +1610,26 @@ out:
		* across a page fault.
		*/

		static int cpuset_sprintf_cpulist(char page, struct cpuset cs)
		static size_t cpuset_sprintf_cpulist(char page, struct cpuset cs)
		{
		int ret;
		size_t count;

		mutex_lock(&callback_mutex);
		ret = cpulist_scnprintf(page, PAGE_SIZE, cs->cpus_allowed);
		count = cpulist_scnprintf(page, PAGE_SIZE, cs->cpus_allowed);
		mutex_unlock(&callback_mutex);

		return ret;
		return count;
		}

		static int cpuset_sprintf_memlist(char page, struct cpuset cs)
		static size_t cpuset_sprintf_memlist(char page, struct cpuset cs)
		{
		NODEMASK_ALLOC(nodemask_t, mask, GFP_KERNEL);
		int retval;

		if (mask == NULL)
		return -ENOMEM;
		size_t count;

		mutex_lock(&callback_mutex);
		*mask = cs->mems_allowed;
		count = nodelist_scnprintf(page, PAGE_SIZE, cs->mems_allowed);
		mutex_unlock(&callback_mutex);

		retval = nodelist_scnprintf(page, PAGE_SIZE, *mask);

		NODEMASK_FREE(mask);

		return retval;
		return count;
		}

		static ssize_t cpuset_common_file_read(struct cgroup *cont,

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