[PATCH] cpuset: allow a larger buffer for writes to cpuset files

When using fake NUMA setup, the number of memory nodes can greatly exceed
the number of CPUs.  So the current limit in cpuset_common_file_write() is
insufficient.
Signed-off-by: NPaul Menage <menage@google.com>
Acked-by: NPaul Jackson <pj@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

kernel/cpuset.c

@@ -1280,7 +1280,8 @@ typedef enum {
 	FILE_TASKLIST,
 } cpuset_filetype_t;
 
-static ssize_t cpuset_common_file_write(struct file *file, const char __user *userbuf,
+static ssize_t cpuset_common_file_write(struct file *file,
+					const char __user *userbuf,
 					size_t nbytes, loff_t *unused_ppos)
 {
 	struct cpuset *cs = __d_cs(file->f_dentry->d_parent);
@@ -1291,7 +1292,7 @@ static ssize_t cpuset_common_file_write(struct file *file, const char __user *us
 	int retval = 0;
 
 	/* Crude upper limit on largest legitimate cpulist user might write. */
-	if (nbytes > 100 + 6 * NR_CPUS)
+	if (nbytes > 100 + 6 * max(NR_CPUS, MAX_NUMNODES))
 		return -E2BIG;
 
 	/* +1 for nul-terminator */