seq_file: add seq_cpumask_list(), seq_nodemask_list()

seq_cpumask_list(), seq_nodemask_list() are very like seq_cpumask(),
seq_nodemask(), but they print human readable string.
Signed-off-by: NLai Jiangshan <laijs@cn.fujitsu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Paul Menage <menage@google.com>
Cc: Paul Jackson <pj@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

fs/seq_file.c

@@ -465,6 +465,22 @@ int seq_bitmap(struct seq_file *m, unsigned long *bits, unsigned int nr_bits)
 }
 EXPORT_SYMBOL(seq_bitmap);
 
+int seq_bitmap_list(struct seq_file *m, unsigned long *bits,
+		unsigned int nr_bits)
+{
+	if (m->count < m->size) {
+		int len = bitmap_scnlistprintf(m->buf + m->count,
+				m->size - m->count, bits, nr_bits);
+		if (m->count + len < m->size) {
+			m->count += len;
+			return 0;
+		}
+	}
+	m->count = m->size;
+	return -1;
+}
+EXPORT_SYMBOL(seq_bitmap_list);
+
 static void *single_start(struct seq_file *p, loff_t *pos)
 {
 	return NULL + (*pos == 0);

include/linux/seq_file.h

@@ -60,6 +60,19 @@ static inline int seq_nodemask(struct seq_file *m, nodemask_t *mask)
 	return seq_bitmap(m, mask->bits, MAX_NUMNODES);
 }
 
+int seq_bitmap_list(struct seq_file *m, unsigned long *bits,
+		unsigned int nr_bits);
+
+static inline int seq_cpumask_list(struct seq_file *m, cpumask_t *mask)
+{
+	return seq_bitmap_list(m, mask->bits, NR_CPUS);
+}
+
+static inline int seq_nodemask_list(struct seq_file *m, nodemask_t *mask)
+{
+	return seq_bitmap_list(m, mask->bits, MAX_NUMNODES);
+}
+
 int single_open(struct file *, int (*)(struct seq_file *, void *), void *);
 int single_release(struct inode *, struct file *);
 void *__seq_open_private(struct file *, const struct seq_operations *, int);