seq_file: don't call bitmap_scnprintf_len()

"m->count + len < m->size" is true commonly, so bitmap_scnprintf()
is commonly called. this fix saves a call to bitmap_scnprintf_len().

Signed-off-by: Lai 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 8 insertions, 7 deletions

diff --git a/fs/seq_file.c b/fs/seq_file.c
index bd20f7f5a933..11c85fec6b4f 100644
--- a/fs/seq_file.c
+++ b/fs/seq_file.c
@@ -452,17 +452,18 @@ int seq_dentry(struct seq_file *m, struct dentry *dentry, char *esc)
 
 int seq_bitmap(struct seq_file *m, unsigned long *bits, unsigned int nr_bits)
 {
-        size_t len = bitmap_scnprintf_len(nr_bits);
-
-        if (m->count + len < m->size) {
-                bitmap_scnprintf(m->buf + m->count, m->size - m->count,
-                                 bits, nr_bits);
-                m->count += len;
-                return 0;
+        if (m->count < m->size) {
+                int len = bitmap_scnprintf(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);
 
 static void *single_start(struct seq_file *p, loff_t *pos)
 {