[PATCH v2 05/17] seq_buf: Create seq_buf_used() to find out how much was written

[Wang Long <long.wanglong@huawei.com>]

From: "Steven Rostedt (Red Hat)" <rostedt@goodmis.org>

commit eeab98154dc0b49afd398afdd71c464a8af5911f upstream.

Add a helper function seq_buf_used() that replaces the SEQ_BUF_USED()
private macro to let callers have a method to know how much of the
seq_buf was written to.

Link: http://lkml.kernel.org/r/20141114011412.170377300@goodmis.org
Link: http://lkml.kernel.org/r/20141114011413.321654244@goodmis.org

Reviewed-by: Petr Mladek <pmladek@suse.cz>
[wanglong: backport to 3.10 stable]
Signed-off-by: Wang Long <long.wanglong@huawei.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 include/linux/seq_buf.h | 6 ++++++
 kernel/trace/seq_buf.c  | 5 +----
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/include/linux/seq_buf.h b/include/linux/seq_buf.h
index 5d91262..93718e5 100644
--- a/include/linux/seq_buf.h
+++ b/include/linux/seq_buf.h
@@ -64,6 +64,12 @@ seq_buf_buffer_left(struct seq_buf *s)
 	return (s->size - 1) - s->len;
 }
 
+/* How much buffer was written? */
+static inline unsigned int seq_buf_used(struct seq_buf *s)
+{
+	return min(s->len, s->size);
+}
+
 extern __printf(2, 3)
 int seq_buf_printf(struct seq_buf *s, const char *fmt, ...);
 extern __printf(2, 0)
diff --git a/kernel/trace/seq_buf.c b/kernel/trace/seq_buf.c
index 7dac34d..9ec5305 100644
--- a/kernel/trace/seq_buf.c
+++ b/kernel/trace/seq_buf.c
@@ -16,9 +16,6 @@
 #include <linux/seq_file.h>
 #include <linux/seq_buf.h>
 
-/* How much buffer is written? */
-#define SEQ_BUF_USED(s) min((s)->len, (s)->size - 1)
-
 /**
  * seq_buf_print_seq - move the contents of seq_buf into a seq_file
  * @m: the seq_file descriptor that is the destination
@@ -28,7 +25,7 @@
  */
 int seq_buf_print_seq(struct seq_file *m, struct seq_buf *s)
 {
-	unsigned int len = SEQ_BUF_USED(s);
+	unsigned int len = seq_buf_used(s);
 
 	return seq_write(m, s->buffer, len);
 }
-- 
1.8.3.4