From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755470AbaKOFIm (ORCPT ); Sat, 15 Nov 2014 00:08:42 -0500 Received: from cdptpa-outbound-snat.email.rr.com ([107.14.166.227]:48451 "EHLO cdptpa-oedge-vip.email.rr.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751903AbaKOFGH (ORCPT ); Sat, 15 Nov 2014 00:06:07 -0500 Message-Id: <20141115050604.377172084@goodmis.org> User-Agent: quilt/0.61-1 Date: Fri, 14 Nov 2014 23:59:09 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Jiri Kosina , Petr Mladek Subject: [PATCH 22/26 v5] tracing: Add seq_buf_get_buf() and seq_buf_commit() helper functions References: <20141115045847.712848224@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Disposition: inline; filename=0022-tracing-Add-seq_buf_get_buf-and-seq_buf_commit-helpe.patch X-RR-Connecting-IP: 107.14.168.130:25 X-Cloudmark-Score: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Steven Rostedt (Red Hat)" Add two helper functions; seq_buf_get_buf() and seq_buf_commit() that are used by seq_buf_path(). This makes the code similar to the seq_file: seq_path() function, and will help to be able to consolidate the functions between seq_file and trace_seq. Link: http://lkml.kernel.org/r/20141104160222.644881406@goodmis.org Link: http://lkml.kernel.org/r/20141114011412.977571447@goodmis.org Tested-by: Jiri Kosina Acked-by: Jiri Kosina Reviewed-by: Petr Mladek Signed-off-by: Steven Rostedt --- include/linux/seq_buf.h | 41 +++++++++++++++++++++++++++++++++++++++++ kernel/trace/seq_buf.c | 7 +++---- 2 files changed, 44 insertions(+), 4 deletions(-) diff --git a/include/linux/seq_buf.h b/include/linux/seq_buf.h index 0800a24b4348..12c64282aa98 100644 --- a/include/linux/seq_buf.h +++ b/include/linux/seq_buf.h @@ -70,6 +70,47 @@ static inline unsigned int seq_buf_used(struct seq_buf *s) return min(s->len, s->size); } +/** + * seq_buf_get_buf - get buffer to write arbitrary data to + * @s: the seq_buf handle + * @bufp: the beginning of the buffer is stored here + * + * Return the number of bytes available in the buffer, or zero if + * there's no space. + */ +static inline size_t seq_buf_get_buf(struct seq_buf *s, char **bufp) +{ + WARN_ON(s->len > s->size + 1); + + if (s->len < s->size) { + *bufp = s->buffer + s->len; + return s->size - s->len; + } + + *bufp = NULL; + return 0; +} + +/** + * seq_buf_commit - commit data to the buffer + * @s: the seq_buf handle + * @num: the number of bytes to commit + * + * Commit @num bytes of data written to a buffer previously acquired + * by seq_buf_get. To signal an error condition, or that the data + * didn't fit in the available space, pass a negative @num value. + */ +static inline void seq_buf_commit(struct seq_buf *s, int num) +{ + if (num < 0) { + seq_buf_set_overflow(s); + } else { + /* num must be negative on overflow */ + BUG_ON(s->len + num > s->size); + s->len += num; + } +} + 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 27e48348ae67..3319dfbbb75b 100644 --- a/kernel/trace/seq_buf.c +++ b/kernel/trace/seq_buf.c @@ -285,8 +285,8 @@ int seq_buf_putmem_hex(struct seq_buf *s, const void *mem, */ int seq_buf_path(struct seq_buf *s, const struct path *path, const char *esc) { - char *buf = s->buffer + s->len; - size_t size = seq_buf_buffer_left(s); + char *buf; + size_t size = seq_buf_get_buf(s, &buf); int res = -1; WARN_ON(s->size == 0); @@ -299,8 +299,7 @@ int seq_buf_path(struct seq_buf *s, const struct path *path, const char *esc) res = end - buf; } } - if (res > 0) - s->len += res; + seq_buf_commit(s, res); return res; } -- 2.1.1