Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161971AbaKNU6v (ORCPT ); Fri, 14 Nov 2014 15:58:51 -0500 Received: from cdptpa-outbound-snat.email.rr.com ([107.14.166.225]:15012 "EHLO cdptpa-oedge-vip.email.rr.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1161200AbaKNU6t convert rfc822-to-8bit (ORCPT ); Fri, 14 Nov 2014 15:58:49 -0500 Date: Fri, 14 Nov 2014 15:58:47 -0500 From: Steven Rostedt To: Petr Mladek Cc: linux-kernel@vger.kernel.org, Ingo Molnar , Andrew Morton , Jiri Kosina Subject: Re: [RFC][PATCH 18/23 v4] tracing: Add seq_buf_get_buf() and seq_buf_commit() helper functions Message-ID: <20141114155847.5e82af8f@gandalf.local.home> In-Reply-To: <20141114153123.2e1d8db6@gandalf.local.home> References: <20141114011244.256115061@goodmis.org> <20141114011412.977571447@goodmis.org> <20141114171828.GD14538@dhcp128.suse.cz> <20141114153123.2e1d8db6@gandalf.local.home> X-Mailer: Claws Mail 3.10.1 (GTK+ 2.24.25; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8BIT 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 On Fri, 14 Nov 2014 15:31:23 -0500 Steven Rostedt wrote: > Hmm, I guess I can still make this change. The seq_commit() comment > states that @num needs to be < 0 if the data did not fit, and if it is > in overflow state, then it should be -1 not size + 1 (or size for the > old way). I made the change, and here it is: -- Steve >From 69488bad76c4af9f9b5948c8990b5ed1196b2bc1 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Wed, 29 Oct 2014 17:30:50 -0400 Subject: [PATCH] tracing: Add seq_buf_get_buf() and seq_buf_commit() helper functions 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 86e50f47894b..3657af4b5f53 100644 --- a/kernel/trace/seq_buf.c +++ b/kernel/trace/seq_buf.c @@ -280,8 +280,8 @@ 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); @@ -294,8 +294,7 @@ 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; } -- 1.8.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/