Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161356AbaKNQxP (ORCPT ); Fri, 14 Nov 2014 11:53:15 -0500 Received: from cantor2.suse.de ([195.135.220.15]:38003 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161065AbaKNQxO (ORCPT ); Fri, 14 Nov 2014 11:53:14 -0500 Date: Fri, 14 Nov 2014 17:53:08 +0100 From: Petr Mladek To: Steven Rostedt Cc: linux-kernel@vger.kernel.org, Ingo Molnar , Andrew Morton , Jiri Kosina Subject: Re: [RFC][PATCH 14/23 v4] tracing: Convert seq_buf_path() to be like seq_path() Message-ID: <20141114165308.GB14538@dhcp128.suse.cz> References: <20141114011244.256115061@goodmis.org> <20141114011412.338523371@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20141114011412.338523371@goodmis.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu 2014-11-13 20:12:58, Steven Rostedt wrote: > From: "Steven Rostedt (Red Hat)" > > Rewrite seq_buf_path() like it is done in seq_path() and allow > it to accept any escape character instead of just "\n". > > Making seq_buf_path() like seq_path() will help prevent problems > when converting seq_file to use the seq_buf logic. > > Link: http://lkml.kernel.org/r/20141104160222.048795666@goodmis.org > > Tested-by: Jiri Kosina > Acked-by: Jiri Kosina > Reviewed-by: Petr Mladek > Signed-off-by: Steven Rostedt > --- > include/linux/seq_buf.h | 2 +- > kernel/trace/seq_buf.c | 28 ++++++++++++++++------------ > kernel/trace/trace_seq.c | 4 ++-- > 3 files changed, 19 insertions(+), 15 deletions(-) > > diff --git a/include/linux/seq_buf.h b/include/linux/seq_buf.h > index 4f7a96a9d71a..38770688a627 100644 > --- a/include/linux/seq_buf.h > +++ b/include/linux/seq_buf.h > @@ -73,7 +73,7 @@ extern int seq_buf_putc(struct seq_buf *s, unsigned char c); > extern int seq_buf_putmem(struct seq_buf *s, const void *mem, unsigned int len); > extern int seq_buf_putmem_hex(struct seq_buf *s, const void *mem, > unsigned int len); > -extern int seq_buf_path(struct seq_buf *s, const struct path *path); > +extern int seq_buf_path(struct seq_buf *s, const struct path *path, const char *esc); > > extern int seq_buf_bitmask(struct seq_buf *s, const unsigned long *maskp, > int nmaskbits); > diff --git a/kernel/trace/seq_buf.c b/kernel/trace/seq_buf.c > index e9a7861595d2..7dac34d1235b 100644 > --- a/kernel/trace/seq_buf.c > +++ b/kernel/trace/seq_buf.c > @@ -272,28 +272,32 @@ int seq_buf_putmem_hex(struct seq_buf *s, const void *mem, > * seq_buf_path - copy a path into the sequence buffer > * @s: seq_buf descriptor > * @path: path to write into the sequence buffer. > + * @esc: set of characters to escape in the output > * > * Write a path name into the sequence buffer. > * > - * Returns zero on success, -1 on overflow > + * Returns the number of written bytes on success, -1 on overflow > */ > -int seq_buf_path(struct seq_buf *s, const struct path *path) > +int seq_buf_path(struct seq_buf *s, const struct path *path, const char *esc) > { > - unsigned int len = seq_buf_buffer_left(s); > - unsigned char *p; > + char *buf = s->buffer + s->len; > + size_t size = seq_buf_buffer_left(s); > + int res = -1; > > WARN_ON(s->size == 0); > > - p = d_path(path, s->buffer + s->len, len); > - if (!IS_ERR(p)) { > - p = mangle_path(s->buffer + s->len, p, "\n"); > - if (p) { > - s->len = p - s->buffer; > - return 0; > + if (size) { > + char *p = d_path(path, buf, size); > + if (!IS_ERR(p)) { > + char *end = mangle_path(buf, p, esc); > + if (end) > + res = end - buf; > } > } > - seq_buf_set_overflow(s); > - return -1; > + if (res > 0) > + s->len += res; > + > + return res; > } > > /** > diff --git a/kernel/trace/trace_seq.c b/kernel/trace/trace_seq.c > index 3c63b619d6b7..475412e31de5 100644 > --- a/kernel/trace/trace_seq.c > +++ b/kernel/trace/trace_seq.c > @@ -342,7 +342,7 @@ int trace_seq_path(struct trace_seq *s, const struct path *path) > return 0; > } > > - ret = seq_buf_path(&s->seq, path); > + ret = seq_buf_path(&s->seq, path, "\n"); > > if (unlikely(seq_buf_has_overflowed(&s->seq))) { > s->seq.len = save_len; > @@ -350,7 +350,7 @@ int trace_seq_path(struct trace_seq *s, const struct path *path) > return 0; > } > > - return ret; > + return 1; Ah, I have just realized that this should return -1 when seq_buf_path() returns -1. Note that set_buf_path() does not longer calls seq_buf_set_overflow(s) when the path handling fails. Therefore the above check for overflow will probably never happen. Best Regards, Petr > } > EXPORT_SYMBOL_GPL(trace_seq_path); > > -- > 2.1.1 > > -- 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/