From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760294AbYEFEhl (ORCPT ); Tue, 6 May 2008 00:37:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752864AbYEFEhP (ORCPT ); Tue, 6 May 2008 00:37:15 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:52311 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757292AbYEFEhN (ORCPT ); Tue, 6 May 2008 00:37:13 -0400 Date: Mon, 5 May 2008 21:36:44 -0700 From: Andrew Morton To: Peter Oberparleiter Cc: linux-kernel@vger.kernel.org, ltp-list@lists.sourceforge.net, ltp-coverage@lists.sourceforge.net, Al Viro Subject: Re: [RFC PATCH 4/6] seq_file: add function to write binary data Message-Id: <20080505213644.b153ee68.akpm@linux-foundation.org> In-Reply-To: <481F26B5.7010708@de.ibm.com> References: <481F26B5.7010708@de.ibm.com> X-Mailer: Sylpheed 2.4.8 (GTK+ 2.12.5; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 05 May 2008 17:24:37 +0200 Peter Oberparleiter wrote: > From: Peter Oberparleiter > > seq_write() can be used to construct seq_files containing arbitrary > data. Required by the gcov-profiling interface to synthesize binary > profiling data files. > > Signed-off-by: Peter Oberparleiter > --- > fs/seq_file.c | 12 ++++++++++++ > include/linux/seq_file.h | 1 + > 2 files changed, 13 insertions(+) > > Index: linux-2.6.26-rc1/fs/seq_file.c > =================================================================== > --- linux-2.6.26-rc1.orig/fs/seq_file.c > +++ linux-2.6.26-rc1/fs/seq_file.c > @@ -554,6 +554,18 @@ int seq_puts(struct seq_file *m, const c > } > EXPORT_SYMBOL(seq_puts); > > +int seq_write(struct seq_file *m, const void *s, size_t len) Most of the other seq_file interface functions are nicely documented. > +{ > + if (m->count + len < m->size) { Are you sure that shouldn't be >=? > + memcpy(m->buf + m->count, s, len); > + m->count += len; > + return 0; > + } > + m->count = m->size; > + return -1; > +} > +EXPORT_SYMBOL(seq_write); Usually when a write-style function is passed too much data it will write as much as it can and will then return a smaller-than-requested value. That's inappropriate for your application of seq_write(), but perhaps is appropriate for other future callers? This function has an upper limit of PAGE_SIZE bytes, I think? The covering documentation should explain such things. > struct list_head *seq_list_start(struct list_head *head, loff_t pos) > { > struct list_head *lh; > Index: linux-2.6.26-rc1/include/linux/seq_file.h > =================================================================== > --- linux-2.6.26-rc1.orig/include/linux/seq_file.h > +++ linux-2.6.26-rc1/include/linux/seq_file.h > @@ -39,6 +39,7 @@ int seq_release(struct inode *, struct f > int seq_escape(struct seq_file *, const char *, const char *); > int seq_putc(struct seq_file *m, char c); > int seq_puts(struct seq_file *m, const char *s); > +int seq_write(struct seq_file *m, const void *s, size_t len); > > int seq_printf(struct seq_file *, const char *, ...) > __attribute__ ((format (printf,2,3))); >