From patchwork Sat Aug 20 08:00:16 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joe Perches X-Patchwork-Id: 9291627 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id EA24360572 for ; Sat, 20 Aug 2016 08:00:55 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CE89F28E03 for ; Sat, 20 Aug 2016 08:00:55 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C1CD628EAF; Sat, 20 Aug 2016 08:00:55 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7D7F128CA7 for ; Sat, 20 Aug 2016 08:00:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753656AbcHTIA0 (ORCPT ); Sat, 20 Aug 2016 04:00:26 -0400 Received: from smtprelay0164.hostedemail.com ([216.40.44.164]:51025 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751350AbcHTIAY (ORCPT ); Sat, 20 Aug 2016 04:00:24 -0400 Received: from filter.hostedemail.com (unknown [216.40.38.60]) by smtprelay03.hostedemail.com (Postfix) with ESMTP id EBD7D6B103; Sat, 20 Aug 2016 08:00:22 +0000 (UTC) X-Session-Marker: 6A6F6540706572636865732E636F6D X-HE-Tag: dogs76_3252c92bd04c X-Filterd-Recvd-Size: 3086 Received: from joe-laptop.perches.com (unknown [96.251.125.34]) (Authenticated sender: joe@perches.com) by omf02.hostedemail.com (Postfix) with ESMTPA; Sat, 20 Aug 2016 08:00:21 +0000 (UTC) From: Joe Perches To: Michal Hocko , Alexander Viro Cc: Andrew Morton , Jann Horn , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/2] seq_file: Add __seq_open_private_bufsize for seq file_operation sizes Date: Sat, 20 Aug 2016 01:00:16 -0700 Message-Id: <4c686b178bf96e2cc01cea05c55fbd7d6a0fb66e.1471679737.git.joe@perches.com> X-Mailer: git-send-email 2.8.0.rc4.16.g56331f8 In-Reply-To: <20160820072927.GA23645@dhcp22.suse.cz> References: <20160820072927.GA23645@dhcp22.suse.cz> In-Reply-To: References: Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Specifying an initial output buffer size can reduce the number of regenerations of the seq_ buffers when the buffer overflows. Add another version of __seq_open_private that takes an initial buffer size. Signed-off-by: Joe Perches --- fs/seq_file.c | 31 +++++++++++++++++++++++++++++++ include/linux/seq_file.h | 3 +++ 2 files changed, 34 insertions(+) diff --git a/fs/seq_file.c b/fs/seq_file.c index b8ac757e..d98fa77 100644 --- a/fs/seq_file.c +++ b/fs/seq_file.c @@ -652,6 +652,37 @@ int seq_open_private(struct file *filp, const struct seq_operations *ops, } EXPORT_SYMBOL(seq_open_private); +void *__seq_open_private_bufsize(struct file *f, + const struct seq_operations *ops, + int psize, size_t bufsize) +{ + int rc; + void *private; + struct seq_file *seq; + + private = kzalloc(psize, GFP_KERNEL); + if (private == NULL) + goto out; + + rc = seq_open(f, ops); + if (rc < 0) + goto out_free; + + seq = f->private_data; + seq->private = private; + + kfree(seq->buf); + seq->buf = seq_buf_alloc(seq->size = round_up(bufsize, PAGE_SIZE)); + + return private; + +out_free: + kfree(private); +out: + return NULL; +} +EXPORT_SYMBOL(__seq_open_private_bufsize); + void seq_putc(struct seq_file *m, char c) { if (m->count >= m->size) diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h index e305b66..719f1b8 100644 --- a/include/linux/seq_file.h +++ b/include/linux/seq_file.h @@ -136,6 +136,9 @@ int single_open(struct file *, int (*)(struct seq_file *, void *), void *); int single_open_size(struct file *, int (*)(struct seq_file *, void *), void *, size_t); int single_release(struct inode *, struct file *); void *__seq_open_private(struct file *, const struct seq_operations *, int); +void *__seq_open_private_bufsize(struct file *f, + const struct seq_operations *ops, + int psize, size_t bufsize); int seq_open_private(struct file *, const struct seq_operations *, int); int seq_release_private(struct inode *, struct file *);