From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-f69.google.com (mail-oi0-f69.google.com [209.85.218.69]) by kanga.kvack.org (Postfix) with ESMTP id 031886B0069 for ; Sat, 20 Aug 2016 04:00:24 -0400 (EDT) Received: by mail-oi0-f69.google.com with SMTP id j67so172657826oih.3 for ; Sat, 20 Aug 2016 01:00:23 -0700 (PDT) Received: from smtprelay.hostedemail.com (smtprelay0083.hostedemail.com. [216.40.44.83]) by mx.google.com with ESMTPS id q71si11331880iod.242.2016.08.20.01.00.23 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 20 Aug 2016 01:00:23 -0700 (PDT) From: Joe Perches 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> In-Reply-To: <20160820072927.GA23645@dhcp22.suse.cz> References: <20160820072927.GA23645@dhcp22.suse.cz> In-Reply-To: References: Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko , Alexander Viro Cc: Andrew Morton , Jann Horn , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org 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 *); -- 2.8.0.rc4.16.g56331f8 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org