From patchwork Thu Sep 3 14:22:31 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11753723 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D0DE914E3 for ; Thu, 3 Sep 2020 14:26:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B478A2072A for ; Thu, 3 Sep 2020 14:26:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="SbA4Ermb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728788AbgICO0B (ORCPT ); Thu, 3 Sep 2020 10:26:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35166 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729166AbgICOX1 (ORCPT ); Thu, 3 Sep 2020 10:23:27 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C0DB0C06123A; Thu, 3 Sep 2020 07:22:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=GwBdpIiwC2/H13uoaD81joKeq/bh8CR8vbkN01NmQb8=; b=SbA4ErmbdCRIGV1PaNDyOgDFPM WOOiPDFGt5XBXfY5jP3ztB9vrJDDiTR3S831moFSwBWUyfChZFA1BRQyvkGlC4vN6lIlYL31/eVpQ 4AZ/cMaZgHPOscMzV+WC/lo7EDhbN6cT4yHXmo8UUQdHbIdKsugCkPPCeHoLQmyy2ajyyl1HCObXN dj+uFNX/JF/U5HPn9nHMlQ9Pywqvz2sdtEcNQUADBxGUgwOgUPSXjjzUvlPRHTvAFfIzHtMEXNFst f548siR/l2sI0jQVLbHQdGVTZCCgvbgDJNNoQ5+zgVnaQl8a2szvK8Yw6jk21Qfeo4BxY81HFnhg5 HmT3L4Cw==; Received: from [2001:4bb8:184:af1:c70:4a89:bc61:2] (helo=localhost) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kDq8V-0004aL-IH; Thu, 03 Sep 2020 14:22:47 +0000 From: Christoph Hellwig To: Linus Torvalds , Al Viro , Michael Ellerman , x86@kernel.org Cc: Alexey Dobriyan , Luis Chamberlain , Kees Cook , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: [PATCH 03/14] proc: add a read_iter method to proc proc_ops Date: Thu, 3 Sep 2020 16:22:31 +0200 Message-Id: <20200903142242.925828-4-hch@lst.de> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200903142242.925828-1-hch@lst.de> References: <20200903142242.925828-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org This will allow proc files to implement iter read semantics. Signed-off-by: Christoph Hellwig --- fs/proc/inode.c | 53 ++++++++++++++++++++++++++++++++++++++--- include/linux/proc_fs.h | 1 + 2 files changed, 51 insertions(+), 3 deletions(-) diff --git a/fs/proc/inode.c b/fs/proc/inode.c index 93dd2045737504..58c075e2a452d6 100644 --- a/fs/proc/inode.c +++ b/fs/proc/inode.c @@ -297,6 +297,21 @@ static loff_t proc_reg_llseek(struct file *file, loff_t offset, int whence) return rv; } +static ssize_t proc_reg_read_iter(struct kiocb *iocb, struct iov_iter *iter) +{ + struct proc_dir_entry *pde = PDE(file_inode(iocb->ki_filp)); + ssize_t ret; + + if (pde_is_permanent(pde)) + return pde->proc_ops->proc_read_iter(iocb, iter); + + if (!use_pde(pde)) + return -EIO; + ret = pde->proc_ops->proc_read_iter(iocb, iter); + unuse_pde(pde); + return ret; +} + static ssize_t pde_read(struct proc_dir_entry *pde, struct file *file, char __user *buf, size_t count, loff_t *ppos) { typeof_member(struct proc_ops, proc_read) read; @@ -578,6 +593,18 @@ static const struct file_operations proc_reg_file_ops = { .release = proc_reg_release, }; +static const struct file_operations proc_iter_file_ops = { + .llseek = proc_reg_llseek, + .read_iter = proc_reg_read_iter, + .write = proc_reg_write, + .poll = proc_reg_poll, + .unlocked_ioctl = proc_reg_unlocked_ioctl, + .mmap = proc_reg_mmap, + .get_unmapped_area = proc_reg_get_unmapped_area, + .open = proc_reg_open, + .release = proc_reg_release, +}; + #ifdef CONFIG_COMPAT static const struct file_operations proc_reg_file_ops_compat = { .llseek = proc_reg_llseek, @@ -591,6 +618,19 @@ static const struct file_operations proc_reg_file_ops_compat = { .open = proc_reg_open, .release = proc_reg_release, }; + +static const struct file_operations proc_iter_file_ops_compat = { + .llseek = proc_reg_llseek, + .read_iter = proc_reg_read_iter, + .write = proc_reg_write, + .poll = proc_reg_poll, + .unlocked_ioctl = proc_reg_unlocked_ioctl, + .compat_ioctl = proc_reg_compat_ioctl, + .mmap = proc_reg_mmap, + .get_unmapped_area = proc_reg_get_unmapped_area, + .open = proc_reg_open, + .release = proc_reg_release, +}; #endif static void proc_put_link(void *p) @@ -642,10 +682,17 @@ struct inode *proc_get_inode(struct super_block *sb, struct proc_dir_entry *de) if (S_ISREG(inode->i_mode)) { inode->i_op = de->proc_iops; - inode->i_fop = &proc_reg_file_ops; + if (de->proc_ops->proc_read_iter) + inode->i_fop = &proc_iter_file_ops; + else + inode->i_fop = &proc_reg_file_ops; #ifdef CONFIG_COMPAT - if (de->proc_ops->proc_compat_ioctl) - inode->i_fop = &proc_reg_file_ops_compat; + if (de->proc_ops->proc_compat_ioctl) { + if (de->proc_ops->proc_read_iter) + inode->i_fop = &proc_iter_file_ops_compat; + else + inode->i_fop = &proc_reg_file_ops_compat; + } #endif } else if (S_ISDIR(inode->i_mode)) { inode->i_op = de->proc_iops; diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h index 2df965cd09742d..270cab43ca3dad 100644 --- a/include/linux/proc_fs.h +++ b/include/linux/proc_fs.h @@ -30,6 +30,7 @@ struct proc_ops { unsigned int proc_flags; int (*proc_open)(struct inode *, struct file *); ssize_t (*proc_read)(struct file *, char __user *, size_t, loff_t *); + ssize_t (*proc_read_iter)(struct kiocb *, struct iov_iter *); ssize_t (*proc_write)(struct file *, const char __user *, size_t, loff_t *); loff_t (*proc_lseek)(struct file *, loff_t, int); int (*proc_release)(struct inode *, struct file *);