From patchwork Sun Mar 6 23:49:38 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 12771027 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id D8CB7C433EF for ; Sun, 6 Mar 2022 23:51:31 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 6DC448D0005; Sun, 6 Mar 2022 18:51:31 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 68BEF8D0001; Sun, 6 Mar 2022 18:51:31 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5058B8D0005; Sun, 6 Mar 2022 18:51:31 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0021.hostedemail.com [216.40.44.21]) by kanga.kvack.org (Postfix) with ESMTP id 40E238D0001 for ; Sun, 6 Mar 2022 18:51:31 -0500 (EST) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id ED0F1181E4E31 for ; Sun, 6 Mar 2022 23:51:30 +0000 (UTC) X-FDA: 79215610740.23.755569B Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by imf07.hostedemail.com (Postfix) with ESMTP id 72CFE40007 for ; Sun, 6 Mar 2022 23:51:30 +0000 (UTC) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 7292F210FC; Sun, 6 Mar 2022 23:51:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1646610689; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=jngo5Bo3wdO5HfY7AV8JY8HyvrejXGQE08t8AS2N2u8=; b=o76x26hRbop+hpVl403EUUo0cauluLPNSFM2EanEoHzXyzQfETFljvGNrE5Qah1yS8yw8n E05yj1qD5ql2TZwKU0exOLTo5sUI/Rj5st/x+0u8thYsgrjCMR75sZxk7F4Pqf7oQ8ePZD sj+yZUqAVFcFxTcmW5w6YDNjkfkGn+I= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1646610689; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=jngo5Bo3wdO5HfY7AV8JY8HyvrejXGQE08t8AS2N2u8=; b=qFIjiF7B1wCrUJ7fBCa5eULbdwu+RoMUAao0whugh1kKTS42VudmOSs9jqS3c84MQOTSgs 5CofiHuu8HrRzxCQ== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 7BFC7134CD; Sun, 6 Mar 2022 23:51:27 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id 3XryDf9IJWKBWgAAMHmgww (envelope-from ); Sun, 06 Mar 2022 23:51:27 +0000 Subject: [PATCH 10/10] VFS: Add FMODE_CAN_ODIRECT file flag From: NeilBrown To: Andrew Morton Cc: Christoph Hellwig , David Howells , linux-nfs@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Date: Mon, 07 Mar 2022 10:49:38 +1100 Message-ID: <164661057808.13454.4020322316652952783.stgit@noble.brown> In-Reply-To: <164661047081.13454.11679636335222534920.stgit@noble.brown> References: <164661047081.13454.11679636335222534920.stgit@noble.brown> User-Agent: StGit/0.23 MIME-Version: 1.0 X-Rspamd-Queue-Id: 72CFE40007 X-Stat-Signature: twye7mson7h9przy4mrx1mzqfhawx5ee X-Rspam-User: Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=o76x26hR; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=qFIjiF7B; dmarc=pass (policy=none) header.from=suse.de; spf=pass (imf07.hostedemail.com: domain of neilb@suse.de designates 195.135.220.28 as permitted sender) smtp.mailfrom=neilb@suse.de X-Rspamd-Server: rspam03 X-HE-Tag: 1646610690-747851 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Currently various places test if direct IO is possible on a file by checking for the existence of the direct_IO address space operation. This is a poor choice, as the direct_IO operation may not be used - it is only used if the generic_file_*_iter functions are called for direct IO and some filesystems - particularly NFS - don't do this. Instead, introduce a new f_mode flag: FMODE_CAN_ODIRECT and change the various places to check this (avoiding pointer dereferences). do_dentry_open() will set this flag if ->direct_IO is present, so filesystems do not need to be changed. NFS *is* changed, to set the flag explicitly and discard the direct_IO entry in the address_space_operations for files. Other filesystems which currently use noop_direct_IO could usefully be changed to set this flag instead. Reviewed-by: Christoph Hellwig Signed-off-by: NeilBrown --- drivers/block/loop.c | 4 ++-- fs/fcntl.c | 9 ++++----- fs/nfs/file.c | 3 ++- fs/open.c | 9 ++++----- fs/overlayfs/file.c | 13 ++++--------- include/linux/fs.h | 3 +++ 6 files changed, 19 insertions(+), 22 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 19fe19eaa50e..59166c7bbcc0 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -185,8 +185,8 @@ static void __loop_update_dio(struct loop_device *lo, bool dio) */ if (dio) { if (queue_logical_block_size(lo->lo_queue) >= sb_bsize && - !(lo->lo_offset & dio_align) && - mapping->a_ops->direct_IO) + !(lo->lo_offset & dio_align) && + (file->f_mode & FMODE_CAN_ODIRECT)) use_dio = true; else use_dio = false; diff --git a/fs/fcntl.c b/fs/fcntl.c index 9c6c6a3e2de5..11e665242a76 100644 --- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -56,11 +56,10 @@ static int setfl(int fd, struct file * filp, unsigned long arg) arg |= O_NONBLOCK; /* Pipe packetized mode is controlled by O_DIRECT flag */ - if (!S_ISFIFO(inode->i_mode) && (arg & O_DIRECT)) { - if (!filp->f_mapping || !filp->f_mapping->a_ops || - !filp->f_mapping->a_ops->direct_IO) - return -EINVAL; - } + if (!S_ISFIFO(inode->i_mode) && + (arg & O_DIRECT) && + !(filp->f_mode & FMODE_CAN_ODIRECT)) + return -EINVAL; if (filp->f_op->check_flags) error = filp->f_op->check_flags(arg); diff --git a/fs/nfs/file.c b/fs/nfs/file.c index 3dbef2c31567..9e2def045111 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -74,6 +74,8 @@ nfs_file_open(struct inode *inode, struct file *filp) return res; res = nfs_open(inode, filp); + if (res == 0) + filp->f_mode |= FMODE_CAN_ODIRECT; return res; } @@ -535,7 +537,6 @@ const struct address_space_operations nfs_file_aops = { .write_end = nfs_write_end, .invalidatepage = nfs_invalidate_page, .releasepage = nfs_release_page, - .direct_IO = nfs_direct_IO, #ifdef CONFIG_MIGRATION .migratepage = nfs_migrate_page, #endif diff --git a/fs/open.c b/fs/open.c index 9ff2f621b760..76ddf9014499 100644 --- a/fs/open.c +++ b/fs/open.c @@ -834,17 +834,16 @@ static int do_dentry_open(struct file *f, if ((f->f_mode & FMODE_WRITE) && likely(f->f_op->write || f->f_op->write_iter)) f->f_mode |= FMODE_CAN_WRITE; + if (f->f_mapping->a_ops && f->f_mapping->a_ops->direct_IO) + f->f_mode |= FMODE_CAN_ODIRECT; f->f_write_hint = WRITE_LIFE_NOT_SET; f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC); file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping); - /* NB: we're sure to have correct a_ops only after f_op->open */ - if (f->f_flags & O_DIRECT) { - if (!f->f_mapping->a_ops || !f->f_mapping->a_ops->direct_IO) - return -EINVAL; - } + if ((f->f_flags & O_DIRECT) && !(f->f_mode & FMODE_CAN_ODIRECT)) + return -EINVAL; /* * XXX: Huge page cache doesn't support writing yet. Drop all page diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c index fa125feed0ff..9d69b4dbb8c4 100644 --- a/fs/overlayfs/file.c +++ b/fs/overlayfs/file.c @@ -82,11 +82,8 @@ static int ovl_change_flags(struct file *file, unsigned int flags) if (((flags ^ file->f_flags) & O_APPEND) && IS_APPEND(inode)) return -EPERM; - if (flags & O_DIRECT) { - if (!file->f_mapping->a_ops || - !file->f_mapping->a_ops->direct_IO) - return -EINVAL; - } + if ((flags & O_DIRECT) && !(file->f_mode & FMODE_CAN_ODIRECT)) + return -EINVAL; if (file->f_op->check_flags) { err = file->f_op->check_flags(flags); @@ -306,8 +303,7 @@ static ssize_t ovl_read_iter(struct kiocb *iocb, struct iov_iter *iter) ret = -EINVAL; if (iocb->ki_flags & IOCB_DIRECT && - (!real.file->f_mapping->a_ops || - !real.file->f_mapping->a_ops->direct_IO)) + !(real.file->f_mode & FMODE_CAN_ODIRECT)) goto out_fdput; old_cred = ovl_override_creds(file_inode(file)->i_sb); @@ -367,8 +363,7 @@ static ssize_t ovl_write_iter(struct kiocb *iocb, struct iov_iter *iter) ret = -EINVAL; if (iocb->ki_flags & IOCB_DIRECT && - (!real.file->f_mapping->a_ops || - !real.file->f_mapping->a_ops->direct_IO)) + !(real.file->f_mode & FMODE_CAN_ODIRECT)) goto out_fdput; if (!ovl_should_sync(OVL_FS(inode->i_sb))) diff --git a/include/linux/fs.h b/include/linux/fs.h index 57e3b387cb17..c34c53267415 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -161,6 +161,9 @@ typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset, /* File is stream-like */ #define FMODE_STREAM ((__force fmode_t)0x200000) +/* File supports DIRECT IO */ +#define FMODE_CAN_ODIRECT ((__force fmode_t)0x400000) + /* File was opened by fanotify and shouldn't generate fanotify events */ #define FMODE_NONOTIFY ((__force fmode_t)0x4000000)