From patchwork Tue Mar 29 23:49:41 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 12795359 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 42192C433EF for ; Tue, 29 Mar 2022 23:54:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234968AbiC2Xzr (ORCPT ); Tue, 29 Mar 2022 19:55:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47206 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241295AbiC2XzU (ORCPT ); Tue, 29 Mar 2022 19:55:20 -0400 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B9C0F2261D2; Tue, 29 Mar 2022 16:52:52 -0700 (PDT) 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 70BF9218F9; Tue, 29 Mar 2022 23:52:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1648597971; 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=4Nhl/gv+xJp+ByGDT5YVjTNRimHHTfVAVx6ENwNFDnA=; b=MZjJOPQZUFCfkGoWPznlD46FTghqaNHvn9Mqg5X5+zMFGTdMOOEI6thyMr1E5EyQ4IljTb oTSSt81OOTQWH4rXDHtkwrHe0NDzIzUi0rJ5rm8Fa8MF9IdUvhVZiYWMrO1qC+GsGHOCTn Dmb7lfyTLShn241RqjzAgAs3eT7/Y+0= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1648597971; 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=4Nhl/gv+xJp+ByGDT5YVjTNRimHHTfVAVx6ENwNFDnA=; b=YFdItVT8i4IyKH/d06xEQvLP3mRbqho5lYqyulNC1s8hwHT9QQgIL+Mb/9ikn3DyhYLt5J VjxaHKAn+FzUX2BA== 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 57A4D13A7E; Tue, 29 Mar 2022 23:52:49 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id 9xIDBdGbQ2JfLwAAMHmgww (envelope-from ); Tue, 29 Mar 2022 23:52:49 +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: Wed, 30 Mar 2022 10:49:41 +1100 Message-ID: <164859778128.29473.15189737957277399416.stgit@noble.brown> In-Reply-To: <164859751830.29473.5309689752169286816.stgit@noble.brown> References: <164859751830.29473.5309689752169286816.stgit@noble.brown> User-Agent: StGit/0.23 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org 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 3e636a75c83a..74cd550a8952 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -186,8 +186,8 @@ 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 f15d885b9796..34a3faa4886d 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 6da81a4f3bff..143412226bab 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, .invalidate_folio = nfs_invalidate_folio, .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 1315253e0247..7b50d7a2f51d 100644 --- a/fs/open.c +++ b/fs/open.c @@ -834,16 +834,15 @@ 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_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 7c65e09c09a6..781361562a27 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -162,6 +162,9 @@ 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)