From patchwork Mon Jan 24 03:48:32 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 12721488 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 870A5C433FE for ; Mon, 24 Jan 2022 03:52:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241192AbiAXDwx (ORCPT ); Sun, 23 Jan 2022 22:52:53 -0500 Received: from smtp-out1.suse.de ([195.135.220.28]:56842 "EHLO smtp-out1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241200AbiAXDwx (ORCPT ); Sun, 23 Jan 2022 22:52:53 -0500 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 EE71321997; Mon, 24 Jan 2022 03:52:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1642996371; 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=Ceo+7tr0pXIBwAY1V2k9H3/l1Y7n6GRK1pkwlK65lYo=; b=lLj4nf8igFAfu4Ik+74JXEmmTkQOHU4byW570y8EKr/iGTF1XOx9dFTRJvtFTF6XgWUduL 2NwVIJGOx6Jt3sfVwWSd4zScsuc7XrTD5boEV1xk1LPkO9FMpCAE7u/gcFVMSrpmPsAg6d wMplTJN7lpMlw7j42XnSn18GcAp/K/8= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1642996371; 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=Ceo+7tr0pXIBwAY1V2k9H3/l1Y7n6GRK1pkwlK65lYo=; b=4nsYAxNuhOIH2b+do3G/Wsh7rlmS9fAYTdnoiNsVKN95nUj/Ybjbxv+UeR5ZDCbDy04sjM UTFqN0IZE3Kv8YDw== 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 14D3913305; Mon, 24 Jan 2022 03:52:48 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id 5qpHMZAi7mF4RQAAMHmgww (envelope-from ); Mon, 24 Jan 2022 03:52:48 +0000 Subject: [PATCH 11/23] VFS: Add FMODE_CAN_ODIRECT file flag From: NeilBrown To: Trond Myklebust , Anna Schumaker , Chuck Lever , Andrew Morton , Mel Gorman , Christoph Hellwig , David Howells Cc: linux-nfs@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Date: Mon, 24 Jan 2022 14:48:32 +1100 Message-ID: <164299611280.26253.2845018521780218144.stgit@noble.brown> In-Reply-To: <164299573337.26253.7538614611220034049.stgit@noble.brown> References: <164299573337.26253.7538614611220034049.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. Signed-off-by: NeilBrown Reviewed-by: Christoph Hellwig --- 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 01cbbfc4e9e2..a2609dd79370 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -184,8 +184,8 @@ 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 4fade3b20c87..48c021cbe327 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)