From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D0841C433DF for ; Mon, 12 Oct 2020 16:03:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8DEE920797 for ; Mon, 12 Oct 2020 16:03:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Dag1db25" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390200AbgJLQDS (ORCPT ); Mon, 12 Oct 2020 12:03:18 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:23265 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390201AbgJLQDR (ORCPT ); Mon, 12 Oct 2020 12:03:17 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1602518595; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=WtXGWBunas8n5o+z8jbwam4wAOgJw6mF0z49dWjSiZs=; b=Dag1db25K36oVDLWGkouMnl8LFfGpZuLzeF1nQyB6GuPMvDUuBUrHXpFrACow2KWvUsI5a nx0+2cQA+fN/dKBccRhPFK050JvWgeyhfV2OqKaXjwlaaYFyffHioNWT2tCn67Qx1sBNdW heg+LkOd7IIPkX0eLKx5Jsd6DzKoai0= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-469-NcPdc_wuNwOG20oXHiW35w-1; Mon, 12 Oct 2020 12:03:11 -0400 X-MC-Unique: NcPdc_wuNwOG20oXHiW35w-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 995FD8030A9 for ; Mon, 12 Oct 2020 16:03:10 +0000 (UTC) Received: from bfoster (ovpn-112-249.rdu2.redhat.com [10.10.112.249]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 334EF73663; Mon, 12 Oct 2020 16:03:10 +0000 (UTC) Date: Mon, 12 Oct 2020 12:03:08 -0400 From: Brian Foster To: Pavel Reichl Cc: linux-xfs@vger.kernel.org Subject: Re: [PATCH v11 1/4] xfs: Refactor xfs_isilocked() Message-ID: <20201012160308.GH917726@bfoster> References: <20201009195515.82889-1-preichl@redhat.com> <20201009195515.82889-2-preichl@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201009195515.82889-2-preichl@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Fri, Oct 09, 2020 at 09:55:12PM +0200, Pavel Reichl wrote: > Refactor xfs_isilocked() to use newly introduced __xfs_rwsem_islocked(). > __xfs_rwsem_islocked() is a helper function which encapsulates checking > state of rw_semaphores hold by inode. > > Signed-off-by: Pavel Reichl > Suggested-by: Dave Chinner > Suggested-by: Eric Sandeen > Suggested-by: Darrick J. Wong > Reviewed-by: Darrick J. Wong > --- > fs/xfs/xfs_inode.c | 48 ++++++++++++++++++++++++++++++++++++++-------- > fs/xfs/xfs_inode.h | 21 +++++++++++++------- > 2 files changed, 54 insertions(+), 15 deletions(-) > > diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c > index c06129cffba9..7c1ceb4df4ec 100644 > --- a/fs/xfs/xfs_inode.c > +++ b/fs/xfs/xfs_inode.c > @@ -345,9 +345,43 @@ xfs_ilock_demote( > } > > #if defined(DEBUG) || defined(XFS_WARN) > -int > +static inline bool > +__xfs_rwsem_islocked( > + struct rw_semaphore *rwsem, > + int lock_flags) > +{ > + int arg; > + > + if (!debug_locks) > + return rwsem_is_locked(rwsem); > + > + if (lock_flags & (1 << XFS_SHARED_LOCK_SHIFT)) { > + /* > + * The caller could be asking if we have (shared | excl) > + * access to the lock. Ask lockdep if the rwsem is > + * locked either for read or write access. > + * > + * The caller could also be asking if we have only > + * shared access to the lock. Holding a rwsem > + * write-locked implies read access as well, so the > + * request to lockdep is the same for this case. > + */ > + arg = -1; > + } else { > + /* > + * The caller is asking if we have only exclusive access > + * to the lock. Ask lockdep if the rwsem is locked for > + * write access. > + */ > + arg = 0; > + } Are these arg values documented somewhere? A quick look at the function below didn't show anything.. Also, I find the pattern of shifting in the caller slightly confusing, particularly with the 'lock_flags' name being passed down through the caller. Any reason we couldn't pass the shift value as a parameter and do the shift at the top of the function so the logic is clear and in one place? > + > + return lockdep_is_held_type(rwsem, arg); > +} > + > +bool > xfs_isilocked( > - xfs_inode_t *ip, > + struct xfs_inode *ip, > uint lock_flags) > { > if (lock_flags & (XFS_ILOCK_EXCL|XFS_ILOCK_SHARED)) { ... > diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h > index e9a8bb184d1f..77776af75c77 100644 > --- a/fs/xfs/xfs_inode.h > +++ b/fs/xfs/xfs_inode.h > @@ -268,12 +268,19 @@ static inline void xfs_ifunlock(struct xfs_inode *ip) > * Bit ranges: 1<<1 - 1<<16-1 -- iolock/ilock modes (bitfield) > * 1<<16 - 1<<32-1 -- lockdep annotation (integers) > */ > -#define XFS_IOLOCK_EXCL (1<<0) > -#define XFS_IOLOCK_SHARED (1<<1) > -#define XFS_ILOCK_EXCL (1<<2) > -#define XFS_ILOCK_SHARED (1<<3) > -#define XFS_MMAPLOCK_EXCL (1<<4) > -#define XFS_MMAPLOCK_SHARED (1<<5) > + > +#define XFS_IOLOCK_FLAG_SHIFT 0 > +#define XFS_ILOCK_FLAG_SHIFT 2 > +#define XFS_MMAPLOCK_FLAG_SHIFT 4 > + > +#define XFS_SHARED_LOCK_SHIFT 1 > + > +#define XFS_IOLOCK_EXCL (1 << (XFS_IOLOCK_FLAG_SHIFT)) > +#define XFS_IOLOCK_SHARED (XFS_IOLOCK_EXCL << (XFS_SHARED_LOCK_SHIFT)) > +#define XFS_ILOCK_EXCL (1 << (XFS_ILOCK_FLAG_SHIFT)) > +#define XFS_ILOCK_SHARED (XFS_ILOCK_EXCL << (XFS_SHARED_LOCK_SHIFT)) > +#define XFS_MMAPLOCK_EXCL (1 << (XFS_MMAPLOCK_FLAG_SHIFT)) > +#define XFS_MMAPLOCK_SHARED (XFS_MMAPLOCK_EXCL << (XFS_SHARED_LOCK_SHIFT)) > Any reason for the extra params around the shift values? Brian > #define XFS_LOCK_MASK (XFS_IOLOCK_EXCL | XFS_IOLOCK_SHARED \ > | XFS_ILOCK_EXCL | XFS_ILOCK_SHARED \ > @@ -412,7 +419,7 @@ void xfs_ilock(xfs_inode_t *, uint); > int xfs_ilock_nowait(xfs_inode_t *, uint); > void xfs_iunlock(xfs_inode_t *, uint); > void xfs_ilock_demote(xfs_inode_t *, uint); > -int xfs_isilocked(xfs_inode_t *, uint); > +bool xfs_isilocked(struct xfs_inode *, uint); > uint xfs_ilock_data_map_shared(struct xfs_inode *); > uint xfs_ilock_attr_map_shared(struct xfs_inode *); > > -- > 2.26.2 >