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=-17.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 C76B5C47082 for ; Wed, 26 May 2021 10:07:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ACEA761437 for ; Wed, 26 May 2021 10:07:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233812AbhEZKIg (ORCPT ); Wed, 26 May 2021 06:08:36 -0400 Received: from mx2.suse.de ([195.135.220.15]:46298 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233803AbhEZKIf (ORCPT ); Wed, 26 May 2021 06:08:35 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1622023623; h=from:from:reply-to: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=CZxNqCRr5czRb56ktpxOWnOSu0fMulpRezdytlVC9QQ=; b=MUD4K8oZyRkdjWXxo9HyOuILAC4V4vxmrSA2puCD1iiJPv8jaP+OiF8l+HEBDcKpaVp3/h 7onqU4PqBHfM45G/uKaLxUlJv3zQzDi8HpsqqlwG/16TY4CmFD/oNOcXgIeoljs82BjeKG BWqBVJ7bKd8IeS58qNbom5KI0ThJpMQ= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1622023623; h=from:from:reply-to: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=CZxNqCRr5czRb56ktpxOWnOSu0fMulpRezdytlVC9QQ=; b=hZUsEKYXJUCCkMAN57O+Y8WvBmPX15w3AXW2eO+doBR566bf0sVhZ7r7OxXtui0gC6+R4Q /hxlBSr/JveL4MCQ== Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 2D67DB237; Wed, 26 May 2021 10:07:03 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 0EB141F2CAC; Wed, 26 May 2021 12:07:02 +0200 (CEST) Date: Wed, 26 May 2021 12:07:02 +0200 From: Jan Kara To: "Darrick J. Wong" Cc: Jan Kara , linux-fsdevel@vger.kernel.org, Christoph Hellwig , Dave Chinner , ceph-devel@vger.kernel.org, Chao Yu , Damien Le Moal , "Darrick J. Wong" , Jaegeuk Kim , Jeff Layton , Johannes Thumshirn , linux-cifs@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-mm@kvack.org, linux-xfs@vger.kernel.org, Miklos Szeredi , Steve French , Ted Tso , Matthew Wilcox Subject: Re: [PATCH 04/13] mm: Add functions to lock invalidate_lock for two mappings Message-ID: <20210526100702.GB30369@quack2.suse.cz> References: <20210525125652.20457-1-jack@suse.cz> <20210525135100.11221-4-jack@suse.cz> <20210525204805.GM202121@locust> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210525204805.GM202121@locust> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org On Tue 25-05-21 13:48:05, Darrick J. Wong wrote: > On Tue, May 25, 2021 at 03:50:41PM +0200, Jan Kara wrote: > > Some operations such as reflinking blocks among files will need to lock > > invalidate_lock for two mappings. Add helper functions to do that. > > > > Signed-off-by: Jan Kara > > --- > > include/linux/fs.h | 6 ++++++ > > mm/filemap.c | 38 ++++++++++++++++++++++++++++++++++++++ > > 2 files changed, 44 insertions(+) > > > > diff --git a/include/linux/fs.h b/include/linux/fs.h > > index 897238d9f1e0..e6f7447505f5 100644 > > --- a/include/linux/fs.h > > +++ b/include/linux/fs.h > > @@ -822,6 +822,12 @@ static inline void inode_lock_shared_nested(struct inode *inode, unsigned subcla > > void lock_two_nondirectories(struct inode *, struct inode*); > > void unlock_two_nondirectories(struct inode *, struct inode*); > > > > +void filemap_invalidate_down_write_two(struct address_space *mapping1, > > + struct address_space *mapping2); > > +void filemap_invalidate_up_write_two(struct address_space *mapping1, > > TBH I find myself wishing that the invalidate_lock used the same > lock/unlock style wrappers that we use for i_rwsem. > > filemap_invalidate_lock(inode1->mapping); > filemap_invalidate_lock_two(inode1->i_mapping, inode2->i_mapping); OK, and filemap_invalidate_lock_shared() for down_read()? I guess that works for me. Honza > To be fair, I've never been able to keep straight that down means lock > and up means unlock. Ah well, at least you didn't use "p" and "v". > > Mechanically, the changes look ok to me. > Acked-by: Darrick J. Wong > > --D > > > + struct address_space *mapping2); > > + > > + > > /* > > * NOTE: in a 32bit arch with a preemptable kernel and > > * an UP compile the i_size_read/write must be atomic > > diff --git a/mm/filemap.c b/mm/filemap.c > > index 4d9ec4c6cc34..d3801a9739aa 100644 > > --- a/mm/filemap.c > > +++ b/mm/filemap.c > > @@ -1009,6 +1009,44 @@ struct page *__page_cache_alloc(gfp_t gfp) > > EXPORT_SYMBOL(__page_cache_alloc); > > #endif > > > > +/* > > + * filemap_invalidate_down_write_two - lock invalidate_lock for two mappings > > + * > > + * Lock exclusively invalidate_lock of any passed mapping that is not NULL. > > + * > > + * @mapping1: the first mapping to lock > > + * @mapping2: the second mapping to lock > > + */ > > +void filemap_invalidate_down_write_two(struct address_space *mapping1, > > + struct address_space *mapping2) > > +{ > > + if (mapping1 > mapping2) > > + swap(mapping1, mapping2); > > + if (mapping1) > > + down_write(&mapping1->invalidate_lock); > > + if (mapping2 && mapping1 != mapping2) > > + down_write_nested(&mapping2->invalidate_lock, 1); > > +} > > +EXPORT_SYMBOL(filemap_invalidate_down_write_two); > > + > > +/* > > + * filemap_invalidate_up_write_two - unlock invalidate_lock for two mappings > > + * > > + * Unlock exclusive invalidate_lock of any passed mapping that is not NULL. > > + * > > + * @mapping1: the first mapping to unlock > > + * @mapping2: the second mapping to unlock > > + */ > > +void filemap_invalidate_up_write_two(struct address_space *mapping1, > > + struct address_space *mapping2) > > +{ > > + if (mapping1) > > + up_write(&mapping1->invalidate_lock); > > + if (mapping2 && mapping1 != mapping2) > > + up_write(&mapping2->invalidate_lock); > > +} > > +EXPORT_SYMBOL(filemap_invalidate_up_write_two); > > + > > /* > > * In order to wait for pages to become available there must be > > * waitqueues associated with pages. By using a hash table of > > -- > > 2.26.2 > > -- Jan Kara SUSE Labs, CR