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=-12.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNWANTED_LANGUAGE_BODY, USER_AGENT_SANE_1 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 DAD1AC433B4 for ; Mon, 26 Apr 2021 16:24:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A606F60C3D for ; Mon, 26 Apr 2021 16:24:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234527AbhDZQZO (ORCPT ); Mon, 26 Apr 2021 12:25:14 -0400 Received: from mx2.suse.de ([195.135.220.15]:57172 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234528AbhDZQZN (ORCPT ); Mon, 26 Apr 2021 12:25:13 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id B6F48ACF6; Mon, 26 Apr 2021 16:24:30 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 08DF71E0CB7; Mon, 26 Apr 2021 18:24:30 +0200 (CEST) Date: Mon, 26 Apr 2021 18:24:29 +0200 From: Jan Kara To: Damien Le Moal Cc: Jan Kara , "linux-fsdevel@vger.kernel.org" , "hch@infradead.org" , Amir Goldstein , Dave Chinner , Ted Tso , Johannes Thumshirn Subject: Re: [PATCH 06/12] zonefs: Convert to using invalidate_lock Message-ID: <20210426162429.GC23895@quack2.suse.cz> References: <20210423171010.12-1-jack@suse.cz> <20210423173018.23133-6-jack@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Mon 26-04-21 06:40:27, Damien Le Moal wrote: > On 2021/04/24 2:30, Jan Kara wrote: > > Use invalidate_lock instead of zonefs' private i_mmap_sem. The intended > > purpose is exactly the same. By this conversion we also fix a race > > between hole punching and read(2) / readahead(2) paths that can lead to > > stale page cache contents. > > zonefs does not support hole punching since the blocks of a file are determined > by the device zone configuration and cannot change, ever. So I think you can > remove the second sentence above. Sure, thanks for correction. Updated. Honza > > > > > CC: Damien Le Moal > > CC: Johannes Thumshirn > > CC: > > Signed-off-by: Jan Kara > > --- > > fs/zonefs/super.c | 23 +++++------------------ > > fs/zonefs/zonefs.h | 7 +++---- > > 2 files changed, 8 insertions(+), 22 deletions(-) > > > > diff --git a/fs/zonefs/super.c b/fs/zonefs/super.c > > index 049e36c69ed7..60ac5587c880 100644 > > --- a/fs/zonefs/super.c > > +++ b/fs/zonefs/super.c > > @@ -462,7 +462,7 @@ static int zonefs_file_truncate(struct inode *inode, loff_t isize) > > inode_dio_wait(inode); > > > > /* Serialize against page faults */ > > - down_write(&zi->i_mmap_sem); > > + down_write(&inode->i_mapping->invalidate_lock); > > > > /* Serialize against zonefs_iomap_begin() */ > > mutex_lock(&zi->i_truncate_mutex); > > @@ -500,7 +500,7 @@ static int zonefs_file_truncate(struct inode *inode, loff_t isize) > > > > unlock: > > mutex_unlock(&zi->i_truncate_mutex); > > - up_write(&zi->i_mmap_sem); > > + up_write(&inode->i_mapping->invalidate_lock); > > > > return ret; > > } > > @@ -575,18 +575,6 @@ static int zonefs_file_fsync(struct file *file, loff_t start, loff_t end, > > return ret; > > } > > > > -static vm_fault_t zonefs_filemap_fault(struct vm_fault *vmf) > > -{ > > - struct zonefs_inode_info *zi = ZONEFS_I(file_inode(vmf->vma->vm_file)); > > - vm_fault_t ret; > > - > > - down_read(&zi->i_mmap_sem); > > - ret = filemap_fault(vmf); > > - up_read(&zi->i_mmap_sem); > > - > > - return ret; > > -} > > - > > static vm_fault_t zonefs_filemap_page_mkwrite(struct vm_fault *vmf) > > { > > struct inode *inode = file_inode(vmf->vma->vm_file); > > @@ -607,16 +595,16 @@ static vm_fault_t zonefs_filemap_page_mkwrite(struct vm_fault *vmf) > > file_update_time(vmf->vma->vm_file); > > > > /* Serialize against truncates */ > > - down_read(&zi->i_mmap_sem); > > + down_read(&inode->i_mapping->invalidate_lock); > > ret = iomap_page_mkwrite(vmf, &zonefs_iomap_ops); > > - up_read(&zi->i_mmap_sem); > > + up_read(&inode->i_mapping->invalidate_lock); > > > > sb_end_pagefault(inode->i_sb); > > return ret; > > } > > > > static const struct vm_operations_struct zonefs_file_vm_ops = { > > - .fault = zonefs_filemap_fault, > > + .fault = filemap_fault, > > .map_pages = filemap_map_pages, > > .page_mkwrite = zonefs_filemap_page_mkwrite, > > }; > > @@ -1158,7 +1146,6 @@ static struct inode *zonefs_alloc_inode(struct super_block *sb) > > > > inode_init_once(&zi->i_vnode); > > mutex_init(&zi->i_truncate_mutex); > > - init_rwsem(&zi->i_mmap_sem); > > zi->i_wr_refcnt = 0; > > > > return &zi->i_vnode; > > diff --git a/fs/zonefs/zonefs.h b/fs/zonefs/zonefs.h > > index 51141907097c..7b147907c328 100644 > > --- a/fs/zonefs/zonefs.h > > +++ b/fs/zonefs/zonefs.h > > @@ -70,12 +70,11 @@ struct zonefs_inode_info { > > * and changes to the inode private data, and in particular changes to > > * a sequential file size on completion of direct IO writes. > > * Serialization of mmap read IOs with truncate and syscall IO > > - * operations is done with i_mmap_sem in addition to i_truncate_mutex. > > - * Only zonefs_seq_file_truncate() takes both lock (i_mmap_sem first, > > - * i_truncate_mutex second). > > + * operations is done with invalidate_lock in addition to > > + * i_truncate_mutex. Only zonefs_seq_file_truncate() takes both lock > > + * (invalidate_lock first, i_truncate_mutex second). > > */ > > struct mutex i_truncate_mutex; > > - struct rw_semaphore i_mmap_sem; > > > > /* guarded by i_truncate_mutex */ > > unsigned int i_wr_refcnt; > > > > > -- > Damien Le Moal > Western Digital Research -- Jan Kara SUSE Labs, CR