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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 29FBBC433E0 for ; Fri, 15 May 2020 09:32:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 06CC7206F1 for ; Fri, 15 May 2020 09:32:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728053AbgEOJca (ORCPT ); Fri, 15 May 2020 05:32:30 -0400 Received: from mx2.suse.de ([195.135.220.15]:51732 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727116AbgEOJc3 (ORCPT ); Fri, 15 May 2020 05:32:29 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 86733B1C1; Fri, 15 May 2020 09:32:28 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 6F43D1E056A; Fri, 15 May 2020 11:32:24 +0200 (CEST) Date: Fri, 15 May 2020 11:32:24 +0200 From: Jan Kara To: ira.weiny@intel.com Cc: linux-ext4@vger.kernel.org, Andreas Dilger , "Theodore Y. Ts'o" , Jan Kara , Al Viro , Dan Williams , Dave Chinner , Christoph Hellwig , Jeff Moyer , "Darrick J. Wong" , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 7/9] fs/ext4: Make DAX mount option a tri-state Message-ID: <20200515093224.GI9569@quack2.suse.cz> References: <20200515044121.2987940-1-ira.weiny@intel.com> <20200515044121.2987940-8-ira.weiny@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200515044121.2987940-8-ira.weiny@intel.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu 14-05-20 21:41:19, ira.weiny@intel.com wrote: > From: Ira Weiny > > We add 'always', 'never', and 'inode' (default). '-o dax' continues to > operate the same which is equivalent to 'always'. This new > functionality is limited to ext4 only. > > Specifically we introduce a 2nd DAX mount flag EXT4_MOUNT2_DAX_NEVER and set > it and EXT4_MOUNT_DAX_ALWAYS appropriately for the mode. > > We also force EXT4_MOUNT2_DAX_NEVER if !CONFIG_FS_DAX. > > Finally, EXT4_MOUNT2_DAX_INODE is used solely to detect if the user > specified that option for printing. > > Signed-off-by: Ira Weiny Thanks. The patch looks good to me now. You can add: Reviewed-by: Jan Kara Honza > > --- > Changes from V1: > Fix up mounting options to only show an option if specified > Fix remount to prevent dax changes > Isolate behavior to ext4 only > > Changes from RFC: > Combine remount check for DAX_NEVER with DAX_ALWAYS > Update ext4_should_enable_dax() > --- > fs/ext4/ext4.h | 2 ++ > fs/ext4/inode.c | 2 ++ > fs/ext4/super.c | 67 +++++++++++++++++++++++++++++++++++++++++-------- > 3 files changed, 61 insertions(+), 10 deletions(-) > > diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h > index 86a0994332ce..6235440e4c39 100644 > --- a/fs/ext4/ext4.h > +++ b/fs/ext4/ext4.h > @@ -1168,6 +1168,8 @@ struct ext4_inode_info { > blocks */ > #define EXT4_MOUNT2_HURD_COMPAT 0x00000004 /* Support HURD-castrated > file systems */ > +#define EXT4_MOUNT2_DAX_NEVER 0x00000008 /* Do not allow Direct Access */ > +#define EXT4_MOUNT2_DAX_INODE 0x00000010 /* For printing options only */ > > #define EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM 0x00000008 /* User explicitly > specified journal checksum */ > diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c > index 23e42a223235..140b1930e2f4 100644 > --- a/fs/ext4/inode.c > +++ b/fs/ext4/inode.c > @@ -4400,6 +4400,8 @@ int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc) > > static bool ext4_should_enable_dax(struct inode *inode) > { > + if (test_opt2(inode->i_sb, DAX_NEVER)) > + return false; > if (!S_ISREG(inode->i_mode)) > return false; > if (ext4_should_journal_data(inode)) > diff --git a/fs/ext4/super.c b/fs/ext4/super.c > index 5ec900fdf73c..4753de53b186 100644 > --- a/fs/ext4/super.c > +++ b/fs/ext4/super.c > @@ -1504,7 +1504,8 @@ enum { > Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota, > Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota, > Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err, > - Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, Opt_dax, > + Opt_usrquota, Opt_grpquota, Opt_prjquota, Opt_i_version, > + Opt_dax, Opt_dax_always, Opt_dax_inode, Opt_dax_never, > Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_warn_on_error, > Opt_nowarn_on_error, Opt_mblk_io_submit, > Opt_lazytime, Opt_nolazytime, Opt_debug_want_extra_isize, > @@ -1571,6 +1572,9 @@ static const match_table_t tokens = { > {Opt_nobarrier, "nobarrier"}, > {Opt_i_version, "i_version"}, > {Opt_dax, "dax"}, > + {Opt_dax_always, "dax=always"}, > + {Opt_dax_inode, "dax=inode"}, > + {Opt_dax_never, "dax=never"}, > {Opt_stripe, "stripe=%u"}, > {Opt_delalloc, "delalloc"}, > {Opt_warn_on_error, "warn_on_error"}, > @@ -1718,6 +1722,7 @@ static int clear_qf_name(struct super_block *sb, int qtype) > #define MOPT_NO_EXT3 0x0200 > #define MOPT_EXT4_ONLY (MOPT_NO_EXT2 | MOPT_NO_EXT3) > #define MOPT_STRING 0x0400 > +#define MOPT_SKIP 0x0800 > > static const struct mount_opts { > int token; > @@ -1767,7 +1772,13 @@ static const struct mount_opts { > {Opt_min_batch_time, 0, MOPT_GTE0}, > {Opt_inode_readahead_blks, 0, MOPT_GTE0}, > {Opt_init_itable, 0, MOPT_GTE0}, > - {Opt_dax, EXT4_MOUNT_DAX_ALWAYS, MOPT_SET}, > + {Opt_dax, EXT4_MOUNT_DAX_ALWAYS, MOPT_SET | MOPT_SKIP}, > + {Opt_dax_always, EXT4_MOUNT_DAX_ALWAYS, > + MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP}, > + {Opt_dax_inode, EXT4_MOUNT2_DAX_INODE, > + MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP}, > + {Opt_dax_never, EXT4_MOUNT2_DAX_NEVER, > + MOPT_EXT4_ONLY | MOPT_SET | MOPT_SKIP}, > {Opt_stripe, 0, MOPT_GTE0}, > {Opt_resuid, 0, MOPT_GTE0}, > {Opt_resgid, 0, MOPT_GTE0}, > @@ -2076,13 +2087,32 @@ static int handle_mount_opt(struct super_block *sb, char *opt, int token, > } > sbi->s_jquota_fmt = m->mount_opt; > #endif > - } else if (token == Opt_dax) { > + } else if (token == Opt_dax || token == Opt_dax_always || > + token == Opt_dax_inode || token == Opt_dax_never) { > #ifdef CONFIG_FS_DAX > - ext4_msg(sb, KERN_WARNING, > - "DAX enabled. Warning: EXPERIMENTAL, use at your own risk"); > - sbi->s_mount_opt |= m->mount_opt; > + switch (token) { > + case Opt_dax: > + case Opt_dax_always: > + ext4_msg(sb, KERN_WARNING, > + "DAX enabled. Warning: EXPERIMENTAL, use at your own risk"); > + sbi->s_mount_opt |= EXT4_MOUNT_DAX_ALWAYS; > + sbi->s_mount_opt2 &= ~EXT4_MOUNT2_DAX_NEVER; > + break; > + case Opt_dax_never: > + sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_NEVER; > + sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS; > + break; > + case Opt_dax_inode: > + sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS; > + sbi->s_mount_opt2 &= ~EXT4_MOUNT2_DAX_NEVER; > + /* Strictly for printing options */ > + sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_INODE; > + break; > + } > #else > ext4_msg(sb, KERN_INFO, "dax option not supported"); > + sbi->s_mount_opt2 |= EXT4_MOUNT2_DAX_NEVER; > + sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS; > return -1; > #endif > } else if (token == Opt_data_err_abort) { > @@ -2246,7 +2276,7 @@ static int _ext4_show_options(struct seq_file *seq, struct super_block *sb, > for (m = ext4_mount_opts; m->token != Opt_err; m++) { > int want_set = m->flags & MOPT_SET; > if (((m->flags & (MOPT_SET|MOPT_CLEAR)) == 0) || > - (m->flags & MOPT_CLEAR_ERR)) > + (m->flags & MOPT_CLEAR_ERR) || m->flags & MOPT_SKIP) > continue; > if (!nodefs && !(m->mount_opt & (sbi->s_mount_opt ^ def_mount_opt))) > continue; /* skip if same as the default */ > @@ -2306,6 +2336,17 @@ static int _ext4_show_options(struct seq_file *seq, struct super_block *sb, > if (DUMMY_ENCRYPTION_ENABLED(sbi)) > SEQ_OPTS_PUTS("test_dummy_encryption"); > > + if (test_opt(sb, DAX_ALWAYS)) { > + if (IS_EXT2_SB(sb)) > + SEQ_OPTS_PUTS("dax"); > + else > + SEQ_OPTS_PUTS("dax=always"); > + } else if (test_opt2(sb, DAX_NEVER)) { > + SEQ_OPTS_PUTS("dax=never"); > + } else if (test_opt2(sb, DAX_INODE)) { > + SEQ_OPTS_PUTS("dax=inode"); > + } > + > ext4_show_quota_options(seq, sb); > return 0; > } > @@ -5425,10 +5466,16 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data) > goto restore_opts; > } > > - if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX_ALWAYS) { > + if ((sbi->s_mount_opt ^ old_opts.s_mount_opt) & EXT4_MOUNT_DAX_ALWAYS || > + (sbi->s_mount_opt2 ^ old_opts.s_mount_opt2) & EXT4_MOUNT2_DAX_NEVER || > + (sbi->s_mount_opt2 ^ old_opts.s_mount_opt2) & EXT4_MOUNT2_DAX_INODE) { > ext4_msg(sb, KERN_WARNING, "warning: refusing change of " > - "dax flag with busy inodes while remounting"); > - sbi->s_mount_opt ^= EXT4_MOUNT_DAX_ALWAYS; > + "dax mount option with busy inodes while remounting"); > + sbi->s_mount_opt &= ~EXT4_MOUNT_DAX_ALWAYS; > + sbi->s_mount_opt |= old_opts.s_mount_opt & EXT4_MOUNT_DAX_ALWAYS; > + sbi->s_mount_opt2 &= ~(EXT4_MOUNT2_DAX_NEVER | EXT4_MOUNT2_DAX_INODE); > + sbi->s_mount_opt2 |= old_opts.s_mount_opt2 & > + (EXT4_MOUNT2_DAX_NEVER | EXT4_MOUNT2_DAX_INODE); > } > > if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) > -- > 2.25.1 > -- Jan Kara SUSE Labs, CR