From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:33874 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752473AbdK3Q7v (ORCPT ); Thu, 30 Nov 2017 11:59:51 -0500 Date: Thu, 30 Nov 2017 17:59:48 +0100 From: Jan Kara Subject: Re: [PATCH 02/11] fs: provide unlocked helper thaw_super() Message-ID: <20171130165948.GF28180@quack2.suse.cz> References: <20171129232356.28296-1-mcgrof@kernel.org> <20171129232356.28296-3-mcgrof@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171129232356.28296-3-mcgrof@kernel.org> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: "Luis R. Rodriguez" Cc: viro@zeniv.linux.org.uk, bart.vanassche@wdc.com, ming.lei@redhat.com, tytso@mit.edu, darrick.wong@oracle.com, jikos@kernel.org, rjw@rjwysocki.net, pavel@ucw.cz, len.brown@intel.com, linux-fsdevel@vger.kernel.org, boris.ostrovsky@oracle.com, jgross@suse.com, todd.e.brandt@linux.intel.com, nborisov@suse.com, jack@suse.cz, martin.petersen@oracle.com, ONeukum@suse.com, oleksandr@natalenko.name, oleg.b.antonyan@gmail.com, yu.chen.surf@gmail.com, dan.j.williams@intel.com, linux-pm@vger.kernel.org, linux-block@vger.kernel.org, linux-xfs@vger.kernel.org, linux-kernel@vger.kernel.org On Wed 29-11-17 15:23:47, Luis R. Rodriguez wrote: > thaw_super() hold a write lock, however we wish to also enable > callers which already hold the write lock. To do this provide a helper > and make thaw_super() use it. This way, all that thaw_super() does > now is lock handling and active count management. > > This change has no functional changes. > > Suggested-by: Dave Chinner > Signed-off-by: Luis R. Rodriguez Looks good to me. You can add: Reviewed-by: Jan Kara Honza > --- > fs/super.c | 39 ++++++++++++++++++++++++++------------- > 1 file changed, 26 insertions(+), 13 deletions(-) > > diff --git a/fs/super.c b/fs/super.c > index a7650ff22f0e..cecc279beecd 100644 > --- a/fs/super.c > +++ b/fs/super.c > @@ -1493,21 +1493,13 @@ int freeze_super(struct super_block *sb) > } > EXPORT_SYMBOL(freeze_super); > > -/** > - * thaw_super -- unlock filesystem > - * @sb: the super to thaw > - * > - * Unlocks the filesystem and marks it writeable again after freeze_super(). > - */ > -int thaw_super(struct super_block *sb) > +/* Caller takes lock and handles active count */ > +static int thaw_locked_super(struct super_block *sb) > { > int error; > > - down_write(&sb->s_umount); > - if (sb->s_writers.frozen != SB_FREEZE_COMPLETE) { > - up_write(&sb->s_umount); > + if (sb->s_writers.frozen != SB_FREEZE_COMPLETE) > return -EINVAL; > - } > > if (sb_rdonly(sb)) { > sb->s_writers.frozen = SB_UNFROZEN; > @@ -1522,7 +1514,6 @@ int thaw_super(struct super_block *sb) > printk(KERN_ERR > "VFS:Filesystem thaw failed\n"); > lockdep_sb_freeze_release(sb); > - up_write(&sb->s_umount); > return error; > } > } > @@ -1531,7 +1522,29 @@ int thaw_super(struct super_block *sb) > sb_freeze_unlock(sb); > out: > wake_up(&sb->s_writers.wait_unfrozen); > - deactivate_locked_super(sb); > return 0; > } > + > +/** > + * thaw_super -- unlock filesystem > + * @sb: the super to thaw > + * > + * Unlocks the filesystem and marks it writeable again after freeze_super(). > + */ > +int thaw_super(struct super_block *sb) > +{ > + int error; > + > + down_write(&sb->s_umount); > + error = thaw_locked_super(sb); > + if (error) { > + up_write(&sb->s_umount); > + goto out; > + } > + > + deactivate_locked_super(sb); > + > +out: > + return error; > +} > EXPORT_SYMBOL(thaw_super); > -- > 2.15.0 > -- Jan Kara SUSE Labs, CR