From: Jan Kara <jack@suse.cz>
To: "Luis R. Rodriguez" <mcgrof@kernel.org>
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
Subject: Re: [PATCH 02/11] fs: provide unlocked helper thaw_super()
Date: Thu, 30 Nov 2017 17:59:48 +0100 [thread overview]
Message-ID: <20171130165948.GF28180@quack2.suse.cz> (raw)
In-Reply-To: <20171129232356.28296-3-mcgrof@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 <david@fromorbit.com>
> Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Looks good to me. You can add:
Reviewed-by: Jan Kara <jack@suse.cz>
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 <jack@suse.com>
SUSE Labs, CR
next prev parent reply other threads:[~2017-11-30 16:59 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-29 23:23 [PATCH 00/11] fs: use freeze_fs on suspend/hibernate Luis R. Rodriguez
2017-11-29 23:23 ` [PATCH 01/11] fs: provide unlocked helper for freeze_super() Luis R. Rodriguez
2017-11-30 16:58 ` Jan Kara
2017-11-29 23:23 ` [PATCH 02/11] fs: provide unlocked helper thaw_super() Luis R. Rodriguez
2017-11-30 16:59 ` Jan Kara [this message]
2017-11-29 23:23 ` [PATCH 03/11] fs: add frozen sb state helpers Luis R. Rodriguez
2017-11-30 17:13 ` Jan Kara
2017-11-30 19:05 ` Luis R. Rodriguez
2017-12-01 11:47 ` Jan Kara
2017-12-01 21:13 ` Luis R. Rodriguez
2017-12-21 11:03 ` Jan Kara
2018-04-18 0:59 ` Luis R. Rodriguez
2018-04-18 10:12 ` Jan Kara
2018-04-20 18:49 ` Luis R. Rodriguez
2018-04-21 23:53 ` Jan Kara
2018-04-22 1:22 ` Luis R. Rodriguez
2018-04-22 2:53 ` Luis R. Rodriguez
2017-11-29 23:23 ` [PATCH 04/11] fs: distinguish between user initiated freeze and kernel initiated freeze Luis R. Rodriguez
2017-11-29 23:23 ` [PATCH 05/11] fs: add iterate_supers_excl() and iterate_supers_reverse_excl() Luis R. Rodriguez
2017-11-29 23:48 ` Rafael J. Wysocki
2017-11-30 0:22 ` Luis R. Rodriguez
2017-11-30 1:34 ` Dave Chinner
2017-11-30 1:40 ` Rafael J. Wysocki
2017-11-30 16:57 ` Jan Kara
2017-11-29 23:23 ` [PATCH 06/11] fs: freeze on suspend and thaw on resume Luis R. Rodriguez
2017-11-29 23:23 ` [PATCH 07/11] xfs: remove not needed freezing calls Luis R. Rodriguez
2017-11-30 16:21 ` Jan Kara
2017-11-30 20:32 ` Rafael J. Wysocki
2017-11-30 23:30 ` Dave Chinner
2017-11-30 23:40 ` Rafael J. Wysocki
2017-11-29 23:23 ` [PATCH 08/11] ext4: " Luis R. Rodriguez
2017-11-29 23:23 ` [PATCH 09/11] f2fs: " Luis R. Rodriguez
2017-11-29 23:23 ` [PATCH 10/11] nilfs2: " Luis R. Rodriguez
2017-11-29 23:23 ` [PATCH 11/11] jfs: " Luis R. Rodriguez
2017-11-30 16:36 ` [PATCH 00/11] fs: use freeze_fs on suspend/hibernate Yu Chen
2017-11-30 16:41 ` Jiri Kosina
2017-11-30 16:50 ` Yu Chen
2017-12-01 19:05 ` Jeff Layton
2017-12-01 21:51 ` Dave Chinner
2017-11-30 17:01 ` Bart Van Assche
2017-11-30 19:42 ` Luis R. Rodriguez
2017-11-30 20:53 ` Bart Van Assche
2017-11-30 21:03 ` Dave Chinner
2017-11-30 21:51 ` Pavel Machek
2017-12-01 0:44 ` Luis R. Rodriguez
2017-12-13 1:09 ` Rafael J. Wysocki
2017-12-19 16:50 ` Luis R. Rodriguez
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