From: Christoph Hellwig <hch@infradead.org>
To: Sascha Hauer <s.hauer@pengutronix.de>
Cc: linux-fsdevel@vger.kernel.org,
Richard Weinberger <richard@nod.at>,
linux-mtd@lists.infradead.org, kernel@pengutronix.de,
Jan Kara <jack@suse.com>
Subject: Re: [PATCH 1/8] quota: Allow to pass mount path to quotactl
Date: Fri, 22 Jan 2021 17:16:58 +0000 [thread overview]
Message-ID: <20210122171658.GA237653@infradead.org> (raw)
In-Reply-To: <20210122151536.7982-2-s.hauer@pengutronix.de>
On Fri, Jan 22, 2021 at 04:15:29PM +0100, Sascha Hauer wrote:
> This patch introduces the Q_PATH flag to the quotactl cmd argument.
> When given, the path given in the special argument to quotactl will
> be the mount path where the filesystem is mounted, instead of a path
> to the block device.
> This is necessary for filesystems which do not have a block device as
> backing store. Particularly this is done for upcoming UBIFS support.
>
> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
I hate overloading quotactl even more. Why not add a new quotactl_path
syscall instead?
> +static struct super_block *quotactl_sb(dev_t dev, int cmd)
> {
> struct super_block *sb;
> bool excl = false, thawed = false;
>
> if (quotactl_cmd_onoff(cmd)) {
> excl = true;
> @@ -901,12 +887,50 @@ static struct super_block *quotactl_block(const char __user *special, int cmd)
> goto retry;
> }
> return sb;
> +}
> +
> +/*
> + * look up a superblock on which quota ops will be performed
> + * - use the name of a block device to find the superblock thereon
> + */
> +static struct super_block *quotactl_block(const char __user *special, int cmd)
> +{
> +#ifdef CONFIG_BLOCK
> + struct filename *tmp = getname(special);
> + int error;
> + dev_t dev;
>
> + if (IS_ERR(tmp))
> + return ERR_CAST(tmp);
> + error = lookup_bdev(tmp->name, &dev);
> + putname(tmp);
> + if (error)
> + return ERR_PTR(error);
> +
> + return quotactl_sb(dev, cmd);
> #else
> return ERR_PTR(-ENODEV);
> #endif
Normal kernel style would be to keep the ifdef entirely outside the
function.
> +static struct super_block *quotactl_path(const char __user *special, int cmd)
> +{
> + struct super_block *sb;
> + struct path path;
> + int error;
> +
> + error = user_path_at(AT_FDCWD, special, LOOKUP_FOLLOW | LOOKUP_AUTOMOUNT,
> + &path);
This adds an overly long line.
> + if (error)
> + return ERR_PTR(error);
> +
> + sb = quotactl_sb(path.mnt->mnt_sb->s_dev, cmd);
I think quotactl_sb should take the superblock directly. This will
need a little refactoring of user_get_super, but will lead to much
better logic.
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next prev parent reply other threads:[~2021-01-22 17:18 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-22 15:15 [PATCH v5 0/8] Add quota support to UBIFS Sascha Hauer
2021-01-22 15:15 ` [PATCH 1/8] quota: Allow to pass mount path to quotactl Sascha Hauer
2021-01-22 17:16 ` Christoph Hellwig [this message]
2021-01-25 8:38 ` Sascha Hauer
2021-01-25 15:45 ` Jan Kara
2021-01-25 20:42 ` Christoph Hellwig
2021-01-26 13:17 ` Jan Kara
2021-01-26 13:34 ` Christoph Hellwig
2021-01-26 16:18 ` Jan Kara
2021-01-27 14:05 ` Sascha Hauer
2021-01-27 14:19 ` Jan Kara
2021-01-26 10:45 ` Sascha Hauer
2021-01-27 14:46 ` Jan Kara
2021-01-27 16:25 ` Christoph Hellwig
2021-01-22 15:15 ` [PATCH 2/8] ubifs: move checks and preparation into setflags() Sascha Hauer
2021-01-22 15:15 ` [PATCH 3/8] ubifs: Add support for FS_IOC_FS[SG]ETXATTR ioctls Sascha Hauer
2021-01-22 17:18 ` Christoph Hellwig
2021-01-22 15:15 ` [PATCH 4/8] ubifs: do not ubifs_inode() on potentially NULL pointer Sascha Hauer
2021-01-22 15:15 ` [PATCH 5/8] ubifs: Factor out ubifs_set_feature_flag() Sascha Hauer
2021-01-22 15:15 ` [PATCH 6/8] ubifs: Add support for project id Sascha Hauer
2021-01-22 15:15 ` [PATCH 7/8] ubifs: export get_znode Sascha Hauer
2021-01-22 17:20 ` Christoph Hellwig
2021-01-22 15:15 ` [PATCH 8/8] ubifs: Add quota support Sascha Hauer
-- strict thread matches above, loose matches on Subject: below --
2020-01-24 13:13 [PATCH v4 0/8] Add quota support to UBIFS Sascha Hauer
2020-01-24 13:13 ` [PATCH 1/8] quota: Allow to pass mount path to quotactl Sascha Hauer
2020-01-27 10:45 ` Jan Kara
2020-01-28 10:06 ` Sascha Hauer
2020-01-28 11:41 ` Jan Kara
2020-01-29 1:29 ` Al Viro
2020-01-29 16:14 ` Jan Kara
2020-02-04 10:35 ` Sascha Hauer
2020-02-18 9:22 ` Jan Kara
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