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Commit 3e2af67e authored by Jan Kara's avatar Jan Kara
Browse files

quota: Add ->quota_{enable,disable} callbacks for VFS quotas 



Add functions which translate ->quota_enable / ->quota_disable calls
into appropriate changes in VFS quota. This will enable filesystems
supporting VFS quota files in system inodes to be controlled via
Q_XQUOTA[ON|OFF] quotactls for better userspace compatibility.

Also provide a vector for quotactl using these functions which can be
used by filesystems with quota files stored in hidden system files.

Signed-off-by: default avatarJan Kara <jack@suse.cz>
parent d3b86324

fs/quota/dquot.c

+91 −0
Original line number Diff line number Diff line
@@ -2385,6 +2385,86 @@ int dquot_quota_on_mount(struct super_block *sb, char *qf_name, 
}

EXPORT_SYMBOL(dquot_quota_on_mount);



static int dquot_quota_enable(struct super_block *sb, unsigned int flags)

{

	int ret;

	int type;

	struct quota_info *dqopt = sb_dqopt(sb);



	if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE))

		return -ENOSYS;

	/* Accounting cannot be turned on while fs is mounted */

	flags &= ~(FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT);

	if (!flags)

		return -EINVAL;

	for (type = 0; type < MAXQUOTAS; type++) {

		if (!(flags & qtype_enforce_flag(type)))

			continue;

		/* Can't enforce without accounting */

		if (!sb_has_quota_usage_enabled(sb, type))

			return -EINVAL;

		ret = dquot_enable(dqopt->files[type], type,

				   dqopt->info[type].dqi_fmt_id,

				   DQUOT_LIMITS_ENABLED);

		if (ret < 0)

			goto out_err;

	}

	return 0;

out_err:

	/* Backout enforcement enablement we already did */

	for (type--; type >= 0; type--)  {

		if (flags & qtype_enforce_flag(type))

			dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);

	}

	/* Error code translation for better compatibility with XFS */

	if (ret == -EBUSY)

		ret = -EEXIST;

	return ret;

}



static int dquot_quota_disable(struct super_block *sb, unsigned int flags)

{

	int ret;

	int type;

	struct quota_info *dqopt = sb_dqopt(sb);



	if (!(dqopt->flags & DQUOT_QUOTA_SYS_FILE))

		return -ENOSYS;

	/*

	 * We don't support turning off accounting via quotactl. In principle

	 * quota infrastructure can do this but filesystems don't expect

	 * userspace to be able to do it.

	 */

	if (flags &

		  (FS_QUOTA_UDQ_ACCT | FS_QUOTA_GDQ_ACCT | FS_QUOTA_PDQ_ACCT))

		return -EOPNOTSUPP;



	/* Filter out limits not enabled */

	for (type = 0; type < MAXQUOTAS; type++)

		if (!sb_has_quota_limits_enabled(sb, type))

			flags &= ~qtype_enforce_flag(type);

	/* Nothing left? */

	if (!flags)

		return -EEXIST;

	for (type = 0; type < MAXQUOTAS; type++) {

		if (flags & qtype_enforce_flag(type)) {

			ret = dquot_disable(sb, type, DQUOT_LIMITS_ENABLED);

			if (ret < 0)

				goto out_err;

		}

	}

	return 0;

out_err:

	/* Backout enforcement disabling we already did */

	for (type--; type >= 0; type--)  {

		if (flags & qtype_enforce_flag(type))

			dquot_enable(dqopt->files[type], type,

				     dqopt->info[type].dqi_fmt_id,

				     DQUOT_LIMITS_ENABLED);

	}

	return ret;

}



static inline qsize_t qbtos(qsize_t blocks)

{

	return blocks << QIF_DQBLKSIZE_BITS;
@@ -2614,6 +2694,17 @@ const struct quotactl_ops dquot_quotactl_ops = { 
};

EXPORT_SYMBOL(dquot_quotactl_ops);



const struct quotactl_ops dquot_quotactl_sysfile_ops = {

	.quota_enable	= dquot_quota_enable,

	.quota_disable	= dquot_quota_disable,

	.quota_sync	= dquot_quota_sync,

	.get_info	= dquot_get_dqinfo,

	.set_info	= dquot_set_dqinfo,

	.get_dqblk	= dquot_get_dqblk,

	.set_dqblk	= dquot_set_dqblk

};

EXPORT_SYMBOL(dquot_quotactl_sysfile_ops);



static int do_proc_dqstats(struct ctl_table *table, int write,

		     void __user *buffer, size_t *lenp, loff_t *ppos)

{

include/linux/quotaops.h

+1 −0
Original line number Diff line number Diff line
@@ -166,6 +166,7 @@ static inline bool sb_has_quota_active(struct super_block *sb, int type) 
 */

extern const struct dquot_operations dquot_operations;

extern const struct quotactl_ops dquot_quotactl_ops;

extern const struct quotactl_ops dquot_quotactl_sysfile_ops;



#else