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: Jan Kara <jack@suse.cz>
This commit is contained in:
Jan Kara 2014-10-06 18:40:51 +02:00
parent d3b8632485
commit 3e2af67e66
2 changed files with 92 additions and 0 deletions

View File

@ -2385,6 +2385,86 @@ out:
}
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)
{

View File

@ -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