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@xxxxxxx>
---
fs/quota/dquot.c | 91 ++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/quotaops.h | 1 +
2 files changed, 92 insertions(+)
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 29eb9dc5728a..b47d0c17ea6f 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -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)
{
diff --git a/include/linux/quotaops.h b/include/linux/quotaops.h
index ff0b665591d0..df73258cca47 100644
--- a/include/linux/quotaops.h
+++ b/include/linux/quotaops.h
@@ -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
--
2.1.2
--
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