quota: Allow to separately enable quota accounting and enforcing limits

Split DQUOT_USR_ENABLED (and DQUOT_GRP_ENABLED) into DQUOT_USR_USAGE_ENABLED
and DQUOT_USR_LIMITS_ENABLED. This way we are able to separately enable /
disable whether we should:
1) ignore quotas completely
2) just keep uptodate information about usage
3) actually enforce quota limits

This is going to be useful when quota is treated as filesystem metadata - we
then want to keep quota information uptodate all the time and just enable /
disable limits enforcement.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>

1 files changed, 26 insertions, 4 deletions

diff --git a/include/linux/quota.h b/include/linux/quota.h
index 9ea468363f9f..93717abcd35b 100644
--- a/include/linux/quota.h
+++ b/include/linux/quota.h
@@ -318,12 +318,34 @@ struct quota_format_type {
         struct quota_format_type *qf_next;
 };
 
-#define DQUOT_USR_ENABLED       0x01            /* User diskquotas enabled */
-#define DQUOT_GRP_ENABLED       0x02            /* Group diskquotas enabled */
-#define DQUOT_USR_SUSPENDED     0x04            /* User diskquotas are off, but
+/* Quota state flags - they actually come in two flavors - for users and groups */
+enum {
+        _DQUOT_USAGE_ENABLED = 0,               /* Track disk usage for users */
+        _DQUOT_LIMITS_ENABLED,                  /* Enforce quota limits for users */
+        _DQUOT_SUSPENDED,                       /* User diskquotas are off, but
                                                  * we have necessary info in
                                                  * memory to turn them on */
-#define DQUOT_GRP_SUSPENDED     0x08            /* The same for group quotas */
+        _DQUOT_STATE_FLAGS
+};
+#define DQUOT_USAGE_ENABLED     (1 << _DQUOT_USAGE_ENABLED)
+#define DQUOT_LIMITS_ENABLED    (1 << _DQUOT_LIMITS_ENABLED)
+#define DQUOT_SUSPENDED         (1 << _DQUOT_SUSPENDED)
+#define DQUOT_STATE_FLAGS       (DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED | \
+                                 DQUOT_SUSPENDED)
+
+static inline unsigned int dquot_state_flag(unsigned int flags, int type)
+{
+        if (type == USRQUOTA)
+                return flags;
+        return flags << _DQUOT_STATE_FLAGS;
+}
+
+static inline unsigned int dquot_generic_flag(unsigned int flags, int type)
+{
+        if (type == USRQUOTA)
+                return flags;
+        return flags >> _DQUOT_STATE_FLAGS;
+}
 
 struct quota_info {
         unsigned int flags;                     /* Flags for diskquotas on this device */