quota: reorder flags in quota state

Flags in struct quota_state keep flags for each quota type and
some common flags. This patch reorders typed flags:

Before:

0 USRQUOTA DQUOT_USAGE_ENABLED
1 USRQUOTA DQUOT_LIMITS_ENABLED
2 USRQUOTA DQUOT_SUSPENDED
3 GRPQUOTA DQUOT_USAGE_ENABLED
4 GRPQUOTA DQUOT_LIMITS_ENABLED
5 GRPQUOTA DQUOT_SUSPENDED
6          DQUOT_QUOTA_SYS_FILE
7          DQUOT_NEGATIVE_USAGE

After:

0 USRQUOTA DQUOT_USAGE_ENABLED
1 GRPQUOTA DQUOT_USAGE_ENABLED
2 USRQUOTA DQUOT_LIMITS_ENABLED
3 GRPQUOTA DQUOT_LIMITS_ENABLED
4 USRQUOTA DQUOT_SUSPENDED
5 GRPQUOTA DQUOT_SUSPENDED
6          DQUOT_QUOTA_SYS_FILE
7          DQUOT_NEGATIVE_USAGE

Now we can get bitmap of all enabled/suspended quota types without loop.
For example suspended: (flags / DQUOT_SUSPENDED) & ((1 << MAXQUOTAS) - 1).

add/remove: 0/1 grow/shrink: 3/11 up/down: 56/-215 (-159)
function                                     old     new   delta
__dquot_initialize                           423     447     +24
dquot_transfer                               181     197     +16
dquot_alloc_inode                            286     302     +16
dquot_reclaim_space_nodirty                  316     313      -3
dquot_claim_space_nodirty                    314     311      -3
dquot_resume                                 286     281      -5
dquot_free_inode                             332     324      -8
__dquot_alloc_space                          500     492      -8
dquot_disable                               1944    1929     -15
dquot_quota_enable                           252     236     -16
__dquot_free_space                           750     734     -16
dquot_writeback_dquots                       625     608     -17
__dquot_transfer                            1186    1154     -32
dquot_quota_sync                             299     261     -38
dquot_active.isra                             54       -     -54
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jan Kara <jack@suse.cz>

include/linux/quota.h

@@ -389,7 +389,19 @@ struct quota_format_type {
 	struct quota_format_type *qf_next;
 };
 
-/* Quota state flags - they actually come in two flavors - for users and groups */
+/**
+ * Quota state flags - they actually come in two flavors - for users and groups.
+ *
+ * Actual typed flags layout:
+ *				USRQUOTA	GRPQUOTA
+ *  DQUOT_USAGE_ENABLED		0x0001		0x0002
+ *  DQUOT_LIMITS_ENABLED	0x0004		0x0008
+ *  DQUOT_SUSPENDED		0x0010		0x0020
+ *
+ * Following bits are used for non-typed flags:
+ *  DQUOT_QUOTA_SYS_FILE	0x0040
+ *  DQUOT_NEGATIVE_USAGE	0x0080
+ */
 enum {
 	_DQUOT_USAGE_ENABLED = 0,		/* Track disk usage for users */
 	_DQUOT_LIMITS_ENABLED,			/* Enforce quota limits for users */
@@ -398,9 +410,9 @@ enum {
 						 * memory to turn them on */
 	_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_USAGE_ENABLED	(1 << _DQUOT_USAGE_ENABLED * MAXQUOTAS)
+#define DQUOT_LIMITS_ENABLED	(1 << _DQUOT_LIMITS_ENABLED * MAXQUOTAS)
+#define DQUOT_SUSPENDED		(1 << _DQUOT_SUSPENDED * MAXQUOTAS)
 #define DQUOT_STATE_FLAGS	(DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED | \
 				 DQUOT_SUSPENDED)
 /* Other quota flags */
@@ -414,15 +426,21 @@ enum {
 						 */
 #define DQUOT_NEGATIVE_USAGE	(1 << (DQUOT_STATE_LAST + 1))
 					       /* Allow negative quota usage */
-
 static inline unsigned int dquot_state_flag(unsigned int flags, int type)
 {
-	return flags << _DQUOT_STATE_FLAGS * type;
+	return flags << type;
 }
 
 static inline unsigned int dquot_generic_flag(unsigned int flags, int type)
 {
-	return (flags >> _DQUOT_STATE_FLAGS * type) & DQUOT_STATE_FLAGS;
+	return (flags >> type) & DQUOT_STATE_FLAGS;
+}
+
+/* Bitmap of quota types where flag is set in flags */
+static __always_inline unsigned dquot_state_types(unsigned flags, unsigned flag)
+{
+	BUILD_BUG_ON_NOT_POWER_OF_2(flag);
+	return (flags / flag) & ((1 << MAXQUOTAS) - 1);
 }
 
 #ifdef CONFIG_QUOTA_NETLINK_INTERFACE

include/linux/quotaops.h

@@ -134,10 +134,7 @@ static inline bool sb_has_quota_suspended(struct super_block *sb, int type)
 
 static inline unsigned sb_any_quota_suspended(struct super_block *sb)
 {
-	unsigned type, tmsk = 0;
-	for (type = 0; type < MAXQUOTAS; type++)
-		tmsk |= sb_has_quota_suspended(sb, type) << type;
-	return tmsk;
+	return dquot_state_types(sb_dqopt(sb)->flags, DQUOT_SUSPENDED);
 }
 
 /* Does kernel know about any quota information for given sb + type? */
@@ -149,10 +146,7 @@ static inline bool sb_has_quota_loaded(struct super_block *sb, int type)
 
 static inline unsigned sb_any_quota_loaded(struct super_block *sb)
 {
-	unsigned type, tmsk = 0;
-	for (type = 0; type < MAXQUOTAS; type++)
-		tmsk |= sb_has_quota_loaded(sb, type) << type;
-	return	tmsk;
+	return dquot_state_types(sb_dqopt(sb)->flags, DQUOT_USAGE_ENABLED);
 }
 
 static inline bool sb_has_quota_active(struct super_block *sb, int type)