[PATCH v2] quota: reorder flags in quota state

Konstantin Khlebnikov
2015-02-12T16:08:22Z

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>
---
include/linux/quota.h | 32 +++++++++++++++++++++++++-------
include/linux/quotaops.h | 10 ++--------
2 files changed, 27 insertions(+), 15 deletions(-)

diff --git a/include/linux/quota.h b/include/linux/quota.h
index d534e8e..a3374dc 100644
--- a/include/linux/quota.h
+++ b/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
diff --git a/include/linux/quotaops.h b/include/linux/quotaops.h
index df73258..8778ec4 100644
--- a/include/linux/quotaops.h
+++ b/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)