Re: [PATCH v2] quota: reorder flags in quota state

[Jan Kara]

On Thu 12-02-15 19:08:16, Konstantin Khlebnikov wrote:
> 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
  Thanks. Applied to my tree.

								Honza

> 
> Signed-off-by: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx>
> ---
>  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)
> 
-- 
Jan Kara <jack@xxxxxxx>
SUSE Labs, CR
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