Commit 937621c3 authored by Song Liu's avatar Song Liu Committed by Shaohua Li
Browse files

md/r5cache: move some code to raid5.h 



Move some define and inline functions to raid5.h, so they can be
used in raid5-cache.c

Signed-off-by: default avatarSong Liu <songliubraving@fb.com>
Signed-off-by: default avatarShaohua Li <shli@fb.com>
parent c757ec95

drivers/md/raid5.c

+0 −71
Original line number Diff line number Diff line
@@ -70,19 +70,6 @@ module_param(devices_handle_discard_safely, bool, 0644); 
MODULE_PARM_DESC(devices_handle_discard_safely,

		 "Set to Y if all devices in each array reliably return zeroes on reads from discarded regions");

static struct workqueue_struct *raid5_wq;

/*

 * Stripe cache

 */



#define NR_STRIPES		256

#define STRIPE_SIZE		PAGE_SIZE

#define STRIPE_SHIFT		(PAGE_SHIFT - 9)

#define STRIPE_SECTORS		(STRIPE_SIZE>>9)

#define	IO_THRESHOLD		1

#define BYPASS_THRESHOLD	1

#define NR_HASH			(PAGE_SIZE / sizeof(struct hlist_head))

#define HASH_MASK		(NR_HASH - 1)

#define MAX_STRIPE_BATCH	8



static inline struct hlist_head *stripe_hash(struct r5conf *conf, sector_t sect)

{
@@ -126,64 +113,6 @@ static inline void unlock_all_device_hash_locks_irq(struct r5conf *conf) 
	local_irq_enable();

}



/* bio's attached to a stripe+device for I/O are linked together in bi_sector

 * order without overlap.  There may be several bio's per stripe+device, and

 * a bio could span several devices.

 * When walking this list for a particular stripe+device, we must never proceed

 * beyond a bio that extends past this device, as the next bio might no longer

 * be valid.

 * This function is used to determine the 'next' bio in the list, given the sector

 * of the current stripe+device

 */

static inline struct bio *r5_next_bio(struct bio *bio, sector_t sector)

{

	int sectors = bio_sectors(bio);

	if (bio->bi_iter.bi_sector + sectors < sector + STRIPE_SECTORS)

		return bio->bi_next;

	else

		return NULL;

}



/*

 * We maintain a biased count of active stripes in the bottom 16 bits of

 * bi_phys_segments, and a count of processed stripes in the upper 16 bits

 */

static inline int raid5_bi_processed_stripes(struct bio *bio)

{

	atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;

	return (atomic_read(segments) >> 16) & 0xffff;

}



static inline int raid5_dec_bi_active_stripes(struct bio *bio)

{

	atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;

	return atomic_sub_return(1, segments) & 0xffff;

}



static inline void raid5_inc_bi_active_stripes(struct bio *bio)

{

	atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;

	atomic_inc(segments);

}



static inline void raid5_set_bi_processed_stripes(struct bio *bio,

	unsigned int cnt)

{

	atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;

	int old, new;



	do {

		old = atomic_read(segments);

		new = (old & 0xffff) | (cnt << 16);

	} while (atomic_cmpxchg(segments, old, new) != old);

}



static inline void raid5_set_bi_stripes(struct bio *bio, unsigned int cnt)

{

	atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;

	atomic_set(segments, cnt);

}



/* Find first data disk in a raid6 stripe */

static inline int raid6_d0(struct stripe_head *sh)

{

drivers/md/raid5.h

+77 −0
Original line number Diff line number Diff line
@@ -410,6 +410,83 @@ struct disk_info { 
	struct md_rdev	*rdev, *replacement;

};



/*

 * Stripe cache

 */



#define NR_STRIPES		256

#define STRIPE_SIZE		PAGE_SIZE

#define STRIPE_SHIFT		(PAGE_SHIFT - 9)

#define STRIPE_SECTORS		(STRIPE_SIZE>>9)

#define	IO_THRESHOLD		1

#define BYPASS_THRESHOLD	1

#define NR_HASH			(PAGE_SIZE / sizeof(struct hlist_head))

#define HASH_MASK		(NR_HASH - 1)

#define MAX_STRIPE_BATCH	8



/* bio's attached to a stripe+device for I/O are linked together in bi_sector

 * order without overlap.  There may be several bio's per stripe+device, and

 * a bio could span several devices.

 * When walking this list for a particular stripe+device, we must never proceed

 * beyond a bio that extends past this device, as the next bio might no longer

 * be valid.

 * This function is used to determine the 'next' bio in the list, given the

 * sector of the current stripe+device

 */

static inline struct bio *r5_next_bio(struct bio *bio, sector_t sector)

{

	int sectors = bio_sectors(bio);



	if (bio->bi_iter.bi_sector + sectors < sector + STRIPE_SECTORS)

		return bio->bi_next;

	else

		return NULL;

}



/*

 * We maintain a biased count of active stripes in the bottom 16 bits of

 * bi_phys_segments, and a count of processed stripes in the upper 16 bits

 */

static inline int raid5_bi_processed_stripes(struct bio *bio)

{

	atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;



	return (atomic_read(segments) >> 16) & 0xffff;

}



static inline int raid5_dec_bi_active_stripes(struct bio *bio)

{

	atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;



	return atomic_sub_return(1, segments) & 0xffff;

}



static inline void raid5_inc_bi_active_stripes(struct bio *bio)

{

	atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;



	atomic_inc(segments);

}



static inline void raid5_set_bi_processed_stripes(struct bio *bio,

	unsigned int cnt)

{

	atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;

	int old, new;



	do {

		old = atomic_read(segments);

		new = (old & 0xffff) | (cnt << 16);

	} while (atomic_cmpxchg(segments, old, new) != old);

}



static inline void raid5_set_bi_stripes(struct bio *bio, unsigned int cnt)

{

	atomic_t *segments = (atomic_t *)&bio->bi_phys_segments;



	atomic_set(segments, cnt);

}



/* NOTE NR_STRIPE_HASH_LOCKS must remain below 64.

 * This is because we sometimes take all the spinlocks

 * and creating that much locking depth can cause