Skip to content

Commit

Permalink
md/r5cache: move some code to raid5.h
Browse files Browse the repository at this point in the history
Move some define and inline functions to raid5.h, so they can be
used in raid5-cache.c

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
  • Loading branch information
Song Liu authored and Shaohua Li committed Nov 18, 2016
1 parent c757ec9 commit 937621c
Showing 2 changed files with 77 additions and 71 deletions.
71 changes: 0 additions & 71 deletions drivers/md/raid5.c
Original file line number Diff line number Diff line change
@@ -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)
{
77 changes: 77 additions & 0 deletions drivers/md/raid5.h
Original file line number Diff line number Diff line change
@@ -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

0 comments on commit 937621c

Please sign in to comment.