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Commit fccddba0 authored by NeilBrown's avatar NeilBrown Committed by Linus Torvalds
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[PATCH] md: tidy up raid5/6 hash table code 

- replace open-coded hash chain with hlist macros

- Fix hash-table size at one page - it is already quite generous, so there
  will never be a need to use multiple pages, so no need for __get_free_pages

No functional change.
Signed-off-by: default avatarNeil Brown <neilb@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 9ffae0cf
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Inline Side-by-side
Showing with 33 additions and 57 deletions
drivers/md/raid5.c
View file @ fccddba0
......@@ -35,12 +35,10 @@
#define STRIPE_SHIFT (PAGE_SHIFT - 9)
#define STRIPE_SECTORS (STRIPE_SIZE>>9)
#define IO_THRESHOLD 1
#define HASH_PAGES 1
#define HASH_PAGES_ORDER 0
#define NR_HASH (HASH_PAGES * PAGE_SIZE / sizeof(struct stripe_head *))
#define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head))
#define HASH_MASK (NR_HASH - 1)
#define stripe_hash(conf, sect) ((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK])
#define stripe_hash(conf, sect) (&((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK]))
/* 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
......@@ -113,29 +111,21 @@ static void release_stripe(struct stripe_head *sh)
spin_unlock_irqrestore(&conf->device_lock, flags);
}
static void remove_hash(struct stripe_head *sh)
static inline void remove_hash(struct stripe_head *sh)
{
PRINTK("remove_hash(), stripe %llu\n", (unsigned long long)sh->sector);
if (sh->hash_pprev) {
if (sh->hash_next)
sh->hash_next->hash_pprev = sh->hash_pprev;
*sh->hash_pprev = sh->hash_next;
sh->hash_pprev = NULL;
}
hlist_del_init(&sh->hash);
}
static __inline__ void insert_hash(raid5_conf_t *conf, struct stripe_head *sh)
static inline void insert_hash(raid5_conf_t *conf, struct stripe_head *sh)
{
struct stripe_head **shp = &stripe_hash(conf, sh->sector);
struct hlist_head *hp = stripe_hash(conf, sh->sector);
PRINTK("insert_hash(), stripe %llu\n", (unsigned long long)sh->sector);
CHECK_DEVLOCK();
if ((sh->hash_next = *shp) != NULL)
(*shp)->hash_pprev = &sh->hash_next;
*shp = sh;
sh->hash_pprev = shp;
hlist_add_head(&sh->hash, hp);
}
......@@ -228,10 +218,11 @@ static inline void init_stripe(struct stripe_head *sh, sector_t sector, int pd_i
static struct stripe_head *__find_stripe(raid5_conf_t *conf, sector_t sector)
{
struct stripe_head *sh;
struct hlist_node *hn;
CHECK_DEVLOCK();
PRINTK("__find_stripe, sector %llu\n", (unsigned long long)sector);
for (sh = stripe_hash(conf, sector); sh; sh = sh->hash_next)
hlist_for_each_entry(sh, hn, stripe_hash(conf, sector), hash)
if (sh->sector == sector)
return sh;
PRINTK("__stripe %llu not in cache\n", (unsigned long long)sector);
......@@ -1835,9 +1826,8 @@ static int run(mddev_t *mddev)
conf->mddev = mddev;
if ((conf->stripe_hashtbl = (struct stripe_head **) __get_free_pages(GFP_ATOMIC, HASH_PAGES_ORDER)) == NULL)
if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL)
goto abort;
memset(conf->stripe_hashtbl, 0, HASH_PAGES * PAGE_SIZE);
spin_lock_init(&conf->device_lock);
init_waitqueue_head(&conf->wait_for_stripe);
......@@ -1972,9 +1962,7 @@ static int run(mddev_t *mddev)
abort:
if (conf) {
print_raid5_conf(conf);
if (conf->stripe_hashtbl)
free_pages((unsigned long) conf->stripe_hashtbl,
HASH_PAGES_ORDER);
kfree(conf->stripe_hashtbl);
kfree(conf);
}
mddev->private = NULL;
......@@ -1991,7 +1979,7 @@ static int stop(mddev_t *mddev)
md_unregister_thread(mddev->thread);
mddev->thread = NULL;
shrink_stripes(conf);
free_pages((unsigned long) conf->stripe_hashtbl, HASH_PAGES_ORDER);
kfree(conf->stripe_hashtbl);
blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
sysfs_remove_group(&mddev->kobj, &raid5_attrs_group);
kfree(conf);
......@@ -2019,12 +2007,12 @@ static void print_sh (struct stripe_head *sh)
static void printall (raid5_conf_t *conf)
{
struct stripe_head *sh;
struct hlist_node *hn;
int i;
spin_lock_irq(&conf->device_lock);
for (i = 0; i < NR_HASH; i++) {
sh = conf->stripe_hashtbl[i];
for (; sh; sh = sh->hash_next) {
hlist_for_each_entry(sh, hn, &conf->stripe_hashtbl[i], hash) {
if (sh->raid_conf != conf)
continue;
print_sh(sh);
......
drivers/md/raid6main.c
View file @ fccddba0
......@@ -40,12 +40,10 @@
#define STRIPE_SHIFT (PAGE_SHIFT - 9)
#define STRIPE_SECTORS (STRIPE_SIZE>>9)
#define IO_THRESHOLD 1
#define HASH_PAGES 1
#define HASH_PAGES_ORDER 0
#define NR_HASH (HASH_PAGES * PAGE_SIZE / sizeof(struct stripe_head *))
#define NR_HASH (PAGE_SIZE / sizeof(struct hlist_head))
#define HASH_MASK (NR_HASH - 1)
#define stripe_hash(conf, sect) ((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK])
#define stripe_hash(conf, sect) (&((conf)->stripe_hashtbl[((sect) >> STRIPE_SHIFT) & HASH_MASK]))
/* 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
......@@ -132,29 +130,21 @@ static void release_stripe(struct stripe_head *sh)
spin_unlock_irqrestore(&conf->device_lock, flags);
}
static void remove_hash(struct stripe_head *sh)
static inline void remove_hash(struct stripe_head *sh)
{
PRINTK("remove_hash(), stripe %llu\n", (unsigned long long)sh->sector);
if (sh->hash_pprev) {
if (sh->hash_next)
sh->hash_next->hash_pprev = sh->hash_pprev;
*sh->hash_pprev = sh->hash_next;
sh->hash_pprev = NULL;
}
hlist_del_init(&sh->hash);
}
static __inline__ void insert_hash(raid6_conf_t *conf, struct stripe_head *sh)
static inline void insert_hash(raid6_conf_t *conf, struct stripe_head *sh)
{
struct stripe_head **shp = &stripe_hash(conf, sh->sector);
struct hlist_head *hp = stripe_hash(conf, sh->sector);
PRINTK("insert_hash(), stripe %llu\n", (unsigned long long)sh->sector);
CHECK_DEVLOCK();
if ((sh->hash_next = *shp) != NULL)
(*shp)->hash_pprev = &sh->hash_next;
*shp = sh;
sh->hash_pprev = shp;
hlist_add_head(&sh->hash, hp);
}
......@@ -247,10 +237,11 @@ static inline void init_stripe(struct stripe_head *sh, sector_t sector, int pd_i
static struct stripe_head *__find_stripe(raid6_conf_t *conf, sector_t sector)
{
struct stripe_head *sh;
struct hlist_node *hn;
CHECK_DEVLOCK();
PRINTK("__find_stripe, sector %llu\n", (unsigned long long)sector);
for (sh = stripe_hash(conf, sector); sh; sh = sh->hash_next)
hlist_for_each_entry (sh, hn, stripe_hash(conf, sector), hash)
if (sh->sector == sector)
return sh;
PRINTK("__stripe %llu not in cache\n", (unsigned long long)sector);
......@@ -1931,17 +1922,15 @@ static int run(mddev_t *mddev)
return -EIO;
}
mddev->private = kmalloc (sizeof (raid6_conf_t)
mddev->private = kzalloc(sizeof (raid6_conf_t)
+ mddev->raid_disks * sizeof(struct disk_info),
GFP_KERNEL);
if ((conf = mddev->private) == NULL)
goto abort;
memset (conf, 0, sizeof (*conf) + mddev->raid_disks * sizeof(struct disk_info) );
conf->mddev = mddev;
if ((conf->stripe_hashtbl = (struct stripe_head **) __get_free_pages(GFP_ATOMIC, HASH_PAGES_ORDER)) == NULL)
if ((conf->stripe_hashtbl = kzalloc(PAGE_SIZE, GFP_KERNEL)) == NULL)
goto abort;
memset(conf->stripe_hashtbl, 0, HASH_PAGES * PAGE_SIZE);
conf->spare_page = alloc_page(GFP_KERNEL);
if (!conf->spare_page)
......@@ -2085,9 +2074,7 @@ static int run(mddev_t *mddev)
print_raid6_conf(conf);
if (conf->spare_page)
put_page(conf->spare_page);
if (conf->stripe_hashtbl)
free_pages((unsigned long) conf->stripe_hashtbl,
HASH_PAGES_ORDER);
kfree(conf->stripe_hashtbl);
kfree(conf);
}
mddev->private = NULL;
......@@ -2104,7 +2091,7 @@ static int stop (mddev_t *mddev)
md_unregister_thread(mddev->thread);
mddev->thread = NULL;
shrink_stripes(conf);
free_pages((unsigned long) conf->stripe_hashtbl, HASH_PAGES_ORDER);
kfree(conf->stripe_hashtbl);
blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
kfree(conf);
mddev->private = NULL;
......@@ -2131,12 +2118,13 @@ static void print_sh (struct seq_file *seq, struct stripe_head *sh)
static void printall (struct seq_file *seq, raid6_conf_t *conf)
{
struct stripe_head *sh;
struct hlist_node *hn;
int i;
spin_lock_irq(&conf->device_lock);
for (i = 0; i < NR_HASH; i++) {
sh = conf->stripe_hashtbl[i];
for (; sh; sh = sh->hash_next) {
hlist_for_each_entry(sh, hn, &conf->stripe_hashtbl[i], hash) {
if (sh->raid_conf != conf)
continue;
print_sh(seq, sh);
......
include/linux/raid/raid5.h
View file @ fccddba0
......@@ -126,7 +126,7 @@
*/
struct stripe_head {
struct stripe_head *hash_next, **hash_pprev; /* hash pointers */
struct hlist_node hash;
struct list_head lru; /* inactive_list or handle_list */
struct raid5_private_data *raid_conf;
sector_t sector; /* sector of this row */
......@@ -204,7 +204,7 @@ struct disk_info {
};
struct raid5_private_data {
struct stripe_head **stripe_hashtbl;
struct hlist_head *stripe_hashtbl;
mddev_t *mddev;
struct disk_info *spare;
int chunk_size, level, algorithm;
......
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