From: NeilBrown Date: Fri, 6 Jan 2006 08:20:33 +0000 (-0800) Subject: [PATCH] md: tidy up raid5/6 hash table code X-Git-Tag: v2.6.16-rc1~936^2~29 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fccddba060f2b4916a30aa27acc3d03b01bb981e;p=linux-2.6 [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: Neil Brown Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 9fc50487e2..6e4db95ceb 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -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); diff --git a/drivers/md/raid6main.c b/drivers/md/raid6main.c index 4062fc16ac..79b5244f44 100644 --- a/drivers/md/raid6main.c +++ b/drivers/md/raid6main.c @@ -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->raid_disks * sizeof(struct disk_info), - GFP_KERNEL); + 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 @@ abort: 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); diff --git a/include/linux/raid/raid5.h b/include/linux/raid/raid5.h index 28fcd7533a..394da8207b 100644 --- a/include/linux/raid/raid5.h +++ b/include/linux/raid/raid5.h @@ -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;