From 35849c75d7750a254119c1a4b88c90156919df2a Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Thu, 2 Feb 2006 14:28:06 -0800 Subject: [PATCH] [PATCH] md: Add sysfs access to raid6 stripe cache size .. just as we already have for raid5. Signed-off-by: Neil Brown Cc: Greg KH Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/md/raid6main.c | 149 +++++++++++++++++++++++++++++++---------- 1 file changed, 115 insertions(+), 34 deletions(-) diff --git a/drivers/md/raid6main.c b/drivers/md/raid6main.c index f618a53b98be..ed2abb2e2e2d 100644 --- a/drivers/md/raid6main.c +++ b/drivers/md/raid6main.c @@ -115,7 +115,7 @@ static void __release_stripe(raid6_conf_t *conf, struct stripe_head *sh) list_add_tail(&sh->lru, &conf->inactive_list); atomic_dec(&conf->active_stripes); if (!conf->inactive_blocked || - atomic_read(&conf->active_stripes) < (NR_STRIPES*3/4)) + atomic_read(&conf->active_stripes) < (conf->max_nr_stripes*3/4)) wake_up(&conf->wait_for_stripe); } } @@ -273,7 +273,8 @@ static struct stripe_head *get_active_stripe(raid6_conf_t *conf, sector_t sector conf->inactive_blocked = 1; wait_event_lock_irq(conf->wait_for_stripe, !list_empty(&conf->inactive_list) && - (atomic_read(&conf->active_stripes) < (NR_STRIPES *3/4) + (atomic_read(&conf->active_stripes) + < (conf->max_nr_stripes *3/4) || !conf->inactive_blocked), conf->device_lock, unplug_slaves(conf->mddev); @@ -302,9 +303,31 @@ static struct stripe_head *get_active_stripe(raid6_conf_t *conf, sector_t sector return sh; } -static int grow_stripes(raid6_conf_t *conf, int num) +static int grow_one_stripe(raid6_conf_t *conf) { struct stripe_head *sh; + sh = kmem_cache_alloc(conf->slab_cache, GFP_KERNEL); + if (!sh) + return 0; + memset(sh, 0, sizeof(*sh) + (conf->raid_disks-1)*sizeof(struct r5dev)); + sh->raid_conf = conf; + spin_lock_init(&sh->lock); + + if (grow_buffers(sh, conf->raid_disks)) { + shrink_buffers(sh, conf->raid_disks); + kmem_cache_free(conf->slab_cache, sh); + return 0; + } + /* we just created an active stripe so... */ + atomic_set(&sh->count, 1); + atomic_inc(&conf->active_stripes); + INIT_LIST_HEAD(&sh->lru); + release_stripe(sh); + return 1; +} + +static int grow_stripes(raid6_conf_t *conf, int num) +{ kmem_cache_t *sc; int devs = conf->raid_disks; @@ -316,44 +339,33 @@ static int grow_stripes(raid6_conf_t *conf, int num) if (!sc) return 1; conf->slab_cache = sc; - while (num--) { - sh = kmem_cache_alloc(sc, GFP_KERNEL); - if (!sh) + while (num--) + if (!grow_one_stripe(conf)) return 1; - memset(sh, 0, sizeof(*sh) + (devs-1)*sizeof(struct r5dev)); - sh->raid_conf = conf; - spin_lock_init(&sh->lock); - - if (grow_buffers(sh, conf->raid_disks)) { - shrink_buffers(sh, conf->raid_disks); - kmem_cache_free(sc, sh); - return 1; - } - /* we just created an active stripe so... */ - atomic_set(&sh->count, 1); - atomic_inc(&conf->active_stripes); - INIT_LIST_HEAD(&sh->lru); - release_stripe(sh); - } return 0; } +static int drop_one_stripe(raid6_conf_t *conf) +{ + struct stripe_head *sh; + spin_lock_irq(&conf->device_lock); + sh = get_free_stripe(conf); + spin_unlock_irq(&conf->device_lock); + if (!sh) + return 0; + if (atomic_read(&sh->count)) + BUG(); + shrink_buffers(sh, conf->raid_disks); + kmem_cache_free(conf->slab_cache, sh); + atomic_dec(&conf->active_stripes); + return 1; +} + static void shrink_stripes(raid6_conf_t *conf) { - struct stripe_head *sh; + while (drop_one_stripe(conf)) + ; - while (1) { - spin_lock_irq(&conf->device_lock); - sh = get_free_stripe(conf); - spin_unlock_irq(&conf->device_lock); - if (!sh) - break; - if (atomic_read(&sh->count)) - BUG(); - shrink_buffers(sh, conf->raid_disks); - kmem_cache_free(conf->slab_cache, sh); - atomic_dec(&conf->active_stripes); - } kmem_cache_destroy(conf->slab_cache); conf->slab_cache = NULL; } @@ -1912,6 +1924,74 @@ static void raid6d (mddev_t *mddev) PRINTK("--- raid6d inactive\n"); } +static ssize_t +raid6_show_stripe_cache_size(mddev_t *mddev, char *page) +{ + raid6_conf_t *conf = mddev_to_conf(mddev); + if (conf) + return sprintf(page, "%d\n", conf->max_nr_stripes); + else + return 0; +} + +static ssize_t +raid6_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len) +{ + raid6_conf_t *conf = mddev_to_conf(mddev); + char *end; + int new; + if (len >= PAGE_SIZE) + return -EINVAL; + if (!conf) + return -ENODEV; + + new = simple_strtoul(page, &end, 10); + if (!*page || (*end && *end != '\n') ) + return -EINVAL; + if (new <= 16 || new > 32768) + return -EINVAL; + while (new < conf->max_nr_stripes) { + if (drop_one_stripe(conf)) + conf->max_nr_stripes--; + else + break; + } + while (new > conf->max_nr_stripes) { + if (grow_one_stripe(conf)) + conf->max_nr_stripes++; + else break; + } + return len; +} + +static struct md_sysfs_entry +raid6_stripecache_size = __ATTR(stripe_cache_size, S_IRUGO | S_IWUSR, + raid6_show_stripe_cache_size, + raid6_store_stripe_cache_size); + +static ssize_t +stripe_cache_active_show(mddev_t *mddev, char *page) +{ + raid6_conf_t *conf = mddev_to_conf(mddev); + if (conf) + return sprintf(page, "%d\n", atomic_read(&conf->active_stripes)); + else + return 0; +} + +static struct md_sysfs_entry +raid6_stripecache_active = __ATTR_RO(stripe_cache_active); + +static struct attribute *raid6_attrs[] = { + &raid6_stripecache_size.attr, + &raid6_stripecache_active.attr, + NULL, +}; +static struct attribute_group raid6_attrs_group = { + .name = NULL, + .attrs = raid6_attrs, +}; + static int run(mddev_t *mddev) { raid6_conf_t *conf; @@ -2095,6 +2175,7 @@ static int stop (mddev_t *mddev) shrink_stripes(conf); kfree(conf->stripe_hashtbl); blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ + sysfs_remove_group(&mddev->kobj, &raid6_attrs_group); kfree(conf); mddev->private = NULL; return 0;