From 3f294f4fb6f2ba887b717674da26c21f3d57f3fc Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 8 Nov 2005 21:39:25 -0800 Subject: [PATCH] md: add kobject/sysfs support to raid5 /sys/block/mdX/md/raid5/ contains raid5-related attributes. Currently stripe_cache_size is number of entries in stripe cache, and is settable. stripe_cache_active is number of active entries, and in only readable. Signed-off-by: Neil Brown Cc: Greg KH Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/md/raid5.c | 183 +++++++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 151 insertions(+), 32 deletions(-) (limited to 'drivers/md/raid5.c') diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 8cf1ae8b8a7..121fbaa9ed5 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -293,9 +293,31 @@ static struct stripe_head *get_active_stripe(raid5_conf_t *conf, sector_t sector return sh; } -static int grow_stripes(raid5_conf_t *conf, int num) +static int grow_one_stripe(raid5_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(raid5_conf_t *conf, int num) +{ kmem_cache_t *sc; int devs = conf->raid_disks; @@ -308,43 +330,34 @@ static int grow_stripes(raid5_conf_t *conf, int num) return 1; conf->slab_cache = sc; while (num--) { - sh = kmem_cache_alloc(sc, GFP_KERNEL); - if (!sh) - 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); + if (!grow_one_stripe(conf)) 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 void shrink_stripes(raid5_conf_t *conf) +static int drop_one_stripe(raid5_conf_t *conf) { struct stripe_head *sh; - 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); - } + 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(raid5_conf_t *conf) +{ + while (drop_one_stripe(conf)) + ; + kmem_cache_destroy(conf->slab_cache); conf->slab_cache = NULL; } @@ -1714,6 +1727,108 @@ static void raid5d (mddev_t *mddev) PRINTK("--- raid5d inactive\n"); } +struct raid5_sysfs_entry { + struct attribute attr; + ssize_t (*show)(raid5_conf_t *, char *); + ssize_t (*store)(raid5_conf_t *, const char *, ssize_t); +}; + +static ssize_t +raid5_show_stripe_cache_size(raid5_conf_t *conf, char *page) +{ + return sprintf(page, "%d\n", conf->max_nr_stripes); +} + +static ssize_t +raid5_store_stripe_cache_size(raid5_conf_t *conf, const char *page, ssize_t len) +{ + char *end; + int new; + if (len >= PAGE_SIZE) + return -EINVAL; + + 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 raid5_sysfs_entry raid5_stripecache_size = { + .attr = {.name = "stripe_cache_size", .mode = S_IRUGO | S_IWUSR }, + .show = raid5_show_stripe_cache_size, + .store = raid5_store_stripe_cache_size, +}; + +static ssize_t +raid5_show_stripe_cache_active(raid5_conf_t *conf, char *page) +{ + return sprintf(page, "%d\n", atomic_read(&conf->active_stripes)); +} + +static struct raid5_sysfs_entry raid5_stripecache_active = { + .attr = {.name = "stripe_cache_active", .mode = S_IRUGO}, + .show = raid5_show_stripe_cache_active, +}; + +static struct attribute *raid5_default_attrs[] = { + &raid5_stripecache_size.attr, + &raid5_stripecache_active.attr, + NULL, +}; + +static ssize_t +raid5_attr_show(struct kobject *kobj, struct attribute *attr, char *page) +{ + struct raid5_sysfs_entry *entry = container_of(attr, struct raid5_sysfs_entry, attr); + raid5_conf_t *conf = container_of(kobj, raid5_conf_t, kobj); + + if (!entry->show) + return -EIO; + return entry->show(conf, page); +} + +static ssize_t +raid5_attr_store(struct kobject *kobj, struct attribute *attr, + const char *page, size_t length) +{ + struct raid5_sysfs_entry *entry = container_of(attr, struct raid5_sysfs_entry, attr); + raid5_conf_t *conf = container_of(kobj, raid5_conf_t, kobj); + + if (!entry->store) + return -EIO; + return entry->store(conf, page, length); +} + +static void raid5_free(struct kobject *ko) +{ + raid5_conf_t *conf = container_of(ko, raid5_conf_t, kobj); + kfree(conf); +} + + +static struct sysfs_ops raid5_sysfs_ops = { + .show = raid5_attr_show, + .store = raid5_attr_store, +}; + +static struct kobj_type raid5_ktype = { + .release = raid5_free, + .sysfs_ops = &raid5_sysfs_ops, + .default_attrs = raid5_default_attrs, +}; + static int run(mddev_t *mddev) { raid5_conf_t *conf; @@ -1855,6 +1970,10 @@ memory = conf->max_nr_stripes * (sizeof(struct stripe_head) + } /* Ok, everything is just fine now */ + conf->kobj.parent = kobject_get(&mddev->kobj); + strcpy(conf->kobj.name, "raid5"); + conf->kobj.ktype = &raid5_ktype; + kobject_register(&conf->kobj); if (mddev->bitmap) mddev->thread->timeout = mddev->bitmap->daemon_sleep * HZ; @@ -1879,7 +1998,7 @@ abort: -static int stop (mddev_t *mddev) +static int stop(mddev_t *mddev) { raid5_conf_t *conf = (raid5_conf_t *) mddev->private; @@ -1888,7 +2007,7 @@ static int stop (mddev_t *mddev) shrink_stripes(conf); free_pages((unsigned long) conf->stripe_hashtbl, HASH_PAGES_ORDER); blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ - kfree(conf); + kobject_unregister(&conf->kobj); mddev->private = NULL; return 0; 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