/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 <neilb@xxxxxxx>
### Diffstat output
./drivers/md/raid5.c | 183 +++++++++++++++++++++++++++++++++++--------
./include/linux/raid/raid5.h | 1
2 files changed, 152 insertions(+), 32 deletions(-)
diff ./drivers/md/raid5.c~current~ ./drivers/md/raid5.c
--- ./drivers/md/raid5.c~current~ 2005-10-04 13:08:41.000000000 +1000
+++ ./drivers/md/raid5.c 2005-10-04 13:08:44.000000000 +1000
@@ -293,9 +293,31 @@ static struct stripe_head *get_active_st
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 *co
return 1;
conf->slab_cache = sc;
while (num--) {
- sh = kmem_cache_alloc(sc, GFP_KERNEL);
- if (!sh)
+ 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 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;
}
@@ -1718,6 +1731,108 @@ 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;
@@ -1859,6 +1974,10 @@ memory = conf->max_nr_stripes * (sizeof(
}
/* 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;
@@ -1883,7 +2002,7 @@ abort:
-static int stop (mddev_t *mddev)
+static int stop(mddev_t *mddev)
{
raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
@@ -1892,7 +2011,7 @@ 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;
}
diff ./include/linux/raid/raid5.h~current~ ./include/linux/raid/raid5.h
--- ./include/linux/raid/raid5.h~current~ 2005-10-04 13:08:41.000000000 +1000
+++ ./include/linux/raid/raid5.h 2005-10-04 12:57:00.000000000 +1000
@@ -228,6 +228,7 @@ struct raid5_private_data {
* Cleared when a sync completes.
*/
+ struct kobject kobj;
/*
* Free stripes pool
*/
-
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