Commit 3b5408b9 authored by Yufen Yu's avatar Yufen Yu Committed by Song Liu

md/raid5: support config stripe_size by sysfs entry

Adding a new 'stripe_size' sysfs entry to set and show stripe_size.
stripe_size should not be bigger than PAGE_SIZE, and it requires to
be multiple of 4096. We can adjust stripe_size by writing value into
sysfs entry, likely, set stripe_size as 16KB:

          echo 16384 > /sys/block/md1/md/stripe_size

Show current stripe_size value:

          cat /sys/block/md1/md/stripe_size

For PAGE_SIZE is equal to 4096, 'stripe_size' can just be read.
Signed-off-by: default avatarYufen Yu <yuyufen@huawei.com>
Signed-off-by: default avatarSong Liu <songliubraving@fb.com>
parent e2368582
......@@ -6503,6 +6503,77 @@ raid5_rmw_level = __ATTR(rmw_level, S_IRUGO | S_IWUSR,
raid5_show_rmw_level,
raid5_store_rmw_level);
static ssize_t
raid5_show_stripe_size(struct mddev *mddev, char *page)
{
struct r5conf *conf;
int ret = 0;
spin_lock(&mddev->lock);
conf = mddev->private;
if (conf)
ret = sprintf(page, "%lu\n", RAID5_STRIPE_SIZE(conf));
spin_unlock(&mddev->lock);
return ret;
}
#if PAGE_SIZE != DEFAULT_STRIPE_SIZE
static ssize_t
raid5_store_stripe_size(struct mddev *mddev, const char *page, size_t len)
{
struct r5conf *conf;
unsigned long new;
int err;
if (len >= PAGE_SIZE)
return -EINVAL;
if (kstrtoul(page, 10, &new))
return -EINVAL;
/*
* The value should not be bigger than PAGE_SIZE. It requires to
* be multiple of DEFAULT_STRIPE_SIZE.
*/
if (new % DEFAULT_STRIPE_SIZE != 0 || new > PAGE_SIZE || new == 0)
return -EINVAL;
err = mddev_lock(mddev);
if (err)
return err;
conf = mddev->private;
if (!conf) {
err = -ENODEV;
goto out_unlock;
}
if (new == conf->stripe_size)
goto out_unlock;
pr_debug("md/raid: change stripe_size from %lu to %lu\n",
conf->stripe_size, new);
mddev_suspend(mddev);
conf->stripe_size = new;
conf->stripe_shift = ilog2(new) - 9;
conf->stripe_sectors = new >> 9;
mddev_resume(mddev);
out_unlock:
mddev_unlock(mddev);
return err ?: len;
}
static struct md_sysfs_entry
raid5_stripe_size = __ATTR(stripe_size, 0644,
raid5_show_stripe_size,
raid5_store_stripe_size);
#else
static struct md_sysfs_entry
raid5_stripe_size = __ATTR(stripe_size, 0444,
raid5_show_stripe_size,
NULL);
#endif
static ssize_t
raid5_show_preread_threshold(struct mddev *mddev, char *page)
......@@ -6691,6 +6762,7 @@ static struct attribute *raid5_attrs[] = {
&raid5_group_thread_cnt.attr,
&raid5_skip_copy.attr,
&raid5_rmw_level.attr,
&raid5_stripe_size.attr,
&r5c_journal_mode.attr,
&ppl_write_hint.attr,
NULL,
......
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