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authorYufen Yu <yuyufen@huawei.com>2020-07-18 05:29:09 -0400
committerSong Liu <songliubraving@fb.com>2020-07-21 17:18:22 -0700
commit3b5408b98e4db62b322f8516a0d08f95f197c42f (patch)
tree30f49a337e78de8f331802cdbfe37eca4e92faa1 /drivers/md/raid5.c
parente236858243d7a8e0ac60972d2f9522146088a736 (diff)
downloadlinux-3b5408b98e4db62b322f8516a0d08f95f197c42f.tar.bz2
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: Yufen Yu <yuyufen@huawei.com> Signed-off-by: Song Liu <songliubraving@fb.com>
Diffstat (limited to 'drivers/md/raid5.c')
-rw-r--r--drivers/md/raid5.c72
1 files changed, 72 insertions, 0 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 60cfa397f2d6..40961dd1777b 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -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,