From 3938f5fb82aedbf39792ffee448c61c819e6ab38 Mon Sep 17 00:00:00 2001
From: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Date: Mon, 23 Dec 2019 10:48:56 +0100
Subject: [PATCH] md: add serialize_policy sysfs node for raid1
Git-commit: 3938f5fb82aedbf39792ffee448c61c819e6ab38
Patch-mainline: v5.6-rc1
References: jsc#SLE-13984
With the new sysfs node, we can use it to control if raid1 array
wants io serialization or not. So mddev_create_serial_pool and
mddev_destroy_serial_pool are called in serialize_policy_store
to enable or disable the serialization.
Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Coly Li <colyli@suse.de>
---
drivers/md/md.c | 52 +++++++++++++++++++++++++++++++++++++++++++++++++
drivers/md/md.h | 1 +
2 files changed, 53 insertions(+)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index b9b041b7e196..796cf70e1c9f 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -5304,6 +5304,57 @@ static struct md_sysfs_entry md_fail_last_dev =
__ATTR(fail_last_dev, S_IRUGO | S_IWUSR, fail_last_dev_show,
fail_last_dev_store);
+static ssize_t serialize_policy_show(struct mddev *mddev, char *page)
+{
+ if (mddev->pers == NULL || (mddev->pers->level != 1))
+ return sprintf(page, "n/a\n");
+ else
+ return sprintf(page, "%d\n", mddev->serialize_policy);
+}
+
+/*
+ * Setting serialize_policy to true to enforce write IO is not reordered
+ * for raid1.
+ */
+static ssize_t
+serialize_policy_store(struct mddev *mddev, const char *buf, size_t len)
+{
+ int err;
+ bool value;
+
+ err = kstrtobool(buf, &value);
+ if (err)
+ return err;
+
+ if (value == mddev->serialize_policy)
+ return len;
+
+ err = mddev_lock(mddev);
+ if (err)
+ return err;
+ if (mddev->pers == NULL || (mddev->pers->level != 1)) {
+ pr_err("md: serialize_policy is only effective for raid1\n");
+ err = -EINVAL;
+ goto unlock;
+ }
+
+ mddev_suspend(mddev);
+ if (value)
+ mddev_create_serial_pool(mddev, NULL, true);
+ else
+ mddev_destroy_serial_pool(mddev, NULL, true);
+ mddev->serialize_policy = value;
+ mddev_resume(mddev);
+unlock:
+ mddev_unlock(mddev);
+ return err ?: len;
+}
+
+static struct md_sysfs_entry md_serialize_policy =
+__ATTR(serialize_policy, S_IRUGO | S_IWUSR, serialize_policy_show,
+ serialize_policy_store);
+
+
static struct attribute *md_default_attrs[] = {
&md_level.attr,
&md_layout.attr,
@@ -5321,6 +5372,7 @@ static struct attribute *md_default_attrs[] = {
&max_corr_read_errors.attr,
&md_consistency_policy.attr,
&md_fail_last_dev.attr,
+ &md_serialize_policy.attr,
NULL,
};
diff --git a/drivers/md/md.h b/drivers/md/md.h
index de04a8d3a67a..f51a3afaee1b 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -494,6 +494,7 @@ struct mddev {
bool has_superblocks:1;
bool fail_last_dev:1;
+ bool serialize_policy:1;
};
enum recovery_flags {
--
2.26.2