Added new sysfs attribute to change write hint classification for parity
Signed-off-by: Mariusz Dabrowski <mariusz.dabrowski@xxxxxxxxx>
Reviewed-by: Artur Paszkiewicz <artur.paszkiewicz@xxxxxxxxx>
Reviewed-by: Pawel Baldysiak <pawel.baldysiak@xxxxxxxxx>
---
drivers/md/raid5.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
drivers/md/raid5.h | 5 +++++
2 files changed, 67 insertions(+)
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index bd99f1651b66..088b97bbcbe2 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -6631,6 +6631,67 @@ raid5_group_thread_cnt = __ATTR(group_thread_cnt, S_IRUGO | S_IWUSR,
raid5_show_group_thread_cnt,
raid5_store_group_thread_cnt);
+static ssize_t
+raid5_show_write_hint_policy(struct mddev *mddev, char *buf)
+{
+ char *sep = ",";
+ size_t len = 0;
+ unsigned long flags = 0;
+ struct r5conf *conf;
+
+ spin_lock(&mddev->lock);
+ conf = mddev->private;
+ if (conf) {
+ flags = conf->write_hint_flags;
+
+ if (!flags) {
+ len = sprintf(buf, "off");
+ } else {
+ if (test_bit(WH_POLICY_PARITY, &flags))
+ len += sprintf(buf+len, "parity%s", sep);
+ len -= strlen(sep);
+ }
+ }
+ spin_unlock(&mddev->lock);
+ len += sprintf(buf + len, "\n");
+
+ return len;
+}
+
+static ssize_t
+raid5_store_write_hint_policy(struct mddev *mddev, const char *page, size_t len)
+{
+ struct r5conf *conf;
+ int err = 0;
+
+ err = mddev_lock(mddev);
+ if (err)
+ return err;
+
+ conf = mddev->private;
+ if (!conf) {
+ err = -ENODEV;
+ } else {
+ if (strncmp(page, "parity", 6) == 0)
+ set_bit(WH_POLICY_PARITY, &conf->write_hint_flags);
+ else if (strncmp(page, "-parity", 7) == 0)
+ clear_bit(WH_POLICY_PARITY, &conf->write_hint_flags);
+ else if (strncmp(page, "off", 3) == 0)
+ conf->write_hint_flags = 0;
+ else
+ err = -EINVAL;
+ }
+
+ mddev_unlock(mddev);
+
+ return err ?: len;
+}
+
+static struct md_sysfs_entry
+raid5_write_hint_policy = __ATTR(write_hint_policy, S_IRUGO | S_IWUSR,
+ raid5_show_write_hint_policy,
+ raid5_store_write_hint_policy);
+
static struct attribute *raid5_attrs[] = {
&raid5_stripecache_size.attr,
&raid5_stripecache_active.attr,
@@ -6639,6 +6700,7 @@ static struct attribute *raid5_attrs[] = {
&raid5_skip_copy.attr,
&raid5_rmw_level.attr,
&r5c_journal_mode.attr,
+ &raid5_write_hint_policy.attr,
NULL,
};
static struct attribute_group raid5_attrs_group = {
diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
index 69686616d2ca..e08071dc4202 100644
--- a/drivers/md/raid5.h
+++ b/drivers/md/raid5.h
@@ -195,6 +195,10 @@ enum reconstruct_states {
reconstruct_state_result,
};
+enum write_hint_flags {
+ WH_POLICY_PARITY = 0,
+};
+
struct stripe_head {
struct hlist_node hash;
struct list_head lru; /* inactive_list or handle_list */
@@ -565,6 +569,7 @@ struct r5conf {
int raid_disks;
int max_nr_stripes;
int min_nr_stripes;
+ unsigned long write_hint_flags;
/* reshape_progress is the leading edge of a 'reshape'
* It has value MaxSector when no reshape is happening
--
2.16.1
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