From 11d3a9f65018c9fb3d4f2032aec76af2ba98431c Mon Sep 17 00:00:00 2001
From: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Date: Mon, 23 Dec 2019 10:48:55 +0100
Subject: [PATCH] md: prepare for enable raid1 io serialization
Git-commit: 11d3a9f65018c9fb3d4f2032aec76af2ba98431c
Patch-mainline: v5.6-rc1
References: jsc#SLE-13984
1. The related resources (spin_lock, list and waitqueue) are needed for
address raid1 reorder overlap issue too, in this case, rdev is set to
NULL for mddev_create/destroy_serial_pool which implies all rdevs need
to handle these resources.
And also add "is_suspend" to mddev_destroy_serial_pool since it will
be called under suspended situation, which also makes both create and
destroy pool have same arguments.
2. Introduce rdevs_init_serial which is called if raid1 io serialization
is enabled since all rdevs need to init related stuffs.
3. rdev_init_serial and clear_bit(CollisionCheck, &rdev->flags) should
be called between suspend and resume.
No need to export mddev_create_serial_pool since it is only called in
md-mod module.
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 | 65 ++++++++++++++++++++++++++++++++++---------------
drivers/md/md.h | 2 +-
2 files changed, 46 insertions(+), 21 deletions(-)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 8f5def0cb60a..b9b041b7e196 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -127,9 +127,6 @@ static inline int speed_max(struct mddev *mddev)
static int rdev_init_serial(struct md_rdev *rdev)
{
- if (rdev->bdev->bd_queue->nr_hw_queues == 1)
- return 0;
-
spin_lock_init(&rdev->serial_list_lock);
INIT_LIST_HEAD(&rdev->serial_list);
init_waitqueue_head(&rdev->serial_io_wait);
@@ -138,17 +135,29 @@ static int rdev_init_serial(struct md_rdev *rdev)
return 1;
}
+static void rdevs_init_serial(struct mddev *mddev)
+{
+ struct md_rdev *rdev;
+
+ rdev_for_each(rdev, mddev) {
+ if (test_bit(CollisionCheck, &rdev->flags))
+ continue;
+ rdev_init_serial(rdev);
+ }
+}
+
/*
- * Create serial_info_pool if rdev is the first multi-queue device flaged
- * with writemostly, also write-behind mode is enabled.
+ * Create serial_info_pool for raid1 under conditions:
+ * 1. rdev is the first multi-queue device flaged with writemostly,
+ * also write-behind mode is enabled.
+ * 2. rdev is NULL, means want to enable serialization for all rdevs.
*/
void mddev_create_serial_pool(struct mddev *mddev, struct md_rdev *rdev,
- bool is_suspend)
+ bool is_suspend)
{
- if (mddev->bitmap_info.max_write_behind == 0)
- return;
-
- if (!test_bit(WriteMostly, &rdev->flags) || !rdev_init_serial(rdev))
+ if (rdev && (mddev->bitmap_info.max_write_behind == 0 ||
+ rdev->bdev->bd_queue->nr_hw_queues == 1 ||
+ !test_bit(WriteMostly, &rdev->flags)))
return;
if (mddev->serial_info_pool == NULL) {
@@ -156,6 +165,10 @@ void mddev_create_serial_pool(struct mddev *mddev, struct md_rdev *rdev,
if (!is_suspend)
mddev_suspend(mddev);
+ if (!rdev)
+ rdevs_init_serial(mddev);
+ else
+ rdev_init_serial(rdev);
noio_flag = memalloc_noio_save();
mddev->serial_info_pool =
mempool_create_kmalloc_pool(NR_SERIAL_INFOS,
@@ -167,15 +180,16 @@ void mddev_create_serial_pool(struct mddev *mddev, struct md_rdev *rdev,
mddev_resume(mddev);
}
}
-EXPORT_SYMBOL_GPL(mddev_create_serial_pool);
/*
* Destroy serial_info_pool if rdev is the last device flaged with
- * CollisionCheck.
+ * CollisionCheck, or rdev is NULL when we disable serialization
+ * for normal raid1.
*/
-static void mddev_destroy_serial_pool(struct mddev *mddev, struct md_rdev *rdev)
+static void mddev_destroy_serial_pool(struct mddev *mddev, struct md_rdev *rdev,
+ bool is_suspend)
{
- if (!test_and_clear_bit(CollisionCheck, &rdev->flags))
+ if (rdev && !test_bit(CollisionCheck, &rdev->flags))
return;
if (mddev->serial_info_pool) {
@@ -185,16 +199,27 @@ static void mddev_destroy_serial_pool(struct mddev *mddev, struct md_rdev *rdev)
/*
* Check if other rdevs need serial_info_pool.
*/
- rdev_for_each(temp, mddev)
+ if (!is_suspend)
+ mddev_suspend(mddev);
+ rdev_for_each(temp, mddev) {
+ if (!rdev) {
+ clear_bit(CollisionCheck, &temp->flags);
+ continue;
+ }
+
if (temp != rdev &&
test_bit(CollisionCheck, &temp->flags))
num++;
- if (!num) {
- mddev_suspend(rdev->mddev);
+ }
+
+ if (rdev)
+ clear_bit(CollisionCheck, &rdev->flags);
+ if (!rdev || !num) {
mempool_destroy(mddev->serial_info_pool);
mddev->serial_info_pool = NULL;
- mddev_resume(rdev->mddev);
}
+ if (!is_suspend)
+ mddev_resume(mddev);
}
}
@@ -2377,7 +2402,7 @@ static void unbind_rdev_from_array(struct md_rdev *rdev)
bd_unlink_disk_holder(rdev->bdev, rdev->mddev->gendisk);
list_del_rcu(&rdev->same_set);
pr_debug("md: unbind<%s>\n", bdevname(rdev->bdev,b));
- mddev_destroy_serial_pool(rdev->mddev, rdev);
+ mddev_destroy_serial_pool(rdev->mddev, rdev, false);
rdev->mddev = NULL;
sysfs_remove_link(&rdev->kobj, "block");
sysfs_put(rdev->sysfs_state);
@@ -2893,7 +2918,7 @@ state_store(struct md_rdev *rdev, const char *buf, size_t len)
mddev_create_serial_pool(rdev->mddev, rdev, false);
err = 0;
} else if (cmd_match(buf, "-writemostly")) {
- mddev_destroy_serial_pool(rdev->mddev, rdev);
+ mddev_destroy_serial_pool(rdev->mddev, rdev, false);
clear_bit(WriteMostly, &rdev->flags);
err = 0;
} else if (cmd_match(buf, "blocked")) {
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 7b811645cec7..de04a8d3a67a 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -738,7 +738,7 @@ extern void md_reload_sb(struct mddev *mddev, int raid_disk);
extern void md_update_sb(struct mddev *mddev, int force);
extern void md_kick_rdev_from_array(struct md_rdev * rdev);
extern void mddev_create_serial_pool(struct mddev *mddev, struct md_rdev *rdev,
- bool is_suspend);
+ bool is_suspend);
struct md_rdev *md_find_rdev_nr_rcu(struct mddev *mddev, int nr);
struct md_rdev *md_find_rdev_rcu(struct mddev *mddev, dev_t dev);
--
2.26.2