[PATCH -next 20/29] md: use new apis to suspend array for adding/removing rdev from state_store()

From: Yu Kuai
Date: Thu Aug 03 2023 - 09:35:25 EST


From: Yu Kuai <yukuai3@xxxxxxxxxx>

User can write 'remove' and 're-add' to trigger array reconfiguration
through sysfs, suspend array in this case so that io won't concurrent
with array reconfiguration.

Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
---
drivers/md/md.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 66bb6a585291..4a522558a570 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2916,11 +2916,7 @@ static int add_bound_rdev(struct md_rdev *rdev)
*/
super_types[mddev->major_version].
validate_super(mddev, rdev);
- if (add_journal)
- mddev_suspend(mddev);
err = mddev->pers->hot_add_disk(mddev, rdev);
- if (add_journal)
- mddev_resume(mddev);
if (err) {
md_kick_rdev_from_array(rdev);
return err;
@@ -3687,6 +3683,7 @@ rdev_attr_store(struct kobject *kobj, struct attribute *attr,
struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
struct md_rdev *rdev = container_of(kobj, struct md_rdev, kobj);
struct kernfs_node *kn = NULL;
+ bool suspended = false;
ssize_t rv;
struct mddev *mddev = rdev->mddev;

@@ -3695,8 +3692,14 @@ rdev_attr_store(struct kobject *kobj, struct attribute *attr,
if (!capable(CAP_SYS_ADMIN))
return -EACCES;

- if (entry->store == state_store && cmd_match(page, "remove"))
- kn = sysfs_break_active_protection(kobj, attr);
+ if (entry->store == state_store) {
+ if (cmd_match(page, "remove"))
+ kn = sysfs_break_active_protection(kobj, attr);
+ if (cmd_match(page, "remove") || cmd_match(page, "re-add")) {
+ __mddev_suspend(mddev);
+ suspended = true;
+ }
+ }

rv = mddev ? mddev_lock(mddev) : -ENODEV;
if (!rv) {
@@ -3705,6 +3708,9 @@ rdev_attr_store(struct kobject *kobj, struct attribute *attr,
else
rv = entry->store(rdev, page, length);
mddev_unlock(mddev);
+
+ if (suspended)
+ __mddev_resume(mddev);
}

if (kn)
--
2.39.2