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Message-Id: <20231110172834.3939490-7-yukuai1@huaweicloud.com>
Date: Sat, 11 Nov 2023 01:28:32 +0800
From: Yu Kuai <yukuai1@...weicloud.com>
To: song@...nel.org, xni@...hat.com, yukuai3@...wei.com, neilb@...e.de
Cc: linux-kernel@...r.kernel.org, linux-raid@...r.kernel.org,
yukuai1@...weicloud.com, yi.zhang@...wei.com, yangerkun@...wei.com
Subject: [PATCH -next 6/8] md: factor out a helper to stop sync_thread
From: Yu Kuai <yukuai3@...wei.com>
stop_sync_thread(), md_set_readonly() and do_md_stop() are trying to
stop sync_thread() the same way, hence factor out a helper to make code
cleaner, and also prepare to use the new helper to fix problems later.
Signed-off-by: Yu Kuai <yukuai3@...wei.com>
Signed-off-by: Yu Kuai <yukuai1@...weicloud.com>
---
drivers/md/md.c | 129 ++++++++++++++++++++++++++----------------------
1 file changed, 69 insertions(+), 60 deletions(-)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index c0f2bdafe46a..7252fae0c989 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -4848,29 +4848,46 @@ action_show(struct mddev *mddev, char *page)
return sprintf(page, "%s\n", type);
}
-static int stop_sync_thread(struct mddev *mddev)
+static bool sync_thread_stopped(struct mddev *mddev, int *seq_ptr)
{
- int ret = 0;
+ if (seq_ptr && *seq_ptr != atomic_read(&mddev->sync_seq))
+ return true;
- if (!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
- return 0;
+ return (!mddev->sync_thread &&
+ !test_bit(MD_RECOVERY_RUNNING, &mddev->recovery));
+}
- ret = mddev_lock(mddev);
- if (ret)
- return ret;
+/*
+ * stop_sync_thread() - stop running sync_thread.
+ * @mddev: the array that sync_thread belongs to.
+ * @freeze: set true to prevent new sync_thread to start.
+ * @interruptible: if set true, then user can interrupt while waiting for
+ * sync_thread to be done.
+ *
+ * Noted that this function must be called with 'reconfig_mutex' grabbed, and
+ * fter this function return, 'reconfig_mtuex' will be released.
+ */
+static int stop_sync_thread(struct mddev *mddev, bool freeze,
+ bool interruptible)
+ __releases(&mddev->reconfig_mutex)
+{
+ int *seq_ptr = NULL;
+ int sync_seq;
+ int ret = 0;
+
+ if (freeze) {
+ set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
+ } else {
+ clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
+ sync_seq = atomic_read(&mddev->sync_seq);
+ seq_ptr = &sync_seq;
+ }
- /*
- * Check again in case MD_RECOVERY_RUNNING is cleared before lock is
- * held.
- */
if (!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) {
mddev_unlock(mddev);
return 0;
}
- if (work_pending(&mddev->sync_work))
- flush_workqueue(md_misc_wq);
-
set_bit(MD_RECOVERY_INTR, &mddev->recovery);
/*
* Thread might be blocked waiting for metadata update which will now
@@ -4879,53 +4896,58 @@ static int stop_sync_thread(struct mddev *mddev)
md_wakeup_thread_directly(mddev->sync_thread);
mddev_unlock(mddev);
- return 0;
+ if (work_pending(&mddev->sync_work))
+ flush_work(&mddev->sync_work);
+
+ if (interruptible)
+ ret = wait_event_interruptible(resync_wait,
+ sync_thread_stopped(mddev, seq_ptr));
+ else
+ wait_event(resync_wait, sync_thread_stopped(mddev, seq_ptr));
+
+ return ret;
}
static int idle_sync_thread(struct mddev *mddev)
{
int ret;
- int sync_seq = atomic_read(&mddev->sync_seq);
bool flag;
ret = mutex_lock_interruptible(&mddev->sync_mutex);
if (ret)
return ret;
- flag = test_and_clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
- ret = stop_sync_thread(mddev);
+ flag = test_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
+ ret = mddev_lock(mddev);
if (ret)
- goto out;
+ goto unlock;
- ret = wait_event_interruptible(resync_wait,
- sync_seq != atomic_read(&mddev->sync_seq) ||
- !test_bit(MD_RECOVERY_RUNNING, &mddev->recovery));
-out:
+ ret = stop_sync_thread(mddev, false, true);
if (ret && flag)
set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
+unlock:
mutex_unlock(&mddev->sync_mutex);
return ret;
}
static int frozen_sync_thread(struct mddev *mddev)
{
- int ret = mutex_lock_interruptible(&mddev->sync_mutex);
+ int ret;
bool flag;
+ ret = mutex_lock_interruptible(&mddev->sync_mutex);
if (ret)
return ret;
- flag = test_and_set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
- ret = stop_sync_thread(mddev);
+ flag = test_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
+ ret = mddev_lock(mddev);
if (ret)
- goto out;
+ goto unlock;
- ret = wait_event_interruptible(resync_wait,
- mddev->sync_thread == NULL &&
- !test_bit(MD_RECOVERY_RUNNING, &mddev->recovery));
-out:
+ ret = stop_sync_thread(mddev, true, true);
if (ret && !flag)
clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
+unlock:
mutex_unlock(&mddev->sync_mutex);
return ret;
}
@@ -6397,22 +6419,10 @@ static int md_set_readonly(struct mddev *mddev, struct block_device *bdev)
if (mddev->external && test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags))
return -EBUSY;
- if (!test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)) {
+ if (!test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
did_freeze = 1;
- set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
- }
- if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
- set_bit(MD_RECOVERY_INTR, &mddev->recovery);
- /*
- * Thread might be blocked waiting for metadata update which will now
- * never happen
- */
- md_wakeup_thread_directly(mddev->sync_thread);
-
- mddev_unlock(mddev);
- wait_event(resync_wait, !test_bit(MD_RECOVERY_RUNNING,
- &mddev->recovery));
+ stop_sync_thread(mddev, true, false);
wait_event(mddev->sb_wait,
!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags));
mddev_lock_nointr(mddev);
@@ -6421,6 +6431,10 @@ static int md_set_readonly(struct mddev *mddev, struct block_device *bdev)
if ((mddev->pers && atomic_read(&mddev->openers) > !!bdev) ||
mddev->sync_thread ||
test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) {
+ /*
+ * This could happen if user change array state through
+ * ioctl/sysfs while reconfig_mutex is released.
+ */
pr_warn("md: %s still in use.\n",mdname(mddev));
err = -EBUSY;
goto out;
@@ -6457,30 +6471,25 @@ static int do_md_stop(struct mddev *mddev, int mode,
struct md_rdev *rdev;
int did_freeze = 0;
- if (!test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)) {
+ if (!test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
did_freeze = 1;
+
+ if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) {
+ stop_sync_thread(mddev, true, false);
+ mddev_lock_nointr(mddev);
+ } else {
set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
}
- if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
- set_bit(MD_RECOVERY_INTR, &mddev->recovery);
-
- /*
- * Thread might be blocked waiting for metadata update which will now
- * never happen
- */
- md_wakeup_thread_directly(mddev->sync_thread);
-
- mddev_unlock(mddev);
- wait_event(resync_wait, (mddev->sync_thread == NULL &&
- !test_bit(MD_RECOVERY_RUNNING,
- &mddev->recovery)));
- mddev_lock_nointr(mddev);
mutex_lock(&mddev->open_mutex);
if ((mddev->pers && atomic_read(&mddev->openers) > !!bdev) ||
mddev->sysfs_active ||
mddev->sync_thread ||
test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) {
+ /*
+ * This could happen if user change array state through
+ * ioctl/sysfs while reconfig_mutex is released.
+ */
pr_warn("md: %s still in use.\n",mdname(mddev));
mutex_unlock(&mddev->open_mutex);
if (did_freeze) {
--
2.39.2
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