Commit b03e0ccb authored by NeilBrown's avatar NeilBrown Committed by Shaohua Li
Browse files

md: remove special meaning of ->quiesce(.., 2) 



The '2' argument means "wake up anything that is waiting".
This is an inelegant part of the design and was added
to help support management of suspend_lo/suspend_hi setting.
Now that suspend_lo/hi is managed in mddev_suspend/resume,
that need is gone.
These is still a couple of places where we call 'quiesce'
with an argument of '2', but they can safely be changed to
call ->quiesce(.., 1); ->quiesce(.., 0) which
achieve the same result at the small cost of pausing IO
briefly.

This removes a small "optimization" from suspend_{hi,lo}_store,
but it isn't clear that optimization served a useful purpose.
The code now is a lot clearer.

Suggested-by: default avatarShaohua Li <shli@kernel.org>
Signed-off-by: default avatarNeilBrown <neilb@suse.com>
Signed-off-by: default avatarShaohua Li <shli@fb.com>
parent 35bfc521

drivers/md/md-cluster.c

+3 −3
Original line number Diff line number Diff line
@@ -442,10 +442,11 @@ static void __remove_suspend_info(struct md_cluster_info *cinfo, int slot) 
static void remove_suspend_info(struct mddev *mddev, int slot)

{

	struct md_cluster_info *cinfo = mddev->cluster_info;

	mddev->pers->quiesce(mddev, 1);

	spin_lock_irq(&cinfo->suspend_lock);

	__remove_suspend_info(cinfo, slot);

	spin_unlock_irq(&cinfo->suspend_lock);

	mddev->pers->quiesce(mddev, 2);

	mddev->pers->quiesce(mddev, 0);

}
@@ -492,13 +493,12 @@ static void process_suspend_info(struct mddev *mddev, 
	s->lo = lo;

	s->hi = hi;

	mddev->pers->quiesce(mddev, 1);

	mddev->pers->quiesce(mddev, 0);

	spin_lock_irq(&cinfo->suspend_lock);

	/* Remove existing entry (if exists) before adding */

	__remove_suspend_info(cinfo, slot);

	list_add(&s->list, &cinfo->suspend_list);

	spin_unlock_irq(&cinfo->suspend_lock);

	mddev->pers->quiesce(mddev, 2);

	mddev->pers->quiesce(mddev, 0);

}



static void process_add_new_disk(struct mddev *mddev, struct cluster_msg *cmsg)

drivers/md/md.c

+10 −24
Original line number Diff line number Diff line
@@ -4846,7 +4846,7 @@ suspend_lo_show(struct mddev *mddev, char *page) 
static ssize_t

suspend_lo_store(struct mddev *mddev, const char *buf, size_t len)

{

	unsigned long long old, new;

	unsigned long long new;

	int err;



	err = kstrtoull(buf, 10, &new);
@@ -4862,17 +4862,10 @@ suspend_lo_store(struct mddev *mddev, const char *buf, size_t len) 
	if (mddev->pers == NULL ||

	    mddev->pers->quiesce == NULL)

		goto unlock;

	old = mddev->suspend_lo;

	mddev->suspend_lo = new;

	if (new >= old) {

		/* Shrinking suspended region */

		wake_up(&mddev->sb_wait);

		mddev->pers->quiesce(mddev, 2);

	} else {

		/* Expanding suspended region - need to wait */

	mddev_suspend(mddev);

	mddev->suspend_lo = new;

	mddev_resume(mddev);

	}



	err = 0;

unlock:

	mddev_unlock(mddev);
@@ -4890,7 +4883,7 @@ suspend_hi_show(struct mddev *mddev, char *page) 
static ssize_t

suspend_hi_store(struct mddev *mddev, const char *buf, size_t len)

{

	unsigned long long old, new;

	unsigned long long new;

	int err;



	err = kstrtoull(buf, 10, &new);
@@ -4903,20 +4896,13 @@ suspend_hi_store(struct mddev *mddev, const char *buf, size_t len) 
	if (err)

		return err;

	err = -EINVAL;

	if (mddev->pers == NULL ||

	    mddev->pers->quiesce == NULL)

	if (mddev->pers == NULL)

		goto unlock;

	old = mddev->suspend_hi;

	mddev->suspend_hi = new;

	if (new <= old) {

		/* Shrinking suspended region */

		wake_up(&mddev->sb_wait);

		mddev->pers->quiesce(mddev, 2);

	} else {

		/* Expanding suspended region - need to wait */



	mddev_suspend(mddev);

	mddev->suspend_hi = new;

	mddev_resume(mddev);

	}



	err = 0;

unlock:

	mddev_unlock(mddev);

drivers/md/md.h

+4 −5
Original line number Diff line number Diff line
@@ -544,12 +544,11 @@ struct md_personality 
	int (*check_reshape) (struct mddev *mddev);

	int (*start_reshape) (struct mddev *mddev);

	void (*finish_reshape) (struct mddev *mddev);

	/* quiesce moves between quiescence states

	 * 0 - fully active

	 * 1 - no new requests allowed

	 * others - reserved

	/* quiesce suspends or resumes internal processing.

	 * 1 - stop new actions and wait for action io to complete

	 * 0 - return to normal behaviour

	 */

	void (*quiesce) (struct mddev *mddev, int state);

	void (*quiesce) (struct mddev *mddev, int quiesce);

	/* takeover is used to transition an array from one

	 * personality to another.  The new personality must be able

	 * to handle the data in the current layout.

drivers/md/raid0.c

+1 −1
Original line number Diff line number Diff line
@@ -768,7 +768,7 @@ static void *raid0_takeover(struct mddev *mddev) 
	return ERR_PTR(-EINVAL);

}



static void raid0_quiesce(struct mddev *mddev, int state)

static void raid0_quiesce(struct mddev *mddev, int quiesce)

{

}

drivers/md/raid1.c

+3 −10
Original line number Diff line number Diff line
@@ -3273,21 +3273,14 @@ static int raid1_reshape(struct mddev *mddev) 
	return 0;

}



static void raid1_quiesce(struct mddev *mddev, int state)

static void raid1_quiesce(struct mddev *mddev, int quiesce)

{

	struct r1conf *conf = mddev->private;



	switch(state) {

	case 2: /* wake for suspend */

		wake_up(&conf->wait_barrier);

		break;

	case 1:

	if (quiesce)

		freeze_array(conf, 0);

		break;

	case 0:

	else

		unfreeze_array(conf);

		break;

	}

}



static void *raid1_takeover(struct mddev *mddev)

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