Commit 39a1aa7f authored by Philipp Reisner's avatar Philipp Reisner
Browse files

drbd: Protect accesses to the uuid set with a spinlock 



There is at least the worker context, the receiver context, the context of
receiving netlink packts.

Signed-off-by: default avatarPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: default avatarLars Ellenberg <lars.ellenberg@linbit.com>
parent fef45d29

drivers/block/drbd/drbd_int.h

+3 −1
Original line number Diff line number Diff line
@@ -747,6 +747,7 @@ struct drbd_md { 
	u64 md_offset;		/* sector offset to 'super' block */



	u64 la_size_sect;	/* last agreed size, unit sectors */

	spinlock_t uuid_lock;

	u64 uuid[UI_SIZE];

	u64 device_uuid;

	u32 flags;
@@ -1119,8 +1120,9 @@ extern int drbd_md_read(struct drbd_conf *mdev, struct drbd_backing_dev *bdev); 
extern void drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local);

extern void _drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local);

extern void drbd_uuid_new_current(struct drbd_conf *mdev) __must_hold(local);

extern void _drbd_uuid_new_current(struct drbd_conf *mdev) __must_hold(local);

extern void drbd_uuid_set_bm(struct drbd_conf *mdev, u64 val) __must_hold(local);

extern void drbd_uuid_move_history(struct drbd_conf *mdev) __must_hold(local);

extern void __drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local);

extern void drbd_md_set_flag(struct drbd_conf *mdev, int flags) __must_hold(local);

extern void drbd_md_clear_flag(struct drbd_conf *mdev, int flags)__must_hold(local);

extern int drbd_md_test_flag(struct drbd_backing_dev *, int);

drivers/block/drbd/drbd_main.c

+27 −6
Original line number Diff line number Diff line
@@ -838,8 +838,10 @@ int _drbd_send_uuids(struct drbd_conf *mdev, u64 uuid_flags) 
		put_ldev(mdev);

		return -EIO;

	}

	spin_lock_irq(&mdev->ldev->md.uuid_lock);

	for (i = UI_CURRENT; i < UI_SIZE; i++)

		p->uuid[i] = mdev->ldev ? cpu_to_be64(mdev->ldev->md.uuid[i]) : 0;

	spin_unlock_irq(&mdev->ldev->md.uuid_lock);



	mdev->comm_bm_set = drbd_bm_total_weight(mdev);

	p->uuid[UI_SIZE] = cpu_to_be64(mdev->comm_bm_set);
@@ -3015,7 +3017,7 @@ void drbd_md_mark_dirty(struct drbd_conf *mdev) 
}

#endif



static void drbd_uuid_move_history(struct drbd_conf *mdev) __must_hold(local)

void drbd_uuid_move_history(struct drbd_conf *mdev) __must_hold(local)

{

	int i;
@@ -3023,7 +3025,7 @@ static void drbd_uuid_move_history(struct drbd_conf *mdev) __must_hold(local) 
		mdev->ldev->md.uuid[i+1] = mdev->ldev->md.uuid[i];

}



void _drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local)

void __drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local)

{

	if (idx == UI_CURRENT) {

		if (mdev->state.role == R_PRIMARY)
@@ -3038,14 +3040,24 @@ void _drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local) 
	drbd_md_mark_dirty(mdev);

}



void _drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local)

{

	unsigned long flags;

	spin_lock_irqsave(&mdev->ldev->md.uuid_lock, flags);

	__drbd_uuid_set(mdev, idx, val);

	spin_unlock_irqrestore(&mdev->ldev->md.uuid_lock, flags);

}



void drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local)

{

	unsigned long flags;

	spin_lock_irqsave(&mdev->ldev->md.uuid_lock, flags);

	if (mdev->ldev->md.uuid[idx]) {

		drbd_uuid_move_history(mdev);

		mdev->ldev->md.uuid[UI_HISTORY_START] = mdev->ldev->md.uuid[idx];

	}

	_drbd_uuid_set(mdev, idx, val);

	__drbd_uuid_set(mdev, idx, val);

	spin_unlock_irqrestore(&mdev->ldev->md.uuid_lock, flags);

}



/**
@@ -3058,15 +3070,20 @@ void drbd_uuid_set(struct drbd_conf *mdev, int idx, u64 val) __must_hold(local) 
void drbd_uuid_new_current(struct drbd_conf *mdev) __must_hold(local)

{

	u64 val;

	unsigned long long bm_uuid = mdev->ldev->md.uuid[UI_BITMAP];

	unsigned long long bm_uuid;



	get_random_bytes(&val, sizeof(u64));



	spin_lock_irq(&mdev->ldev->md.uuid_lock);

	bm_uuid = mdev->ldev->md.uuid[UI_BITMAP];



	if (bm_uuid)

		dev_warn(DEV, "bm UUID was already set: %llX\n", bm_uuid);



	mdev->ldev->md.uuid[UI_BITMAP] = mdev->ldev->md.uuid[UI_CURRENT];

	__drbd_uuid_set(mdev, UI_CURRENT, val);

	spin_unlock_irq(&mdev->ldev->md.uuid_lock);



	get_random_bytes(&val, sizeof(u64));

	_drbd_uuid_set(mdev, UI_CURRENT, val);

	drbd_print_uuids(mdev, "new current UUID");

	/* get it to stable storage _now_ */

	drbd_md_sync(mdev);
@@ -3074,9 +3091,11 @@ void drbd_uuid_new_current(struct drbd_conf *mdev) __must_hold(local) 


void drbd_uuid_set_bm(struct drbd_conf *mdev, u64 val) __must_hold(local)

{

	unsigned long flags;

	if (mdev->ldev->md.uuid[UI_BITMAP] == 0 && val == 0)

		return;



	spin_lock_irqsave(&mdev->ldev->md.uuid_lock, flags);

	if (val == 0) {

		drbd_uuid_move_history(mdev);

		mdev->ldev->md.uuid[UI_HISTORY_START] = mdev->ldev->md.uuid[UI_BITMAP];
@@ -3088,6 +3107,8 @@ void drbd_uuid_set_bm(struct drbd_conf *mdev, u64 val) __must_hold(local) 


		mdev->ldev->md.uuid[UI_BITMAP] = val & ~((u64)1);

	}

	spin_unlock_irqrestore(&mdev->ldev->md.uuid_lock, flags);



	drbd_md_mark_dirty(mdev);

}

drivers/block/drbd/drbd_nl.c

+11 −1
Original line number Diff line number Diff line
@@ -1320,6 +1320,8 @@ int drbd_adm_attach(struct sk_buff *skb, struct genl_info *info) 
		retcode = ERR_NOMEM;

		goto fail;

	}

	spin_lock_init(&nbc->md.uuid_lock);



	new_disk_conf = kzalloc(sizeof(struct disk_conf), GFP_KERNEL);

	if (!new_disk_conf) {

		retcode = ERR_NOMEM;
@@ -2679,8 +2681,16 @@ int nla_put_status_info(struct sk_buff *skb, struct drbd_conf *mdev, 
		goto nla_put_failure;



	if (got_ldev) {

		int err;



		spin_lock_irq(&mdev->ldev->md.uuid_lock);

		err = nla_put(skb, T_uuids, sizeof(si->uuids), mdev->ldev->md.uuid);

		spin_unlock_irq(&mdev->ldev->md.uuid_lock);



		if (err)

			goto nla_put_failure;



		if (nla_put_u32(skb, T_disk_flags, mdev->ldev->md.flags) ||

		    nla_put(skb, T_uuids, sizeof(si->uuids), mdev->ldev->md.uuid) ||

		    nla_put_u64(skb, T_bits_total, drbd_bm_bits(mdev)) ||

		    nla_put_u64(skb, T_bits_oos, drbd_bm_total_weight(mdev)))

			goto nla_put_failure;

drivers/block/drbd/drbd_receiver.c

+8 −3
Original line number Diff line number Diff line
@@ -2796,7 +2796,9 @@ static int drbd_uuid_compare(struct drbd_conf *mdev, int *rule_nr) __must_hold(l 
			if ((mdev->ldev->md.uuid[UI_BITMAP] & ~((u64)1)) == (mdev->p_uuid[UI_HISTORY_START] & ~((u64)1)) &&

			    (mdev->ldev->md.uuid[UI_HISTORY_START] & ~((u64)1)) == (mdev->p_uuid[UI_HISTORY_START + 1] & ~((u64)1))) {

				dev_info(DEV, "was SyncSource, missed the resync finished event, corrected myself:\n");

				drbd_uuid_set_bm(mdev, 0UL);

				drbd_uuid_move_history(mdev);

				mdev->ldev->md.uuid[UI_HISTORY_START] = mdev->ldev->md.uuid[UI_BITMAP];

				mdev->ldev->md.uuid[UI_BITMAP] = 0;



				drbd_uuid_dump(mdev, "self", mdev->ldev->md.uuid,

					       mdev->state.disk >= D_NEGOTIATING ? drbd_bm_total_weight(mdev) : 0, 0);
@@ -2904,8 +2906,8 @@ static int drbd_uuid_compare(struct drbd_conf *mdev, int *rule_nr) __must_hold(l 
			if (mdev->tconn->agreed_pro_version < 91)

				return -1091;



			_drbd_uuid_set(mdev, UI_BITMAP, mdev->ldev->md.uuid[UI_HISTORY_START]);

			_drbd_uuid_set(mdev, UI_HISTORY_START, mdev->ldev->md.uuid[UI_HISTORY_START + 1]);

			__drbd_uuid_set(mdev, UI_BITMAP, mdev->ldev->md.uuid[UI_HISTORY_START]);

			__drbd_uuid_set(mdev, UI_HISTORY_START, mdev->ldev->md.uuid[UI_HISTORY_START + 1]);



			dev_info(DEV, "Last syncUUID did not get through, corrected:\n");

			drbd_uuid_dump(mdev, "self", mdev->ldev->md.uuid,
@@ -2959,11 +2961,14 @@ static enum drbd_conns drbd_sync_handshake(struct drbd_conf *mdev, enum drbd_rol 
		mydisk = mdev->new_state_tmp.disk;



	dev_info(DEV, "drbd_sync_handshake:\n");



	spin_lock_irq(&mdev->ldev->md.uuid_lock);

	drbd_uuid_dump(mdev, "self", mdev->ldev->md.uuid, mdev->comm_bm_set, 0);

	drbd_uuid_dump(mdev, "peer", mdev->p_uuid,

		       mdev->p_uuid[UI_SIZE], mdev->p_uuid[UI_FLAGS]);



	hg = drbd_uuid_compare(mdev, &rule_nr);

	spin_unlock_irq(&mdev->ldev->md.uuid_lock);



	dev_info(DEV, "uuid_compare()=%d by rule %d\n", hg, rule_nr);