Commit 2f18d466 authored by Ilya Dryomov's avatar Ilya Dryomov
Browse files

rbd: refactor rbd_wait_state_locked() 



In preparation for lock_timeout option, make rbd_wait_state_locked()
return error codes.

Signed-off-by: default avatarIlya Dryomov <idryomov@gmail.com>
parent 60cc43fc

drivers/block/rbd.c

+26 −17
Original line number Diff line number Diff line
@@ -3533,9 +3533,21 @@ static int rbd_obj_method_sync(struct rbd_device *rbd_dev, 
/*

 * lock_rwsem must be held for read

 */

static void rbd_wait_state_locked(struct rbd_device *rbd_dev)

static int rbd_wait_state_locked(struct rbd_device *rbd_dev, bool may_acquire)

{

	DEFINE_WAIT(wait);

	int ret = 0;



	if (test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags))

		return -EBLACKLISTED;



	if (rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED)

		return 0;



	if (!may_acquire) {

		rbd_warn(rbd_dev, "exclusive lock required");

		return -EROFS;

	}



	do {

		/*
@@ -3549,10 +3561,14 @@ static void rbd_wait_state_locked(struct rbd_device *rbd_dev) 
		up_read(&rbd_dev->lock_rwsem);

		schedule();

		down_read(&rbd_dev->lock_rwsem);

	} while (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED &&

		 !test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags));

		if (test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags)) {

			ret = -EBLACKLISTED;

			break;

		}

	} while (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED);



	finish_wait(&rbd_dev->lock_waitq, &wait);

	return ret;

}



static void rbd_queue_workfn(struct work_struct *work)
@@ -3638,20 +3654,11 @@ static void rbd_queue_workfn(struct work_struct *work) 
	    (op_type != OBJ_OP_READ || rbd_dev->opts->lock_on_read);

	if (must_be_locked) {

		down_read(&rbd_dev->lock_rwsem);

		if (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED &&

		    !test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags)) {

			if (rbd_dev->opts->exclusive) {

				rbd_warn(rbd_dev, "exclusive lock required");

				result = -EROFS;

				goto err_unlock;

			}

			rbd_wait_state_locked(rbd_dev);

		}

		if (test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags)) {

			result = -EBLACKLISTED;

		result = rbd_wait_state_locked(rbd_dev,

					       !rbd_dev->opts->exclusive);

		if (result)

			goto err_unlock;

	}

	}



	img_request = rbd_img_request_create(rbd_dev, op_type, snapc);

	if (!img_request) {
@@ -5216,6 +5223,8 @@ static void rbd_dev_image_unlock(struct rbd_device *rbd_dev) 


static int rbd_add_acquire_lock(struct rbd_device *rbd_dev)

{

	int ret;



	if (!(rbd_dev->header.features & RBD_FEATURE_EXCLUSIVE_LOCK)) {

		rbd_warn(rbd_dev, "exclusive-lock feature is not enabled");

		return -EINVAL;
@@ -5223,9 +5232,9 @@ static int rbd_add_acquire_lock(struct rbd_device *rbd_dev) 


	/* FIXME: "rbd map --exclusive" should be in interruptible */

	down_read(&rbd_dev->lock_rwsem);

	rbd_wait_state_locked(rbd_dev);

	ret = rbd_wait_state_locked(rbd_dev, true);

	up_read(&rbd_dev->lock_rwsem);

	if (test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags)) {

	if (ret) {

		rbd_warn(rbd_dev, "failed to acquire exclusive lock");

		return -EROFS;

	}