rbd: refactor rbd_wait_state_locked()

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

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
This commit is contained in:
Ilya Dryomov 2018-04-04 10:15:38 +02:00
parent 60cc43fc88
commit 2f18d46683

View file

@ -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)
@ -3638,19 +3654,10 @@ 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);
@ -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;
}