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D45113.id138202.diff
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D45113.id138202.diff
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diff --git a/sys/vm/device_pager.c b/sys/vm/device_pager.c
--- a/sys/vm/device_pager.c
+++ b/sys/vm/device_pager.c
@@ -41,6 +41,7 @@
#include <sys/proc.h>
#include <sys/mutex.h>
#include <sys/mman.h>
+#include <sys/refcount.h>
#include <sys/rwlock.h>
#include <sys/sx.h>
#include <sys/user.h>
@@ -115,8 +116,15 @@
{
vm_object_t object;
+again:
mtx_lock(&dev_pager_mtx);
object = vm_pager_object_lookup(&dev_pager_object_list, handle);
+ if (object->un_pager.devp.dev == NULL) {
+ msleep(&object->un_pager.devp.dev, &dev_pager_mtx,
+ PVM | PDROP, "cdplkp", 0);
+ vm_object_deallocate(object);
+ goto again;
+ }
mtx_unlock(&dev_pager_mtx);
return (object);
}
@@ -154,8 +162,7 @@
pindex < OFF_TO_IDX(size))
return (NULL);
- if (ops->cdev_pg_ctor(handle, size, prot, foff, cred, &color) != 0)
- return (NULL);
+again:
mtx_lock(&dev_pager_mtx);
/*
@@ -171,15 +178,19 @@
*/
mtx_unlock(&dev_pager_mtx);
object1 = vm_object_allocate(tp, pindex);
- object1->flags |= OBJ_COLORED;
- object1->pg_color = color;
- object1->handle = handle;
- object1->un_pager.devp.ops = ops;
- object1->un_pager.devp.dev = handle;
- TAILQ_INIT(&object1->un_pager.devp.devp_pglist);
mtx_lock(&dev_pager_mtx);
object = vm_pager_object_lookup(&dev_pager_object_list, handle);
if (object != NULL) {
+ object1->type = OBJT_DEAD;
+ vm_object_deallocate(object1);
+ object1 = NULL;
+ if (object->un_pager.devp.dev == NULL) {
+ msleep(&object->un_pager.devp.dev,
+ &dev_pager_mtx, PVM | PDROP, "cdplkp", 0);
+ vm_object_deallocate(object);
+ goto again;
+ }
+
/*
* We raced with other thread while allocating object.
*/
@@ -193,27 +204,46 @@
} else {
object = object1;
object1 = NULL;
+ object->flags |= OBJ_COLORED;
object->handle = handle;
+ object->un_pager.devp.ops = ops;
+ TAILQ_INIT(&object->un_pager.devp.devp_pglist);
TAILQ_INSERT_TAIL(&dev_pager_object_list, object,
pager_object_list);
+ mtx_unlock(&dev_pager_mtx);
if (ops->cdev_pg_populate != NULL)
vm_object_set_flag(object, OBJ_POPULATE);
+ if (ops->cdev_pg_ctor(handle, size, prot, foff,
+ cred, &color) != 0) {
+ mtx_lock(&dev_pager_mtx);
+ TAILQ_REMOVE(&dev_pager_object_list, object,
+ pager_object_list);
+ wakeup(&object->un_pager.devp.dev);
+ mtx_unlock(&dev_pager_mtx);
+ vm_object_terminate(object);
+ object = NULL;
+ mtx_lock(&dev_pager_mtx);
+ } else {
+ mtx_lock(&dev_pager_mtx);
+ object->pg_color = color;
+ object->un_pager.devp.dev = handle;
+ wakeup(&object->un_pager.devp.dev);
+ }
}
} else {
+ if (object->un_pager.devp.dev == NULL) {
+ msleep(&object->un_pager.devp.dev,
+ &dev_pager_mtx, PVM | PDROP, "cdplkp", 0);
+ vm_object_deallocate(object);
+ goto again;
+ }
if (pindex > object->size)
object->size = pindex;
KASSERT(object->type == tp,
("Inconsistent device pager type %p %d", object, tp));
}
mtx_unlock(&dev_pager_mtx);
- if (object1 != NULL) {
- object1->handle = object1;
- mtx_lock(&dev_pager_mtx);
- TAILQ_INSERT_TAIL(&dev_pager_object_list, object1,
- pager_object_list);
- mtx_unlock(&dev_pager_mtx);
- vm_object_deallocate(object1);
- }
+ MPASS(object1 == NULL);
return (object);
}

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