a reference to a by them not yet referenced cache was not correct.
They only incremented the reference count, but a vnode cache reference
includes also a vnode reference. In case of the page daemon this would
cause vnode references to be lost (causing bug #1465).
* The page daemon used an unsafe method to access a yet unreferenced
page cache. There was nothing that prevented the cache from being
deleted while the page daemon tried to get a reference. The
vm_page::cache field is now protected by the page cache table
spinlock, too, which the new function
vm_cache_acquire_page_cache_ref(), used by the page daemon, also
acquires while trying to get the reference.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@22208 a95241bf-73f2-0310-859d-f6bbb57e9c96
c8a342a476