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- Finish vm object and page locking in vnode_pager_setsize().

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- Make some small style changes to vnode_pager_setsize(); most notably,
   move two comments to a more logical place.
This commit is contained in:
Alan Cox 2003-06-10 20:28:41 +00:00
parent cc264d0083
commit 2a8f9ab57f
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=116167
1 changed files with 21 additions and 26 deletions
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47
sys/vm/vnode_pager.c
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@ -292,32 +292,28 @@ vnode_pager_setsize(vp, nsize)
struct vnode *vp;
vm_ooffset_t nsize;
{
vm_object_t object;
vm_page_t m;
vm_pindex_t nobjsize;
vm_object_t object = vp->v_object;
GIANT_REQUIRED;
if (object == NULL)
if ((object = vp->v_object) == NULL)
return;
/*
* Hasn't changed size
*/
if (nsize == object->un_pager.vnp.vnp_size)
VM_OBJECT_LOCK(object);
if (nsize == object->un_pager.vnp.vnp_size) {
/*
* Hasn't changed size
*/
VM_OBJECT_UNLOCK(object);
return;
}
nobjsize = OFF_TO_IDX(nsize + PAGE_MASK);
/*
* File has shrunk. Toss any cached pages beyond the new EOF.
*/
if (nsize < object->un_pager.vnp.vnp_size) {
if (nobjsize < object->size) {
VM_OBJECT_LOCK(object);
/*
* File has shrunk. Toss any cached pages beyond the new EOF.
*/
if (nobjsize < object->size)
vm_object_page_remove(object, nobjsize, object->size,
FALSE);
VM_OBJECT_UNLOCK(object);
}
FALSE);
/*
* this gets rid of garbage at the end of a page that is now
* only partially backed by the vnode.
@ -326,11 +322,10 @@ vnode_pager_setsize(vp, nsize)
* completely invalid page and mark it partially valid
* it can screw up NFS reads, so we don't allow the case.
*/
if (nsize & PAGE_MASK) {
vm_page_t m;
m = vm_page_lookup(object, OFF_TO_IDX(nsize));
if (m && m->valid) {
if ((nsize & PAGE_MASK) &&
(m = vm_page_lookup(object, OFF_TO_IDX(nsize))) != NULL) {
vm_page_lock_queues();
if (m->valid) {
int base = (int)nsize & PAGE_MASK;
int size = PAGE_SIZE - base;
@ -340,7 +335,6 @@ vnode_pager_setsize(vp, nsize)
*/
pmap_zero_page_area(m, base, size);
vm_page_lock_queues();
/*
* XXX work around SMP data integrity race
* by unmapping the page from user processes.
@ -371,12 +365,13 @@ vnode_pager_setsize(vp, nsize)
vm_page_set_validclean(m, base, size);
if (m->dirty != 0)
m->dirty = VM_PAGE_BITS_ALL;
vm_page_unlock_queues();
}
vm_page_unlock_queues();
}
}
object->un_pager.vnp.vnp_size = nsize;
object->size = nobjsize;
VM_OBJECT_UNLOCK(object);
}
/*