[haiku-commits] r34871 - haiku/trunk/src/system/kernel/fs
- From: ingo_weinhold@xxxxxx
- To: haiku-commits@xxxxxxxxxxxxx
- Date: Sun, 3 Jan 2010 14:54:23 +0100 (CET)
Author: bonefish
Date: 2010-01-03 14:54:22 +0100 (Sun, 03 Jan 2010)
New Revision: 34871
Changeset: http://dev.haiku-os.org/changeset/34871/haiku
Modified:
haiku/trunk/src/system/kernel/fs/vfs.cpp
Log:
* free_unused_vnodes(): Be a good citizen and use vnode_used() instead of
playing with the unused list manually. This also clears the vnode's unused
flag, which wasn't done before and would thus cause corruption of the
unused list a bit later.
* fs_unmount():
- Fixed an iteration bug I introduced previously. The iterator would be
advanced twice per iteration, leading to NULL pointer dereferencing
when the vnode count was odd and skipping the checks for every other
vnode.
- All vnodes are going to be freed, so vnode_to_be_freed() has to invoked
for every one of them. The code wasn't adjusted correctly when
introducing the hot vnodes handling.
* Adjusted/improved some comments.
Modified: haiku/trunk/src/system/kernel/fs/vfs.cpp
===================================================================
--- haiku/trunk/src/system/kernel/fs/vfs.cpp 2010-01-03 13:33:20 UTC (rev
34870)
+++ haiku/trunk/src/system/kernel/fs/vfs.cpp 2010-01-03 13:54:22 UTC (rev
34871)
@@ -1075,8 +1075,8 @@
In the second case the caller is responsible for dealing with the ref
count
0 -> 1 transition. That is 1. this function must not be invoked when the
- node is busy in the first place and 2. the node must possibly be removed
- from the unused node list and the unused node counter must be
incremented.
+ node is busy in the first place and 2. vnode_used() must be called for
the
+ node.
\param vnode the vnode.
*/
@@ -1295,18 +1295,22 @@
// lock the node
AutoLocker<Vnode> nodeLocker(vnode);
- // check whether the node is still unused
+ // Check whether the node is still unused -- since we only
append to the
+ // the tail of the unused queue, the vnode should still be at
its head.
+ // Alternatively we could check its ref count for 0 and its
busy flag,
+ // but if the node is no longer at the head of the queue, it
means it
+ // has been touched in the meantime, i.e. it is no longer the
least
+ // recently used unused vnode and we rather don't free it.
unusedVnodesLocker.Lock();
if (vnode != list_get_first_item(&sUnusedVnodeList))
continue;
-
- // remove it
- list_remove_head_item(&sUnusedVnodeList);
- sUnusedVnodes--;
unusedVnodesLocker.Unlock();
+ ASSERT(!vnode->IsBusy());
+
// grab a reference
inc_vnode_ref_count(vnode);
+ vnode_used(vnode);
// write back changes and free the node
nodeLocker.Unlock();
@@ -7236,8 +7240,6 @@
// make sure all of them are not busy or have refs on them
VnodeList::Iterator iterator = mount->vnodes.GetIterator();
while (struct vnode* vnode = iterator.Next()) {
- vnode = iterator.Next();
-
AutoLocker<Vnode> nodeLocker(vnode);
// The root vnode ref_count needs to be 1 here (the
mount has a
@@ -7290,18 +7292,13 @@
while (struct vnode* vnode = iterator.Next()) {
AutoLocker<Vnode> nodeLocker(vnode);
vnode->SetBusy(true);
-
- if (vnode->ref_count == 0) {
- // this vnode has been unused before
- vnode_used(vnode);
- }
+ vnode_to_be_freed(vnode);
}
// The ref_count of the root node is 1 at this point, see above why
this is
mount->root_vnode->Lock();
- MutexLocker unusedVnodesLocker(sUnusedVnodesLock);
mount->root_vnode->ref_count--;
- unusedVnodesLocker.Unlock();
+ vnode_to_be_freed(mount->root_vnode);
mount->root_vnode->Unlock();
vnodesReadLocker.Unlock();
Other related posts:
- » [haiku-commits] r34871 - haiku/trunk/src/system/kernel/fs - ingo_weinhold
