nfs4: Remove CacheRevalidator

There is no point in periodically revalidating all existing directory caches.
Directory snapshot can be revalidated when readdir is invoked.

src/add-ons/kernel/file_systems/nfs4/CacheRevalidator.cpp

@@ -1,122 +0,0 @@
-/*
- * Copyright 2012 Haiku, Inc. All rights reserved.
- * Distributed under the terms of the MIT License.
- *
- * Authors:
- *		Paweł Dziepak, [email protected]
- */
-
-
-#include "CacheRevalidator.h"
-
-#include <fs_cache.h>
-
-#include "NFS4Defs.h"
-
-
-CacheRevalidator::CacheRevalidator()
-	:
-	fThreadCancel(false),
-	fWaitCancel(create_sem(0, NULL))
-{
-	mutex_init(&fDirectoryCachesLock, NULL);
-
-	_StartRevalidator();
-}
-
-
-CacheRevalidator::~CacheRevalidator()
-{
-	fThreadCancel = true;
-	release_sem(fWaitCancel);
-	status_t result;
-	wait_for_thread(fThread, &result);
-
-	delete_sem(fThreadCancel);
-	mutex_destroy(&fDirectoryCachesLock);
-}
-
-
-status_t
-CacheRevalidator::_StartRevalidator()
-{
-	fThreadCancel = false;
-	fThread = spawn_kernel_thread(&CacheRevalidator::_DirectoryRevalidatorStart,
-		"NFSv4 Cache Revalidator", B_NORMAL_PRIORITY, this);
-	if (fThread < B_OK)
-		return fThread;
-
-	status_t result = resume_thread(fThread);
-	if (result != B_OK) {
-		kill_thread(fThread);
-		return result;
-	}
-
-	return B_OK;
-}
-
-
-status_t
-CacheRevalidator::_DirectoryRevalidatorStart(void* object)
-{
-	ASSERT(object != NULL);
-
-	CacheRevalidator* revalidator = reinterpret_cast<CacheRevalidator*>(object);
-	revalidator->_DirectoryCacheRevalidator();
-	return B_OK;
-}
-
-
-void
-CacheRevalidator::_DirectoryCacheRevalidator()
-{
-	while (!fThreadCancel) {
-		MutexLocker locker(fDirectoryCachesLock);
-		DirectoryCache* current = fDirectoryCaches.Head();
-
-		if (current == NULL) {
-			locker.Unlock();
-
-			status_t result = acquire_sem_etc(fWaitCancel, 1,
-				B_RELATIVE_TIMEOUT,	DirectoryCache::kExpirationTime);
-
-			if (result != B_TIMED_OUT) {
-				if (result == B_OK)
-					release_sem(fWaitCancel);
-				return;
-			}
-			continue;
-		}
-
-		current->Lock();
-		if (!current->Valid()) {
-			RemoveDirectory(current);
-			current->Unlock();
-			continue;
-		}
-
-		if (current->ExpireTime() > system_time()) {
-			current->Unlock();
-			locker.Unlock();
-
-			status_t result = acquire_sem_etc(fWaitCancel, 1,
-				B_ABSOLUTE_TIMEOUT, current->ExpireTime());
-			if (result != B_TIMED_OUT) {
-				if (result == B_OK)
-					release_sem(fWaitCancel);
-				return;
-			}
-
-			continue;
-		}
-
-		fDirectoryCaches.RemoveHead();
-		current->fRevalidated = false;
-
-		if (current->Revalidate() == B_OK)
-			AddDirectory(current);
-
-		current->Unlock();
-	}
-}
-

src/add-ons/kernel/file_systems/nfs4/CacheRevalidator.h

@@ -1,83 +0,0 @@
-/*
- * Copyright 2012 Haiku, Inc. All rights reserved.
- * Distributed under the terms of the MIT License.
- *
- * Authors:
- *		Paweł Dziepak, [email protected]
- */
-#ifndef CACHEREVALIDATOR_H
-#define CACHEREVALIDATOR_H
-
-
-#include <lock.h>
-#include <util/AutoLock.h>
-#include <util/DoublyLinkedList.h>
-
-#include "DirectoryCache.h"
-
-
-class CacheRevalidator {
-public:
-							CacheRevalidator();
-							~CacheRevalidator();
-
-	inline	void			Lock();
-	inline	void			Unlock();
-
-
-	inline	void			AddDirectory(DirectoryCache* cache);
-	inline	void			RemoveDirectory(DirectoryCache* cache);
-
-private:
-			void			_DirectoryCacheRevalidator();
-	static	status_t		_DirectoryRevalidatorStart(void* object);
-			status_t		_StartRevalidator();
-
-			thread_id		fThread;
-			bool			fThreadCancel;
-			sem_id			fWaitCancel;
-
-			DoublyLinkedList<DirectoryCache>	fDirectoryCaches;
-			mutex			fDirectoryCachesLock;
-};
-
-
-inline void
-CacheRevalidator::Lock()
-{
-	mutex_lock(&fDirectoryCachesLock);
-}
-
-
-inline void
-CacheRevalidator::Unlock()
-{
-	mutex_unlock(&fDirectoryCachesLock);
-}
-
-
-inline void
-CacheRevalidator::AddDirectory(DirectoryCache* cache)
-{
-	ASSERT(cache != NULL);
-
-	if (!cache->fRevalidated) {
-		cache->fRevalidated = true;
-		fDirectoryCaches.InsertAfter(fDirectoryCaches.Tail(), cache);
-	}
-}
-
-
-inline void
-CacheRevalidator::RemoveDirectory(DirectoryCache* cache)
-{
-	ASSERT(cache != NULL);
-
-	if (cache->fRevalidated == true)
-		fDirectoryCaches.Remove(cache);
-	cache->fRevalidated = false;
-}
-
-
-#endif	// CACHEREVALIDATOR_H
-

src/add-ons/kernel/file_systems/nfs4/Cookie.h

@@ -11,6 +11,7 @@
 
 #include <SupportDefs.h>
 
+#include "DirectoryCache.h"
 #include "FileSystem.h"
 
 

src/add-ons/kernel/file_systems/nfs4/DirectoryCache.cpp

@@ -92,10 +92,6 @@ DirectoryCache::DirectoryCache(Inode* inode, bool attr)
 
 DirectoryCache::~DirectoryCache()
 {
-	fInode->GetFileSystem()->Revalidator().Lock();
-	fInode->GetFileSystem()->Revalidator().RemoveDirectory(this);
-	fInode->GetFileSystem()->Revalidator().Unlock();
-
 	mutex_destroy(&fLock);
 }
 
@@ -119,7 +115,7 @@ DirectoryCache::Trash()
 		delete current;
 	}
 
-	SetSnapshot(NULL);
+	_SetSnapshot(NULL);
 
 	fTrashed = true;
 }
@@ -207,7 +203,7 @@ DirectoryCache::RemoveEntry(const char* name)
 
 
 void
-DirectoryCache::SetSnapshot(DirectoryCacheSnapshot* snapshot)
+DirectoryCache::_SetSnapshot(DirectoryCacheSnapshot* snapshot)
 {
 	if (fDirectoryCache != NULL)
 		fDirectoryCache->ReleaseReference();
@@ -215,9 +211,48 @@ DirectoryCache::SetSnapshot(DirectoryCacheSnapshot* snapshot)
 }
 
 
+status_t
+DirectoryCache::_LoadSnapshot(bool trash)
+{
+	DirectoryCacheSnapshot* oldSnapshot = fDirectoryCache;
+	if (oldSnapshot != NULL)
+		oldSnapshot->AcquireReference();
+
+	if (trash)
+		Trash();
+
+	DirectoryCacheSnapshot* newSnapshot;
+	status_t result = fInode->GetDirSnapshot(&newSnapshot, NULL, &fChange,
+		fAttrDir);
+	if (result != B_OK) {
+		if (oldSnapshot != NULL)
+			oldSnapshot->ReleaseReference();
+		return result;
+	}
+	newSnapshot->AcquireReference();
+
+	_SetSnapshot(newSnapshot);
+	fExpireTime = system_time() + kExpirationTime;
+
+	fTrashed = false;
+
+	if (oldSnapshot != NULL)
+		NotifyChanges(oldSnapshot, newSnapshot);
+
+	if (oldSnapshot != NULL)
+		oldSnapshot->ReleaseReference();
+
+	newSnapshot->ReleaseReference();
+	return B_OK;
+}
+
+
 status_t
 DirectoryCache::Revalidate()
 {
+	if (fExpireTime < system_time())
+		return B_OK;
+
 	uint64 change;
 	if (fInode->GetChangeInfo(&change, fAttrDir) != B_OK) {
 		Trash();
@@ -229,34 +264,7 @@ DirectoryCache::Revalidate()
 		return B_OK;
 	}
 
-	DirectoryCacheSnapshot* oldSnapshot = fDirectoryCache;
-	if (oldSnapshot == NULL) {
-		Trash();
-		return B_ERROR;
-	}
-
-	oldSnapshot->AcquireReference();
-
-	Trash();
-
-	DirectoryCacheSnapshot* newSnapshot;
-	status_t result = fInode->GetDirSnapshot(&newSnapshot, NULL, &fChange,
-		fAttrDir);
-	if (result != B_OK) {
-		oldSnapshot->ReleaseReference();
-		return B_ERROR;
-	}
-	newSnapshot->AcquireReference();
-
-	SetSnapshot(newSnapshot);
-	fExpireTime = system_time() + kExpirationTime;
-	fTrashed = false;
-
-	NotifyChanges(oldSnapshot, newSnapshot);
-	oldSnapshot->ReleaseReference();
-	newSnapshot->ReleaseReference();
-
-	return B_OK;
+	return _LoadSnapshot(true);
 }
 
 

src/add-ons/kernel/file_systems/nfs4/DirectoryCache.h

@@ -38,7 +38,7 @@ struct DirectoryCacheSnapshot : public KernelReferenceable {
 							~DirectoryCacheSnapshot();
 };
 
-class DirectoryCache : public DoublyLinkedListLinkImpl<DirectoryCache> {
+class DirectoryCache {
 public:
 							DirectoryCache(Inode* inode, bool attr = false);
 							~DirectoryCache();
@@ -54,7 +54,6 @@ public:
 								bool created = false);
 			void			RemoveEntry(const char* name);
 
-			void			SetSnapshot(DirectoryCacheSnapshot* snapshot);
 	inline	DirectoryCacheSnapshot* GetSnapshot();
 
 	inline	SinglyLinkedList<NameCacheEntry>&	EntriesList();
@@ -66,7 +65,6 @@ public:
 	inline	uint64			ChangeInfo();
 
 	inline	Inode*			GetInode();
-	inline	time_t			ExpireTime();
 
 	static	const bigtime_t	kExpirationTime		= 15000000;
 
@@ -76,6 +74,9 @@ protected:
 								DirectoryCacheSnapshot* newSnapshot);
 
 private:
+			void			_SetSnapshot(DirectoryCacheSnapshot* snapshot);
+			status_t		_LoadSnapshot(bool trash);
+
 			SinglyLinkedList<NameCacheEntry>	fNameCache;
 
 			DirectoryCacheSnapshot*	fDirectoryCache;
@@ -115,6 +116,8 @@ DirectoryCache::Valid()
 inline DirectoryCacheSnapshot*
 DirectoryCache::GetSnapshot()
 {
+	if (fDirectoryCache == NULL)
+		_LoadSnapshot(false);
 	return fDirectoryCache;
 }
 
@@ -164,12 +167,5 @@ DirectoryCache::GetInode()
 }
 
 
-inline time_t
-DirectoryCache::ExpireTime()
-{
-	return fExpireTime;
-}
-
-
 #endif	// DIRECTORYCACHE_H
 			

src/add-ons/kernel/file_systems/nfs4/FileSystem.h

@@ -9,7 +9,6 @@
 #define FILESYSTEM_H
 
 
-#include "CacheRevalidator.h"
 #include "Delegation.h"
 #include "InodeIdMap.h"
 #include "NFS4Defs.h"
@@ -51,8 +50,6 @@ public:
 			void				RemoveDelegation(Delegation* delegation);
 			Delegation*			GetDelegation(const FileHandle& handle);
 
-	inline	CacheRevalidator&	Revalidator();
-
 	inline	bool				IsAttrSupported(Attribute attr) const;
 	inline	uint32				ExpireType() const;
 
@@ -79,8 +76,6 @@ public:
 private:
 								FileSystem(const MountConfiguration& config);
 
-			CacheRevalidator	fCacheRevalidator;
-
 			mutex				fDelegationLock;
 			DoublyLinkedList<Delegation>	fDelegationList;
 			AVLTreeMap<FileHandle, Delegation*> fHandleToDelegation;
@@ -113,13 +108,6 @@ private:
 };
 
 
-inline CacheRevalidator&
-FileSystem::Revalidator()
-{
-	return fCacheRevalidator;
-}
-
-
 inline RootInode*
 FileSystem::Root()
 {

src/add-ons/kernel/file_systems/nfs4/Inode.cpp

@@ -204,20 +204,15 @@ Inode::LookUp(const char* name, ino_t* id)
 	if (result != B_OK)
 		return result;
 
-	fFileSystem->Revalidator().Lock();
 	fCache->Lock();
 	if (!fCache->Valid()) {
 		fCache->Reset();
 		fCache->SetChangeInfo(change);
-	} else {
-		fFileSystem->Revalidator().RemoveDirectory(fCache);
+	} else
 		fCache->ValidateChangeInfo(change);
-	}
 
 	fCache->AddEntry(name, *id);
-	fFileSystem->Revalidator().AddDirectory(fCache);
 	fCache->Unlock();
-	fFileSystem->Revalidator().Unlock();
 
 	return B_OK;
 }

src/add-ons/kernel/file_systems/nfs4/Inode.h

@@ -9,6 +9,7 @@
 #define INODE_H
 
 
+#include "DirectoryCache.h"
 #include "MetadataCache.h"
 #include "NFS4Inode.h"
 #include "OpenState.h"

src/add-ons/kernel/file_systems/nfs4/InodeDir.cpp

@@ -317,30 +317,21 @@ Inode::ReadDir(void* _buffer, uint32 size, uint32* _count,
 	status_t result;
 	DirectoryCache* cache = cookie->fAttrDir ? fAttrCache : fCache;
 	if (cookie->fSnapshot == NULL) {
-		fFileSystem->Revalidator().Lock();
 		cache->Lock();
-		if (!cache->Valid())
-			cache->Reset();
-		else
-			fFileSystem->Revalidator().RemoveDirectory(cache);
+		result = cache->Revalidate();
+		if (result != B_OK) {
+			cache->Unlock();
+			return result;
+		}
 
 		DirectoryCacheSnapshot* snapshot = cache->GetSnapshot();
-		if (snapshot == NULL) {
-			uint64 change;
-			result = GetDirSnapshot(&snapshot, cookie, &change,
-				cookie->fAttrDir);
-			if (result != B_OK) {
-				cache->Unlock();
-				fFileSystem->Revalidator().Unlock();
-				return result;
-			}
-			cache->ValidateChangeInfo(change);
-			cache->SetSnapshot(snapshot);
-		}
+		ASSERT(snapshot != NULL);
+
 		cookie->fSnapshot = new DirectoryCacheSnapshot(*snapshot);
-		fFileSystem->Revalidator().AddDirectory(cache);
 		cache->Unlock();
-		fFileSystem->Revalidator().Unlock();
+
+		if (cookie->fSnapshot == NULL)
+			return B_NO_MEMORY;
 	}
 
 	char* buffer = reinterpret_cast<char*>(_buffer);

src/add-ons/kernel/file_systems/nfs4/Jamfile

@@ -4,7 +4,6 @@ UsePrivateKernelHeaders ;
 UsePrivateHeaders shared ;
 
 KernelAddon nfs4 :
-	CacheRevalidator.cpp
 	Cookie.cpp
 	Connection.cpp
 	Delegation.cpp