nfs4: Allow customization of DirectoryCache expiration time

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

@@ -78,7 +78,7 @@ DirectoryCacheSnapshot::~DirectoryCacheSnapshot()
 
 DirectoryCache::DirectoryCache(Inode* inode, bool attr)
 	:
-	fRevalidated(false),
+	fExpirationTime(inode->fFileSystem->GetConfiguration().fDirectoryCacheTime),
 	fDirectoryCache(NULL),
 	fInode(inode),
 	fAttrDir(attr),
@@ -100,7 +100,7 @@ void
 DirectoryCache::Reset()
 {
 	Trash();
-	fExpireTime = system_time() + kExpirationTime;
+	fExpireTime = system_time() + fExpirationTime;
 	fTrashed = false;
 }
 
@@ -232,7 +232,7 @@ DirectoryCache::_LoadSnapshot(bool trash)
 	newSnapshot->AcquireReference();
 
 	_SetSnapshot(newSnapshot);
-	fExpireTime = system_time() + kExpirationTime;
+	fExpireTime = system_time() + fExpirationTime;
 
 	fTrashed = false;
 
@@ -260,7 +260,7 @@ DirectoryCache::Revalidate()
 	}
 
 	if (change == fChange) {
-		fExpireTime = system_time() + kExpirationTime;
+		fExpireTime = system_time() + fExpirationTime;
 		return B_OK;
 	}
 

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

@@ -66,9 +66,7 @@ public:
 
 	inline	Inode*			GetInode();
 
-	static	const bigtime_t	kExpirationTime		= 15000000;
+	const	bigtime_t		fExpirationTime;
-
-			bool			fRevalidated;
 protected:
 			void			NotifyChanges(DirectoryCacheSnapshot* oldSnapshot,
 								DirectoryCacheSnapshot* newSnapshot);
@@ -139,7 +137,7 @@ DirectoryCache::ValidateChangeInfo(uint64 change)
 	if (fTrashed || change != fChange) {
 		Trash();
 		fChange = change;
-		fExpireTime = system_time() + kExpirationTime;
+		fExpireTime = system_time() + fExpirationTime;
 		fTrashed = false;
 
 		return B_ERROR;
@@ -152,7 +150,7 @@ DirectoryCache::ValidateChangeInfo(uint64 change)
 inline void
 DirectoryCache::SetChangeInfo(uint64 change)
 {
-	fExpireTime = system_time() + kExpirationTime;
+	fExpireTime = system_time() + fExpirationTime;
 	fChange = change;
 }
 

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

@@ -25,6 +25,8 @@ struct MountConfiguration {
 
 	bool		fEmulateNamedAttrs;
 	bool		fCacheMetadata;
+
+	bigtime_t	fDirectoryCacheTime;
 };
 
 class FileSystem : public DoublyLinkedListLinkImpl<FileSystem> {

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

@@ -71,6 +71,8 @@ CreateNFS4Server(RPC::Server* serv)
 //	noxattr-emu	- do not emulate named attributes (default)
 //	port=X		- connect to port X (default: 2049)
 //	proto=X		- user transport protocol X (default: tcp)
+//	dirtime=X	- attempt revalidate directory cache not more often than each X
+//				  seconds
 static status_t
 ParseArguments(const char* _args, AddressResolver** address, char** _path,
 	MountConfiguration* conf)
@@ -107,6 +109,7 @@ ParseArguments(const char* _args, AddressResolver** address, char** _path,
 	conf->fRequestTimeout = sSecToBigTime(60);
 	conf->fEmulateNamedAttrs = false;
 	conf->fCacheMetadata = true;
+	conf->fDirectoryCacheTime = sSecToBigTime(5);
 
 	char* optionsEnd = NULL;
 	if (options != NULL)
@@ -133,6 +136,9 @@ ParseArguments(const char* _args, AddressResolver** address, char** _path,
 		} else if (strncmp(options, "proto=", 6) == 0) {
 			options += strlen("proto=");
 			(*address)->ForceProtocol(options);
+		} else if (strncmp(options, "dirtime=", 8) == 0) {
+			options += strlen("dirtime=");
+			conf->fDirectoryCacheTime = sSecToBigTime(atoi(options));
 		}
 
 		options = optionsEnd;