Changes to mmap to make COPY and SHARED work correctly (I hope)

git-svn-id: file:///srv/svn/repos/haiku/trunk/current@2358 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/kernel/vm2/area.C

@@ -53,7 +53,7 @@ unsigned long area::mapAddressSpecToAddress(addressSpec type,void * req,int page
 }
 
 // This is the really interesting part of creating an area
-status_t area::createAreaGuts( char *inName, int pageCount, void **address, addressSpec type, pageState inState, protectType protect, bool inFinalWrite, int fd, size_t offset, area *originalArea=NULL /* For clone only*/) {
+status_t area::createAreaGuts( char *inName, int pageCount, void **address, addressSpec type, pageState inState, protectType protect, bool inFinalWrite, int fd, size_t offset, area *originalArea /* For clone only*/, mmapSharing share) {
 	error ("area::createAreaGuts : name = %s, pageCount = %d, address = %lx, addressSpec = %d, pageState = %d, protection = %d, inFinalWrite = %d, fd = %d, offset = %d,originalArea=%ld\n",
 					inName,pageCount,address,type,inState,protect,inFinalWrite,fd,offset,originalArea);
 	vpage *newPage;
@@ -78,7 +78,7 @@ status_t area::createAreaGuts( char *inName, int pageCount, void **address, addr
 				newVnode.fd=fd;
 				newVnode.offset=offset;
 //				vmBlock->vnodeManager->addVNode(newVnode,newPage);
-				newPage->setup(base+PAGE_SIZE*i,&newVnode,NULL,protect,inState);
+				newPage->setup(base+PAGE_SIZE*i,&newVnode,NULL,protect,inState,share);
 				}
 			else
 				newPage->setup(base+PAGE_SIZE*i,NULL,NULL,protect,inState);
@@ -99,8 +99,8 @@ status_t area::createAreaGuts( char *inName, int pageCount, void **address, addr
 	return B_OK;
 }
 
-status_t area::createAreaMappingFile(char *inName, int pageCount,void **address, addressSpec type,pageState inState,protectType protect,int fd,size_t offset) {
+status_t area::createAreaMappingFile(char *inName, int pageCount,void **address, addressSpec type,pageState inState,protectType protect,int fd,size_t offset, mmapSharing share) {
-	return createAreaGuts(inName,pageCount,address,type,inState,protect,true,fd,offset);
+	return createAreaGuts(inName,pageCount,address,type,inState,protect,true,fd,offset,NULL,share);
 	}
 
 status_t area::createArea(char *inName, int pageCount,void **address, addressSpec type,pageState inState,protectType protect) {

src/kernel/vm2/area.h

@@ -29,8 +29,8 @@ class area : public node
 		area(void);
 		void setup(areaManager *myManager);
 		void freeArea(void);
-		status_t createAreaGuts( char *inName, int pageCount, void **address, addressSpec type, pageState inState, protectType protect, bool inFinalWrite, int fd, size_t offset, area *originalArea=NULL /* For clone only*/);
+		status_t createAreaGuts( char *inName, int pageCount, void **address, addressSpec type, pageState inState, protectType protect, bool inFinalWrite, int fd, size_t offset, area *originalArea=NULL,mmapSharing share=CLONEAREA /* For clone only*/);
-		status_t createAreaMappingFile(char *name, int pageCount,void **address, addressSpec type,pageState state,protectType protect,int fd,size_t offset);
+		status_t createAreaMappingFile(char *name, int pageCount,void **address, addressSpec type,pageState state,protectType protect,int fd,size_t offset, mmapSharing share=CLONEAREA);
 		status_t createArea (char *name, int pageCount,void **address, addressSpec type,pageState state,protectType protect);
 		status_t cloneArea(area *area, char *inName, void **address, addressSpec type,pageState inState,protectType protect);
 		unsigned long mapAddressSpecToAddress(addressSpec type,void *requested,int pageCount);

src/kernel/vm2/areaManager.C

@@ -285,8 +285,9 @@ void *areaManager::mmap(void *addr, size_t len, int prot, int flags, int fd, off
 	strcpy(	name,"mmap - need to include fileName");
 		
 	addressSpec addType=((flags&MAP_FIXED)?EXACT:ANY);
-	protectType protType=(prot&PROT_WRITE)?writable:(prot&PROT_READ)?readable:none;
+
-	// Not doing anything with MAP_SHARED and MAP_COPY - needs to be done
+	protectType protType;
+	protType=(flags&PROT_WRITE)?writable:(flags&(PROT_READ|PROT_EXEC))?readable:none;
 	//error ("flags = %x, anon = %x\n",flags,MAP_ANON);
 	lock();
 	if (flags & MAP_ANON) {
@@ -294,10 +295,17 @@ void *areaManager::mmap(void *addr, size_t len, int prot, int flags, int fd, off
 		return addr;
 		}
 
+	int shareCount=0;
+	mmapSharing share;
+	if (flags & MAP_SHARED) { share=SHARED;shareCount++;}
+	if (flags & MAP_PRIVATE) { share=PRIVATE;shareCount++;}
+	if (flags & MAP_COPY){ share=COPY;shareCount++;}
+	if (shareCount!=1)
+		return NULL;
 	area *newArea = new (vmBlock->areaPool->get()) area;
 	newArea->setup(this);
 	//error ("area = %x, start = %x\n",newArea, newArea->getStartAddress());
-	newArea->createAreaMappingFile(name,(int)((len+PAGE_SIZE-1)/PAGE_SIZE),&addr,addType,LAZY,protType,fd,offset);
+	newArea->createAreaMappingFile(name,(int)((len+PAGE_SIZE-1)/PAGE_SIZE),&addr,addType,LAZY,protType,fd,offset,share);
  	atomic_add(&nextAreaID,1);
 	newArea->setAreaID(nextAreaID);
 	addArea(newArea);

src/kernel/vm2/vm.h

@@ -47,6 +47,8 @@ enum pageState {FULL,CONTIGUOUS,LAZY,NO_LOCK,LOMEM};
 #define B_DMA_IO       0x00000001
 #define B_READ_DEVICE  0x00000002  
 
+enum mmapSharing {CLONEAREA,SHARED,PRIVATE,COPY};
+
 struct physical_entry  {void *address; 
 		ulong size; 
 		};

src/kernel/vm2/vpage.C

@@ -40,7 +40,7 @@ vpage::vpage(void) : physPage(NULL),backingNode(NULL),protection(none),dirty(fal
 
 // Does the real setup work for making a vpage.
 // backing and/or physMem can be NULL/0.
-void vpage::setup(unsigned long start,vnode *backing, page *physMem,protectType prot,pageState state) { 
+void vpage::setup(unsigned long start,vnode *backing, page *physMem,protectType prot,pageState state, mmapSharing share) { 
 	// Basic setup from parameters
 	vpage *clonedPage; // This is the page that this page is to be the clone of...
 	error ("vpage::setup: start = %x, vnode.fd=%d, vnode.offset=%d, physMem = %x\n",start,((backing)?backing->fd:0),((backing)?backing->offset:0), ((physMem)?(physMem->getAddress()):0));
@@ -53,21 +53,35 @@ void vpage::setup(unsigned long start,vnode *backing, page *physMem,protectType
 	end_address=start+PAGE_SIZE-1;
 
 // Set up the backing store. If one is specified, use it; if not, get a swap file page.
-	if (backingNode) {
+	if (backingNode) { // This is an mmapped file (or a cloned area)
-		clonedPage=vmBlock->vnodeMan->addVnode(*backingNode,*this); // Use the reference version which will make a new one if this one is not found
+		switch (share) {
-		if (clonedPage) {
+			case CLONE: // This is a cloned area
-			physPage=clonedPage->physPage;	
+			case SHARED: // This is a shared mmap
-			protection=(protection<=readable)?protection: copyOnWrite;
+				clonedPage=vmBlock->vnodeMan->addVnode(*backingNode,*this); // Use the reference version which will make a new one if this one is not found
-			if (clonedPage->getProtection()<=readable)
+				if (clonedPage) physPage=clonedPage->physPage;	
-				clonedPage->setProtection(copyOnWrite);
+				break;
+			case PRIVATE: // This is a one way share - we get others changes (until we make a change) but no one gets our changes
+				clonedPage=vmBlock->vnodeMan->addVnode(*backingNode,*this); // Use the reference version which will make a new one if this one is not found
+				if (clonedPage) physPage=clonedPage->physPage;	
+				protection=(protection<=readable)?protection: copyOnWrite;
+				break;
+			case COPY: // This is not shared - get a fresh page and fresh swap file space and copy the original page
+				physPage=vmBlock->pageMan->getPage();
+				clonedPage=vmBlock->vnodeMan->findVnode(*backing); // Find out if the page we are copying is in memory already...
+				if (clonedPage && clonedPage->physPage) // If it is in memory, copy its values
+					memcpy((void *)(physPage->getAddress()),(void *)(clonedPage->physPage->getAddress()),PAGE_SIZE);
+				else 
+					refresh(); // otherwise, get a copy from disk...
+				backingNode=&(vmBlock->swapMan->findNode()); // Now get swap space (since we don't want to be backed by the file...
+				clonedPage=vmBlock->vnodeMan->addVnode(backingNode,*this); // Add this vnode to the vnode keeper
+				break;
 			}
 		}
 	else { // Going to swap file.
 		backingNode=&(vmBlock->swapMan->findNode());
 		clonedPage=vmBlock->vnodeMan->addVnode(backingNode,*this); // Use the pointer version which will use this one. Should always return NULL
 	}
-
+// If there is no physical page already and we can't wait to get one, then get one now	
-	// If there is no physical page already and we can't wait to get one, then get one now	
 	if (!physPage && (state!=LAZY) && (state!=NO_LOCK)) {
 		physPage=vmBlock->pageMan->getPage();
 		error ("vpage::setup, state = %d, allocated page %x\n",state,physPage);
@@ -76,6 +90,7 @@ void vpage::setup(unsigned long start,vnode *backing, page *physMem,protectType
 		if (physPage)
 			atomic_add(&(physPage->count),1);
 		}
+
 	error ("vpage::setup: ended : start = %x, vnode.fd=%d, vnode.offset=%d, physMem = %x\n",start,((backing)?backing->fd:0),((backing)?backing->offset:0), ((physMem)?(physMem->getAddress()):0));
 	}
 

src/kernel/vm2/vpage.h

@@ -21,7 +21,7 @@ class vpage : public node
 		vpage(void);
 		vpage(unsigned long address) {start_address=address-address%PAGE_SIZE;end_address=start_address+PAGE_SIZE-1;} // Only for lookups
 		// Setup should now only be called by the vpage manager...
-		void setup(unsigned long  start,vnode *backing, page *physMem,protectType prot,pageState state); // backing and/or physMem can be NULL/0.
+		void setup(unsigned long  start,vnode *backing, page *physMem,protectType prot,pageState state, mmapSharing share=CLONEAREA); // backing and/or physMem can be NULL/0.
 		void cleanup(void);
 
 		// Mutators