Added a "reenter" parameter to the {read|write}_pages() functions to give file

systems a chance to know if they have locked already.
This fixes a locking problem in BFS where one thread tried to acquire two read
locks (where someone else trying to acquire a write lock would have caused a
dead lock).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@17108 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/os/drivers/fs_interface.h

@@ -1,6 +1,6 @@
 /* File System Interface Layer Definition
  *
- * Copyright 2004-2005, Haiku Inc. All Rights Reserved.
+ * Copyright 2004-2006, Haiku Inc. All Rights Reserved.
  * Distributed under the terms of the MIT License.
  */
 #ifndef _FS_INTERFACE_H
@@ -87,8 +87,10 @@ typedef struct file_system_module_info {
 
 	/* VM file access */
 	bool (*can_page)(fs_volume fs, fs_vnode vnode, fs_cookie cookie);
-	status_t (*read_pages)(fs_volume fs, fs_vnode vnode, fs_cookie cookie, off_t pos, const iovec *vecs, size_t count, size_t *_numBytes);
+	status_t (*read_pages)(fs_volume fs, fs_vnode vnode, fs_cookie cookie, off_t pos,
-	status_t (*write_pages)(fs_volume fs, fs_vnode vnode, fs_cookie cookie, off_t pos, const iovec *vecs, size_t count, size_t *_numBytes);
+				const iovec *vecs, size_t count, size_t *_numBytes, bool reenter);
+	status_t (*write_pages)(fs_volume fs, fs_vnode vnode, fs_cookie cookie, off_t pos,
+				const iovec *vecs, size_t count, size_t *_numBytes, bool reenter);
 
 	/* cache file access */
 	status_t (*get_file_map)(fs_volume fs, fs_vnode vnode, off_t offset, size_t size, struct file_io_vec *vecs, size_t *_count);

headers/private/kernel/vfs.h

@@ -87,9 +87,9 @@ void vfs_acquire_vnode(void *vnode);
 status_t vfs_get_cookie_from_fd(int fd, void **_cookie);
 bool vfs_can_page(void *vnode, void *cookie);
 status_t vfs_read_pages(void *vnode, void *cookie, off_t pos,
-			const iovec *vecs, size_t count, size_t *_numBytes);
+			const iovec *vecs, size_t count, size_t *_numBytes, bool fsReenter);
 status_t vfs_write_pages(void *vnode, void *cookie, off_t pos,
-			const iovec *vecs, size_t count, size_t *_numBytes);
+			const iovec *vecs, size_t count, size_t *_numBytes, bool fsReenter);
 status_t vfs_get_vnode_cache(void *vnode, struct vm_cache_ref **_cache, bool allocate);
 status_t vfs_get_file_map( void *_vnode, off_t offset, size_t size,
 			struct file_io_vec *vecs, size_t *_count);

headers/private/kernel/vm_cache.h

@@ -27,7 +27,7 @@ void vm_cache_release_ref(vm_cache_ref *cache_ref);
 vm_page *vm_cache_lookup_page(vm_cache_ref *cacheRef, off_t page);
 void vm_cache_insert_page(vm_cache_ref *cacheRef, vm_page *page, off_t offset);
 void vm_cache_remove_page(vm_cache_ref *cacheRef, vm_page *page);
-status_t vm_cache_write_modified(vm_cache_ref *ref);
+status_t vm_cache_write_modified(vm_cache_ref *ref, bool fsReenter);
 status_t vm_cache_set_minimal_commitment(vm_cache_ref *ref, off_t commitment);
 status_t vm_cache_resize(vm_cache_ref *cacheRef, off_t newSize);
 status_t vm_cache_insert_area(vm_cache_ref *cacheRef, vm_area *area);

headers/private/kernel/vm_page.h

@@ -34,7 +34,7 @@ status_t vm_page_set_state(vm_page *page, int state);
 size_t vm_page_num_pages(void);
 size_t vm_page_num_free_pages(void);
 
-status_t vm_page_write_modified(vm_cache *cache);
+status_t vm_page_write_modified(vm_cache *cache, bool fsReenter);
 
 vm_page *vm_page_allocate_page(int state);
 status_t vm_page_allocate_pages(int pageState, vm_page **pages, uint32 numPages);

headers/private/kernel/vm_types.h

@@ -1,5 +1,5 @@
 /* 
- * Copyright 2002-2005, Axel Dörfler, axeld@pinc-software.de.
+ * Copyright 2002-2006, Axel Dörfler, axeld@pinc-software.de.
  * Distributed under the terms of the MIT License.
  *
  * Copyright 2001-2002, Travis Geiselbrecht. All rights reserved.
@@ -137,9 +137,12 @@ typedef struct vm_store_ops {
 	void (*destroy)(struct vm_store *backing_store);
 	status_t (*commit)(struct vm_store *backing_store, off_t size);
 	bool (*has_page)(struct vm_store *backing_store, off_t offset);
-	status_t (*read)(struct vm_store *backing_store, off_t offset, const iovec *vecs, size_t count, size_t *_numBytes);
+	status_t (*read)(struct vm_store *backing_store, off_t offset, const iovec *vecs,
-	status_t (*write)(struct vm_store *backing_store, off_t offset, const iovec *vecs, size_t count, size_t *_numBytes);
+				size_t count, size_t *_numBytes, bool fsReenter);
-	status_t (*fault)(struct vm_store *backing_store, struct vm_address_space *aspace, off_t offset);
+	status_t (*write)(struct vm_store *backing_store, off_t offset, const iovec *vecs,
+				size_t count, size_t *_numBytes, bool fsReenter);
+	status_t (*fault)(struct vm_store *backing_store, struct vm_address_space *aspace,
+				off_t offset);
 	void (*acquire_ref)(struct vm_store *backing_store);
 	void (*release_ref)(struct vm_store *backing_store);
 } vm_store_ops;

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

@@ -369,53 +369,45 @@ bfs_can_page(fs_volume _fs, fs_vnode _v, fs_cookie _cookie)
 
 static status_t
 bfs_read_pages(fs_volume _fs, fs_vnode _node, fs_cookie _cookie, off_t pos,
-	const iovec *vecs, size_t count, size_t *_numBytes)
+	const iovec *vecs, size_t count, size_t *_numBytes, bool reenter)
 {
 	Inode *inode = (Inode *)_node;
 
 	if (inode->FileCache() == NULL)
 		RETURN_ERROR(B_BAD_VALUE);
 
-	ReadLocked locked(inode->Lock());
+	if (!reenter)
-	return file_cache_read_pages(inode->FileCache(), pos, vecs, count, _numBytes);
+		inode->Lock().Lock();
-#if 0
-	for (uint32 i = 0; i < count; i++) {
-		if (pos >= inode->Size()) {
-			memset(vecs[i].iov_base, 0, vecs[i].iov_len);
-			pos += vecs[i].iov_len;
-			*_numBytes -= vecs[i].iov_len;
-		} else {
-			uint32 length = vecs[i].iov_len;
-			if (length > inode->Size() - pos)
-				length = inode->Size() - pos;
 
-			inode->ReadAt(pos, (uint8 *)vecs[i].iov_base, &length);
+	status_t status = file_cache_read_pages(inode->FileCache(), pos, vecs, count,
+		_numBytes);
 
-			if (length < vecs[i].iov_len) {
+	if (!reenter)
-				memset((char *)vecs[i].iov_base + length, 0, vecs[i].iov_len - length);
+		inode->Lock().Unlock();
-				*_numBytes -= vecs[i].iov_len - length;
-			}
 
-			pos += vecs[i].iov_len;
+	return status;
-		}
-	}
-
-	return B_OK;
-#endif
 }
 
 
 static status_t
 bfs_write_pages(fs_volume _fs, fs_vnode _node, fs_cookie _cookie, off_t pos,
-	const iovec *vecs, size_t count, size_t *_numBytes)
+	const iovec *vecs, size_t count, size_t *_numBytes, bool reenter)
 {
 	Inode *inode = (Inode *)_node;
 
 	if (inode->FileCache() == NULL)
 		RETURN_ERROR(B_BAD_VALUE);
 
-	ReadLocked locked(inode->Lock());
+	if (!reenter)
-	return file_cache_write_pages(inode->FileCache(), pos, vecs, count, _numBytes);
+		inode->Lock().Lock();
+
+	status_t status = file_cache_write_pages(inode->FileCache(), pos, vecs, count,
+		_numBytes);
+
+	if (!reenter)
+		inode->Lock().Unlock();
+
+	return status;
 }
 
 

src/system/kernel/cache/file_cache.cpp

@@ -317,7 +317,8 @@ pages_io(file_cache_ref *ref, off_t offset, const iovec *vecs, size_t count,
 		if (size > numBytes)
 			size = numBytes;
 
-		status = vfs_read_pages(ref->device, ref->cookie, fileVecs[0].offset, vecs, count, &size);
+		status = vfs_read_pages(ref->device, ref->cookie, fileVecs[0].offset, vecs,
+			count, &size, false);
 		if (status < B_OK)
 			return status;
 
@@ -394,10 +395,13 @@ pages_io(file_cache_ref *ref, off_t offset, const iovec *vecs, size_t count,
 		}
 
 		size_t bytes = size;
-		if (doWrite)
+		if (doWrite) {
-			status = vfs_write_pages(ref->device, ref->cookie, fileVec.offset, tempVecs, tempCount, &bytes);
+			status = vfs_write_pages(ref->device, ref->cookie, fileVec.offset, tempVecs,
-		else
+				tempCount, &bytes, false);
-			status = vfs_read_pages(ref->device, ref->cookie, fileVec.offset, tempVecs, tempCount, &bytes);
+		} else {
+			status = vfs_read_pages(ref->device, ref->cookie, fileVec.offset, tempVecs,
+				tempCount, &bytes, false);
+		}
 		if (status < B_OK)
 			return status;
 
@@ -1221,7 +1225,7 @@ file_cache_sync(void *_cacheRef)
 	if (ref == NULL)
 		return B_BAD_VALUE;
 
-	return vm_cache_write_modified(ref->cache);
+	return vm_cache_write_modified(ref->cache, true);
 }
 
 

src/system/kernel/cache/vnode_store.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2004-2005, Axel Dörfler, axeld@pinc-software.de.
+ * Copyright 2004-2006, Axel Dörfler, axeld@pinc-software.de.
  * Distributed under the terms of the MIT License.
  */
 
@@ -41,12 +41,14 @@ store_has_page(struct vm_store *_store, off_t offset)
 
 
 static status_t
-store_read(struct vm_store *_store, off_t offset, const iovec *vecs, size_t count, size_t *_numBytes)
+store_read(struct vm_store *_store, off_t offset, const iovec *vecs, size_t count,
+	size_t *_numBytes, bool fsReenter)
 {
 	vnode_store *store = (vnode_store *)_store;
 	size_t bytesUntouched = *_numBytes;
 
-	status_t status = vfs_read_pages(store->vnode, NULL, offset, vecs, count, _numBytes);
+	status_t status = vfs_read_pages(store->vnode, NULL, offset, vecs, count,
+		_numBytes, fsReenter);
 
 	bytesUntouched -= *_numBytes;
 
@@ -70,10 +72,11 @@ store_read(struct vm_store *_store, off_t offset, const iovec *vecs, size_t coun
 
 
 static status_t
-store_write(struct vm_store *_store, off_t offset, const iovec *vecs, size_t count, size_t *_numBytes)
+store_write(struct vm_store *_store, off_t offset, const iovec *vecs, size_t count,
+	size_t *_numBytes, bool fsReenter)
 {
 	vnode_store *store = (vnode_store *)_store;
-	return vfs_write_pages(store->vnode, NULL, offset, vecs, count, _numBytes);
+	return vfs_write_pages(store->vnode, NULL, offset, vecs, count, _numBytes, fsReenter);
 }
 
 

src/system/kernel/fs/devfs.cpp

@@ -1643,7 +1643,8 @@ devfs_can_page(fs_volume _fs, fs_vnode _vnode, fs_cookie cookie)
 
 
 static status_t
-devfs_read_pages(fs_volume _fs, fs_vnode _vnode, fs_cookie _cookie, off_t pos, const iovec *vecs, size_t count, size_t *_numBytes)
+devfs_read_pages(fs_volume _fs, fs_vnode _vnode, fs_cookie _cookie, off_t pos,
+	const iovec *vecs, size_t count, size_t *_numBytes, bool reenter)
 {
 	struct devfs_vnode *vnode = (devfs_vnode *)_vnode;
 	struct devfs_cookie *cookie = (struct devfs_cookie *)_cookie;
@@ -1663,7 +1664,8 @@ devfs_read_pages(fs_volume _fs, fs_vnode _vnode, fs_cookie _cookie, off_t pos, c
 
 
 static status_t
-devfs_write_pages(fs_volume _fs, fs_vnode _vnode, fs_cookie _cookie, off_t pos, const iovec *vecs, size_t count, size_t *_numBytes)
+devfs_write_pages(fs_volume _fs, fs_vnode _vnode, fs_cookie _cookie, off_t pos,
+	const iovec *vecs, size_t count, size_t *_numBytes, bool reenter)
 {
 	struct devfs_vnode *vnode = (devfs_vnode *)_vnode;
 	struct devfs_cookie *cookie = (struct devfs_cookie *)_cookie;

src/system/kernel/fs/pipefs.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2003-2005, Axel Dörfler, axeld@pinc-software.de.
+ * Copyright 2003-2006, Axel Dörfler, axeld@pinc-software.de.
  * Distributed under the terms of the MIT License.
  */
 
@@ -1571,14 +1571,16 @@ pipefs_can_page(fs_volume _volume, fs_vnode _v, fs_cookie cookie)
 
 
 static status_t
-pipefs_read_pages(fs_volume _volume, fs_vnode _v, fs_cookie cookie, off_t pos, const iovec *vecs, size_t count, size_t *_numBytes)
+pipefs_read_pages(fs_volume _volume, fs_vnode _v, fs_cookie cookie, off_t pos,
+	const iovec *vecs, size_t count, size_t *_numBytes, bool reenter)
 {
 	return EPERM;
 }
 
 
 static status_t
-pipefs_write_pages(fs_volume _volume, fs_vnode _v, fs_cookie cookie, off_t pos, const iovec *vecs, size_t count, size_t *_numBytes)
+pipefs_write_pages(fs_volume _volume, fs_vnode _v, fs_cookie cookie, off_t pos,
+	const iovec *vecs, size_t count, size_t *_numBytes, bool reenter)
 {
 	return EPERM;
 }

src/system/kernel/fs/rootfs.c

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2005, Axel Dörfler, axeld@pinc-software.de. All rights reserved.
+ * Copyright 2002-2006, Axel Dörfler, axeld@pinc-software.de. All rights reserved.
  * Distributed under the terms of the MIT License.
  *
  * Copyright 2001-2002, Travis Geiselbrecht. All rights reserved.
@@ -769,14 +769,16 @@ rootfs_can_page(fs_volume _fs, fs_vnode _v, fs_cookie cookie)
 
 
 static status_t
-rootfs_read_pages(fs_volume _fs, fs_vnode _v, fs_cookie cookie, off_t pos, const iovec *vecs, size_t count, size_t *_numBytes)
+rootfs_read_pages(fs_volume _fs, fs_vnode _v, fs_cookie cookie, off_t pos,
+	const iovec *vecs, size_t count, size_t *_numBytes, bool reenter)
 {
 	return B_NOT_ALLOWED;
 }
 
 
 static status_t
-rootfs_write_pages(fs_volume _fs, fs_vnode _v, fs_cookie cookie, off_t pos, const iovec *vecs, size_t count, size_t *_numBytes)
+rootfs_write_pages(fs_volume _fs, fs_vnode _v, fs_cookie cookie, off_t pos,
+	const iovec *vecs, size_t count, size_t *_numBytes, bool reenter)
 {
 	return B_NOT_ALLOWED;
 }

src/system/kernel/fs/vfs.cpp

@@ -3005,24 +3005,28 @@ vfs_can_page(void *_vnode, void *cookie)
 
 
 extern "C" status_t
-vfs_read_pages(void *_vnode, void *cookie, off_t pos, const iovec *vecs, size_t count, size_t *_numBytes)
+vfs_read_pages(void *_vnode, void *cookie, off_t pos, const iovec *vecs, size_t count,
+	size_t *_numBytes, bool fsReenter)
 {
 	struct vnode *vnode = (struct vnode *)_vnode;
 
 	FUNCTION(("vfs_read_pages: vnode %p, vecs %p, pos %Ld\n", vnode, vecs, pos));
 
-	return FS_CALL(vnode, read_pages)(vnode->mount->cookie, vnode->private_node, cookie, pos, vecs, count, _numBytes);
+	return FS_CALL(vnode, read_pages)(vnode->mount->cookie, vnode->private_node,
+		cookie, pos, vecs, count, _numBytes, fsReenter);
 }
 
 
 extern "C" status_t
-vfs_write_pages(void *_vnode, void *cookie, off_t pos, const iovec *vecs, size_t count, size_t *_numBytes)
+vfs_write_pages(void *_vnode, void *cookie, off_t pos, const iovec *vecs, size_t count,
+	size_t *_numBytes, bool fsReenter)
 {
 	struct vnode *vnode = (struct vnode *)_vnode;
 
 	FUNCTION(("vfs_write_pages: vnode %p, vecs %p, pos %Ld\n", vnode, vecs, pos));
 
-	return FS_CALL(vnode, write_pages)(vnode->mount->cookie, vnode->private_node, cookie, pos, vecs, count, _numBytes);
+	return FS_CALL(vnode, write_pages)(vnode->mount->cookie, vnode->private_node,
+		cookie, pos, vecs, count, _numBytes, fsReenter);
 }
 
 

src/system/kernel/vm/vm.cpp

@@ -1382,7 +1382,7 @@ _vm_put_area(vm_area *area, bool aspaceLocked)
 	addressSpace = area->address_space;
 
 	// ToDo: do that only for vnode stores
-	vm_cache_write_modified(area->cache_ref);
+	vm_cache_write_modified(area->cache_ref, false);
 
 	arch_vm_unset_memory_type(area);
 	remove_area_from_address_space(addressSpace, area, aspaceLocked);
@@ -2630,7 +2630,8 @@ vm_soft_fault(addr_t originalAddress, bool isWrite, bool isUser)
 
 			addressSpace->translation_map.ops->get_physical_page(page->physical_page_number * B_PAGE_SIZE, (addr_t *)&vec.iov_base, PHYSICAL_PAGE_CAN_WAIT);
 			// ToDo: handle errors here
-			err = cache_ref->cache->store->ops->read(cache_ref->cache->store, cacheOffset, &vec, 1, &bytesRead);
+			err = cache_ref->cache->store->ops->read(cache_ref->cache->store,
+				cacheOffset, &vec, 1, &bytesRead, false);
 			addressSpace->translation_map.ops->put_physical_page((addr_t)vec.iov_base);
 
 			mutex_lock(&cache_ref->lock);

src/system/kernel/vm/vm_cache.c

@@ -311,14 +311,14 @@ vm_cache_remove_page(vm_cache_ref *cacheRef, vm_page *page)
 
 
 status_t
-vm_cache_write_modified(vm_cache_ref *ref)
+vm_cache_write_modified(vm_cache_ref *ref, bool fsReenter)
 {
 	status_t status;
 
 	TRACE(("vm_cache_write_modified(ref = %p)\n", ref));
 
 	mutex_lock(&ref->lock);
-	status = vm_page_write_modified(ref->cache);
+	status = vm_page_write_modified(ref->cache, fsReenter);
 	mutex_unlock(&ref->lock);
 
 	return status;

src/system/kernel/vm/vm_page.c

@@ -134,7 +134,7 @@ move_page_to_queue(page_queue *from_q, page_queue *to_q, vm_page *page)
 
 
 static status_t
-write_page(vm_page *page)
+write_page(vm_page *page, bool fsReenter)
 {
 	vm_store *store = page->cache->store;
 	size_t length = B_PAGE_SIZE;
@@ -150,7 +150,7 @@ write_page(vm_page *page)
 	vecs->iov_len = B_PAGE_SIZE;
 
 	status = store->ops->write(store, (off_t)page->cache_offset << PAGE_SHIFT,
-		vecs, 1, &length);
+		vecs, 1, &length, fsReenter);
 
 	vm_put_physical_page((addr_t)vecs[0].iov_base);
 
@@ -164,7 +164,7 @@ write_page(vm_page *page)
 
 
 status_t
-vm_page_write_modified(vm_cache *cache)
+vm_page_write_modified(vm_cache *cache, bool fsReenter)
 {
 	vm_page *page = cache->page_list;
 
@@ -230,7 +230,7 @@ vm_page_write_modified(vm_cache *cache)
 			continue;
 
 		mutex_unlock(&cache->ref->lock);
-		status = write_page(page);
+		status = write_page(page, fsReenter);
 		mutex_lock(&cache->ref->lock);
 
 		if (status == B_OK) {

src/system/kernel/vm/vm_store_anonymous_noswap.c

@@ -1,5 +1,5 @@
 /* 
- * Copyright 2002-2005, Axel Dörfler, axeld@pinc-software.de.
+ * Copyright 2002-2006, Axel Dörfler, axeld@pinc-software.de.
  * Distributed under the terms of the MIT License.
  *
  * Copyright 2001-2002, Travis Geiselbrecht. All rights reserved.
@@ -77,7 +77,8 @@ anonymous_has_page(struct vm_store *store, off_t offset)
 
 
 static status_t
-anonymous_read(struct vm_store *store, off_t offset, const iovec *vecs, size_t count, size_t *_numBytes)
+anonymous_read(struct vm_store *store, off_t offset, const iovec *vecs, size_t count,
+	size_t *_numBytes, bool fsReenter)
 {
 	panic("anonymous_store: read called. Invalid!\n");
 	return B_ERROR;
@@ -85,7 +86,8 @@ anonymous_read(struct vm_store *store, off_t offset, const iovec *vecs, size_t c
 
 
 static status_t
-anonymous_write(struct vm_store *store, off_t offset, const iovec *vecs, size_t count, size_t *_numBytes)
+anonymous_write(struct vm_store *store, off_t offset, const iovec *vecs, size_t count,
+	size_t *_numBytes, bool fsReenter)
 {
 	// no place to write, this will cause the page daemon to skip this store
 	return 0;

src/system/kernel/vm/vm_store_device.c

@@ -1,5 +1,5 @@
 /*
- * Copyright 2004-2005, Axel Dörfler, axeld@pinc-software.de.
+ * Copyright 2004-2006, Axel Dörfler, axeld@pinc-software.de.
  * Distributed under the terms of the MIT License.
  *
  * Copyright 2001-2002, Travis Geiselbrecht. All rights reserved.
@@ -45,7 +45,8 @@ device_has_page(struct vm_store *store, off_t offset)
 
 
 static status_t
-device_read(struct vm_store *store, off_t offset, const iovec *vecs, size_t count, size_t *_numBytes)
+device_read(struct vm_store *store, off_t offset, const iovec *vecs, size_t count,
+	size_t *_numBytes, bool fsReenter)
 {
 	panic("device_store: read called. Invalid!\n");
 	return B_ERROR;
@@ -53,7 +54,8 @@ device_read(struct vm_store *store, off_t offset, const iovec *vecs, size_t coun
 
 
 static status_t
-device_write(struct vm_store *store, off_t offset, const iovec *vecs, size_t count, size_t *_numBytes)
+device_write(struct vm_store *store, off_t offset, const iovec *vecs, size_t count,
+	size_t *_numBytes, bool fsReenter)
 {
 	// no place to write, this will cause the page daemon to skip this store
 	return B_OK;

src/system/kernel/vm/vm_store_null.c

@@ -1,6 +1,9 @@
 /*
-** Copyright 2001-2002, Travis Geiselbrecht. All rights reserved.
+ * Copyright 2004-2006, Axel Dörfler, axeld@pinc-software.de.
-** Distributed under the terms of the NewOS License.
+ * Distributed under the terms of the MIT License.
+ *
+ * Copyright 2001-2002, Travis Geiselbrecht. All rights reserved.
+ * Distributed under the terms of the NewOS License.
  */
 
 
@@ -32,14 +35,16 @@ null_has_page(struct vm_store *store, off_t offset)
 
 
 static status_t
-null_read(struct vm_store *store, off_t offset, const iovec *vecs, size_t count, size_t *_numBytes)
+null_read(struct vm_store *store, off_t offset, const iovec *vecs, size_t count,
+	size_t *_numBytes, bool fsReenter)
 {
 	return -1;
 }
 
 
 static status_t
-null_write(struct vm_store *store, off_t offset, const iovec *vecs, size_t count, size_t *_numBytes)
+null_write(struct vm_store *store, off_t offset, const iovec *vecs, size_t count,
+	size_t *_numBytes, bool fsReenter)
 {
 	return -1;
 }