VFS: Fix broken zero_pages()

Besides that it failed to actually iterate through the vectors, it
shouldn't try to clear physical memory in the first place. The iovecs
refer to virtual address ranges. Rename it to zero_iovecs() to avoid
confusion.

src/system/kernel/fs/vfs.cpp

@@ -3401,29 +3401,17 @@ dump_vnode_usage(int argc, char** argv)
 
 #endif	// ADD_DEBUGGER_COMMANDS
 
-/*!	Clears an iovec array of physical pages.
-	Returns in \a _bytes the number of bytes successfully cleared.
+
+/*!	Clears memory specified by an iovec array.
 */
-static status_t
-zero_pages(const iovec* vecs, size_t vecCount, size_t* _bytes)
+static void
+zero_iovecs(const iovec* vecs, size_t vecCount, size_t bytes)
 {
-	size_t bytes = *_bytes;
-	size_t index = 0;
-
-	while (bytes > 0) {
-		size_t length = min_c(vecs[index].iov_len, bytes);
-
-		status_t status = vm_memset_physical((addr_t)vecs[index].iov_base, 0,
-			length);
-		if (status != B_OK) {
-			*_bytes -= bytes;
-			return status;
-		}
-
+	for (size_t i = 0; i < vecCount && bytes > 0; i++) {
+		size_t length = std::min(vecs[i].iov_len, bytes);
+		memset(vecs[i].iov_base, 0, length);
 		bytes -= length;
 	}
-
-	return B_OK;
 }
 
 
@@ -3463,7 +3451,8 @@ common_file_io_vec_pages(struct vnode* vnode, void* cookie,
 				&vecs[vecIndex], vecCount - vecIndex, &size);
 		} else {
 			// sparse read
-			status = zero_pages(&vecs[vecIndex], vecCount - vecIndex, &size);
+			zero_iovecs(&vecs[vecIndex], vecCount - vecIndex, size);
+			status = B_OK;
 		}
 		if (status != B_OK)
 			return status;
@@ -3566,7 +3555,8 @@ common_file_io_vec_pages(struct vnode* vnode, void* cookie,
 					status = B_IO_ERROR;
 				} else {
 					// sparse read
-					status = zero_pages(tempVecs, tempCount, &bytes);
+					zero_iovecs(tempVecs, tempCount, bytes);
+					status = B_OK;
 				}
 			} else if (doWrite) {
 				status = FS_CALL(vnode, write_pages, cookie, fileOffset,