add an offset parameter to read() and write()

3 files changed, 10 insertions, 6 deletions

diff --git a/src/kernel/syscalls.c b/src/kernel/syscalls.c
index bc185bd..d321d33 100644
--- a/src/kernel/syscalls.c
+++ b/src/kernel/syscalls.c
@@ -136,7 +136,7 @@ fail:
 	return -1;
 }
 
-int _syscall_read(handle_t handle_num, char __user *buf, int len) {
+int _syscall_read(handle_t handle_num, char __user *buf, int len, int offset) {
 	struct handle *handle = &process_current->handles[handle_num];
 	if (handle_num < 0 || handle_num >= HANDLE_MAX) return -1;
 	if (handle->type != HANDLE_FILE) return -1;
@@ -147,12 +147,13 @@ int _syscall_read(handle_t handle_num, char __user *buf, int len) {
 				.len = len,
 			},
 			.id = handle->file.id,
+			.offset = offset,
 			.caller = process_current,
 			.backend = handle->file.backend,
 		});
 }
 
-int _syscall_write(handle_t handle_num, const char __user *buf, int len) {
+int _syscall_write(handle_t handle_num, const char __user *buf, int len, int offset) {
 	struct handle *handle = &process_current->handles[handle_num];
 	if (handle_num < 0 || handle_num >= HANDLE_MAX) return -1;
 	if (handle->type != HANDLE_FILE) return -1;
@@ -163,6 +164,7 @@ int _syscall_write(handle_t handle_num, const char __user *buf, int len) {
 				.len = len,
 			},
 			.id = handle->file.id,
+			.offset = offset,
 			.caller = process_current,
 			.backend = handle->file.backend,
 		});
@@ -286,9 +288,9 @@ int _syscall(int num, int a, int b, int c, int d) {
 		case _SYSCALL_MOUNT:
 			return _syscall_mount(a, (userptr_t)b, c);
 		case _SYSCALL_READ:
-			return _syscall_read(a, (userptr_t)b, c);
+			return _syscall_read(a, (userptr_t)b, c, d);
 		case _SYSCALL_WRITE:
-			return _syscall_write(a, (userptr_t)b, c);
+			return _syscall_write(a, (userptr_t)b, c, d);
 		case _SYSCALL_CLOSE:
 			return _syscall_close(a);
 		case _SYSCALL_FS_CREATE:
diff --git a/src/kernel/vfs/request.c b/src/kernel/vfs/request.c
index 33a8458..b197f4b 100644
--- a/src/kernel/vfs/request.c
+++ b/src/kernel/vfs/request.c
@@ -64,8 +64,9 @@ _Noreturn void vfs_request_pass2handler(struct vfs_request *req) {
 			goto fail; // can't copy buffer
 	}
 
-	res.len = len;
-	res.id = req->id;
+	res.len    = len;
+	res.id     = req->id;
+	res.offset = req->offset;
 
 	if (!virt_cpy_to(handler->pages,
 				handler->awaited_req.res, &res, sizeof res))
diff --git a/src/kernel/vfs/request.h b/src/kernel/vfs/request.h
index a03fba9..0e96db6 100644
--- a/src/kernel/vfs/request.h
+++ b/src/kernel/vfs/request.h
@@ -34,6 +34,7 @@ struct vfs_request {
 	} output;
 
 	int id; // handle.file.id
+	int offset;
 
 	struct process *caller;
 	struct vfs_backend *backend;