kernel: remove HANDLE_NULLFS

It was a dumb hack that wasn't even necessary - an error when mounting should
shadow over the mountpoint anyways.

2 files changed, 21 insertions, 27 deletions

diff --git a/src/kernel/handleset.c b/src/kernel/handleset.c
index b52eaa0..a25f5c7 100644
--- a/src/kernel/handleset.c
+++ b/src/kernel/handleset.c
@@ -55,15 +55,7 @@ hs_findfree(HandleSet *hs, hid_t start)
 Handle *
 hs_get(HandleSet *hs, hid_t id)
 {
-	if (id == HANDLE_NULLFS) {
-		// TODO get rid of this stupid hack
-		static Handle h = (Handle){
-			.type = HANDLE_FS_FRONT,
-			.backend = NULL,
-			.refcount = 2, /* never free */
-		};
-		return &h;
-	} else if (0 <= id && id < HANDLE_MAX) {
+	if (0 <= id && id < HANDLE_MAX) {
 		return hs->h[id];
 	} else {
 		return NULL;
@@ -107,7 +99,7 @@ Handle *
 hs_take(HandleSet *hs, hid_t hid)
 {
 	if (hid < 0 || hid >= HANDLE_MAX) {
-		return hs_get(hs, hid); // TODO can't this cause HANDLE_NULLFS to be freed?
+		return NULL;
 	}
 	Handle *h = hs->h[hid];
 	hs->h[hid] = NULL;
diff --git a/src/kernel/syscalls.c b/src/kernel/syscalls.c
index da6b48f..9b0746a 100644
--- a/src/kernel/syscalls.c
+++ b/src/kernel/syscalls.c
@@ -63,7 +63,7 @@ hid_t _sys_open(const char __user *path, long len, int flags) {
 	if (flags & ~(OPEN_RW | OPEN_CREATE)) SYSCALL_RETURN(-ENOSYS);
 
 	if (PATH_MAX < len)
-		SYSCALL_RETURN(-1);
+		SYSCALL_RETURN(-ENAMETOOLONG);
 	/* Doesn't check for free handles. Another thread could use up all
 	 * handles in the meantime anyways, or free some up. */
 
@@ -86,16 +86,16 @@ hid_t _sys_open(const char __user *path, long len, int flags) {
 	}
 
 	vfsreq_create((VfsReq) {
-			.type = VFSOP_OPEN,
-			.input = {
-				.kern = true,
-				.buf_kern = path_buf,
-				.len = len,
-			},
-			.caller = proc_cur,
-			.backend = mount->backend,
-			.flags = flags,
-		});
+		.type = VFSOP_OPEN,
+		.input = {
+			.kern = true,
+			.buf_kern = path_buf,
+			.len = len,
+		},
+		.caller = proc_cur,
+		.backend = mount->backend,
+		.flags = flags,
+	});
 	return -1; // dummy
 fail:
 	kfree(path_buf);
@@ -125,12 +125,14 @@ long _sys_mount(hid_t hid, const char __user *path, long len) {
 	}
 
 	Handle *handle = hs_get(proc_cur->hs, hid);
-	if (!handle || handle->type != HANDLE_FS_FRONT)
-		goto fail;
-	backend = handle->backend;
-	if (backend) {
-		assert(backend->usehcnt);
-		backend->usehcnt++;
+	if (handle && handle->type == HANDLE_FS_FRONT) {
+		backend = handle->backend;
+		if (backend) {
+			assert(backend->usehcnt);
+			backend->usehcnt++;
+		}
+	} else {
+		backend = NULL;
 	}
 
 	// append to mount list