cowfs is bootable now!

2007-08-06 11:42:32 +00:00
parent afc51a247f
commit 64a552ae2d
3 changed files with 94 additions and 55 deletions
@@ -67,11 +67,17 @@ struct private_cowfs_t {
 	pthread_t thread;
 };

+/**
+ * get this pointer stored in fuse context
+ */
 static private_cowfs_t *get_this()
 {
 	return (fuse_get_context())->private_data;
 }

+/**
+ * make a path relative
+ */
 static void rel(const char **path)
 {
 	if (**path == '/')
@@ -85,7 +91,7 @@ static void rel(const char **path)
 }

 /**
- * get the filesystem to read something from
+ * get the highest overlay in which path exists
 */
 static int get_rd(const char *path)
 {
@@ -103,7 +109,7 @@ static int get_rd(const char *path)
 }

 /**
- * get the filesystem to write something to
+ * get the highest overlay available, to write something
 */
 static int get_wr(const char *path)
 {
@@ -116,7 +122,7 @@ static int get_wr(const char *path)
 }

 /**
- * create all directories need to create the file "path"
+ * create full "path" at "wr" the same way they exist at "rd"
 */
 static bool clone_path(int rd, int wr, const char *path)
 {
@@ -130,7 +136,7 @@ static bool clone_path(int rd, int wr, const char *path)
 		*pos = '\0';
 		if (fstatat(wr, full, &st, 0) < 0)
 		{
-			/* TODO: handle symlinks! */
+			/* TODO: handle symlinks!? */
 			if (fstatat(rd, full, &st, 0) < 0)
 			{
 				return FALSE;
@@ -147,7 +153,7 @@ static bool clone_path(int rd, int wr, const char *path)
 }

 /**
- * copy a file from a readonly to a read-write overlay
+ * copy a (special) file from a readonly to a read-write overlay
 */
 static int copy(const char *path)
 {
@@ -169,35 +175,44 @@ static int copy(const char *path)
 	{
 		return -1;
 	}
-	from = openat(rd, path, O_RDONLY, st.st_mode);
-	if (from < 0)
-	{
-		return -1;
-	}
 	if (!clone_path(rd, wr, path))
 	{
 		return -1;
 	}
-	to = openat(wr, path, O_WRONLY | O_CREAT, st.st_mode);
-	if (to < 0)
+	if (mknodat(wr, path, st.st_mode, st.st_rdev) < 0)
 	{
-		close(from);
 		return -1;
 	}
-	while ((len = read(from, buf, sizeof(buf))) > 0)
+	/* copy if no special file */
+	if (st.st_size)
 	{
-		if (write(to, buf, len) < len)
+		from = openat(rd, path, O_RDONLY, st.st_mode);
+		if (from < 0)
+		{
+			return -1;
+		}
+		to = openat(wr, path, O_WRONLY , st.st_mode);
+		if (to < 0)
+		{
+			close(from);
+			return -1;
+		}
+		while ((len = read(from, buf, sizeof(buf))) > 0)
+		{
+			if (write(to, buf, len) < len)
+			{
+				/* TODO: only on len < 0 ? */
+				close(from);
+				close(to);
+				return -1;
+			}
+		}
+		close(from);
+		close(to);
+		if (len < 0)
 		{
-			close(from);
-			close(to);
 			return -1;
 		}
-	}
-	close(from);
-	close(to);
-	if (len < 0)
-	{
-		return -1;
 	}
 	return wr;
 }
@@ -423,10 +438,18 @@ static int cowfs_rmdir(const char *path)
 */
 static int cowfs_symlink(const char *from, const char *to)
 {
-	rel(&to);
+	int fd;
+	const char *fromrel = from;

-	/* TODO: relative from? */
-	if (symlinkat(from, get_wr(to), to) < 0)
+	rel(&to);
+	rel(&fromrel);
+
+	fd = get_wr(to);
+	if (!clone_path(get_rd(fromrel), fd, fromrel))
+	{
+		return -errno;
+	}
+	if (symlinkat(from, fd, to) < 0)
 	{
 		return -errno;
 	}
@@ -466,11 +489,22 @@ static int cowfs_rename(const char *from, const char *to)
 */
 static int cowfs_link(const char *from, const char *to)
 {
+	int rd, wr;
+
 	rel(&from);
 	rel(&to);
-
-    if (linkat(get_rd(from), from, get_wr(to), to, 0) < 0)
+	
+	rd = get_rd(from);
+	wr = get_wr(to);
+	
+	if (!clone_path(rd, wr, to))
+	{
+		DBG1("cloning path '%s' failed", to);
+		return -errno;
+	}
+    if (linkat(rd, from, wr, to, 0) < 0)
    {
+		DBG1("linking '%s' to '%s' failed", from, to);
    	return -errno;
 	}
    return 0;
@@ -551,6 +585,7 @@ static int cowfs_truncate(const char *path, off_t size)
 {
 	int fd;
 	struct stat st;
+	
 	private_cowfs_t *this = get_this();

 	rel(&path);
@@ -653,6 +688,7 @@ static int cowfs_read(const char *path, char *buf, size_t size, off_t offset,
 	{
 		return -errno;
 	}
+	
 	res = pread(file, buf, size, offset);
 	if (res < 0)
 	{
@@ -848,7 +884,7 @@ cowfs_t *cowfs_create(char *master, char *host, char *mount)
    this->host = strdup(host);
    this->scen = NULL;
 	
-	if (pthread_create(&this->thread, NULL, (void*)fuse_loop_mt, this->fuse) != 0)
+	if (pthread_create(&this->thread, NULL, (void*)fuse_loop, this->fuse) != 0)
 	{
    	DBG1("creating thread to handle FUSE failed");
    	fuse_unmount(mount, this->chan);
@@ -96,25 +96,25 @@ static iterator_t* create_bridge_iterator(private_dumm_t *this)
 */
 void signal_handler(int sig, siginfo_t *info, void *ucontext)
 {
-	private_dumm_t *this;
-	guest_t *guest;
-	iterator_t *iterator, *guests;
-
 	if (sig == SIGCHLD)
 	{
-		iterator = instances->create_iterator(instances, TRUE);
-		while (iterator->iterate(iterator, (void**)&this))
+		switch (info->si_code)
 		{
-			if (this->destroying)
+			case CLD_EXITED:
+			case CLD_KILLED:
+			case CLD_DUMPED:
 			{
-				continue;
-			}
-			switch (info->si_code)
-			{
-				case CLD_EXITED:
-				case CLD_KILLED:
-				case CLD_DUMPED:
+				private_dumm_t *this;
+				guest_t *guest;
+				iterator_t *iterator, *guests;
+				
+				iterator = instances->create_iterator(instances, TRUE);
+				while (iterator->iterate(iterator, (void**)&this))
 				{
+					if (this->destroying)
+					{
+						continue;
+					}
 					guests = this->guests->create_iterator(this->guests, TRUE);
 					while (guests->iterate(guests, (void**)&guest))
 					{
@@ -125,13 +125,14 @@ void signal_handler(int sig, siginfo_t *info, void *ucontext)
 						}
 					}
 					guests->destroy(guests);
-					break;
 				}
-				default:
-					break;
+				iterator->destroy(iterator);
+				break;
 			}
+			default:
+				break;
 		}
-		iterator->destroy(iterator);
+
 	}
 	/* SIGHUP is currently just ignored */
 }
@@ -170,10 +170,8 @@ static void stop(private_guest_t *this)
 		this->ifaces->destroy_offset(this->ifaces, offsetof(iface_t, destroy));
 		this->ifaces = linked_list_create();
 		kill(this->pid, SIGINT);
-		while (this->state == GUEST_STOPPING)
-		{
-			sched_yield();
-		}
+		waitpid(this->pid, NULL, 0);
+		this->state = GUEST_STOPPED;
 	}
 }

@@ -208,7 +206,8 @@ static bool start(private_guest_t *this, char *kernel)
 	args[i++] = write_arg(&pos, &left, "mconsole=notify:%s", notify);
 	/*args[i++] = write_arg(&pos, &left, "con=pts");*/
 	args[i++] = write_arg(&pos, &left, "con0=null,fd:%d", this->bootlog);
-	/*args[i++] = write_arg(&pos, &left, "con1=fd:0,fd:1");*/
+	//args[i++] = write_arg(&pos, &left, "con0=fd:0,fd:1");
+	//args[i++] = write_arg(&pos, &left, "con1=null,null");
 	args[i++] = write_arg(&pos, &left, "con2=null,null");
 	args[i++] = write_arg(&pos, &left, "con3=null,null");
 	args[i++] = write_arg(&pos, &left, "con4=null,null");
@@ -221,8 +220,8 @@ static bool start(private_guest_t *this, char *kernel)
 	{
 		case 0: /* child,  */
 			dup2(open("/dev/null", 0), 0);
-			dup2(open("/dev/null", 0), 1);
-			dup2(open("/dev/null", 0), 2);
+			dup2(this->bootlog, 1);
+			dup2(this->bootlog, 2);
 			execvp(args[0], args);
 			DBG1("starting UML kernel '%s' failed: %m", args[0]);
 			exit(1);
@@ -249,7 +248,10 @@ static bool start(private_guest_t *this, char *kernel)
 */
 static void sigchild(private_guest_t *this)
 {
-	waitpid(this->pid, NULL, WNOHANG);
+	if (this->state != GUEST_STOPPING)
+	{	/* collect zombie if uml crashed */
+		waitpid(this->pid, NULL, WNOHANG);
+	}
 	DESTROY_IF(this->mconsole);
 	this->mconsole = NULL;
 	this->state = GUEST_STOPPED;