X-Git-Url: http://git.annexia.org/?p=libguestfs.git;a=blobdiff_plain;f=src%2Fguestfs.c;h=72cd2f36693f7d4b2cf8b06b944f44942bec71fa;hp=dec9a1b0da5cb3f2c83b3a70845f52be4ba44a1d;hb=7c3a90f94cd6b8fec9cdd1c052b91a14c0ee0e0e;hpb=c5b2282111ead9a0c59db5f40229d20fe0203681

diff --git a/src/guestfs.c b/src/guestfs.c
index dec9a1b..72cd2f3 100644
--- a/src/guestfs.c
+++ b/src/guestfs.c
@@ -1,5 +1,5 @@
 /* libguestfs
- * Copyright (C) 2009 Red Hat Inc. 
+ * Copyright (C) 2009 Red Hat Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -24,12 +24,16 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdarg.h>
+#include <stddef.h>
 #include <unistd.h>
 #include <ctype.h>
 #include <string.h>
 #include <fcntl.h>
 #include <time.h>
+#include <sys/stat.h>
 #include <sys/select.h>
+#include <dirent.h>
+
 #include <rpc/types.h>
 #include <rpc/xdr.h>
 
@@ -56,6 +60,15 @@
 #include "guestfs.h"
 #include "guestfs_protocol.h"
 
+#ifdef HAVE_GETTEXT
+#include "gettext.h"
+#define _(str) dgettext(PACKAGE, (str))
+#define N_(str) dgettext(PACKAGE, (str))
+#else
+#define _(str) str
+#define N_(str) str
+#endif
+
 #define error guestfs_error
 #define perrorf guestfs_perrorf
 #define safe_malloc guestfs_safe_malloc
@@ -141,7 +154,8 @@ struct guestfs_h
 
   int fd[2];			/* Stdin/stdout of qemu. */
   int sock;			/* Daemon communications socket. */
-  int pid;			/* Qemu PID. */
+  pid_t pid;			/* Qemu PID. */
+  pid_t recoverypid;		/* Recovery process PID. */
   time_t start_t;		/* The time when we started qemu. */
 
   int stdout_watch;		/* Watches qemu stdout for log messages. */
@@ -149,14 +163,19 @@ struct guestfs_h
 
   char *tmpdir;			/* Temporary directory containing socket. */
 
+  char *qemu_help, *qemu_version; /* Output of qemu -help, qemu -version. */
+
   char **cmdline;		/* Qemu command line. */
   int cmdline_size;
 
   int verbose;
   int autosync;
 
-  const char *path;
-  const char *qemu;
+  char *path;			/* Path to kernel, initrd. */
+  char *qemu;			/* Qemu binary. */
+  char *append;			/* Append to kernel command line. */
+
+  int memsize;			/* Size of RAM (megabytes). */
 
   char *last_error;
 
@@ -217,10 +236,34 @@ guestfs_create (void)
   g->verbose = str != NULL && strcmp (str, "1") == 0;
 
   str = getenv ("LIBGUESTFS_PATH");
-  g->path = str != NULL ? str : GUESTFS_DEFAULT_PATH;
+  g->path = str != NULL ? strdup (str) : strdup (GUESTFS_DEFAULT_PATH);
+  if (!g->path) goto error;
 
   str = getenv ("LIBGUESTFS_QEMU");
-  g->qemu = str != NULL ? str : QEMU;
+  g->qemu = str != NULL ? strdup (str) : strdup (QEMU);
+  if (!g->qemu) goto error;
+
+  str = getenv ("LIBGUESTFS_APPEND");
+  if (str) {
+    g->append = strdup (str);
+    if (!g->append) goto error;
+  }
+
+  /* Choose a suitable memory size.  Previously we tried to choose
+   * a minimal memory size, but this isn't really necessary since
+   * recent QEMU and KVM don't do anything nasty like locking
+   * memory into core any more.  Thus we can safely choose a
+   * large, generous amount of memory, and it'll just get swapped
+   * on smaller systems.
+   */
+  str = getenv ("LIBGUESTFS_MEMSIZE");
+  if (str) {
+    if (sscanf (str, "%d", &g->memsize) != 1 || g->memsize <= 256) {
+      fprintf (stderr, "libguestfs: non-numeric or too small value for LIBGUESTFS_MEMSIZE\n");
+      goto error;
+    }
+  } else
+    g->memsize = 500;
 
   g->main_loop = guestfs_get_default_main_loop ();
 
@@ -245,6 +288,13 @@ guestfs_create (void)
     fprintf (stderr, "new guestfs handle %p\n", g);
 
   return g;
+
+ error:
+  free (g->path);
+  free (g->qemu);
+  free (g->append);
+  free (g);
+  return NULL;
 }
 
 void
@@ -256,7 +306,7 @@ guestfs_close (guestfs_h *g)
 
   if (g->state == NO_HANDLE) {
     /* Not safe to call 'error' here, so ... */
-    fprintf (stderr, "guestfs_close: called twice on the same handle\n");
+    fprintf (stderr, _("guestfs_close: called twice on the same handle\n"));
     return;
   }
 
@@ -264,8 +314,10 @@ guestfs_close (guestfs_h *g)
     fprintf (stderr, "closing guestfs handle %p (state %d)\n", g, g->state);
 
   /* Try to sync if autosync flag is set. */
-  if (g->autosync && g->state == READY)
+  if (g->autosync && g->state == READY) {
+    guestfs_umount_all (g);
     guestfs_sync (g);
+  }
 
   /* Remove any handlers that might be called back before we kill the
    * subprocess.
@@ -275,10 +327,35 @@ guestfs_close (guestfs_h *g)
   if (g->state != CONFIG)
     guestfs_kill_subprocess (g);
 
+  /* Close any sockets and deregister any handlers. */
+  if (g->stdout_watch >= 0)
+    g->main_loop->remove_handle (g->main_loop, g, g->stdout_watch);
+  if (g->sock_watch >= 0)
+    g->main_loop->remove_handle (g->main_loop, g, g->sock_watch);
+  g->stdout_watch = -1;
+  g->sock_watch = -1;
+
+  if (g->fd[0] >= 0)
+    close (g->fd[0]);
+  if (g->fd[1] >= 0)
+    close (g->fd[1]);
+  if (g->sock >= 0)
+    close (g->sock);
+  g->fd[0] = -1;
+  g->fd[1] = -1;
+  g->sock = -1;
+
+  /* Remove tmpfiles. */
   if (g->tmpdir) {
     snprintf (filename, sizeof filename, "%s/sock", g->tmpdir);
     unlink (filename);
 
+    snprintf (filename, sizeof filename, "%s/initrd", g->tmpdir);
+    unlink (filename);
+
+    snprintf (filename, sizeof filename, "%s/kernel", g->tmpdir);
+    unlink (filename);
+
     rmdir (g->tmpdir);
 
     free (g->tmpdir);
@@ -303,7 +380,14 @@ guestfs_close (guestfs_h *g)
   }
   /* release mutex (XXX) */
 
+  free (g->msg_in);
+  free (g->msg_out);
   free (g->last_error);
+  free (g->path);
+  free (g->qemu);
+  free (g->append);
+  free (g->qemu_help);
+  free (g->qemu_version);
   free (g);
 }
 
@@ -330,7 +414,7 @@ set_last_error (guestfs_h *g, const char *msg)
 static void
 default_error_cb (guestfs_h *g, void *data, const char *msg)
 {
-  fprintf (stderr, "libguestfs: error: %s\n", msg);
+  fprintf (stderr, _("libguestfs: error: %s\n"), msg);
 }
 
 void
@@ -340,9 +424,11 @@ guestfs_error (guestfs_h *g, const char *fs, ...)
   char *msg;
 
   va_start (args, fs);
-  vasprintf (&msg, fs, args);
+  int err = vasprintf (&msg, fs, args);
   va_end (args);
 
+  if (err < 0) return;
+
   if (g->error_cb) g->error_cb (g, g->error_cb_data, msg);
   set_last_error (g, msg);
 
@@ -383,15 +469,51 @@ void *
 guestfs_safe_malloc (guestfs_h *g, size_t nbytes)
 {
   void *ptr = malloc (nbytes);
-  if (!ptr) g->abort_cb ();
+  if (nbytes > 0 && !ptr) g->abort_cb ();
   return ptr;
 }
 
+/* Return 1 if an array of N objects, each of size S, cannot exist due
+   to size arithmetic overflow.  S must be positive and N must be
+   nonnegative.  This is a macro, not an inline function, so that it
+   works correctly even when SIZE_MAX < N.
+
+   By gnulib convention, SIZE_MAX represents overflow in size
+   calculations, so the conservative dividend to use here is
+   SIZE_MAX - 1, since SIZE_MAX might represent an overflowed value.
+   However, malloc (SIZE_MAX) fails on all known hosts where
+   sizeof (ptrdiff_t) <= sizeof (size_t), so do not bother to test for
+   exactly-SIZE_MAX allocations on such hosts; this avoids a test and
+   branch when S is known to be 1.  */
+# define xalloc_oversized(n, s) \
+    ((size_t) (sizeof (ptrdiff_t) <= sizeof (size_t) ? -1 : -2) / (s) < (n))
+
+/* Technically we should add an autoconf test for this, testing for the desired
+   functionality, like what's done in gnulib, but for now, this is fine.  */
+#define HAVE_GNU_CALLOC (__GLIBC__ >= 2)
+
+/* Allocate zeroed memory for N elements of S bytes, with error
+   checking.  S must be nonzero.  */
+void *
+guestfs_safe_calloc (guestfs_h *g, size_t n, size_t s)
+{
+  /* From gnulib's calloc function in xmalloc.c.  */
+  void *p;
+  /* Test for overflow, since some calloc implementations don't have
+     proper overflow checks.  But omit overflow and size-zero tests if
+     HAVE_GNU_CALLOC, since GNU calloc catches overflow and never
+     returns NULL if successful.  */
+  if ((! HAVE_GNU_CALLOC && xalloc_oversized (n, s))
+      || (! (p = calloc (n, s)) && (HAVE_GNU_CALLOC || n != 0)))
+    g->abort_cb ();
+  return p;
+}
+
 void *
 guestfs_safe_realloc (guestfs_h *g, void *ptr, int nbytes)
 {
   void *p = realloc (ptr, nbytes);
-  if (!p) g->abort_cb ();
+  if (nbytes > 0 && !p) g->abort_cb ();
   return p;
 }
 
@@ -436,8 +558,11 @@ xread (int fd, void *buf, size_t len)
 
   while (len > 0) {
     r = read (fd, buf, len);
-    if (r == -1)
+    if (r == -1) {
+      if (errno == EINTR || errno == EAGAIN)
+	continue;
       return -1;
+    }
 
     buf += r;
     len -= r;
@@ -501,10 +626,12 @@ guestfs_get_autosync (guestfs_h *g)
 int
 guestfs_set_path (guestfs_h *g, const char *path)
 {
-  if (path == NULL)
-    g->path = GUESTFS_DEFAULT_PATH;
-  else
-    g->path = path;
+  free (g->path);
+  g->path = NULL;
+
+  g->path =
+    path == NULL ?
+    safe_strdup (g, GUESTFS_DEFAULT_PATH) : safe_strdup (g, path);
   return 0;
 }
 
@@ -517,10 +644,10 @@ guestfs_get_path (guestfs_h *g)
 int
 guestfs_set_qemu (guestfs_h *g, const char *qemu)
 {
-  if (qemu == NULL)
-    g->qemu = QEMU;
-  else
-    g->qemu = qemu;
+  free (g->qemu);
+  g->qemu = NULL;
+
+  g->qemu = qemu == NULL ? safe_strdup (g, QEMU) : safe_strdup (g, qemu);
   return 0;
 }
 
@@ -530,6 +657,59 @@ guestfs_get_qemu (guestfs_h *g)
   return g->qemu;
 }
 
+int
+guestfs_set_append (guestfs_h *g, const char *append)
+{
+  free (g->append);
+  g->append = NULL;
+
+  g->append = append ? safe_strdup (g, append) : NULL;
+  return 0;
+}
+
+const char *
+guestfs_get_append (guestfs_h *g)
+{
+  return g->append;
+}
+
+int
+guestfs_set_memsize (guestfs_h *g, int memsize)
+{
+  g->memsize = memsize;
+  return 0;
+}
+
+int
+guestfs_get_memsize (guestfs_h *g)
+{
+  return g->memsize;
+}
+
+int
+guestfs_get_pid (guestfs_h *g)
+{
+  if (g->pid > 0)
+    return g->pid;
+  else {
+    error (g, "get_pid: no qemu subprocess");
+    return -1;
+  }
+}
+
+struct guestfs_version *
+guestfs_version (guestfs_h *g)
+{
+  struct guestfs_version *r;
+
+  r = safe_malloc (g, sizeof *r);
+  r->major = PACKAGE_VERSION_MAJOR;
+  r->minor = PACKAGE_VERSION_MINOR;
+  r->release = PACKAGE_VERSION_RELEASE;
+  r->extra = safe_strdup (g, PACKAGE_VERSION_EXTRA);
+  return r;
+}
+
 /* Add a string to the current command line. */
 static void
 incr_cmdline_size (guestfs_h *g)
@@ -549,7 +729,8 @@ static int
 add_cmdline (guestfs_h *g, const char *str)
 {
   if (g->state != CONFIG) {
-    error (g, "command line cannot be altered after qemu subprocess launched");
+    error (g,
+        _("command line cannot be altered after qemu subprocess launched"));
     return -1;
   }
 
@@ -563,7 +744,7 @@ guestfs_config (guestfs_h *g,
 		const char *qemu_param, const char *qemu_value)
 {
   if (qemu_param[0] != '-') {
-    error (g, "guestfs_config: parameter must begin with '-' character");
+    error (g, _("guestfs_config: parameter must begin with '-' character"));
     return -1;
   }
 
@@ -574,11 +755,10 @@ guestfs_config (guestfs_h *g,
       strcmp (qemu_param, "-initrd") == 0 ||
       strcmp (qemu_param, "-nographic") == 0 ||
       strcmp (qemu_param, "-serial") == 0 ||
-      strcmp (qemu_param, "-vnc") == 0 ||
       strcmp (qemu_param, "-full-screen") == 0 ||
       strcmp (qemu_param, "-std-vga") == 0 ||
       strcmp (qemu_param, "-vnc") == 0) {
-    error (g, "guestfs_config: parameter '%s' isn't allowed", qemu_param);
+    error (g, _("guestfs_config: parameter '%s' isn't allowed"), qemu_param);
     return -1;
   }
 
@@ -594,11 +774,11 @@ guestfs_config (guestfs_h *g,
 int
 guestfs_add_drive (guestfs_h *g, const char *filename)
 {
-  int len = strlen (filename) + 64;
+  size_t len = strlen (filename) + 64;
   char buf[len];
 
   if (strchr (filename, ',') != NULL) {
-    error (g, "filename cannot contain ',' (comma) character");
+    error (g, _("filename cannot contain ',' (comma) character"));
     return -1;
   }
 
@@ -607,7 +787,29 @@ guestfs_add_drive (guestfs_h *g, const char *filename)
     return -1;
   }
 
-  snprintf (buf, len, "file=%s", filename);
+  /* cache=off improves reliability in the event of a host crash. */
+  snprintf (buf, len, "file=%s,cache=off,if=%s", filename, DRIVE_IF);
+
+  return guestfs_config (g, "-drive", buf);
+}
+
+int
+guestfs_add_drive_ro (guestfs_h *g, const char *filename)
+{
+  size_t len = strlen (filename) + 64;
+  char buf[len];
+
+  if (strchr (filename, ',') != NULL) {
+    error (g, _("filename cannot contain ',' (comma) character"));
+    return -1;
+  }
+
+  if (access (filename, F_OK) == -1) {
+    perrorf (g, "%s", filename);
+    return -1;
+  }
+
+  snprintf (buf, len, "file=%s,snapshot=on,if=%s", filename, DRIVE_IF);
 
   return guestfs_config (g, "-drive", buf);
 }
@@ -616,7 +818,7 @@ int
 guestfs_add_cdrom (guestfs_h *g, const char *filename)
 {
   if (strchr (filename, ',') != NULL) {
-    error (g, "filename cannot contain ',' (comma) character");
+    error (g, _("filename cannot contain ',' (comma) character"));
     return -1;
   }
 
@@ -628,32 +830,96 @@ guestfs_add_cdrom (guestfs_h *g, const char *filename)
   return guestfs_config (g, "-cdrom", filename);
 }
 
+/* Returns true iff file is contained in dir. */
+static int
+dir_contains_file (const char *dir, const char *file)
+{
+  int dirlen = strlen (dir);
+  int filelen = strlen (file);
+  int len = dirlen+filelen+2;
+  char path[len];
+
+  snprintf (path, len, "%s/%s", dir, file);
+  return access (path, F_OK) == 0;
+}
+
+/* Returns true iff every listed file is contained in 'dir'. */
+static int
+dir_contains_files (const char *dir, ...)
+{
+  va_list args;
+  const char *file;
+
+  va_start (args, dir);
+  while ((file = va_arg (args, const char *)) != NULL) {
+    if (!dir_contains_file (dir, file)) {
+      va_end (args);
+      return 0;
+    }
+  }
+  va_end (args);
+  return 1;
+}
+
+static int build_supermin_appliance (guestfs_h *g, const char *path, char **kernel, char **initrd);
+static int test_qemu (guestfs_h *g);
+static int qemu_supports (guestfs_h *g, const char *option);
+
+static const char *kernel_name = "vmlinuz." REPO "." host_cpu;
+static const char *initrd_name = "initramfs." REPO "." host_cpu ".img";
+static const char *supermin_name =
+  "initramfs." REPO "." host_cpu ".supermin.img";
+static const char *supermin_hostfiles_name =
+  "initramfs." REPO "." host_cpu ".supermin.hostfiles";
+
 int
 guestfs_launch (guestfs_h *g)
 {
-  static const char *dir_template = "/tmp/libguestfsXXXXXX";
-  int r, i, len, pmore;
+  const char *tmpdir;
+  char dir_template[PATH_MAX];
+  int r, i, pmore;
+  size_t len;
   int wfd[2], rfd[2];
   int tries;
-  const char *kernel_name = "vmlinuz." REPO "." host_cpu;
-  const char *initrd_name = "initramfs." REPO "." host_cpu ".img";
   char *path, *pelem, *pend;
   char *kernel = NULL, *initrd = NULL;
   char unixsock[256];
   struct sockaddr_un addr;
 
+#ifdef P_tmpdir
+  tmpdir = P_tmpdir;
+#else
+  tmpdir = "/tmp";
+#endif
+
+  tmpdir = getenv ("TMPDIR") ? : tmpdir;
+  snprintf (dir_template, sizeof dir_template, "%s/libguestfsXXXXXX", tmpdir);
+
   /* Configured? */
   if (!g->cmdline) {
-    error (g, "you must call guestfs_add_drive before guestfs_launch");
+    error (g, _("you must call guestfs_add_drive before guestfs_launch"));
     return -1;
   }
 
   if (g->state != CONFIG) {
-    error (g, "qemu has already been launched");
+    error (g, _("qemu has already been launched"));
     return -1;
   }
 
-  /* Search g->path for the kernel and initrd. */
+  /* Make the temporary directory. */
+  if (!g->tmpdir) {
+    g->tmpdir = safe_strdup (g, dir_template);
+    if (mkdtemp (g->tmpdir) == NULL) {
+      perrorf (g, _("%s: cannot create temporary directory"), dir_template);
+      goto cleanup0;
+    }
+  }
+
+  /* First search g->path for the supermin appliance, and try to
+   * synthesize a kernel and initrd from that.  If it fails, we
+   * try the path search again looking for a backup ordinary
+   * appliance.
+   */
   pelem = path = safe_strdup (g, g->path);
   do {
     pend = strchrnul (pelem, ':');
@@ -661,32 +927,31 @@ guestfs_launch (guestfs_h *g)
     *pend = '\0';
     len = pend - pelem;
 
-    /* Empty element or "." means cwd. */
+    /* Empty element of "." means cwd. */
     if (len == 0 || (len == 1 && *pelem == '.')) {
       if (g->verbose)
 	fprintf (stderr,
-		 "looking for kernel and initrd in current directory\n");
-      if (access (kernel_name, F_OK) == 0 && access (initrd_name, F_OK) == 0) {
-	kernel = safe_strdup (g, kernel_name);
-	initrd = safe_strdup (g, initrd_name);
+		 "looking for supermin appliance in current directory\n");
+      if (dir_contains_files (".",
+			      supermin_name, supermin_hostfiles_name,
+			      "kmod.whitelist", NULL)) {
+	if (build_supermin_appliance (g, ".", &kernel, &initrd) == -1)
+	  return -1;
 	break;
       }
     }
-    /* Look at <path>/kernel etc. */
+    /* Look at <path>/supermin* etc. */
     else {
-      kernel = safe_malloc (g, len + strlen (kernel_name) + 2);
-      initrd = safe_malloc (g, len + strlen (initrd_name) + 2);
-      sprintf (kernel, "%s/%s", pelem, kernel_name);
-      sprintf (initrd, "%s/%s", pelem, initrd_name);
-
       if (g->verbose)
-	fprintf (stderr, "looking for %s and %s\n", kernel, initrd);
+	fprintf (stderr, "looking for supermin appliance in %s\n", pelem);
 
-      if (access (kernel, F_OK) == 0 && access (initrd, F_OK) == 0)
+      if (dir_contains_files (pelem,
+			      supermin_name, supermin_hostfiles_name,
+			      "kmod.whitelist", NULL)) {
+	if (build_supermin_appliance (g, pelem, &kernel, &initrd) == -1)
+	  return -1;
 	break;
-      free (kernel);
-      free (initrd);
-      kernel = initrd = NULL;
+      }
     }
 
     pelem = pend + 1;
@@ -695,20 +960,56 @@ guestfs_launch (guestfs_h *g)
   free (path);
 
   if (kernel == NULL || initrd == NULL) {
-    error (g, "cannot find %s or %s on LIBGUESTFS_PATH (current path = %s)",
+    /* Search g->path for the kernel and initrd. */
+    pelem = path = safe_strdup (g, g->path);
+    do {
+      pend = strchrnul (pelem, ':');
+      pmore = *pend == ':';
+      *pend = '\0';
+      len = pend - pelem;
+
+      /* Empty element or "." means cwd. */
+      if (len == 0 || (len == 1 && *pelem == '.')) {
+	if (g->verbose)
+	  fprintf (stderr,
+		   "looking for appliance in current directory\n");
+	if (dir_contains_files (".", kernel_name, initrd_name, NULL)) {
+	  kernel = safe_strdup (g, kernel_name);
+	  initrd = safe_strdup (g, initrd_name);
+	  break;
+	}
+      }
+      /* Look at <path>/kernel etc. */
+      else {
+	if (g->verbose)
+	  fprintf (stderr, "looking for appliance in %s\n", pelem);
+
+	if (dir_contains_files (pelem, kernel_name, initrd_name, NULL)) {
+	  kernel = safe_malloc (g, len + strlen (kernel_name) + 2);
+	  initrd = safe_malloc (g, len + strlen (initrd_name) + 2);
+	  sprintf (kernel, "%s/%s", pelem, kernel_name);
+	  sprintf (initrd, "%s/%s", pelem, initrd_name);
+	  break;
+	}
+      }
+
+      pelem = pend + 1;
+    } while (pmore);
+
+    free (path);
+  }
+
+  if (kernel == NULL || initrd == NULL) {
+    error (g, _("cannot find %s or %s on LIBGUESTFS_PATH (current path = %s)"),
 	   kernel_name, initrd_name, g->path);
     goto cleanup0;
   }
 
-  /* Make the temporary directory containing the socket. */
-  if (!g->tmpdir) {
-    g->tmpdir = safe_strdup (g, dir_template);
-    if (mkdtemp (g->tmpdir) == NULL) {
-      perrorf (g, "%s: cannot create temporary directory", dir_template);
-      goto cleanup0;
-    }
-  }
+  /* Get qemu help text and version. */
+  if (test_qemu (g) == -1)
+    goto cleanup0;
 
+  /* Make the vmchannel socket. */
   snprintf (unixsock, sizeof unixsock, "%s/sock", g->tmpdir);
   unlink (unixsock);
 
@@ -730,28 +1031,33 @@ guestfs_launch (guestfs_h *g)
   if (r == 0) {			/* Child (qemu). */
     char vmchannel[256];
     char append[256];
+    char memsize_str[256];
 
     /* Set up the full command line.  Do this in the subprocess so we
      * don't need to worry about cleaning up.
      */
-    g->cmdline[0] = (char *) g->qemu;
+    g->cmdline[0] = g->qemu;
 
-    /* Construct the -net channel parameter for qemu. */
-    snprintf (vmchannel, sizeof vmchannel,
-	      "channel,%d:unix:%s,server,nowait",
-	      VMCHANNEL_PORT, unixsock);
+#define LINUX_CMDLINE							\
+    "panic=1 "         /* force kernel to panic if daemon exits */	\
+    "console=ttyS0 "   /* serial console */				\
+    "udevtimeout=300 " /* good for very slow systems (RHBZ#480319) */	\
+    "noapic "          /* workaround for RHBZ#502058 - ok if not SMP */ \
+    "acpi=off "        /* we don't need ACPI, turn it off */		\
+    "cgroup_disable=memory " /* saves us about 5 MB of RAM */
 
     /* Linux kernel command line. */
     snprintf (append, sizeof append,
-	      "console=ttyS0 guestfs=%s:%d%s",
+	      LINUX_CMDLINE "guestfs=%s:%d%s%s%s",
 	      VMCHANNEL_ADDR, VMCHANNEL_PORT,
-	      g->verbose ? " guestfs_verbose=1" : "");
+	      g->verbose ? " guestfs_verbose=1" : "",
+	      g->append ? " " : "", g->append ? g->append : "");
+
+    snprintf (memsize_str, sizeof memsize_str, "%d", g->memsize);
 
     add_cmdline (g, "-m");
-    add_cmdline (g, "384");	  /* XXX Choose best size. */
-#if 0
-    add_cmdline (g, "-no-kqemu"); /* Avoids a warning. */
-#endif
+    add_cmdline (g, memsize_str);
+    add_cmdline (g, "-no-reboot"); /* Force exit instead of reboot on panic */
     add_cmdline (g, "-kernel");
     add_cmdline (g, (char *) kernel);
     add_cmdline (g, "-initrd");
@@ -761,12 +1067,49 @@ guestfs_launch (guestfs_h *g)
     add_cmdline (g, "-nographic");
     add_cmdline (g, "-serial");
     add_cmdline (g, "stdio");
+
+#if 0
+    /* Doesn't work.  See:
+     * http://lists.gnu.org/archive/html/qemu-devel/2009-07/threads.html
+     * Subject "guestfwd option doesn't allow supplementary ,server,nowait"
+     */
+    if (qemu_supports (g, "guestfwd")) {
+      /* New-style -net user,guestfwd=... syntax for vmchannel.  See:
+       * http://git.savannah.gnu.org/cgit/qemu.git/commit/?id=c92ef6a22d3c71538fcc48fb61ad353f7ba03b62
+       */
+      snprintf (vmchannel, sizeof vmchannel,
+		"user,vlan=0,guestfwd=tcp:%s:%d-unix:%s,server,nowait",
+		VMCHANNEL_ADDR, VMCHANNEL_PORT, unixsock);
+
+      add_cmdline (g, "-net");
+      add_cmdline (g, vmchannel);
+    } else {
+#endif
+      /* Not guestfwd.  HOPEFULLY this qemu uses the older -net channel
+       * syntax, or if not then we'll get a quick failure.
+       */
+      snprintf (vmchannel, sizeof vmchannel,
+		"channel,%d:unix:%s,server,nowait",
+		VMCHANNEL_PORT, unixsock);
+
+      add_cmdline (g, "-net");
+      add_cmdline (g, vmchannel);
+      add_cmdline (g, "-net");
+      add_cmdline (g, "user,vlan=0");
+#if 0
+    }
+#endif
     add_cmdline (g, "-net");
-    add_cmdline (g, vmchannel);
-    add_cmdline (g, "-net");
-    add_cmdline (g, "user,vlan=0");
-    add_cmdline (g, "-net");
-    add_cmdline (g, "nic,model=rtl8139,vlan=0");
+    add_cmdline (g, "nic,model=virtio,vlan=0");
+
+    /* These options recommended by KVM developers to improve reliability. */
+    if (qemu_supports (g, "-no-hpet"))
+      add_cmdline (g, "-no-hpet");
+
+    if (qemu_supports (g, "-rtc-td-hack"))
+      add_cmdline (g, "-rtc-td-hack");
+
+    /* Finish off the command line. */
     incr_cmdline_size (g);
     g->cmdline[g->cmdline_size-1] = NULL;
 
@@ -802,6 +1145,45 @@ guestfs_launch (guestfs_h *g)
   /* Parent (library). */
   g->pid = r;
 
+  free (kernel);
+  kernel = NULL;
+  free (initrd);
+  initrd = NULL;
+
+  /* Fork the recovery process off which will kill qemu if the parent
+   * process fails to do so (eg. if the parent segfaults).
+   */
+  r = fork ();
+  if (r == 0) {
+    pid_t qemu_pid = g->pid;
+    pid_t parent_pid = getppid ();
+
+    /* Writing to argv is hideously complicated and error prone.  See:
+     * http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/misc/ps_status.c?rev=1.33.2.1;content-type=text%2Fplain
+     */
+
+    /* Loop around waiting for one or both of the other processes to
+     * disappear.  It's fair to say this is very hairy.  The PIDs that
+     * we are looking at might be reused by another process.  We are
+     * effectively polling.  Is the cure worse than the disease?
+     */
+    for (;;) {
+      if (kill (qemu_pid, 0) == -1) /* qemu's gone away, we aren't needed */
+	_exit (0);
+      if (kill (parent_pid, 0) == -1) {
+	/* Parent's gone away, qemu still around, so kill qemu. */
+	kill (qemu_pid, 9);
+	_exit (0);
+      }
+      sleep (2);
+    }
+  }
+
+  /* Don't worry, if the fork failed, this will be -1.  The recovery
+   * process isn't essential.
+   */
+  g->recoverypid = r;
+
   /* Start the clock ... */
   time (&g->start_t);
 
@@ -843,10 +1225,9 @@ guestfs_launch (guestfs_h *g)
   addr.sun_path[UNIX_PATH_MAX-1] = '\0';
 
   tries = 100;
+  /* Always sleep at least once to give qemu a small chance to start up. */
+  usleep (10000);
   while (tries > 0) {
-    /* Always sleep at least once to give qemu a small chance to start up. */
-    usleep (10000);
-
     r = connect (g->sock, (struct sockaddr *) &addr, sizeof addr);
     if ((r == -1 && errno == EINPROGRESS) || r == 0)
       goto connected;
@@ -854,9 +1235,10 @@ guestfs_launch (guestfs_h *g)
     if (errno != ENOENT)
       perrorf (g, "connect");
     tries--;
+    usleep (100000);
   }
 
-  error (g, "failed to connect to vmchannel socket");
+  error (g, _("failed to connect to vmchannel socket"));
   goto cleanup2;
 
  connected:
@@ -875,7 +1257,7 @@ guestfs_launch (guestfs_h *g)
 			      GUESTFS_HANDLE_READABLE,
 			      stdout_event, NULL);
   if (g->stdout_watch == -1) {
-    error (g, "could not watch qemu stdout");
+    error (g, _("could not watch qemu stdout"));
     goto cleanup3;
   }
 
@@ -898,11 +1280,14 @@ guestfs_launch (guestfs_h *g)
   close (wfd[1]);
   close (rfd[0]);
   kill (g->pid, 9);
+  if (g->recoverypid > 0) kill (g->recoverypid, 9);
   waitpid (g->pid, NULL, 0);
+  if (g->recoverypid > 0) waitpid (g->recoverypid, NULL, 0);
   g->fd[0] = -1;
   g->fd[1] = -1;
   g->sock = -1;
   g->pid = 0;
+  g->recoverypid = 0;
   g->start_t = 0;
   g->stdout_watch = -1;
   g->sock_watch = -1;
@@ -913,6 +1298,127 @@ guestfs_launch (guestfs_h *g)
   return -1;
 }
 
+/* This function does the hard work of building the supermin appliance
+ * on the fly.  'path' is the directory containing the control files.
+ * 'kernel' and 'initrd' are where we will return the names of the
+ * kernel and initrd (only initrd is built).  The work is done by
+ * an external script.  We just tell it where to put the result.
+ */
+static int
+build_supermin_appliance (guestfs_h *g, const char *path,
+			  char **kernel, char **initrd)
+{
+  char cmd[4096];
+  int r, len;
+
+  len = strlen (g->tmpdir);
+  *kernel = safe_malloc (g, len + 8);
+  snprintf (*kernel, len+8, "%s/kernel", g->tmpdir);
+  *initrd = safe_malloc (g, len + 8);
+  snprintf (*initrd, len+8, "%s/initrd", g->tmpdir);
+
+  snprintf (cmd, sizeof cmd,
+	    "PATH='%s':$PATH "
+	    "libguestfs-supermin-helper '%s' %s %s",
+	    path,
+	    path, *kernel, *initrd);
+
+  r = system (cmd);
+  if (r == -1 || WEXITSTATUS(r) != 0) {
+    error (g, _("external command failed: %s"), cmd);
+    free (*kernel);
+    free (*initrd);
+    *kernel = *initrd = NULL;
+    return -1;
+  }
+
+  return 0;
+}
+
+static int read_all (guestfs_h *g, FILE *fp, char **ret);
+
+/* Test qemu binary (or wrapper) runs, and do 'qemu -help' and
+ * 'qemu -version' so we know what options this qemu supports and
+ * the version.
+ */
+static int
+test_qemu (guestfs_h *g)
+{
+  char cmd[1024];
+  FILE *fp;
+
+  free (g->qemu_help);
+  free (g->qemu_version);
+  g->qemu_help = NULL;
+  g->qemu_version = NULL;
+
+  snprintf (cmd, sizeof cmd, "'%s' -help", g->qemu);
+
+  fp = popen (cmd, "r");
+  /* qemu -help should always work (qemu -version OTOH wasn't
+   * supported by qemu 0.9).  If this command doesn't work then it
+   * probably indicates that the qemu binary is missing.
+   */
+  if (!fp) {
+    /* XXX This error is never printed, even if the qemu binary
+     * doesn't exist.  Why?
+     */
+  error:
+    perrorf (g, _("%s: command failed: If qemu is located on a non-standard path, try setting the LIBGUESTFS_QEMU environment variable."), cmd);
+    return -1;
+  }
+
+  if (read_all (g, fp, &g->qemu_help) == -1)
+    goto error;
+
+  if (pclose (fp) == -1)
+    goto error;
+
+  snprintf (cmd, sizeof cmd, "'%s' -version 2>/dev/null", g->qemu);
+
+  fp = popen (cmd, "r");
+  if (fp) {
+    /* Intentionally ignore errors. */
+    read_all (g, fp, &g->qemu_version);
+    pclose (fp);
+  }
+
+  return 0;
+}
+
+static int
+read_all (guestfs_h *g, FILE *fp, char **ret)
+{
+  int r, n = 0;
+  char *p;
+
+ again:
+  if (feof (fp)) {
+    *ret = safe_realloc (g, *ret, n + 1);
+    (*ret)[n] = '\0';
+    return n;
+  }
+
+  *ret = safe_realloc (g, *ret, n + BUFSIZ);
+  p = &(*ret)[n];
+  r = fread (p, 1, BUFSIZ, fp);
+  if (ferror (fp)) {
+    perrorf (g, "read");
+    return -1;
+  }
+  n += r;
+  goto again;
+}
+
+/* Test if option is supported by qemu command line (just by grepping
+ * the help text).
+ */
+static int
+qemu_supports (guestfs_h *g, const char *option)
+{
+  return g->qemu_help && strstr (g->qemu_help, option) != NULL;
+}
+
 static void
 finish_wait_ready (guestfs_h *g, void *vp)
 {
@@ -931,12 +1437,12 @@ guestfs_wait_ready (guestfs_h *g)
   if (g->state == READY) return 0;
 
   if (g->state == BUSY) {
-    error (g, "qemu has finished launching already");
+    error (g, _("qemu has finished launching already"));
     return -1;
   }
 
   if (g->state != LAUNCHING) {
-    error (g, "qemu has not been launched yet");
+    error (g, _("qemu has not been launched yet"));
     return -1;
   }
 
@@ -949,7 +1455,7 @@ guestfs_wait_ready (guestfs_h *g)
   if (r == -1) return -1;
 
   if (finished != 1) {
-    error (g, "guestfs_wait_ready failed, see earlier error messages");
+    error (g, _("guestfs_wait_ready failed, see earlier error messages"));
     return -1;
   }
 
@@ -959,7 +1465,7 @@ guestfs_wait_ready (guestfs_h *g)
    * commands after this function returns.
    */
   if (g->state != READY) {
-    error (g, "qemu launched and contacted daemon, but state != READY");
+    error (g, _("qemu launched and contacted daemon, but state != READY"));
     return -1;
   }
 
@@ -970,7 +1476,7 @@ int
 guestfs_kill_subprocess (guestfs_h *g)
 {
   if (g->state == CONFIG) {
-    error (g, "no subprocess to kill");
+    error (g, _("no subprocess to kill"));
     return -1;
   }
 
@@ -978,6 +1484,7 @@ guestfs_kill_subprocess (guestfs_h *g)
     fprintf (stderr, "sending SIGTERM to process %d\n", g->pid);
 
   kill (g->pid, SIGTERM);
+  if (g->recoverypid > 0) kill (g->recoverypid, 9);
 
   return 0;
 }
@@ -1017,7 +1524,8 @@ int
 guestfs_set_ready (guestfs_h *g)
 {
   if (g->state != BUSY) {
-    error (g, "guestfs_set_ready: called when in state %d != BUSY", g->state);
+    error (g, _("guestfs_set_ready: called when in state %d != BUSY"),
+	   g->state);
     return -1;
   }
   g->state = READY;
@@ -1028,42 +1536,64 @@ int
 guestfs_set_busy (guestfs_h *g)
 {
   if (g->state != READY) {
-    error (g, "guestfs_set_busy: called when in state %d != READY", g->state);
+    error (g, _("guestfs_set_busy: called when in state %d != READY"),
+	   g->state);
     return -1;
   }
   g->state = BUSY;
   return 0;
 }
 
-/* Structure-freeing functions.  These rely on the fact that the
- * structure format is identical to the XDR format.  See note in
- * generator.ml.
- */
-void
-guestfs_free_int_bool (struct guestfs_int_bool *x)
-{
-  free (x);
-}
-
-void
-guestfs_free_lvm_pv_list (struct guestfs_lvm_pv_list *x)
-{
-  xdr_free ((xdrproc_t) xdr_guestfs_lvm_int_pv_list, (char *) x);
-  free (x);
-}
-
-void
-guestfs_free_lvm_vg_list (struct guestfs_lvm_vg_list *x)
+int
+guestfs_end_busy (guestfs_h *g)
 {
-  xdr_free ((xdrproc_t) xdr_guestfs_lvm_int_vg_list, (char *) x);
-  free (x);
+  switch (g->state)
+    {
+    case BUSY:
+      g->state = READY;
+      break;
+    case CONFIG:
+    case READY:
+      break;
+    case LAUNCHING:
+    case NO_HANDLE:
+      error (g, _("guestfs_end_busy: called when in state %d"), g->state);
+      return -1;
+    }
+  return 0;
 }
 
-void
-guestfs_free_lvm_lv_list (struct guestfs_lvm_lv_list *x)
+/* We don't know if stdout_event or sock_read_event will be the
+ * first to receive EOF if the qemu process dies.  This function
+ * has the common cleanup code for both.
+ */
+static void
+child_cleanup (guestfs_h *g)
 {
-  xdr_free ((xdrproc_t) xdr_guestfs_lvm_int_lv_list, (char *) x);
-  free (x);
+  if (g->verbose)
+    fprintf (stderr, "stdout_event: %p: child process died\n", g);
+  /*kill (g->pid, SIGTERM);*/
+  if (g->recoverypid > 0) kill (g->recoverypid, 9);
+  waitpid (g->pid, NULL, 0);
+  if (g->recoverypid > 0) waitpid (g->recoverypid, NULL, 0);
+  if (g->stdout_watch >= 0)
+    g->main_loop->remove_handle (g->main_loop, g, g->stdout_watch);
+  if (g->sock_watch >= 0)
+    g->main_loop->remove_handle (g->main_loop, g, g->sock_watch);
+  close (g->fd[0]);
+  close (g->fd[1]);
+  close (g->sock);
+  g->fd[0] = -1;
+  g->fd[1] = -1;
+  g->sock = -1;
+  g->pid = 0;
+  g->recoverypid = 0;
+  g->start_t = 0;
+  g->stdout_watch = -1;
+  g->sock_watch = -1;
+  g->state = CONFIG;
+  if (g->subprocess_quit_cb)
+    g->subprocess_quit_cb (g, g->subprocess_quit_cb_data);
 }
 
 /* This function is called whenever qemu prints something on stdout.
@@ -1085,39 +1615,19 @@ stdout_event (struct guestfs_main_loop *ml, guestfs_h *g, void *data,
 #endif
 
   if (g->fd[1] != fd) {
-    error (g, "stdout_event: internal error: %d != %d", g->fd[1], fd);
+    error (g, _("stdout_event: internal error: %d != %d"), g->fd[1], fd);
     return;
   }
 
   n = read (fd, buf, sizeof buf);
   if (n == 0) {
     /* Hopefully this indicates the qemu child process has died. */
-    if (g->verbose)
-      fprintf (stderr, "stdout_event: %p: child process died\n", g);
-    /*kill (g->pid, SIGTERM);*/
-    waitpid (g->pid, NULL, 0);
-    if (g->stdout_watch >= 0)
-      g->main_loop->remove_handle (g->main_loop, g, g->stdout_watch);
-    if (g->sock_watch >= 0)
-      g->main_loop->remove_handle (g->main_loop, g, g->sock_watch);
-    close (g->fd[0]);
-    close (g->fd[1]);
-    close (g->sock);
-    g->fd[0] = -1;
-    g->fd[1] = -1;
-    g->sock = -1;
-    g->pid = 0;
-    g->start_t = 0;
-    g->stdout_watch = -1;
-    g->sock_watch = -1;
-    g->state = CONFIG;
-    if (g->subprocess_quit_cb)
-      g->subprocess_quit_cb (g, g->subprocess_quit_cb_data);
+    child_cleanup (g);
     return;
   }
 
   if (n == -1) {
-    if (errno != EAGAIN)
+    if (errno != EINTR && errno != EAGAIN)
       perrorf (g, "read");
     return;
   }
@@ -1139,7 +1649,7 @@ sock_read_event (struct guestfs_main_loop *ml, guestfs_h *g, void *data,
 		 int watch, int fd, int events)
 {
   XDR xdr;
-  unsigned len;
+  u_int32_t len;
   int n;
 
   if (g->verbose)
@@ -1148,7 +1658,7 @@ sock_read_event (struct guestfs_main_loop *ml, guestfs_h *g, void *data,
 	     g, g->state, fd, events);
 
   if (g->sock != fd) {
-    error (g, "sock_read_event: internal error: %d != %d", g->sock, fd);
+    error (g, _("sock_read_event: internal error: %d != %d"), g->sock, fd);
     return;
   }
 
@@ -1158,14 +1668,14 @@ sock_read_event (struct guestfs_main_loop *ml, guestfs_h *g, void *data,
   }
   n = read (g->sock, g->msg_in + g->msg_in_size,
 	    g->msg_in_allocated - g->msg_in_size);
-  if (n == 0)
-    /* Disconnected?  Ignore it because stdout_watch will get called
-     * and will do the cleanup.
-     */
+  if (n == 0) {
+    /* Disconnected. */
+    child_cleanup (g);
     return;
+  }
 
   if (n == -1) {
-    if (errno != EAGAIN)
+    if (errno != EINTR && errno != EAGAIN)
       perrorf (g, "read");
     return;
   }
@@ -1178,7 +1688,7 @@ sock_read_event (struct guestfs_main_loop *ml, guestfs_h *g, void *data,
 
   xdrmem_create (&xdr, g->msg_in, g->msg_in_size, XDR_DECODE);
   if (!xdr_uint32_t (&xdr, &len)) {
-    error (g, "can't decode length word");
+    error (g, _("can't decode length word"));
     goto cleanup;
   }
 
@@ -1188,10 +1698,10 @@ sock_read_event (struct guestfs_main_loop *ml, guestfs_h *g, void *data,
    */
   if (len == GUESTFS_LAUNCH_FLAG) {
     if (g->state != LAUNCHING)
-      error (g, "received magic signature from guestfsd, but in state %d",
+      error (g, _("received magic signature from guestfsd, but in state %d"),
 	     g->state);
     else if (g->msg_in_size != 4)
-      error (g, "received magic signature from guestfsd, but msg size is %d",
+      error (g, _("received magic signature from guestfsd, but msg size is %d"),
 	     g->msg_in_size);
     else {
       g->state = READY;
@@ -1216,7 +1726,7 @@ sock_read_event (struct guestfs_main_loop *ml, guestfs_h *g, void *data,
    * synchronization.
    */
   if (len > GUESTFS_MESSAGE_MAX) {
-    error (g, "message length (%u) > maximum possible size (%d)",
+    error (g, _("message length (%u) > maximum possible size (%d)"),
 	   len, GUESTFS_MESSAGE_MAX);
     goto cleanup;
   }
@@ -1224,6 +1734,7 @@ sock_read_event (struct guestfs_main_loop *ml, guestfs_h *g, void *data,
   if (g->msg_in_size-4 < len) return; /* Need more of this message. */
 
   /* Got the full message, begin processing it. */
+#if 0
   if (g->verbose) {
     int i, j;
 
@@ -1244,14 +1755,18 @@ sock_read_event (struct guestfs_main_loop *ml, guestfs_h *g, void *data,
       printf ("|\n");
     }
   }
+#endif
 
   /* Not in the expected state. */
   if (g->state != BUSY)
-    error (g, "state %d != BUSY", g->state);
+    error (g, _("state %d != BUSY"), g->state);
 
   /* Push the message up to the higher layer. */
   if (g->reply_cb)
     g->reply_cb (g, g->reply_cb_data, &xdr);
+  else
+    /* This message (probably) should never be printed. */
+    fprintf (stderr, "libguesfs: sock_read_event: !!! dropped message !!!\n");
 
   g->msg_in_size -= len + 4;
   memmove (g->msg_in, g->msg_in+len+4, g->msg_in_size);
@@ -1276,7 +1791,7 @@ static void
 sock_write_event (struct guestfs_main_loop *ml, guestfs_h *g, void *data,
 		  int watch, int fd, int events)
 {
-  int n;
+  int n, err;
 
   if (g->verbose)
     fprintf (stderr,
@@ -1284,12 +1799,12 @@ sock_write_event (struct guestfs_main_loop *ml, guestfs_h *g, void *data,
 	     g, g->state, fd, events);
 
   if (g->sock != fd) {
-    error (g, "sock_write_event: internal error: %d != %d", g->sock, fd);
+    error (g, _("sock_write_event: internal error: %d != %d"), g->sock, fd);
     return;
   }
 
   if (g->state != BUSY) {
-    error (g, "sock_write_event: state %d != BUSY", g->state);
+    error (g, _("sock_write_event: state %d != BUSY"), g->state);
     return;
   }
 
@@ -1300,8 +1815,11 @@ sock_write_event (struct guestfs_main_loop *ml, guestfs_h *g, void *data,
   n = write (g->sock, g->msg_out + g->msg_out_pos,
 	     g->msg_out_size - g->msg_out_pos);
   if (n == -1) {
-    if (errno != EAGAIN)
+    err = errno;
+    if (err != EAGAIN)
       perrorf (g, "write");
+    if (err == EPIPE)	/* Disconnected from guest (RHBZ#508713). */
+      child_cleanup (g);
     return;
   }
 
@@ -1393,7 +1911,7 @@ guestfs__switch_to_sending (guestfs_h *g)
 {
   if (g->sock_watch >= 0) {
     if (g->main_loop->remove_handle (g->main_loop, g, g->sock_watch) == -1) {
-      error (g, "remove_handle failed");
+      error (g, _("remove_handle failed"));
       g->sock_watch = -1;
       return -1;
     }
@@ -1404,7 +1922,7 @@ guestfs__switch_to_sending (guestfs_h *g)
 			      GUESTFS_HANDLE_WRITABLE,
 			      sock_write_event, NULL);
   if (g->sock_watch == -1) {
-    error (g, "add_handle failed");
+    error (g, _("add_handle failed"));
     return -1;
   }
 
@@ -1416,7 +1934,7 @@ guestfs__switch_to_receiving (guestfs_h *g)
 {
   if (g->sock_watch >= 0) {
     if (g->main_loop->remove_handle (g->main_loop, g, g->sock_watch) == -1) {
-      error (g, "remove_handle failed");
+      error (g, _("remove_handle failed"));
       g->sock_watch = -1;
       return -1;
     }
@@ -1427,7 +1945,7 @@ guestfs__switch_to_receiving (guestfs_h *g)
 			      GUESTFS_HANDLE_READABLE,
 			      sock_read_event, NULL);
   if (g->sock_watch == -1) {
-    error (g, "add_handle failed");
+    error (g, _("add_handle failed"));
     return -1;
   }
 
@@ -1452,19 +1970,35 @@ int
 guestfs__send_sync (guestfs_h *g, int proc_nr,
 		    xdrproc_t xdrp, char *args)
 {
-  char buffer[GUESTFS_MESSAGE_MAX];
   struct guestfs_message_header hdr;
   XDR xdr;
-  unsigned len;
+  u_int32_t len;
   int serial = g->msg_next_serial++;
   int sent;
   guestfs_main_loop *ml = guestfs_get_main_loop (g);
 
   if (g->state != BUSY) {
-    error (g, "guestfs__send_sync: state %d != BUSY", g->state);
+    error (g, _("guestfs__send_sync: state %d != BUSY"), g->state);
     return -1;
   }
 
+  /* This is probably an internal error.  Or perhaps we should just
+   * free the buffer anyway?
+   */
+  if (g->msg_out != NULL) {
+    error (g, _("guestfs__send_sync: msg_out should be NULL"));
+    return -1;
+  }
+
+  /* We have to allocate this message buffer on the heap because
+   * it is quite large (although will be mostly unused).  We
+   * can't allocate it on the stack because in some environments
+   * we have quite limited stack space available, notably when
+   * running in the JVM.
+   */
+  g->msg_out = safe_malloc (g, GUESTFS_MESSAGE_MAX + 4);
+  xdrmem_create (&xdr, g->msg_out + 4, GUESTFS_MESSAGE_MAX, XDR_ENCODE);
+
   /* Serialize the header. */
   hdr.prog = GUESTFS_PROGRAM;
   hdr.vers = GUESTFS_PROTOCOL_VERSION;
@@ -1473,10 +2007,9 @@ guestfs__send_sync (guestfs_h *g, int proc_nr,
   hdr.serial = serial;
   hdr.status = GUESTFS_STATUS_OK;
 
-  xdrmem_create (&xdr, buffer, sizeof buffer, XDR_ENCODE);
   if (!xdr_guestfs_message_header (&xdr, &hdr)) {
-    error (g, "xdr_guestfs_message_header failed");
-    return -1;
+    error (g, _("xdr_guestfs_message_header failed"));
+    goto cleanup1;
   }
 
   /* Serialize the args.  If any, because some message types
@@ -1484,25 +2017,24 @@ guestfs__send_sync (guestfs_h *g, int proc_nr,
    */
   if (xdrp) {
     if (!(*xdrp) (&xdr, args)) {
-      error (g, "dispatch failed to marshal args");
-      return -1;
+      error (g, _("dispatch failed to marshal args"));
+      goto cleanup1;
     }
   }
 
+  /* Get the actual length of the message, resize the buffer to match
+   * the actual length, and write the length word at the beginning.
+   */
   len = xdr_getpos (&xdr);
   xdr_destroy (&xdr);
 
-  /* Allocate the outgoing message buffer. */
-  g->msg_out = safe_malloc (g, len + 4);
-
+  g->msg_out = safe_realloc (g, g->msg_out, len + 4);
   g->msg_out_size = len + 4;
   g->msg_out_pos = 0;
 
   xdrmem_create (&xdr, g->msg_out, 4, XDR_ENCODE);
   xdr_uint32_t (&xdr, &len);
 
-  memcpy (g->msg_out + 4, buffer, len);
-
   if (guestfs__switch_to_sending (g) == -1)
     goto cleanup1;
 
@@ -1511,7 +2043,7 @@ guestfs__send_sync (guestfs_h *g, int proc_nr,
   if (ml->main_loop_run (ml, g) == -1)
     goto cleanup1;
   if (sent != 1) {
-    error (g, "send failed, see earlier error messages");
+    error (g, _("send failed, see earlier error messages"));
     goto cleanup1;
   }
 
@@ -1553,7 +2085,11 @@ guestfs__send_file_sync (guestfs_h *g, const char *filename)
   }
 
   /* Send file in chunked encoding. */
-  while (!cancel && (r = read (fd, buf, sizeof buf)) > 0) {
+  while (!cancel) {
+    r = read (fd, buf, sizeof buf);
+    if (r == -1 && (errno == EINTR || errno == EAGAIN))
+      continue;
+    if (r <= 0) break;
     err = send_file_data_sync (g, buf, r);
     if (err < 0) {
       if (err == -2)		/* daemon sent cancellation */
@@ -1613,17 +2149,24 @@ send_file_complete_sync (guestfs_h *g)
 static int check_for_daemon_cancellation (guestfs_h *g);
 
 static int
-send_file_chunk_sync (guestfs_h *g, int cancel, const char *buf, size_t len)
+send_file_chunk_sync (guestfs_h *g, int cancel, const char *buf, size_t buflen)
 {
-  char data[GUESTFS_MAX_CHUNK_SIZE + 48];
-  unsigned datalen;
+  u_int32_t len;
   int sent;
   guestfs_chunk chunk;
   XDR xdr;
   guestfs_main_loop *ml = guestfs_get_main_loop (g);
 
   if (g->state != BUSY) {
-    error (g, "send_file_chunk_sync: state %d != READY", g->state);
+    error (g, _("send_file_chunk_sync: state %d != READY"), g->state);
+    return -1;
+  }
+
+  /* This is probably an internal error.  Or perhaps we should just
+   * free the buffer anyway?
+   */
+  if (g->msg_out != NULL) {
+    error (g, _("guestfs__send_sync: msg_out should be NULL"));
     return -1;
   }
 
@@ -1634,35 +2177,34 @@ send_file_chunk_sync (guestfs_h *g, int cancel, const char *buf, size_t len)
     return -2;
   }
 
+  /* Allocate the chunk buffer.  Don't use the stack to avoid
+   * excessive stack usage and unnecessary copies.
+   */
+  g->msg_out = safe_malloc (g, GUESTFS_MAX_CHUNK_SIZE + 4 + 48);
+  xdrmem_create (&xdr, g->msg_out + 4, GUESTFS_MAX_CHUNK_SIZE + 48, XDR_ENCODE);
+
   /* Serialize the chunk. */
   chunk.cancel = cancel;
-  chunk.data.data_len = len;
+  chunk.data.data_len = buflen;
   chunk.data.data_val = (char *) buf;
 
-  if (g->verbose)
-    fprintf (stderr,
-	     "library sending chunk cancel = %d, len = %zu, buf = %p\n",
-	     cancel, len, buf);
-
-  xdrmem_create (&xdr, data, sizeof data, XDR_ENCODE);
   if (!xdr_guestfs_chunk (&xdr, &chunk)) {
-    error (g, "xdr_guestfs_chunk failed (buf = %p, len = %zu)", buf, len);
+    error (g, _("xdr_guestfs_chunk failed (buf = %p, buflen = %zu)"),
+	   buf, buflen);
     xdr_destroy (&xdr);
-    return -1;
+    goto cleanup1;
   }
 
-  datalen = xdr_getpos (&xdr);
+  len = xdr_getpos (&xdr);
   xdr_destroy (&xdr);
 
-  /* Allocate outgoing message buffer. */
-  g->msg_out = safe_malloc (g, datalen + 4);
-  g->msg_out_size = datalen + 4;
+  /* Reduce the size of the outgoing message buffer to the real length. */
+  g->msg_out = safe_realloc (g, g->msg_out, len + 4);
+  g->msg_out_size = len + 4;
   g->msg_out_pos = 0;
 
   xdrmem_create (&xdr, g->msg_out, 4, XDR_ENCODE);
-  xdr_uint32_t (&xdr, &datalen);
-
-  memcpy (g->msg_out + 4, data, datalen);
+  xdr_uint32_t (&xdr, &len);
 
   if (guestfs__switch_to_sending (g) == -1)
     goto cleanup1;
@@ -1672,7 +2214,7 @@ send_file_chunk_sync (guestfs_h *g, int cancel, const char *buf, size_t len)
   if (ml->main_loop_run (ml, g) == -1)
     goto cleanup1;
   if (sent != 1) {
-    error (g, "send file chunk failed, see earlier error messages");
+    error (g, _("send file chunk failed, see earlier error messages"));
     goto cleanup1;
   }
 
@@ -1723,7 +2265,7 @@ check_for_daemon_cancellation (guestfs_h *g)
   xdr_destroy (&xdr);
 
   if (flag != GUESTFS_CANCEL_FLAG) {
-    error (g, "check_for_daemon_cancellation: read 0x%x from daemon, expected 0x%x\n",
+    error (g, _("check_for_daemon_cancellation: read 0x%x from daemon, expected 0x%x\n"),
 	   flag, GUESTFS_CANCEL_FLAG);
     return 0;
   }
@@ -1733,13 +2275,15 @@ check_for_daemon_cancellation (guestfs_h *g)
 
 /* Synchronously receive a file. */
 
-static int receive_file_data_sync (guestfs_h *g, void **buf);
+/* Returns -1 = error, 0 = EOF, 1 = more data */
+static int receive_file_data_sync (guestfs_h *g, void **buf, size_t *len);
 
 int
 guestfs__receive_file_sync (guestfs_h *g, const char *filename)
 {
   void *buf;
   int fd, r;
+  size_t len;
 
   fd = open (filename, O_WRONLY|O_CREAT|O_TRUNC|O_NOCTTY, 0666);
   if (fd == -1) {
@@ -1748,17 +2292,18 @@ guestfs__receive_file_sync (guestfs_h *g, const char *filename)
   }
 
   /* Receive the file in chunked encoding. */
-  while ((r = receive_file_data_sync (g, &buf)) > 0) {
-    if (xwrite (fd, buf, r) == -1) {
+  while ((r = receive_file_data_sync (g, &buf, &len)) >= 0) {
+    if (xwrite (fd, buf, len) == -1) {
       perrorf (g, "%s: write", filename);
       free (buf);
       goto cancel;
     }
     free (buf);
+    if (r == 0) break; /* End of file. */
   }
 
   if (r == -1) {
-    error (g, "%s: error in chunked encoding", filename);
+    error (g, _("%s: error in chunked encoding"), filename);
     return -1;
   }
 
@@ -1777,84 +2322,137 @@ guestfs__receive_file_sync (guestfs_h *g, const char *filename)
   char fbuf[4];
   uint32_t flag = GUESTFS_CANCEL_FLAG;
 
+  if (g->verbose)
+    fprintf (stderr, "%s: waiting for daemon to acknowledge cancellation\n",
+	     __func__);
+
   xdrmem_create (&xdr, fbuf, sizeof fbuf, XDR_ENCODE);
   xdr_uint32_t (&xdr, &flag);
   xdr_destroy (&xdr);
 
   if (xwrite (g->sock, fbuf, sizeof fbuf) == -1) {
-    perrorf (g, "write to daemon socket");
+    perrorf (g, _("write to daemon socket"));
     return -1;
   }
 
-  while ((r = receive_file_data_sync (g, &buf)) > 0)
-    free (buf);			/* just discard it */
+  while ((r = receive_file_data_sync (g, NULL, NULL)) > 0)
+    ;				/* just discard it */
 
   return -1;
 }
 
+/* Note that the reply callback can be called multiple times before
+ * the main loop quits and we get back to the synchronous code.  So
+ * we have to be prepared to save multiple chunks on a list here.
+ */
 struct receive_file_ctx {
-  int code;
-  void **buf;
+  int count;			/* 0 if receive_file_cb not called, or
+				 * else count number of chunks.
+				 */
+  guestfs_chunk *chunks;	/* Array of chunks. */
 };
 
 static void
+free_chunks (struct receive_file_ctx *ctx)
+{
+  int i;
+
+  for (i = 0; i < ctx->count; ++i)
+    free (ctx->chunks[i].data.data_val);
+
+  free (ctx->chunks);
+}
+
+static void
 receive_file_cb (guestfs_h *g, void *data, XDR *xdr)
 {
   guestfs_main_loop *ml = guestfs_get_main_loop (g);
   struct receive_file_ctx *ctx = (struct receive_file_ctx *) data;
   guestfs_chunk chunk;
 
+  if (ctx->count == -1)		/* Parse error occurred previously. */
+    return;
+
   ml->main_loop_quit (ml, g);
 
   memset (&chunk, 0, sizeof chunk);
 
   if (!xdr_guestfs_chunk (xdr, &chunk)) {
-    error (g, "failed to parse file chunk");
-    ctx->code = -1;
-    return;
-  }
-  if (chunk.cancel) {
-    error (g, "file receive cancelled by daemon");
-    ctx->code = -2;
-    return;
-  }
-  if (chunk.data.data_len == 0) { /* end of transfer */
-    ctx->code = 0;
+    error (g, _("failed to parse file chunk"));
+    free_chunks (ctx);
+    ctx->chunks = NULL;
+    ctx->count = -1;
     return;
   }
 
-  ctx->code = chunk.data.data_len;
-  *ctx->buf = chunk.data.data_val; /* caller frees */
+  /* Copy the chunk to the list. */
+  ctx->chunks = safe_realloc (g, ctx->chunks,
+			      sizeof (guestfs_chunk) * (ctx->count+1));
+  ctx->chunks[ctx->count] = chunk;
+  ctx->count++;
 }
 
 /* Receive a chunk of file data. */
+/* Returns -1 = error, 0 = EOF, 1 = more data */
 static int
-receive_file_data_sync (guestfs_h *g, void **buf)
+receive_file_data_sync (guestfs_h *g, void **buf, size_t *len_r)
 {
   struct receive_file_ctx ctx;
   guestfs_main_loop *ml = guestfs_get_main_loop (g);
+  int i;
+  size_t len;
 
-  ctx.code = -3;
-  ctx.buf = buf;
+  ctx.count = 0;
+  ctx.chunks = NULL;
 
   guestfs_set_reply_callback (g, receive_file_cb, &ctx);
   (void) ml->main_loop_run (ml, g);
   guestfs_set_reply_callback (g, NULL, NULL);
 
-  if (g->verbose)
-    fprintf (stderr, "receive_file_data_sync: code %d\n", ctx.code);
-
-  switch (ctx.code) {
-  case 0:			/* end of file */
-    return 0;
-  case -1: case -2:
+  if (ctx.count == 0) {
+    error (g, _("receive_file_data_sync: reply callback not called\n"));
     return -1;
-  case -3:
-    error (g, "failed to call receive_file_cb");
+  }
+
+  if (ctx.count == -1) {
+    error (g, _("receive_file_data_sync: parse error in reply callback\n"));
+    /* callback already freed the chunks */
     return -1;
-  default:			/* received n bytes of data */
-    return ctx.code;
   }
+
+  if (g->verbose)
+    fprintf (stderr, "receive_file_data_sync: got %d chunks\n", ctx.count);
+
+  /* Process each chunk in the list. */
+  if (buf) *buf = NULL;		/* Accumulate data in this buffer. */
+  len = 0;
+
+  for (i = 0; i < ctx.count; ++i) {
+    if (ctx.chunks[i].cancel) {
+      error (g, _("file receive cancelled by daemon"));
+      free_chunks (&ctx);
+      if (buf) free (*buf);
+      if (len_r) *len_r = 0;
+      return -1;
+    }
+
+    if (ctx.chunks[i].data.data_len == 0) { /* end of transfer */
+      free_chunks (&ctx);
+      if (len_r) *len_r = len;
+      return 0;
+    }
+
+    if (buf) {
+      *buf = safe_realloc (g, *buf, len + ctx.chunks[i].data.data_len);
+      memcpy (*buf+len, ctx.chunks[i].data.data_val,
+	      ctx.chunks[i].data.data_len);
+    }
+    len += ctx.chunks[i].data.data_len;
+  }
+
+  if (len_r) *len_r = len;
+  free_chunks (&ctx);
+  return 1;
 }
 
 /* This is the default main loop implementation, using select(2). */
@@ -1866,7 +2464,7 @@ select_add_handle (guestfs_main_loop *mlv, guestfs_h *g, int fd, int events,
   struct select_main_loop *ml = (struct select_main_loop *) mlv;
 
   if (fd < 0 || fd >= FD_SETSIZE) {
-    error (g, "fd %d is out of range", fd);
+    error (g, _("fd %d is out of range"), fd);
     return -1;
   }
 
@@ -1874,24 +2472,24 @@ select_add_handle (guestfs_main_loop *mlv, guestfs_h *g, int fd, int events,
 		  GUESTFS_HANDLE_WRITABLE |
 		  GUESTFS_HANDLE_HANGUP |
 		  GUESTFS_HANDLE_ERROR)) != 0) {
-    error (g, "set of events (0x%x) contains unknown events", events);
+    error (g, _("set of events (0x%x) contains unknown events"), events);
     return -1;
   }
 
   if (events == 0) {
-    error (g, "set of events is empty");
+    error (g, _("set of events is empty"));
     return -1;
   }
 
   if (FD_ISSET (fd, &ml->rset) ||
       FD_ISSET (fd, &ml->wset) ||
       FD_ISSET (fd, &ml->xset)) {
-    error (g, "fd %d is already registered", fd);
+    error (g, _("fd %d is already registered"), fd);
     return -1;
   }
 
   if (cb == NULL) {
-    error (g, "callback is NULL");
+    error (g, _("callback is NULL"));
     return -1;
   }
 
@@ -1924,14 +2522,14 @@ select_remove_handle (guestfs_main_loop *mlv, guestfs_h *g, int fd)
   struct select_main_loop *ml = (struct select_main_loop *) mlv;
 
   if (fd < 0 || fd >= FD_SETSIZE) {
-    error (g, "fd %d is out of range", fd);
+    error (g, _("fd %d is out of range"), fd);
     return -1;
   }
 
   if (!FD_ISSET (fd, &ml->rset) &&
       !FD_ISSET (fd, &ml->wset) &&
       !FD_ISSET (fd, &ml->xset)) {
-    error (g, "fd %d was not registered", fd);
+    error (g, _("fd %d was not registered"), fd);
     return -1;
   }
 
@@ -1980,7 +2578,7 @@ select_main_loop_run (guestfs_main_loop *mlv, guestfs_h *g)
   fd_set rset2, wset2, xset2;
 
   if (ml->is_running) {
-    error (g, "select_main_loop_run: this cannot be called recursively");
+    error (g, _("select_main_loop_run: this cannot be called recursively"));
     return -1;
   }
 
@@ -1995,6 +2593,8 @@ select_main_loop_run (guestfs_main_loop *mlv, guestfs_h *g)
     xset2 = ml->xset;
     r = select (ml->max_fd+1, &rset2, &wset2, &xset2, NULL);
     if (r == -1) {
+      if (errno == EINTR || errno == EAGAIN)
+	continue;
       perrorf (g, "select");
       ml->is_running = 0;
       return -1;