X-Git-Url: http://git.annexia.org/?p=libguestfs.git;a=blobdiff_plain;f=src%2Fguestfs.c;h=72cd2f36693f7d4b2cf8b06b944f44942bec71fa;hp=c5056d441dd9d89662be76848360b82f88010361;hb=7c3a90f94cd6b8fec9cdd1c052b91a14c0ee0e0e;hpb=afa6f05e2e0d784250ab6408ff13152920d74495

diff --git a/src/guestfs.c b/src/guestfs.c
index c5056d4..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
@@ -24,6 +24,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdarg.h>
+#include <stddef.h>
 #include <unistd.h>
 #include <ctype.h>
 #include <string.h>
@@ -31,6 +32,7 @@
 #include <time.h>
 #include <sys/stat.h>
 #include <sys/select.h>
+#include <dirent.h>
 
 #include <rpc/types.h>
 #include <rpc/xdr.h>
@@ -161,6 +163,8 @@ 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;
 
@@ -171,6 +175,8 @@ struct guestfs_h
   char *qemu;			/* Qemu binary. */
   char *append;			/* Append to kernel command line. */
 
+  int memsize;			/* Size of RAM (megabytes). */
+
   char *last_error;
 
   /* Callbacks. */
@@ -243,6 +249,22 @@ guestfs_create (void)
     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 ();
 
   /* Start with large serial numbers so they are easy to spot
@@ -305,10 +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);
@@ -339,6 +386,8 @@ guestfs_close (guestfs_h *g)
   free (g->path);
   free (g->qemu);
   free (g->append);
+  free (g->qemu_help);
+  free (g->qemu_version);
   free (g);
 }
 
@@ -375,9 +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);
 
@@ -422,6 +473,42 @@ guestfs_safe_malloc (guestfs_h *g, size_t nbytes)
   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)
 {
@@ -586,6 +673,43 @@ 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)
@@ -631,7 +755,6 @@ 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) {
@@ -664,7 +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);
 }
@@ -685,21 +830,71 @@ 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, pmore, memsize;
+  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"));
@@ -711,7 +906,20 @@ guestfs_launch (guestfs_h *g)
     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, ':');
@@ -719,32 +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;
@@ -753,29 +960,56 @@ guestfs_launch (guestfs_h *g)
   free (path);
 
   if (kernel == NULL || initrd == NULL) {
+    /* 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;
   }
 
-  /* 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.  This we can safely choose a
-   * large, generous amount of memory, and it'll just get swapped
-   * on smaller systems.
-   */
-  memsize = 384;
-
-  /* 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);
 
@@ -804,25 +1038,25 @@ guestfs_launch (guestfs_h *g)
      */
     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,
-	      "panic=1 console=ttyS0 guestfs=%s:%d%s%s%s",
+	      LINUX_CMDLINE "guestfs=%s:%d%s%s%s",
 	      VMCHANNEL_ADDR, VMCHANNEL_PORT,
 	      g->verbose ? " guestfs_verbose=1" : "",
 	      g->append ? " " : "", g->append ? g->append : "");
 
-    snprintf (memsize_str, sizeof memsize_str, "%d", memsize);
+    snprintf (memsize_str, sizeof memsize_str, "%d", g->memsize);
 
     add_cmdline (g, "-m");
     add_cmdline (g, memsize_str);
-#if 0
-    add_cmdline (g, "-no-kqemu"); /* Avoids a warning. */
-#endif
     add_cmdline (g, "-no-reboot"); /* Force exit instead of reboot on panic */
     add_cmdline (g, "-kernel");
     add_cmdline (g, (char *) kernel);
@@ -833,12 +1067,49 @@ guestfs_launch (guestfs_h *g)
     add_cmdline (g, "-nographic");
     add_cmdline (g, "-serial");
     add_cmdline (g, "stdio");
-    add_cmdline (g, "-net");
-    add_cmdline (g, vmchannel);
-    add_cmdline (g, "-net");
-    add_cmdline (g, "user,vlan=0");
+
+#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, "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;
 
@@ -1027,6 +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)
 {
@@ -1171,37 +1563,6 @@ guestfs_end_busy (guestfs_h *g)
   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)
-{
-  xdr_free ((xdrproc_t) xdr_guestfs_lvm_int_vg_list, (char *) x);
-  free (x);
-}
-
-void
-guestfs_free_lvm_lv_list (struct guestfs_lvm_lv_list *x)
-{
-  xdr_free ((xdrproc_t) xdr_guestfs_lvm_int_lv_list, (char *) x);
-  free (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.
@@ -1430,7 +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,
@@ -1454,8 +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;
   }
 
@@ -1958,6 +2322,10 @@ 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);