1 files changed, 436 insertions, 0 deletions
diff --git a/df/domains.c b/df/domains.c
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+++ b/df/domains.c
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+/* virt-df
+ * Copyright (C) 2010 Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+
+#ifdef HAVE_LIBVIRT
+#include <libvirt/libvirt.h>
+#include <libvirt/virterror.h>
+#endif
+
+#include "progname.h"
+
+#define GUESTFS_PRIVATE_FOR_EACH_DISK 1
+
+#include "guestfs.h"
+#include "options.h"
+#include "virt-df.h"
+
+#ifdef HAVE_LIBVIRT
+
+/* Limit the number of devices we will ever add to the appliance.  The
+ * overall limit in current libguestfs is 25: 26 = number of letters
+ * in the English alphabet since we are only confident that
+ * /dev/sd[a-z] will work because of various limits, minus 1 because
+ * that may be used by the ext2 initial filesystem.  (RHBZ#635373).
+ */
+#define MAX_DISKS 25
+
+/* The list of domains and disks that we build up in
+ * get_domains_from_libvirt.
+ */
+struct disk {
+  struct disk *next;
+  char *filename;
+  char *format; /* could be NULL */
+};
+
+struct domain {
+  char *name;
+  char *uuid;
+  struct disk *disks;
+  size_t nr_disks;
+};
+
+struct domain *domains = NULL;
+size_t nr_domains;
+
+static int
+compare_domain_names (const void *p1, const void *p2)
+{
+  const struct domain *d1 = p1;
+  const struct domain *d2 = p2;
+
+  return strcmp (d1->name, d2->name);
+}
+
+static void
+free_domain (struct domain *domain)
+{
+  struct disk *disk, *next;
+
+  for (disk = domain->disks; disk; disk = next) {
+    next = disk->next;
+    free (disk->filename);
+    free (disk->format);
+    free (disk);
+  }
+
+  free (domain->name);
+  free (domain->uuid);
+}
+
+static void add_domains_by_id (virConnectPtr conn, int *ids, size_t n);
+static void add_domains_by_name (virConnectPtr conn, char **names, size_t n);
+static void add_domain (virDomainPtr dom);
+static int add_disk (guestfs_h *g, const char *filename, const char *format, void *domain_vp);
+static void multi_df (struct domain *, size_t n);
+
+void
+get_domains_from_libvirt (void)
+{
+  virErrorPtr err;
+  virConnectPtr conn;
+  int n;
+  size_t i, j, nr_disks_added;
+
+  nr_domains = 0;
+  domains = NULL;
+
+  /* Get the list of all domains. */
+  conn = virConnectOpenReadOnly (libvirt_uri);
+  if (!conn) {
+    err = virGetLastError ();
+    fprintf (stderr,
+             _("%s: could not connect to libvirt (code %d, domain %d): %s"),
+             program_name, err->code, err->domain, err->message);
+    exit (EXIT_FAILURE);
+  }
+
+  n = virConnectNumOfDomains (conn);
+  if (n == -1) {
+    err = virGetLastError ();
+    fprintf (stderr,
+             _("%s: could not get number of running domains (code %d, domain %d): %s"),
+             program_name, err->code, err->domain, err->message);
+    exit (EXIT_FAILURE);
+  }
+
+  int ids[n];
+  n = virConnectListDomains (conn, ids, n);
+  if (n == -1) {
+    err = virGetLastError ();
+    fprintf (stderr,
+             _("%s: could not list running domains (code %d, domain %d): %s"),
+             program_name, err->code, err->domain, err->message);
+    exit (EXIT_FAILURE);
+  }
+
+  add_domains_by_id (conn, ids, n);
+
+  n = virConnectNumOfDefinedDomains (conn);
+  if (n == -1) {
+    err = virGetLastError ();
+    fprintf (stderr,
+             _("%s: could not get number of inactive domains (code %d, domain %d): %s"),
+             program_name, err->code, err->domain, err->message);
+    exit (EXIT_FAILURE);
+  }
+
+  char *names[n];
+  n = virConnectListDefinedDomains (conn, names, n);
+  if (n == -1) {
+    err = virGetLastError ();
+    fprintf (stderr,
+             _("%s: could not list inactive domains (code %d, domain %d): %s"),
+             program_name, err->code, err->domain, err->message);
+    exit (EXIT_FAILURE);
+  }
+
+  add_domains_by_name (conn, names, n);
+
+  /* You must free these even though the libvirt documentation doesn't
+   * mention it.
+   */
+  for (i = 0; i < (size_t) n; ++i)
+    free (names[i]);
+
+  virConnectClose (conn);
+
+  /* No domains? */
+  if (nr_domains == 0)
+    return;
+
+  /* Sort the domains alphabetically by name for display. */
+  qsort (domains, nr_domains, sizeof (struct domain), compare_domain_names);
+
+  print_title ();
+
+  /* To minimize the number of times we have to launch the appliance,
+   * shuffle as many domains together as we can, but not exceeding
+   * MAX_DISKS per request.  If --one-per-guest was requested then only
+   * request disks from a single guest each time.
+   * Interesting application for NP-complete knapsack problem here.
+   */
+  if (one_per_guest) {
+    for (i = 0; i < nr_domains; ++i)
+      multi_df (&domains[i], 1);
+  } else {
+    for (i = 0; i < nr_domains; /**/) {
+      nr_disks_added = 0;
+
+      /* Make a request with domains [i..j-1]. */
+      for (j = i; j < nr_domains; ++j) {
+        if (nr_disks_added + domains[j].nr_disks > MAX_DISKS)
+          break;
+        nr_disks_added += domains[j].nr_disks;
+      }
+      multi_df (&domains[i], j-i);
+
+      i = j;
+    }
+  }
+
+  /* Free up domains structure. */
+  for (i = 0; i < nr_domains; ++i)
+    free_domain (&domains[i]);
+  free (domains);
+}
+
+static void
+add_domains_by_id (virConnectPtr conn, int *ids, size_t n)
+{
+  size_t i;
+  virDomainPtr dom;
+
+  for (i = 0; i < n; ++i) {
+    if (ids[i] != 0) {          /* RHBZ#538041 */
+      dom = virDomainLookupByID (conn, ids[i]);
+      if (dom) { /* transient errors are possible here, ignore them */
+        add_domain (dom);
+        virDomainFree (dom);
+      }
+    }
+  }
+}
+
+static void
+add_domains_by_name (virConnectPtr conn, char **names, size_t n)
+{
+  size_t i;
+  virDomainPtr dom;
+
+  for (i = 0; i < n; ++i) {
+    dom = virDomainLookupByName (conn, names[i]);
+    if (dom) { /* transient errors are possible here, ignore them */
+      add_domain (dom);
+      virDomainFree (dom);
+    }
+  }
+}
+
+static void
+add_domain (virDomainPtr dom)
+{
+  struct domain *domain;
+
+  domains = realloc (domains, (nr_domains + 1) * sizeof (struct domain));
+  if (domains == NULL) {
+    perror ("realloc");
+    exit (EXIT_FAILURE);
+  }
+
+  domain = &domains[nr_domains];
+  nr_domains++;
+
+  domain->name = strdup (virDomainGetName (dom));
+  if (domain->name == NULL) {
+    perror ("strdup");
+    exit (EXIT_FAILURE);
+  }
+
+  char uuid[VIR_UUID_STRING_BUFLEN];
+  if (virDomainGetUUIDString (dom, uuid) == 0) {
+    domain->uuid = strdup (uuid);
+    if (domain->uuid == NULL) {
+      perror ("strdup");
+      exit (EXIT_FAILURE);
+    }
+  }
+  else
+    domain->uuid = NULL;
+
+  domain->disks = NULL;
+  int n = guestfs___for_each_disk (g, dom, add_disk, domain);
+  if (n == -1)
+    exit (EXIT_FAILURE);
+  domain->nr_disks = n;
+
+  if (domain->nr_disks > MAX_DISKS) {
+    fprintf (stderr,
+             _("%s: ignoring %s, it has too many disks (%zu > %d)"),
+             program_name, domain->name, domain->nr_disks, MAX_DISKS);
+    free_domain (domain);
+    nr_domains--;
+    return;
+  }
+}
+
+static int
+add_disk (guestfs_h *g, const char *filename, const char *format,
+          void *domain_vp)
+{
+  struct domain *domain = domain_vp;
+  struct disk *disk;
+
+  disk = malloc (sizeof *disk);
+  if (disk == NULL) {
+    perror ("malloc");
+    return -1;
+  }
+
+  disk->next = domain->disks;
+  domain->disks = disk;
+
+  disk->filename = strdup (filename);
+  if (disk->filename == NULL) {
+    perror ("malloc");
+    return -1;
+  }
+  if (format) {
+    disk->format = strdup (format);
+    if (disk->format == NULL) {
+      perror ("malloc");
+      return -1;
+    }
+  }
+  else
+    disk->format = NULL;
+
+  return 0;
+}
+
+static size_t
+count_strings (char **argv)
+{
+  size_t i;
+
+  for (i = 0; argv[i] != NULL; ++i)
+    ;
+  return i;
+}
+
+static void reset_guestfs_handle (void);
+static void add_disks_to_handle_reverse (struct disk *disk);
+
+/* Perform 'df' operation on the domain(s) given in the list. */
+static void
+multi_df (struct domain *domains, size_t n)
+{
+  size_t i;
+  size_t nd;
+  int r;
+  char **devices;
+
+  /* Add all the disks to the handle (since they were added in reverse
+   * order, we must add them here in reverse too).
+   */
+  for (i = 0; i < n; ++i)
+    add_disks_to_handle_reverse (domains[i].disks);
+
+  /* Launch the handle. */
+  if (guestfs_launch (g) == -1)
+    exit (EXIT_FAILURE);
+
+  devices = guestfs_list_devices (g);
+  if (devices == NULL)
+    exit (EXIT_FAILURE);
+
+  /* Check the number of disks we think we added is the same as the
+   * number of devices returned by libguestfs.
+   */
+  nd = 0;
+  for (i = 0; i < n; ++i)
+    nd += domains[i].nr_disks;
+  assert (nd == count_strings (devices));
+
+  nd = 0;
+  for (i = 0; i < n; ++i) {
+    /* So that &devices[nd] is a NULL-terminated list of strings. */
+    char *p = devices[nd + domains[i].nr_disks];
+    devices[nd + domains[i].nr_disks] = NULL;
+
+    r = df_on_handle (domains[i].name, domains[i].uuid, &devices[nd], nd);
+
+    /* Restore devices to original. */
+    devices[nd + domains[i].nr_disks] = p;
+    nd += domains[i].nr_disks;
+
+    /* Something broke in df_on_handle.  Give up on the remaining
+     * devices for this handle, but keep going on the next handle.
+     */
+    if (r == -1)
+      break;
+  }
+
+  for (i = 0; devices[i] != NULL; ++i)
+    free (devices[i]);
+  free (devices);
+
+  /* Reset the handle. */
+  reset_guestfs_handle ();
+}
+
+static void
+add_disks_to_handle_reverse (struct disk *disk)
+{
+  if (disk == NULL)
+    return;
+
+  add_disks_to_handle_reverse (disk->next);
+
+  struct guestfs_add_drive_opts_argv optargs = { .bitmask = 0 };
+
+  optargs.bitmask |= GUESTFS_ADD_DRIVE_OPTS_READONLY_BITMASK;
+  optargs.readonly = 1;
+
+  if (disk->format) {
+    optargs.bitmask |= GUESTFS_ADD_DRIVE_OPTS_FORMAT_BITMASK;
+    optargs.format = disk->format;
+  }
+
+  if (guestfs_add_drive_opts_argv (g, disk->filename, &optargs) == -1)
+    exit (EXIT_FAILURE);
+}
+
+/* Close and reopen the libguestfs handle. */
+static void
+reset_guestfs_handle (void)
+{
+  /* Copy the settings from the old handle. */
+  int verbose = guestfs_get_verbose (g);
+  int trace = guestfs_get_trace (g);
+
+  guestfs_close (g);
+
+  g = guestfs_create ();
+  if (g == NULL) {
+    fprintf (stderr, _("guestfs_create: failed to create handle\n"));
+    exit (EXIT_FAILURE);
+  }
+
+  guestfs_set_verbose (g, verbose);
+  guestfs_set_trace (g, trace);
+}
+
+#endif