df: Rewrite virt-df in C.

[libguestfs.git] / df / df.c

diff --git a/df/df.c b/df/df.c
new file mode 100644 (file)
index 0000000..c2db970
--- /dev/null
+++ b/df/df.c
@@ -0,0 +1,158 @@
+/* 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 <stdint.h>
+#include <inttypes.h>
+
+#ifdef HAVE_LIBVIRT
+#include <libvirt/libvirt.h>
+#include <libvirt/virterror.h>
+#endif
+
+#include "progname.h"
+
+#include "guestfs.h"
+#include "options.h"
+#include "virt-df.h"
+
+static void try_df (const char *name, const char *uuid, const char *dev, int offset);
+static int find_dev_in_devices (const char *dev, char **devices);
+
+/* Since we want this function to be robust against very bad failure
+ * cases (hello, https://bugzilla.kernel.org/show_bug.cgi?id=18792) it
+ * won't exit on guestfs failures.
+ */
+int
+df_on_handle (const char *name, const char *uuid, char **devices, int offset)
+{
+  int ret = -1;
+  size_t i;
+  char **fses = NULL;
+  int free_devices = 0, is_lv;
+
+  if (verbose) {
+    fprintf (stderr, "df_on_handle %s devices=", name);
+    if (devices) {
+      fputc ('[', stderr);
+      for (i = 0; devices[i] != NULL; ++i) {
+        if (i > 0)
+          fputc (' ', stderr);
+        fputs (devices[i], stderr);
+      }
+      fputc (']', stderr);
+    }
+    else
+      fprintf (stderr, "null");
+    fputc ('\n', stderr);
+  }
+
+  if (devices == NULL) {
+    devices = guestfs_list_devices (g);
+    if (devices == NULL)
+      goto cleanup;
+    free_devices = 1;
+  } else {
+    /* Mask LVM for just the devices in the set. */
+    if (guestfs_lvm_set_filter (g, devices) == -1)
+      goto cleanup;
+  }
+
+  /* list-filesystems will return filesystems on every device ... */
+  fses = guestfs_list_filesystems (g);
+  if (fses == NULL)
+    goto cleanup;
+
+  /* ... so we need to filter out only the devices we are interested in. */
+  for (i = 0; fses[i] != NULL; i += 2) {
+    if (STRNEQ (fses[i+1], "") &&
+        STRNEQ (fses[i+1], "swap") &&
+        STRNEQ (fses[i+1], "unknown")) {
+      is_lv = guestfs_is_lv (g, fses[i]);
+      if (is_lv > 0)        /* LVs are OK because of the LVM filter */
+        try_df (name, uuid, fses[i], -1);
+      else if (is_lv == 0) {
+        if (find_dev_in_devices (fses[i], devices))
+          try_df (name, uuid, fses[i], offset);
+      }
+    }
+  }
+
+  ret = 0;
+
+ cleanup:
+  if (fses) {
+    for (i = 0; fses[i] != NULL; ++i)
+      free (fses[i]);
+    free (fses);
+  }
+
+  if (free_devices) {
+    for (i = 0; devices[i] != NULL; ++i)
+      free (devices[i]);
+    free (devices);
+  }
+
+  return ret;
+}
+
+static int
+find_dev_in_devices (const char *dev, char **devices)
+{
+  size_t i;
+
+  for (i = 0; devices[i] != NULL; ++i) {
+    if (STRPREFIX (dev, devices[i]))
+      return 1;
+  }
+
+  return 0;
+}
+
+static void
+try_df (const char *name, const char *uuid,
+        const char *dev, int offset)
+{
+  struct guestfs_statvfs *stat = NULL;
+  guestfs_error_handler_cb old_error_cb;
+  void *old_error_data;
+
+  if (verbose)
+    fprintf (stderr, "try_df %s %s %d\n", name, dev, offset);
+
+  /* Try mounting and stating the device.  This might reasonably fail,
+   * so don't show errors.
+   */
+  old_error_cb = guestfs_get_error_handler (g, &old_error_data);
+  guestfs_set_error_handler (g, NULL, NULL);
+
+  if (guestfs_mount_ro (g, dev, "/") == 0) {
+    stat = guestfs_statvfs (g, "/");
+    guestfs_umount_all (g);
+  }
+
+  guestfs_set_error_handler (g, old_error_cb, old_error_data);
+
+  if (stat) {
+    print_stat (name, uuid, dev, offset, stat);
+    guestfs_free_statvfs (stat);
+  }
+}