/* libguestfs - the guestfsd daemon
- * Copyright (C) 2009 Red Hat Inc.
+ * Copyright (C) 2009 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
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <mntent.h>
#include "daemon.h"
#include "actions.h"
-/* You must mount something on "/" first, hence: */
-int root_mounted = 0;
+/* You must mount something on "/" first before many operations.
+ * Hence we have an internal function which can test if something is
+ * mounted on *or under* the sysroot directory. (It has to be *or
+ * under* because of mkmountpoint and friends).
+ */
+int
+is_root_mounted (void)
+{
+ FILE *fp;
+ struct mntent *m;
+
+ /* NB: Eventually we should aim to parse /proc/self/mountinfo, but
+ * that requires custom parsing code.
+ */
+ fp = setmntent ("/proc/mounts", "r");
+ if (fp == NULL) {
+ perror ("/proc/mounts");
+ exit (EXIT_FAILURE);
+ }
+
+ while ((m = getmntent (fp)) != NULL) {
+ /* Allow a mount directory like "/sysroot". */
+ if (sysroot_len > 0 && STREQ (m->mnt_dir, sysroot)) {
+ gotit:
+ endmntent (fp);
+ return 1;
+ }
+ /* Or allow a mount directory like "/sysroot/...". */
+ if (STRPREFIX (m->mnt_dir, sysroot) && m->mnt_dir[sysroot_len] == '/')
+ goto gotit;
+ }
+
+ endmntent (fp);
+ return 0;
+}
/* The "simple mount" call offers no complex options, you can just
- * mount a device on a mountpoint.
+ * mount a device on a mountpoint. The variations like mount_ro,
+ * mount_options and mount_vfs let you set progressively more things.
*
* It's tempting to try a direct mount(2) syscall, but that doesn't
* do any autodetection, so we are better off calling out to
*/
int
-do_mount (const char *device, const char *mountpoint)
+do_mount_vfs (const char *options, const char *vfstype,
+ const char *device, const char *mountpoint)
{
- int len, r, is_root;
+ int r;
char *mp;
char *error;
+ struct stat statbuf;
+
+ ABS_PATH (mountpoint, , return -1);
+
+ mp = sysroot_path (mountpoint);
+ if (!mp) {
+ reply_with_perror ("malloc");
+ return -1;
+ }
+
+ /* Check the mountpoint exists and is a directory. */
+ if (stat (mp, &statbuf) == -1) {
+ reply_with_perror ("mount: %s", mountpoint);
+ free (mp);
+ return -1;
+ }
+ if (!S_ISDIR (statbuf.st_mode)) {
+ reply_with_perror ("mount: %s: mount point is not a directory", mountpoint);
+ free (mp);
+ return -1;
+ }
+
+ if (vfstype)
+ r = command (NULL, &error,
+ "mount", "-o", options, "-t", vfstype, device, mp, NULL);
+ else
+ r = command (NULL, &error,
+ "mount", "-o", options, device, mp, NULL);
+ free (mp);
+ if (r == -1) {
+ reply_with_error ("%s on %s: %s", device, mountpoint, error);
+ free (error);
+ return -1;
+ }
+
+ free (error);
+ return 0;
+}
+
+int
+do_mount (const char *device, const char *mountpoint)
+{
+ return do_mount_vfs ("sync,noatime", NULL, device, mountpoint);
+}
+
+int
+do_mount_ro (const char *device, const char *mountpoint)
+{
+ return do_mount_vfs ("ro", NULL, device, mountpoint);
+}
+
+int
+do_mount_options (const char *options, const char *device,
+ const char *mountpoint)
+{
+ return do_mount_vfs (options, NULL, device, mountpoint);
+}
+
+/* Again, use the external /bin/umount program, so that /etc/mtab
+ * is kept updated.
+ */
+int
+do_umount (const char *pathordevice)
+{
+ int r;
+ char *err;
+ char *buf;
+ int is_dev;
+
+ is_dev = STREQLEN (pathordevice, "/dev/", 5);
+ buf = is_dev ? strdup (pathordevice)
+ : sysroot_path (pathordevice);
+ if (buf == NULL) {
+ reply_with_perror ("malloc");
+ return -1;
+ }
+
+ if (is_dev)
+ RESOLVE_DEVICE (buf, , { free (buf); return -1; });
- is_root = strcmp (mountpoint, "/") == 0;
+ r = command (NULL, &err, "umount", buf, NULL);
+ free (buf);
- if (!root_mounted && !is_root) {
- reply_with_error ("mount: you must mount something on / first");
+ if (r == -1) {
+ reply_with_error ("%s: %s", pathordevice, err);
+ free (err);
return -1;
}
- len = strlen (mountpoint) + 9;
+ free (err);
+
+ return 0;
+}
+
+/* Implement 'mounts' (mp==0) and 'mountpoints' (mp==1) calls. */
+static char **
+mounts_or_mountpoints (int mp)
+{
+ FILE *fp;
+ struct mntent *m;
+ char **ret = NULL;
+ int size = 0, alloc = 0;
+ size_t i;
+ int r;
+
+ /* NB: Eventually we should aim to parse /proc/self/mountinfo, but
+ * that requires custom parsing code.
+ */
+ fp = setmntent ("/proc/mounts", "r");
+ if (fp == NULL) {
+ perror ("/proc/mounts");
+ exit (EXIT_FAILURE);
+ }
+
+ while ((m = getmntent (fp)) != NULL) {
+ /* Allow a mount directory like "/sysroot". */
+ if (sysroot_len > 0 && STREQ (m->mnt_dir, sysroot)) {
+ if (add_string (&ret, &size, &alloc, m->mnt_fsname) == -1) {
+ error:
+ endmntent (fp);
+ return NULL;
+ }
+ if (mp &&
+ add_string (&ret, &size, &alloc, "/") == -1)
+ goto error;
+ }
+ /* Or allow a mount directory like "/sysroot/...". */
+ if (STRPREFIX (m->mnt_dir, sysroot) && m->mnt_dir[sysroot_len] == '/') {
+ if (add_string (&ret, &size, &alloc, m->mnt_fsname) == -1)
+ goto error;
+ if (mp &&
+ add_string (&ret, &size, &alloc, &m->mnt_dir[sysroot_len]) == -1)
+ goto error;
+ }
+ }
+
+ endmntent (fp);
+
+ if (add_string (&ret, &size, &alloc, NULL) == -1)
+ return NULL;
- mp = malloc (len);
+ /* Convert /dev/mapper LV paths into canonical paths (RHBZ#646432). */
+ for (i = 0; ret[i] != NULL; i += mp ? 2 : 1) {
+ if (STRPREFIX (ret[i], "/dev/mapper/") || STRPREFIX (ret[i], "/dev/dm-")) {
+ char *canonical;
+ r = lv_canonical (ret[i], &canonical);
+ if (r == -1) {
+ free_strings (ret);
+ return NULL;
+ }
+ if (r == 1) {
+ free (ret[i]);
+ ret[i] = canonical;
+ }
+ /* Ignore the case where r == 0. This might happen where
+ * eg. a LUKS /dev/mapper device is mounted, but that won't
+ * correspond to any LV.
+ */
+ }
+ }
+
+ return ret;
+}
+
+char **
+do_mounts (void)
+{
+ return mounts_or_mountpoints (0);
+}
+
+char **
+do_mountpoints (void)
+{
+ return mounts_or_mountpoints (1);
+}
+
+/* Unmount everything mounted under /sysroot.
+ *
+ * We have to unmount in the correct order, so we sort the paths by
+ * longest first to ensure that child paths are unmounted by parent
+ * paths.
+ *
+ * This call is more important than it appears at first, because it
+ * is widely used by both test and production code in order to
+ * get back to a known state (nothing mounted, everything synchronized).
+ */
+static int
+compare_longest_first (const void *vp1, const void *vp2)
+{
+ char * const *p1 = (char * const *) vp1;
+ char * const *p2 = (char * const *) vp2;
+ int n1 = strlen (*p1);
+ int n2 = strlen (*p2);
+ return n2 - n1;
+}
+
+int
+do_umount_all (void)
+{
+ FILE *fp;
+ struct mntent *m;
+ char **mounts = NULL;
+ int size = 0, alloc = 0;
+ char *err;
+ int i, r;
+
+ /* NB: Eventually we should aim to parse /proc/self/mountinfo, but
+ * that requires custom parsing code.
+ */
+ fp = setmntent ("/proc/mounts", "r");
+ if (fp == NULL) {
+ perror ("/proc/mounts");
+ exit (EXIT_FAILURE);
+ }
+
+ while ((m = getmntent (fp)) != NULL) {
+ /* Allow a mount directory like "/sysroot". */
+ if (sysroot_len > 0 && STREQ (m->mnt_dir, sysroot)) {
+ if (add_string (&mounts, &size, &alloc, m->mnt_dir) == -1) {
+ endmntent (fp);
+ return -1;
+ }
+ }
+ /* Or allow a mount directory like "/sysroot/...". */
+ if (STRPREFIX (m->mnt_dir, sysroot) && m->mnt_dir[sysroot_len] == '/') {
+ if (add_string (&mounts, &size, &alloc, m->mnt_dir) == -1) {
+ endmntent (fp);
+ return -1;
+ }
+ }
+ }
+
+ endmntent (fp);
+
+ qsort (mounts, size, sizeof (char *), compare_longest_first);
+
+ /* Unmount them. */
+ for (i = 0; i < size; ++i) {
+ r = command (NULL, &err, "umount", mounts[i], NULL);
+ if (r == -1) {
+ reply_with_error ("umount: %s: %s", mounts[i], err);
+ free (err);
+ free_stringslen (mounts, size);
+ return -1;
+ }
+ free (err);
+ }
+
+ free_stringslen (mounts, size);
+
+ return 0;
+}
+
+/* Mount using the loopback device. You can't use the generic
+ * do_mount call for this because the first parameter isn't a
+ * device.
+ */
+int
+do_mount_loop (const char *file, const char *mountpoint)
+{
+ int r;
+ char *buf, *mp;
+ char *error;
+
+ /* We have to prefix /sysroot on both the filename and the mountpoint. */
+ mp = sysroot_path (mountpoint);
if (!mp) {
reply_with_perror ("malloc");
return -1;
}
- snprintf (mp, len, "/sysroot%s", mountpoint);
+ buf = sysroot_path (file);
+ if (!buf) {
+ reply_with_perror ("malloc");
+ free (mp);
+ return -1;
+ }
- r = command (NULL, &error,
- "mount", "-o", "sync,noatime", device, mp, NULL);
+ r = command (NULL, &error, "mount", "-o", "loop", buf, mp, NULL);
+ free (mp);
+ free (buf);
if (r == -1) {
- reply_with_error ("mount: %s on %s: %s", device, mountpoint, error);
+ reply_with_error ("%s on %s: %s", file, mountpoint, error);
free (error);
return -1;
}
- if (is_root)
- root_mounted = 1;
+ free (error);
+ return 0;
+}
+
+/* Specialized calls mkmountpoint and rmmountpoint are really
+ * variations on mkdir and rmdir which do no checking of the
+ * is_root_mounted() flag.
+ */
+int
+do_mkmountpoint (const char *path)
+{
+ int r;
+
+ /* NEED_ROOT (return -1); - we don't want this test for this call. */
+ ABS_PATH (path, , return -1);
+
+ CHROOT_IN;
+ r = mkdir (path, 0777);
+ CHROOT_OUT;
+
+ if (r == -1) {
+ reply_with_perror ("%s", path);
+ return -1;
+ }
+
+ return 0;
+}
+
+int
+do_rmmountpoint (const char *path)
+{
+ int r;
+
+ /* NEED_ROOT (return -1); - we don't want this test for this call. */
+ ABS_PATH (path, , return -1);
+
+ CHROOT_IN;
+ r = rmdir (path);
+ CHROOT_OUT;
+
+ if (r == -1) {
+ reply_with_perror ("%s", path);
+ return -1;
+ }
return 0;
}
git.annexia.org / libguestfs.git / blobdiff