X-Git-Url: http://git.annexia.org/?p=libguestfs.git;a=blobdiff_plain;f=daemon%2Fmount.c;h=0c990c3192b233b63c2322f352923a1d16cf530d;hp=4955fcf307704557f3110ea87af6dad28349ea72;hb=dc8e4b057ecd3984d7c27c8e;hpb=887290e949d54c6ac4c9b787231e588f84f2367c diff --git a/daemon/mount.c b/daemon/mount.c index 4955fcf..0c990c3 100644 --- a/daemon/mount.c +++ b/daemon/mount.c @@ -1,5 +1,5 @@ /* 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 @@ -22,12 +22,48 @@ #include #include #include +#include +#include +#include #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. The variations like mount_ro, @@ -39,65 +75,65 @@ int root_mounted = 0; */ int -do_mount_vfs (char *options, char *vfstype, - char *device, 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; - IS_DEVICE (device, -1); - - is_root = strcmp (mountpoint, "/") == 0; + ABS_PATH (mountpoint, 0, return -1); - if (!root_mounted && !is_root) { - reply_with_error ("mount: you must mount something on / first"); - return -1; - } - - len = strlen (mountpoint) + 9; - - mp = malloc (len); + mp = sysroot_path (mountpoint); if (!mp) { reply_with_perror ("malloc"); return -1; } - snprintf (mp, len, "/sysroot%s", mountpoint); + /* 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); + "mount", "-o", options, "-t", vfstype, device, mp, NULL); else r = command (NULL, &error, - "mount", "-o", options, device, mp, NULL); + "mount", "-o", options, device, mp, NULL); + free (mp); if (r == -1) { - reply_with_error ("mount: %s on %s: %s", device, mountpoint, error); + reply_with_error ("%s on %s: %s", device, mountpoint, error); free (error); return -1; } - if (is_root) - root_mounted = 1; - return 0; } int -do_mount (char *device, char *mountpoint) +do_mount (const char *device, const char *mountpoint) { return do_mount_vfs ("sync,noatime", NULL, device, mountpoint); } int -do_mount_ro (char *device, char *mountpoint) +do_mount_ro (const char *device, const char *mountpoint) { return do_mount_vfs ("ro", NULL, device, mountpoint); } int -do_mount_options (char *options, char *device, - char *mountpoint) +do_mount_options (const char *options, const char *device, + const char *mountpoint) { return do_mount_vfs (options, NULL, device, mountpoint); } @@ -106,49 +142,49 @@ do_mount_options (char *options, char *device, * is kept updated. */ int -do_umount (char *pathordevice) +do_umount (const char *pathordevice) { - int len, freeit = 0, r; - char *buf; + int r; char *err; + char *buf; + int is_dev; - if (strncmp (pathordevice, "/dev/", 5) == 0) { - buf = pathordevice; - IS_DEVICE (buf, -1); - } else { - len = strlen (pathordevice) + 9; - freeit = 1; - buf = malloc (len); - if (buf == NULL) { - reply_with_perror ("malloc"); - return -1; - } - snprintf (buf, len, "/sysroot%s", pathordevice); + 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, 0, { free (buf); return -1; }); + r = command (NULL, &err, "umount", buf, NULL); - if (freeit) free (buf); + free (buf); + if (r == -1) { - reply_with_error ("umount: %s: %s", pathordevice, err); + reply_with_error ("%s: %s", pathordevice, err); free (err); return -1; } free (err); - /* update root_mounted? */ - return 0; } -char ** -do_mounts (void) +static char ** +mounts_or_mountpoints (int mp) { char *out, *err; int r; char **ret = NULL; int size = 0, alloc = 0; char *p, *pend, *p2; + int len; + char matching[5 + sysroot_len]; + size_t i; r = command (&out, &err, "mount", NULL); if (r == -1) { @@ -160,6 +196,11 @@ do_mounts (void) free (err); + /* Lines have the format: + * /dev/foo on /mountpoint type ... + */ + snprintf (matching, 5 + sysroot_len, " on %s", sysroot); + p = out; while (p) { pend = strchr (p, '\n'); @@ -168,15 +209,26 @@ do_mounts (void) pend++; } - /* Lines have the format: - * /dev/foo on /mountpoint type ... - */ - p2 = strstr (p, " on /sysroot"); + p2 = strstr (p, matching); if (p2 != NULL) { *p2 = '\0'; if (add_string (&ret, &size, &alloc, p) == -1) { - free (out); - return NULL; + free (out); + return NULL; + } + if (mp) { + p2 += 4 + sysroot_len; /* skip " on /sysroot" */ + len = strcspn (p2, " "); + + if (len == 0) /* .. just /sysroot, so we turn it into "/" */ + p2 = (char *) "/"; + else + p2[len] = '\0'; + + if (add_string (&ret, &size, &alloc, p2) == -1) { + free (out); + return NULL; + } } } @@ -188,9 +240,41 @@ do_mounts (void) if (add_string (&ret, &size, &alloc, NULL) == -1) return NULL; + /* 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 @@ -219,6 +303,7 @@ do_umount_all (void) char **mounts = NULL; int size = 0, alloc = 0; char *p, *p2, *p3, *pend; + char matching[5 + sysroot_len]; r = command (&out, &err, "mount", NULL); if (r == -1) { @@ -230,6 +315,11 @@ do_umount_all (void) free (err); + /* Lines have the format: + * /dev/foo on /mountpoint type ... + */ + snprintf (matching, 5 + sysroot_len, " on %s", sysroot); + p = out; while (p) { pend = strchr (p, '\n'); @@ -238,17 +328,14 @@ do_umount_all (void) pend++; } - /* Lines have the format: - * /dev/foo on /mountpoint type ... - */ - p2 = strstr (p, " on /sysroot"); + p2 = strstr (p, matching); if (p2 != NULL) { p2 += 4; p3 = p2 + strcspn (p2, " "); *p3 = '\0'; if (add_string (&mounts, &size, &alloc, p2) == -1) { - free (out); - return -1; + free (out); + return -1; } } @@ -272,8 +359,86 @@ do_umount_all (void) free_stringslen (mounts, size); - /* We've unmounted root now, so ... */ - root_mounted = 0; + 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; + } + + buf = sysroot_path (file); + if (!file) { + reply_with_perror ("malloc"); + free (mp); + return -1; + } + + r = command (NULL, &error, "mount", "-o", "loop", buf, mp, NULL); + free (mp); + free (buf); + if (r == -1) { + reply_with_error ("%s on %s: %s", file, mountpoint, error); + free (error); + return -1; + } + + 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, 0, 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, 0, return -1); + + CHROOT_IN; + r = rmdir (path); + CHROOT_OUT; + + if (r == -1) { + reply_with_perror ("%s", path); + return -1; + } return 0; }