This functions will unmount all filesystem that aren't api (and those which fail will be remounted read-only). Filesystems are being read from /proc/self/mountinfo. --- Makefile.am | 1 + src/umount.c | 184 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ src/umount.h | 27 +++++++++ 3 files changed, 212 insertions(+), 0 deletions(-) create mode 100644 src/umount.c create mode 100644 src/umount.h
diff --git a/Makefile.am b/Makefile.am index 70a6c19..b1c0438 100644 --- a/Makefile.am +++ b/Makefile.am @@ -337,6 +337,7 @@ libsystemd_core_la_SOURCES = \ src/service.c \ src/automount.c \ src/mount.c \ + src/umount.c \ src/swap.c \ src/device.c \ src/target.c \ diff --git a/src/umount.c b/src/umount.c new file mode 100644 index 0000000..f38113e --- /dev/null +++ b/src/umount.c @@ -0,0 +1,184 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +/*** + This file is part of systemd. + + Copyright 2010 ProFUSION embedded systems + + systemd 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. + + systemd 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 systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <sys/mount.h> +#include <string.h> +#include <errno.h> +#include <unistd.h> + +#include "list.h" +#include "log.h" +#include "mount-setup.h" +#include "umount.h" +#include "util.h" + +typedef struct MountPoint { + char *path; + bool read_only; + LIST_FIELDS (struct MountPoint, mount_point); +} MountPoint; + +static MountPoint *mount_point_alloc(char *path) { + MountPoint *mp; + + mp = new(MountPoint, 1); + mp->path = path; + mp->read_only = false; + + return mp; +} + +static void mount_point_remove_and_free(MountPoint *mp, MountPoint **mp_list_head) { + LIST_REMOVE(MountPoint, mount_point, *mp_list_head, mp); + + free(mp->path); + free(mp); +} + +static void mount_points_list_free(MountPoint **mp_list_head) { + MountPoint *mp, *mp_next; + LIST_FOREACH_SAFE(mount_point, mp, mp_next, *mp_list_head) + mount_point_remove_and_free(mp, mp_list_head); +} + +static int mount_points_list_get(MountPoint **mp_list_head) { + FILE *proc_self_mountinfo; + char *path, *p; + int r; + + if (!(proc_self_mountinfo = fopen("/proc/self/mountinfo", "re"))) + return -errno; + + for (;;) { + int k; + MountPoint *mp; + + path = p = NULL; + + if ((k = fscanf(proc_self_mountinfo, + "%*s " /* (1) mount id */ + "%*s " /* (2) parent id */ + "%*s " /* (3) major:minor */ + "%*s " /* (4) root */ + "%ms " /* (5) mount point */ + "%*s" /* (6) mount options */ + "%*[^-]" /* (7) optional fields */ + "- " /* (8) seperator */ + "%*s " /* (9) file system type */ + "%*s" /* (10) mount source */ + "%*s" /* (11) mount options 2 */ + "%*[^\n]", /* some rubbish at the end */ + &path)) != 1) { + if (k == EOF) + break; + + r = -EBADMSG; + goto finish; + } + + if (mount_point_is_api(path)) + goto free; + + if (!(p = cunescape(path))) { + r = -ENOMEM; + free(p); + goto finish; + } + + mp = mount_point_alloc(p); + LIST_PREPEND(MountPoint, mount_point, *mp_list_head, mp); +free: + free(path); + } + + r = 0; + +finish: + fclose(proc_self_mountinfo); + + free(path); + + return r; +} + +static void mount_points_list_umount(MountPoint **mp_list_head, bool *changed) { + MountPoint *mp, *mp_next; + + LIST_FOREACH_SAFE(mount_point, mp, mp_next, *mp_list_head) { + if (!(strcmp(mp->path, "/"))) + continue; + + /* Trying to umount. Forcing to umount if busy (only for NFS mounts) */ + if (umount2(mp->path, MNT_FORCE) == 0) { + if (!(*changed)) + *changed = true; + mount_point_remove_and_free(mp, mp_list_head); + log_debug("umount: \"%s\" was umounted succesfully\n", mp->path); + + } else + log_debug("umount: forced umount of \"%s\" failed!\n", mp->path); + + } +} + +static void mount_points_list_remount_read_only(MountPoint **mp_list_head, bool *changed) { + MountPoint *mp, *mp_next; + + LIST_FOREACH_SAFE(mount_point, mp, mp_next, *mp_list_head) { + if (mp->read_only) + continue; + + /* Trying to remount read-only */ + if (mount(NULL, mp->path, NULL, MS_MGC_VAL|MS_REMOUNT|MS_RDONLY, NULL) == 0) { + mp->read_only = true; + if (!(*changed)) + *changed = true; + mount_point_remove_and_free(mp, mp_list_head); + log_debug("umount: \"%s\" busy - remounted read-only\n", mp->path); + } else { + log_error("Cannot remount \"%s\" read-only\n", mp->path); + sleep(1); + } + } +} + +void umount_init(void) { + LIST_HEAD(MountPoint, mp_list_head); + int r; + bool changed; + + LIST_HEAD_INIT(MountPoint, mp_list_head); + if ((r = mount_points_list_get(&mp_list_head)) < 0) + log_debug("An error [%d] ocurred getting mount point's list - " + "umounting the mount points that are possible", r); + + do { + changed = false; + mount_points_list_umount(&mp_list_head, &changed); + } while (!changed); + + do { + changed = false; + mount_points_list_remount_read_only(&mp_list_head, &changed); + } while (!changed); + + mount_points_list_free(&mp_list_head); +} diff --git a/src/umount.h b/src/umount.h new file mode 100644 index 0000000..6a69e67 --- /dev/null +++ b/src/umount.h @@ -0,0 +1,27 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +#ifndef fooumounthfoo +#define fooumounthfoo + +/*** + This file is part of systemd. + + Copyright 2010 ProFUSION embedded systems + + systemd 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. + + systemd 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 systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +void umount_init(void); + +#endif -- 1.7.3 _______________________________________________ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel