diff options
| -rw-r--r-- | src/core/namespace.c | 6 | ||||
| -rw-r--r-- | src/shared/util.c | 68 | ||||
| -rw-r--r-- | src/shared/util.h | 2 |
3 files changed, 76 insertions, 0 deletions
diff --git a/src/core/namespace.c b/src/core/namespace.c index b6deab7081..fcbfd87d47 100644 --- a/src/core/namespace.c +++ b/src/core/namespace.c @@ -284,6 +284,12 @@ static int apply_mount( return mount_dev(m); case INACCESSIBLE: + + /* First, get rid of everything that is below if there + * is anything... Then, overmount it with an + * inaccessible directory. */ + umount_recursive(m->path, 0); + what = "/run/systemd/inaccessible"; break; diff --git a/src/shared/util.c b/src/shared/util.c index 49185a99a9..011fb36f49 100644 --- a/src/shared/util.c +++ b/src/shared/util.c @@ -54,6 +54,7 @@ #include <grp.h> #include <sys/mman.h> #include <sys/vfs.h> +#include <sys/mount.h> #include <linux/magic.h> #include <limits.h> #include <langinfo.h> @@ -6502,3 +6503,70 @@ int update_reboot_param_file(const char *param) { return r; } + +int umount_recursive(const char *prefix, int flags) { + bool again; + int n = 0, r; + + /* Try to umount everything recursively below a + * directory. Also, take care of stacked mounts, and keep + * unmounting them until they are gone. */ + + do { + _cleanup_fclose_ FILE *proc_self_mountinfo = NULL; + + again = false; + r = 0; + + proc_self_mountinfo = fopen("/proc/self/mountinfo", "re"); + if (!proc_self_mountinfo) + return -errno; + + for (;;) { + _cleanup_free_ char *path = NULL, *p = NULL; + int k; + + 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) separator */ + "%*s " /* (9) file system type */ + "%*s" /* (10) mount source */ + "%*s" /* (11) mount options 2 */ + "%*[^\n]", /* some rubbish at the end */ + &path); + + if (k != 1) { + if (k == EOF) + break; + + continue; + } + + p = cunescape(path); + if (!p) + return -ENOMEM; + + if (!path_startswith(p, prefix)) + continue; + + if (umount2(p, flags) < 0) { + r = -errno; + continue; + } + + again = true; + n++; + + break; + } + + } while (again); + + return r ? r : n; +} diff --git a/src/shared/util.h b/src/shared/util.h index 62eb60402d..ac851fa4d6 100644 --- a/src/shared/util.h +++ b/src/shared/util.h @@ -942,3 +942,5 @@ union file_handle_union { }; int update_reboot_param_file(const char *param); + +int umount_recursive(const char *target, int flags); |