| /*** |
| This file is part of systemd. |
| |
| Copyright 2015 Lennart Poettering |
| |
| systemd is free software; you can redistribute it and/or modify it |
| under the terms of the GNU Lesser General Public License as published by |
| the Free Software Foundation; either version 2.1 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 |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public License |
| along with systemd; If not, see <http://www.gnu.org/licenses/>. |
| ***/ |
| |
| #include <dirent.h> |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <stdbool.h> |
| #include <stddef.h> |
| #include <sys/stat.h> |
| #include <sys/statfs.h> |
| #include <unistd.h> |
| |
| #include "btrfs-util.h" |
| #include "fd-util.h" |
| #include "log.h" |
| #include "macro.h" |
| #include "mount-util.h" |
| #include "path-util.h" |
| #include "rm-rf.h" |
| #include "stat-util.h" |
| #include "string-util.h" |
| |
| int rm_rf_children(int fd, RemoveFlags flags, struct stat *root_dev) { |
| _cleanup_closedir_ DIR *d = NULL; |
| int ret = 0, r; |
| |
| assert(fd >= 0); |
| |
| /* This returns the first error we run into, but nevertheless |
| * tries to go on. This closes the passed fd. */ |
| |
| if (!(flags & REMOVE_PHYSICAL)) { |
| |
| r = fd_is_temporary_fs(fd); |
| if (r < 0) { |
| safe_close(fd); |
| return r; |
| } |
| |
| if (!r) { |
| /* We refuse to clean physical file systems |
| * with this call, unless explicitly |
| * requested. This is extra paranoia just to |
| * be sure we never ever remove non-state |
| * data */ |
| |
| log_error("Attempted to remove disk file system, and we can't allow that."); |
| safe_close(fd); |
| return -EPERM; |
| } |
| } |
| |
| d = fdopendir(fd); |
| if (!d) { |
| safe_close(fd); |
| return errno == ENOENT ? 0 : -errno; |
| } |
| |
| for (;;) { |
| struct dirent *de; |
| bool is_dir; |
| struct stat st; |
| |
| errno = 0; |
| de = readdir(d); |
| if (!de) { |
| if (errno > 0 && ret == 0) |
| ret = -errno; |
| return ret; |
| } |
| |
| if (streq(de->d_name, ".") || streq(de->d_name, "..")) |
| continue; |
| |
| if (de->d_type == DT_UNKNOWN || |
| (de->d_type == DT_DIR && (root_dev || (flags & REMOVE_SUBVOLUME)))) { |
| if (fstatat(fd, de->d_name, &st, AT_SYMLINK_NOFOLLOW) < 0) { |
| if (ret == 0 && errno != ENOENT) |
| ret = -errno; |
| continue; |
| } |
| |
| is_dir = S_ISDIR(st.st_mode); |
| } else |
| is_dir = de->d_type == DT_DIR; |
| |
| if (is_dir) { |
| int subdir_fd; |
| |
| /* if root_dev is set, remove subdirectories only if device is same */ |
| if (root_dev && st.st_dev != root_dev->st_dev) |
| continue; |
| |
| subdir_fd = openat(fd, de->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|O_NOFOLLOW|O_NOATIME); |
| if (subdir_fd < 0) { |
| if (ret == 0 && errno != ENOENT) |
| ret = -errno; |
| continue; |
| } |
| |
| /* Stop at mount points */ |
| r = fd_is_mount_point(fd, de->d_name, 0); |
| if (r < 0) { |
| if (ret == 0 && r != -ENOENT) |
| ret = r; |
| |
| safe_close(subdir_fd); |
| continue; |
| } |
| if (r) { |
| safe_close(subdir_fd); |
| continue; |
| } |
| |
| if ((flags & REMOVE_SUBVOLUME) && st.st_ino == 256) { |
| |
| /* This could be a subvolume, try to remove it */ |
| |
| r = btrfs_subvol_remove_fd(fd, de->d_name, BTRFS_REMOVE_RECURSIVE|BTRFS_REMOVE_QUOTA); |
| if (r < 0) { |
| if (r != -ENOTTY && r != -EINVAL) { |
| if (ret == 0) |
| ret = r; |
| |
| safe_close(subdir_fd); |
| continue; |
| } |
| |
| /* ENOTTY, then it wasn't a |
| * btrfs subvolume, continue |
| * below. */ |
| } else { |
| /* It was a subvolume, continue. */ |
| safe_close(subdir_fd); |
| continue; |
| } |
| } |
| |
| /* We pass REMOVE_PHYSICAL here, to avoid |
| * doing the fstatfs() to check the file |
| * system type again for each directory */ |
| r = rm_rf_children(subdir_fd, flags | REMOVE_PHYSICAL, root_dev); |
| if (r < 0 && ret == 0) |
| ret = r; |
| |
| if (unlinkat(fd, de->d_name, AT_REMOVEDIR) < 0) { |
| if (ret == 0 && errno != ENOENT) |
| ret = -errno; |
| } |
| |
| } else if (!(flags & REMOVE_ONLY_DIRECTORIES)) { |
| |
| if (unlinkat(fd, de->d_name, 0) < 0) { |
| if (ret == 0 && errno != ENOENT) |
| ret = -errno; |
| } |
| } |
| } |
| } |
| |
| int rm_rf(const char *path, RemoveFlags flags) { |
| int fd, r; |
| struct statfs s; |
| |
| assert(path); |
| |
| /* We refuse to clean the root file system with this |
| * call. This is extra paranoia to never cause a really |
| * seriously broken system. */ |
| if (path_equal(path, "/")) { |
| log_error("Attempted to remove entire root file system, and we can't allow that."); |
| return -EPERM; |
| } |
| |
| if ((flags & (REMOVE_SUBVOLUME|REMOVE_ROOT|REMOVE_PHYSICAL)) == (REMOVE_SUBVOLUME|REMOVE_ROOT|REMOVE_PHYSICAL)) { |
| /* Try to remove as subvolume first */ |
| r = btrfs_subvol_remove(path, BTRFS_REMOVE_RECURSIVE|BTRFS_REMOVE_QUOTA); |
| if (r >= 0) |
| return r; |
| |
| if (r != -ENOTTY && r != -EINVAL && r != -ENOTDIR) |
| return r; |
| |
| /* Not btrfs or not a subvolume */ |
| } |
| |
| fd = open(path, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|O_NOFOLLOW|O_NOATIME); |
| if (fd < 0) { |
| |
| if (errno != ENOTDIR && errno != ELOOP) |
| return -errno; |
| |
| if (!(flags & REMOVE_PHYSICAL)) { |
| if (statfs(path, &s) < 0) |
| return -errno; |
| |
| if (!is_temporary_fs(&s)) { |
| log_error("Attempted to remove disk file system, and we can't allow that."); |
| return -EPERM; |
| } |
| } |
| |
| if ((flags & REMOVE_ROOT) && !(flags & REMOVE_ONLY_DIRECTORIES)) |
| if (unlink(path) < 0 && errno != ENOENT) |
| return -errno; |
| |
| return 0; |
| } |
| |
| r = rm_rf_children(fd, flags, NULL); |
| |
| if (flags & REMOVE_ROOT) { |
| if (rmdir(path) < 0) { |
| if (r == 0 && errno != ENOENT) |
| r = -errno; |
| } |
| } |
| |
| return r; |
| } |