1 /* SPDX-License-Identifier: LGPL-2.1+ */
9 #include <linux/magic.h>
13 #include "alloc-util.h"
14 #include "dirent-util.h"
20 //#include "missing.h"
22 #include "parse-util.h"
23 #include "path-util.h"
24 //#include "process-util.h"
25 #include "stat-util.h"
26 #include "stdio-util.h"
27 #include "string-util.h"
29 //#include "time-util.h"
30 #include "user-util.h"
33 /// Additional includes needed by elogind
34 #include "process-util.h"
36 int unlink_noerrno(const char *path) {
47 #if 0 /// UNNEEDED by elogind
48 int rmdir_parents(const char *path, const char *stop) {
57 /* Skip trailing slashes */
58 while (l > 0 && path[l-1] == '/')
64 /* Skip last component */
65 while (l > 0 && path[l-1] != '/')
68 /* Skip trailing slashes */
69 while (l > 0 && path[l-1] == '/')
79 if (path_startswith(stop, t)) {
95 int rename_noreplace(int olddirfd, const char *oldpath, int newdirfd, const char *newpath) {
99 ret = renameat2(olddirfd, oldpath, newdirfd, newpath, RENAME_NOREPLACE);
103 /* renameat2() exists since Linux 3.15, btrfs added support for it later.
104 * If it is not implemented, fallback to another method. */
105 if (!IN_SET(errno, EINVAL, ENOSYS))
108 /* The link()/unlink() fallback does not work on directories. But
109 * renameat() without RENAME_NOREPLACE gives the same semantics on
110 * directories, except when newpath is an *empty* directory. This is
112 ret = fstatat(olddirfd, oldpath, &buf, AT_SYMLINK_NOFOLLOW);
113 if (ret >= 0 && S_ISDIR(buf.st_mode)) {
114 ret = renameat(olddirfd, oldpath, newdirfd, newpath);
115 return ret >= 0 ? 0 : -errno;
118 /* If it is not a directory, use the link()/unlink() fallback. */
119 ret = linkat(olddirfd, oldpath, newdirfd, newpath, 0);
123 ret = unlinkat(olddirfd, oldpath, 0);
125 /* backup errno before the following unlinkat() alters it */
127 (void) unlinkat(newdirfd, newpath, 0);
136 int readlinkat_malloc(int fd, const char *p, char **ret) {
151 n = readlinkat(fd, p, c, l-1);
158 if ((size_t) n < l-1) {
169 int readlink_malloc(const char *p, char **ret) {
170 return readlinkat_malloc(AT_FDCWD, p, ret);
173 #if 0 /// UNNEEDED by elogind
174 int readlink_value(const char *p, char **ret) {
175 _cleanup_free_ char *link = NULL;
179 r = readlink_malloc(p, &link);
183 value = basename(link);
187 value = strdup(value);
197 int readlink_and_make_absolute(const char *p, char **r) {
198 _cleanup_free_ char *target = NULL;
205 j = readlink_malloc(p, &target);
209 k = file_in_same_dir(p, target);
217 #if 0 /// UNNEEDED by elogind
219 int chmod_and_chown(const char *path, mode_t mode, uid_t uid, gid_t gid) {
222 /* Under the assumption that we are running privileged we
223 * first change the access mode and only then hand out
224 * ownership to avoid a window where access is too open. */
226 if (mode != MODE_INVALID)
227 if (chmod(path, mode) < 0)
230 if (uid != UID_INVALID || gid != GID_INVALID)
231 if (chown(path, uid, gid) < 0)
237 int fchmod_and_chown(int fd, mode_t mode, uid_t uid, gid_t gid) {
238 /* Under the assumption that we are running privileged we
239 * first change the access mode and only then hand out
240 * ownership to avoid a window where access is too open. */
242 if (mode != MODE_INVALID)
243 if (fchmod(fd, mode) < 0)
246 if (uid != UID_INVALID || gid != GID_INVALID)
247 if (fchown(fd, uid, gid) < 0)
253 int fchmod_umask(int fd, mode_t m) {
258 r = fchmod(fd, m & (~u)) < 0 ? -errno : 0;
264 int fchmod_opath(int fd, mode_t m) {
265 char procfs_path[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(int)];
267 /* This function operates also on fd that might have been opened with
268 * O_PATH. Indeed fchmodat() doesn't have the AT_EMPTY_PATH flag like
269 * fchownat() does. */
271 xsprintf(procfs_path, "/proc/self/fd/%i", fd);
273 if (chmod(procfs_path, m) < 0)
279 int fd_warn_permissions(const char *path, int fd) {
282 if (fstat(fd, &st) < 0)
285 if (st.st_mode & 0111)
286 log_warning("Configuration file %s is marked executable. Please remove executable permission bits. Proceeding anyway.", path);
288 if (st.st_mode & 0002)
289 log_warning("Configuration file %s is marked world-writable. Please remove world writability permission bits. Proceeding anyway.", path);
291 if (getpid_cached() == 1 && (st.st_mode & 0044) != 0044)
292 log_warning("Configuration file %s is marked world-inaccessible. This has no effect as configuration data is accessible via APIs without restrictions. Proceeding anyway.", path);
297 int touch_file(const char *path, bool parents, usec_t stamp, uid_t uid, gid_t gid, mode_t mode) {
298 char fdpath[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(int)];
299 _cleanup_close_ int fd = -1;
304 /* Note that touch_file() does not follow symlinks: if invoked on an existing symlink, then it is the symlink
305 * itself which is updated, not its target
307 * Returns the first error we encounter, but tries to apply as much as possible. */
310 (void) mkdir_parents(path, 0755);
312 /* Initially, we try to open the node with O_PATH, so that we get a reference to the node. This is useful in
313 * case the path refers to an existing device or socket node, as we can open it successfully in all cases, and
314 * won't trigger any driver magic or so. */
315 fd = open(path, O_PATH|O_CLOEXEC|O_NOFOLLOW);
320 /* if the node doesn't exist yet, we create it, but with O_EXCL, so that we only create a regular file
321 * here, and nothing else */
322 fd = open(path, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC, IN_SET(mode, 0, MODE_INVALID) ? 0644 : mode);
327 /* Let's make a path from the fd, and operate on that. With this logic, we can adjust the access mode,
328 * ownership and time of the file node in all cases, even if the fd refers to an O_PATH object â which is
329 * something fchown(), fchmod(), futimensat() don't allow. */
330 xsprintf(fdpath, "/proc/self/fd/%i", fd);
332 if (mode != MODE_INVALID)
333 if (chmod(fdpath, mode) < 0)
336 if (uid_is_valid(uid) || gid_is_valid(gid))
337 if (chown(fdpath, uid, gid) < 0 && ret >= 0)
340 if (stamp != USEC_INFINITY) {
341 struct timespec ts[2];
343 timespec_store(&ts[0], stamp);
345 r = utimensat(AT_FDCWD, fdpath, ts, 0);
347 r = utimensat(AT_FDCWD, fdpath, NULL, 0);
348 if (r < 0 && ret >= 0)
354 int touch(const char *path) {
355 return touch_file(path, false, USEC_INFINITY, UID_INVALID, GID_INVALID, MODE_INVALID);
358 #if 0 /// UNNEEDED by elogind
359 int symlink_idempotent(const char *from, const char *to) {
365 if (symlink(from, to) < 0) {
366 _cleanup_free_ char *p = NULL;
371 r = readlink_malloc(to, &p);
372 if (r == -EINVAL) /* Not a symlink? In that case return the original error we encountered: -EEXIST */
374 if (r < 0) /* Any other error? In that case propagate it as is */
377 if (!streq(p, from)) /* Not the symlink we want it to be? In that case, propagate the original -EEXIST */
384 int symlink_atomic(const char *from, const char *to) {
385 _cleanup_free_ char *t = NULL;
391 r = tempfn_random(to, NULL, &t);
395 if (symlink(from, t) < 0)
398 if (rename(t, to) < 0) {
406 int mknod_atomic(const char *path, mode_t mode, dev_t dev) {
407 _cleanup_free_ char *t = NULL;
412 r = tempfn_random(path, NULL, &t);
416 if (mknod(t, mode, dev) < 0)
419 if (rename(t, path) < 0) {
427 int mkfifo_atomic(const char *path, mode_t mode) {
428 _cleanup_free_ char *t = NULL;
433 r = tempfn_random(path, NULL, &t);
437 if (mkfifo(t, mode) < 0)
440 if (rename(t, path) < 0) {
449 int get_files_in_directory(const char *path, char ***list) {
450 _cleanup_closedir_ DIR *d = NULL;
452 size_t bufsize = 0, n = 0;
453 _cleanup_strv_free_ char **l = NULL;
457 /* Returns all files in a directory in *list, and the number
458 * of files as return value. If list is NULL returns only the
465 FOREACH_DIRENT_ALL(de, d, return -errno) {
466 dirent_ensure_type(d, de);
468 if (!dirent_is_file(de))
472 /* one extra slot is needed for the terminating NULL */
473 if (!GREEDY_REALLOC(l, bufsize, n + 2))
476 l[n] = strdup(de->d_name);
491 static int getenv_tmp_dir(const char **ret_path) {
497 /* We use the same order of environment variables python uses in tempfile.gettempdir():
498 * https://docs.python.org/3/library/tempfile.html#tempfile.gettempdir */
499 FOREACH_STRING(n, "TMPDIR", "TEMP", "TMP") {
502 e = secure_getenv(n);
505 if (!path_is_absolute(e)) {
509 if (!path_is_normalized(e)) {
526 /* Remember first error, to make this more debuggable */
538 static int tmp_dir_internal(const char *def, const char **ret) {
545 r = getenv_tmp_dir(&e);
551 k = is_dir(def, true);
555 return r < 0 ? r : k;
561 #if 0 /// UNNEEDED by elogind
562 int var_tmp_dir(const char **ret) {
564 /* Returns the location for "larger" temporary files, that is backed by physical storage if available, and thus
565 * even might survive a boot: /var/tmp. If $TMPDIR (or related environment variables) are set, its value is
566 * returned preferably however. Note that both this function and tmp_dir() below are affected by $TMPDIR,
567 * making it a variable that overrides all temporary file storage locations. */
569 return tmp_dir_internal("/var/tmp", ret);
573 int tmp_dir(const char **ret) {
575 /* Similar to var_tmp_dir() above, but returns the location for "smaller" temporary files, which is usually
576 * backed by an in-memory file system: /tmp. */
578 return tmp_dir_internal("/tmp", ret);
581 int unlink_or_warn(const char *filename) {
582 if (unlink(filename) < 0 && errno != ENOENT)
583 /* If the file doesn't exist and the fs simply was read-only (in which
584 * case unlink() returns EROFS even if the file doesn't exist), don't
586 if (errno != EROFS || access(filename, F_OK) >= 0)
587 return log_error_errno(errno, "Failed to remove \"%s\": %m", filename);
592 #if 0 /// UNNEEDED by elogind
593 int inotify_add_watch_fd(int fd, int what, uint32_t mask) {
594 char path[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(int) + 1];
597 /* This is like inotify_add_watch(), except that the file to watch is not referenced by a path, but by an fd */
598 xsprintf(path, "/proc/self/fd/%i", what);
600 r = inotify_add_watch(fd, path, mask);
608 static bool safe_transition(const struct stat *a, const struct stat *b) {
609 /* Returns true if the transition from a to b is safe, i.e. that we never transition from unprivileged to
610 * privileged files or directories. Why bother? So that unprivileged code can't symlink to privileged files
611 * making us believe we read something safe even though it isn't safe in the specific context we open it in. */
613 if (a->st_uid == 0) /* Transitioning from privileged to unprivileged is always fine */
616 return a->st_uid == b->st_uid; /* Otherwise we need to stay within the same UID */
619 int chase_symlinks(const char *path, const char *original_root, unsigned flags, char **ret) {
620 _cleanup_free_ char *buffer = NULL, *done = NULL, *root = NULL;
621 _cleanup_close_ int fd = -1;
622 unsigned max_follow = CHASE_SYMLINKS_MAX; /* how many symlinks to follow before giving up and returning ELOOP */
623 struct stat previous_stat;
630 /* Either the file may be missing, or we return an fd to the final object, but both make no sense */
631 if (FLAGS_SET(flags, CHASE_NONEXISTENT | CHASE_OPEN))
634 if (FLAGS_SET(flags, CHASE_STEP | CHASE_OPEN))
640 /* This is a lot like canonicalize_file_name(), but takes an additional "root" parameter, that allows following
641 * symlinks relative to a root directory, instead of the root of the host.
643 * Note that "root" primarily matters if we encounter an absolute symlink. It is also used when following
644 * relative symlinks to ensure they cannot be used to "escape" the root directory. The path parameter passed is
645 * assumed to be already prefixed by it, except if the CHASE_PREFIX_ROOT flag is set, in which case it is first
646 * prefixed accordingly.
648 * Algorithmically this operates on two path buffers: "done" are the components of the path we already
649 * processed and resolved symlinks, "." and ".." of. "todo" are the components of the path we still need to
650 * process. On each iteration, we move one component from "todo" to "done", processing it's special meaning
651 * each time. The "todo" path always starts with at least one slash, the "done" path always ends in no
652 * slash. We always keep an O_PATH fd to the component we are currently processing, thus keeping lookup races
655 * Suggested usage: whenever you want to canonicalize a path, use this function. Pass the absolute path you got
656 * as-is: fully qualified and relative to your host's root. Optionally, specify the root parameter to tell this
657 * function what to do when encountering a symlink with an absolute path as directory: prefix it by the
660 * There are three ways to invoke this function:
662 * 1. Without CHASE_STEP or CHASE_OPEN: in this case the path is resolved and the normalized path is returned
663 * in `ret`. The return value is < 0 on error. If CHASE_NONEXISTENT is also set 0 is returned if the file
664 * doesn't exist, > 0 otherwise. If CHASE_NONEXISTENT is not set >= 0 is returned if the destination was
665 * found, -ENOENT if it doesn't.
667 * 2. With CHASE_OPEN: in this case the destination is opened after chasing it as O_PATH and this file
668 * descriptor is returned as return value. This is useful to open files relative to some root
669 * directory. Note that the returned O_PATH file descriptors must be converted into a regular one (using
670 * fd_reopen() or such) before it can be used for reading/writing. CHASE_OPEN may not be combined with
673 * 3. With CHASE_STEP: in this case only a single step of the normalization is executed, i.e. only the first
674 * symlink or ".." component of the path is resolved, and the resulting path is returned. This is useful if
675 * a caller wants to trace the a path through the file system verbosely. Returns < 0 on error, > 0 if the
676 * path is fully normalized, and == 0 for each normalization step. This may be combined with
677 * CHASE_NONEXISTENT, in which case 1 is returned when a component is not found.
681 /* A root directory of "/" or "" is identical to none */
682 if (empty_or_root(original_root))
683 original_root = NULL;
685 if (!original_root && !ret && (flags & (CHASE_NONEXISTENT|CHASE_NO_AUTOFS|CHASE_SAFE|CHASE_OPEN|CHASE_STEP)) == CHASE_OPEN) {
686 /* Shortcut the CHASE_OPEN case if the caller isn't interested in the actual path and has no root set
687 * and doesn't care about any of the other special features we provide either. */
688 r = open(path, O_PATH|O_CLOEXEC);
696 r = path_make_absolute_cwd(original_root, &root);
700 if (flags & CHASE_PREFIX_ROOT) {
702 /* We don't support relative paths in combination with a root directory */
703 if (!path_is_absolute(path))
706 path = prefix_roota(root, path);
710 r = path_make_absolute_cwd(path, &buffer);
714 fd = open("/", O_CLOEXEC|O_NOFOLLOW|O_PATH);
718 if (flags & CHASE_SAFE) {
719 if (fstat(fd, &previous_stat) < 0)
725 _cleanup_free_ char *first = NULL;
726 _cleanup_close_ int child = -1;
730 /* Determine length of first component in the path */
731 n = strspn(todo, "/"); /* The slashes */
732 m = n + strcspn(todo + n, "/"); /* The entire length of the component */
734 /* Extract the first component. */
735 first = strndup(todo, m);
741 /* Empty? Then we reached the end. */
745 /* Just a single slash? Then we reached the end. */
746 if (path_equal(first, "/")) {
747 /* Preserve the trailing slash */
749 if (flags & CHASE_TRAIL_SLASH)
750 if (!strextend(&done, "/", NULL))
756 /* Just a dot? Then let's eat this up. */
757 if (path_equal(first, "/."))
760 /* Two dots? Then chop off the last bit of what we already found out. */
761 if (path_equal(first, "/..")) {
762 _cleanup_free_ char *parent = NULL;
763 _cleanup_close_ int fd_parent = -1;
765 /* If we already are at the top, then going up will not change anything. This is in-line with
766 * how the kernel handles this. */
767 if (empty_or_root(done))
770 parent = dirname_malloc(done);
774 /* Don't allow this to leave the root dir. */
776 path_startswith(done, root) &&
777 !path_startswith(parent, root))
780 free_and_replace(done, parent);
782 if (flags & CHASE_STEP)
785 fd_parent = openat(fd, "..", O_CLOEXEC|O_NOFOLLOW|O_PATH);
789 if (flags & CHASE_SAFE) {
790 if (fstat(fd_parent, &st) < 0)
793 if (!safe_transition(&previous_stat, &st))
800 fd = TAKE_FD(fd_parent);
805 /* Otherwise let's see what this is. */
806 child = openat(fd, first + n, O_CLOEXEC|O_NOFOLLOW|O_PATH);
809 if (errno == ENOENT &&
810 (flags & CHASE_NONEXISTENT) &&
811 (isempty(todo) || path_is_normalized(todo))) {
813 /* If CHASE_NONEXISTENT is set, and the path does not exist, then that's OK, return
814 * what we got so far. But don't allow this if the remaining path contains "../ or "./"
815 * or something else weird. */
817 /* If done is "/", as first also contains slash at the head, then remove this redundant slash. */
818 if (streq_ptr(done, "/"))
821 if (!strextend(&done, first, todo, NULL))
831 if (fstat(child, &st) < 0)
833 if ((flags & CHASE_SAFE) &&
834 !safe_transition(&previous_stat, &st))
839 if ((flags & CHASE_NO_AUTOFS) &&
840 fd_is_fs_type(child, AUTOFS_SUPER_MAGIC) > 0)
843 if (S_ISLNK(st.st_mode)) {
846 _cleanup_free_ char *destination = NULL;
848 /* This is a symlink, in this case read the destination. But let's make sure we don't follow
849 * symlinks without bounds. */
850 if (--max_follow <= 0)
853 r = readlinkat_malloc(fd, first + n, &destination);
856 if (isempty(destination))
859 if (path_is_absolute(destination)) {
861 /* An absolute destination. Start the loop from the beginning, but use the root
862 * directory as base. */
865 fd = open(root ?: "/", O_CLOEXEC|O_NOFOLLOW|O_PATH);
869 if (flags & CHASE_SAFE) {
870 if (fstat(fd, &st) < 0)
873 if (!safe_transition(&previous_stat, &st))
881 /* Note that we do not revalidate the root, we take it as is. */
890 /* Prefix what's left to do with what we just read, and start the loop again, but
891 * remain in the current directory. */
892 joined = strjoin(destination, todo);
894 joined = strjoin("/", destination, todo);
899 todo = buffer = joined;
901 if (flags & CHASE_STEP)
907 /* If this is not a symlink, then let's just add the name we read to what we already verified. */
909 done = TAKE_PTR(first);
911 /* If done is "/", as first also contains slash at the head, then remove this redundant slash. */
912 if (streq(done, "/"))
915 if (!strextend(&done, first, NULL))
919 /* And iterate again, but go one directory further down. */
925 /* Special case, turn the empty string into "/", to indicate the root directory. */
932 *ret = TAKE_PTR(done);
934 if (flags & CHASE_OPEN) {
935 /* Return the O_PATH fd we currently are looking to the caller. It can translate it to a proper fd by
936 * opening /proc/self/fd/xyz. */
942 if (flags & CHASE_STEP)
951 c = strjoin(strempty(done), todo);
961 int chase_symlinks_and_open(
964 unsigned chase_flags,
968 _cleanup_close_ int path_fd = -1;
969 _cleanup_free_ char *p = NULL;
972 if (chase_flags & CHASE_NONEXISTENT)
975 if (empty_or_root(root) && !ret_path && (chase_flags & (CHASE_NO_AUTOFS|CHASE_SAFE)) == 0) {
976 /* Shortcut this call if none of the special features of this call are requested */
977 r = open(path, open_flags);
984 path_fd = chase_symlinks(path, root, chase_flags|CHASE_OPEN, ret_path ? &p : NULL);
988 r = fd_reopen(path_fd, open_flags);
993 *ret_path = TAKE_PTR(p);
998 int chase_symlinks_and_opendir(
1001 unsigned chase_flags,
1005 char procfs_path[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(int)];
1006 _cleanup_close_ int path_fd = -1;
1007 _cleanup_free_ char *p = NULL;
1012 if (chase_flags & CHASE_NONEXISTENT)
1015 if (empty_or_root(root) && !ret_path && (chase_flags & (CHASE_NO_AUTOFS|CHASE_SAFE)) == 0) {
1016 /* Shortcut this call if none of the special features of this call are requested */
1025 path_fd = chase_symlinks(path, root, chase_flags|CHASE_OPEN, ret_path ? &p : NULL);
1029 xsprintf(procfs_path, "/proc/self/fd/%i", path_fd);
1030 d = opendir(procfs_path);
1035 *ret_path = TAKE_PTR(p);
1041 int chase_symlinks_and_stat(
1044 unsigned chase_flags,
1046 struct stat *ret_stat) {
1048 _cleanup_close_ int path_fd = -1;
1049 _cleanup_free_ char *p = NULL;
1054 if (chase_flags & CHASE_NONEXISTENT)
1057 if (empty_or_root(root) && !ret_path && (chase_flags & (CHASE_NO_AUTOFS|CHASE_SAFE)) == 0) {
1058 /* Shortcut this call if none of the special features of this call are requested */
1059 if (stat(path, ret_stat) < 0)
1065 path_fd = chase_symlinks(path, root, chase_flags|CHASE_OPEN, ret_path ? &p : NULL);
1069 if (fstat(path_fd, ret_stat) < 0)
1073 *ret_path = TAKE_PTR(p);
1075 if (chase_flags & CHASE_OPEN)
1076 return TAKE_FD(path_fd);
1081 int access_fd(int fd, int mode) {
1082 char p[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(fd) + 1];
1085 /* Like access() but operates on an already open fd */
1087 xsprintf(p, "/proc/self/fd/%i", fd);
1088 r = access(p, mode);
1095 void unlink_tempfilep(char (*p)[]) {
1096 /* If the file is created with mkstemp(), it will (almost always)
1097 * change the suffix. Treat this as a sign that the file was
1098 * successfully created. We ignore both the rare case where the
1099 * original suffix is used and unlink failures. */
1100 if (!endswith(*p, ".XXXXXX"))
1101 (void) unlink_noerrno(*p);
1104 int unlinkat_deallocate(int fd, const char *name, int flags) {
1105 _cleanup_close_ int truncate_fd = -1;
1109 /* Operates like unlinkat() but also deallocates the file contents if it is a regular file and there's no other
1110 * link to it. This is useful to ensure that other processes that might have the file open for reading won't be
1111 * able to keep the data pinned on disk forever. This call is particular useful whenever we execute clean-up
1112 * jobs ("vacuuming"), where we want to make sure the data is really gone and the disk space released and
1113 * returned to the free pool.
1115 * Deallocation is preferably done by FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE (đ) if supported, which means
1116 * the file won't change size. That's a good thing since we shouldn't needlessly trigger SIGBUS in other
1117 * programs that have mmap()ed the file. (The assumption here is that changing file contents to all zeroes
1118 * underneath those programs is the better choice than simply triggering SIGBUS in them which truncation does.)
1119 * However if hole punching is not implemented in the kernel or file system we'll fall back to normal file
1120 * truncation (đĒ), as our goal of deallocating the data space trumps our goal of being nice to readers (đ).
1122 * Note that we attempt deallocation, but failure to succeed with that is not considered fatal, as long as the
1123 * primary job â to delete the file â is accomplished. */
1125 if ((flags & AT_REMOVEDIR) == 0) {
1126 truncate_fd = openat(fd, name, O_WRONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW|O_NONBLOCK);
1127 if (truncate_fd < 0) {
1129 /* If this failed because the file doesn't exist propagate the error right-away. Also,
1130 * AT_REMOVEDIR wasn't set, and we tried to open the file for writing, which means EISDIR is
1131 * returned when this is a directory but we are not supposed to delete those, hence propagate
1132 * the error right-away too. */
1133 if (IN_SET(errno, ENOENT, EISDIR))
1136 if (errno != ELOOP) /* don't complain if this is a symlink */
1137 log_debug_errno(errno, "Failed to open file '%s' for deallocation, ignoring: %m", name);
1141 if (unlinkat(fd, name, flags) < 0)
1144 if (truncate_fd < 0) /* Don't have a file handle, can't do more âšī¸ */
1147 if (fstat(truncate_fd, &st) < 0) {
1148 log_debug_errno(errno, "Failed to stat file '%s' for deallocation, ignoring.", name);
1152 if (!S_ISREG(st.st_mode) || st.st_blocks == 0 || st.st_nlink > 0)
1155 /* If this is a regular file, it actually took up space on disk and there are no other links it's time to
1156 * punch-hole/truncate this to release the disk space. */
1158 bs = MAX(st.st_blksize, 512);
1159 l = DIV_ROUND_UP(st.st_size, bs) * bs; /* Round up to next block size */
1161 if (fallocate(truncate_fd, FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE, 0, l) >= 0)
1162 return 0; /* Successfully punched a hole! đ */
1164 /* Fall back to truncation */
1165 if (ftruncate(truncate_fd, 0) < 0) {
1166 log_debug_errno(errno, "Failed to truncate file to 0, ignoring: %m");
1173 int fsync_directory_of_file(int fd) {
1174 _cleanup_free_ char *path = NULL, *dn = NULL;
1175 _cleanup_close_ int dfd = -1;
1178 r = fd_verify_regular(fd);
1182 r = fd_get_path(fd, &path);
1184 log_debug_errno(r, "Failed to query /proc/self/fd/%d%s: %m",
1186 r == -EOPNOTSUPP ? ", ignoring" : "");
1188 if (r == -EOPNOTSUPP)
1189 /* If /proc is not available, we're most likely running in some
1190 * chroot environment, and syncing the directory is not very
1191 * important in that case. Let's just silently do nothing. */
1197 if (!path_is_absolute(path))
1200 dn = dirname_malloc(path);
1204 dfd = open(dn, O_RDONLY|O_CLOEXEC|O_DIRECTORY);