18988181302

Committed 31 Oct 2025 09:30PM UTC coverage: 72.241% (+0.2%) from 72.046%

Build # 18988181302

Build Type

push

github

Committed by

web-flow

Commit Message

core: Add RootDirectoryFileDescriptor= (#39480)

RootDirectory= but via a open_tree() file descriptor. This allows
setting up the execution environment for a service by the client in a
mount namespace and then starting a transient unit in that execution
environment using the new property.

We also add --root-directory= and --same-root-dir= to systemd-run to
have it run services within the given root directory. As systemd-run
might be invoked from a different mount namespace than what systemd is
running in, systemd-run opens the given path with open_tree() and then
sends it to systemd using the new RootDirectoryFileDescriptor= property.

Run Details

45 of 76 new or added lines in 8 files covered. (59.21%)

2101 existing lines in 44 files now uncovered.

305020 of 422226 relevant lines covered (72.24%)

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Source File
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92.13

/src/basic/stat-util.c

/* SPDX-License-Identifier: LGPL-2.1-or-later */

#include <fcntl.h>
#include <linux/magic.h>
#include <sys/statvfs.h>
#include <unistd.h>

#include "alloc-util.h"
#include "chase.h"
#include "dirent-util.h"
#include "errno-util.h"
#include "fd-util.h"
#include "filesystems.h"
#include "fs-util.h"
#include "hash-funcs.h"
#include "log.h"
#include "mountpoint-util.h"
#include "path-util.h"
#include "siphash24.h"
#include "stat-util.h"
#include "string-util.h"
#include "time-util.h"

static int verify_stat_at(
                int fd,
                const char *path,
                bool follow,
                int (*verify_func)(const struct stat *st),
                bool verify) {

        struct stat st;
        int r;

        assert(fd >= 0 || fd == AT_FDCWD);
        assert(!isempty(path) || !follow);
        assert(verify_func);

        if (fstatat(fd, strempty(path), &st,
                    (isempty(path) ? AT_EMPTY_PATH : 0) | (follow ? 0 : AT_SYMLINK_NOFOLLOW)) < 0)
                return -errno;

        r = verify_func(&st);
        return verify ? r : r >= 0;
}

int stat_verify_regular(const struct stat *st) {
        assert(st);

        /* Checks whether the specified stat() structure refers to a regular file. If not returns an
         * appropriate error code. */

        if (S_ISDIR(st->st_mode))
                return -EISDIR;

        if (S_ISLNK(st->st_mode))
                return -ELOOP;

        if (!S_ISREG(st->st_mode))
                return -EBADFD;

        return 0;
}

int verify_regular_at(int fd, const char *path, bool follow) {
        return verify_stat_at(fd, path, follow, stat_verify_regular, true);
}

int fd_verify_regular(int fd) {
        assert(fd >= 0);
        return verify_regular_at(fd, NULL, false);
}

int stat_verify_directory(const struct stat *st) {
        assert(st);

        if (S_ISLNK(st->st_mode))
                return -ELOOP;

        if (!S_ISDIR(st->st_mode))
                return -ENOTDIR;

        return 0;
}

int fd_verify_directory(int fd) {
        assert(fd >= 0);
        return verify_stat_at(fd, NULL, false, stat_verify_directory, true);
}

int is_dir_at(int fd, const char *path, bool follow) {
        return verify_stat_at(fd, path, follow, stat_verify_directory, false);
}

int is_dir(const char *path, bool follow) {
        assert(!isempty(path));
        return is_dir_at(AT_FDCWD, path, follow);
}

int stat_verify_symlink(const struct stat *st) {
        assert(st);

        if (S_ISDIR(st->st_mode))
                return -EISDIR;

        if (!S_ISLNK(st->st_mode))
                return -ENOLINK;

        return 0;
}

int fd_verify_symlink(int fd) {
        return verify_stat_at(fd, /* path= */ NULL, /* follow= */ false, stat_verify_symlink, /* verify= */ true);
}

int is_symlink(const char *path) {
        assert(!isempty(path));
        return verify_stat_at(AT_FDCWD, path, false, stat_verify_symlink, false);
}

int stat_verify_linked(const struct stat *st) {
        assert(st);

        if (st->st_nlink <= 0)
                return -EIDRM; /* recognizable error. */

        return 0;
}

int fd_verify_linked(int fd) {
        assert(fd >= 0);
        return verify_stat_at(fd, NULL, false, stat_verify_linked, true);
}

int stat_verify_device_node(const struct stat *st) {
        assert(st);

        if (S_ISLNK(st->st_mode))
                return -ELOOP;

        if (S_ISDIR(st->st_mode))
                return -EISDIR;

        if (!S_ISBLK(st->st_mode) && !S_ISCHR(st->st_mode))
                return -ENOTTY;

        return 0;
}

int is_device_node(const char *path) {
        assert(!isempty(path));
        return verify_stat_at(AT_FDCWD, path, false, stat_verify_device_node, false);
}

int dir_is_empty_at(int dir_fd, const char *path, bool ignore_hidden_or_backup) {
        _cleanup_close_ int fd = -EBADF;
        struct dirent *buf;
        size_t m;

        fd = xopenat(dir_fd, path, O_DIRECTORY|O_CLOEXEC);
        if (fd < 0)
                return fd;

        /* Allocate space for at least 3 full dirents, since every dir has at least two entries ("."  +
         * ".."), and only once we have seen if there's a third we know whether the dir is empty or not. If
         * 'ignore_hidden_or_backup' is true we'll allocate a bit more, since we might skip over a bunch of
         * entries that we end up ignoring. */
        m = (ignore_hidden_or_backup ? 16 : 3) * DIRENT_SIZE_MAX;
        buf = alloca(m);

        for (;;) {
                struct dirent *de;
                ssize_t n;

                n = getdents64(fd, buf, m);
                if (n < 0)
                        return -errno;
                if (n == 0)
                        break;

                assert((size_t) n <= m);
                msan_unpoison(buf, n);

                FOREACH_DIRENT_IN_BUFFER(de, buf, n)
                        if (!(ignore_hidden_or_backup ? hidden_or_backup_file(de->d_name) : dot_or_dot_dot(de->d_name)))
                                return 0;
        }

        return 1;
}

bool stat_may_be_dev_null(struct stat *st) {
        assert(st);

        /* We don't want to hardcode the major/minor of /dev/null, hence we do a simpler "is this a character
         * device node?" check. */

        return S_ISCHR(st->st_mode);
}

bool stat_is_empty(struct stat *st) {
        assert(st);

        return S_ISREG(st->st_mode) && st->st_size <= 0;
}

int null_or_empty_path_with_root(const char *fn, const char *root) {
        struct stat st;
        int r;

        assert(fn);

        /* A symlink to /dev/null or an empty file?
         * When looking under root_dir, we can't expect /dev/ to be mounted,
         * so let's see if the path is a (possibly dangling) symlink to /dev/null. */

        if (path_equal(path_startswith(fn, root ?: "/"), "dev/null"))
                return true;

        r = chase_and_stat(fn, root, CHASE_PREFIX_ROOT, NULL, &st);
        if (r < 0)
                return r;

        return null_or_empty(&st);
}

int fd_is_read_only_fs(int fd) {
        struct statfs st;

        assert(fd >= 0);

        if (fstatfs(fd, &st) < 0)
                return -errno;

        if (st.f_flags & ST_RDONLY)
                return true;

        if (is_network_fs(&st)) {
                /* On NFS, fstatfs() might not reflect whether we can actually write to the remote share.
                 * Let's try again with access(W_OK) which is more reliable, at least sometimes. */
                if (access_fd(fd, W_OK) == -EROFS)
                        return true;
        }

        return false;
}

int path_is_read_only_fs(const char *path) {
        _cleanup_close_ int fd = -EBADF;

        assert(path);

        fd = open(path, O_CLOEXEC | O_PATH);
        if (fd < 0)
                return -errno;

        return fd_is_read_only_fs(fd);
}

int inode_same_at(int fda, const char *filea, int fdb, const char *fileb, int flags) {
        struct stat sta, stb;
        int r;

        assert(fda >= 0 || fda == AT_FDCWD);
        assert(fdb >= 0 || fdb == AT_FDCWD);
        assert((flags & ~(AT_EMPTY_PATH|AT_SYMLINK_NOFOLLOW|AT_NO_AUTOMOUNT)) == 0);

        /* Refuse an unset filea or fileb early unless AT_EMPTY_PATH is set */
        if ((isempty(filea) || isempty(fileb)) && !FLAGS_SET(flags, AT_EMPTY_PATH))
                return -EINVAL;

        /* Shortcut: comparing the same fd with itself means we can return true */
        if (fda >= 0 && fda == fdb && isempty(filea) && isempty(fileb) && FLAGS_SET(flags, AT_SYMLINK_NOFOLLOW))
                return true;

        _cleanup_close_ int pin_a = -EBADF, pin_b = -EBADF;
        if (!FLAGS_SET(flags, AT_NO_AUTOMOUNT)) {
                /* Let's try to use the name_to_handle_at() AT_HANDLE_FID API to identify identical
                 * inodes. We have to issue multiple calls on the same file for that (first, to acquire the
                 * FID, and then to check if .st_dev is actually the same). Hence let's pin the inode in
                 * between via O_PATH, unless we already have an fd for it. */

                if (!isempty(filea)) {
                        pin_a = openat(fda, filea, O_PATH|O_CLOEXEC|(FLAGS_SET(flags, AT_SYMLINK_NOFOLLOW) ? O_NOFOLLOW : 0));
                        if (pin_a < 0)
                                return -errno;

                        fda = pin_a;
                        filea = NULL;
                        flags |= AT_EMPTY_PATH;
                }

                if (!isempty(fileb)) {
                        pin_b = openat(fdb, fileb, O_PATH|O_CLOEXEC|(FLAGS_SET(flags, AT_SYMLINK_NOFOLLOW) ? O_NOFOLLOW : 0));
                        if (pin_b < 0)
                                return -errno;

                        fdb = pin_b;
                        fileb = NULL;
                        flags |= AT_EMPTY_PATH;
                }

                int ntha_flags = at_flags_normalize_follow(flags) & (AT_EMPTY_PATH|AT_SYMLINK_FOLLOW);
                _cleanup_free_ struct file_handle *ha = NULL, *hb = NULL;
                int mntida = -1, mntidb = -1;

                r = name_to_handle_at_try_fid(
                                fda,
                                filea,
                                &ha,
                                &mntida,
                                ntha_flags);
                if (r < 0) {
                        if (is_name_to_handle_at_fatal_error(r))
                                return r;

                        goto fallback;
                }

                r = name_to_handle_at_try_fid(
                                fdb,
                                fileb,
                                &hb,
                                &mntidb,
                                ntha_flags);
                if (r < 0) {
                        if (is_name_to_handle_at_fatal_error(r))
                                return r;

                        goto fallback;
                }

                /* Now compare the two file handles */
                if (!file_handle_equal(ha, hb))
                        return false;

                /* If the file handles are the same and they come from the same mount ID? Great, then we are
                 * good, they are definitely the same */
                if (mntida == mntidb)
                        return true;

                /* File handles are the same, they are not on the same mount id. This might either be because
                 * they are on two entirely different file systems, that just happen to have the same FIDs
                 * (because they originally where created off the same disk images), or it could be because
                 * they are located on two distinct bind mounts of the same fs. To check that, let's look at
                 * .st_rdev of the inode. We simply reuse the fallback codepath for that, since it checks
                 * exactly that (it checks slightly more, but we don't care.) */
        }

fallback:
        if (fstatat(fda, strempty(filea), &sta, flags) < 0)
                return log_debug_errno(errno, "Cannot stat %s: %m", strna(filea));

        if (fstatat(fdb, strempty(fileb), &stb, flags) < 0)
                return log_debug_errno(errno, "Cannot stat %s: %m", strna(fileb));

        return stat_inode_same(&sta, &stb);
}

bool is_fs_type(const struct statfs *s, statfs_f_type_t magic_value) {
        assert(s);
        assert_cc(sizeof(statfs_f_type_t) >= sizeof(s->f_type));

        return F_TYPE_EQUAL(s->f_type, magic_value);
}

int is_fs_type_at(int dir_fd, const char *path, statfs_f_type_t magic_value) {
        struct statfs s;
        int r;

        r = xstatfsat(dir_fd, path, &s);
        if (r < 0)
                return r;

        return is_fs_type(&s, magic_value);
}

bool is_temporary_fs(const struct statfs *s) {
        return fs_in_group(s, FILESYSTEM_SET_TEMPORARY);
}

bool is_network_fs(const struct statfs *s) {
        return fs_in_group(s, FILESYSTEM_SET_NETWORK);
}

int fd_is_temporary_fs(int fd) {
        struct statfs s;

        if (fstatfs(fd, &s) < 0)
                return -errno;

        return is_temporary_fs(&s);
}

int fd_is_network_fs(int fd) {
        struct statfs s;

        if (fstatfs(fd, &s) < 0)
                return -errno;

        return is_network_fs(&s);
}

int path_is_temporary_fs(const char *path) {
        struct statfs s;

        if (statfs(path, &s) < 0)
                return -errno;

        return is_temporary_fs(&s);
}

int path_is_network_fs(const char *path) {
        struct statfs s;

        if (statfs(path, &s) < 0)
                return -errno;

        return is_network_fs(&s);
}

int proc_mounted(void) {
        int r;

        /* A quick check of procfs is properly mounted */

        r = path_is_fs_type("/proc/", PROC_SUPER_MAGIC);
        if (r == -ENOENT) /* not mounted at all */
                return false;

        return r;
}

bool stat_inode_same(const struct stat *a, const struct stat *b) {

        /* Returns if the specified stat structure references the same (though possibly modified) inode. Does
         * a thorough check, comparing inode nr, backing device and if the inode is still of the same type. */

        return stat_is_set(a) && stat_is_set(b) &&
                ((a->st_mode ^ b->st_mode) & S_IFMT) == 0 &&  /* same inode type */
                a->st_dev == b->st_dev &&
                a->st_ino == b->st_ino;
}

bool stat_inode_unmodified(const struct stat *a, const struct stat *b) {

        /* Returns if the specified stat structures reference the same, unmodified inode. This check tries to
         * be reasonably careful when detecting changes: we check both inode and mtime, to cater for file
         * systems where mtimes are fixed to 0 (think: ostree/nixos type installations). We also check file
         * size, backing device, inode type and if this refers to a device not the major/minor.
         *
         * Note that we don't care if file attributes such as ownership or access mode change, this here is
         * about contents of the file. The purpose here is to detect file contents changes, and nothing
         * else. */

        return stat_inode_same(a, b) &&
                a->st_mtim.tv_sec == b->st_mtim.tv_sec &&
                a->st_mtim.tv_nsec == b->st_mtim.tv_nsec &&
                (!S_ISREG(a->st_mode) || a->st_size == b->st_size) && /* if regular file, compare file size */
                (!(S_ISCHR(a->st_mode) || S_ISBLK(a->st_mode)) || a->st_rdev == b->st_rdev); /* if device node, also compare major/minor, because we can */
}

bool statx_inode_same(const struct statx *a, const struct statx *b) {

        /* Same as stat_inode_same() but for struct statx */

        return statx_is_set(a) && statx_is_set(b) &&
                FLAGS_SET(a->stx_mask, STATX_TYPE|STATX_INO) && FLAGS_SET(b->stx_mask, STATX_TYPE|STATX_INO) &&
                ((a->stx_mode ^ b->stx_mode) & S_IFMT) == 0 &&
                a->stx_dev_major == b->stx_dev_major &&
                a->stx_dev_minor == b->stx_dev_minor &&
                a->stx_ino == b->stx_ino;
}

bool statx_mount_same(const struct statx *a, const struct statx *b) {
        if (!statx_is_set(a) || !statx_is_set(b))
                return false;

        /* if we have the mount ID, that's all we need */
        if (FLAGS_SET(a->stx_mask, STATX_MNT_ID) && FLAGS_SET(b->stx_mask, STATX_MNT_ID))
                return a->stx_mnt_id == b->stx_mnt_id;

        /* Otherwise, major/minor of backing device must match */
        return a->stx_dev_major == b->stx_dev_major &&
                a->stx_dev_minor == b->stx_dev_minor;
}

int xstatfsat(int dir_fd, const char *path, struct statfs *ret) {
        _cleanup_close_ int fd = -EBADF;

        assert(dir_fd >= 0 || dir_fd == AT_FDCWD);
        assert(ret);

        if (!isempty(path)) {
                fd = xopenat(dir_fd, path, O_PATH|O_CLOEXEC|O_NOCTTY);
                if (fd < 0)
                        return fd;
                dir_fd = fd;
        }

        return RET_NERRNO(fstatfs(dir_fd, ret));
}

usec_t statx_timestamp_load(const struct statx_timestamp *ts) {
        return timespec_load(&(const struct timespec) { .tv_sec = ts->tv_sec, .tv_nsec = ts->tv_nsec });
}
nsec_t statx_timestamp_load_nsec(const struct statx_timestamp *ts) {
        return timespec_load_nsec(&(const struct timespec) { .tv_sec = ts->tv_sec, .tv_nsec = ts->tv_nsec });
}

void inode_hash_func(const struct stat *q, struct siphash *state) {
        siphash24_compress_typesafe(q->st_dev, state);
        siphash24_compress_typesafe(q->st_ino, state);
}

int inode_compare_func(const struct stat *a, const struct stat *b) {
        int r;

        r = CMP(a->st_dev, b->st_dev);
        if (r != 0)
                return r;

        return CMP(a->st_ino, b->st_ino);
}

DEFINE_HASH_OPS_WITH_KEY_DESTRUCTOR(inode_hash_ops, struct stat, inode_hash_func, inode_compare_func, free);

const char* inode_type_to_string(mode_t m) {

        /* Returns a short string for the inode type. We use the same name as the underlying macros for each
         * inode type. */

        switch (m & S_IFMT) {
        case S_IFREG:
                return "reg";
        case S_IFDIR:
                return "dir";
        case S_IFLNK:
                return "lnk";
        case S_IFCHR:
                return "chr";
        case S_IFBLK:
                return "blk";
        case S_IFIFO:
                return "fifo";
        case S_IFSOCK:
                return "sock";
        }

        /* Note anonymous inodes in the kernel will have a zero type. Hence fstat() of an eventfd() will
         * return an .st_mode where we'll return NULL here! */
        return NULL;
}

mode_t inode_type_from_string(const char *s) {
        if (!s)
                return MODE_INVALID;

        if (streq(s, "reg"))
                return S_IFREG;
        if (streq(s, "dir"))
                return S_IFDIR;
        if (streq(s, "lnk"))
                return S_IFLNK;
        if (streq(s, "chr"))
                return S_IFCHR;
        if (streq(s, "blk"))
                return S_IFBLK;
        if (streq(s, "fifo"))
                return S_IFIFO;
        if (streq(s, "sock"))
                return S_IFSOCK;

        return MODE_INVALID;
}

1	/* SPDX-License-Identifier: LGPL-2.1-or-later */
2
3	#include <fcntl.h>
4	#include <linux/magic.h>
5	#include <sys/statvfs.h>
6	#include <unistd.h>
7
8	#include "alloc-util.h"
9	#include "chase.h"
10	#include "dirent-util.h"
11	#include "errno-util.h"
12	#include "fd-util.h"
13	#include "filesystems.h"
14	#include "fs-util.h"
15	#include "hash-funcs.h"
16	#include "log.h"
17	#include "mountpoint-util.h"
18	#include "path-util.h"
19	#include "siphash24.h"
20	#include "stat-util.h"
21	#include "string-util.h"
22	#include "time-util.h"
23
24	static int verify_stat_at(	1,847,769✔
25	int fd,
26	const char *path,
27	bool follow,
28	int (verify_func)(const struct stat st),
29	bool verify) {
30
31	struct stat st;	1,847,769✔
32	int r;	1,847,769✔
33
34	assert(fd >= 0 \|\| fd == AT_FDCWD);	1,847,769✔
35	assert(!isempty(path) \|\| !follow);	1,847,769✔
36	assert(verify_func);	1,847,769✔
37
38	if (fstatat(fd, strempty(path), &st,	4,528,507✔
39	(isempty(path) ? AT_EMPTY_PATH : 0) \| (follow ? 0 : AT_SYMLINK_NOFOLLOW)) < 0)	1,847,769✔
40	return -errno;	7,327✔
41
42	r = verify_func(&st);	1,840,442✔
43	return verify ? r : r >= 0;	1,840,442✔
44	}
45
46	int stat_verify_regular(const struct stat *st) {	2,657,449✔
47	assert(st);	2,657,449✔
48
49	/* Checks whether the specified stat() structure refers to a regular file. If not returns an
50	* appropriate error code. */
51
52	if (S_ISDIR(st->st_mode))	2,657,449✔
53	return -EISDIR;
54
55	if (S_ISLNK(st->st_mode))	2,655,261✔
56	return -ELOOP;
57
58	if (!S_ISREG(st->st_mode))	2,655,227✔
59	return -EBADFD;	17✔
60
61	return 0;
62	}
63
64	int verify_regular_at(int fd, const char *path, bool follow) {	830,879✔
65	return verify_stat_at(fd, path, follow, stat_verify_regular, true);	830,879✔
66	}
67
68	int fd_verify_regular(int fd) {	830,602✔
69	assert(fd >= 0);	830,602✔
70	return verify_regular_at(fd, NULL, false);	830,602✔
71	}
72
73	int stat_verify_directory(const struct stat *st) {	1,044,140✔
74	assert(st);	1,044,140✔
75
76	if (S_ISLNK(st->st_mode))	1,044,140✔
77	return -ELOOP;
78
79	if (!S_ISDIR(st->st_mode))	1,044,130✔
80	return -ENOTDIR;	2✔
81
82	return 0;
83	}
84
85	int fd_verify_directory(int fd) {	34✔
86	assert(fd >= 0);	34✔
87	return verify_stat_at(fd, NULL, false, stat_verify_directory, true);	34✔
88	}
89
90	int is_dir_at(int fd, const char *path, bool follow) {	998,800✔
91	return verify_stat_at(fd, path, follow, stat_verify_directory, false);	998,800✔
92	}
93
94	int is_dir(const char *path, bool follow) {	355,661✔
95	assert(!isempty(path));	355,661✔
96	return is_dir_at(AT_FDCWD, path, follow);	355,661✔
97	}
98
99	int stat_verify_symlink(const struct stat *st) {	17,924✔
100	assert(st);	17,924✔
101
102	if (S_ISDIR(st->st_mode))	17,924✔
103	return -EISDIR;
104
105	if (!S_ISLNK(st->st_mode))	17,907✔
106	return -ENOLINK;	268✔
107
108	return 0;
109	}
110
111	int fd_verify_symlink(int fd) {	2,330✔
112	return verify_stat_at(fd, /* path= / NULL, / follow= / false, stat_verify_symlink, / verify= */ true);	2,330✔
113	}
114
115	int is_symlink(const char *path) {	15,594✔
116	assert(!isempty(path));	15,594✔
117	return verify_stat_at(AT_FDCWD, path, false, stat_verify_symlink, false);	15,594✔
118	}
119
120	int stat_verify_linked(const struct stat *st) {	1,794,753✔
121	assert(st);	1,794,753✔
122
123	if (st->st_nlink <= 0)	1,794,753✔
124	return -EIDRM; /* recognizable error. */	2✔
125
126	return 0;
127	}
128
129	int fd_verify_linked(int fd) {	3✔
130	assert(fd >= 0);	3✔
131	return verify_stat_at(fd, NULL, false, stat_verify_linked, true);	3✔
132	}
133
134	int stat_verify_device_node(const struct stat *st) {	3,448✔
135	assert(st);	3,448✔
136
137	if (S_ISLNK(st->st_mode))	3,448✔
138	return -ELOOP;
139
140	if (S_ISDIR(st->st_mode))	3,448✔
141	return -EISDIR;
142
143	if (!S_ISBLK(st->st_mode) && !S_ISCHR(st->st_mode))	3,328✔
144	return -ENOTTY;	5✔
145
146	return 0;
147	}
148
149	int is_device_node(const char *path) {	129✔
150	assert(!isempty(path));	129✔
151	return verify_stat_at(AT_FDCWD, path, false, stat_verify_device_node, false);	129✔
152	}
153
154	int dir_is_empty_at(int dir_fd, const char *path, bool ignore_hidden_or_backup) {	36,892✔
155	_cleanup_close_ int fd = -EBADF;	36,892✔
156	struct dirent *buf;	36,892✔
157	size_t m;	36,892✔
158
159	fd = xopenat(dir_fd, path, O_DIRECTORY\|O_CLOEXEC);	36,892✔
160	if (fd < 0)	36,892✔
161	return fd;
162
163	/* Allocate space for at least 3 full dirents, since every dir has at least two entries ("." +
164	* ".."), and only once we have seen if there's a third we know whether the dir is empty or not. If
165	* 'ignore_hidden_or_backup' is true we'll allocate a bit more, since we might skip over a bunch of
166	* entries that we end up ignoring. */
167	m = (ignore_hidden_or_backup ? 16 : 3) * DIRENT_SIZE_MAX;	2,221✔
168	buf = alloca(m);	2,221✔
169
170	for (;;) {	3,549✔
171	struct dirent *de;	3,549✔
172	ssize_t n;	3,549✔
173
174	n = getdents64(fd, buf, m);	3,549✔
175	if (n < 0)	3,549✔
176	return -errno;	×
177	if (n == 0)	3,549✔
178	break;
179
180	assert((size_t) n <= m);	2,221✔
181	msan_unpoison(buf, n);	2,221✔
182
183	FOREACH_DIRENT_IN_BUFFER(de, buf, n)	5,937✔
184	if (!(ignore_hidden_or_backup ? hidden_or_backup_file(de->d_name) : dot_or_dot_dot(de->d_name)))	4,609✔
185	return 0;
186	}
187
188	return 1;
189	}
190
191	bool stat_may_be_dev_null(struct stat *st) {	408,724✔
192	assert(st);	408,724✔
193
194	/* We don't want to hardcode the major/minor of /dev/null, hence we do a simpler "is this a character
195	* device node?" check. */
196
197	return S_ISCHR(st->st_mode);	408,724✔
198	}
199
200	bool stat_is_empty(struct stat *st) {	392,735✔
201	assert(st);	392,735✔
202
203	return S_ISREG(st->st_mode) && st->st_size <= 0;	392,735✔
204	}
205
206	int null_or_empty_path_with_root(const char fn, const char root) {	294,476✔
207	struct stat st;	294,476✔
208	int r;	294,476✔
209
210	assert(fn);	294,476✔
211
212	/* A symlink to /dev/null or an empty file?
213	* When looking under root_dir, we can't expect /dev/ to be mounted,
214	* so let's see if the path is a (possibly dangling) symlink to /dev/null. */
215
216	if (path_equal(path_startswith(fn, root ?: "/"), "dev/null"))	588,952✔
217	return true;	294,476✔
218
219	r = chase_and_stat(fn, root, CHASE_PREFIX_ROOT, NULL, &st);	294,314✔
220	if (r < 0)	294,314✔
221	return r;
222
223	return null_or_empty(&st);	294,199✔
224	}
225
226	int fd_is_read_only_fs(int fd) {	1,833✔
227	struct statfs st;	1,833✔
228
229	assert(fd >= 0);	1,833✔
230
231	if (fstatfs(fd, &st) < 0)	1,833✔
232	return -errno;	×
233
234	if (st.f_flags & ST_RDONLY)	1,833✔
235	return true;
236
237	if (is_network_fs(&st)) {	1,469✔
238	/* On NFS, fstatfs() might not reflect whether we can actually write to the remote share.
239	* Let's try again with access(W_OK) which is more reliable, at least sometimes. */
240	if (access_fd(fd, W_OK) == -EROFS)	×
241	return true;	×
242	}
243
244	return false;
245	}
246
247	int path_is_read_only_fs(const char *path) {	1,542✔
248	_cleanup_close_ int fd = -EBADF;	1,542✔
249
250	assert(path);	1,542✔
251
252	fd = open(path, O_CLOEXEC \| O_PATH);	1,542✔
253	if (fd < 0)	1,542✔
254	return -errno;	146✔
255
256	return fd_is_read_only_fs(fd);	1,396✔
257	}
258
259	int inode_same_at(int fda, const char filea, int fdb, const char fileb, int flags) {	11,865✔
260	struct stat sta, stb;	11,865✔
261	int r;	11,865✔
262
263	assert(fda >= 0 \|\| fda == AT_FDCWD);	11,865✔
264	assert(fdb >= 0 \|\| fdb == AT_FDCWD);	11,865✔
265	assert((flags & ~(AT_EMPTY_PATH\|AT_SYMLINK_NOFOLLOW\|AT_NO_AUTOMOUNT)) == 0);	11,865✔
266
267	/* Refuse an unset filea or fileb early unless AT_EMPTY_PATH is set */
268	if ((isempty(filea) \|\| isempty(fileb)) && !FLAGS_SET(flags, AT_EMPTY_PATH))	23,414✔
269	return -EINVAL;	11,865✔
270
271	/* Shortcut: comparing the same fd with itself means we can return true */
272	if (fda >= 0 && fda == fdb && isempty(filea) && isempty(fileb) && FLAGS_SET(flags, AT_SYMLINK_NOFOLLOW))	11,867✔
273	return true;
274
275	_cleanup_close_ int pin_a = -EBADF, pin_b = -EBADF;	23,729✔
276	if (!FLAGS_SET(flags, AT_NO_AUTOMOUNT)) {	11,864✔
277	/* Let's try to use the name_to_handle_at() AT_HANDLE_FID API to identify identical
278	* inodes. We have to issue multiple calls on the same file for that (first, to acquire the
279	* FID, and then to check if .st_dev is actually the same). Hence let's pin the inode in
280	* between via O_PATH, unless we already have an fd for it. */
281
282	if (!isempty(filea)) {	11,864✔
283	pin_a = openat(fda, filea, O_PATH\|O_CLOEXEC\|(FLAGS_SET(flags, AT_SYMLINK_NOFOLLOW) ? O_NOFOLLOW : 0));	11,549✔
284	if (pin_a < 0)	11,549✔
285	return -errno;	11,667✔
286
287	fda = pin_a;	11,229✔
288	filea = NULL;	11,229✔
289	flags \|= AT_EMPTY_PATH;	11,229✔
290	}
291
292	if (!isempty(fileb)) {	11,544✔
293	pin_b = openat(fdb, fileb, O_PATH\|O_CLOEXEC\|(FLAGS_SET(flags, AT_SYMLINK_NOFOLLOW) ? O_NOFOLLOW : 0));	11,227✔
294	if (pin_b < 0)	11,227✔
295	return -errno;	4✔
296
297	fdb = pin_b;	11,223✔
298	fileb = NULL;	11,223✔
299	flags \|= AT_EMPTY_PATH;	11,223✔
300	}
301
302	int ntha_flags = at_flags_normalize_follow(flags) & (AT_EMPTY_PATH\|AT_SYMLINK_FOLLOW);	11,540✔
303	_cleanup_free_ struct file_handle ha = NULL, hb = NULL;	11,540✔
304	int mntida = -1, mntidb = -1;	11,540✔
305
306	r = name_to_handle_at_try_fid(	11,540✔
307	fda,
308	filea,
309	&ha,
310	&mntida,
311	ntha_flags);
312	if (r < 0) {	11,540✔
UNCOV 313	if (is_name_to_handle_at_fatal_error(r))	×
314	return r;
315
UNCOV 316	goto fallback;	×
317	}
318
319	r = name_to_handle_at_try_fid(	11,540✔
320	fdb,
321	fileb,
322	&hb,
323	&mntidb,
324	ntha_flags);
325	if (r < 0) {	11,540✔
UNCOV 326	if (is_name_to_handle_at_fatal_error(r))	×
327	return r;
328
UNCOV 329	goto fallback;	×
330	}
331
332	/* Now compare the two file handles */
333	if (!file_handle_equal(ha, hb))	11,540✔
334	return false;
335
336	/* If the file handles are the same and they come from the same mount ID? Great, then we are
337	* good, they are definitely the same */
338	if (mntida == mntidb)	11,198✔
339	return true;
340
341	/* File handles are the same, they are not on the same mount id. This might either be because
342	* they are on two entirely different file systems, that just happen to have the same FIDs
343	* (because they originally where created off the same disk images), or it could be because
344	* they are located on two distinct bind mounts of the same fs. To check that, let's look at
345	* .st_rdev of the inode. We simply reuse the fallback codepath for that, since it checks
346	* exactly that (it checks slightly more, but we don't care.) */
347	}
348
349	fallback:	×
350	if (fstatat(fda, strempty(filea), &sta, flags) < 0)	394✔
351	return log_debug_errno(errno, "Cannot stat %s: %m", strna(filea));	×
352
353	if (fstatat(fdb, strempty(fileb), &stb, flags) < 0)	394✔
354	return log_debug_errno(errno, "Cannot stat %s: %m", strna(fileb));	×
355
356	return stat_inode_same(&sta, &stb);	197✔
357	}
358
359	bool is_fs_type(const struct statfs *s, statfs_f_type_t magic_value) {	6,862,864✔
360	assert(s);	6,862,864✔
361	assert_cc(sizeof(statfs_f_type_t) >= sizeof(s->f_type));	6,862,864✔
362
363	return F_TYPE_EQUAL(s->f_type, magic_value);	6,862,864✔
364	}
365
366	int is_fs_type_at(int dir_fd, const char *path, statfs_f_type_t magic_value) {	6,857,900✔
367	struct statfs s;	6,857,900✔
368	int r;	6,857,900✔
369
370	r = xstatfsat(dir_fd, path, &s);	6,857,900✔
371	if (r < 0)	6,857,900✔
372	return r;	6,857,900✔
373
374	return is_fs_type(&s, magic_value);	6,857,899✔
375	}
376
377	bool is_temporary_fs(const struct statfs *s) {	10,050✔
378	return fs_in_group(s, FILESYSTEM_SET_TEMPORARY);	10,050✔
379	}
380
381	bool is_network_fs(const struct statfs *s) {	22,160✔
382	return fs_in_group(s, FILESYSTEM_SET_NETWORK);	22,160✔
383	}
384
385	int fd_is_temporary_fs(int fd) {	152✔
386	struct statfs s;	152✔
387
388	if (fstatfs(fd, &s) < 0)	152✔
389	return -errno;	×
390
391	return is_temporary_fs(&s);	152✔
392	}
393
394	int fd_is_network_fs(int fd) {	20,585✔
395	struct statfs s;	20,585✔
396
397	if (fstatfs(fd, &s) < 0)	20,585✔
398	return -errno;	×
399
400	return is_network_fs(&s);	20,585✔
401	}
402
403	int path_is_temporary_fs(const char *path) {	11✔
404	struct statfs s;	11✔
405
406	if (statfs(path, &s) < 0)	11✔
407	return -errno;	2✔
408
409	return is_temporary_fs(&s);	9✔
410	}
411
412	int path_is_network_fs(const char *path) {	×
413	struct statfs s;	×
414
415	if (statfs(path, &s) < 0)	×
416	return -errno;	×
417
418	return is_network_fs(&s);	×
419	}
420
421	int proc_mounted(void) {	23,364✔
422	int r;	23,364✔
423
424	/* A quick check of procfs is properly mounted */
425
426	r = path_is_fs_type("/proc/", PROC_SUPER_MAGIC);	23,364✔
427	if (r == -ENOENT) /* not mounted at all */	23,364✔
428	return false;	×
429
430	return r;
431	}
432
433	bool stat_inode_same(const struct stat a, const struct stat b) {	942,433✔
434
435	/* Returns if the specified stat structure references the same (though possibly modified) inode. Does
436	* a thorough check, comparing inode nr, backing device and if the inode is still of the same type. */
437
438	return stat_is_set(a) && stat_is_set(b) &&	1,882,749✔
439	((a->st_mode ^ b->st_mode) & S_IFMT) == 0 && /* same inode type */	906,475✔
440	a->st_dev == b->st_dev &&	1,806,903✔
441	a->st_ino == b->st_ino;	864,470✔
442	}
443
444	bool stat_inode_unmodified(const struct stat a, const struct stat b) {	121,321✔
445
446	/* Returns if the specified stat structures reference the same, unmodified inode. This check tries to
447	* be reasonably careful when detecting changes: we check both inode and mtime, to cater for file
448	* systems where mtimes are fixed to 0 (think: ostree/nixos type installations). We also check file
449	* size, backing device, inode type and if this refers to a device not the major/minor.
450	*
451	* Note that we don't care if file attributes such as ownership or access mode change, this here is
452	* about contents of the file. The purpose here is to detect file contents changes, and nothing
453	* else. */
454
455	return stat_inode_same(a, b) &&	121,321✔
456	a->st_mtim.tv_sec == b->st_mtim.tv_sec &&	78,456✔
457	a->st_mtim.tv_nsec == b->st_mtim.tv_nsec &&	78,286✔
458	(!S_ISREG(a->st_mode) \|\| a->st_size == b->st_size) && /* if regular file, compare file size */	199,580✔
459	(!(S_ISCHR(a->st_mode) \|\| S_ISBLK(a->st_mode)) \|\| a->st_rdev == b->st_rdev); /* if device node, also compare major/minor, because we can */	78,259✔
460	}
461
462	bool statx_inode_same(const struct statx a, const struct statx b) {	3,735,483✔
463
464	/* Same as stat_inode_same() but for struct statx */
465
466	return statx_is_set(a) && statx_is_set(b) &&	7,470,966✔
467	FLAGS_SET(a->stx_mask, STATX_TYPE\|STATX_INO) && FLAGS_SET(b->stx_mask, STATX_TYPE\|STATX_INO) &&	3,735,483✔
468	((a->stx_mode ^ b->stx_mode) & S_IFMT) == 0 &&	3,735,483✔
469	a->stx_dev_major == b->stx_dev_major &&	3,735,483✔
470	a->stx_dev_minor == b->stx_dev_minor &&	3,624,197✔
471	a->stx_ino == b->stx_ino;	3,622,468✔
472	}
473
474	bool statx_mount_same(const struct statx a, const struct statx b) {	3,584,626✔
475	if (!statx_is_set(a) \|\| !statx_is_set(b))	7,169,252✔
476	return false;
477
478	/* if we have the mount ID, that's all we need */
479	if (FLAGS_SET(a->stx_mask, STATX_MNT_ID) && FLAGS_SET(b->stx_mask, STATX_MNT_ID))	3,584,626✔
480	return a->stx_mnt_id == b->stx_mnt_id;	3,584,626✔
481
482	/* Otherwise, major/minor of backing device must match */
483	return a->stx_dev_major == b->stx_dev_major &&	×
484	a->stx_dev_minor == b->stx_dev_minor;	×
485	}
486
487	int xstatfsat(int dir_fd, const char path, struct statfs ret) {	6,858,322✔
488	_cleanup_close_ int fd = -EBADF;	6,858,322✔
489
490	assert(dir_fd >= 0 \|\| dir_fd == AT_FDCWD);	6,858,322✔
491	assert(ret);	6,858,322✔
492
493	if (!isempty(path)) {	6,858,322✔
494	fd = xopenat(dir_fd, path, O_PATH\|O_CLOEXEC\|O_NOCTTY);	23,914✔
495	if (fd < 0)	23,914✔
496	return fd;
497	dir_fd = fd;
498	}
499
500	return RET_NERRNO(fstatfs(dir_fd, ret));	6,858,322✔
501	}
502
503	usec_t statx_timestamp_load(const struct statx_timestamp *ts) {	5,013✔
504	return timespec_load(&(const struct timespec) { .tv_sec = ts->tv_sec, .tv_nsec = ts->tv_nsec });	5,013✔
505	}
506	nsec_t statx_timestamp_load_nsec(const struct statx_timestamp *ts) {	820✔
507	return timespec_load_nsec(&(const struct timespec) { .tv_sec = ts->tv_sec, .tv_nsec = ts->tv_nsec });	820✔
508	}
509
510	void inode_hash_func(const struct stat q, struct siphash state) {	37,566✔
511	siphash24_compress_typesafe(q->st_dev, state);	37,566✔
512	siphash24_compress_typesafe(q->st_ino, state);	37,566✔
513	}	37,566✔
514
515	int inode_compare_func(const struct stat a, const struct stat b) {	31,411✔
516	int r;	31,411✔
517
518	r = CMP(a->st_dev, b->st_dev);	31,411✔
519	if (r != 0)	26,368✔
520	return r;	5,138✔
521
522	return CMP(a->st_ino, b->st_ino);	26,273✔
523	}
524
525	DEFINE_HASH_OPS_WITH_KEY_DESTRUCTOR(inode_hash_ops, struct stat, inode_hash_func, inode_compare_func, free);	840✔
526
527	const char* inode_type_to_string(mode_t m) {	7,560✔
528
529	/* Returns a short string for the inode type. We use the same name as the underlying macros for each
530	* inode type. */
531
532	switch (m & S_IFMT) {	7,560✔
533	case S_IFREG:
534	return "reg";
535	case S_IFDIR:	2,892✔
536	return "dir";	2,892✔
537	case S_IFLNK:	1✔
538	return "lnk";	1✔
539	case S_IFCHR:	993✔
540	return "chr";	993✔
541	case S_IFBLK:	464✔
542	return "blk";	464✔
543	case S_IFIFO:	464✔
544	return "fifo";	464✔
545	case S_IFSOCK:	596✔
546	return "sock";	596✔
547	}
548
549	/* Note anonymous inodes in the kernel will have a zero type. Hence fstat() of an eventfd() will
550	* return an .st_mode where we'll return NULL here! */
551	return NULL;	3✔
552	}
553
554	mode_t inode_type_from_string(const char *s) {	13✔
555	if (!s)	13✔
556	return MODE_INVALID;
557
558	if (streq(s, "reg"))	13✔
559	return S_IFREG;
560	if (streq(s, "dir"))	10✔
561	return S_IFDIR;
562	if (streq(s, "lnk"))	7✔
563	return S_IFLNK;
564	if (streq(s, "chr"))	6✔
565	return S_IFCHR;
566	if (streq(s, "blk"))	5✔
567	return S_IFBLK;
568	if (streq(s, "fifo"))	4✔
569	return S_IFIFO;
570	if (streq(s, "sock"))	2✔
571	return S_IFSOCK;	2✔
572
573	return MODE_INVALID;
574	}

systemd / systemd / 18988181302

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