X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Fshared%2Futil.c;h=e7ff0f8840fdbe5d85c82e0c55d0367a4833c2b7;hp=dd67c2264164b0c04c32a630e11cc872e162245e;hb=e1d758033dc7e101ab32323a0f1649d8daf56a22;hpb=3d94f76c99da13e5603831d0b278f8c8c21bcb02 diff --git a/src/shared/util.c b/src/shared/util.c index dd67c2264..e7ff0f884 100644 --- a/src/shared/util.c +++ b/src/shared/util.c @@ -54,6 +54,7 @@ #include #include #include +#include #include #include #include @@ -73,6 +74,7 @@ #include "log.h" #include "strv.h" #include "label.h" +#include "mkdir.h" #include "path-util.h" #include "exit-status.h" #include "hashmap.h" @@ -83,7 +85,6 @@ #include "gunicode.h" #include "virt.h" #include "def.h" -#include "missing.h" int saved_argc = 0; char **saved_argv = NULL; @@ -166,19 +167,19 @@ int close_nointr(int fd) { assert(fd >= 0); r = close(fd); - - /* Just ignore EINTR; a retry loop is the wrong - * thing to do on Linux. - * - * http://lkml.indiana.edu/hypermail/linux/kernel/0509.1/0877.html - * https://bugzilla.gnome.org/show_bug.cgi?id=682819 - * http://utcc.utoronto.ca/~cks/space/blog/unix/CloseEINTR - * https://sites.google.com/site/michaelsafyan/software-engineering/checkforeintrwheninvokingclosethinkagain - */ - if (_unlikely_(r < 0 && errno == EINTR)) - return 0; - else if (r >= 0) + if (r >= 0) return r; + else if (errno == EINTR) + /* + * Just ignore EINTR; a retry loop is the wrong + * thing to do on Linux. + * + * http://lkml.indiana.edu/hypermail/linux/kernel/0509.1/0877.html + * https://bugzilla.gnome.org/show_bug.cgi?id=682819 + * http://utcc.utoronto.ca/~cks/space/blog/unix/CloseEINTR + * https://sites.google.com/site/michaelsafyan/software-engineering/checkforeintrwheninvokingclosethinkagain + */ + return 0; else return -errno; } @@ -195,7 +196,13 @@ int safe_close(int fd) { if (fd >= 0) { PROTECT_ERRNO; - assert_se(close_nointr(fd) == 0); + + /* The kernel might return pretty much any error code + * via close(), but the fd will be closed anyway. The + * only condition we want to check for here is whether + * the fd was invalid at all... */ + + assert_se(close_nointr(fd) != -EBADF); } return -1; @@ -797,7 +804,7 @@ char *strappend(const char *s, const char *suffix) { return strnappend(s, suffix, suffix ? strlen(suffix) : 0); } -int readlink_malloc(const char *p, char **ret) { +int readlinkat_malloc(int fd, const char *p, char **ret) { size_t l = 100; int r; @@ -812,7 +819,7 @@ int readlink_malloc(const char *p, char **ret) { if (!c) return -ENOMEM; - n = readlink(p, c, l-1); + n = readlinkat(fd, p, c, l-1); if (n < 0) { r = -errno; free(c); @@ -830,6 +837,10 @@ int readlink_malloc(const char *p, char **ret) { } } +int readlink_malloc(const char *p, char **ret) { + return readlinkat_malloc(AT_FDCWD, p, ret); +} + int readlink_and_make_absolute(const char *p, char **r) { _cleanup_free_ char *target = NULL; char *k; @@ -1365,44 +1376,52 @@ bool ignore_file(const char *filename) { assert(filename); if (endswith(filename, "~")) - return false; + return true; return ignore_file_allow_backup(filename); } int fd_nonblock(int fd, bool nonblock) { - int flags; + int flags, nflags; assert(fd >= 0); - if ((flags = fcntl(fd, F_GETFL, 0)) < 0) + flags = fcntl(fd, F_GETFL, 0); + if (flags < 0) return -errno; if (nonblock) - flags |= O_NONBLOCK; + nflags = flags | O_NONBLOCK; else - flags &= ~O_NONBLOCK; + nflags = flags & ~O_NONBLOCK; - if (fcntl(fd, F_SETFL, flags) < 0) + if (nflags == flags) + return 0; + + if (fcntl(fd, F_SETFL, nflags) < 0) return -errno; return 0; } int fd_cloexec(int fd, bool cloexec) { - int flags; + int flags, nflags; assert(fd >= 0); - if ((flags = fcntl(fd, F_GETFD, 0)) < 0) + flags = fcntl(fd, F_GETFD, 0); + if (flags < 0) return -errno; if (cloexec) - flags |= FD_CLOEXEC; + nflags = flags | FD_CLOEXEC; else - flags &= ~FD_CLOEXEC; + nflags = flags & ~FD_CLOEXEC; - if (fcntl(fd, F_SETFD, flags) < 0) + if (nflags == flags) + return 0; + + if (fcntl(fd, F_SETFD, nflags) < 0) return -errno; return 0; @@ -1421,7 +1440,7 @@ _pure_ static bool fd_in_set(int fd, const int fdset[], unsigned n_fdset) { } int close_all_fds(const int except[], unsigned n_except) { - DIR *d; + _cleanup_closedir_ DIR *d = NULL; struct dirent *de; int r = 0; @@ -1476,7 +1495,6 @@ int close_all_fds(const int except[], unsigned n_except) { } } - closedir(d); return r; } @@ -1495,12 +1513,20 @@ bool fstype_is_network(const char *fstype) { static const char table[] = "cifs\0" "smbfs\0" + "sshfs\0" "ncpfs\0" "ncp\0" "nfs\0" "nfs4\0" "gfs\0" - "gfs2\0"; + "gfs2\0" + "glusterfs\0"; + + const char *x; + + x = startswith(fstype, "fuse."); + if (x) + fstype = x; return nulstr_contains(table, fstype); } @@ -2004,7 +2030,6 @@ int ignore_signals(int sig, ...) { va_list ap; int r = 0; - if (sigaction(sig, &sa, NULL) < 0) r = -errno; @@ -2430,6 +2455,24 @@ void sigset_add_many(sigset_t *ss, ...) { va_end(ap); } +int sigprocmask_many(int how, ...) { + va_list ap; + sigset_t ss; + int sig; + + assert_se(sigemptyset(&ss) == 0); + + va_start(ap, how); + while ((sig = va_arg(ap, int)) > 0) + assert_se(sigaddset(&ss, sig) == 0); + va_end(ap); + + if (sigprocmask(how, &ss, NULL) < 0) + return -errno; + + return 0; +} + char* gethostname_malloc(void) { struct utsname u; @@ -2470,7 +2513,7 @@ static char *lookup_uid(uid_t uid) { if (getpwuid_r(uid, &pwbuf, buf, bufsize, &pw) == 0 && pw) return strdup(pw->pw_name); - if (asprintf(&name, "%lu", (unsigned long) uid) < 0) + if (asprintf(&name, UID_FMT, uid) < 0) return NULL; return name; @@ -2595,7 +2638,7 @@ int get_ctty(pid_t pid, dev_t *_devnr, char **r) { /* This is an ugly hack */ if (major(devnr) == 136) { - asprintf(&b, "pts/%lu", (unsigned long) minor(devnr)); + asprintf(&b, "pts/%u", minor(devnr)); goto finish; } @@ -2628,7 +2671,7 @@ finish: } int rm_rf_children_dangerous(int fd, bool only_dirs, bool honour_sticky, struct stat *root_dev) { - DIR *d; + _cleanup_closedir_ DIR *d = NULL; int ret = 0; assert(fd >= 0); @@ -2651,15 +2694,12 @@ int rm_rf_children_dangerous(int fd, bool only_dirs, bool honour_sticky, struct errno = 0; de = readdir(d); - if (!de && errno != 0) { - if (ret == 0) + if (!de) { + if (errno != 0 && ret == 0) ret = -errno; - break; + return ret; } - if (!de) - break; - if (streq(de->d_name, ".") || streq(de->d_name, "..")) continue; @@ -2715,10 +2755,6 @@ int rm_rf_children_dangerous(int fd, bool only_dirs, bool honour_sticky, struct } } } - - closedir(d); - - return ret; } _pure_ static int is_temporary_fs(struct statfs *s) { @@ -3315,22 +3351,49 @@ char *ellipsize(const char *s, size_t length, unsigned percent) { return ellipsize_mem(s, strlen(s), length, percent); } -int touch(const char *path) { +int touch_file(const char *path, bool parents, usec_t stamp, uid_t uid, gid_t gid, mode_t mode) { _cleanup_close_ int fd; + int r; assert(path); - /* This just opens the file for writing, ensuring it - * exists. It doesn't call utimensat() the way /usr/bin/touch - * does it. */ + if (parents) + mkdir_parents(path, 0755); - fd = open(path, O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY, 0644); + fd = open(path, O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY, mode > 0 ? mode : 0644); if (fd < 0) return -errno; + if (mode > 0) { + r = fchmod(fd, mode); + if (r < 0) + return -errno; + } + + if (uid != (uid_t) -1 || gid != (gid_t) -1) { + r = fchown(fd, uid, gid); + if (r < 0) + return -errno; + } + + if (stamp != (usec_t) -1) { + struct timespec ts[2]; + + timespec_store(&ts[0], stamp); + ts[1] = ts[0]; + r = futimens(fd, ts); + } else + r = futimens(fd, NULL); + if (r < 0) + return -errno; + return 0; } +int touch(const char *path) { + return touch_file(path, false, (usec_t) -1, (uid_t) -1, (gid_t) -1, 0); +} + char *unquote(const char *s, const char* quotes) { size_t l; assert(s); @@ -3549,9 +3612,6 @@ char *fstab_node_to_udev_node(const char *p) { bool tty_is_vc(const char *tty) { assert(tty); - if (startswith(tty, "/dev/")) - tty += 5; - return vtnr_from_tty(tty) >= 0; } @@ -3937,24 +3997,16 @@ int fd_wait_for_event(int fd, int event, usec_t t) { int fopen_temporary(const char *path, FILE **_f, char **_temp_path) { FILE *f; char *t; - const char *fn; - size_t k; int fd; assert(path); assert(_f); assert(_temp_path); - t = new(char, strlen(path) + 1 + 6 + 1); + t = tempfn_xxxxxx(path); if (!t) return -ENOMEM; - fn = basename(path); - k = fn - path; - memcpy(t, path, k); - t[k] = '.'; - stpcpy(stpcpy(t+k+1, fn), "XXXXXX"); - fd = mkostemp_safe(t, O_WRONLY|O_CLOEXEC); if (fd < 0) { free(t); @@ -4062,97 +4114,62 @@ int vt_disallocate(const char *name) { return 0; } -int copy_file(const char *from, const char *to, int flags) { - _cleanup_close_ int fdf = -1; - int r, fdt; +int symlink_atomic(const char *from, const char *to) { + _cleanup_free_ char *t = NULL; assert(from); assert(to); - fdf = open(from, O_RDONLY|O_CLOEXEC|O_NOCTTY); - if (fdf < 0) - return -errno; + t = tempfn_random(to); + if (!t) + return -ENOMEM; - fdt = open(to, flags|O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY, 0644); - if (fdt < 0) + if (symlink(from, t) < 0) return -errno; - for (;;) { - char buf[PIPE_BUF]; - ssize_t n, k; - - n = read(fdf, buf, sizeof(buf)); - if (n < 0) { - r = -errno; - - close_nointr(fdt); - unlink(to); - - return r; - } + if (rename(t, to) < 0) { + unlink_noerrno(t); + return -errno; + } - if (n == 0) - break; + return 0; +} - errno = 0; - k = loop_write(fdt, buf, n, false); - if (n != k) { - r = k < 0 ? k : (errno ? -errno : -EIO); +int mknod_atomic(const char *path, mode_t mode, dev_t dev) { + _cleanup_free_ char *t = NULL; - close_nointr(fdt); - unlink(to); + assert(path); - return r; - } - } + t = tempfn_random(path); + if (!t) + return -ENOMEM; - r = close_nointr(fdt); + if (mknod(t, mode, dev) < 0) + return -errno; - if (r < 0) { - unlink(to); - return r; + if (rename(t, path) < 0) { + unlink_noerrno(t); + return -errno; } return 0; } -int symlink_atomic(const char *from, const char *to) { - char *x; - _cleanup_free_ char *t; - const char *fn; - size_t k; - uint64_t u; - unsigned i; - int r; +int mkfifo_atomic(const char *path, mode_t mode) { + _cleanup_free_ char *t = NULL; - assert(from); - assert(to); + assert(path); - t = new(char, strlen(to) + 1 + 16 + 1); + t = tempfn_random(path); if (!t) return -ENOMEM; - fn = basename(to); - k = fn-to; - memcpy(t, to, k); - t[k] = '.'; - x = stpcpy(t+k+1, fn); - - u = random_u64(); - for (i = 0; i < 16; i++) { - *(x++) = hexchar(u & 0xF); - u >>= 4; - } - - *x = 0; - - if (symlink(from, t) < 0) + if (mkfifo(t, mode) < 0) return -errno; - if (rename(t, to) < 0) { - r = -errno; - unlink(t); - return r; + if (rename(t, path) < 0) { + unlink_noerrno(t); + return -errno; } return 0; @@ -4270,7 +4287,7 @@ char* uid_to_name(uid_t uid) { if (p) return strdup(p->pw_name); - if (asprintf(&r, "%lu", (unsigned long) uid) < 0) + if (asprintf(&r, UID_FMT, uid) < 0) return NULL; return r; @@ -4287,7 +4304,7 @@ char* gid_to_name(gid_t gid) { if (p) return strdup(p->gr_name); - if (asprintf(&r, "%lu", (unsigned long) gid) < 0) + if (asprintf(&r, GID_FMT, gid) < 0) return NULL; return r; @@ -4436,22 +4453,6 @@ int dirent_ensure_type(DIR *d, struct dirent *de) { return 0; } -int in_search_path(const char *path, char **search) { - char **i; - _cleanup_free_ char *parent = NULL; - int r; - - r = path_get_parent(path, &parent); - if (r < 0) - return r; - - STRV_FOREACH(i, search) - if (path_equal(parent, *i)) - return 1; - - return 0; -} - int get_files_in_directory(const char *path, char ***list) { _cleanup_closedir_ DIR *d = NULL; size_t bufsize = 0, n = 0; @@ -5432,21 +5433,27 @@ out: const char *draw_special_char(DrawSpecialChar ch) { static const char *draw_table[2][_DRAW_SPECIAL_CHAR_MAX] = { + /* UTF-8 */ { - [DRAW_TREE_VERT] = "\342\224\202 ", /* │ */ + [DRAW_TREE_VERTICAL] = "\342\224\202 ", /* │ */ [DRAW_TREE_BRANCH] = "\342\224\234\342\224\200", /* ├─ */ [DRAW_TREE_RIGHT] = "\342\224\224\342\224\200", /* └─ */ [DRAW_TREE_SPACE] = " ", /* */ - [DRAW_TRIANGULAR_BULLET] = "\342\200\243 ", /* ‣ */ - [DRAW_BLACK_CIRCLE] = "\342\227\217 ", /* ● */ + [DRAW_TRIANGULAR_BULLET] = "\342\200\243", /* ‣ */ + [DRAW_BLACK_CIRCLE] = "\342\227\217", /* ● */ + [DRAW_ARROW] = "\342\206\222", /* → */ + [DRAW_DASH] = "\342\200\223", /* – */ }, + /* ASCII fallback */ { - [DRAW_TREE_VERT] = "| ", + [DRAW_TREE_VERTICAL] = "| ", [DRAW_TREE_BRANCH] = "|-", [DRAW_TREE_RIGHT] = "`-", [DRAW_TREE_SPACE] = " ", - [DRAW_TRIANGULAR_BULLET] = "> ", - [DRAW_BLACK_CIRCLE] = "* ", + [DRAW_TRIANGULAR_BULLET] = ">", + [DRAW_BLACK_CIRCLE] = "*", + [DRAW_ARROW] = "->", + [DRAW_DASH] = "-", } }; @@ -5669,14 +5676,17 @@ static int search_and_fopen_internal(const char *path, const char *mode, const c assert(mode); assert(_f); - if (!path_strv_canonicalize_absolute_uniq(search, root)) + if (!path_strv_resolve_uniq(search, root)) return -ENOMEM; STRV_FOREACH(i, search) { _cleanup_free_ char *p = NULL; FILE *f; - p = strjoin(*i, "/", path, NULL); + if (root) + p = strjoin(root, *i, "/", path, NULL); + else + p = strjoin(*i, "/", path, NULL); if (!p) return -ENOMEM; @@ -5812,8 +5822,8 @@ char *strrep(const char *s, unsigned n) { return r; } -void* greedy_realloc(void **p, size_t *allocated, size_t need) { - size_t a; +void* greedy_realloc(void **p, size_t *allocated, size_t need, size_t size) { + size_t a, newalloc; void *q; assert(p); @@ -5822,10 +5832,11 @@ void* greedy_realloc(void **p, size_t *allocated, size_t need) { if (*allocated >= need) return *p; - a = MAX(64u, need * 2); + newalloc = MAX(need * 2, 64u / size); + a = newalloc * size; /* check for overflows */ - if (a < need) + if (a < size * need) return NULL; q = realloc(*p, a); @@ -5833,11 +5844,11 @@ void* greedy_realloc(void **p, size_t *allocated, size_t need) { return NULL; *p = q; - *allocated = a; + *allocated = newalloc; return q; } -void* greedy_realloc0(void **p, size_t *allocated, size_t need) { +void* greedy_realloc0(void **p, size_t *allocated, size_t need, size_t size) { size_t prev; uint8_t *q; @@ -5846,12 +5857,12 @@ void* greedy_realloc0(void **p, size_t *allocated, size_t need) { prev = *allocated; - q = greedy_realloc(p, allocated, need); + q = greedy_realloc(p, allocated, need, size); if (!q) return NULL; if (*allocated > prev) - memzero(&q[prev], *allocated - prev); + memzero(q + prev * size, (*allocated - prev) * size); return q; } @@ -6057,60 +6068,93 @@ int container_get_leader(const char *machine, pid_t *pid) { return 0; } -int namespace_open(pid_t pid, int *pidns_fd, int *mntns_fd, int *root_fd) { - _cleanup_close_ int pidnsfd = -1, mntnsfd = -1; - const char *pidns, *mntns, *root; - int rfd; +int namespace_open(pid_t pid, int *pidns_fd, int *mntns_fd, int *netns_fd, int *root_fd) { + _cleanup_close_ int pidnsfd = -1, mntnsfd = -1, netnsfd = -1; + int rfd = -1; assert(pid >= 0); - assert(pidns_fd); - assert(mntns_fd); - assert(root_fd); - mntns = procfs_file_alloca(pid, "ns/mnt"); - mntnsfd = open(mntns, O_RDONLY|O_NOCTTY|O_CLOEXEC); - if (mntnsfd < 0) - return -errno; + if (mntns_fd) { + const char *mntns; - pidns = procfs_file_alloca(pid, "ns/pid"); - pidnsfd = open(pidns, O_RDONLY|O_NOCTTY|O_CLOEXEC); - if (pidnsfd < 0) - return -errno; + mntns = procfs_file_alloca(pid, "ns/mnt"); + mntnsfd = open(mntns, O_RDONLY|O_NOCTTY|O_CLOEXEC); + if (mntnsfd < 0) + return -errno; + } - root = procfs_file_alloca(pid, "root"); - rfd = open(root, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY); - if (rfd < 0) - return -errno; + if (pidns_fd) { + const char *pidns; + + pidns = procfs_file_alloca(pid, "ns/pid"); + pidnsfd = open(pidns, O_RDONLY|O_NOCTTY|O_CLOEXEC); + if (pidnsfd < 0) + return -errno; + } + + if (netns_fd) { + const char *netns; + + netns = procfs_file_alloca(pid, "ns/net"); + netnsfd = open(netns, O_RDONLY|O_NOCTTY|O_CLOEXEC); + if (netnsfd < 0) + return -errno; + } + + if (root_fd) { + const char *root; + + root = procfs_file_alloca(pid, "root"); + rfd = open(root, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY); + if (rfd < 0) + return -errno; + } + + if (pidns_fd) + *pidns_fd = pidnsfd; - *pidns_fd = pidnsfd; - *mntns_fd = mntnsfd; - *root_fd = rfd; - pidnsfd = -1; - mntnsfd = -1; + if (mntns_fd) + *mntns_fd = mntnsfd; + + if (netns_fd) + *netns_fd = netnsfd; + + if (root_fd) + *root_fd = rfd; + + pidnsfd = mntnsfd = netnsfd = -1; return 0; } -int namespace_enter(int pidns_fd, int mntns_fd, int root_fd) { - assert(pidns_fd >= 0); - assert(mntns_fd >= 0); - assert(root_fd >= 0); +int namespace_enter(int pidns_fd, int mntns_fd, int netns_fd, int root_fd) { - if (setns(pidns_fd, CLONE_NEWPID) < 0) - return -errno; + if (pidns_fd >= 0) + if (setns(pidns_fd, CLONE_NEWPID) < 0) + return -errno; - if (setns(mntns_fd, CLONE_NEWNS) < 0) - return -errno; + if (mntns_fd >= 0) + if (setns(mntns_fd, CLONE_NEWNS) < 0) + return -errno; - if (fchdir(root_fd) < 0) - return -errno; + if (netns_fd >= 0) + if (setns(netns_fd, CLONE_NEWNET) < 0) + return -errno; - if (chroot(".") < 0) - return -errno; + if (root_fd >= 0) { + if (fchdir(root_fd) < 0) + return -errno; + + if (chroot(".") < 0) + return -errno; + } if (setresgid(0, 0, 0) < 0) return -errno; + if (setgroups(0, NULL) < 0) + return -errno; + if (setresuid(0, 0, 0) < 0) return -errno; @@ -6384,3 +6428,288 @@ void hexdump(FILE *f, const void *p, size_t s) { s -= 16; } } + +int update_reboot_param_file(const char *param) { + int r = 0; + + if (param) { + + r = write_string_file(REBOOT_PARAM_FILE, param); + if (r < 0) + log_error("Failed to write reboot param to " + REBOOT_PARAM_FILE": %s", strerror(-r)); + } else + unlink(REBOOT_PARAM_FILE); + + 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; +} + +int bind_remount_recursive(const char *prefix, bool ro) { + _cleanup_set_free_free_ Set *done = NULL; + _cleanup_free_ char *cleaned = NULL; + int r; + + /* Recursively remount a directory (and all its submounts) + * read-only or read-write. If the directory is already + * mounted, we reuse the mount and simply mark it + * MS_BIND|MS_RDONLY (or remove the MS_RDONLY for read-write + * operation). If it isn't we first make it one. Afterwards we + * apply MS_BIND|MS_RDONLY (or remove MS_RDONLY) to all + * submounts we can access, too. When mounts are stacked on + * the same mount point we only care for each individual + * "top-level" mount on each point, as we cannot + * influence/access the underlying mounts anyway. We do not + * have any effect on future submounts that might get + * propagated, they migt be writable. This includes future + * submounts that have been triggered via autofs. */ + + cleaned = strdup(prefix); + if (!cleaned) + return -ENOMEM; + + path_kill_slashes(cleaned); + + done = set_new(string_hash_func, string_compare_func); + if (!done) + return -ENOMEM; + + for (;;) { + _cleanup_fclose_ FILE *proc_self_mountinfo = NULL; + _cleanup_set_free_free_ Set *todo = NULL; + bool top_autofs = false; + char *x; + + todo = set_new(string_hash_func, string_compare_func); + if (!todo) + return -ENOMEM; + + proc_self_mountinfo = fopen("/proc/self/mountinfo", "re"); + if (!proc_self_mountinfo) + return -errno; + + for (;;) { + _cleanup_free_ char *path = NULL, *p = NULL, *type = 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 (superblock) */ + "%*[^-]" /* (7) optional fields */ + "- " /* (8) separator */ + "%ms " /* (9) file system type */ + "%*s" /* (10) mount source */ + "%*s" /* (11) mount options (bind mount) */ + "%*[^\n]", /* some rubbish at the end */ + &path, + &type); + if (k != 2) { + if (k == EOF) + break; + + continue; + } + + p = cunescape(path); + if (!p) + return -ENOMEM; + + /* Let's ignore autofs mounts. If they aren't + * triggered yet, we want to avoid triggering + * them, as we don't make any guarantees for + * future submounts anyway. If they are + * already triggered, then we will find + * another entry for this. */ + if (streq(type, "autofs")) { + top_autofs = top_autofs || path_equal(cleaned, p); + continue; + } + + if (path_startswith(p, cleaned) && + !set_contains(done, p)) { + + r = set_consume(todo, p); + p = NULL; + + if (r == -EEXIST) + continue; + if (r < 0) + return r; + } + } + + /* If we have no submounts to process anymore and if + * the root is either already done, or an autofs, we + * are done */ + if (set_isempty(todo) && + (top_autofs || set_contains(done, cleaned))) + return 0; + + if (!set_contains(done, cleaned) && + !set_contains(todo, cleaned)) { + /* The prefix directory itself is not yet a + * mount, make it one. */ + if (mount(cleaned, cleaned, NULL, MS_BIND|MS_REC, NULL) < 0) + return -errno; + + if (mount(NULL, prefix, NULL, MS_BIND|MS_REMOUNT|(ro ? MS_RDONLY : 0), NULL) < 0) + return -errno; + + x = strdup(cleaned); + if (!x) + return -ENOMEM; + + r = set_consume(done, x); + if (r < 0) + return r; + } + + while ((x = set_steal_first(todo))) { + + r = set_consume(done, x); + if (r == -EEXIST) + continue; + if (r < 0) + return r; + + if (mount(NULL, x, NULL, MS_BIND|MS_REMOUNT|(ro ? MS_RDONLY : 0), NULL) < 0) { + + /* Deal with mount points that are + * obstructed by a later mount */ + + if (errno != ENOENT) + return -errno; + } + + } + } +} + +int fflush_and_check(FILE *f) { + assert(f); + + errno = 0; + fflush(f); + + if (ferror(f)) + return errno ? -errno : -EIO; + + return 0; +} + +char *tempfn_xxxxxx(const char *p) { + const char *fn; + char *t; + size_t k; + + assert(p); + + t = new(char, strlen(p) + 1 + 6 + 1); + if (!t) + return NULL; + + fn = basename(p); + k = fn - p; + + strcpy(stpcpy(stpcpy(mempcpy(t, p, k), "."), fn), "XXXXXX"); + + return t; +} + +char *tempfn_random(const char *p) { + const char *fn; + char *t, *x; + uint64_t u; + size_t k; + unsigned i; + + assert(p); + + t = new(char, strlen(p) + 1 + 16 + 1); + if (!t) + return NULL; + + fn = basename(p); + k = fn - p; + + x = stpcpy(stpcpy(mempcpy(t, p, k), "."), fn); + + u = random_u64(); + for (i = 0; i < 16; i++) { + *(x++) = hexchar(u & 0xF); + u >>= 4; + } + + *x = 0; + + return t; +}