chiark / gitweb /
fstab-generator: simplify add_root_mount
[elogind.git] / src / fstab-generator / fstab-generator.c
index d5f9db49ca8b6016afd34bb5548070bad0ee5067..98772fb56be0e7655e39ba9b10aa4acdd72e3691 100644 (file)
 #include "mount-setup.h"
 #include "special.h"
 #include "mkdir.h"
-#include "virt.h"
 #include "fileio.h"
+#include "generator.h"
+#include "strv.h"
+#include "virt.h"
 
 static const char *arg_dest = "/tmp";
-static bool arg_enabled = true;
-
-static int device_name(const char *path, char **unit) {
-        char *p;
-
-        assert(path);
-
-        if (!is_device_path(path))
-                return 0;
-
-        p = unit_name_from_path(path, ".device");
-        if (!p)
-                return log_oom();
-
-        *unit = p;
-        return 1;
-}
+static bool arg_fstab_enabled = true;
+static char *arg_root_what = NULL;
+static char *arg_root_fstype = NULL;
+static char *arg_root_options = NULL;
+static int arg_root_rw = -1;
 
 static int mount_find_pri(struct mntent *me, int *ret) {
         char *end, *pri;
@@ -69,7 +59,7 @@ static int mount_find_pri(struct mntent *me, int *ret) {
 
         errno = 0;
         r = strtoul(pri, &end, 10);
-        if (errno != 0)
+        if (errno > 0)
                 return -errno;
 
         if (end == pri || (*end != ',' && *end != 0))
@@ -80,14 +70,19 @@ static int mount_find_pri(struct mntent *me, int *ret) {
 }
 
 static int add_swap(const char *what, struct mntent *me) {
-        char _cleanup_free_ *name = NULL, *unit = NULL, *lnk = NULL, *device = NULL;
-        FILE _cleanup_fclose_ *f = NULL;
-        bool noauto, nofail;
+        _cleanup_free_ char *name = NULL, *unit = NULL, *lnk = NULL;
+        _cleanup_fclose_ FILE *f = NULL;
+        bool noauto;
         int r, pri = -1;
 
         assert(what);
         assert(me);
 
+        if (detect_container(NULL) > 0) {
+                log_info("Running in a container, ignoring fstab swap entry for %s.", what);
+                return 0;
+        }
+
         r = mount_find_pri(me, &pri);
         if (r < 0) {
                 log_error("Failed to parse priority");
@@ -95,7 +90,6 @@ static int add_swap(const char *what, struct mntent *me) {
         }
 
         noauto = !!hasmntopt(me, "noauto");
-        nofail = !!hasmntopt(me, "nofail");
 
         name = unit_name_from_path(what, ".swap");
         if (!name)
@@ -114,18 +108,11 @@ static int add_swap(const char *what, struct mntent *me) {
                 return -errno;
         }
 
-        fputs("# Automatically generated by systemd-fstab-generator\n\n"
-              "[Unit]\n"
-              "SourcePath=/etc/fstab\n"
-              "DefaultDependencies=no\n"
-              "Conflicts=" SPECIAL_UMOUNT_TARGET "\n"
-              "Before=" SPECIAL_UMOUNT_TARGET "\n", f);
-
-        if (!noauto && !nofail)
-                fputs("Before=" SPECIAL_SWAP_TARGET "\n", f);
-
         fprintf(f,
-                "\n"
+                "# Automatically generated by systemd-fstab-generator\n\n"
+                "[Unit]\n"
+                "SourcePath=/etc/fstab\n"
+                "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n\n"
                 "[Swap]\n"
                 "What=%s\n",
                 what);
@@ -151,38 +138,11 @@ static int add_swap(const char *what, struct mntent *me) {
                         log_error("Failed to create symlink %s: %m", lnk);
                         return -errno;
                 }
-
-                r = device_name(what, &device);
-                if (r < 0)
-                        return r;
-
-                if (r > 0) {
-                        free(lnk);
-                        lnk = strjoin(arg_dest, "/", device, ".wants/", name, NULL);
-                        if (!lnk)
-                                return log_oom();
-
-                        mkdir_parents_label(lnk, 0755);
-                        if (symlink(unit, lnk) < 0) {
-                                log_error("Failed to create symlink %s: %m", lnk);
-                                return -errno;
-                        }
-                }
         }
 
         return 0;
 }
 
-static bool mount_is_bind(struct mntent *me) {
-        assert(me);
-
-        return
-                hasmntopt(me, "bind") ||
-                streq(me->mnt_type, "bind") ||
-                hasmntopt(me, "rbind") ||
-                streq(me->mnt_type, "rbind");
-}
-
 static bool mount_is_network(struct mntent *me) {
         assert(me);
 
@@ -199,28 +159,30 @@ static bool mount_in_initrd(struct mntent *me) {
                 streq(me->mnt_dir, "/usr");
 }
 
-static bool mount_is_rootfs(struct mntent *me) {
-        assert(me);
-
-        return hasmntopt(me, "x-initrd.rootfs");
-}
-
-static int add_mount(const char *what, const char *where, const char *type, const char *opts,
-                     int passno, bool noauto, bool nofail, bool automount, bool isbind,
-                     const char *pre, const char *post, const char *source) {
-        char _cleanup_free_
-                *name = NULL, *unit = NULL, *lnk = NULL, *device = NULL,
+static int add_mount(
+                const char *what,
+                const char *where,
+                const char *fstype,
+                const char *opts,
+                int passno,
+                bool noauto,
+                bool nofail,
+                bool automount,
+                const char *post,
+                const char *source) {
+
+        _cleanup_free_ char
+                *name = NULL, *unit = NULL, *lnk = NULL,
                 *automount_name = NULL, *automount_unit = NULL;
-        FILE _cleanup_fclose_ *f = NULL;
+        _cleanup_fclose_ FILE *f = NULL;
         int r;
 
         assert(what);
         assert(where);
-        assert(type);
         assert(opts);
         assert(source);
 
-        if (streq(type, "autofs"))
+        if (streq_ptr(fstype, "autofs"))
                 return 0;
 
         if (!is_path(where)) {
@@ -232,6 +194,13 @@ static int add_mount(const char *what, const char *where, const char *type, cons
             mount_point_ignore(where))
                 return 0;
 
+        if (path_equal(where, "/")) {
+                /* The root disk is not an option */
+                automount = false;
+                noauto = false;
+                nofail = false;
+        }
+
         name = unit_name_from_path(where, ".mount");
         if (!name)
                 return log_oom();
@@ -250,46 +219,34 @@ static int add_mount(const char *what, const char *where, const char *type, cons
         }
 
         fprintf(f,
-              "# Automatically generated by systemd-fstab-generator\n\n"
-              "[Unit]\n"
-              "SourcePath=%s\n"
-              "DefaultDependencies=no\n",
-              source);
-
-        if (!path_equal(where, "/")) {
-                if (pre)
-                        fprintf(f,
-                                "After=%s\n"
-                                "Wants=%s\n",
-                                pre,
-                                pre);
-                fprintf(f,
-                        "Conflicts=" SPECIAL_UMOUNT_TARGET "\n"
-                        "Before=" SPECIAL_UMOUNT_TARGET "\n");
-        }
+                "# Automatically generated by systemd-fstab-generator\n\n"
+                "[Unit]\n"
+                "SourcePath=%s\n"
+                "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n",
+                source);
 
         if (post && !noauto && !nofail && !automount)
-                fprintf(f,
-                        "Before=%s\n",
-                        post);
+                fprintf(f, "Before=%s\n", post);
+
+        if (passno != 0) {
+                r = generator_write_fsck_deps(f, arg_dest, what, where, fstype);
+                if (r < 0)
+                        return r;
+        }
 
         fprintf(f,
                 "\n"
                 "[Mount]\n"
                 "What=%s\n"
-                "Where=%s\n"
-                "Type=%s\n"
-                "FsckPassNo=%i\n",
+                "Where=%s\n",
                 what,
-                where,
-                type,
-                passno);
+                where);
 
-        if (!isempty(opts) &&
-            !streq(opts, "defaults"))
-                fprintf(f,
-                        "Options=%s\n",
-                        opts);
+        if (!isempty(fstype) && !streq(fstype, "auto"))
+                fprintf(f, "Type=%s\n", fstype);
+
+        if (!isempty(opts) && !streq(opts, "defaults"))
+                fprintf(f, "Options=%s\n", opts);
 
         fflush(f);
         if (ferror(f)) {
@@ -297,44 +254,21 @@ static int add_mount(const char *what, const char *where, const char *type, cons
                 return -errno;
         }
 
-        if (!noauto) {
-                if (post) {
-                        lnk = strjoin(arg_dest, "/", post, nofail || automount ? ".wants/" : ".requires/", name, NULL);
-                        if (!lnk)
-                                return log_oom();
-
-                        mkdir_parents_label(lnk, 0755);
-                        if (symlink(unit, lnk) < 0) {
-                                log_error("Failed to create symlink %s: %m", lnk);
-                                return -errno;
-                        }
-                }
+        if (!noauto && post) {
+                lnk = strjoin(arg_dest, "/", post, nofail || automount ? ".wants/" : ".requires/", name, NULL);
+                if (!lnk)
+                        return log_oom();
 
-                if (!isbind &&
-                    !path_equal(where, "/")) {
-
-                        r = device_name(what, &device);
-                        if (r < 0)
-                                return r;
-
-                        if (r > 0) {
-                                free(lnk);
-                                lnk = strjoin(arg_dest, "/", device, ".wants/", name, NULL);
-                                if (!lnk)
-                                        return log_oom();
-
-                                mkdir_parents_label(lnk, 0755);
-                                if (symlink(unit, lnk) < 0) {
-                                        log_error("Failed to create symlink %s: %m", lnk);
-                                        return -errno;
-                                }
-                        }
+                mkdir_parents_label(lnk, 0755);
+                if (symlink(unit, lnk) < 0) {
+                        log_error("Failed to create symlink %s: %m", lnk);
+                        return -errno;
                 }
         }
 
-        if (automount && !path_equal(where, "/")) {
+        if (automount) {
                 automount_name = unit_name_from_path(where, ".automount");
-                if (!name)
+                if (!automount_name)
                         return log_oom();
 
                 automount_unit = strjoin(arg_dest, "/", automount_name, NULL);
@@ -352,14 +286,12 @@ static int add_mount(const char *what, const char *where, const char *type, cons
                         "# Automatically generated by systemd-fstab-generator\n\n"
                         "[Unit]\n"
                         "SourcePath=%s\n"
-                        "DefaultDependencies=no\n"
-                        "Conflicts=" SPECIAL_UMOUNT_TARGET "\n"
-                        "Before=" SPECIAL_UMOUNT_TARGET "\n",
+                        "Documentation=man:fstab(5) man:systemd-fstab-generator(8)\n",
                         source);
 
                 if (post)
                         fprintf(f,
-                                "Before= %s\n",
+                                "Before=%s\n",
                                 post);
 
                 fprintf(f,
@@ -388,37 +320,42 @@ static int add_mount(const char *what, const char *where, const char *type, cons
         return 0;
 }
 
-static int parse_fstab(const char *prefix, bool initrd) {
-        FILE *f;
-        _cleanup_free_ char *fstab_path = NULL;
-        int r = 0;
+static int parse_fstab(bool initrd) {
+        _cleanup_endmntent_ FILE *f = NULL;
+        const char *fstab_path;
         struct mntent *me;
+        int r = 0;
 
-        errno = 0;
-        fstab_path = strjoin(prefix, "/etc/fstab", NULL);
-        f = setmntent(fstab_path, "r");
+        fstab_path = initrd ? "/sysroot/etc/fstab" : "/etc/fstab";
+        f = setmntent(fstab_path, "re");
         if (!f) {
                 if (errno == ENOENT)
                         return 0;
 
-                log_error("Failed to open %s/etc/fstab: %m", prefix);
+                log_error("Failed to open %s: %m", fstab_path);
                 return -errno;
         }
 
         while ((me = getmntent(f))) {
-                char _cleanup_free_ *where = NULL, *what = NULL;
+                _cleanup_free_ char *where = NULL, *what = NULL;
                 int k;
 
                 if (initrd && !mount_in_initrd(me))
                         continue;
 
                 what = fstab_node_to_udev_node(me->mnt_fsname);
-                where = strjoin(prefix, me->mnt_dir, NULL);
-                if (!what || !where) {
-                        r = log_oom();
-                        goto finish;
+                if (!what)
+                        return log_oom();
+
+                if (detect_container(NULL) > 0 && is_device_path(what)) {
+                        log_info("Running in a container, ignoring fstab device entry for %s.", what);
+                        continue;
                 }
 
+                where = initrd ? strappend("/sysroot/", me->mnt_dir) : strdup(me->mnt_dir);
+                if (!where)
+                        return log_oom();
+
                 if (is_path(where))
                         path_kill_slashes(where);
 
@@ -427,169 +364,131 @@ static int parse_fstab(const char *prefix, bool initrd) {
                 if (streq(me->mnt_type, "swap"))
                         k = add_swap(what, me);
                 else {
-                        bool noauto, nofail, automount, isbind;
-                        const char *pre, *post;
+                        bool noauto, nofail, automount;
+                        const char *post;
 
                         noauto = !!hasmntopt(me, "noauto");
                         nofail = !!hasmntopt(me, "nofail");
                         automount =
                                   hasmntopt(me, "comment=systemd.automount") ||
                                   hasmntopt(me, "x-systemd.automount");
-                        isbind = mount_is_bind(me);
 
-                        if (initrd) {
+                        if (initrd)
                                 post = SPECIAL_INITRD_FS_TARGET;
-                                pre = NULL;
-                        } else if (mount_is_rootfs(me)) {
+                        else if (mount_in_initrd(me))
                                 post = SPECIAL_INITRD_ROOT_FS_TARGET;
-                                pre = NULL;
-                        } else if (mount_is_network(me)) {
+                        else if (mount_is_network(me))
                                 post = SPECIAL_REMOTE_FS_TARGET;
-                                pre = SPECIAL_REMOTE_FS_PRE_TARGET;
-                        } else {
+                        else
                                 post = SPECIAL_LOCAL_FS_TARGET;
-                                pre = SPECIAL_LOCAL_FS_PRE_TARGET;
-                        }
 
-                        k = add_mount(what, where, me->mnt_type, me->mnt_opts,
-                                     me->mnt_passno, noauto, nofail, automount,
-                                     isbind, pre, post, fstab_path);
+                        k = add_mount(what,
+                                      where,
+                                      me->mnt_type,
+                                      me->mnt_opts,
+                                      me->mnt_passno,
+                                      noauto,
+                                      nofail,
+                                      automount,
+                                      post,
+                                      fstab_path);
                 }
 
                 if (k < 0)
                         r = k;
         }
 
-finish:
-        endmntent(f);
         return r;
 }
 
-static int parse_new_root_from_proc_cmdline(void) {
-        char *w, *state;
-        _cleanup_free_ char *what = NULL, *type = NULL, *opts = NULL, *line = NULL;
-        int r;
-        size_t l;
+static int add_root_mount(void) {
+        _cleanup_free_ char *what = NULL;
+        const char *opts;
 
-        r = read_one_line_file("/proc/cmdline", &line);
-        if (r < 0) {
-                log_error("Failed to read /proc/cmdline, ignoring: %s", strerror(-r));
+        if (isempty(arg_root_what)) {
+                log_debug("Could not find a root= entry on the kernel commandline.");
                 return 0;
         }
 
-        opts = strdup("ro");
-        type = strdup("auto");
-        if (!opts || !type)
-                return log_oom();
-
-        /* root= and roofstype= may occur more than once, the last instance should take precedence.
-         * In the case of multiple rootflags= the arguments should be concatenated */
-        FOREACH_WORD_QUOTED(w, l, line, state) {
-                char *word, *tmp_word;
-
-                word = strndup(w, l);
-                if (!word)
-                        return log_oom();
-
-                else if (startswith(word, "root=")) {
-                        free(what);
-                        what = fstab_node_to_udev_node(word+5);
-                        if (!what)
-                                return log_oom();
-
-                } else if (startswith(word, "rootfstype=")) {
-                        free(type);
-                        type = strdup(word + 11);
-                        if (!type)
-                                return log_oom();
-
-                } else if (startswith(word, "rootflags=")) {
-                        tmp_word = opts;
-                        opts = strjoin(opts, ",", word + 10, NULL);
-                        free(tmp_word);
-                        if (!opts)
-                                return log_oom();
-
-                } else if (streq(word, "ro") || streq(word, "rw")) {
-                        tmp_word = opts;
-                        opts = strjoin(opts, ",", word, NULL);
-                        free(tmp_word);
-                        if (!opts)
-                                return log_oom();
-
-                }
-
-                free(word);
-        }
-
-        if (!what) {
-                log_error("Could not find a root= entry on the kernel commandline.");
+        what = fstab_node_to_udev_node(arg_root_what);
+        if (!path_is_absolute(what)) {
+                log_debug("Skipping entry what=%s where=/sysroot type=%s", what, strna(arg_root_fstype));
                 return 0;
         }
 
-        if (what[0] != '/') {
-                log_debug("Skipping entry what=%s where=/sysroot type=%s", what, type);
-                return 0;
-        }
-
-        log_debug("Found entry what=%s where=/sysroot type=%s", what, type);
-        r = add_mount(what, "/sysroot", type, opts, 0, false, false, false,
-                      false, NULL, SPECIAL_INITRD_ROOT_FS_TARGET, "/proc/cmdline");
-
-        return (r < 0) ? r : 0;
+        if (!arg_root_options)
+                opts = arg_root_rw > 0 ? "rw" : "ro";
+        else if (arg_root_rw >= 0 ||
+                 (!mount_test_option(arg_root_options, "ro") &&
+                  !mount_test_option(arg_root_options, "rw")))
+                opts = strappenda3(arg_root_options, ",", arg_root_rw > 0 ? "rw" : "ro");
+        else
+                opts = arg_root_options;
+
+        log_debug("Found entry what=%s where=/sysroot type=%s", what, strna(arg_root_fstype));
+        return add_mount(what,
+                         "/sysroot",
+                         arg_root_fstype,
+                         opts,
+                         1,
+                         false,
+                         false,
+                         false,
+                         SPECIAL_INITRD_ROOT_FS_TARGET,
+                         "/proc/cmdline");
 }
 
-static int parse_proc_cmdline(void) {
-        char _cleanup_free_ *line = NULL;
-        char *w, *state;
+static int parse_proc_cmdline_item(const char *key, const char *value) {
         int r;
-        size_t l;
 
-        if (detect_container(NULL) > 0)
-                return 0;
+        /* root= and roofstype= may occur more than once, the last
+         * instance should take precedence.  In the case of multiple
+         * rootflags= the arguments should be concatenated */
 
-        r = read_one_line_file("/proc/cmdline", &line);
-        if (r < 0) {
-                log_warning("Failed to read /proc/cmdline, ignoring: %s", strerror(-r));
-                return 0;
-        }
+        if (STR_IN_SET(key, "fstab", "rd.fstab") && value) {
 
-        FOREACH_WORD_QUOTED(w, l, line, state) {
-                char _cleanup_free_ *word = NULL;
+                r = parse_boolean(value);
+                if (r < 0)
+                        log_warning("Failed to parse fstab switch %s. Ignoring.", value);
+                else
+                        arg_fstab_enabled = r;
+
+        } else if (streq(key, "root") && value) {
 
-                word = strndup(w, l);
-                if (!word)
+                free(arg_root_what);
+                arg_root_what = strdup(value);
+                if (!arg_root_what)
                         return log_oom();
 
-                if (startswith(word, "fstab=")) {
-                        r = parse_boolean(word + 6);
-                        if (r < 0)
-                                log_warning("Failed to parse fstab switch %s. Ignoring.", word + 6);
-                        else
-                                arg_enabled = r;
+        } else if (streq(key, "rootfstype") && value) {
+
+                free(arg_root_fstype);
+                arg_root_fstype = strdup(value);
+                if (!arg_root_fstype)
+                        return log_oom();
 
-                } else if (startswith(word, "rd.fstab=")) {
+        } else if (streq(key, "rootflags") && value) {
+                char *o;
 
-                        if (in_initrd()) {
-                                r = parse_boolean(word + 6);
-                                if (r < 0)
-                                        log_warning("Failed to parse fstab switch %s. Ignoring.", word + 6);
-                                else
-                                        arg_enabled = r;
-                        }
+                o = arg_root_options ?
+                        strjoin(arg_root_options, ",", value, NULL) :
+                        strdup(value);
+                if (!o)
+                        return log_oom();
 
-                } else if (startswith(word, "fstab.") ||
-                           (in_initrd() && startswith(word, "rd.fstab."))) {
+                free(arg_root_options);
+                arg_root_options = o;
 
-                        log_warning("Unknown kernel switch %s. Ignoring.", word);
-                }
-        }
+        } else if (streq(key, "rw") && !value)
+                arg_root_rw = true;
+        else if (streq(key, "ro") && !value)
+                arg_root_rw = false;
 
         return 0;
 }
 
 int main(int argc, char *argv[]) {
-        int r = 0, k, l = 0;
+        int r = 0;
 
         if (argc > 1 && argc != 4) {
                 log_error("This program takes three or no arguments.");
@@ -605,19 +504,33 @@ int main(int argc, char *argv[]) {
 
         umask(0022);
 
-        if (parse_proc_cmdline() < 0)
+        if (parse_proc_cmdline(parse_proc_cmdline_item) < 0)
                 return EXIT_FAILURE;
 
+        /* Always honour root= in the kernel command line if we are in an initrd */
         if (in_initrd())
-                r = parse_new_root_from_proc_cmdline();
+                r = add_root_mount();
 
-        if (!arg_enabled)
-                return (r < 0) ? EXIT_FAILURE : EXIT_SUCCESS;
+        /* Honour /etc/fstab only when that's enabled */
+        if (arg_fstab_enabled) {
+                int k;
 
-        k = parse_fstab("", false);
+                log_debug("Parsing /etc/fstab");
 
-        if (in_initrd())
-                l = parse_fstab("/sysroot", true);
+                /* Parse the local /etc/fstab, possibly from the initrd */
+                k = parse_fstab(false);
+                if (k < 0)
+                        r = k;
+
+                /* If running in the initrd also parse the /etc/fstab from the host */
+                if (in_initrd()) {
+                        log_debug("Parsing /sysroot/etc/fstab");
+
+                        k = parse_fstab(true);
+                        if (k < 0)
+                                r = k;
+                }
+        }
 
-        return (r < 0) || (k < 0) || (l < 0) ? EXIT_FAILURE : EXIT_SUCCESS;
+        return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 }