mount: be more careful about errors when parsing mtab

[elogind.git] / src / core / mount.c

diff --git a/src/core/mount.c b/src/core/mount.c
index d257925fa7a74d0a9105d5e42556d7ff1d7fc90a..679d15c50a4767618d6e4d803dc6fe060cc914ce 100644 (file)
--- a/src/core/mount.c
+++ b/src/core/mount.c
@@ -25,6 +25,7 @@
 #include <sys/epoll.h>
 #include <signal.h>
 #include <libmount.h>
+#include <sys/inotify.h>
 
 #include "manager.h"
 #include "unit.h"
@@ -63,18 +64,22 @@ static const UnitActiveState state_translation_table[_MOUNT_STATE_MAX] = {
 static int mount_dispatch_timer(sd_event_source *source, usec_t usec, void *userdata);
 static int mount_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata);
 
-static bool mount_is_network(MountParameters *p) {
-        assert(p);
-
-        if (mount_test_option(p->options, "_netdev"))
+static bool mount_needs_network(const char *options, const char *fstype) {
+        if (mount_test_option(options, "_netdev"))
                 return true;
 
-        if (p->fstype && fstype_is_network(p->fstype))
+        if (fstype && fstype_is_network(fstype))
                 return true;
 
         return false;
 }
 
+static bool mount_is_network(MountParameters *p) {
+        assert(p);
+
+        return mount_needs_network(p->options, p->fstype);
+}
+
 static bool mount_is_bind(MountParameters *p) {
         assert(p);
 
@@ -1411,8 +1416,7 @@ static int mount_add_one(
                 if (m->running_as == SYSTEMD_SYSTEM) {
                         const char* target;
 
-                        target = fstype_is_network(fstype) ? SPECIAL_REMOTE_FS_TARGET : SPECIAL_LOCAL_FS_TARGET;
-
+                        target = mount_needs_network(options, fstype) ?  SPECIAL_REMOTE_FS_TARGET : SPECIAL_LOCAL_FS_TARGET;
                         r = unit_add_dependency_by_name(u, UNIT_BEFORE, target, NULL, true);
                         if (r < 0)
                                 goto fail;
@@ -1437,6 +1441,15 @@ static int mount_add_one(
                         }
                 }
 
+                if (m->running_as == SYSTEMD_SYSTEM &&
+                    mount_needs_network(options, fstype)) {
+                        /* _netdev option may have shown up late, or on a
+                         * remount. Add remote-fs dependencies, even though
+                         * local-fs ones may already be there. */
+                        unit_add_dependency_by_name(u, UNIT_BEFORE, SPECIAL_REMOTE_FS_TARGET, NULL, true);
+                        load_extras = true;
+                }
+
                 if (u->load_state == UNIT_NOT_FOUND) {
                         u->load_state = UNIT_LOADED;
                         u->load_error = 0;
@@ -1522,15 +1535,22 @@ static int mount_load_proc_self_mountinfo(Manager *m, bool set_flags) {
         if (!tb || !itr)
                 return log_oom();
 
-        mnt_table_parse_mtab(tb, NULL);
-        if (r)
+        r = mnt_table_parse_mtab(tb, NULL);
+        if (r < 0)
                 return r;
 
-        while (mnt_table_next_fs(tb, itr, &fs) == 0) {
+        r = 0;
+        for (;;) {
                 const char *device, *path, *options, *fstype;
                 _cleanup_free_ const char *d = NULL, *p = NULL;
                 int k;
 
+                k = mnt_table_next_fs(tb, itr, &fs);
+                if (k == 1)
+                        break;
+                else if (k < 0)
+                        return log_error_errno(k, "Failed to get next entry from /etc/fstab: %m");
+
                 device = mnt_fs_get_source(fs);
                 path = mnt_fs_get_target(fs);
                 options = mnt_fs_get_options(fs);
@@ -1542,7 +1562,7 @@ static int mount_load_proc_self_mountinfo(Manager *m, bool set_flags) {
                         return log_oom();
 
                 k = mount_add_one(m, d, p, options, fstype, set_flags);
-                if (k < 0)
+                if (r == 0 && k < 0)
                         r = k;
         }
 
@@ -1553,11 +1573,13 @@ static void mount_shutdown(Manager *m) {
         assert(m);
 
         m->mount_event_source = sd_event_source_unref(m->mount_event_source);
+        m->mount_utab_event_source = sd_event_source_unref(m->mount_utab_event_source);
 
         if (m->proc_self_mountinfo) {
                 fclose(m->proc_self_mountinfo);
                 m->proc_self_mountinfo = NULL;
         }
+        m->utab_inotify_fd = safe_close(m->utab_inotify_fd);
 }
 
 static int mount_get_timeout(Unit *u, uint64_t *timeout) {
@@ -1597,12 +1619,32 @@ static int mount_enumerate(Manager *m) {
                         goto fail;
         }
 
+        if (m->utab_inotify_fd < 0) {
+                m->utab_inotify_fd = inotify_init1(IN_NONBLOCK|IN_CLOEXEC);
+                if (m->utab_inotify_fd < 0)
+                        goto fail_with_errno;
+
+                r = inotify_add_watch(m->utab_inotify_fd, "/run/mount", IN_MOVED_TO);
+                if (r < 0)
+                        goto fail_with_errno;
+
+                r = sd_event_add_io(m->event, &m->mount_utab_event_source, m->utab_inotify_fd, EPOLLIN, mount_dispatch_io, m);
+                if (r < 0)
+                        goto fail;
+
+                r = sd_event_source_set_priority(m->mount_utab_event_source, -10);
+                if (r < 0)
+                        goto fail;
+        }
+
         r = mount_load_proc_self_mountinfo(m, false);
         if (r < 0)
                 goto fail;
 
         return 0;
 
+fail_with_errno:
+        r = -errno;
 fail:
         mount_shutdown(m);
         return r;
@@ -1614,11 +1656,34 @@ static int mount_dispatch_io(sd_event_source *source, int fd, uint32_t revents,
         int r;
 
         assert(m);
-        assert(revents & EPOLLPRI);
+        assert(revents & (EPOLLPRI | EPOLLIN));
 
         /* The manager calls this for every fd event happening on the
          * /proc/self/mountinfo file, which informs us about mounting
-         * table changes */
+         * table changes
+         * This may also be called for /run/mount events */
+
+        if (fd == m->utab_inotify_fd) {
+                char inotify_buffer[sizeof(struct inotify_event) + NAME_MAX + 1];
+                struct inotify_event *event;
+                char *p;
+                int rescan = 0;
+
+                while ((r = read(fd, inotify_buffer, sizeof(inotify_buffer))) > 0) {
+                        for (p = inotify_buffer; p < inotify_buffer + r; ) {
+                                event = (struct inotify_event *) p;
+                                /* only care about changes to utab, but we have
+                                 * to monitor the directory to reliably get
+                                 * notifications about when utab is replaced
+                                 * using rename(2) */
+                                if (strcmp(event->name, "utab") == 0)
+                                        rescan = 1;
+                                p += sizeof(struct inotify_event) + event->len;
+                        }
+                }
+                if (!rescan)
+                        return 0;
+        }
 
         r = mount_load_proc_self_mountinfo(m, true);
         if (r < 0) {