sd-bus: sync with kdbus upstream (ABI break)

kdbus has seen a larger update than expected lately, most notably with
kdbusfs, a file system to expose the kdbus control files:

 * Each time a file system of this type is mounted, a new kdbus
   domain is created.

 * The layout inside each mount point is the same as before, except
   that domains are not hierarchically nested anymore.

 * Domains are therefore also unnamed now.

 * Unmounting a kdbusfs will automatically also detroy the
   associated domain.

 * Hence, the action of creating a kdbus domain is now as
   privileged as mounting a filesystem.

 * This way, we can get around creating dev nodes for everything,
   which is last but not least something that is not limited by
   20-bit minor numbers.

The kdbus specific bits in nspawn have all been dropped now, as nspawn
can rely on the container OS to set up its own kdbus domain, simply by
mounting a new instance.

A new set of mounts has been added to mount things *after* the kernel
modules have been loaded. For now, only kdbus is in this set, which is
invoked with mount_setup_late().

1 files changed, 4 insertions, 56 deletions

diff --git a/src/libsystemd/sd-bus/bus-kernel.c b/src/libsystemd/sd-bus/bus-kernel.c
index 5e7bc12239..afac3b6bcc 100644
--- a/src/libsystemd/sd-bus/bus-kernel.c
+++ b/src/libsystemd/sd-bus/bus-kernel.c
@@ -1282,7 +1282,7 @@ int bus_kernel_create_bus(const char *name, bool world, char **s) {
         assert(name);
         assert(s);
 
-        fd = open("/dev/kdbus/control", O_RDWR|O_NOCTTY|O_CLOEXEC);
+        fd = open("/sys/fs/kdbus/control", O_RDWR|O_NOCTTY|O_CLOEXEC);
         if (fd < 0)
                 return -errno;
 
@@ -1323,7 +1323,7 @@ int bus_kernel_create_bus(const char *name, bool world, char **s) {
         if (s) {
                 char *p;
 
-                p = strjoin("/dev/kdbus/", n->str, "/bus", NULL);
+                p = strjoin("/sys/fs/kdbus/", n->str, "/bus", NULL);
                 if (!p) {
                         safe_close(fd);
                         return -ENOMEM;
@@ -1403,7 +1403,7 @@ int bus_kernel_open_bus_fd(const char *bus, char **path) {
         int fd;
         size_t len;
 
-        len = strlen("/dev/kdbus/") + DECIMAL_STR_MAX(uid_t) + 1 + strlen(bus) + strlen("/bus") + 1;
+        len = strlen("/sys/fs/kdbus/") + DECIMAL_STR_MAX(uid_t) + 1 + strlen(bus) + strlen("/bus") + 1;
 
         if (path) {
                 p = malloc(len);
@@ -1412,7 +1412,7 @@ int bus_kernel_open_bus_fd(const char *bus, char **path) {
                 *path = p;
         } else
                 p = alloca(len);
-        sprintf(p, "/dev/kdbus/" UID_FMT "-%s/bus", getuid(), bus);
+        sprintf(p, "/sys/fs/kdbus/" UID_FMT "-%s/bus", getuid(), bus);
 
         fd = open(p, O_RDWR|O_NOCTTY|O_CLOEXEC);
         if (fd < 0)
@@ -1585,58 +1585,6 @@ int bus_kernel_make_starter(
         return fd;
 }
 
-int bus_kernel_create_domain(const char *name, char **s) {
-        struct kdbus_cmd_make *make;
-        struct kdbus_item *n;
-        int fd;
-
-        assert(name);
-        assert(s);
-
-        fd = open("/dev/kdbus/control", O_RDWR|O_NOCTTY|O_CLOEXEC);
-        if (fd < 0)
-                return -errno;
-
-        make = alloca0_align(ALIGN8(offsetof(struct kdbus_cmd_make, items) +
-                                    offsetof(struct kdbus_item, str) +
-                                    strlen(name) + 1),
-                             8);
-
-        n = make->items;
-        strcpy(n->str, name);
-        n->size = offsetof(struct kdbus_item, str) + strlen(n->str) + 1;
-        n->type = KDBUS_ITEM_MAKE_NAME;
-
-        make->size = ALIGN8(offsetof(struct kdbus_cmd_make, items) + n->size);
-        make->flags = KDBUS_MAKE_ACCESS_WORLD;
-
-        if (ioctl(fd, KDBUS_CMD_DOMAIN_MAKE, make) < 0) {
-                safe_close(fd);
-                return -errno;
-        }
-
-        /* The higher 32bit of the flags field are considered
-         * 'incompatible flags'. Refuse them all for now. */
-        if (make->flags > 0xFFFFFFFFULL) {
-                safe_close(fd);
-                return -ENOTSUP;
-        }
-
-        if (s) {
-                char *p;
-
-                p = strappend("/dev/kdbus/domain/", name);
-                if (!p) {
-                        safe_close(fd);
-                        return -ENOMEM;
-                }
-
-                *s = p;
-        }
-
-        return fd;
-}
-
 int bus_kernel_try_close(sd_bus *bus) {
         assert(bus);
         assert(bus->is_kernel);