bus: reduce calls to KDBUS_CMD_MEMFD_SIZE_SET ioctl

[elogind.git] / src / libsystemd-bus / bus-kernel.c

diff --git a/src/libsystemd-bus/bus-kernel.c b/src/libsystemd-bus/bus-kernel.c
index f32f271b7dddffd0967f79dde5969bff541d0d20..7d514616a4d7c08bee2e8f597375947046fb422b 100644 (file)
--- a/src/libsystemd-bus/bus-kernel.c
+++ b/src/libsystemd-bus/bus-kernel.c
@@ -515,19 +515,19 @@ static int translate_name_change(sd_bus *bus, struct kdbus_msg *k, struct kdbus_
         assert(k);
         assert(d);
 
-        if (d->type == KDBUS_ITEM_NAME_ADD || (d->name_change.old_flags & (KDBUS_NAME_IN_QUEUE|KDBUS_NAME_ACTIVATOR)))
+        if (d->type == KDBUS_ITEM_NAME_ADD || (d->name_change.old.flags & (KDBUS_NAME_IN_QUEUE|KDBUS_NAME_ACTIVATOR)))
                 old_owner[0] = 0;
         else
-                sprintf(old_owner, ":1.%llu", (unsigned long long) d->name_change.old_id);
+                sprintf(old_owner, ":1.%llu", (unsigned long long) d->name_change.old.id);
 
-        if (d->type == KDBUS_ITEM_NAME_REMOVE || (d->name_change.new_flags & (KDBUS_NAME_IN_QUEUE|KDBUS_NAME_ACTIVATOR))) {
+        if (d->type == KDBUS_ITEM_NAME_REMOVE || (d->name_change.new.flags & (KDBUS_NAME_IN_QUEUE|KDBUS_NAME_ACTIVATOR))) {
 
                 if (isempty(old_owner))
                         return 0;
 
                 new_owner[0] = 0;
         } else
-                sprintf(new_owner, ":1.%llu", (unsigned long long) d->name_change.new_id);
+                sprintf(new_owner, ":1.%llu", (unsigned long long) d->name_change.new.id);
 
         return push_name_owner_changed(bus, d->name_change.name, old_owner, new_owner);
 }
@@ -919,12 +919,13 @@ int bus_kernel_read_message(sd_bus *bus) {
         return r < 0 ? r : 1;
 }
 
-int bus_kernel_pop_memfd(sd_bus *bus, void **address, size_t *size) {
+int bus_kernel_pop_memfd(sd_bus *bus, void **address, size_t *mapped, size_t *allocated) {
         struct memfd_cache *c;
         int fd;
 
         assert(address);
-        assert(size);
+        assert(mapped);
+        assert(allocated);
 
         if (!bus || !bus->is_kernel)
                 return -ENOTSUP;
@@ -941,17 +942,19 @@ int bus_kernel_pop_memfd(sd_bus *bus, void **address, size_t *size) {
                         return -errno;
 
                 *address = NULL;
-                *size = 0;
+                *mapped = 0;
+                *allocated = 0;
                 return fd;
         }
 
         c = &bus->memfd_cache[--bus->n_memfd_cache];
 
         assert(c->fd >= 0);
-        assert(c->size == 0 || c->address);
+        assert(c->mapped == 0 || c->address);
 
         *address = c->address;
-        *size = c->size;
+        *mapped = c->mapped;
+        *allocated = c->allocated;
         fd = c->fd;
 
         assert_se(pthread_mutex_unlock(&bus->memfd_cache_mutex) >= 0);
@@ -966,15 +969,15 @@ static void close_and_munmap(int fd, void *address, size_t size) {
         close_nointr_nofail(fd);
 }
 
-void bus_kernel_push_memfd(sd_bus *bus, int fd, void *address, size_t size) {
+void bus_kernel_push_memfd(sd_bus *bus, int fd, void *address, size_t mapped, size_t allocated) {
         struct memfd_cache *c;
-        uint64_t max_sz = PAGE_ALIGN(MEMFD_CACHE_ITEM_SIZE_MAX);
+        uint64_t max_mapped = PAGE_ALIGN(MEMFD_CACHE_ITEM_SIZE_MAX);
 
         assert(fd >= 0);
-        assert(size == 0 || address);
+        assert(mapped == 0 || address);
 
         if (!bus || !bus->is_kernel) {
-                close_and_munmap(fd, address, size);
+                close_and_munmap(fd, address, mapped);
                 return;
         }
 
@@ -983,7 +986,7 @@ void bus_kernel_push_memfd(sd_bus *bus, int fd, void *address, size_t size) {
         if (bus->n_memfd_cache >= ELEMENTSOF(bus->memfd_cache)) {
                 assert_se(pthread_mutex_unlock(&bus->memfd_cache_mutex) >= 0);
 
-                close_and_munmap(fd, address, size);
+                close_and_munmap(fd, address, mapped);
                 return;
         }
 
@@ -992,12 +995,14 @@ void bus_kernel_push_memfd(sd_bus *bus, int fd, void *address, size_t size) {
         c->address = address;
 
         /* If overly long, let's return a bit to the OS */
-        if (size > max_sz) {
-                assert_se(ioctl(fd, KDBUS_CMD_MEMFD_SIZE_SET, &max_sz) >= 0);
-                assert_se(munmap((uint8_t*) address + max_sz, PAGE_ALIGN(size - max_sz)) >= 0);
-                c->size = max_sz;
-        } else
-                c->size = size;
+        if (mapped > max_mapped) {
+                assert_se(ioctl(fd, KDBUS_CMD_MEMFD_SIZE_SET, &max_mapped) >= 0);
+                assert_se(munmap((uint8_t*) address + max_mapped, PAGE_ALIGN(mapped - max_mapped)) >= 0);
+                c->mapped = c->allocated = max_mapped;
+        } else {
+                c->mapped = mapped;
+                c->allocated = allocated;
+        }
 
         assert_se(pthread_mutex_unlock(&bus->memfd_cache_mutex) >= 0);
 }
@@ -1008,7 +1013,7 @@ void bus_kernel_flush_memfd(sd_bus *b) {
         assert(b);
 
         for (i = 0; i < b->n_memfd_cache; i++)
-                close_and_munmap(b->memfd_cache[i].fd, b->memfd_cache[i].address, b->memfd_cache[i].size);
+                close_and_munmap(b->memfd_cache[i].fd, b->memfd_cache[i].address, b->memfd_cache[i].mapped);
 }
 
 int kdbus_translate_request_name_flags(uint64_t flags, uint64_t *kdbus_flags) {
@@ -1066,7 +1071,7 @@ int kdbus_translate_attach_flags(uint64_t mask, uint64_t *kdbus_mask) {
 }
 
 int bus_kernel_create_bus(const char *name, char **s) {
-        struct kdbus_cmd_bus_make *make;
+        struct kdbus_cmd_make *make;
         struct kdbus_item *n;
         int fd;
 
@@ -1077,19 +1082,27 @@ int bus_kernel_create_bus(const char *name, char **s) {
         if (fd < 0)
                 return -errno;
 
-        make = alloca0(ALIGN8(offsetof(struct kdbus_cmd_bus_make, items) +
+        make = alloca0(ALIGN8(offsetof(struct kdbus_cmd_make, items) +
+                              offsetof(struct kdbus_item, data64) + sizeof(uint64_t) +
                               offsetof(struct kdbus_item, str) +
                               DECIMAL_STR_MAX(uid_t) + 1 + strlen(name) + 1));
 
+        make->size = offsetof(struct kdbus_cmd_make, items);
+
         n = make->items;
+        n->size = offsetof(struct kdbus_item, data64) + sizeof(uint64_t);
+        n->type = KDBUS_ITEM_BLOOM_SIZE;
+        n->data64[0] = BLOOM_SIZE;
+        assert_cc(BLOOM_SIZE % 8 == 0);
+        make->size += ALIGN8(n->size);
+
+        n = KDBUS_ITEM_NEXT(n);
         sprintf(n->str, "%lu-%s", (unsigned long) getuid(), name);
         n->size = offsetof(struct kdbus_item, str) + strlen(n->str) + 1;
         n->type = KDBUS_ITEM_MAKE_NAME;
+        make->size += ALIGN8(n->size);
 
-        make->size = ALIGN8(offsetof(struct kdbus_cmd_bus_make, items) + n->size);
         make->flags = KDBUS_MAKE_POLICY_OPEN;
-        make->bloom_size = BLOOM_SIZE;
-        assert_cc(BLOOM_SIZE % 8 == 0);
 
         if (ioctl(fd, KDBUS_CMD_BUS_MAKE, make) < 0) {
                 close_nointr_nofail(fd);
@@ -1169,7 +1182,7 @@ int bus_kernel_create_starter(const char *bus, const char *name) {
 }
 
 int bus_kernel_create_namespace(const char *name, char **s) {
-        struct kdbus_cmd_ns_make *make;
+        struct kdbus_cmd_make *make;
         struct kdbus_item *n;
         int fd;
 
@@ -1180,7 +1193,7 @@ int bus_kernel_create_namespace(const char *name, char **s) {
         if (fd < 0)
                 return -errno;
 
-        make = alloca0(ALIGN8(offsetof(struct kdbus_cmd_ns_make, items) +
+        make = alloca0(ALIGN8(offsetof(struct kdbus_cmd_make, items) +
                               offsetof(struct kdbus_item, str) +
                               strlen(name) + 1));
 
@@ -1189,7 +1202,7 @@ int bus_kernel_create_namespace(const char *name, char **s) {
         n->size = offsetof(struct kdbus_item, str) + strlen(n->str) + 1;
         n->type = KDBUS_ITEM_MAKE_NAME;
 
-        make->size = ALIGN8(offsetof(struct kdbus_cmd_ns_make, items) + n->size);
+        make->size = ALIGN8(offsetof(struct kdbus_cmd_make, items) + n->size);
         make->flags = KDBUS_MAKE_POLICY_OPEN | KDBUS_MAKE_ACCESS_WORLD;
 
         if (ioctl(fd, KDBUS_CMD_NS_MAKE, make) < 0) {