+++ /dev/null
-commit e266c068b5597e18b2299f9c9d3ee6cf04198c41
-Author: Michal Sekletar <msekleta@redhat.com>
-Date: Mon Jan 23 17:12:35 2017 +0100
-
- service: serialize information about currently executing command
-
- Stored information will help us to resume execution after the
- daemon-reload.
-
- This commit implements following scheme,
-
- * On serialization:
- - we count rank of the currently executing command
- - we store command type, its rank and command line arguments
-
- * On deserialization:
- - configuration is parsed and loaded
- - we deserialize stored data, command type, rank and arguments
- - we look at the given rank in the list and if command there has same
- arguments then we restore execution at that point
- - otherwise we search respective command list and we look for command
- that has the same arguments
- - if both methods fail we do not do not resume execution at all
-
- To better illustrate how does above scheme works, please consider
- following cases (<<< denotes position where we resume execution after reload)
-
- ; Original unit file
- [Service]
- ExecStart=/bin/true <<<
- ExecStart=/bin/false
-
- ; Swapped commands
- ; Second command is not going to be executed
- [Service]
- ExecStart=/bin/false
- ExecStart=/bin/true <<<
-
- ; Commands added before
- ; Same commands are problematic and execution could be restarted at wrong place
- [Service]
- ExecStart=/bin/foo
- ExecStart=/bin/bar
- ExecStart=/bin/true <<<
- ExecStart=/bin/false
-
- ; Commands added after
- ; Same commands are not an issue in this case
- [Service]
- ExecStart=/bin/true <<<
- ExecStart=/bin/false
- ExecStart=/bin/foo
- ExecStart=/bin/bar
-
- ; New commands interleaved with old commands
- ; Some new commands will be executed while others won't
- ExecStart=/bin/foo
- ExecStart=/bin/true <<<
- ExecStart=/bin/bar
- ExecStart=/bin/false
-
- As you can see, above scheme has some drawbacks. However, in most
- cases (we assume that in most common case unit file command list is not
- changed while some other command is running for the same unit) it
- should cause that systemd does the right thing, which is restoring
- execution exactly at the point we were before daemon-reload.
-
- Fixes #518
-
-Signed-off-by: Scott Murray <scott.murray@konsulko.com>
-
-Upstream-Status: backport
-
-diff --git a/src/core/service.c b/src/core/service.c
-index 74054887b..5e681fb71 100644
---- a/src/core/service.c
-+++ b/src/core/service.c
-@@ -45,6 +45,7 @@
- #include "service.h"
- #include "signal-util.h"
- #include "special.h"
-+#include "stdio-util.h"
- #include "string-table.h"
- #include "string-util.h"
- #include "strv.h"
-@@ -2140,6 +2141,80 @@ _pure_ static bool service_can_reload(Unit *u) {
- return !!s->exec_command[SERVICE_EXEC_RELOAD];
- }
-
-+static unsigned service_exec_command_index(Unit *u, ServiceExecCommand id, ExecCommand *current) {
-+ Service *s = SERVICE(u);
-+ unsigned idx = 0;
-+ ExecCommand *first, *c;
-+
-+ assert(s);
-+
-+ first = s->exec_command[id];
-+
-+ /* Figure out where we are in the list by walking back to the beginning */
-+ for (c = current; c != first; c = c->command_prev)
-+ idx++;
-+
-+ return idx;
-+}
-+
-+static int service_serialize_exec_command(Unit *u, FILE *f, ExecCommand *command) {
-+ Service *s = SERVICE(u);
-+ ServiceExecCommand id;
-+ unsigned idx;
-+ const char *type;
-+ char **arg;
-+ _cleanup_strv_free_ char **escaped_args = NULL;
-+ _cleanup_free_ char *args = NULL, *p = NULL;
-+ size_t allocated = 0, length = 0;
-+
-+ assert(s);
-+ assert(f);
-+
-+ if (!command)
-+ return 0;
-+
-+ if (command == s->control_command) {
-+ type = "control";
-+ id = s->control_command_id;
-+ } else {
-+ type = "main";
-+ id = SERVICE_EXEC_START;
-+ }
-+
-+ idx = service_exec_command_index(u, id, command);
-+
-+ STRV_FOREACH(arg, command->argv) {
-+ size_t n;
-+ _cleanup_free_ char *e = NULL;
-+
-+ e = xescape(*arg, WHITESPACE);
-+ if (!e)
-+ return -ENOMEM;
-+
-+ n = strlen(e);
-+ if (!GREEDY_REALLOC(args, allocated, length + 1 + n + 1))
-+ return -ENOMEM;
-+
-+ if (length > 0)
-+ args[length++] = ' ';
-+
-+ memcpy(args + length, e, n);
-+ length += n;
-+ }
-+
-+ if (!GREEDY_REALLOC(args, allocated, length + 1))
-+ return -ENOMEM;
-+ args[length++] = 0;
-+
-+ p = xescape(command->path, WHITESPACE);
-+ if (!p)
-+ return -ENOMEM;
-+
-+ fprintf(f, "%s-command=%s %u %s %s\n", type, service_exec_command_to_string(id), idx, p, args);
-+
-+ return 0;
-+}
-+
- static int service_serialize(Unit *u, FILE *f, FDSet *fds) {
- Service *s = SERVICE(u);
- ServiceFDStore *fs;
-@@ -2167,11 +2242,8 @@ static int service_serialize(Unit *u, FILE *f, FDSet *fds) {
- if (r < 0)
- return r;
-
-- /* FIXME: There's a minor uncleanliness here: if there are
-- * multiple commands attached here, we will start from the
-- * first one again */
-- if (s->control_command_id >= 0)
-- unit_serialize_item(u, f, "control-command", service_exec_command_to_string(s->control_command_id));
-+ service_serialize_exec_command(u, f, s->control_command);
-+ service_serialize_exec_command(u, f, s->main_command);
-
- r = unit_serialize_item_fd(u, f, fds, "stdin-fd", s->stdin_fd);
- if (r < 0)
-@@ -2227,6 +2299,106 @@ static int service_serialize(Unit *u, FILE *f, FDSet *fds) {
- return 0;
- }
-
-+static int service_deserialize_exec_command(Unit *u, const char *key, const char *value) {
-+ Service *s = SERVICE(u);
-+ int r;
-+ unsigned idx = 0, i;
-+ bool control, found = false;
-+ ServiceExecCommand id = _SERVICE_EXEC_COMMAND_INVALID;
-+ ExecCommand *command = NULL;
-+ _cleanup_free_ char *args = NULL, *path = NULL;
-+ _cleanup_strv_free_ char **argv = NULL;
-+
-+ enum ExecCommandState {
-+ STATE_EXEC_COMMAND_TYPE,
-+ STATE_EXEC_COMMAND_INDEX,
-+ STATE_EXEC_COMMAND_PATH,
-+ STATE_EXEC_COMMAND_ARGS,
-+ _STATE_EXEC_COMMAND_MAX,
-+ _STATE_EXEC_COMMAND_INVALID = -1,
-+ } state;
-+
-+ assert(s);
-+ assert(key);
-+ assert(value);
-+
-+ control = streq(key, "control-command");
-+
-+ state = STATE_EXEC_COMMAND_TYPE;
-+
-+ for (;;) {
-+ _cleanup_free_ char *arg = NULL;
-+
-+ r = extract_first_word(&value, &arg, NULL, EXTRACT_CUNESCAPE);
-+ if (r == 0)
-+ break;
-+ else if (r < 0)
-+ return r;
-+
-+ switch (state) {
-+ case STATE_EXEC_COMMAND_TYPE:
-+ id = service_exec_command_from_string(arg);
-+ if (id < 0)
-+ return -EINVAL;
-+
-+ state = STATE_EXEC_COMMAND_INDEX;
-+ break;
-+ case STATE_EXEC_COMMAND_INDEX:
-+ r = safe_atou(arg, &idx);
-+ if (r < 0)
-+ return -EINVAL;
-+
-+ state = STATE_EXEC_COMMAND_PATH;
-+ break;
-+ case STATE_EXEC_COMMAND_PATH:
-+ path = arg;
-+ arg = NULL;
-+ state = STATE_EXEC_COMMAND_ARGS;
-+
-+ if (!path_is_absolute(path))
-+ return -EINVAL;
-+ break;
-+ case STATE_EXEC_COMMAND_ARGS:
-+ r = strv_extend(&argv, arg);
-+ if (r < 0)
-+ return -ENOMEM;
-+ break;
-+ default:
-+ assert_not_reached("Unknown error at deserialization of exec command");
-+ break;
-+ }
-+ }
-+
-+ if (state != STATE_EXEC_COMMAND_ARGS)
-+ return -EINVAL;
-+
-+ /* Let's check whether exec command on given offset matches data that we just deserialized */
-+ for (command = s->exec_command[id], i = 0; command; command = command->command_next, i++) {
-+ if (i != idx)
-+ continue;
-+
-+ found = strv_equal(argv, command->argv) && streq(command->path, path);
-+ break;
-+ }
-+
-+ if (!found) {
-+ /* Command at the index we serialized is different, let's look for command that exactly
-+ * matches but is on different index. If there is no such command we will not resume execution. */
-+ for (command = s->exec_command[id]; command; command = command->command_next)
-+ if (strv_equal(command->argv, argv) && streq(command->path, path))
-+ break;
-+ }
-+
-+ if (command && control)
-+ s->control_command = command;
-+ else if (command)
-+ s->main_command = command;
-+ else
-+ log_unit_warning(u, "Current command vanished from the unit file, execution of the command list won't be resumed.");
-+
-+ return 0;
-+}
-+
- static int service_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
- Service *s = SERVICE(u);
- int r;
-@@ -2309,16 +2481,6 @@ static int service_deserialize_item(Unit *u, const char *key, const char *value,
- s->status_text = t;
- }
-
-- } else if (streq(key, "control-command")) {
-- ServiceExecCommand id;
--
-- id = service_exec_command_from_string(value);
-- if (id < 0)
-- log_unit_debug(u, "Failed to parse exec-command value: %s", value);
-- else {
-- s->control_command_id = id;
-- s->control_command = s->exec_command[id];
-- }
- } else if (streq(key, "accept-socket")) {
- Unit *socket;
-
-@@ -2437,6 +2599,10 @@ static int service_deserialize_item(Unit *u, const char *key, const char *value,
- s->watchdog_override_enable = true;
- s->watchdog_override_usec = watchdog_override_usec;
- }
-+ } else if (STR_IN_SET(key, "main-command", "control-command")) {
-+ r = service_deserialize_exec_command(u, key, value);
-+ if (r < 0)
-+ log_unit_debug_errno(u, r, "Failed to parse serialized command \"%s\": %m", value);
- } else
- log_unit_debug(u, "Unknown serialization key: %s", key);
-
Code Review / AGL / meta-agl.git / commitdiff