hotplug2: Fix event blocking when there are no available children (#6958, #7030)

SVN-Revision: 20684

diff --git a/package/hotplug2/patches/160-event_block_fix.patch b/package/hotplug2/patches/160-event_block_fix.patch
new file mode 100644 (file)
index 0000000..fd037b1
--- /dev/null
+++ b/package/hotplug2/patches/160-event_block_fix.patch
@@ -0,0 +1,203 @@
+diff -x '*~' -ur hotplug2-201/uevent.c hotplug2-201.patched/uevent.c
+--- hotplug2-201/uevent.c      2009-12-09 20:44:14.000000000 +0200
++++ hotplug2-201.patched/uevent.c      2010-04-02 23:03:11.000000000 +0300
+@@ -132,6 +132,8 @@
+       
+       dest = xmalloc(sizeof(struct uevent_t));
+       dest->action = src->action;
++      dest->seqnum = src->seqnum;
++      dest->action_str = strdup(src->action_str);
+       dest->env_vars_c = src->env_vars_c;
+       dest->env_vars = xmalloc(sizeof(struct env_var_t) * dest->env_vars_c);
+       dest->plain_s = src->plain_s;
+diff -x '*~' -ur hotplug2-201/workers/worker_fork.c hotplug2-201.patched/workers/worker_fork.c
+--- hotplug2-201/workers/worker_fork.c 2010-04-03 17:02:15.000000000 +0300
++++ hotplug2-201.patched/workers/worker_fork.c 2010-04-03 17:04:27.000000000 +0300
+@@ -1,6 +1,69 @@
+ #include "worker_fork.h"
+ 
+ static struct worker_fork_ctx_t *global_ctx;
++static struct worker_fork_uevent_t *uevent_list;
++
++static void worker_fork_uevent_free(struct worker_fork_uevent_t *node) {
++      uevent_free(node->uevent);
++      free(node);
++}
++
++static void worker_fork_uevent_add(void *in_ctx, struct uevent_t *uevent) {
++      char **env;
++      int i;
++      struct worker_fork_ctx_t *ctx = in_ctx;
++      struct worker_fork_uevent_t *node, *walker;
++
++      node = malloc(sizeof (struct worker_fork_uevent_t));
++      node->uevent = uevent_dup(uevent);
++      node->next = NULL;
++
++      if (!uevent_list) uevent_list = node;
++      else {
++              /*
++               * Put events that need to fork first and in reverse order
++               */
++              env = xmalloc(sizeof(char *) * node->uevent->env_vars_c);
++              for (i = 0; i < node->uevent->env_vars_c; i++) {
++                      env[i] = alloc_env(node->uevent->env_vars[i].key, node->uevent->env_vars[i].value);
++                      putenv(env[i]);
++              }
++              if (ruleset_flags(&ctx->settings->rules, uevent) & FLAG_SLOW) {
++                      node->next = uevent_list;
++                      uevent_list = node;
++              }
++              else {
++                      for (walker = uevent_list; walker->next; walker = walker->next);
++                      walker->next = node;
++              }
++              for (i = 0; i < node->uevent->env_vars_c; i++) {
++                      unsetenv(node->uevent->env_vars[i].key);
++                      free(env[i]);
++              }
++              free(env);
++      }
++}
++
++static void worker_fork_uevent_del(struct worker_fork_uevent_t *node) {
++      struct worker_fork_uevent_t *walker;
++
++      if (node == uevent_list) {
++              uevent_list = node->next;
++      }
++      else {
++              for (walker = uevent_list; walker->next; walker = walker->next)
++                      if (walker->next == node) walker->next = node->next;
++      }
++      worker_fork_uevent_free(node);
++}
++
++static void worker_fork_uevent_empty(void) {
++      struct worker_fork_uevent_t *walker;
++
++      if (!uevent_list) return;
++      for (walker = uevent_list; walker->next; walker = walker->next) worker_fork_uevent_free(walker);
++      uevent_list = NULL;
++}
+ 
+ /**
+  * Destroys data structures related to the given child ID (not PID).
+@@ -315,6 +378,8 @@
+       struct worker_fork_ctx_t *ctx;
+       PRINTFUNC();
+ 
++      uevent_list = NULL;
++
+       ctx = malloc(sizeof(struct worker_fork_ctx_t));
+       ctx->children = NULL;
+       ctx->children_count = 0;
+@@ -376,6 +441,7 @@
+       free(ctx->children);
+       free(ctx);
+       global_ctx = NULL;
++      worker_fork_uevent_empty();
+ }
+ 
+ 
+@@ -384,15 +450,26 @@
+       int i;
+       struct worker_fork_child_t *child;
+       struct worker_fork_ctx_t *ctx = in_ctx;
++      struct worker_fork_uevent_t *node, *walker;
++      event_seqnum_t seqnum;
++
++      worker_fork_uevent_add(ctx, uevent);
++      walker = uevent_list;
+ 
+       /*
+-       * A big loop, because if we fail to process the event,
++       * A big loop, because if we fail to process the events,
+        * we don't want to give up.
+        *
+        * TODO: Decide if we want to limit the number of attempts
+        * or set a time limit before reporting terminal failure.
+        */
+       do {
++              /*
++               * If more events are waiting, return to receive them
++               */
++              if (!seqnum_get(&seqnum) && seqnum > uevent->seqnum) break;
++
++              node = walker;
+               worker_fork_update_children(ctx);
+ 
+               child = NULL;
+@@ -407,9 +484,9 @@
+                * No child process is currently available.
+                */
+               if (child == NULL) {
+-                      env = xmalloc(sizeof(char *) * uevent->env_vars_c);
+-                      for (i = 0; i < uevent->env_vars_c; i++) {
+-                              env[i] = alloc_env(uevent->env_vars[i].key, uevent->env_vars[i].value);
++                      env = xmalloc(sizeof(char *) * node->uevent->env_vars_c);
++                      for (i = 0; i < node->uevent->env_vars_c; i++) {
++                              env[i] = alloc_env(node->uevent->env_vars[i].key, node->uevent->env_vars[i].value);
+                               putenv(env[i]);
+                       }
+ 
+@@ -418,8 +495,11 @@
+                        * can execute them in the main process?
+                        */
+                       if (ctx->always_fork == 0 && ctx->settings->dumb == 0 && 
+-                      (ruleset_flags(&ctx->settings->rules, uevent) & FLAG_MASK_SLOW) == 0) {
+-                              action_perform(ctx->settings, uevent);
++                      (ruleset_flags(&ctx->settings->rules, node->uevent) & FLAG_MASK_SLOW) == 0) {
++                              action_perform(ctx->settings, node->uevent);
++                              walker = walker->next;
++                              worker_fork_uevent_del(node);
++                              if (walker) continue;
+                               break;
+                       }
+                       
+@@ -427,11 +507,11 @@
+                        * We have to fork off a new child.
+                        */
+                       if (ctx->children_count < ctx->max_children || 
+-                      (ruleset_flags(&ctx->settings->rules, uevent) & FLAG_SLOW))
++                      (ruleset_flags(&ctx->settings->rules, node->uevent) & FLAG_SLOW))
+                               child = worker_fork_spawn(ctx);
+ 
+-                      for (i = 0; i < uevent->env_vars_c; i++) {
+-                              unsetenv(uevent->env_vars[i].key);
++                      for (i = 0; i < node->uevent->env_vars_c; i++) {
++                              unsetenv(node->uevent->env_vars[i].key);
+                               free(env[i]);
+                       }
+                       free(env);
+@@ -442,9 +522,14 @@
+                */
+               if (child != NULL) {
+                       child->busy = 1;
+-                      if (!worker_fork_relay_event(child->event_fd, uevent));
+-                              break;
+-                      child->busy = 0;
++                      if (worker_fork_relay_event(child->event_fd, node->uevent)) {
++                              child->busy = 0;
++                              continue;
++                      }
++                      walker = walker->next;
++                      worker_fork_uevent_del(node);
++                      if (walker) continue;
++                      break;
+               }
+ 
+               /* 
+diff -x '*~' -ur hotplug2-201/workers/worker_fork.h hotplug2-201.patched/workers/worker_fork.h
+--- hotplug2-201/workers/worker_fork.h 2009-12-09 20:44:13.000000000 +0200
++++ hotplug2-201.patched/workers/worker_fork.h 2010-04-03 01:00:24.000000000 +0300
+@@ -35,4 +35,9 @@
+       struct settings_t                       *settings;
+ };
+ 
++struct worker_fork_uevent_t {
++      struct uevent_t *uevent;
++      struct worker_fork_uevent_t *next;
++};
++
+ #endif