Fix for a race in BGSAVE that may result in some data not being saved as soon as...

diff --git a/src/rdb.c b/src/rdb.c
index d8de5f76790e76cc55d823bc14dfe8108a2d84fd..c15fc6f2fee086655551a4d52142d543903c7c00 100644 (file)
--- a/src/rdb.c
+++ b/src/rdb.c
@@ -457,6 +457,7 @@ int rdbSaveBackground(char *filename) {
 
     if (server.bgsavechildpid != -1) return REDIS_ERR;
     if (server.vm_enabled) waitEmptyIOJobsQueue();
 
     if (server.bgsavechildpid != -1) return REDIS_ERR;
     if (server.vm_enabled) waitEmptyIOJobsQueue();

+    server.dirty_before_bgsave = server.dirty;

     if ((childpid = fork()) == 0) {
         /* Child */
         if (server.vm_enabled) vmReopenSwapFile();
     if ((childpid = fork()) == 0) {
         /* Child */
         if (server.vm_enabled) vmReopenSwapFile();


@@ -913,7 +914,7 @@ void backgroundSaveDoneHandler(int statloc) {
     if (!bysignal && exitcode == 0) {
         redisLog(REDIS_NOTICE,
             "Background saving terminated with success");
     if (!bysignal && exitcode == 0) {
         redisLog(REDIS_NOTICE,
             "Background saving terminated with success");

-        server.dirty = 0;
+        server.dirty = server.dirty - server.dirty_before_bgsave;

         server.lastsave = time(NULL);
     } else if (!bysignal && exitcode != 0) {
         redisLog(REDIS_WARNING, "Background saving error");
         server.lastsave = time(NULL);
     } else if (!bysignal && exitcode != 0) {
         redisLog(REDIS_WARNING, "Background saving error");

diff --git a/src/redis.h b/src/redis.h
index a4fdcb197de8ff786bedbec8b4530137503cf468..9e27d724854e1788199286f83e9437c81b7df954 100644 (file)
--- a/src/redis.h
+++ b/src/redis.h
@@ -335,6 +335,7 @@ struct redisServer {
     int fd;
     redisDb *db;
     long long dirty;            /* changes to DB from the last save */
     int fd;
     redisDb *db;
     long long dirty;            /* changes to DB from the last save */

+    long long dirty_before_bgsave; /* used to restore dirty on failed BGSAVE */

     list *clients;
     list *slaves, *monitors;
     char neterr[ANET_ERR_LEN];
     list *clients;
     list *slaves, *monitors;
     char neterr[ANET_ERR_LEN];