Implement maxstorage config

Former-commit-id: 79e07859dfec14edf2a39646013e1a82db033d4f

src/config.cpp

@@ -2619,6 +2619,7 @@ standardConfig configs[] = {
 
     /* Unsigned Long Long configs */
     createULongLongConfig("maxmemory", NULL, MODIFIABLE_CONFIG, 0, LLONG_MAX, g_pserver->maxmemory, 0, MEMORY_CONFIG, NULL, updateMaxmemory),
+    createULongLongConfig("maxstorage", NULL, MODIFIABLE_CONFIG, 0, LLONG_MAX, g_pserver->maxstorage, 0, MEMORY_CONFIG, NULL, NULL),
 
     /* Size_t configs */
     createSizeTConfig("hash-max-ziplist-entries", NULL, MODIFIABLE_CONFIG, 0, LONG_MAX, g_pserver->hash_max_ziplist_entries, 512, INTEGER_CONFIG, NULL, NULL),

src/evict.cpp

@@ -500,6 +500,9 @@ int freeMemoryIfNeeded(bool fQuickCycle, bool fPreSnapshot) {
     int ckeysFailed = 0;
     int keys_freed = 0;
 
+    if (g_pserver->maxstorage && g_pserver->m_pstorageFactory != nullptr && g_pserver->m_pstorageFactory->totalDiskspaceUsed() >= g_pserver->maxstorage)
+        goto cant_free_storage;
+
     /* When clients are paused the dataset should be static not just from the
      * POV of clients not being able to write, but also from the POV of
      * expires and evictions of keys not being performed. */
@@ -726,8 +729,10 @@ cant_free:
         latencyEndMonitor(lazyfree_latency);
         latencyAddSampleIfNeeded("eviction-lazyfree",lazyfree_latency);
     }
+
     latencyEndMonitor(latency);
     latencyAddSampleIfNeeded("eviction-cycle",latency);
+cant_free_storage:
     return result;
 }
 

src/server.h

@@ -2230,6 +2230,7 @@ struct redisServer {
     /* Limits */
     unsigned int maxclients;            /* Max number of simultaneous clients */
     unsigned long long maxmemory;   /* Max number of memory bytes to use */
+    unsigned long long maxstorage;  /* Max number of bytes to use in a storage provider */
     int maxmemory_policy;           /* Policy for key eviction */
     int maxmemory_samples;          /* Precision of random sampling */
     int lfu_log_factor;             /* LFU logarithmic counter factor. */