Cleanup around script_caller, fix tracking of scripts and ACL logging for RM_Call (#11770)

* Make it clear that current_client is the root client that was called by
  external connection
* add executing_client which is the client that runs the current command
  (can be a module or a script)
* Remove script_caller that was used for commands that have CLIENT_SCRIPT
  to get the client that called the script. in most cases, that's the current_client,
  and in others (when being called from a module), it could be an intermediate
  client when we actually want the original one used by the external connection.

bugfixes:
* RM_Call with C flag should log ACL errors with the requested user rather than
  the one used by the original client, this also solves a crash when RM_Call is used
  with C flag from a detached thread safe context.
* addACLLogEntry would have logged info about the script_caller, but in case the
  script was issued by a module command we actually want the current_client. the
  exception is when RM_Call is called from a timer event, in which case we don't
  have a current_client.

behavior changes:
* client side tracking for scripts now tracks the keys that are read by the script
  instead of the keys that are declared by the caller for EVAL

other changes:
* Log both current_client and executing_client in the crash log.
* remove prepareLuaClient and resetLuaClient, being dead code that was forgotten.
* remove scriptTimeSnapshot and snapshot_time and instead add cmd_time_snapshot
  that serves all commands and is reset only when execution nesting starts.
* remove code to propagate CLIENT_FORCE_REPL from the executed command
  to the script caller since scripts aren't propagated anyway these days and anyway
  this flag wouldn't have had an effect since CLIENT_PREVENT_PROP is added by scriptResetRun.
* fix a module GIL violation issue in afterSleep that was introduced in #10300 (unreleased)

1 files changed, 4 insertions, 3 deletions

diff --git a/src/server.h b/src/server.h
index 6ff882d4c..11629c718 100644
--- a/src/server.h
+++ b/src/server.h
@@ -1536,7 +1536,8 @@ struct redisServer {
     list *clients_pending_write; /* There is to write or install handler. */
     list *clients_pending_read;  /* Client has pending read socket buffers. */
     list *slaves, *monitors;    /* List of slaves and MONITORs */
-    client *current_client;     /* Current client executing the command. */
+    client *current_client;     /* The client that triggered the command execution (External or AOF). */
+    client *executing_client;   /* The client executing the current command (possibly script or module). */
 
     /* Stuff for client mem eviction */
     clientMemUsageBucket* client_mem_usage_buckets;
@@ -1873,6 +1874,7 @@ struct redisServer {
     int daylight_active;        /* Currently in daylight saving time. */
     mstime_t mstime;            /* 'unixtime' in milliseconds. */
     ustime_t ustime;            /* 'unixtime' in microseconds. */
+    mstime_t cmd_time_snapshot; /* Time snapshot of the root execution nesting. */
     size_t blocking_op_nesting; /* Nesting level of blocking operation, used to reset blocked_last_cron. */
     long long blocked_last_cron; /* Indicate the mstime of the last time we did cron jobs from a blocking operation */
     /* Pubsub */
@@ -1912,7 +1914,6 @@ struct redisServer {
     int cluster_drop_packet_filter; /* Debug config that allows tactically
                                    * dropping packets of a specific type */
     /* Scripting */
-    client *script_caller;       /* The client running script right now, or NULL */
     mstime_t busy_reply_threshold;  /* Script / module timeout in milliseconds */
     int pre_command_oom_state;         /* OOM before command (script?) was started */
     int script_disable_deny_script;    /* Allow running commands marked "no-script" inside a script. */
@@ -2601,7 +2602,7 @@ void addReplyStatusFormat(client *c, const char *fmt, ...);
 /* Client side caching (tracking mode) */
 void enableTracking(client *c, uint64_t redirect_to, uint64_t options, robj **prefix, size_t numprefix);
 void disableTracking(client *c);
-void trackingRememberKeys(client *c);
+void trackingRememberKeys(client *tracking, client *executing);
 void trackingInvalidateKey(client *c, robj *keyobj, int bcast);
 void trackingScheduleKeyInvalidation(uint64_t client_id, robj *keyobj);
 void trackingHandlePendingKeyInvalidations(void);