logging enhancements

* per translator loglevel introduced, if set, it will override process
  wide log level.
* with extended attribute 'trusted.glusterfs.<xlator-name>.set-log-level'
  with the value being '<LOGLEVEL>', one can change log level of particular
  translator.
* with extended attribute 'trusted.glusterfs.syslog' with the value
  '<BOOLEAN>', one can enable disable syslog for gluster

Signed-off-by: Amar Tumballi <amar@gluster.com>
Signed-off-by: Anand V. Avati <avati@dev.gluster.com>

BUG: 601 (Enable changing 'log-level' of GlusterFS process at runtime)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=601

3 files changed, 104 insertions, 25 deletions

diff --git a/libglusterfs/src/logging.c b/libglusterfs/src/logging.c
index 000c2ccd3..2d3bb4c8f 100644
--- a/libglusterfs/src/logging.c
+++ b/libglusterfs/src/logging.c
@@ -35,39 +35,73 @@
 #include "logging.h"
 #include "defaults.h"
 
+#ifdef GF_LINUX_HOST_OS
+#include <syslog.h>
+#endif
+
+
 static pthread_mutex_t  logfile_mutex;
 static char            *filename = NULL;
 static uint8_t          logrotate = 0;
 
 static FILE            *logfile = NULL;
 static gf_loglevel_t    loglevel = GF_LOG_MAX;
+static int              gf_log_syslog = 0;
 
 gf_loglevel_t           gf_log_loglevel; /* extern'd */
 FILE                   *gf_log_logfile;
 
 
-void 
+void
 gf_log_logrotate (int signum)
 {
 	logrotate = 1;
 }
 
+void
+gf_log_enable_syslog (void)
+{
+        gf_log_syslog = 1;
+}
+
+void
+gf_log_disable_syslog (void)
+{
+        gf_log_syslog = 0;
+}
 
-gf_loglevel_t 
+gf_loglevel_t
 gf_log_get_loglevel (void)
 {
 	return loglevel;
 }
 
-
 void
 gf_log_set_loglevel (gf_loglevel_t level)
 {
-	gf_log_loglevel = loglevel = level;
+        gf_log_loglevel = loglevel = level;
 }
 
 
-void 
+gf_loglevel_t
+gf_log_get_xl_loglevel (void *this)
+{
+        xlator_t *xl = this;
+        if (!xl)
+                return 0;
+        return xl->loglevel;
+}
+
+void
+gf_log_set_xl_loglevel (void *this, gf_loglevel_t level)
+{
+        xlator_t *xl = this;
+        if (!xl)
+                return;
+        xl->loglevel = level;
+}
+
+void
 gf_log_fini (void)
 {
 	pthread_mutex_destroy (&logfile_mutex);
@@ -99,6 +133,12 @@ gf_log_init (const char *file)
 		return -1;
 	}
 
+#ifdef GF_LINUX_HOST_OS
+        /* For the 'syslog' output. one can grep 'GlusterFS' in syslog
+           for serious logs */
+        openlog ("GlusterFS", LOG_PID, LOG_DAEMON);
+#endif
+
 	gf_log_logfile = logfile;
 
 	return 0;
@@ -162,23 +202,37 @@ _gf_log (const char *domain, const char *file, const char *function, int line,
         char        *msg  = NULL;
         size_t       len  = 0;
         int          ret  = 0;
+        xlator_t    *this = NULL;
+        gf_loglevel_t xlator_loglevel = 0;
+
+        this = THIS;
+
+        xlator_loglevel = this->loglevel;
+        if (xlator_loglevel == 0)
+                xlator_loglevel = loglevel;
+
+        if (level > xlator_loglevel)
+                goto out;
 
 	static char *level_strings[] = {"",  /* NONE */
+                                        "M", /* EMERGENCY */
+                                        "A", /* ALERT */
 					"C", /* CRITICAL */
 					"E", /* ERROR */
 					"W", /* WARNING */
-					"N", /* NORMAL */
+					"N", /* NOTICE */
+                                        "I", /* INFO/NORMAL */
 					"D", /* DEBUG */
                                         "T", /* TRACE */
 					""};
-  
+
 	if (!domain || !file || !function || !fmt) {
-		fprintf (stderr, 
-			 "logging: %s:%s():%d: invalid argument\n", 
+		fprintf (stderr,
+			 "logging: %s:%s():%d: invalid argument\n",
 			 __FILE__, __PRETTY_FUNCTION__, __LINE__);
 		return -1;
 	}
-  
+
 	if (!logfile) {
 		fprintf (stderr, "no logfile set\n");
 		return (-1);
@@ -206,7 +260,7 @@ log:
 
 	tm    = localtime (&tv.tv_sec);
 
-	if (level > loglevel) {
+	if (level > xlator_loglevel) {
 		goto out;
 	}
 
@@ -241,13 +295,21 @@ log:
 
                 len = strlen (str1);
                 msg = GF_MALLOC (len + strlen (str2) + 1, gf_common_mt_char);
-                
+
                 strcpy (msg, str1);
                 strcpy (msg + len, str2);
 
 		fprintf (logfile, "%s\n", msg);
 		fflush (logfile);
+
+#ifdef GF_LINUX_HOST_OS
+                /* We want only serious log in 'syslog', not our debug
+                   and trace logs */
+                if (gf_log_syslog && level && (level <= GF_LOG_ERROR))
+                        syslog ((level-1), "%s\n", msg);
+#endif
 	}
+
 unlock:
 	pthread_mutex_unlock (&logfile_mutex);
 
diff --git a/libglusterfs/src/logging.h b/libglusterfs/src/logging.h
index fdb24dab9..f727bfe42 100644
--- a/libglusterfs/src/logging.h
+++ b/libglusterfs/src/logging.h
@@ -1,5 +1,5 @@
 /*
-   Copyright (c) 2006-2009 Gluster, Inc. <http://www.gluster.com>
+   Copyright (c) 2006-2010 Gluster, Inc. <http://www.gluster.com>
    This file is part of GlusterFS.
 
    GlusterFS is free software; you can redistribute it and/or modify
@@ -44,13 +44,28 @@
 #define GF_PRI_BLKSIZE     PRId32
 #define GF_PRI_SIZET       "zu"
 
+#if 0
+/* Syslog definitions :-) */
+#define LOG_EMERG   0           /* system is unusable */
+#define LOG_ALERT   1           /* action must be taken immediately */
+#define LOG_CRIT    2           /* critical conditions */
+#define LOG_ERR     3           /* error conditions */
+#define LOG_WARNING 4           /* warning conditions */
+#define LOG_NOTICE  5           /* normal but significant condition */
+#define LOG_INFO    6           /* informational */
+#define LOG_DEBUG   7           /* debug-level messages */
+#endif
+
 typedef enum {
 	GF_LOG_NONE,
+        GF_LOG_EMERG,
+        GF_LOG_ALERT,
 	GF_LOG_CRITICAL,   /* fatal errors */
 	GF_LOG_ERROR,      /* major failures (not necessarily fatal) */
 	GF_LOG_WARNING,    /* info about normal operation */
+        GF_LOG_NOTICE,
 	GF_LOG_INFO,       /* Normal information */
-#define GF_LOG_NORMAL GF_LOG_INFO
+#define GF_LOG_NORMAL      GF_LOG_INFO
 	GF_LOG_DEBUG,      /* internal errors */
         GF_LOG_TRACE,      /* full trace of operation */
 } gf_loglevel_t;
@@ -60,9 +75,8 @@ typedef enum {
 extern gf_loglevel_t gf_log_loglevel;
 
 #define gf_log(dom, levl, fmt...) do {					\
-		if (levl <= gf_log_loglevel)				\
-			_gf_log (dom, __FILE__, __FUNCTION__, __LINE__, \
-				 levl, ##fmt);				\
+                _gf_log (dom, __FILE__, __FUNCTION__, __LINE__,         \
+                         levl, ##fmt);                                  \
 		if (0) {						\
 			printf (fmt);					\
 		}							\
@@ -73,8 +87,8 @@ extern gf_loglevel_t gf_log_loglevel;
                 gf_log (args);                                                \
         }
 
-			
-void 
+
+void
 gf_log_logrotate (int signum);
 
 int gf_log_init (const char *filename);
@@ -90,10 +104,12 @@ gf_log_from_client (const char *msg, char *identifier);
 void gf_log_lock (void);
 void gf_log_unlock (void);
 
-gf_loglevel_t 
-gf_log_get_loglevel (void);
-void 
-gf_log_set_loglevel (gf_loglevel_t level);
+void gf_log_disable_syslog (void);
+void gf_log_enable_syslog (void);
+gf_loglevel_t gf_log_get_loglevel (void);
+void gf_log_set_loglevel (gf_loglevel_t level);
+gf_loglevel_t gf_log_get_xl_loglevel (void *xl);
+void gf_log_set_xl_loglevel (void *xl, gf_loglevel_t level);
 
 #define GF_DEBUG(xl, format, args...) \
 	gf_log ((xl)->name, GF_LOG_DEBUG, format, ##args)
diff --git a/libglusterfs/src/xlator.h b/libglusterfs/src/xlator.h
index ef79c354f..208f7a64a 100644
--- a/libglusterfs/src/xlator.h
+++ b/libglusterfs/src/xlator.h
@@ -75,8 +75,6 @@ typedef int32_t (*event_notify_fn_t) (xlator_t *this, int32_t event, void *data,
 #include "globals.h"
 #include "iatt.h"
 
-
-
 struct _loc {
 	const char *path;
 	const char *name;
@@ -85,6 +83,7 @@ struct _loc {
 	inode_t    *parent;
 };
 
+
 typedef int32_t (*fop_getspec_cbk_t) (call_frame_t *frame,
 				      void *cookie,
 				      xlator_t *this,
@@ -816,6 +815,8 @@ struct _xlator {
 	int32_t           (*mem_acct_init) (xlator_t *this);
 	event_notify_fn_t notify;
 
+        gf_loglevel_t    loglevel;   /* Log level for translator */
+
         /* for latency measurement */
         fop_latency_t latencies[GF_FOP_MAXVALUE];