Logging.c：

      /*
  Copyright (c) 2008-2012 Red Hat, Inc. <http://www.redhat.com>
  This file is part of GlusterFS.

  This file is licensed to you under your choice of the GNU Lesser
  General Public License, version 3 or any later version (LGPLv3 or
  later), or the GNU General Public License, version 2 (GPLv2), in all
  cases as published by the Free Software Foundation.
*/

#ifndef _CONFIG_H
#define _CONFIG_H
#include "config.h"
#endif

#include <errno.h>
#include <pthread.h>
#include <stdio.h>
#include <stdarg.h>
#include <time.h>
#include <locale.h>
#include <string.h>
#include <stdlib.h>

#include "xlator.h"
#include "logging.h"
#include "defaults.h"
#include "glusterfs.h"

#ifdef GF_LINUX_HOST_OS
#include <syslog.h>
#endif

#ifdef HAVE_BACKTRACE
#include <execinfo.h>
#endif

/* Ideally this should get moved to logging.h */
struct _msg_queue {
        struct list_head msgs;
};

struct _log_msg {
        const char *msg;
        struct list_head queue;
};

void
gf_log_logrotate (int signum)
{
        THIS->ctx->log.logrotate = 1;
}

void
gf_log_enable_syslog (void)
{
        THIS->ctx->log.gf_log_syslog = 1;
}

void
gf_log_disable_syslog (void)
{
        THIS->ctx->log.gf_log_syslog = 0;
}

gf_loglevel_t
gf_log_get_loglevel (void)
{
        return THIS->ctx->log.loglevel;
}

void
gf_log_set_loglevel (gf_loglevel_t level)
{
        THIS->ctx->log.loglevel = level;
}


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->ctx->log.gf_log_xl_log_set = 1;
        xl->loglevel = level;
}

void
gf_log_fini (void)
{
        pthread_mutex_destroy (&THIS->ctx->log.logfile_mutex);
}


void
gf_log_globals_init (void *data)
{
        glusterfs_ctx_t *ctx = data;

        pthread_mutex_init (&ctx->log.logfile_mutex, NULL);

        ctx->log.loglevel         = GF_LOG_INFO;
        ctx->log.gf_log_syslog    = 1;
        ctx->log.sys_log_level    = GF_LOG_CRITICAL;

#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
}

int
gf_log_init (void *data, const char *file)
{
        glusterfs_ctx_t *ctx = NULL;
        int     fd = -1;

        ctx = data;

        if (!file){
                fprintf (stderr, "ERROR: no filename specified\n");
                return -1;
        }

        if (strcmp (file, "-") == 0) {
                ctx->log.gf_log_logfile = stderr;

                return 0;
        }

        ctx->log.filename = gf_strdup (file);
        if (!ctx->log.filename) {
                fprintf (stderr, "ERROR: updating log-filename failed: %s\n",
                         strerror (errno));
                return -1;
        }

        fd = open (file, O_CREAT | O_RDONLY, S_IRUSR | S_IWUSR);
        if (fd < 0) {
                fprintf (stderr, "ERROR: failed to create logfile \"%s\" (%s)\n",
                         file, strerror (errno));
                return -1;
        }
        close (fd);

        ctx->log.logfile = fopen (file, "a");
        if (!ctx->log.logfile){
                fprintf (stderr, "ERROR: failed to open logfile \"%s\" (%s)\n",
                         file, strerror (errno));
                return -1;
        }

        ctx->log.gf_log_logfile = ctx->log.logfile;

        return 0;
}

void
set_sys_log_level (gf_loglevel_t level)
{
        THIS->ctx->log.sys_log_level = level;
}

/*
 * 內存申請失敗日志打印.假設日志級別較高，打印到系統日志中"/var/log/message"
 * 不支持變參
 *
 * 若定義了HAVE_BACKTRACE，則打出函數調用棧
 *
 * @domain 模塊名
 *
 * 假設日志文件不存在，則打印到標準錯誤輸出
 */
int
_gf_log_nomem (const char *domain, const char *file,
               const char *function, int line, gf_loglevel_t level,
               size_t size)
{
        const char     *basename        = NULL;
        xlator_t       *this            = NULL;
        struct timeval  tv              = {0,};
        int             ret             = 0;
        char            msg[8092]       = {0,};
        char            timestr[256]    = {0,};
        char            callstr[4096]   = {0,};
        glusterfs_ctx_t *ctx = NULL;

        this = THIS;
        ctx = this->ctx;

        if (ctx->log.gf_log_xl_log_set) {
                if (this->loglevel && (level > this->loglevel))
                        goto out;
        }
        if (level > ctx->log.loglevel)
                goto out;

        static char *level_strings[] = {"",  /* NONE */
                                        "M", /* EMERGENCY */
                                        "A", /* ALERT */
                                        "C", /* CRITICAL */
                                        "E", /* ERROR */
                                        "W", /* WARNING */
                                        "N", /* NOTICE */
                                        "I", /* INFO */
                                        "D", /* DEBUG */
                                        "T", /* TRACE */
                                        ""};

        if (!domain || !file || !function) {
                fprintf (stderr,
                         "logging: %s:%s():%d: invalid argument\n",
                         __FILE__, __PRETTY_FUNCTION__, __LINE__);
                return -1;
        }

#if HAVE_BACKTRACE
        /* Print 'calling function' */
        do {
                void *array[5];
                char **callingfn = NULL;
                size_t bt_size = 0;

                bt_size = backtrace (array, 5);
                if (bt_size)
                        callingfn = backtrace_symbols (&array[2], bt_size-2);
                if (!callingfn)
                        break;

                if (bt_size == 5)
                        snprintf (callstr, 4096, "(-->%s (-->%s (-->%s)))",
                                  callingfn[2], callingfn[1], callingfn[0]);
                if (bt_size == 4)
                        snprintf (callstr, 4096, "(-->%s (-->%s))",
                                  callingfn[1], callingfn[0]);
                if (bt_size == 3)
                        snprintf (callstr, 4096, "(-->%s)", callingfn[0]);

                free (callingfn);
        } while (0);
#endif /* HAVE_BACKTRACE */

        ret = gettimeofday (&tv, NULL);
        if (-1 == ret)
                goto out;
        gf_time_fmt (timestr, sizeof timestr, tv.tv_sec, gf_timefmt_FT);
        snprintf (timestr + strlen (timestr), sizeof timestr - strlen (timestr),
                  ".%"GF_PRI_SUSECONDS, tv.tv_usec);

        basename = strrchr (file, '/');
        if (basename)
                basename++;
        else
                basename = file;

        ret = sprintf (msg, "[%s] %s [%s:%d:%s] %s %s: no memory "
                       "available for size (%"GF_PRI_SIZET")",
                       timestr, level_strings[level],
                       basename, line, function, callstr,
                       domain, size);
        if (-1 == ret) {
                goto out;
        }

        pthread_mutex_lock (&ctx->log.logfile_mutex);
        {
                if (ctx->log.logfile) {
                        fprintf (ctx->log.logfile, "%s\n", msg);
                } else {
                        fprintf (stderr, "%s\n", msg);
                }

#ifdef GF_LINUX_HOST_OS
                /* We want only serious log in 'syslog', not our debug
                   and trace logs */
                if (ctx->log.gf_log_syslog && level &&
                    (level <= ctx->log.sys_log_level))
                        syslog ((level-1), "%s\n", msg);
#endif
        }

        pthread_mutex_unlock (&ctx->log.logfile_mutex);
out:
        return ret;
 }

/*
 * 函數調用參數無效日志打印.假設日志級別較高，打印到系統日志中"/var/log/message"
 * 支持變參
 *
 * 若定義了HAVE_BACKTRACE，則打出函數調用棧
 *
 * @domain 模塊名
 *
 * 假設日志文件不存在，則打印到標準輸出
 */
int
_gf_log_callingfn (const char *domain, const char *file, const char *function,
                   int line, gf_loglevel_t level, const char *fmt, ...)
{
        const char     *basename        = NULL;
        xlator_t       *this            = NULL;
        char           *str1            = NULL;
        char           *str2            = NULL;
        char           *msg             = NULL;
        char            timestr[256]    = {0,};
        char            callstr[4096]   = {0,};
        struct timeval  tv              = {0,};
        size_t          len             = 0;
        int             ret             = 0;
        va_list         ap;
        glusterfs_ctx_t *ctx = NULL;

        this = THIS;
        ctx = this->ctx;

        if (ctx->log.gf_log_xl_log_set) {
                if (this->loglevel && (level > this->loglevel))
                        goto out;
        }
        if (level > ctx->log.loglevel)
                goto out;

        static char *level_strings[] = {"",  /* NONE */
                                        "M", /* EMERGENCY */
                                        "A", /* ALERT */
                                        "C", /* CRITICAL */
                                        "E", /* ERROR */
                                        "W", /* WARNING */
                                        "N", /* NOTICE */
                                        "I", /* INFO */
                                        "D", /* DEBUG */
                                        "T", /* TRACE */
                                        ""};

        if (!domain || !file || !function || !fmt) {
                fprintf (stderr,
                         "logging: %s:%s():%d: invalid argument\n",
                         __FILE__, __PRETTY_FUNCTION__, __LINE__);
                return -1;
        }

#if HAVE_BACKTRACE
        /* Print 'calling function' */
        do {
                void *array[5];
                char **callingfn = NULL;
                size_t size = 0;

                size = backtrace (array, 5);
                if (size)
                        callingfn = backtrace_symbols (&array[2], size-2);
                if (!callingfn)
                        break;

                if (size == 5)
                        snprintf (callstr, 4096, "(-->%s (-->%s (-->%s)))",
                                  callingfn[2], callingfn[1], callingfn[0]);
                if (size == 4)
                        snprintf (callstr, 4096, "(-->%s (-->%s))",
                                  callingfn[1], callingfn[0]);
                if (size == 3)
                        snprintf (callstr, 4096, "(-->%s)", callingfn[0]);

                free (callingfn);
        } while (0);
#endif /* HAVE_BACKTRACE */

        ret = gettimeofday (&tv, NULL);
        if (-1 == ret)
                goto out;
        va_start (ap, fmt);
        gf_time_fmt (timestr, sizeof timestr, tv.tv_sec, gf_timefmt_FT);
        snprintf (timestr + strlen (timestr), sizeof timestr - strlen (timestr),
                  ".%"GF_PRI_SUSECONDS, tv.tv_usec);

        basename = strrchr (file, '/');
        if (basename)
                basename++;
        else
                basename = file;

        ret = gf_asprintf (&str1, "[%s] %s [%s:%d:%s] %s %d-%s: ",
                           timestr, level_strings[level],
                           basename, line, function, callstr,
                           ((this->graph) ? this->graph->id:0), domain);
        if (-1 == ret) {
                goto out;
        }

        ret = vasprintf (&str2, fmt, ap);
        if (-1 == ret) {
                goto out;
        }

        va_end (ap);

        len = strlen (str1);
        msg = GF_MALLOC (len + strlen (str2) + 1, gf_common_mt_char);

        strcpy (msg, str1);
        strcpy (msg + len, str2);

        pthread_mutex_lock (&ctx->log.logfile_mutex);
        {
                if (ctx->log.logfile) {
                        fprintf (ctx->log.logfile, "%s\n", msg);
                } else {
                        fprintf (stderr, "%s\n", msg);
                }

#ifdef GF_LINUX_HOST_OS
                /* We want only serious log in 'syslog', not our debug
                   and trace logs */
                if (ctx->log.gf_log_syslog && level &&
                    (level <= ctx->log.sys_log_level))
                        syslog ((level-1), "%s\n", msg);
#endif
        }

        pthread_mutex_unlock (&ctx->log.logfile_mutex);

out:
        GF_FREE (msg);

        GF_FREE (str1);

        FREE (str2);

        return ret;
}

/*
 * 記錄系統執行日志到文件
 *
 * 假設日志文件不存在，則打印到標準輸出
 */
int
_gf_log (const char *domain, const char *file, const char *function, int line,
         gf_loglevel_t level, const char *fmt, ...)
{
        const char    *basename = NULL;
        FILE          *new_logfile = NULL;
        va_list        ap;
        char           timestr[256] = {0,};
        struct timeval tv = {0,};
        char          *str1 = NULL;
        char          *str2 = NULL;
        char          *msg  = NULL;
        size_t         len  = 0;
        int            ret  = 0;
        int            fd   = -1;
        xlator_t      *this = NULL;
        glusterfs_ctx_t *ctx = NULL;

        this = THIS;
        ctx = this->ctx;

        if (ctx->log.gf_log_xl_log_set) {
                if (this->loglevel && (level > this->loglevel))
                        goto out;
        }
        if (level > ctx->log.loglevel)
                goto out;

        static char *level_strings[] = {"",  /* NONE */
                                        "M", /* EMERGENCY */
                                        "A", /* ALERT */
                                        "C", /* CRITICAL */
                                        "E", /* ERROR */
                                        "W", /* WARNING */
                                        "N", /* NOTICE */
                                        "I", /* INFO */
                                        "D", /* DEBUG */
                                        "T", /* TRACE */
                                        ""};

        if (!domain || !file || !function || !fmt) {
                fprintf (stderr,
                         "logging: %s:%s():%d: invalid argument\n",
                         __FILE__, __PRETTY_FUNCTION__, __LINE__);
                return -1;
        }


        if (ctx->log.logrotate) {
                ctx->log.logrotate = 0;

                fd = open (ctx->log.filename,
                           O_CREAT | O_RDONLY, S_IRUSR | S_IWUSR);
                if (fd < 0) {
                        gf_log ("logrotate", GF_LOG_ERROR,
                                "%s", strerror (errno));
                        return -1;
                }
                close (fd);

                new_logfile = fopen (ctx->log.filename, "a");
                if (!new_logfile) {
                        gf_log ("logrotate", GF_LOG_CRITICAL,
                                "failed to open logfile %s (%s)",
                                ctx->log.filename, strerror (errno));
                        goto log;
                }

                pthread_mutex_lock (&ctx->log.logfile_mutex);
                {
                        if (ctx->log.logfile)
                                fclose (ctx->log.logfile);

                        ctx->log.gf_log_logfile = ctx->log.logfile = new_logfile;
                }
                pthread_mutex_unlock (&ctx->log.logfile_mutex);

        }

log:
        ret = gettimeofday (&tv, NULL);
        if (-1 == ret)
                goto out;
        va_start (ap, fmt);
        gf_time_fmt (timestr, sizeof timestr, tv.tv_sec, gf_timefmt_FT);
        snprintf (timestr + strlen (timestr), sizeof timestr - strlen (timestr),
                  ".%"GF_PRI_SUSECONDS, tv.tv_usec);

        basename = strrchr (file, '/');
        if (basename)
                basename++;
        else
                basename = file;

        ret = gf_asprintf (&str1, "[%s] %s [%s:%d:%s] %d-%s: ",
                           timestr, level_strings[level],
                           basename, line, function,
                           ((this->graph)?this->graph->id:0), domain);
        if (-1 == ret) {
                goto err;
        }

        ret = vasprintf (&str2, fmt, ap);
        if (-1 == ret) {
                goto err;
        }

        va_end (ap);

        len = strlen (str1);
        msg = GF_MALLOC (len + strlen (str2) + 1, gf_common_mt_char);

        strcpy (msg, str1);
        strcpy (msg + len, str2);

        pthread_mutex_lock (&ctx->log.logfile_mutex);
        {

                if (ctx->log.logfile) {
                        fprintf (ctx->log.logfile, "%s\n", msg);
                        fflush (ctx->log.logfile);
                } else {
                        fprintf (stderr, "%s\n", msg);
                        fflush (stderr);
                }

#ifdef GF_LINUX_HOST_OS
                /* We want only serious log in 'syslog', not our debug
                   and trace logs */
                if (ctx->log.gf_log_syslog && level &&
                    (level <= ctx->log.sys_log_level))
                        syslog ((level-1), "%s\n", msg);
#endif
        }

        pthread_mutex_unlock (&ctx->log.logfile_mutex);

err:
        GF_FREE (msg);

        GF_FREE (str1);

        FREE (str2);

out:
        return (0);
}

int
_gf_log_eh (const char *function, const char *fmt, ...)
{
        int          ret   = -1;
        va_list      ap;
        char         *str1 = NULL;
        char         *str2 = NULL;
        char         *msg  = NULL;
        xlator_t     *this = NULL;

        this = THIS;

        ret = gf_asprintf (&str1, "[%d] %s: ",
                           ((this->graph)?this->graph->id:0),
                           function);
        if (-1 == ret) {
                goto out;
        }

        va_start (ap, fmt);

        ret = vasprintf (&str2, fmt, ap);
        if (-1 == ret) {
                goto out;
        }

        va_end (ap);

        msg = GF_MALLOC (strlen (str1) + strlen (str2) + 1, gf_common_mt_char);
        if (!msg) {
                ret = -1;
                goto out;
        }

        strcpy (msg, str1);
        strcat (msg, str2);

        ret = eh_save_history (this->history, msg);

out:
        GF_FREE (str1);

        /* Use FREE instead of GF_FREE since str2 was allocated by vasprintf */
        if (str2)
                FREE (str2);

         return ret;
}

/*
 * 初始化"命令記錄"日志
 */
int
gf_cmd_log_init (const char *filename)
{
        int         fd   = -1;
        xlator_t   *this = NULL;
        glusterfs_ctx_t *ctx = NULL;

        this = THIS;
        ctx  = this->ctx;

        if (!filename){
                gf_log (this->name, GF_LOG_CRITICAL, "gf_cmd_log_init: no "
                        "filename specified\n");
                return -1;
        }

        ctx->log.cmd_log_filename = gf_strdup (filename);
        if (!ctx->log.cmd_log_filename) {
                gf_log (this->name, GF_LOG_CRITICAL,
                        "gf_cmd_log_init: strdup error\n");
                return -1;
        }
        /* close and reopen cmdlogfile for log rotate*/
        if (ctx->log.cmdlogfile) {
                fclose (ctx->log.cmdlogfile);
                ctx->log.cmdlogfile = NULL;
        }

        fd = open (ctx->log.cmd_log_filename,
                   O_CREAT | O_RDONLY, S_IRUSR | S_IWUSR);
        if (fd < 0) {
                gf_log (this->name, GF_LOG_CRITICAL,
                        "%s", strerror (errno));
                return -1;
        }
        close (fd);

        ctx->log.cmdlogfile = fopen (ctx->log.cmd_log_filename, "a");
        if (!ctx->log.cmdlogfile){
                gf_log (this->name, GF_LOG_CRITICAL,
                        "gf_cmd_log_init: failed to open logfile \"%s\" "
                        "(%s)\n", ctx->log.cmd_log_filename, strerror (errno));
                return -1;
        }
        return 0;
}

/*
 * 記錄命令日志到文件
 */
int
gf_cmd_log (const char *domain, const char *fmt, ...)
{
        va_list        ap;
        char           timestr[64];
        struct timeval tv = {0,};
        char          *str1 = NULL;
        char          *str2 = NULL;
        char          *msg  = NULL;
        size_t         len  = 0;
        int            ret  = 0;
        glusterfs_ctx_t *ctx = NULL;

        ctx = THIS->ctx;
        if (!ctx->log.cmdlogfile)
                return -1;


        if (!domain || !fmt) {
                gf_log ("glusterd", GF_LOG_TRACE,
                        "logging: invalid argument\n");
                return -1;
        }

        ret = gettimeofday (&tv, NULL);
        if (ret == -1)
                goto out;
        va_start (ap, fmt);
        gf_time_fmt (timestr, sizeof timestr, tv.tv_sec, gf_timefmt_FT);
        snprintf (timestr + strlen (timestr), 256 - strlen (timestr),
                  ".%"GF_PRI_SUSECONDS, tv.tv_usec);

        ret = gf_asprintf (&str1, "[%s] %s : ",
                           timestr, domain);
        if (ret == -1) {
                goto out;
        }

        ret = vasprintf (&str2, fmt, ap);
        if (ret == -1) {
                goto out;
        }

        va_end (ap);

        len = strlen (str1);
        msg = GF_MALLOC (len + strlen (str2) + 1, gf_common_mt_char);

        strcpy (msg, str1);
        strcpy (msg + len, str2);

        fprintf (ctx->log.cmdlogfile, "%s\n", msg);
        fflush (ctx->log.cmdlogfile);

out:
        GF_FREE (msg);

        GF_FREE (str1);

        FREE (str2);

        return (0);
}