Cleanup zed logging

This is a set of minor cleanup changes related to zed logging:
- Remove the program identity prefix from messages written to stderr
  since systemd already prepends this output with the program name.
- Replace the copy of the program identity string with a ptr reference.
- Replace "pid" with "PID" for consistency in comments & strings.
- Rename the zed_log.c struct _ctx component "level" to "priority".
- Add the LOG_PID option for messages written to syslog.

Signed-off-by: Chris Dunlap <cdunlap@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2252

diff --git a/cmd/zed/zed_conf.c b/cmd/zed/zed_conf.c
index e6f601f3a2ac086d44690e45e7ccab250157730f..cf68c06fe388c7197efff8cae4eb22340ddd5be8 100644 (file)
--- a/cmd/zed/zed_conf.c
+++ b/cmd/zed/zed_conf.c
@@ -103,7 +103,7 @@ zed_conf_destroy(struct zed_conf *zcp)
        if (zcp->pid_file) {
                if ((unlink(zcp->pid_file) < 0) && (errno != ENOENT))
                        zed_log_msg(LOG_WARNING,
-                           "Failed to remove pid file \"%s\": %s",
+                           "Failed to remove PID file \"%s\": %s",
                            zcp->pid_file, strerror(errno));
        }
        if (zcp->conf_file)
@@ -450,14 +450,14 @@ zed_conf_write_pid(struct zed_conf *zcp)
 
        if (!zcp || !zcp->pid_file) {
                errno = EINVAL;
-               zed_log_msg(LOG_ERR, "Failed to write pid file: %s",
+               zed_log_msg(LOG_ERR, "Failed to write PID file: %s",
                    strerror(errno));
                return (-1);
        }
        n = strlcpy(dirbuf, zcp->pid_file, sizeof (dirbuf));
        if (n >= sizeof (dirbuf)) {
                errno = ENAMETOOLONG;
-               zed_log_msg(LOG_WARNING, "Failed to write pid file: %s",
+               zed_log_msg(LOG_WARNING, "Failed to write PID file: %s",
                    strerror(errno));
                return (-1);
        }
@@ -479,13 +479,13 @@ zed_conf_write_pid(struct zed_conf *zcp)
        umask(mask);
 
        if (!fp) {
-               zed_log_msg(LOG_WARNING, "Failed to open pid file \"%s\": %s",
+               zed_log_msg(LOG_WARNING, "Failed to open PID file \"%s\": %s",
                    zcp->pid_file, strerror(errno));
        } else if (fprintf(fp, "%d\n", (int) getpid()) == EOF) {
-               zed_log_msg(LOG_WARNING, "Failed to write pid file \"%s\": %s",
+               zed_log_msg(LOG_WARNING, "Failed to write PID file \"%s\": %s",
                    zcp->pid_file, strerror(errno));
        } else if (fclose(fp) == EOF) {
-               zed_log_msg(LOG_WARNING, "Failed to close pid file \"%s\": %s",
+               zed_log_msg(LOG_WARNING, "Failed to close PID file \"%s\": %s",
                    zcp->pid_file, strerror(errno));
        } else {
                return (0);
@@ -564,7 +564,7 @@ zed_conf_open_state(struct zed_conf *zcp)
                            zcp->state_file);
                } else if (pid > 0) {
                        zed_log_msg(LOG_WARNING,
-                           "Found pid %d bound to state file \"%s\"",
+                           "Found PID %d bound to state file \"%s\"",
                            pid, zcp->state_file);
                } else {
                        zed_log_msg(LOG_WARNING,

diff --git a/cmd/zed/zed_file.c b/cmd/zed/zed_file.c
index 7b77345d1dd3ea279125c18c076b4c82d4fd0da1..3d62f9fe4894a2c43a11396ae9f23286760e1637 100644 (file)
--- a/cmd/zed/zed_file.c
+++ b/cmd/zed/zed_file.c
@@ -145,7 +145,7 @@ zed_file_unlock(int fd)
 /*
  * Test whether an exclusive advisory lock could be obtained for the open
  *   file descriptor [fd].
- * Return 0 if the file is not locked, >0 for the pid of another process
+ * Return 0 if the file is not locked, >0 for the PID of another process
  *   holding a conflicting lock, or -1 on error (with errno set).
  */
 pid_t

diff --git a/cmd/zed/zed_log.c b/cmd/zed/zed_log.c
index 2a787e357301b8da7c6a0e9c21fef08604a1e6c1..c2bc25edc086452f7ad08c14f092bbfd2fb734ff 100644 (file)
--- a/cmd/zed/zed_log.c
+++ b/cmd/zed/zed_log.c
@@ -33,38 +33,40 @@
 #include <syslog.h>
 #include "zed_log.h"
 
-#define        ZED_LOG_MAX_ID_LEN      64
 #define        ZED_LOG_MAX_LOG_LEN     1024
 
 static struct {
        unsigned do_stderr:1;
        unsigned do_syslog:1;
-       int level;
-       char id[ZED_LOG_MAX_ID_LEN];
+       const char *identity;
+       int priority;
        int pipe_fd[2];
 } _ctx;
 
+/*
+ * Initialize the logging subsystem.
+ */
 void
 zed_log_init(const char *identity)
 {
-       const char *p;
-
        if (identity) {
-               p = (p = strrchr(identity, '/')) ? p + 1 : identity;
-               strlcpy(_ctx.id, p, sizeof (_ctx.id));
+               const char *p = strrchr(identity, '/');
+               _ctx.identity = (p != NULL) ? p + 1 : identity;
        } else {
-               _ctx.id[0] = '\0';
+               _ctx.identity = NULL;
        }
        _ctx.pipe_fd[0] = -1;
        _ctx.pipe_fd[1] = -1;
 }
 
+/*
+ * Shutdown the logging subsystem.
+ */
 void
-zed_log_fini()
+zed_log_fini(void)
 {
-       if (_ctx.do_syslog) {
-               closelog();
-       }
+       zed_log_stderr_close();
+       zed_log_syslog_close();
 }
 
 /*
@@ -158,78 +160,72 @@ zed_log_pipe_wait(void)
        }
 }
 
+/*
+ * Start logging messages at the syslog [priority] level or higher to stderr.
+ *   Refer to syslog(3) for valid priority values.
+ */
 void
-zed_log_stderr_open(int level)
+zed_log_stderr_open(int priority)
 {
        _ctx.do_stderr = 1;
-       _ctx.level = level;
+       _ctx.priority = priority;
 }
 
+/*
+ * Stop logging messages to stderr.
+ */
 void
 zed_log_stderr_close(void)
 {
-       _ctx.do_stderr = 0;
+       if (_ctx.do_stderr)
+               _ctx.do_stderr = 0;
 }
 
+/*
+ * Start logging messages to syslog.
+ *   Refer to syslog(3) for valid option/facility values.
+ */
 void
 zed_log_syslog_open(int facility)
 {
-       const char *identity;
-
        _ctx.do_syslog = 1;
-       identity = (_ctx.id[0] == '\0') ? NULL : _ctx.id;
-       openlog(identity, LOG_NDELAY, facility);
+       openlog(_ctx.identity, LOG_NDELAY | LOG_PID, facility);
 }
 
+/*
+ * Stop logging messages to syslog.
+ */
 void
 zed_log_syslog_close(void)
 {
-       _ctx.do_syslog = 0;
-       closelog();
+       if (_ctx.do_syslog) {
+               _ctx.do_syslog = 0;
+               closelog();
+       }
 }
 
+/*
+ * Auxiliary function to log a message to syslog and/or stderr.
+ */
 static void
 _zed_log_aux(int priority, const char *fmt, va_list vargs)
 {
        char buf[ZED_LOG_MAX_LOG_LEN];
-       char *syslogp;
-       char *p;
-       int len;
        int n;
 
-       assert(fmt != NULL);
-
-       syslogp = NULL;
-       p = buf;
-       len = sizeof (buf);
+       if (!fmt)
+               return;
 
-       if (_ctx.id[0] != '\0') {
-               n = snprintf(p, len, "%s: ", _ctx.id);
-               if ((n < 0) || (n >= len)) {
-                       p += len - 1;
-                       len = 0;
-               } else {
-                       p += n;
-                       len -= n;
-               }
-       }
-       if ((len > 0) && fmt) {
-               syslogp = p;
-               n = vsnprintf(p, len, fmt, vargs);
-               if ((n < 0) || (n >= len)) {
-                       p += len - 1;
-                       len = 0;
-               } else {
-                       p += n;
-                       len -= n;
-               }
+       n = vsnprintf(buf, sizeof (buf), fmt, vargs);
+       if ((n < 0) || (n >= sizeof (buf))) {
+               buf[sizeof (buf) - 2] = '+';
+               buf[sizeof (buf) - 1] = '\0';
        }
-       *p = '\0';
 
-       if (_ctx.do_syslog && syslogp)
-               syslog(priority, "%s", syslogp);
+       if (_ctx.do_syslog)
+               syslog(priority, "%s", buf);
 
-       if (_ctx.do_stderr && priority <= _ctx.level)
+       if (_ctx.do_stderr && (priority <= _ctx.priority))
                fprintf(stderr, "%s\n", buf);
 }
 

diff --git a/cmd/zed/zed_log.h b/cmd/zed/zed_log.h
index 767c4c7dba0f7c8c4e875cd111ea98b9b167fe86..d963089d03a2da2d67614df842a4324da747f48f 100644 (file)
--- a/cmd/zed/zed_log.h
+++ b/cmd/zed/zed_log.h
@@ -41,7 +41,7 @@ void zed_log_pipe_close_writes(void);
 
 void zed_log_pipe_wait(void);
 
-void zed_log_stderr_open(int level);
+void zed_log_stderr_open(int priority);
 
 void zed_log_stderr_close(void);