Mdmonitor: Refactor write_autorebuild_pid()

Add better error handling and check for symlinks when opening MDMON_DIR.

Signed-off-by: Mateusz Grzonka <mateusz.grzonka@intel.com>
Acked-by: Coly Li <colyli@suse.de>
Signed-off-by: Jes Sorensen <jes@trained-monkey.org>

diff --git a/Monitor.c b/Monitor.c
index 39598ba0c913ab88f7c0c743631dbf1584935e31..14a2dfe5c66ee4ced1760037ebb3735a5f306b42 100644 (file)
--- a/Monitor.c
+++ b/Monitor.c
@@ -33,6 +33,7 @@
 #endif
 
 #define EVENT_NAME_MAX 32
+#define AUTOREBUILD_PID_PATH MDMON_DIR "/autorebuild.pid"
 
 struct state {
        char devname[MD_NAME_MAX + sizeof("/dev/md/")]; /* length of "/dev/md/" + device name + terminating byte*/
@@ -126,7 +127,7 @@ static int check_udev_activity(void);
 static void link_containers_with_subarrays(struct state *list);
 static int make_daemon(char *pidfile);
 static void try_spare_migration(struct state *statelist);
-static void write_autorebuild_pid(void);
+static int write_autorebuild_pid(void);
 
 int Monitor(struct mddev_dev *devlist,
            char *mailaddr, char *alert_cmd,
@@ -234,7 +235,8 @@ int Monitor(struct mddev_dev *devlist,
        }
 
        if (share)
-               write_autorebuild_pid();
+               if (write_autorebuild_pid() != 0)
+                       return 1;
 
        if (devlist == NULL) {
                mdlist = conf_get_ident(NULL);
@@ -440,29 +442,44 @@ static int check_one_sharer(int scan)
        return 0;
 }
 
-static void write_autorebuild_pid()
+/*
+ * write_autorebuild_pid() - Writes pid to autorebuild.pid file.
+ *
+ * Return: 0 on success, 1 on error
+ */
+static int write_autorebuild_pid(void)
 {
-       char path[PATH_MAX];
-       int pid;
-       FILE *fp = NULL;
-       sprintf(path, "%s/autorebuild.pid", MDMON_DIR);
+       FILE *fp;
+       int fd;
 
        if (mkdir(MDMON_DIR, 0700) < 0 && errno != EEXIST) {
-               pr_err("Can't create autorebuild.pid file\n");
-       } else {
-               int fd = open(path, O_WRONLY | O_CREAT | O_TRUNC, 0700);
+               pr_err("%s: %s\n", strerror(errno), MDMON_DIR);
+               return 1;
+       }
 
-               if (fd >= 0)
-                       fp = fdopen(fd, "w");
+       if (!is_directory(MDMON_DIR)) {
+               pr_err("%s is not a regular directory.\n", MDMON_DIR);
+               return 1;
+       }
 
-               if (!fp)
-                       pr_err("Can't create autorebuild.pid file\n");
-               else {
-                       pid = getpid();
-                       fprintf(fp, "%d\n", pid);
-                       fclose(fp);
-               }
+       fd = open(AUTOREBUILD_PID_PATH, O_WRONLY | O_CREAT | O_TRUNC, 0700);
+
+       if (fd < 0) {
+               pr_err("Error opening %s file.\n", AUTOREBUILD_PID_PATH);
+               return 1;
        }
+
+       fp = fdopen(fd, "w");
+
+       if (!fp) {
+               pr_err("Error opening fd for %s file.\n", AUTOREBUILD_PID_PATH);
+               return 1;
+       }
+
+       fprintf(fp, "%d\n", getpid());
+
+       fclose(fp);
+       return 0;
 }
 
 #define BASE_MESSAGE "%s event detected on md device %s"