src/common.c: Fixed a race condition in check_create_dir().

[collectd.git] / src / common.c

diff --git a/src/common.c b/src/common.c
index fd7c199..182f923 100644 (file)
--- a/src/common.c
+++ b/src/common.c
@@ -433,7 +433,8 @@ int check_create_dir (const char *file_orig)
                 */
                if (fields[i][0] == '.')
                {
-                       ERROR ("Cowardly refusing to create a directory that begins with a `.' (dot): `%s'", file_orig);
+                       ERROR ("Cowardly refusing to create a directory that "
+                                       "begins with a `.' (dot): `%s'", file_orig);
                        return (-2);
                }
 
@@ -448,32 +449,42 @@ int check_create_dir (const char *file_orig)
                        return (-1);
                }
 
-               if (stat (dir, &statbuf) == -1)
-               {
-                       if (errno == ENOENT)
+               while (42) {
+                       if (stat (dir, &statbuf) == -1)
                        {
-                               if (mkdir (dir, 0755) == -1)
+                               if (errno == ENOENT)
                                {
+                                       if (mkdir (dir, 0755) == 0)
+                                               break;
+
+                                       /* this might happen, if a different thread created
+                                        * the directory in the meantime
+                                        * => call stat() again to check for S_ISDIR() */
+                                       if (EEXIST == errno)
+                                               continue;
+
                                        char errbuf[1024];
                                        ERROR ("check_create_dir: mkdir (%s): %s", dir,
                                                        sstrerror (errno,
                                                                errbuf, sizeof (errbuf)));
                                        return (-1);
                                }
+                               else
+                               {
+                                       char errbuf[1024];
+                                       ERROR ("check_create_dir: stat (%s): %s", dir,
+                                                       sstrerror (errno, errbuf,
+                                                               sizeof (errbuf)));
+                                       return (-1);
+                               }
                        }
-                       else
+                       else if (!S_ISDIR (statbuf.st_mode))
                        {
-                               char errbuf[1024];
-                               ERROR ("stat (%s): %s", dir,
-                                               sstrerror (errno, errbuf,
-                                                       sizeof (errbuf)));
+                               ERROR ("check_create_dir: `%s' exists but is not "
+                                               "a directory!", dir);
                                return (-1);
                        }
-               }
-               else if (!S_ISDIR (statbuf.st_mode))
-               {
-                       ERROR ("stat (%s): Not a directory!", dir);
-                       return (-1);
+                       break;
                }
        }
 
@@ -537,12 +548,12 @@ long long get_kstat_value (kstat_t *ksp, char *name)
 #else
        if (ksp == NULL)
        {
-               fprintf (stderr, "ERROR: %s:%i: ksp == NULL\n", __FILE__, __LINE__);
+               ERROR ("ERROR: %s:%i: ksp == NULL\n", __FILE__, __LINE__);
                return (-1LL);
        }
        else if (ksp->ks_type != KSTAT_TYPE_NAMED)
        {
-               fprintf (stderr, "ERROR: %s:%i: ksp->ks_type != KSTAT_TYPE_NAMED\n", __FILE__, __LINE__);
+               ERROR ("ERROR: %s:%i: ksp->ks_type != KSTAT_TYPE_NAMED\n", __FILE__, __LINE__);
                return (-1LL);
        }
 #endif
@@ -865,32 +876,44 @@ int notification_init (notification_t *n, int severity, const char *message,
        return (0);
 } /* int notification_init */
 
-int walk_directory (const char *dir, dirwalk_callback_f callback)
+int walk_directory (const char *dir, dirwalk_callback_f callback,
+               void *user_data)
 {
        struct dirent *ent;
        DIR *dh;
-       int ok = 0;
+       int success;
+       int failure;
+
+       success = 0;
+       failure = 0;
 
        if ((dh = opendir (dir)) == NULL)
        {
                char errbuf[1024];
-               ERROR ("Cannot open '%s': %s", dir,
+               ERROR ("walk_directory: Cannot open '%s': %s", dir,
                                sstrerror (errno, errbuf, sizeof (errbuf)));
                return -1;
        }
 
        while ((ent = readdir (dh)) != NULL)
        {
+               int status;
+
                if (ent->d_name[0] == '.')
                        continue;
 
-               if (!callback(ent->d_name))
-                       ++ok;
+               status = (*callback) (dir, ent->d_name, user_data);
+               if (status != 0)
+                       failure++;
+               else
+                       success++;
        }
 
        closedir (dh);
 
-       return ok ? 0 : -1;
+       if ((success == 0) && (failure > 0))
+               return (-1);
+       return (0);
 }
 
 int read_file_contents (const char *filename, char *buf, int bufsize)