Use the new locking algorithm from Alan and Miquel.

[freeradius.git] / src / modules / rlm_detail / rlm_detail.c

diff --git a/src/modules/rlm_detail/rlm_detail.c b/src/modules/rlm_detail/rlm_detail.c
index e9289c0..9f9071f 100644 (file)
--- a/src/modules/rlm_detail/rlm_detail.c
+++ b/src/modules/rlm_detail/rlm_detail.c
@@ -68,7 +68,7 @@ struct detail_instance {
        char *last_made_directory;
 
        /* timestamp & stuff */
-       char *header;  
+       char *header;
 
        /* if we want file locking */
        int locking;
@@ -197,41 +197,61 @@ static int do_detail(void *instance, REQUEST *request, RADIUS_PACKET *packet,
                *p = '/';
        } /* else there was no directory delimiter. */
 
-       /*
-        *      Open & create the file, with the given permissions.
-        */
-       if ((outfd = open(buffer, O_WRONLY | O_APPEND | O_CREAT,
-                         inst->detailperm)) < 0) {
-               radlog(L_ERR, "rlm_detail: Couldn't open file %s: %s",
-                      buffer, strerror(errno));
-               return RLM_MODULE_FAIL;
-       }
-
-       /*
-        *      If we're not using locking, we'll just pass straight though
-        *      the while loop.
-        *      If we fail to aquire the filelock in 80 tries (approximately
-        *      two seconds) we bail out.
-        */
        locked = 0;
        lock_count = 0;
        do {
+               /*
+                *      Open & create the file, with the given
+                *      permissions.
+                */
+               if ((outfd = open(buffer, O_WRONLY | O_APPEND | O_CREAT,
+                                 inst->detailperm)) < 0) {
+                       radlog(L_ERR, "rlm_detail: Couldn't open file %s: %s",
+                              buffer, strerror(errno));
+                       return RLM_MODULE_FAIL;
+               }
+
+               /*
+                *      If we fail to aquire the filelock in 80 tries
+                *      (approximately two seconds) we bail out.
+                */
                if (inst->locking) {
                        lseek(outfd, 0L, SEEK_SET);
                        if (rad_lockfd_nonblock(outfd, 0) < 0) {
+                               close(outfd);
                                tv.tv_sec = 0;
                                tv.tv_usec = 25000;
                                select(0, NULL, NULL, NULL, &tv);
                                lock_count++;
-                       } else {
-                               DEBUG("rlm_detail: Acquired filelock, tried %d time(s)",
-                                     lock_count + 1);
-                               locked = 1;
+                               continue;
                        }
+
+                       /*
+                        *      The file might have been deleted by
+                        *      radrelay while we tried to acquire
+                        *      the lock (race condition)
+                        */
+                       if (fstat(outfd, &st) != 0) {
+                               radlog(L_ERR, "rlm_detail: Couldn't stat file %s: %s",
+                                      buffer, strerror(errno));
+                               close(outfd);
+                               return RLM_MODULE_FAIL;
+                       }
+                       if (st.st_nlink == 0) {
+                               DEBUG("rlm_detail: File %s removed by another program, retrying",
+                                     buffer);
+                               close(outfd);
+                               lock_count = 0;
+                               continue;
+                       }
+
+                       DEBUG("rlm_detail: Acquired filelock, tried %d time(s)",
+                             lock_count + 1);
+                       locked = 1;
                }
-       } while (!locked && inst->locking && lock_count < 80);
+       } while (inst->locking && !locked && lock_count < 80);
 
-       if (!locked && inst->locking && lock_count >= 80) {
+       if (inst->locking && !locked) {
                close(outfd);
                radlog(L_ERR, "rlm_detail: Failed to aquire filelock for %s, giving up",
                       buffer);