From: Erez Zadok <ezk@cs.sunysb.edu>
Date: Wed, 26 Oct 2005 14:59:19 +0000 (+0000)
Subject: * amd/amq_subr.c (amqproc_pawd_1_svc): repeatedly resolve path in
X-Git-Tag: am-utils-6_2a2~30
X-Git-Url: https://git.fsl.cs.sunysb.edu/?a=commitdiff_plain;h=245d30750852c121ac7da8f271651db951706bf5;p=am-utils-6.1.git

* amd/amq_subr.c (amqproc_pawd_1_svc): repeatedly resolve path in
Amd, not in pawd (to avoid repeated network RPCs).

* amq/pawd.c (transform_dir): move repeated path resolution into Amd.
---

diff --git a/ChangeLog b/ChangeLog
index d9f1fc6..14838ba 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2005-10-26  Erez Zadok  <ezk@cs.sunysb.edu>
+
+	* amd/amq_subr.c (amqproc_pawd_1_svc): repeatedly resolve path in
+	Amd, not in pawd (to avoid repeated network RPCs).
+
+	* amq/pawd.c (transform_dir): move repeated path resolution into Amd.
+
 2005-10-25  Erez Zadok  <ezk@cs.sunysb.edu>
 
 	* amq/pawd.c (transform_dir): resolve path repeatedly until
diff --git a/amd/amq_subr.c b/amd/amq_subr.c
index 8615508..10cdd72 100644
--- a/amd/amq_subr.c
+++ b/amd/amq_subr.c
@@ -192,37 +192,58 @@ amqproc_getpid_1_svc(voidp argp, struct svc_req *rqstp)
 }
 
 
-/* process PAWD string of remote pawd tool */
+/*
+ * Process PAWD string of remote pawd tool.
+ *
+ * We repeat the resolution of the string until the resolved string resolves
+ * to itself.  This ensures that we follow path resolutions through all
+ * possible Amd mount points until we reach some sort of convergence.  To
+ * prevent possible infinite loops, we break out of this loop if the strings
+ * do not converge after MAX_PAWD_TRIES times.
+ */
 amq_string *
 amqproc_pawd_1_svc(voidp argp, struct svc_req *rqstp)
 {
   static amq_string res;
-  int index, len;
+#define MAX_PAWD_TRIES 10
+  int index, len, maxagain = MAX_PAWD_TRIES;
   am_node *mp;
   char *mountpoint;
   char *dir = *(char **) argp;
   static char tmp_buf[MAXPATHLEN];
-
-  tmp_buf[0] = '\0';		/* default is empty string: no match */
-  for (mp = get_first_exported_ap(&index);
-       mp;
-       mp = get_next_exported_ap(&index)) {
-    if (STREQ(mp->am_mnt->mf_ops->fs_type, "toplvl"))
-      continue;
-    if (STREQ(mp->am_mnt->mf_ops->fs_type, "auto"))
-      continue;
-    mountpoint = (mp->am_link ? mp->am_link : mp->am_mnt->mf_mount);
-    len = strlen(mountpoint);
-    if (len == 0)
-      continue;
-    if (!NSTREQ(mountpoint, dir, len))
-      continue;
-    if (dir[len] != '\0' && dir[len] != '/')
-      continue;
-    xstrlcpy(tmp_buf, mp->am_path, sizeof(tmp_buf));
-    xstrlcat(tmp_buf, &dir[len], sizeof(tmp_buf));
-    break;
-  }
+  char prev_buf[MAXPATHLEN];
+
+  tmp_buf[0] = prev_buf[0] = '\0'; /* default is empty string: no match */
+  do {
+    for (mp = get_first_exported_ap(&index);
+	 mp;
+	 mp = get_next_exported_ap(&index)) {
+      if (STREQ(mp->am_mnt->mf_ops->fs_type, "toplvl"))
+	continue;
+      if (STREQ(mp->am_mnt->mf_ops->fs_type, "auto"))
+	continue;
+      mountpoint = (mp->am_link ? mp->am_link : mp->am_mnt->mf_mount);
+      len = strlen(mountpoint);
+      if (len == 0)
+	continue;
+      if (!NSTREQ(mountpoint, dir, len))
+	continue;
+      if (dir[len] != '\0' && dir[len] != '/')
+	continue;
+      xstrlcpy(tmp_buf, mp->am_path, sizeof(tmp_buf));
+      xstrlcat(tmp_buf, &dir[len], sizeof(tmp_buf));
+      break;
+    } /* end of "for" loop */
+    /* once tmp_buf and prev_buf are equal, break out of "do" loop */
+    if (STREQ(tmp_buf, prev_buf))
+      break;
+    else
+      xstrlcpy(prev_buf, tmp_buf, sizeof(prev_buf));
+  } while (--maxagain);
+  /* check if we couldn't resolve the string after MAX_PAWD_TRIES times */
+  if (maxagain <= 0)
+    plog(XLOG_WARNING, "path \"%s\" did not resolve after %d tries",
+	 tmp_buf, MAX_PAWD_TRIES);
 
   res = tmp_buf;
   return &res;
diff --git a/amq/pawd.c b/amq/pawd.c
index a7d77f6..1b44202 100644
--- a/amq/pawd.c
+++ b/amq/pawd.c
@@ -57,8 +57,6 @@
 #include <am_defs.h>
 #include <amq.h>
 
-/* maximum number of transformations for each path */
-#define MAX_LOOP	10
 
 /* statics */
 static char *localhost = "localhost";
@@ -185,7 +183,6 @@ transform_dir(char *dir)
   struct timeval tmo = {10, 0};
   char *dummystr;
   amq_string *spp;
-  int again = 1, maxloop = MAX_LOOP;
 
 #ifdef DISK_HOME_HACK
   if (ch = hack_name(dir))
@@ -212,21 +209,11 @@ transform_dir(char *dir)
     return dir;
 
   xstrlcpy(transform, dir, sizeof(transform));
-  while (again) {
-    if (--maxloop <= 0) {
-      fprintf(stderr, "pawd: exceeded maximum no. of transformations (%d)\n",
-	      MAX_LOOP);
-      break;
-    }
-    again = 0;
-    dummystr = transform;
-    spp = amqproc_pawd_1((amq_string *) &dummystr, clnt);
-    if (spp && *spp && **spp) {
-      if (STREQ(transform, *spp))
-	again++;
-      xstrlcpy(transform, *spp, sizeof(transform));
-      XFREE(*spp);
-    }
+  dummystr = transform;
+  spp = amqproc_pawd_1((amq_string *) &dummystr, clnt);
+  if (spp && *spp && **spp) {
+    xstrlcpy(transform, *spp, sizeof(transform));
+    XFREE(*spp);
   }
   clnt_destroy(clnt);
   return transform;