From 225c1072f85813bc665f67d67bc61d64a7c00191 Mon Sep 17 00:00:00 2001
From: adilger <adilger>
Date: Fri, 23 Sep 2005 09:02:49 +0000
Subject: [PATCH] Branch b1_4 Description: improve by-nid export eviction on
 the MDS and OST Details    : allow multiple exports with the same NID to be
 evicted at one 	     time without re-searching the exports list.
 b=7304 r=green, tested at Sandia

---
 lustre/ChangeLog         |  6 ++++++
 lustre/obdclass/genops.c | 35 +++++++++++++++++++----------------
 2 files changed, 25 insertions(+), 16 deletions(-)

diff --git a/lustre/ChangeLog b/lustre/ChangeLog
index 73b71d8..4b64143 100644
--- a/lustre/ChangeLog
+++ b/lustre/ChangeLog
@@ -122,6 +122,12 @@ Details    : ping_evictor_main() drops obd_dev_lock if deleting a stale export
 	     but doesn't restart at beginning of obd_exports_timed list
 	     afterward.
 
+Severity   : enhancement
+Bugzilla   : 7304
+Description: improve by-nid export eviction on the MDS and OST
+Details    : allow multiple exports with the same NID to be evicted at one
+	     time without re-searching the exports list.
+
 ------------------------------------------------------------------------------
 
 08-26-2005  Cluster File Systems, Inc. <info@clusterfs.com>
diff --git a/lustre/obdclass/genops.c b/lustre/obdclass/genops.c
index b15e664..9e51686 100644
--- a/lustre/obdclass/genops.c
+++ b/lustre/obdclass/genops.c
@@ -1273,42 +1273,45 @@ char *obd_export_nid2str(struct obd_export *exp, char *ipbuf)
         return ipbuf;
 }
 
+#define EVICT_BATCH 32
 int obd_export_evict_by_nid(struct obd_device *obd, char *nid)
 {
-        struct obd_export *doomed_exp = NULL;
+        struct obd_export *doomed_exp[EVICT_BATCH] = { NULL };
         struct list_head *p;
-        int exports_evicted = 0;
+        int exports_evicted = 0, num_to_evict = 0, i;
 
 search_again:
         spin_lock(&obd->obd_dev_lock);
         list_for_each(p, &obd->obd_exports) {
                 char ipbuf[PTL_NALFMT_SIZE];
 
-                doomed_exp = list_entry(p, struct obd_export, exp_obd_chain);
-                obd_export_nid2str(doomed_exp, ipbuf);
+                doomed_exp[num_to_evict] = list_entry(p, struct obd_export,
+                                                      exp_obd_chain);
+                obd_export_nid2str(doomed_exp[num_to_evict], ipbuf);
 
                 if (strcmp(ipbuf, nid) == 0) {
-                        class_export_get(doomed_exp);
-                        break;
+                        class_export_get(doomed_exp[num_to_evict]);
+                        if (++num_to_evict == EVICT_BATCH)
+                                break;
                 }
-                doomed_exp = NULL;
         }
         spin_unlock(&obd->obd_dev_lock);
 
-        if (doomed_exp == NULL) {
-                goto out;
-        } else {
-                CERROR("evicting nid %s (%s) at adminstrative request\n",
-                       nid, doomed_exp->exp_client_uuid.uuid);
-                class_fail_export(doomed_exp);
-                class_export_put(doomed_exp);
+        for (i = 0; i < num_to_evict; i++) {
                 exports_evicted++;
+                CERROR("evicting NID '%s' (%s) #%d at adminstrative request\n",
+                       nid, doomed_exp[i]->exp_client_uuid.uuid,
+                       exports_evicted);
+                class_fail_export(doomed_exp[i]);
+                class_export_put(doomed_exp[i]);
+        }
+        if (num_to_evict == EVICT_BATCH) {
+                num_to_evict = 0;
                 goto search_again;
         }
 
-out:
         if (!exports_evicted)
-                CERROR("can't disconnect %s: no exports found\n", nid);
+                CERROR("can't disconnect NID '%s': no exports found\n", nid);
         return exports_evicted;
 }
 EXPORT_SYMBOL(obd_export_evict_by_nid);
-- 
1.8.3.1