From 0e80dc9a2e053f9ee0c9ffe488463fee1c2b1ba4 Mon Sep 17 00:00:00 2001
From: johann <johann>
Date: Thu, 17 Sep 2009 21:01:06 +0000
Subject: [PATCH] Branch b_release_1_8_1 b=20518 i=rread i=tappro

Make sure all exports have been properly destroyed by the zombie
thread processed before stopping the target.
---
 lustre/ChangeLog           | 20 ++++++++++++++------
 lustre/include/obd_class.h |  1 +
 lustre/mds/mds_fs.c        |  6 ++++++
 lustre/obdclass/genops.c   | 31 +++++++++++++++++++++++++++++++
 lustre/obdfilter/filter.c  |  5 +++++
 5 files changed, 57 insertions(+), 6 deletions(-)

diff --git a/lustre/ChangeLog b/lustre/ChangeLog
index adb076d..c39153e 100644
--- a/lustre/ChangeLog
+++ b/lustre/ChangeLog
@@ -15,11 +15,17 @@ TBD Sun Microsystems, Inc.
 	* ext4 support for RHEL5 is experimental and thus should not be
 	  used in production.
 
+Severity   : major
+Bugzilla   : 20560
+Description: File checksum failures with OST read cache on
+Details    : Disable page poisoning when the bulk transfer has to be aborted
+	     because the client got evicted.
+
 Severity   : normal
 Bugzilla   : 19557
 Description: Don't allow make backward step on assiging osc next id.
 Details    : race between allocation next id and ll_sync thread can be cause
-             of set wrong osc next id and can be kill valid ost objects.
+	     of set wrong osc next id and can be kill valid ost objects.
 
 Severity   : enhancement
 Bugzilla   : 20400
@@ -29,11 +35,6 @@ Severity   : enhancement
 Bugzilla   : 20758
 Description: Update kernel to SLES10 SP2 2.6.16.60-0.42.4.
 
-Severity   : major
-Bugzilla   : 20560
-Description: File checksum failures with OST read cache on
-Details    : Clear page cache's uptodate bit when its contents are cleared.
-
 Severity   : normal
 Bugzilla   : 20533
 Description: Changes in raid5-large-io-rhel5.patch to calculate sectors properly
@@ -111,6 +112,13 @@ Details    : if a client doesn't respond to a blocking callback within the
 	     adaptive ldlm enqueue timeout, don't adjust the adaptive estimate
 	     when the lock is next granted.
 
+Severity   : normal
+Bugzilla   : 20518
+Description: OST is being unmounted w/o all writes to last_rcvd landing on disk.
+	     Affects recovery negatively.
+Details    : Make sure all exports have been properly destroyed by the zombie
+	     thread processed before stopping the target.
+
 
 -------------------------------------------------------------------------------
 
diff --git a/lustre/include/obd_class.h b/lustre/include/obd_class.h
index 8088f0d..35fdeb8 100644
--- a/lustre/include/obd_class.h
+++ b/lustre/include/obd_class.h
@@ -102,6 +102,7 @@ int obd_export_evict_by_uuid(struct obd_device *obd, char *uuid);
 int obd_zombie_impexp_init(void);
 void obd_zombie_impexp_stop(void);
 void obd_zombie_impexp_cull(void);
+void obd_zombie_barrier(void);
 
 /* obd_config.c */
 int class_process_config(struct lustre_cfg *lcfg);
diff --git a/lustre/mds/mds_fs.c b/lustre/mds/mds_fs.c
index a48a69c..941f7b5 100644
--- a/lustre/mds/mds_fs.c
+++ b/lustre/mds/mds_fs.c
@@ -884,6 +884,12 @@ int mds_fs_cleanup(struct obd_device *obd)
                               "will be preserved.\n", obd->obd_name);
 
         class_disconnect_exports(obd); /* cleans up client info too */
+
+       /* some exports may still be in the zombie queue, so we make sure that
+        * all the exports have been processed, otherwise the last_rcvd slot
+        * may not be updated on time */
+        obd_zombie_barrier();
+
         mds_server_free_data(mds);
 
         push_ctxt(saved, &obd->obd_lvfs_ctxt, NULL);
diff --git a/lustre/obdclass/genops.c b/lustre/obdclass/genops.c
index 9f3ae9f..b328b95 100644
--- a/lustre/obdclass/genops.c
+++ b/lustre/obdclass/genops.c
@@ -1490,6 +1490,31 @@ static void obd_zombie_impexp_notify(void)
         cfs_waitq_signal(&obd_zombie_waitq);
 }
 
+/**
+ * check whether obd_zombie is idle
+ */
+static int obd_zombie_is_idle(void)
+{
+        int rc;
+
+        LASSERT(!test_bit(OBD_ZOMBIE_STOP, &obd_zombie_flags));
+        spin_lock(&obd_zombie_impexp_lock);
+        rc = list_empty(&obd_zombie_imports) &&
+             list_empty(&obd_zombie_exports);
+        spin_unlock(&obd_zombie_impexp_lock);
+        return rc;
+}
+
+/**
+ * wait when obd_zombie import/export queues become empty
+ */
+void obd_zombie_barrier(void)
+{
+        struct l_wait_info lwi = { 0 };
+        l_wait_event(obd_zombie_waitq, obd_zombie_is_idle(), &lwi);
+}
+EXPORT_SYMBOL(obd_zombie_barrier);
+
 #ifdef __KERNEL__
 
 static int obd_zombie_impexp_thread(void *unused)
@@ -1509,6 +1534,12 @@ static int obd_zombie_impexp_thread(void *unused)
                 l_wait_event(obd_zombie_waitq, !obd_zombi_impexp_check(NULL), &lwi);
 
                 obd_zombie_impexp_cull();
+
+                /*
+                 * Notify obd_zombie_barrier callers that queues
+                 * may be empty.
+                 */
+                cfs_waitq_signal(&obd_zombie_waitq);
         }
 
         complete(&obd_zombie_stop);
diff --git a/lustre/obdfilter/filter.c b/lustre/obdfilter/filter.c
index ee6007f..3cb1d67 100644
--- a/lustre/obdfilter/filter.c
+++ b/lustre/obdfilter/filter.c
@@ -2239,6 +2239,11 @@ static int filter_cleanup(struct obd_device *obd)
                 }
         }
 
+       /* some exports may still be in the zombie queue, so we make sure that
+        * all the exports have been processed, otherwise the last_rcvd slot
+        * may not be updated on time */
+        obd_zombie_barrier();
+
         remove_proc_entry("clear", obd->obd_proc_exports_entry);
         lprocfs_free_per_client_stats(obd);
         lprocfs_free_obd_stats(obd);
-- 
1.8.3.1