From: Gregoire Pichon <gregoire.pichon@bull.net>
Date: Wed, 2 Dec 2015 10:12:31 +0000 (+0100)
Subject: LU-7430 mdt: better handle MDT recovery error path
X-Git-Tag: 2.7.65~60
X-Git-Url: https://git.whamcloud.com/?a=commitdiff_plain;h=0d3a07a8aa46bd190813b6e6e3da0e12c61a9d09;p=fs%2Flustre-release.git

LU-7430 mdt: better handle MDT recovery error path

This fix ensures the lu_target structure is still valid before
updating export related data in tgt_client_free().

In case of recovery error, it may happen that lu_target and mdt_device
structures are freed before exports are destroyed.

Signed-off-by: Gregoire Pichon <gregoire.pichon@bull.net>
Change-Id: I0559d42f40d4ecc9078717aa07b988be56ce3bc5
Reviewed-on: http://review.whamcloud.com/17424
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Mike Pershin <mike.pershin@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
---

diff --git a/lustre/target/tgt_lastrcvd.c b/lustre/target/tgt_lastrcvd.c
index 0c9cc87..1bb9b9b 100644
--- a/lustre/target/tgt_lastrcvd.c
+++ b/lustre/target/tgt_lastrcvd.c
@@ -308,7 +308,7 @@ static void tgt_free_reply_data(struct lu_target *lut,
 {
 	CDEBUG(D_TRACE, "%s: free reply data %p: xid %llu, transno %llu, "
 	       "client gen %u, slot idx %d\n",
-	       tgt_name(lut), trd, trd->trd_reply.lrd_xid,
+	       lut == NULL ? "" : tgt_name(lut), trd, trd->trd_reply.lrd_xid,
 	       trd->trd_reply.lrd_transno, trd->trd_reply.lrd_client_gen,
 	       trd->trd_index);
 
@@ -316,7 +316,8 @@ static void tgt_free_reply_data(struct lu_target *lut,
 
 	list_del(&trd->trd_list);
 	ted->ted_reply_cnt--;
-	tgt_clear_reply_slot(lut, trd->trd_index);
+	if (lut != NULL)
+		tgt_clear_reply_slot(lut, trd->trd_index);
 	OBD_FREE_PTR(trd);
 }
 
@@ -331,7 +332,7 @@ static void tgt_release_reply_data(struct lu_target *lut,
 {
 	CDEBUG(D_TRACE, "%s: release reply data %p: xid %llu, transno %llu, "
 	       "client gen %u, slot idx %d\n",
-	       tgt_name(lut), trd, trd->trd_reply.lrd_xid,
+	       lut == NULL ? "" : tgt_name(lut), trd, trd->trd_reply.lrd_xid,
 	       trd->trd_reply.lrd_transno, trd->trd_reply.lrd_client_gen,
 	       trd->trd_index);
 
@@ -418,9 +419,12 @@ void tgt_client_free(struct obd_export *exp)
 	OBD_FREE_PTR(ted->ted_lcd);
 	ted->ted_lcd = NULL;
 
-	/* Slot may be not yet assigned */
-	if (ted->ted_lr_idx < 0)
+	/* Target may have been freed (see LU-7430)
+	 * Slot may be not yet assigned */
+	if (exp->exp_obd->u.obt.obt_magic != OBT_MAGIC ||
+	    ted->ted_lr_idx < 0)
 		return;
+
 	/* Clear bit when lcd is freed */
 	LASSERT(lut && lut->lut_client_bitmap);
 	if (!test_and_clear_bit(ted->ted_lr_idx, lut->lut_client_bitmap)) {
diff --git a/lustre/target/tgt_main.c b/lustre/target/tgt_main.c
index 18574e9..0f0fcd3 100644
--- a/lustre/target/tgt_main.c
+++ b/lustre/target/tgt_main.c
@@ -151,6 +151,8 @@ int tgt_init(const struct lu_env *env, struct lu_target *lut,
 out:
 	dt_txn_callback_del(lut->lut_bottom, &lut->lut_txn_cb);
 out_put:
+	obd->u.obt.obt_magic = 0;
+	obd->u.obt.obt_lut = NULL;
 	if (lut->lut_last_rcvd != NULL) {
 		lu_object_put(env, &lut->lut_last_rcvd->do_lu);
 		lut->lut_last_rcvd = NULL;