From: Alex Zhuravlev <bzzz@whamcloud.com>
Date: Thu, 2 Sep 2021 16:17:03 +0000 (+0300)
Subject: LU-14980 mdd: mdd_layout_swap() to follow tx-lock rule
X-Git-Tag: 2.15.55~87
X-Git-Url: https://git.whamcloud.com/gitweb?a=commitdiff_plain;h=refs%2Fchanges%2F24%2F44824%2F25;p=fs%2Flustre-release.git

LU-14980 mdd: mdd_layout_swap() to follow tx-lock rule

i.e. start transaction first, then take local (osd) locks
on the objects involved.

Signed-off-by: Alex Zhuravlev <bzzz@whamcloud.com>
Change-Id: I9a4add277f0911fa02d9b214e996c441d0952f9c
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/44824
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Reviewed-by: Mikhail Pershin <mpershin@whamcloud.com>
Reviewed-by: Lai Siyao <lai.siyao@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
---

diff --git a/lustre/mdd/mdd_object.c b/lustre/mdd/mdd_object.c
index 982c300..ed8120a 100644
--- a/lustre/mdd/mdd_object.c
+++ b/lustre/mdd/mdd_object.c
@@ -2485,10 +2485,6 @@ static int mdd_swap_layouts(const struct lu_env *env, struct md_object *obj1,
 	if (IS_ERR(handle))
 		RETURN(PTR_ERR(handle));
 
-	/* objects are already sorted */
-	mdd_write_lock(env, fst_o, DT_TGT_CHILD);
-	mdd_write_lock(env, snd_o, DT_TGT_CHILD);
-
 	rc = mdd_stripe_get(env, fst_o, fst_buf, XATTR_NAME_LOV);
 	if (rc < 0 && rc != -ENODATA)
 		GOTO(stop, rc);
@@ -2662,10 +2658,19 @@ static int mdd_swap_layouts(const struct lu_env *env, struct md_object *obj1,
 	if (rc != 0)
 		GOTO(stop, rc);
 
+	/* objects are already sorted */
+	mdd_write_lock(env, fst_o, DT_TGT_CHILD);
+	mdd_write_lock(env, snd_o, DT_TGT_CHILD);
+
+	if (!mdd_object_exists(fst_o))
+		GOTO(unlock, rc = -ENOENT);
+	if (!mdd_object_exists(snd_o))
+		GOTO(unlock, rc = -ENOENT);
+
 	if (flags & SWAP_LAYOUTS_MDS_HSM) {
 		rc = mdd_xattr_hsm_replace(env, fst_o, snd_hsm_buf, handle);
 		if (rc < 0)
-			GOTO(stop, rc);
+			GOTO(unlock, rc);
 
 		rc = mdd_xattr_hsm_replace(env, snd_o, fst_hsm_buf, handle);
 		if (rc < 0) {
@@ -2675,13 +2680,13 @@ static int mdd_swap_layouts(const struct lu_env *env, struct md_object *obj1,
 				CERROR("%s: HSM error restoring "DFID": rc = %d/%d\n",
 				       mdd_obj_dev_name(fst_o),
 				       PFID(mdd_object_fid(fst_o)), rc, rc2);
-			GOTO(stop, rc);
+			GOTO(unlock, rc);
 		}
 	}
 
 	rc = mdo_xattr_set(env, fst_o, snd_buf, XATTR_NAME_LOV, fst_fl, handle);
 	if (rc != 0)
-		GOTO(stop, rc);
+		GOTO(unlock, rc);
 
 	if (unlikely(OBD_FAIL_CHECK(OBD_FAIL_MDS_HSM_SWAP_LAYOUTS))) {
 		rc = -EOPNOTSUPP;
@@ -2699,12 +2704,12 @@ static int mdd_swap_layouts(const struct lu_env *env, struct md_object *obj1,
 	rc = mdd_changelog_data_store(env, mdd, CL_LAYOUT, 0, fst_o, handle,
 				      NULL);
 	if (rc)
-		GOTO(stop, rc);
+		GOTO(unlock, rc);
 
 	rc = mdd_changelog_data_store(env, mdd, CL_LAYOUT, 0, snd_o, handle,
 				      NULL);
 	if (rc)
-		GOTO(stop, rc);
+		GOTO(unlock, rc);
 	EXIT;
 
 out_restore:
@@ -2752,6 +2757,10 @@ out_restore:
 		}
 	}
 
+unlock:
+	mdd_write_unlock(env, snd_o);
+	mdd_write_unlock(env, fst_o);
+
 stop:
 	rc = mdd_trans_stop(env, mdd, rc, handle);
 
@@ -2759,9 +2768,6 @@ stop:
 	if (!rc && dom_o)
 		mdd_dom_data_truncate(env, mdd, dom_o);
 
-	mdd_write_unlock(env, snd_o);
-	mdd_write_unlock(env, fst_o);
-
 	lu_buf_free(fst_buf);
 	lu_buf_free(snd_buf);
 	lu_buf_free(fst_hsm_buf);