LU-14621 mdd: fix lock-tx order in mdd_xattr_merge()

to follow common transaction-first-then-locks rule.

Signed-off-by: Alex Zhuravlev <bzzz@whamcloud.com>
Change-Id: I437c919e498781b8d5dc653bf90aac799df4882a
Reviewed-on: https://review.whamcloud.com/43366
Reviewed-by: Bobi Jam <bobijam@hotmail.com>
Reviewed-by: Lai Siyao <lai.siyao@whamcloud.com>
Reviewed-by: Mike Pershin <mpershin@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>

diff --git a/lustre/mdd/mdd_object.c b/lustre/mdd/mdd_object.c
index 77bf9a7..3a74d17 100644 (file)
--- a/lustre/mdd/mdd_object.c
+++ b/lustre/mdd/mdd_object.c
@@ -1546,58 +1546,58 @@ static int mdd_xattr_merge(const struct lu_env *env, struct md_object *md_obj,
        struct lu_buf *buf_vic = &mdd_env_info(env)->mdi_buf[1];
        struct lov_mds_md *lmm;
        struct thandle *handle;
-       int rc;
+       int rc, lock_order;
        ENTRY;
 
-       rc = lu_fid_cmp(mdd_object_fid(obj), mdd_object_fid(vic));
-       if (rc == 0) /* same fid */
+       lock_order = lu_fid_cmp(mdd_object_fid(obj), mdd_object_fid(vic));
+       if (lock_order == 0) /* same fid */
                RETURN(-EPERM);
 
        handle = mdd_trans_create(env, mdd);
        if (IS_ERR(handle))
                RETURN(PTR_ERR(handle));
 
-       if (rc > 0) {
-               mdd_write_lock(env, obj, DT_TGT_CHILD);
-               mdd_write_lock(env, vic, DT_TGT_CHILD);
-       } else {
-               mdd_write_lock(env, vic, DT_TGT_CHILD);
-               mdd_write_lock(env, obj, DT_TGT_CHILD);
-       }
-
        /* get EA of victim file */
        memset(buf_vic, 0, sizeof(*buf_vic));
        rc = mdd_stripe_get(env, vic, buf_vic, XATTR_NAME_LOV);
        if (rc < 0) {
                if (rc == -ENODATA)
                        rc = 0;
-               GOTO(out, rc);
+               GOTO(stop, rc);
        }
 
        /* parse the layout of victim file */
        lmm = buf_vic->lb_buf;
        if (le32_to_cpu(lmm->lmm_magic) != LOV_MAGIC_COMP_V1)
-               GOTO(out, rc = -EINVAL);
+               GOTO(stop, rc = -EINVAL);
 
        /* save EA of target file for restore */
        memset(buf, 0, sizeof(*buf));
        rc = mdd_stripe_get(env, obj, buf, XATTR_NAME_LOV);
        if (rc < 0)
-               GOTO(out, rc);
+               GOTO(stop, rc);
 
        /* Get rid of the layout from victim object */
        rc = mdd_declare_xattr_del(env, mdd, vic, XATTR_NAME_LOV, handle);
        if (rc)
-               GOTO(out, rc);
+               GOTO(stop, rc);
 
        rc = mdd_declare_xattr_set(env, mdd, obj, buf_vic, XATTR_NAME_LOV,
                                   LU_XATTR_MERGE, handle);
        if (rc)
-               GOTO(out, rc);
+               GOTO(stop, rc);
 
        rc = mdd_trans_start(env, mdd, handle);
        if (rc != 0)
-               GOTO(out, rc);
+               GOTO(stop, rc);
+
+       if (lock_order > 0) {
+               mdd_write_lock(env, obj, DT_TGT_CHILD);
+               mdd_write_lock(env, vic, DT_TGT_CHILD);
+       } else {
+               mdd_write_lock(env, vic, DT_TGT_CHILD);
+               mdd_write_lock(env, obj, DT_TGT_CHILD);
+       }
 
        rc = mdo_xattr_set(env, obj, buf_vic, XATTR_NAME_LOV, LU_XATTR_MERGE,
                           handle);
@@ -1625,9 +1625,10 @@ out_restore:
        }
 
 out:
-       mdd_trans_stop(env, mdd, rc, handle);
        mdd_write_unlock(env, obj);
        mdd_write_unlock(env, vic);
+stop:
+       mdd_trans_stop(env, mdd, rc, handle);
        lu_buf_free(buf);
        lu_buf_free(buf_vic);