LU-4721 obdclass: handle local storage init/fini properly

[fs/lustre-release.git] / lustre / obdclass / local_storage.c

diff --git a/lustre/obdclass/local_storage.c b/lustre/obdclass/local_storage.c
index f0856c2..fd9f352 100644 (file)
--- a/lustre/obdclass/local_storage.c
+++ b/lustre/obdclass/local_storage.c
@@ -695,17 +695,13 @@ int lastid_compat_check(const struct lu_env *env, struct dt_device *dev,
        rc = dt_lookup_dir(env, root, dti->dti_buf, &dti->dti_fid);
        lu_object_put_nocache(env, &root->do_lu);
        if (rc == -ENOENT) {
-               struct lu_object_conf *conf = &dti->dti_conf;
-
                /* old llog lastid accessed by FID only */
                if (lastid_seq != FID_SEQ_LLOG)
                        return 0;
                dti->dti_fid.f_seq = FID_SEQ_LLOG;
                dti->dti_fid.f_oid = 1;
                dti->dti_fid.f_ver = 0;
-               memset(conf, 0, sizeof(*conf));
-               conf->loc_flags = LOC_F_NEW;
-               o = ls_locate(env, ls, &dti->dti_fid, conf);
+               o = ls_locate(env, ls, &dti->dti_fid, NULL);
                if (IS_ERR(o))
                        return PTR_ERR(o);
 
@@ -731,18 +727,18 @@ int lastid_compat_check(const struct lu_env *env, struct dt_device *dev,
        dt_read_lock(env, o, 0);
        rc = dt_record_read(env, o, &dti->dti_lb, &dti->dti_off);
        dt_read_unlock(env, o);
-       lu_object_put_nocache(env, &o->do_lu);
        if (rc == 0 && le32_to_cpu(losd.lso_magic) != LOS_MAGIC) {
                CERROR("%s: wrong content of seq-"LPX64"-lastid file, magic %x\n",
                       o->do_lu.lo_dev->ld_obd->obd_name, lastid_seq,
                       le32_to_cpu(losd.lso_magic));
-               return -EINVAL;
+               rc = -EINVAL;
        } else if (rc < 0) {
                CERROR("%s: failed to read seq-"LPX64"-lastid: rc = %d\n",
                       o->do_lu.lo_dev->ld_obd->obd_name, lastid_seq, rc);
-               return rc;
        }
-       *first_oid = le32_to_cpu(losd.lso_next_oid);
+       lu_object_put_nocache(env, &o->do_lu);
+       if (rc == 0)
+               *first_oid = le32_to_cpu(losd.lso_next_oid);
        return rc;
 }
 
@@ -897,19 +893,18 @@ out:
 EXPORT_SYMBOL(local_oid_storage_init);
 
 void local_oid_storage_fini(const struct lu_env *env,
-                            struct local_oid_storage *los)
+                           struct local_oid_storage *los)
 {
        struct ls_device *ls;
 
-       if (!atomic_dec_and_test(&los->los_refcount))
-               return;
-
        LASSERT(env);
        LASSERT(los->los_dev);
        ls = dt2ls_dev(los->los_dev);
 
+       /* Take the mutex before decreasing the reference to avoid race
+        * conditions as described in LU-4721. */
        mutex_lock(&ls->ls_los_mutex);
-       if (atomic_read(&los->los_refcount) > 0) {
+       if (!atomic_dec_and_test(&los->los_refcount)) {
                mutex_unlock(&ls->ls_los_mutex);
                return;
        }