b=20530

i=johann
i=tianzy

In quota slaves, quota_chk_acq_common() shouldn't retry indefinitely
if relative clients are evicted or reconnect already.

diff --git a/lustre/cmm/cmm_device.c b/lustre/cmm/cmm_device.c
index deda49e..8867fd8 100644 (file)
--- a/lustre/cmm/cmm_device.c
+++ b/lustre/cmm/cmm_device.c
@@ -190,7 +190,7 @@ static int cmm_quota_recovery(const struct lu_env *env, struct md_device *m)
 }
 
 static int cmm_quota_check(const struct lu_env *env, struct md_device *m,
-                           struct obd_export *exp, __u32 type)
+                           __u32 type)
 {
         struct cmm_device *cmm_dev = md2cmm_dev(m);
         int rc;
@@ -202,7 +202,7 @@ static int cmm_quota_check(const struct lu_env *env, struct md_device *m,
 
         rc = cmm_child_ops(cmm_dev)->mdo_quota.mqo_check(env,
                                                          cmm_dev->cmm_child,
-                                                         exp, type);
+                                                         type);
         RETURN(rc);
 }
 

diff --git a/lustre/include/lustre_quota.h b/lustre/include/lustre_quota.h
index 7179ed8..5331f7c 100644 (file)
--- a/lustre/include/lustre_quota.h
+++ b/lustre/include/lustre_quota.h
@@ -526,10 +526,10 @@ typedef struct {
          * can finish a block_write or inode_create rpc. It updates the pending
          * record of block and inode, acquires quota if necessary
          */
-        int (*quota_chkquota) (struct obd_device *, const unsigned int [],
-                               int [], int, quota_acquire,
-                               struct obd_trans_info *, int, struct inode *,
-                               int);
+        int (*quota_chkquota) (struct obd_device *, struct obd_export *,
+                               const unsigned int [], int [],
+                               int, quota_acquire, struct obd_trans_info *,
+                               int, struct inode *, int);
 
         /**
          * For quota client, the actions after the pending write is committed
@@ -765,6 +765,7 @@ static inline int lquota_getflag(quota_interface_t *interface,
 #ifdef __KERNEL__
 static inline int lquota_chkquota(quota_interface_t *interface,
                                   struct obd_device *obd,
+                                  struct obd_export *exp,
                                   const unsigned int id[], int pending[],
                                   int count, struct obd_trans_info *oti,
                                   int isblk, void *data, int frags)
@@ -774,7 +775,7 @@ static inline int lquota_chkquota(quota_interface_t *interface,
 
         QUOTA_CHECK_OP(interface, chkquota);
         QUOTA_CHECK_OP(interface, acquire);
-        rc = QUOTA_OP(interface, chkquota)(obd, id, pending, count,
+        rc = QUOTA_OP(interface, chkquota)(obd, exp, id, pending, count,
                                            QUOTA_OP(interface, acquire), oti,
                                            isblk, (struct inode *)data, frags);
         RETURN(rc);

diff --git a/lustre/include/md_object.h b/lustre/include/md_object.h
index 6f818b5..bfa7de4 100644 (file)
--- a/lustre/include/md_object.h
+++ b/lustre/include/md_object.h
@@ -101,6 +101,10 @@ struct md_capainfo {
         struct lustre_capa     *mc_capa[MD_CAPAINFO_MAX];
 };
 
+struct md_quota {
+        struct obd_export       *mq_exp;
+};
+
 /**
  * Implemented in mdd/mdd_handler.c.
  *
@@ -109,6 +113,7 @@ struct md_capainfo {
  */
 struct md_ucred *md_ucred(const struct lu_env *env);
 struct md_capainfo *md_capainfo(const struct lu_env *env);
+struct md_quota *md_quota(const struct lu_env *env);
 
 /** metadata attributes */
 enum ma_valid {
@@ -352,7 +357,6 @@ struct md_device_operations {
 
                 int (*mqo_check)(const struct lu_env *env,
                                  struct md_device *m,
-                                 struct obd_export *exp,
                                  __u32 type);
 
                 int (*mqo_on)(const struct lu_env *env,

diff --git a/lustre/mdd/mdd_device.c b/lustre/mdd/mdd_device.c
index 48da062..7dc67d1 100644 (file)
--- a/lustre/mdd/mdd_device.c
+++ b/lustre/mdd/mdd_device.c
@@ -1270,6 +1270,25 @@ struct md_capainfo *md_capainfo(const struct lu_env *env)
 }
 EXPORT_SYMBOL(md_capainfo);
 
+/*
+ * context key constructor/destructor:
+ * mdd_quota_key_init, mdd_quota_key_fini
+ */
+LU_KEY_INIT_FINI(mdd_quota, struct md_quota);
+
+struct lu_context_key mdd_quota_key = {
+        .lct_tags = LCT_SESSION,
+        .lct_init = mdd_quota_key_init,
+        .lct_fini = mdd_quota_key_fini
+};
+
+struct md_quota *md_quota(const struct lu_env *env)
+{
+        LASSERT(env->le_ses != NULL);
+        return lu_context_key_get(env->le_ses, &mdd_quota_key);
+}
+EXPORT_SYMBOL(md_quota);
+
 static int mdd_changelog_user_register(struct mdd_device *mdd, int *id)
 {
         struct llog_ctxt *ctxt;
@@ -1491,7 +1510,8 @@ static int mdd_iocontrol(const struct lu_env *env, struct md_device *m,
 }
 
 /* type constructor/destructor: mdd_type_init, mdd_type_fini */
-LU_TYPE_INIT_FINI(mdd, &mdd_thread_key, &mdd_ucred_key, &mdd_capainfo_key);
+LU_TYPE_INIT_FINI(mdd, &mdd_thread_key, &mdd_ucred_key, &mdd_capainfo_key,
+                  &mdd_quota_key);
 
 const struct md_device_operations mdd_ops = {
         .mdo_statfs         = mdd_statfs,

diff --git a/lustre/mdd/mdd_dir.c b/lustre/mdd/mdd_dir.c
index e053f61..fb0c0f3 100644 (file)
--- a/lustre/mdd/mdd_dir.c
+++ b/lustre/mdd/mdd_dir.c
@@ -680,6 +680,7 @@ static int mdd_link(const struct lu_env *env, struct md_object *tgt_obj,
         struct thandle *handle;
 #ifdef HAVE_QUOTA_SUPPORT
         struct obd_device *obd = mdd->mdd_obd_dev;
+        struct obd_export *exp = md_quota(env)->mq_exp;
         struct mds_obd *mds = &obd->u.mds;
         unsigned int qids[MAXQUOTAS] = { 0, 0 };
         int quota_opc = 0, rec_pending[MAXQUOTAS] = { 0, 0 };
@@ -698,7 +699,7 @@ static int mdd_link(const struct lu_env *env, struct md_object *tgt_obj,
                         quota_opc = FSFILT_OP_LINK;
                         mdd_quota_wrapper(la_tmp, qids);
                         /* get block quota for parent */
-                        lquota_chkquota(mds_quota_interface_ref, obd,
+                        lquota_chkquota(mds_quota_interface_ref, obd, exp,
                                         qids, rec_pending, 1, NULL,
                                         LQUOTA_FLAGS_BLK, data, 1);
                 }
@@ -966,6 +967,7 @@ static int mdd_name_insert(const struct lu_env *env,
 #ifdef HAVE_QUOTA_SUPPORT
         struct md_ucred *uc = md_ucred(env);
         struct obd_device *obd = mdd->mdd_obd_dev;
+        struct obd_export *exp = md_quota(env)->mq_exp;
         struct mds_obd *mds = &obd->u.mds;
         unsigned int qids[MAXQUOTAS] = { 0, 0 };
         int quota_opc = 0, rec_pending[MAXQUOTAS] = { 0, 0 };
@@ -987,7 +989,7 @@ static int mdd_name_insert(const struct lu_env *env,
                                 mdd_quota_wrapper(la_tmp, qids);
                                 /* get block quota for parent */
                                 lquota_chkquota(mds_quota_interface_ref, obd,
-                                                qids, rec_pending, 1, NULL,
+                                                exp, qids, rec_pending, 1, NULL,
                                                 LQUOTA_FLAGS_BLK, data, 1);
                         }
                 } else {
@@ -1189,6 +1191,7 @@ static int mdd_rename_tgt(const struct lu_env *env,
         struct thandle *handle;
 #ifdef HAVE_QUOTA_SUPPORT
         struct obd_device *obd = mdd->mdd_obd_dev;
+        struct obd_export *exp = md_quota(env)->mq_exp;
         struct mds_obd *mds = &obd->u.mds;
         unsigned int qcids[MAXQUOTAS] = { 0, 0 };
         unsigned int qpids[MAXQUOTAS] = { 0, 0 };
@@ -1209,7 +1212,7 @@ static int mdd_rename_tgt(const struct lu_env *env,
                         quota_popc = FSFILT_OP_LINK;
                         mdd_quota_wrapper(la_tmp, qpids);
                         /* get block quota for target parent */
-                        lquota_chkquota(mds_quota_interface_ref, obd,
+                        lquota_chkquota(mds_quota_interface_ref, obd, exp,
                                         qpids, rec_pending, 1, NULL,
                                         LQUOTA_FLAGS_BLK, data, 1);
                 }
@@ -1587,6 +1590,7 @@ static int mdd_create(const struct lu_env *env,
         int got_def_acl = 0;
 #ifdef HAVE_QUOTA_SUPPORT
         struct obd_device *obd = mdd->mdd_obd_dev;
+        struct obd_export *exp = md_quota(env)->mq_exp;
         struct mds_obd *mds = &obd->u.mds;
         unsigned int qcids[MAXQUOTAS] = { 0, 0 };
         unsigned int qpids[MAXQUOTAS] = { 0, 0 };
@@ -1650,8 +1654,9 @@ static int mdd_create(const struct lu_env *env,
                         mdd_quota_wrapper(&ma->ma_attr, qcids);
                         mdd_quota_wrapper(la_tmp, qpids);
                         /* get file quota for child */
-                        lquota_chkquota(mds_quota_interface_ref, obd, qcids,
-                                        inode_pending, 1, NULL, 0, NULL, 0);
+                        lquota_chkquota(mds_quota_interface_ref, obd, exp,
+                                        qcids, inode_pending, 1, NULL, 0, NULL,
+                                        0);
                         switch (ma->ma_attr.la_mode & S_IFMT) {
                         case S_IFLNK:
                         case S_IFDIR:
@@ -1669,13 +1674,14 @@ static int mdd_create(const struct lu_env *env,
                         /* get block quota for child and parent */
                         if (block_count)
                                 lquota_chkquota(mds_quota_interface_ref, obd,
-                                                qcids, block_pending,
+                                                exp, qcids, block_pending,
                                                 block_count, NULL,
                                                 LQUOTA_FLAGS_BLK, NULL, 0);
                         if (!same)
                                 lquota_chkquota(mds_quota_interface_ref, obd,
-                                                qpids, parent_pending, 1, NULL,
-                                                LQUOTA_FLAGS_BLK, NULL, 0);
+                                                exp, qpids, parent_pending, 1,
+                                                NULL, LQUOTA_FLAGS_BLK, NULL,
+                                                0);
                 }
         }
 #endif
@@ -1967,6 +1973,7 @@ static int mdd_rename(const struct lu_env *env,
 
 #ifdef HAVE_QUOTA_SUPPORT
         struct obd_device *obd = mdd->mdd_obd_dev;
+        struct obd_export *exp = md_quota(env)->mq_exp;
         struct mds_obd *mds = &obd->u.mds;
         unsigned int qspids[MAXQUOTAS] = { 0, 0 };
         unsigned int qtcids[MAXQUOTAS] = { 0, 0 };
@@ -1999,7 +2006,7 @@ static int mdd_rename(const struct lu_env *env,
                                         mdd_quota_wrapper(la_tmp, qtpids);
                                         /* get block quota for target parent */
                                         lquota_chkquota(mds_quota_interface_ref,
-                                                        obd, qtpids,
+                                                        obd, exp, qtpids,
                                                         rec_pending, 1, NULL,
                                                         LQUOTA_FLAGS_BLK,
                                                         data, 1);

diff --git a/lustre/mdd/mdd_internal.h b/lustre/mdd/mdd_internal.h
index 65ee175..2b79611 100644 (file)
--- a/lustre/mdd/mdd_internal.h
+++ b/lustre/mdd/mdd_internal.h
@@ -387,7 +387,7 @@ int mdd_quota_setup(const struct lu_env *env, struct md_device *m,
 int mdd_quota_cleanup(const struct lu_env *env, struct md_device *m);
 int mdd_quota_recovery(const struct lu_env *env, struct md_device *m);
 int mdd_quota_check(const struct lu_env *env, struct md_device *m,
-                    struct obd_export *exp, __u32 type);
+                    __u32 type);
 int mdd_quota_on(const struct lu_env *env, struct md_device *m,
                  __u32 type);
 int mdd_quota_off(const struct lu_env *env, struct md_device *m,

diff --git a/lustre/mdd/mdd_object.c b/lustre/mdd/mdd_object.c
index 29a6d79..55b9f7b 100644 (file)
--- a/lustre/mdd/mdd_object.c
+++ b/lustre/mdd/mdd_object.c
@@ -1229,6 +1229,7 @@ static int mdd_attr_set(const struct lu_env *env, struct md_object *obj,
         struct lu_attr *la_copy = &mdd_env_info(env)->mti_la_for_fix;
 #ifdef HAVE_QUOTA_SUPPORT
         struct obd_device *obd = mdd->mdd_obd_dev;
+        struct obd_export *exp = md_quota(env)->mq_exp;
         struct mds_obd *mds = &obd->u.mds;
         unsigned int qnids[MAXQUOTAS] = { 0, 0 };
         unsigned int qoids[MAXQUOTAS] = { 0, 0 };
@@ -1278,15 +1279,16 @@ static int mdd_attr_set(const struct lu_env *env, struct md_object *obj,
                         mdd_quota_wrapper(la_copy, qnids);
                         mdd_quota_wrapper(la_tmp, qoids);
                         /* get file quota for new owner */
-                        lquota_chkquota(mds_quota_interface_ref, obd, qnids,
-                                        inode_pending, 1, NULL, 0, NULL, 0);
+                        lquota_chkquota(mds_quota_interface_ref, obd, exp,
+                                        qnids, inode_pending, 1, NULL, 0,
+                                        NULL, 0);
                         block_count = (la_tmp->la_blocks + 7) >> 3;
                         if (block_count) {
                                 void *data = NULL;
                                 mdd_data_get(env, mdd_obj, &data);
                                 /* get block quota for new owner */
                                 lquota_chkquota(mds_quota_interface_ref, obd,
-                                                qnids, block_pending,
+                                                exp, qnids, block_pending,
                                                 block_count, NULL,
                                                 LQUOTA_FLAGS_BLK, data, 1);
                         }
@@ -1585,6 +1587,7 @@ static int mdd_object_create(const struct lu_env *env,
         struct thandle *handle;
 #ifdef HAVE_QUOTA_SUPPORT
         struct obd_device *obd = mdd->mdd_obd_dev;
+        struct obd_export *exp = md_quota(env)->mq_exp;
         struct mds_obd *mds = &obd->u.mds;
         unsigned int qids[MAXQUOTAS] = { 0, 0 };
         int quota_opc = 0, block_count = 0;
@@ -1599,8 +1602,9 @@ static int mdd_object_create(const struct lu_env *env,
                 quota_opc = FSFILT_OP_CREATE_PARTIAL_CHILD;
                 mdd_quota_wrapper(&ma->ma_attr, qids);
                 /* get file quota for child */
-                lquota_chkquota(mds_quota_interface_ref, obd, qids,
-                                inode_pending, 1, NULL, 0, NULL, 0);
+                lquota_chkquota(mds_quota_interface_ref, obd, exp,
+                                qids, inode_pending, 1, NULL, 0,
+                                NULL, 0);
                 switch (ma->ma_attr.la_mode & S_IFMT) {
                 case S_IFLNK:
                 case S_IFDIR:
@@ -1612,9 +1616,9 @@ static int mdd_object_create(const struct lu_env *env,
                 }
                 /* get block quota for child */
                 if (block_count)
-                        lquota_chkquota(mds_quota_interface_ref, obd, qids,
-                                        block_pending, block_count, NULL,
-                                        LQUOTA_FLAGS_BLK, NULL, 0);
+                        lquota_chkquota(mds_quota_interface_ref, obd, exp,
+                                        qids, block_pending, block_count,
+                                        NULL, LQUOTA_FLAGS_BLK, NULL, 0);
         }
 #endif
 

diff --git a/lustre/mdd/mdd_quota.c b/lustre/mdd/mdd_quota.c
index d246a07..0601b2e 100644 (file)
--- a/lustre/mdd/mdd_quota.c
+++ b/lustre/mdd/mdd_quota.c
@@ -93,10 +93,11 @@ int mdd_quota_recovery(const struct lu_env *env, struct md_device *m)
 }
 
 int mdd_quota_check(const struct lu_env *env, struct md_device *m,
-                    struct obd_export *exp, __u32 type)
+                    __u32 type)
 {
         struct mdd_device *mdd = lu2mdd_dev(&m->md_lu_dev);
         struct obd_device *obd = mdd->mdd_obd_dev;
+        struct obd_export *exp = md_quota(env)->mq_exp;
         struct obd_quotactl *oqctl = &mdd_env_info(env)->mti_oqctl;
         int rc;
         ENTRY;

diff --git a/lustre/mdt/mdt_handler.c b/lustre/mdt/mdt_handler.c
index 436523c..760b0cb 100644 (file)
--- a/lustre/mdt/mdt_handler.c
+++ b/lustre/mdt/mdt_handler.c
@@ -1490,6 +1490,7 @@ static int mdt_reint_internal(struct mdt_thread_info *info,
 {
         struct req_capsule      *pill = info->mti_pill;
         struct mdt_device       *mdt = info->mti_mdt;
+        struct md_quota         *mq = md_quota(info->mti_env);
         struct mdt_body         *repbody;
         int                      rc = 0;
         ENTRY;
@@ -1548,6 +1549,7 @@ static int mdt_reint_internal(struct mdt_thread_info *info,
                 rc = lustre_msg_get_status(mdt_info_req(info)->rq_repmsg);
                 GOTO(out_ucred, rc);
         }
+        mq->mq_exp = info->mti_exp;
         rc = mdt_reint_rec(info, lhc);
         EXIT;
 out_ucred:
@@ -1697,6 +1699,7 @@ static int mdt_quotacheck_handle(struct mdt_thread_info *info)
         struct obd_quotactl *oqctl;
         struct req_capsule *pill = info->mti_pill;
         struct obd_export *exp = info->mti_exp;
+        struct md_quota *mq = md_quota(info->mti_env);
         struct md_device *next = info->mti_mdt->mdt_child;
         int rc;
         ENTRY;
@@ -1713,7 +1716,8 @@ static int mdt_quotacheck_handle(struct mdt_thread_info *info)
         if (rc)
                 RETURN(rc);
 
-        rc = next->md_ops->mdo_quota.mqo_check(info->mti_env, next, exp,
+        mq->mq_exp = exp;
+        rc = next->md_ops->mdo_quota.mqo_check(info->mti_env, next,
                                                oqctl->qc_type);
         RETURN(rc);
 }
@@ -1723,6 +1727,7 @@ static int mdt_quotactl_handle(struct mdt_thread_info *info)
         struct obd_quotactl *oqctl, *repoqc;
         struct req_capsule *pill = info->mti_pill;
         struct obd_export *exp = info->mti_exp;
+        struct md_quota *mq = md_quota(info->mti_env);
         struct md_device *next = info->mti_mdt->mdt_child;
         const struct md_quota_operations *mqo = &next->md_ops->mdo_quota;
         int id, rc;
@@ -1766,6 +1771,7 @@ static int mdt_quotactl_handle(struct mdt_thread_info *info)
         repoqc = req_capsule_server_get(pill, &RMF_OBD_QUOTACTL);
         LASSERT(repoqc != NULL);
 
+        mq->mq_exp = exp;
         switch (oqctl->qc_cmd) {
         case Q_QUOTAON:
                 rc = mqo->mqo_on(info->mti_env, next, oqctl->qc_type);

diff --git a/lustre/obdfilter/filter_io_26.c b/lustre/obdfilter/filter_io_26.c
index 56547b3..72e0d65 100644 (file)
--- a/lustre/obdfilter/filter_io_26.c
+++ b/lustre/obdfilter/filter_io_26.c
@@ -644,10 +644,11 @@ int filter_commitrw_write(struct obd_export *exp, struct obdo *oa,
 
         /* we try to get enough quota to write here, and let ldiskfs
          * decide if it is out of quota or not b=14783 */
-        lquota_chkquota(filter_quota_interface_ref, obd, qcids, rec_pending,
-                        quota_pages, oti, LQUOTA_FLAGS_BLK, (void *)inode,
-                        obj->ioo_bufcnt);
-
+        rc = lquota_chkquota(filter_quota_interface_ref, obd, exp, qcids,
+                             rec_pending, quota_pages, oti, LQUOTA_FLAGS_BLK,
+                             (void *)inode, obj->ioo_bufcnt);
+        if (rc == -ENOTCONN)
+                GOTO(cleanup, rc);
 
         push_ctxt(&saved, &obd->obd_lvfs_ctxt, NULL);
         cleanup_phase = 2;

diff --git a/lustre/ost/ost_handler.c b/lustre/ost/ost_handler.c
index 46c5996..2ee5f2b 100644 (file)
--- a/lustre/ost/ost_handler.c
+++ b/lustre/ost/ost_handler.c
@@ -1086,6 +1086,12 @@ static int ost_brw_write(struct ptlrpc_request *req, struct obd_trans_info *oti)
         /* Must commit after prep above in all cases */
         rc = obd_commitrw(OBD_BRW_WRITE, exp, &repbody->oa, objcount, ioo,
                           remote_nb, npages, local_nb, oti, rc);
+        if (rc == -ENOTCONN)
+                /* quota acquire process has been given up because
+                 * either the client has been evicted or the client
+                 * has timed out the request already */
+                no_reply = 1;
+
         if (exp_connect_rmtclient(exp)) {
                 repbody->oa.o_uid = o_uid;
                 repbody->oa.o_gid = o_gid;

diff --git a/lustre/quota/quota_interface.c b/lustre/quota/quota_interface.c
index 3c3b16f..cc103d1 100644 (file)
--- a/lustre/quota/quota_interface.c
+++ b/lustre/quota/quota_interface.c
@@ -396,8 +396,9 @@ int quota_is_set(struct obd_device *obd, const unsigned int id[], int flag)
         return q_set;
 }
 
-static int quota_chk_acq_common(struct obd_device *obd, const unsigned int id[],
-                                int pending[], int count, quota_acquire acquire,
+static int quota_chk_acq_common(struct obd_device *obd, struct obd_export *exp,
+                                const unsigned int id[], int pending[],
+                                int count, quota_acquire acquire,
                                 struct obd_trans_info *oti, int isblk,
                                 struct inode *inode, int frags)
 {
@@ -412,6 +413,12 @@ static int quota_chk_acq_common(struct obd_device *obd, const unsigned int id[],
         if (!quota_is_set(obd, id, isblk ? QB_SET : QI_SET))
                 RETURN(0);
 
+        if (isblk && (exp->exp_failed || exp->exp_abort_active_req))
+                /* If the client has been evicted or if it
+                 * timed out and tried to reconnect already,
+                 * abort the request immediately */
+                RETURN(-ENOTCONN);
+
         CDEBUG(D_QUOTA, "check quota for %s\n", obd->obd_name);
         pending[USRQUOTA] = pending[GRPQUOTA] = 0;
         /* Unfortunately, if quota master is too busy to handle the
@@ -468,6 +475,11 @@ static int quota_chk_acq_common(struct obd_device *obd, const unsigned int id[],
                         break;
                 }
 
+                if (isblk && (exp->exp_failed || exp->exp_abort_active_req))
+                        /* The client has been evicted or tried to
+                         * to reconnect already, abort the request */
+                        RETURN(-ENOTCONN);
+
                 /* -EBUSY and others, wait a second and try again */
                 if (rc < 0) {
                         cfs_waitq_t        waitq;
@@ -511,6 +523,8 @@ static int quota_chk_acq_common(struct obd_device *obd, const unsigned int id[],
                                     LQUOTA_WAIT_FOR_CHK_INO,
                             timediff);
 
+        if (rc > 0)
+                rc = 0;
         RETURN(rc);
 }
 

diff --git a/lustre/tests/sanity-quota.sh b/lustre/tests/sanity-quota.sh
index fe14e19..84f6679 100644 (file)
--- a/lustre/tests/sanity-quota.sh
+++ b/lustre/tests/sanity-quota.sh
@@ -338,8 +338,10 @@ test_1_sub() {
        $RUNAS dd if=/dev/zero of=$TESTFILE bs=$BLK_SZ count=$(($LIMIT/2)) || quota_error g $TSTUSR "(grp) write failure, but expect success"
         etime=`date +%s`
         delta=$((etime - stime))
-        rate=$((BLK_SZ * LIMIT / 2 / delta / 1024))
-        [ $rate -gt 1024 ] || error "SLOW IO for $TSTUSR (group): $rate KB/sec"
+        if [ $delta -gt 0 ]; then
+               rate=$((BLK_SZ * LIMIT / 2 / delta / 1024))
+               [ $rate -gt 1024 ] || error "SLOW IO for $TSTUSR (group): $rate KB/sec"
+       fi
         log "    Done"
         log "    Write out of block quota ..."
        # this time maybe cache write, ignore it's failure