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LU-15132 hsm: Protect against parallel HSM restore requests
[fs/lustre-release.git] / lustre / mdt / mdt_coordinator.c
index 53abb99..b321d94 100644 (file)
@@ -23,7 +23,7 @@
  * Copyright (c) 2011, 2012 Commissariat a l'energie atomique et aux energies
  *                          alternatives
  *
- * Copyright (c) 2013, 2016, Intel Corporation.
+ * Copyright (c) 2013, 2017, Intel Corporation.
  * Use is subject to license terms.
  */
 /*
@@ -47,8 +47,6 @@
 #include <lustre_kernelcomm.h>
 #include "mdt_internal.h"
 
-static struct lprocfs_vars lprocfs_mdt_hsm_vars[];
-
 /**
  * get obj and HSM attributes on a fid
  * \param mti [IN] context
@@ -101,21 +99,21 @@ void mdt_hsm_dump_hal(int level, const char *prefix,
        struct hsm_action_item  *hai;
        char                     buf[12];
 
-       CDEBUG(level, "%s: HAL header: version %X count %d compound %#llx"
+       CDEBUG(level, "%s: HAL header: version %X count %d"
                      " archive_id %d flags %#llx\n",
               prefix, hal->hal_version, hal->hal_count,
-              hal->hal_compound_id, hal->hal_archive_id, hal->hal_flags);
+              hal->hal_archive_id, hal->hal_flags);
 
        hai = hai_first(hal);
        for (i = 0; i < hal->hal_count; i++) {
                sz = hai->hai_len - sizeof(*hai);
                CDEBUG(level, "%s %d: fid="DFID" dfid="DFID
-                      " compound/cookie=%#llx/%#llx"
+                      " cookie=%#llx"
                       " action=%s extent=%#llx-%#llx gid=%#llx"
                       " datalen=%d data=[%s]\n",
                       prefix, i,
                       PFID(&hai->hai_fid), PFID(&hai->hai_dfid),
-                      hal->hal_compound_id, hai->hai_cookie,
+                      hai->hai_cookie,
                       hsm_copytool_action2name(hai->hai_action),
                       hai->hai_extent.offset,
                       hai->hai_extent.length,
@@ -136,69 +134,276 @@ struct hsm_scan_request {
 };
 
 struct hsm_scan_data {
-       struct mdt_thread_info          *mti;
-       char                             fs_name[MTI_NAME_MAXLEN+1];
+       struct mdt_thread_info  *hsd_mti;
+       char                     hsd_fsname[MTI_NAME_MAXLEN + 1];
        /* are we scanning the logs for housekeeping, or just looking
         * for new work?
         */
-       bool                             housekeeping;
-       /* request to be send to agents */
-       int                              max_requests;  /** vector size */
-       int                              request_cnt;   /** used count */
-       struct hsm_scan_request         *request;
+       bool                     hsd_housekeeping;
+       bool                     hsd_one_restore;
+       u32                      hsd_start_cat_idx;
+       u32                      hsd_start_rec_idx;
+       int                      hsd_action_count;
+       int                      hsd_request_len; /* array alloc len */
+       int                      hsd_request_count; /* array used count */
+       struct hsm_scan_request *hsd_request;
 };
 
-struct hsm_thread_data {
-       struct mdt_thread_info  *cdt_mti;
-       struct hsm_scan_request *request;
-};
-/**
- * update status of a request
- * this function is to be called from llog_cat_process()
- * \param mti [IN] context
- * \param llh [IN] llog handle
- * \param hdr [IN] llog record
- * \retval 0 success
- * \retval -ve failure
- */
-static int mdt_hsm_complete_request(struct mdt_thread_info *mti,
-                                   struct llog_handle *llh,
-                                   struct llog_rec_hdr *hdr)
+static int mdt_cdt_waiting_cb(const struct lu_env *env,
+                             struct mdt_device *mdt,
+                             struct llog_handle *llh,
+                             struct llog_agent_req_rec *larr,
+                             struct hsm_scan_data *hsd)
 {
-       struct llog_agent_req_rec *larr = (struct llog_agent_req_rec *)hdr;
-       time64_t now = ktime_get_real_seconds();
-       struct hsm_progress_kernel pgs = {
-               .hpk_fid = larr->arr_hai.hai_fid,
-               .hpk_cookie = larr->arr_hai.hai_cookie,
-               .hpk_extent = larr->arr_hai.hai_extent,
-               .hpk_flags = HP_FLAG_COMPLETED,
-               .hpk_errval = ENOSYS,
-               .hpk_data_version = 0
-       };
-       int rc = 0;
-       ENTRY;
-       /* update request state, but do not record in llog, to
-        * avoid deadlock on cdt_llog_lock */
-       rc = mdt_hsm_update_request_state(mti, &pgs, 0);
-       if (rc) {
-               CERROR("%s: cannot update timed out/cancelled request: "
-                      DFID" for cookie %#llx action=%s\n",
-                      mdt_obd_name(mti->mti_mdt),
-                      PFID(&pgs.hpk_fid), pgs.hpk_cookie,
-                      hsm_copytool_action2name(larr->arr_hai.hai_action));
-               RETURN(rc);
+       struct coordinator *cdt = &mdt->mdt_coordinator;
+       struct hsm_scan_request *request;
+       struct hsm_action_item *hai;
+       size_t hai_size;
+       u32 archive_id;
+       bool wrapped;
+       int i;
+
+       /* Are agents full? */
+       if (atomic_read(&cdt->cdt_request_count) >= cdt->cdt_max_requests)
+               RETURN(hsd->hsd_housekeeping ? 0 : LLOG_PROC_BREAK);
+
+       if (hsd->hsd_action_count + atomic_read(&cdt->cdt_request_count) >=
+           cdt->cdt_max_requests) {
+               /* We cannot send any more request
+                *
+                *                     *** SPECIAL CASE ***
+                *
+                * Restore requests are too important not to schedule at least
+                * one, everytime we can.
+                */
+               if (larr->arr_hai.hai_action != HSMA_RESTORE ||
+                   hsd->hsd_one_restore)
+                       RETURN(hsd->hsd_housekeeping ? 0 : LLOG_PROC_BREAK);
        }
 
-       /* XXX A cancel request cannot be cancelled. */
-       if (larr->arr_hai.hai_action == HSMA_CANCEL)
+       hai_size = cfs_size_round(larr->arr_hai.hai_len);
+       archive_id = larr->arr_archive_id;
+
+       /* Can we add this action to one of the existing HALs in hsd. */
+       request = NULL;
+       for (i = 0; i < hsd->hsd_request_count; i++) {
+               if (hsd->hsd_request[i].hal->hal_archive_id == archive_id &&
+                   hsd->hsd_request[i].hal_used_sz + hai_size <=
+                   LDLM_MAXREQSIZE) {
+                       request = &hsd->hsd_request[i];
+                       break;
+               }
+       }
+
+       /* Are we trying to force-schedule a request? */
+       if (hsd->hsd_action_count + atomic_read(&cdt->cdt_request_count) >=
+           cdt->cdt_max_requests) {
+               /* Is there really no compatible hsm_scan_request? */
+               if (!request) {
+                       for (i -= 1; i >= 0; i--) {
+                               if (hsd->hsd_request[i].hal->hal_archive_id ==
+                                   archive_id) {
+                                       request = &hsd->hsd_request[i];
+                                       break;
+                               }
+                       }
+               }
+
+               /* Make room for the hai */
+               if (request) {
+                       /* Discard the last hai until there is enough space */
+                       do {
+                               request->hal->hal_count--;
+
+                               hai = hai_first(request->hal);
+                               for (i = 0; i < request->hal->hal_count; i++)
+                                       hai = hai_next(hai);
+                               request->hal_used_sz -=
+                                       cfs_size_round(hai->hai_len);
+                               hsd->hsd_action_count--;
+                       } while (request->hal_used_sz + hai_size >
+                                LDLM_MAXREQSIZE);
+               } else if (hsd->hsd_housekeeping) {
+                       struct hsm_scan_request *tmp;
+
+                       /* Discard the (whole) last hal */
+                       hsd->hsd_request_count--;
+                       LASSERT(hsd->hsd_request_count >= 0);
+                       tmp = &hsd->hsd_request[hsd->hsd_request_count];
+                       hsd->hsd_action_count -= tmp->hal->hal_count;
+                       LASSERT(hsd->hsd_action_count >= 0);
+                       OBD_FREE(tmp->hal, tmp->hal_sz);
+               } else {
+                       /* Bailing out, this code path is too hot */
+                       RETURN(LLOG_PROC_BREAK);
+
+               }
+       }
+
+       if (!request) {
+               struct hsm_action_list *hal;
+
+               LASSERT(hsd->hsd_request_count < hsd->hsd_request_len);
+               request = &hsd->hsd_request[hsd->hsd_request_count];
+
+               /* allocates hai vector size just needs to be large
+                * enough */
+               request->hal_sz = sizeof(*request->hal) +
+                       cfs_size_round(MTI_NAME_MAXLEN + 1) + 2 * hai_size;
+               OBD_ALLOC_LARGE(hal, request->hal_sz);
+               if (!hal)
+                       RETURN(-ENOMEM);
+
+               hal->hal_version = HAL_VERSION;
+               strlcpy(hal->hal_fsname, hsd->hsd_fsname, MTI_NAME_MAXLEN + 1);
+               hal->hal_archive_id = larr->arr_archive_id;
+               hal->hal_flags = larr->arr_flags;
+               hal->hal_count = 0;
+               request->hal_used_sz = hal_size(hal);
+               request->hal = hal;
+               hsd->hsd_request_count++;
+       } else if (request->hal_sz < request->hal_used_sz + hai_size) {
+               /* Not enough room, need an extension */
+               void *hal_buffer;
+               int sz;
+
+               sz = min_t(int, 2 * request->hal_sz, LDLM_MAXREQSIZE);
+               LASSERT(request->hal_used_sz + hai_size < sz);
+
+               OBD_ALLOC_LARGE(hal_buffer, sz);
+               if (!hal_buffer)
+                       RETURN(-ENOMEM);
+
+               memcpy(hal_buffer, request->hal, request->hal_used_sz);
+               OBD_FREE_LARGE(request->hal, request->hal_sz);
+               request->hal = hal_buffer;
+               request->hal_sz = sz;
+       }
+
+       hai = hai_first(request->hal);
+       for (i = 0; i < request->hal->hal_count; i++)
+               hai = hai_next(hai);
+
+       memcpy(hai, &larr->arr_hai, larr->arr_hai.hai_len);
+
+       request->hal_used_sz += hai_size;
+       request->hal->hal_count++;
+
+       hsd->hsd_action_count++;
+
+       switch (hai->hai_action) {
+       case HSMA_CANCEL:
+               break;
+       case HSMA_RESTORE:
+               hsd->hsd_one_restore = true;
+               fallthrough;
+       default:
+               cdt_agent_record_hash_add(cdt, hai->hai_cookie,
+                                         llh->lgh_hdr->llh_cat_idx,
+                                         larr->arr_hdr.lrh_index);
+       }
+
+       wrapped = llh->lgh_hdr->llh_cat_idx >= llh->lgh_last_idx &&
+                 llh->lgh_hdr->llh_count > 1;
+       if ((!wrapped && llh->lgh_hdr->llh_cat_idx > hsd->hsd_start_cat_idx) ||
+           (wrapped && llh->lgh_hdr->llh_cat_idx < hsd->hsd_start_cat_idx) ||
+           (llh->lgh_hdr->llh_cat_idx == hsd->hsd_start_cat_idx &&
+            larr->arr_hdr.lrh_index > hsd->hsd_start_rec_idx)) {
+               hsd->hsd_start_cat_idx = llh->lgh_hdr->llh_cat_idx;
+               hsd->hsd_start_rec_idx = larr->arr_hdr.lrh_index;
+       }
+
+       RETURN(0);
+}
+
+static int mdt_cdt_started_cb(const struct lu_env *env,
+                             struct mdt_device *mdt,
+                             struct llog_handle *llh,
+                             struct llog_agent_req_rec *larr,
+                             struct hsm_scan_data *hsd)
+{
+       struct coordinator *cdt = &mdt->mdt_coordinator;
+       struct hsm_action_item *hai = &larr->arr_hai;
+       struct cdt_agent_req *car;
+       time64_t now = ktime_get_real_seconds();
+       time64_t last;
+       enum changelog_rec_flags clf_flags;
+       int rc;
+
+       if (!hsd->hsd_housekeeping)
                RETURN(0);
 
+       /* we search for a running request
+        * error may happen if coordinator crashes or stopped
+        * with running request
+        */
+       car = mdt_cdt_find_request(cdt, hai->hai_cookie);
+       if (car == NULL) {
+               last = larr->arr_req_change;
+       } else {
+               last = car->car_req_update;
+       }
+
+       /* test if request too long, if yes cancel it
+        * the same way the copy tool acknowledge a cancel request */
+       if (now <= last + cdt->cdt_active_req_timeout)
+               GOTO(out_car, rc = 0);
+
+       dump_llog_agent_req_rec("request timed out, start cleaning", larr);
+
+       if (car != NULL) {
+               car->car_req_update = now;
+               mdt_hsm_agent_update_statistics(cdt, 0, 1, 0, &car->car_uuid);
+               /* Remove car from memory list (LU-9075) */
+               mdt_cdt_remove_request(cdt, hai->hai_cookie);
+       }
+
+       /* Emit a changelog record for the failed action.*/
+       clf_flags = 0;
+       hsm_set_cl_error(&clf_flags, ECANCELED);
+
+       switch (hai->hai_action) {
+       case HSMA_ARCHIVE:
+               hsm_set_cl_event(&clf_flags, HE_ARCHIVE);
+               break;
+       case HSMA_RESTORE:
+               hsm_set_cl_event(&clf_flags, HE_RESTORE);
+               break;
+       case HSMA_REMOVE:
+               hsm_set_cl_event(&clf_flags, HE_REMOVE);
+               break;
+       case HSMA_CANCEL:
+               hsm_set_cl_event(&clf_flags, HE_CANCEL);
+               break;
+       default:
+               /* Unknown record type, skip changelog. */
+               clf_flags = 0;
+               break;
+       }
+
+       if (clf_flags != 0)
+               mo_changelog(env, CL_HSM, clf_flags, mdt->mdt_child,
+                            &hai->hai_fid);
+
+       if (hai->hai_action == HSMA_RESTORE)
+               cdt_restore_handle_del(hsd->hsd_mti, cdt, &hai->hai_fid);
+
        larr->arr_status = ARS_CANCELED;
        larr->arr_req_change = now;
-       rc = llog_write(mti->mti_env, llh, hdr, hdr->lrh_index);
-       if (rc < 0)
+       rc = llog_write(hsd->hsd_mti->mti_env, llh, &larr->arr_hdr,
+                       larr->arr_hdr.lrh_index);
+       if (rc < 0) {
                CERROR("%s: cannot update agent log: rc = %d\n",
-                      mdt_obd_name(mti->mti_mdt), rc);
+                      mdt_obd_name(mdt), rc);
+               rc = LLOG_DEL_RECORD;
+       }
+
+       /* ct has completed a request, so a slot is available,
+        * signal the coordinator to find new work */
+       mdt_hsm_cdt_event(cdt);
+out_car:
+       if (car != NULL)
+               mdt_cdt_put_request(car);
 
        RETURN(rc);
 }
@@ -219,252 +424,32 @@ static int mdt_coordinator_cb(const struct lu_env *env,
                              struct llog_rec_hdr *hdr,
                              void *data)
 {
-       struct llog_agent_req_rec       *larr;
-       struct hsm_scan_data            *hsd;
-       struct hsm_action_item          *hai;
-       struct mdt_device               *mdt;
-       struct coordinator              *cdt;
-       int                              rc;
+       struct llog_agent_req_rec *larr = (struct llog_agent_req_rec *)hdr;
+       struct hsm_scan_data *hsd = data;
+       struct mdt_device *mdt = hsd->hsd_mti->mti_mdt;
+       struct coordinator *cdt = &mdt->mdt_coordinator;
        ENTRY;
 
-       hsd = data;
-       mdt = hsd->mti->mti_mdt;
-       cdt = &mdt->mdt_coordinator;
-
        larr = (struct llog_agent_req_rec *)hdr;
        dump_llog_agent_req_rec("mdt_coordinator_cb(): ", larr);
        switch (larr->arr_status) {
-       case ARS_WAITING: {
-               int i;
-               struct hsm_scan_request *request;
-
-               /* Are agents full? */
-               if (atomic_read(&cdt->cdt_request_count) >=
-                   cdt->cdt_max_requests)
-                       break;
-
-               /* first search whether the request is found in the
-                * list we have built. */
-               request = NULL;
-               for (i = 0; i < hsd->request_cnt; i++) {
-                       if (hsd->request[i].hal->hal_compound_id ==
-                           larr->arr_compound_id) {
-                               request = &hsd->request[i];
-                               break;
-                       }
-               }
-
-               if (!request) {
-                       struct hsm_action_list *hal;
-
-                       if (hsd->request_cnt == hsd->max_requests) {
-                               if (!hsd->housekeeping) {
-                                       /* The request array is full,
-                                        * stop here. There might be
-                                        * more known requests that
-                                        * could be merged, but this
-                                        * avoid analyzing too many
-                                        * llogs for minor gains.
-                                        */
-                                       RETURN(LLOG_PROC_BREAK);
-                               } else {
-                                       /* Unknown request and no more room
-                                        * for a new request. Continue to scan
-                                        * to find other entries for already
-                                        * existing requests.
-                                        */
-                                       RETURN(0);
-                               }
-                       }
-
-                       request = &hsd->request[hsd->request_cnt];
-
-                       /* allocates hai vector size just needs to be large
-                        * enough */
-                       request->hal_sz =
-                               sizeof(*request->hal) +
-                               cfs_size_round(MTI_NAME_MAXLEN+1) +
-                               2 * cfs_size_round(larr->arr_hai.hai_len);
-                       OBD_ALLOC(hal, request->hal_sz);
-                       if (!hal)
-                               RETURN(-ENOMEM);
-                       hal->hal_version = HAL_VERSION;
-                       strlcpy(hal->hal_fsname, hsd->fs_name,
-                               MTI_NAME_MAXLEN + 1);
-                       hal->hal_compound_id = larr->arr_compound_id;
-                       hal->hal_archive_id = larr->arr_archive_id;
-                       hal->hal_flags = larr->arr_flags;
-                       hal->hal_count = 0;
-                       request->hal_used_sz = hal_size(hal);
-                       request->hal = hal;
-                       hsd->request_cnt++;
-                       hai = hai_first(hal);
-               } else {
-                       /* request is known */
-                       /* we check if record archive num is the same as the
-                        * known request, if not we will serve it in multiple
-                        * time because we do not know if the agent can serve
-                        * multiple backend
-                        * a use case is a compound made of multiple restore
-                        * where the files are not archived in the same backend
-                        */
-                       if (larr->arr_archive_id !=
-                           request->hal->hal_archive_id)
-                               RETURN(0);
-
-                       if (request->hal_sz <
-                           request->hal_used_sz +
-                           cfs_size_round(larr->arr_hai.hai_len)) {
-                               /* Not enough room, need an extension */
-                               void *hal_buffer;
-                               int sz;
-
-                               sz = 2 * request->hal_sz;
-                               OBD_ALLOC(hal_buffer, sz);
-                               if (!hal_buffer)
-                                       RETURN(-ENOMEM);
-                               memcpy(hal_buffer, request->hal,
-                                      request->hal_used_sz);
-                               OBD_FREE(request->hal,
-                                        request->hal_sz);
-                               request->hal = hal_buffer;
-                               request->hal_sz = sz;
-                       }
-                       hai = hai_first(request->hal);
-                       for (i = 0; i < request->hal->hal_count; i++)
-                               hai = hai_next(hai);
-               }
-               memcpy(hai, &larr->arr_hai, larr->arr_hai.hai_len);
-               hai->hai_cookie = larr->arr_hai.hai_cookie;
-               hai->hai_gid = larr->arr_hai.hai_gid;
-
-               request->hal_used_sz += cfs_size_round(hai->hai_len);
-               request->hal->hal_count++;
-
-               if (hai->hai_action != HSMA_CANCEL)
-                       cdt_agent_record_hash_add(cdt, hai->hai_cookie,
-                                                 llh->lgh_hdr->llh_cat_idx,
-                                                 hdr->lrh_index);
-               break;
-       }
-       case ARS_STARTED: {
-               struct cdt_agent_req *car;
-               time64_t now = ktime_get_real_seconds();
-               time64_t last;
-
-               if (!hsd->housekeeping)
-                       break;
-
-               /* we search for a running request
-                * error may happen if coordinator crashes or stopped
-                * with running request
-                */
-               car = mdt_cdt_find_request(cdt, larr->arr_hai.hai_cookie);
-               if (car == NULL) {
-                       last = larr->arr_req_change;
-               } else {
-                       last = car->car_req_update;
-                       mdt_cdt_put_request(car);
-               }
-
-               /* test if request too long, if yes cancel it
-                * the same way the copy tool acknowledge a cancel request */
-               if (now <= last + cdt->cdt_active_req_timeout)
+       case ARS_WAITING:
+               RETURN(mdt_cdt_waiting_cb(env, mdt, llh, larr, hsd));
+       case ARS_STARTED:
+               RETURN(mdt_cdt_started_cb(env, mdt, llh, larr, hsd));
+       default:
+               if (!hsd->hsd_housekeeping)
                        RETURN(0);
 
-               dump_llog_agent_req_rec("request timed out, start cleaning",
-                                       larr);
-               /* a too old cancel request just needs to be removed
-                * this can happen, if copy tool does not support
-                * cancel for other requests, we have to remove the
-                * running request and notify the copytool */
-               rc = mdt_hsm_complete_request(hsd->mti, llh, hdr);
-               if (rc == -ENOENT) {
-                       /* The request no longer exists, forget
-                        * about it, and do not send a cancel request
-                        * to the client, for which an error will be
-                        * sent back, leading to an endless cycle of
-                        * cancellation. */
-                       cdt_agent_record_hash_del(cdt,
-                                                 larr->arr_hai.hai_cookie);
-                       RETURN(LLOG_DEL_RECORD);
-               }
-               break;
-       }
-       case ARS_CANCELED:
-               if (!hsd->housekeeping)
-                       break;
-               if (larr->arr_req_change + cdt->cdt_grace_delay <
-                   ktime_get_real_seconds()) {
-                       rc = mdt_hsm_complete_request(hsd->mti, llh, hdr);
-                       /* See ENOENT comment above */
-                       if (rc == -ENOENT)
-                               RETURN(LLOG_DEL_RECORD);
-               }
-               break;
-       case ARS_FAILED:
-       case ARS_SUCCEED:
-               if (!hsd->housekeeping)
-                       break;
-
                if ((larr->arr_req_change + cdt->cdt_grace_delay) <
                    ktime_get_real_seconds()) {
                        cdt_agent_record_hash_del(cdt,
                                                  larr->arr_hai.hai_cookie);
                        RETURN(LLOG_DEL_RECORD);
                }
-               break;
-       }
-       RETURN(0);
-}
-
-/**
- * create /proc entries for coordinator
- * \param mdt [IN]
- * \retval 0 success
- * \retval -ve failure
- */
-int hsm_cdt_procfs_init(struct mdt_device *mdt)
-{
-       struct coordinator      *cdt = &mdt->mdt_coordinator;
-       int                      rc = 0;
-       ENTRY;
 
-       /* init /proc entries, failure is not critical */
-       cdt->cdt_proc_dir = lprocfs_register("hsm",
-                                            mdt2obd_dev(mdt)->obd_proc_entry,
-                                            lprocfs_mdt_hsm_vars, mdt);
-       if (IS_ERR(cdt->cdt_proc_dir)) {
-               rc = PTR_ERR(cdt->cdt_proc_dir);
-               CERROR("%s: Cannot create 'hsm' directory in mdt proc dir,"
-                      " rc=%d\n", mdt_obd_name(mdt), rc);
-               cdt->cdt_proc_dir = NULL;
-               RETURN(rc);
+               RETURN(0);
        }
-
-       RETURN(0);
-}
-
-/**
- * remove /proc entries for coordinator
- * \param mdt [IN]
- */
-void hsm_cdt_procfs_fini(struct mdt_device *mdt)
-{
-       struct coordinator *cdt = &mdt->mdt_coordinator;
-
-       if (cdt->cdt_proc_dir != NULL)
-               lprocfs_remove(&cdt->cdt_proc_dir);
-}
-
-/**
- * get vector of hsm cdt /proc vars
- * \param none
- * \retval var vector
- */
-struct lprocfs_vars *hsm_cdt_get_proc_vars(void)
-{
-       return lprocfs_mdt_hsm_vars;
 }
 
 /* Release the ressource used by the coordinator. Called when the
@@ -492,13 +477,20 @@ static void mdt_hsm_cdt_cleanup(struct mdt_device *mdt)
        down_write(&cdt->cdt_agent_lock);
        list_for_each_entry_safe(ha, tmp2, &cdt->cdt_agents, ha_list) {
                list_del(&ha->ha_list);
+               if (ha->ha_archive_cnt != 0)
+                       OBD_FREE_PTR_ARRAY(ha->ha_archive_id,
+                                          ha->ha_archive_cnt);
                OBD_FREE_PTR(ha);
        }
        up_write(&cdt->cdt_agent_lock);
 
        cdt_mti = lu_context_key_get(&cdt->cdt_env.le_ctx, &mdt_thread_key);
        mutex_lock(&cdt->cdt_restore_lock);
-       list_for_each_entry_safe(crh, tmp3, &cdt->cdt_restore_hdl, crh_list) {
+       list_for_each_entry_safe(crh, tmp3, &cdt->cdt_restore_handle_list,
+                                crh_list) {
+               /* not locked yet, cleanup by cdt_restore_handle_add() */
+               if (crh->crh_lh.mlh_type == MDT_NUL_LOCK)
+                       continue;
                list_del(&crh->crh_list);
                /* give back layout lock */
                mdt_object_unlock(cdt_mti, NULL, &crh->crh_lh, 1);
@@ -528,24 +520,18 @@ static bool cdt_transition[CDT_STATES_COUNT][CDT_STATES_COUNT] = {
  * Returns 0 on success, with old_state set if not NULL, or -EINVAL if
  * the transition was not possible.
  */
-static int set_cdt_state(struct coordinator *cdt, enum cdt_states new_state,
-                        enum cdt_states *old_state)
+static int set_cdt_state_locked(struct coordinator *cdt,
+                               enum cdt_states new_state)
 {
        int rc;
        enum cdt_states state;
 
-       spin_lock(&cdt->cdt_state_lock);
-
        state = cdt->cdt_state;
 
        if (cdt_transition[state][new_state]) {
                cdt->cdt_state = new_state;
-               spin_unlock(&cdt->cdt_state_lock);
-               if (old_state)
-                       *old_state = state;
                rc = 0;
        } else {
-               spin_unlock(&cdt->cdt_state_lock);
                CDEBUG(D_HSM,
                       "unexpected coordinator transition, from=%s, to=%s\n",
                       cdt_mdt_state2str(state), cdt_mdt_state2str(new_state));
@@ -555,6 +541,43 @@ static int set_cdt_state(struct coordinator *cdt, enum cdt_states new_state,
        return rc;
 }
 
+static int set_cdt_state(struct coordinator *cdt, enum cdt_states new_state)
+{
+       int rc;
+
+       mutex_lock(&cdt->cdt_state_lock);
+       rc = set_cdt_state_locked(cdt, new_state);
+       mutex_unlock(&cdt->cdt_state_lock);
+
+       return rc;
+}
+
+static int mdt_hsm_pending_restore(struct mdt_thread_info *mti);
+
+static void cdt_start_pending_restore(struct mdt_device *mdt,
+                                     struct coordinator *cdt)
+{
+       struct mdt_thread_info *cdt_mti;
+       unsigned int i = 0;
+       int rc;
+
+       /* wait until MDD initialize hsm actions llog */
+       while (!test_bit(MDT_FL_CFGLOG, &mdt->mdt_state) && i < obd_timeout) {
+               schedule_timeout_interruptible(cfs_time_seconds(1));
+               i++;
+       }
+       if (!test_bit(MDT_FL_CFGLOG, &mdt->mdt_state))
+               CWARN("%s: trying to init HSM before MDD\n", mdt_obd_name(mdt));
+
+       /* set up list of started restore requests */
+       cdt_mti = lu_context_key_get(&cdt->cdt_env.le_ctx, &mdt_thread_key);
+       rc = mdt_hsm_pending_restore(cdt_mti);
+       if (rc)
+               CERROR("%s: cannot take the layout locks needed for registered restore: %d\n",
+                      mdt_obd_name(mdt), rc);
+
+}
+
 /**
  * coordinator thread
  * \param data [IN] obd device
@@ -563,37 +586,35 @@ static int set_cdt_state(struct coordinator *cdt, enum cdt_states new_state,
  */
 static int mdt_coordinator(void *data)
 {
-       struct hsm_thread_data  *thread_data = data;
-       struct mdt_thread_info  *mti = thread_data->cdt_mti;
+       struct mdt_thread_info  *mti = data;
        struct mdt_device       *mdt = mti->mti_mdt;
        struct coordinator      *cdt = &mdt->mdt_coordinator;
        struct hsm_scan_data     hsd = { NULL };
        time64_t                 last_housekeeping = 0;
-       int                      rc = 0;
-       int                      request_sz;
+       size_t request_sz = 0;
+       int rc;
        ENTRY;
 
-       /* set up hsd->request and max_requests */
-       hsd.max_requests = cdt->cdt_max_requests;
-       request_sz = hsd.max_requests * sizeof(*hsd.request);
-       hsd.request = thread_data->request;
-
        CDEBUG(D_HSM, "%s: coordinator thread starting, pid=%d\n",
-              mdt_obd_name(mdt), current_pid());
+              mdt_obd_name(mdt), current->pid);
 
-       hsd.mti = mti;
-       obd_uuid2fsname(hsd.fs_name, mdt_obd_name(mdt), MTI_NAME_MAXLEN);
+       hsd.hsd_mti = mti;
+       obd_uuid2fsname(hsd.hsd_fsname, mdt_obd_name(mdt),
+                       sizeof(hsd.hsd_fsname));
 
-       set_cdt_state(cdt, CDT_RUNNING, NULL);
+       set_cdt_state(cdt, CDT_RUNNING);
 
        /* Inform mdt_hsm_cdt_start(). */
-       wake_up_all(&cdt->cdt_waitq);
+       wake_up(&cdt->cdt_waitq);
+       cdt_start_pending_restore(mdt, cdt);
 
        while (1) {
                int i;
                int update_idx = 0;
                int updates_sz;
                int updates_cnt;
+               u32 start_cat_idx;
+               u32 start_rec_idx;
                struct hsm_record_update *updates;
 
                /* Limit execution of the expensive requests traversal
@@ -626,9 +647,13 @@ static int mdt_coordinator(void *data)
                if (last_housekeeping + cdt->cdt_loop_period <=
                    ktime_get_real_seconds()) {
                        last_housekeeping = ktime_get_real_seconds();
-                       hsd.housekeeping = true;
+                       hsd.hsd_housekeeping = true;
+                       start_cat_idx = 0;
+                       start_rec_idx = 0;
                } else if (cdt->cdt_event) {
-                       hsd.housekeeping = false;
+                       hsd.hsd_housekeeping = false;
+                       start_cat_idx = hsd.hsd_start_cat_idx;
+                       start_rec_idx = hsd.hsd_start_rec_idx;
                } else {
                        continue;
                }
@@ -637,7 +662,7 @@ static int mdt_coordinator(void *data)
 
                CDEBUG(D_HSM, "coordinator starts reading llog\n");
 
-               if (hsd.max_requests != cdt->cdt_max_requests) {
+               if (hsd.hsd_request_len != cdt->cdt_max_requests) {
                        /* cdt_max_requests has changed,
                         * we need to allocate a new buffer
                         */
@@ -648,37 +673,46 @@ static int mdt_coordinator(void *data)
                        if (!tmp) {
                                CERROR("Failed to resize request buffer, "
                                       "keeping it at %d\n",
-                                      hsd.max_requests);
-                               cdt->cdt_max_requests = hsd.max_requests;
+                                      hsd.hsd_request_len);
                        } else {
-                               OBD_FREE_LARGE(hsd.request, request_sz);
-                               hsd.max_requests = max_requests;
-                               request_sz = hsd.max_requests *
+                               if (hsd.hsd_request != NULL)
+                                       OBD_FREE_LARGE(hsd.hsd_request,
+                                                      request_sz);
+
+                               hsd.hsd_request_len = max_requests;
+                               request_sz = hsd.hsd_request_len *
                                        sizeof(struct hsm_scan_request);
-                               hsd.request = tmp;
+                               hsd.hsd_request = tmp;
                        }
                }
 
-               hsd.request_cnt = 0;
+               hsd.hsd_action_count = 0;
+               hsd.hsd_request_count = 0;
+               hsd.hsd_one_restore = false;
 
                rc = cdt_llog_process(mti->mti_env, mdt, mdt_coordinator_cb,
-                                     &hsd, 0, 0, WRITE);
+                                     &hsd, start_cat_idx, start_rec_idx,
+                                     WRITE);
                if (rc < 0)
                        goto clean_cb_alloc;
 
-               CDEBUG(D_HSM, "found %d requests to send\n", hsd.request_cnt);
+               CDEBUG(D_HSM, "found %d requests to send\n",
+                      hsd.hsd_request_count);
 
                if (list_empty(&cdt->cdt_agents)) {
                        CDEBUG(D_HSM, "no agent available, "
                                      "coordinator sleeps\n");
+                       /* reset HSM scanning index range. */
+                       hsd.hsd_start_cat_idx = start_cat_idx;
+                       hsd.hsd_start_rec_idx = start_rec_idx;
                        goto clean_cb_alloc;
                }
 
                /* Compute how many HAI we have in all the requests */
                updates_cnt = 0;
-               for (i = 0; i < hsd.request_cnt; i++) {
+               for (i = 0; i < hsd.hsd_request_count; i++) {
                        const struct hsm_scan_request *request =
-                               &hsd.request[i];
+                               &hsd.hsd_request[i];
 
                        updates_cnt += request->hal->hal_count;
                }
@@ -686,17 +720,17 @@ static int mdt_coordinator(void *data)
                /* Allocate a temporary array to store the cookies to
                 * update, and their status. */
                updates_sz = updates_cnt * sizeof(*updates);
-               OBD_ALLOC(updates, updates_sz);
+               OBD_ALLOC_LARGE(updates, updates_sz);
                if (updates == NULL) {
-                       CERROR("%s: Cannot allocate memory (%d o) "
-                              "for %d updates\n",
+                       CERROR("%s: Cannot allocate memory (%d bytes) "
+                               "for %d updates. Too many HSM requests?\n",
                               mdt_obd_name(mdt), updates_sz, updates_cnt);
-                       continue;
+                       goto clean_cb_alloc;
                }
 
                /* here hsd contains a list of requests to be started */
-               for (i = 0; i < hsd.request_cnt; i++) {
-                       struct hsm_scan_request *request = &hsd.request[i];
+               for (i = 0; i < hsd.hsd_request_count; i++) {
+                       struct hsm_scan_request *request = &hsd.hsd_request[i];
                        struct hsm_action_list  *hal = request->hal;
                        struct hsm_action_item  *hai;
                        int                      j;
@@ -723,11 +757,19 @@ static int mdt_coordinator(void *data)
                                hai = hai_next(hai);
                                update_idx++;
                        }
+
+                       /* TODO: narrow down the HSM action range that already
+                        * scanned accroding to the cookies when a failure
+                        * occurs.
+                        */
+                       if (rc) {
+                               hsd.hsd_start_cat_idx = start_cat_idx;
+                               hsd.hsd_start_rec_idx = start_rec_idx;
+                       }
                }
 
                if (update_idx) {
-                       rc = mdt_agent_record_update(mti->mti_env, mdt,
-                                                    updates, update_idx);
+                       rc = mdt_agent_record_update(mti, updates, update_idx);
                        if (rc)
                                CERROR("%s: mdt_agent_record_update() failed, "
                                       "rc=%d, cannot update records "
@@ -735,34 +777,112 @@ static int mdt_coordinator(void *data)
                                       mdt_obd_name(mdt), rc, update_idx);
                }
 
-               OBD_FREE(updates, updates_sz);
+               OBD_FREE_LARGE(updates, updates_sz);
 
 clean_cb_alloc:
                /* free hal allocated by callback */
-               for (i = 0; i < hsd.request_cnt; i++) {
-                       struct hsm_scan_request *request = &hsd.request[i];
+               for (i = 0; i < hsd.hsd_request_count; i++) {
+                       struct hsm_scan_request *request = &hsd.hsd_request[i];
 
-                       OBD_FREE(request->hal, request->hal_sz);
+                       OBD_FREE_LARGE(request->hal, request->hal_sz);
                }
        }
 
-       if (hsd.request)
-               OBD_FREE_LARGE(hsd.request, request_sz);
+       if (hsd.hsd_request != NULL)
+               OBD_FREE_LARGE(hsd.hsd_request, request_sz);
 
        mdt_hsm_cdt_cleanup(mdt);
 
        if (rc != 0)
                CERROR("%s: coordinator thread exiting, process=%d, rc=%d\n",
-                      mdt_obd_name(mdt), current_pid(), rc);
+                      mdt_obd_name(mdt), current->pid, rc);
        else
                CDEBUG(D_HSM, "%s: coordinator thread exiting, process=%d,"
                              " no error\n",
-                      mdt_obd_name(mdt), current_pid());
+                      mdt_obd_name(mdt), current->pid);
 
        RETURN(rc);
 }
 
 /**
+ * register a new HSM restore handle for a file and take EX lock on the layout
+ * \param mti [IN] thread info
+ * \param cdt [IN] coordinator
+ * \param fid [IN] fid of the file to restore
+ * \param he  [IN] HSM extent
+ * \retval 0 success
+ * \retval 1 restore handle already exists for the fid
+ * \retval -ve failure
+ */
+int cdt_restore_handle_add(struct mdt_thread_info *mti, struct coordinator *cdt,
+                          const struct lu_fid *fid,
+                          const struct hsm_extent *he)
+{
+       struct mdt_lock_handle lh = { 0 };
+       struct cdt_restore_handle *crh;
+       struct mdt_object *obj;
+       int rc;
+       ENTRY;
+
+       OBD_SLAB_ALLOC_PTR(crh, mdt_hsm_cdt_kmem);
+       if (crh == NULL)
+               RETURN(-ENOMEM);
+
+       crh->crh_fid = *fid;
+       /* in V1 all file is restored
+        * crh->extent.start = he->offset;
+        * crh->extent.end = he->offset + he->length;
+        */
+       crh->crh_extent.start = 0;
+       crh->crh_extent.end = he->length;
+       crh->crh_lh.mlh_type = MDT_NUL_LOCK;
+
+       mutex_lock(&cdt->cdt_restore_lock);
+       if (cdt_restore_handle_find(cdt, fid) != NULL)
+               GOTO(out_crl, rc = 1);
+
+       if (unlikely(cdt->cdt_state == CDT_STOPPED ||
+                    cdt->cdt_state == CDT_STOPPING))
+               GOTO(out_crl, rc = -EAGAIN);
+
+       list_add_tail(&crh->crh_list, &cdt->cdt_restore_handle_list);
+       mutex_unlock(&cdt->cdt_restore_lock);
+
+       /* get the layout lock */
+       mdt_lock_reg_init(&lh, LCK_EX);
+       obj = mdt_object_find_lock(mti, &crh->crh_fid, &lh,
+                                  MDS_INODELOCK_LAYOUT);
+       if (IS_ERR(obj)) {
+               mutex_lock(&cdt->cdt_restore_lock);
+               GOTO(out_ldel, rc = PTR_ERR(obj));
+       }
+
+       /* We do not keep a reference on the object during the restore
+        * which can be very long.
+        */
+       mdt_object_put(mti->mti_env, obj);
+
+       mutex_lock(&cdt->cdt_restore_lock);
+       if (unlikely(cdt->cdt_state == CDT_STOPPED ||
+                    cdt->cdt_state == CDT_STOPPING))
+               GOTO(out_lh, rc = -EAGAIN);
+
+       crh->crh_lh = lh;
+       mutex_unlock(&cdt->cdt_restore_lock);
+
+       RETURN(0);
+out_lh:
+       mdt_object_unlock(mti, NULL, &crh->crh_lh, 1);
+out_ldel:
+       list_del(&crh->crh_list);
+out_crl:
+       mutex_unlock(&cdt->cdt_restore_lock);
+       OBD_SLAB_FREE_PTR(crh, mdt_hsm_cdt_kmem);
+
+       return rc;
+}
+
+/**
  * lookup a restore handle by FID
  * caller needs to hold cdt_restore_lock
  * \param cdt [IN] coordinator
@@ -770,19 +890,41 @@ clean_cb_alloc:
  * \retval cdt_restore_handle found
  * \retval NULL not found
  */
-struct cdt_restore_handle *mdt_hsm_restore_hdl_find(struct coordinator *cdt,
-                                                      const struct lu_fid *fid)
+struct cdt_restore_handle *cdt_restore_handle_find(struct coordinator *cdt,
+                                                  const struct lu_fid *fid)
 {
-       struct cdt_restore_handle       *crh;
+       struct cdt_restore_handle *crh;
        ENTRY;
 
-       list_for_each_entry(crh, &cdt->cdt_restore_hdl, crh_list) {
+       list_for_each_entry(crh, &cdt->cdt_restore_handle_list, crh_list) {
                if (lu_fid_eq(&crh->crh_fid, fid))
                        RETURN(crh);
        }
+
        RETURN(NULL);
 }
 
+void cdt_restore_handle_del(struct mdt_thread_info *mti,
+                           struct coordinator *cdt, const struct lu_fid *fid)
+{
+       struct cdt_restore_handle *crh;
+
+       /* give back layout lock */
+       mutex_lock(&cdt->cdt_restore_lock);
+       crh = cdt_restore_handle_find(cdt, fid);
+       if (crh != NULL)
+               list_del(&crh->crh_list);
+       mutex_unlock(&cdt->cdt_restore_lock);
+
+       if (crh == NULL)
+               return;
+
+       /* XXX We pass a NULL object since the restore handle does not
+        * keep a reference on the object being restored. */
+       mdt_object_unlock(mti, NULL, &crh->crh_lh, 1);
+       OBD_SLAB_FREE_PTR(crh, mdt_hsm_cdt_kmem);
+}
+
 /**
  * data passed to llog_cat_process() callback
  * to scan requests and take actions
@@ -807,11 +949,9 @@ static int hsm_restore_cb(const struct lu_env *env,
 {
        struct llog_agent_req_rec       *larr;
        struct hsm_restore_data         *hrd;
-       struct cdt_restore_handle       *crh;
        struct hsm_action_item          *hai;
        struct mdt_thread_info          *mti;
        struct coordinator              *cdt;
-       struct mdt_object               *child;
        int rc;
        ENTRY;
 
@@ -821,9 +961,10 @@ static int hsm_restore_cb(const struct lu_env *env,
 
        larr = (struct llog_agent_req_rec *)hdr;
        hai = &larr->arr_hai;
-       if (hai->hai_cookie > cdt->cdt_last_cookie)
+       if (hai->hai_cookie >= cdt->cdt_last_cookie) {
                /* update the cookie to avoid collision */
                cdt->cdt_last_cookie = hai->hai_cookie + 1;
+       }
 
        if (hai->hai_action != HSMA_RESTORE ||
            agent_req_in_final_state(larr->arr_status))
@@ -834,41 +975,17 @@ static int hsm_restore_cb(const struct lu_env *env,
        /* force replay of restore requests left in started state from previous
         * CDT context, to be canceled later if finally found to be incompatible
         * when being re-started */
-       if (larr->arr_status == ARS_STARTED) {
-               larr->arr_status = ARS_WAITING;
-               larr->arr_req_change = ktime_get_real_seconds();
-               rc = llog_write(env, llh, hdr, hdr->lrh_index);
-               if (rc != 0)
-                       GOTO(out, rc);
-       }
-
-       OBD_SLAB_ALLOC_PTR(crh, mdt_hsm_cdt_kmem);
-       if (crh == NULL)
-               RETURN(-ENOMEM);
-
-       crh->crh_fid = hai->hai_fid;
-       /* in V1 all file is restored
-       crh->extent.start = hai->hai_extent.offset;
-       crh->extent.end = hai->hai_extent.offset + hai->hai_extent.length;
-       */
-       crh->crh_extent.start = 0;
-       crh->crh_extent.end = hai->hai_extent.length;
-       /* get the layout lock */
-       mdt_lock_reg_init(&crh->crh_lh, LCK_EX);
-       child = mdt_object_find_lock(mti, &crh->crh_fid, &crh->crh_lh,
-                                    MDS_INODELOCK_LAYOUT);
-       if (IS_ERR(child))
-               GOTO(out, rc = PTR_ERR(child));
-
-       rc = 0;
-       /* we choose to not keep a reference
-        * on the object during the restore time which can be very long */
-       mdt_object_put(mti->mti_env, child);
-
-       mutex_lock(&cdt->cdt_restore_lock);
-       list_add_tail(&crh->crh_list, &cdt->cdt_restore_hdl);
-       mutex_unlock(&cdt->cdt_restore_lock);
+       if (larr->arr_status == ARS_STARTED) {
+               larr->arr_status = ARS_WAITING;
+               larr->arr_req_change = ktime_get_real_seconds();
+               rc = llog_write(env, llh, hdr, hdr->lrh_index);
+               if (rc != 0)
+                       GOTO(out, rc);
+       }
 
+       rc = cdt_restore_handle_add(mti, cdt, &hai->hai_fid, &hai->hai_extent);
+       if (rc == 1)
+               rc = 0;
 out:
        RETURN(rc);
 }
@@ -892,10 +1009,9 @@ static int mdt_hsm_pending_restore(struct mdt_thread_info *mti)
        RETURN(rc);
 }
 
-static int hsm_init_ucred(struct lu_ucred *uc)
+int hsm_init_ucred(struct lu_ucred *uc)
 {
        ENTRY;
-
        uc->uc_valid = UCRED_OLD;
        uc->uc_o_uid = 0;
        uc->uc_o_gid = 0;
@@ -907,10 +1023,12 @@ static int hsm_init_ucred(struct lu_ucred *uc)
        uc->uc_fsgid = 0;
        uc->uc_suppgids[0] = -1;
        uc->uc_suppgids[1] = -1;
-       uc->uc_cap = CFS_CAP_FS_MASK;
+       uc->uc_cap = cap_combine(CAP_FS_SET, CAP_NFSD_SET);
        uc->uc_umask = 0777;
        uc->uc_ginfo = NULL;
        uc->uc_identity = NULL;
+       /* always record internal HSM activity if also enabled globally */
+       uc->uc_enable_audit = 1;
 
        RETURN(0);
 }
@@ -933,12 +1051,12 @@ int mdt_hsm_cdt_init(struct mdt_device *mdt)
        init_rwsem(&cdt->cdt_agent_lock);
        init_rwsem(&cdt->cdt_request_lock);
        mutex_init(&cdt->cdt_restore_lock);
-       spin_lock_init(&cdt->cdt_state_lock);
-       set_cdt_state(cdt, CDT_STOPPED, NULL);
+       mutex_init(&cdt->cdt_state_lock);
+       set_cdt_state(cdt, CDT_STOPPED);
 
        INIT_LIST_HEAD(&cdt->cdt_request_list);
        INIT_LIST_HEAD(&cdt->cdt_agents);
-       INIT_LIST_HEAD(&cdt->cdt_restore_hdl);
+       INIT_LIST_HEAD(&cdt->cdt_restore_handle_list);
 
        cdt->cdt_request_cookie_hash = cfs_hash_create("REQUEST_COOKIE_HASH",
                                                       CFS_HASH_BITS_MIN,
@@ -984,7 +1102,7 @@ int mdt_hsm_cdt_init(struct mdt_device *mdt)
 
        hsm_init_ucred(mdt_ucred(cdt_mti));
 
-       /* default values for /proc tunnables
+       /* default values for sysfs tunnables
         * can be override by MGS conf */
        cdt->cdt_default_archive_id = 1;
        cdt->cdt_grace_delay = 60;
@@ -993,10 +1111,6 @@ int mdt_hsm_cdt_init(struct mdt_device *mdt)
        cdt->cdt_policy = CDT_DEFAULT_POLICY;
        cdt->cdt_active_req_timeout = 3600;
 
-       /* Initialize cdt_compound_id here to allow its usage for
-        * delayed requests from RAoLU policy */
-       atomic_set(&cdt->cdt_compound_id, ktime_get_real_seconds());
-
        /* by default do not remove archives on last unlink */
        cdt->cdt_remove_archive_on_last_unlink = false;
 
@@ -1045,12 +1159,11 @@ int  mdt_hsm_cdt_fini(struct mdt_device *mdt)
  */
 static int mdt_hsm_cdt_start(struct mdt_device *mdt)
 {
-       struct coordinator      *cdt = &mdt->mdt_coordinator;
-       int                      rc;
-       void                    *ptr;
-       struct task_struct      *task;
-       int                      request_sz;
-       struct hsm_thread_data   thread_data;
+       struct coordinator *cdt = &mdt->mdt_coordinator;
+       struct mdt_thread_info *cdt_mti;
+       int rc;
+       void *ptr;
+       struct task_struct *task;
        ENTRY;
 
        /* functions defined but not yet used
@@ -1058,52 +1171,38 @@ static int mdt_hsm_cdt_start(struct mdt_device *mdt)
         */
        ptr = dump_requests;
 
-       rc = set_cdt_state(cdt, CDT_INIT, NULL);
+       rc = set_cdt_state(cdt, CDT_INIT);
        if (rc) {
                CERROR("%s: Coordinator already started or stopping\n",
                       mdt_obd_name(mdt));
                RETURN(-EALREADY);
        }
 
-       CLASSERT(1 << (CDT_POLICY_SHIFT_COUNT - 1) == CDT_POLICY_LAST);
+       BUILD_BUG_ON(BIT(CDT_POLICY_SHIFT_COUNT - 1) != CDT_POLICY_LAST);
        cdt->cdt_policy = CDT_DEFAULT_POLICY;
 
        /* just need to be larger than previous one */
        /* cdt_last_cookie is protected by cdt_llog_lock */
        cdt->cdt_last_cookie = ktime_get_real_seconds();
        atomic_set(&cdt->cdt_request_count, 0);
+       atomic_set(&cdt->cdt_archive_count, 0);
+       atomic_set(&cdt->cdt_restore_count, 0);
+       atomic_set(&cdt->cdt_remove_count, 0);
        cdt->cdt_user_request_mask = (1UL << HSMA_RESTORE);
        cdt->cdt_group_request_mask = (1UL << HSMA_RESTORE);
        cdt->cdt_other_request_mask = (1UL << HSMA_RESTORE);
 
-       /* to avoid deadlock when start is made through /proc
-        * /proc entries are created by the coordinator thread */
-
-       /* set up list of started restore requests */
-       thread_data.cdt_mti =
-               lu_context_key_get(&cdt->cdt_env.le_ctx, &mdt_thread_key);
-       rc = mdt_hsm_pending_restore(thread_data.cdt_mti);
-       if (rc)
-               CERROR("%s: cannot take the layout locks needed"
-                      " for registered restore: %d\n",
-                      mdt_obd_name(mdt), rc);
-
+       /* to avoid deadlock when start is made through sysfs
+        * sysfs entries are created by the coordinator thread
+        */
        if (mdt->mdt_bottom->dd_rdonly)
                RETURN(0);
 
-       /* Allocate the initial hsd.request[] vector*/
-       request_sz = cdt->cdt_max_requests * sizeof(struct hsm_scan_request);
-       OBD_ALLOC_LARGE(thread_data.request, request_sz);
-       if (!thread_data.request) {
-               set_cdt_state(cdt, CDT_STOPPED, NULL);
-               RETURN(-ENOMEM);
-       }
-
-       task = kthread_run(mdt_coordinator, &thread_data, "hsm_cdtr");
+       cdt_mti = lu_context_key_get(&cdt->cdt_env.le_ctx, &mdt_thread_key);
+       task = kthread_run(mdt_coordinator, cdt_mti, "hsm_cdtr");
        if (IS_ERR(task)) {
                rc = PTR_ERR(task);
-               set_cdt_state(cdt, CDT_STOPPED, NULL);
-               OBD_FREE(thread_data.request, request_sz);
+               set_cdt_state(cdt, CDT_STOPPED);
                CERROR("%s: error starting coordinator thread: %d\n",
                       mdt_obd_name(mdt), rc);
        } else {
@@ -1129,11 +1228,11 @@ int mdt_hsm_cdt_stop(struct mdt_device *mdt)
 
        ENTRY;
        /* stop coordinator thread */
-       rc = set_cdt_state(cdt, CDT_STOPPING, NULL);
+       rc = set_cdt_state(cdt, CDT_STOPPING);
        if (rc == 0) {
                kthread_stop(cdt->cdt_task);
                cdt->cdt_task = NULL;
-               set_cdt_state(cdt, CDT_STOPPED, NULL);
+               set_cdt_state(cdt, CDT_STOPPED);
        }
 
        RETURN(rc);
@@ -1199,8 +1298,7 @@ int mdt_hsm_add_hal(struct mdt_thread_info *mti,
                                .status = ARS_CANCELED,
                        };
 
-                       rc = mdt_agent_record_update(mti->mti_env, mti->mti_mdt,
-                                                    &update, 1);
+                       rc = mdt_agent_record_update(mti, &update, 1);
                        if (rc) {
                                CERROR("%s: mdt_agent_record_update() failed, "
                                       "rc=%d, cannot update status to %s "
@@ -1215,7 +1313,6 @@ int mdt_hsm_add_hal(struct mdt_thread_info *mti,
                        car = mdt_cdt_find_request(cdt, hai->hai_cookie);
                        if (car != NULL) {
                                car->car_canceled = 1;
-                               car->car_delay_update = 1;
                                /* uuid has to be changed to the one running the
                                * request to cancel */
                                *uuid = car->car_uuid;
@@ -1237,8 +1334,7 @@ int mdt_hsm_add_hal(struct mdt_thread_info *mti,
                                GOTO(out, rc);
                }
 
-               car = mdt_cdt_alloc_request(hal->hal_compound_id,
-                                           hal->hal_archive_id, hal->hal_flags,
+               car = mdt_cdt_alloc_request(hal->hal_archive_id, hal->hal_flags,
                                            uuid, hai);
                if (IS_ERR(car))
                        GOTO(out, rc = PTR_ERR(car));
@@ -1301,7 +1397,15 @@ static int hsm_swap_layouts(struct mdt_thread_info *mti,
                                     mdt_object_child(obj),
                                     mdt_object_child(dobj),
                                     SWAP_LAYOUTS_MDS_HSM);
-
+       if (rc == 0) {
+               rc = mdt_lsom_downgrade(mti, obj);
+               if (rc)
+                       CDEBUG(D_INODE,
+                              "%s: File fid="DFID" SOM "
+                              "downgrade failed, rc = %d\n",
+                              mdt_obd_name(mti->mti_mdt),
+                              PFID(mdt_object_fid(obj)), rc);
+       }
 out_dobj:
        mdt_object_unlock_put(mti, dobj, dlh, 1);
 out:
@@ -1312,7 +1416,6 @@ out:
  * update status of a completed request
  * \param mti [IN] context
  * \param pgs [IN] progress of the copy tool
- * \param update_record [IN] update llog record
  * \retval 0 success
  * \retval -ve failure
  */
@@ -1321,16 +1424,17 @@ static int hsm_cdt_request_completed(struct mdt_thread_info *mti,
                                     const struct cdt_agent_req *car,
                                     enum agent_req_status *status)
 {
-       const struct lu_env     *env = mti->mti_env;
-       struct mdt_device       *mdt = mti->mti_mdt;
-       struct coordinator      *cdt = &mdt->mdt_coordinator;
-       struct mdt_object       *obj = NULL;
-       int                      cl_flags = 0, rc = 0;
-       struct md_hsm            mh;
-       bool                     is_mh_changed;
-       bool                     need_changelog = true;
-       ENTRY;
+       const struct lu_env *env = mti->mti_env;
+       struct mdt_device *mdt = mti->mti_mdt;
+       struct coordinator *cdt = &mdt->mdt_coordinator;
+       struct mdt_object *obj = NULL;
+       enum changelog_rec_flags clf_flags = 0;
+       struct md_hsm mh;
+       bool is_mh_changed;
+       bool need_changelog = true;
+       int rc = 0;
 
+       ENTRY;
        /* default is to retry */
        *status = ARS_WAITING;
 
@@ -1380,25 +1484,24 @@ static int hsm_cdt_request_completed(struct mdt_thread_info *mti,
                               mdt_obd_name(mdt),
                               pgs->hpk_cookie, PFID(&pgs->hpk_fid),
                               pgs->hpk_errval);
-                       hsm_set_cl_error(&cl_flags,
-                                        CLF_HSM_ERROVERFLOW);
+                       hsm_set_cl_error(&clf_flags, CLF_HSM_ERROVERFLOW);
                        rc = -EINVAL;
                } else {
-                       hsm_set_cl_error(&cl_flags, pgs->hpk_errval);
+                       hsm_set_cl_error(&clf_flags, pgs->hpk_errval);
                }
 
                switch (car->car_hai->hai_action) {
                case HSMA_ARCHIVE:
-                       hsm_set_cl_event(&cl_flags, HE_ARCHIVE);
+                       hsm_set_cl_event(&clf_flags, HE_ARCHIVE);
                        break;
                case HSMA_RESTORE:
-                       hsm_set_cl_event(&cl_flags, HE_RESTORE);
+                       hsm_set_cl_event(&clf_flags, HE_RESTORE);
                        break;
                case HSMA_REMOVE:
-                       hsm_set_cl_event(&cl_flags, HE_REMOVE);
+                       hsm_set_cl_event(&clf_flags, HE_REMOVE);
                        break;
                case HSMA_CANCEL:
-                       hsm_set_cl_event(&cl_flags, HE_CANCEL);
+                       hsm_set_cl_event(&clf_flags, HE_CANCEL);
                        CERROR("%s: Failed request %#llx on "DFID
                               " cannot be a CANCEL\n",
                               mdt_obd_name(mdt),
@@ -1418,7 +1521,7 @@ static int hsm_cdt_request_completed(struct mdt_thread_info *mti,
                *status = ARS_SUCCEED;
                switch (car->car_hai->hai_action) {
                case HSMA_ARCHIVE:
-                       hsm_set_cl_event(&cl_flags, HE_ARCHIVE);
+                       hsm_set_cl_event(&clf_flags, HE_ARCHIVE);
                        /* set ARCHIVE keep EXIST and clear LOST and
                         * DIRTY */
                        mh.mh_arch_ver = pgs->hpk_data_version;
@@ -1427,7 +1530,7 @@ static int hsm_cdt_request_completed(struct mdt_thread_info *mti,
                        is_mh_changed = true;
                        break;
                case HSMA_RESTORE:
-                       hsm_set_cl_event(&cl_flags, HE_RESTORE);
+                       hsm_set_cl_event(&clf_flags, HE_RESTORE);
 
                        /* do not clear RELEASED and DIRTY here
                         * this will occur in hsm_swap_layouts()
@@ -1439,13 +1542,13 @@ static int hsm_cdt_request_completed(struct mdt_thread_info *mti,
                        is_mh_changed = true;
                        break;
                case HSMA_REMOVE:
-                       hsm_set_cl_event(&cl_flags, HE_REMOVE);
+                       hsm_set_cl_event(&clf_flags, HE_REMOVE);
                        /* clear ARCHIVED EXISTS and LOST */
                        mh.mh_flags &= ~(HS_ARCHIVED | HS_EXISTS | HS_LOST);
                        is_mh_changed = true;
                        break;
                case HSMA_CANCEL:
-                       hsm_set_cl_event(&cl_flags, HE_CANCEL);
+                       hsm_set_cl_event(&clf_flags, HE_CANCEL);
                        CERROR("%s: Successful request %#llx on "DFID" cannot be a CANCEL\n",
                               mdt_obd_name(mdt),
                               pgs->hpk_cookie,
@@ -1467,7 +1570,7 @@ static int hsm_cdt_request_completed(struct mdt_thread_info *mti,
         * filled
         */
        if (rc == 0 && !IS_ERR(obj))
-               hsm_set_cl_flags(&cl_flags,
+               hsm_set_cl_flags(&clf_flags,
                                 mh.mh_flags & HS_DIRTY ? CLF_HSM_DIRTY : 0);
 
        /* unlock is done later, after layout lock management */
@@ -1478,7 +1581,7 @@ static int hsm_cdt_request_completed(struct mdt_thread_info *mti,
         * if no retry will be attempted and if object is still alive,
         * in other cases we just unlock the object */
        if (car->car_hai->hai_action == HSMA_RESTORE) {
-               struct cdt_restore_handle       *crh;
+               struct mdt_lock_handle *lh;
 
                /* restore in data FID done, we swap the layouts
                 * only if restore is successful */
@@ -1498,25 +1601,18 @@ static int hsm_cdt_request_completed(struct mdt_thread_info *mti,
                /* restore special case, need to create ChangeLog record
                 * before to give back layout lock to avoid concurrent
                 * file updater to post out of order ChangeLog */
-               mo_changelog(env, CL_HSM, cl_flags, mdt->mdt_child,
+               mo_changelog(env, CL_HSM, clf_flags, mdt->mdt_child,
                             &car->car_hai->hai_fid);
                need_changelog = false;
 
-               /* give back layout lock */
-               mutex_lock(&cdt->cdt_restore_lock);
-               crh = mdt_hsm_restore_hdl_find(cdt, &car->car_hai->hai_fid);
-               if (crh != NULL)
-                       list_del(&crh->crh_list);
-               mutex_unlock(&cdt->cdt_restore_lock);
-               /* Just give back layout lock, we keep the reference
-                * which is given back later with the lock for HSM
-                * flags.
-                * XXX obj may be invalid so we do not pass it. */
-               if (crh != NULL)
-                       mdt_object_unlock(mti, NULL, &crh->crh_lh, 1);
-
-               if (crh != NULL)
-                       OBD_SLAB_FREE_PTR(crh, mdt_hsm_cdt_kmem);
+               cdt_restore_handle_del(mti, cdt, &car->car_hai->hai_fid);
+               if (!IS_ERR_OR_NULL(obj)) {
+                       /* flush UPDATE lock so attributes are upadated */
+                       lh = &mti->mti_lh[MDT_LH_OLD];
+                       mdt_lock_reg_init(lh, LCK_EX);
+                       mdt_object_lock(mti, obj, lh, MDS_INODELOCK_UPDATE);
+                       mdt_object_unlock(mti, obj, lh, 1);
+               }
        }
 
        GOTO(out, rc);
@@ -1524,7 +1620,7 @@ static int hsm_cdt_request_completed(struct mdt_thread_info *mti,
 out:
        /* always add a ChangeLog record */
        if (need_changelog)
-               mo_changelog(env, CL_HSM, cl_flags, mdt->mdt_child,
+               mo_changelog(env, CL_HSM, clf_flags, mdt->mdt_child,
                             &car->car_hai->hai_fid);
 
        if (!IS_ERR(obj))
@@ -1537,13 +1633,11 @@ out:
  * update status of a request
  * \param mti [IN] context
  * \param pgs [IN] progress of the copy tool
- * \param update_record [IN] update llog record
  * \retval 0 success
  * \retval -ve failure
  */
 int mdt_hsm_update_request_state(struct mdt_thread_info *mti,
-                                struct hsm_progress_kernel *pgs,
-                                const int update_record)
+                                struct hsm_progress_kernel *pgs)
 {
        struct mdt_device       *mdt = mti->mti_mdt;
        struct coordinator      *cdt = &mdt->mdt_coordinator;
@@ -1566,19 +1660,6 @@ int mdt_hsm_update_request_state(struct mdt_thread_info *mti,
                RETURN(PTR_ERR(car));
        }
 
-       /* wait for update request from copytool if hsm cancel is
-        * initiated by user. If update request is as a result of
-        * kill of copytool or eviction data mover node then skip
-        * delaying and update the request as copytool is unavailable
-        * to send the update request
-        */
-       if (car->car_delay_update == 1) {
-               if (pgs->hpk_flags & HP_FLAG_COMPLETE_DELAYED)
-                       car->car_delay_update = 0;
-               else
-                       GOTO(out, rc = -ECANCELED);
-       }
-
        CDEBUG(D_HSM, "Progress received for fid="DFID" cookie=%#llx"
                      " action=%s flags=%d err=%d fid="DFID" dfid="DFID"\n",
                      PFID(&pgs->hpk_fid), pgs->hpk_cookie,
@@ -1625,36 +1706,31 @@ int mdt_hsm_update_request_state(struct mdt_thread_info *mti,
        hsm_init_ucred(mdt_ucred(mti));
 
        if (pgs->hpk_flags & HP_FLAG_COMPLETED) {
-               enum agent_req_status    status;
+               enum agent_req_status status;
+               struct hsm_record_update update;
+               int rc1;
 
                rc = hsm_cdt_request_completed(mti, pgs, car, &status);
 
-               CDEBUG(D_HSM, "%s record: fid="DFID" cookie=%#llx action=%s "
+               CDEBUG(D_HSM, "updating record: fid="DFID" cookie=%#llx action=%s "
                              "status=%s\n",
-                      update_record ? "Updating" : "Not updating",
                       PFID(&pgs->hpk_fid), pgs->hpk_cookie,
                       hsm_copytool_action2name(car->car_hai->hai_action),
                       agent_req_status2name(status));
 
                /* update record first (LU-9075) */
-               if (update_record) {
-                       int rc1;
-                       struct hsm_record_update update = {
-                               .cookie = pgs->hpk_cookie,
-                               .status = status,
-                       };
-
-                       rc1 = mdt_agent_record_update(mti->mti_env, mdt,
-                                                     &update, 1);
-                       if (rc1)
-                               CERROR("%s: mdt_agent_record_update() failed,"
-                                      " rc=%d, cannot update status to %s"
-                                      " for cookie %#llx\n",
-                                      mdt_obd_name(mdt), rc1,
-                                      agent_req_status2name(status),
-                                      pgs->hpk_cookie);
-                       rc = (rc != 0 ? rc : rc1);
-               }
+               update.cookie = pgs->hpk_cookie;
+               update.status = status;
+
+               rc1 = mdt_agent_record_update(mti, &update, 1);
+               if (rc1)
+                       CERROR("%s: mdt_agent_record_update() failed,"
+                              " rc=%d, cannot update status to %s"
+                              " for cookie %#llx\n",
+                              mdt_obd_name(mdt), rc1,
+                              agent_req_status2name(status),
+                              pgs->hpk_cookie);
+               rc = (rc != 0 ? rc : rc1);
 
                /* then remove request from memory list (LU-9075) */
                mdt_cdt_remove_request(cdt, pgs->hpk_cookie);
@@ -1680,20 +1756,12 @@ out:
 
 
 /**
- * data passed to llog_cat_process() callback
- * to cancel requests
- */
-struct hsm_cancel_all_data {
-       struct mdt_device       *mdt;
-};
-
-/**
  *  llog_cat_process() callback, used to:
  *  - purge all requests
  * \param env [IN] environment
  * \param llh [IN] llog handle
  * \param hdr [IN] llog record
- * \param data [IN] cb data = struct hsm_cancel_all_data
+ * \param data [IN] cb data = struct mdt_thread_info
  * \retval 0 success
  * \retval -ve failure
  */
@@ -1701,132 +1769,29 @@ static int mdt_cancel_all_cb(const struct lu_env *env,
                             struct llog_handle *llh,
                             struct llog_rec_hdr *hdr, void *data)
 {
-       struct llog_agent_req_rec       *larr;
-       struct hsm_cancel_all_data      *hcad;
-       int                              rc = 0;
-       ENTRY;
-
-       larr = (struct llog_agent_req_rec *)hdr;
-       hcad = data;
-       if (larr->arr_status == ARS_WAITING ||
-           larr->arr_status == ARS_STARTED) {
-               larr->arr_status = ARS_CANCELED;
-               larr->arr_req_change = ktime_get_real_seconds();
-               rc = llog_write(env, llh, hdr, hdr->lrh_index);
-       }
-
-       RETURN(rc);
-}
-
-/**
- * prepare cancel request
- * \param hal [IN] pointer to allocate memory
- * \param car [IN] coordinator agent request
- * \param mdt_obd_name [IN] mdt object device name
- * \param hal_sz [IN, OUT] old size of hal_sz buffer
- */
-static struct hsm_action_list *
-hsm_create_cancel_request(struct hsm_action_list *hal,
-                         struct cdt_agent_req *car,
-                         char *mdt_obd_name, int *hal_sz)
-{
-       struct hsm_action_item *hai;
-       int hal_sz_needed;
-
-       /* needed size */
-       hal_sz_needed = sizeof(*hal) + cfs_size_round(MTI_NAME_MAXLEN + 1) +
-                 cfs_size_round(car->car_hai->hai_len);
-
-       if (hal_sz_needed > *hal_sz) {
-               /* not enough room, free old buffer */
-               if (hal != NULL)
-                       OBD_FREE(hal, *hal_sz);
-               *hal_sz = hal_sz_needed;
-               OBD_ALLOC(hal, *hal_sz);
-               if (hal == NULL) {
-                       CERROR("Cannot allocate memory for hal\n");
-                       RETURN(NULL);
-               }
-       }
-
-       hal->hal_version = HAL_VERSION;
-       obd_uuid2fsname(hal->hal_fsname, mdt_obd_name,
-                       MTI_NAME_MAXLEN);
-       hal->hal_fsname[MTI_NAME_MAXLEN] = '\0';
-       hal->hal_compound_id = car->car_compound_id;
-       hal->hal_archive_id = car->car_archive_id;
-       hal->hal_flags = car->car_flags;
-       hal->hal_count = 0;
-
-       hai = hai_first(hal);
-       memcpy(hai, car->car_hai, car->car_hai->hai_len);
-       hai->hai_action = HSMA_CANCEL;
-       hal->hal_count = 1;
-
-       RETURN(hal);
-}
-
-/**
- * cancel actions running on a agent
- * \param mdt [IN] MDT device
- * \param uuid [IN] the obd_uuid of the agent whose requests are to be canceled
- */
-int hsm_cancel_agent_requests(struct mdt_device *mdt,
-                             const struct obd_uuid *uuid)
-{
-       struct mdt_thread_info *mti;
-       struct coordinator *cdt = &mdt->mdt_coordinator;
-       struct cdt_agent_req *car;
-       int rc = 0;
-       enum cdt_states save_state;
-       struct hsm_record_update update;
+       struct llog_agent_req_rec *larr = (struct llog_agent_req_rec *)hdr;
+       struct hsm_action_item *hai = &larr->arr_hai;
+       struct mdt_thread_info  *mti = data;
+       struct coordinator *cdt = &mti->mti_mdt->mdt_coordinator;
+       int rc;
        ENTRY;
 
-       /* retrieve coordinator context */
-       mti = lu_context_key_get(&cdt->cdt_env.le_ctx, &mdt_thread_key);
-
-       /* disable coordinator */
-       save_state = cdt->cdt_state;
-       cdt->cdt_state = CDT_DISABLE;
-
-       down_read(&cdt->cdt_request_lock);
-       list_for_each_entry(car, &cdt->cdt_request_list, car_request_list) {
-               mdt_cdt_get_request(car);
-               /* request is not yet removed from list, it will be done
-                * when copytool will return progress
-                */
-               if (!obd_uuid_equals(&car->car_uuid, uuid)) {
-                       mdt_cdt_put_request(car);
-                       continue;
-               }
-
-               if (car->car_hai->hai_action == HSMA_CANCEL) {
-                       mdt_cdt_put_request(car);
-                       continue;
-               }
-
-               update.cookie = car->car_hai->hai_cookie;
-               update.status = ARS_CANCELED;
-
-               rc = mdt_agent_record_update(mti->mti_env, mti->mti_mdt,
-                                            &update, 1);
+       if (larr->arr_status != ARS_WAITING &&
+           larr->arr_status != ARS_STARTED)
+               RETURN(0);
 
-               if (rc == 0)
-                       car->car_canceled = 1;
-               else
-                       CERROR("%s: mdt_agent_record_update() failed, "
-                              "rc=%d, cannot update status to %s "
-                              "for cookie %#llx\n",
-                              mdt_obd_name(mdt), rc,
-                              agent_req_status2name(ARS_CANCELED),
-                              car->car_hai->hai_cookie);
+       /* Unlock the EX layout lock */
+       if (hai->hai_action == HSMA_RESTORE)
+               cdt_restore_handle_del(mti, cdt, &hai->hai_fid);
 
-               mdt_cdt_put_request(car);
+       larr->arr_status = ARS_CANCELED;
+       larr->arr_req_change = ktime_get_real_seconds();
+       rc = llog_write(env, llh, hdr, hdr->lrh_index);
+       if (rc < 0) {
+               CERROR("%s: cannot update agent log: rc = %d\n",
+                      mdt_obd_name(mti->mti_mdt), rc);
+               rc = LLOG_DEL_RECORD;
        }
-       up_read(&cdt->cdt_request_lock);
-
-       /* enable coordinator */
-       cdt->cdt_state = save_state;
 
        RETURN(rc);
 }
@@ -1843,8 +1808,8 @@ static int hsm_cancel_all_actions(struct mdt_device *mdt)
        struct coordinator              *cdt = &mdt->mdt_coordinator;
        struct cdt_agent_req            *car;
        struct hsm_action_list          *hal = NULL;
-       struct hsm_cancel_all_data       hcad;
-       int                              hal_sz = 0, rc;
+       struct hsm_action_item          *hai;
+       int                              hal_sz = 0, hal_len, rc;
        enum cdt_states                  old_state;
        ENTRY;
 
@@ -1868,10 +1833,13 @@ static int hsm_cancel_all_actions(struct mdt_device *mdt)
 
        hsm_init_ucred(mdt_ucred(mti));
 
+       mutex_lock(&cdt->cdt_state_lock);
+       old_state = cdt->cdt_state;
+
        /* disable coordinator */
-       rc = set_cdt_state(cdt, CDT_DISABLE, &old_state);
+       rc = set_cdt_state_locked(cdt, CDT_DISABLE);
        if (rc)
-               RETURN(rc);
+               GOTO(out_cdt_state_unlock, rc);
 
        /* send cancel to all running requests */
        down_read(&cdt->cdt_request_lock);
@@ -1886,15 +1854,40 @@ static int hsm_cancel_all_actions(struct mdt_device *mdt)
                        continue;
                }
 
-               hal = hsm_create_cancel_request(hal, car,
-                                               mdt_obd_name(mdt),
-                                               &hal_sz);
+               /* needed size */
+               hal_len = sizeof(*hal) + cfs_size_round(MTI_NAME_MAXLEN + 1) +
+                         cfs_size_round(car->car_hai->hai_len);
+
+               if (hal_len > hal_sz && hal_sz > 0) {
+                       /* not enough room, free old buffer */
+                       OBD_FREE(hal, hal_sz);
+                       hal = NULL;
+               }
+
+               /* empty buffer, allocate one */
                if (hal == NULL) {
-                       mdt_cdt_put_request(car);
-                       up_read(&cdt->cdt_request_lock);
-                       GOTO(out_cdt_state, rc = -ENOMEM);
+                       hal_sz = hal_len;
+                       OBD_ALLOC(hal, hal_sz);
+                       if (hal == NULL) {
+                               mdt_cdt_put_request(car);
+                               up_read(&cdt->cdt_request_lock);
+                               GOTO(out_cdt_state, rc = -ENOMEM);
+                       }
                }
 
+               hal->hal_version = HAL_VERSION;
+               obd_uuid2fsname(hal->hal_fsname, mdt_obd_name(mdt),
+                               MTI_NAME_MAXLEN);
+               hal->hal_fsname[MTI_NAME_MAXLEN] = '\0';
+               hal->hal_archive_id = car->car_archive_id;
+               hal->hal_flags = car->car_flags;
+               hal->hal_count = 0;
+
+               hai = hai_first(hal);
+               memcpy(hai, car->car_hai, car->car_hai->hai_len);
+               hai->hai_action = HSMA_CANCEL;
+               hal->hal_count = 1;
+
                /* it is possible to safely call mdt_hsm_agent_send()
                 * (ie without a deadlock on cdt_request_lock), because the
                 * write lock is taken only if we are not in purge mode
@@ -1903,7 +1896,7 @@ static int hsm_cancel_all_actions(struct mdt_device *mdt)
                 */
                /* no conflict with cdt thread because cdt is disable and we
                 * have the request lock */
-               mdt_hsm_agent_send(mti, hal, true);
+               mdt_hsm_agent_send(mti, hal, 1);
 
                mdt_cdt_put_request(car);
        }
@@ -1913,13 +1906,14 @@ static int hsm_cancel_all_actions(struct mdt_device *mdt)
                OBD_FREE(hal, hal_sz);
 
        /* cancel all on-disk records */
-       hcad.mdt = mdt;
-
        rc = cdt_llog_process(mti->mti_env, mti->mti_mdt, mdt_cancel_all_cb,
-                             &hcad, 0, 0, WRITE);
+                             (void *)mti, 0, 0, WRITE);
 out_cdt_state:
        /* Enable coordinator, unless the coordinator was stopping. */
-       set_cdt_state(cdt, old_state, NULL);
+       set_cdt_state_locked(cdt, old_state);
+out_cdt_state_unlock:
+       mutex_unlock(&cdt->cdt_state_lock);
+
        lu_context_exit(&session);
        lu_context_fini(&session);
 out_env:
@@ -1983,7 +1977,7 @@ bool mdt_hsm_is_action_compat(const struct hsm_action_item *hai,
 }
 
 /*
- * /proc interface used to get/set HSM behaviour (cdt->cdt_policy)
+ * sysfs interface used to get/set HSM behaviour (cdt->cdt_policy)
  */
 static const struct {
        __u64            bit;
@@ -2142,45 +2136,149 @@ out:
        OBD_FREE(buf, count + 1);
        RETURN(rc);
 }
-LPROC_SEQ_FOPS(mdt_hsm_policy);
-
-#define GENERATE_PROC_METHOD(VAR)                                      \
-static int mdt_hsm_##VAR##_seq_show(struct seq_file *m, void *data)    \
-{                                                                      \
-       struct mdt_device       *mdt = m->private;                      \
-       struct coordinator      *cdt = &mdt->mdt_coordinator;           \
-       ENTRY;                                                          \
-                                                                       \
-       seq_printf(m, "%llu\n", (__u64)cdt->VAR);                       \
-       RETURN(0);                                                      \
-}                                                                      \
-static ssize_t                                                         \
-mdt_hsm_##VAR##_seq_write(struct file *file, const char __user *buffer,        \
-                         size_t count, loff_t *off)                    \
-                                                                       \
-{                                                                      \
-       struct seq_file         *m = file->private_data;                \
-       struct mdt_device       *mdt = m->private;                      \
-       struct coordinator      *cdt = &mdt->mdt_coordinator;           \
-       __s64                    val;                                   \
-       int                      rc;                                    \
-       ENTRY;                                                          \
-                                                                       \
-       rc = lprocfs_str_to_s64(buffer, count, &val);                   \
-       if (rc)                                                         \
-               RETURN(rc);                                             \
-       if (val > 0 && val < INT_MAX) {                                 \
-               cdt->VAR = val;                                         \
-               RETURN(count);                                          \
-       }                                                               \
-       RETURN(-EINVAL);                                                \
-}                                                                      \
-
-GENERATE_PROC_METHOD(cdt_loop_period)
-GENERATE_PROC_METHOD(cdt_grace_delay)
-GENERATE_PROC_METHOD(cdt_active_req_timeout)
-GENERATE_PROC_METHOD(cdt_max_requests)
-GENERATE_PROC_METHOD(cdt_default_archive_id)
+LDEBUGFS_SEQ_FOPS(mdt_hsm_policy);
+
+ssize_t loop_period_show(struct kobject *kobj, struct attribute *attr,
+                        char *buf)
+{
+       struct coordinator *cdt = container_of(kobj, struct coordinator,
+                                              cdt_hsm_kobj);
+
+       return scnprintf(buf, PAGE_SIZE, "%u\n", cdt->cdt_loop_period);
+}
+
+ssize_t loop_period_store(struct kobject *kobj, struct attribute *attr,
+                         const char *buffer, size_t count)
+{
+       struct coordinator *cdt = container_of(kobj, struct coordinator,
+                                              cdt_hsm_kobj);
+       unsigned int val;
+       int rc;
+
+       rc = kstrtouint(buffer, 0, &val);
+       if (rc)
+               return rc;
+
+       if (val != 0)
+               cdt->cdt_loop_period = val;
+
+       return val ? count : -EINVAL;
+}
+LUSTRE_RW_ATTR(loop_period);
+
+ssize_t grace_delay_show(struct kobject *kobj, struct attribute *attr,
+                        char *buf)
+{
+       struct coordinator *cdt = container_of(kobj, struct coordinator,
+                                              cdt_hsm_kobj);
+
+       return scnprintf(buf, PAGE_SIZE, "%u\n", cdt->cdt_grace_delay);
+}
+
+ssize_t grace_delay_store(struct kobject *kobj, struct attribute *attr,
+                         const char *buffer, size_t count)
+{
+       struct coordinator *cdt = container_of(kobj, struct coordinator,
+                                              cdt_hsm_kobj);
+       unsigned int val;
+       int rc;
+
+       rc = kstrtouint(buffer, 0, &val);
+       if (rc)
+               return rc;
+
+       if (val != 0)
+               cdt->cdt_grace_delay = val;
+
+       return val ? count : -EINVAL;
+}
+LUSTRE_RW_ATTR(grace_delay);
+
+ssize_t active_request_timeout_show(struct kobject *kobj,
+                                   struct attribute *attr,
+                                   char *buf)
+{
+       struct coordinator *cdt = container_of(kobj, struct coordinator,
+                                              cdt_hsm_kobj);
+
+       return scnprintf(buf, PAGE_SIZE, "%d\n", cdt->cdt_active_req_timeout);
+}
+
+ssize_t active_request_timeout_store(struct kobject *kobj,
+                                    struct attribute *attr,
+                                    const char *buffer, size_t count)
+{
+       struct coordinator *cdt = container_of(kobj, struct coordinator,
+                                              cdt_hsm_kobj);
+       unsigned int val;
+       int rc;
+
+       rc = kstrtouint(buffer, 0, &val);
+       if (rc)
+               return rc;
+
+       if (val != 0)
+               cdt->cdt_active_req_timeout = val;
+
+       return val ? count : -EINVAL;
+}
+LUSTRE_RW_ATTR(active_request_timeout);
+
+ssize_t max_requests_show(struct kobject *kobj, struct attribute *attr,
+                         char *buf)
+{
+       struct coordinator *cdt = container_of(kobj, struct coordinator,
+                                              cdt_hsm_kobj);
+
+       return scnprintf(buf, PAGE_SIZE, "%llu\n", cdt->cdt_max_requests);
+}
+
+ssize_t max_requests_store(struct kobject *kobj, struct attribute *attr,
+                          const char *buffer, size_t count)
+{
+       struct coordinator *cdt = container_of(kobj, struct coordinator,
+                                              cdt_hsm_kobj);
+       unsigned long long val;
+       int rc;
+
+       rc = kstrtoull(buffer, 0, &val);
+       if (rc)
+               return rc;
+
+       if (val != 0)
+               cdt->cdt_max_requests = val;
+
+       return val ? count : -EINVAL;
+}
+LUSTRE_RW_ATTR(max_requests);
+
+ssize_t default_archive_id_show(struct kobject *kobj, struct attribute *attr,
+                               char *buf)
+{
+       struct coordinator *cdt = container_of(kobj, struct coordinator,
+                                              cdt_hsm_kobj);
+
+       return scnprintf(buf, PAGE_SIZE, "%u\n", cdt->cdt_default_archive_id);
+}
+
+ssize_t default_archive_id_store(struct kobject *kobj, struct attribute *attr,
+                                const char *buffer, size_t count)
+{
+       struct coordinator *cdt = container_of(kobj, struct coordinator,
+                                              cdt_hsm_kobj);
+       unsigned int val;
+       int rc;
+
+       rc = kstrtouint(buffer, 0, &val);
+       if (rc)
+               return rc;
+
+       if (val != 0)
+               cdt->cdt_default_archive_id = val;
+
+       return val ? count : -EINVAL;
+}
+LUSTRE_RW_ATTR(default_archive_id);
 
 /*
  * procfs write method for MDT/hsm_control
@@ -2193,58 +2291,55 @@ GENERATE_PROC_METHOD(cdt_default_archive_id)
 #define CDT_HELP_CMD     "help"
 #define CDT_MAX_CMD_LEN  10
 
-ssize_t
-mdt_hsm_cdt_control_seq_write(struct file *file, const char __user *buffer,
-                             size_t count, loff_t *off)
+ssize_t hsm_control_store(struct kobject *kobj, struct attribute *attr,
+                         const char *buffer, size_t count)
 {
-       struct seq_file         *m = file->private_data;
-       struct obd_device       *obd = m->private;
-       struct mdt_device       *mdt = mdt_dev(obd->obd_lu_dev);
-       struct coordinator      *cdt = &(mdt->mdt_coordinator);
-       int                      rc, usage = 0;
-       char                     kernbuf[CDT_MAX_CMD_LEN];
-       ENTRY;
-
-       if (count == 0 || count >= sizeof(kernbuf))
-               RETURN(-EINVAL);
-
-       if (copy_from_user(kernbuf, buffer, count))
-               RETURN(-EFAULT);
-       kernbuf[count] = 0;
+       struct obd_device *obd = container_of(kobj, struct obd_device,
+                                             obd_kset.kobj);
+       struct mdt_device *mdt = mdt_dev(obd->obd_lu_dev);
+       struct coordinator *cdt = &(mdt->mdt_coordinator);
+       int usage = 0;
+       int rc = 0;
 
-       if (kernbuf[count - 1] == '\n')
-               kernbuf[count - 1] = 0;
+       if (count == 0 || count >= CDT_MAX_CMD_LEN)
+               return -EINVAL;
 
-       rc = 0;
-       if (strcmp(kernbuf, CDT_ENABLE_CMD) == 0) {
+       if (strncmp(buffer, CDT_ENABLE_CMD, strlen(CDT_ENABLE_CMD)) == 0) {
                if (cdt->cdt_state == CDT_DISABLE) {
-                       rc = set_cdt_state(cdt, CDT_RUNNING, NULL);
+                       rc = set_cdt_state(cdt, CDT_RUNNING);
                        mdt_hsm_cdt_event(cdt);
                        wake_up(&cdt->cdt_waitq);
+               } else if (cdt->cdt_state == CDT_RUNNING) {
+                       rc = 0;
                } else {
                        rc = mdt_hsm_cdt_start(mdt);
                }
-       } else if (strcmp(kernbuf, CDT_STOP_CMD) == 0) {
-               if ((cdt->cdt_state == CDT_STOPPING) ||
-                   (cdt->cdt_state == CDT_STOPPED)) {
-                       CERROR("%s: Coordinator already stopped\n",
+       } else if (strncmp(buffer, CDT_STOP_CMD, strlen(CDT_STOP_CMD)) == 0) {
+               if (cdt->cdt_state == CDT_STOPPING) {
+                       CERROR("%s: Coordinator is already stopping\n",
                               mdt_obd_name(mdt));
                        rc = -EALREADY;
+               } else if (cdt->cdt_state == CDT_STOPPED) {
+                       rc = 0;
                } else {
                        rc = mdt_hsm_cdt_stop(mdt);
                }
-       } else if (strcmp(kernbuf, CDT_DISABLE_CMD) == 0) {
+       } else if (strncmp(buffer, CDT_DISABLE_CMD,
+                          strlen(CDT_DISABLE_CMD)) == 0) {
                if ((cdt->cdt_state == CDT_STOPPING) ||
                    (cdt->cdt_state == CDT_STOPPED)) {
-                       CERROR("%s: Coordinator is stopped\n",
-                              mdt_obd_name(mdt));
-                       rc = -EINVAL;
+                       /* exit gracefully if coordinator is being stopped
+                        * or stopped already.
+                        */
+                       rc = 0;
                } else {
-                       rc = set_cdt_state(cdt, CDT_DISABLE, NULL);
+                       rc = set_cdt_state(cdt, CDT_DISABLE);
                }
-       } else if (strcmp(kernbuf, CDT_PURGE_CMD) == 0) {
+       } else if (strncmp(buffer, CDT_PURGE_CMD,
+                          strlen(CDT_PURGE_CMD)) == 0) {
                rc = hsm_cancel_all_actions(mdt);
-       } else if (strcmp(kernbuf, CDT_HELP_CMD) == 0) {
+       } else if (strncmp(buffer, CDT_HELP_CMD,
+                          strlen(CDT_HELP_CMD)) == 0) {
                usage = 1;
        } else {
                usage = 1;
@@ -2263,17 +2358,17 @@ mdt_hsm_cdt_control_seq_write(struct file *file, const char __user *buffer,
        RETURN(count);
 }
 
-int mdt_hsm_cdt_control_seq_show(struct seq_file *m, void *data)
+ssize_t hsm_control_show(struct kobject *kobj, struct attribute *attr,
+                        char *buf)
 {
-       struct obd_device       *obd = m->private;
-       struct coordinator      *cdt;
-       ENTRY;
+       struct obd_device *obd = container_of(kobj, struct obd_device,
+                                             obd_kset.kobj);
+       struct coordinator *cdt;
 
        cdt = &(mdt_dev(obd->obd_lu_dev)->mdt_coordinator);
 
-       seq_printf(m, "%s\n", cdt_mdt_state2str(cdt->cdt_state));
-
-       RETURN(0);
+       return scnprintf(buf, PAGE_SIZE, "%s\n",
+                        cdt_mdt_state2str(cdt->cdt_state));
 }
 
 static int
@@ -2421,64 +2516,82 @@ mdt_hsm_other_request_mask_seq_write(struct file *file, const char __user *buf,
                                           &cdt->cdt_other_request_mask);
 }
 
-static int mdt_hsm_cdt_raolu_seq_show(struct seq_file *m, void *data)
+static ssize_t remove_archive_on_last_unlink_show(struct kobject *kobj,
+                                                 struct attribute *attr,
+                                                 char *buf)
 {
-       struct mdt_device *mdt = m->private;
-       struct coordinator *cdt = &mdt->mdt_coordinator;
-       ENTRY;
+       struct coordinator *cdt = container_of(kobj, struct coordinator,
+                                              cdt_hsm_kobj);
 
-       seq_printf(m, "%d\n", (int)cdt->cdt_remove_archive_on_last_unlink);
-       RETURN(0);
+       return scnprintf(buf, PAGE_SIZE, "%u\n",
+                        cdt->cdt_remove_archive_on_last_unlink);
 }
 
-static ssize_t
-mdt_hsm_cdt_raolu_seq_write(struct file *file, const char __user *buffer,
-                           size_t count, loff_t *off)
-
+static ssize_t remove_archive_on_last_unlink_store(struct kobject *kobj,
+                                                  struct attribute *attr,
+                                                  const char *buffer,
+                                                  size_t count)
 {
-       struct seq_file *m = file->private_data;
-       struct mdt_device *mdt = m->private;
-       struct coordinator *cdt = &mdt->mdt_coordinator;
-       __s64 val;
+       struct coordinator *cdt = container_of(kobj, struct coordinator,
+                                              cdt_hsm_kobj);
+       bool val;
        int rc;
-       ENTRY;
 
-       rc = lprocfs_str_to_s64(buffer, count, &val);
+       rc = kstrtobool(buffer, &val);
        if (rc < 0)
-               RETURN(rc);
+               return rc;
 
        cdt->cdt_remove_archive_on_last_unlink = val;
-       RETURN(count);
+       return count;
+}
+LUSTRE_RW_ATTR(remove_archive_on_last_unlink);
+
+LDEBUGFS_SEQ_FOPS(mdt_hsm_user_request_mask);
+LDEBUGFS_SEQ_FOPS(mdt_hsm_group_request_mask);
+LDEBUGFS_SEQ_FOPS(mdt_hsm_other_request_mask);
+
+/* Read-only sysfs files for request counters */
+static ssize_t archive_count_show(struct kobject *kobj, struct attribute *attr,
+                                 char *buf)
+{
+       struct coordinator *cdt = container_of(kobj, struct coordinator,
+                                              cdt_hsm_kobj);
+
+       return scnprintf(buf, PAGE_SIZE, "%d\n",
+                        atomic_read(&cdt->cdt_archive_count));
+}
+LUSTRE_RO_ATTR(archive_count);
+
+static ssize_t restore_count_show(struct kobject *kobj, struct attribute *attr,
+                                 char *buf)
+{
+       struct coordinator *cdt = container_of(kobj, struct coordinator,
+                                              cdt_hsm_kobj);
+
+       return scnprintf(buf, PAGE_SIZE, "%d\n",
+                        atomic_read(&cdt->cdt_restore_count));
+}
+LUSTRE_RO_ATTR(restore_count);
+
+static ssize_t remove_count_show(struct kobject *kobj, struct attribute *attr,
+                                char *buf)
+{
+       struct coordinator *cdt = container_of(kobj, struct coordinator,
+                                              cdt_hsm_kobj);
+
+       return scnprintf(buf, PAGE_SIZE, "%d\n",
+                        atomic_read(&cdt->cdt_remove_count));
 }
+LUSTRE_RO_ATTR(remove_count);
 
-LPROC_SEQ_FOPS(mdt_hsm_cdt_loop_period);
-LPROC_SEQ_FOPS(mdt_hsm_cdt_grace_delay);
-LPROC_SEQ_FOPS(mdt_hsm_cdt_active_req_timeout);
-LPROC_SEQ_FOPS(mdt_hsm_cdt_max_requests);
-LPROC_SEQ_FOPS(mdt_hsm_cdt_default_archive_id);
-LPROC_SEQ_FOPS(mdt_hsm_user_request_mask);
-LPROC_SEQ_FOPS(mdt_hsm_group_request_mask);
-LPROC_SEQ_FOPS(mdt_hsm_other_request_mask);
-LPROC_SEQ_FOPS(mdt_hsm_cdt_raolu);
-
-static struct lprocfs_vars lprocfs_mdt_hsm_vars[] = {
+static struct ldebugfs_vars ldebugfs_mdt_hsm_vars[] = {
        { .name =       "agents",
          .fops =       &mdt_hsm_agent_fops                     },
        { .name =       "actions",
          .fops =       &mdt_hsm_actions_fops,
          .proc_mode =  0444                                    },
-       { .name =       "default_archive_id",
-         .fops =       &mdt_hsm_cdt_default_archive_id_fops    },
-       { .name =       "grace_delay",
-         .fops =       &mdt_hsm_cdt_grace_delay_fops           },
-       { .name =       "loop_period",
-         .fops =       &mdt_hsm_cdt_loop_period_fops           },
-       { .name =       "max_requests",
-         .fops =       &mdt_hsm_cdt_max_requests_fops          },
        { .name =       "policy",
          .fops =       &mdt_hsm_policy_fops                    },
-       { .name =       "active_request_timeout",
-         .fops =       &mdt_hsm_cdt_active_req_timeout_fops    },
        { .name =       "active_requests",
          .fops =       &mdt_hsm_active_requests_fops           },
        { .name =       "user_request_mask",
@@ -2487,7 +2600,76 @@ static struct lprocfs_vars lprocfs_mdt_hsm_vars[] = {
          .fops =       &mdt_hsm_group_request_mask_fops,       },
        { .name =       "other_request_mask",
          .fops =       &mdt_hsm_other_request_mask_fops,       },
-       { .name =       "remove_archive_on_last_unlink",
-         .fops =       &mdt_hsm_cdt_raolu_fops,                },
        { 0 }
 };
+
+static struct attribute *hsm_attrs[] = {
+       &lustre_attr_loop_period.attr,
+       &lustre_attr_grace_delay.attr,
+       &lustre_attr_active_request_timeout.attr,
+       &lustre_attr_max_requests.attr,
+       &lustre_attr_default_archive_id.attr,
+       &lustre_attr_remove_archive_on_last_unlink.attr,
+       &lustre_attr_archive_count.attr,
+       &lustre_attr_restore_count.attr,
+       &lustre_attr_remove_count.attr,
+       NULL,
+};
+
+static void hsm_kobj_release(struct kobject *kobj)
+{
+       struct coordinator *cdt = container_of(kobj, struct coordinator,
+                                              cdt_hsm_kobj);
+
+       debugfs_remove_recursive(cdt->cdt_debugfs_dir);
+       cdt->cdt_debugfs_dir = NULL;
+
+       complete(&cdt->cdt_kobj_unregister);
+}
+
+static struct kobj_type hsm_ktype = {
+       .default_attrs  = hsm_attrs,
+       .sysfs_ops      = &lustre_sysfs_ops,
+       .release        = hsm_kobj_release,
+};
+
+/**
+ * create sysfs entries for coordinator
+ * \param mdt [IN]
+ * \retval 0 success
+ * \retval -ve failure
+ */
+int hsm_cdt_tunables_init(struct mdt_device *mdt)
+{
+       struct coordinator *cdt = &mdt->mdt_coordinator;
+       struct obd_device *obd = mdt2obd_dev(mdt);
+       int rc;
+
+       init_completion(&cdt->cdt_kobj_unregister);
+       rc = kobject_init_and_add(&cdt->cdt_hsm_kobj, &hsm_ktype,
+                                 &obd->obd_kset.kobj, "%s", "hsm");
+       if (rc) {
+               kobject_put(&cdt->cdt_hsm_kobj);
+               return rc;
+       }
+
+       /* init debugfs entries, failure is not critical */
+       cdt->cdt_debugfs_dir = debugfs_create_dir("hsm",
+                                                 obd->obd_debugfs_entry);
+       ldebugfs_add_vars(cdt->cdt_debugfs_dir, ldebugfs_mdt_hsm_vars, mdt);
+
+       return 0;
+}
+
+/**
+ * remove sysfs entries for coordinator
+ *
+ * @mdt
+ */
+void hsm_cdt_tunables_fini(struct mdt_device *mdt)
+{
+       struct coordinator *cdt = &mdt->mdt_coordinator;
+
+       kobject_put(&cdt->cdt_hsm_kobj);
+       wait_for_completion(&cdt->cdt_kobj_unregister);
+}