lustre/ptlrpc/nrs_orr.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License version 2 for more details.  A copy is
  14  * included in the COPYING file that accompanied this code.
  15
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  19  *
  20  * GPL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 2013, 2016, Intel Corporation.
  24  *
  25  * Copyright 2012 Xyratex Technology Limited
  26  */
  27 /*
  28  * lustre/ptlrpc/nrs_orr.c
  29  *
  30  * Network Request Scheduler (NRS) ORR and TRR policies
  31  *
  32  * Request scheduling in a Round-Robin manner over backend-fs objects and OSTs
  33  * respectively
  34  *
  35  * Author: Liang Zhen <liang@whamcloud.com>
  36  * Author: Nikitas Angelinas <nikitas_angelinas@xyratex.com>
  37  */
  38 #ifdef HAVE_SERVER_SUPPORT
  39
  40 /**
  41  * \addtogoup nrs
  42  * @{
  43  */
  44 #define DEBUG_SUBSYSTEM S_RPC
  45 #include <obd_support.h>
  46 #include <obd_class.h>
  47 #include <lustre_net.h>
  48 #include <lustre/lustre_idl.h>
  49 #include <lustre_req_layout.h>
  50 #include "ptlrpc_internal.h"
  51
  52 /**
  53  * \name ORR/TRR policy
  54  *
  55  * ORR/TRR (Object-based Round Robin/Target-based Round Robin) NRS policies
  56  *
  57  * ORR performs batched Round Robin shceduling of brw RPCs, based on the FID of
  58  * the backend-fs object that the brw RPC pertains to; the TRR policy performs
  59  * batched Round Robin scheduling of brw RPCs, based on the OST index that the
  60  * RPC pertains to. Both policies also order RPCs in each batch in ascending
  61  * offset order, which is lprocfs-tunable between logical file offsets, and
  62  * physical disk offsets, as reported by fiemap.
  63  *
  64  * The TRR policy reuses much of the functionality of ORR. These two scheduling
  65  * algorithms could alternatively be implemented under a single NRS policy, that
  66  * uses an lprocfs tunable in order to switch between the two types of
  67  * scheduling behaviour. The two algorithms have been implemented as separate
  68  * policies for reasons of clarity to the user, and to avoid issues that would
  69  * otherwise arise at the point of switching between behaviours in the case of
  70  * having a single policy, such as resource cleanup for nrs_orr_object
  71  * instances. It is possible that this may need to be re-examined in the future,
  72  * along with potentially coalescing other policies that perform batched request
  73  * scheduling in a Round-Robin manner, all into one policy.
  74  *
  75  * @{
  76  */
  77
  78 #define NRS_POL_NAME_ORR        "orr"
  79 #define NRS_POL_NAME_TRR        "trr"
  80
  81 /**
  82  * Checks if the RPC type of \a nrq is currently handled by an ORR/TRR policy
  83  *
  84  * \param[in]  orrd   the ORR/TRR policy scheduler instance
  85  * \param[in]  nrq    the request
  86  * \param[out] opcode the opcode is saved here, just in order to avoid calling
  87  *                    lustre_msg_get_opc() again later
  88  *
  89  * \retval true  request type is supported by the policy instance
  90  * \retval false request type is not supported by the policy instance
  91  */
  92 static bool nrs_orr_req_supported(struct nrs_orr_data *orrd,
  93                                   struct ptlrpc_nrs_request *nrq, __u32 *opcode)
  94 {
  95         struct ptlrpc_request  *req = container_of(nrq, struct ptlrpc_request,
  96                                                    rq_nrq);
  97         __u32                   opc = lustre_msg_get_opc(req->rq_reqmsg);
  98         bool                    rc = false;
  99
 100         /**
 101          * XXX: nrs_orr_data::od_supp accessed unlocked.
 102          */
 103         switch (opc) {
 104         case OST_READ:
 105                 rc = orrd->od_supp & NOS_OST_READ;
 106                 break;
 107         case OST_WRITE:
 108                 rc = orrd->od_supp & NOS_OST_WRITE;
 109                 break;
 110         }
 111
 112         if (rc)
 113                 *opcode = opc;
 114
 115         return rc;
 116 }
 117
 118 /**
 119  * Returns the ORR/TRR key fields for the request \a nrq in \a key.
 120  *
 121  * \param[in]  orrd the ORR/TRR policy scheduler instance
 122  * \param[in]  nrq  the request
 123  * \param[in]  opc  the request's opcode
 124  * \param[in]  name the policy name
 125  * \param[out] key  fields of the key are returned here.
 126  *
 127  * \retval 0   key filled successfully
 128  * \retval < 0 error
 129  */
 130 static int nrs_orr_key_fill(struct nrs_orr_data *orrd,
 131                             struct ptlrpc_nrs_request *nrq, __u32 opc,
 132                             char *name, struct nrs_orr_key *key)
 133 {
 134         struct ptlrpc_request  *req = container_of(nrq, struct ptlrpc_request,
 135                                                    rq_nrq);
 136         struct ost_body        *body;
 137         __u32                   ost_idx;
 138         bool                    is_orr = strncmp(name, NRS_POL_NAME_ORR,
 139                                                  NRS_POL_NAME_MAX) == 0;
 140
 141         LASSERT(req != NULL);
 142
 143         /**
 144          * This is an attempt to fill in the request key fields while
 145          * moving a request from the regular to the high-priority NRS
 146          * head (via ldlm_lock_reorder_req()), but the request key has
 147          * been adequately filled when nrs_orr_res_get() was called through
 148          * ptlrpc_nrs_req_initialize() for the regular NRS head's ORR/TRR
 149          * policy, so there is nothing to do.
 150          */
 151         if ((is_orr && nrq->nr_u.orr.or_orr_set) ||
 152             (!is_orr && nrq->nr_u.orr.or_trr_set)) {
 153                 *key = nrq->nr_u.orr.or_key;
 154                 return 0;
 155         }
 156
 157         /* Bounce unconnected requests to the default policy. */
 158         if (req->rq_export == NULL)
 159                 return -ENOTCONN;
 160
 161         if (nrq->nr_u.orr.or_orr_set || nrq->nr_u.orr.or_trr_set)
 162                 memset(&nrq->nr_u.orr.or_key, 0, sizeof(nrq->nr_u.orr.or_key));
 163
 164         ost_idx = class_server_data(req->rq_export->exp_obd)->lsd_osd_index;
 165
 166         if (is_orr) {
 167                 int     rc;
 168                 /**
 169                  * The request pill for OST_READ and OST_WRITE requests is
 170                  * initialized in the ost_io service's
 171                  * ptlrpc_service_ops::so_hpreq_handler, ost_io_hpreq_handler(),
 172                  * so no need to redo it here.
 173                  */
 174                 body = req_capsule_client_get(&req->rq_pill, &RMF_OST_BODY);
 175                 if (body == NULL)
 176                         RETURN(-EFAULT);
 177
 178                 rc = ostid_to_fid(&key->ok_fid, &body->oa.o_oi, ost_idx);
 179                 if (rc < 0)
 180                         return rc;
 181
 182                 nrq->nr_u.orr.or_orr_set = 1;
 183         } else {
 184                 key->ok_idx = ost_idx;
 185                 nrq->nr_u.orr.or_trr_set = 1;
 186         }
 187
 188         return 0;
 189 }
 190
 191 /**
 192  * Populates the range values in \a range with logical offsets obtained via
 193  * \a nb.
 194  *
 195  * \param[in]  nb       niobuf_remote struct array for this request
 196  * \param[in]  niocount count of niobuf_remote structs for this request
 197  * \param[out] range    the offset range is returned here
 198  */
 199 static void nrs_orr_range_fill_logical(struct niobuf_remote *nb, int niocount,
 200                                        struct nrs_orr_req_range *range)
 201 {
 202         /* Should we do this at page boundaries ? */
 203         range->or_start = nb[0].rnb_offset & PAGE_MASK;
 204         range->or_end = (nb[niocount - 1].rnb_offset +
 205                          nb[niocount - 1].rnb_len - 1) | ~PAGE_MASK;
 206 }
 207
 208 /**
 209  * We obtain information just for a single extent, as the request can only be in
 210  * a single place in the binary heap anyway.
 211  */
 212 #define ORR_NUM_EXTENTS 1
 213
 214 /**
 215  * Converts the logical file offset range in \a range, to a physical disk offset
 216  * range in \a range, for a request. Uses obd_get_info() in order to carry out a
 217  * fiemap call and obtain backend-fs extent information. The returned range is
 218  * in physical block numbers.
 219  *
 220  * \param[in]     nrq   the request
 221  * \param[in]     oa    obdo struct for this request
 222  * \param[in,out] range the offset range in bytes; logical range in, physical
 223  *                      range out
 224  *
 225  * \retval 0    physical offsets obtained successfully
 226  * \retvall < 0 error
 227  */
 228 static int nrs_orr_range_fill_physical(struct ptlrpc_nrs_request *nrq,
 229                                        struct obdo *oa,
 230                                        struct nrs_orr_req_range *range)
 231 {
 232         struct ptlrpc_request     *req = container_of(nrq,
 233                                                       struct ptlrpc_request,
 234                                                       rq_nrq);
 235         char                       fiemap_buf[offsetof(struct fiemap,
 236                                                   fm_extents[ORR_NUM_EXTENTS])];
 237         struct fiemap              *fiemap = (struct fiemap *)fiemap_buf;
 238         struct ll_fiemap_info_key  key;
 239         loff_t                     start;
 240         loff_t                     end;
 241         int                        rc;
 242
 243         key = (typeof(key)) {
 244                 .lfik_name = KEY_FIEMAP,
 245                 .lfik_oa = *oa,
 246                 .lfik_fiemap = {
 247                         .fm_start = range->or_start,
 248                         .fm_length = range->or_end - range->or_start,
 249                         .fm_extent_count = ORR_NUM_EXTENTS
 250                 }
 251         };
 252
 253         rc = obd_get_info(req->rq_svc_thread->t_env, req->rq_export,
 254                           sizeof(key), &key, NULL, fiemap);
 255         if (rc < 0)
 256                 GOTO(out, rc);
 257
 258         if (fiemap->fm_mapped_extents == 0 ||
 259             fiemap->fm_mapped_extents > ORR_NUM_EXTENTS)
 260                 GOTO(out, rc = -EFAULT);
 261
 262         /**
 263          * Calculate the physical offset ranges for the request from the extent
 264          * information and the logical request offsets.
 265          */
 266         start = fiemap->fm_extents[0].fe_physical + range->or_start -
 267                 fiemap->fm_extents[0].fe_logical;
 268         end = start + range->or_end - range->or_start;
 269
 270         range->or_start = start;
 271         range->or_end = end;
 272
 273         nrq->nr_u.orr.or_physical_set = 1;
 274 out:
 275         return rc;
 276 }
 277
 278 /**
 279  * Sets the offset range the request covers; either in logical file
 280  * offsets or in physical disk offsets.
 281  *
 282  * \param[in] nrq        the request
 283  * \param[in] orrd       the ORR/TRR policy scheduler instance
 284  * \param[in] opc        the request's opcode
 285  * \param[in] moving_req is the request in the process of moving onto the
 286  *                       high-priority NRS head?
 287  *
 288  * \retval 0    range filled successfully
 289  * \retval != 0 error
 290  */
 291 static int nrs_orr_range_fill(struct ptlrpc_nrs_request *nrq,
 292                               struct nrs_orr_data *orrd, __u32 opc,
 293                               bool moving_req)
 294 {
 295         struct ptlrpc_request       *req = container_of(nrq,
 296                                                         struct ptlrpc_request,
 297                                                         rq_nrq);
 298         struct obd_ioobj            *ioo;
 299         struct niobuf_remote        *nb;
 300         struct ost_body             *body;
 301         struct nrs_orr_req_range     range;
 302         int                          niocount;
 303         int                          rc = 0;
 304
 305         /**
 306          * If we are scheduling using physical disk offsets, but we have filled
 307          * the offset information in the request previously
 308          * (i.e. ldlm_lock_reorder_req() is moving the request to the
 309          * high-priority NRS head), there is no need to do anything, and we can
 310          * exit. Moreover than the lack of need, we would be unable to perform
 311          * the obd_get_info() call required in nrs_orr_range_fill_physical(),
 312          * because ldlm_lock_reorder_lock() calls into here while holding a
 313          * spinlock, and retrieving fiemap information via obd_get_info() is a
 314          * potentially sleeping operation.
 315          */
 316         if (orrd->od_physical && nrq->nr_u.orr.or_physical_set)
 317                 return 0;
 318
 319         ioo = req_capsule_client_get(&req->rq_pill, &RMF_OBD_IOOBJ);
 320         if (ioo == NULL)
 321                 GOTO(out, rc = -EFAULT);
 322
 323         niocount = ioo->ioo_bufcnt;
 324
 325         nb = req_capsule_client_get(&req->rq_pill, &RMF_NIOBUF_REMOTE);
 326         if (nb == NULL)
 327                 GOTO(out, rc = -EFAULT);
 328
 329         /**
 330          * Use logical information from niobuf_remote structures.
 331          */
 332         nrs_orr_range_fill_logical(nb, niocount, &range);
 333
 334         /**
 335          * Obtain physical offsets if selected, and this is an OST_READ RPC
 336          * RPC. We do not enter this block if moving_req is set which indicates
 337          * that the request is being moved to the high-priority NRS head by
 338          * ldlm_lock_reorder_req(), as that function calls in here while holding
 339          * a spinlock, and nrs_orr_range_physical() can sleep, so we just use
 340          * logical file offsets for the range values for such requests.
 341          */
 342         if (orrd->od_physical && opc == OST_READ && !moving_req) {
 343                 body = req_capsule_client_get(&req->rq_pill, &RMF_OST_BODY);
 344                 if (body == NULL)
 345                         GOTO(out, rc = -EFAULT);
 346
 347                 /**
 348                  * Translate to physical block offsets from backend filesystem
 349                  * extents.
 350                  * Ignore return values; if obtaining the physical offsets
 351                  * fails, use the logical offsets.
 352                  */
 353                 nrs_orr_range_fill_physical(nrq, &body->oa, &range);
 354         }
 355
 356         nrq->nr_u.orr.or_range = range;
 357 out:
 358         return rc;
 359 }
 360
 361 /**
 362  * Generates a character string that can be used in order to register uniquely
 363  * named libcfs_hash and slab objects for ORR/TRR policy instances. The
 364  * character string is unique per policy instance, as it includes the policy's
 365  * name, the CPT number, and a {reg|hp} token, and there is one policy instance
 366  * per NRS head on each CPT, and the policy is only compatible with the ost_io
 367  * service.
 368  *
 369  * \param[in] policy the policy instance
 370  * \param[out] name  the character array that will hold the generated name
 371  */
 372 static void nrs_orr_genobjname(struct ptlrpc_nrs_policy *policy, char *name)
 373 {
 374         snprintf(name, NRS_ORR_OBJ_NAME_MAX, "%s%s%s%d",
 375                  "nrs_", policy->pol_desc->pd_name,
 376                  policy->pol_nrs->nrs_queue_type == PTLRPC_NRS_QUEUE_REG ?
 377                  "_reg_" : "_hp_", nrs_pol2cptid(policy));
 378 }
 379
 380 /**
 381  * ORR/TRR hash operations
 382  */
 383 #define NRS_ORR_BITS            24
 384 #define NRS_ORR_BKT_BITS        12
 385 #define NRS_ORR_HASH_FLAGS      (CFS_HASH_SPIN_BKTLOCK | CFS_HASH_ASSERT_EMPTY)
 386
 387 #define NRS_TRR_BITS            4
 388 #define NRS_TRR_BKT_BITS        2
 389 #define NRS_TRR_HASH_FLAGS      CFS_HASH_SPIN_BKTLOCK
 390
 391 static unsigned
 392 nrs_orr_hop_hash(struct cfs_hash *hs, const void *key, unsigned mask)
 393 {
 394         return cfs_hash_djb2_hash(key, sizeof(struct nrs_orr_key), mask);
 395 }
 396
 397 static void *nrs_orr_hop_key(struct hlist_node *hnode)
 398 {
 399         struct nrs_orr_object *orro = hlist_entry(hnode,
 400                                                       struct nrs_orr_object,
 401                                                       oo_hnode);
 402         return &orro->oo_key;
 403 }
 404
 405 static int nrs_orr_hop_keycmp(const void *key, struct hlist_node *hnode)
 406 {
 407         struct nrs_orr_object *orro = hlist_entry(hnode,
 408                                                       struct nrs_orr_object,
 409                                                       oo_hnode);
 410
 411         return lu_fid_eq(&orro->oo_key.ok_fid,
 412                          &((struct nrs_orr_key *)key)->ok_fid);
 413 }
 414
 415 static void *nrs_orr_hop_object(struct hlist_node *hnode)
 416 {
 417         return hlist_entry(hnode, struct nrs_orr_object, oo_hnode);
 418 }
 419
 420 static void nrs_orr_hop_get(struct cfs_hash *hs, struct hlist_node *hnode)
 421 {
 422         struct nrs_orr_object *orro = hlist_entry(hnode,
 423                                                       struct nrs_orr_object,
 424                                                       oo_hnode);
 425         orro->oo_ref++;
 426 }
 427
 428 /**
 429  * Removes an nrs_orr_object the hash and frees its memory, if the object has
 430  * no active users.
 431  */
 432 static void nrs_orr_hop_put_free(struct cfs_hash *hs, struct hlist_node *hnode)
 433 {
 434         struct nrs_orr_object *orro = hlist_entry(hnode,
 435                                                       struct nrs_orr_object,
 436                                                       oo_hnode);
 437         struct nrs_orr_data   *orrd = container_of(orro->oo_res.res_parent,
 438                                                    struct nrs_orr_data, od_res);
 439         struct cfs_hash_bd     bd;
 440
 441         cfs_hash_bd_get_and_lock(hs, &orro->oo_key, &bd, 1);
 442
 443         if (--orro->oo_ref > 1) {
 444                 cfs_hash_bd_unlock(hs, &bd, 1);
 445
 446                 return;
 447         }
 448         LASSERT(orro->oo_ref == 1);
 449
 450         cfs_hash_bd_del_locked(hs, &bd, hnode);
 451         cfs_hash_bd_unlock(hs, &bd, 1);
 452
 453         OBD_SLAB_FREE_PTR(orro, orrd->od_cache);
 454 }
 455
 456 static void nrs_orr_hop_put(struct cfs_hash *hs, struct hlist_node *hnode)
 457 {
 458         struct nrs_orr_object *orro = hlist_entry(hnode,
 459                                                       struct nrs_orr_object,
 460                                                       oo_hnode);
 461         orro->oo_ref--;
 462 }
 463
 464 static int nrs_trr_hop_keycmp(const void *key, struct hlist_node *hnode)
 465 {
 466         struct nrs_orr_object *orro = hlist_entry(hnode,
 467                                                       struct nrs_orr_object,
 468                                                       oo_hnode);
 469
 470         return orro->oo_key.ok_idx == ((struct nrs_orr_key *)key)->ok_idx;
 471 }
 472
 473 static void nrs_trr_hop_exit(struct cfs_hash *hs, struct hlist_node *hnode)
 474 {
 475         struct nrs_orr_object *orro = hlist_entry(hnode,
 476                                                       struct nrs_orr_object,
 477                                                       oo_hnode);
 478         struct nrs_orr_data   *orrd = container_of(orro->oo_res.res_parent,
 479                                                    struct nrs_orr_data, od_res);
 480
 481         LASSERTF(orro->oo_ref == 0,
 482                  "Busy NRS TRR policy object for OST with index %u, with %ld "
 483                  "refs\n", orro->oo_key.ok_idx, orro->oo_ref);
 484
 485         OBD_SLAB_FREE_PTR(orro, orrd->od_cache);
 486 }
 487
 488 static struct cfs_hash_ops nrs_orr_hash_ops = {
 489         .hs_hash        = nrs_orr_hop_hash,
 490         .hs_key         = nrs_orr_hop_key,
 491         .hs_keycmp      = nrs_orr_hop_keycmp,
 492         .hs_object      = nrs_orr_hop_object,
 493         .hs_get         = nrs_orr_hop_get,
 494         .hs_put         = nrs_orr_hop_put_free,
 495         .hs_put_locked  = nrs_orr_hop_put,
 496 };
 497
 498 static struct cfs_hash_ops nrs_trr_hash_ops = {
 499         .hs_hash        = nrs_orr_hop_hash,
 500         .hs_key         = nrs_orr_hop_key,
 501         .hs_keycmp      = nrs_trr_hop_keycmp,
 502         .hs_object      = nrs_orr_hop_object,
 503         .hs_get         = nrs_orr_hop_get,
 504         .hs_put         = nrs_orr_hop_put,
 505         .hs_put_locked  = nrs_orr_hop_put,
 506         .hs_exit        = nrs_trr_hop_exit,
 507 };
 508
 509 #define NRS_ORR_QUANTUM_DFLT    256
 510
 511 /**
 512  * Binary heap predicate.
 513  *
 514  * Uses
 515  * ptlrpc_nrs_request::nr_u::orr::or_round,
 516  * ptlrpc_nrs_request::nr_u::orr::or_sequence, and
 517  * ptlrpc_nrs_request::nr_u::orr::or_range to compare two binheap nodes and
 518  * produce a binary predicate that indicates their relative priority, so that
 519  * the binary heap can perform the necessary sorting operations.
 520  *
 521  * \param[in] e1 the first binheap node to compare
 522  * \param[in] e2 the second binheap node to compare
 523  *
 524  * \retval 0 e1 > e2
 525  * \retval 1 e1 < e2
 526  */
 527 static int
 528 orr_req_compare(struct cfs_binheap_node *e1, struct cfs_binheap_node *e2)
 529 {
 530         struct ptlrpc_nrs_request *nrq1;
 531         struct ptlrpc_nrs_request *nrq2;
 532
 533         nrq1 = container_of(e1, struct ptlrpc_nrs_request, nr_node);
 534         nrq2 = container_of(e2, struct ptlrpc_nrs_request, nr_node);
 535
 536         /**
 537          * Requests have been scheduled against a different scheduling round.
 538          */
 539         if (nrq1->nr_u.orr.or_round < nrq2->nr_u.orr.or_round)
 540                 return 1;
 541         else if (nrq1->nr_u.orr.or_round > nrq2->nr_u.orr.or_round)
 542                 return 0;
 543
 544         /**
 545          * Requests have been scheduled against the same scheduling round, but
 546          * belong to a different batch, i.e. they pertain to a different
 547          * backend-fs object (for ORR policy instances) or OST (for TRR policy
 548          * instances).
 549          */
 550         if (nrq1->nr_u.orr.or_sequence < nrq2->nr_u.orr.or_sequence)
 551                 return 1;
 552         else if (nrq1->nr_u.orr.or_sequence > nrq2->nr_u.orr.or_sequence)
 553                 return 0;
 554
 555         /**
 556          * If round numbers and sequence numbers are equal, the two requests
 557          * have been scheduled on the same round, and belong to the same batch,
 558          * which means they pertain to the same backend-fs object (if this is an
 559          * ORR policy instance), or to the same OST (if this is a TRR policy
 560          * instance), so these requests should be sorted by ascending offset
 561          * order.
 562          */
 563         if (nrq1->nr_u.orr.or_range.or_start <
 564             nrq2->nr_u.orr.or_range.or_start) {
 565                 return 1;
 566         } else if (nrq1->nr_u.orr.or_range.or_start >
 567                  nrq2->nr_u.orr.or_range.or_start) {
 568                 return 0;
 569         } else {
 570                 /**
 571                  * Requests start from the same offset; Dispatch the shorter one
 572                  * first; perhaps slightly more chances of hitting caches like
 573                  * this.
 574                  */
 575                 return nrq1->nr_u.orr.or_range.or_end <
 576                        nrq2->nr_u.orr.or_range.or_end;
 577         }
 578 }
 579
 580 /**
 581  * ORR binary heap operations
 582  */
 583 static struct cfs_binheap_ops nrs_orr_heap_ops = {
 584         .hop_enter      = NULL,
 585         .hop_exit       = NULL,
 586         .hop_compare    = orr_req_compare,
 587 };
 588
 589 /**
 590  * Prints a warning message if an ORR/TRR policy is started on a service with
 591  * more than one CPT.  Not printed on the console for now, since we don't
 592  * have any performance metrics in the first place, and it is annoying.
 593  *
 594  * \param[in] policy the policy instance
 595  *
 596  * \retval 0 success
 597  */
 598 static int nrs_orr_init(struct ptlrpc_nrs_policy *policy)
 599 {
 600         if (policy->pol_nrs->nrs_svcpt->scp_service->srv_ncpts > 1)
 601                 CDEBUG(D_CONFIG, "%s: The %s NRS policy was registered on a "
 602                       "service with multiple service partitions. This policy "
 603                       "may perform better with a single partition.\n",
 604                       policy->pol_nrs->nrs_svcpt->scp_service->srv_name,
 605                       policy->pol_desc->pd_name);
 606
 607         return 0;
 608 }
 609
 610 /**
 611  * Called when an ORR policy instance is started.
 612  *
 613  * \param[in] policy the policy
 614  *
 615  * \retval -ENOMEM OOM error
 616  * \retval 0       success
 617  */
 618 static int nrs_orr_start(struct ptlrpc_nrs_policy *policy, char *arg)
 619 {
 620         struct nrs_orr_data    *orrd;
 621         struct cfs_hash_ops            *ops;
 622         unsigned                cur_bits;
 623         unsigned                max_bits;
 624         unsigned                bkt_bits;
 625         unsigned                flags;
 626         int                     rc = 0;
 627         ENTRY;
 628
 629         OBD_CPT_ALLOC_PTR(orrd, nrs_pol2cptab(policy), nrs_pol2cptid(policy));
 630         if (orrd == NULL)
 631                 RETURN(-ENOMEM);
 632
 633         /*
 634          * Binary heap instance for sorted incoming requests.
 635          */
 636         orrd->od_binheap = cfs_binheap_create(&nrs_orr_heap_ops,
 637                                               CBH_FLAG_ATOMIC_GROW, 4096, NULL,
 638                                               nrs_pol2cptab(policy),
 639                                               nrs_pol2cptid(policy));
 640         if (orrd->od_binheap == NULL)
 641                 GOTO(failed, rc = -ENOMEM);
 642
 643         nrs_orr_genobjname(policy, orrd->od_objname);
 644
 645         /**
 646          * Slab cache for NRS ORR/TRR objects.
 647          */
 648         orrd->od_cache = kmem_cache_create(orrd->od_objname,
 649                                            sizeof(struct nrs_orr_object),
 650                                            0, 0, NULL);
 651         if (orrd->od_cache == NULL)
 652                 GOTO(failed, rc = -ENOMEM);
 653
 654         if (strncmp(policy->pol_desc->pd_name, NRS_POL_NAME_ORR,
 655                     NRS_POL_NAME_MAX) == 0) {
 656                 ops = &nrs_orr_hash_ops;
 657                 cur_bits = NRS_ORR_BITS;
 658                 max_bits = NRS_ORR_BITS;
 659                 bkt_bits = NRS_ORR_BKT_BITS;
 660                 flags = NRS_ORR_HASH_FLAGS;
 661         } else {
 662                 ops = &nrs_trr_hash_ops;
 663                 cur_bits = NRS_TRR_BITS;
 664                 max_bits = NRS_TRR_BITS;
 665                 bkt_bits = NRS_TRR_BKT_BITS;
 666                 flags = NRS_TRR_HASH_FLAGS;
 667         }
 668
 669         /**
 670          * Hash for finding objects by struct nrs_orr_key.
 671          * XXX: For TRR, it might be better to avoid using libcfs_hash?
 672          * All that needs to be resolved are OST indices, and they
 673          * will stay relatively stable during an OSS node's lifetime.
 674          */
 675         orrd->od_obj_hash = cfs_hash_create(orrd->od_objname, cur_bits,
 676                                             max_bits, bkt_bits, 0,
 677                                             CFS_HASH_MIN_THETA,
 678                                             CFS_HASH_MAX_THETA, ops, flags);
 679         if (orrd->od_obj_hash == NULL)
 680                 GOTO(failed, rc = -ENOMEM);
 681
 682         /* XXX: Fields accessed unlocked */
 683         orrd->od_quantum = NRS_ORR_QUANTUM_DFLT;
 684         orrd->od_supp = NOS_DFLT;
 685         orrd->od_physical = true;
 686         /**
 687          * Set to 1 so that the test inside nrs_orr_req_add() can evaluate to
 688          * true.
 689          */
 690         orrd->od_sequence = 1;
 691
 692         policy->pol_private = orrd;
 693
 694         RETURN(rc);
 695
 696 failed:
 697         if (orrd->od_cache)
 698                 kmem_cache_destroy(orrd->od_cache);
 699         if (orrd->od_binheap != NULL)
 700                 cfs_binheap_destroy(orrd->od_binheap);
 701
 702         OBD_FREE_PTR(orrd);
 703
 704         RETURN(rc);
 705 }
 706
 707 /**
 708  * Called when an ORR/TRR policy instance is stopped.
 709  *
 710  * Called when the policy has been instructed to transition to the
 711  * ptlrpc_nrs_pol_state::NRS_POL_STATE_STOPPED state and has no more
 712  * pending requests to serve.
 713  *
 714  * \param[in] policy the policy
 715  */
 716 static void nrs_orr_stop(struct ptlrpc_nrs_policy *policy)
 717 {
 718         struct nrs_orr_data *orrd = policy->pol_private;
 719         ENTRY;
 720
 721         LASSERT(orrd != NULL);
 722         LASSERT(orrd->od_binheap != NULL);
 723         LASSERT(orrd->od_obj_hash != NULL);
 724         LASSERT(orrd->od_cache != NULL);
 725         LASSERT(cfs_binheap_is_empty(orrd->od_binheap));
 726
 727         cfs_binheap_destroy(orrd->od_binheap);
 728         cfs_hash_putref(orrd->od_obj_hash);
 729         kmem_cache_destroy(orrd->od_cache);
 730
 731         OBD_FREE_PTR(orrd);
 732 }
 733
 734 /**
 735  * Performs a policy-specific ctl function on ORR/TRR policy instances; similar
 736  * to ioctl.
 737  *
 738  * \param[in]     policy the policy instance
 739  * \param[in]     opc    the opcode
 740  * \param[in,out] arg    used for passing parameters and information
 741  *
 742  * \pre assert_spin_locked(&policy->pol_nrs->->nrs_lock)
 743  * \post assert_spin_locked(&policy->pol_nrs->->nrs_lock)
 744  *
 745  * \retval 0   operation carried successfully
 746  * \retval -ve error
 747  */
 748 static int nrs_orr_ctl(struct ptlrpc_nrs_policy *policy,
 749                        enum ptlrpc_nrs_ctl opc, void *arg)
 750 {
 751         assert_spin_locked(&policy->pol_nrs->nrs_lock);
 752
 753         switch((enum nrs_ctl_orr)opc) {
 754         default:
 755                 RETURN(-EINVAL);
 756
 757         case NRS_CTL_ORR_RD_QUANTUM: {
 758                 struct nrs_orr_data     *orrd = policy->pol_private;
 759
 760                 *(__u16 *)arg = orrd->od_quantum;
 761                 }
 762                 break;
 763
 764         case NRS_CTL_ORR_WR_QUANTUM: {
 765                 struct nrs_orr_data     *orrd = policy->pol_private;
 766
 767                 orrd->od_quantum = *(__u16 *)arg;
 768                 LASSERT(orrd->od_quantum != 0);
 769                 }
 770                 break;
 771
 772         case NRS_CTL_ORR_RD_OFF_TYPE: {
 773                 struct nrs_orr_data     *orrd = policy->pol_private;
 774
 775                 *(bool *)arg = orrd->od_physical;
 776                 }
 777                 break;
 778
 779         case NRS_CTL_ORR_WR_OFF_TYPE: {
 780                 struct nrs_orr_data     *orrd = policy->pol_private;
 781
 782                 orrd->od_physical = *(bool *)arg;
 783                 }
 784                 break;
 785
 786         case NRS_CTL_ORR_RD_SUPP_REQ: {
 787                 struct nrs_orr_data     *orrd = policy->pol_private;
 788
 789                 *(enum nrs_orr_supp *)arg = orrd->od_supp;
 790                 }
 791                 break;
 792
 793         case NRS_CTL_ORR_WR_SUPP_REQ: {
 794                 struct nrs_orr_data     *orrd = policy->pol_private;
 795
 796                 orrd->od_supp = *(enum nrs_orr_supp *)arg;
 797                 LASSERT((orrd->od_supp & NOS_OST_RW) != 0);
 798                 }
 799                 break;
 800         }
 801         RETURN(0);
 802 }
 803
 804 /**
 805  * Obtains resources for ORR/TRR policy instances. The top-level resource lives
 806  * inside \e nrs_orr_data and the second-level resource inside
 807  * \e nrs_orr_object instances.
 808  *
 809  * \param[in]  policy     the policy for which resources are being taken for
 810  *                        request \a nrq
 811  * \param[in]  nrq        the request for which resources are being taken
 812  * \param[in]  parent     parent resource, embedded in nrs_orr_data for the
 813  *                        ORR/TRR policies
 814  * \param[out] resp       used to return resource references
 815  * \param[in]  moving_req signifies limited caller context; used to perform
 816  *                        memory allocations in an atomic context in this
 817  *                        policy
 818  *
 819  * \retval 0   we are returning a top-level, parent resource, one that is
 820  *             embedded in an nrs_orr_data object
 821  * \retval 1   we are returning a bottom-level resource, one that is embedded
 822  *             in an nrs_orr_object object
 823  *
 824  * \see nrs_resource_get_safe()
 825  */
 826 static int nrs_orr_res_get(struct ptlrpc_nrs_policy *policy,
 827                            struct ptlrpc_nrs_request *nrq,
 828                            const struct ptlrpc_nrs_resource *parent,
 829                            struct ptlrpc_nrs_resource **resp, bool moving_req)
 830 {
 831         struct nrs_orr_data            *orrd;
 832         struct nrs_orr_object          *orro;
 833         struct nrs_orr_object          *tmp;
 834         struct nrs_orr_key              key = { { { 0 } } };
 835         __u32                           opc;
 836         int                             rc = 0;
 837
 838         /**
 839          * struct nrs_orr_data is requested.
 840          */
 841         if (parent == NULL) {
 842                 *resp = &((struct nrs_orr_data *)policy->pol_private)->od_res;
 843                 return 0;
 844         }
 845
 846         orrd = container_of(parent, struct nrs_orr_data, od_res);
 847
 848         /**
 849          * If the request type is not supported, fail the enqueuing; the RPC
 850          * will be handled by the fallback NRS policy.
 851          */
 852         if (!nrs_orr_req_supported(orrd, nrq, &opc))
 853                 return -1;
 854
 855         /**
 856          * Fill in the key for the request; OST FID for ORR policy instances,
 857          * and OST index for TRR policy instances.
 858          */
 859         rc = nrs_orr_key_fill(orrd, nrq, opc, policy->pol_desc->pd_name, &key);
 860         if (rc < 0)
 861                 RETURN(rc);
 862
 863         /**
 864          * Set the offset range the request covers
 865          */
 866         rc = nrs_orr_range_fill(nrq, orrd, opc, moving_req);
 867         if (rc < 0)
 868                 RETURN(rc);
 869
 870         orro = cfs_hash_lookup(orrd->od_obj_hash, &key);
 871         if (orro != NULL)
 872                 goto out;
 873
 874         OBD_SLAB_CPT_ALLOC_PTR_GFP(orro, orrd->od_cache,
 875                                    nrs_pol2cptab(policy), nrs_pol2cptid(policy),
 876                                    moving_req ? GFP_ATOMIC : GFP_NOFS);
 877         if (orro == NULL)
 878                 RETURN(-ENOMEM);
 879
 880         orro->oo_key = key;
 881         orro->oo_ref = 1;
 882
 883         tmp = cfs_hash_findadd_unique(orrd->od_obj_hash, &orro->oo_key,
 884                                       &orro->oo_hnode);
 885         if (tmp != orro) {
 886                 OBD_SLAB_FREE_PTR(orro, orrd->od_cache);
 887                 orro = tmp;
 888         }
 889 out:
 890         /**
 891          * For debugging purposes
 892          */
 893         nrq->nr_u.orr.or_key = orro->oo_key;
 894
 895         *resp = &orro->oo_res;
 896
 897         return 1;
 898 }
 899
 900 /**
 901  * Called when releasing references to the resource hierachy obtained for a
 902  * request for scheduling using ORR/TRR policy instances
 903  *
 904  * \param[in] policy   the policy the resource belongs to
 905  * \param[in] res      the resource to be released
 906  */
 907 static void nrs_orr_res_put(struct ptlrpc_nrs_policy *policy,
 908                             const struct ptlrpc_nrs_resource *res)
 909 {
 910         struct nrs_orr_data     *orrd;
 911         struct nrs_orr_object   *orro;
 912
 913         /**
 914          * Do nothing for freeing parent, nrs_orr_data resources.
 915          */
 916         if (res->res_parent == NULL)
 917                 return;
 918
 919         orro = container_of(res, struct nrs_orr_object, oo_res);
 920         orrd = container_of(res->res_parent, struct nrs_orr_data, od_res);
 921
 922         cfs_hash_put(orrd->od_obj_hash, &orro->oo_hnode);
 923 }
 924
 925 /**
 926  * Called when polling an ORR/TRR policy instance for a request so that it can
 927  * be served. Returns the request that is at the root of the binary heap, as
 928  * that is the lowest priority one (i.e. libcfs_heap is an implementation of a
 929  * min-heap)
 930  *
 931  * \param[in] policy the policy instance being polled
 932  * \param[in] peek   when set, signifies that we just want to examine the
 933  *                   request, and not handle it, so the request is not removed
 934  *                   from the policy.
 935  * \param[in] force  force the policy to return a request; unused in this policy
 936  *
 937  * \retval the request to be handled
 938  * \retval NULL no request available
 939  *
 940  * \see ptlrpc_nrs_req_get_nolock()
 941  * \see nrs_request_get()
 942  */
 943 static
 944 struct ptlrpc_nrs_request *nrs_orr_req_get(struct ptlrpc_nrs_policy *policy,
 945                                            bool peek, bool force)
 946 {
 947         struct nrs_orr_data       *orrd = policy->pol_private;
 948         struct cfs_binheap_node   *node = cfs_binheap_root(orrd->od_binheap);
 949         struct ptlrpc_nrs_request *nrq;
 950
 951         nrq = unlikely(node == NULL) ? NULL :
 952               container_of(node, struct ptlrpc_nrs_request, nr_node);
 953
 954         if (likely(!peek && nrq != NULL)) {
 955                 struct nrs_orr_object *orro;
 956
 957                 orro = container_of(nrs_request_resource(nrq),
 958                                     struct nrs_orr_object, oo_res);
 959
 960                 LASSERT(nrq->nr_u.orr.or_round <= orro->oo_round);
 961
 962                 cfs_binheap_remove(orrd->od_binheap, &nrq->nr_node);
 963                 orro->oo_active--;
 964
 965                 if (strncmp(policy->pol_desc->pd_name, NRS_POL_NAME_ORR,
 966                                  NRS_POL_NAME_MAX) == 0)
 967                         CDEBUG(D_RPCTRACE,
 968                                "NRS: starting to handle %s request for object "
 969                                "with FID "DFID", from OST with index %u, with "
 970                                "round %llu\n", NRS_POL_NAME_ORR,
 971                                PFID(&orro->oo_key.ok_fid),
 972                                nrq->nr_u.orr.or_key.ok_idx,
 973                                nrq->nr_u.orr.or_round);
 974                 else
 975                         CDEBUG(D_RPCTRACE,
 976                                "NRS: starting to handle %s request from OST "
 977                                "with index %u, with round %llu\n",
 978                                NRS_POL_NAME_TRR, nrq->nr_u.orr.or_key.ok_idx,
 979                                nrq->nr_u.orr.or_round);
 980
 981                 /** Peek at the next request to be served */
 982                 node = cfs_binheap_root(orrd->od_binheap);
 983
 984                 /** No more requests */
 985                 if (unlikely(node == NULL)) {
 986                         orrd->od_round++;
 987                 } else {
 988                         struct ptlrpc_nrs_request *next;
 989
 990                         next = container_of(node, struct ptlrpc_nrs_request,
 991                                             nr_node);
 992
 993                         if (orrd->od_round < next->nr_u.orr.or_round)
 994                                 orrd->od_round = next->nr_u.orr.or_round;
 995                 }
 996         }
 997
 998         return nrq;
 999 }
1000
1001 /**
1002  * Sort-adds request \a nrq to an ORR/TRR \a policy instance's set of queued
1003  * requests in the policy's binary heap.
1004  *
1005  * A scheduling round is a stream of requests that have been sorted in batches
1006  * according to the backend-fs object (for ORR policy instances) or OST (for TRR
1007  * policy instances) that they pertain to (as identified by its IDIF FID or OST
1008  * index respectively); there can be only one batch for each object or OST in
1009  * each round. The batches are of maximum size nrs_orr_data:od_quantum. When a
1010  * new request arrives for scheduling for an object or OST that has exhausted
1011  * its quantum in its current round, the request will be scheduled on the next
1012  * scheduling round. Requests are allowed to be scheduled against a round until
1013  * all requests for the round are serviced, so an object or OST might miss a
1014  * round if requests are not scheduled for it for a long enough period of time.
1015  * Objects or OSTs that miss a round will continue with having their next
1016  * request scheduled, starting at the round that requests are being dispatched
1017  * for, at the time of arrival of this request.
1018  *
1019  * Requests are tagged with the round number and a sequence number; the sequence
1020  * number indicates the relative ordering amongst the batches of requests in a
1021  * round, and is identical for all requests in a batch, as is the round number.
1022  * The round and sequence numbers are used by orr_req_compare() in order to use
1023  * nrs_orr_data::od_binheap in order to maintain an ordered set of rounds, with
1024  * each round consisting of an ordered set of batches of requests, and each
1025  * batch consisting of an ordered set of requests according to their logical
1026  * file or physical disk offsets.
1027  *
1028  * \param[in] policy the policy
1029  * \param[in] nrq    the request to add
1030  *
1031  * \retval 0    request successfully added
1032  * \retval != 0 error
1033  */
1034 static int nrs_orr_req_add(struct ptlrpc_nrs_policy *policy,
1035                            struct ptlrpc_nrs_request *nrq)
1036 {
1037         struct nrs_orr_data     *orrd;
1038         struct nrs_orr_object   *orro;
1039         int                      rc;
1040
1041         orro = container_of(nrs_request_resource(nrq),
1042                             struct nrs_orr_object, oo_res);
1043         orrd = container_of(nrs_request_resource(nrq)->res_parent,
1044                             struct nrs_orr_data, od_res);
1045
1046         if (orro->oo_quantum == 0 || orro->oo_round < orrd->od_round ||
1047             (orro->oo_active == 0 && orro->oo_quantum > 0)) {
1048
1049                 /**
1050                  * If there are no pending requests for the object/OST, but some
1051                  * of its quantum still remains unused, which implies we did not
1052                  * get a chance to schedule up to its maximum allowed batch size
1053                  * of requests in the previous round this object/OST
1054                  * participated in, schedule this next request on a new round;
1055                  * this avoids fragmentation of request batches caused by
1056                  * intermittent inactivity on the object/OST, at the expense of
1057                  * potentially slightly increased service time for the request
1058                  * batch this request will be a part of.
1059                  */
1060                 if (orro->oo_active == 0 && orro->oo_quantum > 0)
1061                         orro->oo_round++;
1062
1063                 /** A new scheduling round has commenced */
1064                 if (orro->oo_round < orrd->od_round)
1065                         orro->oo_round = orrd->od_round;
1066
1067                 /** I was not the last object/OST that scheduled a request */
1068                 if (orro->oo_sequence < orrd->od_sequence)
1069                         orro->oo_sequence = ++orrd->od_sequence;
1070                 /**
1071                  * Reset the quantum if we have reached the maximum quantum
1072                  * size for this batch, or even if we have not managed to
1073                  * complete a batch size up to its maximum allowed size.
1074                  * XXX: Accessed unlocked
1075                  */
1076                 orro->oo_quantum = orrd->od_quantum;
1077         }
1078
1079         nrq->nr_u.orr.or_round = orro->oo_round;
1080         nrq->nr_u.orr.or_sequence = orro->oo_sequence;
1081
1082         rc = cfs_binheap_insert(orrd->od_binheap, &nrq->nr_node);
1083         if (rc == 0) {
1084                 orro->oo_active++;
1085                 if (--orro->oo_quantum == 0)
1086                         orro->oo_round++;
1087         }
1088         return rc;
1089 }
1090
1091 /**
1092  * Removes request \a nrq from an ORR/TRR \a policy instance's set of queued
1093  * requests.
1094  *
1095  * \param[in] policy the policy
1096  * \param[in] nrq    the request to remove
1097  */
1098 static void nrs_orr_req_del(struct ptlrpc_nrs_policy *policy,
1099                             struct ptlrpc_nrs_request *nrq)
1100 {
1101         struct nrs_orr_data     *orrd;
1102         struct nrs_orr_object   *orro;
1103         bool                     is_root;
1104
1105         orro = container_of(nrs_request_resource(nrq),
1106                             struct nrs_orr_object, oo_res);
1107         orrd = container_of(nrs_request_resource(nrq)->res_parent,
1108                             struct nrs_orr_data, od_res);
1109
1110         LASSERT(nrq->nr_u.orr.or_round <= orro->oo_round);
1111
1112         is_root = &nrq->nr_node == cfs_binheap_root(orrd->od_binheap);
1113
1114         cfs_binheap_remove(orrd->od_binheap, &nrq->nr_node);
1115         orro->oo_active--;
1116
1117         /**
1118          * If we just deleted the node at the root of the binheap, we may have
1119          * to adjust round numbers.
1120          */
1121         if (unlikely(is_root)) {
1122                 /** Peek at the next request to be served */
1123                 struct cfs_binheap_node *node = cfs_binheap_root(orrd->od_binheap);
1124
1125                 /** No more requests */
1126                 if (unlikely(node == NULL)) {
1127                         orrd->od_round++;
1128                 } else {
1129                         nrq = container_of(node, struct ptlrpc_nrs_request,
1130                                            nr_node);
1131
1132                         if (orrd->od_round < nrq->nr_u.orr.or_round)
1133                                 orrd->od_round = nrq->nr_u.orr.or_round;
1134                 }
1135         }
1136 }
1137
1138 /**
1139  * Called right after the request \a nrq finishes being handled by ORR policy
1140  * instance \a policy.
1141  *
1142  * \param[in] policy the policy that handled the request
1143  * \param[in] nrq    the request that was handled
1144  */
1145 static void nrs_orr_req_stop(struct ptlrpc_nrs_policy *policy,
1146                              struct ptlrpc_nrs_request *nrq)
1147 {
1148         /** NB: resource control, credits etc can be added here */
1149         if (strncmp(policy->pol_desc->pd_name, NRS_POL_NAME_ORR,
1150                     NRS_POL_NAME_MAX) == 0)
1151                 CDEBUG(D_RPCTRACE,
1152                        "NRS: finished handling %s request for object with FID "
1153                        DFID", from OST with index %u, with round %llu\n",
1154                        NRS_POL_NAME_ORR, PFID(&nrq->nr_u.orr.or_key.ok_fid),
1155                        nrq->nr_u.orr.or_key.ok_idx, nrq->nr_u.orr.or_round);
1156         else
1157                 CDEBUG(D_RPCTRACE,
1158                        "NRS: finished handling %s request from OST with index %u,"
1159                        " with round %llu\n",
1160                        NRS_POL_NAME_TRR, nrq->nr_u.orr.or_key.ok_idx,
1161                        nrq->nr_u.orr.or_round);
1162 }
1163
1164 /**
1165  * lprocfs interface
1166  */
1167
1168 #ifdef CONFIG_PROC_FS
1169
1170 /**
1171  * This allows to bundle the policy name into the lprocfs_vars::data pointer
1172  * so that lprocfs read/write functions can be used by both the ORR and TRR
1173  * policies.
1174  */
1175 static struct nrs_lprocfs_orr_data {
1176         struct ptlrpc_service   *svc;
1177         char                    *name;
1178 } lprocfs_orr_data = {
1179         .name = NRS_POL_NAME_ORR
1180 }, lprocfs_trr_data = {
1181         .name = NRS_POL_NAME_TRR
1182 };
1183
1184 /**
1185  * Retrieves the value of the Round Robin quantum (i.e. the maximum batch size)
1186  * for ORR/TRR policy instances on both the regular and high-priority NRS head
1187  * of a service, as long as a policy instance is not in the
1188  * ptlrpc_nrs_pol_state::NRS_POL_STATE_STOPPED state; policy instances in this
1189  * state are skipped later by nrs_orr_ctl().
1190  *
1191  * Quantum values are in # of RPCs, and the output is in YAML format.
1192  *
1193  * For example:
1194  *
1195  *      reg_quantum:256
1196  *      hp_quantum:8
1197  *
1198  * XXX: the CRR-N version of this, ptlrpc_lprocfs_rd_nrs_crrn_quantum() is
1199  * almost identical; it can be reworked and then reused for ORR/TRR.
1200  */
1201 static int
1202 ptlrpc_lprocfs_nrs_orr_quantum_seq_show(struct seq_file *m, void *data)
1203 {
1204         struct nrs_lprocfs_orr_data *orr_data = m->private;
1205         struct ptlrpc_service       *svc = orr_data->svc;
1206         __u16                        quantum;
1207         int                          rc;
1208
1209         /**
1210          * Perform two separate calls to this as only one of the NRS heads'
1211          * policies may be in the ptlrpc_nrs_pol_state::NRS_POL_STATE_STARTED or
1212          * ptlrpc_nrs_pol_state::NRS_POL_STATE_STOPPING state.
1213          */
1214         rc = ptlrpc_nrs_policy_control(svc, PTLRPC_NRS_QUEUE_REG,
1215                                        orr_data->name,
1216                                        NRS_CTL_ORR_RD_QUANTUM,
1217                                        true, &quantum);
1218         if (rc == 0) {
1219                 seq_printf(m, NRS_LPROCFS_QUANTUM_NAME_REG "%-5d\n", quantum);
1220                 /**
1221                  * Ignore -ENODEV as the regular NRS head's policy may be in the
1222                  * ptlrpc_nrs_pol_state::NRS_POL_STATE_STOPPED state.
1223                  */
1224         } else if (rc != -ENODEV) {
1225                 return rc;
1226         }
1227
1228         /**
1229          * We know the ost_io service which is the only one ORR/TRR policies are
1230          * compatible with, do have an HP NRS head, but it may be best to guard
1231          * against a possible change of this in the future.
1232          */
1233         if (!nrs_svc_has_hp(svc))
1234                 goto no_hp;
1235
1236         rc = ptlrpc_nrs_policy_control(svc, PTLRPC_NRS_QUEUE_HP,
1237                                        orr_data->name, NRS_CTL_ORR_RD_QUANTUM,
1238                                        true, &quantum);
1239         if (rc == 0) {
1240                 seq_printf(m, NRS_LPROCFS_QUANTUM_NAME_HP"%-5d\n", quantum);
1241                 /**
1242                  * Ignore -ENODEV as the high priority NRS head's policy may be
1243                  * in the ptlrpc_nrs_pol_state::NRS_POL_STATE_STOPPED state.
1244                  */
1245         } else if (rc != -ENODEV) {
1246                 return rc;
1247         }
1248
1249 no_hp:
1250
1251         return rc;
1252 }
1253
1254 /**
1255  * Sets the value of the Round Robin quantum (i.e. the maximum batch size)
1256  * for ORR/TRR policy instances of a service. The user can set the quantum size
1257  * for the regular and high priority NRS head separately by specifying each
1258  * value, or both together in a single invocation.
1259  *
1260  * For example:
1261  *
1262  * lctl set_param ost.OSS.ost_io.nrs_orr_quantum=req_quantum:64, to set the
1263  * request quantum size of the ORR policy instance on the regular NRS head of
1264  * the ost_io service to 64
1265  *
1266  * lctl set_param ost.OSS.ost_io.nrs_trr_quantum=hp_quantum:8 to set the request
1267  * quantum size of the TRR policy instance on the high priority NRS head of the
1268  * ost_io service to 8
1269  *
1270  * lctl set_param ost.OSS.ost_io.nrs_orr_quantum=32, to set both the request
1271  * quantum size of the ORR policy instance on both the regular and the high
1272  * priority NRS head of the ost_io service to 32
1273  *
1274  * policy instances in the ptlrpc_nrs_pol_state::NRS_POL_STATE_STOPPED state
1275  * are skipped later by nrs_orr_ctl().
1276  *
1277  * XXX: the CRR-N version of this, ptlrpc_lprocfs_wr_nrs_crrn_quantum() is
1278  * almost identical; it can be reworked and then reused for ORR/TRR.
1279  */
1280 static ssize_t
1281 ptlrpc_lprocfs_nrs_orr_quantum_seq_write(struct file *file,
1282                                          const char __user *buffer,
1283                                          size_t count, loff_t *off)
1284 {
1285         struct seq_file             *m = file->private_data;
1286         struct nrs_lprocfs_orr_data *orr_data = m->private;
1287         struct ptlrpc_service       *svc = orr_data->svc;
1288         enum ptlrpc_nrs_queue_type   queue = 0;
1289         char                         kernbuf[LPROCFS_NRS_WR_QUANTUM_MAX_CMD];
1290         char                        *val;
1291         long                         quantum_reg;
1292         long                         quantum_hp;
1293         /** lprocfs_find_named_value() modifies its argument, so keep a copy */
1294         size_t                       count_copy;
1295         int                          rc = 0;
1296         int                          rc2 = 0;
1297
1298         if (count > (sizeof(kernbuf) - 1))
1299                 return -EINVAL;
1300
1301         if (copy_from_user(kernbuf, buffer, count))
1302                 return -EFAULT;
1303
1304         kernbuf[count] = '\0';
1305
1306         count_copy = count;
1307
1308         /**
1309          * Check if the regular quantum value has been specified
1310          */
1311         val = lprocfs_find_named_value(kernbuf, NRS_LPROCFS_QUANTUM_NAME_REG,
1312                                        &count_copy);
1313         if (val != kernbuf) {
1314                 quantum_reg = simple_strtol(val, NULL, 10);
1315
1316                 queue |= PTLRPC_NRS_QUEUE_REG;
1317         }
1318
1319         count_copy = count;
1320
1321         /**
1322          * Check if the high priority quantum value has been specified
1323          */
1324         val = lprocfs_find_named_value(kernbuf, NRS_LPROCFS_QUANTUM_NAME_HP,
1325                                        &count_copy);
1326         if (val != kernbuf) {
1327                 if (!nrs_svc_has_hp(svc))
1328                         return -ENODEV;
1329
1330                 quantum_hp = simple_strtol(val, NULL, 10);
1331
1332                 queue |= PTLRPC_NRS_QUEUE_HP;
1333         }
1334
1335         /**
1336          * If none of the queues has been specified, look for a valid numerical
1337          * value
1338          */
1339         if (queue == 0) {
1340                 if (!isdigit(kernbuf[0]))
1341                         return -EINVAL;
1342
1343                 quantum_reg = simple_strtol(kernbuf, NULL, 10);
1344
1345                 queue = PTLRPC_NRS_QUEUE_REG;
1346
1347                 if (nrs_svc_has_hp(svc)) {
1348                         queue |= PTLRPC_NRS_QUEUE_HP;
1349                         quantum_hp = quantum_reg;
1350                 }
1351         }
1352
1353         if ((((queue & PTLRPC_NRS_QUEUE_REG) != 0) &&
1354             ((quantum_reg > LPROCFS_NRS_QUANTUM_MAX || quantum_reg <= 0))) ||
1355             (((queue & PTLRPC_NRS_QUEUE_HP) != 0) &&
1356             ((quantum_hp > LPROCFS_NRS_QUANTUM_MAX || quantum_hp <= 0))))
1357                 return -EINVAL;
1358
1359         /**
1360          * We change the values on regular and HP NRS heads separately, so that
1361          * we do not exit early from ptlrpc_nrs_policy_control() with an error
1362          * returned by nrs_policy_ctl_locked(), in cases where the user has not
1363          * started the policy on either the regular or HP NRS head; i.e. we are
1364          * ignoring -ENODEV within nrs_policy_ctl_locked(). -ENODEV is returned
1365          * only if the operation fails with -ENODEV on all heads that have been
1366          * specified by the command; if at least one operation succeeds,
1367          * success is returned.
1368          */
1369         if ((queue & PTLRPC_NRS_QUEUE_REG) != 0) {
1370                 rc = ptlrpc_nrs_policy_control(svc, PTLRPC_NRS_QUEUE_REG,
1371                                                orr_data->name,
1372                                                NRS_CTL_ORR_WR_QUANTUM, false,
1373                                                &quantum_reg);
1374                 if ((rc < 0 && rc != -ENODEV) ||
1375                     (rc == -ENODEV && queue == PTLRPC_NRS_QUEUE_REG))
1376                         return rc;
1377         }
1378
1379         if ((queue & PTLRPC_NRS_QUEUE_HP) != 0) {
1380                 rc2 = ptlrpc_nrs_policy_control(svc, PTLRPC_NRS_QUEUE_HP,
1381                                                 orr_data->name,
1382                                                 NRS_CTL_ORR_WR_QUANTUM, false,
1383                                                 &quantum_hp);
1384                 if ((rc2 < 0 && rc2 != -ENODEV) ||
1385                     (rc2 == -ENODEV && queue == PTLRPC_NRS_QUEUE_HP))
1386                         return rc2;
1387         }
1388
1389         return rc == -ENODEV && rc2 == -ENODEV ? -ENODEV : count;
1390 }
1391 LPROC_SEQ_FOPS(ptlrpc_lprocfs_nrs_orr_quantum);
1392
1393 #define LPROCFS_NRS_OFF_NAME_REG                "reg_offset_type:"
1394 #define LPROCFS_NRS_OFF_NAME_HP                 "hp_offset_type:"
1395
1396 #define LPROCFS_NRS_OFF_NAME_PHYSICAL           "physical"
1397 #define LPROCFS_NRS_OFF_NAME_LOGICAL            "logical"
1398
1399 /**
1400  * Retrieves the offset type used by ORR/TRR policy instances on both the
1401  * regular and high-priority NRS head of a service, as long as a policy
1402  * instance is not in the ptlrpc_nrs_pol_state::NRS_POL_STATE_STOPPED state;
1403  * policy instances in this state are skipped later by nrs_orr_ctl().
1404  *
1405  * Offset type information is a (physical|logical) string, and output is
1406  * in YAML format.
1407  *
1408  * For example:
1409  *
1410  *      reg_offset_type:physical
1411  *      hp_offset_type:logical
1412  */
1413 static int
1414 ptlrpc_lprocfs_nrs_orr_offset_type_seq_show(struct seq_file *m, void *data)
1415 {
1416         struct nrs_lprocfs_orr_data *orr_data = m->private;
1417         struct ptlrpc_service       *svc = orr_data->svc;
1418         bool                         physical;
1419         int                          rc;
1420
1421         /**
1422          * Perform two separate calls to this as only one of the NRS heads'
1423          * policies may be in the ptlrpc_nrs_pol_state::NRS_POL_STATE_STARTED
1424          * or ptlrpc_nrs_pol_state::NRS_POL_STATE_STOPPING state.
1425          */
1426         rc = ptlrpc_nrs_policy_control(svc, PTLRPC_NRS_QUEUE_REG,
1427                                        orr_data->name, NRS_CTL_ORR_RD_OFF_TYPE,
1428                                        true, &physical);
1429         if (rc == 0) {
1430                 seq_printf(m, LPROCFS_NRS_OFF_NAME_REG"%s\n",
1431                            physical ? LPROCFS_NRS_OFF_NAME_PHYSICAL :
1432                            LPROCFS_NRS_OFF_NAME_LOGICAL);
1433                 /**
1434                  * Ignore -ENODEV as the regular NRS head's policy may be in the
1435                  * ptlrpc_nrs_pol_state::NRS_POL_STATE_STOPPED state.
1436                  */
1437         } else if (rc != -ENODEV) {
1438                 return rc;
1439         }
1440
1441         /**
1442          * We know the ost_io service which is the only one ORR/TRR policies are
1443          * compatible with, do have an HP NRS head, but it may be best to guard
1444          * against a possible change of this in the future.
1445          */
1446         if (!nrs_svc_has_hp(svc))
1447                 goto no_hp;
1448
1449         rc = ptlrpc_nrs_policy_control(svc, PTLRPC_NRS_QUEUE_HP,
1450                                        orr_data->name, NRS_CTL_ORR_RD_OFF_TYPE,
1451                                        true, &physical);
1452         if (rc == 0) {
1453                 seq_printf(m, LPROCFS_NRS_OFF_NAME_HP"%s\n",
1454                            physical ? LPROCFS_NRS_OFF_NAME_PHYSICAL :
1455                            LPROCFS_NRS_OFF_NAME_LOGICAL);
1456                 /**
1457                  * Ignore -ENODEV as the high priority NRS head's policy may be
1458                  * in the ptlrpc_nrs_pol_state::NRS_POL_STATE_STOPPED state.
1459                  */
1460         } else if (rc != -ENODEV) {
1461                 return rc;
1462         }
1463
1464 no_hp:
1465         return rc;
1466 }
1467
1468 /**
1469  * Max valid command string is the size of the labels, plus "physical" twice.
1470  * plus a separating ' '
1471  */
1472 #define LPROCFS_NRS_WR_OFF_TYPE_MAX_CMD                                        \
1473         sizeof(LPROCFS_NRS_OFF_NAME_REG LPROCFS_NRS_OFF_NAME_PHYSICAL " "      \
1474                LPROCFS_NRS_OFF_NAME_HP LPROCFS_NRS_OFF_NAME_PHYSICAL)
1475
1476 /**
1477  * Sets the type of offsets used to order RPCs in ORR/TRR policy instances. The
1478  * user can set offset type for the regular or high priority NRS head
1479  * separately by specifying each value, or both together in a single invocation.
1480  *
1481  * For example:
1482  *
1483  * lctl set_param ost.OSS.ost_io.nrs_orr_offset_type=
1484  * reg_offset_type:physical, to enable the ORR policy instance on the regular
1485  * NRS head of the ost_io service to use physical disk offset ordering.
1486  *
1487  * lctl set_param ost.OSS.ost_io.nrs_trr_offset_type=logical, to enable the TRR
1488  * policy instances on both the regular ang high priority NRS heads of the
1489  * ost_io service to use logical file offset ordering.
1490  *
1491  * policy instances in the ptlrpc_nrs_pol_state::NRS_POL_STATE_STOPPED state are
1492  * are skipped later by nrs_orr_ctl().
1493  */
1494 static ssize_t
1495 ptlrpc_lprocfs_nrs_orr_offset_type_seq_write(struct file *file,
1496                                              const char __user *buffer,
1497                                               size_t count,
1498                                              loff_t *off)
1499 {
1500         struct seq_file             *m = file->private_data;
1501         struct nrs_lprocfs_orr_data *orr_data = m->private;
1502         struct ptlrpc_service       *svc = orr_data->svc;
1503         enum ptlrpc_nrs_queue_type   queue = 0;
1504         char                         kernbuf[LPROCFS_NRS_WR_OFF_TYPE_MAX_CMD];
1505         char                        *val_reg;
1506         char                        *val_hp;
1507         bool                         physical_reg;
1508         bool                         physical_hp;
1509         size_t                       count_copy;
1510         int                          rc = 0;
1511         int                          rc2 = 0;
1512
1513         if (count > (sizeof(kernbuf) - 1))
1514                 return -EINVAL;
1515
1516         if (copy_from_user(kernbuf, buffer, count))
1517                 return -EFAULT;
1518
1519         kernbuf[count] = '\0';
1520
1521         count_copy = count;
1522
1523         /**
1524          * Check if the regular offset type has been specified
1525          */
1526         val_reg = lprocfs_find_named_value(kernbuf,
1527                                            LPROCFS_NRS_OFF_NAME_REG,
1528                                            &count_copy);
1529         if (val_reg != kernbuf)
1530                 queue |= PTLRPC_NRS_QUEUE_REG;
1531
1532         count_copy = count;
1533
1534         /**
1535          * Check if the high priority offset type has been specified
1536          */
1537         val_hp = lprocfs_find_named_value(kernbuf, LPROCFS_NRS_OFF_NAME_HP,
1538                                           &count_copy);
1539         if (val_hp != kernbuf) {
1540                 if (!nrs_svc_has_hp(svc))
1541                         return -ENODEV;
1542
1543                 queue |= PTLRPC_NRS_QUEUE_HP;
1544         }
1545
1546         /**
1547          * If none of the queues has been specified, there may be a valid
1548          * command string at the start of the buffer.
1549          */
1550         if (queue == 0) {
1551                 queue = PTLRPC_NRS_QUEUE_REG;
1552
1553                 if (nrs_svc_has_hp(svc))
1554                         queue |= PTLRPC_NRS_QUEUE_HP;
1555         }
1556
1557         if ((queue & PTLRPC_NRS_QUEUE_REG) != 0) {
1558                 if (strncmp(val_reg, LPROCFS_NRS_OFF_NAME_PHYSICAL,
1559                             sizeof(LPROCFS_NRS_OFF_NAME_PHYSICAL) - 1) == 0)
1560                         physical_reg = true;
1561                 else if (strncmp(val_reg, LPROCFS_NRS_OFF_NAME_LOGICAL,
1562                          sizeof(LPROCFS_NRS_OFF_NAME_LOGICAL) - 1) == 0)
1563                         physical_reg = false;
1564                 else
1565                         return -EINVAL;
1566         }
1567
1568         if ((queue & PTLRPC_NRS_QUEUE_HP) != 0) {
1569                 if (strncmp(val_hp, LPROCFS_NRS_OFF_NAME_PHYSICAL,
1570                             sizeof(LPROCFS_NRS_OFF_NAME_PHYSICAL) - 1) == 0)
1571                         physical_hp = true;
1572                 else if (strncmp(val_hp, LPROCFS_NRS_OFF_NAME_LOGICAL,
1573                                  sizeof(LPROCFS_NRS_OFF_NAME_LOGICAL) - 1) == 0)
1574                         physical_hp = false;
1575                 else
1576                         return -EINVAL;
1577         }
1578
1579         /**
1580          * We change the values on regular and HP NRS heads separately, so that
1581          * we do not exit early from ptlrpc_nrs_policy_control() with an error
1582          * returned by nrs_policy_ctl_locked(), in cases where the user has not
1583          * started the policy on either the regular or HP NRS head; i.e. we are
1584          * ignoring -ENODEV within nrs_policy_ctl_locked(). -ENODEV is returned
1585          * only if the operation fails with -ENODEV on all heads that have been
1586          * specified by the command; if at least one operation succeeds,
1587          * success is returned.
1588          */
1589         if ((queue & PTLRPC_NRS_QUEUE_REG) != 0) {
1590                 rc = ptlrpc_nrs_policy_control(svc, PTLRPC_NRS_QUEUE_REG,
1591                                                orr_data->name,
1592                                                NRS_CTL_ORR_WR_OFF_TYPE, false,
1593                                                &physical_reg);
1594                 if ((rc < 0 && rc != -ENODEV) ||
1595                     (rc == -ENODEV && queue == PTLRPC_NRS_QUEUE_REG))
1596                         return rc;
1597         }
1598
1599         if ((queue & PTLRPC_NRS_QUEUE_HP) != 0) {
1600                 rc2 = ptlrpc_nrs_policy_control(svc, PTLRPC_NRS_QUEUE_HP,
1601                                                 orr_data->name,
1602                                                 NRS_CTL_ORR_WR_OFF_TYPE, false,
1603                                                 &physical_hp);
1604                 if ((rc2 < 0 && rc2 != -ENODEV) ||
1605                     (rc2 == -ENODEV && queue == PTLRPC_NRS_QUEUE_HP))
1606                         return rc2;
1607         }
1608
1609         return rc == -ENODEV && rc2 == -ENODEV ? -ENODEV : count;
1610 }
1611 LPROC_SEQ_FOPS(ptlrpc_lprocfs_nrs_orr_offset_type);
1612
1613 #define NRS_LPROCFS_REQ_SUPP_NAME_REG           "reg_supported:"
1614 #define NRS_LPROCFS_REQ_SUPP_NAME_HP            "hp_supported:"
1615
1616 #define LPROCFS_NRS_SUPP_NAME_READS             "reads"
1617 #define LPROCFS_NRS_SUPP_NAME_WRITES            "writes"
1618 #define LPROCFS_NRS_SUPP_NAME_READWRITES        "reads_and_writes"
1619
1620 /**
1621  * Translates enum nrs_orr_supp values to a corresponding string.
1622  */
1623 static const char *nrs_orr_supp2str(enum nrs_orr_supp supp)
1624 {
1625         switch(supp) {
1626         default:
1627                 LBUG();
1628         case NOS_OST_READ:
1629                 return LPROCFS_NRS_SUPP_NAME_READS;
1630         case NOS_OST_WRITE:
1631                 return LPROCFS_NRS_SUPP_NAME_WRITES;
1632         case NOS_OST_RW:
1633                 return LPROCFS_NRS_SUPP_NAME_READWRITES;
1634         }
1635 }
1636
1637 /**
1638  * Translates strings to the corresponding enum nrs_orr_supp value
1639  */
1640 static enum nrs_orr_supp nrs_orr_str2supp(const char *val)
1641 {
1642         if (strncmp(val, LPROCFS_NRS_SUPP_NAME_READWRITES,
1643                     sizeof(LPROCFS_NRS_SUPP_NAME_READWRITES) - 1) == 0)
1644                 return NOS_OST_RW;
1645         else if (strncmp(val, LPROCFS_NRS_SUPP_NAME_READS,
1646                          sizeof(LPROCFS_NRS_SUPP_NAME_READS) - 1) == 0)
1647                 return NOS_OST_READ;
1648         else if (strncmp(val, LPROCFS_NRS_SUPP_NAME_WRITES,
1649                          sizeof(LPROCFS_NRS_SUPP_NAME_WRITES) - 1) == 0)
1650                 return NOS_OST_WRITE;
1651         else
1652                 return -EINVAL;
1653 }
1654
1655 /**
1656  * Retrieves the type of RPCs handled at the point of invocation by ORR/TRR
1657  * policy instances on both the regular and high-priority NRS head of a service,
1658  * as long as a policy instance is not in the
1659  * ptlrpc_nrs_pol_state::NRS_POL_STATE_STOPPED state; policy instances in this
1660  * state are skipped later by nrs_orr_ctl().
1661  *
1662  * Supported RPC type information is a (reads|writes|reads_and_writes) string,
1663  * and output is in YAML format.
1664  *
1665  * For example:
1666  *
1667  *      reg_supported:reads
1668  *      hp_supported:reads_and_writes
1669  */
1670 static int
1671 ptlrpc_lprocfs_nrs_orr_supported_seq_show(struct seq_file *m, void *data)
1672 {
1673         struct nrs_lprocfs_orr_data *orr_data = m->private;
1674         struct ptlrpc_service       *svc = orr_data->svc;
1675         enum nrs_orr_supp            supported;
1676         int                          rc;
1677
1678         /**
1679          * Perform two separate calls to this as only one of the NRS heads'
1680          * policies may be in the ptlrpc_nrs_pol_state::NRS_POL_STATE_STARTED
1681          * or ptlrpc_nrs_pol_state::NRS_POL_STATE_STOPPING state.
1682          */
1683         rc = ptlrpc_nrs_policy_control(svc, PTLRPC_NRS_QUEUE_REG,
1684                                        orr_data->name,
1685                                        NRS_CTL_ORR_RD_SUPP_REQ, true,
1686                                        &supported);
1687
1688         if (rc == 0) {
1689                 seq_printf(m, NRS_LPROCFS_REQ_SUPP_NAME_REG"%s\n",
1690                            nrs_orr_supp2str(supported));
1691                 /**
1692                  * Ignore -ENODEV as the regular NRS head's policy may be in the
1693                  * ptlrpc_nrs_pol_state::NRS_POL_STATE_STOPPED state.
1694                  */
1695         } else if (rc != -ENODEV) {
1696                 return rc;
1697         }
1698
1699         /**
1700          * We know the ost_io service which is the only one ORR/TRR policies are
1701          * compatible with, do have an HP NRS head, but it may be best to guard
1702          * against a possible change of this in the future.
1703          */
1704         if (!nrs_svc_has_hp(svc))
1705                 goto no_hp;
1706
1707         rc = ptlrpc_nrs_policy_control(svc, PTLRPC_NRS_QUEUE_HP,
1708                                        orr_data->name,
1709                                        NRS_CTL_ORR_RD_SUPP_REQ, true,
1710                                        &supported);
1711         if (rc == 0) {
1712                 seq_printf(m, NRS_LPROCFS_REQ_SUPP_NAME_HP"%s\n",
1713                            nrs_orr_supp2str(supported));
1714                 /**
1715                  * Ignore -ENODEV as the high priority NRS head's policy may be
1716                  * in the ptlrpc_nrs_pol_state::NRS_POL_STATE_STOPPED state.
1717                  */
1718         } else if (rc != -ENODEV) {
1719                 return rc;
1720         }
1721
1722 no_hp:
1723
1724         return rc;
1725 }
1726
1727 /**
1728  * Max valid command string is the size of the labels, plus "reads_and_writes"
1729  * twice, plus a separating ' '
1730  */
1731 #define LPROCFS_NRS_WR_REQ_SUPP_MAX_CMD                                        \
1732         sizeof(NRS_LPROCFS_REQ_SUPP_NAME_REG LPROCFS_NRS_SUPP_NAME_READWRITES  \
1733                NRS_LPROCFS_REQ_SUPP_NAME_HP LPROCFS_NRS_SUPP_NAME_READWRITES   \
1734                " ")
1735
1736 /**
1737  * Sets the type of RPCs handled by ORR/TRR policy instances. The user can
1738  * modify this setting for the regular or high priority NRS heads separately, or
1739  * both together in a single invocation.
1740  *
1741  * For example:
1742  *
1743  * lctl set_param ost.OSS.ost_io.nrs_orr_supported=
1744  * "reg_supported:reads", to enable the ORR policy instance on the regular NRS
1745  * head of the ost_io service to handle OST_READ RPCs.
1746  *
1747  * lctl set_param ost.OSS.ost_io.nrs_trr_supported=reads_and_writes, to enable
1748  * the TRR policy instances on both the regular ang high priority NRS heads of
1749  * the ost_io service to use handle OST_READ and OST_WRITE RPCs.
1750  *
1751  * policy instances in the ptlrpc_nrs_pol_state::NRS_POL_STATE_STOPPED state are
1752  * are skipped later by nrs_orr_ctl().
1753  */
1754 static ssize_t
1755 ptlrpc_lprocfs_nrs_orr_supported_seq_write(struct file *file,
1756                                            const char __user *buffer,
1757                                            size_t count,
1758                                            loff_t *off)
1759 {
1760         struct seq_file             *m = file->private_data;
1761         struct nrs_lprocfs_orr_data *orr_data = m->private;
1762         struct ptlrpc_service       *svc = orr_data->svc;
1763         enum ptlrpc_nrs_queue_type   queue = 0;
1764         char                         kernbuf[LPROCFS_NRS_WR_REQ_SUPP_MAX_CMD];
1765         char                        *val_reg;
1766         char                        *val_hp;
1767         enum nrs_orr_supp            supp_reg;
1768         enum nrs_orr_supp            supp_hp;
1769         size_t                       count_copy;
1770         int                          rc = 0;
1771         int                          rc2 = 0;
1772
1773         if (count > (sizeof(kernbuf) - 1))
1774                 return -EINVAL;
1775
1776         if (copy_from_user(kernbuf, buffer, count))
1777                 return -EFAULT;
1778
1779         kernbuf[count] = '\0';
1780
1781         count_copy = count;
1782
1783         /**
1784          * Check if the regular supported requests setting has been specified
1785          */
1786         val_reg = lprocfs_find_named_value(kernbuf,
1787                                            NRS_LPROCFS_REQ_SUPP_NAME_REG,
1788                                            &count_copy);
1789         if (val_reg != kernbuf)
1790                 queue |= PTLRPC_NRS_QUEUE_REG;
1791
1792         count_copy = count;
1793
1794         /**
1795          * Check if the high priority supported requests setting has been
1796          * specified
1797          */
1798         val_hp = lprocfs_find_named_value(kernbuf, NRS_LPROCFS_REQ_SUPP_NAME_HP,
1799                                           &count_copy);
1800         if (val_hp != kernbuf) {
1801                 if (!nrs_svc_has_hp(svc))
1802                         return -ENODEV;
1803
1804                 queue |= PTLRPC_NRS_QUEUE_HP;
1805         }
1806
1807         /**
1808          * If none of the queues has been specified, there may be a valid
1809          * command string at the start of the buffer.
1810          */
1811         if (queue == 0) {
1812                 queue = PTLRPC_NRS_QUEUE_REG;
1813
1814                 if (nrs_svc_has_hp(svc))
1815                         queue |= PTLRPC_NRS_QUEUE_HP;
1816         }
1817
1818         if ((queue & PTLRPC_NRS_QUEUE_REG) != 0) {
1819                 supp_reg = nrs_orr_str2supp(val_reg);
1820                 if (supp_reg == -EINVAL)
1821                         return -EINVAL;
1822         }
1823
1824         if ((queue & PTLRPC_NRS_QUEUE_HP) != 0) {
1825                 supp_hp = nrs_orr_str2supp(val_hp);
1826                 if (supp_hp == -EINVAL)
1827                         return -EINVAL;
1828         }
1829
1830         /**
1831          * We change the values on regular and HP NRS heads separately, so that
1832          * we do not exit early from ptlrpc_nrs_policy_control() with an error
1833          * returned by nrs_policy_ctl_locked(), in cases where the user has not
1834          * started the policy on either the regular or HP NRS head; i.e. we are
1835          * ignoring -ENODEV within nrs_policy_ctl_locked(). -ENODEV is returned
1836          * only if the operation fails with -ENODEV on all heads that have been
1837          * specified by the command; if at least one operation succeeds,
1838          * success is returned.
1839          */
1840         if ((queue & PTLRPC_NRS_QUEUE_REG) != 0) {
1841                 rc = ptlrpc_nrs_policy_control(svc, PTLRPC_NRS_QUEUE_REG,
1842                                                orr_data->name,
1843                                                NRS_CTL_ORR_WR_SUPP_REQ, false,
1844                                                &supp_reg);
1845                 if ((rc < 0 && rc != -ENODEV) ||
1846                     (rc == -ENODEV && queue == PTLRPC_NRS_QUEUE_REG))
1847                         return rc;
1848         }
1849
1850         if ((queue & PTLRPC_NRS_QUEUE_HP) != 0) {
1851                 rc2 = ptlrpc_nrs_policy_control(svc, PTLRPC_NRS_QUEUE_HP,
1852                                                 orr_data->name,
1853                                                 NRS_CTL_ORR_WR_SUPP_REQ, false,
1854                                                 &supp_hp);
1855                 if ((rc2 < 0 && rc2 != -ENODEV) ||
1856                     (rc2 == -ENODEV && queue == PTLRPC_NRS_QUEUE_HP))
1857                         return rc2;
1858         }
1859
1860         return rc == -ENODEV && rc2 == -ENODEV ? -ENODEV : count;
1861 }
1862 LPROC_SEQ_FOPS(ptlrpc_lprocfs_nrs_orr_supported);
1863
1864 static int nrs_orr_lprocfs_init(struct ptlrpc_service *svc)
1865 {
1866         int     i;
1867
1868         struct lprocfs_vars nrs_orr_lprocfs_vars[] = {
1869                 { .name         = "nrs_orr_quantum",
1870                   .fops         = &ptlrpc_lprocfs_nrs_orr_quantum_fops  },
1871                 { .name         = "nrs_orr_offset_type",
1872                   .fops         = &ptlrpc_lprocfs_nrs_orr_offset_type_fops },
1873                 { .name         = "nrs_orr_supported",
1874                   .fops         = &ptlrpc_lprocfs_nrs_orr_supported_fops },
1875                 { NULL }
1876         };
1877
1878         if (svc->srv_procroot == NULL)
1879                 return 0;
1880
1881         lprocfs_orr_data.svc = svc;
1882
1883         for (i = 0; i < ARRAY_SIZE(nrs_orr_lprocfs_vars); i++)
1884                 nrs_orr_lprocfs_vars[i].data = &lprocfs_orr_data;
1885
1886         return lprocfs_add_vars(svc->srv_procroot, nrs_orr_lprocfs_vars, NULL);
1887 }
1888
1889 static void nrs_orr_lprocfs_fini(struct ptlrpc_service *svc)
1890 {
1891         if (svc->srv_procroot == NULL)
1892                 return;
1893
1894         lprocfs_remove_proc_entry("nrs_orr_quantum", svc->srv_procroot);
1895         lprocfs_remove_proc_entry("nrs_orr_offset_type", svc->srv_procroot);
1896         lprocfs_remove_proc_entry("nrs_orr_supported", svc->srv_procroot);
1897 }
1898
1899 #endif /* CONFIG_PROC_FS */
1900
1901 static const struct ptlrpc_nrs_pol_ops nrs_orr_ops = {
1902         .op_policy_init         = nrs_orr_init,
1903         .op_policy_start        = nrs_orr_start,
1904         .op_policy_stop         = nrs_orr_stop,
1905         .op_policy_ctl          = nrs_orr_ctl,
1906         .op_res_get             = nrs_orr_res_get,
1907         .op_res_put             = nrs_orr_res_put,
1908         .op_req_get             = nrs_orr_req_get,
1909         .op_req_enqueue         = nrs_orr_req_add,
1910         .op_req_dequeue         = nrs_orr_req_del,
1911         .op_req_stop            = nrs_orr_req_stop,
1912 #ifdef CONFIG_PROC_FS
1913         .op_lprocfs_init        = nrs_orr_lprocfs_init,
1914         .op_lprocfs_fini        = nrs_orr_lprocfs_fini,
1915 #endif
1916 };
1917
1918 struct ptlrpc_nrs_pol_conf nrs_conf_orr = {
1919         .nc_name                = NRS_POL_NAME_ORR,
1920         .nc_ops                 = &nrs_orr_ops,
1921         .nc_compat              = nrs_policy_compat_one,
1922         .nc_compat_svc_name     = "ost_io",
1923 };
1924
1925 /**
1926  * TRR, Target-based Round Robin policy
1927  *
1928  * TRR reuses much of the functions and data structures of ORR
1929  */
1930
1931 #ifdef CONFIG_PROC_FS
1932
1933 static int nrs_trr_lprocfs_init(struct ptlrpc_service *svc)
1934 {
1935         int     i;
1936
1937         struct lprocfs_vars nrs_trr_lprocfs_vars[] = {
1938                 { .name         = "nrs_trr_quantum",
1939                   .fops         = &ptlrpc_lprocfs_nrs_orr_quantum_fops },
1940                 { .name         = "nrs_trr_offset_type",
1941                   .fops         = &ptlrpc_lprocfs_nrs_orr_offset_type_fops },
1942                 { .name         = "nrs_trr_supported",
1943                   .fops         = &ptlrpc_lprocfs_nrs_orr_supported_fops },
1944                 { NULL }
1945         };
1946
1947         if (svc->srv_procroot == NULL)
1948                 return 0;
1949
1950         lprocfs_trr_data.svc = svc;
1951
1952         for (i = 0; i < ARRAY_SIZE(nrs_trr_lprocfs_vars); i++)
1953                 nrs_trr_lprocfs_vars[i].data = &lprocfs_trr_data;
1954
1955         return lprocfs_add_vars(svc->srv_procroot, nrs_trr_lprocfs_vars, NULL);
1956 }
1957
1958 static void nrs_trr_lprocfs_fini(struct ptlrpc_service *svc)
1959 {
1960         if (svc->srv_procroot == NULL)
1961                 return;
1962
1963         lprocfs_remove_proc_entry("nrs_trr_quantum", svc->srv_procroot);
1964         lprocfs_remove_proc_entry("nrs_trr_offset_type", svc->srv_procroot);
1965         lprocfs_remove_proc_entry("nrs_trr_supported", svc->srv_procroot);
1966 }
1967
1968 #endif /* CONFIG_PROC_FS */
1969
1970 /**
1971  * Reuse much of the ORR functionality for TRR.
1972  */
1973 static const struct ptlrpc_nrs_pol_ops nrs_trr_ops = {
1974         .op_policy_init         = nrs_orr_init,
1975         .op_policy_start        = nrs_orr_start,
1976         .op_policy_stop         = nrs_orr_stop,
1977         .op_policy_ctl          = nrs_orr_ctl,
1978         .op_res_get             = nrs_orr_res_get,
1979         .op_res_put             = nrs_orr_res_put,
1980         .op_req_get             = nrs_orr_req_get,
1981         .op_req_enqueue         = nrs_orr_req_add,
1982         .op_req_dequeue         = nrs_orr_req_del,
1983         .op_req_stop            = nrs_orr_req_stop,
1984 #ifdef CONFIG_PROC_FS
1985         .op_lprocfs_init        = nrs_trr_lprocfs_init,
1986         .op_lprocfs_fini        = nrs_trr_lprocfs_fini,
1987 #endif
1988 };
1989
1990 struct ptlrpc_nrs_pol_conf nrs_conf_trr = {
1991         .nc_name                = NRS_POL_NAME_TRR,
1992         .nc_ops                 = &nrs_trr_ops,
1993         .nc_compat              = nrs_policy_compat_one,
1994         .nc_compat_svc_name     = "ost_io",
1995 };
1996
1997 /** @} ORR/TRR policy */
1998
1999 /** @} nrs */
2000
2001 #endif /* HAVE_SERVER_SUPPORT */