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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Common NFS I/O  operations for the pnfs file based
   4 * layout drivers.
   5 *
   6 * Copyright (c) 2014, Primary Data, Inc. All rights reserved.
   7 *
   8 * Tom Haynes <loghyr@primarydata.com>
   9 */
  10
  11#include <linux/nfs_fs.h>
  12#include <linux/nfs_page.h>
  13#include <linux/sunrpc/addr.h>
  14#include <linux/module.h>
  15
  16#include "nfs4session.h"
  17#include "internal.h"
  18#include "pnfs.h"
  19
  20#define NFSDBG_FACILITY		NFSDBG_PNFS
  21
  22void pnfs_generic_rw_release(void *data)
  23{
  24	struct nfs_pgio_header *hdr = data;
  25
  26	nfs_put_client(hdr->ds_clp);
  27	hdr->mds_ops->rpc_release(data);
  28}
  29EXPORT_SYMBOL_GPL(pnfs_generic_rw_release);
  30
  31/* Fake up some data that will cause nfs_commit_release to retry the writes. */
  32void pnfs_generic_prepare_to_resend_writes(struct nfs_commit_data *data)
  33{
  34	struct nfs_writeverf *verf = data->res.verf;
  35
  36	data->task.tk_status = 0;
  37	memset(&verf->verifier, 0, sizeof(verf->verifier));
  38	verf->committed = NFS_UNSTABLE;
  39}
  40EXPORT_SYMBOL_GPL(pnfs_generic_prepare_to_resend_writes);
  41
  42void pnfs_generic_write_commit_done(struct rpc_task *task, void *data)
  43{
  44	struct nfs_commit_data *wdata = data;
  45
  46	/* Note this may cause RPC to be resent */
  47	wdata->mds_ops->rpc_call_done(task, data);
  48}
  49EXPORT_SYMBOL_GPL(pnfs_generic_write_commit_done);
  50
  51void pnfs_generic_commit_release(void *calldata)
  52{
  53	struct nfs_commit_data *data = calldata;
  54
  55	data->completion_ops->completion(data);
  56	pnfs_put_lseg(data->lseg);
  57	nfs_put_client(data->ds_clp);
  58	nfs_commitdata_release(data);
  59}
  60EXPORT_SYMBOL_GPL(pnfs_generic_commit_release);
  61
  62static struct pnfs_layout_segment *
  63pnfs_free_bucket_lseg(struct pnfs_commit_bucket *bucket)
  64{
  65	if (list_empty(&bucket->committing) && list_empty(&bucket->written)) {
  66		struct pnfs_layout_segment *freeme = bucket->lseg;
  67		bucket->lseg = NULL;
  68		return freeme;
  69	}
  70	return NULL;
  71}
  72
  73/* The generic layer is about to remove the req from the commit list.
  74 * If this will make the bucket empty, it will need to put the lseg reference.
  75 * Note this must be called holding nfsi->commit_mutex
  76 */
  77void
  78pnfs_generic_clear_request_commit(struct nfs_page *req,
  79				  struct nfs_commit_info *cinfo)
  80{
  81	struct pnfs_commit_bucket *bucket = NULL;
  82
  83	if (!test_and_clear_bit(PG_COMMIT_TO_DS, &req->wb_flags))
  84		goto out;
  85	cinfo->ds->nwritten--;
  86	if (list_is_singular(&req->wb_list))
  87		bucket = list_first_entry(&req->wb_list,
  88					  struct pnfs_commit_bucket, written);
  89out:
  90	nfs_request_remove_commit_list(req, cinfo);
  91	if (bucket)
  92		pnfs_put_lseg(pnfs_free_bucket_lseg(bucket));
  93}
  94EXPORT_SYMBOL_GPL(pnfs_generic_clear_request_commit);
  95
  96struct pnfs_commit_array *
  97pnfs_alloc_commit_array(size_t n, gfp_t gfp_flags)
  98{
  99	struct pnfs_commit_array *p;
 100	struct pnfs_commit_bucket *b;
 101
 102	p = kmalloc(struct_size(p, buckets, n), gfp_flags);
 103	if (!p)
 104		return NULL;
 105	p->nbuckets = n;
 106	INIT_LIST_HEAD(&p->cinfo_list);
 107	INIT_LIST_HEAD(&p->lseg_list);
 108	p->lseg = NULL;
 109	for (b = &p->buckets[0]; n != 0; b++, n--) {
 110		INIT_LIST_HEAD(&b->written);
 111		INIT_LIST_HEAD(&b->committing);
 112		b->lseg = NULL;
 113		b->direct_verf.committed = NFS_INVALID_STABLE_HOW;
 114	}
 115	return p;
 116}
 117EXPORT_SYMBOL_GPL(pnfs_alloc_commit_array);
 118
 119void
 120pnfs_free_commit_array(struct pnfs_commit_array *p)
 121{
 122	kfree_rcu(p, rcu);
 123}
 124EXPORT_SYMBOL_GPL(pnfs_free_commit_array);
 125
 126static struct pnfs_commit_array *
 127pnfs_find_commit_array_by_lseg(struct pnfs_ds_commit_info *fl_cinfo,
 128		struct pnfs_layout_segment *lseg)
 129{
 130	struct pnfs_commit_array *array;
 131
 132	list_for_each_entry_rcu(array, &fl_cinfo->commits, cinfo_list) {
 133		if (array->lseg == lseg)
 134			return array;
 135	}
 136	return NULL;
 137}
 138
 139struct pnfs_commit_array *
 140pnfs_add_commit_array(struct pnfs_ds_commit_info *fl_cinfo,
 141		struct pnfs_commit_array *new,
 142		struct pnfs_layout_segment *lseg)
 143{
 144	struct pnfs_commit_array *array;
 145
 146	array = pnfs_find_commit_array_by_lseg(fl_cinfo, lseg);
 147	if (array)
 148		return array;
 149	new->lseg = lseg;
 150	refcount_set(&new->refcount, 1);
 151	list_add_rcu(&new->cinfo_list, &fl_cinfo->commits);
 152	list_add(&new->lseg_list, &lseg->pls_commits);
 153	return new;
 154}
 155EXPORT_SYMBOL_GPL(pnfs_add_commit_array);
 156
 157static struct pnfs_commit_array *
 158pnfs_lookup_commit_array(struct pnfs_ds_commit_info *fl_cinfo,
 159		struct pnfs_layout_segment *lseg)
 160{
 161	struct pnfs_commit_array *array;
 162
 163	rcu_read_lock();
 164	array = pnfs_find_commit_array_by_lseg(fl_cinfo, lseg);
 165	if (!array) {
 166		rcu_read_unlock();
 167		fl_cinfo->ops->setup_ds_info(fl_cinfo, lseg);
 168		rcu_read_lock();
 169		array = pnfs_find_commit_array_by_lseg(fl_cinfo, lseg);
 170	}
 171	rcu_read_unlock();
 172	return array;
 173}
 174
 175static void
 176pnfs_release_commit_array_locked(struct pnfs_commit_array *array)
 177{
 178	list_del_rcu(&array->cinfo_list);
 179	list_del(&array->lseg_list);
 180	pnfs_free_commit_array(array);
 181}
 182
 183static void
 184pnfs_put_commit_array_locked(struct pnfs_commit_array *array)
 185{
 186	if (refcount_dec_and_test(&array->refcount))
 187		pnfs_release_commit_array_locked(array);
 188}
 189
 190static void
 191pnfs_put_commit_array(struct pnfs_commit_array *array, struct inode *inode)
 192{
 193	if (refcount_dec_and_lock(&array->refcount, &inode->i_lock)) {
 194		pnfs_release_commit_array_locked(array);
 195		spin_unlock(&inode->i_lock);
 196	}
 197}
 198
 199static struct pnfs_commit_array *
 200pnfs_get_commit_array(struct pnfs_commit_array *array)
 201{
 202	if (refcount_inc_not_zero(&array->refcount))
 203		return array;
 204	return NULL;
 205}
 206
 207static void
 208pnfs_remove_and_free_commit_array(struct pnfs_commit_array *array)
 209{
 210	array->lseg = NULL;
 211	list_del_init(&array->lseg_list);
 212	pnfs_put_commit_array_locked(array);
 213}
 214
 215void
 216pnfs_generic_ds_cinfo_release_lseg(struct pnfs_ds_commit_info *fl_cinfo,
 217		struct pnfs_layout_segment *lseg)
 218{
 219	struct pnfs_commit_array *array, *tmp;
 220
 221	list_for_each_entry_safe(array, tmp, &lseg->pls_commits, lseg_list)
 222		pnfs_remove_and_free_commit_array(array);
 223}
 224EXPORT_SYMBOL_GPL(pnfs_generic_ds_cinfo_release_lseg);
 225
 226void
 227pnfs_generic_ds_cinfo_destroy(struct pnfs_ds_commit_info *fl_cinfo)
 228{
 229	struct pnfs_commit_array *array, *tmp;
 230
 231	list_for_each_entry_safe(array, tmp, &fl_cinfo->commits, cinfo_list)
 232		pnfs_remove_and_free_commit_array(array);
 233}
 234EXPORT_SYMBOL_GPL(pnfs_generic_ds_cinfo_destroy);
 235
 236/*
 237 * Locks the nfs_page requests for commit and moves them to
 238 * @bucket->committing.
 239 */
 240static int
 241pnfs_bucket_scan_ds_commit_list(struct pnfs_commit_bucket *bucket,
 242				struct nfs_commit_info *cinfo,
 243				int max)
 244{
 245	struct list_head *src = &bucket->written;
 246	struct list_head *dst = &bucket->committing;
 247	int ret;
 248
 249	lockdep_assert_held(&NFS_I(cinfo->inode)->commit_mutex);
 250	ret = nfs_scan_commit_list(src, dst, cinfo, max);
 251	if (ret) {
 252		cinfo->ds->nwritten -= ret;
 253		cinfo->ds->ncommitting += ret;
 254	}
 255	return ret;
 256}
 257
 258static int pnfs_bucket_scan_array(struct nfs_commit_info *cinfo,
 259				  struct pnfs_commit_bucket *buckets,
 260				  unsigned int nbuckets,
 261				  int max)
 262{
 263	unsigned int i;
 264	int rv = 0, cnt;
 265
 266	for (i = 0; i < nbuckets && max != 0; i++) {
 267		cnt = pnfs_bucket_scan_ds_commit_list(&buckets[i], cinfo, max);
 268		rv += cnt;
 269		max -= cnt;
 270	}
 271	return rv;
 272}
 273
 274/* Move reqs from written to committing lists, returning count
 275 * of number moved.
 276 */
 277int pnfs_generic_scan_commit_lists(struct nfs_commit_info *cinfo, int max)
 278{
 279	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
 280	struct pnfs_commit_array *array;
 281	int rv = 0, cnt;
 282
 283	rcu_read_lock();
 284	list_for_each_entry_rcu(array, &fl_cinfo->commits, cinfo_list) {
 285		if (!array->lseg || !pnfs_get_commit_array(array))
 286			continue;
 287		rcu_read_unlock();
 288		cnt = pnfs_bucket_scan_array(cinfo, array->buckets,
 289				array->nbuckets, max);
 290		rcu_read_lock();
 291		pnfs_put_commit_array(array, cinfo->inode);
 292		rv += cnt;
 293		max -= cnt;
 294		if (!max)
 295			break;
 296	}
 297	rcu_read_unlock();
 298	return rv;
 299}
 300EXPORT_SYMBOL_GPL(pnfs_generic_scan_commit_lists);
 301
 302static unsigned int
 303pnfs_bucket_recover_commit_reqs(struct list_head *dst,
 304			        struct pnfs_commit_bucket *buckets,
 305				unsigned int nbuckets,
 306				struct nfs_commit_info *cinfo)
 307{
 308	struct pnfs_commit_bucket *b;
 309	struct pnfs_layout_segment *freeme;
 310	unsigned int nwritten, ret = 0;
 311	unsigned int i;
 312
 313restart:
 314	for (i = 0, b = buckets; i < nbuckets; i++, b++) {
 315		nwritten = nfs_scan_commit_list(&b->written, dst, cinfo, 0);
 316		if (!nwritten)
 317			continue;
 318		ret += nwritten;
 319		freeme = pnfs_free_bucket_lseg(b);
 320		if (freeme) {
 321			pnfs_put_lseg(freeme);
 322			goto restart;
 323		}
 324	}
 325	return ret;
 326}
 327
 328/* Pull everything off the committing lists and dump into @dst.  */
 329void pnfs_generic_recover_commit_reqs(struct list_head *dst,
 330				      struct nfs_commit_info *cinfo)
 331{
 332	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
 333	struct pnfs_commit_array *array;
 334	unsigned int nwritten;
 335
 336	lockdep_assert_held(&NFS_I(cinfo->inode)->commit_mutex);
 337	rcu_read_lock();
 338	list_for_each_entry_rcu(array, &fl_cinfo->commits, cinfo_list) {
 339		if (!array->lseg || !pnfs_get_commit_array(array))
 340			continue;
 341		rcu_read_unlock();
 342		nwritten = pnfs_bucket_recover_commit_reqs(dst,
 343							   array->buckets,
 344							   array->nbuckets,
 345							   cinfo);
 346		rcu_read_lock();
 347		pnfs_put_commit_array(array, cinfo->inode);
 348		fl_cinfo->nwritten -= nwritten;
 349	}
 350	rcu_read_unlock();
 351}
 352EXPORT_SYMBOL_GPL(pnfs_generic_recover_commit_reqs);
 353
 354static struct nfs_page *
 355pnfs_bucket_search_commit_reqs(struct pnfs_commit_bucket *buckets,
 356		unsigned int nbuckets, struct page *page)
 357{
 358	struct nfs_page *req;
 359	struct pnfs_commit_bucket *b;
 360	unsigned int i;
 361
 362	/* Linearly search the commit lists for each bucket until a matching
 363	 * request is found */
 364	for (i = 0, b = buckets; i < nbuckets; i++, b++) {
 365		list_for_each_entry(req, &b->written, wb_list) {
 366			if (req->wb_page == page)
 367				return req->wb_head;
 368		}
 369		list_for_each_entry(req, &b->committing, wb_list) {
 370			if (req->wb_page == page)
 371				return req->wb_head;
 372		}
 373	}
 374	return NULL;
 375}
 376
 377/* pnfs_generic_search_commit_reqs - Search lists in @cinfo for the head reqest
 378 *				   for @page
 379 * @cinfo - commit info for current inode
 380 * @page - page to search for matching head request
 381 *
 382 * Returns a the head request if one is found, otherwise returns NULL.
 383 */
 384struct nfs_page *
 385pnfs_generic_search_commit_reqs(struct nfs_commit_info *cinfo, struct page *page)
 386{
 387	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
 388	struct pnfs_commit_array *array;
 389	struct nfs_page *req;
 390
 391	list_for_each_entry(array, &fl_cinfo->commits, cinfo_list) {
 392		req = pnfs_bucket_search_commit_reqs(array->buckets,
 393				array->nbuckets, page);
 394		if (req)
 395			return req;
 396	}
 397	return NULL;
 398}
 399EXPORT_SYMBOL_GPL(pnfs_generic_search_commit_reqs);
 400
 401static struct pnfs_layout_segment *
 402pnfs_bucket_get_committing(struct list_head *head,
 403			   struct pnfs_commit_bucket *bucket,
 404			   struct nfs_commit_info *cinfo)
 405{
 406	struct pnfs_layout_segment *lseg;
 407	struct list_head *pos;
 408
 409	list_for_each(pos, &bucket->committing)
 410		cinfo->ds->ncommitting--;
 411	list_splice_init(&bucket->committing, head);
 412	lseg = pnfs_free_bucket_lseg(bucket);
 413	if (!lseg)
 414		lseg = pnfs_get_lseg(bucket->lseg);
 415	return lseg;
 416}
 417
 418static struct nfs_commit_data *
 419pnfs_bucket_fetch_commitdata(struct pnfs_commit_bucket *bucket,
 420			     struct nfs_commit_info *cinfo)
 421{
 422	struct nfs_commit_data *data = nfs_commitdata_alloc(false);
 423
 424	if (!data)
 425		return NULL;
 426	data->lseg = pnfs_bucket_get_committing(&data->pages, bucket, cinfo);
 427	return data;
 428}
 429
 430static void pnfs_generic_retry_commit(struct pnfs_commit_bucket *buckets,
 431				      unsigned int nbuckets,
 432				      struct nfs_commit_info *cinfo,
 433				      unsigned int idx)
 434{
 435	struct pnfs_commit_bucket *bucket;
 436	struct pnfs_layout_segment *freeme;
 437	LIST_HEAD(pages);
 438
 439	for (bucket = buckets; idx < nbuckets; bucket++, idx++) {
 440		if (list_empty(&bucket->committing))
 441			continue;
 442		mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
 443		freeme = pnfs_bucket_get_committing(&pages, bucket, cinfo);
 444		mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
 445		nfs_retry_commit(&pages, freeme, cinfo, idx);
 446		pnfs_put_lseg(freeme);
 447	}
 448}
 449
 450static unsigned int
 451pnfs_bucket_alloc_ds_commits(struct list_head *list,
 452			     struct pnfs_commit_bucket *buckets,
 453			     unsigned int nbuckets,
 454			     struct nfs_commit_info *cinfo)
 455{
 456	struct pnfs_commit_bucket *bucket;
 457	struct nfs_commit_data *data;
 458	unsigned int i;
 459	unsigned int nreq = 0;
 460
 461	for (i = 0, bucket = buckets; i < nbuckets; i++, bucket++) {
 462		if (list_empty(&bucket->committing))
 463			continue;
 464		mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
 465		if (!list_empty(&bucket->committing)) {
 466			data = pnfs_bucket_fetch_commitdata(bucket, cinfo);
 467			if (!data)
 468				goto out_error;
 469			data->ds_commit_index = i;
 470			list_add_tail(&data->list, list);
 471			atomic_inc(&cinfo->mds->rpcs_out);
 472			nreq++;
 473		}
 474		mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
 475	}
 476	return nreq;
 477out_error:
 478	mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
 479	/* Clean up on error */
 480	pnfs_generic_retry_commit(buckets, nbuckets, cinfo, i);
 481	return nreq;
 482}
 483
 484static unsigned int
 485pnfs_alloc_ds_commits_list(struct list_head *list,
 486			   struct pnfs_ds_commit_info *fl_cinfo,
 487			   struct nfs_commit_info *cinfo)
 488{
 489	struct pnfs_commit_array *array;
 490	unsigned int ret = 0;
 491
 492	rcu_read_lock();
 493	list_for_each_entry_rcu(array, &fl_cinfo->commits, cinfo_list) {
 494		if (!array->lseg || !pnfs_get_commit_array(array))
 495			continue;
 496		rcu_read_unlock();
 497		ret += pnfs_bucket_alloc_ds_commits(list, array->buckets,
 498				array->nbuckets, cinfo);
 499		rcu_read_lock();
 500		pnfs_put_commit_array(array, cinfo->inode);
 501	}
 502	rcu_read_unlock();
 503	return ret;
 504}
 505
 506/* This follows nfs_commit_list pretty closely */
 507int
 508pnfs_generic_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
 509			     int how, struct nfs_commit_info *cinfo,
 510			     int (*initiate_commit)(struct nfs_commit_data *data,
 511						    int how))
 512{
 513	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
 514	struct nfs_commit_data *data, *tmp;
 515	LIST_HEAD(list);
 516	unsigned int nreq = 0;
 517
 518	if (!list_empty(mds_pages)) {
 519		data = nfs_commitdata_alloc(true);
 520		data->ds_commit_index = -1;
 521		list_splice_init(mds_pages, &data->pages);
 522		list_add_tail(&data->list, &list);
 523		atomic_inc(&cinfo->mds->rpcs_out);
 524		nreq++;
 525	}
 526
 527	nreq += pnfs_alloc_ds_commits_list(&list, fl_cinfo, cinfo);
 528	if (nreq == 0)
 529		goto out;
 530
 531	list_for_each_entry_safe(data, tmp, &list, list) {
 532		list_del(&data->list);
 533		if (data->ds_commit_index < 0) {
 534			nfs_init_commit(data, NULL, NULL, cinfo);
 535			nfs_initiate_commit(NFS_CLIENT(inode), data,
 536					    NFS_PROTO(data->inode),
 537					    data->mds_ops, how,
 538					    RPC_TASK_CRED_NOREF);
 539		} else {
 540			nfs_init_commit(data, NULL, data->lseg, cinfo);
 541			initiate_commit(data, how);
 542		}
 543	}
 544out:
 545	return PNFS_ATTEMPTED;
 546}
 547EXPORT_SYMBOL_GPL(pnfs_generic_commit_pagelist);
 548
 549/*
 550 * Data server cache
 551 *
 552 * Data servers can be mapped to different device ids.
 553 * nfs4_pnfs_ds reference counting
 554 *   - set to 1 on allocation
 555 *   - incremented when a device id maps a data server already in the cache.
 556 *   - decremented when deviceid is removed from the cache.
 557 */
 558static DEFINE_SPINLOCK(nfs4_ds_cache_lock);
 559static LIST_HEAD(nfs4_data_server_cache);
 560
 561/* Debug routines */
 562static void
 563print_ds(struct nfs4_pnfs_ds *ds)
 564{
 565	if (ds == NULL) {
 566		printk(KERN_WARNING "%s NULL device\n", __func__);
 567		return;
 568	}
 569	printk(KERN_WARNING "        ds %s\n"
 570		"        ref count %d\n"
 571		"        client %p\n"
 572		"        cl_exchange_flags %x\n",
 573		ds->ds_remotestr,
 574		refcount_read(&ds->ds_count), ds->ds_clp,
 575		ds->ds_clp ? ds->ds_clp->cl_exchange_flags : 0);
 576}
 577
 578static bool
 579same_sockaddr(struct sockaddr *addr1, struct sockaddr *addr2)
 580{
 581	struct sockaddr_in *a, *b;
 582	struct sockaddr_in6 *a6, *b6;
 583
 584	if (addr1->sa_family != addr2->sa_family)
 585		return false;
 586
 587	switch (addr1->sa_family) {
 588	case AF_INET:
 589		a = (struct sockaddr_in *)addr1;
 590		b = (struct sockaddr_in *)addr2;
 591
 592		if (a->sin_addr.s_addr == b->sin_addr.s_addr &&
 593		    a->sin_port == b->sin_port)
 594			return true;
 595		break;
 596
 597	case AF_INET6:
 598		a6 = (struct sockaddr_in6 *)addr1;
 599		b6 = (struct sockaddr_in6 *)addr2;
 600
 601		/* LINKLOCAL addresses must have matching scope_id */
 602		if (ipv6_addr_src_scope(&a6->sin6_addr) ==
 603		    IPV6_ADDR_SCOPE_LINKLOCAL &&
 604		    a6->sin6_scope_id != b6->sin6_scope_id)
 605			return false;
 606
 607		if (ipv6_addr_equal(&a6->sin6_addr, &b6->sin6_addr) &&
 608		    a6->sin6_port == b6->sin6_port)
 609			return true;
 610		break;
 611
 612	default:
 613		dprintk("%s: unhandled address family: %u\n",
 614			__func__, addr1->sa_family);
 615		return false;
 616	}
 617
 618	return false;
 619}
 620
 621/*
 622 * Checks if 'dsaddrs1' contains a subset of 'dsaddrs2'. If it does,
 623 * declare a match.
 624 */
 625static bool
 626_same_data_server_addrs_locked(const struct list_head *dsaddrs1,
 627			       const struct list_head *dsaddrs2)
 628{
 629	struct nfs4_pnfs_ds_addr *da1, *da2;
 630	struct sockaddr *sa1, *sa2;
 631	bool match = false;
 632
 633	list_for_each_entry(da1, dsaddrs1, da_node) {
 634		sa1 = (struct sockaddr *)&da1->da_addr;
 635		match = false;
 636		list_for_each_entry(da2, dsaddrs2, da_node) {
 637			sa2 = (struct sockaddr *)&da2->da_addr;
 638			match = same_sockaddr(sa1, sa2);
 639			if (match)
 640				break;
 641		}
 642		if (!match)
 643			break;
 644	}
 645	return match;
 646}
 647
 648/*
 649 * Lookup DS by addresses.  nfs4_ds_cache_lock is held
 650 */
 651static struct nfs4_pnfs_ds *
 652_data_server_lookup_locked(const struct list_head *dsaddrs)
 653{
 654	struct nfs4_pnfs_ds *ds;
 655
 656	list_for_each_entry(ds, &nfs4_data_server_cache, ds_node)
 657		if (_same_data_server_addrs_locked(&ds->ds_addrs, dsaddrs))
 658			return ds;
 659	return NULL;
 660}
 661
 662static struct nfs4_pnfs_ds_addr *nfs4_pnfs_ds_addr_alloc(gfp_t gfp_flags)
 663{
 664	struct nfs4_pnfs_ds_addr *da = kzalloc(sizeof(*da), gfp_flags);
 665	if (da)
 666		INIT_LIST_HEAD(&da->da_node);
 667	return da;
 668}
 669
 670static void nfs4_pnfs_ds_addr_free(struct nfs4_pnfs_ds_addr *da)
 671{
 672	kfree(da->da_remotestr);
 673	kfree(da->da_netid);
 674	kfree(da);
 675}
 676
 677static void destroy_ds(struct nfs4_pnfs_ds *ds)
 678{
 679	struct nfs4_pnfs_ds_addr *da;
 680
 681	dprintk("--> %s\n", __func__);
 682	ifdebug(FACILITY)
 683		print_ds(ds);
 684
 685	nfs_put_client(ds->ds_clp);
 686
 687	while (!list_empty(&ds->ds_addrs)) {
 688		da = list_first_entry(&ds->ds_addrs,
 689				      struct nfs4_pnfs_ds_addr,
 690				      da_node);
 691		list_del_init(&da->da_node);
 692		nfs4_pnfs_ds_addr_free(da);
 693	}
 694
 695	kfree(ds->ds_remotestr);
 696	kfree(ds);
 697}
 698
 699void nfs4_pnfs_ds_put(struct nfs4_pnfs_ds *ds)
 700{
 701	if (refcount_dec_and_lock(&ds->ds_count,
 702				&nfs4_ds_cache_lock)) {
 703		list_del_init(&ds->ds_node);
 704		spin_unlock(&nfs4_ds_cache_lock);
 705		destroy_ds(ds);
 706	}
 707}
 708EXPORT_SYMBOL_GPL(nfs4_pnfs_ds_put);
 709
 710/*
 711 * Create a string with a human readable address and port to avoid
 712 * complicated setup around many dprinks.
 713 */
 714static char *
 715nfs4_pnfs_remotestr(struct list_head *dsaddrs, gfp_t gfp_flags)
 716{
 717	struct nfs4_pnfs_ds_addr *da;
 718	char *remotestr;
 719	size_t len;
 720	char *p;
 721
 722	len = 3;        /* '{', '}' and eol */
 723	list_for_each_entry(da, dsaddrs, da_node) {
 724		len += strlen(da->da_remotestr) + 1;    /* string plus comma */
 725	}
 726
 727	remotestr = kzalloc(len, gfp_flags);
 728	if (!remotestr)
 729		return NULL;
 730
 731	p = remotestr;
 732	*(p++) = '{';
 733	len--;
 734	list_for_each_entry(da, dsaddrs, da_node) {
 735		size_t ll = strlen(da->da_remotestr);
 736
 737		if (ll > len)
 738			goto out_err;
 739
 740		memcpy(p, da->da_remotestr, ll);
 741		p += ll;
 742		len -= ll;
 743
 744		if (len < 1)
 745			goto out_err;
 746		(*p++) = ',';
 747		len--;
 748	}
 749	if (len < 2)
 750		goto out_err;
 751	*(p++) = '}';
 752	*p = '\0';
 753	return remotestr;
 754out_err:
 755	kfree(remotestr);
 756	return NULL;
 757}
 758
 759/*
 760 * Given a list of multipath struct nfs4_pnfs_ds_addr, add it to ds cache if
 761 * uncached and return cached struct nfs4_pnfs_ds.
 762 */
 763struct nfs4_pnfs_ds *
 764nfs4_pnfs_ds_add(struct list_head *dsaddrs, gfp_t gfp_flags)
 765{
 766	struct nfs4_pnfs_ds *tmp_ds, *ds = NULL;
 767	char *remotestr;
 768
 769	if (list_empty(dsaddrs)) {
 770		dprintk("%s: no addresses defined\n", __func__);
 771		goto out;
 772	}
 773
 774	ds = kzalloc(sizeof(*ds), gfp_flags);
 775	if (!ds)
 776		goto out;
 777
 778	/* this is only used for debugging, so it's ok if its NULL */
 779	remotestr = nfs4_pnfs_remotestr(dsaddrs, gfp_flags);
 780
 781	spin_lock(&nfs4_ds_cache_lock);
 782	tmp_ds = _data_server_lookup_locked(dsaddrs);
 783	if (tmp_ds == NULL) {
 784		INIT_LIST_HEAD(&ds->ds_addrs);
 785		list_splice_init(dsaddrs, &ds->ds_addrs);
 786		ds->ds_remotestr = remotestr;
 787		refcount_set(&ds->ds_count, 1);
 788		INIT_LIST_HEAD(&ds->ds_node);
 789		ds->ds_clp = NULL;
 790		list_add(&ds->ds_node, &nfs4_data_server_cache);
 791		dprintk("%s add new data server %s\n", __func__,
 792			ds->ds_remotestr);
 793	} else {
 794		kfree(remotestr);
 795		kfree(ds);
 796		refcount_inc(&tmp_ds->ds_count);
 797		dprintk("%s data server %s found, inc'ed ds_count to %d\n",
 798			__func__, tmp_ds->ds_remotestr,
 799			refcount_read(&tmp_ds->ds_count));
 800		ds = tmp_ds;
 801	}
 802	spin_unlock(&nfs4_ds_cache_lock);
 803out:
 804	return ds;
 805}
 806EXPORT_SYMBOL_GPL(nfs4_pnfs_ds_add);
 807
 808static int nfs4_wait_ds_connect(struct nfs4_pnfs_ds *ds)
 809{
 810	might_sleep();
 811	return wait_on_bit(&ds->ds_state, NFS4DS_CONNECTING, TASK_KILLABLE);
 812}
 813
 814static void nfs4_clear_ds_conn_bit(struct nfs4_pnfs_ds *ds)
 815{
 816	smp_mb__before_atomic();
 817	clear_and_wake_up_bit(NFS4DS_CONNECTING, &ds->ds_state);
 818}
 819
 820static struct nfs_client *(*get_v3_ds_connect)(
 821			struct nfs_server *mds_srv,
 822			const struct sockaddr *ds_addr,
 823			int ds_addrlen,
 824			int ds_proto,
 825			unsigned int ds_timeo,
 826			unsigned int ds_retrans);
 827
 828static bool load_v3_ds_connect(void)
 829{
 830	if (!get_v3_ds_connect) {
 831		get_v3_ds_connect = symbol_request(nfs3_set_ds_client);
 832		WARN_ON_ONCE(!get_v3_ds_connect);
 833	}
 834
 835	return(get_v3_ds_connect != NULL);
 836}
 837
 838void nfs4_pnfs_v3_ds_connect_unload(void)
 839{
 840	if (get_v3_ds_connect) {
 841		symbol_put(nfs3_set_ds_client);
 842		get_v3_ds_connect = NULL;
 843	}
 844}
 845
 846static int _nfs4_pnfs_v3_ds_connect(struct nfs_server *mds_srv,
 847				 struct nfs4_pnfs_ds *ds,
 848				 unsigned int timeo,
 849				 unsigned int retrans)
 850{
 851	struct nfs_client *clp = ERR_PTR(-EIO);
 852	struct nfs4_pnfs_ds_addr *da;
 853	int status = 0;
 854
 855	dprintk("--> %s DS %s\n", __func__, ds->ds_remotestr);
 856
 857	if (!load_v3_ds_connect())
 858		return -EPROTONOSUPPORT;
 859
 860	list_for_each_entry(da, &ds->ds_addrs, da_node) {
 861		dprintk("%s: DS %s: trying address %s\n",
 862			__func__, ds->ds_remotestr, da->da_remotestr);
 863
 864		if (!IS_ERR(clp)) {
 865			struct xprt_create xprt_args = {
 866				.ident = da->da_transport,
 867				.net = clp->cl_net,
 868				.dstaddr = (struct sockaddr *)&da->da_addr,
 869				.addrlen = da->da_addrlen,
 870				.servername = clp->cl_hostname,
 871			};
 872
 873			if (da->da_transport != clp->cl_proto)
 874				continue;
 875			if (da->da_addr.ss_family != clp->cl_addr.ss_family)
 876				continue;
 877			/* Add this address as an alias */
 878			rpc_clnt_add_xprt(clp->cl_rpcclient, &xprt_args,
 879					rpc_clnt_test_and_add_xprt, NULL);
 880			continue;
 881		}
 882		clp = get_v3_ds_connect(mds_srv,
 883				(struct sockaddr *)&da->da_addr,
 884				da->da_addrlen, da->da_transport,
 885				timeo, retrans);
 886		if (IS_ERR(clp))
 887			continue;
 888		clp->cl_rpcclient->cl_softerr = 0;
 889		clp->cl_rpcclient->cl_softrtry = 0;
 890	}
 891
 892	if (IS_ERR(clp)) {
 893		status = PTR_ERR(clp);
 894		goto out;
 895	}
 896
 897	smp_wmb();
 898	ds->ds_clp = clp;
 899	dprintk("%s [new] addr: %s\n", __func__, ds->ds_remotestr);
 900out:
 901	return status;
 902}
 903
 904static int _nfs4_pnfs_v4_ds_connect(struct nfs_server *mds_srv,
 905				 struct nfs4_pnfs_ds *ds,
 906				 unsigned int timeo,
 907				 unsigned int retrans,
 908				 u32 minor_version)
 909{
 910	struct nfs_client *clp = ERR_PTR(-EIO);
 911	struct nfs4_pnfs_ds_addr *da;
 912	int status = 0;
 913
 914	dprintk("--> %s DS %s\n", __func__, ds->ds_remotestr);
 915
 916	list_for_each_entry(da, &ds->ds_addrs, da_node) {
 917		dprintk("%s: DS %s: trying address %s\n",
 918			__func__, ds->ds_remotestr, da->da_remotestr);
 919
 920		if (!IS_ERR(clp) && clp->cl_mvops->session_trunk) {
 921			struct xprt_create xprt_args = {
 922				.ident = da->da_transport,
 923				.net = clp->cl_net,
 924				.dstaddr = (struct sockaddr *)&da->da_addr,
 925				.addrlen = da->da_addrlen,
 926				.servername = clp->cl_hostname,
 927			};
 928			struct nfs4_add_xprt_data xprtdata = {
 929				.clp = clp,
 930			};
 931			struct rpc_add_xprt_test rpcdata = {
 932				.add_xprt_test = clp->cl_mvops->session_trunk,
 933				.data = &xprtdata,
 934			};
 935
 936			if (da->da_transport != clp->cl_proto)
 937				continue;
 938			if (da->da_addr.ss_family != clp->cl_addr.ss_family)
 939				continue;
 940			/**
 941			* Test this address for session trunking and
 942			* add as an alias
 943			*/
 944			xprtdata.cred = nfs4_get_clid_cred(clp),
 945			rpc_clnt_add_xprt(clp->cl_rpcclient, &xprt_args,
 946					  rpc_clnt_setup_test_and_add_xprt,
 947					  &rpcdata);
 948			if (xprtdata.cred)
 949				put_cred(xprtdata.cred);
 950		} else {
 951			clp = nfs4_set_ds_client(mds_srv,
 952						(struct sockaddr *)&da->da_addr,
 953						da->da_addrlen,
 954						da->da_transport, timeo,
 955						retrans, minor_version);
 956			if (IS_ERR(clp))
 957				continue;
 958
 959			status = nfs4_init_ds_session(clp,
 960					mds_srv->nfs_client->cl_lease_time);
 961			if (status) {
 962				nfs_put_client(clp);
 963				clp = ERR_PTR(-EIO);
 964				continue;
 965			}
 966
 967		}
 968	}
 969
 970	if (IS_ERR(clp)) {
 971		status = PTR_ERR(clp);
 972		goto out;
 973	}
 974
 975	smp_wmb();
 976	ds->ds_clp = clp;
 977	dprintk("%s [new] addr: %s\n", __func__, ds->ds_remotestr);
 978out:
 979	return status;
 980}
 981
 982/*
 983 * Create an rpc connection to the nfs4_pnfs_ds data server.
 984 * Currently only supports IPv4 and IPv6 addresses.
 985 * If connection fails, make devid unavailable and return a -errno.
 986 */
 987int nfs4_pnfs_ds_connect(struct nfs_server *mds_srv, struct nfs4_pnfs_ds *ds,
 988			  struct nfs4_deviceid_node *devid, unsigned int timeo,
 989			  unsigned int retrans, u32 version, u32 minor_version)
 990{
 991	int err;
 992
 993	do {
 994		err = nfs4_wait_ds_connect(ds);
 995		if (err || ds->ds_clp)
 996			goto out;
 997		if (nfs4_test_deviceid_unavailable(devid))
 998			return -ENODEV;
 999	} while (test_and_set_bit(NFS4DS_CONNECTING, &ds->ds_state) != 0);
1000
1001	if (ds->ds_clp)
1002		goto connect_done;
1003
1004	switch (version) {
1005	case 3:
1006		err = _nfs4_pnfs_v3_ds_connect(mds_srv, ds, timeo, retrans);
1007		break;
1008	case 4:
1009		err = _nfs4_pnfs_v4_ds_connect(mds_srv, ds, timeo, retrans,
1010					       minor_version);
1011		break;
1012	default:
1013		dprintk("%s: unsupported DS version %d\n", __func__, version);
1014		err = -EPROTONOSUPPORT;
1015	}
1016
1017connect_done:
1018	nfs4_clear_ds_conn_bit(ds);
1019out:
1020	/*
1021	 * At this point the ds->ds_clp should be ready, but it might have
1022	 * hit an error.
1023	 */
1024	if (!err) {
1025		if (!ds->ds_clp || !nfs_client_init_is_complete(ds->ds_clp)) {
1026			WARN_ON_ONCE(ds->ds_clp ||
1027				!nfs4_test_deviceid_unavailable(devid));
1028			return -EINVAL;
1029		}
1030		err = nfs_client_init_status(ds->ds_clp);
1031	}
1032
1033	return err;
1034}
1035EXPORT_SYMBOL_GPL(nfs4_pnfs_ds_connect);
1036
1037/*
1038 * Currently only supports ipv4, ipv6 and one multi-path address.
1039 */
1040struct nfs4_pnfs_ds_addr *
1041nfs4_decode_mp_ds_addr(struct net *net, struct xdr_stream *xdr, gfp_t gfp_flags)
1042{
1043	struct nfs4_pnfs_ds_addr *da = NULL;
1044	char *buf, *portstr;
1045	__be16 port;
1046	ssize_t nlen, rlen;
1047	int tmp[2];
1048	char *netid;
1049	size_t len;
1050	char *startsep = "";
1051	char *endsep = "";
1052
1053
1054	/* r_netid */
1055	nlen = xdr_stream_decode_string_dup(xdr, &netid, XDR_MAX_NETOBJ,
1056					    gfp_flags);
1057	if (unlikely(nlen < 0))
1058		goto out_err;
1059
1060	/* r_addr: ip/ip6addr with port in dec octets - see RFC 5665 */
1061	/* port is ".ABC.DEF", 8 chars max */
1062	rlen = xdr_stream_decode_string_dup(xdr, &buf, INET6_ADDRSTRLEN +
1063					    IPV6_SCOPE_ID_LEN + 8, gfp_flags);
1064	if (unlikely(rlen < 0))
1065		goto out_free_netid;
1066
1067	/* replace port '.' with '-' */
1068	portstr = strrchr(buf, '.');
1069	if (!portstr) {
1070		dprintk("%s: Failed finding expected dot in port\n",
1071			__func__);
1072		goto out_free_buf;
1073	}
1074	*portstr = '-';
1075
1076	/* find '.' between address and port */
1077	portstr = strrchr(buf, '.');
1078	if (!portstr) {
1079		dprintk("%s: Failed finding expected dot between address and "
1080			"port\n", __func__);
1081		goto out_free_buf;
1082	}
1083	*portstr = '\0';
1084
1085	da = nfs4_pnfs_ds_addr_alloc(gfp_flags);
1086	if (unlikely(!da))
1087		goto out_free_buf;
1088
1089	if (!rpc_pton(net, buf, portstr-buf, (struct sockaddr *)&da->da_addr,
1090		      sizeof(da->da_addr))) {
1091		dprintk("%s: error parsing address %s\n", __func__, buf);
1092		goto out_free_da;
1093	}
1094
1095	portstr++;
1096	sscanf(portstr, "%d-%d", &tmp[0], &tmp[1]);
1097	port = htons((tmp[0] << 8) | (tmp[1]));
1098
1099	switch (da->da_addr.ss_family) {
1100	case AF_INET:
1101		((struct sockaddr_in *)&da->da_addr)->sin_port = port;
1102		da->da_addrlen = sizeof(struct sockaddr_in);
1103		break;
1104
1105	case AF_INET6:
1106		((struct sockaddr_in6 *)&da->da_addr)->sin6_port = port;
1107		da->da_addrlen = sizeof(struct sockaddr_in6);
1108		startsep = "[";
1109		endsep = "]";
1110		break;
1111
1112	default:
1113		dprintk("%s: unsupported address family: %u\n",
1114			__func__, da->da_addr.ss_family);
1115		goto out_free_da;
1116	}
1117
1118	da->da_transport = xprt_find_transport_ident(netid);
1119	if (da->da_transport < 0) {
1120		dprintk("%s: ERROR: unknown r_netid \"%s\"\n",
1121			__func__, netid);
1122		goto out_free_da;
1123	}
1124
1125	da->da_netid = netid;
1126
1127	/* save human readable address */
1128	len = strlen(startsep) + strlen(buf) + strlen(endsep) + 7;
1129	da->da_remotestr = kzalloc(len, gfp_flags);
1130
1131	/* NULL is ok, only used for dprintk */
1132	if (da->da_remotestr)
1133		snprintf(da->da_remotestr, len, "%s%s%s:%u", startsep,
1134			 buf, endsep, ntohs(port));
1135
1136	dprintk("%s: Parsed DS addr %s\n", __func__, da->da_remotestr);
1137	kfree(buf);
1138	return da;
1139
1140out_free_da:
1141	kfree(da);
1142out_free_buf:
1143	dprintk("%s: Error parsing DS addr: %s\n", __func__, buf);
1144	kfree(buf);
1145out_free_netid:
1146	kfree(netid);
1147out_err:
1148	return NULL;
1149}
1150EXPORT_SYMBOL_GPL(nfs4_decode_mp_ds_addr);
1151
1152void
1153pnfs_layout_mark_request_commit(struct nfs_page *req,
1154				struct pnfs_layout_segment *lseg,
1155				struct nfs_commit_info *cinfo,
1156				u32 ds_commit_idx)
1157{
1158	struct list_head *list;
1159	struct pnfs_commit_array *array;
1160	struct pnfs_commit_bucket *bucket;
1161
1162	mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
1163	array = pnfs_lookup_commit_array(cinfo->ds, lseg);
1164	if (!array || !pnfs_is_valid_lseg(lseg))
1165		goto out_resched;
1166	bucket = &array->buckets[ds_commit_idx];
1167	list = &bucket->written;
1168	/* Non-empty buckets hold a reference on the lseg.  That ref
1169	 * is normally transferred to the COMMIT call and released
1170	 * there.  It could also be released if the last req is pulled
1171	 * off due to a rewrite, in which case it will be done in
1172	 * pnfs_common_clear_request_commit
1173	 */
1174	if (!bucket->lseg)
1175		bucket->lseg = pnfs_get_lseg(lseg);
1176	set_bit(PG_COMMIT_TO_DS, &req->wb_flags);
1177	cinfo->ds->nwritten++;
1178
1179	nfs_request_add_commit_list_locked(req, list, cinfo);
1180	mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
1181	nfs_mark_page_unstable(req->wb_page, cinfo);
1182	return;
1183out_resched:
1184	mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
1185	cinfo->completion_ops->resched_write(cinfo, req);
1186}
1187EXPORT_SYMBOL_GPL(pnfs_layout_mark_request_commit);
1188
1189int
1190pnfs_nfs_generic_sync(struct inode *inode, bool datasync)
1191{
1192	int ret;
1193
1194	if (!pnfs_layoutcommit_outstanding(inode))
1195		return 0;
1196	ret = nfs_commit_inode(inode, FLUSH_SYNC);
1197	if (ret < 0)
1198		return ret;
1199	if (datasync)
1200		return 0;
1201	return pnfs_layoutcommit_inode(inode, true);
1202}
1203EXPORT_SYMBOL_GPL(pnfs_nfs_generic_sync);
1204