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v4.17
   1/*
   2 *  pNFS functions to call and manage layout drivers.
   3 *
   4 *  Copyright (c) 2002 [year of first publication]
   5 *  The Regents of the University of Michigan
   6 *  All Rights Reserved
   7 *
   8 *  Dean Hildebrand <dhildebz@umich.edu>
   9 *
  10 *  Permission is granted to use, copy, create derivative works, and
  11 *  redistribute this software and such derivative works for any purpose,
  12 *  so long as the name of the University of Michigan is not used in
  13 *  any advertising or publicity pertaining to the use or distribution
  14 *  of this software without specific, written prior authorization. If
  15 *  the above copyright notice or any other identification of the
  16 *  University of Michigan is included in any copy of any portion of
  17 *  this software, then the disclaimer below must also be included.
  18 *
  19 *  This software is provided as is, without representation or warranty
  20 *  of any kind either express or implied, including without limitation
  21 *  the implied warranties of merchantability, fitness for a particular
  22 *  purpose, or noninfringement.  The Regents of the University of
  23 *  Michigan shall not be liable for any damages, including special,
  24 *  indirect, incidental, or consequential damages, with respect to any
  25 *  claim arising out of or in connection with the use of the software,
  26 *  even if it has been or is hereafter advised of the possibility of
  27 *  such damages.
  28 */
  29
  30#include <linux/nfs_fs.h>
  31#include <linux/nfs_page.h>
  32#include <linux/module.h>
  33#include <linux/sort.h>
  34#include "internal.h"
  35#include "pnfs.h"
  36#include "iostat.h"
  37#include "nfs4trace.h"
  38#include "delegation.h"
  39#include "nfs42.h"
  40
  41#define NFSDBG_FACILITY		NFSDBG_PNFS
  42#define PNFS_LAYOUTGET_RETRY_TIMEOUT (120*HZ)
  43
  44/* Locking:
  45 *
  46 * pnfs_spinlock:
  47 *      protects pnfs_modules_tbl.
  48 */
  49static DEFINE_SPINLOCK(pnfs_spinlock);
  50
  51/*
  52 * pnfs_modules_tbl holds all pnfs modules
  53 */
  54static LIST_HEAD(pnfs_modules_tbl);
  55
  56static void pnfs_layoutreturn_before_put_layout_hdr(struct pnfs_layout_hdr *lo);
  57static void pnfs_free_returned_lsegs(struct pnfs_layout_hdr *lo,
  58		struct list_head *free_me,
  59		const struct pnfs_layout_range *range,
  60		u32 seq);
  61static bool pnfs_lseg_dec_and_remove_zero(struct pnfs_layout_segment *lseg,
  62		                struct list_head *tmp_list);
  63
  64/* Return the registered pnfs layout driver module matching given id */
  65static struct pnfs_layoutdriver_type *
  66find_pnfs_driver_locked(u32 id)
  67{
  68	struct pnfs_layoutdriver_type *local;
  69
  70	list_for_each_entry(local, &pnfs_modules_tbl, pnfs_tblid)
  71		if (local->id == id)
  72			goto out;
  73	local = NULL;
  74out:
  75	dprintk("%s: Searching for id %u, found %p\n", __func__, id, local);
  76	return local;
  77}
  78
  79static struct pnfs_layoutdriver_type *
  80find_pnfs_driver(u32 id)
  81{
  82	struct pnfs_layoutdriver_type *local;
  83
  84	spin_lock(&pnfs_spinlock);
  85	local = find_pnfs_driver_locked(id);
  86	if (local != NULL && !try_module_get(local->owner)) {
  87		dprintk("%s: Could not grab reference on module\n", __func__);
  88		local = NULL;
  89	}
  90	spin_unlock(&pnfs_spinlock);
  91	return local;
  92}
  93
  94void
  95unset_pnfs_layoutdriver(struct nfs_server *nfss)
  96{
  97	if (nfss->pnfs_curr_ld) {
  98		if (nfss->pnfs_curr_ld->clear_layoutdriver)
  99			nfss->pnfs_curr_ld->clear_layoutdriver(nfss);
 100		/* Decrement the MDS count. Purge the deviceid cache if zero */
 101		if (atomic_dec_and_test(&nfss->nfs_client->cl_mds_count))
 102			nfs4_deviceid_purge_client(nfss->nfs_client);
 103		module_put(nfss->pnfs_curr_ld->owner);
 104	}
 105	nfss->pnfs_curr_ld = NULL;
 106}
 107
 108/*
 109 * When the server sends a list of layout types, we choose one in the order
 110 * given in the list below.
 111 *
 112 * FIXME: should this list be configurable in some fashion? module param?
 113 * 	  mount option? something else?
 114 */
 115static const u32 ld_prefs[] = {
 116	LAYOUT_SCSI,
 117	LAYOUT_BLOCK_VOLUME,
 118	LAYOUT_OSD2_OBJECTS,
 119	LAYOUT_FLEX_FILES,
 120	LAYOUT_NFSV4_1_FILES,
 121	0
 122};
 123
 124static int
 125ld_cmp(const void *e1, const void *e2)
 126{
 127	u32 ld1 = *((u32 *)e1);
 128	u32 ld2 = *((u32 *)e2);
 129	int i;
 130
 131	for (i = 0; ld_prefs[i] != 0; i++) {
 132		if (ld1 == ld_prefs[i])
 133			return -1;
 134
 135		if (ld2 == ld_prefs[i])
 136			return 1;
 137	}
 138	return 0;
 139}
 140
 141/*
 142 * Try to set the server's pnfs module to the pnfs layout type specified by id.
 143 * Currently only one pNFS layout driver per filesystem is supported.
 144 *
 145 * @ids array of layout types supported by MDS.
 146 */
 147void
 148set_pnfs_layoutdriver(struct nfs_server *server, const struct nfs_fh *mntfh,
 149		      struct nfs_fsinfo *fsinfo)
 150{
 151	struct pnfs_layoutdriver_type *ld_type = NULL;
 152	u32 id;
 153	int i;
 154
 155	if (fsinfo->nlayouttypes == 0)
 156		goto out_no_driver;
 157	if (!(server->nfs_client->cl_exchange_flags &
 158		 (EXCHGID4_FLAG_USE_NON_PNFS | EXCHGID4_FLAG_USE_PNFS_MDS))) {
 159		printk(KERN_ERR "NFS: %s: cl_exchange_flags 0x%x\n",
 160			__func__, server->nfs_client->cl_exchange_flags);
 161		goto out_no_driver;
 162	}
 163
 164	sort(fsinfo->layouttype, fsinfo->nlayouttypes,
 165		sizeof(*fsinfo->layouttype), ld_cmp, NULL);
 166
 167	for (i = 0; i < fsinfo->nlayouttypes; i++) {
 168		id = fsinfo->layouttype[i];
 169		ld_type = find_pnfs_driver(id);
 170		if (!ld_type) {
 171			request_module("%s-%u", LAYOUT_NFSV4_1_MODULE_PREFIX,
 172					id);
 173			ld_type = find_pnfs_driver(id);
 174		}
 175		if (ld_type)
 176			break;
 177	}
 178
 179	if (!ld_type) {
 180		dprintk("%s: No pNFS module found!\n", __func__);
 181		goto out_no_driver;
 182	}
 183
 184	server->pnfs_curr_ld = ld_type;
 185	if (ld_type->set_layoutdriver
 186	    && ld_type->set_layoutdriver(server, mntfh)) {
 187		printk(KERN_ERR "NFS: %s: Error initializing pNFS layout "
 188			"driver %u.\n", __func__, id);
 189		module_put(ld_type->owner);
 190		goto out_no_driver;
 191	}
 192	/* Bump the MDS count */
 193	atomic_inc(&server->nfs_client->cl_mds_count);
 194
 195	dprintk("%s: pNFS module for %u set\n", __func__, id);
 196	return;
 197
 198out_no_driver:
 199	dprintk("%s: Using NFSv4 I/O\n", __func__);
 200	server->pnfs_curr_ld = NULL;
 201}
 202
 203int
 204pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
 205{
 206	int status = -EINVAL;
 207	struct pnfs_layoutdriver_type *tmp;
 208
 209	if (ld_type->id == 0) {
 210		printk(KERN_ERR "NFS: %s id 0 is reserved\n", __func__);
 211		return status;
 212	}
 213	if (!ld_type->alloc_lseg || !ld_type->free_lseg) {
 214		printk(KERN_ERR "NFS: %s Layout driver must provide "
 215		       "alloc_lseg and free_lseg.\n", __func__);
 216		return status;
 217	}
 218
 219	spin_lock(&pnfs_spinlock);
 220	tmp = find_pnfs_driver_locked(ld_type->id);
 221	if (!tmp) {
 222		list_add(&ld_type->pnfs_tblid, &pnfs_modules_tbl);
 223		status = 0;
 224		dprintk("%s Registering id:%u name:%s\n", __func__, ld_type->id,
 225			ld_type->name);
 226	} else {
 227		printk(KERN_ERR "NFS: %s Module with id %d already loaded!\n",
 228			__func__, ld_type->id);
 229	}
 230	spin_unlock(&pnfs_spinlock);
 231
 232	return status;
 233}
 234EXPORT_SYMBOL_GPL(pnfs_register_layoutdriver);
 235
 236void
 237pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
 238{
 239	dprintk("%s Deregistering id:%u\n", __func__, ld_type->id);
 240	spin_lock(&pnfs_spinlock);
 241	list_del(&ld_type->pnfs_tblid);
 242	spin_unlock(&pnfs_spinlock);
 243}
 244EXPORT_SYMBOL_GPL(pnfs_unregister_layoutdriver);
 245
 246/*
 247 * pNFS client layout cache
 248 */
 249
 250/* Need to hold i_lock if caller does not already hold reference */
 251void
 252pnfs_get_layout_hdr(struct pnfs_layout_hdr *lo)
 253{
 254	refcount_inc(&lo->plh_refcount);
 255}
 256
 257static struct pnfs_layout_hdr *
 258pnfs_alloc_layout_hdr(struct inode *ino, gfp_t gfp_flags)
 259{
 260	struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
 261	return ld->alloc_layout_hdr(ino, gfp_flags);
 262}
 263
 264static void
 265pnfs_free_layout_hdr(struct pnfs_layout_hdr *lo)
 266{
 267	struct nfs_server *server = NFS_SERVER(lo->plh_inode);
 268	struct pnfs_layoutdriver_type *ld = server->pnfs_curr_ld;
 269
 270	if (!list_empty(&lo->plh_layouts)) {
 271		struct nfs_client *clp = server->nfs_client;
 272
 273		spin_lock(&clp->cl_lock);
 274		list_del_init(&lo->plh_layouts);
 275		spin_unlock(&clp->cl_lock);
 276	}
 277	put_rpccred(lo->plh_lc_cred);
 278	return ld->free_layout_hdr(lo);
 279}
 280
 281static void
 282pnfs_detach_layout_hdr(struct pnfs_layout_hdr *lo)
 283{
 284	struct nfs_inode *nfsi = NFS_I(lo->plh_inode);
 285	dprintk("%s: freeing layout cache %p\n", __func__, lo);
 286	nfsi->layout = NULL;
 287	/* Reset MDS Threshold I/O counters */
 288	nfsi->write_io = 0;
 289	nfsi->read_io = 0;
 290}
 291
 292void
 293pnfs_put_layout_hdr(struct pnfs_layout_hdr *lo)
 294{
 295	struct inode *inode;
 296
 297	if (!lo)
 298		return;
 299	inode = lo->plh_inode;
 300	pnfs_layoutreturn_before_put_layout_hdr(lo);
 301
 302	if (refcount_dec_and_lock(&lo->plh_refcount, &inode->i_lock)) {
 303		if (!list_empty(&lo->plh_segs))
 304			WARN_ONCE(1, "NFS: BUG unfreed layout segments.\n");
 305		pnfs_detach_layout_hdr(lo);
 306		spin_unlock(&inode->i_lock);
 307		pnfs_free_layout_hdr(lo);
 308	}
 309}
 310
 311static void
 312pnfs_set_plh_return_info(struct pnfs_layout_hdr *lo, enum pnfs_iomode iomode,
 313			 u32 seq)
 314{
 315	if (lo->plh_return_iomode != 0 && lo->plh_return_iomode != iomode)
 316		iomode = IOMODE_ANY;
 317	lo->plh_return_iomode = iomode;
 318	set_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags);
 319	if (seq != 0) {
 320		WARN_ON_ONCE(lo->plh_return_seq != 0 && lo->plh_return_seq != seq);
 321		lo->plh_return_seq = seq;
 322	}
 323}
 324
 325static void
 326pnfs_clear_layoutreturn_info(struct pnfs_layout_hdr *lo)
 327{
 328	struct pnfs_layout_segment *lseg;
 329	lo->plh_return_iomode = 0;
 330	lo->plh_return_seq = 0;
 331	clear_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags);
 332	list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
 333		if (!test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
 334			continue;
 335		pnfs_set_plh_return_info(lo, lseg->pls_range.iomode, 0);
 336	}
 337}
 338
 339static void pnfs_clear_layoutreturn_waitbit(struct pnfs_layout_hdr *lo)
 340{
 341	clear_bit_unlock(NFS_LAYOUT_RETURN, &lo->plh_flags);
 342	clear_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags);
 343	smp_mb__after_atomic();
 344	wake_up_bit(&lo->plh_flags, NFS_LAYOUT_RETURN);
 345	rpc_wake_up(&NFS_SERVER(lo->plh_inode)->roc_rpcwaitq);
 346}
 347
 348static void
 349pnfs_clear_lseg_state(struct pnfs_layout_segment *lseg,
 350		struct list_head *free_me)
 351{
 352	clear_bit(NFS_LSEG_ROC, &lseg->pls_flags);
 353	clear_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
 354	if (test_and_clear_bit(NFS_LSEG_VALID, &lseg->pls_flags))
 355		pnfs_lseg_dec_and_remove_zero(lseg, free_me);
 356	if (test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
 357		pnfs_lseg_dec_and_remove_zero(lseg, free_me);
 358}
 359
 360/*
 361 * Update the seqid of a layout stateid
 362 */
 363bool nfs4_refresh_layout_stateid(nfs4_stateid *dst, struct inode *inode)
 364{
 365	struct pnfs_layout_hdr *lo;
 366	bool ret = false;
 367
 368	spin_lock(&inode->i_lock);
 369	lo = NFS_I(inode)->layout;
 370	if (lo && nfs4_stateid_match_other(dst, &lo->plh_stateid)) {
 371		dst->seqid = lo->plh_stateid.seqid;
 372		ret = true;
 373	}
 374	spin_unlock(&inode->i_lock);
 375	return ret;
 376}
 377
 378/*
 379 * Mark a pnfs_layout_hdr and all associated layout segments as invalid
 380 *
 381 * In order to continue using the pnfs_layout_hdr, a full recovery
 382 * is required.
 383 * Note that caller must hold inode->i_lock.
 384 */
 385int
 386pnfs_mark_layout_stateid_invalid(struct pnfs_layout_hdr *lo,
 387		struct list_head *lseg_list)
 388{
 389	struct pnfs_layout_range range = {
 390		.iomode = IOMODE_ANY,
 391		.offset = 0,
 392		.length = NFS4_MAX_UINT64,
 393	};
 394	struct pnfs_layout_segment *lseg, *next;
 395
 396	set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
 
 397	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
 398		pnfs_clear_lseg_state(lseg, lseg_list);
 399	pnfs_clear_layoutreturn_info(lo);
 400	pnfs_free_returned_lsegs(lo, lseg_list, &range, 0);
 401	if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags) &&
 402	    !test_and_set_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags))
 403		pnfs_clear_layoutreturn_waitbit(lo);
 404	return !list_empty(&lo->plh_segs);
 405}
 406
 407static int
 408pnfs_iomode_to_fail_bit(u32 iomode)
 409{
 410	return iomode == IOMODE_RW ?
 411		NFS_LAYOUT_RW_FAILED : NFS_LAYOUT_RO_FAILED;
 412}
 413
 414static void
 415pnfs_layout_set_fail_bit(struct pnfs_layout_hdr *lo, int fail_bit)
 416{
 417	lo->plh_retry_timestamp = jiffies;
 418	if (!test_and_set_bit(fail_bit, &lo->plh_flags))
 419		refcount_inc(&lo->plh_refcount);
 420}
 421
 422static void
 423pnfs_layout_clear_fail_bit(struct pnfs_layout_hdr *lo, int fail_bit)
 424{
 425	if (test_and_clear_bit(fail_bit, &lo->plh_flags))
 426		refcount_dec(&lo->plh_refcount);
 427}
 428
 429static void
 430pnfs_layout_io_set_failed(struct pnfs_layout_hdr *lo, u32 iomode)
 431{
 432	struct inode *inode = lo->plh_inode;
 433	struct pnfs_layout_range range = {
 434		.iomode = iomode,
 435		.offset = 0,
 436		.length = NFS4_MAX_UINT64,
 437	};
 438	LIST_HEAD(head);
 439
 440	spin_lock(&inode->i_lock);
 441	pnfs_layout_set_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
 442	pnfs_mark_matching_lsegs_invalid(lo, &head, &range, 0);
 443	spin_unlock(&inode->i_lock);
 444	pnfs_free_lseg_list(&head);
 445	dprintk("%s Setting layout IOMODE_%s fail bit\n", __func__,
 446			iomode == IOMODE_RW ?  "RW" : "READ");
 447}
 448
 449static bool
 450pnfs_layout_io_test_failed(struct pnfs_layout_hdr *lo, u32 iomode)
 451{
 452	unsigned long start, end;
 453	int fail_bit = pnfs_iomode_to_fail_bit(iomode);
 454
 455	if (test_bit(fail_bit, &lo->plh_flags) == 0)
 456		return false;
 457	end = jiffies;
 458	start = end - PNFS_LAYOUTGET_RETRY_TIMEOUT;
 459	if (!time_in_range(lo->plh_retry_timestamp, start, end)) {
 460		/* It is time to retry the failed layoutgets */
 461		pnfs_layout_clear_fail_bit(lo, fail_bit);
 462		return false;
 463	}
 464	return true;
 465}
 466
 467static void
 468pnfs_init_lseg(struct pnfs_layout_hdr *lo, struct pnfs_layout_segment *lseg,
 469		const struct pnfs_layout_range *range,
 470		const nfs4_stateid *stateid)
 471{
 472	INIT_LIST_HEAD(&lseg->pls_list);
 473	INIT_LIST_HEAD(&lseg->pls_lc_list);
 474	refcount_set(&lseg->pls_refcount, 1);
 475	set_bit(NFS_LSEG_VALID, &lseg->pls_flags);
 476	lseg->pls_layout = lo;
 477	lseg->pls_range = *range;
 478	lseg->pls_seq = be32_to_cpu(stateid->seqid);
 479}
 480
 481static void pnfs_free_lseg(struct pnfs_layout_segment *lseg)
 482{
 483	if (lseg != NULL) {
 484		struct inode *inode = lseg->pls_layout->plh_inode;
 485		NFS_SERVER(inode)->pnfs_curr_ld->free_lseg(lseg);
 486	}
 487}
 488
 489static void
 490pnfs_layout_remove_lseg(struct pnfs_layout_hdr *lo,
 491		struct pnfs_layout_segment *lseg)
 492{
 493	WARN_ON(test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
 494	list_del_init(&lseg->pls_list);
 495	/* Matched by pnfs_get_layout_hdr in pnfs_layout_insert_lseg */
 496	refcount_dec(&lo->plh_refcount);
 497	if (test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
 498		return;
 499	if (list_empty(&lo->plh_segs) &&
 500	    !test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags) &&
 501	    !test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
 502		if (atomic_read(&lo->plh_outstanding) == 0)
 503			set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
 504		clear_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
 505	}
 506}
 507
 508static bool
 509pnfs_cache_lseg_for_layoutreturn(struct pnfs_layout_hdr *lo,
 510		struct pnfs_layout_segment *lseg)
 511{
 512	if (test_and_clear_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags) &&
 513	    pnfs_layout_is_valid(lo)) {
 514		pnfs_set_plh_return_info(lo, lseg->pls_range.iomode, 0);
 515		list_move_tail(&lseg->pls_list, &lo->plh_return_segs);
 516		return true;
 517	}
 518	return false;
 519}
 520
 521void
 522pnfs_put_lseg(struct pnfs_layout_segment *lseg)
 523{
 524	struct pnfs_layout_hdr *lo;
 525	struct inode *inode;
 526
 527	if (!lseg)
 528		return;
 529
 530	dprintk("%s: lseg %p ref %d valid %d\n", __func__, lseg,
 531		refcount_read(&lseg->pls_refcount),
 532		test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
 533
 534	lo = lseg->pls_layout;
 535	inode = lo->plh_inode;
 536
 537	if (refcount_dec_and_lock(&lseg->pls_refcount, &inode->i_lock)) {
 538		if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags)) {
 539			spin_unlock(&inode->i_lock);
 540			return;
 541		}
 542		pnfs_get_layout_hdr(lo);
 543		pnfs_layout_remove_lseg(lo, lseg);
 544		if (pnfs_cache_lseg_for_layoutreturn(lo, lseg))
 545			lseg = NULL;
 546		spin_unlock(&inode->i_lock);
 547		pnfs_free_lseg(lseg);
 548		pnfs_put_layout_hdr(lo);
 549	}
 550}
 551EXPORT_SYMBOL_GPL(pnfs_put_lseg);
 552
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 553/*
 554 * is l2 fully contained in l1?
 555 *   start1                             end1
 556 *   [----------------------------------)
 557 *           start2           end2
 558 *           [----------------)
 559 */
 560static bool
 561pnfs_lseg_range_contained(const struct pnfs_layout_range *l1,
 562		 const struct pnfs_layout_range *l2)
 563{
 564	u64 start1 = l1->offset;
 565	u64 end1 = pnfs_end_offset(start1, l1->length);
 566	u64 start2 = l2->offset;
 567	u64 end2 = pnfs_end_offset(start2, l2->length);
 568
 569	return (start1 <= start2) && (end1 >= end2);
 570}
 571
 572static bool pnfs_lseg_dec_and_remove_zero(struct pnfs_layout_segment *lseg,
 573		struct list_head *tmp_list)
 574{
 575	if (!refcount_dec_and_test(&lseg->pls_refcount))
 576		return false;
 577	pnfs_layout_remove_lseg(lseg->pls_layout, lseg);
 578	list_add(&lseg->pls_list, tmp_list);
 579	return true;
 580}
 581
 582/* Returns 1 if lseg is removed from list, 0 otherwise */
 583static int mark_lseg_invalid(struct pnfs_layout_segment *lseg,
 584			     struct list_head *tmp_list)
 585{
 586	int rv = 0;
 587
 588	if (test_and_clear_bit(NFS_LSEG_VALID, &lseg->pls_flags)) {
 589		/* Remove the reference keeping the lseg in the
 590		 * list.  It will now be removed when all
 591		 * outstanding io is finished.
 592		 */
 593		dprintk("%s: lseg %p ref %d\n", __func__, lseg,
 594			refcount_read(&lseg->pls_refcount));
 595		if (pnfs_lseg_dec_and_remove_zero(lseg, tmp_list))
 596			rv = 1;
 597	}
 598	return rv;
 599}
 600
 601/*
 602 * Compare 2 layout stateid sequence ids, to see which is newer,
 603 * taking into account wraparound issues.
 604 */
 605static bool pnfs_seqid_is_newer(u32 s1, u32 s2)
 606{
 607	return (s32)(s1 - s2) > 0;
 608}
 609
 610static bool
 611pnfs_should_free_range(const struct pnfs_layout_range *lseg_range,
 612		 const struct pnfs_layout_range *recall_range)
 613{
 614	return (recall_range->iomode == IOMODE_ANY ||
 615		lseg_range->iomode == recall_range->iomode) &&
 616	       pnfs_lseg_range_intersecting(lseg_range, recall_range);
 617}
 618
 619static bool
 620pnfs_match_lseg_recall(const struct pnfs_layout_segment *lseg,
 621		const struct pnfs_layout_range *recall_range,
 622		u32 seq)
 623{
 624	if (seq != 0 && pnfs_seqid_is_newer(lseg->pls_seq, seq))
 625		return false;
 626	if (recall_range == NULL)
 627		return true;
 628	return pnfs_should_free_range(&lseg->pls_range, recall_range);
 629}
 630
 631/**
 632 * pnfs_mark_matching_lsegs_invalid - tear down lsegs or mark them for later
 633 * @lo: layout header containing the lsegs
 634 * @tmp_list: list head where doomed lsegs should go
 635 * @recall_range: optional recall range argument to match (may be NULL)
 636 * @seq: only invalidate lsegs obtained prior to this sequence (may be 0)
 637 *
 638 * Walk the list of lsegs in the layout header, and tear down any that should
 639 * be destroyed. If "recall_range" is specified then the segment must match
 640 * that range. If "seq" is non-zero, then only match segments that were handed
 641 * out at or before that sequence.
 642 *
 643 * Returns number of matching invalid lsegs remaining in list after scanning
 644 * it and purging them.
 645 */
 646int
 647pnfs_mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo,
 648			    struct list_head *tmp_list,
 649			    const struct pnfs_layout_range *recall_range,
 650			    u32 seq)
 651{
 652	struct pnfs_layout_segment *lseg, *next;
 653	int remaining = 0;
 654
 655	dprintk("%s:Begin lo %p\n", __func__, lo);
 656
 657	if (list_empty(&lo->plh_segs))
 658		return 0;
 659	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
 660		if (pnfs_match_lseg_recall(lseg, recall_range, seq)) {
 661			dprintk("%s: freeing lseg %p iomode %d seq %u "
 662				"offset %llu length %llu\n", __func__,
 663				lseg, lseg->pls_range.iomode, lseg->pls_seq,
 664				lseg->pls_range.offset, lseg->pls_range.length);
 665			if (!mark_lseg_invalid(lseg, tmp_list))
 666				remaining++;
 667		}
 668	dprintk("%s:Return %i\n", __func__, remaining);
 669	return remaining;
 670}
 671
 672static void
 673pnfs_free_returned_lsegs(struct pnfs_layout_hdr *lo,
 674		struct list_head *free_me,
 675		const struct pnfs_layout_range *range,
 676		u32 seq)
 677{
 678	struct pnfs_layout_segment *lseg, *next;
 679
 680	list_for_each_entry_safe(lseg, next, &lo->plh_return_segs, pls_list) {
 681		if (pnfs_match_lseg_recall(lseg, range, seq))
 682			list_move_tail(&lseg->pls_list, free_me);
 683	}
 684}
 685
 686/* note free_me must contain lsegs from a single layout_hdr */
 687void
 688pnfs_free_lseg_list(struct list_head *free_me)
 689{
 690	struct pnfs_layout_segment *lseg, *tmp;
 691
 692	if (list_empty(free_me))
 693		return;
 694
 695	list_for_each_entry_safe(lseg, tmp, free_me, pls_list) {
 696		list_del(&lseg->pls_list);
 697		pnfs_free_lseg(lseg);
 698	}
 699}
 700
 701void
 702pnfs_destroy_layout(struct nfs_inode *nfsi)
 703{
 704	struct pnfs_layout_hdr *lo;
 705	LIST_HEAD(tmp_list);
 706
 707	spin_lock(&nfsi->vfs_inode.i_lock);
 708	lo = nfsi->layout;
 709	if (lo) {
 710		pnfs_get_layout_hdr(lo);
 711		pnfs_mark_layout_stateid_invalid(lo, &tmp_list);
 712		pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RO_FAILED);
 713		pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RW_FAILED);
 714		spin_unlock(&nfsi->vfs_inode.i_lock);
 715		pnfs_free_lseg_list(&tmp_list);
 716		nfs_commit_inode(&nfsi->vfs_inode, 0);
 717		pnfs_put_layout_hdr(lo);
 718	} else
 719		spin_unlock(&nfsi->vfs_inode.i_lock);
 720}
 721EXPORT_SYMBOL_GPL(pnfs_destroy_layout);
 722
 723static bool
 724pnfs_layout_add_bulk_destroy_list(struct inode *inode,
 725		struct list_head *layout_list)
 726{
 727	struct pnfs_layout_hdr *lo;
 728	bool ret = false;
 729
 730	spin_lock(&inode->i_lock);
 731	lo = NFS_I(inode)->layout;
 732	if (lo != NULL && list_empty(&lo->plh_bulk_destroy)) {
 733		pnfs_get_layout_hdr(lo);
 734		list_add(&lo->plh_bulk_destroy, layout_list);
 735		ret = true;
 736	}
 737	spin_unlock(&inode->i_lock);
 738	return ret;
 739}
 740
 741/* Caller must hold rcu_read_lock and clp->cl_lock */
 742static int
 743pnfs_layout_bulk_destroy_byserver_locked(struct nfs_client *clp,
 744		struct nfs_server *server,
 745		struct list_head *layout_list)
 746{
 747	struct pnfs_layout_hdr *lo, *next;
 748	struct inode *inode;
 749
 750	list_for_each_entry_safe(lo, next, &server->layouts, plh_layouts) {
 751		if (test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags))
 752			continue;
 753		inode = igrab(lo->plh_inode);
 754		if (inode == NULL)
 755			continue;
 756		list_del_init(&lo->plh_layouts);
 757		if (pnfs_layout_add_bulk_destroy_list(inode, layout_list))
 758			continue;
 759		rcu_read_unlock();
 760		spin_unlock(&clp->cl_lock);
 761		iput(inode);
 762		spin_lock(&clp->cl_lock);
 763		rcu_read_lock();
 764		return -EAGAIN;
 765	}
 766	return 0;
 767}
 768
 769static int
 770pnfs_layout_free_bulk_destroy_list(struct list_head *layout_list,
 771		bool is_bulk_recall)
 772{
 773	struct pnfs_layout_hdr *lo;
 774	struct inode *inode;
 775	LIST_HEAD(lseg_list);
 776	int ret = 0;
 777
 778	while (!list_empty(layout_list)) {
 779		lo = list_entry(layout_list->next, struct pnfs_layout_hdr,
 780				plh_bulk_destroy);
 781		dprintk("%s freeing layout for inode %lu\n", __func__,
 782			lo->plh_inode->i_ino);
 783		inode = lo->plh_inode;
 784
 785		pnfs_layoutcommit_inode(inode, false);
 786
 787		spin_lock(&inode->i_lock);
 788		list_del_init(&lo->plh_bulk_destroy);
 789		if (pnfs_mark_layout_stateid_invalid(lo, &lseg_list)) {
 790			if (is_bulk_recall)
 791				set_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
 792			ret = -EAGAIN;
 793		}
 794		spin_unlock(&inode->i_lock);
 795		pnfs_free_lseg_list(&lseg_list);
 796		/* Free all lsegs that are attached to commit buckets */
 797		nfs_commit_inode(inode, 0);
 798		pnfs_put_layout_hdr(lo);
 799		iput(inode);
 800	}
 801	return ret;
 802}
 803
 804int
 805pnfs_destroy_layouts_byfsid(struct nfs_client *clp,
 806		struct nfs_fsid *fsid,
 807		bool is_recall)
 808{
 809	struct nfs_server *server;
 810	LIST_HEAD(layout_list);
 811
 812	spin_lock(&clp->cl_lock);
 813	rcu_read_lock();
 814restart:
 815	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 816		if (memcmp(&server->fsid, fsid, sizeof(*fsid)) != 0)
 817			continue;
 818		if (pnfs_layout_bulk_destroy_byserver_locked(clp,
 819				server,
 820				&layout_list) != 0)
 821			goto restart;
 822	}
 823	rcu_read_unlock();
 824	spin_unlock(&clp->cl_lock);
 825
 826	if (list_empty(&layout_list))
 827		return 0;
 828	return pnfs_layout_free_bulk_destroy_list(&layout_list, is_recall);
 829}
 830
 831int
 832pnfs_destroy_layouts_byclid(struct nfs_client *clp,
 833		bool is_recall)
 834{
 835	struct nfs_server *server;
 836	LIST_HEAD(layout_list);
 837
 838	spin_lock(&clp->cl_lock);
 839	rcu_read_lock();
 840restart:
 841	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 842		if (pnfs_layout_bulk_destroy_byserver_locked(clp,
 843					server,
 844					&layout_list) != 0)
 845			goto restart;
 846	}
 847	rcu_read_unlock();
 848	spin_unlock(&clp->cl_lock);
 849
 850	if (list_empty(&layout_list))
 851		return 0;
 852	return pnfs_layout_free_bulk_destroy_list(&layout_list, is_recall);
 853}
 854
 855/*
 856 * Called by the state manger to remove all layouts established under an
 857 * expired lease.
 858 */
 859void
 860pnfs_destroy_all_layouts(struct nfs_client *clp)
 861{
 862	nfs4_deviceid_mark_client_invalid(clp);
 863	nfs4_deviceid_purge_client(clp);
 864
 865	pnfs_destroy_layouts_byclid(clp, false);
 866}
 867
 868/* update lo->plh_stateid with new if is more recent */
 869void
 870pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo, const nfs4_stateid *new,
 871			bool update_barrier)
 872{
 873	u32 oldseq, newseq, new_barrier = 0;
 874
 875	oldseq = be32_to_cpu(lo->plh_stateid.seqid);
 876	newseq = be32_to_cpu(new->seqid);
 877
 878	if (!pnfs_layout_is_valid(lo)) {
 879		nfs4_stateid_copy(&lo->plh_stateid, new);
 880		lo->plh_barrier = newseq;
 881		pnfs_clear_layoutreturn_info(lo);
 882		clear_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
 883		return;
 884	}
 885	if (pnfs_seqid_is_newer(newseq, oldseq)) {
 886		nfs4_stateid_copy(&lo->plh_stateid, new);
 887		/*
 888		 * Because of wraparound, we want to keep the barrier
 889		 * "close" to the current seqids.
 890		 */
 891		new_barrier = newseq - atomic_read(&lo->plh_outstanding);
 892	}
 893	if (update_barrier)
 894		new_barrier = be32_to_cpu(new->seqid);
 895	else if (new_barrier == 0)
 896		return;
 897	if (pnfs_seqid_is_newer(new_barrier, lo->plh_barrier))
 898		lo->plh_barrier = new_barrier;
 899}
 900
 901static bool
 902pnfs_layout_stateid_blocked(const struct pnfs_layout_hdr *lo,
 903		const nfs4_stateid *stateid)
 904{
 905	u32 seqid = be32_to_cpu(stateid->seqid);
 906
 907	return !pnfs_seqid_is_newer(seqid, lo->plh_barrier);
 908}
 909
 910/* lget is set to 1 if called from inside send_layoutget call chain */
 911static bool
 912pnfs_layoutgets_blocked(const struct pnfs_layout_hdr *lo)
 913{
 914	return lo->plh_block_lgets ||
 915		test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
 916}
 917
 918/*
 919 * Get layout from server.
 920 *    for now, assume that whole file layouts are requested.
 921 *    arg->offset: 0
 922 *    arg->length: all ones
 923 */
 924static struct pnfs_layout_segment *
 925send_layoutget(struct pnfs_layout_hdr *lo,
 926	   struct nfs_open_context *ctx,
 927	   nfs4_stateid *stateid,
 928	   const struct pnfs_layout_range *range,
 929	   long *timeout, gfp_t gfp_flags)
 930{
 931	struct inode *ino = lo->plh_inode;
 932	struct nfs_server *server = NFS_SERVER(ino);
 933	struct nfs4_layoutget *lgp;
 934	loff_t i_size;
 935
 936	dprintk("--> %s\n", __func__);
 937
 938	/*
 939	 * Synchronously retrieve layout information from server and
 940	 * store in lseg. If we race with a concurrent seqid morphing
 941	 * op, then re-send the LAYOUTGET.
 942	 */
 943	lgp = kzalloc(sizeof(*lgp), gfp_flags);
 944	if (lgp == NULL)
 945		return ERR_PTR(-ENOMEM);
 946
 947	i_size = i_size_read(ino);
 948
 949	lgp->args.minlength = PAGE_SIZE;
 950	if (lgp->args.minlength > range->length)
 951		lgp->args.minlength = range->length;
 952	if (range->iomode == IOMODE_READ) {
 953		if (range->offset >= i_size)
 954			lgp->args.minlength = 0;
 955		else if (i_size - range->offset < lgp->args.minlength)
 956			lgp->args.minlength = i_size - range->offset;
 957	}
 958	lgp->args.maxcount = PNFS_LAYOUT_MAXSIZE;
 959	pnfs_copy_range(&lgp->args.range, range);
 960	lgp->args.type = server->pnfs_curr_ld->id;
 961	lgp->args.inode = ino;
 962	lgp->args.ctx = get_nfs_open_context(ctx);
 963	nfs4_stateid_copy(&lgp->args.stateid, stateid);
 964	lgp->gfp_flags = gfp_flags;
 965	lgp->cred = lo->plh_lc_cred;
 966
 967	return nfs4_proc_layoutget(lgp, timeout, gfp_flags);
 968}
 969
 970static void pnfs_clear_layoutcommit(struct inode *inode,
 971		struct list_head *head)
 972{
 973	struct nfs_inode *nfsi = NFS_I(inode);
 974	struct pnfs_layout_segment *lseg, *tmp;
 975
 976	if (!test_and_clear_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags))
 977		return;
 978	list_for_each_entry_safe(lseg, tmp, &nfsi->layout->plh_segs, pls_list) {
 979		if (!test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
 980			continue;
 981		pnfs_lseg_dec_and_remove_zero(lseg, head);
 982	}
 983}
 984
 985void pnfs_layoutreturn_free_lsegs(struct pnfs_layout_hdr *lo,
 986		const nfs4_stateid *arg_stateid,
 987		const struct pnfs_layout_range *range,
 988		const nfs4_stateid *stateid)
 989{
 990	struct inode *inode = lo->plh_inode;
 991	LIST_HEAD(freeme);
 992
 993	spin_lock(&inode->i_lock);
 994	if (!pnfs_layout_is_valid(lo) || !arg_stateid ||
 995	    !nfs4_stateid_match_other(&lo->plh_stateid, arg_stateid))
 996		goto out_unlock;
 997	if (stateid) {
 998		u32 seq = be32_to_cpu(arg_stateid->seqid);
 999
1000		pnfs_mark_matching_lsegs_invalid(lo, &freeme, range, seq);
1001		pnfs_free_returned_lsegs(lo, &freeme, range, seq);
1002		pnfs_set_layout_stateid(lo, stateid, true);
1003	} else
1004		pnfs_mark_layout_stateid_invalid(lo, &freeme);
1005out_unlock:
1006	pnfs_clear_layoutreturn_waitbit(lo);
1007	spin_unlock(&inode->i_lock);
1008	pnfs_free_lseg_list(&freeme);
1009
1010}
1011
1012static bool
1013pnfs_prepare_layoutreturn(struct pnfs_layout_hdr *lo,
1014		nfs4_stateid *stateid,
1015		enum pnfs_iomode *iomode)
1016{
1017	/* Serialise LAYOUTGET/LAYOUTRETURN */
1018	if (atomic_read(&lo->plh_outstanding) != 0)
1019		return false;
1020	if (test_and_set_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags))
1021		return false;
1022	set_bit(NFS_LAYOUT_RETURN, &lo->plh_flags);
1023	pnfs_get_layout_hdr(lo);
1024	if (test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags)) {
1025		if (stateid != NULL) {
1026			nfs4_stateid_copy(stateid, &lo->plh_stateid);
1027			if (lo->plh_return_seq != 0)
1028				stateid->seqid = cpu_to_be32(lo->plh_return_seq);
1029		}
1030		if (iomode != NULL)
1031			*iomode = lo->plh_return_iomode;
1032		pnfs_clear_layoutreturn_info(lo);
1033		return true;
1034	}
1035	if (stateid != NULL)
1036		nfs4_stateid_copy(stateid, &lo->plh_stateid);
1037	if (iomode != NULL)
1038		*iomode = IOMODE_ANY;
1039	return true;
1040}
1041
1042static void
1043pnfs_init_layoutreturn_args(struct nfs4_layoutreturn_args *args,
1044		struct pnfs_layout_hdr *lo,
1045		const nfs4_stateid *stateid,
1046		enum pnfs_iomode iomode)
1047{
1048	struct inode *inode = lo->plh_inode;
1049
1050	args->layout_type = NFS_SERVER(inode)->pnfs_curr_ld->id;
1051	args->inode = inode;
1052	args->range.iomode = iomode;
1053	args->range.offset = 0;
1054	args->range.length = NFS4_MAX_UINT64;
1055	args->layout = lo;
1056	nfs4_stateid_copy(&args->stateid, stateid);
1057}
1058
1059static int
1060pnfs_send_layoutreturn(struct pnfs_layout_hdr *lo, const nfs4_stateid *stateid,
1061		       enum pnfs_iomode iomode, bool sync)
1062{
1063	struct inode *ino = lo->plh_inode;
1064	struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
1065	struct nfs4_layoutreturn *lrp;
1066	int status = 0;
1067
1068	lrp = kzalloc(sizeof(*lrp), GFP_NOFS);
1069	if (unlikely(lrp == NULL)) {
1070		status = -ENOMEM;
1071		spin_lock(&ino->i_lock);
1072		pnfs_clear_layoutreturn_waitbit(lo);
1073		spin_unlock(&ino->i_lock);
1074		pnfs_put_layout_hdr(lo);
1075		goto out;
1076	}
1077
1078	pnfs_init_layoutreturn_args(&lrp->args, lo, stateid, iomode);
1079	lrp->args.ld_private = &lrp->ld_private;
1080	lrp->clp = NFS_SERVER(ino)->nfs_client;
1081	lrp->cred = lo->plh_lc_cred;
1082	if (ld->prepare_layoutreturn)
1083		ld->prepare_layoutreturn(&lrp->args);
1084
1085	status = nfs4_proc_layoutreturn(lrp, sync);
1086out:
1087	dprintk("<-- %s status: %d\n", __func__, status);
1088	return status;
1089}
1090
1091/* Return true if layoutreturn is needed */
1092static bool
1093pnfs_layout_need_return(struct pnfs_layout_hdr *lo)
1094{
1095	struct pnfs_layout_segment *s;
1096
1097	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
1098		return false;
1099
1100	/* Defer layoutreturn until all lsegs are done */
1101	list_for_each_entry(s, &lo->plh_segs, pls_list) {
1102		if (test_bit(NFS_LSEG_LAYOUTRETURN, &s->pls_flags))
1103			return false;
1104	}
1105
1106	return true;
1107}
1108
1109static void pnfs_layoutreturn_before_put_layout_hdr(struct pnfs_layout_hdr *lo)
1110{
1111	struct inode *inode= lo->plh_inode;
1112
1113	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
1114		return;
1115	spin_lock(&inode->i_lock);
1116	if (pnfs_layout_need_return(lo)) {
1117		nfs4_stateid stateid;
1118		enum pnfs_iomode iomode;
1119		bool send;
1120
1121		send = pnfs_prepare_layoutreturn(lo, &stateid, &iomode);
1122		spin_unlock(&inode->i_lock);
1123		if (send) {
1124			/* Send an async layoutreturn so we dont deadlock */
1125			pnfs_send_layoutreturn(lo, &stateid, iomode, false);
1126		}
1127	} else
1128		spin_unlock(&inode->i_lock);
1129}
1130
1131/*
1132 * Initiates a LAYOUTRETURN(FILE), and removes the pnfs_layout_hdr
1133 * when the layout segment list is empty.
1134 *
1135 * Note that a pnfs_layout_hdr can exist with an empty layout segment
1136 * list when LAYOUTGET has failed, or when LAYOUTGET succeeded, but the
1137 * deviceid is marked invalid.
1138 */
1139int
1140_pnfs_return_layout(struct inode *ino)
1141{
1142	struct pnfs_layout_hdr *lo = NULL;
1143	struct nfs_inode *nfsi = NFS_I(ino);
1144	LIST_HEAD(tmp_list);
1145	nfs4_stateid stateid;
1146	int status = 0;
1147	bool send;
1148
1149	dprintk("NFS: %s for inode %lu\n", __func__, ino->i_ino);
1150
1151	spin_lock(&ino->i_lock);
1152	lo = nfsi->layout;
1153	if (!lo) {
1154		spin_unlock(&ino->i_lock);
1155		dprintk("NFS: %s no layout to return\n", __func__);
1156		goto out;
1157	}
1158	/* Reference matched in nfs4_layoutreturn_release */
1159	pnfs_get_layout_hdr(lo);
1160	/* Is there an outstanding layoutreturn ? */
1161	if (test_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags)) {
1162		spin_unlock(&ino->i_lock);
1163		if (wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN,
1164					TASK_UNINTERRUPTIBLE))
1165			goto out_put_layout_hdr;
1166		spin_lock(&ino->i_lock);
1167	}
1168	pnfs_clear_layoutcommit(ino, &tmp_list);
1169	pnfs_mark_matching_lsegs_invalid(lo, &tmp_list, NULL, 0);
1170
1171	if (NFS_SERVER(ino)->pnfs_curr_ld->return_range) {
1172		struct pnfs_layout_range range = {
1173			.iomode		= IOMODE_ANY,
1174			.offset		= 0,
1175			.length		= NFS4_MAX_UINT64,
1176		};
1177		NFS_SERVER(ino)->pnfs_curr_ld->return_range(lo, &range);
1178	}
1179
1180	/* Don't send a LAYOUTRETURN if list was initially empty */
1181	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags)) {
1182		spin_unlock(&ino->i_lock);
1183		dprintk("NFS: %s no layout segments to return\n", __func__);
1184		goto out_put_layout_hdr;
1185	}
1186
1187	send = pnfs_prepare_layoutreturn(lo, &stateid, NULL);
1188	spin_unlock(&ino->i_lock);
1189	if (send)
1190		status = pnfs_send_layoutreturn(lo, &stateid, IOMODE_ANY, true);
1191out_put_layout_hdr:
1192	pnfs_free_lseg_list(&tmp_list);
1193	pnfs_put_layout_hdr(lo);
1194out:
1195	dprintk("<-- %s status: %d\n", __func__, status);
1196	return status;
1197}
 
1198
1199int
1200pnfs_commit_and_return_layout(struct inode *inode)
1201{
1202	struct pnfs_layout_hdr *lo;
1203	int ret;
1204
1205	spin_lock(&inode->i_lock);
1206	lo = NFS_I(inode)->layout;
1207	if (lo == NULL) {
1208		spin_unlock(&inode->i_lock);
1209		return 0;
1210	}
1211	pnfs_get_layout_hdr(lo);
1212	/* Block new layoutgets and read/write to ds */
1213	lo->plh_block_lgets++;
1214	spin_unlock(&inode->i_lock);
1215	filemap_fdatawait(inode->i_mapping);
1216	ret = pnfs_layoutcommit_inode(inode, true);
1217	if (ret == 0)
1218		ret = _pnfs_return_layout(inode);
1219	spin_lock(&inode->i_lock);
1220	lo->plh_block_lgets--;
1221	spin_unlock(&inode->i_lock);
1222	pnfs_put_layout_hdr(lo);
1223	return ret;
1224}
1225
1226bool pnfs_roc(struct inode *ino,
1227		struct nfs4_layoutreturn_args *args,
1228		struct nfs4_layoutreturn_res *res,
1229		const struct rpc_cred *cred)
1230{
1231	struct nfs_inode *nfsi = NFS_I(ino);
1232	struct nfs_open_context *ctx;
1233	struct nfs4_state *state;
1234	struct pnfs_layout_hdr *lo;
1235	struct pnfs_layout_segment *lseg, *next;
1236	nfs4_stateid stateid;
1237	enum pnfs_iomode iomode = 0;
1238	bool layoutreturn = false, roc = false;
1239	bool skip_read = false;
1240
1241	if (!nfs_have_layout(ino))
1242		return false;
1243retry:
1244	spin_lock(&ino->i_lock);
1245	lo = nfsi->layout;
1246	if (!lo || !pnfs_layout_is_valid(lo) ||
1247	    test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
1248		lo = NULL;
1249		goto out_noroc;
1250	}
1251	pnfs_get_layout_hdr(lo);
1252	if (test_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags)) {
 
1253		spin_unlock(&ino->i_lock);
1254		wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN,
1255				TASK_UNINTERRUPTIBLE);
1256		pnfs_put_layout_hdr(lo);
1257		goto retry;
1258	}
1259
1260	/* no roc if we hold a delegation */
1261	if (nfs4_check_delegation(ino, FMODE_READ)) {
1262		if (nfs4_check_delegation(ino, FMODE_WRITE))
1263			goto out_noroc;
1264		skip_read = true;
1265	}
1266
1267	list_for_each_entry(ctx, &nfsi->open_files, list) {
1268		state = ctx->state;
1269		if (state == NULL)
1270			continue;
1271		/* Don't return layout if there is open file state */
1272		if (state->state & FMODE_WRITE)
1273			goto out_noroc;
1274		if (state->state & FMODE_READ)
1275			skip_read = true;
1276	}
1277
1278
1279	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list) {
1280		if (skip_read && lseg->pls_range.iomode == IOMODE_READ)
1281			continue;
1282		/* If we are sending layoutreturn, invalidate all valid lsegs */
1283		if (!test_and_clear_bit(NFS_LSEG_ROC, &lseg->pls_flags))
1284			continue;
1285		/*
1286		 * Note: mark lseg for return so pnfs_layout_remove_lseg
1287		 * doesn't invalidate the layout for us.
1288		 */
1289		set_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
1290		if (!mark_lseg_invalid(lseg, &lo->plh_return_segs))
1291			continue;
1292		pnfs_set_plh_return_info(lo, lseg->pls_range.iomode, 0);
1293	}
1294
1295	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
1296		goto out_noroc;
1297
1298	/* ROC in two conditions:
1299	 * 1. there are ROC lsegs
1300	 * 2. we don't send layoutreturn
1301	 */
1302	/* lo ref dropped in pnfs_roc_release() */
1303	layoutreturn = pnfs_prepare_layoutreturn(lo, &stateid, &iomode);
1304	/* If the creds don't match, we can't compound the layoutreturn */
1305	if (!layoutreturn || cred != lo->plh_lc_cred)
1306		goto out_noroc;
1307
1308	roc = layoutreturn;
1309	pnfs_init_layoutreturn_args(args, lo, &stateid, iomode);
1310	res->lrs_present = 0;
1311	layoutreturn = false;
1312
1313out_noroc:
1314	spin_unlock(&ino->i_lock);
1315	pnfs_layoutcommit_inode(ino, true);
1316	if (roc) {
1317		struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
1318		if (ld->prepare_layoutreturn)
1319			ld->prepare_layoutreturn(args);
1320		pnfs_put_layout_hdr(lo);
1321		return true;
1322	}
1323	if (layoutreturn)
1324		pnfs_send_layoutreturn(lo, &stateid, iomode, true);
1325	pnfs_put_layout_hdr(lo);
1326	return false;
1327}
1328
1329void pnfs_roc_release(struct nfs4_layoutreturn_args *args,
1330		struct nfs4_layoutreturn_res *res,
1331		int ret)
1332{
1333	struct pnfs_layout_hdr *lo = args->layout;
1334	const nfs4_stateid *arg_stateid = NULL;
1335	const nfs4_stateid *res_stateid = NULL;
1336	struct nfs4_xdr_opaque_data *ld_private = args->ld_private;
1337
1338	if (ret == 0) {
1339		arg_stateid = &args->stateid;
1340		if (res->lrs_present)
1341			res_stateid = &res->stateid;
1342	}
1343	pnfs_layoutreturn_free_lsegs(lo, arg_stateid, &args->range,
1344			res_stateid);
1345	if (ld_private && ld_private->ops && ld_private->ops->free)
1346		ld_private->ops->free(ld_private);
1347	pnfs_put_layout_hdr(lo);
1348	trace_nfs4_layoutreturn_on_close(args->inode, 0);
1349}
1350
1351bool pnfs_wait_on_layoutreturn(struct inode *ino, struct rpc_task *task)
1352{
1353	struct nfs_inode *nfsi = NFS_I(ino);
1354        struct pnfs_layout_hdr *lo;
1355        bool sleep = false;
1356
1357	/* we might not have grabbed lo reference. so need to check under
1358	 * i_lock */
1359        spin_lock(&ino->i_lock);
1360        lo = nfsi->layout;
1361        if (lo && test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
1362                rpc_sleep_on(&NFS_SERVER(ino)->roc_rpcwaitq, task, NULL);
1363                sleep = true;
1364	}
1365        spin_unlock(&ino->i_lock);
1366        return sleep;
1367}
1368
1369/*
1370 * Compare two layout segments for sorting into layout cache.
1371 * We want to preferentially return RW over RO layouts, so ensure those
1372 * are seen first.
1373 */
1374static s64
1375pnfs_lseg_range_cmp(const struct pnfs_layout_range *l1,
1376	   const struct pnfs_layout_range *l2)
1377{
1378	s64 d;
1379
1380	/* high offset > low offset */
1381	d = l1->offset - l2->offset;
1382	if (d)
1383		return d;
1384
1385	/* short length > long length */
1386	d = l2->length - l1->length;
1387	if (d)
1388		return d;
1389
1390	/* read > read/write */
1391	return (int)(l1->iomode == IOMODE_READ) - (int)(l2->iomode == IOMODE_READ);
1392}
1393
1394static bool
1395pnfs_lseg_range_is_after(const struct pnfs_layout_range *l1,
1396		const struct pnfs_layout_range *l2)
1397{
1398	return pnfs_lseg_range_cmp(l1, l2) > 0;
1399}
1400
1401static bool
1402pnfs_lseg_no_merge(struct pnfs_layout_segment *lseg,
1403		struct pnfs_layout_segment *old)
1404{
1405	return false;
1406}
1407
1408void
1409pnfs_generic_layout_insert_lseg(struct pnfs_layout_hdr *lo,
1410		   struct pnfs_layout_segment *lseg,
1411		   bool (*is_after)(const struct pnfs_layout_range *,
1412			   const struct pnfs_layout_range *),
1413		   bool (*do_merge)(struct pnfs_layout_segment *,
1414			   struct pnfs_layout_segment *),
1415		   struct list_head *free_me)
1416{
1417	struct pnfs_layout_segment *lp, *tmp;
1418
1419	dprintk("%s:Begin\n", __func__);
1420
1421	list_for_each_entry_safe(lp, tmp, &lo->plh_segs, pls_list) {
1422		if (test_bit(NFS_LSEG_VALID, &lp->pls_flags) == 0)
1423			continue;
1424		if (do_merge(lseg, lp)) {
1425			mark_lseg_invalid(lp, free_me);
1426			continue;
1427		}
1428		if (is_after(&lseg->pls_range, &lp->pls_range))
1429			continue;
1430		list_add_tail(&lseg->pls_list, &lp->pls_list);
1431		dprintk("%s: inserted lseg %p "
1432			"iomode %d offset %llu length %llu before "
1433			"lp %p iomode %d offset %llu length %llu\n",
1434			__func__, lseg, lseg->pls_range.iomode,
1435			lseg->pls_range.offset, lseg->pls_range.length,
1436			lp, lp->pls_range.iomode, lp->pls_range.offset,
1437			lp->pls_range.length);
1438		goto out;
1439	}
1440	list_add_tail(&lseg->pls_list, &lo->plh_segs);
1441	dprintk("%s: inserted lseg %p "
1442		"iomode %d offset %llu length %llu at tail\n",
1443		__func__, lseg, lseg->pls_range.iomode,
1444		lseg->pls_range.offset, lseg->pls_range.length);
1445out:
1446	pnfs_get_layout_hdr(lo);
1447
1448	dprintk("%s:Return\n", __func__);
1449}
1450EXPORT_SYMBOL_GPL(pnfs_generic_layout_insert_lseg);
1451
1452static void
1453pnfs_layout_insert_lseg(struct pnfs_layout_hdr *lo,
1454		   struct pnfs_layout_segment *lseg,
1455		   struct list_head *free_me)
1456{
1457	struct inode *inode = lo->plh_inode;
1458	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
1459
1460	if (ld->add_lseg != NULL)
1461		ld->add_lseg(lo, lseg, free_me);
1462	else
1463		pnfs_generic_layout_insert_lseg(lo, lseg,
1464				pnfs_lseg_range_is_after,
1465				pnfs_lseg_no_merge,
1466				free_me);
1467}
1468
1469static struct pnfs_layout_hdr *
1470alloc_init_layout_hdr(struct inode *ino,
1471		      struct nfs_open_context *ctx,
1472		      gfp_t gfp_flags)
1473{
1474	struct pnfs_layout_hdr *lo;
1475
1476	lo = pnfs_alloc_layout_hdr(ino, gfp_flags);
1477	if (!lo)
1478		return NULL;
1479	refcount_set(&lo->plh_refcount, 1);
1480	INIT_LIST_HEAD(&lo->plh_layouts);
1481	INIT_LIST_HEAD(&lo->plh_segs);
1482	INIT_LIST_HEAD(&lo->plh_return_segs);
1483	INIT_LIST_HEAD(&lo->plh_bulk_destroy);
1484	lo->plh_inode = ino;
1485	lo->plh_lc_cred = get_rpccred(ctx->cred);
1486	lo->plh_flags |= 1 << NFS_LAYOUT_INVALID_STID;
1487	return lo;
1488}
1489
1490static struct pnfs_layout_hdr *
1491pnfs_find_alloc_layout(struct inode *ino,
1492		       struct nfs_open_context *ctx,
1493		       gfp_t gfp_flags)
1494	__releases(&ino->i_lock)
1495	__acquires(&ino->i_lock)
1496{
1497	struct nfs_inode *nfsi = NFS_I(ino);
1498	struct pnfs_layout_hdr *new = NULL;
1499
1500	dprintk("%s Begin ino=%p layout=%p\n", __func__, ino, nfsi->layout);
1501
1502	if (nfsi->layout != NULL)
1503		goto out_existing;
1504	spin_unlock(&ino->i_lock);
1505	new = alloc_init_layout_hdr(ino, ctx, gfp_flags);
1506	spin_lock(&ino->i_lock);
1507
1508	if (likely(nfsi->layout == NULL)) {	/* Won the race? */
1509		nfsi->layout = new;
1510		return new;
1511	} else if (new != NULL)
1512		pnfs_free_layout_hdr(new);
1513out_existing:
1514	pnfs_get_layout_hdr(nfsi->layout);
1515	return nfsi->layout;
1516}
1517
1518/*
1519 * iomode matching rules:
1520 * iomode	lseg	strict match
1521 *                      iomode
1522 * -----	-----	------ -----
1523 * ANY		READ	N/A    true
1524 * ANY		RW	N/A    true
1525 * RW		READ	N/A    false
1526 * RW		RW	N/A    true
1527 * READ		READ	N/A    true
1528 * READ		RW	true   false
1529 * READ		RW	false  true
1530 */
1531static bool
1532pnfs_lseg_range_match(const struct pnfs_layout_range *ls_range,
1533		 const struct pnfs_layout_range *range,
1534		 bool strict_iomode)
1535{
1536	struct pnfs_layout_range range1;
1537
1538	if ((range->iomode == IOMODE_RW &&
1539	     ls_range->iomode != IOMODE_RW) ||
1540	    (range->iomode != ls_range->iomode &&
1541	     strict_iomode) ||
1542	    !pnfs_lseg_range_intersecting(ls_range, range))
1543		return 0;
1544
1545	/* range1 covers only the first byte in the range */
1546	range1 = *range;
1547	range1.length = 1;
1548	return pnfs_lseg_range_contained(ls_range, &range1);
1549}
1550
1551/*
1552 * lookup range in layout
1553 */
1554static struct pnfs_layout_segment *
1555pnfs_find_lseg(struct pnfs_layout_hdr *lo,
1556		struct pnfs_layout_range *range,
1557		bool strict_iomode)
1558{
1559	struct pnfs_layout_segment *lseg, *ret = NULL;
1560
1561	dprintk("%s:Begin\n", __func__);
1562
1563	list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
1564		if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags) &&
1565		    !test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags) &&
1566		    pnfs_lseg_range_match(&lseg->pls_range, range,
1567					  strict_iomode)) {
1568			ret = pnfs_get_lseg(lseg);
1569			break;
1570		}
1571	}
1572
1573	dprintk("%s:Return lseg %p ref %d\n",
1574		__func__, ret, ret ? refcount_read(&ret->pls_refcount) : 0);
1575	return ret;
1576}
1577
1578/*
1579 * Use mdsthreshold hints set at each OPEN to determine if I/O should go
1580 * to the MDS or over pNFS
1581 *
1582 * The nfs_inode read_io and write_io fields are cumulative counters reset
1583 * when there are no layout segments. Note that in pnfs_update_layout iomode
1584 * is set to IOMODE_READ for a READ request, and set to IOMODE_RW for a
1585 * WRITE request.
1586 *
1587 * A return of true means use MDS I/O.
1588 *
1589 * From rfc 5661:
1590 * If a file's size is smaller than the file size threshold, data accesses
1591 * SHOULD be sent to the metadata server.  If an I/O request has a length that
1592 * is below the I/O size threshold, the I/O SHOULD be sent to the metadata
1593 * server.  If both file size and I/O size are provided, the client SHOULD
1594 * reach or exceed  both thresholds before sending its read or write
1595 * requests to the data server.
1596 */
1597static bool pnfs_within_mdsthreshold(struct nfs_open_context *ctx,
1598				     struct inode *ino, int iomode)
1599{
1600	struct nfs4_threshold *t = ctx->mdsthreshold;
1601	struct nfs_inode *nfsi = NFS_I(ino);
1602	loff_t fsize = i_size_read(ino);
1603	bool size = false, size_set = false, io = false, io_set = false, ret = false;
1604
1605	if (t == NULL)
1606		return ret;
1607
1608	dprintk("%s bm=0x%x rd_sz=%llu wr_sz=%llu rd_io=%llu wr_io=%llu\n",
1609		__func__, t->bm, t->rd_sz, t->wr_sz, t->rd_io_sz, t->wr_io_sz);
1610
1611	switch (iomode) {
1612	case IOMODE_READ:
1613		if (t->bm & THRESHOLD_RD) {
1614			dprintk("%s fsize %llu\n", __func__, fsize);
1615			size_set = true;
1616			if (fsize < t->rd_sz)
1617				size = true;
1618		}
1619		if (t->bm & THRESHOLD_RD_IO) {
1620			dprintk("%s nfsi->read_io %llu\n", __func__,
1621				nfsi->read_io);
1622			io_set = true;
1623			if (nfsi->read_io < t->rd_io_sz)
1624				io = true;
1625		}
1626		break;
1627	case IOMODE_RW:
1628		if (t->bm & THRESHOLD_WR) {
1629			dprintk("%s fsize %llu\n", __func__, fsize);
1630			size_set = true;
1631			if (fsize < t->wr_sz)
1632				size = true;
1633		}
1634		if (t->bm & THRESHOLD_WR_IO) {
1635			dprintk("%s nfsi->write_io %llu\n", __func__,
1636				nfsi->write_io);
1637			io_set = true;
1638			if (nfsi->write_io < t->wr_io_sz)
1639				io = true;
1640		}
1641		break;
1642	}
1643	if (size_set && io_set) {
1644		if (size && io)
1645			ret = true;
1646	} else if (size || io)
1647		ret = true;
1648
1649	dprintk("<-- %s size %d io %d ret %d\n", __func__, size, io, ret);
1650	return ret;
1651}
1652
1653static bool pnfs_prepare_to_retry_layoutget(struct pnfs_layout_hdr *lo)
1654{
1655	/*
1656	 * send layoutcommit as it can hold up layoutreturn due to lseg
1657	 * reference
1658	 */
1659	pnfs_layoutcommit_inode(lo->plh_inode, false);
1660	return !wait_on_bit_action(&lo->plh_flags, NFS_LAYOUT_RETURN,
1661				   nfs_wait_bit_killable,
1662				   TASK_UNINTERRUPTIBLE);
1663}
1664
1665static void pnfs_clear_first_layoutget(struct pnfs_layout_hdr *lo)
1666{
1667	unsigned long *bitlock = &lo->plh_flags;
1668
1669	clear_bit_unlock(NFS_LAYOUT_FIRST_LAYOUTGET, bitlock);
1670	smp_mb__after_atomic();
1671	wake_up_bit(bitlock, NFS_LAYOUT_FIRST_LAYOUTGET);
1672}
1673
1674/*
1675 * Layout segment is retreived from the server if not cached.
1676 * The appropriate layout segment is referenced and returned to the caller.
1677 */
1678struct pnfs_layout_segment *
1679pnfs_update_layout(struct inode *ino,
1680		   struct nfs_open_context *ctx,
1681		   loff_t pos,
1682		   u64 count,
1683		   enum pnfs_iomode iomode,
1684		   bool strict_iomode,
1685		   gfp_t gfp_flags)
1686{
1687	struct pnfs_layout_range arg = {
1688		.iomode = iomode,
1689		.offset = pos,
1690		.length = count,
1691	};
1692	unsigned pg_offset;
1693	struct nfs_server *server = NFS_SERVER(ino);
1694	struct nfs_client *clp = server->nfs_client;
1695	struct pnfs_layout_hdr *lo = NULL;
1696	struct pnfs_layout_segment *lseg = NULL;
1697	nfs4_stateid stateid;
1698	long timeout = 0;
1699	unsigned long giveup = jiffies + (clp->cl_lease_time << 1);
1700	bool first;
1701
1702	if (!pnfs_enabled_sb(NFS_SERVER(ino))) {
1703		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1704				 PNFS_UPDATE_LAYOUT_NO_PNFS);
1705		goto out;
1706	}
1707
1708	if (iomode == IOMODE_READ && i_size_read(ino) == 0) {
1709		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1710				 PNFS_UPDATE_LAYOUT_RD_ZEROLEN);
1711		goto out;
1712	}
1713
1714	if (pnfs_within_mdsthreshold(ctx, ino, iomode)) {
1715		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1716				 PNFS_UPDATE_LAYOUT_MDSTHRESH);
1717		goto out;
1718	}
1719
1720lookup_again:
1721	nfs4_client_recover_expired_lease(clp);
1722	first = false;
1723	spin_lock(&ino->i_lock);
1724	lo = pnfs_find_alloc_layout(ino, ctx, gfp_flags);
1725	if (lo == NULL) {
1726		spin_unlock(&ino->i_lock);
1727		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1728				 PNFS_UPDATE_LAYOUT_NOMEM);
1729		goto out;
1730	}
1731
1732	/* Do we even need to bother with this? */
1733	if (test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
1734		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1735				 PNFS_UPDATE_LAYOUT_BULK_RECALL);
1736		dprintk("%s matches recall, use MDS\n", __func__);
1737		goto out_unlock;
1738	}
1739
1740	/* if LAYOUTGET already failed once we don't try again */
1741	if (pnfs_layout_io_test_failed(lo, iomode)) {
1742		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1743				 PNFS_UPDATE_LAYOUT_IO_TEST_FAIL);
1744		goto out_unlock;
1745	}
1746
1747	lseg = pnfs_find_lseg(lo, &arg, strict_iomode);
1748	if (lseg) {
1749		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1750				PNFS_UPDATE_LAYOUT_FOUND_CACHED);
1751		goto out_unlock;
1752	}
1753
1754	if (!nfs4_valid_open_stateid(ctx->state)) {
1755		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1756				PNFS_UPDATE_LAYOUT_INVALID_OPEN);
1757		goto out_unlock;
1758	}
1759
1760	/*
1761	 * Choose a stateid for the LAYOUTGET. If we don't have a layout
1762	 * stateid, or it has been invalidated, then we must use the open
1763	 * stateid.
1764	 */
1765	if (test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags)) {
1766
1767		/*
1768		 * The first layoutget for the file. Need to serialize per
1769		 * RFC 5661 Errata 3208.
1770		 */
1771		if (test_and_set_bit(NFS_LAYOUT_FIRST_LAYOUTGET,
1772				     &lo->plh_flags)) {
1773			spin_unlock(&ino->i_lock);
1774			wait_on_bit(&lo->plh_flags, NFS_LAYOUT_FIRST_LAYOUTGET,
1775				    TASK_UNINTERRUPTIBLE);
1776			pnfs_put_layout_hdr(lo);
1777			dprintk("%s retrying\n", __func__);
1778			goto lookup_again;
1779		}
1780
1781		first = true;
1782		if (nfs4_select_rw_stateid(ctx->state,
1783					iomode == IOMODE_RW ? FMODE_WRITE : FMODE_READ,
1784					NULL, &stateid, NULL) != 0) {
1785			trace_pnfs_update_layout(ino, pos, count,
1786					iomode, lo, lseg,
1787					PNFS_UPDATE_LAYOUT_INVALID_OPEN);
1788			goto out_unlock;
1789		}
1790	} else {
1791		nfs4_stateid_copy(&stateid, &lo->plh_stateid);
1792	}
1793
1794	/*
1795	 * Because we free lsegs before sending LAYOUTRETURN, we need to wait
1796	 * for LAYOUTRETURN even if first is true.
1797	 */
1798	if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
1799		spin_unlock(&ino->i_lock);
1800		dprintk("%s wait for layoutreturn\n", __func__);
1801		if (pnfs_prepare_to_retry_layoutget(lo)) {
1802			if (first)
1803				pnfs_clear_first_layoutget(lo);
1804			pnfs_put_layout_hdr(lo);
1805			dprintk("%s retrying\n", __func__);
1806			trace_pnfs_update_layout(ino, pos, count, iomode, lo,
1807					lseg, PNFS_UPDATE_LAYOUT_RETRY);
1808			goto lookup_again;
1809		}
1810		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1811				PNFS_UPDATE_LAYOUT_RETURN);
1812		goto out_put_layout_hdr;
1813	}
1814
1815	if (pnfs_layoutgets_blocked(lo)) {
1816		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1817				PNFS_UPDATE_LAYOUT_BLOCKED);
1818		goto out_unlock;
1819	}
1820	atomic_inc(&lo->plh_outstanding);
1821	spin_unlock(&ino->i_lock);
1822
1823	if (list_empty(&lo->plh_layouts)) {
1824		/* The lo must be on the clp list if there is any
1825		 * chance of a CB_LAYOUTRECALL(FILE) coming in.
1826		 */
1827		spin_lock(&clp->cl_lock);
1828		if (list_empty(&lo->plh_layouts))
1829			list_add_tail(&lo->plh_layouts, &server->layouts);
1830		spin_unlock(&clp->cl_lock);
1831	}
1832
1833	pg_offset = arg.offset & ~PAGE_MASK;
1834	if (pg_offset) {
1835		arg.offset -= pg_offset;
1836		arg.length += pg_offset;
1837	}
1838	if (arg.length != NFS4_MAX_UINT64)
1839		arg.length = PAGE_ALIGN(arg.length);
1840
1841	lseg = send_layoutget(lo, ctx, &stateid, &arg, &timeout, gfp_flags);
1842	trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1843				 PNFS_UPDATE_LAYOUT_SEND_LAYOUTGET);
1844	atomic_dec(&lo->plh_outstanding);
1845	if (IS_ERR(lseg)) {
1846		switch(PTR_ERR(lseg)) {
1847		case -EBUSY:
1848			if (time_after(jiffies, giveup))
1849				lseg = NULL;
1850			break;
1851		case -ERECALLCONFLICT:
1852			/* Huh? We hold no layouts, how is there a recall? */
1853			if (first) {
1854				lseg = NULL;
1855				break;
1856			}
1857			/* Destroy the existing layout and start over */
1858			if (time_after(jiffies, giveup))
1859				pnfs_destroy_layout(NFS_I(ino));
1860			/* Fallthrough */
1861		case -EAGAIN:
1862			break;
1863		default:
1864			if (!nfs_error_is_fatal(PTR_ERR(lseg))) {
1865				pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
1866				lseg = NULL;
1867			}
1868			goto out_put_layout_hdr;
1869		}
1870		if (lseg) {
1871			if (first)
1872				pnfs_clear_first_layoutget(lo);
1873			trace_pnfs_update_layout(ino, pos, count,
1874				iomode, lo, lseg, PNFS_UPDATE_LAYOUT_RETRY);
1875			pnfs_put_layout_hdr(lo);
1876			goto lookup_again;
1877		}
1878	} else {
1879		pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
1880	}
1881
1882out_put_layout_hdr:
1883	if (first)
1884		pnfs_clear_first_layoutget(lo);
1885	pnfs_put_layout_hdr(lo);
1886out:
1887	dprintk("%s: inode %s/%llu pNFS layout segment %s for "
1888			"(%s, offset: %llu, length: %llu)\n",
1889			__func__, ino->i_sb->s_id,
1890			(unsigned long long)NFS_FILEID(ino),
1891			IS_ERR_OR_NULL(lseg) ? "not found" : "found",
1892			iomode==IOMODE_RW ?  "read/write" : "read-only",
1893			(unsigned long long)pos,
1894			(unsigned long long)count);
1895	return lseg;
1896out_unlock:
1897	spin_unlock(&ino->i_lock);
1898	goto out_put_layout_hdr;
1899}
1900EXPORT_SYMBOL_GPL(pnfs_update_layout);
1901
1902static bool
1903pnfs_sanity_check_layout_range(struct pnfs_layout_range *range)
1904{
1905	switch (range->iomode) {
1906	case IOMODE_READ:
1907	case IOMODE_RW:
1908		break;
1909	default:
1910		return false;
1911	}
1912	if (range->offset == NFS4_MAX_UINT64)
1913		return false;
1914	if (range->length == 0)
1915		return false;
1916	if (range->length != NFS4_MAX_UINT64 &&
1917	    range->length > NFS4_MAX_UINT64 - range->offset)
1918		return false;
1919	return true;
1920}
1921
1922struct pnfs_layout_segment *
1923pnfs_layout_process(struct nfs4_layoutget *lgp)
1924{
1925	struct pnfs_layout_hdr *lo = NFS_I(lgp->args.inode)->layout;
1926	struct nfs4_layoutget_res *res = &lgp->res;
1927	struct pnfs_layout_segment *lseg;
1928	struct inode *ino = lo->plh_inode;
1929	LIST_HEAD(free_me);
1930
1931	if (!pnfs_sanity_check_layout_range(&res->range))
1932		return ERR_PTR(-EINVAL);
1933
1934	/* Inject layout blob into I/O device driver */
1935	lseg = NFS_SERVER(ino)->pnfs_curr_ld->alloc_lseg(lo, res, lgp->gfp_flags);
1936	if (IS_ERR_OR_NULL(lseg)) {
1937		if (!lseg)
1938			lseg = ERR_PTR(-ENOMEM);
1939
1940		dprintk("%s: Could not allocate layout: error %ld\n",
1941		       __func__, PTR_ERR(lseg));
1942		return lseg;
1943	}
1944
1945	pnfs_init_lseg(lo, lseg, &res->range, &res->stateid);
1946
1947	spin_lock(&ino->i_lock);
1948	if (pnfs_layoutgets_blocked(lo)) {
1949		dprintk("%s forget reply due to state\n", __func__);
1950		goto out_forget;
1951	}
1952
1953	if (!pnfs_layout_is_valid(lo)) {
1954		/* We have a completely new layout */
1955		pnfs_set_layout_stateid(lo, &res->stateid, true);
1956	} else if (nfs4_stateid_match_other(&lo->plh_stateid, &res->stateid)) {
1957		/* existing state ID, make sure the sequence number matches. */
1958		if (pnfs_layout_stateid_blocked(lo, &res->stateid)) {
1959			dprintk("%s forget reply due to sequence\n", __func__);
1960			goto out_forget;
1961		}
1962		pnfs_set_layout_stateid(lo, &res->stateid, false);
1963	} else {
1964		/*
1965		 * We got an entirely new state ID.  Mark all segments for the
1966		 * inode invalid, and retry the layoutget
1967		 */
1968		pnfs_mark_layout_stateid_invalid(lo, &free_me);
1969		goto out_forget;
1970	}
1971
1972	pnfs_get_lseg(lseg);
1973	pnfs_layout_insert_lseg(lo, lseg, &free_me);
1974
1975
1976	if (res->return_on_close)
1977		set_bit(NFS_LSEG_ROC, &lseg->pls_flags);
1978
1979	spin_unlock(&ino->i_lock);
1980	pnfs_free_lseg_list(&free_me);
1981	return lseg;
1982
1983out_forget:
1984	spin_unlock(&ino->i_lock);
1985	lseg->pls_layout = lo;
1986	NFS_SERVER(ino)->pnfs_curr_ld->free_lseg(lseg);
1987	if (!pnfs_layout_is_valid(lo))
1988		nfs_commit_inode(ino, 0);
1989	return ERR_PTR(-EAGAIN);
1990}
1991
1992/**
1993 * pnfs_mark_matching_lsegs_return - Free or return matching layout segments
1994 * @lo: pointer to layout header
1995 * @tmp_list: list header to be used with pnfs_free_lseg_list()
1996 * @return_range: describe layout segment ranges to be returned
1997 *
1998 * This function is mainly intended for use by layoutrecall. It attempts
1999 * to free the layout segment immediately, or else to mark it for return
2000 * as soon as its reference count drops to zero.
2001 */
2002int
2003pnfs_mark_matching_lsegs_return(struct pnfs_layout_hdr *lo,
2004				struct list_head *tmp_list,
2005				const struct pnfs_layout_range *return_range,
2006				u32 seq)
2007{
2008	struct pnfs_layout_segment *lseg, *next;
2009	int remaining = 0;
2010
2011	dprintk("%s:Begin lo %p\n", __func__, lo);
2012
2013	if (list_empty(&lo->plh_segs))
2014		return 0;
2015
2016	assert_spin_locked(&lo->plh_inode->i_lock);
2017
2018	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
2019		if (pnfs_match_lseg_recall(lseg, return_range, seq)) {
2020			dprintk("%s: marking lseg %p iomode %d "
2021				"offset %llu length %llu\n", __func__,
2022				lseg, lseg->pls_range.iomode,
2023				lseg->pls_range.offset,
2024				lseg->pls_range.length);
2025			if (mark_lseg_invalid(lseg, tmp_list))
2026				continue;
2027			remaining++;
2028			set_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
2029		}
2030
2031	if (remaining)
2032		pnfs_set_plh_return_info(lo, return_range->iomode, seq);
2033
2034	return remaining;
2035}
2036
2037void pnfs_error_mark_layout_for_return(struct inode *inode,
2038				       struct pnfs_layout_segment *lseg)
2039{
2040	struct pnfs_layout_hdr *lo = NFS_I(inode)->layout;
2041	struct pnfs_layout_range range = {
2042		.iomode = lseg->pls_range.iomode,
2043		.offset = 0,
2044		.length = NFS4_MAX_UINT64,
2045	};
2046	bool return_now = false;
2047
2048	spin_lock(&inode->i_lock);
2049	if (!pnfs_layout_is_valid(lo)) {
2050		spin_unlock(&inode->i_lock);
2051		return;
2052	}
2053	pnfs_set_plh_return_info(lo, range.iomode, 0);
 
 
2054	/*
2055	 * mark all matching lsegs so that we are sure to have no live
2056	 * segments at hand when sending layoutreturn. See pnfs_put_lseg()
2057	 * for how it works.
2058	 */
2059	if (!pnfs_mark_matching_lsegs_return(lo, &lo->plh_return_segs, &range, 0)) {
2060		nfs4_stateid stateid;
2061		enum pnfs_iomode iomode;
2062
2063		return_now = pnfs_prepare_layoutreturn(lo, &stateid, &iomode);
2064		spin_unlock(&inode->i_lock);
2065		if (return_now)
2066			pnfs_send_layoutreturn(lo, &stateid, iomode, false);
2067	} else {
2068		spin_unlock(&inode->i_lock);
2069		nfs_commit_inode(inode, 0);
2070	}
2071}
2072EXPORT_SYMBOL_GPL(pnfs_error_mark_layout_for_return);
2073
2074void
2075pnfs_generic_pg_check_layout(struct nfs_pageio_descriptor *pgio)
2076{
2077	if (pgio->pg_lseg == NULL ||
2078	    test_bit(NFS_LSEG_VALID, &pgio->pg_lseg->pls_flags))
2079		return;
2080	pnfs_put_lseg(pgio->pg_lseg);
2081	pgio->pg_lseg = NULL;
2082}
2083EXPORT_SYMBOL_GPL(pnfs_generic_pg_check_layout);
2084
2085/*
2086 * Check for any intersection between the request and the pgio->pg_lseg,
2087 * and if none, put this pgio->pg_lseg away.
2088 */
2089static void
2090pnfs_generic_pg_check_range(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
2091{
2092	if (pgio->pg_lseg && !pnfs_lseg_request_intersecting(pgio->pg_lseg, req)) {
2093		pnfs_put_lseg(pgio->pg_lseg);
2094		pgio->pg_lseg = NULL;
2095	}
2096}
2097
2098void
2099pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
2100{
2101	u64 rd_size = req->wb_bytes;
2102
2103	pnfs_generic_pg_check_layout(pgio);
2104	pnfs_generic_pg_check_range(pgio, req);
2105	if (pgio->pg_lseg == NULL) {
2106		if (pgio->pg_dreq == NULL)
2107			rd_size = i_size_read(pgio->pg_inode) - req_offset(req);
2108		else
2109			rd_size = nfs_dreq_bytes_left(pgio->pg_dreq);
2110
2111		pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
2112						   req->wb_context,
2113						   req_offset(req),
2114						   rd_size,
2115						   IOMODE_READ,
2116						   false,
2117						   GFP_KERNEL);
2118		if (IS_ERR(pgio->pg_lseg)) {
2119			pgio->pg_error = PTR_ERR(pgio->pg_lseg);
2120			pgio->pg_lseg = NULL;
2121			return;
2122		}
2123	}
2124	/* If no lseg, fall back to read through mds */
2125	if (pgio->pg_lseg == NULL)
2126		nfs_pageio_reset_read_mds(pgio);
2127
2128}
2129EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_read);
2130
2131void
2132pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio,
2133			   struct nfs_page *req, u64 wb_size)
2134{
2135	pnfs_generic_pg_check_layout(pgio);
2136	pnfs_generic_pg_check_range(pgio, req);
2137	if (pgio->pg_lseg == NULL) {
2138		pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
2139						   req->wb_context,
2140						   req_offset(req),
2141						   wb_size,
2142						   IOMODE_RW,
2143						   false,
2144						   GFP_NOFS);
2145		if (IS_ERR(pgio->pg_lseg)) {
2146			pgio->pg_error = PTR_ERR(pgio->pg_lseg);
2147			pgio->pg_lseg = NULL;
2148			return;
2149		}
2150	}
2151	/* If no lseg, fall back to write through mds */
2152	if (pgio->pg_lseg == NULL)
2153		nfs_pageio_reset_write_mds(pgio);
2154}
2155EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_write);
2156
2157void
2158pnfs_generic_pg_cleanup(struct nfs_pageio_descriptor *desc)
2159{
2160	if (desc->pg_lseg) {
2161		pnfs_put_lseg(desc->pg_lseg);
2162		desc->pg_lseg = NULL;
2163	}
2164}
2165EXPORT_SYMBOL_GPL(pnfs_generic_pg_cleanup);
2166
2167/*
2168 * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
2169 * of bytes (maximum @req->wb_bytes) that can be coalesced.
2170 */
2171size_t
2172pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio,
2173		     struct nfs_page *prev, struct nfs_page *req)
2174{
2175	unsigned int size;
2176	u64 seg_end, req_start, seg_left;
2177
2178	size = nfs_generic_pg_test(pgio, prev, req);
2179	if (!size)
2180		return 0;
2181
2182	/*
2183	 * 'size' contains the number of bytes left in the current page (up
2184	 * to the original size asked for in @req->wb_bytes).
2185	 *
2186	 * Calculate how many bytes are left in the layout segment
2187	 * and if there are less bytes than 'size', return that instead.
2188	 *
2189	 * Please also note that 'end_offset' is actually the offset of the
2190	 * first byte that lies outside the pnfs_layout_range. FIXME?
2191	 *
2192	 */
2193	if (pgio->pg_lseg) {
2194		seg_end = pnfs_end_offset(pgio->pg_lseg->pls_range.offset,
2195				     pgio->pg_lseg->pls_range.length);
2196		req_start = req_offset(req);
2197
2198		/* start of request is past the last byte of this segment */
2199		if (req_start >= seg_end)
 
 
 
 
 
2200			return 0;
 
2201
2202		/* adjust 'size' iff there are fewer bytes left in the
2203		 * segment than what nfs_generic_pg_test returned */
2204		seg_left = seg_end - req_start;
2205		if (seg_left < size)
2206			size = (unsigned int)seg_left;
2207	}
2208
2209	return size;
2210}
2211EXPORT_SYMBOL_GPL(pnfs_generic_pg_test);
2212
2213int pnfs_write_done_resend_to_mds(struct nfs_pgio_header *hdr)
2214{
2215	struct nfs_pageio_descriptor pgio;
2216
2217	/* Resend all requests through the MDS */
2218	nfs_pageio_init_write(&pgio, hdr->inode, FLUSH_STABLE, true,
2219			      hdr->completion_ops);
2220	set_bit(NFS_CONTEXT_RESEND_WRITES, &hdr->args.context->flags);
2221	return nfs_pageio_resend(&pgio, hdr);
2222}
2223EXPORT_SYMBOL_GPL(pnfs_write_done_resend_to_mds);
2224
2225static void pnfs_ld_handle_write_error(struct nfs_pgio_header *hdr)
2226{
2227
2228	dprintk("pnfs write error = %d\n", hdr->pnfs_error);
2229	if (NFS_SERVER(hdr->inode)->pnfs_curr_ld->flags &
2230	    PNFS_LAYOUTRET_ON_ERROR) {
2231		pnfs_return_layout(hdr->inode);
2232	}
2233	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))
2234		hdr->task.tk_status = pnfs_write_done_resend_to_mds(hdr);
2235}
2236
2237/*
2238 * Called by non rpc-based layout drivers
2239 */
2240void pnfs_ld_write_done(struct nfs_pgio_header *hdr)
2241{
2242	if (likely(!hdr->pnfs_error)) {
2243		pnfs_set_layoutcommit(hdr->inode, hdr->lseg,
2244				hdr->mds_offset + hdr->res.count);
2245		hdr->mds_ops->rpc_call_done(&hdr->task, hdr);
2246	}
2247	trace_nfs4_pnfs_write(hdr, hdr->pnfs_error);
2248	if (unlikely(hdr->pnfs_error))
2249		pnfs_ld_handle_write_error(hdr);
2250	hdr->mds_ops->rpc_release(hdr);
2251}
2252EXPORT_SYMBOL_GPL(pnfs_ld_write_done);
2253
2254static void
2255pnfs_write_through_mds(struct nfs_pageio_descriptor *desc,
2256		struct nfs_pgio_header *hdr)
2257{
2258	struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
2259
2260	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2261		list_splice_tail_init(&hdr->pages, &mirror->pg_list);
2262		nfs_pageio_reset_write_mds(desc);
2263		mirror->pg_recoalesce = 1;
2264	}
2265	hdr->completion_ops->completion(hdr);
 
2266}
2267
2268static enum pnfs_try_status
2269pnfs_try_to_write_data(struct nfs_pgio_header *hdr,
2270			const struct rpc_call_ops *call_ops,
2271			struct pnfs_layout_segment *lseg,
2272			int how)
2273{
2274	struct inode *inode = hdr->inode;
2275	enum pnfs_try_status trypnfs;
2276	struct nfs_server *nfss = NFS_SERVER(inode);
2277
2278	hdr->mds_ops = call_ops;
2279
2280	dprintk("%s: Writing ino:%lu %u@%llu (how %d)\n", __func__,
2281		inode->i_ino, hdr->args.count, hdr->args.offset, how);
2282	trypnfs = nfss->pnfs_curr_ld->write_pagelist(hdr, how);
2283	if (trypnfs != PNFS_NOT_ATTEMPTED)
2284		nfs_inc_stats(inode, NFSIOS_PNFS_WRITE);
2285	dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
2286	return trypnfs;
2287}
2288
2289static void
2290pnfs_do_write(struct nfs_pageio_descriptor *desc,
2291	      struct nfs_pgio_header *hdr, int how)
2292{
2293	const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
2294	struct pnfs_layout_segment *lseg = desc->pg_lseg;
2295	enum pnfs_try_status trypnfs;
2296
2297	trypnfs = pnfs_try_to_write_data(hdr, call_ops, lseg, how);
2298	switch (trypnfs) {
2299	case PNFS_NOT_ATTEMPTED:
2300		pnfs_write_through_mds(desc, hdr);
2301	case PNFS_ATTEMPTED:
2302		break;
2303	case PNFS_TRY_AGAIN:
2304		/* cleanup hdr and prepare to redo pnfs */
2305		if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2306			struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
2307			list_splice_init(&hdr->pages, &mirror->pg_list);
2308			mirror->pg_recoalesce = 1;
2309		}
2310		hdr->mds_ops->rpc_release(hdr);
2311	}
2312}
2313
2314static void pnfs_writehdr_free(struct nfs_pgio_header *hdr)
2315{
2316	pnfs_put_lseg(hdr->lseg);
2317	nfs_pgio_header_free(hdr);
2318}
2319
2320int
2321pnfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
2322{
2323	struct nfs_pgio_header *hdr;
2324	int ret;
2325
2326	hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
2327	if (!hdr) {
2328		desc->pg_error = -ENOMEM;
2329		return desc->pg_error;
2330	}
2331	nfs_pgheader_init(desc, hdr, pnfs_writehdr_free);
2332
2333	hdr->lseg = pnfs_get_lseg(desc->pg_lseg);
2334	ret = nfs_generic_pgio(desc, hdr);
2335	if (!ret)
2336		pnfs_do_write(desc, hdr, desc->pg_ioflags);
2337
2338	return ret;
2339}
2340EXPORT_SYMBOL_GPL(pnfs_generic_pg_writepages);
2341
2342int pnfs_read_done_resend_to_mds(struct nfs_pgio_header *hdr)
2343{
2344	struct nfs_pageio_descriptor pgio;
2345
2346	/* Resend all requests through the MDS */
2347	nfs_pageio_init_read(&pgio, hdr->inode, true, hdr->completion_ops);
2348	return nfs_pageio_resend(&pgio, hdr);
2349}
2350EXPORT_SYMBOL_GPL(pnfs_read_done_resend_to_mds);
2351
2352static void pnfs_ld_handle_read_error(struct nfs_pgio_header *hdr)
2353{
2354	dprintk("pnfs read error = %d\n", hdr->pnfs_error);
2355	if (NFS_SERVER(hdr->inode)->pnfs_curr_ld->flags &
2356	    PNFS_LAYOUTRET_ON_ERROR) {
2357		pnfs_return_layout(hdr->inode);
2358	}
2359	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))
2360		hdr->task.tk_status = pnfs_read_done_resend_to_mds(hdr);
2361}
2362
2363/*
2364 * Called by non rpc-based layout drivers
2365 */
2366void pnfs_ld_read_done(struct nfs_pgio_header *hdr)
2367{
2368	if (likely(!hdr->pnfs_error))
2369		hdr->mds_ops->rpc_call_done(&hdr->task, hdr);
2370	trace_nfs4_pnfs_read(hdr, hdr->pnfs_error);
2371	if (unlikely(hdr->pnfs_error))
2372		pnfs_ld_handle_read_error(hdr);
2373	hdr->mds_ops->rpc_release(hdr);
2374}
2375EXPORT_SYMBOL_GPL(pnfs_ld_read_done);
2376
2377static void
2378pnfs_read_through_mds(struct nfs_pageio_descriptor *desc,
2379		struct nfs_pgio_header *hdr)
2380{
2381	struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
2382
2383	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2384		list_splice_tail_init(&hdr->pages, &mirror->pg_list);
2385		nfs_pageio_reset_read_mds(desc);
2386		mirror->pg_recoalesce = 1;
2387	}
2388	hdr->completion_ops->completion(hdr);
 
2389}
2390
2391/*
2392 * Call the appropriate parallel I/O subsystem read function.
2393 */
2394static enum pnfs_try_status
2395pnfs_try_to_read_data(struct nfs_pgio_header *hdr,
2396		       const struct rpc_call_ops *call_ops,
2397		       struct pnfs_layout_segment *lseg)
2398{
2399	struct inode *inode = hdr->inode;
2400	struct nfs_server *nfss = NFS_SERVER(inode);
2401	enum pnfs_try_status trypnfs;
2402
2403	hdr->mds_ops = call_ops;
2404
2405	dprintk("%s: Reading ino:%lu %u@%llu\n",
2406		__func__, inode->i_ino, hdr->args.count, hdr->args.offset);
2407
2408	trypnfs = nfss->pnfs_curr_ld->read_pagelist(hdr);
2409	if (trypnfs != PNFS_NOT_ATTEMPTED)
2410		nfs_inc_stats(inode, NFSIOS_PNFS_READ);
2411	dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
2412	return trypnfs;
2413}
2414
2415/* Resend all requests through pnfs. */
2416void pnfs_read_resend_pnfs(struct nfs_pgio_header *hdr)
2417{
2418	struct nfs_pageio_descriptor pgio;
2419
2420	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2421		/* Prevent deadlocks with layoutreturn! */
2422		pnfs_put_lseg(hdr->lseg);
2423		hdr->lseg = NULL;
2424
2425		nfs_pageio_init_read(&pgio, hdr->inode, false,
2426					hdr->completion_ops);
2427		hdr->task.tk_status = nfs_pageio_resend(&pgio, hdr);
2428	}
2429}
2430EXPORT_SYMBOL_GPL(pnfs_read_resend_pnfs);
2431
2432static void
2433pnfs_do_read(struct nfs_pageio_descriptor *desc, struct nfs_pgio_header *hdr)
2434{
2435	const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
2436	struct pnfs_layout_segment *lseg = desc->pg_lseg;
2437	enum pnfs_try_status trypnfs;
2438
2439	trypnfs = pnfs_try_to_read_data(hdr, call_ops, lseg);
2440	switch (trypnfs) {
2441	case PNFS_NOT_ATTEMPTED:
 
2442		pnfs_read_through_mds(desc, hdr);
2443	case PNFS_ATTEMPTED:
2444		break;
2445	case PNFS_TRY_AGAIN:
2446		/* cleanup hdr and prepare to redo pnfs */
2447		if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2448			struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
2449			list_splice_init(&hdr->pages, &mirror->pg_list);
2450			mirror->pg_recoalesce = 1;
2451		}
2452		hdr->mds_ops->rpc_release(hdr);
2453	}
2454}
2455
2456static void pnfs_readhdr_free(struct nfs_pgio_header *hdr)
2457{
2458	pnfs_put_lseg(hdr->lseg);
2459	nfs_pgio_header_free(hdr);
2460}
2461
2462int
2463pnfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc)
2464{
2465	struct nfs_pgio_header *hdr;
2466	int ret;
2467
2468	hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
2469	if (!hdr) {
2470		desc->pg_error = -ENOMEM;
2471		return desc->pg_error;
2472	}
2473	nfs_pgheader_init(desc, hdr, pnfs_readhdr_free);
2474	hdr->lseg = pnfs_get_lseg(desc->pg_lseg);
2475	ret = nfs_generic_pgio(desc, hdr);
2476	if (!ret)
2477		pnfs_do_read(desc, hdr);
2478	return ret;
2479}
2480EXPORT_SYMBOL_GPL(pnfs_generic_pg_readpages);
2481
2482static void pnfs_clear_layoutcommitting(struct inode *inode)
2483{
2484	unsigned long *bitlock = &NFS_I(inode)->flags;
2485
2486	clear_bit_unlock(NFS_INO_LAYOUTCOMMITTING, bitlock);
2487	smp_mb__after_atomic();
2488	wake_up_bit(bitlock, NFS_INO_LAYOUTCOMMITTING);
2489}
2490
2491/*
2492 * There can be multiple RW segments.
2493 */
2494static void pnfs_list_write_lseg(struct inode *inode, struct list_head *listp)
2495{
2496	struct pnfs_layout_segment *lseg;
2497
2498	list_for_each_entry(lseg, &NFS_I(inode)->layout->plh_segs, pls_list) {
2499		if (lseg->pls_range.iomode == IOMODE_RW &&
2500		    test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
2501			list_add(&lseg->pls_lc_list, listp);
2502	}
2503}
2504
2505static void pnfs_list_write_lseg_done(struct inode *inode, struct list_head *listp)
2506{
2507	struct pnfs_layout_segment *lseg, *tmp;
2508
2509	/* Matched by references in pnfs_set_layoutcommit */
2510	list_for_each_entry_safe(lseg, tmp, listp, pls_lc_list) {
2511		list_del_init(&lseg->pls_lc_list);
2512		pnfs_put_lseg(lseg);
2513	}
2514
2515	pnfs_clear_layoutcommitting(inode);
2516}
2517
2518void pnfs_set_lo_fail(struct pnfs_layout_segment *lseg)
2519{
2520	pnfs_layout_io_set_failed(lseg->pls_layout, lseg->pls_range.iomode);
2521}
2522EXPORT_SYMBOL_GPL(pnfs_set_lo_fail);
2523
2524void
2525pnfs_set_layoutcommit(struct inode *inode, struct pnfs_layout_segment *lseg,
2526		loff_t end_pos)
2527{
2528	struct nfs_inode *nfsi = NFS_I(inode);
2529	bool mark_as_dirty = false;
2530
2531	spin_lock(&inode->i_lock);
2532	if (!test_and_set_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags)) {
2533		nfsi->layout->plh_lwb = end_pos;
2534		mark_as_dirty = true;
2535		dprintk("%s: Set layoutcommit for inode %lu ",
2536			__func__, inode->i_ino);
2537	} else if (end_pos > nfsi->layout->plh_lwb)
2538		nfsi->layout->plh_lwb = end_pos;
2539	if (!test_and_set_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags)) {
2540		/* references matched in nfs4_layoutcommit_release */
2541		pnfs_get_lseg(lseg);
2542	}
2543	spin_unlock(&inode->i_lock);
2544	dprintk("%s: lseg %p end_pos %llu\n",
2545		__func__, lseg, nfsi->layout->plh_lwb);
2546
2547	/* if pnfs_layoutcommit_inode() runs between inode locks, the next one
2548	 * will be a noop because NFS_INO_LAYOUTCOMMIT will not be set */
2549	if (mark_as_dirty)
2550		mark_inode_dirty_sync(inode);
2551}
2552EXPORT_SYMBOL_GPL(pnfs_set_layoutcommit);
2553
2554void pnfs_cleanup_layoutcommit(struct nfs4_layoutcommit_data *data)
2555{
2556	struct nfs_server *nfss = NFS_SERVER(data->args.inode);
2557
2558	if (nfss->pnfs_curr_ld->cleanup_layoutcommit)
2559		nfss->pnfs_curr_ld->cleanup_layoutcommit(data);
2560	pnfs_list_write_lseg_done(data->args.inode, &data->lseg_list);
2561}
2562
2563/*
2564 * For the LAYOUT4_NFSV4_1_FILES layout type, NFS_DATA_SYNC WRITEs and
2565 * NFS_UNSTABLE WRITEs with a COMMIT to data servers must store enough
2566 * data to disk to allow the server to recover the data if it crashes.
2567 * LAYOUTCOMMIT is only needed when the NFL4_UFLG_COMMIT_THRU_MDS flag
2568 * is off, and a COMMIT is sent to a data server, or
2569 * if WRITEs to a data server return NFS_DATA_SYNC.
2570 */
2571int
2572pnfs_layoutcommit_inode(struct inode *inode, bool sync)
2573{
2574	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
2575	struct nfs4_layoutcommit_data *data;
2576	struct nfs_inode *nfsi = NFS_I(inode);
2577	loff_t end_pos;
2578	int status;
2579
2580	if (!pnfs_layoutcommit_outstanding(inode))
2581		return 0;
2582
2583	dprintk("--> %s inode %lu\n", __func__, inode->i_ino);
2584
2585	status = -EAGAIN;
2586	if (test_and_set_bit(NFS_INO_LAYOUTCOMMITTING, &nfsi->flags)) {
2587		if (!sync)
2588			goto out;
2589		status = wait_on_bit_lock_action(&nfsi->flags,
2590				NFS_INO_LAYOUTCOMMITTING,
2591				nfs_wait_bit_killable,
2592				TASK_KILLABLE);
2593		if (status)
2594			goto out;
2595	}
2596
2597	status = -ENOMEM;
2598	/* Note kzalloc ensures data->res.seq_res.sr_slot == NULL */
2599	data = kzalloc(sizeof(*data), GFP_NOFS);
2600	if (!data)
2601		goto clear_layoutcommitting;
2602
2603	status = 0;
2604	spin_lock(&inode->i_lock);
2605	if (!test_and_clear_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags))
2606		goto out_unlock;
2607
2608	INIT_LIST_HEAD(&data->lseg_list);
2609	pnfs_list_write_lseg(inode, &data->lseg_list);
2610
2611	end_pos = nfsi->layout->plh_lwb;
2612
2613	nfs4_stateid_copy(&data->args.stateid, &nfsi->layout->plh_stateid);
2614	spin_unlock(&inode->i_lock);
2615
2616	data->args.inode = inode;
2617	data->cred = get_rpccred(nfsi->layout->plh_lc_cred);
2618	nfs_fattr_init(&data->fattr);
2619	data->args.bitmask = NFS_SERVER(inode)->cache_consistency_bitmask;
2620	data->res.fattr = &data->fattr;
2621	if (end_pos != 0)
2622		data->args.lastbytewritten = end_pos - 1;
2623	else
2624		data->args.lastbytewritten = U64_MAX;
2625	data->res.server = NFS_SERVER(inode);
2626
2627	if (ld->prepare_layoutcommit) {
2628		status = ld->prepare_layoutcommit(&data->args);
2629		if (status) {
2630			put_rpccred(data->cred);
2631			spin_lock(&inode->i_lock);
2632			set_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags);
2633			if (end_pos > nfsi->layout->plh_lwb)
2634				nfsi->layout->plh_lwb = end_pos;
2635			goto out_unlock;
2636		}
2637	}
2638
2639
2640	status = nfs4_proc_layoutcommit(data, sync);
2641out:
2642	if (status)
2643		mark_inode_dirty_sync(inode);
2644	dprintk("<-- %s status %d\n", __func__, status);
2645	return status;
2646out_unlock:
2647	spin_unlock(&inode->i_lock);
2648	kfree(data);
2649clear_layoutcommitting:
2650	pnfs_clear_layoutcommitting(inode);
2651	goto out;
2652}
2653EXPORT_SYMBOL_GPL(pnfs_layoutcommit_inode);
2654
2655int
2656pnfs_generic_sync(struct inode *inode, bool datasync)
2657{
2658	return pnfs_layoutcommit_inode(inode, true);
2659}
2660EXPORT_SYMBOL_GPL(pnfs_generic_sync);
2661
2662struct nfs4_threshold *pnfs_mdsthreshold_alloc(void)
2663{
2664	struct nfs4_threshold *thp;
2665
2666	thp = kzalloc(sizeof(*thp), GFP_NOFS);
2667	if (!thp) {
2668		dprintk("%s mdsthreshold allocation failed\n", __func__);
2669		return NULL;
2670	}
2671	return thp;
2672}
2673
2674#if IS_ENABLED(CONFIG_NFS_V4_2)
2675int
2676pnfs_report_layoutstat(struct inode *inode, gfp_t gfp_flags)
2677{
2678	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
2679	struct nfs_server *server = NFS_SERVER(inode);
2680	struct nfs_inode *nfsi = NFS_I(inode);
2681	struct nfs42_layoutstat_data *data;
2682	struct pnfs_layout_hdr *hdr;
2683	int status = 0;
2684
2685	if (!pnfs_enabled_sb(server) || !ld->prepare_layoutstats)
2686		goto out;
2687
2688	if (!nfs_server_capable(inode, NFS_CAP_LAYOUTSTATS))
2689		goto out;
2690
2691	if (test_and_set_bit(NFS_INO_LAYOUTSTATS, &nfsi->flags))
2692		goto out;
2693
2694	spin_lock(&inode->i_lock);
2695	if (!NFS_I(inode)->layout) {
2696		spin_unlock(&inode->i_lock);
2697		goto out_clear_layoutstats;
2698	}
2699	hdr = NFS_I(inode)->layout;
2700	pnfs_get_layout_hdr(hdr);
2701	spin_unlock(&inode->i_lock);
2702
2703	data = kzalloc(sizeof(*data), gfp_flags);
2704	if (!data) {
2705		status = -ENOMEM;
2706		goto out_put;
2707	}
2708
2709	data->args.fh = NFS_FH(inode);
2710	data->args.inode = inode;
2711	status = ld->prepare_layoutstats(&data->args);
2712	if (status)
2713		goto out_free;
2714
2715	status = nfs42_proc_layoutstats_generic(NFS_SERVER(inode), data);
2716
2717out:
2718	dprintk("%s returns %d\n", __func__, status);
2719	return status;
2720
2721out_free:
2722	kfree(data);
2723out_put:
2724	pnfs_put_layout_hdr(hdr);
2725out_clear_layoutstats:
2726	smp_mb__before_atomic();
2727	clear_bit(NFS_INO_LAYOUTSTATS, &nfsi->flags);
2728	smp_mb__after_atomic();
2729	goto out;
2730}
2731EXPORT_SYMBOL_GPL(pnfs_report_layoutstat);
2732#endif
2733
2734unsigned int layoutstats_timer;
2735module_param(layoutstats_timer, uint, 0644);
2736EXPORT_SYMBOL_GPL(layoutstats_timer);
v4.10.11
   1/*
   2 *  pNFS functions to call and manage layout drivers.
   3 *
   4 *  Copyright (c) 2002 [year of first publication]
   5 *  The Regents of the University of Michigan
   6 *  All Rights Reserved
   7 *
   8 *  Dean Hildebrand <dhildebz@umich.edu>
   9 *
  10 *  Permission is granted to use, copy, create derivative works, and
  11 *  redistribute this software and such derivative works for any purpose,
  12 *  so long as the name of the University of Michigan is not used in
  13 *  any advertising or publicity pertaining to the use or distribution
  14 *  of this software without specific, written prior authorization. If
  15 *  the above copyright notice or any other identification of the
  16 *  University of Michigan is included in any copy of any portion of
  17 *  this software, then the disclaimer below must also be included.
  18 *
  19 *  This software is provided as is, without representation or warranty
  20 *  of any kind either express or implied, including without limitation
  21 *  the implied warranties of merchantability, fitness for a particular
  22 *  purpose, or noninfringement.  The Regents of the University of
  23 *  Michigan shall not be liable for any damages, including special,
  24 *  indirect, incidental, or consequential damages, with respect to any
  25 *  claim arising out of or in connection with the use of the software,
  26 *  even if it has been or is hereafter advised of the possibility of
  27 *  such damages.
  28 */
  29
  30#include <linux/nfs_fs.h>
  31#include <linux/nfs_page.h>
  32#include <linux/module.h>
  33#include <linux/sort.h>
  34#include "internal.h"
  35#include "pnfs.h"
  36#include "iostat.h"
  37#include "nfs4trace.h"
  38#include "delegation.h"
  39#include "nfs42.h"
  40
  41#define NFSDBG_FACILITY		NFSDBG_PNFS
  42#define PNFS_LAYOUTGET_RETRY_TIMEOUT (120*HZ)
  43
  44/* Locking:
  45 *
  46 * pnfs_spinlock:
  47 *      protects pnfs_modules_tbl.
  48 */
  49static DEFINE_SPINLOCK(pnfs_spinlock);
  50
  51/*
  52 * pnfs_modules_tbl holds all pnfs modules
  53 */
  54static LIST_HEAD(pnfs_modules_tbl);
  55
  56static void pnfs_layoutreturn_before_put_layout_hdr(struct pnfs_layout_hdr *lo);
  57static void pnfs_free_returned_lsegs(struct pnfs_layout_hdr *lo,
  58		struct list_head *free_me,
  59		const struct pnfs_layout_range *range,
  60		u32 seq);
  61static bool pnfs_lseg_dec_and_remove_zero(struct pnfs_layout_segment *lseg,
  62		                struct list_head *tmp_list);
  63
  64/* Return the registered pnfs layout driver module matching given id */
  65static struct pnfs_layoutdriver_type *
  66find_pnfs_driver_locked(u32 id)
  67{
  68	struct pnfs_layoutdriver_type *local;
  69
  70	list_for_each_entry(local, &pnfs_modules_tbl, pnfs_tblid)
  71		if (local->id == id)
  72			goto out;
  73	local = NULL;
  74out:
  75	dprintk("%s: Searching for id %u, found %p\n", __func__, id, local);
  76	return local;
  77}
  78
  79static struct pnfs_layoutdriver_type *
  80find_pnfs_driver(u32 id)
  81{
  82	struct pnfs_layoutdriver_type *local;
  83
  84	spin_lock(&pnfs_spinlock);
  85	local = find_pnfs_driver_locked(id);
  86	if (local != NULL && !try_module_get(local->owner)) {
  87		dprintk("%s: Could not grab reference on module\n", __func__);
  88		local = NULL;
  89	}
  90	spin_unlock(&pnfs_spinlock);
  91	return local;
  92}
  93
  94void
  95unset_pnfs_layoutdriver(struct nfs_server *nfss)
  96{
  97	if (nfss->pnfs_curr_ld) {
  98		if (nfss->pnfs_curr_ld->clear_layoutdriver)
  99			nfss->pnfs_curr_ld->clear_layoutdriver(nfss);
 100		/* Decrement the MDS count. Purge the deviceid cache if zero */
 101		if (atomic_dec_and_test(&nfss->nfs_client->cl_mds_count))
 102			nfs4_deviceid_purge_client(nfss->nfs_client);
 103		module_put(nfss->pnfs_curr_ld->owner);
 104	}
 105	nfss->pnfs_curr_ld = NULL;
 106}
 107
 108/*
 109 * When the server sends a list of layout types, we choose one in the order
 110 * given in the list below.
 111 *
 112 * FIXME: should this list be configurable in some fashion? module param?
 113 * 	  mount option? something else?
 114 */
 115static const u32 ld_prefs[] = {
 116	LAYOUT_SCSI,
 117	LAYOUT_BLOCK_VOLUME,
 118	LAYOUT_OSD2_OBJECTS,
 119	LAYOUT_FLEX_FILES,
 120	LAYOUT_NFSV4_1_FILES,
 121	0
 122};
 123
 124static int
 125ld_cmp(const void *e1, const void *e2)
 126{
 127	u32 ld1 = *((u32 *)e1);
 128	u32 ld2 = *((u32 *)e2);
 129	int i;
 130
 131	for (i = 0; ld_prefs[i] != 0; i++) {
 132		if (ld1 == ld_prefs[i])
 133			return -1;
 134
 135		if (ld2 == ld_prefs[i])
 136			return 1;
 137	}
 138	return 0;
 139}
 140
 141/*
 142 * Try to set the server's pnfs module to the pnfs layout type specified by id.
 143 * Currently only one pNFS layout driver per filesystem is supported.
 144 *
 145 * @ids array of layout types supported by MDS.
 146 */
 147void
 148set_pnfs_layoutdriver(struct nfs_server *server, const struct nfs_fh *mntfh,
 149		      struct nfs_fsinfo *fsinfo)
 150{
 151	struct pnfs_layoutdriver_type *ld_type = NULL;
 152	u32 id;
 153	int i;
 154
 155	if (fsinfo->nlayouttypes == 0)
 156		goto out_no_driver;
 157	if (!(server->nfs_client->cl_exchange_flags &
 158		 (EXCHGID4_FLAG_USE_NON_PNFS | EXCHGID4_FLAG_USE_PNFS_MDS))) {
 159		printk(KERN_ERR "NFS: %s: cl_exchange_flags 0x%x\n",
 160			__func__, server->nfs_client->cl_exchange_flags);
 161		goto out_no_driver;
 162	}
 163
 164	sort(fsinfo->layouttype, fsinfo->nlayouttypes,
 165		sizeof(*fsinfo->layouttype), ld_cmp, NULL);
 166
 167	for (i = 0; i < fsinfo->nlayouttypes; i++) {
 168		id = fsinfo->layouttype[i];
 169		ld_type = find_pnfs_driver(id);
 170		if (!ld_type) {
 171			request_module("%s-%u", LAYOUT_NFSV4_1_MODULE_PREFIX,
 172					id);
 173			ld_type = find_pnfs_driver(id);
 174		}
 175		if (ld_type)
 176			break;
 177	}
 178
 179	if (!ld_type) {
 180		dprintk("%s: No pNFS module found!\n", __func__);
 181		goto out_no_driver;
 182	}
 183
 184	server->pnfs_curr_ld = ld_type;
 185	if (ld_type->set_layoutdriver
 186	    && ld_type->set_layoutdriver(server, mntfh)) {
 187		printk(KERN_ERR "NFS: %s: Error initializing pNFS layout "
 188			"driver %u.\n", __func__, id);
 189		module_put(ld_type->owner);
 190		goto out_no_driver;
 191	}
 192	/* Bump the MDS count */
 193	atomic_inc(&server->nfs_client->cl_mds_count);
 194
 195	dprintk("%s: pNFS module for %u set\n", __func__, id);
 196	return;
 197
 198out_no_driver:
 199	dprintk("%s: Using NFSv4 I/O\n", __func__);
 200	server->pnfs_curr_ld = NULL;
 201}
 202
 203int
 204pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
 205{
 206	int status = -EINVAL;
 207	struct pnfs_layoutdriver_type *tmp;
 208
 209	if (ld_type->id == 0) {
 210		printk(KERN_ERR "NFS: %s id 0 is reserved\n", __func__);
 211		return status;
 212	}
 213	if (!ld_type->alloc_lseg || !ld_type->free_lseg) {
 214		printk(KERN_ERR "NFS: %s Layout driver must provide "
 215		       "alloc_lseg and free_lseg.\n", __func__);
 216		return status;
 217	}
 218
 219	spin_lock(&pnfs_spinlock);
 220	tmp = find_pnfs_driver_locked(ld_type->id);
 221	if (!tmp) {
 222		list_add(&ld_type->pnfs_tblid, &pnfs_modules_tbl);
 223		status = 0;
 224		dprintk("%s Registering id:%u name:%s\n", __func__, ld_type->id,
 225			ld_type->name);
 226	} else {
 227		printk(KERN_ERR "NFS: %s Module with id %d already loaded!\n",
 228			__func__, ld_type->id);
 229	}
 230	spin_unlock(&pnfs_spinlock);
 231
 232	return status;
 233}
 234EXPORT_SYMBOL_GPL(pnfs_register_layoutdriver);
 235
 236void
 237pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
 238{
 239	dprintk("%s Deregistering id:%u\n", __func__, ld_type->id);
 240	spin_lock(&pnfs_spinlock);
 241	list_del(&ld_type->pnfs_tblid);
 242	spin_unlock(&pnfs_spinlock);
 243}
 244EXPORT_SYMBOL_GPL(pnfs_unregister_layoutdriver);
 245
 246/*
 247 * pNFS client layout cache
 248 */
 249
 250/* Need to hold i_lock if caller does not already hold reference */
 251void
 252pnfs_get_layout_hdr(struct pnfs_layout_hdr *lo)
 253{
 254	atomic_inc(&lo->plh_refcount);
 255}
 256
 257static struct pnfs_layout_hdr *
 258pnfs_alloc_layout_hdr(struct inode *ino, gfp_t gfp_flags)
 259{
 260	struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
 261	return ld->alloc_layout_hdr(ino, gfp_flags);
 262}
 263
 264static void
 265pnfs_free_layout_hdr(struct pnfs_layout_hdr *lo)
 266{
 267	struct nfs_server *server = NFS_SERVER(lo->plh_inode);
 268	struct pnfs_layoutdriver_type *ld = server->pnfs_curr_ld;
 269
 270	if (!list_empty(&lo->plh_layouts)) {
 271		struct nfs_client *clp = server->nfs_client;
 272
 273		spin_lock(&clp->cl_lock);
 274		list_del_init(&lo->plh_layouts);
 275		spin_unlock(&clp->cl_lock);
 276	}
 277	put_rpccred(lo->plh_lc_cred);
 278	return ld->free_layout_hdr(lo);
 279}
 280
 281static void
 282pnfs_detach_layout_hdr(struct pnfs_layout_hdr *lo)
 283{
 284	struct nfs_inode *nfsi = NFS_I(lo->plh_inode);
 285	dprintk("%s: freeing layout cache %p\n", __func__, lo);
 286	nfsi->layout = NULL;
 287	/* Reset MDS Threshold I/O counters */
 288	nfsi->write_io = 0;
 289	nfsi->read_io = 0;
 290}
 291
 292void
 293pnfs_put_layout_hdr(struct pnfs_layout_hdr *lo)
 294{
 295	struct inode *inode = lo->plh_inode;
 296
 
 
 
 297	pnfs_layoutreturn_before_put_layout_hdr(lo);
 298
 299	if (atomic_dec_and_lock(&lo->plh_refcount, &inode->i_lock)) {
 300		if (!list_empty(&lo->plh_segs))
 301			WARN_ONCE(1, "NFS: BUG unfreed layout segments.\n");
 302		pnfs_detach_layout_hdr(lo);
 303		spin_unlock(&inode->i_lock);
 304		pnfs_free_layout_hdr(lo);
 305	}
 306}
 307
 308static void
 309pnfs_set_plh_return_info(struct pnfs_layout_hdr *lo, enum pnfs_iomode iomode,
 310			 u32 seq)
 311{
 312	if (lo->plh_return_iomode != 0 && lo->plh_return_iomode != iomode)
 313		iomode = IOMODE_ANY;
 314	lo->plh_return_iomode = iomode;
 315	set_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags);
 316	if (seq != 0) {
 317		WARN_ON_ONCE(lo->plh_return_seq != 0 && lo->plh_return_seq != seq);
 318		lo->plh_return_seq = seq;
 319	}
 320}
 321
 322static void
 323pnfs_clear_layoutreturn_info(struct pnfs_layout_hdr *lo)
 324{
 
 325	lo->plh_return_iomode = 0;
 326	lo->plh_return_seq = 0;
 327	clear_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags);
 
 
 
 
 
 328}
 329
 330static void pnfs_clear_layoutreturn_waitbit(struct pnfs_layout_hdr *lo)
 331{
 332	clear_bit_unlock(NFS_LAYOUT_RETURN, &lo->plh_flags);
 333	clear_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags);
 334	smp_mb__after_atomic();
 335	wake_up_bit(&lo->plh_flags, NFS_LAYOUT_RETURN);
 336	rpc_wake_up(&NFS_SERVER(lo->plh_inode)->roc_rpcwaitq);
 337}
 338
 339static void
 340pnfs_clear_lseg_state(struct pnfs_layout_segment *lseg,
 341		struct list_head *free_me)
 342{
 343	clear_bit(NFS_LSEG_ROC, &lseg->pls_flags);
 344	clear_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
 345	if (test_and_clear_bit(NFS_LSEG_VALID, &lseg->pls_flags))
 346		pnfs_lseg_dec_and_remove_zero(lseg, free_me);
 347	if (test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
 348		pnfs_lseg_dec_and_remove_zero(lseg, free_me);
 349}
 350
 351/*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 352 * Mark a pnfs_layout_hdr and all associated layout segments as invalid
 353 *
 354 * In order to continue using the pnfs_layout_hdr, a full recovery
 355 * is required.
 356 * Note that caller must hold inode->i_lock.
 357 */
 358int
 359pnfs_mark_layout_stateid_invalid(struct pnfs_layout_hdr *lo,
 360		struct list_head *lseg_list)
 361{
 362	struct pnfs_layout_range range = {
 363		.iomode = IOMODE_ANY,
 364		.offset = 0,
 365		.length = NFS4_MAX_UINT64,
 366	};
 367	struct pnfs_layout_segment *lseg, *next;
 368
 369	set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
 370	pnfs_clear_layoutreturn_info(lo);
 371	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
 372		pnfs_clear_lseg_state(lseg, lseg_list);
 
 373	pnfs_free_returned_lsegs(lo, lseg_list, &range, 0);
 374	if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags) &&
 375	    !test_and_set_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags))
 376		pnfs_clear_layoutreturn_waitbit(lo);
 377	return !list_empty(&lo->plh_segs);
 378}
 379
 380static int
 381pnfs_iomode_to_fail_bit(u32 iomode)
 382{
 383	return iomode == IOMODE_RW ?
 384		NFS_LAYOUT_RW_FAILED : NFS_LAYOUT_RO_FAILED;
 385}
 386
 387static void
 388pnfs_layout_set_fail_bit(struct pnfs_layout_hdr *lo, int fail_bit)
 389{
 390	lo->plh_retry_timestamp = jiffies;
 391	if (!test_and_set_bit(fail_bit, &lo->plh_flags))
 392		atomic_inc(&lo->plh_refcount);
 393}
 394
 395static void
 396pnfs_layout_clear_fail_bit(struct pnfs_layout_hdr *lo, int fail_bit)
 397{
 398	if (test_and_clear_bit(fail_bit, &lo->plh_flags))
 399		atomic_dec(&lo->plh_refcount);
 400}
 401
 402static void
 403pnfs_layout_io_set_failed(struct pnfs_layout_hdr *lo, u32 iomode)
 404{
 405	struct inode *inode = lo->plh_inode;
 406	struct pnfs_layout_range range = {
 407		.iomode = iomode,
 408		.offset = 0,
 409		.length = NFS4_MAX_UINT64,
 410	};
 411	LIST_HEAD(head);
 412
 413	spin_lock(&inode->i_lock);
 414	pnfs_layout_set_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
 415	pnfs_mark_matching_lsegs_invalid(lo, &head, &range, 0);
 416	spin_unlock(&inode->i_lock);
 417	pnfs_free_lseg_list(&head);
 418	dprintk("%s Setting layout IOMODE_%s fail bit\n", __func__,
 419			iomode == IOMODE_RW ?  "RW" : "READ");
 420}
 421
 422static bool
 423pnfs_layout_io_test_failed(struct pnfs_layout_hdr *lo, u32 iomode)
 424{
 425	unsigned long start, end;
 426	int fail_bit = pnfs_iomode_to_fail_bit(iomode);
 427
 428	if (test_bit(fail_bit, &lo->plh_flags) == 0)
 429		return false;
 430	end = jiffies;
 431	start = end - PNFS_LAYOUTGET_RETRY_TIMEOUT;
 432	if (!time_in_range(lo->plh_retry_timestamp, start, end)) {
 433		/* It is time to retry the failed layoutgets */
 434		pnfs_layout_clear_fail_bit(lo, fail_bit);
 435		return false;
 436	}
 437	return true;
 438}
 439
 440static void
 441pnfs_init_lseg(struct pnfs_layout_hdr *lo, struct pnfs_layout_segment *lseg,
 442		const struct pnfs_layout_range *range,
 443		const nfs4_stateid *stateid)
 444{
 445	INIT_LIST_HEAD(&lseg->pls_list);
 446	INIT_LIST_HEAD(&lseg->pls_lc_list);
 447	atomic_set(&lseg->pls_refcount, 1);
 448	set_bit(NFS_LSEG_VALID, &lseg->pls_flags);
 449	lseg->pls_layout = lo;
 450	lseg->pls_range = *range;
 451	lseg->pls_seq = be32_to_cpu(stateid->seqid);
 452}
 453
 454static void pnfs_free_lseg(struct pnfs_layout_segment *lseg)
 455{
 456	if (lseg != NULL) {
 457		struct inode *inode = lseg->pls_layout->plh_inode;
 458		NFS_SERVER(inode)->pnfs_curr_ld->free_lseg(lseg);
 459	}
 460}
 461
 462static void
 463pnfs_layout_remove_lseg(struct pnfs_layout_hdr *lo,
 464		struct pnfs_layout_segment *lseg)
 465{
 466	WARN_ON(test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
 467	list_del_init(&lseg->pls_list);
 468	/* Matched by pnfs_get_layout_hdr in pnfs_layout_insert_lseg */
 469	atomic_dec(&lo->plh_refcount);
 470	if (test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
 471		return;
 472	if (list_empty(&lo->plh_segs) &&
 473	    !test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags) &&
 474	    !test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
 475		if (atomic_read(&lo->plh_outstanding) == 0)
 476			set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
 477		clear_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
 478	}
 479}
 480
 481static bool
 482pnfs_cache_lseg_for_layoutreturn(struct pnfs_layout_hdr *lo,
 483		struct pnfs_layout_segment *lseg)
 484{
 485	if (test_and_clear_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags) &&
 486	    pnfs_layout_is_valid(lo)) {
 487		pnfs_set_plh_return_info(lo, lseg->pls_range.iomode, 0);
 488		list_move_tail(&lseg->pls_list, &lo->plh_return_segs);
 489		return true;
 490	}
 491	return false;
 492}
 493
 494void
 495pnfs_put_lseg(struct pnfs_layout_segment *lseg)
 496{
 497	struct pnfs_layout_hdr *lo;
 498	struct inode *inode;
 499
 500	if (!lseg)
 501		return;
 502
 503	dprintk("%s: lseg %p ref %d valid %d\n", __func__, lseg,
 504		atomic_read(&lseg->pls_refcount),
 505		test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
 506
 507	lo = lseg->pls_layout;
 508	inode = lo->plh_inode;
 509
 510	if (atomic_dec_and_lock(&lseg->pls_refcount, &inode->i_lock)) {
 511		if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags)) {
 512			spin_unlock(&inode->i_lock);
 513			return;
 514		}
 515		pnfs_get_layout_hdr(lo);
 516		pnfs_layout_remove_lseg(lo, lseg);
 517		if (pnfs_cache_lseg_for_layoutreturn(lo, lseg))
 518			lseg = NULL;
 519		spin_unlock(&inode->i_lock);
 520		pnfs_free_lseg(lseg);
 521		pnfs_put_layout_hdr(lo);
 522	}
 523}
 524EXPORT_SYMBOL_GPL(pnfs_put_lseg);
 525
 526static void pnfs_free_lseg_async_work(struct work_struct *work)
 527{
 528	struct pnfs_layout_segment *lseg;
 529	struct pnfs_layout_hdr *lo;
 530
 531	lseg = container_of(work, struct pnfs_layout_segment, pls_work);
 532	lo = lseg->pls_layout;
 533
 534	pnfs_free_lseg(lseg);
 535	pnfs_put_layout_hdr(lo);
 536}
 537
 538static void pnfs_free_lseg_async(struct pnfs_layout_segment *lseg)
 539{
 540	INIT_WORK(&lseg->pls_work, pnfs_free_lseg_async_work);
 541	schedule_work(&lseg->pls_work);
 542}
 543
 544void
 545pnfs_put_lseg_locked(struct pnfs_layout_segment *lseg)
 546{
 547	if (!lseg)
 548		return;
 549
 550	assert_spin_locked(&lseg->pls_layout->plh_inode->i_lock);
 551
 552	dprintk("%s: lseg %p ref %d valid %d\n", __func__, lseg,
 553		atomic_read(&lseg->pls_refcount),
 554		test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
 555	if (atomic_dec_and_test(&lseg->pls_refcount)) {
 556		struct pnfs_layout_hdr *lo = lseg->pls_layout;
 557		if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags))
 558			return;
 559		pnfs_layout_remove_lseg(lo, lseg);
 560		if (!pnfs_cache_lseg_for_layoutreturn(lo, lseg)) {
 561			pnfs_get_layout_hdr(lo);
 562			pnfs_free_lseg_async(lseg);
 563		}
 564	}
 565}
 566EXPORT_SYMBOL_GPL(pnfs_put_lseg_locked);
 567
 568/*
 569 * is l2 fully contained in l1?
 570 *   start1                             end1
 571 *   [----------------------------------)
 572 *           start2           end2
 573 *           [----------------)
 574 */
 575static bool
 576pnfs_lseg_range_contained(const struct pnfs_layout_range *l1,
 577		 const struct pnfs_layout_range *l2)
 578{
 579	u64 start1 = l1->offset;
 580	u64 end1 = pnfs_end_offset(start1, l1->length);
 581	u64 start2 = l2->offset;
 582	u64 end2 = pnfs_end_offset(start2, l2->length);
 583
 584	return (start1 <= start2) && (end1 >= end2);
 585}
 586
 587static bool pnfs_lseg_dec_and_remove_zero(struct pnfs_layout_segment *lseg,
 588		struct list_head *tmp_list)
 589{
 590	if (!atomic_dec_and_test(&lseg->pls_refcount))
 591		return false;
 592	pnfs_layout_remove_lseg(lseg->pls_layout, lseg);
 593	list_add(&lseg->pls_list, tmp_list);
 594	return true;
 595}
 596
 597/* Returns 1 if lseg is removed from list, 0 otherwise */
 598static int mark_lseg_invalid(struct pnfs_layout_segment *lseg,
 599			     struct list_head *tmp_list)
 600{
 601	int rv = 0;
 602
 603	if (test_and_clear_bit(NFS_LSEG_VALID, &lseg->pls_flags)) {
 604		/* Remove the reference keeping the lseg in the
 605		 * list.  It will now be removed when all
 606		 * outstanding io is finished.
 607		 */
 608		dprintk("%s: lseg %p ref %d\n", __func__, lseg,
 609			atomic_read(&lseg->pls_refcount));
 610		if (pnfs_lseg_dec_and_remove_zero(lseg, tmp_list))
 611			rv = 1;
 612	}
 613	return rv;
 614}
 615
 616/*
 617 * Compare 2 layout stateid sequence ids, to see which is newer,
 618 * taking into account wraparound issues.
 619 */
 620static bool pnfs_seqid_is_newer(u32 s1, u32 s2)
 621{
 622	return (s32)(s1 - s2) > 0;
 623}
 624
 625static bool
 626pnfs_should_free_range(const struct pnfs_layout_range *lseg_range,
 627		 const struct pnfs_layout_range *recall_range)
 628{
 629	return (recall_range->iomode == IOMODE_ANY ||
 630		lseg_range->iomode == recall_range->iomode) &&
 631	       pnfs_lseg_range_intersecting(lseg_range, recall_range);
 632}
 633
 634static bool
 635pnfs_match_lseg_recall(const struct pnfs_layout_segment *lseg,
 636		const struct pnfs_layout_range *recall_range,
 637		u32 seq)
 638{
 639	if (seq != 0 && pnfs_seqid_is_newer(lseg->pls_seq, seq))
 640		return false;
 641	if (recall_range == NULL)
 642		return true;
 643	return pnfs_should_free_range(&lseg->pls_range, recall_range);
 644}
 645
 646/**
 647 * pnfs_mark_matching_lsegs_invalid - tear down lsegs or mark them for later
 648 * @lo: layout header containing the lsegs
 649 * @tmp_list: list head where doomed lsegs should go
 650 * @recall_range: optional recall range argument to match (may be NULL)
 651 * @seq: only invalidate lsegs obtained prior to this sequence (may be 0)
 652 *
 653 * Walk the list of lsegs in the layout header, and tear down any that should
 654 * be destroyed. If "recall_range" is specified then the segment must match
 655 * that range. If "seq" is non-zero, then only match segments that were handed
 656 * out at or before that sequence.
 657 *
 658 * Returns number of matching invalid lsegs remaining in list after scanning
 659 * it and purging them.
 660 */
 661int
 662pnfs_mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo,
 663			    struct list_head *tmp_list,
 664			    const struct pnfs_layout_range *recall_range,
 665			    u32 seq)
 666{
 667	struct pnfs_layout_segment *lseg, *next;
 668	int remaining = 0;
 669
 670	dprintk("%s:Begin lo %p\n", __func__, lo);
 671
 672	if (list_empty(&lo->plh_segs))
 673		return 0;
 674	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
 675		if (pnfs_match_lseg_recall(lseg, recall_range, seq)) {
 676			dprintk("%s: freeing lseg %p iomode %d seq %u"
 677				"offset %llu length %llu\n", __func__,
 678				lseg, lseg->pls_range.iomode, lseg->pls_seq,
 679				lseg->pls_range.offset, lseg->pls_range.length);
 680			if (!mark_lseg_invalid(lseg, tmp_list))
 681				remaining++;
 682		}
 683	dprintk("%s:Return %i\n", __func__, remaining);
 684	return remaining;
 685}
 686
 687static void
 688pnfs_free_returned_lsegs(struct pnfs_layout_hdr *lo,
 689		struct list_head *free_me,
 690		const struct pnfs_layout_range *range,
 691		u32 seq)
 692{
 693	struct pnfs_layout_segment *lseg, *next;
 694
 695	list_for_each_entry_safe(lseg, next, &lo->plh_return_segs, pls_list) {
 696		if (pnfs_match_lseg_recall(lseg, range, seq))
 697			list_move_tail(&lseg->pls_list, free_me);
 698	}
 699}
 700
 701/* note free_me must contain lsegs from a single layout_hdr */
 702void
 703pnfs_free_lseg_list(struct list_head *free_me)
 704{
 705	struct pnfs_layout_segment *lseg, *tmp;
 706
 707	if (list_empty(free_me))
 708		return;
 709
 710	list_for_each_entry_safe(lseg, tmp, free_me, pls_list) {
 711		list_del(&lseg->pls_list);
 712		pnfs_free_lseg(lseg);
 713	}
 714}
 715
 716void
 717pnfs_destroy_layout(struct nfs_inode *nfsi)
 718{
 719	struct pnfs_layout_hdr *lo;
 720	LIST_HEAD(tmp_list);
 721
 722	spin_lock(&nfsi->vfs_inode.i_lock);
 723	lo = nfsi->layout;
 724	if (lo) {
 725		pnfs_get_layout_hdr(lo);
 726		pnfs_mark_layout_stateid_invalid(lo, &tmp_list);
 727		pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RO_FAILED);
 728		pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RW_FAILED);
 729		spin_unlock(&nfsi->vfs_inode.i_lock);
 730		pnfs_free_lseg_list(&tmp_list);
 
 731		pnfs_put_layout_hdr(lo);
 732	} else
 733		spin_unlock(&nfsi->vfs_inode.i_lock);
 734}
 735EXPORT_SYMBOL_GPL(pnfs_destroy_layout);
 736
 737static bool
 738pnfs_layout_add_bulk_destroy_list(struct inode *inode,
 739		struct list_head *layout_list)
 740{
 741	struct pnfs_layout_hdr *lo;
 742	bool ret = false;
 743
 744	spin_lock(&inode->i_lock);
 745	lo = NFS_I(inode)->layout;
 746	if (lo != NULL && list_empty(&lo->plh_bulk_destroy)) {
 747		pnfs_get_layout_hdr(lo);
 748		list_add(&lo->plh_bulk_destroy, layout_list);
 749		ret = true;
 750	}
 751	spin_unlock(&inode->i_lock);
 752	return ret;
 753}
 754
 755/* Caller must hold rcu_read_lock and clp->cl_lock */
 756static int
 757pnfs_layout_bulk_destroy_byserver_locked(struct nfs_client *clp,
 758		struct nfs_server *server,
 759		struct list_head *layout_list)
 760{
 761	struct pnfs_layout_hdr *lo, *next;
 762	struct inode *inode;
 763
 764	list_for_each_entry_safe(lo, next, &server->layouts, plh_layouts) {
 765		if (test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags))
 766			continue;
 767		inode = igrab(lo->plh_inode);
 768		if (inode == NULL)
 769			continue;
 770		list_del_init(&lo->plh_layouts);
 771		if (pnfs_layout_add_bulk_destroy_list(inode, layout_list))
 772			continue;
 773		rcu_read_unlock();
 774		spin_unlock(&clp->cl_lock);
 775		iput(inode);
 776		spin_lock(&clp->cl_lock);
 777		rcu_read_lock();
 778		return -EAGAIN;
 779	}
 780	return 0;
 781}
 782
 783static int
 784pnfs_layout_free_bulk_destroy_list(struct list_head *layout_list,
 785		bool is_bulk_recall)
 786{
 787	struct pnfs_layout_hdr *lo;
 788	struct inode *inode;
 789	LIST_HEAD(lseg_list);
 790	int ret = 0;
 791
 792	while (!list_empty(layout_list)) {
 793		lo = list_entry(layout_list->next, struct pnfs_layout_hdr,
 794				plh_bulk_destroy);
 795		dprintk("%s freeing layout for inode %lu\n", __func__,
 796			lo->plh_inode->i_ino);
 797		inode = lo->plh_inode;
 798
 799		pnfs_layoutcommit_inode(inode, false);
 800
 801		spin_lock(&inode->i_lock);
 802		list_del_init(&lo->plh_bulk_destroy);
 803		if (pnfs_mark_layout_stateid_invalid(lo, &lseg_list)) {
 804			if (is_bulk_recall)
 805				set_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
 806			ret = -EAGAIN;
 807		}
 808		spin_unlock(&inode->i_lock);
 809		pnfs_free_lseg_list(&lseg_list);
 810		/* Free all lsegs that are attached to commit buckets */
 811		nfs_commit_inode(inode, 0);
 812		pnfs_put_layout_hdr(lo);
 813		iput(inode);
 814	}
 815	return ret;
 816}
 817
 818int
 819pnfs_destroy_layouts_byfsid(struct nfs_client *clp,
 820		struct nfs_fsid *fsid,
 821		bool is_recall)
 822{
 823	struct nfs_server *server;
 824	LIST_HEAD(layout_list);
 825
 826	spin_lock(&clp->cl_lock);
 827	rcu_read_lock();
 828restart:
 829	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 830		if (memcmp(&server->fsid, fsid, sizeof(*fsid)) != 0)
 831			continue;
 832		if (pnfs_layout_bulk_destroy_byserver_locked(clp,
 833				server,
 834				&layout_list) != 0)
 835			goto restart;
 836	}
 837	rcu_read_unlock();
 838	spin_unlock(&clp->cl_lock);
 839
 840	if (list_empty(&layout_list))
 841		return 0;
 842	return pnfs_layout_free_bulk_destroy_list(&layout_list, is_recall);
 843}
 844
 845int
 846pnfs_destroy_layouts_byclid(struct nfs_client *clp,
 847		bool is_recall)
 848{
 849	struct nfs_server *server;
 850	LIST_HEAD(layout_list);
 851
 852	spin_lock(&clp->cl_lock);
 853	rcu_read_lock();
 854restart:
 855	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 856		if (pnfs_layout_bulk_destroy_byserver_locked(clp,
 857					server,
 858					&layout_list) != 0)
 859			goto restart;
 860	}
 861	rcu_read_unlock();
 862	spin_unlock(&clp->cl_lock);
 863
 864	if (list_empty(&layout_list))
 865		return 0;
 866	return pnfs_layout_free_bulk_destroy_list(&layout_list, is_recall);
 867}
 868
 869/*
 870 * Called by the state manger to remove all layouts established under an
 871 * expired lease.
 872 */
 873void
 874pnfs_destroy_all_layouts(struct nfs_client *clp)
 875{
 876	nfs4_deviceid_mark_client_invalid(clp);
 877	nfs4_deviceid_purge_client(clp);
 878
 879	pnfs_destroy_layouts_byclid(clp, false);
 880}
 881
 882/* update lo->plh_stateid with new if is more recent */
 883void
 884pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo, const nfs4_stateid *new,
 885			bool update_barrier)
 886{
 887	u32 oldseq, newseq, new_barrier = 0;
 888
 889	oldseq = be32_to_cpu(lo->plh_stateid.seqid);
 890	newseq = be32_to_cpu(new->seqid);
 891
 892	if (!pnfs_layout_is_valid(lo)) {
 893		nfs4_stateid_copy(&lo->plh_stateid, new);
 894		lo->plh_barrier = newseq;
 895		pnfs_clear_layoutreturn_info(lo);
 896		clear_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
 897		return;
 898	}
 899	if (pnfs_seqid_is_newer(newseq, oldseq)) {
 900		nfs4_stateid_copy(&lo->plh_stateid, new);
 901		/*
 902		 * Because of wraparound, we want to keep the barrier
 903		 * "close" to the current seqids.
 904		 */
 905		new_barrier = newseq - atomic_read(&lo->plh_outstanding);
 906	}
 907	if (update_barrier)
 908		new_barrier = be32_to_cpu(new->seqid);
 909	else if (new_barrier == 0)
 910		return;
 911	if (pnfs_seqid_is_newer(new_barrier, lo->plh_barrier))
 912		lo->plh_barrier = new_barrier;
 913}
 914
 915static bool
 916pnfs_layout_stateid_blocked(const struct pnfs_layout_hdr *lo,
 917		const nfs4_stateid *stateid)
 918{
 919	u32 seqid = be32_to_cpu(stateid->seqid);
 920
 921	return !pnfs_seqid_is_newer(seqid, lo->plh_barrier);
 922}
 923
 924/* lget is set to 1 if called from inside send_layoutget call chain */
 925static bool
 926pnfs_layoutgets_blocked(const struct pnfs_layout_hdr *lo)
 927{
 928	return lo->plh_block_lgets ||
 929		test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
 930}
 931
 932/*
 933 * Get layout from server.
 934 *    for now, assume that whole file layouts are requested.
 935 *    arg->offset: 0
 936 *    arg->length: all ones
 937 */
 938static struct pnfs_layout_segment *
 939send_layoutget(struct pnfs_layout_hdr *lo,
 940	   struct nfs_open_context *ctx,
 941	   nfs4_stateid *stateid,
 942	   const struct pnfs_layout_range *range,
 943	   long *timeout, gfp_t gfp_flags)
 944{
 945	struct inode *ino = lo->plh_inode;
 946	struct nfs_server *server = NFS_SERVER(ino);
 947	struct nfs4_layoutget *lgp;
 948	loff_t i_size;
 949
 950	dprintk("--> %s\n", __func__);
 951
 952	/*
 953	 * Synchronously retrieve layout information from server and
 954	 * store in lseg. If we race with a concurrent seqid morphing
 955	 * op, then re-send the LAYOUTGET.
 956	 */
 957	lgp = kzalloc(sizeof(*lgp), gfp_flags);
 958	if (lgp == NULL)
 959		return ERR_PTR(-ENOMEM);
 960
 961	i_size = i_size_read(ino);
 962
 963	lgp->args.minlength = PAGE_SIZE;
 964	if (lgp->args.minlength > range->length)
 965		lgp->args.minlength = range->length;
 966	if (range->iomode == IOMODE_READ) {
 967		if (range->offset >= i_size)
 968			lgp->args.minlength = 0;
 969		else if (i_size - range->offset < lgp->args.minlength)
 970			lgp->args.minlength = i_size - range->offset;
 971	}
 972	lgp->args.maxcount = PNFS_LAYOUT_MAXSIZE;
 973	pnfs_copy_range(&lgp->args.range, range);
 974	lgp->args.type = server->pnfs_curr_ld->id;
 975	lgp->args.inode = ino;
 976	lgp->args.ctx = get_nfs_open_context(ctx);
 977	nfs4_stateid_copy(&lgp->args.stateid, stateid);
 978	lgp->gfp_flags = gfp_flags;
 979	lgp->cred = lo->plh_lc_cred;
 980
 981	return nfs4_proc_layoutget(lgp, timeout, gfp_flags);
 982}
 983
 984static void pnfs_clear_layoutcommit(struct inode *inode,
 985		struct list_head *head)
 986{
 987	struct nfs_inode *nfsi = NFS_I(inode);
 988	struct pnfs_layout_segment *lseg, *tmp;
 989
 990	if (!test_and_clear_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags))
 991		return;
 992	list_for_each_entry_safe(lseg, tmp, &nfsi->layout->plh_segs, pls_list) {
 993		if (!test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
 994			continue;
 995		pnfs_lseg_dec_and_remove_zero(lseg, head);
 996	}
 997}
 998
 999void pnfs_layoutreturn_free_lsegs(struct pnfs_layout_hdr *lo,
1000		const nfs4_stateid *arg_stateid,
1001		const struct pnfs_layout_range *range,
1002		const nfs4_stateid *stateid)
1003{
1004	struct inode *inode = lo->plh_inode;
1005	LIST_HEAD(freeme);
1006
1007	spin_lock(&inode->i_lock);
1008	if (!pnfs_layout_is_valid(lo) || !arg_stateid ||
1009	    !nfs4_stateid_match_other(&lo->plh_stateid, arg_stateid))
1010		goto out_unlock;
1011	if (stateid) {
1012		u32 seq = be32_to_cpu(arg_stateid->seqid);
1013
1014		pnfs_mark_matching_lsegs_invalid(lo, &freeme, range, seq);
1015		pnfs_free_returned_lsegs(lo, &freeme, range, seq);
1016		pnfs_set_layout_stateid(lo, stateid, true);
1017	} else
1018		pnfs_mark_layout_stateid_invalid(lo, &freeme);
1019out_unlock:
1020	pnfs_clear_layoutreturn_waitbit(lo);
1021	spin_unlock(&inode->i_lock);
1022	pnfs_free_lseg_list(&freeme);
1023
1024}
1025
1026static bool
1027pnfs_prepare_layoutreturn(struct pnfs_layout_hdr *lo,
1028		nfs4_stateid *stateid,
1029		enum pnfs_iomode *iomode)
1030{
1031	/* Serialise LAYOUTGET/LAYOUTRETURN */
1032	if (atomic_read(&lo->plh_outstanding) != 0)
1033		return false;
1034	if (test_and_set_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags))
1035		return false;
1036	set_bit(NFS_LAYOUT_RETURN, &lo->plh_flags);
1037	pnfs_get_layout_hdr(lo);
1038	if (test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags)) {
1039		if (stateid != NULL) {
1040			nfs4_stateid_copy(stateid, &lo->plh_stateid);
1041			if (lo->plh_return_seq != 0)
1042				stateid->seqid = cpu_to_be32(lo->plh_return_seq);
1043		}
1044		if (iomode != NULL)
1045			*iomode = lo->plh_return_iomode;
1046		pnfs_clear_layoutreturn_info(lo);
1047		return true;
1048	}
1049	if (stateid != NULL)
1050		nfs4_stateid_copy(stateid, &lo->plh_stateid);
1051	if (iomode != NULL)
1052		*iomode = IOMODE_ANY;
1053	return true;
1054}
1055
1056static void
1057pnfs_init_layoutreturn_args(struct nfs4_layoutreturn_args *args,
1058		struct pnfs_layout_hdr *lo,
1059		const nfs4_stateid *stateid,
1060		enum pnfs_iomode iomode)
1061{
1062	struct inode *inode = lo->plh_inode;
1063
1064	args->layout_type = NFS_SERVER(inode)->pnfs_curr_ld->id;
1065	args->inode = inode;
1066	args->range.iomode = iomode;
1067	args->range.offset = 0;
1068	args->range.length = NFS4_MAX_UINT64;
1069	args->layout = lo;
1070	nfs4_stateid_copy(&args->stateid, stateid);
1071}
1072
1073static int
1074pnfs_send_layoutreturn(struct pnfs_layout_hdr *lo, const nfs4_stateid *stateid,
1075		       enum pnfs_iomode iomode, bool sync)
1076{
1077	struct inode *ino = lo->plh_inode;
1078	struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
1079	struct nfs4_layoutreturn *lrp;
1080	int status = 0;
1081
1082	lrp = kzalloc(sizeof(*lrp), GFP_NOFS);
1083	if (unlikely(lrp == NULL)) {
1084		status = -ENOMEM;
1085		spin_lock(&ino->i_lock);
1086		pnfs_clear_layoutreturn_waitbit(lo);
1087		spin_unlock(&ino->i_lock);
1088		pnfs_put_layout_hdr(lo);
1089		goto out;
1090	}
1091
1092	pnfs_init_layoutreturn_args(&lrp->args, lo, stateid, iomode);
1093	lrp->args.ld_private = &lrp->ld_private;
1094	lrp->clp = NFS_SERVER(ino)->nfs_client;
1095	lrp->cred = lo->plh_lc_cred;
1096	if (ld->prepare_layoutreturn)
1097		ld->prepare_layoutreturn(&lrp->args);
1098
1099	status = nfs4_proc_layoutreturn(lrp, sync);
1100out:
1101	dprintk("<-- %s status: %d\n", __func__, status);
1102	return status;
1103}
1104
1105/* Return true if layoutreturn is needed */
1106static bool
1107pnfs_layout_need_return(struct pnfs_layout_hdr *lo)
1108{
1109	struct pnfs_layout_segment *s;
1110
1111	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
1112		return false;
1113
1114	/* Defer layoutreturn until all lsegs are done */
1115	list_for_each_entry(s, &lo->plh_segs, pls_list) {
1116		if (test_bit(NFS_LSEG_LAYOUTRETURN, &s->pls_flags))
1117			return false;
1118	}
1119
1120	return true;
1121}
1122
1123static void pnfs_layoutreturn_before_put_layout_hdr(struct pnfs_layout_hdr *lo)
1124{
1125	struct inode *inode= lo->plh_inode;
1126
1127	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
1128		return;
1129	spin_lock(&inode->i_lock);
1130	if (pnfs_layout_need_return(lo)) {
1131		nfs4_stateid stateid;
1132		enum pnfs_iomode iomode;
1133		bool send;
1134
1135		send = pnfs_prepare_layoutreturn(lo, &stateid, &iomode);
1136		spin_unlock(&inode->i_lock);
1137		if (send) {
1138			/* Send an async layoutreturn so we dont deadlock */
1139			pnfs_send_layoutreturn(lo, &stateid, iomode, false);
1140		}
1141	} else
1142		spin_unlock(&inode->i_lock);
1143}
1144
1145/*
1146 * Initiates a LAYOUTRETURN(FILE), and removes the pnfs_layout_hdr
1147 * when the layout segment list is empty.
1148 *
1149 * Note that a pnfs_layout_hdr can exist with an empty layout segment
1150 * list when LAYOUTGET has failed, or when LAYOUTGET succeeded, but the
1151 * deviceid is marked invalid.
1152 */
1153int
1154_pnfs_return_layout(struct inode *ino)
1155{
1156	struct pnfs_layout_hdr *lo = NULL;
1157	struct nfs_inode *nfsi = NFS_I(ino);
1158	LIST_HEAD(tmp_list);
1159	nfs4_stateid stateid;
1160	int status = 0;
1161	bool send;
1162
1163	dprintk("NFS: %s for inode %lu\n", __func__, ino->i_ino);
1164
1165	spin_lock(&ino->i_lock);
1166	lo = nfsi->layout;
1167	if (!lo) {
1168		spin_unlock(&ino->i_lock);
1169		dprintk("NFS: %s no layout to return\n", __func__);
1170		goto out;
1171	}
1172	/* Reference matched in nfs4_layoutreturn_release */
1173	pnfs_get_layout_hdr(lo);
1174	/* Is there an outstanding layoutreturn ? */
1175	if (test_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags)) {
1176		spin_unlock(&ino->i_lock);
1177		if (wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN,
1178					TASK_UNINTERRUPTIBLE))
1179			goto out_put_layout_hdr;
1180		spin_lock(&ino->i_lock);
1181	}
1182	pnfs_clear_layoutcommit(ino, &tmp_list);
1183	pnfs_mark_matching_lsegs_invalid(lo, &tmp_list, NULL, 0);
1184
1185	if (NFS_SERVER(ino)->pnfs_curr_ld->return_range) {
1186		struct pnfs_layout_range range = {
1187			.iomode		= IOMODE_ANY,
1188			.offset		= 0,
1189			.length		= NFS4_MAX_UINT64,
1190		};
1191		NFS_SERVER(ino)->pnfs_curr_ld->return_range(lo, &range);
1192	}
1193
1194	/* Don't send a LAYOUTRETURN if list was initially empty */
1195	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags)) {
1196		spin_unlock(&ino->i_lock);
1197		dprintk("NFS: %s no layout segments to return\n", __func__);
1198		goto out_put_layout_hdr;
1199	}
1200
1201	send = pnfs_prepare_layoutreturn(lo, &stateid, NULL);
1202	spin_unlock(&ino->i_lock);
1203	if (send)
1204		status = pnfs_send_layoutreturn(lo, &stateid, IOMODE_ANY, true);
1205out_put_layout_hdr:
1206	pnfs_free_lseg_list(&tmp_list);
1207	pnfs_put_layout_hdr(lo);
1208out:
1209	dprintk("<-- %s status: %d\n", __func__, status);
1210	return status;
1211}
1212EXPORT_SYMBOL_GPL(_pnfs_return_layout);
1213
1214int
1215pnfs_commit_and_return_layout(struct inode *inode)
1216{
1217	struct pnfs_layout_hdr *lo;
1218	int ret;
1219
1220	spin_lock(&inode->i_lock);
1221	lo = NFS_I(inode)->layout;
1222	if (lo == NULL) {
1223		spin_unlock(&inode->i_lock);
1224		return 0;
1225	}
1226	pnfs_get_layout_hdr(lo);
1227	/* Block new layoutgets and read/write to ds */
1228	lo->plh_block_lgets++;
1229	spin_unlock(&inode->i_lock);
1230	filemap_fdatawait(inode->i_mapping);
1231	ret = pnfs_layoutcommit_inode(inode, true);
1232	if (ret == 0)
1233		ret = _pnfs_return_layout(inode);
1234	spin_lock(&inode->i_lock);
1235	lo->plh_block_lgets--;
1236	spin_unlock(&inode->i_lock);
1237	pnfs_put_layout_hdr(lo);
1238	return ret;
1239}
1240
1241bool pnfs_roc(struct inode *ino,
1242		struct nfs4_layoutreturn_args *args,
1243		struct nfs4_layoutreturn_res *res,
1244		const struct rpc_cred *cred)
1245{
1246	struct nfs_inode *nfsi = NFS_I(ino);
1247	struct nfs_open_context *ctx;
1248	struct nfs4_state *state;
1249	struct pnfs_layout_hdr *lo;
1250	struct pnfs_layout_segment *lseg, *next;
1251	nfs4_stateid stateid;
1252	enum pnfs_iomode iomode = 0;
1253	bool layoutreturn = false, roc = false;
1254	bool skip_read = false;
1255
1256	if (!nfs_have_layout(ino))
1257		return false;
1258retry:
1259	spin_lock(&ino->i_lock);
1260	lo = nfsi->layout;
1261	if (!lo || !pnfs_layout_is_valid(lo) ||
1262	    test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags))
 
1263		goto out_noroc;
 
 
1264	if (test_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags)) {
1265		pnfs_get_layout_hdr(lo);
1266		spin_unlock(&ino->i_lock);
1267		wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN,
1268				TASK_UNINTERRUPTIBLE);
1269		pnfs_put_layout_hdr(lo);
1270		goto retry;
1271	}
1272
1273	/* no roc if we hold a delegation */
1274	if (nfs4_check_delegation(ino, FMODE_READ)) {
1275		if (nfs4_check_delegation(ino, FMODE_WRITE))
1276			goto out_noroc;
1277		skip_read = true;
1278	}
1279
1280	list_for_each_entry(ctx, &nfsi->open_files, list) {
1281		state = ctx->state;
1282		if (state == NULL)
1283			continue;
1284		/* Don't return layout if there is open file state */
1285		if (state->state & FMODE_WRITE)
1286			goto out_noroc;
1287		if (state->state & FMODE_READ)
1288			skip_read = true;
1289	}
1290
1291
1292	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list) {
1293		if (skip_read && lseg->pls_range.iomode == IOMODE_READ)
1294			continue;
1295		/* If we are sending layoutreturn, invalidate all valid lsegs */
1296		if (!test_and_clear_bit(NFS_LSEG_ROC, &lseg->pls_flags))
1297			continue;
1298		/*
1299		 * Note: mark lseg for return so pnfs_layout_remove_lseg
1300		 * doesn't invalidate the layout for us.
1301		 */
1302		set_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
1303		if (!mark_lseg_invalid(lseg, &lo->plh_return_segs))
1304			continue;
1305		pnfs_set_plh_return_info(lo, lseg->pls_range.iomode, 0);
1306	}
1307
1308	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
1309		goto out_noroc;
1310
1311	/* ROC in two conditions:
1312	 * 1. there are ROC lsegs
1313	 * 2. we don't send layoutreturn
1314	 */
1315	/* lo ref dropped in pnfs_roc_release() */
1316	layoutreturn = pnfs_prepare_layoutreturn(lo, &stateid, &iomode);
1317	/* If the creds don't match, we can't compound the layoutreturn */
1318	if (!layoutreturn || cred != lo->plh_lc_cred)
1319		goto out_noroc;
1320
1321	roc = layoutreturn;
1322	pnfs_init_layoutreturn_args(args, lo, &stateid, iomode);
1323	res->lrs_present = 0;
1324	layoutreturn = false;
1325
1326out_noroc:
1327	spin_unlock(&ino->i_lock);
1328	pnfs_layoutcommit_inode(ino, true);
1329	if (roc) {
1330		struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
1331		if (ld->prepare_layoutreturn)
1332			ld->prepare_layoutreturn(args);
 
1333		return true;
1334	}
1335	if (layoutreturn)
1336		pnfs_send_layoutreturn(lo, &stateid, iomode, true);
 
1337	return false;
1338}
1339
1340void pnfs_roc_release(struct nfs4_layoutreturn_args *args,
1341		struct nfs4_layoutreturn_res *res,
1342		int ret)
1343{
1344	struct pnfs_layout_hdr *lo = args->layout;
1345	const nfs4_stateid *arg_stateid = NULL;
1346	const nfs4_stateid *res_stateid = NULL;
1347	struct nfs4_xdr_opaque_data *ld_private = args->ld_private;
1348
1349	if (ret == 0) {
1350		arg_stateid = &args->stateid;
1351		if (res->lrs_present)
1352			res_stateid = &res->stateid;
1353	}
1354	pnfs_layoutreturn_free_lsegs(lo, arg_stateid, &args->range,
1355			res_stateid);
1356	if (ld_private && ld_private->ops && ld_private->ops->free)
1357		ld_private->ops->free(ld_private);
1358	pnfs_put_layout_hdr(lo);
1359	trace_nfs4_layoutreturn_on_close(args->inode, 0);
1360}
1361
1362bool pnfs_wait_on_layoutreturn(struct inode *ino, struct rpc_task *task)
1363{
1364	struct nfs_inode *nfsi = NFS_I(ino);
1365        struct pnfs_layout_hdr *lo;
1366        bool sleep = false;
1367
1368	/* we might not have grabbed lo reference. so need to check under
1369	 * i_lock */
1370        spin_lock(&ino->i_lock);
1371        lo = nfsi->layout;
1372        if (lo && test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
1373                rpc_sleep_on(&NFS_SERVER(ino)->roc_rpcwaitq, task, NULL);
1374                sleep = true;
1375	}
1376        spin_unlock(&ino->i_lock);
1377        return sleep;
1378}
1379
1380/*
1381 * Compare two layout segments for sorting into layout cache.
1382 * We want to preferentially return RW over RO layouts, so ensure those
1383 * are seen first.
1384 */
1385static s64
1386pnfs_lseg_range_cmp(const struct pnfs_layout_range *l1,
1387	   const struct pnfs_layout_range *l2)
1388{
1389	s64 d;
1390
1391	/* high offset > low offset */
1392	d = l1->offset - l2->offset;
1393	if (d)
1394		return d;
1395
1396	/* short length > long length */
1397	d = l2->length - l1->length;
1398	if (d)
1399		return d;
1400
1401	/* read > read/write */
1402	return (int)(l1->iomode == IOMODE_READ) - (int)(l2->iomode == IOMODE_READ);
1403}
1404
1405static bool
1406pnfs_lseg_range_is_after(const struct pnfs_layout_range *l1,
1407		const struct pnfs_layout_range *l2)
1408{
1409	return pnfs_lseg_range_cmp(l1, l2) > 0;
1410}
1411
1412static bool
1413pnfs_lseg_no_merge(struct pnfs_layout_segment *lseg,
1414		struct pnfs_layout_segment *old)
1415{
1416	return false;
1417}
1418
1419void
1420pnfs_generic_layout_insert_lseg(struct pnfs_layout_hdr *lo,
1421		   struct pnfs_layout_segment *lseg,
1422		   bool (*is_after)(const struct pnfs_layout_range *,
1423			   const struct pnfs_layout_range *),
1424		   bool (*do_merge)(struct pnfs_layout_segment *,
1425			   struct pnfs_layout_segment *),
1426		   struct list_head *free_me)
1427{
1428	struct pnfs_layout_segment *lp, *tmp;
1429
1430	dprintk("%s:Begin\n", __func__);
1431
1432	list_for_each_entry_safe(lp, tmp, &lo->plh_segs, pls_list) {
1433		if (test_bit(NFS_LSEG_VALID, &lp->pls_flags) == 0)
1434			continue;
1435		if (do_merge(lseg, lp)) {
1436			mark_lseg_invalid(lp, free_me);
1437			continue;
1438		}
1439		if (is_after(&lseg->pls_range, &lp->pls_range))
1440			continue;
1441		list_add_tail(&lseg->pls_list, &lp->pls_list);
1442		dprintk("%s: inserted lseg %p "
1443			"iomode %d offset %llu length %llu before "
1444			"lp %p iomode %d offset %llu length %llu\n",
1445			__func__, lseg, lseg->pls_range.iomode,
1446			lseg->pls_range.offset, lseg->pls_range.length,
1447			lp, lp->pls_range.iomode, lp->pls_range.offset,
1448			lp->pls_range.length);
1449		goto out;
1450	}
1451	list_add_tail(&lseg->pls_list, &lo->plh_segs);
1452	dprintk("%s: inserted lseg %p "
1453		"iomode %d offset %llu length %llu at tail\n",
1454		__func__, lseg, lseg->pls_range.iomode,
1455		lseg->pls_range.offset, lseg->pls_range.length);
1456out:
1457	pnfs_get_layout_hdr(lo);
1458
1459	dprintk("%s:Return\n", __func__);
1460}
1461EXPORT_SYMBOL_GPL(pnfs_generic_layout_insert_lseg);
1462
1463static void
1464pnfs_layout_insert_lseg(struct pnfs_layout_hdr *lo,
1465		   struct pnfs_layout_segment *lseg,
1466		   struct list_head *free_me)
1467{
1468	struct inode *inode = lo->plh_inode;
1469	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
1470
1471	if (ld->add_lseg != NULL)
1472		ld->add_lseg(lo, lseg, free_me);
1473	else
1474		pnfs_generic_layout_insert_lseg(lo, lseg,
1475				pnfs_lseg_range_is_after,
1476				pnfs_lseg_no_merge,
1477				free_me);
1478}
1479
1480static struct pnfs_layout_hdr *
1481alloc_init_layout_hdr(struct inode *ino,
1482		      struct nfs_open_context *ctx,
1483		      gfp_t gfp_flags)
1484{
1485	struct pnfs_layout_hdr *lo;
1486
1487	lo = pnfs_alloc_layout_hdr(ino, gfp_flags);
1488	if (!lo)
1489		return NULL;
1490	atomic_set(&lo->plh_refcount, 1);
1491	INIT_LIST_HEAD(&lo->plh_layouts);
1492	INIT_LIST_HEAD(&lo->plh_segs);
1493	INIT_LIST_HEAD(&lo->plh_return_segs);
1494	INIT_LIST_HEAD(&lo->plh_bulk_destroy);
1495	lo->plh_inode = ino;
1496	lo->plh_lc_cred = get_rpccred(ctx->cred);
1497	lo->plh_flags |= 1 << NFS_LAYOUT_INVALID_STID;
1498	return lo;
1499}
1500
1501static struct pnfs_layout_hdr *
1502pnfs_find_alloc_layout(struct inode *ino,
1503		       struct nfs_open_context *ctx,
1504		       gfp_t gfp_flags)
1505	__releases(&ino->i_lock)
1506	__acquires(&ino->i_lock)
1507{
1508	struct nfs_inode *nfsi = NFS_I(ino);
1509	struct pnfs_layout_hdr *new = NULL;
1510
1511	dprintk("%s Begin ino=%p layout=%p\n", __func__, ino, nfsi->layout);
1512
1513	if (nfsi->layout != NULL)
1514		goto out_existing;
1515	spin_unlock(&ino->i_lock);
1516	new = alloc_init_layout_hdr(ino, ctx, gfp_flags);
1517	spin_lock(&ino->i_lock);
1518
1519	if (likely(nfsi->layout == NULL)) {	/* Won the race? */
1520		nfsi->layout = new;
1521		return new;
1522	} else if (new != NULL)
1523		pnfs_free_layout_hdr(new);
1524out_existing:
1525	pnfs_get_layout_hdr(nfsi->layout);
1526	return nfsi->layout;
1527}
1528
1529/*
1530 * iomode matching rules:
1531 * iomode	lseg	strict match
1532 *                      iomode
1533 * -----	-----	------ -----
1534 * ANY		READ	N/A    true
1535 * ANY		RW	N/A    true
1536 * RW		READ	N/A    false
1537 * RW		RW	N/A    true
1538 * READ		READ	N/A    true
1539 * READ		RW	true   false
1540 * READ		RW	false  true
1541 */
1542static bool
1543pnfs_lseg_range_match(const struct pnfs_layout_range *ls_range,
1544		 const struct pnfs_layout_range *range,
1545		 bool strict_iomode)
1546{
1547	struct pnfs_layout_range range1;
1548
1549	if ((range->iomode == IOMODE_RW &&
1550	     ls_range->iomode != IOMODE_RW) ||
1551	    (range->iomode != ls_range->iomode &&
1552	     strict_iomode == true) ||
1553	    !pnfs_lseg_range_intersecting(ls_range, range))
1554		return 0;
1555
1556	/* range1 covers only the first byte in the range */
1557	range1 = *range;
1558	range1.length = 1;
1559	return pnfs_lseg_range_contained(ls_range, &range1);
1560}
1561
1562/*
1563 * lookup range in layout
1564 */
1565static struct pnfs_layout_segment *
1566pnfs_find_lseg(struct pnfs_layout_hdr *lo,
1567		struct pnfs_layout_range *range,
1568		bool strict_iomode)
1569{
1570	struct pnfs_layout_segment *lseg, *ret = NULL;
1571
1572	dprintk("%s:Begin\n", __func__);
1573
1574	list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
1575		if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags) &&
1576		    !test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags) &&
1577		    pnfs_lseg_range_match(&lseg->pls_range, range,
1578					  strict_iomode)) {
1579			ret = pnfs_get_lseg(lseg);
1580			break;
1581		}
1582	}
1583
1584	dprintk("%s:Return lseg %p ref %d\n",
1585		__func__, ret, ret ? atomic_read(&ret->pls_refcount) : 0);
1586	return ret;
1587}
1588
1589/*
1590 * Use mdsthreshold hints set at each OPEN to determine if I/O should go
1591 * to the MDS or over pNFS
1592 *
1593 * The nfs_inode read_io and write_io fields are cumulative counters reset
1594 * when there are no layout segments. Note that in pnfs_update_layout iomode
1595 * is set to IOMODE_READ for a READ request, and set to IOMODE_RW for a
1596 * WRITE request.
1597 *
1598 * A return of true means use MDS I/O.
1599 *
1600 * From rfc 5661:
1601 * If a file's size is smaller than the file size threshold, data accesses
1602 * SHOULD be sent to the metadata server.  If an I/O request has a length that
1603 * is below the I/O size threshold, the I/O SHOULD be sent to the metadata
1604 * server.  If both file size and I/O size are provided, the client SHOULD
1605 * reach or exceed  both thresholds before sending its read or write
1606 * requests to the data server.
1607 */
1608static bool pnfs_within_mdsthreshold(struct nfs_open_context *ctx,
1609				     struct inode *ino, int iomode)
1610{
1611	struct nfs4_threshold *t = ctx->mdsthreshold;
1612	struct nfs_inode *nfsi = NFS_I(ino);
1613	loff_t fsize = i_size_read(ino);
1614	bool size = false, size_set = false, io = false, io_set = false, ret = false;
1615
1616	if (t == NULL)
1617		return ret;
1618
1619	dprintk("%s bm=0x%x rd_sz=%llu wr_sz=%llu rd_io=%llu wr_io=%llu\n",
1620		__func__, t->bm, t->rd_sz, t->wr_sz, t->rd_io_sz, t->wr_io_sz);
1621
1622	switch (iomode) {
1623	case IOMODE_READ:
1624		if (t->bm & THRESHOLD_RD) {
1625			dprintk("%s fsize %llu\n", __func__, fsize);
1626			size_set = true;
1627			if (fsize < t->rd_sz)
1628				size = true;
1629		}
1630		if (t->bm & THRESHOLD_RD_IO) {
1631			dprintk("%s nfsi->read_io %llu\n", __func__,
1632				nfsi->read_io);
1633			io_set = true;
1634			if (nfsi->read_io < t->rd_io_sz)
1635				io = true;
1636		}
1637		break;
1638	case IOMODE_RW:
1639		if (t->bm & THRESHOLD_WR) {
1640			dprintk("%s fsize %llu\n", __func__, fsize);
1641			size_set = true;
1642			if (fsize < t->wr_sz)
1643				size = true;
1644		}
1645		if (t->bm & THRESHOLD_WR_IO) {
1646			dprintk("%s nfsi->write_io %llu\n", __func__,
1647				nfsi->write_io);
1648			io_set = true;
1649			if (nfsi->write_io < t->wr_io_sz)
1650				io = true;
1651		}
1652		break;
1653	}
1654	if (size_set && io_set) {
1655		if (size && io)
1656			ret = true;
1657	} else if (size || io)
1658		ret = true;
1659
1660	dprintk("<-- %s size %d io %d ret %d\n", __func__, size, io, ret);
1661	return ret;
1662}
1663
1664static bool pnfs_prepare_to_retry_layoutget(struct pnfs_layout_hdr *lo)
1665{
1666	/*
1667	 * send layoutcommit as it can hold up layoutreturn due to lseg
1668	 * reference
1669	 */
1670	pnfs_layoutcommit_inode(lo->plh_inode, false);
1671	return !wait_on_bit_action(&lo->plh_flags, NFS_LAYOUT_RETURN,
1672				   nfs_wait_bit_killable,
1673				   TASK_UNINTERRUPTIBLE);
1674}
1675
1676static void pnfs_clear_first_layoutget(struct pnfs_layout_hdr *lo)
1677{
1678	unsigned long *bitlock = &lo->plh_flags;
1679
1680	clear_bit_unlock(NFS_LAYOUT_FIRST_LAYOUTGET, bitlock);
1681	smp_mb__after_atomic();
1682	wake_up_bit(bitlock, NFS_LAYOUT_FIRST_LAYOUTGET);
1683}
1684
1685/*
1686 * Layout segment is retreived from the server if not cached.
1687 * The appropriate layout segment is referenced and returned to the caller.
1688 */
1689struct pnfs_layout_segment *
1690pnfs_update_layout(struct inode *ino,
1691		   struct nfs_open_context *ctx,
1692		   loff_t pos,
1693		   u64 count,
1694		   enum pnfs_iomode iomode,
1695		   bool strict_iomode,
1696		   gfp_t gfp_flags)
1697{
1698	struct pnfs_layout_range arg = {
1699		.iomode = iomode,
1700		.offset = pos,
1701		.length = count,
1702	};
1703	unsigned pg_offset, seq;
1704	struct nfs_server *server = NFS_SERVER(ino);
1705	struct nfs_client *clp = server->nfs_client;
1706	struct pnfs_layout_hdr *lo = NULL;
1707	struct pnfs_layout_segment *lseg = NULL;
1708	nfs4_stateid stateid;
1709	long timeout = 0;
1710	unsigned long giveup = jiffies + (clp->cl_lease_time << 1);
1711	bool first;
1712
1713	if (!pnfs_enabled_sb(NFS_SERVER(ino))) {
1714		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1715				 PNFS_UPDATE_LAYOUT_NO_PNFS);
1716		goto out;
1717	}
1718
1719	if (iomode == IOMODE_READ && i_size_read(ino) == 0) {
1720		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1721				 PNFS_UPDATE_LAYOUT_RD_ZEROLEN);
1722		goto out;
1723	}
1724
1725	if (pnfs_within_mdsthreshold(ctx, ino, iomode)) {
1726		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1727				 PNFS_UPDATE_LAYOUT_MDSTHRESH);
1728		goto out;
1729	}
1730
1731lookup_again:
1732	nfs4_client_recover_expired_lease(clp);
1733	first = false;
1734	spin_lock(&ino->i_lock);
1735	lo = pnfs_find_alloc_layout(ino, ctx, gfp_flags);
1736	if (lo == NULL) {
1737		spin_unlock(&ino->i_lock);
1738		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1739				 PNFS_UPDATE_LAYOUT_NOMEM);
1740		goto out;
1741	}
1742
1743	/* Do we even need to bother with this? */
1744	if (test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
1745		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1746				 PNFS_UPDATE_LAYOUT_BULK_RECALL);
1747		dprintk("%s matches recall, use MDS\n", __func__);
1748		goto out_unlock;
1749	}
1750
1751	/* if LAYOUTGET already failed once we don't try again */
1752	if (pnfs_layout_io_test_failed(lo, iomode)) {
1753		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1754				 PNFS_UPDATE_LAYOUT_IO_TEST_FAIL);
1755		goto out_unlock;
1756	}
1757
1758	lseg = pnfs_find_lseg(lo, &arg, strict_iomode);
1759	if (lseg) {
1760		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1761				PNFS_UPDATE_LAYOUT_FOUND_CACHED);
1762		goto out_unlock;
1763	}
1764
1765	if (!nfs4_valid_open_stateid(ctx->state)) {
1766		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1767				PNFS_UPDATE_LAYOUT_INVALID_OPEN);
1768		goto out_unlock;
1769	}
1770
1771	/*
1772	 * Choose a stateid for the LAYOUTGET. If we don't have a layout
1773	 * stateid, or it has been invalidated, then we must use the open
1774	 * stateid.
1775	 */
1776	if (test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags)) {
1777
1778		/*
1779		 * The first layoutget for the file. Need to serialize per
1780		 * RFC 5661 Errata 3208.
1781		 */
1782		if (test_and_set_bit(NFS_LAYOUT_FIRST_LAYOUTGET,
1783				     &lo->plh_flags)) {
1784			spin_unlock(&ino->i_lock);
1785			wait_on_bit(&lo->plh_flags, NFS_LAYOUT_FIRST_LAYOUTGET,
1786				    TASK_UNINTERRUPTIBLE);
1787			pnfs_put_layout_hdr(lo);
1788			dprintk("%s retrying\n", __func__);
1789			goto lookup_again;
1790		}
1791
1792		first = true;
1793		do {
1794			seq = read_seqbegin(&ctx->state->seqlock);
1795			nfs4_stateid_copy(&stateid, &ctx->state->stateid);
1796		} while (read_seqretry(&ctx->state->seqlock, seq));
 
 
 
 
1797	} else {
1798		nfs4_stateid_copy(&stateid, &lo->plh_stateid);
1799	}
1800
1801	/*
1802	 * Because we free lsegs before sending LAYOUTRETURN, we need to wait
1803	 * for LAYOUTRETURN even if first is true.
1804	 */
1805	if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
1806		spin_unlock(&ino->i_lock);
1807		dprintk("%s wait for layoutreturn\n", __func__);
1808		if (pnfs_prepare_to_retry_layoutget(lo)) {
1809			if (first)
1810				pnfs_clear_first_layoutget(lo);
1811			pnfs_put_layout_hdr(lo);
1812			dprintk("%s retrying\n", __func__);
1813			trace_pnfs_update_layout(ino, pos, count, iomode, lo,
1814					lseg, PNFS_UPDATE_LAYOUT_RETRY);
1815			goto lookup_again;
1816		}
1817		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1818				PNFS_UPDATE_LAYOUT_RETURN);
1819		goto out_put_layout_hdr;
1820	}
1821
1822	if (pnfs_layoutgets_blocked(lo)) {
1823		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1824				PNFS_UPDATE_LAYOUT_BLOCKED);
1825		goto out_unlock;
1826	}
1827	atomic_inc(&lo->plh_outstanding);
1828	spin_unlock(&ino->i_lock);
1829
1830	if (list_empty(&lo->plh_layouts)) {
1831		/* The lo must be on the clp list if there is any
1832		 * chance of a CB_LAYOUTRECALL(FILE) coming in.
1833		 */
1834		spin_lock(&clp->cl_lock);
1835		if (list_empty(&lo->plh_layouts))
1836			list_add_tail(&lo->plh_layouts, &server->layouts);
1837		spin_unlock(&clp->cl_lock);
1838	}
1839
1840	pg_offset = arg.offset & ~PAGE_MASK;
1841	if (pg_offset) {
1842		arg.offset -= pg_offset;
1843		arg.length += pg_offset;
1844	}
1845	if (arg.length != NFS4_MAX_UINT64)
1846		arg.length = PAGE_ALIGN(arg.length);
1847
1848	lseg = send_layoutget(lo, ctx, &stateid, &arg, &timeout, gfp_flags);
1849	trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1850				 PNFS_UPDATE_LAYOUT_SEND_LAYOUTGET);
1851	atomic_dec(&lo->plh_outstanding);
1852	if (IS_ERR(lseg)) {
1853		switch(PTR_ERR(lseg)) {
1854		case -EBUSY:
1855			if (time_after(jiffies, giveup))
1856				lseg = NULL;
1857			break;
1858		case -ERECALLCONFLICT:
1859			/* Huh? We hold no layouts, how is there a recall? */
1860			if (first) {
1861				lseg = NULL;
1862				break;
1863			}
1864			/* Destroy the existing layout and start over */
1865			if (time_after(jiffies, giveup))
1866				pnfs_destroy_layout(NFS_I(ino));
1867			/* Fallthrough */
1868		case -EAGAIN:
1869			break;
1870		default:
1871			if (!nfs_error_is_fatal(PTR_ERR(lseg))) {
1872				pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
1873				lseg = NULL;
1874			}
1875			goto out_put_layout_hdr;
1876		}
1877		if (lseg) {
1878			if (first)
1879				pnfs_clear_first_layoutget(lo);
1880			trace_pnfs_update_layout(ino, pos, count,
1881				iomode, lo, lseg, PNFS_UPDATE_LAYOUT_RETRY);
1882			pnfs_put_layout_hdr(lo);
1883			goto lookup_again;
1884		}
1885	} else {
1886		pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
1887	}
1888
1889out_put_layout_hdr:
1890	if (first)
1891		pnfs_clear_first_layoutget(lo);
1892	pnfs_put_layout_hdr(lo);
1893out:
1894	dprintk("%s: inode %s/%llu pNFS layout segment %s for "
1895			"(%s, offset: %llu, length: %llu)\n",
1896			__func__, ino->i_sb->s_id,
1897			(unsigned long long)NFS_FILEID(ino),
1898			IS_ERR_OR_NULL(lseg) ? "not found" : "found",
1899			iomode==IOMODE_RW ?  "read/write" : "read-only",
1900			(unsigned long long)pos,
1901			(unsigned long long)count);
1902	return lseg;
1903out_unlock:
1904	spin_unlock(&ino->i_lock);
1905	goto out_put_layout_hdr;
1906}
1907EXPORT_SYMBOL_GPL(pnfs_update_layout);
1908
1909static bool
1910pnfs_sanity_check_layout_range(struct pnfs_layout_range *range)
1911{
1912	switch (range->iomode) {
1913	case IOMODE_READ:
1914	case IOMODE_RW:
1915		break;
1916	default:
1917		return false;
1918	}
1919	if (range->offset == NFS4_MAX_UINT64)
1920		return false;
1921	if (range->length == 0)
1922		return false;
1923	if (range->length != NFS4_MAX_UINT64 &&
1924	    range->length > NFS4_MAX_UINT64 - range->offset)
1925		return false;
1926	return true;
1927}
1928
1929struct pnfs_layout_segment *
1930pnfs_layout_process(struct nfs4_layoutget *lgp)
1931{
1932	struct pnfs_layout_hdr *lo = NFS_I(lgp->args.inode)->layout;
1933	struct nfs4_layoutget_res *res = &lgp->res;
1934	struct pnfs_layout_segment *lseg;
1935	struct inode *ino = lo->plh_inode;
1936	LIST_HEAD(free_me);
1937
1938	if (!pnfs_sanity_check_layout_range(&res->range))
1939		return ERR_PTR(-EINVAL);
1940
1941	/* Inject layout blob into I/O device driver */
1942	lseg = NFS_SERVER(ino)->pnfs_curr_ld->alloc_lseg(lo, res, lgp->gfp_flags);
1943	if (IS_ERR_OR_NULL(lseg)) {
1944		if (!lseg)
1945			lseg = ERR_PTR(-ENOMEM);
1946
1947		dprintk("%s: Could not allocate layout: error %ld\n",
1948		       __func__, PTR_ERR(lseg));
1949		return lseg;
1950	}
1951
1952	pnfs_init_lseg(lo, lseg, &res->range, &res->stateid);
1953
1954	spin_lock(&ino->i_lock);
1955	if (pnfs_layoutgets_blocked(lo)) {
1956		dprintk("%s forget reply due to state\n", __func__);
1957		goto out_forget;
1958	}
1959
1960	if (!pnfs_layout_is_valid(lo)) {
1961		/* We have a completely new layout */
1962		pnfs_set_layout_stateid(lo, &res->stateid, true);
1963	} else if (nfs4_stateid_match_other(&lo->plh_stateid, &res->stateid)) {
1964		/* existing state ID, make sure the sequence number matches. */
1965		if (pnfs_layout_stateid_blocked(lo, &res->stateid)) {
1966			dprintk("%s forget reply due to sequence\n", __func__);
1967			goto out_forget;
1968		}
1969		pnfs_set_layout_stateid(lo, &res->stateid, false);
1970	} else {
1971		/*
1972		 * We got an entirely new state ID.  Mark all segments for the
1973		 * inode invalid, and retry the layoutget
1974		 */
1975		pnfs_mark_layout_stateid_invalid(lo, &free_me);
1976		goto out_forget;
1977	}
1978
1979	pnfs_get_lseg(lseg);
1980	pnfs_layout_insert_lseg(lo, lseg, &free_me);
1981
1982
1983	if (res->return_on_close)
1984		set_bit(NFS_LSEG_ROC, &lseg->pls_flags);
1985
1986	spin_unlock(&ino->i_lock);
1987	pnfs_free_lseg_list(&free_me);
1988	return lseg;
1989
1990out_forget:
1991	spin_unlock(&ino->i_lock);
1992	lseg->pls_layout = lo;
1993	NFS_SERVER(ino)->pnfs_curr_ld->free_lseg(lseg);
 
 
1994	return ERR_PTR(-EAGAIN);
1995}
1996
1997/**
1998 * pnfs_mark_matching_lsegs_return - Free or return matching layout segments
1999 * @lo: pointer to layout header
2000 * @tmp_list: list header to be used with pnfs_free_lseg_list()
2001 * @return_range: describe layout segment ranges to be returned
2002 *
2003 * This function is mainly intended for use by layoutrecall. It attempts
2004 * to free the layout segment immediately, or else to mark it for return
2005 * as soon as its reference count drops to zero.
2006 */
2007int
2008pnfs_mark_matching_lsegs_return(struct pnfs_layout_hdr *lo,
2009				struct list_head *tmp_list,
2010				const struct pnfs_layout_range *return_range,
2011				u32 seq)
2012{
2013	struct pnfs_layout_segment *lseg, *next;
2014	int remaining = 0;
2015
2016	dprintk("%s:Begin lo %p\n", __func__, lo);
2017
2018	if (list_empty(&lo->plh_segs))
2019		return 0;
2020
2021	assert_spin_locked(&lo->plh_inode->i_lock);
2022
2023	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
2024		if (pnfs_match_lseg_recall(lseg, return_range, seq)) {
2025			dprintk("%s: marking lseg %p iomode %d "
2026				"offset %llu length %llu\n", __func__,
2027				lseg, lseg->pls_range.iomode,
2028				lseg->pls_range.offset,
2029				lseg->pls_range.length);
2030			if (mark_lseg_invalid(lseg, tmp_list))
2031				continue;
2032			remaining++;
2033			set_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
2034		}
2035
2036	if (remaining)
2037		pnfs_set_plh_return_info(lo, return_range->iomode, seq);
2038
2039	return remaining;
2040}
2041
2042void pnfs_error_mark_layout_for_return(struct inode *inode,
2043				       struct pnfs_layout_segment *lseg)
2044{
2045	struct pnfs_layout_hdr *lo = NFS_I(inode)->layout;
2046	struct pnfs_layout_range range = {
2047		.iomode = lseg->pls_range.iomode,
2048		.offset = 0,
2049		.length = NFS4_MAX_UINT64,
2050	};
2051	bool return_now = false;
2052
2053	spin_lock(&inode->i_lock);
 
 
 
 
2054	pnfs_set_plh_return_info(lo, range.iomode, 0);
2055	/* Block LAYOUTGET */
2056	set_bit(NFS_LAYOUT_RETURN, &lo->plh_flags);
2057	/*
2058	 * mark all matching lsegs so that we are sure to have no live
2059	 * segments at hand when sending layoutreturn. See pnfs_put_lseg()
2060	 * for how it works.
2061	 */
2062	if (!pnfs_mark_matching_lsegs_return(lo, &lo->plh_return_segs, &range, 0)) {
2063		nfs4_stateid stateid;
2064		enum pnfs_iomode iomode;
2065
2066		return_now = pnfs_prepare_layoutreturn(lo, &stateid, &iomode);
2067		spin_unlock(&inode->i_lock);
2068		if (return_now)
2069			pnfs_send_layoutreturn(lo, &stateid, iomode, false);
2070	} else {
2071		spin_unlock(&inode->i_lock);
2072		nfs_commit_inode(inode, 0);
2073	}
2074}
2075EXPORT_SYMBOL_GPL(pnfs_error_mark_layout_for_return);
2076
2077void
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2078pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
2079{
2080	u64 rd_size = req->wb_bytes;
2081
 
 
2082	if (pgio->pg_lseg == NULL) {
2083		if (pgio->pg_dreq == NULL)
2084			rd_size = i_size_read(pgio->pg_inode) - req_offset(req);
2085		else
2086			rd_size = nfs_dreq_bytes_left(pgio->pg_dreq);
2087
2088		pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
2089						   req->wb_context,
2090						   req_offset(req),
2091						   rd_size,
2092						   IOMODE_READ,
2093						   false,
2094						   GFP_KERNEL);
2095		if (IS_ERR(pgio->pg_lseg)) {
2096			pgio->pg_error = PTR_ERR(pgio->pg_lseg);
2097			pgio->pg_lseg = NULL;
2098			return;
2099		}
2100	}
2101	/* If no lseg, fall back to read through mds */
2102	if (pgio->pg_lseg == NULL)
2103		nfs_pageio_reset_read_mds(pgio);
2104
2105}
2106EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_read);
2107
2108void
2109pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio,
2110			   struct nfs_page *req, u64 wb_size)
2111{
 
 
2112	if (pgio->pg_lseg == NULL) {
2113		pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
2114						   req->wb_context,
2115						   req_offset(req),
2116						   wb_size,
2117						   IOMODE_RW,
2118						   false,
2119						   GFP_NOFS);
2120		if (IS_ERR(pgio->pg_lseg)) {
2121			pgio->pg_error = PTR_ERR(pgio->pg_lseg);
2122			pgio->pg_lseg = NULL;
2123			return;
2124		}
2125	}
2126	/* If no lseg, fall back to write through mds */
2127	if (pgio->pg_lseg == NULL)
2128		nfs_pageio_reset_write_mds(pgio);
2129}
2130EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_write);
2131
2132void
2133pnfs_generic_pg_cleanup(struct nfs_pageio_descriptor *desc)
2134{
2135	if (desc->pg_lseg) {
2136		pnfs_put_lseg(desc->pg_lseg);
2137		desc->pg_lseg = NULL;
2138	}
2139}
2140EXPORT_SYMBOL_GPL(pnfs_generic_pg_cleanup);
2141
2142/*
2143 * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
2144 * of bytes (maximum @req->wb_bytes) that can be coalesced.
2145 */
2146size_t
2147pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio,
2148		     struct nfs_page *prev, struct nfs_page *req)
2149{
2150	unsigned int size;
2151	u64 seg_end, req_start, seg_left;
2152
2153	size = nfs_generic_pg_test(pgio, prev, req);
2154	if (!size)
2155		return 0;
2156
2157	/*
2158	 * 'size' contains the number of bytes left in the current page (up
2159	 * to the original size asked for in @req->wb_bytes).
2160	 *
2161	 * Calculate how many bytes are left in the layout segment
2162	 * and if there are less bytes than 'size', return that instead.
2163	 *
2164	 * Please also note that 'end_offset' is actually the offset of the
2165	 * first byte that lies outside the pnfs_layout_range. FIXME?
2166	 *
2167	 */
2168	if (pgio->pg_lseg) {
2169		seg_end = pnfs_end_offset(pgio->pg_lseg->pls_range.offset,
2170				     pgio->pg_lseg->pls_range.length);
2171		req_start = req_offset(req);
2172		WARN_ON_ONCE(req_start >= seg_end);
2173		/* start of request is past the last byte of this segment */
2174		if (req_start >= seg_end) {
2175			/* reference the new lseg */
2176			if (pgio->pg_ops->pg_cleanup)
2177				pgio->pg_ops->pg_cleanup(pgio);
2178			if (pgio->pg_ops->pg_init)
2179				pgio->pg_ops->pg_init(pgio, req);
2180			return 0;
2181		}
2182
2183		/* adjust 'size' iff there are fewer bytes left in the
2184		 * segment than what nfs_generic_pg_test returned */
2185		seg_left = seg_end - req_start;
2186		if (seg_left < size)
2187			size = (unsigned int)seg_left;
2188	}
2189
2190	return size;
2191}
2192EXPORT_SYMBOL_GPL(pnfs_generic_pg_test);
2193
2194int pnfs_write_done_resend_to_mds(struct nfs_pgio_header *hdr)
2195{
2196	struct nfs_pageio_descriptor pgio;
2197
2198	/* Resend all requests through the MDS */
2199	nfs_pageio_init_write(&pgio, hdr->inode, FLUSH_STABLE, true,
2200			      hdr->completion_ops);
2201	set_bit(NFS_CONTEXT_RESEND_WRITES, &hdr->args.context->flags);
2202	return nfs_pageio_resend(&pgio, hdr);
2203}
2204EXPORT_SYMBOL_GPL(pnfs_write_done_resend_to_mds);
2205
2206static void pnfs_ld_handle_write_error(struct nfs_pgio_header *hdr)
2207{
2208
2209	dprintk("pnfs write error = %d\n", hdr->pnfs_error);
2210	if (NFS_SERVER(hdr->inode)->pnfs_curr_ld->flags &
2211	    PNFS_LAYOUTRET_ON_ERROR) {
2212		pnfs_return_layout(hdr->inode);
2213	}
2214	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))
2215		hdr->task.tk_status = pnfs_write_done_resend_to_mds(hdr);
2216}
2217
2218/*
2219 * Called by non rpc-based layout drivers
2220 */
2221void pnfs_ld_write_done(struct nfs_pgio_header *hdr)
2222{
2223	if (likely(!hdr->pnfs_error)) {
2224		pnfs_set_layoutcommit(hdr->inode, hdr->lseg,
2225				hdr->mds_offset + hdr->res.count);
2226		hdr->mds_ops->rpc_call_done(&hdr->task, hdr);
2227	}
2228	trace_nfs4_pnfs_write(hdr, hdr->pnfs_error);
2229	if (unlikely(hdr->pnfs_error))
2230		pnfs_ld_handle_write_error(hdr);
2231	hdr->mds_ops->rpc_release(hdr);
2232}
2233EXPORT_SYMBOL_GPL(pnfs_ld_write_done);
2234
2235static void
2236pnfs_write_through_mds(struct nfs_pageio_descriptor *desc,
2237		struct nfs_pgio_header *hdr)
2238{
2239	struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
2240
2241	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2242		list_splice_tail_init(&hdr->pages, &mirror->pg_list);
2243		nfs_pageio_reset_write_mds(desc);
2244		mirror->pg_recoalesce = 1;
2245	}
2246	nfs_pgio_data_destroy(hdr);
2247	hdr->release(hdr);
2248}
2249
2250static enum pnfs_try_status
2251pnfs_try_to_write_data(struct nfs_pgio_header *hdr,
2252			const struct rpc_call_ops *call_ops,
2253			struct pnfs_layout_segment *lseg,
2254			int how)
2255{
2256	struct inode *inode = hdr->inode;
2257	enum pnfs_try_status trypnfs;
2258	struct nfs_server *nfss = NFS_SERVER(inode);
2259
2260	hdr->mds_ops = call_ops;
2261
2262	dprintk("%s: Writing ino:%lu %u@%llu (how %d)\n", __func__,
2263		inode->i_ino, hdr->args.count, hdr->args.offset, how);
2264	trypnfs = nfss->pnfs_curr_ld->write_pagelist(hdr, how);
2265	if (trypnfs != PNFS_NOT_ATTEMPTED)
2266		nfs_inc_stats(inode, NFSIOS_PNFS_WRITE);
2267	dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
2268	return trypnfs;
2269}
2270
2271static void
2272pnfs_do_write(struct nfs_pageio_descriptor *desc,
2273	      struct nfs_pgio_header *hdr, int how)
2274{
2275	const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
2276	struct pnfs_layout_segment *lseg = desc->pg_lseg;
2277	enum pnfs_try_status trypnfs;
2278
2279	trypnfs = pnfs_try_to_write_data(hdr, call_ops, lseg, how);
2280	if (trypnfs == PNFS_NOT_ATTEMPTED)
 
2281		pnfs_write_through_mds(desc, hdr);
 
 
 
 
 
 
 
 
 
 
 
2282}
2283
2284static void pnfs_writehdr_free(struct nfs_pgio_header *hdr)
2285{
2286	pnfs_put_lseg(hdr->lseg);
2287	nfs_pgio_header_free(hdr);
2288}
2289
2290int
2291pnfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
2292{
2293	struct nfs_pgio_header *hdr;
2294	int ret;
2295
2296	hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
2297	if (!hdr) {
2298		desc->pg_error = -ENOMEM;
2299		return desc->pg_error;
2300	}
2301	nfs_pgheader_init(desc, hdr, pnfs_writehdr_free);
2302
2303	hdr->lseg = pnfs_get_lseg(desc->pg_lseg);
2304	ret = nfs_generic_pgio(desc, hdr);
2305	if (!ret)
2306		pnfs_do_write(desc, hdr, desc->pg_ioflags);
2307
2308	return ret;
2309}
2310EXPORT_SYMBOL_GPL(pnfs_generic_pg_writepages);
2311
2312int pnfs_read_done_resend_to_mds(struct nfs_pgio_header *hdr)
2313{
2314	struct nfs_pageio_descriptor pgio;
2315
2316	/* Resend all requests through the MDS */
2317	nfs_pageio_init_read(&pgio, hdr->inode, true, hdr->completion_ops);
2318	return nfs_pageio_resend(&pgio, hdr);
2319}
2320EXPORT_SYMBOL_GPL(pnfs_read_done_resend_to_mds);
2321
2322static void pnfs_ld_handle_read_error(struct nfs_pgio_header *hdr)
2323{
2324	dprintk("pnfs read error = %d\n", hdr->pnfs_error);
2325	if (NFS_SERVER(hdr->inode)->pnfs_curr_ld->flags &
2326	    PNFS_LAYOUTRET_ON_ERROR) {
2327		pnfs_return_layout(hdr->inode);
2328	}
2329	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))
2330		hdr->task.tk_status = pnfs_read_done_resend_to_mds(hdr);
2331}
2332
2333/*
2334 * Called by non rpc-based layout drivers
2335 */
2336void pnfs_ld_read_done(struct nfs_pgio_header *hdr)
2337{
2338	if (likely(!hdr->pnfs_error))
2339		hdr->mds_ops->rpc_call_done(&hdr->task, hdr);
2340	trace_nfs4_pnfs_read(hdr, hdr->pnfs_error);
2341	if (unlikely(hdr->pnfs_error))
2342		pnfs_ld_handle_read_error(hdr);
2343	hdr->mds_ops->rpc_release(hdr);
2344}
2345EXPORT_SYMBOL_GPL(pnfs_ld_read_done);
2346
2347static void
2348pnfs_read_through_mds(struct nfs_pageio_descriptor *desc,
2349		struct nfs_pgio_header *hdr)
2350{
2351	struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
2352
2353	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2354		list_splice_tail_init(&hdr->pages, &mirror->pg_list);
2355		nfs_pageio_reset_read_mds(desc);
2356		mirror->pg_recoalesce = 1;
2357	}
2358	nfs_pgio_data_destroy(hdr);
2359	hdr->release(hdr);
2360}
2361
2362/*
2363 * Call the appropriate parallel I/O subsystem read function.
2364 */
2365static enum pnfs_try_status
2366pnfs_try_to_read_data(struct nfs_pgio_header *hdr,
2367		       const struct rpc_call_ops *call_ops,
2368		       struct pnfs_layout_segment *lseg)
2369{
2370	struct inode *inode = hdr->inode;
2371	struct nfs_server *nfss = NFS_SERVER(inode);
2372	enum pnfs_try_status trypnfs;
2373
2374	hdr->mds_ops = call_ops;
2375
2376	dprintk("%s: Reading ino:%lu %u@%llu\n",
2377		__func__, inode->i_ino, hdr->args.count, hdr->args.offset);
2378
2379	trypnfs = nfss->pnfs_curr_ld->read_pagelist(hdr);
2380	if (trypnfs != PNFS_NOT_ATTEMPTED)
2381		nfs_inc_stats(inode, NFSIOS_PNFS_READ);
2382	dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
2383	return trypnfs;
2384}
2385
2386/* Resend all requests through pnfs. */
2387void pnfs_read_resend_pnfs(struct nfs_pgio_header *hdr)
2388{
2389	struct nfs_pageio_descriptor pgio;
2390
2391	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2392		/* Prevent deadlocks with layoutreturn! */
2393		pnfs_put_lseg(hdr->lseg);
2394		hdr->lseg = NULL;
2395
2396		nfs_pageio_init_read(&pgio, hdr->inode, false,
2397					hdr->completion_ops);
2398		hdr->task.tk_status = nfs_pageio_resend(&pgio, hdr);
2399	}
2400}
2401EXPORT_SYMBOL_GPL(pnfs_read_resend_pnfs);
2402
2403static void
2404pnfs_do_read(struct nfs_pageio_descriptor *desc, struct nfs_pgio_header *hdr)
2405{
2406	const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
2407	struct pnfs_layout_segment *lseg = desc->pg_lseg;
2408	enum pnfs_try_status trypnfs;
2409
2410	trypnfs = pnfs_try_to_read_data(hdr, call_ops, lseg);
2411	if (trypnfs == PNFS_TRY_AGAIN)
2412		pnfs_read_resend_pnfs(hdr);
2413	if (trypnfs == PNFS_NOT_ATTEMPTED || hdr->task.tk_status)
2414		pnfs_read_through_mds(desc, hdr);
 
 
 
 
 
 
 
 
 
 
 
2415}
2416
2417static void pnfs_readhdr_free(struct nfs_pgio_header *hdr)
2418{
2419	pnfs_put_lseg(hdr->lseg);
2420	nfs_pgio_header_free(hdr);
2421}
2422
2423int
2424pnfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc)
2425{
2426	struct nfs_pgio_header *hdr;
2427	int ret;
2428
2429	hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
2430	if (!hdr) {
2431		desc->pg_error = -ENOMEM;
2432		return desc->pg_error;
2433	}
2434	nfs_pgheader_init(desc, hdr, pnfs_readhdr_free);
2435	hdr->lseg = pnfs_get_lseg(desc->pg_lseg);
2436	ret = nfs_generic_pgio(desc, hdr);
2437	if (!ret)
2438		pnfs_do_read(desc, hdr);
2439	return ret;
2440}
2441EXPORT_SYMBOL_GPL(pnfs_generic_pg_readpages);
2442
2443static void pnfs_clear_layoutcommitting(struct inode *inode)
2444{
2445	unsigned long *bitlock = &NFS_I(inode)->flags;
2446
2447	clear_bit_unlock(NFS_INO_LAYOUTCOMMITTING, bitlock);
2448	smp_mb__after_atomic();
2449	wake_up_bit(bitlock, NFS_INO_LAYOUTCOMMITTING);
2450}
2451
2452/*
2453 * There can be multiple RW segments.
2454 */
2455static void pnfs_list_write_lseg(struct inode *inode, struct list_head *listp)
2456{
2457	struct pnfs_layout_segment *lseg;
2458
2459	list_for_each_entry(lseg, &NFS_I(inode)->layout->plh_segs, pls_list) {
2460		if (lseg->pls_range.iomode == IOMODE_RW &&
2461		    test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
2462			list_add(&lseg->pls_lc_list, listp);
2463	}
2464}
2465
2466static void pnfs_list_write_lseg_done(struct inode *inode, struct list_head *listp)
2467{
2468	struct pnfs_layout_segment *lseg, *tmp;
2469
2470	/* Matched by references in pnfs_set_layoutcommit */
2471	list_for_each_entry_safe(lseg, tmp, listp, pls_lc_list) {
2472		list_del_init(&lseg->pls_lc_list);
2473		pnfs_put_lseg(lseg);
2474	}
2475
2476	pnfs_clear_layoutcommitting(inode);
2477}
2478
2479void pnfs_set_lo_fail(struct pnfs_layout_segment *lseg)
2480{
2481	pnfs_layout_io_set_failed(lseg->pls_layout, lseg->pls_range.iomode);
2482}
2483EXPORT_SYMBOL_GPL(pnfs_set_lo_fail);
2484
2485void
2486pnfs_set_layoutcommit(struct inode *inode, struct pnfs_layout_segment *lseg,
2487		loff_t end_pos)
2488{
2489	struct nfs_inode *nfsi = NFS_I(inode);
2490	bool mark_as_dirty = false;
2491
2492	spin_lock(&inode->i_lock);
2493	if (!test_and_set_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags)) {
2494		nfsi->layout->plh_lwb = end_pos;
2495		mark_as_dirty = true;
2496		dprintk("%s: Set layoutcommit for inode %lu ",
2497			__func__, inode->i_ino);
2498	} else if (end_pos > nfsi->layout->plh_lwb)
2499		nfsi->layout->plh_lwb = end_pos;
2500	if (!test_and_set_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags)) {
2501		/* references matched in nfs4_layoutcommit_release */
2502		pnfs_get_lseg(lseg);
2503	}
2504	spin_unlock(&inode->i_lock);
2505	dprintk("%s: lseg %p end_pos %llu\n",
2506		__func__, lseg, nfsi->layout->plh_lwb);
2507
2508	/* if pnfs_layoutcommit_inode() runs between inode locks, the next one
2509	 * will be a noop because NFS_INO_LAYOUTCOMMIT will not be set */
2510	if (mark_as_dirty)
2511		mark_inode_dirty_sync(inode);
2512}
2513EXPORT_SYMBOL_GPL(pnfs_set_layoutcommit);
2514
2515void pnfs_cleanup_layoutcommit(struct nfs4_layoutcommit_data *data)
2516{
2517	struct nfs_server *nfss = NFS_SERVER(data->args.inode);
2518
2519	if (nfss->pnfs_curr_ld->cleanup_layoutcommit)
2520		nfss->pnfs_curr_ld->cleanup_layoutcommit(data);
2521	pnfs_list_write_lseg_done(data->args.inode, &data->lseg_list);
2522}
2523
2524/*
2525 * For the LAYOUT4_NFSV4_1_FILES layout type, NFS_DATA_SYNC WRITEs and
2526 * NFS_UNSTABLE WRITEs with a COMMIT to data servers must store enough
2527 * data to disk to allow the server to recover the data if it crashes.
2528 * LAYOUTCOMMIT is only needed when the NFL4_UFLG_COMMIT_THRU_MDS flag
2529 * is off, and a COMMIT is sent to a data server, or
2530 * if WRITEs to a data server return NFS_DATA_SYNC.
2531 */
2532int
2533pnfs_layoutcommit_inode(struct inode *inode, bool sync)
2534{
2535	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
2536	struct nfs4_layoutcommit_data *data;
2537	struct nfs_inode *nfsi = NFS_I(inode);
2538	loff_t end_pos;
2539	int status;
2540
2541	if (!pnfs_layoutcommit_outstanding(inode))
2542		return 0;
2543
2544	dprintk("--> %s inode %lu\n", __func__, inode->i_ino);
2545
2546	status = -EAGAIN;
2547	if (test_and_set_bit(NFS_INO_LAYOUTCOMMITTING, &nfsi->flags)) {
2548		if (!sync)
2549			goto out;
2550		status = wait_on_bit_lock_action(&nfsi->flags,
2551				NFS_INO_LAYOUTCOMMITTING,
2552				nfs_wait_bit_killable,
2553				TASK_KILLABLE);
2554		if (status)
2555			goto out;
2556	}
2557
2558	status = -ENOMEM;
2559	/* Note kzalloc ensures data->res.seq_res.sr_slot == NULL */
2560	data = kzalloc(sizeof(*data), GFP_NOFS);
2561	if (!data)
2562		goto clear_layoutcommitting;
2563
2564	status = 0;
2565	spin_lock(&inode->i_lock);
2566	if (!test_and_clear_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags))
2567		goto out_unlock;
2568
2569	INIT_LIST_HEAD(&data->lseg_list);
2570	pnfs_list_write_lseg(inode, &data->lseg_list);
2571
2572	end_pos = nfsi->layout->plh_lwb;
2573
2574	nfs4_stateid_copy(&data->args.stateid, &nfsi->layout->plh_stateid);
2575	spin_unlock(&inode->i_lock);
2576
2577	data->args.inode = inode;
2578	data->cred = get_rpccred(nfsi->layout->plh_lc_cred);
2579	nfs_fattr_init(&data->fattr);
2580	data->args.bitmask = NFS_SERVER(inode)->cache_consistency_bitmask;
2581	data->res.fattr = &data->fattr;
2582	if (end_pos != 0)
2583		data->args.lastbytewritten = end_pos - 1;
2584	else
2585		data->args.lastbytewritten = U64_MAX;
2586	data->res.server = NFS_SERVER(inode);
2587
2588	if (ld->prepare_layoutcommit) {
2589		status = ld->prepare_layoutcommit(&data->args);
2590		if (status) {
2591			put_rpccred(data->cred);
2592			spin_lock(&inode->i_lock);
2593			set_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags);
2594			if (end_pos > nfsi->layout->plh_lwb)
2595				nfsi->layout->plh_lwb = end_pos;
2596			goto out_unlock;
2597		}
2598	}
2599
2600
2601	status = nfs4_proc_layoutcommit(data, sync);
2602out:
2603	if (status)
2604		mark_inode_dirty_sync(inode);
2605	dprintk("<-- %s status %d\n", __func__, status);
2606	return status;
2607out_unlock:
2608	spin_unlock(&inode->i_lock);
2609	kfree(data);
2610clear_layoutcommitting:
2611	pnfs_clear_layoutcommitting(inode);
2612	goto out;
2613}
2614EXPORT_SYMBOL_GPL(pnfs_layoutcommit_inode);
2615
2616int
2617pnfs_generic_sync(struct inode *inode, bool datasync)
2618{
2619	return pnfs_layoutcommit_inode(inode, true);
2620}
2621EXPORT_SYMBOL_GPL(pnfs_generic_sync);
2622
2623struct nfs4_threshold *pnfs_mdsthreshold_alloc(void)
2624{
2625	struct nfs4_threshold *thp;
2626
2627	thp = kzalloc(sizeof(*thp), GFP_NOFS);
2628	if (!thp) {
2629		dprintk("%s mdsthreshold allocation failed\n", __func__);
2630		return NULL;
2631	}
2632	return thp;
2633}
2634
2635#if IS_ENABLED(CONFIG_NFS_V4_2)
2636int
2637pnfs_report_layoutstat(struct inode *inode, gfp_t gfp_flags)
2638{
2639	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
2640	struct nfs_server *server = NFS_SERVER(inode);
2641	struct nfs_inode *nfsi = NFS_I(inode);
2642	struct nfs42_layoutstat_data *data;
2643	struct pnfs_layout_hdr *hdr;
2644	int status = 0;
2645
2646	if (!pnfs_enabled_sb(server) || !ld->prepare_layoutstats)
2647		goto out;
2648
2649	if (!nfs_server_capable(inode, NFS_CAP_LAYOUTSTATS))
2650		goto out;
2651
2652	if (test_and_set_bit(NFS_INO_LAYOUTSTATS, &nfsi->flags))
2653		goto out;
2654
2655	spin_lock(&inode->i_lock);
2656	if (!NFS_I(inode)->layout) {
2657		spin_unlock(&inode->i_lock);
2658		goto out_clear_layoutstats;
2659	}
2660	hdr = NFS_I(inode)->layout;
2661	pnfs_get_layout_hdr(hdr);
2662	spin_unlock(&inode->i_lock);
2663
2664	data = kzalloc(sizeof(*data), gfp_flags);
2665	if (!data) {
2666		status = -ENOMEM;
2667		goto out_put;
2668	}
2669
2670	data->args.fh = NFS_FH(inode);
2671	data->args.inode = inode;
2672	status = ld->prepare_layoutstats(&data->args);
2673	if (status)
2674		goto out_free;
2675
2676	status = nfs42_proc_layoutstats_generic(NFS_SERVER(inode), data);
2677
2678out:
2679	dprintk("%s returns %d\n", __func__, status);
2680	return status;
2681
2682out_free:
2683	kfree(data);
2684out_put:
2685	pnfs_put_layout_hdr(hdr);
2686out_clear_layoutstats:
2687	smp_mb__before_atomic();
2688	clear_bit(NFS_INO_LAYOUTSTATS, &nfsi->flags);
2689	smp_mb__after_atomic();
2690	goto out;
2691}
2692EXPORT_SYMBOL_GPL(pnfs_report_layoutstat);
2693#endif
2694
2695unsigned int layoutstats_timer;
2696module_param(layoutstats_timer, uint, 0644);
2697EXPORT_SYMBOL_GPL(layoutstats_timer);