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v5.14.15
   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#include "nfs4_fs.h"
  41
  42#define NFSDBG_FACILITY		NFSDBG_PNFS
  43#define PNFS_LAYOUTGET_RETRY_TIMEOUT (120*HZ)
  44
  45/* Locking:
  46 *
  47 * pnfs_spinlock:
  48 *      protects pnfs_modules_tbl.
  49 */
  50static DEFINE_SPINLOCK(pnfs_spinlock);
  51
  52/*
  53 * pnfs_modules_tbl holds all pnfs modules
  54 */
  55static LIST_HEAD(pnfs_modules_tbl);
  56
  57static void pnfs_layoutreturn_before_put_layout_hdr(struct pnfs_layout_hdr *lo);
  58static void pnfs_free_returned_lsegs(struct pnfs_layout_hdr *lo,
  59		struct list_head *free_me,
  60		const struct pnfs_layout_range *range,
  61		u32 seq);
  62static bool pnfs_lseg_dec_and_remove_zero(struct pnfs_layout_segment *lseg,
  63		                struct list_head *tmp_list);
  64
  65/* Return the registered pnfs layout driver module matching given id */
  66static struct pnfs_layoutdriver_type *
  67find_pnfs_driver_locked(u32 id)
  68{
  69	struct pnfs_layoutdriver_type *local;
  70
  71	list_for_each_entry(local, &pnfs_modules_tbl, pnfs_tblid)
  72		if (local->id == id)
  73			goto out;
  74	local = NULL;
  75out:
  76	dprintk("%s: Searching for id %u, found %p\n", __func__, id, local);
  77	return local;
  78}
  79
  80static struct pnfs_layoutdriver_type *
  81find_pnfs_driver(u32 id)
  82{
  83	struct pnfs_layoutdriver_type *local;
  84
  85	spin_lock(&pnfs_spinlock);
  86	local = find_pnfs_driver_locked(id);
  87	if (local != NULL && !try_module_get(local->owner)) {
  88		dprintk("%s: Could not grab reference on module\n", __func__);
  89		local = NULL;
  90	}
  91	spin_unlock(&pnfs_spinlock);
  92	return local;
  93}
  94
  95void
  96unset_pnfs_layoutdriver(struct nfs_server *nfss)
  97{
  98	if (nfss->pnfs_curr_ld) {
  99		if (nfss->pnfs_curr_ld->clear_layoutdriver)
 100			nfss->pnfs_curr_ld->clear_layoutdriver(nfss);
 101		/* Decrement the MDS count. Purge the deviceid cache if zero */
 102		if (atomic_dec_and_test(&nfss->nfs_client->cl_mds_count))
 103			nfs4_deviceid_purge_client(nfss->nfs_client);
 104		module_put(nfss->pnfs_curr_ld->owner);
 105	}
 106	nfss->pnfs_curr_ld = NULL;
 107}
 108
 109/*
 110 * When the server sends a list of layout types, we choose one in the order
 111 * given in the list below.
 112 *
 113 * FIXME: should this list be configurable in some fashion? module param?
 114 * 	  mount option? something else?
 115 */
 116static const u32 ld_prefs[] = {
 117	LAYOUT_SCSI,
 118	LAYOUT_BLOCK_VOLUME,
 119	LAYOUT_OSD2_OBJECTS,
 120	LAYOUT_FLEX_FILES,
 121	LAYOUT_NFSV4_1_FILES,
 122	0
 123};
 124
 125static int
 126ld_cmp(const void *e1, const void *e2)
 127{
 128	u32 ld1 = *((u32 *)e1);
 129	u32 ld2 = *((u32 *)e2);
 130	int i;
 131
 132	for (i = 0; ld_prefs[i] != 0; i++) {
 133		if (ld1 == ld_prefs[i])
 134			return -1;
 135
 136		if (ld2 == ld_prefs[i])
 137			return 1;
 138	}
 139	return 0;
 140}
 141
 142/*
 143 * Try to set the server's pnfs module to the pnfs layout type specified by id.
 144 * Currently only one pNFS layout driver per filesystem is supported.
 145 *
 146 * @ids array of layout types supported by MDS.
 147 */
 148void
 149set_pnfs_layoutdriver(struct nfs_server *server, const struct nfs_fh *mntfh,
 150		      struct nfs_fsinfo *fsinfo)
 151{
 152	struct pnfs_layoutdriver_type *ld_type = NULL;
 153	u32 id;
 154	int i;
 155
 156	if (fsinfo->nlayouttypes == 0)
 157		goto out_no_driver;
 158	if (!(server->nfs_client->cl_exchange_flags &
 159		 (EXCHGID4_FLAG_USE_NON_PNFS | EXCHGID4_FLAG_USE_PNFS_MDS))) {
 160		printk(KERN_ERR "NFS: %s: cl_exchange_flags 0x%x\n",
 161			__func__, server->nfs_client->cl_exchange_flags);
 162		goto out_no_driver;
 163	}
 164
 165	sort(fsinfo->layouttype, fsinfo->nlayouttypes,
 166		sizeof(*fsinfo->layouttype), ld_cmp, NULL);
 167
 168	for (i = 0; i < fsinfo->nlayouttypes; i++) {
 169		id = fsinfo->layouttype[i];
 170		ld_type = find_pnfs_driver(id);
 171		if (!ld_type) {
 172			request_module("%s-%u", LAYOUT_NFSV4_1_MODULE_PREFIX,
 173					id);
 174			ld_type = find_pnfs_driver(id);
 175		}
 176		if (ld_type)
 177			break;
 178	}
 179
 180	if (!ld_type) {
 181		dprintk("%s: No pNFS module found!\n", __func__);
 182		goto out_no_driver;
 183	}
 184
 185	server->pnfs_curr_ld = ld_type;
 186	if (ld_type->set_layoutdriver
 187	    && ld_type->set_layoutdriver(server, mntfh)) {
 188		printk(KERN_ERR "NFS: %s: Error initializing pNFS layout "
 189			"driver %u.\n", __func__, id);
 190		module_put(ld_type->owner);
 191		goto out_no_driver;
 192	}
 193	/* Bump the MDS count */
 194	atomic_inc(&server->nfs_client->cl_mds_count);
 195
 196	dprintk("%s: pNFS module for %u set\n", __func__, id);
 197	return;
 198
 199out_no_driver:
 200	dprintk("%s: Using NFSv4 I/O\n", __func__);
 201	server->pnfs_curr_ld = NULL;
 202}
 203
 204int
 205pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
 206{
 207	int status = -EINVAL;
 208	struct pnfs_layoutdriver_type *tmp;
 209
 210	if (ld_type->id == 0) {
 211		printk(KERN_ERR "NFS: %s id 0 is reserved\n", __func__);
 212		return status;
 213	}
 214	if (!ld_type->alloc_lseg || !ld_type->free_lseg) {
 215		printk(KERN_ERR "NFS: %s Layout driver must provide "
 216		       "alloc_lseg and free_lseg.\n", __func__);
 217		return status;
 218	}
 219
 220	spin_lock(&pnfs_spinlock);
 221	tmp = find_pnfs_driver_locked(ld_type->id);
 222	if (!tmp) {
 223		list_add(&ld_type->pnfs_tblid, &pnfs_modules_tbl);
 224		status = 0;
 225		dprintk("%s Registering id:%u name:%s\n", __func__, ld_type->id,
 226			ld_type->name);
 227	} else {
 228		printk(KERN_ERR "NFS: %s Module with id %d already loaded!\n",
 229			__func__, ld_type->id);
 230	}
 231	spin_unlock(&pnfs_spinlock);
 232
 233	return status;
 234}
 235EXPORT_SYMBOL_GPL(pnfs_register_layoutdriver);
 236
 237void
 238pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
 239{
 240	dprintk("%s Deregistering id:%u\n", __func__, ld_type->id);
 241	spin_lock(&pnfs_spinlock);
 242	list_del(&ld_type->pnfs_tblid);
 243	spin_unlock(&pnfs_spinlock);
 244}
 245EXPORT_SYMBOL_GPL(pnfs_unregister_layoutdriver);
 246
 247/*
 248 * pNFS client layout cache
 249 */
 250
 251/* Need to hold i_lock if caller does not already hold reference */
 252void
 253pnfs_get_layout_hdr(struct pnfs_layout_hdr *lo)
 254{
 255	refcount_inc(&lo->plh_refcount);
 256}
 257
 258static struct pnfs_layout_hdr *
 259pnfs_alloc_layout_hdr(struct inode *ino, gfp_t gfp_flags)
 260{
 261	struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
 262	return ld->alloc_layout_hdr(ino, gfp_flags);
 263}
 264
 265static void
 266pnfs_free_layout_hdr(struct pnfs_layout_hdr *lo)
 267{
 268	struct nfs_server *server = NFS_SERVER(lo->plh_inode);
 269	struct pnfs_layoutdriver_type *ld = server->pnfs_curr_ld;
 270
 271	if (test_and_clear_bit(NFS_LAYOUT_HASHED, &lo->plh_flags)) {
 272		struct nfs_client *clp = server->nfs_client;
 273
 274		spin_lock(&clp->cl_lock);
 275		list_del_rcu(&lo->plh_layouts);
 276		spin_unlock(&clp->cl_lock);
 277	}
 278	put_cred(lo->plh_lc_cred);
 279	return ld->free_layout_hdr(lo);
 280}
 281
 282static void
 283pnfs_detach_layout_hdr(struct pnfs_layout_hdr *lo)
 284{
 285	struct nfs_inode *nfsi = NFS_I(lo->plh_inode);
 286	dprintk("%s: freeing layout cache %p\n", __func__, lo);
 287	nfsi->layout = NULL;
 288	/* Reset MDS Threshold I/O counters */
 289	nfsi->write_io = 0;
 290	nfsi->read_io = 0;
 291}
 292
 293void
 294pnfs_put_layout_hdr(struct pnfs_layout_hdr *lo)
 295{
 296	struct inode *inode;
 297	unsigned long i_state;
 298
 299	if (!lo)
 300		return;
 301	inode = lo->plh_inode;
 302	pnfs_layoutreturn_before_put_layout_hdr(lo);
 303
 304	if (refcount_dec_and_lock(&lo->plh_refcount, &inode->i_lock)) {
 305		if (!list_empty(&lo->plh_segs))
 306			WARN_ONCE(1, "NFS: BUG unfreed layout segments.\n");
 307		pnfs_detach_layout_hdr(lo);
 308		i_state = inode->i_state;
 309		spin_unlock(&inode->i_lock);
 310		pnfs_free_layout_hdr(lo);
 311		/* Notify pnfs_destroy_layout_final() that we're done */
 312		if (i_state & (I_FREEING | I_CLEAR))
 313			wake_up_var(lo);
 314	}
 315}
 316
 317static struct inode *
 318pnfs_grab_inode_layout_hdr(struct pnfs_layout_hdr *lo)
 319{
 320	struct inode *inode = igrab(lo->plh_inode);
 321	if (inode)
 322		return inode;
 323	set_bit(NFS_LAYOUT_INODE_FREEING, &lo->plh_flags);
 324	return NULL;
 325}
 326
 327/*
 328 * Compare 2 layout stateid sequence ids, to see which is newer,
 329 * taking into account wraparound issues.
 330 */
 331static bool pnfs_seqid_is_newer(u32 s1, u32 s2)
 332{
 333	return (s32)(s1 - s2) > 0;
 334}
 335
 336static void pnfs_barrier_update(struct pnfs_layout_hdr *lo, u32 newseq)
 337{
 338	if (pnfs_seqid_is_newer(newseq, lo->plh_barrier) || !lo->plh_barrier)
 339		lo->plh_barrier = newseq;
 340}
 341
 342static void
 343pnfs_set_plh_return_info(struct pnfs_layout_hdr *lo, enum pnfs_iomode iomode,
 344			 u32 seq)
 345{
 346	if (lo->plh_return_iomode != 0 && lo->plh_return_iomode != iomode)
 347		iomode = IOMODE_ANY;
 348	lo->plh_return_iomode = iomode;
 349	set_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags);
 350	/*
 351	 * We must set lo->plh_return_seq to avoid livelocks with
 352	 * pnfs_layout_need_return()
 353	 */
 354	if (seq == 0)
 355		seq = be32_to_cpu(lo->plh_stateid.seqid);
 356	if (!lo->plh_return_seq || pnfs_seqid_is_newer(seq, lo->plh_return_seq))
 357		lo->plh_return_seq = seq;
 358	pnfs_barrier_update(lo, seq);
 359}
 360
 361static void
 362pnfs_clear_layoutreturn_info(struct pnfs_layout_hdr *lo)
 363{
 364	struct pnfs_layout_segment *lseg;
 365	lo->plh_return_iomode = 0;
 366	lo->plh_return_seq = 0;
 367	clear_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags);
 368	list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
 369		if (!test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
 370			continue;
 371		pnfs_set_plh_return_info(lo, lseg->pls_range.iomode, 0);
 372	}
 373}
 374
 375static void pnfs_clear_layoutreturn_waitbit(struct pnfs_layout_hdr *lo)
 376{
 377	clear_bit_unlock(NFS_LAYOUT_RETURN, &lo->plh_flags);
 378	clear_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags);
 379	smp_mb__after_atomic();
 380	wake_up_bit(&lo->plh_flags, NFS_LAYOUT_RETURN);
 381	rpc_wake_up(&NFS_SERVER(lo->plh_inode)->roc_rpcwaitq);
 382}
 383
 384static void
 385pnfs_clear_lseg_state(struct pnfs_layout_segment *lseg,
 386		struct list_head *free_me)
 387{
 388	clear_bit(NFS_LSEG_ROC, &lseg->pls_flags);
 389	clear_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
 390	if (test_and_clear_bit(NFS_LSEG_VALID, &lseg->pls_flags))
 391		pnfs_lseg_dec_and_remove_zero(lseg, free_me);
 392	if (test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
 393		pnfs_lseg_dec_and_remove_zero(lseg, free_me);
 394}
 395
 396/*
 397 * Update the seqid of a layout stateid after receiving
 398 * NFS4ERR_OLD_STATEID
 399 */
 400bool nfs4_layout_refresh_old_stateid(nfs4_stateid *dst,
 401		struct pnfs_layout_range *dst_range,
 402		struct inode *inode)
 403{
 404	struct pnfs_layout_hdr *lo;
 405	struct pnfs_layout_range range = {
 406		.iomode = IOMODE_ANY,
 407		.offset = 0,
 408		.length = NFS4_MAX_UINT64,
 409	};
 410	bool ret = false;
 411	LIST_HEAD(head);
 412	int err;
 413
 414	spin_lock(&inode->i_lock);
 415	lo = NFS_I(inode)->layout;
 416	if (lo &&  pnfs_layout_is_valid(lo) &&
 417	    nfs4_stateid_match_other(dst, &lo->plh_stateid)) {
 418		/* Is our call using the most recent seqid? If so, bump it */
 419		if (!nfs4_stateid_is_newer(&lo->plh_stateid, dst)) {
 420			nfs4_stateid_seqid_inc(dst);
 421			ret = true;
 422			goto out;
 423		}
 424		/* Try to update the seqid to the most recent */
 425		err = pnfs_mark_matching_lsegs_return(lo, &head, &range, 0);
 426		if (err != -EBUSY) {
 427			dst->seqid = lo->plh_stateid.seqid;
 428			*dst_range = range;
 429			ret = true;
 430		}
 431	}
 432out:
 433	spin_unlock(&inode->i_lock);
 434	pnfs_free_lseg_list(&head);
 435	return ret;
 436}
 437
 438/*
 439 * Mark a pnfs_layout_hdr and all associated layout segments as invalid
 440 *
 441 * In order to continue using the pnfs_layout_hdr, a full recovery
 442 * is required.
 443 * Note that caller must hold inode->i_lock.
 444 */
 445int
 446pnfs_mark_layout_stateid_invalid(struct pnfs_layout_hdr *lo,
 447		struct list_head *lseg_list)
 448{
 449	struct pnfs_layout_range range = {
 450		.iomode = IOMODE_ANY,
 451		.offset = 0,
 452		.length = NFS4_MAX_UINT64,
 453	};
 454	struct pnfs_layout_segment *lseg, *next;
 455
 456	set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
 457	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
 458		pnfs_clear_lseg_state(lseg, lseg_list);
 459	pnfs_clear_layoutreturn_info(lo);
 460	pnfs_free_returned_lsegs(lo, lseg_list, &range, 0);
 461	if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags) &&
 462	    !test_and_set_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags))
 463		pnfs_clear_layoutreturn_waitbit(lo);
 464	return !list_empty(&lo->plh_segs);
 465}
 466
 467static int
 468pnfs_iomode_to_fail_bit(u32 iomode)
 469{
 470	return iomode == IOMODE_RW ?
 471		NFS_LAYOUT_RW_FAILED : NFS_LAYOUT_RO_FAILED;
 472}
 473
 474static void
 475pnfs_layout_set_fail_bit(struct pnfs_layout_hdr *lo, int fail_bit)
 476{
 477	lo->plh_retry_timestamp = jiffies;
 478	if (!test_and_set_bit(fail_bit, &lo->plh_flags))
 479		refcount_inc(&lo->plh_refcount);
 480}
 481
 482static void
 483pnfs_layout_clear_fail_bit(struct pnfs_layout_hdr *lo, int fail_bit)
 484{
 485	if (test_and_clear_bit(fail_bit, &lo->plh_flags))
 486		refcount_dec(&lo->plh_refcount);
 487}
 488
 489static void
 490pnfs_layout_io_set_failed(struct pnfs_layout_hdr *lo, u32 iomode)
 491{
 492	struct inode *inode = lo->plh_inode;
 493	struct pnfs_layout_range range = {
 494		.iomode = iomode,
 495		.offset = 0,
 496		.length = NFS4_MAX_UINT64,
 497	};
 498	LIST_HEAD(head);
 499
 500	spin_lock(&inode->i_lock);
 501	pnfs_layout_set_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
 502	pnfs_mark_matching_lsegs_invalid(lo, &head, &range, 0);
 503	spin_unlock(&inode->i_lock);
 504	pnfs_free_lseg_list(&head);
 505	dprintk("%s Setting layout IOMODE_%s fail bit\n", __func__,
 506			iomode == IOMODE_RW ?  "RW" : "READ");
 507}
 508
 509static bool
 510pnfs_layout_io_test_failed(struct pnfs_layout_hdr *lo, u32 iomode)
 511{
 512	unsigned long start, end;
 513	int fail_bit = pnfs_iomode_to_fail_bit(iomode);
 514
 515	if (test_bit(fail_bit, &lo->plh_flags) == 0)
 516		return false;
 517	end = jiffies;
 518	start = end - PNFS_LAYOUTGET_RETRY_TIMEOUT;
 519	if (!time_in_range(lo->plh_retry_timestamp, start, end)) {
 520		/* It is time to retry the failed layoutgets */
 521		pnfs_layout_clear_fail_bit(lo, fail_bit);
 522		return false;
 523	}
 524	return true;
 525}
 526
 527static void
 528pnfs_init_lseg(struct pnfs_layout_hdr *lo, struct pnfs_layout_segment *lseg,
 529		const struct pnfs_layout_range *range,
 530		const nfs4_stateid *stateid)
 531{
 532	INIT_LIST_HEAD(&lseg->pls_list);
 533	INIT_LIST_HEAD(&lseg->pls_lc_list);
 534	INIT_LIST_HEAD(&lseg->pls_commits);
 535	refcount_set(&lseg->pls_refcount, 1);
 536	set_bit(NFS_LSEG_VALID, &lseg->pls_flags);
 537	lseg->pls_layout = lo;
 538	lseg->pls_range = *range;
 539	lseg->pls_seq = be32_to_cpu(stateid->seqid);
 540}
 541
 542static void pnfs_free_lseg(struct pnfs_layout_segment *lseg)
 543{
 544	if (lseg != NULL) {
 545		struct inode *inode = lseg->pls_layout->plh_inode;
 546		NFS_SERVER(inode)->pnfs_curr_ld->free_lseg(lseg);
 547	}
 548}
 549
 550static void
 551pnfs_layout_remove_lseg(struct pnfs_layout_hdr *lo,
 552		struct pnfs_layout_segment *lseg)
 553{
 554	WARN_ON(test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
 555	list_del_init(&lseg->pls_list);
 556	/* Matched by pnfs_get_layout_hdr in pnfs_layout_insert_lseg */
 557	refcount_dec(&lo->plh_refcount);
 558	if (test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
 559		return;
 560	if (list_empty(&lo->plh_segs) &&
 561	    !test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags) &&
 562	    !test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
 563		if (atomic_read(&lo->plh_outstanding) == 0)
 564			set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
 565		clear_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
 566	}
 567}
 568
 569static bool
 570pnfs_cache_lseg_for_layoutreturn(struct pnfs_layout_hdr *lo,
 571		struct pnfs_layout_segment *lseg)
 572{
 573	if (test_and_clear_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags) &&
 574	    pnfs_layout_is_valid(lo)) {
 575		pnfs_set_plh_return_info(lo, lseg->pls_range.iomode, 0);
 576		list_move_tail(&lseg->pls_list, &lo->plh_return_segs);
 577		return true;
 578	}
 579	return false;
 580}
 581
 582void
 583pnfs_put_lseg(struct pnfs_layout_segment *lseg)
 584{
 585	struct pnfs_layout_hdr *lo;
 586	struct inode *inode;
 587
 588	if (!lseg)
 589		return;
 590
 591	dprintk("%s: lseg %p ref %d valid %d\n", __func__, lseg,
 592		refcount_read(&lseg->pls_refcount),
 593		test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
 594
 595	lo = lseg->pls_layout;
 596	inode = lo->plh_inode;
 597
 598	if (refcount_dec_and_lock(&lseg->pls_refcount, &inode->i_lock)) {
 599		if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags)) {
 600			spin_unlock(&inode->i_lock);
 601			return;
 602		}
 603		pnfs_get_layout_hdr(lo);
 604		pnfs_layout_remove_lseg(lo, lseg);
 605		if (pnfs_cache_lseg_for_layoutreturn(lo, lseg))
 606			lseg = NULL;
 607		spin_unlock(&inode->i_lock);
 608		pnfs_free_lseg(lseg);
 609		pnfs_put_layout_hdr(lo);
 610	}
 611}
 612EXPORT_SYMBOL_GPL(pnfs_put_lseg);
 613
 614/*
 615 * is l2 fully contained in l1?
 616 *   start1                             end1
 617 *   [----------------------------------)
 618 *           start2           end2
 619 *           [----------------)
 620 */
 621static bool
 622pnfs_lseg_range_contained(const struct pnfs_layout_range *l1,
 623		 const struct pnfs_layout_range *l2)
 624{
 625	u64 start1 = l1->offset;
 626	u64 end1 = pnfs_end_offset(start1, l1->length);
 627	u64 start2 = l2->offset;
 628	u64 end2 = pnfs_end_offset(start2, l2->length);
 629
 630	return (start1 <= start2) && (end1 >= end2);
 631}
 632
 633static bool pnfs_lseg_dec_and_remove_zero(struct pnfs_layout_segment *lseg,
 634		struct list_head *tmp_list)
 635{
 636	if (!refcount_dec_and_test(&lseg->pls_refcount))
 637		return false;
 638	pnfs_layout_remove_lseg(lseg->pls_layout, lseg);
 639	list_add(&lseg->pls_list, tmp_list);
 640	return true;
 641}
 642
 643/* Returns 1 if lseg is removed from list, 0 otherwise */
 644static int mark_lseg_invalid(struct pnfs_layout_segment *lseg,
 645			     struct list_head *tmp_list)
 646{
 647	int rv = 0;
 648
 649	if (test_and_clear_bit(NFS_LSEG_VALID, &lseg->pls_flags)) {
 650		/* Remove the reference keeping the lseg in the
 651		 * list.  It will now be removed when all
 652		 * outstanding io is finished.
 653		 */
 654		dprintk("%s: lseg %p ref %d\n", __func__, lseg,
 655			refcount_read(&lseg->pls_refcount));
 656		if (pnfs_lseg_dec_and_remove_zero(lseg, tmp_list))
 657			rv = 1;
 658	}
 659	return rv;
 660}
 661
 
 
 
 
 
 
 
 
 
 662static bool
 663pnfs_should_free_range(const struct pnfs_layout_range *lseg_range,
 664		 const struct pnfs_layout_range *recall_range)
 665{
 666	return (recall_range->iomode == IOMODE_ANY ||
 667		lseg_range->iomode == recall_range->iomode) &&
 668	       pnfs_lseg_range_intersecting(lseg_range, recall_range);
 669}
 670
 671static bool
 672pnfs_match_lseg_recall(const struct pnfs_layout_segment *lseg,
 673		const struct pnfs_layout_range *recall_range,
 674		u32 seq)
 675{
 676	if (seq != 0 && pnfs_seqid_is_newer(lseg->pls_seq, seq))
 677		return false;
 678	if (recall_range == NULL)
 679		return true;
 680	return pnfs_should_free_range(&lseg->pls_range, recall_range);
 681}
 682
 683/**
 684 * pnfs_mark_matching_lsegs_invalid - tear down lsegs or mark them for later
 685 * @lo: layout header containing the lsegs
 686 * @tmp_list: list head where doomed lsegs should go
 687 * @recall_range: optional recall range argument to match (may be NULL)
 688 * @seq: only invalidate lsegs obtained prior to this sequence (may be 0)
 689 *
 690 * Walk the list of lsegs in the layout header, and tear down any that should
 691 * be destroyed. If "recall_range" is specified then the segment must match
 692 * that range. If "seq" is non-zero, then only match segments that were handed
 693 * out at or before that sequence.
 694 *
 695 * Returns number of matching invalid lsegs remaining in list after scanning
 696 * it and purging them.
 697 */
 698int
 699pnfs_mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo,
 700			    struct list_head *tmp_list,
 701			    const struct pnfs_layout_range *recall_range,
 702			    u32 seq)
 703{
 704	struct pnfs_layout_segment *lseg, *next;
 705	int remaining = 0;
 706
 707	dprintk("%s:Begin lo %p\n", __func__, lo);
 708
 709	if (list_empty(&lo->plh_segs))
 710		return 0;
 711	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
 712		if (pnfs_match_lseg_recall(lseg, recall_range, seq)) {
 713			dprintk("%s: freeing lseg %p iomode %d seq %u "
 714				"offset %llu length %llu\n", __func__,
 715				lseg, lseg->pls_range.iomode, lseg->pls_seq,
 716				lseg->pls_range.offset, lseg->pls_range.length);
 717			if (!mark_lseg_invalid(lseg, tmp_list))
 718				remaining++;
 719		}
 720	dprintk("%s:Return %i\n", __func__, remaining);
 721	return remaining;
 722}
 723
 724static void
 725pnfs_free_returned_lsegs(struct pnfs_layout_hdr *lo,
 726		struct list_head *free_me,
 727		const struct pnfs_layout_range *range,
 728		u32 seq)
 729{
 730	struct pnfs_layout_segment *lseg, *next;
 731
 732	list_for_each_entry_safe(lseg, next, &lo->plh_return_segs, pls_list) {
 733		if (pnfs_match_lseg_recall(lseg, range, seq))
 734			list_move_tail(&lseg->pls_list, free_me);
 735	}
 736}
 737
 738/* note free_me must contain lsegs from a single layout_hdr */
 739void
 740pnfs_free_lseg_list(struct list_head *free_me)
 741{
 742	struct pnfs_layout_segment *lseg, *tmp;
 743
 744	if (list_empty(free_me))
 745		return;
 746
 747	list_for_each_entry_safe(lseg, tmp, free_me, pls_list) {
 748		list_del(&lseg->pls_list);
 749		pnfs_free_lseg(lseg);
 750	}
 751}
 752
 753static struct pnfs_layout_hdr *__pnfs_destroy_layout(struct nfs_inode *nfsi)
 
 754{
 755	struct pnfs_layout_hdr *lo;
 756	LIST_HEAD(tmp_list);
 757
 758	spin_lock(&nfsi->vfs_inode.i_lock);
 759	lo = nfsi->layout;
 760	if (lo) {
 761		pnfs_get_layout_hdr(lo);
 762		pnfs_mark_layout_stateid_invalid(lo, &tmp_list);
 763		pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RO_FAILED);
 764		pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RW_FAILED);
 765		spin_unlock(&nfsi->vfs_inode.i_lock);
 766		pnfs_free_lseg_list(&tmp_list);
 767		nfs_commit_inode(&nfsi->vfs_inode, 0);
 768		pnfs_put_layout_hdr(lo);
 769	} else
 770		spin_unlock(&nfsi->vfs_inode.i_lock);
 771	return lo;
 772}
 773
 774void pnfs_destroy_layout(struct nfs_inode *nfsi)
 775{
 776	__pnfs_destroy_layout(nfsi);
 777}
 778EXPORT_SYMBOL_GPL(pnfs_destroy_layout);
 779
 780static bool pnfs_layout_removed(struct nfs_inode *nfsi,
 781				struct pnfs_layout_hdr *lo)
 782{
 783	bool ret;
 784
 785	spin_lock(&nfsi->vfs_inode.i_lock);
 786	ret = nfsi->layout != lo;
 787	spin_unlock(&nfsi->vfs_inode.i_lock);
 788	return ret;
 789}
 790
 791void pnfs_destroy_layout_final(struct nfs_inode *nfsi)
 792{
 793	struct pnfs_layout_hdr *lo = __pnfs_destroy_layout(nfsi);
 794
 795	if (lo)
 796		wait_var_event(lo, pnfs_layout_removed(nfsi, lo));
 797}
 798
 799static bool
 800pnfs_layout_add_bulk_destroy_list(struct inode *inode,
 801		struct list_head *layout_list)
 802{
 803	struct pnfs_layout_hdr *lo;
 804	bool ret = false;
 805
 806	spin_lock(&inode->i_lock);
 807	lo = NFS_I(inode)->layout;
 808	if (lo != NULL && list_empty(&lo->plh_bulk_destroy)) {
 809		pnfs_get_layout_hdr(lo);
 810		list_add(&lo->plh_bulk_destroy, layout_list);
 811		ret = true;
 812	}
 813	spin_unlock(&inode->i_lock);
 814	return ret;
 815}
 816
 817/* Caller must hold rcu_read_lock and clp->cl_lock */
 818static int
 819pnfs_layout_bulk_destroy_byserver_locked(struct nfs_client *clp,
 820		struct nfs_server *server,
 821		struct list_head *layout_list)
 822	__must_hold(&clp->cl_lock)
 823	__must_hold(RCU)
 824{
 825	struct pnfs_layout_hdr *lo, *next;
 826	struct inode *inode;
 827
 828	list_for_each_entry_safe(lo, next, &server->layouts, plh_layouts) {
 829		if (test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags) ||
 830		    test_bit(NFS_LAYOUT_INODE_FREEING, &lo->plh_flags) ||
 831		    !list_empty(&lo->plh_bulk_destroy))
 832			continue;
 833		/* If the sb is being destroyed, just bail */
 834		if (!nfs_sb_active(server->super))
 835			break;
 836		inode = pnfs_grab_inode_layout_hdr(lo);
 837		if (inode != NULL) {
 838			if (test_and_clear_bit(NFS_LAYOUT_HASHED, &lo->plh_flags))
 839				list_del_rcu(&lo->plh_layouts);
 840			if (pnfs_layout_add_bulk_destroy_list(inode,
 841						layout_list))
 842				continue;
 843			rcu_read_unlock();
 844			spin_unlock(&clp->cl_lock);
 845			iput(inode);
 846		} else {
 847			rcu_read_unlock();
 848			spin_unlock(&clp->cl_lock);
 849		}
 850		nfs_sb_deactive(server->super);
 851		spin_lock(&clp->cl_lock);
 852		rcu_read_lock();
 853		return -EAGAIN;
 854	}
 855	return 0;
 856}
 857
 858static int
 859pnfs_layout_free_bulk_destroy_list(struct list_head *layout_list,
 860		bool is_bulk_recall)
 861{
 862	struct pnfs_layout_hdr *lo;
 863	struct inode *inode;
 864	LIST_HEAD(lseg_list);
 865	int ret = 0;
 866
 867	while (!list_empty(layout_list)) {
 868		lo = list_entry(layout_list->next, struct pnfs_layout_hdr,
 869				plh_bulk_destroy);
 870		dprintk("%s freeing layout for inode %lu\n", __func__,
 871			lo->plh_inode->i_ino);
 872		inode = lo->plh_inode;
 873
 874		pnfs_layoutcommit_inode(inode, false);
 875
 876		spin_lock(&inode->i_lock);
 877		list_del_init(&lo->plh_bulk_destroy);
 878		if (pnfs_mark_layout_stateid_invalid(lo, &lseg_list)) {
 879			if (is_bulk_recall)
 880				set_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
 881			ret = -EAGAIN;
 882		}
 883		spin_unlock(&inode->i_lock);
 884		pnfs_free_lseg_list(&lseg_list);
 885		/* Free all lsegs that are attached to commit buckets */
 886		nfs_commit_inode(inode, 0);
 887		pnfs_put_layout_hdr(lo);
 888		nfs_iput_and_deactive(inode);
 889	}
 890	return ret;
 891}
 892
 893int
 894pnfs_destroy_layouts_byfsid(struct nfs_client *clp,
 895		struct nfs_fsid *fsid,
 896		bool is_recall)
 897{
 898	struct nfs_server *server;
 899	LIST_HEAD(layout_list);
 900
 901	spin_lock(&clp->cl_lock);
 902	rcu_read_lock();
 903restart:
 904	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 905		if (memcmp(&server->fsid, fsid, sizeof(*fsid)) != 0)
 906			continue;
 907		if (pnfs_layout_bulk_destroy_byserver_locked(clp,
 908				server,
 909				&layout_list) != 0)
 910			goto restart;
 911	}
 912	rcu_read_unlock();
 913	spin_unlock(&clp->cl_lock);
 914
 915	if (list_empty(&layout_list))
 916		return 0;
 917	return pnfs_layout_free_bulk_destroy_list(&layout_list, is_recall);
 918}
 919
 920int
 921pnfs_destroy_layouts_byclid(struct nfs_client *clp,
 922		bool is_recall)
 923{
 924	struct nfs_server *server;
 925	LIST_HEAD(layout_list);
 926
 927	spin_lock(&clp->cl_lock);
 928	rcu_read_lock();
 929restart:
 930	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 931		if (pnfs_layout_bulk_destroy_byserver_locked(clp,
 932					server,
 933					&layout_list) != 0)
 934			goto restart;
 935	}
 936	rcu_read_unlock();
 937	spin_unlock(&clp->cl_lock);
 938
 939	if (list_empty(&layout_list))
 940		return 0;
 941	return pnfs_layout_free_bulk_destroy_list(&layout_list, is_recall);
 942}
 943
 944/*
 945 * Called by the state manager to remove all layouts established under an
 946 * expired lease.
 947 */
 948void
 949pnfs_destroy_all_layouts(struct nfs_client *clp)
 950{
 951	nfs4_deviceid_mark_client_invalid(clp);
 952	nfs4_deviceid_purge_client(clp);
 953
 954	pnfs_destroy_layouts_byclid(clp, false);
 955}
 956
 957static void
 958pnfs_set_layout_cred(struct pnfs_layout_hdr *lo, const struct cred *cred)
 959{
 960	const struct cred *old;
 961
 962	if (cred && cred_fscmp(lo->plh_lc_cred, cred) != 0) {
 963		old = xchg(&lo->plh_lc_cred, get_cred(cred));
 964		put_cred(old);
 965	}
 966}
 967
 968/* update lo->plh_stateid with new if is more recent */
 969void
 970pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo, const nfs4_stateid *new,
 971			const struct cred *cred, bool update_barrier)
 972{
 973	u32 oldseq = be32_to_cpu(lo->plh_stateid.seqid);
 974	u32 newseq = be32_to_cpu(new->seqid);
 
 
 975
 976	if (!pnfs_layout_is_valid(lo)) {
 977		pnfs_set_layout_cred(lo, cred);
 978		nfs4_stateid_copy(&lo->plh_stateid, new);
 979		lo->plh_barrier = newseq;
 980		pnfs_clear_layoutreturn_info(lo);
 981		clear_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
 982		return;
 983	}
 984
 985	if (pnfs_seqid_is_newer(newseq, oldseq))
 986		nfs4_stateid_copy(&lo->plh_stateid, new);
 987
 988	if (update_barrier) {
 989		pnfs_barrier_update(lo, newseq);
 990		return;
 
 991	}
 992	/*
 993	 * Because of wraparound, we want to keep the barrier
 994	 * "close" to the current seqids. We really only want to
 995	 * get here from a layoutget call.
 996	 */
 997	if (atomic_read(&lo->plh_outstanding) == 1)
 998		 pnfs_barrier_update(lo, be32_to_cpu(lo->plh_stateid.seqid));
 999}
1000
1001static bool
1002pnfs_layout_stateid_blocked(const struct pnfs_layout_hdr *lo,
1003		const nfs4_stateid *stateid)
1004{
1005	u32 seqid = be32_to_cpu(stateid->seqid);
1006
1007	return lo->plh_barrier && pnfs_seqid_is_newer(lo->plh_barrier, seqid);
1008}
1009
1010/* lget is set to 1 if called from inside send_layoutget call chain */
1011static bool
1012pnfs_layoutgets_blocked(const struct pnfs_layout_hdr *lo)
1013{
1014	return lo->plh_block_lgets ||
1015		test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
1016}
1017
1018static struct nfs_server *
1019pnfs_find_server(struct inode *inode, struct nfs_open_context *ctx)
1020{
1021	struct nfs_server *server;
1022
1023	if (inode) {
1024		server = NFS_SERVER(inode);
1025	} else {
1026		struct dentry *parent_dir = dget_parent(ctx->dentry);
1027		server = NFS_SERVER(parent_dir->d_inode);
1028		dput(parent_dir);
1029	}
1030	return server;
1031}
1032
1033static void nfs4_free_pages(struct page **pages, size_t size)
1034{
1035	int i;
1036
1037	if (!pages)
1038		return;
1039
1040	for (i = 0; i < size; i++) {
1041		if (!pages[i])
1042			break;
1043		__free_page(pages[i]);
1044	}
1045	kfree(pages);
1046}
1047
1048static struct page **nfs4_alloc_pages(size_t size, gfp_t gfp_flags)
1049{
1050	struct page **pages;
1051	int i;
1052
1053	pages = kmalloc_array(size, sizeof(struct page *), gfp_flags);
1054	if (!pages) {
1055		dprintk("%s: can't alloc array of %zu pages\n", __func__, size);
1056		return NULL;
1057	}
1058
1059	for (i = 0; i < size; i++) {
1060		pages[i] = alloc_page(gfp_flags);
1061		if (!pages[i]) {
1062			dprintk("%s: failed to allocate page\n", __func__);
1063			nfs4_free_pages(pages, i);
1064			return NULL;
1065		}
1066	}
1067
1068	return pages;
1069}
1070
1071static struct nfs4_layoutget *
1072pnfs_alloc_init_layoutget_args(struct inode *ino,
1073	   struct nfs_open_context *ctx,
1074	   const nfs4_stateid *stateid,
1075	   const struct pnfs_layout_range *range,
1076	   gfp_t gfp_flags)
1077{
1078	struct nfs_server *server = pnfs_find_server(ino, ctx);
1079	size_t max_reply_sz = server->pnfs_curr_ld->max_layoutget_response;
1080	size_t max_pages = max_response_pages(server);
1081	struct nfs4_layoutget *lgp;
1082
1083	dprintk("--> %s\n", __func__);
1084
1085	lgp = kzalloc(sizeof(*lgp), gfp_flags);
1086	if (lgp == NULL)
1087		return NULL;
1088
1089	if (max_reply_sz) {
1090		size_t npages = (max_reply_sz + PAGE_SIZE - 1) >> PAGE_SHIFT;
1091		if (npages < max_pages)
1092			max_pages = npages;
1093	}
1094
1095	lgp->args.layout.pages = nfs4_alloc_pages(max_pages, gfp_flags);
1096	if (!lgp->args.layout.pages) {
1097		kfree(lgp);
1098		return NULL;
1099	}
1100	lgp->args.layout.pglen = max_pages * PAGE_SIZE;
1101	lgp->res.layoutp = &lgp->args.layout;
1102
1103	/* Don't confuse uninitialised result and success */
1104	lgp->res.status = -NFS4ERR_DELAY;
1105
1106	lgp->args.minlength = PAGE_SIZE;
1107	if (lgp->args.minlength > range->length)
1108		lgp->args.minlength = range->length;
1109	if (ino) {
1110		loff_t i_size = i_size_read(ino);
1111
1112		if (range->iomode == IOMODE_READ) {
1113			if (range->offset >= i_size)
1114				lgp->args.minlength = 0;
1115			else if (i_size - range->offset < lgp->args.minlength)
1116				lgp->args.minlength = i_size - range->offset;
1117		}
1118	}
1119	lgp->args.maxcount = PNFS_LAYOUT_MAXSIZE;
1120	pnfs_copy_range(&lgp->args.range, range);
1121	lgp->args.type = server->pnfs_curr_ld->id;
1122	lgp->args.inode = ino;
1123	lgp->args.ctx = get_nfs_open_context(ctx);
1124	nfs4_stateid_copy(&lgp->args.stateid, stateid);
1125	lgp->gfp_flags = gfp_flags;
1126	lgp->cred = ctx->cred;
1127	return lgp;
1128}
1129
1130void pnfs_layoutget_free(struct nfs4_layoutget *lgp)
1131{
1132	size_t max_pages = lgp->args.layout.pglen / PAGE_SIZE;
1133
1134	nfs4_free_pages(lgp->args.layout.pages, max_pages);
1135	pnfs_put_layout_hdr(lgp->lo);
 
1136	put_nfs_open_context(lgp->args.ctx);
1137	kfree(lgp);
1138}
1139
1140static void pnfs_clear_layoutcommit(struct inode *inode,
1141		struct list_head *head)
1142{
1143	struct nfs_inode *nfsi = NFS_I(inode);
1144	struct pnfs_layout_segment *lseg, *tmp;
1145
1146	if (!test_and_clear_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags))
1147		return;
1148	list_for_each_entry_safe(lseg, tmp, &nfsi->layout->plh_segs, pls_list) {
1149		if (!test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
1150			continue;
1151		pnfs_lseg_dec_and_remove_zero(lseg, head);
1152	}
1153}
1154
1155void pnfs_layoutreturn_free_lsegs(struct pnfs_layout_hdr *lo,
1156		const nfs4_stateid *arg_stateid,
1157		const struct pnfs_layout_range *range,
1158		const nfs4_stateid *stateid)
1159{
1160	struct inode *inode = lo->plh_inode;
1161	LIST_HEAD(freeme);
1162
1163	spin_lock(&inode->i_lock);
1164	if (!pnfs_layout_is_valid(lo) ||
1165	    !nfs4_stateid_match_other(&lo->plh_stateid, arg_stateid))
1166		goto out_unlock;
1167	if (stateid) {
1168		u32 seq = be32_to_cpu(arg_stateid->seqid);
1169
1170		pnfs_mark_matching_lsegs_invalid(lo, &freeme, range, seq);
1171		pnfs_free_returned_lsegs(lo, &freeme, range, seq);
1172		pnfs_set_layout_stateid(lo, stateid, NULL, true);
1173	} else
1174		pnfs_mark_layout_stateid_invalid(lo, &freeme);
1175out_unlock:
1176	pnfs_clear_layoutreturn_waitbit(lo);
1177	spin_unlock(&inode->i_lock);
1178	pnfs_free_lseg_list(&freeme);
1179
1180}
1181
1182static bool
1183pnfs_prepare_layoutreturn(struct pnfs_layout_hdr *lo,
1184		nfs4_stateid *stateid,
1185		const struct cred **cred,
1186		enum pnfs_iomode *iomode)
1187{
1188	/* Serialise LAYOUTGET/LAYOUTRETURN */
1189	if (atomic_read(&lo->plh_outstanding) != 0)
1190		return false;
1191	if (test_and_set_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags))
1192		return false;
1193	set_bit(NFS_LAYOUT_RETURN, &lo->plh_flags);
1194	pnfs_get_layout_hdr(lo);
1195	nfs4_stateid_copy(stateid, &lo->plh_stateid);
1196	*cred = get_cred(lo->plh_lc_cred);
1197	if (test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags)) {
 
 
1198		if (lo->plh_return_seq != 0)
1199			stateid->seqid = cpu_to_be32(lo->plh_return_seq);
1200		if (iomode != NULL)
1201			*iomode = lo->plh_return_iomode;
1202		pnfs_clear_layoutreturn_info(lo);
1203	} else if (iomode != NULL)
 
 
 
 
1204		*iomode = IOMODE_ANY;
1205	pnfs_barrier_update(lo, be32_to_cpu(stateid->seqid));
1206	return true;
1207}
1208
1209static void
1210pnfs_init_layoutreturn_args(struct nfs4_layoutreturn_args *args,
1211		struct pnfs_layout_hdr *lo,
1212		const nfs4_stateid *stateid,
1213		enum pnfs_iomode iomode)
1214{
1215	struct inode *inode = lo->plh_inode;
1216
1217	args->layout_type = NFS_SERVER(inode)->pnfs_curr_ld->id;
1218	args->inode = inode;
1219	args->range.iomode = iomode;
1220	args->range.offset = 0;
1221	args->range.length = NFS4_MAX_UINT64;
1222	args->layout = lo;
1223	nfs4_stateid_copy(&args->stateid, stateid);
1224}
1225
1226static int
1227pnfs_send_layoutreturn(struct pnfs_layout_hdr *lo,
1228		       const nfs4_stateid *stateid,
1229		       const struct cred **pcred,
1230		       enum pnfs_iomode iomode,
1231		       bool sync)
1232{
1233	struct inode *ino = lo->plh_inode;
1234	struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
1235	struct nfs4_layoutreturn *lrp;
1236	const struct cred *cred = *pcred;
1237	int status = 0;
1238
1239	*pcred = NULL;
1240	lrp = kzalloc(sizeof(*lrp), GFP_NOFS);
1241	if (unlikely(lrp == NULL)) {
1242		status = -ENOMEM;
1243		spin_lock(&ino->i_lock);
1244		pnfs_clear_layoutreturn_waitbit(lo);
1245		spin_unlock(&ino->i_lock);
1246		put_cred(cred);
1247		pnfs_put_layout_hdr(lo);
1248		goto out;
1249	}
1250
1251	pnfs_init_layoutreturn_args(&lrp->args, lo, stateid, iomode);
1252	lrp->args.ld_private = &lrp->ld_private;
1253	lrp->clp = NFS_SERVER(ino)->nfs_client;
1254	lrp->cred = cred;
1255	if (ld->prepare_layoutreturn)
1256		ld->prepare_layoutreturn(&lrp->args);
1257
1258	status = nfs4_proc_layoutreturn(lrp, sync);
1259out:
1260	dprintk("<-- %s status: %d\n", __func__, status);
1261	return status;
1262}
1263
1264static bool
1265pnfs_layout_segments_returnable(struct pnfs_layout_hdr *lo,
1266				enum pnfs_iomode iomode,
1267				u32 seq)
1268{
1269	struct pnfs_layout_range recall_range = {
1270		.length = NFS4_MAX_UINT64,
1271		.iomode = iomode,
1272	};
1273	return pnfs_mark_matching_lsegs_return(lo, &lo->plh_return_segs,
1274					       &recall_range, seq) != -EBUSY;
1275}
1276
1277/* Return true if layoutreturn is needed */
1278static bool
1279pnfs_layout_need_return(struct pnfs_layout_hdr *lo)
1280{
1281	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
1282		return false;
1283	return pnfs_layout_segments_returnable(lo, lo->plh_return_iomode,
1284					       lo->plh_return_seq);
1285}
1286
1287static void pnfs_layoutreturn_before_put_layout_hdr(struct pnfs_layout_hdr *lo)
1288{
1289	struct inode *inode= lo->plh_inode;
1290
1291	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
1292		return;
1293	spin_lock(&inode->i_lock);
1294	if (pnfs_layout_need_return(lo)) {
1295		const struct cred *cred;
1296		nfs4_stateid stateid;
1297		enum pnfs_iomode iomode;
1298		bool send;
1299
1300		send = pnfs_prepare_layoutreturn(lo, &stateid, &cred, &iomode);
1301		spin_unlock(&inode->i_lock);
1302		if (send) {
1303			/* Send an async layoutreturn so we dont deadlock */
1304			pnfs_send_layoutreturn(lo, &stateid, &cred, iomode, false);
1305		}
1306	} else
1307		spin_unlock(&inode->i_lock);
1308}
1309
1310/*
1311 * Initiates a LAYOUTRETURN(FILE), and removes the pnfs_layout_hdr
1312 * when the layout segment list is empty.
1313 *
1314 * Note that a pnfs_layout_hdr can exist with an empty layout segment
1315 * list when LAYOUTGET has failed, or when LAYOUTGET succeeded, but the
1316 * deviceid is marked invalid.
1317 */
1318int
1319_pnfs_return_layout(struct inode *ino)
1320{
1321	struct pnfs_layout_hdr *lo = NULL;
1322	struct nfs_inode *nfsi = NFS_I(ino);
1323	struct pnfs_layout_range range = {
1324		.iomode		= IOMODE_ANY,
1325		.offset		= 0,
1326		.length		= NFS4_MAX_UINT64,
1327	};
1328	LIST_HEAD(tmp_list);
1329	const struct cred *cred;
1330	nfs4_stateid stateid;
1331	int status = 0;
1332	bool send, valid_layout;
1333
1334	dprintk("NFS: %s for inode %lu\n", __func__, ino->i_ino);
1335
1336	spin_lock(&ino->i_lock);
1337	lo = nfsi->layout;
1338	if (!lo) {
1339		spin_unlock(&ino->i_lock);
1340		dprintk("NFS: %s no layout to return\n", __func__);
1341		goto out;
1342	}
1343	/* Reference matched in nfs4_layoutreturn_release */
1344	pnfs_get_layout_hdr(lo);
1345	/* Is there an outstanding layoutreturn ? */
1346	if (test_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags)) {
1347		spin_unlock(&ino->i_lock);
1348		if (wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN,
1349					TASK_UNINTERRUPTIBLE))
1350			goto out_put_layout_hdr;
1351		spin_lock(&ino->i_lock);
1352	}
1353	valid_layout = pnfs_layout_is_valid(lo);
1354	pnfs_clear_layoutcommit(ino, &tmp_list);
1355	pnfs_mark_matching_lsegs_return(lo, &tmp_list, &range, 0);
1356
1357	if (NFS_SERVER(ino)->pnfs_curr_ld->return_range)
 
 
 
 
 
1358		NFS_SERVER(ino)->pnfs_curr_ld->return_range(lo, &range);
 
1359
1360	/* Don't send a LAYOUTRETURN if list was initially empty */
1361	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags) ||
1362			!valid_layout) {
1363		spin_unlock(&ino->i_lock);
1364		dprintk("NFS: %s no layout segments to return\n", __func__);
1365		goto out_wait_layoutreturn;
1366	}
1367
1368	send = pnfs_prepare_layoutreturn(lo, &stateid, &cred, NULL);
1369	spin_unlock(&ino->i_lock);
1370	if (send)
1371		status = pnfs_send_layoutreturn(lo, &stateid, &cred, IOMODE_ANY, true);
1372out_wait_layoutreturn:
1373	wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN, TASK_UNINTERRUPTIBLE);
1374out_put_layout_hdr:
1375	pnfs_free_lseg_list(&tmp_list);
1376	pnfs_put_layout_hdr(lo);
1377out:
1378	dprintk("<-- %s status: %d\n", __func__, status);
1379	return status;
1380}
1381
1382int
1383pnfs_commit_and_return_layout(struct inode *inode)
1384{
1385	struct pnfs_layout_hdr *lo;
1386	int ret;
1387
1388	spin_lock(&inode->i_lock);
1389	lo = NFS_I(inode)->layout;
1390	if (lo == NULL) {
1391		spin_unlock(&inode->i_lock);
1392		return 0;
1393	}
1394	pnfs_get_layout_hdr(lo);
1395	/* Block new layoutgets and read/write to ds */
1396	lo->plh_block_lgets++;
1397	spin_unlock(&inode->i_lock);
1398	filemap_fdatawait(inode->i_mapping);
1399	ret = pnfs_layoutcommit_inode(inode, true);
1400	if (ret == 0)
1401		ret = _pnfs_return_layout(inode);
1402	spin_lock(&inode->i_lock);
1403	lo->plh_block_lgets--;
1404	spin_unlock(&inode->i_lock);
1405	pnfs_put_layout_hdr(lo);
1406	return ret;
1407}
1408
1409bool pnfs_roc(struct inode *ino,
1410		struct nfs4_layoutreturn_args *args,
1411		struct nfs4_layoutreturn_res *res,
1412		const struct cred *cred)
1413{
1414	struct nfs_inode *nfsi = NFS_I(ino);
1415	struct nfs_open_context *ctx;
1416	struct nfs4_state *state;
1417	struct pnfs_layout_hdr *lo;
1418	struct pnfs_layout_segment *lseg, *next;
1419	const struct cred *lc_cred;
1420	nfs4_stateid stateid;
1421	enum pnfs_iomode iomode = 0;
1422	bool layoutreturn = false, roc = false;
1423	bool skip_read = false;
1424
1425	if (!nfs_have_layout(ino))
1426		return false;
1427retry:
1428	rcu_read_lock();
1429	spin_lock(&ino->i_lock);
1430	lo = nfsi->layout;
1431	if (!lo || !pnfs_layout_is_valid(lo) ||
1432	    test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
1433		lo = NULL;
1434		goto out_noroc;
1435	}
1436	pnfs_get_layout_hdr(lo);
1437	if (test_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags)) {
1438		spin_unlock(&ino->i_lock);
1439		rcu_read_unlock();
1440		wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN,
1441				TASK_UNINTERRUPTIBLE);
1442		pnfs_put_layout_hdr(lo);
1443		goto retry;
1444	}
1445
1446	/* no roc if we hold a delegation */
1447	if (nfs4_check_delegation(ino, FMODE_READ)) {
1448		if (nfs4_check_delegation(ino, FMODE_WRITE))
1449			goto out_noroc;
1450		skip_read = true;
1451	}
1452
1453	list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
1454		state = ctx->state;
1455		if (state == NULL)
1456			continue;
1457		/* Don't return layout if there is open file state */
1458		if (state->state & FMODE_WRITE)
1459			goto out_noroc;
1460		if (state->state & FMODE_READ)
1461			skip_read = true;
1462	}
1463
1464
1465	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list) {
1466		if (skip_read && lseg->pls_range.iomode == IOMODE_READ)
1467			continue;
1468		/* If we are sending layoutreturn, invalidate all valid lsegs */
1469		if (!test_and_clear_bit(NFS_LSEG_ROC, &lseg->pls_flags))
1470			continue;
1471		/*
1472		 * Note: mark lseg for return so pnfs_layout_remove_lseg
1473		 * doesn't invalidate the layout for us.
1474		 */
1475		set_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
1476		if (!mark_lseg_invalid(lseg, &lo->plh_return_segs))
1477			continue;
1478		pnfs_set_plh_return_info(lo, lseg->pls_range.iomode, 0);
1479	}
1480
1481	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
1482		goto out_noroc;
1483
1484	/* ROC in two conditions:
1485	 * 1. there are ROC lsegs
1486	 * 2. we don't send layoutreturn
1487	 */
1488	/* lo ref dropped in pnfs_roc_release() */
1489	layoutreturn = pnfs_prepare_layoutreturn(lo, &stateid, &lc_cred, &iomode);
1490	/* If the creds don't match, we can't compound the layoutreturn */
1491	if (!layoutreturn || cred_fscmp(cred, lc_cred) != 0)
1492		goto out_noroc;
1493
1494	roc = layoutreturn;
1495	pnfs_init_layoutreturn_args(args, lo, &stateid, iomode);
1496	res->lrs_present = 0;
1497	layoutreturn = false;
1498	put_cred(lc_cred);
1499
1500out_noroc:
1501	spin_unlock(&ino->i_lock);
1502	rcu_read_unlock();
1503	pnfs_layoutcommit_inode(ino, true);
1504	if (roc) {
1505		struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
1506		if (ld->prepare_layoutreturn)
1507			ld->prepare_layoutreturn(args);
1508		pnfs_put_layout_hdr(lo);
1509		return true;
1510	}
1511	if (layoutreturn)
1512		pnfs_send_layoutreturn(lo, &stateid, &lc_cred, iomode, true);
1513	pnfs_put_layout_hdr(lo);
1514	return false;
1515}
1516
1517int pnfs_roc_done(struct rpc_task *task, struct nfs4_layoutreturn_args **argpp,
1518		  struct nfs4_layoutreturn_res **respp, int *ret)
 
 
1519{
1520	struct nfs4_layoutreturn_args *arg = *argpp;
1521	int retval = -EAGAIN;
1522
1523	if (!arg)
1524		return 0;
1525	/* Handle Layoutreturn errors */
1526	switch (*ret) {
1527	case 0:
1528		retval = 0;
1529		break;
1530	case -NFS4ERR_NOMATCHING_LAYOUT:
1531		/* Was there an RPC level error? If not, retry */
1532		if (task->tk_rpc_status == 0)
1533			break;
1534		/* If the call was not sent, let caller handle it */
1535		if (!RPC_WAS_SENT(task))
1536			return 0;
1537		/*
1538		 * Otherwise, assume the call succeeded and
1539		 * that we need to release the layout
1540		 */
1541		*ret = 0;
1542		(*respp)->lrs_present = 0;
1543		retval = 0;
1544		break;
1545	case -NFS4ERR_DELAY:
1546		/* Let the caller handle the retry */
1547		*ret = -NFS4ERR_NOMATCHING_LAYOUT;
1548		return 0;
1549	case -NFS4ERR_OLD_STATEID:
1550		if (!nfs4_layout_refresh_old_stateid(&arg->stateid,
1551						     &arg->range, arg->inode))
1552			break;
1553		*ret = -NFS4ERR_NOMATCHING_LAYOUT;
1554		return -EAGAIN;
1555	}
1556	*argpp = NULL;
1557	*respp = NULL;
1558	return retval;
1559}
1560
1561void pnfs_roc_release(struct nfs4_layoutreturn_args *args,
1562		struct nfs4_layoutreturn_res *res,
1563		int ret)
1564{
1565	struct pnfs_layout_hdr *lo = args->layout;
1566	struct inode *inode = args->inode;
1567	const nfs4_stateid *res_stateid = NULL;
1568	struct nfs4_xdr_opaque_data *ld_private = args->ld_private;
1569
1570	switch (ret) {
1571	case -NFS4ERR_NOMATCHING_LAYOUT:
1572		spin_lock(&inode->i_lock);
1573		if (pnfs_layout_is_valid(lo) &&
1574		    nfs4_stateid_match_other(&args->stateid, &lo->plh_stateid))
1575			pnfs_set_plh_return_info(lo, args->range.iomode, 0);
1576		pnfs_clear_layoutreturn_waitbit(lo);
1577		spin_unlock(&inode->i_lock);
1578		break;
1579	case 0:
1580		if (res->lrs_present)
1581			res_stateid = &res->stateid;
1582		fallthrough;
1583	default:
1584		pnfs_layoutreturn_free_lsegs(lo, &args->stateid, &args->range,
1585					     res_stateid);
1586	}
1587	trace_nfs4_layoutreturn_on_close(args->inode, &args->stateid, ret);
 
 
1588	if (ld_private && ld_private->ops && ld_private->ops->free)
1589		ld_private->ops->free(ld_private);
1590	pnfs_put_layout_hdr(lo);
1591}
1592
1593bool pnfs_wait_on_layoutreturn(struct inode *ino, struct rpc_task *task)
1594{
1595	struct nfs_inode *nfsi = NFS_I(ino);
1596        struct pnfs_layout_hdr *lo;
1597        bool sleep = false;
1598
1599	/* we might not have grabbed lo reference. so need to check under
1600	 * i_lock */
1601        spin_lock(&ino->i_lock);
1602        lo = nfsi->layout;
1603        if (lo && test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
1604                rpc_sleep_on(&NFS_SERVER(ino)->roc_rpcwaitq, task, NULL);
1605                sleep = true;
1606	}
1607        spin_unlock(&ino->i_lock);
1608        return sleep;
1609}
1610
1611/*
1612 * Compare two layout segments for sorting into layout cache.
1613 * We want to preferentially return RW over RO layouts, so ensure those
1614 * are seen first.
1615 */
1616static s64
1617pnfs_lseg_range_cmp(const struct pnfs_layout_range *l1,
1618	   const struct pnfs_layout_range *l2)
1619{
1620	s64 d;
1621
1622	/* high offset > low offset */
1623	d = l1->offset - l2->offset;
1624	if (d)
1625		return d;
1626
1627	/* short length > long length */
1628	d = l2->length - l1->length;
1629	if (d)
1630		return d;
1631
1632	/* read > read/write */
1633	return (int)(l1->iomode == IOMODE_READ) - (int)(l2->iomode == IOMODE_READ);
1634}
1635
1636static bool
1637pnfs_lseg_range_is_after(const struct pnfs_layout_range *l1,
1638		const struct pnfs_layout_range *l2)
1639{
1640	return pnfs_lseg_range_cmp(l1, l2) > 0;
1641}
1642
1643static bool
1644pnfs_lseg_no_merge(struct pnfs_layout_segment *lseg,
1645		struct pnfs_layout_segment *old)
1646{
1647	return false;
1648}
1649
1650void
1651pnfs_generic_layout_insert_lseg(struct pnfs_layout_hdr *lo,
1652		   struct pnfs_layout_segment *lseg,
1653		   bool (*is_after)(const struct pnfs_layout_range *,
1654			   const struct pnfs_layout_range *),
1655		   bool (*do_merge)(struct pnfs_layout_segment *,
1656			   struct pnfs_layout_segment *),
1657		   struct list_head *free_me)
1658{
1659	struct pnfs_layout_segment *lp, *tmp;
1660
1661	dprintk("%s:Begin\n", __func__);
1662
1663	list_for_each_entry_safe(lp, tmp, &lo->plh_segs, pls_list) {
1664		if (test_bit(NFS_LSEG_VALID, &lp->pls_flags) == 0)
1665			continue;
1666		if (do_merge(lseg, lp)) {
1667			mark_lseg_invalid(lp, free_me);
1668			continue;
1669		}
1670		if (is_after(&lseg->pls_range, &lp->pls_range))
1671			continue;
1672		list_add_tail(&lseg->pls_list, &lp->pls_list);
1673		dprintk("%s: inserted lseg %p "
1674			"iomode %d offset %llu length %llu before "
1675			"lp %p iomode %d offset %llu length %llu\n",
1676			__func__, lseg, lseg->pls_range.iomode,
1677			lseg->pls_range.offset, lseg->pls_range.length,
1678			lp, lp->pls_range.iomode, lp->pls_range.offset,
1679			lp->pls_range.length);
1680		goto out;
1681	}
1682	list_add_tail(&lseg->pls_list, &lo->plh_segs);
1683	dprintk("%s: inserted lseg %p "
1684		"iomode %d offset %llu length %llu at tail\n",
1685		__func__, lseg, lseg->pls_range.iomode,
1686		lseg->pls_range.offset, lseg->pls_range.length);
1687out:
1688	pnfs_get_layout_hdr(lo);
1689
1690	dprintk("%s:Return\n", __func__);
1691}
1692EXPORT_SYMBOL_GPL(pnfs_generic_layout_insert_lseg);
1693
1694static void
1695pnfs_layout_insert_lseg(struct pnfs_layout_hdr *lo,
1696		   struct pnfs_layout_segment *lseg,
1697		   struct list_head *free_me)
1698{
1699	struct inode *inode = lo->plh_inode;
1700	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
1701
1702	if (ld->add_lseg != NULL)
1703		ld->add_lseg(lo, lseg, free_me);
1704	else
1705		pnfs_generic_layout_insert_lseg(lo, lseg,
1706				pnfs_lseg_range_is_after,
1707				pnfs_lseg_no_merge,
1708				free_me);
1709}
1710
1711static struct pnfs_layout_hdr *
1712alloc_init_layout_hdr(struct inode *ino,
1713		      struct nfs_open_context *ctx,
1714		      gfp_t gfp_flags)
1715{
1716	struct pnfs_layout_hdr *lo;
1717
1718	lo = pnfs_alloc_layout_hdr(ino, gfp_flags);
1719	if (!lo)
1720		return NULL;
1721	refcount_set(&lo->plh_refcount, 1);
1722	INIT_LIST_HEAD(&lo->plh_layouts);
1723	INIT_LIST_HEAD(&lo->plh_segs);
1724	INIT_LIST_HEAD(&lo->plh_return_segs);
1725	INIT_LIST_HEAD(&lo->plh_bulk_destroy);
1726	lo->plh_inode = ino;
1727	lo->plh_lc_cred = get_cred(ctx->cred);
1728	lo->plh_flags |= 1 << NFS_LAYOUT_INVALID_STID;
1729	return lo;
1730}
1731
1732static struct pnfs_layout_hdr *
1733pnfs_find_alloc_layout(struct inode *ino,
1734		       struct nfs_open_context *ctx,
1735		       gfp_t gfp_flags)
1736	__releases(&ino->i_lock)
1737	__acquires(&ino->i_lock)
1738{
1739	struct nfs_inode *nfsi = NFS_I(ino);
1740	struct pnfs_layout_hdr *new = NULL;
1741
1742	dprintk("%s Begin ino=%p layout=%p\n", __func__, ino, nfsi->layout);
1743
1744	if (nfsi->layout != NULL)
1745		goto out_existing;
1746	spin_unlock(&ino->i_lock);
1747	new = alloc_init_layout_hdr(ino, ctx, gfp_flags);
1748	spin_lock(&ino->i_lock);
1749
1750	if (likely(nfsi->layout == NULL)) {	/* Won the race? */
1751		nfsi->layout = new;
1752		return new;
1753	} else if (new != NULL)
1754		pnfs_free_layout_hdr(new);
1755out_existing:
1756	pnfs_get_layout_hdr(nfsi->layout);
1757	return nfsi->layout;
1758}
1759
1760/*
1761 * iomode matching rules:
1762 * iomode	lseg	strict match
1763 *                      iomode
1764 * -----	-----	------ -----
1765 * ANY		READ	N/A    true
1766 * ANY		RW	N/A    true
1767 * RW		READ	N/A    false
1768 * RW		RW	N/A    true
1769 * READ		READ	N/A    true
1770 * READ		RW	true   false
1771 * READ		RW	false  true
1772 */
1773static bool
1774pnfs_lseg_range_match(const struct pnfs_layout_range *ls_range,
1775		 const struct pnfs_layout_range *range,
1776		 bool strict_iomode)
1777{
1778	struct pnfs_layout_range range1;
1779
1780	if ((range->iomode == IOMODE_RW &&
1781	     ls_range->iomode != IOMODE_RW) ||
1782	    (range->iomode != ls_range->iomode &&
1783	     strict_iomode) ||
1784	    !pnfs_lseg_range_intersecting(ls_range, range))
1785		return false;
1786
1787	/* range1 covers only the first byte in the range */
1788	range1 = *range;
1789	range1.length = 1;
1790	return pnfs_lseg_range_contained(ls_range, &range1);
1791}
1792
1793/*
1794 * lookup range in layout
1795 */
1796static struct pnfs_layout_segment *
1797pnfs_find_lseg(struct pnfs_layout_hdr *lo,
1798		struct pnfs_layout_range *range,
1799		bool strict_iomode)
1800{
1801	struct pnfs_layout_segment *lseg, *ret = NULL;
1802
1803	dprintk("%s:Begin\n", __func__);
1804
1805	list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
1806		if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags) &&
1807		    pnfs_lseg_range_match(&lseg->pls_range, range,
1808					  strict_iomode)) {
1809			ret = pnfs_get_lseg(lseg);
1810			break;
1811		}
1812	}
1813
1814	dprintk("%s:Return lseg %p ref %d\n",
1815		__func__, ret, ret ? refcount_read(&ret->pls_refcount) : 0);
1816	return ret;
1817}
1818
1819/*
1820 * Use mdsthreshold hints set at each OPEN to determine if I/O should go
1821 * to the MDS or over pNFS
1822 *
1823 * The nfs_inode read_io and write_io fields are cumulative counters reset
1824 * when there are no layout segments. Note that in pnfs_update_layout iomode
1825 * is set to IOMODE_READ for a READ request, and set to IOMODE_RW for a
1826 * WRITE request.
1827 *
1828 * A return of true means use MDS I/O.
1829 *
1830 * From rfc 5661:
1831 * If a file's size is smaller than the file size threshold, data accesses
1832 * SHOULD be sent to the metadata server.  If an I/O request has a length that
1833 * is below the I/O size threshold, the I/O SHOULD be sent to the metadata
1834 * server.  If both file size and I/O size are provided, the client SHOULD
1835 * reach or exceed  both thresholds before sending its read or write
1836 * requests to the data server.
1837 */
1838static bool pnfs_within_mdsthreshold(struct nfs_open_context *ctx,
1839				     struct inode *ino, int iomode)
1840{
1841	struct nfs4_threshold *t = ctx->mdsthreshold;
1842	struct nfs_inode *nfsi = NFS_I(ino);
1843	loff_t fsize = i_size_read(ino);
1844	bool size = false, size_set = false, io = false, io_set = false, ret = false;
1845
1846	if (t == NULL)
1847		return ret;
1848
1849	dprintk("%s bm=0x%x rd_sz=%llu wr_sz=%llu rd_io=%llu wr_io=%llu\n",
1850		__func__, t->bm, t->rd_sz, t->wr_sz, t->rd_io_sz, t->wr_io_sz);
1851
1852	switch (iomode) {
1853	case IOMODE_READ:
1854		if (t->bm & THRESHOLD_RD) {
1855			dprintk("%s fsize %llu\n", __func__, fsize);
1856			size_set = true;
1857			if (fsize < t->rd_sz)
1858				size = true;
1859		}
1860		if (t->bm & THRESHOLD_RD_IO) {
1861			dprintk("%s nfsi->read_io %llu\n", __func__,
1862				nfsi->read_io);
1863			io_set = true;
1864			if (nfsi->read_io < t->rd_io_sz)
1865				io = true;
1866		}
1867		break;
1868	case IOMODE_RW:
1869		if (t->bm & THRESHOLD_WR) {
1870			dprintk("%s fsize %llu\n", __func__, fsize);
1871			size_set = true;
1872			if (fsize < t->wr_sz)
1873				size = true;
1874		}
1875		if (t->bm & THRESHOLD_WR_IO) {
1876			dprintk("%s nfsi->write_io %llu\n", __func__,
1877				nfsi->write_io);
1878			io_set = true;
1879			if (nfsi->write_io < t->wr_io_sz)
1880				io = true;
1881		}
1882		break;
1883	}
1884	if (size_set && io_set) {
1885		if (size && io)
1886			ret = true;
1887	} else if (size || io)
1888		ret = true;
1889
1890	dprintk("<-- %s size %d io %d ret %d\n", __func__, size, io, ret);
1891	return ret;
1892}
1893
1894static int pnfs_prepare_to_retry_layoutget(struct pnfs_layout_hdr *lo)
1895{
1896	/*
1897	 * send layoutcommit as it can hold up layoutreturn due to lseg
1898	 * reference
1899	 */
1900	pnfs_layoutcommit_inode(lo->plh_inode, false);
1901	return wait_on_bit_action(&lo->plh_flags, NFS_LAYOUT_RETURN,
1902				   nfs_wait_bit_killable,
1903				   TASK_KILLABLE);
1904}
1905
1906static void nfs_layoutget_begin(struct pnfs_layout_hdr *lo)
1907{
1908	atomic_inc(&lo->plh_outstanding);
1909}
1910
1911static void nfs_layoutget_end(struct pnfs_layout_hdr *lo)
1912{
1913	if (atomic_dec_and_test(&lo->plh_outstanding))
1914		wake_up_var(&lo->plh_outstanding);
1915}
1916
1917static bool pnfs_is_first_layoutget(struct pnfs_layout_hdr *lo)
1918{
1919	return test_bit(NFS_LAYOUT_FIRST_LAYOUTGET, &lo->plh_flags);
1920}
1921
1922static void pnfs_clear_first_layoutget(struct pnfs_layout_hdr *lo)
1923{
1924	unsigned long *bitlock = &lo->plh_flags;
1925
1926	clear_bit_unlock(NFS_LAYOUT_FIRST_LAYOUTGET, bitlock);
1927	smp_mb__after_atomic();
1928	wake_up_bit(bitlock, NFS_LAYOUT_FIRST_LAYOUTGET);
1929}
1930
1931static void _add_to_server_list(struct pnfs_layout_hdr *lo,
1932				struct nfs_server *server)
1933{
1934	if (!test_and_set_bit(NFS_LAYOUT_HASHED, &lo->plh_flags)) {
1935		struct nfs_client *clp = server->nfs_client;
1936
1937		/* The lo must be on the clp list if there is any
1938		 * chance of a CB_LAYOUTRECALL(FILE) coming in.
1939		 */
1940		spin_lock(&clp->cl_lock);
1941		list_add_tail_rcu(&lo->plh_layouts, &server->layouts);
1942		spin_unlock(&clp->cl_lock);
1943	}
1944}
1945
1946/*
1947 * Layout segment is retreived from the server if not cached.
1948 * The appropriate layout segment is referenced and returned to the caller.
1949 */
1950struct pnfs_layout_segment *
1951pnfs_update_layout(struct inode *ino,
1952		   struct nfs_open_context *ctx,
1953		   loff_t pos,
1954		   u64 count,
1955		   enum pnfs_iomode iomode,
1956		   bool strict_iomode,
1957		   gfp_t gfp_flags)
1958{
1959	struct pnfs_layout_range arg = {
1960		.iomode = iomode,
1961		.offset = pos,
1962		.length = count,
1963	};
1964	unsigned pg_offset;
1965	struct nfs_server *server = NFS_SERVER(ino);
1966	struct nfs_client *clp = server->nfs_client;
1967	struct pnfs_layout_hdr *lo = NULL;
1968	struct pnfs_layout_segment *lseg = NULL;
1969	struct nfs4_layoutget *lgp;
1970	nfs4_stateid stateid;
1971	long timeout = 0;
1972	unsigned long giveup = jiffies + (clp->cl_lease_time << 1);
1973	bool first;
1974
1975	if (!pnfs_enabled_sb(NFS_SERVER(ino))) {
1976		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1977				 PNFS_UPDATE_LAYOUT_NO_PNFS);
1978		goto out;
1979	}
1980
1981	if (pnfs_within_mdsthreshold(ctx, ino, iomode)) {
1982		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1983				 PNFS_UPDATE_LAYOUT_MDSTHRESH);
1984		goto out;
1985	}
1986
1987lookup_again:
1988	lseg = ERR_PTR(nfs4_client_recover_expired_lease(clp));
1989	if (IS_ERR(lseg))
1990		goto out;
1991	first = false;
1992	spin_lock(&ino->i_lock);
1993	lo = pnfs_find_alloc_layout(ino, ctx, gfp_flags);
1994	if (lo == NULL) {
1995		spin_unlock(&ino->i_lock);
1996		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1997				 PNFS_UPDATE_LAYOUT_NOMEM);
1998		goto out;
1999	}
2000
2001	/* Do we even need to bother with this? */
2002	if (test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
2003		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2004				 PNFS_UPDATE_LAYOUT_BULK_RECALL);
2005		dprintk("%s matches recall, use MDS\n", __func__);
2006		goto out_unlock;
2007	}
2008
2009	/* if LAYOUTGET already failed once we don't try again */
2010	if (pnfs_layout_io_test_failed(lo, iomode)) {
2011		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2012				 PNFS_UPDATE_LAYOUT_IO_TEST_FAIL);
2013		goto out_unlock;
2014	}
2015
2016	/*
2017	 * If the layout segment list is empty, but there are outstanding
2018	 * layoutget calls, then they might be subject to a layoutrecall.
2019	 */
2020	if ((list_empty(&lo->plh_segs) || !pnfs_layout_is_valid(lo)) &&
2021	    atomic_read(&lo->plh_outstanding) != 0) {
2022		spin_unlock(&ino->i_lock);
2023		lseg = ERR_PTR(wait_var_event_killable(&lo->plh_outstanding,
2024					!atomic_read(&lo->plh_outstanding)));
2025		if (IS_ERR(lseg))
2026			goto out_put_layout_hdr;
2027		pnfs_put_layout_hdr(lo);
2028		goto lookup_again;
2029	}
2030
2031	/*
2032	 * Because we free lsegs when sending LAYOUTRETURN, we need to wait
2033	 * for LAYOUTRETURN.
2034	 */
2035	if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
2036		spin_unlock(&ino->i_lock);
2037		dprintk("%s wait for layoutreturn\n", __func__);
2038		lseg = ERR_PTR(pnfs_prepare_to_retry_layoutget(lo));
2039		if (!IS_ERR(lseg)) {
2040			pnfs_put_layout_hdr(lo);
2041			dprintk("%s retrying\n", __func__);
2042			trace_pnfs_update_layout(ino, pos, count, iomode, lo,
2043						 lseg,
2044						 PNFS_UPDATE_LAYOUT_RETRY);
2045			goto lookup_again;
2046		}
2047		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2048					 PNFS_UPDATE_LAYOUT_RETURN);
2049		goto out_put_layout_hdr;
2050	}
2051
2052	lseg = pnfs_find_lseg(lo, &arg, strict_iomode);
2053	if (lseg) {
2054		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2055				PNFS_UPDATE_LAYOUT_FOUND_CACHED);
2056		goto out_unlock;
2057	}
2058
2059	/*
2060	 * Choose a stateid for the LAYOUTGET. If we don't have a layout
2061	 * stateid, or it has been invalidated, then we must use the open
2062	 * stateid.
2063	 */
2064	if (test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags)) {
2065		int status;
2066
2067		/*
2068		 * The first layoutget for the file. Need to serialize per
2069		 * RFC 5661 Errata 3208.
2070		 */
2071		if (test_and_set_bit(NFS_LAYOUT_FIRST_LAYOUTGET,
2072				     &lo->plh_flags)) {
2073			spin_unlock(&ino->i_lock);
2074			lseg = ERR_PTR(wait_on_bit(&lo->plh_flags,
2075						NFS_LAYOUT_FIRST_LAYOUTGET,
2076						TASK_KILLABLE));
2077			if (IS_ERR(lseg))
2078				goto out_put_layout_hdr;
2079			pnfs_put_layout_hdr(lo);
2080			dprintk("%s retrying\n", __func__);
2081			goto lookup_again;
2082		}
2083
2084		spin_unlock(&ino->i_lock);
2085		first = true;
2086		status = nfs4_select_rw_stateid(ctx->state,
2087					iomode == IOMODE_RW ? FMODE_WRITE : FMODE_READ,
2088					NULL, &stateid, NULL);
2089		if (status != 0) {
2090			lseg = ERR_PTR(status);
2091			trace_pnfs_update_layout(ino, pos, count,
2092					iomode, lo, lseg,
2093					PNFS_UPDATE_LAYOUT_INVALID_OPEN);
2094			nfs4_schedule_stateid_recovery(server, ctx->state);
2095			pnfs_clear_first_layoutget(lo);
2096			pnfs_put_layout_hdr(lo);
2097			goto lookup_again;
2098		}
2099		spin_lock(&ino->i_lock);
2100	} else {
2101		nfs4_stateid_copy(&stateid, &lo->plh_stateid);
2102	}
2103
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2104	if (pnfs_layoutgets_blocked(lo)) {
2105		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2106				PNFS_UPDATE_LAYOUT_BLOCKED);
2107		goto out_unlock;
2108	}
2109	nfs_layoutget_begin(lo);
2110	spin_unlock(&ino->i_lock);
2111
2112	_add_to_server_list(lo, server);
2113
2114	pg_offset = arg.offset & ~PAGE_MASK;
2115	if (pg_offset) {
2116		arg.offset -= pg_offset;
2117		arg.length += pg_offset;
2118	}
2119	if (arg.length != NFS4_MAX_UINT64)
2120		arg.length = PAGE_ALIGN(arg.length);
2121
2122	lgp = pnfs_alloc_init_layoutget_args(ino, ctx, &stateid, &arg, gfp_flags);
2123	if (!lgp) {
2124		trace_pnfs_update_layout(ino, pos, count, iomode, lo, NULL,
2125					 PNFS_UPDATE_LAYOUT_NOMEM);
2126		nfs_layoutget_end(lo);
2127		goto out_put_layout_hdr;
2128	}
2129
2130	lgp->lo = lo;
2131	pnfs_get_layout_hdr(lo);
2132
2133	lseg = nfs4_proc_layoutget(lgp, &timeout);
2134	trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2135				 PNFS_UPDATE_LAYOUT_SEND_LAYOUTGET);
2136	nfs_layoutget_end(lo);
2137	if (IS_ERR(lseg)) {
2138		switch(PTR_ERR(lseg)) {
2139		case -EBUSY:
2140			if (time_after(jiffies, giveup))
2141				lseg = NULL;
2142			break;
2143		case -ERECALLCONFLICT:
2144		case -EAGAIN:
2145			break;
2146		default:
2147			if (!nfs_error_is_fatal(PTR_ERR(lseg))) {
2148				pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
2149				lseg = NULL;
2150			}
2151			goto out_put_layout_hdr;
2152		}
2153		if (lseg) {
2154			if (first)
2155				pnfs_clear_first_layoutget(lo);
2156			trace_pnfs_update_layout(ino, pos, count,
2157				iomode, lo, lseg, PNFS_UPDATE_LAYOUT_RETRY);
2158			pnfs_put_layout_hdr(lo);
2159			goto lookup_again;
2160		}
2161	} else {
2162		pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
2163	}
2164
2165out_put_layout_hdr:
2166	if (first)
2167		pnfs_clear_first_layoutget(lo);
2168	trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2169				 PNFS_UPDATE_LAYOUT_EXIT);
2170	pnfs_put_layout_hdr(lo);
2171out:
2172	dprintk("%s: inode %s/%llu pNFS layout segment %s for "
2173			"(%s, offset: %llu, length: %llu)\n",
2174			__func__, ino->i_sb->s_id,
2175			(unsigned long long)NFS_FILEID(ino),
2176			IS_ERR_OR_NULL(lseg) ? "not found" : "found",
2177			iomode==IOMODE_RW ?  "read/write" : "read-only",
2178			(unsigned long long)pos,
2179			(unsigned long long)count);
2180	return lseg;
2181out_unlock:
2182	spin_unlock(&ino->i_lock);
2183	goto out_put_layout_hdr;
2184}
2185EXPORT_SYMBOL_GPL(pnfs_update_layout);
2186
2187static bool
2188pnfs_sanity_check_layout_range(struct pnfs_layout_range *range)
2189{
2190	switch (range->iomode) {
2191	case IOMODE_READ:
2192	case IOMODE_RW:
2193		break;
2194	default:
2195		return false;
2196	}
2197	if (range->offset == NFS4_MAX_UINT64)
2198		return false;
2199	if (range->length == 0)
2200		return false;
2201	if (range->length != NFS4_MAX_UINT64 &&
2202	    range->length > NFS4_MAX_UINT64 - range->offset)
2203		return false;
2204	return true;
2205}
2206
2207static struct pnfs_layout_hdr *
2208_pnfs_grab_empty_layout(struct inode *ino, struct nfs_open_context *ctx)
2209{
2210	struct pnfs_layout_hdr *lo;
2211
2212	spin_lock(&ino->i_lock);
2213	lo = pnfs_find_alloc_layout(ino, ctx, GFP_KERNEL);
2214	if (!lo)
2215		goto out_unlock;
2216	if (!test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags))
2217		goto out_unlock;
2218	if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags))
2219		goto out_unlock;
2220	if (pnfs_layoutgets_blocked(lo))
2221		goto out_unlock;
2222	if (test_and_set_bit(NFS_LAYOUT_FIRST_LAYOUTGET, &lo->plh_flags))
2223		goto out_unlock;
2224	nfs_layoutget_begin(lo);
2225	spin_unlock(&ino->i_lock);
2226	_add_to_server_list(lo, NFS_SERVER(ino));
2227	return lo;
2228
2229out_unlock:
2230	spin_unlock(&ino->i_lock);
2231	pnfs_put_layout_hdr(lo);
2232	return NULL;
2233}
2234
2235static void _lgopen_prepare_attached(struct nfs4_opendata *data,
2236				     struct nfs_open_context *ctx)
2237{
2238	struct inode *ino = data->dentry->d_inode;
2239	struct pnfs_layout_range rng = {
2240		.iomode = (data->o_arg.fmode & FMODE_WRITE) ?
2241			  IOMODE_RW: IOMODE_READ,
2242		.offset = 0,
2243		.length = NFS4_MAX_UINT64,
2244	};
2245	struct nfs4_layoutget *lgp;
2246	struct pnfs_layout_hdr *lo;
2247
2248	/* Heuristic: don't send layoutget if we have cached data */
2249	if (rng.iomode == IOMODE_READ &&
2250	   (i_size_read(ino) == 0 || ino->i_mapping->nrpages != 0))
2251		return;
2252
2253	lo = _pnfs_grab_empty_layout(ino, ctx);
2254	if (!lo)
2255		return;
2256	lgp = pnfs_alloc_init_layoutget_args(ino, ctx, &current_stateid,
2257					     &rng, GFP_KERNEL);
2258	if (!lgp) {
2259		pnfs_clear_first_layoutget(lo);
2260		nfs_layoutget_end(lo);
2261		pnfs_put_layout_hdr(lo);
2262		return;
2263	}
2264	lgp->lo = lo;
2265	data->lgp = lgp;
2266	data->o_arg.lg_args = &lgp->args;
2267	data->o_res.lg_res = &lgp->res;
2268}
2269
2270static void _lgopen_prepare_floating(struct nfs4_opendata *data,
2271				     struct nfs_open_context *ctx)
2272{
2273	struct inode *ino = data->dentry->d_inode;
2274	struct pnfs_layout_range rng = {
2275		.iomode = (data->o_arg.fmode & FMODE_WRITE) ?
2276			  IOMODE_RW: IOMODE_READ,
2277		.offset = 0,
2278		.length = NFS4_MAX_UINT64,
2279	};
2280	struct nfs4_layoutget *lgp;
2281
2282	lgp = pnfs_alloc_init_layoutget_args(ino, ctx, &current_stateid,
2283					     &rng, GFP_KERNEL);
2284	if (!lgp)
2285		return;
2286	data->lgp = lgp;
2287	data->o_arg.lg_args = &lgp->args;
2288	data->o_res.lg_res = &lgp->res;
2289}
2290
2291void pnfs_lgopen_prepare(struct nfs4_opendata *data,
2292			 struct nfs_open_context *ctx)
2293{
2294	struct nfs_server *server = NFS_SERVER(data->dir->d_inode);
2295
2296	if (!(pnfs_enabled_sb(server) &&
2297	      server->pnfs_curr_ld->flags & PNFS_LAYOUTGET_ON_OPEN))
2298		return;
2299	/* Could check on max_ops, but currently hardcoded high enough */
2300	if (!nfs_server_capable(data->dir->d_inode, NFS_CAP_LGOPEN))
2301		return;
2302	if (data->lgp)
2303		return;
2304	if (data->state)
2305		_lgopen_prepare_attached(data, ctx);
2306	else
2307		_lgopen_prepare_floating(data, ctx);
2308}
2309
2310void pnfs_parse_lgopen(struct inode *ino, struct nfs4_layoutget *lgp,
2311		       struct nfs_open_context *ctx)
2312{
2313	struct pnfs_layout_hdr *lo;
2314	struct pnfs_layout_segment *lseg;
2315	struct nfs_server *srv = NFS_SERVER(ino);
2316	u32 iomode;
2317
2318	if (!lgp)
2319		return;
2320	dprintk("%s: entered with status %i\n", __func__, lgp->res.status);
2321	if (lgp->res.status) {
2322		switch (lgp->res.status) {
2323		default:
2324			break;
2325		/*
2326		 * Halt lgopen attempts if the server doesn't recognise
2327		 * the "current stateid" value, the layout type, or the
2328		 * layoutget operation as being valid.
2329		 * Also if it complains about too many ops in the compound
2330		 * or of the request/reply being too big.
2331		 */
2332		case -NFS4ERR_BAD_STATEID:
2333		case -NFS4ERR_NOTSUPP:
2334		case -NFS4ERR_REP_TOO_BIG:
2335		case -NFS4ERR_REP_TOO_BIG_TO_CACHE:
2336		case -NFS4ERR_REQ_TOO_BIG:
2337		case -NFS4ERR_TOO_MANY_OPS:
2338		case -NFS4ERR_UNKNOWN_LAYOUTTYPE:
2339			srv->caps &= ~NFS_CAP_LGOPEN;
2340		}
2341		return;
2342	}
2343	if (!lgp->lo) {
2344		lo = _pnfs_grab_empty_layout(ino, ctx);
2345		if (!lo)
2346			return;
2347		lgp->lo = lo;
2348	} else
2349		lo = lgp->lo;
2350
2351	lseg = pnfs_layout_process(lgp);
2352	if (!IS_ERR(lseg)) {
2353		iomode = lgp->args.range.iomode;
2354		pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
2355		pnfs_put_lseg(lseg);
2356	}
2357}
2358
2359void nfs4_lgopen_release(struct nfs4_layoutget *lgp)
2360{
2361	if (lgp != NULL) {
2362		if (lgp->lo) {
2363			pnfs_clear_first_layoutget(lgp->lo);
2364			nfs_layoutget_end(lgp->lo);
 
 
2365		}
2366		pnfs_layoutget_free(lgp);
2367	}
2368}
2369
2370struct pnfs_layout_segment *
2371pnfs_layout_process(struct nfs4_layoutget *lgp)
2372{
2373	struct pnfs_layout_hdr *lo = lgp->lo;
2374	struct nfs4_layoutget_res *res = &lgp->res;
2375	struct pnfs_layout_segment *lseg;
2376	struct inode *ino = lo->plh_inode;
2377	LIST_HEAD(free_me);
2378
2379	if (!pnfs_sanity_check_layout_range(&res->range))
2380		return ERR_PTR(-EINVAL);
2381
2382	/* Inject layout blob into I/O device driver */
2383	lseg = NFS_SERVER(ino)->pnfs_curr_ld->alloc_lseg(lo, res, lgp->gfp_flags);
2384	if (IS_ERR_OR_NULL(lseg)) {
2385		if (!lseg)
2386			lseg = ERR_PTR(-ENOMEM);
2387
2388		dprintk("%s: Could not allocate layout: error %ld\n",
2389		       __func__, PTR_ERR(lseg));
2390		return lseg;
2391	}
2392
2393	pnfs_init_lseg(lo, lseg, &res->range, &res->stateid);
2394
2395	spin_lock(&ino->i_lock);
2396	if (pnfs_layoutgets_blocked(lo)) {
2397		dprintk("%s forget reply due to state\n", __func__);
2398		goto out_forget;
2399	}
2400
2401	if (!pnfs_layout_is_valid(lo) && !pnfs_is_first_layoutget(lo))
2402		goto out_forget;
2403
2404	if (nfs4_stateid_match_other(&lo->plh_stateid, &res->stateid)) {
2405		/* existing state ID, make sure the sequence number matches. */
2406		if (pnfs_layout_stateid_blocked(lo, &res->stateid)) {
2407			if (!pnfs_layout_is_valid(lo))
2408				lo->plh_barrier = 0;
2409			dprintk("%s forget reply due to sequence\n", __func__);
2410			goto out_forget;
2411		}
2412		pnfs_set_layout_stateid(lo, &res->stateid, lgp->cred, false);
2413	} else if (pnfs_layout_is_valid(lo)) {
2414		/*
2415		 * We got an entirely new state ID.  Mark all segments for the
2416		 * inode invalid, and retry the layoutget
2417		 */
2418		struct pnfs_layout_range range = {
2419			.iomode = IOMODE_ANY,
2420			.length = NFS4_MAX_UINT64,
2421		};
2422		pnfs_mark_matching_lsegs_return(lo, &free_me, &range, 0);
2423		goto out_forget;
2424	} else {
2425		/* We have a completely new layout */
2426		pnfs_set_layout_stateid(lo, &res->stateid, lgp->cred, true);
2427	}
2428
2429	pnfs_get_lseg(lseg);
2430	pnfs_layout_insert_lseg(lo, lseg, &free_me);
2431
2432
2433	if (res->return_on_close)
2434		set_bit(NFS_LSEG_ROC, &lseg->pls_flags);
2435
2436	spin_unlock(&ino->i_lock);
2437	pnfs_free_lseg_list(&free_me);
2438	return lseg;
2439
2440out_forget:
2441	spin_unlock(&ino->i_lock);
2442	lseg->pls_layout = lo;
2443	NFS_SERVER(ino)->pnfs_curr_ld->free_lseg(lseg);
2444	return ERR_PTR(-EAGAIN);
2445}
2446
2447/**
2448 * pnfs_mark_matching_lsegs_return - Free or return matching layout segments
2449 * @lo: pointer to layout header
2450 * @tmp_list: list header to be used with pnfs_free_lseg_list()
2451 * @return_range: describe layout segment ranges to be returned
2452 * @seq: stateid seqid to match
2453 *
2454 * This function is mainly intended for use by layoutrecall. It attempts
2455 * to free the layout segment immediately, or else to mark it for return
2456 * as soon as its reference count drops to zero.
2457 *
2458 * Returns
2459 * - 0: a layoutreturn needs to be scheduled.
2460 * - EBUSY: there are layout segment that are still in use.
2461 * - ENOENT: there are no layout segments that need to be returned.
2462 */
2463int
2464pnfs_mark_matching_lsegs_return(struct pnfs_layout_hdr *lo,
2465				struct list_head *tmp_list,
2466				const struct pnfs_layout_range *return_range,
2467				u32 seq)
2468{
2469	struct pnfs_layout_segment *lseg, *next;
2470	int remaining = 0;
2471
2472	dprintk("%s:Begin lo %p\n", __func__, lo);
2473
2474	assert_spin_locked(&lo->plh_inode->i_lock);
2475
2476	if (test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
2477		tmp_list = &lo->plh_return_segs;
2478
2479	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
2480		if (pnfs_match_lseg_recall(lseg, return_range, seq)) {
2481			dprintk("%s: marking lseg %p iomode %d "
2482				"offset %llu length %llu\n", __func__,
2483				lseg, lseg->pls_range.iomode,
2484				lseg->pls_range.offset,
2485				lseg->pls_range.length);
2486			if (test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
2487				tmp_list = &lo->plh_return_segs;
2488			if (mark_lseg_invalid(lseg, tmp_list))
2489				continue;
2490			remaining++;
2491			set_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
2492		}
2493
2494	if (remaining) {
2495		pnfs_set_plh_return_info(lo, return_range->iomode, seq);
2496		return -EBUSY;
2497	}
2498
2499	if (!list_empty(&lo->plh_return_segs)) {
2500		pnfs_set_plh_return_info(lo, return_range->iomode, seq);
2501		return 0;
2502	}
2503
2504	return -ENOENT;
2505}
2506
2507static void
2508pnfs_mark_layout_for_return(struct inode *inode,
2509			    const struct pnfs_layout_range *range)
2510{
2511	struct pnfs_layout_hdr *lo;
2512	bool return_now = false;
2513
2514	spin_lock(&inode->i_lock);
2515	lo = NFS_I(inode)->layout;
2516	if (!pnfs_layout_is_valid(lo)) {
2517		spin_unlock(&inode->i_lock);
2518		return;
2519	}
2520	pnfs_set_plh_return_info(lo, range->iomode, 0);
2521	/*
2522	 * mark all matching lsegs so that we are sure to have no live
2523	 * segments at hand when sending layoutreturn. See pnfs_put_lseg()
2524	 * for how it works.
2525	 */
2526	if (pnfs_mark_matching_lsegs_return(lo, &lo->plh_return_segs, range, 0) != -EBUSY) {
2527		const struct cred *cred;
2528		nfs4_stateid stateid;
2529		enum pnfs_iomode iomode;
2530
2531		return_now = pnfs_prepare_layoutreturn(lo, &stateid, &cred, &iomode);
2532		spin_unlock(&inode->i_lock);
2533		if (return_now)
2534			pnfs_send_layoutreturn(lo, &stateid, &cred, iomode, false);
2535	} else {
2536		spin_unlock(&inode->i_lock);
2537		nfs_commit_inode(inode, 0);
2538	}
2539}
2540
2541void pnfs_error_mark_layout_for_return(struct inode *inode,
2542				       struct pnfs_layout_segment *lseg)
2543{
2544	struct pnfs_layout_range range = {
2545		.iomode = lseg->pls_range.iomode,
2546		.offset = 0,
2547		.length = NFS4_MAX_UINT64,
2548	};
2549
2550	pnfs_mark_layout_for_return(inode, &range);
2551}
2552EXPORT_SYMBOL_GPL(pnfs_error_mark_layout_for_return);
2553
2554static bool
2555pnfs_layout_can_be_returned(struct pnfs_layout_hdr *lo)
2556{
2557	return pnfs_layout_is_valid(lo) &&
2558		!test_bit(NFS_LAYOUT_INODE_FREEING, &lo->plh_flags) &&
2559		!test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags);
2560}
2561
2562static struct pnfs_layout_segment *
2563pnfs_find_first_lseg(struct pnfs_layout_hdr *lo,
2564		     const struct pnfs_layout_range *range,
2565		     enum pnfs_iomode iomode)
2566{
2567	struct pnfs_layout_segment *lseg;
2568
2569	list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
2570		if (!test_bit(NFS_LSEG_VALID, &lseg->pls_flags))
2571			continue;
2572		if (test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
2573			continue;
2574		if (lseg->pls_range.iomode != iomode && iomode != IOMODE_ANY)
2575			continue;
2576		if (pnfs_lseg_range_intersecting(&lseg->pls_range, range))
2577			return lseg;
2578	}
2579	return NULL;
2580}
2581
2582/* Find open file states whose mode matches that of the range */
2583static bool
2584pnfs_should_return_unused_layout(struct pnfs_layout_hdr *lo,
2585				 const struct pnfs_layout_range *range)
2586{
2587	struct list_head *head;
2588	struct nfs_open_context *ctx;
2589	fmode_t mode = 0;
2590
2591	if (!pnfs_layout_can_be_returned(lo) ||
2592	    !pnfs_find_first_lseg(lo, range, range->iomode))
2593		return false;
2594
2595	head = &NFS_I(lo->plh_inode)->open_files;
2596	list_for_each_entry_rcu(ctx, head, list) {
2597		if (ctx->state)
2598			mode |= ctx->state->state & (FMODE_READ|FMODE_WRITE);
2599	}
2600
2601	switch (range->iomode) {
2602	default:
2603		break;
2604	case IOMODE_READ:
2605		mode &= ~FMODE_WRITE;
2606		break;
2607	case IOMODE_RW:
2608		if (pnfs_find_first_lseg(lo, range, IOMODE_READ))
2609			mode &= ~FMODE_READ;
2610	}
2611	return mode == 0;
2612}
2613
2614static int
2615pnfs_layout_return_unused_byserver(struct nfs_server *server, void *data)
2616{
2617	const struct pnfs_layout_range *range = data;
2618	struct pnfs_layout_hdr *lo;
2619	struct inode *inode;
2620restart:
2621	rcu_read_lock();
2622	list_for_each_entry_rcu(lo, &server->layouts, plh_layouts) {
2623		if (!pnfs_layout_can_be_returned(lo) ||
2624		    test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
2625			continue;
2626		inode = lo->plh_inode;
2627		spin_lock(&inode->i_lock);
2628		if (!pnfs_should_return_unused_layout(lo, range)) {
2629			spin_unlock(&inode->i_lock);
2630			continue;
2631		}
2632		spin_unlock(&inode->i_lock);
2633		inode = pnfs_grab_inode_layout_hdr(lo);
2634		if (!inode)
2635			continue;
2636		rcu_read_unlock();
2637		pnfs_mark_layout_for_return(inode, range);
2638		iput(inode);
2639		cond_resched();
2640		goto restart;
2641	}
2642	rcu_read_unlock();
2643	return 0;
2644}
2645
2646void
2647pnfs_layout_return_unused_byclid(struct nfs_client *clp,
2648				 enum pnfs_iomode iomode)
2649{
2650	struct pnfs_layout_range range = {
2651		.iomode = iomode,
2652		.offset = 0,
2653		.length = NFS4_MAX_UINT64,
2654	};
2655
2656	nfs_client_for_each_server(clp, pnfs_layout_return_unused_byserver,
2657			&range);
2658}
2659
2660void
2661pnfs_generic_pg_check_layout(struct nfs_pageio_descriptor *pgio)
2662{
2663	if (pgio->pg_lseg == NULL ||
2664	    test_bit(NFS_LSEG_VALID, &pgio->pg_lseg->pls_flags))
2665		return;
2666	pnfs_put_lseg(pgio->pg_lseg);
2667	pgio->pg_lseg = NULL;
2668}
2669EXPORT_SYMBOL_GPL(pnfs_generic_pg_check_layout);
2670
2671/*
2672 * Check for any intersection between the request and the pgio->pg_lseg,
2673 * and if none, put this pgio->pg_lseg away.
2674 */
2675void
2676pnfs_generic_pg_check_range(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
2677{
2678	if (pgio->pg_lseg && !pnfs_lseg_request_intersecting(pgio->pg_lseg, req)) {
2679		pnfs_put_lseg(pgio->pg_lseg);
2680		pgio->pg_lseg = NULL;
2681	}
2682}
2683EXPORT_SYMBOL_GPL(pnfs_generic_pg_check_range);
2684
2685void
2686pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
2687{
2688	u64 rd_size;
2689
2690	pnfs_generic_pg_check_layout(pgio);
2691	pnfs_generic_pg_check_range(pgio, req);
2692	if (pgio->pg_lseg == NULL) {
2693		if (pgio->pg_dreq == NULL)
2694			rd_size = i_size_read(pgio->pg_inode) - req_offset(req);
2695		else
2696			rd_size = nfs_dreq_bytes_left(pgio->pg_dreq);
2697
2698		pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
2699						   nfs_req_openctx(req),
2700						   req_offset(req),
2701						   rd_size,
2702						   IOMODE_READ,
2703						   false,
2704						   GFP_KERNEL);
2705		if (IS_ERR(pgio->pg_lseg)) {
2706			pgio->pg_error = PTR_ERR(pgio->pg_lseg);
2707			pgio->pg_lseg = NULL;
2708			return;
2709		}
2710	}
2711	/* If no lseg, fall back to read through mds */
2712	if (pgio->pg_lseg == NULL)
2713		nfs_pageio_reset_read_mds(pgio);
2714
2715}
2716EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_read);
2717
2718void
2719pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio,
2720			   struct nfs_page *req, u64 wb_size)
2721{
2722	pnfs_generic_pg_check_layout(pgio);
2723	pnfs_generic_pg_check_range(pgio, req);
2724	if (pgio->pg_lseg == NULL) {
2725		pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
2726						   nfs_req_openctx(req),
2727						   req_offset(req),
2728						   wb_size,
2729						   IOMODE_RW,
2730						   false,
2731						   GFP_KERNEL);
2732		if (IS_ERR(pgio->pg_lseg)) {
2733			pgio->pg_error = PTR_ERR(pgio->pg_lseg);
2734			pgio->pg_lseg = NULL;
2735			return;
2736		}
2737	}
2738	/* If no lseg, fall back to write through mds */
2739	if (pgio->pg_lseg == NULL)
2740		nfs_pageio_reset_write_mds(pgio);
2741}
2742EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_write);
2743
2744void
2745pnfs_generic_pg_cleanup(struct nfs_pageio_descriptor *desc)
2746{
2747	if (desc->pg_lseg) {
2748		pnfs_put_lseg(desc->pg_lseg);
2749		desc->pg_lseg = NULL;
2750	}
2751}
2752EXPORT_SYMBOL_GPL(pnfs_generic_pg_cleanup);
2753
2754/*
2755 * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
2756 * of bytes (maximum @req->wb_bytes) that can be coalesced.
2757 */
2758size_t
2759pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio,
2760		     struct nfs_page *prev, struct nfs_page *req)
2761{
2762	unsigned int size;
2763	u64 seg_end, req_start, seg_left;
2764
2765	size = nfs_generic_pg_test(pgio, prev, req);
2766	if (!size)
2767		return 0;
2768
2769	/*
2770	 * 'size' contains the number of bytes left in the current page (up
2771	 * to the original size asked for in @req->wb_bytes).
2772	 *
2773	 * Calculate how many bytes are left in the layout segment
2774	 * and if there are less bytes than 'size', return that instead.
2775	 *
2776	 * Please also note that 'end_offset' is actually the offset of the
2777	 * first byte that lies outside the pnfs_layout_range. FIXME?
2778	 *
2779	 */
2780	if (pgio->pg_lseg) {
2781		seg_end = pnfs_end_offset(pgio->pg_lseg->pls_range.offset,
2782				     pgio->pg_lseg->pls_range.length);
2783		req_start = req_offset(req);
2784
2785		/* start of request is past the last byte of this segment */
2786		if (req_start >= seg_end)
2787			return 0;
2788
2789		/* adjust 'size' iff there are fewer bytes left in the
2790		 * segment than what nfs_generic_pg_test returned */
2791		seg_left = seg_end - req_start;
2792		if (seg_left < size)
2793			size = (unsigned int)seg_left;
2794	}
2795
2796	return size;
2797}
2798EXPORT_SYMBOL_GPL(pnfs_generic_pg_test);
2799
2800int pnfs_write_done_resend_to_mds(struct nfs_pgio_header *hdr)
2801{
2802	struct nfs_pageio_descriptor pgio;
2803
2804	/* Resend all requests through the MDS */
2805	nfs_pageio_init_write(&pgio, hdr->inode, FLUSH_STABLE, true,
2806			      hdr->completion_ops);
2807	set_bit(NFS_CONTEXT_RESEND_WRITES, &hdr->args.context->flags);
2808	return nfs_pageio_resend(&pgio, hdr);
2809}
2810EXPORT_SYMBOL_GPL(pnfs_write_done_resend_to_mds);
2811
2812static void pnfs_ld_handle_write_error(struct nfs_pgio_header *hdr)
2813{
2814
2815	dprintk("pnfs write error = %d\n", hdr->pnfs_error);
2816	if (NFS_SERVER(hdr->inode)->pnfs_curr_ld->flags &
2817	    PNFS_LAYOUTRET_ON_ERROR) {
2818		pnfs_return_layout(hdr->inode);
2819	}
2820	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))
2821		hdr->task.tk_status = pnfs_write_done_resend_to_mds(hdr);
2822}
2823
2824/*
2825 * Called by non rpc-based layout drivers
2826 */
2827void pnfs_ld_write_done(struct nfs_pgio_header *hdr)
2828{
2829	if (likely(!hdr->pnfs_error)) {
2830		pnfs_set_layoutcommit(hdr->inode, hdr->lseg,
2831				hdr->mds_offset + hdr->res.count);
2832		hdr->mds_ops->rpc_call_done(&hdr->task, hdr);
2833	}
2834	trace_nfs4_pnfs_write(hdr, hdr->pnfs_error);
2835	if (unlikely(hdr->pnfs_error))
2836		pnfs_ld_handle_write_error(hdr);
2837	hdr->mds_ops->rpc_release(hdr);
2838}
2839EXPORT_SYMBOL_GPL(pnfs_ld_write_done);
2840
2841static void
2842pnfs_write_through_mds(struct nfs_pageio_descriptor *desc,
2843		struct nfs_pgio_header *hdr)
2844{
2845	struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
2846
2847	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2848		list_splice_tail_init(&hdr->pages, &mirror->pg_list);
2849		nfs_pageio_reset_write_mds(desc);
2850		mirror->pg_recoalesce = 1;
2851	}
2852	hdr->completion_ops->completion(hdr);
2853}
2854
2855static enum pnfs_try_status
2856pnfs_try_to_write_data(struct nfs_pgio_header *hdr,
2857			const struct rpc_call_ops *call_ops,
2858			struct pnfs_layout_segment *lseg,
2859			int how)
2860{
2861	struct inode *inode = hdr->inode;
2862	enum pnfs_try_status trypnfs;
2863	struct nfs_server *nfss = NFS_SERVER(inode);
2864
2865	hdr->mds_ops = call_ops;
2866
2867	dprintk("%s: Writing ino:%lu %u@%llu (how %d)\n", __func__,
2868		inode->i_ino, hdr->args.count, hdr->args.offset, how);
2869	trypnfs = nfss->pnfs_curr_ld->write_pagelist(hdr, how);
2870	if (trypnfs != PNFS_NOT_ATTEMPTED)
2871		nfs_inc_stats(inode, NFSIOS_PNFS_WRITE);
2872	dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
2873	return trypnfs;
2874}
2875
2876static void
2877pnfs_do_write(struct nfs_pageio_descriptor *desc,
2878	      struct nfs_pgio_header *hdr, int how)
2879{
2880	const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
2881	struct pnfs_layout_segment *lseg = desc->pg_lseg;
2882	enum pnfs_try_status trypnfs;
2883
2884	trypnfs = pnfs_try_to_write_data(hdr, call_ops, lseg, how);
2885	switch (trypnfs) {
2886	case PNFS_NOT_ATTEMPTED:
2887		pnfs_write_through_mds(desc, hdr);
2888		break;
2889	case PNFS_ATTEMPTED:
2890		break;
2891	case PNFS_TRY_AGAIN:
2892		/* cleanup hdr and prepare to redo pnfs */
2893		if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2894			struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
2895			list_splice_init(&hdr->pages, &mirror->pg_list);
2896			mirror->pg_recoalesce = 1;
2897		}
2898		hdr->mds_ops->rpc_release(hdr);
2899	}
2900}
2901
2902static void pnfs_writehdr_free(struct nfs_pgio_header *hdr)
2903{
2904	pnfs_put_lseg(hdr->lseg);
2905	nfs_pgio_header_free(hdr);
2906}
2907
2908int
2909pnfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
2910{
2911	struct nfs_pgio_header *hdr;
2912	int ret;
2913
2914	hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
2915	if (!hdr) {
2916		desc->pg_error = -ENOMEM;
2917		return desc->pg_error;
2918	}
2919	nfs_pgheader_init(desc, hdr, pnfs_writehdr_free);
2920
2921	hdr->lseg = pnfs_get_lseg(desc->pg_lseg);
2922	ret = nfs_generic_pgio(desc, hdr);
2923	if (!ret)
2924		pnfs_do_write(desc, hdr, desc->pg_ioflags);
2925
2926	return ret;
2927}
2928EXPORT_SYMBOL_GPL(pnfs_generic_pg_writepages);
2929
2930int pnfs_read_done_resend_to_mds(struct nfs_pgio_header *hdr)
2931{
2932	struct nfs_pageio_descriptor pgio;
2933
2934	/* Resend all requests through the MDS */
2935	nfs_pageio_init_read(&pgio, hdr->inode, true, hdr->completion_ops);
2936	return nfs_pageio_resend(&pgio, hdr);
2937}
2938EXPORT_SYMBOL_GPL(pnfs_read_done_resend_to_mds);
2939
2940static void pnfs_ld_handle_read_error(struct nfs_pgio_header *hdr)
2941{
2942	dprintk("pnfs read error = %d\n", hdr->pnfs_error);
2943	if (NFS_SERVER(hdr->inode)->pnfs_curr_ld->flags &
2944	    PNFS_LAYOUTRET_ON_ERROR) {
2945		pnfs_return_layout(hdr->inode);
2946	}
2947	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))
2948		hdr->task.tk_status = pnfs_read_done_resend_to_mds(hdr);
2949}
2950
2951/*
2952 * Called by non rpc-based layout drivers
2953 */
2954void pnfs_ld_read_done(struct nfs_pgio_header *hdr)
2955{
2956	if (likely(!hdr->pnfs_error))
2957		hdr->mds_ops->rpc_call_done(&hdr->task, hdr);
2958	trace_nfs4_pnfs_read(hdr, hdr->pnfs_error);
2959	if (unlikely(hdr->pnfs_error))
2960		pnfs_ld_handle_read_error(hdr);
2961	hdr->mds_ops->rpc_release(hdr);
2962}
2963EXPORT_SYMBOL_GPL(pnfs_ld_read_done);
2964
2965static void
2966pnfs_read_through_mds(struct nfs_pageio_descriptor *desc,
2967		struct nfs_pgio_header *hdr)
2968{
2969	struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
2970
2971	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2972		list_splice_tail_init(&hdr->pages, &mirror->pg_list);
2973		nfs_pageio_reset_read_mds(desc);
2974		mirror->pg_recoalesce = 1;
2975	}
2976	hdr->completion_ops->completion(hdr);
2977}
2978
2979/*
2980 * Call the appropriate parallel I/O subsystem read function.
2981 */
2982static enum pnfs_try_status
2983pnfs_try_to_read_data(struct nfs_pgio_header *hdr,
2984		       const struct rpc_call_ops *call_ops,
2985		       struct pnfs_layout_segment *lseg)
2986{
2987	struct inode *inode = hdr->inode;
2988	struct nfs_server *nfss = NFS_SERVER(inode);
2989	enum pnfs_try_status trypnfs;
2990
2991	hdr->mds_ops = call_ops;
2992
2993	dprintk("%s: Reading ino:%lu %u@%llu\n",
2994		__func__, inode->i_ino, hdr->args.count, hdr->args.offset);
2995
2996	trypnfs = nfss->pnfs_curr_ld->read_pagelist(hdr);
2997	if (trypnfs != PNFS_NOT_ATTEMPTED)
2998		nfs_inc_stats(inode, NFSIOS_PNFS_READ);
2999	dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
3000	return trypnfs;
3001}
3002
3003/* Resend all requests through pnfs. */
3004void pnfs_read_resend_pnfs(struct nfs_pgio_header *hdr,
3005			   unsigned int mirror_idx)
3006{
3007	struct nfs_pageio_descriptor pgio;
3008
3009	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
3010		/* Prevent deadlocks with layoutreturn! */
3011		pnfs_put_lseg(hdr->lseg);
3012		hdr->lseg = NULL;
3013
3014		nfs_pageio_init_read(&pgio, hdr->inode, false,
3015					hdr->completion_ops);
3016		pgio.pg_mirror_idx = mirror_idx;
3017		hdr->task.tk_status = nfs_pageio_resend(&pgio, hdr);
3018	}
3019}
3020EXPORT_SYMBOL_GPL(pnfs_read_resend_pnfs);
3021
3022static void
3023pnfs_do_read(struct nfs_pageio_descriptor *desc, struct nfs_pgio_header *hdr)
3024{
3025	const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
3026	struct pnfs_layout_segment *lseg = desc->pg_lseg;
3027	enum pnfs_try_status trypnfs;
3028
3029	trypnfs = pnfs_try_to_read_data(hdr, call_ops, lseg);
3030	switch (trypnfs) {
3031	case PNFS_NOT_ATTEMPTED:
3032		pnfs_read_through_mds(desc, hdr);
3033		break;
3034	case PNFS_ATTEMPTED:
3035		break;
3036	case PNFS_TRY_AGAIN:
3037		/* cleanup hdr and prepare to redo pnfs */
3038		if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
3039			struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
3040			list_splice_init(&hdr->pages, &mirror->pg_list);
3041			mirror->pg_recoalesce = 1;
3042		}
3043		hdr->mds_ops->rpc_release(hdr);
3044	}
3045}
3046
3047static void pnfs_readhdr_free(struct nfs_pgio_header *hdr)
3048{
3049	pnfs_put_lseg(hdr->lseg);
3050	nfs_pgio_header_free(hdr);
3051}
3052
3053int
3054pnfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc)
3055{
3056	struct nfs_pgio_header *hdr;
3057	int ret;
3058
3059	hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
3060	if (!hdr) {
3061		desc->pg_error = -ENOMEM;
3062		return desc->pg_error;
3063	}
3064	nfs_pgheader_init(desc, hdr, pnfs_readhdr_free);
3065	hdr->lseg = pnfs_get_lseg(desc->pg_lseg);
3066	ret = nfs_generic_pgio(desc, hdr);
3067	if (!ret)
3068		pnfs_do_read(desc, hdr);
3069	return ret;
3070}
3071EXPORT_SYMBOL_GPL(pnfs_generic_pg_readpages);
3072
3073static void pnfs_clear_layoutcommitting(struct inode *inode)
3074{
3075	unsigned long *bitlock = &NFS_I(inode)->flags;
3076
3077	clear_bit_unlock(NFS_INO_LAYOUTCOMMITTING, bitlock);
3078	smp_mb__after_atomic();
3079	wake_up_bit(bitlock, NFS_INO_LAYOUTCOMMITTING);
3080}
3081
3082/*
3083 * There can be multiple RW segments.
3084 */
3085static void pnfs_list_write_lseg(struct inode *inode, struct list_head *listp)
3086{
3087	struct pnfs_layout_segment *lseg;
3088
3089	list_for_each_entry(lseg, &NFS_I(inode)->layout->plh_segs, pls_list) {
3090		if (lseg->pls_range.iomode == IOMODE_RW &&
3091		    test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
3092			list_add(&lseg->pls_lc_list, listp);
3093	}
3094}
3095
3096static void pnfs_list_write_lseg_done(struct inode *inode, struct list_head *listp)
3097{
3098	struct pnfs_layout_segment *lseg, *tmp;
3099
3100	/* Matched by references in pnfs_set_layoutcommit */
3101	list_for_each_entry_safe(lseg, tmp, listp, pls_lc_list) {
3102		list_del_init(&lseg->pls_lc_list);
3103		pnfs_put_lseg(lseg);
3104	}
3105
3106	pnfs_clear_layoutcommitting(inode);
3107}
3108
3109void pnfs_set_lo_fail(struct pnfs_layout_segment *lseg)
3110{
3111	pnfs_layout_io_set_failed(lseg->pls_layout, lseg->pls_range.iomode);
3112}
3113EXPORT_SYMBOL_GPL(pnfs_set_lo_fail);
3114
3115void
3116pnfs_set_layoutcommit(struct inode *inode, struct pnfs_layout_segment *lseg,
3117		loff_t end_pos)
3118{
3119	struct nfs_inode *nfsi = NFS_I(inode);
3120	bool mark_as_dirty = false;
3121
3122	spin_lock(&inode->i_lock);
3123	if (!test_and_set_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags)) {
3124		nfsi->layout->plh_lwb = end_pos;
3125		mark_as_dirty = true;
3126		dprintk("%s: Set layoutcommit for inode %lu ",
3127			__func__, inode->i_ino);
3128	} else if (end_pos > nfsi->layout->plh_lwb)
3129		nfsi->layout->plh_lwb = end_pos;
3130	if (!test_and_set_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags)) {
3131		/* references matched in nfs4_layoutcommit_release */
3132		pnfs_get_lseg(lseg);
3133	}
3134	spin_unlock(&inode->i_lock);
3135	dprintk("%s: lseg %p end_pos %llu\n",
3136		__func__, lseg, nfsi->layout->plh_lwb);
3137
3138	/* if pnfs_layoutcommit_inode() runs between inode locks, the next one
3139	 * will be a noop because NFS_INO_LAYOUTCOMMIT will not be set */
3140	if (mark_as_dirty)
3141		mark_inode_dirty_sync(inode);
3142}
3143EXPORT_SYMBOL_GPL(pnfs_set_layoutcommit);
3144
3145void pnfs_cleanup_layoutcommit(struct nfs4_layoutcommit_data *data)
3146{
3147	struct nfs_server *nfss = NFS_SERVER(data->args.inode);
3148
3149	if (nfss->pnfs_curr_ld->cleanup_layoutcommit)
3150		nfss->pnfs_curr_ld->cleanup_layoutcommit(data);
3151	pnfs_list_write_lseg_done(data->args.inode, &data->lseg_list);
3152}
3153
3154/*
3155 * For the LAYOUT4_NFSV4_1_FILES layout type, NFS_DATA_SYNC WRITEs and
3156 * NFS_UNSTABLE WRITEs with a COMMIT to data servers must store enough
3157 * data to disk to allow the server to recover the data if it crashes.
3158 * LAYOUTCOMMIT is only needed when the NFL4_UFLG_COMMIT_THRU_MDS flag
3159 * is off, and a COMMIT is sent to a data server, or
3160 * if WRITEs to a data server return NFS_DATA_SYNC.
3161 */
3162int
3163pnfs_layoutcommit_inode(struct inode *inode, bool sync)
3164{
3165	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
3166	struct nfs4_layoutcommit_data *data;
3167	struct nfs_inode *nfsi = NFS_I(inode);
3168	loff_t end_pos;
3169	int status;
3170
3171	if (!pnfs_layoutcommit_outstanding(inode))
3172		return 0;
3173
3174	dprintk("--> %s inode %lu\n", __func__, inode->i_ino);
3175
3176	status = -EAGAIN;
3177	if (test_and_set_bit(NFS_INO_LAYOUTCOMMITTING, &nfsi->flags)) {
3178		if (!sync)
3179			goto out;
3180		status = wait_on_bit_lock_action(&nfsi->flags,
3181				NFS_INO_LAYOUTCOMMITTING,
3182				nfs_wait_bit_killable,
3183				TASK_KILLABLE);
3184		if (status)
3185			goto out;
3186	}
3187
3188	status = -ENOMEM;
3189	/* Note kzalloc ensures data->res.seq_res.sr_slot == NULL */
3190	data = kzalloc(sizeof(*data), GFP_NOFS);
3191	if (!data)
3192		goto clear_layoutcommitting;
3193
3194	status = 0;
3195	spin_lock(&inode->i_lock);
3196	if (!test_and_clear_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags))
3197		goto out_unlock;
3198
3199	INIT_LIST_HEAD(&data->lseg_list);
3200	pnfs_list_write_lseg(inode, &data->lseg_list);
3201
3202	end_pos = nfsi->layout->plh_lwb;
3203
3204	nfs4_stateid_copy(&data->args.stateid, &nfsi->layout->plh_stateid);
3205	data->cred = get_cred(nfsi->layout->plh_lc_cred);
3206	spin_unlock(&inode->i_lock);
3207
3208	data->args.inode = inode;
3209	nfs_fattr_init(&data->fattr);
3210	data->args.bitmask = NFS_SERVER(inode)->cache_consistency_bitmask;
3211	data->res.fattr = &data->fattr;
3212	if (end_pos != 0)
3213		data->args.lastbytewritten = end_pos - 1;
3214	else
3215		data->args.lastbytewritten = U64_MAX;
3216	data->res.server = NFS_SERVER(inode);
3217
3218	if (ld->prepare_layoutcommit) {
3219		status = ld->prepare_layoutcommit(&data->args);
3220		if (status) {
3221			put_cred(data->cred);
3222			spin_lock(&inode->i_lock);
3223			set_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags);
3224			if (end_pos > nfsi->layout->plh_lwb)
3225				nfsi->layout->plh_lwb = end_pos;
3226			goto out_unlock;
3227		}
3228	}
3229
3230
3231	status = nfs4_proc_layoutcommit(data, sync);
3232out:
3233	if (status)
3234		mark_inode_dirty_sync(inode);
3235	dprintk("<-- %s status %d\n", __func__, status);
3236	return status;
3237out_unlock:
3238	spin_unlock(&inode->i_lock);
3239	kfree(data);
3240clear_layoutcommitting:
3241	pnfs_clear_layoutcommitting(inode);
3242	goto out;
3243}
3244EXPORT_SYMBOL_GPL(pnfs_layoutcommit_inode);
3245
3246int
3247pnfs_generic_sync(struct inode *inode, bool datasync)
3248{
3249	return pnfs_layoutcommit_inode(inode, true);
3250}
3251EXPORT_SYMBOL_GPL(pnfs_generic_sync);
3252
3253struct nfs4_threshold *pnfs_mdsthreshold_alloc(void)
3254{
3255	struct nfs4_threshold *thp;
3256
3257	thp = kzalloc(sizeof(*thp), GFP_NOFS);
3258	if (!thp) {
3259		dprintk("%s mdsthreshold allocation failed\n", __func__);
3260		return NULL;
3261	}
3262	return thp;
3263}
3264
3265#if IS_ENABLED(CONFIG_NFS_V4_2)
3266int
3267pnfs_report_layoutstat(struct inode *inode, gfp_t gfp_flags)
3268{
3269	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
3270	struct nfs_server *server = NFS_SERVER(inode);
3271	struct nfs_inode *nfsi = NFS_I(inode);
3272	struct nfs42_layoutstat_data *data;
3273	struct pnfs_layout_hdr *hdr;
3274	int status = 0;
3275
3276	if (!pnfs_enabled_sb(server) || !ld->prepare_layoutstats)
3277		goto out;
3278
3279	if (!nfs_server_capable(inode, NFS_CAP_LAYOUTSTATS))
3280		goto out;
3281
3282	if (test_and_set_bit(NFS_INO_LAYOUTSTATS, &nfsi->flags))
3283		goto out;
3284
3285	spin_lock(&inode->i_lock);
3286	if (!NFS_I(inode)->layout) {
3287		spin_unlock(&inode->i_lock);
3288		goto out_clear_layoutstats;
3289	}
3290	hdr = NFS_I(inode)->layout;
3291	pnfs_get_layout_hdr(hdr);
3292	spin_unlock(&inode->i_lock);
3293
3294	data = kzalloc(sizeof(*data), gfp_flags);
3295	if (!data) {
3296		status = -ENOMEM;
3297		goto out_put;
3298	}
3299
3300	data->args.fh = NFS_FH(inode);
3301	data->args.inode = inode;
3302	status = ld->prepare_layoutstats(&data->args);
3303	if (status)
3304		goto out_free;
3305
3306	status = nfs42_proc_layoutstats_generic(NFS_SERVER(inode), data);
3307
3308out:
3309	dprintk("%s returns %d\n", __func__, status);
3310	return status;
3311
3312out_free:
3313	kfree(data);
3314out_put:
3315	pnfs_put_layout_hdr(hdr);
3316out_clear_layoutstats:
3317	smp_mb__before_atomic();
3318	clear_bit(NFS_INO_LAYOUTSTATS, &nfsi->flags);
3319	smp_mb__after_atomic();
3320	goto out;
3321}
3322EXPORT_SYMBOL_GPL(pnfs_report_layoutstat);
3323#endif
3324
3325unsigned int layoutstats_timer;
3326module_param(layoutstats_timer, uint, 0644);
3327EXPORT_SYMBOL_GPL(layoutstats_timer);
v5.9
   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#include "nfs4_fs.h"
  41
  42#define NFSDBG_FACILITY		NFSDBG_PNFS
  43#define PNFS_LAYOUTGET_RETRY_TIMEOUT (120*HZ)
  44
  45/* Locking:
  46 *
  47 * pnfs_spinlock:
  48 *      protects pnfs_modules_tbl.
  49 */
  50static DEFINE_SPINLOCK(pnfs_spinlock);
  51
  52/*
  53 * pnfs_modules_tbl holds all pnfs modules
  54 */
  55static LIST_HEAD(pnfs_modules_tbl);
  56
  57static void pnfs_layoutreturn_before_put_layout_hdr(struct pnfs_layout_hdr *lo);
  58static void pnfs_free_returned_lsegs(struct pnfs_layout_hdr *lo,
  59		struct list_head *free_me,
  60		const struct pnfs_layout_range *range,
  61		u32 seq);
  62static bool pnfs_lseg_dec_and_remove_zero(struct pnfs_layout_segment *lseg,
  63		                struct list_head *tmp_list);
  64
  65/* Return the registered pnfs layout driver module matching given id */
  66static struct pnfs_layoutdriver_type *
  67find_pnfs_driver_locked(u32 id)
  68{
  69	struct pnfs_layoutdriver_type *local;
  70
  71	list_for_each_entry(local, &pnfs_modules_tbl, pnfs_tblid)
  72		if (local->id == id)
  73			goto out;
  74	local = NULL;
  75out:
  76	dprintk("%s: Searching for id %u, found %p\n", __func__, id, local);
  77	return local;
  78}
  79
  80static struct pnfs_layoutdriver_type *
  81find_pnfs_driver(u32 id)
  82{
  83	struct pnfs_layoutdriver_type *local;
  84
  85	spin_lock(&pnfs_spinlock);
  86	local = find_pnfs_driver_locked(id);
  87	if (local != NULL && !try_module_get(local->owner)) {
  88		dprintk("%s: Could not grab reference on module\n", __func__);
  89		local = NULL;
  90	}
  91	spin_unlock(&pnfs_spinlock);
  92	return local;
  93}
  94
  95void
  96unset_pnfs_layoutdriver(struct nfs_server *nfss)
  97{
  98	if (nfss->pnfs_curr_ld) {
  99		if (nfss->pnfs_curr_ld->clear_layoutdriver)
 100			nfss->pnfs_curr_ld->clear_layoutdriver(nfss);
 101		/* Decrement the MDS count. Purge the deviceid cache if zero */
 102		if (atomic_dec_and_test(&nfss->nfs_client->cl_mds_count))
 103			nfs4_deviceid_purge_client(nfss->nfs_client);
 104		module_put(nfss->pnfs_curr_ld->owner);
 105	}
 106	nfss->pnfs_curr_ld = NULL;
 107}
 108
 109/*
 110 * When the server sends a list of layout types, we choose one in the order
 111 * given in the list below.
 112 *
 113 * FIXME: should this list be configurable in some fashion? module param?
 114 * 	  mount option? something else?
 115 */
 116static const u32 ld_prefs[] = {
 117	LAYOUT_SCSI,
 118	LAYOUT_BLOCK_VOLUME,
 119	LAYOUT_OSD2_OBJECTS,
 120	LAYOUT_FLEX_FILES,
 121	LAYOUT_NFSV4_1_FILES,
 122	0
 123};
 124
 125static int
 126ld_cmp(const void *e1, const void *e2)
 127{
 128	u32 ld1 = *((u32 *)e1);
 129	u32 ld2 = *((u32 *)e2);
 130	int i;
 131
 132	for (i = 0; ld_prefs[i] != 0; i++) {
 133		if (ld1 == ld_prefs[i])
 134			return -1;
 135
 136		if (ld2 == ld_prefs[i])
 137			return 1;
 138	}
 139	return 0;
 140}
 141
 142/*
 143 * Try to set the server's pnfs module to the pnfs layout type specified by id.
 144 * Currently only one pNFS layout driver per filesystem is supported.
 145 *
 146 * @ids array of layout types supported by MDS.
 147 */
 148void
 149set_pnfs_layoutdriver(struct nfs_server *server, const struct nfs_fh *mntfh,
 150		      struct nfs_fsinfo *fsinfo)
 151{
 152	struct pnfs_layoutdriver_type *ld_type = NULL;
 153	u32 id;
 154	int i;
 155
 156	if (fsinfo->nlayouttypes == 0)
 157		goto out_no_driver;
 158	if (!(server->nfs_client->cl_exchange_flags &
 159		 (EXCHGID4_FLAG_USE_NON_PNFS | EXCHGID4_FLAG_USE_PNFS_MDS))) {
 160		printk(KERN_ERR "NFS: %s: cl_exchange_flags 0x%x\n",
 161			__func__, server->nfs_client->cl_exchange_flags);
 162		goto out_no_driver;
 163	}
 164
 165	sort(fsinfo->layouttype, fsinfo->nlayouttypes,
 166		sizeof(*fsinfo->layouttype), ld_cmp, NULL);
 167
 168	for (i = 0; i < fsinfo->nlayouttypes; i++) {
 169		id = fsinfo->layouttype[i];
 170		ld_type = find_pnfs_driver(id);
 171		if (!ld_type) {
 172			request_module("%s-%u", LAYOUT_NFSV4_1_MODULE_PREFIX,
 173					id);
 174			ld_type = find_pnfs_driver(id);
 175		}
 176		if (ld_type)
 177			break;
 178	}
 179
 180	if (!ld_type) {
 181		dprintk("%s: No pNFS module found!\n", __func__);
 182		goto out_no_driver;
 183	}
 184
 185	server->pnfs_curr_ld = ld_type;
 186	if (ld_type->set_layoutdriver
 187	    && ld_type->set_layoutdriver(server, mntfh)) {
 188		printk(KERN_ERR "NFS: %s: Error initializing pNFS layout "
 189			"driver %u.\n", __func__, id);
 190		module_put(ld_type->owner);
 191		goto out_no_driver;
 192	}
 193	/* Bump the MDS count */
 194	atomic_inc(&server->nfs_client->cl_mds_count);
 195
 196	dprintk("%s: pNFS module for %u set\n", __func__, id);
 197	return;
 198
 199out_no_driver:
 200	dprintk("%s: Using NFSv4 I/O\n", __func__);
 201	server->pnfs_curr_ld = NULL;
 202}
 203
 204int
 205pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
 206{
 207	int status = -EINVAL;
 208	struct pnfs_layoutdriver_type *tmp;
 209
 210	if (ld_type->id == 0) {
 211		printk(KERN_ERR "NFS: %s id 0 is reserved\n", __func__);
 212		return status;
 213	}
 214	if (!ld_type->alloc_lseg || !ld_type->free_lseg) {
 215		printk(KERN_ERR "NFS: %s Layout driver must provide "
 216		       "alloc_lseg and free_lseg.\n", __func__);
 217		return status;
 218	}
 219
 220	spin_lock(&pnfs_spinlock);
 221	tmp = find_pnfs_driver_locked(ld_type->id);
 222	if (!tmp) {
 223		list_add(&ld_type->pnfs_tblid, &pnfs_modules_tbl);
 224		status = 0;
 225		dprintk("%s Registering id:%u name:%s\n", __func__, ld_type->id,
 226			ld_type->name);
 227	} else {
 228		printk(KERN_ERR "NFS: %s Module with id %d already loaded!\n",
 229			__func__, ld_type->id);
 230	}
 231	spin_unlock(&pnfs_spinlock);
 232
 233	return status;
 234}
 235EXPORT_SYMBOL_GPL(pnfs_register_layoutdriver);
 236
 237void
 238pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
 239{
 240	dprintk("%s Deregistering id:%u\n", __func__, ld_type->id);
 241	spin_lock(&pnfs_spinlock);
 242	list_del(&ld_type->pnfs_tblid);
 243	spin_unlock(&pnfs_spinlock);
 244}
 245EXPORT_SYMBOL_GPL(pnfs_unregister_layoutdriver);
 246
 247/*
 248 * pNFS client layout cache
 249 */
 250
 251/* Need to hold i_lock if caller does not already hold reference */
 252void
 253pnfs_get_layout_hdr(struct pnfs_layout_hdr *lo)
 254{
 255	refcount_inc(&lo->plh_refcount);
 256}
 257
 258static struct pnfs_layout_hdr *
 259pnfs_alloc_layout_hdr(struct inode *ino, gfp_t gfp_flags)
 260{
 261	struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
 262	return ld->alloc_layout_hdr(ino, gfp_flags);
 263}
 264
 265static void
 266pnfs_free_layout_hdr(struct pnfs_layout_hdr *lo)
 267{
 268	struct nfs_server *server = NFS_SERVER(lo->plh_inode);
 269	struct pnfs_layoutdriver_type *ld = server->pnfs_curr_ld;
 270
 271	if (test_and_clear_bit(NFS_LAYOUT_HASHED, &lo->plh_flags)) {
 272		struct nfs_client *clp = server->nfs_client;
 273
 274		spin_lock(&clp->cl_lock);
 275		list_del_rcu(&lo->plh_layouts);
 276		spin_unlock(&clp->cl_lock);
 277	}
 278	put_cred(lo->plh_lc_cred);
 279	return ld->free_layout_hdr(lo);
 280}
 281
 282static void
 283pnfs_detach_layout_hdr(struct pnfs_layout_hdr *lo)
 284{
 285	struct nfs_inode *nfsi = NFS_I(lo->plh_inode);
 286	dprintk("%s: freeing layout cache %p\n", __func__, lo);
 287	nfsi->layout = NULL;
 288	/* Reset MDS Threshold I/O counters */
 289	nfsi->write_io = 0;
 290	nfsi->read_io = 0;
 291}
 292
 293void
 294pnfs_put_layout_hdr(struct pnfs_layout_hdr *lo)
 295{
 296	struct inode *inode;
 
 297
 298	if (!lo)
 299		return;
 300	inode = lo->plh_inode;
 301	pnfs_layoutreturn_before_put_layout_hdr(lo);
 302
 303	if (refcount_dec_and_lock(&lo->plh_refcount, &inode->i_lock)) {
 304		if (!list_empty(&lo->plh_segs))
 305			WARN_ONCE(1, "NFS: BUG unfreed layout segments.\n");
 306		pnfs_detach_layout_hdr(lo);
 
 307		spin_unlock(&inode->i_lock);
 308		pnfs_free_layout_hdr(lo);
 
 
 
 309	}
 310}
 311
 312static struct inode *
 313pnfs_grab_inode_layout_hdr(struct pnfs_layout_hdr *lo)
 314{
 315	struct inode *inode = igrab(lo->plh_inode);
 316	if (inode)
 317		return inode;
 318	set_bit(NFS_LAYOUT_INODE_FREEING, &lo->plh_flags);
 319	return NULL;
 320}
 321
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 322static void
 323pnfs_set_plh_return_info(struct pnfs_layout_hdr *lo, enum pnfs_iomode iomode,
 324			 u32 seq)
 325{
 326	if (lo->plh_return_iomode != 0 && lo->plh_return_iomode != iomode)
 327		iomode = IOMODE_ANY;
 328	lo->plh_return_iomode = iomode;
 329	set_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags);
 330	if (seq != 0) {
 331		WARN_ON_ONCE(lo->plh_return_seq != 0 && lo->plh_return_seq != seq);
 
 
 
 
 
 332		lo->plh_return_seq = seq;
 333	}
 334}
 335
 336static void
 337pnfs_clear_layoutreturn_info(struct pnfs_layout_hdr *lo)
 338{
 339	struct pnfs_layout_segment *lseg;
 340	lo->plh_return_iomode = 0;
 341	lo->plh_return_seq = 0;
 342	clear_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags);
 343	list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
 344		if (!test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
 345			continue;
 346		pnfs_set_plh_return_info(lo, lseg->pls_range.iomode, 0);
 347	}
 348}
 349
 350static void pnfs_clear_layoutreturn_waitbit(struct pnfs_layout_hdr *lo)
 351{
 352	clear_bit_unlock(NFS_LAYOUT_RETURN, &lo->plh_flags);
 353	clear_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags);
 354	smp_mb__after_atomic();
 355	wake_up_bit(&lo->plh_flags, NFS_LAYOUT_RETURN);
 356	rpc_wake_up(&NFS_SERVER(lo->plh_inode)->roc_rpcwaitq);
 357}
 358
 359static void
 360pnfs_clear_lseg_state(struct pnfs_layout_segment *lseg,
 361		struct list_head *free_me)
 362{
 363	clear_bit(NFS_LSEG_ROC, &lseg->pls_flags);
 364	clear_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
 365	if (test_and_clear_bit(NFS_LSEG_VALID, &lseg->pls_flags))
 366		pnfs_lseg_dec_and_remove_zero(lseg, free_me);
 367	if (test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
 368		pnfs_lseg_dec_and_remove_zero(lseg, free_me);
 369}
 370
 371/*
 372 * Update the seqid of a layout stateid after receiving
 373 * NFS4ERR_OLD_STATEID
 374 */
 375bool nfs4_layout_refresh_old_stateid(nfs4_stateid *dst,
 376		struct pnfs_layout_range *dst_range,
 377		struct inode *inode)
 378{
 379	struct pnfs_layout_hdr *lo;
 380	struct pnfs_layout_range range = {
 381		.iomode = IOMODE_ANY,
 382		.offset = 0,
 383		.length = NFS4_MAX_UINT64,
 384	};
 385	bool ret = false;
 386	LIST_HEAD(head);
 387	int err;
 388
 389	spin_lock(&inode->i_lock);
 390	lo = NFS_I(inode)->layout;
 391	if (lo &&  pnfs_layout_is_valid(lo) &&
 392	    nfs4_stateid_match_other(dst, &lo->plh_stateid)) {
 393		/* Is our call using the most recent seqid? If so, bump it */
 394		if (!nfs4_stateid_is_newer(&lo->plh_stateid, dst)) {
 395			nfs4_stateid_seqid_inc(dst);
 396			ret = true;
 397			goto out;
 398		}
 399		/* Try to update the seqid to the most recent */
 400		err = pnfs_mark_matching_lsegs_return(lo, &head, &range, 0);
 401		if (err != -EBUSY) {
 402			dst->seqid = lo->plh_stateid.seqid;
 403			*dst_range = range;
 404			ret = true;
 405		}
 406	}
 407out:
 408	spin_unlock(&inode->i_lock);
 409	pnfs_free_lseg_list(&head);
 410	return ret;
 411}
 412
 413/*
 414 * Mark a pnfs_layout_hdr and all associated layout segments as invalid
 415 *
 416 * In order to continue using the pnfs_layout_hdr, a full recovery
 417 * is required.
 418 * Note that caller must hold inode->i_lock.
 419 */
 420int
 421pnfs_mark_layout_stateid_invalid(struct pnfs_layout_hdr *lo,
 422		struct list_head *lseg_list)
 423{
 424	struct pnfs_layout_range range = {
 425		.iomode = IOMODE_ANY,
 426		.offset = 0,
 427		.length = NFS4_MAX_UINT64,
 428	};
 429	struct pnfs_layout_segment *lseg, *next;
 430
 431	set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
 432	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
 433		pnfs_clear_lseg_state(lseg, lseg_list);
 434	pnfs_clear_layoutreturn_info(lo);
 435	pnfs_free_returned_lsegs(lo, lseg_list, &range, 0);
 436	if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags) &&
 437	    !test_and_set_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags))
 438		pnfs_clear_layoutreturn_waitbit(lo);
 439	return !list_empty(&lo->plh_segs);
 440}
 441
 442static int
 443pnfs_iomode_to_fail_bit(u32 iomode)
 444{
 445	return iomode == IOMODE_RW ?
 446		NFS_LAYOUT_RW_FAILED : NFS_LAYOUT_RO_FAILED;
 447}
 448
 449static void
 450pnfs_layout_set_fail_bit(struct pnfs_layout_hdr *lo, int fail_bit)
 451{
 452	lo->plh_retry_timestamp = jiffies;
 453	if (!test_and_set_bit(fail_bit, &lo->plh_flags))
 454		refcount_inc(&lo->plh_refcount);
 455}
 456
 457static void
 458pnfs_layout_clear_fail_bit(struct pnfs_layout_hdr *lo, int fail_bit)
 459{
 460	if (test_and_clear_bit(fail_bit, &lo->plh_flags))
 461		refcount_dec(&lo->plh_refcount);
 462}
 463
 464static void
 465pnfs_layout_io_set_failed(struct pnfs_layout_hdr *lo, u32 iomode)
 466{
 467	struct inode *inode = lo->plh_inode;
 468	struct pnfs_layout_range range = {
 469		.iomode = iomode,
 470		.offset = 0,
 471		.length = NFS4_MAX_UINT64,
 472	};
 473	LIST_HEAD(head);
 474
 475	spin_lock(&inode->i_lock);
 476	pnfs_layout_set_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
 477	pnfs_mark_matching_lsegs_invalid(lo, &head, &range, 0);
 478	spin_unlock(&inode->i_lock);
 479	pnfs_free_lseg_list(&head);
 480	dprintk("%s Setting layout IOMODE_%s fail bit\n", __func__,
 481			iomode == IOMODE_RW ?  "RW" : "READ");
 482}
 483
 484static bool
 485pnfs_layout_io_test_failed(struct pnfs_layout_hdr *lo, u32 iomode)
 486{
 487	unsigned long start, end;
 488	int fail_bit = pnfs_iomode_to_fail_bit(iomode);
 489
 490	if (test_bit(fail_bit, &lo->plh_flags) == 0)
 491		return false;
 492	end = jiffies;
 493	start = end - PNFS_LAYOUTGET_RETRY_TIMEOUT;
 494	if (!time_in_range(lo->plh_retry_timestamp, start, end)) {
 495		/* It is time to retry the failed layoutgets */
 496		pnfs_layout_clear_fail_bit(lo, fail_bit);
 497		return false;
 498	}
 499	return true;
 500}
 501
 502static void
 503pnfs_init_lseg(struct pnfs_layout_hdr *lo, struct pnfs_layout_segment *lseg,
 504		const struct pnfs_layout_range *range,
 505		const nfs4_stateid *stateid)
 506{
 507	INIT_LIST_HEAD(&lseg->pls_list);
 508	INIT_LIST_HEAD(&lseg->pls_lc_list);
 509	INIT_LIST_HEAD(&lseg->pls_commits);
 510	refcount_set(&lseg->pls_refcount, 1);
 511	set_bit(NFS_LSEG_VALID, &lseg->pls_flags);
 512	lseg->pls_layout = lo;
 513	lseg->pls_range = *range;
 514	lseg->pls_seq = be32_to_cpu(stateid->seqid);
 515}
 516
 517static void pnfs_free_lseg(struct pnfs_layout_segment *lseg)
 518{
 519	if (lseg != NULL) {
 520		struct inode *inode = lseg->pls_layout->plh_inode;
 521		NFS_SERVER(inode)->pnfs_curr_ld->free_lseg(lseg);
 522	}
 523}
 524
 525static void
 526pnfs_layout_remove_lseg(struct pnfs_layout_hdr *lo,
 527		struct pnfs_layout_segment *lseg)
 528{
 529	WARN_ON(test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
 530	list_del_init(&lseg->pls_list);
 531	/* Matched by pnfs_get_layout_hdr in pnfs_layout_insert_lseg */
 532	refcount_dec(&lo->plh_refcount);
 533	if (test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
 534		return;
 535	if (list_empty(&lo->plh_segs) &&
 536	    !test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags) &&
 537	    !test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
 538		if (atomic_read(&lo->plh_outstanding) == 0)
 539			set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
 540		clear_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
 541	}
 542}
 543
 544static bool
 545pnfs_cache_lseg_for_layoutreturn(struct pnfs_layout_hdr *lo,
 546		struct pnfs_layout_segment *lseg)
 547{
 548	if (test_and_clear_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags) &&
 549	    pnfs_layout_is_valid(lo)) {
 550		pnfs_set_plh_return_info(lo, lseg->pls_range.iomode, 0);
 551		list_move_tail(&lseg->pls_list, &lo->plh_return_segs);
 552		return true;
 553	}
 554	return false;
 555}
 556
 557void
 558pnfs_put_lseg(struct pnfs_layout_segment *lseg)
 559{
 560	struct pnfs_layout_hdr *lo;
 561	struct inode *inode;
 562
 563	if (!lseg)
 564		return;
 565
 566	dprintk("%s: lseg %p ref %d valid %d\n", __func__, lseg,
 567		refcount_read(&lseg->pls_refcount),
 568		test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
 569
 570	lo = lseg->pls_layout;
 571	inode = lo->plh_inode;
 572
 573	if (refcount_dec_and_lock(&lseg->pls_refcount, &inode->i_lock)) {
 574		if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags)) {
 575			spin_unlock(&inode->i_lock);
 576			return;
 577		}
 578		pnfs_get_layout_hdr(lo);
 579		pnfs_layout_remove_lseg(lo, lseg);
 580		if (pnfs_cache_lseg_for_layoutreturn(lo, lseg))
 581			lseg = NULL;
 582		spin_unlock(&inode->i_lock);
 583		pnfs_free_lseg(lseg);
 584		pnfs_put_layout_hdr(lo);
 585	}
 586}
 587EXPORT_SYMBOL_GPL(pnfs_put_lseg);
 588
 589/*
 590 * is l2 fully contained in l1?
 591 *   start1                             end1
 592 *   [----------------------------------)
 593 *           start2           end2
 594 *           [----------------)
 595 */
 596static bool
 597pnfs_lseg_range_contained(const struct pnfs_layout_range *l1,
 598		 const struct pnfs_layout_range *l2)
 599{
 600	u64 start1 = l1->offset;
 601	u64 end1 = pnfs_end_offset(start1, l1->length);
 602	u64 start2 = l2->offset;
 603	u64 end2 = pnfs_end_offset(start2, l2->length);
 604
 605	return (start1 <= start2) && (end1 >= end2);
 606}
 607
 608static bool pnfs_lseg_dec_and_remove_zero(struct pnfs_layout_segment *lseg,
 609		struct list_head *tmp_list)
 610{
 611	if (!refcount_dec_and_test(&lseg->pls_refcount))
 612		return false;
 613	pnfs_layout_remove_lseg(lseg->pls_layout, lseg);
 614	list_add(&lseg->pls_list, tmp_list);
 615	return true;
 616}
 617
 618/* Returns 1 if lseg is removed from list, 0 otherwise */
 619static int mark_lseg_invalid(struct pnfs_layout_segment *lseg,
 620			     struct list_head *tmp_list)
 621{
 622	int rv = 0;
 623
 624	if (test_and_clear_bit(NFS_LSEG_VALID, &lseg->pls_flags)) {
 625		/* Remove the reference keeping the lseg in the
 626		 * list.  It will now be removed when all
 627		 * outstanding io is finished.
 628		 */
 629		dprintk("%s: lseg %p ref %d\n", __func__, lseg,
 630			refcount_read(&lseg->pls_refcount));
 631		if (pnfs_lseg_dec_and_remove_zero(lseg, tmp_list))
 632			rv = 1;
 633	}
 634	return rv;
 635}
 636
 637/*
 638 * Compare 2 layout stateid sequence ids, to see which is newer,
 639 * taking into account wraparound issues.
 640 */
 641static bool pnfs_seqid_is_newer(u32 s1, u32 s2)
 642{
 643	return (s32)(s1 - s2) > 0;
 644}
 645
 646static bool
 647pnfs_should_free_range(const struct pnfs_layout_range *lseg_range,
 648		 const struct pnfs_layout_range *recall_range)
 649{
 650	return (recall_range->iomode == IOMODE_ANY ||
 651		lseg_range->iomode == recall_range->iomode) &&
 652	       pnfs_lseg_range_intersecting(lseg_range, recall_range);
 653}
 654
 655static bool
 656pnfs_match_lseg_recall(const struct pnfs_layout_segment *lseg,
 657		const struct pnfs_layout_range *recall_range,
 658		u32 seq)
 659{
 660	if (seq != 0 && pnfs_seqid_is_newer(lseg->pls_seq, seq))
 661		return false;
 662	if (recall_range == NULL)
 663		return true;
 664	return pnfs_should_free_range(&lseg->pls_range, recall_range);
 665}
 666
 667/**
 668 * pnfs_mark_matching_lsegs_invalid - tear down lsegs or mark them for later
 669 * @lo: layout header containing the lsegs
 670 * @tmp_list: list head where doomed lsegs should go
 671 * @recall_range: optional recall range argument to match (may be NULL)
 672 * @seq: only invalidate lsegs obtained prior to this sequence (may be 0)
 673 *
 674 * Walk the list of lsegs in the layout header, and tear down any that should
 675 * be destroyed. If "recall_range" is specified then the segment must match
 676 * that range. If "seq" is non-zero, then only match segments that were handed
 677 * out at or before that sequence.
 678 *
 679 * Returns number of matching invalid lsegs remaining in list after scanning
 680 * it and purging them.
 681 */
 682int
 683pnfs_mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo,
 684			    struct list_head *tmp_list,
 685			    const struct pnfs_layout_range *recall_range,
 686			    u32 seq)
 687{
 688	struct pnfs_layout_segment *lseg, *next;
 689	int remaining = 0;
 690
 691	dprintk("%s:Begin lo %p\n", __func__, lo);
 692
 693	if (list_empty(&lo->plh_segs))
 694		return 0;
 695	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
 696		if (pnfs_match_lseg_recall(lseg, recall_range, seq)) {
 697			dprintk("%s: freeing lseg %p iomode %d seq %u "
 698				"offset %llu length %llu\n", __func__,
 699				lseg, lseg->pls_range.iomode, lseg->pls_seq,
 700				lseg->pls_range.offset, lseg->pls_range.length);
 701			if (!mark_lseg_invalid(lseg, tmp_list))
 702				remaining++;
 703		}
 704	dprintk("%s:Return %i\n", __func__, remaining);
 705	return remaining;
 706}
 707
 708static void
 709pnfs_free_returned_lsegs(struct pnfs_layout_hdr *lo,
 710		struct list_head *free_me,
 711		const struct pnfs_layout_range *range,
 712		u32 seq)
 713{
 714	struct pnfs_layout_segment *lseg, *next;
 715
 716	list_for_each_entry_safe(lseg, next, &lo->plh_return_segs, pls_list) {
 717		if (pnfs_match_lseg_recall(lseg, range, seq))
 718			list_move_tail(&lseg->pls_list, free_me);
 719	}
 720}
 721
 722/* note free_me must contain lsegs from a single layout_hdr */
 723void
 724pnfs_free_lseg_list(struct list_head *free_me)
 725{
 726	struct pnfs_layout_segment *lseg, *tmp;
 727
 728	if (list_empty(free_me))
 729		return;
 730
 731	list_for_each_entry_safe(lseg, tmp, free_me, pls_list) {
 732		list_del(&lseg->pls_list);
 733		pnfs_free_lseg(lseg);
 734	}
 735}
 736
 737void
 738pnfs_destroy_layout(struct nfs_inode *nfsi)
 739{
 740	struct pnfs_layout_hdr *lo;
 741	LIST_HEAD(tmp_list);
 742
 743	spin_lock(&nfsi->vfs_inode.i_lock);
 744	lo = nfsi->layout;
 745	if (lo) {
 746		pnfs_get_layout_hdr(lo);
 747		pnfs_mark_layout_stateid_invalid(lo, &tmp_list);
 748		pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RO_FAILED);
 749		pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RW_FAILED);
 750		spin_unlock(&nfsi->vfs_inode.i_lock);
 751		pnfs_free_lseg_list(&tmp_list);
 752		nfs_commit_inode(&nfsi->vfs_inode, 0);
 753		pnfs_put_layout_hdr(lo);
 754	} else
 755		spin_unlock(&nfsi->vfs_inode.i_lock);
 
 
 
 
 
 
 756}
 757EXPORT_SYMBOL_GPL(pnfs_destroy_layout);
 758
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 759static bool
 760pnfs_layout_add_bulk_destroy_list(struct inode *inode,
 761		struct list_head *layout_list)
 762{
 763	struct pnfs_layout_hdr *lo;
 764	bool ret = false;
 765
 766	spin_lock(&inode->i_lock);
 767	lo = NFS_I(inode)->layout;
 768	if (lo != NULL && list_empty(&lo->plh_bulk_destroy)) {
 769		pnfs_get_layout_hdr(lo);
 770		list_add(&lo->plh_bulk_destroy, layout_list);
 771		ret = true;
 772	}
 773	spin_unlock(&inode->i_lock);
 774	return ret;
 775}
 776
 777/* Caller must hold rcu_read_lock and clp->cl_lock */
 778static int
 779pnfs_layout_bulk_destroy_byserver_locked(struct nfs_client *clp,
 780		struct nfs_server *server,
 781		struct list_head *layout_list)
 782	__must_hold(&clp->cl_lock)
 783	__must_hold(RCU)
 784{
 785	struct pnfs_layout_hdr *lo, *next;
 786	struct inode *inode;
 787
 788	list_for_each_entry_safe(lo, next, &server->layouts, plh_layouts) {
 789		if (test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags) ||
 790		    test_bit(NFS_LAYOUT_INODE_FREEING, &lo->plh_flags) ||
 791		    !list_empty(&lo->plh_bulk_destroy))
 792			continue;
 793		/* If the sb is being destroyed, just bail */
 794		if (!nfs_sb_active(server->super))
 795			break;
 796		inode = pnfs_grab_inode_layout_hdr(lo);
 797		if (inode != NULL) {
 798			if (test_and_clear_bit(NFS_LAYOUT_HASHED, &lo->plh_flags))
 799				list_del_rcu(&lo->plh_layouts);
 800			if (pnfs_layout_add_bulk_destroy_list(inode,
 801						layout_list))
 802				continue;
 803			rcu_read_unlock();
 804			spin_unlock(&clp->cl_lock);
 805			iput(inode);
 806		} else {
 807			rcu_read_unlock();
 808			spin_unlock(&clp->cl_lock);
 809		}
 810		nfs_sb_deactive(server->super);
 811		spin_lock(&clp->cl_lock);
 812		rcu_read_lock();
 813		return -EAGAIN;
 814	}
 815	return 0;
 816}
 817
 818static int
 819pnfs_layout_free_bulk_destroy_list(struct list_head *layout_list,
 820		bool is_bulk_recall)
 821{
 822	struct pnfs_layout_hdr *lo;
 823	struct inode *inode;
 824	LIST_HEAD(lseg_list);
 825	int ret = 0;
 826
 827	while (!list_empty(layout_list)) {
 828		lo = list_entry(layout_list->next, struct pnfs_layout_hdr,
 829				plh_bulk_destroy);
 830		dprintk("%s freeing layout for inode %lu\n", __func__,
 831			lo->plh_inode->i_ino);
 832		inode = lo->plh_inode;
 833
 834		pnfs_layoutcommit_inode(inode, false);
 835
 836		spin_lock(&inode->i_lock);
 837		list_del_init(&lo->plh_bulk_destroy);
 838		if (pnfs_mark_layout_stateid_invalid(lo, &lseg_list)) {
 839			if (is_bulk_recall)
 840				set_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
 841			ret = -EAGAIN;
 842		}
 843		spin_unlock(&inode->i_lock);
 844		pnfs_free_lseg_list(&lseg_list);
 845		/* Free all lsegs that are attached to commit buckets */
 846		nfs_commit_inode(inode, 0);
 847		pnfs_put_layout_hdr(lo);
 848		nfs_iput_and_deactive(inode);
 849	}
 850	return ret;
 851}
 852
 853int
 854pnfs_destroy_layouts_byfsid(struct nfs_client *clp,
 855		struct nfs_fsid *fsid,
 856		bool is_recall)
 857{
 858	struct nfs_server *server;
 859	LIST_HEAD(layout_list);
 860
 861	spin_lock(&clp->cl_lock);
 862	rcu_read_lock();
 863restart:
 864	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 865		if (memcmp(&server->fsid, fsid, sizeof(*fsid)) != 0)
 866			continue;
 867		if (pnfs_layout_bulk_destroy_byserver_locked(clp,
 868				server,
 869				&layout_list) != 0)
 870			goto restart;
 871	}
 872	rcu_read_unlock();
 873	spin_unlock(&clp->cl_lock);
 874
 875	if (list_empty(&layout_list))
 876		return 0;
 877	return pnfs_layout_free_bulk_destroy_list(&layout_list, is_recall);
 878}
 879
 880int
 881pnfs_destroy_layouts_byclid(struct nfs_client *clp,
 882		bool is_recall)
 883{
 884	struct nfs_server *server;
 885	LIST_HEAD(layout_list);
 886
 887	spin_lock(&clp->cl_lock);
 888	rcu_read_lock();
 889restart:
 890	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 891		if (pnfs_layout_bulk_destroy_byserver_locked(clp,
 892					server,
 893					&layout_list) != 0)
 894			goto restart;
 895	}
 896	rcu_read_unlock();
 897	spin_unlock(&clp->cl_lock);
 898
 899	if (list_empty(&layout_list))
 900		return 0;
 901	return pnfs_layout_free_bulk_destroy_list(&layout_list, is_recall);
 902}
 903
 904/*
 905 * Called by the state manger to remove all layouts established under an
 906 * expired lease.
 907 */
 908void
 909pnfs_destroy_all_layouts(struct nfs_client *clp)
 910{
 911	nfs4_deviceid_mark_client_invalid(clp);
 912	nfs4_deviceid_purge_client(clp);
 913
 914	pnfs_destroy_layouts_byclid(clp, false);
 915}
 916
 917static void
 918pnfs_set_layout_cred(struct pnfs_layout_hdr *lo, const struct cred *cred)
 919{
 920	const struct cred *old;
 921
 922	if (cred && cred_fscmp(lo->plh_lc_cred, cred) != 0) {
 923		old = xchg(&lo->plh_lc_cred, get_cred(cred));
 924		put_cred(old);
 925	}
 926}
 927
 928/* update lo->plh_stateid with new if is more recent */
 929void
 930pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo, const nfs4_stateid *new,
 931			const struct cred *cred, bool update_barrier)
 932{
 933	u32 oldseq, newseq, new_barrier = 0;
 934
 935	oldseq = be32_to_cpu(lo->plh_stateid.seqid);
 936	newseq = be32_to_cpu(new->seqid);
 937
 938	if (!pnfs_layout_is_valid(lo)) {
 939		pnfs_set_layout_cred(lo, cred);
 940		nfs4_stateid_copy(&lo->plh_stateid, new);
 941		lo->plh_barrier = newseq;
 942		pnfs_clear_layoutreturn_info(lo);
 943		clear_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
 944		return;
 945	}
 946	if (pnfs_seqid_is_newer(newseq, oldseq)) {
 
 947		nfs4_stateid_copy(&lo->plh_stateid, new);
 948		/*
 949		 * Because of wraparound, we want to keep the barrier
 950		 * "close" to the current seqids.
 951		 */
 952		new_barrier = newseq - atomic_read(&lo->plh_outstanding);
 953	}
 954	if (update_barrier)
 955		new_barrier = be32_to_cpu(new->seqid);
 956	else if (new_barrier == 0)
 957		return;
 958	if (pnfs_seqid_is_newer(new_barrier, lo->plh_barrier))
 959		lo->plh_barrier = new_barrier;
 
 960}
 961
 962static bool
 963pnfs_layout_stateid_blocked(const struct pnfs_layout_hdr *lo,
 964		const nfs4_stateid *stateid)
 965{
 966	u32 seqid = be32_to_cpu(stateid->seqid);
 967
 968	return !pnfs_seqid_is_newer(seqid, lo->plh_barrier);
 969}
 970
 971/* lget is set to 1 if called from inside send_layoutget call chain */
 972static bool
 973pnfs_layoutgets_blocked(const struct pnfs_layout_hdr *lo)
 974{
 975	return lo->plh_block_lgets ||
 976		test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
 977}
 978
 979static struct nfs_server *
 980pnfs_find_server(struct inode *inode, struct nfs_open_context *ctx)
 981{
 982	struct nfs_server *server;
 983
 984	if (inode) {
 985		server = NFS_SERVER(inode);
 986	} else {
 987		struct dentry *parent_dir = dget_parent(ctx->dentry);
 988		server = NFS_SERVER(parent_dir->d_inode);
 989		dput(parent_dir);
 990	}
 991	return server;
 992}
 993
 994static void nfs4_free_pages(struct page **pages, size_t size)
 995{
 996	int i;
 997
 998	if (!pages)
 999		return;
1000
1001	for (i = 0; i < size; i++) {
1002		if (!pages[i])
1003			break;
1004		__free_page(pages[i]);
1005	}
1006	kfree(pages);
1007}
1008
1009static struct page **nfs4_alloc_pages(size_t size, gfp_t gfp_flags)
1010{
1011	struct page **pages;
1012	int i;
1013
1014	pages = kmalloc_array(size, sizeof(struct page *), gfp_flags);
1015	if (!pages) {
1016		dprintk("%s: can't alloc array of %zu pages\n", __func__, size);
1017		return NULL;
1018	}
1019
1020	for (i = 0; i < size; i++) {
1021		pages[i] = alloc_page(gfp_flags);
1022		if (!pages[i]) {
1023			dprintk("%s: failed to allocate page\n", __func__);
1024			nfs4_free_pages(pages, i);
1025			return NULL;
1026		}
1027	}
1028
1029	return pages;
1030}
1031
1032static struct nfs4_layoutget *
1033pnfs_alloc_init_layoutget_args(struct inode *ino,
1034	   struct nfs_open_context *ctx,
1035	   const nfs4_stateid *stateid,
1036	   const struct pnfs_layout_range *range,
1037	   gfp_t gfp_flags)
1038{
1039	struct nfs_server *server = pnfs_find_server(ino, ctx);
1040	size_t max_reply_sz = server->pnfs_curr_ld->max_layoutget_response;
1041	size_t max_pages = max_response_pages(server);
1042	struct nfs4_layoutget *lgp;
1043
1044	dprintk("--> %s\n", __func__);
1045
1046	lgp = kzalloc(sizeof(*lgp), gfp_flags);
1047	if (lgp == NULL)
1048		return NULL;
1049
1050	if (max_reply_sz) {
1051		size_t npages = (max_reply_sz + PAGE_SIZE - 1) >> PAGE_SHIFT;
1052		if (npages < max_pages)
1053			max_pages = npages;
1054	}
1055
1056	lgp->args.layout.pages = nfs4_alloc_pages(max_pages, gfp_flags);
1057	if (!lgp->args.layout.pages) {
1058		kfree(lgp);
1059		return NULL;
1060	}
1061	lgp->args.layout.pglen = max_pages * PAGE_SIZE;
1062	lgp->res.layoutp = &lgp->args.layout;
1063
1064	/* Don't confuse uninitialised result and success */
1065	lgp->res.status = -NFS4ERR_DELAY;
1066
1067	lgp->args.minlength = PAGE_SIZE;
1068	if (lgp->args.minlength > range->length)
1069		lgp->args.minlength = range->length;
1070	if (ino) {
1071		loff_t i_size = i_size_read(ino);
1072
1073		if (range->iomode == IOMODE_READ) {
1074			if (range->offset >= i_size)
1075				lgp->args.minlength = 0;
1076			else if (i_size - range->offset < lgp->args.minlength)
1077				lgp->args.minlength = i_size - range->offset;
1078		}
1079	}
1080	lgp->args.maxcount = PNFS_LAYOUT_MAXSIZE;
1081	pnfs_copy_range(&lgp->args.range, range);
1082	lgp->args.type = server->pnfs_curr_ld->id;
1083	lgp->args.inode = ino;
1084	lgp->args.ctx = get_nfs_open_context(ctx);
1085	nfs4_stateid_copy(&lgp->args.stateid, stateid);
1086	lgp->gfp_flags = gfp_flags;
1087	lgp->cred = ctx->cred;
1088	return lgp;
1089}
1090
1091void pnfs_layoutget_free(struct nfs4_layoutget *lgp)
1092{
1093	size_t max_pages = lgp->args.layout.pglen / PAGE_SIZE;
1094
1095	nfs4_free_pages(lgp->args.layout.pages, max_pages);
1096	if (lgp->args.inode)
1097		pnfs_put_layout_hdr(NFS_I(lgp->args.inode)->layout);
1098	put_nfs_open_context(lgp->args.ctx);
1099	kfree(lgp);
1100}
1101
1102static void pnfs_clear_layoutcommit(struct inode *inode,
1103		struct list_head *head)
1104{
1105	struct nfs_inode *nfsi = NFS_I(inode);
1106	struct pnfs_layout_segment *lseg, *tmp;
1107
1108	if (!test_and_clear_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags))
1109		return;
1110	list_for_each_entry_safe(lseg, tmp, &nfsi->layout->plh_segs, pls_list) {
1111		if (!test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
1112			continue;
1113		pnfs_lseg_dec_and_remove_zero(lseg, head);
1114	}
1115}
1116
1117void pnfs_layoutreturn_free_lsegs(struct pnfs_layout_hdr *lo,
1118		const nfs4_stateid *arg_stateid,
1119		const struct pnfs_layout_range *range,
1120		const nfs4_stateid *stateid)
1121{
1122	struct inode *inode = lo->plh_inode;
1123	LIST_HEAD(freeme);
1124
1125	spin_lock(&inode->i_lock);
1126	if (!pnfs_layout_is_valid(lo) || !arg_stateid ||
1127	    !nfs4_stateid_match_other(&lo->plh_stateid, arg_stateid))
1128		goto out_unlock;
1129	if (stateid) {
1130		u32 seq = be32_to_cpu(arg_stateid->seqid);
1131
1132		pnfs_mark_matching_lsegs_invalid(lo, &freeme, range, seq);
1133		pnfs_free_returned_lsegs(lo, &freeme, range, seq);
1134		pnfs_set_layout_stateid(lo, stateid, NULL, true);
1135	} else
1136		pnfs_mark_layout_stateid_invalid(lo, &freeme);
1137out_unlock:
1138	pnfs_clear_layoutreturn_waitbit(lo);
1139	spin_unlock(&inode->i_lock);
1140	pnfs_free_lseg_list(&freeme);
1141
1142}
1143
1144static bool
1145pnfs_prepare_layoutreturn(struct pnfs_layout_hdr *lo,
1146		nfs4_stateid *stateid,
1147		const struct cred **cred,
1148		enum pnfs_iomode *iomode)
1149{
1150	/* Serialise LAYOUTGET/LAYOUTRETURN */
1151	if (atomic_read(&lo->plh_outstanding) != 0)
1152		return false;
1153	if (test_and_set_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags))
1154		return false;
1155	set_bit(NFS_LAYOUT_RETURN, &lo->plh_flags);
1156	pnfs_get_layout_hdr(lo);
 
 
1157	if (test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags)) {
1158		nfs4_stateid_copy(stateid, &lo->plh_stateid);
1159		*cred = get_cred(lo->plh_lc_cred);
1160		if (lo->plh_return_seq != 0)
1161			stateid->seqid = cpu_to_be32(lo->plh_return_seq);
1162		if (iomode != NULL)
1163			*iomode = lo->plh_return_iomode;
1164		pnfs_clear_layoutreturn_info(lo);
1165		return true;
1166	}
1167	nfs4_stateid_copy(stateid, &lo->plh_stateid);
1168	*cred = get_cred(lo->plh_lc_cred);
1169	if (iomode != NULL)
1170		*iomode = IOMODE_ANY;
 
1171	return true;
1172}
1173
1174static void
1175pnfs_init_layoutreturn_args(struct nfs4_layoutreturn_args *args,
1176		struct pnfs_layout_hdr *lo,
1177		const nfs4_stateid *stateid,
1178		enum pnfs_iomode iomode)
1179{
1180	struct inode *inode = lo->plh_inode;
1181
1182	args->layout_type = NFS_SERVER(inode)->pnfs_curr_ld->id;
1183	args->inode = inode;
1184	args->range.iomode = iomode;
1185	args->range.offset = 0;
1186	args->range.length = NFS4_MAX_UINT64;
1187	args->layout = lo;
1188	nfs4_stateid_copy(&args->stateid, stateid);
1189}
1190
1191static int
1192pnfs_send_layoutreturn(struct pnfs_layout_hdr *lo,
1193		       const nfs4_stateid *stateid,
1194		       const struct cred **pcred,
1195		       enum pnfs_iomode iomode,
1196		       bool sync)
1197{
1198	struct inode *ino = lo->plh_inode;
1199	struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
1200	struct nfs4_layoutreturn *lrp;
1201	const struct cred *cred = *pcred;
1202	int status = 0;
1203
1204	*pcred = NULL;
1205	lrp = kzalloc(sizeof(*lrp), GFP_NOFS);
1206	if (unlikely(lrp == NULL)) {
1207		status = -ENOMEM;
1208		spin_lock(&ino->i_lock);
1209		pnfs_clear_layoutreturn_waitbit(lo);
1210		spin_unlock(&ino->i_lock);
1211		put_cred(cred);
1212		pnfs_put_layout_hdr(lo);
1213		goto out;
1214	}
1215
1216	pnfs_init_layoutreturn_args(&lrp->args, lo, stateid, iomode);
1217	lrp->args.ld_private = &lrp->ld_private;
1218	lrp->clp = NFS_SERVER(ino)->nfs_client;
1219	lrp->cred = cred;
1220	if (ld->prepare_layoutreturn)
1221		ld->prepare_layoutreturn(&lrp->args);
1222
1223	status = nfs4_proc_layoutreturn(lrp, sync);
1224out:
1225	dprintk("<-- %s status: %d\n", __func__, status);
1226	return status;
1227}
1228
1229static bool
1230pnfs_layout_segments_returnable(struct pnfs_layout_hdr *lo,
1231				enum pnfs_iomode iomode,
1232				u32 seq)
1233{
1234	struct pnfs_layout_range recall_range = {
1235		.length = NFS4_MAX_UINT64,
1236		.iomode = iomode,
1237	};
1238	return pnfs_mark_matching_lsegs_return(lo, &lo->plh_return_segs,
1239					       &recall_range, seq) != -EBUSY;
1240}
1241
1242/* Return true if layoutreturn is needed */
1243static bool
1244pnfs_layout_need_return(struct pnfs_layout_hdr *lo)
1245{
1246	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
1247		return false;
1248	return pnfs_layout_segments_returnable(lo, lo->plh_return_iomode,
1249					       lo->plh_return_seq);
1250}
1251
1252static void pnfs_layoutreturn_before_put_layout_hdr(struct pnfs_layout_hdr *lo)
1253{
1254	struct inode *inode= lo->plh_inode;
1255
1256	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
1257		return;
1258	spin_lock(&inode->i_lock);
1259	if (pnfs_layout_need_return(lo)) {
1260		const struct cred *cred;
1261		nfs4_stateid stateid;
1262		enum pnfs_iomode iomode;
1263		bool send;
1264
1265		send = pnfs_prepare_layoutreturn(lo, &stateid, &cred, &iomode);
1266		spin_unlock(&inode->i_lock);
1267		if (send) {
1268			/* Send an async layoutreturn so we dont deadlock */
1269			pnfs_send_layoutreturn(lo, &stateid, &cred, iomode, false);
1270		}
1271	} else
1272		spin_unlock(&inode->i_lock);
1273}
1274
1275/*
1276 * Initiates a LAYOUTRETURN(FILE), and removes the pnfs_layout_hdr
1277 * when the layout segment list is empty.
1278 *
1279 * Note that a pnfs_layout_hdr can exist with an empty layout segment
1280 * list when LAYOUTGET has failed, or when LAYOUTGET succeeded, but the
1281 * deviceid is marked invalid.
1282 */
1283int
1284_pnfs_return_layout(struct inode *ino)
1285{
1286	struct pnfs_layout_hdr *lo = NULL;
1287	struct nfs_inode *nfsi = NFS_I(ino);
 
 
 
 
 
1288	LIST_HEAD(tmp_list);
1289	const struct cred *cred;
1290	nfs4_stateid stateid;
1291	int status = 0;
1292	bool send, valid_layout;
1293
1294	dprintk("NFS: %s for inode %lu\n", __func__, ino->i_ino);
1295
1296	spin_lock(&ino->i_lock);
1297	lo = nfsi->layout;
1298	if (!lo) {
1299		spin_unlock(&ino->i_lock);
1300		dprintk("NFS: %s no layout to return\n", __func__);
1301		goto out;
1302	}
1303	/* Reference matched in nfs4_layoutreturn_release */
1304	pnfs_get_layout_hdr(lo);
1305	/* Is there an outstanding layoutreturn ? */
1306	if (test_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags)) {
1307		spin_unlock(&ino->i_lock);
1308		if (wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN,
1309					TASK_UNINTERRUPTIBLE))
1310			goto out_put_layout_hdr;
1311		spin_lock(&ino->i_lock);
1312	}
1313	valid_layout = pnfs_layout_is_valid(lo);
1314	pnfs_clear_layoutcommit(ino, &tmp_list);
1315	pnfs_mark_matching_lsegs_invalid(lo, &tmp_list, NULL, 0);
1316
1317	if (NFS_SERVER(ino)->pnfs_curr_ld->return_range) {
1318		struct pnfs_layout_range range = {
1319			.iomode		= IOMODE_ANY,
1320			.offset		= 0,
1321			.length		= NFS4_MAX_UINT64,
1322		};
1323		NFS_SERVER(ino)->pnfs_curr_ld->return_range(lo, &range);
1324	}
1325
1326	/* Don't send a LAYOUTRETURN if list was initially empty */
1327	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags) ||
1328			!valid_layout) {
1329		spin_unlock(&ino->i_lock);
1330		dprintk("NFS: %s no layout segments to return\n", __func__);
1331		goto out_wait_layoutreturn;
1332	}
1333
1334	send = pnfs_prepare_layoutreturn(lo, &stateid, &cred, NULL);
1335	spin_unlock(&ino->i_lock);
1336	if (send)
1337		status = pnfs_send_layoutreturn(lo, &stateid, &cred, IOMODE_ANY, true);
1338out_wait_layoutreturn:
1339	wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN, TASK_UNINTERRUPTIBLE);
1340out_put_layout_hdr:
1341	pnfs_free_lseg_list(&tmp_list);
1342	pnfs_put_layout_hdr(lo);
1343out:
1344	dprintk("<-- %s status: %d\n", __func__, status);
1345	return status;
1346}
1347
1348int
1349pnfs_commit_and_return_layout(struct inode *inode)
1350{
1351	struct pnfs_layout_hdr *lo;
1352	int ret;
1353
1354	spin_lock(&inode->i_lock);
1355	lo = NFS_I(inode)->layout;
1356	if (lo == NULL) {
1357		spin_unlock(&inode->i_lock);
1358		return 0;
1359	}
1360	pnfs_get_layout_hdr(lo);
1361	/* Block new layoutgets and read/write to ds */
1362	lo->plh_block_lgets++;
1363	spin_unlock(&inode->i_lock);
1364	filemap_fdatawait(inode->i_mapping);
1365	ret = pnfs_layoutcommit_inode(inode, true);
1366	if (ret == 0)
1367		ret = _pnfs_return_layout(inode);
1368	spin_lock(&inode->i_lock);
1369	lo->plh_block_lgets--;
1370	spin_unlock(&inode->i_lock);
1371	pnfs_put_layout_hdr(lo);
1372	return ret;
1373}
1374
1375bool pnfs_roc(struct inode *ino,
1376		struct nfs4_layoutreturn_args *args,
1377		struct nfs4_layoutreturn_res *res,
1378		const struct cred *cred)
1379{
1380	struct nfs_inode *nfsi = NFS_I(ino);
1381	struct nfs_open_context *ctx;
1382	struct nfs4_state *state;
1383	struct pnfs_layout_hdr *lo;
1384	struct pnfs_layout_segment *lseg, *next;
1385	const struct cred *lc_cred;
1386	nfs4_stateid stateid;
1387	enum pnfs_iomode iomode = 0;
1388	bool layoutreturn = false, roc = false;
1389	bool skip_read = false;
1390
1391	if (!nfs_have_layout(ino))
1392		return false;
1393retry:
1394	rcu_read_lock();
1395	spin_lock(&ino->i_lock);
1396	lo = nfsi->layout;
1397	if (!lo || !pnfs_layout_is_valid(lo) ||
1398	    test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
1399		lo = NULL;
1400		goto out_noroc;
1401	}
1402	pnfs_get_layout_hdr(lo);
1403	if (test_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags)) {
1404		spin_unlock(&ino->i_lock);
1405		rcu_read_unlock();
1406		wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN,
1407				TASK_UNINTERRUPTIBLE);
1408		pnfs_put_layout_hdr(lo);
1409		goto retry;
1410	}
1411
1412	/* no roc if we hold a delegation */
1413	if (nfs4_check_delegation(ino, FMODE_READ)) {
1414		if (nfs4_check_delegation(ino, FMODE_WRITE))
1415			goto out_noroc;
1416		skip_read = true;
1417	}
1418
1419	list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
1420		state = ctx->state;
1421		if (state == NULL)
1422			continue;
1423		/* Don't return layout if there is open file state */
1424		if (state->state & FMODE_WRITE)
1425			goto out_noroc;
1426		if (state->state & FMODE_READ)
1427			skip_read = true;
1428	}
1429
1430
1431	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list) {
1432		if (skip_read && lseg->pls_range.iomode == IOMODE_READ)
1433			continue;
1434		/* If we are sending layoutreturn, invalidate all valid lsegs */
1435		if (!test_and_clear_bit(NFS_LSEG_ROC, &lseg->pls_flags))
1436			continue;
1437		/*
1438		 * Note: mark lseg for return so pnfs_layout_remove_lseg
1439		 * doesn't invalidate the layout for us.
1440		 */
1441		set_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
1442		if (!mark_lseg_invalid(lseg, &lo->plh_return_segs))
1443			continue;
1444		pnfs_set_plh_return_info(lo, lseg->pls_range.iomode, 0);
1445	}
1446
1447	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
1448		goto out_noroc;
1449
1450	/* ROC in two conditions:
1451	 * 1. there are ROC lsegs
1452	 * 2. we don't send layoutreturn
1453	 */
1454	/* lo ref dropped in pnfs_roc_release() */
1455	layoutreturn = pnfs_prepare_layoutreturn(lo, &stateid, &lc_cred, &iomode);
1456	/* If the creds don't match, we can't compound the layoutreturn */
1457	if (!layoutreturn || cred_fscmp(cred, lc_cred) != 0)
1458		goto out_noroc;
1459
1460	roc = layoutreturn;
1461	pnfs_init_layoutreturn_args(args, lo, &stateid, iomode);
1462	res->lrs_present = 0;
1463	layoutreturn = false;
1464	put_cred(lc_cred);
1465
1466out_noroc:
1467	spin_unlock(&ino->i_lock);
1468	rcu_read_unlock();
1469	pnfs_layoutcommit_inode(ino, true);
1470	if (roc) {
1471		struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
1472		if (ld->prepare_layoutreturn)
1473			ld->prepare_layoutreturn(args);
1474		pnfs_put_layout_hdr(lo);
1475		return true;
1476	}
1477	if (layoutreturn)
1478		pnfs_send_layoutreturn(lo, &stateid, &lc_cred, iomode, true);
1479	pnfs_put_layout_hdr(lo);
1480	return false;
1481}
1482
1483int pnfs_roc_done(struct rpc_task *task, struct inode *inode,
1484		struct nfs4_layoutreturn_args **argpp,
1485		struct nfs4_layoutreturn_res **respp,
1486		int *ret)
1487{
1488	struct nfs4_layoutreturn_args *arg = *argpp;
1489	int retval = -EAGAIN;
1490
1491	if (!arg)
1492		return 0;
1493	/* Handle Layoutreturn errors */
1494	switch (*ret) {
1495	case 0:
1496		retval = 0;
1497		break;
1498	case -NFS4ERR_NOMATCHING_LAYOUT:
1499		/* Was there an RPC level error? If not, retry */
1500		if (task->tk_rpc_status == 0)
1501			break;
1502		/* If the call was not sent, let caller handle it */
1503		if (!RPC_WAS_SENT(task))
1504			return 0;
1505		/*
1506		 * Otherwise, assume the call succeeded and
1507		 * that we need to release the layout
1508		 */
1509		*ret = 0;
1510		(*respp)->lrs_present = 0;
1511		retval = 0;
1512		break;
1513	case -NFS4ERR_DELAY:
1514		/* Let the caller handle the retry */
1515		*ret = -NFS4ERR_NOMATCHING_LAYOUT;
1516		return 0;
1517	case -NFS4ERR_OLD_STATEID:
1518		if (!nfs4_layout_refresh_old_stateid(&arg->stateid,
1519					&arg->range, inode))
1520			break;
1521		*ret = -NFS4ERR_NOMATCHING_LAYOUT;
1522		return -EAGAIN;
1523	}
1524	*argpp = NULL;
1525	*respp = NULL;
1526	return retval;
1527}
1528
1529void pnfs_roc_release(struct nfs4_layoutreturn_args *args,
1530		struct nfs4_layoutreturn_res *res,
1531		int ret)
1532{
1533	struct pnfs_layout_hdr *lo = args->layout;
1534	const nfs4_stateid *arg_stateid = NULL;
1535	const nfs4_stateid *res_stateid = NULL;
1536	struct nfs4_xdr_opaque_data *ld_private = args->ld_private;
1537
1538	switch (ret) {
1539	case -NFS4ERR_NOMATCHING_LAYOUT:
 
 
 
 
 
 
1540		break;
1541	case 0:
1542		if (res->lrs_present)
1543			res_stateid = &res->stateid;
1544		fallthrough;
1545	default:
1546		arg_stateid = &args->stateid;
 
1547	}
1548	trace_nfs4_layoutreturn_on_close(args->inode, &args->stateid, ret);
1549	pnfs_layoutreturn_free_lsegs(lo, arg_stateid, &args->range,
1550			res_stateid);
1551	if (ld_private && ld_private->ops && ld_private->ops->free)
1552		ld_private->ops->free(ld_private);
1553	pnfs_put_layout_hdr(lo);
1554}
1555
1556bool pnfs_wait_on_layoutreturn(struct inode *ino, struct rpc_task *task)
1557{
1558	struct nfs_inode *nfsi = NFS_I(ino);
1559        struct pnfs_layout_hdr *lo;
1560        bool sleep = false;
1561
1562	/* we might not have grabbed lo reference. so need to check under
1563	 * i_lock */
1564        spin_lock(&ino->i_lock);
1565        lo = nfsi->layout;
1566        if (lo && test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
1567                rpc_sleep_on(&NFS_SERVER(ino)->roc_rpcwaitq, task, NULL);
1568                sleep = true;
1569	}
1570        spin_unlock(&ino->i_lock);
1571        return sleep;
1572}
1573
1574/*
1575 * Compare two layout segments for sorting into layout cache.
1576 * We want to preferentially return RW over RO layouts, so ensure those
1577 * are seen first.
1578 */
1579static s64
1580pnfs_lseg_range_cmp(const struct pnfs_layout_range *l1,
1581	   const struct pnfs_layout_range *l2)
1582{
1583	s64 d;
1584
1585	/* high offset > low offset */
1586	d = l1->offset - l2->offset;
1587	if (d)
1588		return d;
1589
1590	/* short length > long length */
1591	d = l2->length - l1->length;
1592	if (d)
1593		return d;
1594
1595	/* read > read/write */
1596	return (int)(l1->iomode == IOMODE_READ) - (int)(l2->iomode == IOMODE_READ);
1597}
1598
1599static bool
1600pnfs_lseg_range_is_after(const struct pnfs_layout_range *l1,
1601		const struct pnfs_layout_range *l2)
1602{
1603	return pnfs_lseg_range_cmp(l1, l2) > 0;
1604}
1605
1606static bool
1607pnfs_lseg_no_merge(struct pnfs_layout_segment *lseg,
1608		struct pnfs_layout_segment *old)
1609{
1610	return false;
1611}
1612
1613void
1614pnfs_generic_layout_insert_lseg(struct pnfs_layout_hdr *lo,
1615		   struct pnfs_layout_segment *lseg,
1616		   bool (*is_after)(const struct pnfs_layout_range *,
1617			   const struct pnfs_layout_range *),
1618		   bool (*do_merge)(struct pnfs_layout_segment *,
1619			   struct pnfs_layout_segment *),
1620		   struct list_head *free_me)
1621{
1622	struct pnfs_layout_segment *lp, *tmp;
1623
1624	dprintk("%s:Begin\n", __func__);
1625
1626	list_for_each_entry_safe(lp, tmp, &lo->plh_segs, pls_list) {
1627		if (test_bit(NFS_LSEG_VALID, &lp->pls_flags) == 0)
1628			continue;
1629		if (do_merge(lseg, lp)) {
1630			mark_lseg_invalid(lp, free_me);
1631			continue;
1632		}
1633		if (is_after(&lseg->pls_range, &lp->pls_range))
1634			continue;
1635		list_add_tail(&lseg->pls_list, &lp->pls_list);
1636		dprintk("%s: inserted lseg %p "
1637			"iomode %d offset %llu length %llu before "
1638			"lp %p iomode %d offset %llu length %llu\n",
1639			__func__, lseg, lseg->pls_range.iomode,
1640			lseg->pls_range.offset, lseg->pls_range.length,
1641			lp, lp->pls_range.iomode, lp->pls_range.offset,
1642			lp->pls_range.length);
1643		goto out;
1644	}
1645	list_add_tail(&lseg->pls_list, &lo->plh_segs);
1646	dprintk("%s: inserted lseg %p "
1647		"iomode %d offset %llu length %llu at tail\n",
1648		__func__, lseg, lseg->pls_range.iomode,
1649		lseg->pls_range.offset, lseg->pls_range.length);
1650out:
1651	pnfs_get_layout_hdr(lo);
1652
1653	dprintk("%s:Return\n", __func__);
1654}
1655EXPORT_SYMBOL_GPL(pnfs_generic_layout_insert_lseg);
1656
1657static void
1658pnfs_layout_insert_lseg(struct pnfs_layout_hdr *lo,
1659		   struct pnfs_layout_segment *lseg,
1660		   struct list_head *free_me)
1661{
1662	struct inode *inode = lo->plh_inode;
1663	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
1664
1665	if (ld->add_lseg != NULL)
1666		ld->add_lseg(lo, lseg, free_me);
1667	else
1668		pnfs_generic_layout_insert_lseg(lo, lseg,
1669				pnfs_lseg_range_is_after,
1670				pnfs_lseg_no_merge,
1671				free_me);
1672}
1673
1674static struct pnfs_layout_hdr *
1675alloc_init_layout_hdr(struct inode *ino,
1676		      struct nfs_open_context *ctx,
1677		      gfp_t gfp_flags)
1678{
1679	struct pnfs_layout_hdr *lo;
1680
1681	lo = pnfs_alloc_layout_hdr(ino, gfp_flags);
1682	if (!lo)
1683		return NULL;
1684	refcount_set(&lo->plh_refcount, 1);
1685	INIT_LIST_HEAD(&lo->plh_layouts);
1686	INIT_LIST_HEAD(&lo->plh_segs);
1687	INIT_LIST_HEAD(&lo->plh_return_segs);
1688	INIT_LIST_HEAD(&lo->plh_bulk_destroy);
1689	lo->plh_inode = ino;
1690	lo->plh_lc_cred = get_cred(ctx->cred);
1691	lo->plh_flags |= 1 << NFS_LAYOUT_INVALID_STID;
1692	return lo;
1693}
1694
1695static struct pnfs_layout_hdr *
1696pnfs_find_alloc_layout(struct inode *ino,
1697		       struct nfs_open_context *ctx,
1698		       gfp_t gfp_flags)
1699	__releases(&ino->i_lock)
1700	__acquires(&ino->i_lock)
1701{
1702	struct nfs_inode *nfsi = NFS_I(ino);
1703	struct pnfs_layout_hdr *new = NULL;
1704
1705	dprintk("%s Begin ino=%p layout=%p\n", __func__, ino, nfsi->layout);
1706
1707	if (nfsi->layout != NULL)
1708		goto out_existing;
1709	spin_unlock(&ino->i_lock);
1710	new = alloc_init_layout_hdr(ino, ctx, gfp_flags);
1711	spin_lock(&ino->i_lock);
1712
1713	if (likely(nfsi->layout == NULL)) {	/* Won the race? */
1714		nfsi->layout = new;
1715		return new;
1716	} else if (new != NULL)
1717		pnfs_free_layout_hdr(new);
1718out_existing:
1719	pnfs_get_layout_hdr(nfsi->layout);
1720	return nfsi->layout;
1721}
1722
1723/*
1724 * iomode matching rules:
1725 * iomode	lseg	strict match
1726 *                      iomode
1727 * -----	-----	------ -----
1728 * ANY		READ	N/A    true
1729 * ANY		RW	N/A    true
1730 * RW		READ	N/A    false
1731 * RW		RW	N/A    true
1732 * READ		READ	N/A    true
1733 * READ		RW	true   false
1734 * READ		RW	false  true
1735 */
1736static bool
1737pnfs_lseg_range_match(const struct pnfs_layout_range *ls_range,
1738		 const struct pnfs_layout_range *range,
1739		 bool strict_iomode)
1740{
1741	struct pnfs_layout_range range1;
1742
1743	if ((range->iomode == IOMODE_RW &&
1744	     ls_range->iomode != IOMODE_RW) ||
1745	    (range->iomode != ls_range->iomode &&
1746	     strict_iomode) ||
1747	    !pnfs_lseg_range_intersecting(ls_range, range))
1748		return false;
1749
1750	/* range1 covers only the first byte in the range */
1751	range1 = *range;
1752	range1.length = 1;
1753	return pnfs_lseg_range_contained(ls_range, &range1);
1754}
1755
1756/*
1757 * lookup range in layout
1758 */
1759static struct pnfs_layout_segment *
1760pnfs_find_lseg(struct pnfs_layout_hdr *lo,
1761		struct pnfs_layout_range *range,
1762		bool strict_iomode)
1763{
1764	struct pnfs_layout_segment *lseg, *ret = NULL;
1765
1766	dprintk("%s:Begin\n", __func__);
1767
1768	list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
1769		if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags) &&
1770		    pnfs_lseg_range_match(&lseg->pls_range, range,
1771					  strict_iomode)) {
1772			ret = pnfs_get_lseg(lseg);
1773			break;
1774		}
1775	}
1776
1777	dprintk("%s:Return lseg %p ref %d\n",
1778		__func__, ret, ret ? refcount_read(&ret->pls_refcount) : 0);
1779	return ret;
1780}
1781
1782/*
1783 * Use mdsthreshold hints set at each OPEN to determine if I/O should go
1784 * to the MDS or over pNFS
1785 *
1786 * The nfs_inode read_io and write_io fields are cumulative counters reset
1787 * when there are no layout segments. Note that in pnfs_update_layout iomode
1788 * is set to IOMODE_READ for a READ request, and set to IOMODE_RW for a
1789 * WRITE request.
1790 *
1791 * A return of true means use MDS I/O.
1792 *
1793 * From rfc 5661:
1794 * If a file's size is smaller than the file size threshold, data accesses
1795 * SHOULD be sent to the metadata server.  If an I/O request has a length that
1796 * is below the I/O size threshold, the I/O SHOULD be sent to the metadata
1797 * server.  If both file size and I/O size are provided, the client SHOULD
1798 * reach or exceed  both thresholds before sending its read or write
1799 * requests to the data server.
1800 */
1801static bool pnfs_within_mdsthreshold(struct nfs_open_context *ctx,
1802				     struct inode *ino, int iomode)
1803{
1804	struct nfs4_threshold *t = ctx->mdsthreshold;
1805	struct nfs_inode *nfsi = NFS_I(ino);
1806	loff_t fsize = i_size_read(ino);
1807	bool size = false, size_set = false, io = false, io_set = false, ret = false;
1808
1809	if (t == NULL)
1810		return ret;
1811
1812	dprintk("%s bm=0x%x rd_sz=%llu wr_sz=%llu rd_io=%llu wr_io=%llu\n",
1813		__func__, t->bm, t->rd_sz, t->wr_sz, t->rd_io_sz, t->wr_io_sz);
1814
1815	switch (iomode) {
1816	case IOMODE_READ:
1817		if (t->bm & THRESHOLD_RD) {
1818			dprintk("%s fsize %llu\n", __func__, fsize);
1819			size_set = true;
1820			if (fsize < t->rd_sz)
1821				size = true;
1822		}
1823		if (t->bm & THRESHOLD_RD_IO) {
1824			dprintk("%s nfsi->read_io %llu\n", __func__,
1825				nfsi->read_io);
1826			io_set = true;
1827			if (nfsi->read_io < t->rd_io_sz)
1828				io = true;
1829		}
1830		break;
1831	case IOMODE_RW:
1832		if (t->bm & THRESHOLD_WR) {
1833			dprintk("%s fsize %llu\n", __func__, fsize);
1834			size_set = true;
1835			if (fsize < t->wr_sz)
1836				size = true;
1837		}
1838		if (t->bm & THRESHOLD_WR_IO) {
1839			dprintk("%s nfsi->write_io %llu\n", __func__,
1840				nfsi->write_io);
1841			io_set = true;
1842			if (nfsi->write_io < t->wr_io_sz)
1843				io = true;
1844		}
1845		break;
1846	}
1847	if (size_set && io_set) {
1848		if (size && io)
1849			ret = true;
1850	} else if (size || io)
1851		ret = true;
1852
1853	dprintk("<-- %s size %d io %d ret %d\n", __func__, size, io, ret);
1854	return ret;
1855}
1856
1857static int pnfs_prepare_to_retry_layoutget(struct pnfs_layout_hdr *lo)
1858{
1859	/*
1860	 * send layoutcommit as it can hold up layoutreturn due to lseg
1861	 * reference
1862	 */
1863	pnfs_layoutcommit_inode(lo->plh_inode, false);
1864	return wait_on_bit_action(&lo->plh_flags, NFS_LAYOUT_RETURN,
1865				   nfs_wait_bit_killable,
1866				   TASK_KILLABLE);
1867}
1868
1869static void nfs_layoutget_begin(struct pnfs_layout_hdr *lo)
1870{
1871	atomic_inc(&lo->plh_outstanding);
1872}
1873
1874static void nfs_layoutget_end(struct pnfs_layout_hdr *lo)
1875{
1876	if (atomic_dec_and_test(&lo->plh_outstanding))
1877		wake_up_var(&lo->plh_outstanding);
1878}
1879
 
 
 
 
 
1880static void pnfs_clear_first_layoutget(struct pnfs_layout_hdr *lo)
1881{
1882	unsigned long *bitlock = &lo->plh_flags;
1883
1884	clear_bit_unlock(NFS_LAYOUT_FIRST_LAYOUTGET, bitlock);
1885	smp_mb__after_atomic();
1886	wake_up_bit(bitlock, NFS_LAYOUT_FIRST_LAYOUTGET);
1887}
1888
1889static void _add_to_server_list(struct pnfs_layout_hdr *lo,
1890				struct nfs_server *server)
1891{
1892	if (!test_and_set_bit(NFS_LAYOUT_HASHED, &lo->plh_flags)) {
1893		struct nfs_client *clp = server->nfs_client;
1894
1895		/* The lo must be on the clp list if there is any
1896		 * chance of a CB_LAYOUTRECALL(FILE) coming in.
1897		 */
1898		spin_lock(&clp->cl_lock);
1899		list_add_tail_rcu(&lo->plh_layouts, &server->layouts);
1900		spin_unlock(&clp->cl_lock);
1901	}
1902}
1903
1904/*
1905 * Layout segment is retreived from the server if not cached.
1906 * The appropriate layout segment is referenced and returned to the caller.
1907 */
1908struct pnfs_layout_segment *
1909pnfs_update_layout(struct inode *ino,
1910		   struct nfs_open_context *ctx,
1911		   loff_t pos,
1912		   u64 count,
1913		   enum pnfs_iomode iomode,
1914		   bool strict_iomode,
1915		   gfp_t gfp_flags)
1916{
1917	struct pnfs_layout_range arg = {
1918		.iomode = iomode,
1919		.offset = pos,
1920		.length = count,
1921	};
1922	unsigned pg_offset;
1923	struct nfs_server *server = NFS_SERVER(ino);
1924	struct nfs_client *clp = server->nfs_client;
1925	struct pnfs_layout_hdr *lo = NULL;
1926	struct pnfs_layout_segment *lseg = NULL;
1927	struct nfs4_layoutget *lgp;
1928	nfs4_stateid stateid;
1929	long timeout = 0;
1930	unsigned long giveup = jiffies + (clp->cl_lease_time << 1);
1931	bool first;
1932
1933	if (!pnfs_enabled_sb(NFS_SERVER(ino))) {
1934		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1935				 PNFS_UPDATE_LAYOUT_NO_PNFS);
1936		goto out;
1937	}
1938
1939	if (pnfs_within_mdsthreshold(ctx, ino, iomode)) {
1940		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1941				 PNFS_UPDATE_LAYOUT_MDSTHRESH);
1942		goto out;
1943	}
1944
1945lookup_again:
1946	lseg = ERR_PTR(nfs4_client_recover_expired_lease(clp));
1947	if (IS_ERR(lseg))
1948		goto out;
1949	first = false;
1950	spin_lock(&ino->i_lock);
1951	lo = pnfs_find_alloc_layout(ino, ctx, gfp_flags);
1952	if (lo == NULL) {
1953		spin_unlock(&ino->i_lock);
1954		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1955				 PNFS_UPDATE_LAYOUT_NOMEM);
1956		goto out;
1957	}
1958
1959	/* Do we even need to bother with this? */
1960	if (test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
1961		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1962				 PNFS_UPDATE_LAYOUT_BULK_RECALL);
1963		dprintk("%s matches recall, use MDS\n", __func__);
1964		goto out_unlock;
1965	}
1966
1967	/* if LAYOUTGET already failed once we don't try again */
1968	if (pnfs_layout_io_test_failed(lo, iomode)) {
1969		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1970				 PNFS_UPDATE_LAYOUT_IO_TEST_FAIL);
1971		goto out_unlock;
1972	}
1973
1974	/*
1975	 * If the layout segment list is empty, but there are outstanding
1976	 * layoutget calls, then they might be subject to a layoutrecall.
1977	 */
1978	if (list_empty(&lo->plh_segs) &&
1979	    atomic_read(&lo->plh_outstanding) != 0) {
1980		spin_unlock(&ino->i_lock);
1981		lseg = ERR_PTR(wait_var_event_killable(&lo->plh_outstanding,
1982					!atomic_read(&lo->plh_outstanding)));
1983		if (IS_ERR(lseg))
1984			goto out_put_layout_hdr;
1985		pnfs_put_layout_hdr(lo);
1986		goto lookup_again;
1987	}
1988
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1989	lseg = pnfs_find_lseg(lo, &arg, strict_iomode);
1990	if (lseg) {
1991		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1992				PNFS_UPDATE_LAYOUT_FOUND_CACHED);
1993		goto out_unlock;
1994	}
1995
1996	/*
1997	 * Choose a stateid for the LAYOUTGET. If we don't have a layout
1998	 * stateid, or it has been invalidated, then we must use the open
1999	 * stateid.
2000	 */
2001	if (test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags)) {
2002		int status;
2003
2004		/*
2005		 * The first layoutget for the file. Need to serialize per
2006		 * RFC 5661 Errata 3208.
2007		 */
2008		if (test_and_set_bit(NFS_LAYOUT_FIRST_LAYOUTGET,
2009				     &lo->plh_flags)) {
2010			spin_unlock(&ino->i_lock);
2011			lseg = ERR_PTR(wait_on_bit(&lo->plh_flags,
2012						NFS_LAYOUT_FIRST_LAYOUTGET,
2013						TASK_KILLABLE));
2014			if (IS_ERR(lseg))
2015				goto out_put_layout_hdr;
2016			pnfs_put_layout_hdr(lo);
2017			dprintk("%s retrying\n", __func__);
2018			goto lookup_again;
2019		}
2020
2021		spin_unlock(&ino->i_lock);
2022		first = true;
2023		status = nfs4_select_rw_stateid(ctx->state,
2024					iomode == IOMODE_RW ? FMODE_WRITE : FMODE_READ,
2025					NULL, &stateid, NULL);
2026		if (status != 0) {
2027			lseg = ERR_PTR(status);
2028			trace_pnfs_update_layout(ino, pos, count,
2029					iomode, lo, lseg,
2030					PNFS_UPDATE_LAYOUT_INVALID_OPEN);
2031			nfs4_schedule_stateid_recovery(server, ctx->state);
2032			pnfs_clear_first_layoutget(lo);
2033			pnfs_put_layout_hdr(lo);
2034			goto lookup_again;
2035		}
2036		spin_lock(&ino->i_lock);
2037	} else {
2038		nfs4_stateid_copy(&stateid, &lo->plh_stateid);
2039	}
2040
2041	/*
2042	 * Because we free lsegs before sending LAYOUTRETURN, we need to wait
2043	 * for LAYOUTRETURN even if first is true.
2044	 */
2045	if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
2046		spin_unlock(&ino->i_lock);
2047		dprintk("%s wait for layoutreturn\n", __func__);
2048		lseg = ERR_PTR(pnfs_prepare_to_retry_layoutget(lo));
2049		if (!IS_ERR(lseg)) {
2050			if (first)
2051				pnfs_clear_first_layoutget(lo);
2052			pnfs_put_layout_hdr(lo);
2053			dprintk("%s retrying\n", __func__);
2054			trace_pnfs_update_layout(ino, pos, count, iomode, lo,
2055					lseg, PNFS_UPDATE_LAYOUT_RETRY);
2056			goto lookup_again;
2057		}
2058		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2059				PNFS_UPDATE_LAYOUT_RETURN);
2060		goto out_put_layout_hdr;
2061	}
2062
2063	if (pnfs_layoutgets_blocked(lo)) {
2064		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2065				PNFS_UPDATE_LAYOUT_BLOCKED);
2066		goto out_unlock;
2067	}
2068	nfs_layoutget_begin(lo);
2069	spin_unlock(&ino->i_lock);
2070
2071	_add_to_server_list(lo, server);
2072
2073	pg_offset = arg.offset & ~PAGE_MASK;
2074	if (pg_offset) {
2075		arg.offset -= pg_offset;
2076		arg.length += pg_offset;
2077	}
2078	if (arg.length != NFS4_MAX_UINT64)
2079		arg.length = PAGE_ALIGN(arg.length);
2080
2081	lgp = pnfs_alloc_init_layoutget_args(ino, ctx, &stateid, &arg, gfp_flags);
2082	if (!lgp) {
2083		trace_pnfs_update_layout(ino, pos, count, iomode, lo, NULL,
2084					 PNFS_UPDATE_LAYOUT_NOMEM);
2085		nfs_layoutget_end(lo);
2086		goto out_put_layout_hdr;
2087	}
2088
 
 
 
2089	lseg = nfs4_proc_layoutget(lgp, &timeout);
2090	trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2091				 PNFS_UPDATE_LAYOUT_SEND_LAYOUTGET);
2092	nfs_layoutget_end(lo);
2093	if (IS_ERR(lseg)) {
2094		switch(PTR_ERR(lseg)) {
2095		case -EBUSY:
2096			if (time_after(jiffies, giveup))
2097				lseg = NULL;
2098			break;
2099		case -ERECALLCONFLICT:
2100		case -EAGAIN:
2101			break;
2102		default:
2103			if (!nfs_error_is_fatal(PTR_ERR(lseg))) {
2104				pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
2105				lseg = NULL;
2106			}
2107			goto out_put_layout_hdr;
2108		}
2109		if (lseg) {
2110			if (first)
2111				pnfs_clear_first_layoutget(lo);
2112			trace_pnfs_update_layout(ino, pos, count,
2113				iomode, lo, lseg, PNFS_UPDATE_LAYOUT_RETRY);
2114			pnfs_put_layout_hdr(lo);
2115			goto lookup_again;
2116		}
2117	} else {
2118		pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
2119	}
2120
2121out_put_layout_hdr:
2122	if (first)
2123		pnfs_clear_first_layoutget(lo);
2124	trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2125				 PNFS_UPDATE_LAYOUT_EXIT);
2126	pnfs_put_layout_hdr(lo);
2127out:
2128	dprintk("%s: inode %s/%llu pNFS layout segment %s for "
2129			"(%s, offset: %llu, length: %llu)\n",
2130			__func__, ino->i_sb->s_id,
2131			(unsigned long long)NFS_FILEID(ino),
2132			IS_ERR_OR_NULL(lseg) ? "not found" : "found",
2133			iomode==IOMODE_RW ?  "read/write" : "read-only",
2134			(unsigned long long)pos,
2135			(unsigned long long)count);
2136	return lseg;
2137out_unlock:
2138	spin_unlock(&ino->i_lock);
2139	goto out_put_layout_hdr;
2140}
2141EXPORT_SYMBOL_GPL(pnfs_update_layout);
2142
2143static bool
2144pnfs_sanity_check_layout_range(struct pnfs_layout_range *range)
2145{
2146	switch (range->iomode) {
2147	case IOMODE_READ:
2148	case IOMODE_RW:
2149		break;
2150	default:
2151		return false;
2152	}
2153	if (range->offset == NFS4_MAX_UINT64)
2154		return false;
2155	if (range->length == 0)
2156		return false;
2157	if (range->length != NFS4_MAX_UINT64 &&
2158	    range->length > NFS4_MAX_UINT64 - range->offset)
2159		return false;
2160	return true;
2161}
2162
2163static struct pnfs_layout_hdr *
2164_pnfs_grab_empty_layout(struct inode *ino, struct nfs_open_context *ctx)
2165{
2166	struct pnfs_layout_hdr *lo;
2167
2168	spin_lock(&ino->i_lock);
2169	lo = pnfs_find_alloc_layout(ino, ctx, GFP_KERNEL);
2170	if (!lo)
2171		goto out_unlock;
2172	if (!test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags))
2173		goto out_unlock;
2174	if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags))
2175		goto out_unlock;
2176	if (pnfs_layoutgets_blocked(lo))
2177		goto out_unlock;
2178	if (test_and_set_bit(NFS_LAYOUT_FIRST_LAYOUTGET, &lo->plh_flags))
2179		goto out_unlock;
2180	nfs_layoutget_begin(lo);
2181	spin_unlock(&ino->i_lock);
2182	_add_to_server_list(lo, NFS_SERVER(ino));
2183	return lo;
2184
2185out_unlock:
2186	spin_unlock(&ino->i_lock);
2187	pnfs_put_layout_hdr(lo);
2188	return NULL;
2189}
2190
2191static void _lgopen_prepare_attached(struct nfs4_opendata *data,
2192				     struct nfs_open_context *ctx)
2193{
2194	struct inode *ino = data->dentry->d_inode;
2195	struct pnfs_layout_range rng = {
2196		.iomode = (data->o_arg.fmode & FMODE_WRITE) ?
2197			  IOMODE_RW: IOMODE_READ,
2198		.offset = 0,
2199		.length = NFS4_MAX_UINT64,
2200	};
2201	struct nfs4_layoutget *lgp;
2202	struct pnfs_layout_hdr *lo;
2203
2204	/* Heuristic: don't send layoutget if we have cached data */
2205	if (rng.iomode == IOMODE_READ &&
2206	   (i_size_read(ino) == 0 || ino->i_mapping->nrpages != 0))
2207		return;
2208
2209	lo = _pnfs_grab_empty_layout(ino, ctx);
2210	if (!lo)
2211		return;
2212	lgp = pnfs_alloc_init_layoutget_args(ino, ctx, &current_stateid,
2213					     &rng, GFP_KERNEL);
2214	if (!lgp) {
2215		pnfs_clear_first_layoutget(lo);
 
2216		pnfs_put_layout_hdr(lo);
2217		return;
2218	}
 
2219	data->lgp = lgp;
2220	data->o_arg.lg_args = &lgp->args;
2221	data->o_res.lg_res = &lgp->res;
2222}
2223
2224static void _lgopen_prepare_floating(struct nfs4_opendata *data,
2225				     struct nfs_open_context *ctx)
2226{
 
2227	struct pnfs_layout_range rng = {
2228		.iomode = (data->o_arg.fmode & FMODE_WRITE) ?
2229			  IOMODE_RW: IOMODE_READ,
2230		.offset = 0,
2231		.length = NFS4_MAX_UINT64,
2232	};
2233	struct nfs4_layoutget *lgp;
2234
2235	lgp = pnfs_alloc_init_layoutget_args(NULL, ctx, &current_stateid,
2236					     &rng, GFP_KERNEL);
2237	if (!lgp)
2238		return;
2239	data->lgp = lgp;
2240	data->o_arg.lg_args = &lgp->args;
2241	data->o_res.lg_res = &lgp->res;
2242}
2243
2244void pnfs_lgopen_prepare(struct nfs4_opendata *data,
2245			 struct nfs_open_context *ctx)
2246{
2247	struct nfs_server *server = NFS_SERVER(data->dir->d_inode);
2248
2249	if (!(pnfs_enabled_sb(server) &&
2250	      server->pnfs_curr_ld->flags & PNFS_LAYOUTGET_ON_OPEN))
2251		return;
2252	/* Could check on max_ops, but currently hardcoded high enough */
2253	if (!nfs_server_capable(data->dir->d_inode, NFS_CAP_LGOPEN))
2254		return;
 
 
2255	if (data->state)
2256		_lgopen_prepare_attached(data, ctx);
2257	else
2258		_lgopen_prepare_floating(data, ctx);
2259}
2260
2261void pnfs_parse_lgopen(struct inode *ino, struct nfs4_layoutget *lgp,
2262		       struct nfs_open_context *ctx)
2263{
2264	struct pnfs_layout_hdr *lo;
2265	struct pnfs_layout_segment *lseg;
2266	struct nfs_server *srv = NFS_SERVER(ino);
2267	u32 iomode;
2268
2269	if (!lgp)
2270		return;
2271	dprintk("%s: entered with status %i\n", __func__, lgp->res.status);
2272	if (lgp->res.status) {
2273		switch (lgp->res.status) {
2274		default:
2275			break;
2276		/*
2277		 * Halt lgopen attempts if the server doesn't recognise
2278		 * the "current stateid" value, the layout type, or the
2279		 * layoutget operation as being valid.
2280		 * Also if it complains about too many ops in the compound
2281		 * or of the request/reply being too big.
2282		 */
2283		case -NFS4ERR_BAD_STATEID:
2284		case -NFS4ERR_NOTSUPP:
2285		case -NFS4ERR_REP_TOO_BIG:
2286		case -NFS4ERR_REP_TOO_BIG_TO_CACHE:
2287		case -NFS4ERR_REQ_TOO_BIG:
2288		case -NFS4ERR_TOO_MANY_OPS:
2289		case -NFS4ERR_UNKNOWN_LAYOUTTYPE:
2290			srv->caps &= ~NFS_CAP_LGOPEN;
2291		}
2292		return;
2293	}
2294	if (!lgp->args.inode) {
2295		lo = _pnfs_grab_empty_layout(ino, ctx);
2296		if (!lo)
2297			return;
2298		lgp->args.inode = ino;
2299	} else
2300		lo = NFS_I(lgp->args.inode)->layout;
2301
2302	lseg = pnfs_layout_process(lgp);
2303	if (!IS_ERR(lseg)) {
2304		iomode = lgp->args.range.iomode;
2305		pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
2306		pnfs_put_lseg(lseg);
2307	}
2308}
2309
2310void nfs4_lgopen_release(struct nfs4_layoutget *lgp)
2311{
2312	if (lgp != NULL) {
2313		struct inode *inode = lgp->args.inode;
2314		if (inode) {
2315			struct pnfs_layout_hdr *lo = NFS_I(inode)->layout;
2316			pnfs_clear_first_layoutget(lo);
2317			nfs_layoutget_end(lo);
2318		}
2319		pnfs_layoutget_free(lgp);
2320	}
2321}
2322
2323struct pnfs_layout_segment *
2324pnfs_layout_process(struct nfs4_layoutget *lgp)
2325{
2326	struct pnfs_layout_hdr *lo = NFS_I(lgp->args.inode)->layout;
2327	struct nfs4_layoutget_res *res = &lgp->res;
2328	struct pnfs_layout_segment *lseg;
2329	struct inode *ino = lo->plh_inode;
2330	LIST_HEAD(free_me);
2331
2332	if (!pnfs_sanity_check_layout_range(&res->range))
2333		return ERR_PTR(-EINVAL);
2334
2335	/* Inject layout blob into I/O device driver */
2336	lseg = NFS_SERVER(ino)->pnfs_curr_ld->alloc_lseg(lo, res, lgp->gfp_flags);
2337	if (IS_ERR_OR_NULL(lseg)) {
2338		if (!lseg)
2339			lseg = ERR_PTR(-ENOMEM);
2340
2341		dprintk("%s: Could not allocate layout: error %ld\n",
2342		       __func__, PTR_ERR(lseg));
2343		return lseg;
2344	}
2345
2346	pnfs_init_lseg(lo, lseg, &res->range, &res->stateid);
2347
2348	spin_lock(&ino->i_lock);
2349	if (pnfs_layoutgets_blocked(lo)) {
2350		dprintk("%s forget reply due to state\n", __func__);
2351		goto out_forget;
2352	}
2353
2354	if (!pnfs_layout_is_valid(lo)) {
2355		/* We have a completely new layout */
2356		pnfs_set_layout_stateid(lo, &res->stateid, lgp->cred, true);
2357	} else if (nfs4_stateid_match_other(&lo->plh_stateid, &res->stateid)) {
2358		/* existing state ID, make sure the sequence number matches. */
2359		if (pnfs_layout_stateid_blocked(lo, &res->stateid)) {
 
 
2360			dprintk("%s forget reply due to sequence\n", __func__);
2361			goto out_forget;
2362		}
2363		pnfs_set_layout_stateid(lo, &res->stateid, lgp->cred, false);
2364	} else {
2365		/*
2366		 * We got an entirely new state ID.  Mark all segments for the
2367		 * inode invalid, and retry the layoutget
2368		 */
2369		pnfs_mark_layout_stateid_invalid(lo, &free_me);
 
 
 
 
2370		goto out_forget;
 
 
 
2371	}
2372
2373	pnfs_get_lseg(lseg);
2374	pnfs_layout_insert_lseg(lo, lseg, &free_me);
2375
2376
2377	if (res->return_on_close)
2378		set_bit(NFS_LSEG_ROC, &lseg->pls_flags);
2379
2380	spin_unlock(&ino->i_lock);
2381	pnfs_free_lseg_list(&free_me);
2382	return lseg;
2383
2384out_forget:
2385	spin_unlock(&ino->i_lock);
2386	lseg->pls_layout = lo;
2387	NFS_SERVER(ino)->pnfs_curr_ld->free_lseg(lseg);
2388	return ERR_PTR(-EAGAIN);
2389}
2390
2391/**
2392 * pnfs_mark_matching_lsegs_return - Free or return matching layout segments
2393 * @lo: pointer to layout header
2394 * @tmp_list: list header to be used with pnfs_free_lseg_list()
2395 * @return_range: describe layout segment ranges to be returned
2396 * @seq: stateid seqid to match
2397 *
2398 * This function is mainly intended for use by layoutrecall. It attempts
2399 * to free the layout segment immediately, or else to mark it for return
2400 * as soon as its reference count drops to zero.
2401 *
2402 * Returns
2403 * - 0: a layoutreturn needs to be scheduled.
2404 * - EBUSY: there are layout segment that are still in use.
2405 * - ENOENT: there are no layout segments that need to be returned.
2406 */
2407int
2408pnfs_mark_matching_lsegs_return(struct pnfs_layout_hdr *lo,
2409				struct list_head *tmp_list,
2410				const struct pnfs_layout_range *return_range,
2411				u32 seq)
2412{
2413	struct pnfs_layout_segment *lseg, *next;
2414	int remaining = 0;
2415
2416	dprintk("%s:Begin lo %p\n", __func__, lo);
2417
2418	assert_spin_locked(&lo->plh_inode->i_lock);
2419
 
 
 
2420	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
2421		if (pnfs_match_lseg_recall(lseg, return_range, seq)) {
2422			dprintk("%s: marking lseg %p iomode %d "
2423				"offset %llu length %llu\n", __func__,
2424				lseg, lseg->pls_range.iomode,
2425				lseg->pls_range.offset,
2426				lseg->pls_range.length);
 
 
2427			if (mark_lseg_invalid(lseg, tmp_list))
2428				continue;
2429			remaining++;
2430			set_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
2431		}
2432
2433	if (remaining) {
2434		pnfs_set_plh_return_info(lo, return_range->iomode, seq);
2435		return -EBUSY;
2436	}
2437
2438	if (!list_empty(&lo->plh_return_segs)) {
2439		pnfs_set_plh_return_info(lo, return_range->iomode, seq);
2440		return 0;
2441	}
2442
2443	return -ENOENT;
2444}
2445
2446static void
2447pnfs_mark_layout_for_return(struct inode *inode,
2448			    const struct pnfs_layout_range *range)
2449{
2450	struct pnfs_layout_hdr *lo;
2451	bool return_now = false;
2452
2453	spin_lock(&inode->i_lock);
2454	lo = NFS_I(inode)->layout;
2455	if (!pnfs_layout_is_valid(lo)) {
2456		spin_unlock(&inode->i_lock);
2457		return;
2458	}
2459	pnfs_set_plh_return_info(lo, range->iomode, 0);
2460	/*
2461	 * mark all matching lsegs so that we are sure to have no live
2462	 * segments at hand when sending layoutreturn. See pnfs_put_lseg()
2463	 * for how it works.
2464	 */
2465	if (pnfs_mark_matching_lsegs_return(lo, &lo->plh_return_segs, range, 0) != -EBUSY) {
2466		const struct cred *cred;
2467		nfs4_stateid stateid;
2468		enum pnfs_iomode iomode;
2469
2470		return_now = pnfs_prepare_layoutreturn(lo, &stateid, &cred, &iomode);
2471		spin_unlock(&inode->i_lock);
2472		if (return_now)
2473			pnfs_send_layoutreturn(lo, &stateid, &cred, iomode, false);
2474	} else {
2475		spin_unlock(&inode->i_lock);
2476		nfs_commit_inode(inode, 0);
2477	}
2478}
2479
2480void pnfs_error_mark_layout_for_return(struct inode *inode,
2481				       struct pnfs_layout_segment *lseg)
2482{
2483	struct pnfs_layout_range range = {
2484		.iomode = lseg->pls_range.iomode,
2485		.offset = 0,
2486		.length = NFS4_MAX_UINT64,
2487	};
2488
2489	pnfs_mark_layout_for_return(inode, &range);
2490}
2491EXPORT_SYMBOL_GPL(pnfs_error_mark_layout_for_return);
2492
2493static bool
2494pnfs_layout_can_be_returned(struct pnfs_layout_hdr *lo)
2495{
2496	return pnfs_layout_is_valid(lo) &&
2497		!test_bit(NFS_LAYOUT_INODE_FREEING, &lo->plh_flags) &&
2498		!test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags);
2499}
2500
2501static struct pnfs_layout_segment *
2502pnfs_find_first_lseg(struct pnfs_layout_hdr *lo,
2503		     const struct pnfs_layout_range *range,
2504		     enum pnfs_iomode iomode)
2505{
2506	struct pnfs_layout_segment *lseg;
2507
2508	list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
2509		if (!test_bit(NFS_LSEG_VALID, &lseg->pls_flags))
2510			continue;
2511		if (test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
2512			continue;
2513		if (lseg->pls_range.iomode != iomode && iomode != IOMODE_ANY)
2514			continue;
2515		if (pnfs_lseg_range_intersecting(&lseg->pls_range, range))
2516			return lseg;
2517	}
2518	return NULL;
2519}
2520
2521/* Find open file states whose mode matches that of the range */
2522static bool
2523pnfs_should_return_unused_layout(struct pnfs_layout_hdr *lo,
2524				 const struct pnfs_layout_range *range)
2525{
2526	struct list_head *head;
2527	struct nfs_open_context *ctx;
2528	fmode_t mode = 0;
2529
2530	if (!pnfs_layout_can_be_returned(lo) ||
2531	    !pnfs_find_first_lseg(lo, range, range->iomode))
2532		return false;
2533
2534	head = &NFS_I(lo->plh_inode)->open_files;
2535	list_for_each_entry_rcu(ctx, head, list) {
2536		if (ctx->state)
2537			mode |= ctx->state->state & (FMODE_READ|FMODE_WRITE);
2538	}
2539
2540	switch (range->iomode) {
2541	default:
2542		break;
2543	case IOMODE_READ:
2544		mode &= ~FMODE_WRITE;
2545		break;
2546	case IOMODE_RW:
2547		if (pnfs_find_first_lseg(lo, range, IOMODE_READ))
2548			mode &= ~FMODE_READ;
2549	}
2550	return mode == 0;
2551}
2552
2553static int
2554pnfs_layout_return_unused_byserver(struct nfs_server *server, void *data)
2555{
2556	const struct pnfs_layout_range *range = data;
2557	struct pnfs_layout_hdr *lo;
2558	struct inode *inode;
2559restart:
2560	rcu_read_lock();
2561	list_for_each_entry_rcu(lo, &server->layouts, plh_layouts) {
2562		if (!pnfs_layout_can_be_returned(lo) ||
2563		    test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
2564			continue;
2565		inode = lo->plh_inode;
2566		spin_lock(&inode->i_lock);
2567		if (!pnfs_should_return_unused_layout(lo, range)) {
2568			spin_unlock(&inode->i_lock);
2569			continue;
2570		}
2571		spin_unlock(&inode->i_lock);
2572		inode = pnfs_grab_inode_layout_hdr(lo);
2573		if (!inode)
2574			continue;
2575		rcu_read_unlock();
2576		pnfs_mark_layout_for_return(inode, range);
2577		iput(inode);
2578		cond_resched();
2579		goto restart;
2580	}
2581	rcu_read_unlock();
2582	return 0;
2583}
2584
2585void
2586pnfs_layout_return_unused_byclid(struct nfs_client *clp,
2587				 enum pnfs_iomode iomode)
2588{
2589	struct pnfs_layout_range range = {
2590		.iomode = iomode,
2591		.offset = 0,
2592		.length = NFS4_MAX_UINT64,
2593	};
2594
2595	nfs_client_for_each_server(clp, pnfs_layout_return_unused_byserver,
2596			&range);
2597}
2598
2599void
2600pnfs_generic_pg_check_layout(struct nfs_pageio_descriptor *pgio)
2601{
2602	if (pgio->pg_lseg == NULL ||
2603	    test_bit(NFS_LSEG_VALID, &pgio->pg_lseg->pls_flags))
2604		return;
2605	pnfs_put_lseg(pgio->pg_lseg);
2606	pgio->pg_lseg = NULL;
2607}
2608EXPORT_SYMBOL_GPL(pnfs_generic_pg_check_layout);
2609
2610/*
2611 * Check for any intersection between the request and the pgio->pg_lseg,
2612 * and if none, put this pgio->pg_lseg away.
2613 */
2614void
2615pnfs_generic_pg_check_range(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
2616{
2617	if (pgio->pg_lseg && !pnfs_lseg_request_intersecting(pgio->pg_lseg, req)) {
2618		pnfs_put_lseg(pgio->pg_lseg);
2619		pgio->pg_lseg = NULL;
2620	}
2621}
2622EXPORT_SYMBOL_GPL(pnfs_generic_pg_check_range);
2623
2624void
2625pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
2626{
2627	u64 rd_size = req->wb_bytes;
2628
2629	pnfs_generic_pg_check_layout(pgio);
2630	pnfs_generic_pg_check_range(pgio, req);
2631	if (pgio->pg_lseg == NULL) {
2632		if (pgio->pg_dreq == NULL)
2633			rd_size = i_size_read(pgio->pg_inode) - req_offset(req);
2634		else
2635			rd_size = nfs_dreq_bytes_left(pgio->pg_dreq);
2636
2637		pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
2638						   nfs_req_openctx(req),
2639						   req_offset(req),
2640						   rd_size,
2641						   IOMODE_READ,
2642						   false,
2643						   GFP_KERNEL);
2644		if (IS_ERR(pgio->pg_lseg)) {
2645			pgio->pg_error = PTR_ERR(pgio->pg_lseg);
2646			pgio->pg_lseg = NULL;
2647			return;
2648		}
2649	}
2650	/* If no lseg, fall back to read through mds */
2651	if (pgio->pg_lseg == NULL)
2652		nfs_pageio_reset_read_mds(pgio);
2653
2654}
2655EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_read);
2656
2657void
2658pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio,
2659			   struct nfs_page *req, u64 wb_size)
2660{
2661	pnfs_generic_pg_check_layout(pgio);
2662	pnfs_generic_pg_check_range(pgio, req);
2663	if (pgio->pg_lseg == NULL) {
2664		pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
2665						   nfs_req_openctx(req),
2666						   req_offset(req),
2667						   wb_size,
2668						   IOMODE_RW,
2669						   false,
2670						   GFP_KERNEL);
2671		if (IS_ERR(pgio->pg_lseg)) {
2672			pgio->pg_error = PTR_ERR(pgio->pg_lseg);
2673			pgio->pg_lseg = NULL;
2674			return;
2675		}
2676	}
2677	/* If no lseg, fall back to write through mds */
2678	if (pgio->pg_lseg == NULL)
2679		nfs_pageio_reset_write_mds(pgio);
2680}
2681EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_write);
2682
2683void
2684pnfs_generic_pg_cleanup(struct nfs_pageio_descriptor *desc)
2685{
2686	if (desc->pg_lseg) {
2687		pnfs_put_lseg(desc->pg_lseg);
2688		desc->pg_lseg = NULL;
2689	}
2690}
2691EXPORT_SYMBOL_GPL(pnfs_generic_pg_cleanup);
2692
2693/*
2694 * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
2695 * of bytes (maximum @req->wb_bytes) that can be coalesced.
2696 */
2697size_t
2698pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio,
2699		     struct nfs_page *prev, struct nfs_page *req)
2700{
2701	unsigned int size;
2702	u64 seg_end, req_start, seg_left;
2703
2704	size = nfs_generic_pg_test(pgio, prev, req);
2705	if (!size)
2706		return 0;
2707
2708	/*
2709	 * 'size' contains the number of bytes left in the current page (up
2710	 * to the original size asked for in @req->wb_bytes).
2711	 *
2712	 * Calculate how many bytes are left in the layout segment
2713	 * and if there are less bytes than 'size', return that instead.
2714	 *
2715	 * Please also note that 'end_offset' is actually the offset of the
2716	 * first byte that lies outside the pnfs_layout_range. FIXME?
2717	 *
2718	 */
2719	if (pgio->pg_lseg) {
2720		seg_end = pnfs_end_offset(pgio->pg_lseg->pls_range.offset,
2721				     pgio->pg_lseg->pls_range.length);
2722		req_start = req_offset(req);
2723
2724		/* start of request is past the last byte of this segment */
2725		if (req_start >= seg_end)
2726			return 0;
2727
2728		/* adjust 'size' iff there are fewer bytes left in the
2729		 * segment than what nfs_generic_pg_test returned */
2730		seg_left = seg_end - req_start;
2731		if (seg_left < size)
2732			size = (unsigned int)seg_left;
2733	}
2734
2735	return size;
2736}
2737EXPORT_SYMBOL_GPL(pnfs_generic_pg_test);
2738
2739int pnfs_write_done_resend_to_mds(struct nfs_pgio_header *hdr)
2740{
2741	struct nfs_pageio_descriptor pgio;
2742
2743	/* Resend all requests through the MDS */
2744	nfs_pageio_init_write(&pgio, hdr->inode, FLUSH_STABLE, true,
2745			      hdr->completion_ops);
2746	set_bit(NFS_CONTEXT_RESEND_WRITES, &hdr->args.context->flags);
2747	return nfs_pageio_resend(&pgio, hdr);
2748}
2749EXPORT_SYMBOL_GPL(pnfs_write_done_resend_to_mds);
2750
2751static void pnfs_ld_handle_write_error(struct nfs_pgio_header *hdr)
2752{
2753
2754	dprintk("pnfs write error = %d\n", hdr->pnfs_error);
2755	if (NFS_SERVER(hdr->inode)->pnfs_curr_ld->flags &
2756	    PNFS_LAYOUTRET_ON_ERROR) {
2757		pnfs_return_layout(hdr->inode);
2758	}
2759	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))
2760		hdr->task.tk_status = pnfs_write_done_resend_to_mds(hdr);
2761}
2762
2763/*
2764 * Called by non rpc-based layout drivers
2765 */
2766void pnfs_ld_write_done(struct nfs_pgio_header *hdr)
2767{
2768	if (likely(!hdr->pnfs_error)) {
2769		pnfs_set_layoutcommit(hdr->inode, hdr->lseg,
2770				hdr->mds_offset + hdr->res.count);
2771		hdr->mds_ops->rpc_call_done(&hdr->task, hdr);
2772	}
2773	trace_nfs4_pnfs_write(hdr, hdr->pnfs_error);
2774	if (unlikely(hdr->pnfs_error))
2775		pnfs_ld_handle_write_error(hdr);
2776	hdr->mds_ops->rpc_release(hdr);
2777}
2778EXPORT_SYMBOL_GPL(pnfs_ld_write_done);
2779
2780static void
2781pnfs_write_through_mds(struct nfs_pageio_descriptor *desc,
2782		struct nfs_pgio_header *hdr)
2783{
2784	struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
2785
2786	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2787		list_splice_tail_init(&hdr->pages, &mirror->pg_list);
2788		nfs_pageio_reset_write_mds(desc);
2789		mirror->pg_recoalesce = 1;
2790	}
2791	hdr->completion_ops->completion(hdr);
2792}
2793
2794static enum pnfs_try_status
2795pnfs_try_to_write_data(struct nfs_pgio_header *hdr,
2796			const struct rpc_call_ops *call_ops,
2797			struct pnfs_layout_segment *lseg,
2798			int how)
2799{
2800	struct inode *inode = hdr->inode;
2801	enum pnfs_try_status trypnfs;
2802	struct nfs_server *nfss = NFS_SERVER(inode);
2803
2804	hdr->mds_ops = call_ops;
2805
2806	dprintk("%s: Writing ino:%lu %u@%llu (how %d)\n", __func__,
2807		inode->i_ino, hdr->args.count, hdr->args.offset, how);
2808	trypnfs = nfss->pnfs_curr_ld->write_pagelist(hdr, how);
2809	if (trypnfs != PNFS_NOT_ATTEMPTED)
2810		nfs_inc_stats(inode, NFSIOS_PNFS_WRITE);
2811	dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
2812	return trypnfs;
2813}
2814
2815static void
2816pnfs_do_write(struct nfs_pageio_descriptor *desc,
2817	      struct nfs_pgio_header *hdr, int how)
2818{
2819	const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
2820	struct pnfs_layout_segment *lseg = desc->pg_lseg;
2821	enum pnfs_try_status trypnfs;
2822
2823	trypnfs = pnfs_try_to_write_data(hdr, call_ops, lseg, how);
2824	switch (trypnfs) {
2825	case PNFS_NOT_ATTEMPTED:
2826		pnfs_write_through_mds(desc, hdr);
 
2827	case PNFS_ATTEMPTED:
2828		break;
2829	case PNFS_TRY_AGAIN:
2830		/* cleanup hdr and prepare to redo pnfs */
2831		if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2832			struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
2833			list_splice_init(&hdr->pages, &mirror->pg_list);
2834			mirror->pg_recoalesce = 1;
2835		}
2836		hdr->mds_ops->rpc_release(hdr);
2837	}
2838}
2839
2840static void pnfs_writehdr_free(struct nfs_pgio_header *hdr)
2841{
2842	pnfs_put_lseg(hdr->lseg);
2843	nfs_pgio_header_free(hdr);
2844}
2845
2846int
2847pnfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
2848{
2849	struct nfs_pgio_header *hdr;
2850	int ret;
2851
2852	hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
2853	if (!hdr) {
2854		desc->pg_error = -ENOMEM;
2855		return desc->pg_error;
2856	}
2857	nfs_pgheader_init(desc, hdr, pnfs_writehdr_free);
2858
2859	hdr->lseg = pnfs_get_lseg(desc->pg_lseg);
2860	ret = nfs_generic_pgio(desc, hdr);
2861	if (!ret)
2862		pnfs_do_write(desc, hdr, desc->pg_ioflags);
2863
2864	return ret;
2865}
2866EXPORT_SYMBOL_GPL(pnfs_generic_pg_writepages);
2867
2868int pnfs_read_done_resend_to_mds(struct nfs_pgio_header *hdr)
2869{
2870	struct nfs_pageio_descriptor pgio;
2871
2872	/* Resend all requests through the MDS */
2873	nfs_pageio_init_read(&pgio, hdr->inode, true, hdr->completion_ops);
2874	return nfs_pageio_resend(&pgio, hdr);
2875}
2876EXPORT_SYMBOL_GPL(pnfs_read_done_resend_to_mds);
2877
2878static void pnfs_ld_handle_read_error(struct nfs_pgio_header *hdr)
2879{
2880	dprintk("pnfs read error = %d\n", hdr->pnfs_error);
2881	if (NFS_SERVER(hdr->inode)->pnfs_curr_ld->flags &
2882	    PNFS_LAYOUTRET_ON_ERROR) {
2883		pnfs_return_layout(hdr->inode);
2884	}
2885	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))
2886		hdr->task.tk_status = pnfs_read_done_resend_to_mds(hdr);
2887}
2888
2889/*
2890 * Called by non rpc-based layout drivers
2891 */
2892void pnfs_ld_read_done(struct nfs_pgio_header *hdr)
2893{
2894	if (likely(!hdr->pnfs_error))
2895		hdr->mds_ops->rpc_call_done(&hdr->task, hdr);
2896	trace_nfs4_pnfs_read(hdr, hdr->pnfs_error);
2897	if (unlikely(hdr->pnfs_error))
2898		pnfs_ld_handle_read_error(hdr);
2899	hdr->mds_ops->rpc_release(hdr);
2900}
2901EXPORT_SYMBOL_GPL(pnfs_ld_read_done);
2902
2903static void
2904pnfs_read_through_mds(struct nfs_pageio_descriptor *desc,
2905		struct nfs_pgio_header *hdr)
2906{
2907	struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
2908
2909	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2910		list_splice_tail_init(&hdr->pages, &mirror->pg_list);
2911		nfs_pageio_reset_read_mds(desc);
2912		mirror->pg_recoalesce = 1;
2913	}
2914	hdr->completion_ops->completion(hdr);
2915}
2916
2917/*
2918 * Call the appropriate parallel I/O subsystem read function.
2919 */
2920static enum pnfs_try_status
2921pnfs_try_to_read_data(struct nfs_pgio_header *hdr,
2922		       const struct rpc_call_ops *call_ops,
2923		       struct pnfs_layout_segment *lseg)
2924{
2925	struct inode *inode = hdr->inode;
2926	struct nfs_server *nfss = NFS_SERVER(inode);
2927	enum pnfs_try_status trypnfs;
2928
2929	hdr->mds_ops = call_ops;
2930
2931	dprintk("%s: Reading ino:%lu %u@%llu\n",
2932		__func__, inode->i_ino, hdr->args.count, hdr->args.offset);
2933
2934	trypnfs = nfss->pnfs_curr_ld->read_pagelist(hdr);
2935	if (trypnfs != PNFS_NOT_ATTEMPTED)
2936		nfs_inc_stats(inode, NFSIOS_PNFS_READ);
2937	dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
2938	return trypnfs;
2939}
2940
2941/* Resend all requests through pnfs. */
2942void pnfs_read_resend_pnfs(struct nfs_pgio_header *hdr,
2943			   unsigned int mirror_idx)
2944{
2945	struct nfs_pageio_descriptor pgio;
2946
2947	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2948		/* Prevent deadlocks with layoutreturn! */
2949		pnfs_put_lseg(hdr->lseg);
2950		hdr->lseg = NULL;
2951
2952		nfs_pageio_init_read(&pgio, hdr->inode, false,
2953					hdr->completion_ops);
2954		pgio.pg_mirror_idx = mirror_idx;
2955		hdr->task.tk_status = nfs_pageio_resend(&pgio, hdr);
2956	}
2957}
2958EXPORT_SYMBOL_GPL(pnfs_read_resend_pnfs);
2959
2960static void
2961pnfs_do_read(struct nfs_pageio_descriptor *desc, struct nfs_pgio_header *hdr)
2962{
2963	const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
2964	struct pnfs_layout_segment *lseg = desc->pg_lseg;
2965	enum pnfs_try_status trypnfs;
2966
2967	trypnfs = pnfs_try_to_read_data(hdr, call_ops, lseg);
2968	switch (trypnfs) {
2969	case PNFS_NOT_ATTEMPTED:
2970		pnfs_read_through_mds(desc, hdr);
 
2971	case PNFS_ATTEMPTED:
2972		break;
2973	case PNFS_TRY_AGAIN:
2974		/* cleanup hdr and prepare to redo pnfs */
2975		if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2976			struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
2977			list_splice_init(&hdr->pages, &mirror->pg_list);
2978			mirror->pg_recoalesce = 1;
2979		}
2980		hdr->mds_ops->rpc_release(hdr);
2981	}
2982}
2983
2984static void pnfs_readhdr_free(struct nfs_pgio_header *hdr)
2985{
2986	pnfs_put_lseg(hdr->lseg);
2987	nfs_pgio_header_free(hdr);
2988}
2989
2990int
2991pnfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc)
2992{
2993	struct nfs_pgio_header *hdr;
2994	int ret;
2995
2996	hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
2997	if (!hdr) {
2998		desc->pg_error = -ENOMEM;
2999		return desc->pg_error;
3000	}
3001	nfs_pgheader_init(desc, hdr, pnfs_readhdr_free);
3002	hdr->lseg = pnfs_get_lseg(desc->pg_lseg);
3003	ret = nfs_generic_pgio(desc, hdr);
3004	if (!ret)
3005		pnfs_do_read(desc, hdr);
3006	return ret;
3007}
3008EXPORT_SYMBOL_GPL(pnfs_generic_pg_readpages);
3009
3010static void pnfs_clear_layoutcommitting(struct inode *inode)
3011{
3012	unsigned long *bitlock = &NFS_I(inode)->flags;
3013
3014	clear_bit_unlock(NFS_INO_LAYOUTCOMMITTING, bitlock);
3015	smp_mb__after_atomic();
3016	wake_up_bit(bitlock, NFS_INO_LAYOUTCOMMITTING);
3017}
3018
3019/*
3020 * There can be multiple RW segments.
3021 */
3022static void pnfs_list_write_lseg(struct inode *inode, struct list_head *listp)
3023{
3024	struct pnfs_layout_segment *lseg;
3025
3026	list_for_each_entry(lseg, &NFS_I(inode)->layout->plh_segs, pls_list) {
3027		if (lseg->pls_range.iomode == IOMODE_RW &&
3028		    test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
3029			list_add(&lseg->pls_lc_list, listp);
3030	}
3031}
3032
3033static void pnfs_list_write_lseg_done(struct inode *inode, struct list_head *listp)
3034{
3035	struct pnfs_layout_segment *lseg, *tmp;
3036
3037	/* Matched by references in pnfs_set_layoutcommit */
3038	list_for_each_entry_safe(lseg, tmp, listp, pls_lc_list) {
3039		list_del_init(&lseg->pls_lc_list);
3040		pnfs_put_lseg(lseg);
3041	}
3042
3043	pnfs_clear_layoutcommitting(inode);
3044}
3045
3046void pnfs_set_lo_fail(struct pnfs_layout_segment *lseg)
3047{
3048	pnfs_layout_io_set_failed(lseg->pls_layout, lseg->pls_range.iomode);
3049}
3050EXPORT_SYMBOL_GPL(pnfs_set_lo_fail);
3051
3052void
3053pnfs_set_layoutcommit(struct inode *inode, struct pnfs_layout_segment *lseg,
3054		loff_t end_pos)
3055{
3056	struct nfs_inode *nfsi = NFS_I(inode);
3057	bool mark_as_dirty = false;
3058
3059	spin_lock(&inode->i_lock);
3060	if (!test_and_set_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags)) {
3061		nfsi->layout->plh_lwb = end_pos;
3062		mark_as_dirty = true;
3063		dprintk("%s: Set layoutcommit for inode %lu ",
3064			__func__, inode->i_ino);
3065	} else if (end_pos > nfsi->layout->plh_lwb)
3066		nfsi->layout->plh_lwb = end_pos;
3067	if (!test_and_set_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags)) {
3068		/* references matched in nfs4_layoutcommit_release */
3069		pnfs_get_lseg(lseg);
3070	}
3071	spin_unlock(&inode->i_lock);
3072	dprintk("%s: lseg %p end_pos %llu\n",
3073		__func__, lseg, nfsi->layout->plh_lwb);
3074
3075	/* if pnfs_layoutcommit_inode() runs between inode locks, the next one
3076	 * will be a noop because NFS_INO_LAYOUTCOMMIT will not be set */
3077	if (mark_as_dirty)
3078		mark_inode_dirty_sync(inode);
3079}
3080EXPORT_SYMBOL_GPL(pnfs_set_layoutcommit);
3081
3082void pnfs_cleanup_layoutcommit(struct nfs4_layoutcommit_data *data)
3083{
3084	struct nfs_server *nfss = NFS_SERVER(data->args.inode);
3085
3086	if (nfss->pnfs_curr_ld->cleanup_layoutcommit)
3087		nfss->pnfs_curr_ld->cleanup_layoutcommit(data);
3088	pnfs_list_write_lseg_done(data->args.inode, &data->lseg_list);
3089}
3090
3091/*
3092 * For the LAYOUT4_NFSV4_1_FILES layout type, NFS_DATA_SYNC WRITEs and
3093 * NFS_UNSTABLE WRITEs with a COMMIT to data servers must store enough
3094 * data to disk to allow the server to recover the data if it crashes.
3095 * LAYOUTCOMMIT is only needed when the NFL4_UFLG_COMMIT_THRU_MDS flag
3096 * is off, and a COMMIT is sent to a data server, or
3097 * if WRITEs to a data server return NFS_DATA_SYNC.
3098 */
3099int
3100pnfs_layoutcommit_inode(struct inode *inode, bool sync)
3101{
3102	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
3103	struct nfs4_layoutcommit_data *data;
3104	struct nfs_inode *nfsi = NFS_I(inode);
3105	loff_t end_pos;
3106	int status;
3107
3108	if (!pnfs_layoutcommit_outstanding(inode))
3109		return 0;
3110
3111	dprintk("--> %s inode %lu\n", __func__, inode->i_ino);
3112
3113	status = -EAGAIN;
3114	if (test_and_set_bit(NFS_INO_LAYOUTCOMMITTING, &nfsi->flags)) {
3115		if (!sync)
3116			goto out;
3117		status = wait_on_bit_lock_action(&nfsi->flags,
3118				NFS_INO_LAYOUTCOMMITTING,
3119				nfs_wait_bit_killable,
3120				TASK_KILLABLE);
3121		if (status)
3122			goto out;
3123	}
3124
3125	status = -ENOMEM;
3126	/* Note kzalloc ensures data->res.seq_res.sr_slot == NULL */
3127	data = kzalloc(sizeof(*data), GFP_NOFS);
3128	if (!data)
3129		goto clear_layoutcommitting;
3130
3131	status = 0;
3132	spin_lock(&inode->i_lock);
3133	if (!test_and_clear_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags))
3134		goto out_unlock;
3135
3136	INIT_LIST_HEAD(&data->lseg_list);
3137	pnfs_list_write_lseg(inode, &data->lseg_list);
3138
3139	end_pos = nfsi->layout->plh_lwb;
3140
3141	nfs4_stateid_copy(&data->args.stateid, &nfsi->layout->plh_stateid);
3142	data->cred = get_cred(nfsi->layout->plh_lc_cred);
3143	spin_unlock(&inode->i_lock);
3144
3145	data->args.inode = inode;
3146	nfs_fattr_init(&data->fattr);
3147	data->args.bitmask = NFS_SERVER(inode)->cache_consistency_bitmask;
3148	data->res.fattr = &data->fattr;
3149	if (end_pos != 0)
3150		data->args.lastbytewritten = end_pos - 1;
3151	else
3152		data->args.lastbytewritten = U64_MAX;
3153	data->res.server = NFS_SERVER(inode);
3154
3155	if (ld->prepare_layoutcommit) {
3156		status = ld->prepare_layoutcommit(&data->args);
3157		if (status) {
3158			put_cred(data->cred);
3159			spin_lock(&inode->i_lock);
3160			set_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags);
3161			if (end_pos > nfsi->layout->plh_lwb)
3162				nfsi->layout->plh_lwb = end_pos;
3163			goto out_unlock;
3164		}
3165	}
3166
3167
3168	status = nfs4_proc_layoutcommit(data, sync);
3169out:
3170	if (status)
3171		mark_inode_dirty_sync(inode);
3172	dprintk("<-- %s status %d\n", __func__, status);
3173	return status;
3174out_unlock:
3175	spin_unlock(&inode->i_lock);
3176	kfree(data);
3177clear_layoutcommitting:
3178	pnfs_clear_layoutcommitting(inode);
3179	goto out;
3180}
3181EXPORT_SYMBOL_GPL(pnfs_layoutcommit_inode);
3182
3183int
3184pnfs_generic_sync(struct inode *inode, bool datasync)
3185{
3186	return pnfs_layoutcommit_inode(inode, true);
3187}
3188EXPORT_SYMBOL_GPL(pnfs_generic_sync);
3189
3190struct nfs4_threshold *pnfs_mdsthreshold_alloc(void)
3191{
3192	struct nfs4_threshold *thp;
3193
3194	thp = kzalloc(sizeof(*thp), GFP_NOFS);
3195	if (!thp) {
3196		dprintk("%s mdsthreshold allocation failed\n", __func__);
3197		return NULL;
3198	}
3199	return thp;
3200}
3201
3202#if IS_ENABLED(CONFIG_NFS_V4_2)
3203int
3204pnfs_report_layoutstat(struct inode *inode, gfp_t gfp_flags)
3205{
3206	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
3207	struct nfs_server *server = NFS_SERVER(inode);
3208	struct nfs_inode *nfsi = NFS_I(inode);
3209	struct nfs42_layoutstat_data *data;
3210	struct pnfs_layout_hdr *hdr;
3211	int status = 0;
3212
3213	if (!pnfs_enabled_sb(server) || !ld->prepare_layoutstats)
3214		goto out;
3215
3216	if (!nfs_server_capable(inode, NFS_CAP_LAYOUTSTATS))
3217		goto out;
3218
3219	if (test_and_set_bit(NFS_INO_LAYOUTSTATS, &nfsi->flags))
3220		goto out;
3221
3222	spin_lock(&inode->i_lock);
3223	if (!NFS_I(inode)->layout) {
3224		spin_unlock(&inode->i_lock);
3225		goto out_clear_layoutstats;
3226	}
3227	hdr = NFS_I(inode)->layout;
3228	pnfs_get_layout_hdr(hdr);
3229	spin_unlock(&inode->i_lock);
3230
3231	data = kzalloc(sizeof(*data), gfp_flags);
3232	if (!data) {
3233		status = -ENOMEM;
3234		goto out_put;
3235	}
3236
3237	data->args.fh = NFS_FH(inode);
3238	data->args.inode = inode;
3239	status = ld->prepare_layoutstats(&data->args);
3240	if (status)
3241		goto out_free;
3242
3243	status = nfs42_proc_layoutstats_generic(NFS_SERVER(inode), data);
3244
3245out:
3246	dprintk("%s returns %d\n", __func__, status);
3247	return status;
3248
3249out_free:
3250	kfree(data);
3251out_put:
3252	pnfs_put_layout_hdr(hdr);
3253out_clear_layoutstats:
3254	smp_mb__before_atomic();
3255	clear_bit(NFS_INO_LAYOUTSTATS, &nfsi->flags);
3256	smp_mb__after_atomic();
3257	goto out;
3258}
3259EXPORT_SYMBOL_GPL(pnfs_report_layoutstat);
3260#endif
3261
3262unsigned int layoutstats_timer;
3263module_param(layoutstats_timer, uint, 0644);
3264EXPORT_SYMBOL_GPL(layoutstats_timer);