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 "internal.h"
  34#include "pnfs.h"
  35#include "iostat.h"
  36#include "nfs4trace.h"
  37#include "delegation.h"
  38#include "nfs42.h"
  39
  40#define NFSDBG_FACILITY		NFSDBG_PNFS
  41#define PNFS_LAYOUTGET_RETRY_TIMEOUT (120*HZ)
  42
  43/* Locking:
  44 *
  45 * pnfs_spinlock:
  46 *      protects pnfs_modules_tbl.
  47 */
  48static DEFINE_SPINLOCK(pnfs_spinlock);
  49
  50/*
  51 * pnfs_modules_tbl holds all pnfs modules
  52 */
  53static LIST_HEAD(pnfs_modules_tbl);
  54
  55static void pnfs_layoutreturn_before_put_layout_hdr(struct pnfs_layout_hdr *lo);
  56
  57/* Return the registered pnfs layout driver module matching given id */
  58static struct pnfs_layoutdriver_type *
  59find_pnfs_driver_locked(u32 id)
  60{
  61	struct pnfs_layoutdriver_type *local;
  62
  63	list_for_each_entry(local, &pnfs_modules_tbl, pnfs_tblid)
  64		if (local->id == id)
  65			goto out;
  66	local = NULL;
  67out:
  68	dprintk("%s: Searching for id %u, found %p\n", __func__, id, local);
  69	return local;
  70}
  71
  72static struct pnfs_layoutdriver_type *
  73find_pnfs_driver(u32 id)
  74{
  75	struct pnfs_layoutdriver_type *local;
  76
  77	spin_lock(&pnfs_spinlock);
  78	local = find_pnfs_driver_locked(id);
  79	if (local != NULL && !try_module_get(local->owner)) {
  80		dprintk("%s: Could not grab reference on module\n", __func__);
  81		local = NULL;
  82	}
  83	spin_unlock(&pnfs_spinlock);
  84	return local;
  85}
  86
  87void
  88unset_pnfs_layoutdriver(struct nfs_server *nfss)
  89{
  90	if (nfss->pnfs_curr_ld) {
  91		if (nfss->pnfs_curr_ld->clear_layoutdriver)
  92			nfss->pnfs_curr_ld->clear_layoutdriver(nfss);
  93		/* Decrement the MDS count. Purge the deviceid cache if zero */
  94		if (atomic_dec_and_test(&nfss->nfs_client->cl_mds_count))
  95			nfs4_deviceid_purge_client(nfss->nfs_client);
  96		module_put(nfss->pnfs_curr_ld->owner);
  97	}
  98	nfss->pnfs_curr_ld = NULL;
  99}
 100
 101/*
 102 * Try to set the server's pnfs module to the pnfs layout type specified by id.
 103 * Currently only one pNFS layout driver per filesystem is supported.
 104 *
 105 * @id layout type. Zero (illegal layout type) indicates pNFS not in use.
 106 */
 107void
 108set_pnfs_layoutdriver(struct nfs_server *server, const struct nfs_fh *mntfh,
 109		      u32 id)
 110{
 111	struct pnfs_layoutdriver_type *ld_type = NULL;
 112
 113	if (id == 0)
 114		goto out_no_driver;
 115	if (!(server->nfs_client->cl_exchange_flags &
 116		 (EXCHGID4_FLAG_USE_NON_PNFS | EXCHGID4_FLAG_USE_PNFS_MDS))) {
 117		printk(KERN_ERR "NFS: %s: id %u cl_exchange_flags 0x%x\n",
 118			__func__, id, server->nfs_client->cl_exchange_flags);
 119		goto out_no_driver;
 120	}
 121	ld_type = find_pnfs_driver(id);
 122	if (!ld_type) {
 123		request_module("%s-%u", LAYOUT_NFSV4_1_MODULE_PREFIX, id);
 124		ld_type = find_pnfs_driver(id);
 125		if (!ld_type) {
 126			dprintk("%s: No pNFS module found for %u.\n",
 127				__func__, id);
 128			goto out_no_driver;
 129		}
 130	}
 131	server->pnfs_curr_ld = ld_type;
 132	if (ld_type->set_layoutdriver
 133	    && ld_type->set_layoutdriver(server, mntfh)) {
 134		printk(KERN_ERR "NFS: %s: Error initializing pNFS layout "
 135			"driver %u.\n", __func__, id);
 136		module_put(ld_type->owner);
 137		goto out_no_driver;
 138	}
 139	/* Bump the MDS count */
 140	atomic_inc(&server->nfs_client->cl_mds_count);
 141
 142	dprintk("%s: pNFS module for %u set\n", __func__, id);
 143	return;
 144
 145out_no_driver:
 146	dprintk("%s: Using NFSv4 I/O\n", __func__);
 147	server->pnfs_curr_ld = NULL;
 148}
 149
 150int
 151pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
 152{
 153	int status = -EINVAL;
 154	struct pnfs_layoutdriver_type *tmp;
 155
 156	if (ld_type->id == 0) {
 157		printk(KERN_ERR "NFS: %s id 0 is reserved\n", __func__);
 158		return status;
 159	}
 160	if (!ld_type->alloc_lseg || !ld_type->free_lseg) {
 161		printk(KERN_ERR "NFS: %s Layout driver must provide "
 162		       "alloc_lseg and free_lseg.\n", __func__);
 163		return status;
 164	}
 165
 166	spin_lock(&pnfs_spinlock);
 167	tmp = find_pnfs_driver_locked(ld_type->id);
 168	if (!tmp) {
 169		list_add(&ld_type->pnfs_tblid, &pnfs_modules_tbl);
 170		status = 0;
 171		dprintk("%s Registering id:%u name:%s\n", __func__, ld_type->id,
 172			ld_type->name);
 173	} else {
 174		printk(KERN_ERR "NFS: %s Module with id %d already loaded!\n",
 175			__func__, ld_type->id);
 176	}
 177	spin_unlock(&pnfs_spinlock);
 178
 179	return status;
 180}
 181EXPORT_SYMBOL_GPL(pnfs_register_layoutdriver);
 182
 183void
 184pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
 185{
 186	dprintk("%s Deregistering id:%u\n", __func__, ld_type->id);
 187	spin_lock(&pnfs_spinlock);
 188	list_del(&ld_type->pnfs_tblid);
 189	spin_unlock(&pnfs_spinlock);
 190}
 191EXPORT_SYMBOL_GPL(pnfs_unregister_layoutdriver);
 192
 193/*
 194 * pNFS client layout cache
 195 */
 196
 197/* Need to hold i_lock if caller does not already hold reference */
 198void
 199pnfs_get_layout_hdr(struct pnfs_layout_hdr *lo)
 200{
 201	atomic_inc(&lo->plh_refcount);
 202}
 203
 204static struct pnfs_layout_hdr *
 205pnfs_alloc_layout_hdr(struct inode *ino, gfp_t gfp_flags)
 206{
 207	struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
 208	return ld->alloc_layout_hdr(ino, gfp_flags);
 209}
 210
 211static void
 212pnfs_free_layout_hdr(struct pnfs_layout_hdr *lo)
 213{
 214	struct nfs_server *server = NFS_SERVER(lo->plh_inode);
 215	struct pnfs_layoutdriver_type *ld = server->pnfs_curr_ld;
 216
 217	if (!list_empty(&lo->plh_layouts)) {
 218		struct nfs_client *clp = server->nfs_client;
 219
 220		spin_lock(&clp->cl_lock);
 221		list_del_init(&lo->plh_layouts);
 222		spin_unlock(&clp->cl_lock);
 223	}
 224	put_rpccred(lo->plh_lc_cred);
 225	return ld->free_layout_hdr(lo);
 226}
 227
 228static void
 229pnfs_detach_layout_hdr(struct pnfs_layout_hdr *lo)
 230{
 231	struct nfs_inode *nfsi = NFS_I(lo->plh_inode);
 232	dprintk("%s: freeing layout cache %p\n", __func__, lo);
 233	nfsi->layout = NULL;
 234	/* Reset MDS Threshold I/O counters */
 235	nfsi->write_io = 0;
 236	nfsi->read_io = 0;
 237}
 238
 239void
 240pnfs_put_layout_hdr(struct pnfs_layout_hdr *lo)
 241{
 242	struct inode *inode = lo->plh_inode;
 243
 244	pnfs_layoutreturn_before_put_layout_hdr(lo);
 245
 246	if (atomic_dec_and_lock(&lo->plh_refcount, &inode->i_lock)) {
 247		if (!list_empty(&lo->plh_segs))
 248			WARN_ONCE(1, "NFS: BUG unfreed layout segments.\n");
 249		pnfs_detach_layout_hdr(lo);
 250		spin_unlock(&inode->i_lock);
 251		pnfs_free_layout_hdr(lo);
 252	}
 253}
 254
 255/*
 256 * Mark a pnfs_layout_hdr and all associated layout segments as invalid
 257 *
 258 * In order to continue using the pnfs_layout_hdr, a full recovery
 259 * is required.
 260 * Note that caller must hold inode->i_lock.
 261 */
 262static int
 263pnfs_mark_layout_stateid_invalid(struct pnfs_layout_hdr *lo,
 264		struct list_head *lseg_list)
 265{
 266	struct pnfs_layout_range range = {
 267		.iomode = IOMODE_ANY,
 268		.offset = 0,
 269		.length = NFS4_MAX_UINT64,
 270	};
 271
 272	set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
 273	return pnfs_mark_matching_lsegs_invalid(lo, lseg_list, &range);
 274}
 275
 276static int
 277pnfs_iomode_to_fail_bit(u32 iomode)
 278{
 279	return iomode == IOMODE_RW ?
 280		NFS_LAYOUT_RW_FAILED : NFS_LAYOUT_RO_FAILED;
 281}
 282
 283static void
 284pnfs_layout_set_fail_bit(struct pnfs_layout_hdr *lo, int fail_bit)
 285{
 286	lo->plh_retry_timestamp = jiffies;
 287	if (!test_and_set_bit(fail_bit, &lo->plh_flags))
 288		atomic_inc(&lo->plh_refcount);
 289}
 290
 291static void
 292pnfs_layout_clear_fail_bit(struct pnfs_layout_hdr *lo, int fail_bit)
 293{
 294	if (test_and_clear_bit(fail_bit, &lo->plh_flags))
 295		atomic_dec(&lo->plh_refcount);
 296}
 297
 298static void
 299pnfs_layout_io_set_failed(struct pnfs_layout_hdr *lo, u32 iomode)
 300{
 301	struct inode *inode = lo->plh_inode;
 302	struct pnfs_layout_range range = {
 303		.iomode = iomode,
 304		.offset = 0,
 305		.length = NFS4_MAX_UINT64,
 306	};
 307	LIST_HEAD(head);
 308
 309	spin_lock(&inode->i_lock);
 310	pnfs_layout_set_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
 311	pnfs_mark_matching_lsegs_invalid(lo, &head, &range);
 312	spin_unlock(&inode->i_lock);
 313	pnfs_free_lseg_list(&head);
 314	dprintk("%s Setting layout IOMODE_%s fail bit\n", __func__,
 315			iomode == IOMODE_RW ?  "RW" : "READ");
 316}
 317
 318static bool
 319pnfs_layout_io_test_failed(struct pnfs_layout_hdr *lo, u32 iomode)
 320{
 321	unsigned long start, end;
 322	int fail_bit = pnfs_iomode_to_fail_bit(iomode);
 323
 324	if (test_bit(fail_bit, &lo->plh_flags) == 0)
 325		return false;
 326	end = jiffies;
 327	start = end - PNFS_LAYOUTGET_RETRY_TIMEOUT;
 328	if (!time_in_range(lo->plh_retry_timestamp, start, end)) {
 329		/* It is time to retry the failed layoutgets */
 330		pnfs_layout_clear_fail_bit(lo, fail_bit);
 331		return false;
 332	}
 333	return true;
 334}
 335
 336static void
 337init_lseg(struct pnfs_layout_hdr *lo, struct pnfs_layout_segment *lseg)
 338{
 339	INIT_LIST_HEAD(&lseg->pls_list);
 340	INIT_LIST_HEAD(&lseg->pls_lc_list);
 341	atomic_set(&lseg->pls_refcount, 1);
 342	smp_mb();
 343	set_bit(NFS_LSEG_VALID, &lseg->pls_flags);
 344	lseg->pls_layout = lo;
 345}
 346
 347static void pnfs_free_lseg(struct pnfs_layout_segment *lseg)
 348{
 349	struct inode *ino = lseg->pls_layout->plh_inode;
 350
 351	NFS_SERVER(ino)->pnfs_curr_ld->free_lseg(lseg);
 352}
 353
 354static void
 355pnfs_layout_remove_lseg(struct pnfs_layout_hdr *lo,
 356		struct pnfs_layout_segment *lseg)
 357{
 358	struct inode *inode = lo->plh_inode;
 359
 360	WARN_ON(test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
 361	list_del_init(&lseg->pls_list);
 362	/* Matched by pnfs_get_layout_hdr in pnfs_layout_insert_lseg */
 363	atomic_dec(&lo->plh_refcount);
 364	if (list_empty(&lo->plh_segs))
 365		clear_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
 366	rpc_wake_up(&NFS_SERVER(inode)->roc_rpcwaitq);
 367}
 368
 369void
 370pnfs_put_lseg(struct pnfs_layout_segment *lseg)
 371{
 372	struct pnfs_layout_hdr *lo;
 373	struct inode *inode;
 374
 375	if (!lseg)
 376		return;
 377
 378	dprintk("%s: lseg %p ref %d valid %d\n", __func__, lseg,
 379		atomic_read(&lseg->pls_refcount),
 380		test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
 381
 382	lo = lseg->pls_layout;
 383	inode = lo->plh_inode;
 384
 385	if (atomic_dec_and_lock(&lseg->pls_refcount, &inode->i_lock)) {
 386		if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags)) {
 387			spin_unlock(&inode->i_lock);
 388			return;
 389		}
 390		pnfs_get_layout_hdr(lo);
 391		pnfs_layout_remove_lseg(lo, lseg);
 392		spin_unlock(&inode->i_lock);
 393		pnfs_free_lseg(lseg);
 394		pnfs_put_layout_hdr(lo);
 395	}
 396}
 397EXPORT_SYMBOL_GPL(pnfs_put_lseg);
 398
 399static void pnfs_free_lseg_async_work(struct work_struct *work)
 400{
 401	struct pnfs_layout_segment *lseg;
 402	struct pnfs_layout_hdr *lo;
 403
 404	lseg = container_of(work, struct pnfs_layout_segment, pls_work);
 405	lo = lseg->pls_layout;
 406
 407	pnfs_free_lseg(lseg);
 408	pnfs_put_layout_hdr(lo);
 409}
 410
 411static void pnfs_free_lseg_async(struct pnfs_layout_segment *lseg)
 412{
 413	INIT_WORK(&lseg->pls_work, pnfs_free_lseg_async_work);
 414	schedule_work(&lseg->pls_work);
 415}
 416
 417void
 418pnfs_put_lseg_locked(struct pnfs_layout_segment *lseg)
 419{
 420	if (!lseg)
 421		return;
 422
 423	assert_spin_locked(&lseg->pls_layout->plh_inode->i_lock);
 424
 425	dprintk("%s: lseg %p ref %d valid %d\n", __func__, lseg,
 426		atomic_read(&lseg->pls_refcount),
 427		test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
 428	if (atomic_dec_and_test(&lseg->pls_refcount)) {
 429		struct pnfs_layout_hdr *lo = lseg->pls_layout;
 430		if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags))
 431			return;
 432		pnfs_get_layout_hdr(lo);
 433		pnfs_layout_remove_lseg(lo, lseg);
 434		pnfs_free_lseg_async(lseg);
 435	}
 436}
 437EXPORT_SYMBOL_GPL(pnfs_put_lseg_locked);
 438
 439static u64
 440end_offset(u64 start, u64 len)
 441{
 442	u64 end;
 443
 444	end = start + len;
 445	return end >= start ? end : NFS4_MAX_UINT64;
 446}
 447
 448/*
 449 * is l2 fully contained in l1?
 450 *   start1                             end1
 451 *   [----------------------------------)
 452 *           start2           end2
 453 *           [----------------)
 454 */
 455static bool
 456pnfs_lseg_range_contained(const struct pnfs_layout_range *l1,
 457		 const struct pnfs_layout_range *l2)
 458{
 459	u64 start1 = l1->offset;
 460	u64 end1 = end_offset(start1, l1->length);
 461	u64 start2 = l2->offset;
 462	u64 end2 = end_offset(start2, l2->length);
 463
 464	return (start1 <= start2) && (end1 >= end2);
 465}
 466
 467/*
 468 * is l1 and l2 intersecting?
 469 *   start1                             end1
 470 *   [----------------------------------)
 471 *                              start2           end2
 472 *                              [----------------)
 473 */
 474static bool
 475pnfs_lseg_range_intersecting(const struct pnfs_layout_range *l1,
 476		    const struct pnfs_layout_range *l2)
 477{
 478	u64 start1 = l1->offset;
 479	u64 end1 = end_offset(start1, l1->length);
 480	u64 start2 = l2->offset;
 481	u64 end2 = end_offset(start2, l2->length);
 482
 483	return (end1 == NFS4_MAX_UINT64 || end1 > start2) &&
 484	       (end2 == NFS4_MAX_UINT64 || end2 > start1);
 485}
 486
 487static bool
 488should_free_lseg(const struct pnfs_layout_range *lseg_range,
 489		 const struct pnfs_layout_range *recall_range)
 490{
 491	return (recall_range->iomode == IOMODE_ANY ||
 492		lseg_range->iomode == recall_range->iomode) &&
 493	       pnfs_lseg_range_intersecting(lseg_range, recall_range);
 494}
 495
 496static bool pnfs_lseg_dec_and_remove_zero(struct pnfs_layout_segment *lseg,
 497		struct list_head *tmp_list)
 498{
 499	if (!atomic_dec_and_test(&lseg->pls_refcount))
 500		return false;
 501	pnfs_layout_remove_lseg(lseg->pls_layout, lseg);
 502	list_add(&lseg->pls_list, tmp_list);
 503	return true;
 504}
 505
 506/* Returns 1 if lseg is removed from list, 0 otherwise */
 507static int mark_lseg_invalid(struct pnfs_layout_segment *lseg,
 508			     struct list_head *tmp_list)
 509{
 510	int rv = 0;
 511
 512	if (test_and_clear_bit(NFS_LSEG_VALID, &lseg->pls_flags)) {
 513		/* Remove the reference keeping the lseg in the
 514		 * list.  It will now be removed when all
 515		 * outstanding io is finished.
 516		 */
 517		dprintk("%s: lseg %p ref %d\n", __func__, lseg,
 518			atomic_read(&lseg->pls_refcount));
 519		if (pnfs_lseg_dec_and_remove_zero(lseg, tmp_list))
 520			rv = 1;
 521	}
 522	return rv;
 523}
 524
 525/* Returns count of number of matching invalid lsegs remaining in list
 526 * after call.
 527 */
 528int
 529pnfs_mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo,
 530			    struct list_head *tmp_list,
 531			    const struct pnfs_layout_range *recall_range)
 532{
 533	struct pnfs_layout_segment *lseg, *next;
 534	int remaining = 0;
 535
 536	dprintk("%s:Begin lo %p\n", __func__, lo);
 537
 538	if (list_empty(&lo->plh_segs))
 539		return 0;
 540	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
 541		if (!recall_range ||
 542		    should_free_lseg(&lseg->pls_range, recall_range)) {
 543			dprintk("%s: freeing lseg %p iomode %d "
 544				"offset %llu length %llu\n", __func__,
 545				lseg, lseg->pls_range.iomode, lseg->pls_range.offset,
 546				lseg->pls_range.length);
 547			if (!mark_lseg_invalid(lseg, tmp_list))
 548				remaining++;
 549		}
 550	dprintk("%s:Return %i\n", __func__, remaining);
 551	return remaining;
 552}
 553
 554/* note free_me must contain lsegs from a single layout_hdr */
 555void
 556pnfs_free_lseg_list(struct list_head *free_me)
 557{
 558	struct pnfs_layout_segment *lseg, *tmp;
 559
 560	if (list_empty(free_me))
 561		return;
 562
 563	list_for_each_entry_safe(lseg, tmp, free_me, pls_list) {
 564		list_del(&lseg->pls_list);
 565		pnfs_free_lseg(lseg);
 566	}
 567}
 568
 569void
 570pnfs_destroy_layout(struct nfs_inode *nfsi)
 571{
 572	struct pnfs_layout_hdr *lo;
 573	LIST_HEAD(tmp_list);
 574
 575	spin_lock(&nfsi->vfs_inode.i_lock);
 576	lo = nfsi->layout;
 577	if (lo) {
 
 
 578		pnfs_get_layout_hdr(lo);
 579		pnfs_mark_layout_stateid_invalid(lo, &tmp_list);
 580		pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RO_FAILED);
 581		pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RW_FAILED);
 582		spin_unlock(&nfsi->vfs_inode.i_lock);
 583		pnfs_free_lseg_list(&tmp_list);
 584		pnfs_put_layout_hdr(lo);
 585	} else
 586		spin_unlock(&nfsi->vfs_inode.i_lock);
 587}
 588EXPORT_SYMBOL_GPL(pnfs_destroy_layout);
 589
 590static bool
 591pnfs_layout_add_bulk_destroy_list(struct inode *inode,
 592		struct list_head *layout_list)
 593{
 594	struct pnfs_layout_hdr *lo;
 595	bool ret = false;
 596
 597	spin_lock(&inode->i_lock);
 598	lo = NFS_I(inode)->layout;
 599	if (lo != NULL && list_empty(&lo->plh_bulk_destroy)) {
 600		pnfs_get_layout_hdr(lo);
 601		list_add(&lo->plh_bulk_destroy, layout_list);
 602		ret = true;
 603	}
 604	spin_unlock(&inode->i_lock);
 605	return ret;
 606}
 607
 608/* Caller must hold rcu_read_lock and clp->cl_lock */
 609static int
 610pnfs_layout_bulk_destroy_byserver_locked(struct nfs_client *clp,
 611		struct nfs_server *server,
 612		struct list_head *layout_list)
 613{
 614	struct pnfs_layout_hdr *lo, *next;
 615	struct inode *inode;
 616
 617	list_for_each_entry_safe(lo, next, &server->layouts, plh_layouts) {
 618		inode = igrab(lo->plh_inode);
 619		if (inode == NULL)
 620			continue;
 621		list_del_init(&lo->plh_layouts);
 622		if (pnfs_layout_add_bulk_destroy_list(inode, layout_list))
 623			continue;
 624		rcu_read_unlock();
 625		spin_unlock(&clp->cl_lock);
 626		iput(inode);
 627		spin_lock(&clp->cl_lock);
 628		rcu_read_lock();
 629		return -EAGAIN;
 630	}
 631	return 0;
 632}
 633
 634static int
 635pnfs_layout_free_bulk_destroy_list(struct list_head *layout_list,
 636		bool is_bulk_recall)
 637{
 638	struct pnfs_layout_hdr *lo;
 639	struct inode *inode;
 
 
 
 
 
 640	LIST_HEAD(lseg_list);
 641	int ret = 0;
 642
 643	while (!list_empty(layout_list)) {
 644		lo = list_entry(layout_list->next, struct pnfs_layout_hdr,
 645				plh_bulk_destroy);
 646		dprintk("%s freeing layout for inode %lu\n", __func__,
 647			lo->plh_inode->i_ino);
 648		inode = lo->plh_inode;
 649
 650		pnfs_layoutcommit_inode(inode, false);
 651
 652		spin_lock(&inode->i_lock);
 653		list_del_init(&lo->plh_bulk_destroy);
 654		if (pnfs_mark_layout_stateid_invalid(lo, &lseg_list)) {
 655			if (is_bulk_recall)
 656				set_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
 
 657			ret = -EAGAIN;
 658		}
 659		spin_unlock(&inode->i_lock);
 660		pnfs_free_lseg_list(&lseg_list);
 661		/* Free all lsegs that are attached to commit buckets */
 662		nfs_commit_inode(inode, 0);
 663		pnfs_put_layout_hdr(lo);
 664		iput(inode);
 665	}
 666	return ret;
 667}
 668
 669int
 670pnfs_destroy_layouts_byfsid(struct nfs_client *clp,
 671		struct nfs_fsid *fsid,
 672		bool is_recall)
 673{
 674	struct nfs_server *server;
 675	LIST_HEAD(layout_list);
 676
 677	spin_lock(&clp->cl_lock);
 678	rcu_read_lock();
 679restart:
 680	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 681		if (memcmp(&server->fsid, fsid, sizeof(*fsid)) != 0)
 682			continue;
 683		if (pnfs_layout_bulk_destroy_byserver_locked(clp,
 684				server,
 685				&layout_list) != 0)
 686			goto restart;
 687	}
 688	rcu_read_unlock();
 689	spin_unlock(&clp->cl_lock);
 690
 691	if (list_empty(&layout_list))
 692		return 0;
 693	return pnfs_layout_free_bulk_destroy_list(&layout_list, is_recall);
 694}
 695
 696int
 697pnfs_destroy_layouts_byclid(struct nfs_client *clp,
 698		bool is_recall)
 699{
 700	struct nfs_server *server;
 701	LIST_HEAD(layout_list);
 702
 703	spin_lock(&clp->cl_lock);
 704	rcu_read_lock();
 705restart:
 706	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 707		if (pnfs_layout_bulk_destroy_byserver_locked(clp,
 708					server,
 709					&layout_list) != 0)
 710			goto restart;
 711	}
 712	rcu_read_unlock();
 713	spin_unlock(&clp->cl_lock);
 714
 715	if (list_empty(&layout_list))
 716		return 0;
 717	return pnfs_layout_free_bulk_destroy_list(&layout_list, is_recall);
 718}
 719
 720/*
 721 * Called by the state manger to remove all layouts established under an
 722 * expired lease.
 723 */
 724void
 725pnfs_destroy_all_layouts(struct nfs_client *clp)
 726{
 727	nfs4_deviceid_mark_client_invalid(clp);
 728	nfs4_deviceid_purge_client(clp);
 729
 730	pnfs_destroy_layouts_byclid(clp, false);
 731}
 732
 733/*
 734 * Compare 2 layout stateid sequence ids, to see which is newer,
 735 * taking into account wraparound issues.
 736 */
 737static bool pnfs_seqid_is_newer(u32 s1, u32 s2)
 738{
 739	return (s32)(s1 - s2) > 0;
 740}
 741
 
 
 
 
 
 
 
 
 
 
 
 742/* update lo->plh_stateid with new if is more recent */
 743void
 744pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo, const nfs4_stateid *new,
 745			bool update_barrier)
 746{
 747	u32 oldseq, newseq, new_barrier;
 748	int empty = list_empty(&lo->plh_segs);
 749
 750	oldseq = be32_to_cpu(lo->plh_stateid.seqid);
 751	newseq = be32_to_cpu(new->seqid);
 752	if (empty || pnfs_seqid_is_newer(newseq, oldseq)) {
 753		nfs4_stateid_copy(&lo->plh_stateid, new);
 754		if (update_barrier) {
 755			new_barrier = be32_to_cpu(new->seqid);
 756		} else {
 757			/* Because of wraparound, we want to keep the barrier
 758			 * "close" to the current seqids.
 759			 */
 760			new_barrier = newseq - atomic_read(&lo->plh_outstanding);
 761		}
 762		if (empty || pnfs_seqid_is_newer(new_barrier, lo->plh_barrier))
 763			lo->plh_barrier = new_barrier;
 764	}
 765}
 766
 767static bool
 768pnfs_layout_stateid_blocked(const struct pnfs_layout_hdr *lo,
 769		const nfs4_stateid *stateid)
 770{
 771	u32 seqid = be32_to_cpu(stateid->seqid);
 772
 773	return !pnfs_seqid_is_newer(seqid, lo->plh_barrier);
 774}
 775
 776/* lget is set to 1 if called from inside send_layoutget call chain */
 777static bool
 778pnfs_layoutgets_blocked(const struct pnfs_layout_hdr *lo)
 779{
 780	return lo->plh_block_lgets ||
 781		test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
 
 
 782}
 783
 784int
 785pnfs_choose_layoutget_stateid(nfs4_stateid *dst, struct pnfs_layout_hdr *lo,
 786			      const struct pnfs_layout_range *range,
 787			      struct nfs4_state *open_state)
 788{
 789	int status = 0;
 790
 791	dprintk("--> %s\n", __func__);
 792	spin_lock(&lo->plh_inode->i_lock);
 793	if (pnfs_layoutgets_blocked(lo)) {
 794		status = -EAGAIN;
 795	} else if (!nfs4_valid_open_stateid(open_state)) {
 796		status = -EBADF;
 797	} else if (list_empty(&lo->plh_segs) ||
 798		   test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags)) {
 799		int seq;
 800
 801		do {
 802			seq = read_seqbegin(&open_state->seqlock);
 803			nfs4_stateid_copy(dst, &open_state->stateid);
 804		} while (read_seqretry(&open_state->seqlock, seq));
 805	} else
 806		nfs4_stateid_copy(dst, &lo->plh_stateid);
 807	spin_unlock(&lo->plh_inode->i_lock);
 808	dprintk("<-- %s\n", __func__);
 809	return status;
 810}
 811
 812/*
 813* Get layout from server.
 814*    for now, assume that whole file layouts are requested.
 815*    arg->offset: 0
 816*    arg->length: all ones
 817*/
 818static struct pnfs_layout_segment *
 819send_layoutget(struct pnfs_layout_hdr *lo,
 820	   struct nfs_open_context *ctx,
 821	   const struct pnfs_layout_range *range,
 822	   gfp_t gfp_flags)
 823{
 824	struct inode *ino = lo->plh_inode;
 825	struct nfs_server *server = NFS_SERVER(ino);
 826	struct nfs4_layoutget *lgp;
 827	struct pnfs_layout_segment *lseg;
 828	loff_t i_size;
 829
 830	dprintk("--> %s\n", __func__);
 831
 832	/*
 833	 * Synchronously retrieve layout information from server and
 834	 * store in lseg. If we race with a concurrent seqid morphing
 835	 * op, then re-send the LAYOUTGET.
 836	 */
 837	do {
 838		lgp = kzalloc(sizeof(*lgp), gfp_flags);
 839		if (lgp == NULL)
 840			return NULL;
 841
 842		i_size = i_size_read(ino);
 843
 844		lgp->args.minlength = PAGE_SIZE;
 845		if (lgp->args.minlength > range->length)
 846			lgp->args.minlength = range->length;
 847		if (range->iomode == IOMODE_READ) {
 848			if (range->offset >= i_size)
 849				lgp->args.minlength = 0;
 850			else if (i_size - range->offset < lgp->args.minlength)
 851				lgp->args.minlength = i_size - range->offset;
 852		}
 853		lgp->args.maxcount = PNFS_LAYOUT_MAXSIZE;
 854		pnfs_copy_range(&lgp->args.range, range);
 855		lgp->args.type = server->pnfs_curr_ld->id;
 856		lgp->args.inode = ino;
 857		lgp->args.ctx = get_nfs_open_context(ctx);
 858		lgp->gfp_flags = gfp_flags;
 859		lgp->cred = lo->plh_lc_cred;
 860
 861		lseg = nfs4_proc_layoutget(lgp, gfp_flags);
 862	} while (lseg == ERR_PTR(-EAGAIN));
 
 
 
 
 
 
 
 
 863
 864	if (IS_ERR(lseg) && !nfs_error_is_fatal(PTR_ERR(lseg)))
 865		lseg = NULL;
 866	else
 867		pnfs_layout_clear_fail_bit(lo,
 868				pnfs_iomode_to_fail_bit(range->iomode));
 
 
 
 
 
 
 
 
 
 
 869
 870	return lseg;
 871}
 872
 873static void pnfs_clear_layoutcommit(struct inode *inode,
 874		struct list_head *head)
 875{
 876	struct nfs_inode *nfsi = NFS_I(inode);
 877	struct pnfs_layout_segment *lseg, *tmp;
 878
 879	if (!test_and_clear_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags))
 880		return;
 881	list_for_each_entry_safe(lseg, tmp, &nfsi->layout->plh_segs, pls_list) {
 882		if (!test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
 883			continue;
 884		pnfs_lseg_dec_and_remove_zero(lseg, head);
 885	}
 886}
 887
 888void pnfs_clear_layoutreturn_waitbit(struct pnfs_layout_hdr *lo)
 889{
 890	clear_bit_unlock(NFS_LAYOUT_RETURN, &lo->plh_flags);
 891	smp_mb__after_atomic();
 892	wake_up_bit(&lo->plh_flags, NFS_LAYOUT_RETURN);
 893	rpc_wake_up(&NFS_SERVER(lo->plh_inode)->roc_rpcwaitq);
 894}
 895
 896static bool
 897pnfs_prepare_layoutreturn(struct pnfs_layout_hdr *lo)
 898{
 899	if (test_and_set_bit(NFS_LAYOUT_RETURN, &lo->plh_flags))
 900		return false;
 901	lo->plh_return_iomode = 0;
 902	pnfs_get_layout_hdr(lo);
 903	clear_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags);
 904	return true;
 905}
 906
 907static int
 908pnfs_send_layoutreturn(struct pnfs_layout_hdr *lo, const nfs4_stateid *stateid,
 909		       enum pnfs_iomode iomode, bool sync)
 910{
 911	struct inode *ino = lo->plh_inode;
 912	struct nfs4_layoutreturn *lrp;
 913	int status = 0;
 914
 915	lrp = kzalloc(sizeof(*lrp), GFP_NOFS);
 916	if (unlikely(lrp == NULL)) {
 917		status = -ENOMEM;
 918		spin_lock(&ino->i_lock);
 919		pnfs_clear_layoutreturn_waitbit(lo);
 920		spin_unlock(&ino->i_lock);
 921		pnfs_put_layout_hdr(lo);
 922		goto out;
 923	}
 924
 925	nfs4_stateid_copy(&lrp->args.stateid, stateid);
 926	lrp->args.layout_type = NFS_SERVER(ino)->pnfs_curr_ld->id;
 927	lrp->args.inode = ino;
 928	lrp->args.range.iomode = iomode;
 929	lrp->args.range.offset = 0;
 930	lrp->args.range.length = NFS4_MAX_UINT64;
 931	lrp->args.layout = lo;
 932	lrp->clp = NFS_SERVER(ino)->nfs_client;
 933	lrp->cred = lo->plh_lc_cred;
 934
 935	status = nfs4_proc_layoutreturn(lrp, sync);
 936out:
 937	dprintk("<-- %s status: %d\n", __func__, status);
 938	return status;
 939}
 940
 941/* Return true if layoutreturn is needed */
 942static bool
 943pnfs_layout_need_return(struct pnfs_layout_hdr *lo)
 944{
 945	struct pnfs_layout_segment *s;
 946
 947	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
 948		return false;
 949
 950	/* Defer layoutreturn until all lsegs are done */
 951	list_for_each_entry(s, &lo->plh_segs, pls_list) {
 952		if (test_bit(NFS_LSEG_LAYOUTRETURN, &s->pls_flags))
 953			return false;
 954	}
 955
 956	return true;
 957}
 958
 959static void pnfs_layoutreturn_before_put_layout_hdr(struct pnfs_layout_hdr *lo)
 960{
 961	struct inode *inode= lo->plh_inode;
 962
 963	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
 964		return;
 965	spin_lock(&inode->i_lock);
 966	if (pnfs_layout_need_return(lo)) {
 967		nfs4_stateid stateid;
 968		enum pnfs_iomode iomode;
 969		bool send;
 970
 971		nfs4_stateid_copy(&stateid, &lo->plh_stateid);
 972		iomode = lo->plh_return_iomode;
 973		send = pnfs_prepare_layoutreturn(lo);
 974		spin_unlock(&inode->i_lock);
 975		if (send) {
 976			/* Send an async layoutreturn so we dont deadlock */
 977			pnfs_send_layoutreturn(lo, &stateid, iomode, false);
 978		}
 979	} else
 980		spin_unlock(&inode->i_lock);
 981}
 982
 983/*
 984 * Initiates a LAYOUTRETURN(FILE), and removes the pnfs_layout_hdr
 985 * when the layout segment list is empty.
 986 *
 987 * Note that a pnfs_layout_hdr can exist with an empty layout segment
 988 * list when LAYOUTGET has failed, or when LAYOUTGET succeeded, but the
 989 * deviceid is marked invalid.
 990 */
 991int
 992_pnfs_return_layout(struct inode *ino)
 993{
 994	struct pnfs_layout_hdr *lo = NULL;
 995	struct nfs_inode *nfsi = NFS_I(ino);
 996	LIST_HEAD(tmp_list);
 
 997	nfs4_stateid stateid;
 998	int status = 0, empty;
 999	bool send;
1000
1001	dprintk("NFS: %s for inode %lu\n", __func__, ino->i_ino);
1002
1003	spin_lock(&ino->i_lock);
1004	lo = nfsi->layout;
1005	if (!lo) {
1006		spin_unlock(&ino->i_lock);
1007		dprintk("NFS: %s no layout to return\n", __func__);
1008		goto out;
1009	}
1010	nfs4_stateid_copy(&stateid, &nfsi->layout->plh_stateid);
1011	/* Reference matched in nfs4_layoutreturn_release */
1012	pnfs_get_layout_hdr(lo);
1013	empty = list_empty(&lo->plh_segs);
1014	pnfs_clear_layoutcommit(ino, &tmp_list);
1015	pnfs_mark_matching_lsegs_invalid(lo, &tmp_list, NULL);
1016
1017	if (NFS_SERVER(ino)->pnfs_curr_ld->return_range) {
1018		struct pnfs_layout_range range = {
1019			.iomode		= IOMODE_ANY,
1020			.offset		= 0,
1021			.length		= NFS4_MAX_UINT64,
1022		};
1023		NFS_SERVER(ino)->pnfs_curr_ld->return_range(lo, &range);
1024	}
1025
1026	/* Don't send a LAYOUTRETURN if list was initially empty */
1027	if (empty) {
1028		spin_unlock(&ino->i_lock);
 
1029		dprintk("NFS: %s no layout segments to return\n", __func__);
1030		goto out_put_layout_hdr;
1031	}
1032
1033	set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
1034	send = pnfs_prepare_layoutreturn(lo);
1035	spin_unlock(&ino->i_lock);
1036	pnfs_free_lseg_list(&tmp_list);
1037	if (send)
1038		status = pnfs_send_layoutreturn(lo, &stateid, IOMODE_ANY, true);
1039out_put_layout_hdr:
1040	pnfs_put_layout_hdr(lo);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1041out:
1042	dprintk("<-- %s status: %d\n", __func__, status);
1043	return status;
1044}
1045EXPORT_SYMBOL_GPL(_pnfs_return_layout);
1046
1047int
1048pnfs_commit_and_return_layout(struct inode *inode)
1049{
1050	struct pnfs_layout_hdr *lo;
1051	int ret;
1052
1053	spin_lock(&inode->i_lock);
1054	lo = NFS_I(inode)->layout;
1055	if (lo == NULL) {
1056		spin_unlock(&inode->i_lock);
1057		return 0;
1058	}
1059	pnfs_get_layout_hdr(lo);
1060	/* Block new layoutgets and read/write to ds */
1061	lo->plh_block_lgets++;
1062	spin_unlock(&inode->i_lock);
1063	filemap_fdatawait(inode->i_mapping);
1064	ret = pnfs_layoutcommit_inode(inode, true);
1065	if (ret == 0)
1066		ret = _pnfs_return_layout(inode);
1067	spin_lock(&inode->i_lock);
1068	lo->plh_block_lgets--;
1069	spin_unlock(&inode->i_lock);
1070	pnfs_put_layout_hdr(lo);
1071	return ret;
1072}
1073
1074bool pnfs_roc(struct inode *ino)
1075{
1076	struct nfs_inode *nfsi = NFS_I(ino);
1077	struct nfs_open_context *ctx;
1078	struct nfs4_state *state;
1079	struct pnfs_layout_hdr *lo;
1080	struct pnfs_layout_segment *lseg, *tmp;
1081	nfs4_stateid stateid;
1082	LIST_HEAD(tmp_list);
1083	bool found = false, layoutreturn = false, roc = false;
1084
1085	spin_lock(&ino->i_lock);
1086	lo = nfsi->layout;
1087	if (!lo || test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags))
1088		goto out_noroc;
1089
1090	/* no roc if we hold a delegation */
1091	if (nfs4_check_delegation(ino, FMODE_READ))
1092		goto out_noroc;
1093
1094	list_for_each_entry(ctx, &nfsi->open_files, list) {
1095		state = ctx->state;
1096		/* Don't return layout if there is open file state */
1097		if (state != NULL && state->state != 0)
1098			goto out_noroc;
1099	}
1100
1101	nfs4_stateid_copy(&stateid, &lo->plh_stateid);
1102	/* always send layoutreturn if being marked so */
1103	if (test_and_clear_bit(NFS_LAYOUT_RETURN_REQUESTED,
1104				   &lo->plh_flags))
1105		layoutreturn = pnfs_prepare_layoutreturn(lo);
1106
1107	list_for_each_entry_safe(lseg, tmp, &lo->plh_segs, pls_list)
1108		/* If we are sending layoutreturn, invalidate all valid lsegs */
1109		if (layoutreturn || test_bit(NFS_LSEG_ROC, &lseg->pls_flags)) {
1110			mark_lseg_invalid(lseg, &tmp_list);
1111			found = true;
1112		}
1113	/* ROC in two conditions:
1114	 * 1. there are ROC lsegs
1115	 * 2. we don't send layoutreturn
1116	 */
1117	if (found && !layoutreturn) {
1118		/* lo ref dropped in pnfs_roc_release() */
1119		pnfs_get_layout_hdr(lo);
1120		roc = true;
1121	}
1122
1123out_noroc:
1124	spin_unlock(&ino->i_lock);
1125	pnfs_free_lseg_list(&tmp_list);
1126	pnfs_layoutcommit_inode(ino, true);
1127	if (layoutreturn)
1128		pnfs_send_layoutreturn(lo, &stateid, IOMODE_ANY, true);
1129	return roc;
 
1130}
1131
1132void pnfs_roc_release(struct inode *ino)
1133{
1134	struct pnfs_layout_hdr *lo;
1135
1136	spin_lock(&ino->i_lock);
1137	lo = NFS_I(ino)->layout;
1138	pnfs_clear_layoutreturn_waitbit(lo);
1139	if (atomic_dec_and_test(&lo->plh_refcount)) {
1140		pnfs_detach_layout_hdr(lo);
1141		spin_unlock(&ino->i_lock);
1142		pnfs_free_layout_hdr(lo);
1143	} else
1144		spin_unlock(&ino->i_lock);
1145}
1146
1147void pnfs_roc_set_barrier(struct inode *ino, u32 barrier)
1148{
1149	struct pnfs_layout_hdr *lo;
1150
1151	spin_lock(&ino->i_lock);
1152	lo = NFS_I(ino)->layout;
1153	pnfs_mark_layout_returned_if_empty(lo);
1154	if (pnfs_seqid_is_newer(barrier, lo->plh_barrier))
1155		lo->plh_barrier = barrier;
1156	spin_unlock(&ino->i_lock);
1157	trace_nfs4_layoutreturn_on_close(ino, 0);
1158}
1159
1160void pnfs_roc_get_barrier(struct inode *ino, u32 *barrier)
1161{
1162	struct nfs_inode *nfsi = NFS_I(ino);
1163	struct pnfs_layout_hdr *lo;
 
1164	u32 current_seqid;
 
1165
1166	spin_lock(&ino->i_lock);
 
 
 
 
 
 
1167	lo = nfsi->layout;
1168	current_seqid = be32_to_cpu(lo->plh_stateid.seqid);
1169
1170	/* Since close does not return a layout stateid for use as
1171	 * a barrier, we choose the worst-case barrier.
1172	 */
1173	*barrier = current_seqid + atomic_read(&lo->plh_outstanding);
 
1174	spin_unlock(&ino->i_lock);
1175}
1176
1177bool pnfs_wait_on_layoutreturn(struct inode *ino, struct rpc_task *task)
1178{
1179	struct nfs_inode *nfsi = NFS_I(ino);
1180        struct pnfs_layout_hdr *lo;
1181        bool sleep = false;
1182
1183	/* we might not have grabbed lo reference. so need to check under
1184	 * i_lock */
1185        spin_lock(&ino->i_lock);
1186        lo = nfsi->layout;
1187        if (lo && test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags))
1188                sleep = true;
1189        spin_unlock(&ino->i_lock);
1190
1191        if (sleep)
1192                rpc_sleep_on(&NFS_SERVER(ino)->roc_rpcwaitq, task, NULL);
1193
1194        return sleep;
1195}
1196
1197/*
1198 * Compare two layout segments for sorting into layout cache.
1199 * We want to preferentially return RW over RO layouts, so ensure those
1200 * are seen first.
1201 */
1202static s64
1203pnfs_lseg_range_cmp(const struct pnfs_layout_range *l1,
1204	   const struct pnfs_layout_range *l2)
1205{
1206	s64 d;
1207
1208	/* high offset > low offset */
1209	d = l1->offset - l2->offset;
1210	if (d)
1211		return d;
1212
1213	/* short length > long length */
1214	d = l2->length - l1->length;
1215	if (d)
1216		return d;
1217
1218	/* read > read/write */
1219	return (int)(l1->iomode == IOMODE_READ) - (int)(l2->iomode == IOMODE_READ);
1220}
1221
1222static bool
1223pnfs_lseg_range_is_after(const struct pnfs_layout_range *l1,
1224		const struct pnfs_layout_range *l2)
1225{
1226	return pnfs_lseg_range_cmp(l1, l2) > 0;
1227}
1228
1229static bool
1230pnfs_lseg_no_merge(struct pnfs_layout_segment *lseg,
1231		struct pnfs_layout_segment *old)
1232{
1233	return false;
1234}
1235
1236void
1237pnfs_generic_layout_insert_lseg(struct pnfs_layout_hdr *lo,
1238		   struct pnfs_layout_segment *lseg,
1239		   bool (*is_after)(const struct pnfs_layout_range *,
1240			   const struct pnfs_layout_range *),
1241		   bool (*do_merge)(struct pnfs_layout_segment *,
1242			   struct pnfs_layout_segment *),
1243		   struct list_head *free_me)
1244{
1245	struct pnfs_layout_segment *lp, *tmp;
1246
1247	dprintk("%s:Begin\n", __func__);
1248
1249	list_for_each_entry_safe(lp, tmp, &lo->plh_segs, pls_list) {
1250		if (test_bit(NFS_LSEG_VALID, &lp->pls_flags) == 0)
1251			continue;
1252		if (do_merge(lseg, lp)) {
1253			mark_lseg_invalid(lp, free_me);
1254			continue;
1255		}
1256		if (is_after(&lseg->pls_range, &lp->pls_range))
1257			continue;
1258		list_add_tail(&lseg->pls_list, &lp->pls_list);
1259		dprintk("%s: inserted lseg %p "
1260			"iomode %d offset %llu length %llu before "
1261			"lp %p iomode %d offset %llu length %llu\n",
1262			__func__, lseg, lseg->pls_range.iomode,
1263			lseg->pls_range.offset, lseg->pls_range.length,
1264			lp, lp->pls_range.iomode, lp->pls_range.offset,
1265			lp->pls_range.length);
1266		goto out;
1267	}
1268	list_add_tail(&lseg->pls_list, &lo->plh_segs);
1269	dprintk("%s: inserted lseg %p "
1270		"iomode %d offset %llu length %llu at tail\n",
1271		__func__, lseg, lseg->pls_range.iomode,
1272		lseg->pls_range.offset, lseg->pls_range.length);
1273out:
1274	pnfs_get_layout_hdr(lo);
1275
1276	dprintk("%s:Return\n", __func__);
1277}
1278EXPORT_SYMBOL_GPL(pnfs_generic_layout_insert_lseg);
1279
1280static void
1281pnfs_layout_insert_lseg(struct pnfs_layout_hdr *lo,
1282		   struct pnfs_layout_segment *lseg,
1283		   struct list_head *free_me)
1284{
1285	struct inode *inode = lo->plh_inode;
1286	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
1287
1288	if (ld->add_lseg != NULL)
1289		ld->add_lseg(lo, lseg, free_me);
1290	else
1291		pnfs_generic_layout_insert_lseg(lo, lseg,
1292				pnfs_lseg_range_is_after,
1293				pnfs_lseg_no_merge,
1294				free_me);
1295}
1296
1297static struct pnfs_layout_hdr *
1298alloc_init_layout_hdr(struct inode *ino,
1299		      struct nfs_open_context *ctx,
1300		      gfp_t gfp_flags)
1301{
1302	struct pnfs_layout_hdr *lo;
1303
1304	lo = pnfs_alloc_layout_hdr(ino, gfp_flags);
1305	if (!lo)
1306		return NULL;
1307	atomic_set(&lo->plh_refcount, 1);
1308	INIT_LIST_HEAD(&lo->plh_layouts);
1309	INIT_LIST_HEAD(&lo->plh_segs);
1310	INIT_LIST_HEAD(&lo->plh_bulk_destroy);
1311	lo->plh_inode = ino;
1312	lo->plh_lc_cred = get_rpccred(ctx->cred);
1313	return lo;
1314}
1315
1316static struct pnfs_layout_hdr *
1317pnfs_find_alloc_layout(struct inode *ino,
1318		       struct nfs_open_context *ctx,
1319		       gfp_t gfp_flags)
1320{
1321	struct nfs_inode *nfsi = NFS_I(ino);
1322	struct pnfs_layout_hdr *new = NULL;
1323
1324	dprintk("%s Begin ino=%p layout=%p\n", __func__, ino, nfsi->layout);
1325
1326	if (nfsi->layout != NULL)
1327		goto out_existing;
1328	spin_unlock(&ino->i_lock);
1329	new = alloc_init_layout_hdr(ino, ctx, gfp_flags);
1330	spin_lock(&ino->i_lock);
1331
1332	if (likely(nfsi->layout == NULL)) {	/* Won the race? */
1333		nfsi->layout = new;
1334		return new;
1335	} else if (new != NULL)
1336		pnfs_free_layout_hdr(new);
1337out_existing:
1338	pnfs_get_layout_hdr(nfsi->layout);
1339	return nfsi->layout;
1340}
1341
1342/*
1343 * iomode matching rules:
1344 * iomode	lseg	match
1345 * -----	-----	-----
1346 * ANY		READ	true
1347 * ANY		RW	true
1348 * RW		READ	false
1349 * RW		RW	true
1350 * READ		READ	true
1351 * READ		RW	true
1352 */
1353static bool
1354pnfs_lseg_range_match(const struct pnfs_layout_range *ls_range,
1355		 const struct pnfs_layout_range *range)
1356{
1357	struct pnfs_layout_range range1;
1358
1359	if ((range->iomode == IOMODE_RW &&
1360	     ls_range->iomode != IOMODE_RW) ||
1361	    !pnfs_lseg_range_intersecting(ls_range, range))
1362		return 0;
1363
1364	/* range1 covers only the first byte in the range */
1365	range1 = *range;
1366	range1.length = 1;
1367	return pnfs_lseg_range_contained(ls_range, &range1);
1368}
1369
1370/*
1371 * lookup range in layout
1372 */
1373static struct pnfs_layout_segment *
1374pnfs_find_lseg(struct pnfs_layout_hdr *lo,
1375		struct pnfs_layout_range *range)
1376{
1377	struct pnfs_layout_segment *lseg, *ret = NULL;
1378
1379	dprintk("%s:Begin\n", __func__);
1380
1381	list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
1382		if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags) &&
1383		    !test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags) &&
1384		    pnfs_lseg_range_match(&lseg->pls_range, range)) {
1385			ret = pnfs_get_lseg(lseg);
1386			break;
1387		}
 
 
1388	}
1389
1390	dprintk("%s:Return lseg %p ref %d\n",
1391		__func__, ret, ret ? atomic_read(&ret->pls_refcount) : 0);
1392	return ret;
1393}
1394
1395/*
1396 * Use mdsthreshold hints set at each OPEN to determine if I/O should go
1397 * to the MDS or over pNFS
1398 *
1399 * The nfs_inode read_io and write_io fields are cumulative counters reset
1400 * when there are no layout segments. Note that in pnfs_update_layout iomode
1401 * is set to IOMODE_READ for a READ request, and set to IOMODE_RW for a
1402 * WRITE request.
1403 *
1404 * A return of true means use MDS I/O.
1405 *
1406 * From rfc 5661:
1407 * If a file's size is smaller than the file size threshold, data accesses
1408 * SHOULD be sent to the metadata server.  If an I/O request has a length that
1409 * is below the I/O size threshold, the I/O SHOULD be sent to the metadata
1410 * server.  If both file size and I/O size are provided, the client SHOULD
1411 * reach or exceed  both thresholds before sending its read or write
1412 * requests to the data server.
1413 */
1414static bool pnfs_within_mdsthreshold(struct nfs_open_context *ctx,
1415				     struct inode *ino, int iomode)
1416{
1417	struct nfs4_threshold *t = ctx->mdsthreshold;
1418	struct nfs_inode *nfsi = NFS_I(ino);
1419	loff_t fsize = i_size_read(ino);
1420	bool size = false, size_set = false, io = false, io_set = false, ret = false;
1421
1422	if (t == NULL)
1423		return ret;
1424
1425	dprintk("%s bm=0x%x rd_sz=%llu wr_sz=%llu rd_io=%llu wr_io=%llu\n",
1426		__func__, t->bm, t->rd_sz, t->wr_sz, t->rd_io_sz, t->wr_io_sz);
1427
1428	switch (iomode) {
1429	case IOMODE_READ:
1430		if (t->bm & THRESHOLD_RD) {
1431			dprintk("%s fsize %llu\n", __func__, fsize);
1432			size_set = true;
1433			if (fsize < t->rd_sz)
1434				size = true;
1435		}
1436		if (t->bm & THRESHOLD_RD_IO) {
1437			dprintk("%s nfsi->read_io %llu\n", __func__,
1438				nfsi->read_io);
1439			io_set = true;
1440			if (nfsi->read_io < t->rd_io_sz)
1441				io = true;
1442		}
1443		break;
1444	case IOMODE_RW:
1445		if (t->bm & THRESHOLD_WR) {
1446			dprintk("%s fsize %llu\n", __func__, fsize);
1447			size_set = true;
1448			if (fsize < t->wr_sz)
1449				size = true;
1450		}
1451		if (t->bm & THRESHOLD_WR_IO) {
1452			dprintk("%s nfsi->write_io %llu\n", __func__,
1453				nfsi->write_io);
1454			io_set = true;
1455			if (nfsi->write_io < t->wr_io_sz)
1456				io = true;
1457		}
1458		break;
1459	}
1460	if (size_set && io_set) {
1461		if (size && io)
1462			ret = true;
1463	} else if (size || io)
1464		ret = true;
1465
1466	dprintk("<-- %s size %d io %d ret %d\n", __func__, size, io, ret);
1467	return ret;
1468}
1469
1470static bool pnfs_prepare_to_retry_layoutget(struct pnfs_layout_hdr *lo)
1471{
1472	/*
1473	 * send layoutcommit as it can hold up layoutreturn due to lseg
1474	 * reference
1475	 */
1476	pnfs_layoutcommit_inode(lo->plh_inode, false);
1477	return !wait_on_bit_action(&lo->plh_flags, NFS_LAYOUT_RETURN,
1478				   nfs_wait_bit_killable,
1479				   TASK_UNINTERRUPTIBLE);
1480}
1481
1482static void pnfs_clear_first_layoutget(struct pnfs_layout_hdr *lo)
1483{
1484	unsigned long *bitlock = &lo->plh_flags;
1485
1486	clear_bit_unlock(NFS_LAYOUT_FIRST_LAYOUTGET, bitlock);
1487	smp_mb__after_atomic();
1488	wake_up_bit(bitlock, NFS_LAYOUT_FIRST_LAYOUTGET);
1489}
1490
1491/*
1492 * Layout segment is retreived from the server if not cached.
1493 * The appropriate layout segment is referenced and returned to the caller.
1494 */
1495struct pnfs_layout_segment *
1496pnfs_update_layout(struct inode *ino,
1497		   struct nfs_open_context *ctx,
1498		   loff_t pos,
1499		   u64 count,
1500		   enum pnfs_iomode iomode,
1501		   gfp_t gfp_flags)
1502{
1503	struct pnfs_layout_range arg = {
1504		.iomode = iomode,
1505		.offset = pos,
1506		.length = count,
1507	};
1508	unsigned pg_offset;
1509	struct nfs_server *server = NFS_SERVER(ino);
1510	struct nfs_client *clp = server->nfs_client;
1511	struct pnfs_layout_hdr *lo;
1512	struct pnfs_layout_segment *lseg = NULL;
1513	bool first;
1514
1515	if (!pnfs_enabled_sb(NFS_SERVER(ino))) {
1516		trace_pnfs_update_layout(ino, pos, count, iomode, NULL,
1517				 PNFS_UPDATE_LAYOUT_NO_PNFS);
1518		goto out;
1519	}
1520
1521	if (iomode == IOMODE_READ && i_size_read(ino) == 0) {
1522		trace_pnfs_update_layout(ino, pos, count, iomode, NULL,
1523				 PNFS_UPDATE_LAYOUT_RD_ZEROLEN);
1524		goto out;
1525	}
1526
1527	if (pnfs_within_mdsthreshold(ctx, ino, iomode)) {
1528		trace_pnfs_update_layout(ino, pos, count, iomode, NULL,
1529				 PNFS_UPDATE_LAYOUT_MDSTHRESH);
1530		goto out;
1531	}
1532
1533lookup_again:
1534	first = false;
1535	spin_lock(&ino->i_lock);
1536	lo = pnfs_find_alloc_layout(ino, ctx, gfp_flags);
1537	if (lo == NULL) {
1538		spin_unlock(&ino->i_lock);
1539		trace_pnfs_update_layout(ino, pos, count, iomode, NULL,
1540				 PNFS_UPDATE_LAYOUT_NOMEM);
1541		goto out;
1542	}
1543
1544	/* Do we even need to bother with this? */
1545	if (test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
1546		trace_pnfs_update_layout(ino, pos, count, iomode, lo,
1547				 PNFS_UPDATE_LAYOUT_BULK_RECALL);
1548		dprintk("%s matches recall, use MDS\n", __func__);
1549		goto out_unlock;
1550	}
1551
1552	/* if LAYOUTGET already failed once we don't try again */
1553	if (pnfs_layout_io_test_failed(lo, iomode)) {
1554		trace_pnfs_update_layout(ino, pos, count, iomode, lo,
1555				 PNFS_UPDATE_LAYOUT_IO_TEST_FAIL);
1556		goto out_unlock;
1557	}
1558
1559	first = list_empty(&lo->plh_segs);
1560	if (first) {
1561		/* The first layoutget for the file. Need to serialize per
1562		 * RFC 5661 Errata 3208.
1563		 */
1564		if (test_and_set_bit(NFS_LAYOUT_FIRST_LAYOUTGET,
1565				     &lo->plh_flags)) {
1566			spin_unlock(&ino->i_lock);
1567			wait_on_bit(&lo->plh_flags, NFS_LAYOUT_FIRST_LAYOUTGET,
1568				    TASK_UNINTERRUPTIBLE);
1569			pnfs_put_layout_hdr(lo);
1570			goto lookup_again;
1571		}
1572	} else {
1573		/* Check to see if the layout for the given range
1574		 * already exists
1575		 */
1576		lseg = pnfs_find_lseg(lo, &arg);
1577		if (lseg) {
1578			trace_pnfs_update_layout(ino, pos, count, iomode, lo,
1579					PNFS_UPDATE_LAYOUT_FOUND_CACHED);
1580			goto out_unlock;
1581		}
1582	}
1583
1584	/*
1585	 * Because we free lsegs before sending LAYOUTRETURN, we need to wait
1586	 * for LAYOUTRETURN even if first is true.
1587	 */
1588	if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
1589		spin_unlock(&ino->i_lock);
1590		dprintk("%s wait for layoutreturn\n", __func__);
1591		if (pnfs_prepare_to_retry_layoutget(lo)) {
1592			if (first)
1593				pnfs_clear_first_layoutget(lo);
1594			pnfs_put_layout_hdr(lo);
1595			dprintk("%s retrying\n", __func__);
1596			goto lookup_again;
1597		}
1598		trace_pnfs_update_layout(ino, pos, count, iomode, lo,
1599				PNFS_UPDATE_LAYOUT_RETURN);
1600		goto out_put_layout_hdr;
1601	}
1602
1603	if (pnfs_layoutgets_blocked(lo)) {
1604		trace_pnfs_update_layout(ino, pos, count, iomode, lo,
1605				PNFS_UPDATE_LAYOUT_BLOCKED);
1606		goto out_unlock;
1607	}
1608	atomic_inc(&lo->plh_outstanding);
 
 
1609	spin_unlock(&ino->i_lock);
1610
1611	if (list_empty(&lo->plh_layouts)) {
1612		/* The lo must be on the clp list if there is any
1613		 * chance of a CB_LAYOUTRECALL(FILE) coming in.
1614		 */
1615		spin_lock(&clp->cl_lock);
1616		if (list_empty(&lo->plh_layouts))
1617			list_add_tail(&lo->plh_layouts, &server->layouts);
1618		spin_unlock(&clp->cl_lock);
1619	}
1620
1621	pg_offset = arg.offset & ~PAGE_MASK;
1622	if (pg_offset) {
1623		arg.offset -= pg_offset;
1624		arg.length += pg_offset;
1625	}
1626	if (arg.length != NFS4_MAX_UINT64)
1627		arg.length = PAGE_ALIGN(arg.length);
1628
1629	lseg = send_layoutget(lo, ctx, &arg, gfp_flags);
1630	atomic_dec(&lo->plh_outstanding);
1631	trace_pnfs_update_layout(ino, pos, count, iomode, lo,
1632				 PNFS_UPDATE_LAYOUT_SEND_LAYOUTGET);
1633out_put_layout_hdr:
1634	if (first)
1635		pnfs_clear_first_layoutget(lo);
1636	pnfs_put_layout_hdr(lo);
1637out:
1638	dprintk("%s: inode %s/%llu pNFS layout segment %s for "
1639			"(%s, offset: %llu, length: %llu)\n",
1640			__func__, ino->i_sb->s_id,
1641			(unsigned long long)NFS_FILEID(ino),
1642			IS_ERR_OR_NULL(lseg) ? "not found" : "found",
1643			iomode==IOMODE_RW ?  "read/write" : "read-only",
1644			(unsigned long long)pos,
1645			(unsigned long long)count);
1646	return lseg;
1647out_unlock:
1648	spin_unlock(&ino->i_lock);
1649	goto out_put_layout_hdr;
1650}
1651EXPORT_SYMBOL_GPL(pnfs_update_layout);
1652
1653static bool
1654pnfs_sanity_check_layout_range(struct pnfs_layout_range *range)
1655{
1656	switch (range->iomode) {
1657	case IOMODE_READ:
1658	case IOMODE_RW:
1659		break;
1660	default:
1661		return false;
1662	}
1663	if (range->offset == NFS4_MAX_UINT64)
1664		return false;
1665	if (range->length == 0)
1666		return false;
1667	if (range->length != NFS4_MAX_UINT64 &&
1668	    range->length > NFS4_MAX_UINT64 - range->offset)
1669		return false;
1670	return true;
1671}
1672
1673struct pnfs_layout_segment *
1674pnfs_layout_process(struct nfs4_layoutget *lgp)
1675{
1676	struct pnfs_layout_hdr *lo = NFS_I(lgp->args.inode)->layout;
1677	struct nfs4_layoutget_res *res = &lgp->res;
1678	struct pnfs_layout_segment *lseg;
1679	struct inode *ino = lo->plh_inode;
1680	LIST_HEAD(free_me);
1681	int status = -EINVAL;
1682
1683	if (!pnfs_sanity_check_layout_range(&res->range))
1684		goto out;
1685
1686	/* Inject layout blob into I/O device driver */
1687	lseg = NFS_SERVER(ino)->pnfs_curr_ld->alloc_lseg(lo, res, lgp->gfp_flags);
1688	if (!lseg || IS_ERR(lseg)) {
1689		if (!lseg)
1690			status = -ENOMEM;
1691		else
1692			status = PTR_ERR(lseg);
1693		dprintk("%s: Could not allocate layout: error %d\n",
1694		       __func__, status);
1695		goto out;
1696	}
1697
1698	init_lseg(lo, lseg);
1699	lseg->pls_range = res->range;
1700
1701	spin_lock(&ino->i_lock);
1702	if (pnfs_layoutgets_blocked(lo)) {
1703		dprintk("%s forget reply due to state\n", __func__);
1704		goto out_forget_reply;
1705	}
1706
1707	if (nfs4_stateid_match_other(&lo->plh_stateid, &res->stateid)) {
1708		/* existing state ID, make sure the sequence number matches. */
1709		if (pnfs_layout_stateid_blocked(lo, &res->stateid)) {
1710			dprintk("%s forget reply due to sequence\n", __func__);
1711			status = -EAGAIN;
1712			goto out_forget_reply;
1713		}
1714		pnfs_set_layout_stateid(lo, &res->stateid, false);
1715	} else {
1716		/*
1717		 * We got an entirely new state ID.  Mark all segments for the
1718		 * inode invalid, and don't bother validating the stateid
1719		 * sequence number.
1720		 */
1721		pnfs_mark_matching_lsegs_invalid(lo, &free_me, NULL);
1722
1723		nfs4_stateid_copy(&lo->plh_stateid, &res->stateid);
1724		lo->plh_barrier = be32_to_cpu(res->stateid.seqid);
1725	}
1726
1727	clear_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
 
 
 
1728
 
 
1729	pnfs_get_lseg(lseg);
1730	pnfs_layout_insert_lseg(lo, lseg, &free_me);
1731
1732	if (res->return_on_close)
1733		set_bit(NFS_LSEG_ROC, &lseg->pls_flags);
 
 
1734
1735	spin_unlock(&ino->i_lock);
1736	pnfs_free_lseg_list(&free_me);
1737	return lseg;
1738out:
1739	return ERR_PTR(status);
1740
1741out_forget_reply:
1742	spin_unlock(&ino->i_lock);
1743	lseg->pls_layout = lo;
1744	NFS_SERVER(ino)->pnfs_curr_ld->free_lseg(lseg);
1745	goto out;
1746}
1747
1748static void
1749pnfs_set_plh_return_iomode(struct pnfs_layout_hdr *lo, enum pnfs_iomode iomode)
1750{
1751	if (lo->plh_return_iomode == iomode)
1752		return;
1753	if (lo->plh_return_iomode != 0)
1754		iomode = IOMODE_ANY;
1755	lo->plh_return_iomode = iomode;
1756	set_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags);
1757}
1758
1759/**
1760 * pnfs_mark_matching_lsegs_return - Free or return matching layout segments
1761 * @lo: pointer to layout header
1762 * @tmp_list: list header to be used with pnfs_free_lseg_list()
1763 * @return_range: describe layout segment ranges to be returned
1764 *
1765 * This function is mainly intended for use by layoutrecall. It attempts
1766 * to free the layout segment immediately, or else to mark it for return
1767 * as soon as its reference count drops to zero.
1768 */
1769int
1770pnfs_mark_matching_lsegs_return(struct pnfs_layout_hdr *lo,
1771				struct list_head *tmp_list,
1772				const struct pnfs_layout_range *return_range)
1773{
1774	struct pnfs_layout_segment *lseg, *next;
1775	int remaining = 0;
1776
1777	dprintk("%s:Begin lo %p\n", __func__, lo);
1778
1779	if (list_empty(&lo->plh_segs))
1780		return 0;
1781
1782	assert_spin_locked(&lo->plh_inode->i_lock);
1783
1784	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
1785		if (should_free_lseg(&lseg->pls_range, return_range)) {
1786			dprintk("%s: marking lseg %p iomode %d "
1787				"offset %llu length %llu\n", __func__,
1788				lseg, lseg->pls_range.iomode,
1789				lseg->pls_range.offset,
1790				lseg->pls_range.length);
1791			if (mark_lseg_invalid(lseg, tmp_list))
1792				continue;
1793			remaining++;
1794			set_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
1795			pnfs_set_plh_return_iomode(lo, return_range->iomode);
1796		}
1797	return remaining;
1798}
1799
1800void pnfs_error_mark_layout_for_return(struct inode *inode,
1801				       struct pnfs_layout_segment *lseg)
1802{
1803	struct pnfs_layout_hdr *lo = NFS_I(inode)->layout;
1804	struct pnfs_layout_range range = {
1805		.iomode = lseg->pls_range.iomode,
1806		.offset = 0,
1807		.length = NFS4_MAX_UINT64,
1808	};
1809	LIST_HEAD(free_me);
1810	bool return_now = false;
1811
1812	spin_lock(&inode->i_lock);
1813	pnfs_set_plh_return_iomode(lo, range.iomode);
1814	/*
1815	 * mark all matching lsegs so that we are sure to have no live
1816	 * segments at hand when sending layoutreturn. See pnfs_put_lseg()
1817	 * for how it works.
1818	 */
1819	if (!pnfs_mark_matching_lsegs_return(lo, &free_me, &range)) {
1820		nfs4_stateid stateid;
1821		enum pnfs_iomode iomode = lo->plh_return_iomode;
1822
1823		nfs4_stateid_copy(&stateid, &lo->plh_stateid);
1824		return_now = pnfs_prepare_layoutreturn(lo);
1825		spin_unlock(&inode->i_lock);
1826		if (return_now)
1827			pnfs_send_layoutreturn(lo, &stateid, iomode, false);
1828	} else {
1829		spin_unlock(&inode->i_lock);
1830		nfs_commit_inode(inode, 0);
1831	}
1832	pnfs_free_lseg_list(&free_me);
1833}
1834EXPORT_SYMBOL_GPL(pnfs_error_mark_layout_for_return);
1835
1836void
1837pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
1838{
1839	u64 rd_size = req->wb_bytes;
1840
1841	if (pgio->pg_lseg == NULL) {
1842		if (pgio->pg_dreq == NULL)
1843			rd_size = i_size_read(pgio->pg_inode) - req_offset(req);
1844		else
1845			rd_size = nfs_dreq_bytes_left(pgio->pg_dreq);
1846
1847		pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
1848						   req->wb_context,
1849						   req_offset(req),
1850						   rd_size,
1851						   IOMODE_READ,
1852						   GFP_KERNEL);
1853		if (IS_ERR(pgio->pg_lseg)) {
1854			pgio->pg_error = PTR_ERR(pgio->pg_lseg);
1855			pgio->pg_lseg = NULL;
1856			return;
1857		}
1858	}
 
 
 
 
 
 
 
 
 
 
 
 
1859	/* If no lseg, fall back to read through mds */
1860	if (pgio->pg_lseg == NULL)
1861		nfs_pageio_reset_read_mds(pgio);
1862
1863}
1864EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_read);
1865
1866void
1867pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio,
1868			   struct nfs_page *req, u64 wb_size)
1869{
1870	if (pgio->pg_lseg == NULL) {
1871		pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
1872						   req->wb_context,
1873						   req_offset(req),
1874						   wb_size,
1875						   IOMODE_RW,
1876						   GFP_NOFS);
1877		if (IS_ERR(pgio->pg_lseg)) {
1878			pgio->pg_error = PTR_ERR(pgio->pg_lseg);
1879			pgio->pg_lseg = NULL;
1880			return;
1881		}
1882	}
 
 
 
 
 
 
 
1883	/* If no lseg, fall back to write through mds */
1884	if (pgio->pg_lseg == NULL)
1885		nfs_pageio_reset_write_mds(pgio);
1886}
1887EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_write);
1888
1889void
1890pnfs_generic_pg_cleanup(struct nfs_pageio_descriptor *desc)
 
1891{
1892	if (desc->pg_lseg) {
1893		pnfs_put_lseg(desc->pg_lseg);
1894		desc->pg_lseg = NULL;
1895	}
 
 
 
1896}
1897EXPORT_SYMBOL_GPL(pnfs_generic_pg_cleanup);
1898
1899/*
1900 * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
1901 * of bytes (maximum @req->wb_bytes) that can be coalesced.
1902 */
1903size_t
1904pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio,
1905		     struct nfs_page *prev, struct nfs_page *req)
1906{
1907	unsigned int size;
1908	u64 seg_end, req_start, seg_left;
1909
1910	size = nfs_generic_pg_test(pgio, prev, req);
1911	if (!size)
1912		return 0;
 
 
 
 
 
 
 
 
 
1913
1914	/*
1915	 * 'size' contains the number of bytes left in the current page (up
1916	 * to the original size asked for in @req->wb_bytes).
1917	 *
1918	 * Calculate how many bytes are left in the layout segment
1919	 * and if there are less bytes than 'size', return that instead.
 
 
 
1920	 *
1921	 * Please also note that 'end_offset' is actually the offset of the
1922	 * first byte that lies outside the pnfs_layout_range. FIXME?
1923	 *
1924	 */
1925	if (pgio->pg_lseg) {
1926		seg_end = end_offset(pgio->pg_lseg->pls_range.offset,
1927				     pgio->pg_lseg->pls_range.length);
1928		req_start = req_offset(req);
1929		WARN_ON_ONCE(req_start >= seg_end);
1930		/* start of request is past the last byte of this segment */
1931		if (req_start >= seg_end) {
1932			/* reference the new lseg */
1933			if (pgio->pg_ops->pg_cleanup)
1934				pgio->pg_ops->pg_cleanup(pgio);
1935			if (pgio->pg_ops->pg_init)
1936				pgio->pg_ops->pg_init(pgio, req);
1937			return 0;
1938		}
1939
1940		/* adjust 'size' iff there are fewer bytes left in the
1941		 * segment than what nfs_generic_pg_test returned */
1942		seg_left = seg_end - req_start;
1943		if (seg_left < size)
1944			size = (unsigned int)seg_left;
1945	}
1946
1947	return size;
1948}
1949EXPORT_SYMBOL_GPL(pnfs_generic_pg_test);
1950
1951int pnfs_write_done_resend_to_mds(struct nfs_pgio_header *hdr)
 
 
 
1952{
1953	struct nfs_pageio_descriptor pgio;
 
1954
1955	/* Resend all requests through the MDS */
1956	nfs_pageio_init_write(&pgio, hdr->inode, FLUSH_STABLE, true,
1957			      hdr->completion_ops);
1958	set_bit(NFS_CONTEXT_RESEND_WRITES, &hdr->args.context->flags);
1959	return nfs_pageio_resend(&pgio, hdr);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1960}
1961EXPORT_SYMBOL_GPL(pnfs_write_done_resend_to_mds);
1962
1963static void pnfs_ld_handle_write_error(struct nfs_pgio_header *hdr)
1964{
 
1965
1966	dprintk("pnfs write error = %d\n", hdr->pnfs_error);
1967	if (NFS_SERVER(hdr->inode)->pnfs_curr_ld->flags &
1968	    PNFS_LAYOUTRET_ON_ERROR) {
1969		pnfs_return_layout(hdr->inode);
1970	}
1971	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))
1972		hdr->task.tk_status = pnfs_write_done_resend_to_mds(hdr);
 
 
 
1973}
1974
1975/*
1976 * Called by non rpc-based layout drivers
1977 */
1978void pnfs_ld_write_done(struct nfs_pgio_header *hdr)
1979{
1980	if (likely(!hdr->pnfs_error)) {
1981		pnfs_set_layoutcommit(hdr->inode, hdr->lseg,
1982				hdr->mds_offset + hdr->res.count);
1983		hdr->mds_ops->rpc_call_done(&hdr->task, hdr);
1984	}
1985	trace_nfs4_pnfs_write(hdr, hdr->pnfs_error);
1986	if (unlikely(hdr->pnfs_error))
1987		pnfs_ld_handle_write_error(hdr);
1988	hdr->mds_ops->rpc_release(hdr);
1989}
1990EXPORT_SYMBOL_GPL(pnfs_ld_write_done);
1991
1992static void
1993pnfs_write_through_mds(struct nfs_pageio_descriptor *desc,
1994		struct nfs_pgio_header *hdr)
1995{
1996	struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
1997
1998	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
1999		list_splice_tail_init(&hdr->pages, &mirror->pg_list);
2000		nfs_pageio_reset_write_mds(desc);
2001		mirror->pg_recoalesce = 1;
2002	}
2003	nfs_pgio_data_destroy(hdr);
2004	hdr->release(hdr);
2005}
2006
2007static enum pnfs_try_status
2008pnfs_try_to_write_data(struct nfs_pgio_header *hdr,
2009			const struct rpc_call_ops *call_ops,
2010			struct pnfs_layout_segment *lseg,
2011			int how)
2012{
 
2013	struct inode *inode = hdr->inode;
2014	enum pnfs_try_status trypnfs;
2015	struct nfs_server *nfss = NFS_SERVER(inode);
2016
2017	hdr->mds_ops = call_ops;
2018
2019	dprintk("%s: Writing ino:%lu %u@%llu (how %d)\n", __func__,
2020		inode->i_ino, hdr->args.count, hdr->args.offset, how);
2021	trypnfs = nfss->pnfs_curr_ld->write_pagelist(hdr, how);
2022	if (trypnfs != PNFS_NOT_ATTEMPTED)
2023		nfs_inc_stats(inode, NFSIOS_PNFS_WRITE);
2024	dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
2025	return trypnfs;
2026}
2027
2028static void
2029pnfs_do_write(struct nfs_pageio_descriptor *desc,
2030	      struct nfs_pgio_header *hdr, int how)
2031{
 
2032	const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
2033	struct pnfs_layout_segment *lseg = desc->pg_lseg;
2034	enum pnfs_try_status trypnfs;
2035
2036	trypnfs = pnfs_try_to_write_data(hdr, call_ops, lseg, how);
2037	if (trypnfs == PNFS_NOT_ATTEMPTED)
2038		pnfs_write_through_mds(desc, hdr);
 
 
 
 
 
 
 
 
 
2039}
2040
2041static void pnfs_writehdr_free(struct nfs_pgio_header *hdr)
2042{
2043	pnfs_put_lseg(hdr->lseg);
2044	nfs_pgio_header_free(hdr);
2045}
 
2046
2047int
2048pnfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
2049{
 
2050	struct nfs_pgio_header *hdr;
2051	int ret;
2052
2053	hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
2054	if (!hdr) {
2055		desc->pg_error = -ENOMEM;
2056		return desc->pg_error;
 
 
2057	}
 
2058	nfs_pgheader_init(desc, hdr, pnfs_writehdr_free);
2059
2060	hdr->lseg = pnfs_get_lseg(desc->pg_lseg);
2061	ret = nfs_generic_pgio(desc, hdr);
2062	if (!ret)
2063		pnfs_do_write(desc, hdr, desc->pg_ioflags);
2064
 
 
 
 
 
2065	return ret;
2066}
2067EXPORT_SYMBOL_GPL(pnfs_generic_pg_writepages);
2068
2069int pnfs_read_done_resend_to_mds(struct nfs_pgio_header *hdr)
 
 
 
2070{
2071	struct nfs_pageio_descriptor pgio;
 
2072
2073	/* Resend all requests through the MDS */
2074	nfs_pageio_init_read(&pgio, hdr->inode, true, hdr->completion_ops);
2075	return nfs_pageio_resend(&pgio, hdr);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2076}
2077EXPORT_SYMBOL_GPL(pnfs_read_done_resend_to_mds);
2078
2079static void pnfs_ld_handle_read_error(struct nfs_pgio_header *hdr)
2080{
 
 
2081	dprintk("pnfs read error = %d\n", hdr->pnfs_error);
2082	if (NFS_SERVER(hdr->inode)->pnfs_curr_ld->flags &
2083	    PNFS_LAYOUTRET_ON_ERROR) {
2084		pnfs_return_layout(hdr->inode);
2085	}
2086	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))
2087		hdr->task.tk_status = pnfs_read_done_resend_to_mds(hdr);
 
 
 
2088}
2089
2090/*
2091 * Called by non rpc-based layout drivers
2092 */
2093void pnfs_ld_read_done(struct nfs_pgio_header *hdr)
2094{
 
 
 
2095	if (likely(!hdr->pnfs_error)) {
2096		__nfs4_read_done_cb(hdr);
2097		hdr->mds_ops->rpc_call_done(&hdr->task, hdr);
2098	}
2099	trace_nfs4_pnfs_read(hdr, hdr->pnfs_error);
2100	if (unlikely(hdr->pnfs_error))
2101		pnfs_ld_handle_read_error(hdr);
2102	hdr->mds_ops->rpc_release(hdr);
2103}
2104EXPORT_SYMBOL_GPL(pnfs_ld_read_done);
2105
2106static void
2107pnfs_read_through_mds(struct nfs_pageio_descriptor *desc,
2108		struct nfs_pgio_header *hdr)
2109{
2110	struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
2111
2112	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2113		list_splice_tail_init(&hdr->pages, &mirror->pg_list);
2114		nfs_pageio_reset_read_mds(desc);
2115		mirror->pg_recoalesce = 1;
2116	}
2117	nfs_pgio_data_destroy(hdr);
2118	hdr->release(hdr);
2119}
2120
2121/*
2122 * Call the appropriate parallel I/O subsystem read function.
2123 */
2124static enum pnfs_try_status
2125pnfs_try_to_read_data(struct nfs_pgio_header *hdr,
2126		       const struct rpc_call_ops *call_ops,
2127		       struct pnfs_layout_segment *lseg)
2128{
 
2129	struct inode *inode = hdr->inode;
2130	struct nfs_server *nfss = NFS_SERVER(inode);
2131	enum pnfs_try_status trypnfs;
2132
2133	hdr->mds_ops = call_ops;
2134
2135	dprintk("%s: Reading ino:%lu %u@%llu\n",
2136		__func__, inode->i_ino, hdr->args.count, hdr->args.offset);
2137
2138	trypnfs = nfss->pnfs_curr_ld->read_pagelist(hdr);
2139	if (trypnfs != PNFS_NOT_ATTEMPTED)
2140		nfs_inc_stats(inode, NFSIOS_PNFS_READ);
2141	dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
2142	return trypnfs;
2143}
2144
2145/* Resend all requests through pnfs. */
2146int pnfs_read_resend_pnfs(struct nfs_pgio_header *hdr)
2147{
2148	struct nfs_pageio_descriptor pgio;
2149
2150	nfs_pageio_init_read(&pgio, hdr->inode, false, hdr->completion_ops);
2151	return nfs_pageio_resend(&pgio, hdr);
2152}
2153EXPORT_SYMBOL_GPL(pnfs_read_resend_pnfs);
2154
2155static void
2156pnfs_do_read(struct nfs_pageio_descriptor *desc, struct nfs_pgio_header *hdr)
2157{
 
2158	const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
2159	struct pnfs_layout_segment *lseg = desc->pg_lseg;
2160	enum pnfs_try_status trypnfs;
2161	int err = 0;
2162
2163	trypnfs = pnfs_try_to_read_data(hdr, call_ops, lseg);
2164	if (trypnfs == PNFS_TRY_AGAIN)
2165		err = pnfs_read_resend_pnfs(hdr);
2166	if (trypnfs == PNFS_NOT_ATTEMPTED || err)
2167		pnfs_read_through_mds(desc, hdr);
 
 
 
 
 
 
 
2168}
2169
2170static void pnfs_readhdr_free(struct nfs_pgio_header *hdr)
2171{
2172	pnfs_put_lseg(hdr->lseg);
2173	nfs_pgio_header_free(hdr);
2174}
 
2175
2176int
2177pnfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc)
2178{
 
2179	struct nfs_pgio_header *hdr;
2180	int ret;
2181
2182	hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
2183	if (!hdr) {
2184		desc->pg_error = -ENOMEM;
2185		return desc->pg_error;
 
 
 
2186	}
 
2187	nfs_pgheader_init(desc, hdr, pnfs_readhdr_free);
2188	hdr->lseg = pnfs_get_lseg(desc->pg_lseg);
2189	ret = nfs_generic_pgio(desc, hdr);
2190	if (!ret)
2191		pnfs_do_read(desc, hdr);
 
 
 
 
 
 
2192	return ret;
2193}
2194EXPORT_SYMBOL_GPL(pnfs_generic_pg_readpages);
2195
2196static void pnfs_clear_layoutcommitting(struct inode *inode)
2197{
2198	unsigned long *bitlock = &NFS_I(inode)->flags;
2199
2200	clear_bit_unlock(NFS_INO_LAYOUTCOMMITTING, bitlock);
2201	smp_mb__after_atomic();
2202	wake_up_bit(bitlock, NFS_INO_LAYOUTCOMMITTING);
2203}
2204
2205/*
2206 * There can be multiple RW segments.
2207 */
2208static void pnfs_list_write_lseg(struct inode *inode, struct list_head *listp)
2209{
2210	struct pnfs_layout_segment *lseg;
2211
2212	list_for_each_entry(lseg, &NFS_I(inode)->layout->plh_segs, pls_list) {
2213		if (lseg->pls_range.iomode == IOMODE_RW &&
2214		    test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
2215			list_add(&lseg->pls_lc_list, listp);
2216	}
2217}
2218
2219static void pnfs_list_write_lseg_done(struct inode *inode, struct list_head *listp)
2220{
2221	struct pnfs_layout_segment *lseg, *tmp;
2222
2223	/* Matched by references in pnfs_set_layoutcommit */
2224	list_for_each_entry_safe(lseg, tmp, listp, pls_lc_list) {
2225		list_del_init(&lseg->pls_lc_list);
2226		pnfs_put_lseg(lseg);
2227	}
2228
2229	pnfs_clear_layoutcommitting(inode);
2230}
2231
2232void pnfs_set_lo_fail(struct pnfs_layout_segment *lseg)
2233{
2234	pnfs_layout_io_set_failed(lseg->pls_layout, lseg->pls_range.iomode);
2235}
2236EXPORT_SYMBOL_GPL(pnfs_set_lo_fail);
2237
2238void
2239pnfs_set_layoutcommit(struct inode *inode, struct pnfs_layout_segment *lseg,
2240		loff_t end_pos)
2241{
 
 
2242	struct nfs_inode *nfsi = NFS_I(inode);
 
2243	bool mark_as_dirty = false;
2244
2245	spin_lock(&inode->i_lock);
2246	if (!test_and_set_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags)) {
2247		nfsi->layout->plh_lwb = end_pos;
2248		mark_as_dirty = true;
2249		dprintk("%s: Set layoutcommit for inode %lu ",
2250			__func__, inode->i_ino);
2251	} else if (end_pos > nfsi->layout->plh_lwb)
2252		nfsi->layout->plh_lwb = end_pos;
2253	if (!test_and_set_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags)) {
2254		/* references matched in nfs4_layoutcommit_release */
2255		pnfs_get_lseg(lseg);
2256	}
 
 
2257	spin_unlock(&inode->i_lock);
2258	dprintk("%s: lseg %p end_pos %llu\n",
2259		__func__, lseg, nfsi->layout->plh_lwb);
2260
2261	/* if pnfs_layoutcommit_inode() runs between inode locks, the next one
2262	 * will be a noop because NFS_INO_LAYOUTCOMMIT will not be set */
2263	if (mark_as_dirty)
2264		mark_inode_dirty_sync(inode);
2265}
2266EXPORT_SYMBOL_GPL(pnfs_set_layoutcommit);
2267
2268void pnfs_cleanup_layoutcommit(struct nfs4_layoutcommit_data *data)
2269{
2270	struct nfs_server *nfss = NFS_SERVER(data->args.inode);
2271
2272	if (nfss->pnfs_curr_ld->cleanup_layoutcommit)
2273		nfss->pnfs_curr_ld->cleanup_layoutcommit(data);
2274	pnfs_list_write_lseg_done(data->args.inode, &data->lseg_list);
2275}
2276
2277/*
2278 * For the LAYOUT4_NFSV4_1_FILES layout type, NFS_DATA_SYNC WRITEs and
2279 * NFS_UNSTABLE WRITEs with a COMMIT to data servers must store enough
2280 * data to disk to allow the server to recover the data if it crashes.
2281 * LAYOUTCOMMIT is only needed when the NFL4_UFLG_COMMIT_THRU_MDS flag
2282 * is off, and a COMMIT is sent to a data server, or
2283 * if WRITEs to a data server return NFS_DATA_SYNC.
2284 */
2285int
2286pnfs_layoutcommit_inode(struct inode *inode, bool sync)
2287{
2288	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
2289	struct nfs4_layoutcommit_data *data;
2290	struct nfs_inode *nfsi = NFS_I(inode);
2291	loff_t end_pos;
2292	int status;
2293
2294	if (!pnfs_layoutcommit_outstanding(inode))
2295		return 0;
2296
2297	dprintk("--> %s inode %lu\n", __func__, inode->i_ino);
2298
2299	status = -EAGAIN;
2300	if (test_and_set_bit(NFS_INO_LAYOUTCOMMITTING, &nfsi->flags)) {
2301		if (!sync)
2302			goto out;
2303		status = wait_on_bit_lock_action(&nfsi->flags,
2304				NFS_INO_LAYOUTCOMMITTING,
2305				nfs_wait_bit_killable,
2306				TASK_KILLABLE);
2307		if (status)
2308			goto out;
2309	}
2310
2311	status = -ENOMEM;
2312	/* Note kzalloc ensures data->res.seq_res.sr_slot == NULL */
2313	data = kzalloc(sizeof(*data), GFP_NOFS);
2314	if (!data)
2315		goto clear_layoutcommitting;
2316
2317	status = 0;
2318	spin_lock(&inode->i_lock);
2319	if (!test_and_clear_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags))
2320		goto out_unlock;
2321
2322	INIT_LIST_HEAD(&data->lseg_list);
2323	pnfs_list_write_lseg(inode, &data->lseg_list);
2324
2325	end_pos = nfsi->layout->plh_lwb;
 
2326
2327	nfs4_stateid_copy(&data->args.stateid, &nfsi->layout->plh_stateid);
2328	spin_unlock(&inode->i_lock);
2329
2330	data->args.inode = inode;
2331	data->cred = get_rpccred(nfsi->layout->plh_lc_cred);
2332	nfs_fattr_init(&data->fattr);
2333	data->args.bitmask = NFS_SERVER(inode)->cache_consistency_bitmask;
2334	data->res.fattr = &data->fattr;
2335	data->args.lastbytewritten = end_pos - 1;
2336	data->res.server = NFS_SERVER(inode);
2337
2338	if (ld->prepare_layoutcommit) {
2339		status = ld->prepare_layoutcommit(&data->args);
2340		if (status) {
2341			put_rpccred(data->cred);
2342			spin_lock(&inode->i_lock);
2343			set_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags);
2344			if (end_pos > nfsi->layout->plh_lwb)
2345				nfsi->layout->plh_lwb = end_pos;
2346			goto out_unlock;
2347		}
2348	}
2349
2350
2351	status = nfs4_proc_layoutcommit(data, sync);
2352out:
2353	if (status)
2354		mark_inode_dirty_sync(inode);
2355	dprintk("<-- %s status %d\n", __func__, status);
2356	return status;
2357out_unlock:
2358	spin_unlock(&inode->i_lock);
2359	kfree(data);
2360clear_layoutcommitting:
2361	pnfs_clear_layoutcommitting(inode);
2362	goto out;
2363}
2364EXPORT_SYMBOL_GPL(pnfs_layoutcommit_inode);
2365
2366int
2367pnfs_generic_sync(struct inode *inode, bool datasync)
2368{
2369	return pnfs_layoutcommit_inode(inode, true);
2370}
2371EXPORT_SYMBOL_GPL(pnfs_generic_sync);
2372
2373struct nfs4_threshold *pnfs_mdsthreshold_alloc(void)
2374{
2375	struct nfs4_threshold *thp;
2376
2377	thp = kzalloc(sizeof(*thp), GFP_NOFS);
2378	if (!thp) {
2379		dprintk("%s mdsthreshold allocation failed\n", __func__);
2380		return NULL;
2381	}
2382	return thp;
2383}
2384
2385#if IS_ENABLED(CONFIG_NFS_V4_2)
2386int
2387pnfs_report_layoutstat(struct inode *inode, gfp_t gfp_flags)
2388{
2389	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
2390	struct nfs_server *server = NFS_SERVER(inode);
2391	struct nfs_inode *nfsi = NFS_I(inode);
2392	struct nfs42_layoutstat_data *data;
2393	struct pnfs_layout_hdr *hdr;
2394	int status = 0;
2395
2396	if (!pnfs_enabled_sb(server) || !ld->prepare_layoutstats)
2397		goto out;
2398
2399	if (!nfs_server_capable(inode, NFS_CAP_LAYOUTSTATS))
2400		goto out;
2401
2402	if (test_and_set_bit(NFS_INO_LAYOUTSTATS, &nfsi->flags))
2403		goto out;
2404
2405	spin_lock(&inode->i_lock);
2406	if (!NFS_I(inode)->layout) {
2407		spin_unlock(&inode->i_lock);
2408		goto out;
2409	}
2410	hdr = NFS_I(inode)->layout;
2411	pnfs_get_layout_hdr(hdr);
2412	spin_unlock(&inode->i_lock);
2413
2414	data = kzalloc(sizeof(*data), gfp_flags);
2415	if (!data) {
2416		status = -ENOMEM;
2417		goto out_put;
2418	}
2419
2420	data->args.fh = NFS_FH(inode);
2421	data->args.inode = inode;
2422	nfs4_stateid_copy(&data->args.stateid, &hdr->plh_stateid);
2423	status = ld->prepare_layoutstats(&data->args);
2424	if (status)
2425		goto out_free;
2426
2427	status = nfs42_proc_layoutstats_generic(NFS_SERVER(inode), data);
2428
2429out:
2430	dprintk("%s returns %d\n", __func__, status);
2431	return status;
2432
2433out_free:
2434	kfree(data);
2435out_put:
2436	pnfs_put_layout_hdr(hdr);
2437	smp_mb__before_atomic();
2438	clear_bit(NFS_INO_LAYOUTSTATS, &nfsi->flags);
2439	smp_mb__after_atomic();
2440	goto out;
2441}
2442EXPORT_SYMBOL_GPL(pnfs_report_layoutstat);
2443#endif
2444
2445unsigned int layoutstats_timer;
2446module_param(layoutstats_timer, uint, 0644);
2447EXPORT_SYMBOL_GPL(layoutstats_timer);