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v6.9.4
   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
  95const struct pnfs_layoutdriver_type *pnfs_find_layoutdriver(u32 id)
  96{
  97	return find_pnfs_driver(id);
  98}
  99
 100void pnfs_put_layoutdriver(const struct pnfs_layoutdriver_type *ld)
 101{
 102	if (ld)
 103		module_put(ld->owner);
 104}
 105
 106void
 107unset_pnfs_layoutdriver(struct nfs_server *nfss)
 108{
 109	if (nfss->pnfs_curr_ld) {
 110		if (nfss->pnfs_curr_ld->clear_layoutdriver)
 111			nfss->pnfs_curr_ld->clear_layoutdriver(nfss);
 112		/* Decrement the MDS count. Purge the deviceid cache if zero */
 113		if (atomic_dec_and_test(&nfss->nfs_client->cl_mds_count))
 114			nfs4_deviceid_purge_client(nfss->nfs_client);
 115		module_put(nfss->pnfs_curr_ld->owner);
 116	}
 117	nfss->pnfs_curr_ld = NULL;
 118}
 119
 120/*
 121 * When the server sends a list of layout types, we choose one in the order
 122 * given in the list below.
 123 *
 124 * FIXME: should this list be configurable in some fashion? module param?
 125 * 	  mount option? something else?
 126 */
 127static const u32 ld_prefs[] = {
 128	LAYOUT_SCSI,
 129	LAYOUT_BLOCK_VOLUME,
 130	LAYOUT_OSD2_OBJECTS,
 131	LAYOUT_FLEX_FILES,
 132	LAYOUT_NFSV4_1_FILES,
 133	0
 134};
 135
 136static int
 137ld_cmp(const void *e1, const void *e2)
 138{
 139	u32 ld1 = *((u32 *)e1);
 140	u32 ld2 = *((u32 *)e2);
 141	int i;
 142
 143	for (i = 0; ld_prefs[i] != 0; i++) {
 144		if (ld1 == ld_prefs[i])
 145			return -1;
 146
 147		if (ld2 == ld_prefs[i])
 148			return 1;
 149	}
 150	return 0;
 151}
 152
 153/*
 154 * Try to set the server's pnfs module to the pnfs layout type specified by id.
 155 * Currently only one pNFS layout driver per filesystem is supported.
 156 *
 157 * @ids array of layout types supported by MDS.
 158 */
 159void
 160set_pnfs_layoutdriver(struct nfs_server *server, const struct nfs_fh *mntfh,
 161		      struct nfs_fsinfo *fsinfo)
 162{
 163	struct pnfs_layoutdriver_type *ld_type = NULL;
 164	u32 id;
 165	int i;
 166
 167	if (fsinfo->nlayouttypes == 0)
 168		goto out_no_driver;
 169	if (!(server->nfs_client->cl_exchange_flags &
 170		 (EXCHGID4_FLAG_USE_NON_PNFS | EXCHGID4_FLAG_USE_PNFS_MDS))) {
 171		printk(KERN_ERR "NFS: %s: cl_exchange_flags 0x%x\n",
 172			__func__, server->nfs_client->cl_exchange_flags);
 173		goto out_no_driver;
 174	}
 175
 176	sort(fsinfo->layouttype, fsinfo->nlayouttypes,
 177		sizeof(*fsinfo->layouttype), ld_cmp, NULL);
 178
 179	for (i = 0; i < fsinfo->nlayouttypes; i++) {
 180		id = fsinfo->layouttype[i];
 181		ld_type = find_pnfs_driver(id);
 182		if (!ld_type) {
 183			request_module("%s-%u", LAYOUT_NFSV4_1_MODULE_PREFIX,
 184					id);
 185			ld_type = find_pnfs_driver(id);
 186		}
 187		if (ld_type)
 188			break;
 189	}
 190
 191	if (!ld_type) {
 192		dprintk("%s: No pNFS module found!\n", __func__);
 193		goto out_no_driver;
 194	}
 195
 196	server->pnfs_curr_ld = ld_type;
 197	if (ld_type->set_layoutdriver
 198	    && ld_type->set_layoutdriver(server, mntfh)) {
 199		printk(KERN_ERR "NFS: %s: Error initializing pNFS layout "
 200			"driver %u.\n", __func__, id);
 201		module_put(ld_type->owner);
 202		goto out_no_driver;
 203	}
 204	/* Bump the MDS count */
 205	atomic_inc(&server->nfs_client->cl_mds_count);
 206
 207	dprintk("%s: pNFS module for %u set\n", __func__, id);
 208	return;
 209
 210out_no_driver:
 211	dprintk("%s: Using NFSv4 I/O\n", __func__);
 212	server->pnfs_curr_ld = NULL;
 213}
 214
 215int
 216pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
 217{
 218	int status = -EINVAL;
 219	struct pnfs_layoutdriver_type *tmp;
 220
 221	if (ld_type->id == 0) {
 222		printk(KERN_ERR "NFS: %s id 0 is reserved\n", __func__);
 223		return status;
 224	}
 225	if (!ld_type->alloc_lseg || !ld_type->free_lseg) {
 226		printk(KERN_ERR "NFS: %s Layout driver must provide "
 227		       "alloc_lseg and free_lseg.\n", __func__);
 228		return status;
 229	}
 230
 231	spin_lock(&pnfs_spinlock);
 232	tmp = find_pnfs_driver_locked(ld_type->id);
 233	if (!tmp) {
 234		list_add(&ld_type->pnfs_tblid, &pnfs_modules_tbl);
 235		status = 0;
 236		dprintk("%s Registering id:%u name:%s\n", __func__, ld_type->id,
 237			ld_type->name);
 238	} else {
 239		printk(KERN_ERR "NFS: %s Module with id %d already loaded!\n",
 240			__func__, ld_type->id);
 241	}
 242	spin_unlock(&pnfs_spinlock);
 243
 244	return status;
 245}
 246EXPORT_SYMBOL_GPL(pnfs_register_layoutdriver);
 247
 248void
 249pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
 250{
 251	dprintk("%s Deregistering id:%u\n", __func__, ld_type->id);
 252	spin_lock(&pnfs_spinlock);
 253	list_del(&ld_type->pnfs_tblid);
 254	spin_unlock(&pnfs_spinlock);
 255}
 256EXPORT_SYMBOL_GPL(pnfs_unregister_layoutdriver);
 257
 258/*
 259 * pNFS client layout cache
 260 */
 261
 262/* Need to hold i_lock if caller does not already hold reference */
 263void
 264pnfs_get_layout_hdr(struct pnfs_layout_hdr *lo)
 265{
 266	refcount_inc(&lo->plh_refcount);
 267}
 268
 269static struct pnfs_layout_hdr *
 270pnfs_alloc_layout_hdr(struct inode *ino, gfp_t gfp_flags)
 271{
 272	struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
 273	return ld->alloc_layout_hdr(ino, gfp_flags);
 274}
 275
 276static void
 277pnfs_free_layout_hdr(struct pnfs_layout_hdr *lo)
 278{
 279	struct nfs_server *server = NFS_SERVER(lo->plh_inode);
 280	struct pnfs_layoutdriver_type *ld = server->pnfs_curr_ld;
 281
 282	if (test_and_clear_bit(NFS_LAYOUT_HASHED, &lo->plh_flags)) {
 283		struct nfs_client *clp = server->nfs_client;
 284
 285		spin_lock(&clp->cl_lock);
 286		list_del_rcu(&lo->plh_layouts);
 287		spin_unlock(&clp->cl_lock);
 288	}
 289	put_cred(lo->plh_lc_cred);
 290	return ld->free_layout_hdr(lo);
 291}
 292
 293static void
 294pnfs_detach_layout_hdr(struct pnfs_layout_hdr *lo)
 295{
 296	struct nfs_inode *nfsi = NFS_I(lo->plh_inode);
 297	dprintk("%s: freeing layout cache %p\n", __func__, lo);
 298	nfsi->layout = NULL;
 299	/* Reset MDS Threshold I/O counters */
 300	nfsi->write_io = 0;
 301	nfsi->read_io = 0;
 302}
 303
 304void
 305pnfs_put_layout_hdr(struct pnfs_layout_hdr *lo)
 306{
 307	struct inode *inode;
 308	unsigned long i_state;
 309
 310	if (!lo)
 311		return;
 312	inode = lo->plh_inode;
 313	pnfs_layoutreturn_before_put_layout_hdr(lo);
 314
 315	if (refcount_dec_and_lock(&lo->plh_refcount, &inode->i_lock)) {
 316		if (!list_empty(&lo->plh_segs))
 317			WARN_ONCE(1, "NFS: BUG unfreed layout segments.\n");
 318		pnfs_detach_layout_hdr(lo);
 319		i_state = inode->i_state;
 320		spin_unlock(&inode->i_lock);
 321		pnfs_free_layout_hdr(lo);
 322		/* Notify pnfs_destroy_layout_final() that we're done */
 323		if (i_state & (I_FREEING | I_CLEAR))
 324			wake_up_var(lo);
 325	}
 326}
 327
 328static struct inode *
 329pnfs_grab_inode_layout_hdr(struct pnfs_layout_hdr *lo)
 330{
 331	struct inode *inode = igrab(lo->plh_inode);
 332	if (inode)
 333		return inode;
 334	set_bit(NFS_LAYOUT_INODE_FREEING, &lo->plh_flags);
 335	return NULL;
 336}
 337
 338/*
 339 * Compare 2 layout stateid sequence ids, to see which is newer,
 340 * taking into account wraparound issues.
 341 */
 342static bool pnfs_seqid_is_newer(u32 s1, u32 s2)
 343{
 344	return (s32)(s1 - s2) > 0;
 345}
 346
 347static void pnfs_barrier_update(struct pnfs_layout_hdr *lo, u32 newseq)
 348{
 349	if (pnfs_seqid_is_newer(newseq, lo->plh_barrier) || !lo->plh_barrier)
 350		lo->plh_barrier = newseq;
 351}
 352
 353static void
 354pnfs_set_plh_return_info(struct pnfs_layout_hdr *lo, enum pnfs_iomode iomode,
 355			 u32 seq)
 356{
 357	if (lo->plh_return_iomode != 0 && lo->plh_return_iomode != iomode)
 358		iomode = IOMODE_ANY;
 359	lo->plh_return_iomode = iomode;
 360	set_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags);
 361	/*
 362	 * We must set lo->plh_return_seq to avoid livelocks with
 363	 * pnfs_layout_need_return()
 364	 */
 365	if (seq == 0)
 366		seq = be32_to_cpu(lo->plh_stateid.seqid);
 367	if (!lo->plh_return_seq || pnfs_seqid_is_newer(seq, lo->plh_return_seq))
 368		lo->plh_return_seq = seq;
 369	pnfs_barrier_update(lo, seq);
 370}
 371
 372static void
 373pnfs_clear_layoutreturn_info(struct pnfs_layout_hdr *lo)
 374{
 375	struct pnfs_layout_segment *lseg;
 376	lo->plh_return_iomode = 0;
 377	lo->plh_return_seq = 0;
 378	clear_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags);
 379	list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
 380		if (!test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
 381			continue;
 382		pnfs_set_plh_return_info(lo, lseg->pls_range.iomode, 0);
 383	}
 384}
 385
 386static void pnfs_clear_layoutreturn_waitbit(struct pnfs_layout_hdr *lo)
 387{
 388	clear_bit_unlock(NFS_LAYOUT_RETURN, &lo->plh_flags);
 389	clear_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags);
 390	smp_mb__after_atomic();
 391	wake_up_bit(&lo->plh_flags, NFS_LAYOUT_RETURN);
 392	rpc_wake_up(&NFS_SERVER(lo->plh_inode)->roc_rpcwaitq);
 393}
 394
 395static void
 396pnfs_clear_lseg_state(struct pnfs_layout_segment *lseg,
 397		struct list_head *free_me)
 398{
 399	clear_bit(NFS_LSEG_ROC, &lseg->pls_flags);
 400	clear_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
 401	if (test_and_clear_bit(NFS_LSEG_VALID, &lseg->pls_flags))
 402		pnfs_lseg_dec_and_remove_zero(lseg, free_me);
 403	if (test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
 404		pnfs_lseg_dec_and_remove_zero(lseg, free_me);
 405}
 406
 407/*
 408 * Update the seqid of a layout stateid after receiving
 409 * NFS4ERR_OLD_STATEID
 410 */
 411bool nfs4_layout_refresh_old_stateid(nfs4_stateid *dst,
 412		struct pnfs_layout_range *dst_range,
 413		struct inode *inode)
 414{
 415	struct pnfs_layout_hdr *lo;
 416	struct pnfs_layout_range range = {
 417		.iomode = IOMODE_ANY,
 418		.offset = 0,
 419		.length = NFS4_MAX_UINT64,
 420	};
 421	bool ret = false;
 422	LIST_HEAD(head);
 423	int err;
 424
 425	spin_lock(&inode->i_lock);
 426	lo = NFS_I(inode)->layout;
 427	if (lo &&  pnfs_layout_is_valid(lo) &&
 428	    nfs4_stateid_match_other(dst, &lo->plh_stateid)) {
 429		/* Is our call using the most recent seqid? If so, bump it */
 430		if (!nfs4_stateid_is_newer(&lo->plh_stateid, dst)) {
 431			nfs4_stateid_seqid_inc(dst);
 432			ret = true;
 433			goto out;
 434		}
 435		/* Try to update the seqid to the most recent */
 436		err = pnfs_mark_matching_lsegs_return(lo, &head, &range, 0);
 437		if (err != -EBUSY) {
 438			dst->seqid = lo->plh_stateid.seqid;
 439			*dst_range = range;
 440			ret = true;
 441		}
 442	}
 443out:
 444	spin_unlock(&inode->i_lock);
 445	pnfs_free_lseg_list(&head);
 446	return ret;
 447}
 448
 449/*
 450 * Mark a pnfs_layout_hdr and all associated layout segments as invalid
 451 *
 452 * In order to continue using the pnfs_layout_hdr, a full recovery
 453 * is required.
 454 * Note that caller must hold inode->i_lock.
 455 */
 456int
 457pnfs_mark_layout_stateid_invalid(struct pnfs_layout_hdr *lo,
 458		struct list_head *lseg_list)
 459{
 460	struct pnfs_layout_range range = {
 461		.iomode = IOMODE_ANY,
 462		.offset = 0,
 463		.length = NFS4_MAX_UINT64,
 464	};
 465	struct pnfs_layout_segment *lseg, *next;
 466
 467	set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
 468	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
 469		pnfs_clear_lseg_state(lseg, lseg_list);
 470	pnfs_clear_layoutreturn_info(lo);
 471	pnfs_free_returned_lsegs(lo, lseg_list, &range, 0);
 472	set_bit(NFS_LAYOUT_DRAIN, &lo->plh_flags);
 473	if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags) &&
 474	    !test_and_set_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags))
 475		pnfs_clear_layoutreturn_waitbit(lo);
 476	return !list_empty(&lo->plh_segs);
 477}
 478
 
 
 
 
 
 
 
 
 
 
 
 
 479static int
 480pnfs_iomode_to_fail_bit(u32 iomode)
 481{
 482	return iomode == IOMODE_RW ?
 483		NFS_LAYOUT_RW_FAILED : NFS_LAYOUT_RO_FAILED;
 484}
 485
 486static void
 487pnfs_layout_set_fail_bit(struct pnfs_layout_hdr *lo, int fail_bit)
 488{
 489	lo->plh_retry_timestamp = jiffies;
 490	if (!test_and_set_bit(fail_bit, &lo->plh_flags))
 491		refcount_inc(&lo->plh_refcount);
 492}
 493
 494static void
 495pnfs_layout_clear_fail_bit(struct pnfs_layout_hdr *lo, int fail_bit)
 496{
 497	if (test_and_clear_bit(fail_bit, &lo->plh_flags))
 498		refcount_dec(&lo->plh_refcount);
 499}
 500
 501static void
 502pnfs_layout_io_set_failed(struct pnfs_layout_hdr *lo, u32 iomode)
 503{
 504	struct inode *inode = lo->plh_inode;
 505	struct pnfs_layout_range range = {
 506		.iomode = iomode,
 507		.offset = 0,
 508		.length = NFS4_MAX_UINT64,
 509	};
 510	LIST_HEAD(head);
 511
 512	spin_lock(&inode->i_lock);
 513	pnfs_layout_set_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
 514	pnfs_mark_matching_lsegs_return(lo, &head, &range, 0);
 515	spin_unlock(&inode->i_lock);
 516	pnfs_free_lseg_list(&head);
 517	dprintk("%s Setting layout IOMODE_%s fail bit\n", __func__,
 518			iomode == IOMODE_RW ?  "RW" : "READ");
 519}
 520
 521static bool
 522pnfs_layout_io_test_failed(struct pnfs_layout_hdr *lo, u32 iomode)
 523{
 524	unsigned long start, end;
 525	int fail_bit = pnfs_iomode_to_fail_bit(iomode);
 526
 527	if (test_bit(fail_bit, &lo->plh_flags) == 0)
 528		return false;
 529	end = jiffies;
 530	start = end - PNFS_LAYOUTGET_RETRY_TIMEOUT;
 531	if (!time_in_range(lo->plh_retry_timestamp, start, end)) {
 532		/* It is time to retry the failed layoutgets */
 533		pnfs_layout_clear_fail_bit(lo, fail_bit);
 534		return false;
 535	}
 536	return true;
 537}
 538
 539static void
 540pnfs_init_lseg(struct pnfs_layout_hdr *lo, struct pnfs_layout_segment *lseg,
 541		const struct pnfs_layout_range *range,
 542		const nfs4_stateid *stateid)
 543{
 544	INIT_LIST_HEAD(&lseg->pls_list);
 545	INIT_LIST_HEAD(&lseg->pls_lc_list);
 546	INIT_LIST_HEAD(&lseg->pls_commits);
 547	refcount_set(&lseg->pls_refcount, 1);
 548	set_bit(NFS_LSEG_VALID, &lseg->pls_flags);
 549	lseg->pls_layout = lo;
 550	lseg->pls_range = *range;
 551	lseg->pls_seq = be32_to_cpu(stateid->seqid);
 552}
 553
 554static void pnfs_free_lseg(struct pnfs_layout_segment *lseg)
 555{
 556	if (lseg != NULL) {
 557		struct inode *inode = lseg->pls_layout->plh_inode;
 558		NFS_SERVER(inode)->pnfs_curr_ld->free_lseg(lseg);
 559	}
 560}
 561
 562static void
 563pnfs_layout_remove_lseg(struct pnfs_layout_hdr *lo,
 564		struct pnfs_layout_segment *lseg)
 565{
 566	WARN_ON(test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
 567	list_del_init(&lseg->pls_list);
 568	/* Matched by pnfs_get_layout_hdr in pnfs_layout_insert_lseg */
 569	refcount_dec(&lo->plh_refcount);
 570	if (test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
 571		return;
 572	if (list_empty(&lo->plh_segs) &&
 573	    !test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags) &&
 574	    !test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
 575		if (atomic_read(&lo->plh_outstanding) == 0)
 576			set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
 577		clear_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
 578	}
 579}
 580
 581static bool
 582pnfs_cache_lseg_for_layoutreturn(struct pnfs_layout_hdr *lo,
 583		struct pnfs_layout_segment *lseg)
 584{
 585	if (test_and_clear_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags) &&
 586	    pnfs_layout_is_valid(lo)) {
 587		pnfs_set_plh_return_info(lo, lseg->pls_range.iomode, 0);
 588		list_move_tail(&lseg->pls_list, &lo->plh_return_segs);
 589		return true;
 590	}
 591	return false;
 592}
 593
 594void
 595pnfs_put_lseg(struct pnfs_layout_segment *lseg)
 596{
 597	struct pnfs_layout_hdr *lo;
 598	struct inode *inode;
 599
 600	if (!lseg)
 601		return;
 602
 603	dprintk("%s: lseg %p ref %d valid %d\n", __func__, lseg,
 604		refcount_read(&lseg->pls_refcount),
 605		test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
 606
 607	lo = lseg->pls_layout;
 608	inode = lo->plh_inode;
 609
 610	if (refcount_dec_and_lock(&lseg->pls_refcount, &inode->i_lock)) {
 611		pnfs_get_layout_hdr(lo);
 612		pnfs_layout_remove_lseg(lo, lseg);
 613		if (pnfs_cache_lseg_for_layoutreturn(lo, lseg))
 614			lseg = NULL;
 615		spin_unlock(&inode->i_lock);
 616		pnfs_free_lseg(lseg);
 617		pnfs_put_layout_hdr(lo);
 618	}
 619}
 620EXPORT_SYMBOL_GPL(pnfs_put_lseg);
 621
 622/*
 623 * is l2 fully contained in l1?
 624 *   start1                             end1
 625 *   [----------------------------------)
 626 *           start2           end2
 627 *           [----------------)
 628 */
 629static bool
 630pnfs_lseg_range_contained(const struct pnfs_layout_range *l1,
 631		 const struct pnfs_layout_range *l2)
 632{
 633	u64 start1 = l1->offset;
 634	u64 end1 = pnfs_end_offset(start1, l1->length);
 635	u64 start2 = l2->offset;
 636	u64 end2 = pnfs_end_offset(start2, l2->length);
 637
 638	return (start1 <= start2) && (end1 >= end2);
 639}
 640
 641static bool pnfs_lseg_dec_and_remove_zero(struct pnfs_layout_segment *lseg,
 642		struct list_head *tmp_list)
 643{
 644	if (!refcount_dec_and_test(&lseg->pls_refcount))
 645		return false;
 646	pnfs_layout_remove_lseg(lseg->pls_layout, lseg);
 647	list_add(&lseg->pls_list, tmp_list);
 648	return true;
 649}
 650
 651/* Returns 1 if lseg is removed from list, 0 otherwise */
 652static int mark_lseg_invalid(struct pnfs_layout_segment *lseg,
 653			     struct list_head *tmp_list)
 654{
 655	int rv = 0;
 656
 657	if (test_and_clear_bit(NFS_LSEG_VALID, &lseg->pls_flags)) {
 658		/* Remove the reference keeping the lseg in the
 659		 * list.  It will now be removed when all
 660		 * outstanding io is finished.
 661		 */
 662		dprintk("%s: lseg %p ref %d\n", __func__, lseg,
 663			refcount_read(&lseg->pls_refcount));
 664		if (pnfs_lseg_dec_and_remove_zero(lseg, tmp_list))
 665			rv = 1;
 666	}
 667	return rv;
 668}
 669
 670static bool
 671pnfs_should_free_range(const struct pnfs_layout_range *lseg_range,
 672		 const struct pnfs_layout_range *recall_range)
 673{
 674	return (recall_range->iomode == IOMODE_ANY ||
 675		lseg_range->iomode == recall_range->iomode) &&
 676	       pnfs_lseg_range_intersecting(lseg_range, recall_range);
 677}
 678
 679static bool
 680pnfs_match_lseg_recall(const struct pnfs_layout_segment *lseg,
 681		const struct pnfs_layout_range *recall_range,
 682		u32 seq)
 683{
 684	if (seq != 0 && pnfs_seqid_is_newer(lseg->pls_seq, seq))
 685		return false;
 686	if (recall_range == NULL)
 687		return true;
 688	return pnfs_should_free_range(&lseg->pls_range, recall_range);
 689}
 690
 691/**
 692 * pnfs_mark_matching_lsegs_invalid - tear down lsegs or mark them for later
 693 * @lo: layout header containing the lsegs
 694 * @tmp_list: list head where doomed lsegs should go
 695 * @recall_range: optional recall range argument to match (may be NULL)
 696 * @seq: only invalidate lsegs obtained prior to this sequence (may be 0)
 697 *
 698 * Walk the list of lsegs in the layout header, and tear down any that should
 699 * be destroyed. If "recall_range" is specified then the segment must match
 700 * that range. If "seq" is non-zero, then only match segments that were handed
 701 * out at or before that sequence.
 702 *
 703 * Returns number of matching invalid lsegs remaining in list after scanning
 704 * it and purging them.
 705 */
 706int
 707pnfs_mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo,
 708			    struct list_head *tmp_list,
 709			    const struct pnfs_layout_range *recall_range,
 710			    u32 seq)
 711{
 712	struct pnfs_layout_segment *lseg, *next;
 713	struct nfs_server *server = NFS_SERVER(lo->plh_inode);
 714	int remaining = 0;
 715
 716	dprintk("%s:Begin lo %p\n", __func__, lo);
 717
 718	if (list_empty(&lo->plh_segs))
 719		return 0;
 720	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
 721		if (pnfs_match_lseg_recall(lseg, recall_range, seq)) {
 722			dprintk("%s: freeing lseg %p iomode %d seq %u "
 723				"offset %llu length %llu\n", __func__,
 724				lseg, lseg->pls_range.iomode, lseg->pls_seq,
 725				lseg->pls_range.offset, lseg->pls_range.length);
 726			if (mark_lseg_invalid(lseg, tmp_list))
 727				continue;
 728			remaining++;
 729			pnfs_lseg_cancel_io(server, lseg);
 730		}
 731	dprintk("%s:Return %i\n", __func__, remaining);
 732	return remaining;
 733}
 734
 735static void
 736pnfs_free_returned_lsegs(struct pnfs_layout_hdr *lo,
 737		struct list_head *free_me,
 738		const struct pnfs_layout_range *range,
 739		u32 seq)
 740{
 741	struct pnfs_layout_segment *lseg, *next;
 742
 743	list_for_each_entry_safe(lseg, next, &lo->plh_return_segs, pls_list) {
 744		if (pnfs_match_lseg_recall(lseg, range, seq))
 745			list_move_tail(&lseg->pls_list, free_me);
 746	}
 747}
 748
 749/* note free_me must contain lsegs from a single layout_hdr */
 750void
 751pnfs_free_lseg_list(struct list_head *free_me)
 752{
 753	struct pnfs_layout_segment *lseg, *tmp;
 754
 755	if (list_empty(free_me))
 756		return;
 757
 758	list_for_each_entry_safe(lseg, tmp, free_me, pls_list) {
 759		list_del(&lseg->pls_list);
 760		pnfs_free_lseg(lseg);
 761	}
 762}
 763
 764static struct pnfs_layout_hdr *__pnfs_destroy_layout(struct nfs_inode *nfsi)
 765{
 766	struct pnfs_layout_hdr *lo;
 767	LIST_HEAD(tmp_list);
 768
 769	spin_lock(&nfsi->vfs_inode.i_lock);
 770	lo = nfsi->layout;
 771	if (lo) {
 772		pnfs_get_layout_hdr(lo);
 773		pnfs_mark_layout_stateid_invalid(lo, &tmp_list);
 774		pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RO_FAILED);
 775		pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RW_FAILED);
 776		spin_unlock(&nfsi->vfs_inode.i_lock);
 777		pnfs_free_lseg_list(&tmp_list);
 778		nfs_commit_inode(&nfsi->vfs_inode, 0);
 779		pnfs_put_layout_hdr(lo);
 780	} else
 781		spin_unlock(&nfsi->vfs_inode.i_lock);
 782	return lo;
 783}
 784
 785void pnfs_destroy_layout(struct nfs_inode *nfsi)
 786{
 787	__pnfs_destroy_layout(nfsi);
 788}
 789EXPORT_SYMBOL_GPL(pnfs_destroy_layout);
 790
 791static bool pnfs_layout_removed(struct nfs_inode *nfsi,
 792				struct pnfs_layout_hdr *lo)
 793{
 794	bool ret;
 795
 796	spin_lock(&nfsi->vfs_inode.i_lock);
 797	ret = nfsi->layout != lo;
 798	spin_unlock(&nfsi->vfs_inode.i_lock);
 799	return ret;
 800}
 801
 802void pnfs_destroy_layout_final(struct nfs_inode *nfsi)
 803{
 804	struct pnfs_layout_hdr *lo = __pnfs_destroy_layout(nfsi);
 805
 806	if (lo)
 807		wait_var_event(lo, pnfs_layout_removed(nfsi, lo));
 808}
 809
 810static bool
 811pnfs_layout_add_bulk_destroy_list(struct inode *inode,
 812		struct list_head *layout_list)
 813{
 814	struct pnfs_layout_hdr *lo;
 815	bool ret = false;
 816
 817	spin_lock(&inode->i_lock);
 818	lo = NFS_I(inode)->layout;
 819	if (lo != NULL && list_empty(&lo->plh_bulk_destroy)) {
 820		pnfs_get_layout_hdr(lo);
 821		list_add(&lo->plh_bulk_destroy, layout_list);
 822		ret = true;
 823	}
 824	spin_unlock(&inode->i_lock);
 825	return ret;
 826}
 827
 828/* Caller must hold rcu_read_lock and clp->cl_lock */
 829static int
 830pnfs_layout_bulk_destroy_byserver_locked(struct nfs_client *clp,
 831		struct nfs_server *server,
 832		struct list_head *layout_list)
 833	__must_hold(&clp->cl_lock)
 834	__must_hold(RCU)
 835{
 836	struct pnfs_layout_hdr *lo, *next;
 837	struct inode *inode;
 838
 839	list_for_each_entry_safe(lo, next, &server->layouts, plh_layouts) {
 840		if (test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags) ||
 841		    test_bit(NFS_LAYOUT_INODE_FREEING, &lo->plh_flags) ||
 842		    !list_empty(&lo->plh_bulk_destroy))
 843			continue;
 844		/* If the sb is being destroyed, just bail */
 845		if (!nfs_sb_active(server->super))
 846			break;
 847		inode = pnfs_grab_inode_layout_hdr(lo);
 848		if (inode != NULL) {
 849			if (test_and_clear_bit(NFS_LAYOUT_HASHED, &lo->plh_flags))
 850				list_del_rcu(&lo->plh_layouts);
 851			if (pnfs_layout_add_bulk_destroy_list(inode,
 852						layout_list))
 853				continue;
 854			rcu_read_unlock();
 855			spin_unlock(&clp->cl_lock);
 856			iput(inode);
 857		} else {
 858			rcu_read_unlock();
 859			spin_unlock(&clp->cl_lock);
 860		}
 861		nfs_sb_deactive(server->super);
 862		spin_lock(&clp->cl_lock);
 863		rcu_read_lock();
 864		return -EAGAIN;
 865	}
 866	return 0;
 867}
 868
 869static int
 870pnfs_layout_free_bulk_destroy_list(struct list_head *layout_list,
 871		bool is_bulk_recall)
 872{
 873	struct pnfs_layout_hdr *lo;
 874	struct inode *inode;
 875	LIST_HEAD(lseg_list);
 876	int ret = 0;
 877
 878	while (!list_empty(layout_list)) {
 879		lo = list_entry(layout_list->next, struct pnfs_layout_hdr,
 880				plh_bulk_destroy);
 881		dprintk("%s freeing layout for inode %lu\n", __func__,
 882			lo->plh_inode->i_ino);
 883		inode = lo->plh_inode;
 884
 885		pnfs_layoutcommit_inode(inode, false);
 886
 887		spin_lock(&inode->i_lock);
 888		list_del_init(&lo->plh_bulk_destroy);
 889		if (pnfs_mark_layout_stateid_invalid(lo, &lseg_list)) {
 890			if (is_bulk_recall)
 
 
 
 891				set_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
 892			ret = -EAGAIN;
 893		}
 894		spin_unlock(&inode->i_lock);
 895		pnfs_free_lseg_list(&lseg_list);
 896		/* Free all lsegs that are attached to commit buckets */
 897		nfs_commit_inode(inode, 0);
 898		pnfs_put_layout_hdr(lo);
 899		nfs_iput_and_deactive(inode);
 900	}
 901	return ret;
 902}
 903
 904int
 905pnfs_destroy_layouts_byfsid(struct nfs_client *clp,
 906		struct nfs_fsid *fsid,
 907		bool is_recall)
 908{
 909	struct nfs_server *server;
 910	LIST_HEAD(layout_list);
 911
 912	spin_lock(&clp->cl_lock);
 913	rcu_read_lock();
 914restart:
 915	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 916		if (memcmp(&server->fsid, fsid, sizeof(*fsid)) != 0)
 917			continue;
 918		if (pnfs_layout_bulk_destroy_byserver_locked(clp,
 919				server,
 920				&layout_list) != 0)
 921			goto restart;
 922	}
 923	rcu_read_unlock();
 924	spin_unlock(&clp->cl_lock);
 925
 926	if (list_empty(&layout_list))
 927		return 0;
 928	return pnfs_layout_free_bulk_destroy_list(&layout_list, is_recall);
 929}
 930
 931int
 932pnfs_destroy_layouts_byclid(struct nfs_client *clp,
 933		bool is_recall)
 934{
 935	struct nfs_server *server;
 936	LIST_HEAD(layout_list);
 937
 938	spin_lock(&clp->cl_lock);
 939	rcu_read_lock();
 940restart:
 941	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 942		if (pnfs_layout_bulk_destroy_byserver_locked(clp,
 943					server,
 944					&layout_list) != 0)
 945			goto restart;
 946	}
 947	rcu_read_unlock();
 948	spin_unlock(&clp->cl_lock);
 
 949
 950	if (list_empty(&layout_list))
 951		return 0;
 952	return pnfs_layout_free_bulk_destroy_list(&layout_list, is_recall);
 
 
 
 
 
 
 
 
 
 
 
 953}
 954
 955/*
 956 * Called by the state manager to remove all layouts established under an
 957 * expired lease.
 958 */
 959void
 960pnfs_destroy_all_layouts(struct nfs_client *clp)
 961{
 962	nfs4_deviceid_mark_client_invalid(clp);
 963	nfs4_deviceid_purge_client(clp);
 964
 965	pnfs_destroy_layouts_byclid(clp, false);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 966}
 967
 968static void
 969pnfs_set_layout_cred(struct pnfs_layout_hdr *lo, const struct cred *cred)
 970{
 971	const struct cred *old;
 972
 973	if (cred && cred_fscmp(lo->plh_lc_cred, cred) != 0) {
 974		old = xchg(&lo->plh_lc_cred, get_cred(cred));
 975		put_cred(old);
 976	}
 977}
 978
 979/* update lo->plh_stateid with new if is more recent */
 980void
 981pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo, const nfs4_stateid *new,
 982			const struct cred *cred, bool update_barrier)
 983{
 984	u32 oldseq = be32_to_cpu(lo->plh_stateid.seqid);
 985	u32 newseq = be32_to_cpu(new->seqid);
 986
 987	if (!pnfs_layout_is_valid(lo)) {
 988		pnfs_set_layout_cred(lo, cred);
 989		nfs4_stateid_copy(&lo->plh_stateid, new);
 990		lo->plh_barrier = newseq;
 991		pnfs_clear_layoutreturn_info(lo);
 992		clear_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
 993		return;
 994	}
 995
 996	if (pnfs_seqid_is_newer(newseq, oldseq))
 997		nfs4_stateid_copy(&lo->plh_stateid, new);
 998
 999	if (update_barrier) {
1000		pnfs_barrier_update(lo, newseq);
1001		return;
1002	}
1003	/*
1004	 * Because of wraparound, we want to keep the barrier
1005	 * "close" to the current seqids. We really only want to
1006	 * get here from a layoutget call.
1007	 */
1008	if (atomic_read(&lo->plh_outstanding) == 1)
1009		 pnfs_barrier_update(lo, be32_to_cpu(lo->plh_stateid.seqid));
1010}
1011
1012static bool
1013pnfs_layout_stateid_blocked(const struct pnfs_layout_hdr *lo,
1014		const nfs4_stateid *stateid)
1015{
1016	u32 seqid = be32_to_cpu(stateid->seqid);
1017
1018	return lo->plh_barrier && pnfs_seqid_is_newer(lo->plh_barrier, seqid);
1019}
1020
1021/* lget is set to 1 if called from inside send_layoutget call chain */
1022static bool
1023pnfs_layoutgets_blocked(const struct pnfs_layout_hdr *lo)
1024{
1025	return lo->plh_block_lgets ||
1026		test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
1027}
1028
1029static struct nfs_server *
1030pnfs_find_server(struct inode *inode, struct nfs_open_context *ctx)
1031{
1032	struct nfs_server *server;
1033
1034	if (inode) {
1035		server = NFS_SERVER(inode);
1036	} else {
1037		struct dentry *parent_dir = dget_parent(ctx->dentry);
1038		server = NFS_SERVER(parent_dir->d_inode);
1039		dput(parent_dir);
1040	}
1041	return server;
1042}
1043
1044static void nfs4_free_pages(struct page **pages, size_t size)
1045{
1046	int i;
1047
1048	if (!pages)
1049		return;
1050
1051	for (i = 0; i < size; i++) {
1052		if (!pages[i])
1053			break;
1054		__free_page(pages[i]);
1055	}
1056	kfree(pages);
1057}
1058
1059static struct page **nfs4_alloc_pages(size_t size, gfp_t gfp_flags)
1060{
1061	struct page **pages;
1062	int i;
1063
1064	pages = kmalloc_array(size, sizeof(struct page *), gfp_flags);
1065	if (!pages) {
1066		dprintk("%s: can't alloc array of %zu pages\n", __func__, size);
1067		return NULL;
1068	}
1069
1070	for (i = 0; i < size; i++) {
1071		pages[i] = alloc_page(gfp_flags);
1072		if (!pages[i]) {
1073			dprintk("%s: failed to allocate page\n", __func__);
1074			nfs4_free_pages(pages, i);
1075			return NULL;
1076		}
1077	}
1078
1079	return pages;
1080}
1081
1082static struct nfs4_layoutget *
1083pnfs_alloc_init_layoutget_args(struct inode *ino,
1084	   struct nfs_open_context *ctx,
1085	   const nfs4_stateid *stateid,
1086	   const struct pnfs_layout_range *range,
1087	   gfp_t gfp_flags)
1088{
1089	struct nfs_server *server = pnfs_find_server(ino, ctx);
1090	size_t max_reply_sz = server->pnfs_curr_ld->max_layoutget_response;
1091	size_t max_pages = max_response_pages(server);
1092	struct nfs4_layoutget *lgp;
1093
1094	dprintk("--> %s\n", __func__);
1095
1096	lgp = kzalloc(sizeof(*lgp), gfp_flags);
1097	if (lgp == NULL)
1098		return NULL;
1099
1100	if (max_reply_sz) {
1101		size_t npages = (max_reply_sz + PAGE_SIZE - 1) >> PAGE_SHIFT;
1102		if (npages < max_pages)
1103			max_pages = npages;
1104	}
1105
1106	lgp->args.layout.pages = nfs4_alloc_pages(max_pages, gfp_flags);
1107	if (!lgp->args.layout.pages) {
1108		kfree(lgp);
1109		return NULL;
1110	}
1111	lgp->args.layout.pglen = max_pages * PAGE_SIZE;
1112	lgp->res.layoutp = &lgp->args.layout;
1113
1114	/* Don't confuse uninitialised result and success */
1115	lgp->res.status = -NFS4ERR_DELAY;
1116
1117	lgp->args.minlength = PAGE_SIZE;
1118	if (lgp->args.minlength > range->length)
1119		lgp->args.minlength = range->length;
1120	if (ino) {
1121		loff_t i_size = i_size_read(ino);
1122
1123		if (range->iomode == IOMODE_READ) {
1124			if (range->offset >= i_size)
1125				lgp->args.minlength = 0;
1126			else if (i_size - range->offset < lgp->args.minlength)
1127				lgp->args.minlength = i_size - range->offset;
1128		}
1129	}
1130	lgp->args.maxcount = PNFS_LAYOUT_MAXSIZE;
1131	pnfs_copy_range(&lgp->args.range, range);
1132	lgp->args.type = server->pnfs_curr_ld->id;
1133	lgp->args.inode = ino;
1134	lgp->args.ctx = get_nfs_open_context(ctx);
1135	nfs4_stateid_copy(&lgp->args.stateid, stateid);
1136	lgp->gfp_flags = gfp_flags;
1137	lgp->cred = ctx->cred;
1138	return lgp;
1139}
1140
1141void pnfs_layoutget_free(struct nfs4_layoutget *lgp)
1142{
1143	size_t max_pages = lgp->args.layout.pglen / PAGE_SIZE;
1144
1145	nfs4_free_pages(lgp->args.layout.pages, max_pages);
1146	pnfs_put_layout_hdr(lgp->lo);
1147	put_nfs_open_context(lgp->args.ctx);
1148	kfree(lgp);
1149}
1150
1151static void pnfs_clear_layoutcommit(struct inode *inode,
1152		struct list_head *head)
1153{
1154	struct nfs_inode *nfsi = NFS_I(inode);
1155	struct pnfs_layout_segment *lseg, *tmp;
1156
1157	if (!test_and_clear_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags))
1158		return;
1159	list_for_each_entry_safe(lseg, tmp, &nfsi->layout->plh_segs, pls_list) {
1160		if (!test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
1161			continue;
1162		pnfs_lseg_dec_and_remove_zero(lseg, head);
1163	}
1164}
1165
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1166void pnfs_layoutreturn_free_lsegs(struct pnfs_layout_hdr *lo,
1167		const nfs4_stateid *arg_stateid,
1168		const struct pnfs_layout_range *range,
1169		const nfs4_stateid *stateid)
1170{
1171	struct inode *inode = lo->plh_inode;
1172	LIST_HEAD(freeme);
1173
1174	spin_lock(&inode->i_lock);
1175	if (!pnfs_layout_is_valid(lo) ||
1176	    !nfs4_stateid_match_other(&lo->plh_stateid, arg_stateid))
1177		goto out_unlock;
1178	if (stateid) {
1179		u32 seq = be32_to_cpu(arg_stateid->seqid);
1180
1181		pnfs_mark_matching_lsegs_invalid(lo, &freeme, range, seq);
1182		pnfs_free_returned_lsegs(lo, &freeme, range, seq);
1183		pnfs_set_layout_stateid(lo, stateid, NULL, true);
1184	} else
1185		pnfs_mark_layout_stateid_invalid(lo, &freeme);
1186out_unlock:
1187	pnfs_clear_layoutreturn_waitbit(lo);
1188	spin_unlock(&inode->i_lock);
1189	pnfs_free_lseg_list(&freeme);
1190
1191}
1192
1193static bool
1194pnfs_prepare_layoutreturn(struct pnfs_layout_hdr *lo,
1195		nfs4_stateid *stateid,
1196		const struct cred **cred,
1197		enum pnfs_iomode *iomode)
1198{
1199	/* Serialise LAYOUTGET/LAYOUTRETURN */
1200	if (atomic_read(&lo->plh_outstanding) != 0)
1201		return false;
1202	if (test_and_set_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags))
1203		return false;
1204	set_bit(NFS_LAYOUT_RETURN, &lo->plh_flags);
1205	pnfs_get_layout_hdr(lo);
1206	nfs4_stateid_copy(stateid, &lo->plh_stateid);
1207	*cred = get_cred(lo->plh_lc_cred);
1208	if (test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags)) {
1209		if (lo->plh_return_seq != 0)
1210			stateid->seqid = cpu_to_be32(lo->plh_return_seq);
1211		if (iomode != NULL)
1212			*iomode = lo->plh_return_iomode;
1213		pnfs_clear_layoutreturn_info(lo);
1214	} else if (iomode != NULL)
1215		*iomode = IOMODE_ANY;
1216	pnfs_barrier_update(lo, be32_to_cpu(stateid->seqid));
1217	return true;
1218}
1219
1220static void
1221pnfs_init_layoutreturn_args(struct nfs4_layoutreturn_args *args,
1222		struct pnfs_layout_hdr *lo,
1223		const nfs4_stateid *stateid,
1224		enum pnfs_iomode iomode)
1225{
1226	struct inode *inode = lo->plh_inode;
1227
1228	args->layout_type = NFS_SERVER(inode)->pnfs_curr_ld->id;
1229	args->inode = inode;
1230	args->range.iomode = iomode;
1231	args->range.offset = 0;
1232	args->range.length = NFS4_MAX_UINT64;
1233	args->layout = lo;
1234	nfs4_stateid_copy(&args->stateid, stateid);
1235}
1236
1237static int
1238pnfs_send_layoutreturn(struct pnfs_layout_hdr *lo,
1239		       const nfs4_stateid *stateid,
1240		       const struct cred **pcred,
1241		       enum pnfs_iomode iomode,
1242		       bool sync)
1243{
1244	struct inode *ino = lo->plh_inode;
1245	struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
1246	struct nfs4_layoutreturn *lrp;
1247	const struct cred *cred = *pcred;
1248	int status = 0;
1249
1250	*pcred = NULL;
1251	lrp = kzalloc(sizeof(*lrp), nfs_io_gfp_mask());
1252	if (unlikely(lrp == NULL)) {
1253		status = -ENOMEM;
1254		spin_lock(&ino->i_lock);
1255		pnfs_clear_layoutreturn_waitbit(lo);
1256		spin_unlock(&ino->i_lock);
1257		put_cred(cred);
1258		pnfs_put_layout_hdr(lo);
1259		goto out;
1260	}
1261
1262	pnfs_init_layoutreturn_args(&lrp->args, lo, stateid, iomode);
1263	lrp->args.ld_private = &lrp->ld_private;
1264	lrp->clp = NFS_SERVER(ino)->nfs_client;
1265	lrp->cred = cred;
1266	if (ld->prepare_layoutreturn)
1267		ld->prepare_layoutreturn(&lrp->args);
1268
1269	status = nfs4_proc_layoutreturn(lrp, sync);
1270out:
1271	dprintk("<-- %s status: %d\n", __func__, status);
1272	return status;
1273}
1274
1275static bool
1276pnfs_layout_segments_returnable(struct pnfs_layout_hdr *lo,
1277				enum pnfs_iomode iomode,
1278				u32 seq)
1279{
1280	struct pnfs_layout_range recall_range = {
1281		.length = NFS4_MAX_UINT64,
1282		.iomode = iomode,
1283	};
1284	return pnfs_mark_matching_lsegs_return(lo, &lo->plh_return_segs,
1285					       &recall_range, seq) != -EBUSY;
1286}
1287
1288/* Return true if layoutreturn is needed */
1289static bool
1290pnfs_layout_need_return(struct pnfs_layout_hdr *lo)
1291{
1292	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
1293		return false;
1294	return pnfs_layout_segments_returnable(lo, lo->plh_return_iomode,
1295					       lo->plh_return_seq);
 
1296}
1297
1298static void pnfs_layoutreturn_before_put_layout_hdr(struct pnfs_layout_hdr *lo)
1299{
1300	struct inode *inode= lo->plh_inode;
1301
1302	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
1303		return;
1304	spin_lock(&inode->i_lock);
1305	if (pnfs_layout_need_return(lo)) {
1306		const struct cred *cred;
1307		nfs4_stateid stateid;
1308		enum pnfs_iomode iomode;
1309		bool send;
1310
1311		send = pnfs_prepare_layoutreturn(lo, &stateid, &cred, &iomode);
1312		spin_unlock(&inode->i_lock);
1313		if (send) {
1314			/* Send an async layoutreturn so we dont deadlock */
1315			pnfs_send_layoutreturn(lo, &stateid, &cred, iomode, false);
 
1316		}
1317	} else
1318		spin_unlock(&inode->i_lock);
1319}
1320
1321/*
1322 * Initiates a LAYOUTRETURN(FILE), and removes the pnfs_layout_hdr
1323 * when the layout segment list is empty.
1324 *
1325 * Note that a pnfs_layout_hdr can exist with an empty layout segment
1326 * list when LAYOUTGET has failed, or when LAYOUTGET succeeded, but the
1327 * deviceid is marked invalid.
1328 */
1329int
1330_pnfs_return_layout(struct inode *ino)
1331{
1332	struct pnfs_layout_hdr *lo = NULL;
1333	struct nfs_inode *nfsi = NFS_I(ino);
1334	struct pnfs_layout_range range = {
1335		.iomode		= IOMODE_ANY,
1336		.offset		= 0,
1337		.length		= NFS4_MAX_UINT64,
1338	};
1339	LIST_HEAD(tmp_list);
1340	const struct cred *cred;
1341	nfs4_stateid stateid;
1342	int status = 0;
1343	bool send, valid_layout;
1344
1345	dprintk("NFS: %s for inode %lu\n", __func__, ino->i_ino);
1346
1347	spin_lock(&ino->i_lock);
1348	lo = nfsi->layout;
1349	if (!lo) {
1350		spin_unlock(&ino->i_lock);
1351		dprintk("NFS: %s no layout to return\n", __func__);
1352		goto out;
1353	}
1354	/* Reference matched in nfs4_layoutreturn_release */
1355	pnfs_get_layout_hdr(lo);
1356	/* Is there an outstanding layoutreturn ? */
1357	if (test_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags)) {
1358		spin_unlock(&ino->i_lock);
1359		if (wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN,
1360					TASK_UNINTERRUPTIBLE))
1361			goto out_put_layout_hdr;
1362		spin_lock(&ino->i_lock);
1363	}
1364	valid_layout = pnfs_layout_is_valid(lo);
1365	pnfs_clear_layoutcommit(ino, &tmp_list);
1366	pnfs_mark_matching_lsegs_return(lo, &tmp_list, &range, 0);
1367
1368	if (NFS_SERVER(ino)->pnfs_curr_ld->return_range)
1369		NFS_SERVER(ino)->pnfs_curr_ld->return_range(lo, &range);
1370
1371	/* Don't send a LAYOUTRETURN if list was initially empty */
1372	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags) ||
1373			!valid_layout) {
1374		spin_unlock(&ino->i_lock);
1375		dprintk("NFS: %s no layout segments to return\n", __func__);
1376		goto out_wait_layoutreturn;
1377	}
1378
1379	send = pnfs_prepare_layoutreturn(lo, &stateid, &cred, NULL);
1380	spin_unlock(&ino->i_lock);
1381	if (send)
1382		status = pnfs_send_layoutreturn(lo, &stateid, &cred, IOMODE_ANY, true);
 
1383out_wait_layoutreturn:
1384	wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN, TASK_UNINTERRUPTIBLE);
1385out_put_layout_hdr:
1386	pnfs_free_lseg_list(&tmp_list);
1387	pnfs_put_layout_hdr(lo);
1388out:
1389	dprintk("<-- %s status: %d\n", __func__, status);
1390	return status;
1391}
1392
1393int
1394pnfs_commit_and_return_layout(struct inode *inode)
1395{
1396	struct pnfs_layout_hdr *lo;
1397	int ret;
1398
1399	spin_lock(&inode->i_lock);
1400	lo = NFS_I(inode)->layout;
1401	if (lo == NULL) {
1402		spin_unlock(&inode->i_lock);
1403		return 0;
1404	}
1405	pnfs_get_layout_hdr(lo);
1406	/* Block new layoutgets and read/write to ds */
1407	lo->plh_block_lgets++;
1408	spin_unlock(&inode->i_lock);
1409	filemap_fdatawait(inode->i_mapping);
1410	ret = pnfs_layoutcommit_inode(inode, true);
1411	if (ret == 0)
1412		ret = _pnfs_return_layout(inode);
1413	spin_lock(&inode->i_lock);
1414	lo->plh_block_lgets--;
1415	spin_unlock(&inode->i_lock);
1416	pnfs_put_layout_hdr(lo);
1417	return ret;
1418}
1419
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1420bool pnfs_roc(struct inode *ino,
1421		struct nfs4_layoutreturn_args *args,
1422		struct nfs4_layoutreturn_res *res,
1423		const struct cred *cred)
1424{
1425	struct nfs_inode *nfsi = NFS_I(ino);
1426	struct nfs_open_context *ctx;
1427	struct nfs4_state *state;
1428	struct pnfs_layout_hdr *lo;
1429	struct pnfs_layout_segment *lseg, *next;
1430	const struct cred *lc_cred;
1431	nfs4_stateid stateid;
1432	enum pnfs_iomode iomode = 0;
1433	bool layoutreturn = false, roc = false;
1434	bool skip_read = false;
1435
1436	if (!nfs_have_layout(ino))
1437		return false;
1438retry:
1439	rcu_read_lock();
1440	spin_lock(&ino->i_lock);
1441	lo = nfsi->layout;
1442	if (!lo || !pnfs_layout_is_valid(lo) ||
1443	    test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
1444		lo = NULL;
1445		goto out_noroc;
1446	}
1447	pnfs_get_layout_hdr(lo);
1448	if (test_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags)) {
1449		spin_unlock(&ino->i_lock);
1450		rcu_read_unlock();
1451		wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN,
1452				TASK_UNINTERRUPTIBLE);
1453		pnfs_put_layout_hdr(lo);
1454		goto retry;
1455	}
1456
1457	/* no roc if we hold a delegation */
1458	if (nfs4_check_delegation(ino, FMODE_READ)) {
1459		if (nfs4_check_delegation(ino, FMODE_WRITE))
1460			goto out_noroc;
1461		skip_read = true;
1462	}
1463
1464	list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
1465		state = ctx->state;
1466		if (state == NULL)
1467			continue;
1468		/* Don't return layout if there is open file state */
1469		if (state->state & FMODE_WRITE)
1470			goto out_noroc;
1471		if (state->state & FMODE_READ)
1472			skip_read = true;
1473	}
1474
1475
1476	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list) {
1477		if (skip_read && lseg->pls_range.iomode == IOMODE_READ)
1478			continue;
1479		/* If we are sending layoutreturn, invalidate all valid lsegs */
1480		if (!test_and_clear_bit(NFS_LSEG_ROC, &lseg->pls_flags))
1481			continue;
1482		/*
1483		 * Note: mark lseg for return so pnfs_layout_remove_lseg
1484		 * doesn't invalidate the layout for us.
1485		 */
1486		set_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
1487		if (!mark_lseg_invalid(lseg, &lo->plh_return_segs))
1488			continue;
1489		pnfs_set_plh_return_info(lo, lseg->pls_range.iomode, 0);
1490	}
1491
1492	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
1493		goto out_noroc;
1494
1495	/* ROC in two conditions:
1496	 * 1. there are ROC lsegs
1497	 * 2. we don't send layoutreturn
1498	 */
1499	/* lo ref dropped in pnfs_roc_release() */
1500	layoutreturn = pnfs_prepare_layoutreturn(lo, &stateid, &lc_cred, &iomode);
1501	/* If the creds don't match, we can't compound the layoutreturn */
1502	if (!layoutreturn || cred_fscmp(cred, lc_cred) != 0)
1503		goto out_noroc;
1504
1505	roc = layoutreturn;
1506	pnfs_init_layoutreturn_args(args, lo, &stateid, iomode);
1507	res->lrs_present = 0;
1508	layoutreturn = false;
1509	put_cred(lc_cred);
1510
1511out_noroc:
1512	spin_unlock(&ino->i_lock);
1513	rcu_read_unlock();
1514	pnfs_layoutcommit_inode(ino, true);
1515	if (roc) {
1516		struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
1517		if (ld->prepare_layoutreturn)
1518			ld->prepare_layoutreturn(args);
1519		pnfs_put_layout_hdr(lo);
1520		return true;
1521	}
1522	if (layoutreturn)
1523		pnfs_send_layoutreturn(lo, &stateid, &lc_cred, iomode, true);
1524	pnfs_put_layout_hdr(lo);
1525	return false;
1526}
1527
1528int pnfs_roc_done(struct rpc_task *task, struct nfs4_layoutreturn_args **argpp,
1529		  struct nfs4_layoutreturn_res **respp, int *ret)
1530{
1531	struct nfs4_layoutreturn_args *arg = *argpp;
1532	int retval = -EAGAIN;
1533
1534	if (!arg)
1535		return 0;
1536	/* Handle Layoutreturn errors */
1537	switch (*ret) {
1538	case 0:
1539		retval = 0;
1540		break;
1541	case -NFS4ERR_NOMATCHING_LAYOUT:
1542		/* Was there an RPC level error? If not, retry */
1543		if (task->tk_rpc_status == 0)
1544			break;
1545		/* If the call was not sent, let caller handle it */
1546		if (!RPC_WAS_SENT(task))
1547			return 0;
1548		/*
1549		 * Otherwise, assume the call succeeded and
1550		 * that we need to release the layout
1551		 */
1552		*ret = 0;
1553		(*respp)->lrs_present = 0;
1554		retval = 0;
1555		break;
1556	case -NFS4ERR_DELAY:
1557		/* Let the caller handle the retry */
1558		*ret = -NFS4ERR_NOMATCHING_LAYOUT;
1559		return 0;
1560	case -NFS4ERR_OLD_STATEID:
1561		if (!nfs4_layout_refresh_old_stateid(&arg->stateid,
1562						     &arg->range, arg->inode))
1563			break;
1564		*ret = -NFS4ERR_NOMATCHING_LAYOUT;
1565		return -EAGAIN;
1566	}
1567	*argpp = NULL;
1568	*respp = NULL;
1569	return retval;
1570}
1571
1572void pnfs_roc_release(struct nfs4_layoutreturn_args *args,
1573		struct nfs4_layoutreturn_res *res,
1574		int ret)
1575{
1576	struct pnfs_layout_hdr *lo = args->layout;
1577	struct inode *inode = args->inode;
1578	const nfs4_stateid *res_stateid = NULL;
1579	struct nfs4_xdr_opaque_data *ld_private = args->ld_private;
1580
1581	switch (ret) {
 
 
 
1582	case -NFS4ERR_NOMATCHING_LAYOUT:
1583		spin_lock(&inode->i_lock);
1584		if (pnfs_layout_is_valid(lo) &&
1585		    nfs4_stateid_match_other(&args->stateid, &lo->plh_stateid))
1586			pnfs_set_plh_return_info(lo, args->range.iomode, 0);
1587		pnfs_clear_layoutreturn_waitbit(lo);
1588		spin_unlock(&inode->i_lock);
1589		break;
1590	case 0:
1591		if (res->lrs_present)
1592			res_stateid = &res->stateid;
1593		fallthrough;
1594	default:
1595		pnfs_layoutreturn_free_lsegs(lo, &args->stateid, &args->range,
1596					     res_stateid);
1597	}
1598	trace_nfs4_layoutreturn_on_close(args->inode, &args->stateid, ret);
1599	if (ld_private && ld_private->ops && ld_private->ops->free)
1600		ld_private->ops->free(ld_private);
1601	pnfs_put_layout_hdr(lo);
1602}
1603
1604bool pnfs_wait_on_layoutreturn(struct inode *ino, struct rpc_task *task)
1605{
1606	struct nfs_inode *nfsi = NFS_I(ino);
1607        struct pnfs_layout_hdr *lo;
1608        bool sleep = false;
1609
1610	/* we might not have grabbed lo reference. so need to check under
1611	 * i_lock */
1612        spin_lock(&ino->i_lock);
1613        lo = nfsi->layout;
1614        if (lo && test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
1615                rpc_sleep_on(&NFS_SERVER(ino)->roc_rpcwaitq, task, NULL);
1616                sleep = true;
1617	}
1618        spin_unlock(&ino->i_lock);
1619        return sleep;
1620}
1621
1622/*
1623 * Compare two layout segments for sorting into layout cache.
1624 * We want to preferentially return RW over RO layouts, so ensure those
1625 * are seen first.
1626 */
1627static s64
1628pnfs_lseg_range_cmp(const struct pnfs_layout_range *l1,
1629	   const struct pnfs_layout_range *l2)
1630{
1631	s64 d;
1632
1633	/* high offset > low offset */
1634	d = l1->offset - l2->offset;
1635	if (d)
1636		return d;
1637
1638	/* short length > long length */
1639	d = l2->length - l1->length;
1640	if (d)
1641		return d;
1642
1643	/* read > read/write */
1644	return (int)(l1->iomode == IOMODE_READ) - (int)(l2->iomode == IOMODE_READ);
1645}
1646
1647static bool
1648pnfs_lseg_range_is_after(const struct pnfs_layout_range *l1,
1649		const struct pnfs_layout_range *l2)
1650{
1651	return pnfs_lseg_range_cmp(l1, l2) > 0;
1652}
1653
1654static bool
1655pnfs_lseg_no_merge(struct pnfs_layout_segment *lseg,
1656		struct pnfs_layout_segment *old)
1657{
1658	return false;
1659}
1660
1661void
1662pnfs_generic_layout_insert_lseg(struct pnfs_layout_hdr *lo,
1663		   struct pnfs_layout_segment *lseg,
1664		   bool (*is_after)(const struct pnfs_layout_range *,
1665			   const struct pnfs_layout_range *),
1666		   bool (*do_merge)(struct pnfs_layout_segment *,
1667			   struct pnfs_layout_segment *),
1668		   struct list_head *free_me)
1669{
1670	struct pnfs_layout_segment *lp, *tmp;
1671
1672	dprintk("%s:Begin\n", __func__);
1673
1674	list_for_each_entry_safe(lp, tmp, &lo->plh_segs, pls_list) {
1675		if (test_bit(NFS_LSEG_VALID, &lp->pls_flags) == 0)
1676			continue;
1677		if (do_merge(lseg, lp)) {
1678			mark_lseg_invalid(lp, free_me);
1679			continue;
1680		}
1681		if (is_after(&lseg->pls_range, &lp->pls_range))
1682			continue;
1683		list_add_tail(&lseg->pls_list, &lp->pls_list);
1684		dprintk("%s: inserted lseg %p "
1685			"iomode %d offset %llu length %llu before "
1686			"lp %p iomode %d offset %llu length %llu\n",
1687			__func__, lseg, lseg->pls_range.iomode,
1688			lseg->pls_range.offset, lseg->pls_range.length,
1689			lp, lp->pls_range.iomode, lp->pls_range.offset,
1690			lp->pls_range.length);
1691		goto out;
1692	}
1693	list_add_tail(&lseg->pls_list, &lo->plh_segs);
1694	dprintk("%s: inserted lseg %p "
1695		"iomode %d offset %llu length %llu at tail\n",
1696		__func__, lseg, lseg->pls_range.iomode,
1697		lseg->pls_range.offset, lseg->pls_range.length);
1698out:
1699	pnfs_get_layout_hdr(lo);
1700
1701	dprintk("%s:Return\n", __func__);
1702}
1703EXPORT_SYMBOL_GPL(pnfs_generic_layout_insert_lseg);
1704
1705static void
1706pnfs_layout_insert_lseg(struct pnfs_layout_hdr *lo,
1707		   struct pnfs_layout_segment *lseg,
1708		   struct list_head *free_me)
1709{
1710	struct inode *inode = lo->plh_inode;
1711	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
1712
1713	if (ld->add_lseg != NULL)
1714		ld->add_lseg(lo, lseg, free_me);
1715	else
1716		pnfs_generic_layout_insert_lseg(lo, lseg,
1717				pnfs_lseg_range_is_after,
1718				pnfs_lseg_no_merge,
1719				free_me);
1720}
1721
1722static struct pnfs_layout_hdr *
1723alloc_init_layout_hdr(struct inode *ino,
1724		      struct nfs_open_context *ctx,
1725		      gfp_t gfp_flags)
1726{
1727	struct pnfs_layout_hdr *lo;
1728
1729	lo = pnfs_alloc_layout_hdr(ino, gfp_flags);
1730	if (!lo)
1731		return NULL;
1732	refcount_set(&lo->plh_refcount, 1);
1733	INIT_LIST_HEAD(&lo->plh_layouts);
1734	INIT_LIST_HEAD(&lo->plh_segs);
1735	INIT_LIST_HEAD(&lo->plh_return_segs);
1736	INIT_LIST_HEAD(&lo->plh_bulk_destroy);
1737	lo->plh_inode = ino;
1738	lo->plh_lc_cred = get_cred(ctx->cred);
1739	lo->plh_flags |= 1 << NFS_LAYOUT_INVALID_STID;
1740	return lo;
1741}
1742
1743static struct pnfs_layout_hdr *
1744pnfs_find_alloc_layout(struct inode *ino,
1745		       struct nfs_open_context *ctx,
1746		       gfp_t gfp_flags)
1747	__releases(&ino->i_lock)
1748	__acquires(&ino->i_lock)
1749{
1750	struct nfs_inode *nfsi = NFS_I(ino);
1751	struct pnfs_layout_hdr *new = NULL;
1752
1753	dprintk("%s Begin ino=%p layout=%p\n", __func__, ino, nfsi->layout);
1754
1755	if (nfsi->layout != NULL)
1756		goto out_existing;
1757	spin_unlock(&ino->i_lock);
1758	new = alloc_init_layout_hdr(ino, ctx, gfp_flags);
1759	spin_lock(&ino->i_lock);
1760
1761	if (likely(nfsi->layout == NULL)) {	/* Won the race? */
1762		nfsi->layout = new;
1763		return new;
1764	} else if (new != NULL)
1765		pnfs_free_layout_hdr(new);
1766out_existing:
1767	pnfs_get_layout_hdr(nfsi->layout);
1768	return nfsi->layout;
1769}
1770
1771/*
1772 * iomode matching rules:
1773 * iomode	lseg	strict match
1774 *                      iomode
1775 * -----	-----	------ -----
1776 * ANY		READ	N/A    true
1777 * ANY		RW	N/A    true
1778 * RW		READ	N/A    false
1779 * RW		RW	N/A    true
1780 * READ		READ	N/A    true
1781 * READ		RW	true   false
1782 * READ		RW	false  true
1783 */
1784static bool
1785pnfs_lseg_range_match(const struct pnfs_layout_range *ls_range,
1786		 const struct pnfs_layout_range *range,
1787		 bool strict_iomode)
1788{
1789	struct pnfs_layout_range range1;
1790
1791	if ((range->iomode == IOMODE_RW &&
1792	     ls_range->iomode != IOMODE_RW) ||
1793	    (range->iomode != ls_range->iomode &&
1794	     strict_iomode) ||
1795	    !pnfs_lseg_range_intersecting(ls_range, range))
1796		return false;
1797
1798	/* range1 covers only the first byte in the range */
1799	range1 = *range;
1800	range1.length = 1;
1801	return pnfs_lseg_range_contained(ls_range, &range1);
1802}
1803
1804/*
1805 * lookup range in layout
1806 */
1807static struct pnfs_layout_segment *
1808pnfs_find_lseg(struct pnfs_layout_hdr *lo,
1809		struct pnfs_layout_range *range,
1810		bool strict_iomode)
1811{
1812	struct pnfs_layout_segment *lseg, *ret = NULL;
1813
1814	dprintk("%s:Begin\n", __func__);
1815
1816	list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
1817		if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags) &&
1818		    pnfs_lseg_range_match(&lseg->pls_range, range,
1819					  strict_iomode)) {
1820			ret = pnfs_get_lseg(lseg);
1821			break;
1822		}
1823	}
1824
1825	dprintk("%s:Return lseg %p ref %d\n",
1826		__func__, ret, ret ? refcount_read(&ret->pls_refcount) : 0);
1827	return ret;
1828}
1829
1830/*
1831 * Use mdsthreshold hints set at each OPEN to determine if I/O should go
1832 * to the MDS or over pNFS
1833 *
1834 * The nfs_inode read_io and write_io fields are cumulative counters reset
1835 * when there are no layout segments. Note that in pnfs_update_layout iomode
1836 * is set to IOMODE_READ for a READ request, and set to IOMODE_RW for a
1837 * WRITE request.
1838 *
1839 * A return of true means use MDS I/O.
1840 *
1841 * From rfc 5661:
1842 * If a file's size is smaller than the file size threshold, data accesses
1843 * SHOULD be sent to the metadata server.  If an I/O request has a length that
1844 * is below the I/O size threshold, the I/O SHOULD be sent to the metadata
1845 * server.  If both file size and I/O size are provided, the client SHOULD
1846 * reach or exceed  both thresholds before sending its read or write
1847 * requests to the data server.
1848 */
1849static bool pnfs_within_mdsthreshold(struct nfs_open_context *ctx,
1850				     struct inode *ino, int iomode)
1851{
1852	struct nfs4_threshold *t = ctx->mdsthreshold;
1853	struct nfs_inode *nfsi = NFS_I(ino);
1854	loff_t fsize = i_size_read(ino);
1855	bool size = false, size_set = false, io = false, io_set = false, ret = false;
1856
1857	if (t == NULL)
1858		return ret;
1859
1860	dprintk("%s bm=0x%x rd_sz=%llu wr_sz=%llu rd_io=%llu wr_io=%llu\n",
1861		__func__, t->bm, t->rd_sz, t->wr_sz, t->rd_io_sz, t->wr_io_sz);
1862
1863	switch (iomode) {
1864	case IOMODE_READ:
1865		if (t->bm & THRESHOLD_RD) {
1866			dprintk("%s fsize %llu\n", __func__, fsize);
1867			size_set = true;
1868			if (fsize < t->rd_sz)
1869				size = true;
1870		}
1871		if (t->bm & THRESHOLD_RD_IO) {
1872			dprintk("%s nfsi->read_io %llu\n", __func__,
1873				nfsi->read_io);
1874			io_set = true;
1875			if (nfsi->read_io < t->rd_io_sz)
1876				io = true;
1877		}
1878		break;
1879	case IOMODE_RW:
1880		if (t->bm & THRESHOLD_WR) {
1881			dprintk("%s fsize %llu\n", __func__, fsize);
1882			size_set = true;
1883			if (fsize < t->wr_sz)
1884				size = true;
1885		}
1886		if (t->bm & THRESHOLD_WR_IO) {
1887			dprintk("%s nfsi->write_io %llu\n", __func__,
1888				nfsi->write_io);
1889			io_set = true;
1890			if (nfsi->write_io < t->wr_io_sz)
1891				io = true;
1892		}
1893		break;
1894	}
1895	if (size_set && io_set) {
1896		if (size && io)
1897			ret = true;
1898	} else if (size || io)
1899		ret = true;
1900
1901	dprintk("<-- %s size %d io %d ret %d\n", __func__, size, io, ret);
1902	return ret;
1903}
1904
1905static int pnfs_prepare_to_retry_layoutget(struct pnfs_layout_hdr *lo)
1906{
1907	/*
1908	 * send layoutcommit as it can hold up layoutreturn due to lseg
1909	 * reference
1910	 */
1911	pnfs_layoutcommit_inode(lo->plh_inode, false);
1912	return wait_on_bit_action(&lo->plh_flags, NFS_LAYOUT_RETURN,
1913				   nfs_wait_bit_killable,
1914				   TASK_KILLABLE|TASK_FREEZABLE_UNSAFE);
1915}
1916
1917static void nfs_layoutget_begin(struct pnfs_layout_hdr *lo)
1918{
1919	atomic_inc(&lo->plh_outstanding);
1920}
1921
1922static void nfs_layoutget_end(struct pnfs_layout_hdr *lo)
1923{
1924	if (atomic_dec_and_test(&lo->plh_outstanding) &&
1925	    test_and_clear_bit(NFS_LAYOUT_DRAIN, &lo->plh_flags))
1926		wake_up_bit(&lo->plh_flags, NFS_LAYOUT_DRAIN);
1927}
1928
1929static bool pnfs_is_first_layoutget(struct pnfs_layout_hdr *lo)
1930{
1931	return test_bit(NFS_LAYOUT_FIRST_LAYOUTGET, &lo->plh_flags);
1932}
1933
1934static void pnfs_clear_first_layoutget(struct pnfs_layout_hdr *lo)
1935{
1936	unsigned long *bitlock = &lo->plh_flags;
1937
1938	clear_bit_unlock(NFS_LAYOUT_FIRST_LAYOUTGET, bitlock);
1939	smp_mb__after_atomic();
1940	wake_up_bit(bitlock, NFS_LAYOUT_FIRST_LAYOUTGET);
1941}
1942
1943static void _add_to_server_list(struct pnfs_layout_hdr *lo,
1944				struct nfs_server *server)
1945{
1946	if (!test_and_set_bit(NFS_LAYOUT_HASHED, &lo->plh_flags)) {
1947		struct nfs_client *clp = server->nfs_client;
1948
1949		/* The lo must be on the clp list if there is any
1950		 * chance of a CB_LAYOUTRECALL(FILE) coming in.
1951		 */
1952		spin_lock(&clp->cl_lock);
1953		list_add_tail_rcu(&lo->plh_layouts, &server->layouts);
1954		spin_unlock(&clp->cl_lock);
1955	}
1956}
1957
1958/*
1959 * Layout segment is retreived from the server if not cached.
1960 * The appropriate layout segment is referenced and returned to the caller.
1961 */
1962struct pnfs_layout_segment *
1963pnfs_update_layout(struct inode *ino,
1964		   struct nfs_open_context *ctx,
1965		   loff_t pos,
1966		   u64 count,
1967		   enum pnfs_iomode iomode,
1968		   bool strict_iomode,
1969		   gfp_t gfp_flags)
1970{
1971	struct pnfs_layout_range arg = {
1972		.iomode = iomode,
1973		.offset = pos,
1974		.length = count,
1975	};
1976	unsigned pg_offset;
1977	struct nfs_server *server = NFS_SERVER(ino);
1978	struct nfs_client *clp = server->nfs_client;
1979	struct pnfs_layout_hdr *lo = NULL;
1980	struct pnfs_layout_segment *lseg = NULL;
1981	struct nfs4_layoutget *lgp;
1982	nfs4_stateid stateid;
1983	struct nfs4_exception exception = {
1984		.inode = ino,
1985	};
1986	unsigned long giveup = jiffies + (clp->cl_lease_time << 1);
1987	bool first;
1988
1989	if (!pnfs_enabled_sb(NFS_SERVER(ino))) {
1990		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1991				 PNFS_UPDATE_LAYOUT_NO_PNFS);
1992		goto out;
1993	}
1994
1995	if (pnfs_within_mdsthreshold(ctx, ino, iomode)) {
1996		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
1997				 PNFS_UPDATE_LAYOUT_MDSTHRESH);
1998		goto out;
1999	}
2000
2001lookup_again:
2002	if (!nfs4_valid_open_stateid(ctx->state)) {
2003		trace_pnfs_update_layout(ino, pos, count,
2004					 iomode, lo, lseg,
2005					 PNFS_UPDATE_LAYOUT_INVALID_OPEN);
2006		lseg = ERR_PTR(-EIO);
2007		goto out;
2008	}
2009
2010	lseg = ERR_PTR(nfs4_client_recover_expired_lease(clp));
2011	if (IS_ERR(lseg))
2012		goto out;
2013	first = false;
2014	spin_lock(&ino->i_lock);
2015	lo = pnfs_find_alloc_layout(ino, ctx, gfp_flags);
2016	if (lo == NULL) {
2017		spin_unlock(&ino->i_lock);
2018		lseg = ERR_PTR(-ENOMEM);
2019		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2020				 PNFS_UPDATE_LAYOUT_NOMEM);
2021		goto out;
2022	}
2023
2024	/* Do we even need to bother with this? */
2025	if (test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
2026		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2027				 PNFS_UPDATE_LAYOUT_BULK_RECALL);
2028		dprintk("%s matches recall, use MDS\n", __func__);
2029		goto out_unlock;
2030	}
2031
2032	/* if LAYOUTGET already failed once we don't try again */
2033	if (pnfs_layout_io_test_failed(lo, iomode)) {
2034		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2035				 PNFS_UPDATE_LAYOUT_IO_TEST_FAIL);
2036		goto out_unlock;
2037	}
2038
2039	/*
2040	 * If the layout segment list is empty, but there are outstanding
2041	 * layoutget calls, then they might be subject to a layoutrecall.
2042	 */
2043	if (test_bit(NFS_LAYOUT_DRAIN, &lo->plh_flags) &&
2044	    atomic_read(&lo->plh_outstanding) != 0) {
2045		spin_unlock(&ino->i_lock);
2046		lseg = ERR_PTR(wait_on_bit(&lo->plh_flags, NFS_LAYOUT_DRAIN,
2047					   TASK_KILLABLE));
2048		if (IS_ERR(lseg))
2049			goto out_put_layout_hdr;
2050		pnfs_put_layout_hdr(lo);
2051		goto lookup_again;
2052	}
2053
2054	/*
2055	 * Because we free lsegs when sending LAYOUTRETURN, we need to wait
2056	 * for LAYOUTRETURN.
2057	 */
2058	if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
2059		spin_unlock(&ino->i_lock);
2060		dprintk("%s wait for layoutreturn\n", __func__);
2061		lseg = ERR_PTR(pnfs_prepare_to_retry_layoutget(lo));
2062		if (!IS_ERR(lseg)) {
2063			pnfs_put_layout_hdr(lo);
2064			dprintk("%s retrying\n", __func__);
2065			trace_pnfs_update_layout(ino, pos, count, iomode, lo,
2066						 lseg,
2067						 PNFS_UPDATE_LAYOUT_RETRY);
2068			goto lookup_again;
2069		}
2070		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2071					 PNFS_UPDATE_LAYOUT_RETURN);
2072		goto out_put_layout_hdr;
2073	}
2074
2075	lseg = pnfs_find_lseg(lo, &arg, strict_iomode);
2076	if (lseg) {
2077		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2078				PNFS_UPDATE_LAYOUT_FOUND_CACHED);
2079		goto out_unlock;
2080	}
2081
2082	/*
2083	 * Choose a stateid for the LAYOUTGET. If we don't have a layout
2084	 * stateid, or it has been invalidated, then we must use the open
2085	 * stateid.
2086	 */
2087	if (test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags)) {
2088		int status;
2089
2090		/*
2091		 * The first layoutget for the file. Need to serialize per
2092		 * RFC 5661 Errata 3208.
2093		 */
2094		if (test_and_set_bit(NFS_LAYOUT_FIRST_LAYOUTGET,
2095				     &lo->plh_flags)) {
2096			spin_unlock(&ino->i_lock);
2097			lseg = ERR_PTR(wait_on_bit(&lo->plh_flags,
2098						NFS_LAYOUT_FIRST_LAYOUTGET,
2099						TASK_KILLABLE));
2100			if (IS_ERR(lseg))
2101				goto out_put_layout_hdr;
2102			pnfs_put_layout_hdr(lo);
2103			dprintk("%s retrying\n", __func__);
2104			goto lookup_again;
2105		}
2106
2107		spin_unlock(&ino->i_lock);
2108		first = true;
2109		status = nfs4_select_rw_stateid(ctx->state,
2110					iomode == IOMODE_RW ? FMODE_WRITE : FMODE_READ,
2111					NULL, &stateid, NULL);
2112		if (status != 0) {
2113			lseg = ERR_PTR(status);
2114			trace_pnfs_update_layout(ino, pos, count,
2115					iomode, lo, lseg,
2116					PNFS_UPDATE_LAYOUT_INVALID_OPEN);
2117			nfs4_schedule_stateid_recovery(server, ctx->state);
2118			pnfs_clear_first_layoutget(lo);
2119			pnfs_put_layout_hdr(lo);
2120			goto lookup_again;
2121		}
2122		spin_lock(&ino->i_lock);
2123	} else {
2124		nfs4_stateid_copy(&stateid, &lo->plh_stateid);
2125	}
2126
2127	if (pnfs_layoutgets_blocked(lo)) {
2128		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2129				PNFS_UPDATE_LAYOUT_BLOCKED);
2130		goto out_unlock;
2131	}
2132	nfs_layoutget_begin(lo);
2133	spin_unlock(&ino->i_lock);
2134
2135	_add_to_server_list(lo, server);
2136
2137	pg_offset = arg.offset & ~PAGE_MASK;
2138	if (pg_offset) {
2139		arg.offset -= pg_offset;
2140		arg.length += pg_offset;
2141	}
2142	if (arg.length != NFS4_MAX_UINT64)
2143		arg.length = PAGE_ALIGN(arg.length);
2144
2145	lgp = pnfs_alloc_init_layoutget_args(ino, ctx, &stateid, &arg, gfp_flags);
2146	if (!lgp) {
2147		lseg = ERR_PTR(-ENOMEM);
2148		trace_pnfs_update_layout(ino, pos, count, iomode, lo, NULL,
2149					 PNFS_UPDATE_LAYOUT_NOMEM);
2150		nfs_layoutget_end(lo);
2151		goto out_put_layout_hdr;
2152	}
2153
2154	lgp->lo = lo;
2155	pnfs_get_layout_hdr(lo);
2156
2157	lseg = nfs4_proc_layoutget(lgp, &exception);
2158	trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2159				 PNFS_UPDATE_LAYOUT_SEND_LAYOUTGET);
2160	nfs_layoutget_end(lo);
2161	if (IS_ERR(lseg)) {
2162		switch(PTR_ERR(lseg)) {
2163		case -EBUSY:
2164			if (time_after(jiffies, giveup))
2165				lseg = NULL;
2166			break;
2167		case -ERECALLCONFLICT:
2168		case -EAGAIN:
2169			break;
2170		case -ENODATA:
2171			/* The server returned NFS4ERR_LAYOUTUNAVAILABLE */
2172			pnfs_layout_set_fail_bit(
2173				lo, pnfs_iomode_to_fail_bit(iomode));
2174			lseg = NULL;
2175			goto out_put_layout_hdr;
2176		default:
2177			if (!nfs_error_is_fatal(PTR_ERR(lseg))) {
2178				pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
2179				lseg = NULL;
2180			}
2181			goto out_put_layout_hdr;
2182		}
2183		if (lseg) {
2184			if (!exception.retry)
2185				goto out_put_layout_hdr;
2186			if (first)
2187				pnfs_clear_first_layoutget(lo);
2188			trace_pnfs_update_layout(ino, pos, count,
2189				iomode, lo, lseg, PNFS_UPDATE_LAYOUT_RETRY);
2190			pnfs_put_layout_hdr(lo);
2191			goto lookup_again;
2192		}
2193	} else {
2194		pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
2195	}
2196
2197out_put_layout_hdr:
2198	if (first)
2199		pnfs_clear_first_layoutget(lo);
2200	trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2201				 PNFS_UPDATE_LAYOUT_EXIT);
2202	pnfs_put_layout_hdr(lo);
2203out:
2204	dprintk("%s: inode %s/%llu pNFS layout segment %s for "
2205			"(%s, offset: %llu, length: %llu)\n",
2206			__func__, ino->i_sb->s_id,
2207			(unsigned long long)NFS_FILEID(ino),
2208			IS_ERR_OR_NULL(lseg) ? "not found" : "found",
2209			iomode==IOMODE_RW ?  "read/write" : "read-only",
2210			(unsigned long long)pos,
2211			(unsigned long long)count);
2212	return lseg;
2213out_unlock:
2214	spin_unlock(&ino->i_lock);
2215	goto out_put_layout_hdr;
2216}
2217EXPORT_SYMBOL_GPL(pnfs_update_layout);
2218
2219static bool
2220pnfs_sanity_check_layout_range(struct pnfs_layout_range *range)
2221{
2222	switch (range->iomode) {
2223	case IOMODE_READ:
2224	case IOMODE_RW:
2225		break;
2226	default:
2227		return false;
2228	}
2229	if (range->offset == NFS4_MAX_UINT64)
2230		return false;
2231	if (range->length == 0)
2232		return false;
2233	if (range->length != NFS4_MAX_UINT64 &&
2234	    range->length > NFS4_MAX_UINT64 - range->offset)
2235		return false;
2236	return true;
2237}
2238
2239static struct pnfs_layout_hdr *
2240_pnfs_grab_empty_layout(struct inode *ino, struct nfs_open_context *ctx)
2241{
2242	struct pnfs_layout_hdr *lo;
2243
2244	spin_lock(&ino->i_lock);
2245	lo = pnfs_find_alloc_layout(ino, ctx, nfs_io_gfp_mask());
2246	if (!lo)
2247		goto out_unlock;
2248	if (!test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags))
2249		goto out_unlock;
2250	if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags))
2251		goto out_unlock;
2252	if (pnfs_layoutgets_blocked(lo))
2253		goto out_unlock;
2254	if (test_and_set_bit(NFS_LAYOUT_FIRST_LAYOUTGET, &lo->plh_flags))
2255		goto out_unlock;
2256	nfs_layoutget_begin(lo);
2257	spin_unlock(&ino->i_lock);
2258	_add_to_server_list(lo, NFS_SERVER(ino));
2259	return lo;
2260
2261out_unlock:
2262	spin_unlock(&ino->i_lock);
2263	pnfs_put_layout_hdr(lo);
2264	return NULL;
2265}
2266
2267static void _lgopen_prepare_attached(struct nfs4_opendata *data,
2268				     struct nfs_open_context *ctx)
2269{
2270	struct inode *ino = data->dentry->d_inode;
2271	struct pnfs_layout_range rng = {
2272		.iomode = (data->o_arg.fmode & FMODE_WRITE) ?
2273			  IOMODE_RW: IOMODE_READ,
2274		.offset = 0,
2275		.length = NFS4_MAX_UINT64,
2276	};
2277	struct nfs4_layoutget *lgp;
2278	struct pnfs_layout_hdr *lo;
2279
2280	/* Heuristic: don't send layoutget if we have cached data */
2281	if (rng.iomode == IOMODE_READ &&
2282	   (i_size_read(ino) == 0 || ino->i_mapping->nrpages != 0))
2283		return;
2284
2285	lo = _pnfs_grab_empty_layout(ino, ctx);
2286	if (!lo)
2287		return;
2288	lgp = pnfs_alloc_init_layoutget_args(ino, ctx, &current_stateid, &rng,
2289					     nfs_io_gfp_mask());
2290	if (!lgp) {
2291		pnfs_clear_first_layoutget(lo);
2292		nfs_layoutget_end(lo);
2293		pnfs_put_layout_hdr(lo);
2294		return;
2295	}
2296	lgp->lo = lo;
2297	data->lgp = lgp;
2298	data->o_arg.lg_args = &lgp->args;
2299	data->o_res.lg_res = &lgp->res;
2300}
2301
2302static void _lgopen_prepare_floating(struct nfs4_opendata *data,
2303				     struct nfs_open_context *ctx)
2304{
2305	struct inode *ino = data->dentry->d_inode;
2306	struct pnfs_layout_range rng = {
2307		.iomode = (data->o_arg.fmode & FMODE_WRITE) ?
2308			  IOMODE_RW: IOMODE_READ,
2309		.offset = 0,
2310		.length = NFS4_MAX_UINT64,
2311	};
2312	struct nfs4_layoutget *lgp;
2313
2314	lgp = pnfs_alloc_init_layoutget_args(ino, ctx, &current_stateid, &rng,
2315					     nfs_io_gfp_mask());
2316	if (!lgp)
2317		return;
2318	data->lgp = lgp;
2319	data->o_arg.lg_args = &lgp->args;
2320	data->o_res.lg_res = &lgp->res;
2321}
2322
2323void pnfs_lgopen_prepare(struct nfs4_opendata *data,
2324			 struct nfs_open_context *ctx)
2325{
2326	struct nfs_server *server = NFS_SERVER(data->dir->d_inode);
2327
2328	if (!(pnfs_enabled_sb(server) &&
2329	      server->pnfs_curr_ld->flags & PNFS_LAYOUTGET_ON_OPEN))
2330		return;
2331	/* Could check on max_ops, but currently hardcoded high enough */
2332	if (!nfs_server_capable(data->dir->d_inode, NFS_CAP_LGOPEN))
2333		return;
2334	if (data->lgp)
2335		return;
2336	if (data->state)
2337		_lgopen_prepare_attached(data, ctx);
2338	else
2339		_lgopen_prepare_floating(data, ctx);
2340}
2341
2342void pnfs_parse_lgopen(struct inode *ino, struct nfs4_layoutget *lgp,
2343		       struct nfs_open_context *ctx)
2344{
2345	struct pnfs_layout_hdr *lo;
2346	struct pnfs_layout_segment *lseg;
2347	struct nfs_server *srv = NFS_SERVER(ino);
2348	u32 iomode;
2349
2350	if (!lgp)
2351		return;
2352	dprintk("%s: entered with status %i\n", __func__, lgp->res.status);
2353	if (lgp->res.status) {
2354		switch (lgp->res.status) {
2355		default:
2356			break;
2357		/*
2358		 * Halt lgopen attempts if the server doesn't recognise
2359		 * the "current stateid" value, the layout type, or the
2360		 * layoutget operation as being valid.
2361		 * Also if it complains about too many ops in the compound
2362		 * or of the request/reply being too big.
2363		 */
2364		case -NFS4ERR_BAD_STATEID:
2365		case -NFS4ERR_NOTSUPP:
2366		case -NFS4ERR_REP_TOO_BIG:
2367		case -NFS4ERR_REP_TOO_BIG_TO_CACHE:
2368		case -NFS4ERR_REQ_TOO_BIG:
2369		case -NFS4ERR_TOO_MANY_OPS:
2370		case -NFS4ERR_UNKNOWN_LAYOUTTYPE:
2371			srv->caps &= ~NFS_CAP_LGOPEN;
2372		}
2373		return;
2374	}
2375	if (!lgp->lo) {
2376		lo = _pnfs_grab_empty_layout(ino, ctx);
2377		if (!lo)
2378			return;
2379		lgp->lo = lo;
2380	} else
2381		lo = lgp->lo;
2382
2383	lseg = pnfs_layout_process(lgp);
2384	if (!IS_ERR(lseg)) {
2385		iomode = lgp->args.range.iomode;
2386		pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
2387		pnfs_put_lseg(lseg);
2388	}
2389}
2390
2391void nfs4_lgopen_release(struct nfs4_layoutget *lgp)
2392{
2393	if (lgp != NULL) {
2394		if (lgp->lo) {
2395			pnfs_clear_first_layoutget(lgp->lo);
2396			nfs_layoutget_end(lgp->lo);
2397		}
2398		pnfs_layoutget_free(lgp);
2399	}
2400}
2401
2402struct pnfs_layout_segment *
2403pnfs_layout_process(struct nfs4_layoutget *lgp)
2404{
2405	struct pnfs_layout_hdr *lo = lgp->lo;
2406	struct nfs4_layoutget_res *res = &lgp->res;
2407	struct pnfs_layout_segment *lseg;
2408	struct inode *ino = lo->plh_inode;
2409	LIST_HEAD(free_me);
2410
2411	if (!pnfs_sanity_check_layout_range(&res->range))
2412		return ERR_PTR(-EINVAL);
2413
2414	/* Inject layout blob into I/O device driver */
2415	lseg = NFS_SERVER(ino)->pnfs_curr_ld->alloc_lseg(lo, res, lgp->gfp_flags);
2416	if (IS_ERR_OR_NULL(lseg)) {
2417		if (!lseg)
2418			lseg = ERR_PTR(-ENOMEM);
2419
2420		dprintk("%s: Could not allocate layout: error %ld\n",
2421		       __func__, PTR_ERR(lseg));
2422		return lseg;
2423	}
2424
2425	pnfs_init_lseg(lo, lseg, &res->range, &res->stateid);
2426
2427	spin_lock(&ino->i_lock);
2428	if (pnfs_layoutgets_blocked(lo)) {
2429		dprintk("%s forget reply due to state\n", __func__);
2430		goto out_forget;
2431	}
2432
2433	if (test_bit(NFS_LAYOUT_DRAIN, &lo->plh_flags) &&
2434	    !pnfs_is_first_layoutget(lo))
2435		goto out_forget;
2436
2437	if (nfs4_stateid_match_other(&lo->plh_stateid, &res->stateid)) {
2438		/* existing state ID, make sure the sequence number matches. */
2439		if (pnfs_layout_stateid_blocked(lo, &res->stateid)) {
2440			if (!pnfs_layout_is_valid(lo))
2441				lo->plh_barrier = 0;
2442			dprintk("%s forget reply due to sequence\n", __func__);
2443			goto out_forget;
2444		}
2445		pnfs_set_layout_stateid(lo, &res->stateid, lgp->cred, false);
2446	} else if (pnfs_layout_is_valid(lo)) {
2447		/*
2448		 * We got an entirely new state ID.  Mark all segments for the
2449		 * inode invalid, and retry the layoutget
2450		 */
2451		struct pnfs_layout_range range = {
2452			.iomode = IOMODE_ANY,
2453			.length = NFS4_MAX_UINT64,
2454		};
2455		pnfs_mark_matching_lsegs_return(lo, &free_me, &range, 0);
2456		goto out_forget;
2457	} else {
2458		/* We have a completely new layout */
2459		pnfs_set_layout_stateid(lo, &res->stateid, lgp->cred, true);
2460	}
2461
2462	pnfs_get_lseg(lseg);
2463	pnfs_layout_insert_lseg(lo, lseg, &free_me);
2464
2465
2466	if (res->return_on_close)
2467		set_bit(NFS_LSEG_ROC, &lseg->pls_flags);
2468
2469	spin_unlock(&ino->i_lock);
2470	pnfs_free_lseg_list(&free_me);
2471	return lseg;
2472
2473out_forget:
2474	spin_unlock(&ino->i_lock);
2475	lseg->pls_layout = lo;
2476	NFS_SERVER(ino)->pnfs_curr_ld->free_lseg(lseg);
2477	return ERR_PTR(-EAGAIN);
2478}
2479
2480/**
2481 * pnfs_mark_matching_lsegs_return - Free or return matching layout segments
2482 * @lo: pointer to layout header
2483 * @tmp_list: list header to be used with pnfs_free_lseg_list()
2484 * @return_range: describe layout segment ranges to be returned
2485 * @seq: stateid seqid to match
2486 *
2487 * This function is mainly intended for use by layoutrecall. It attempts
2488 * to free the layout segment immediately, or else to mark it for return
2489 * as soon as its reference count drops to zero.
2490 *
2491 * Returns
2492 * - 0: a layoutreturn needs to be scheduled.
2493 * - EBUSY: there are layout segment that are still in use.
2494 * - ENOENT: there are no layout segments that need to be returned.
2495 */
2496int
2497pnfs_mark_matching_lsegs_return(struct pnfs_layout_hdr *lo,
2498				struct list_head *tmp_list,
2499				const struct pnfs_layout_range *return_range,
2500				u32 seq)
2501{
2502	struct pnfs_layout_segment *lseg, *next;
2503	struct nfs_server *server = NFS_SERVER(lo->plh_inode);
2504	int remaining = 0;
2505
2506	dprintk("%s:Begin lo %p\n", __func__, lo);
2507
2508	assert_spin_locked(&lo->plh_inode->i_lock);
2509
2510	if (test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
2511		tmp_list = &lo->plh_return_segs;
2512
2513	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
2514		if (pnfs_match_lseg_recall(lseg, return_range, seq)) {
2515			dprintk("%s: marking lseg %p iomode %d "
2516				"offset %llu length %llu\n", __func__,
2517				lseg, lseg->pls_range.iomode,
2518				lseg->pls_range.offset,
2519				lseg->pls_range.length);
2520			if (test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
2521				tmp_list = &lo->plh_return_segs;
2522			if (mark_lseg_invalid(lseg, tmp_list))
2523				continue;
2524			remaining++;
2525			set_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
2526			pnfs_lseg_cancel_io(server, lseg);
2527		}
2528
2529	if (remaining) {
2530		pnfs_set_plh_return_info(lo, return_range->iomode, seq);
2531		return -EBUSY;
2532	}
2533
2534	if (!list_empty(&lo->plh_return_segs)) {
2535		pnfs_set_plh_return_info(lo, return_range->iomode, seq);
2536		return 0;
2537	}
2538
2539	return -ENOENT;
2540}
2541
2542static void
2543pnfs_mark_layout_for_return(struct inode *inode,
2544			    const struct pnfs_layout_range *range)
2545{
2546	struct pnfs_layout_hdr *lo;
2547	bool return_now = false;
2548
2549	spin_lock(&inode->i_lock);
2550	lo = NFS_I(inode)->layout;
2551	if (!pnfs_layout_is_valid(lo)) {
2552		spin_unlock(&inode->i_lock);
2553		return;
2554	}
2555	pnfs_set_plh_return_info(lo, range->iomode, 0);
2556	/*
2557	 * mark all matching lsegs so that we are sure to have no live
2558	 * segments at hand when sending layoutreturn. See pnfs_put_lseg()
2559	 * for how it works.
2560	 */
2561	if (pnfs_mark_matching_lsegs_return(lo, &lo->plh_return_segs, range, 0) != -EBUSY) {
2562		const struct cred *cred;
2563		nfs4_stateid stateid;
2564		enum pnfs_iomode iomode;
2565
2566		return_now = pnfs_prepare_layoutreturn(lo, &stateid, &cred, &iomode);
2567		spin_unlock(&inode->i_lock);
2568		if (return_now)
2569			pnfs_send_layoutreturn(lo, &stateid, &cred, iomode, false);
 
2570	} else {
2571		spin_unlock(&inode->i_lock);
2572		nfs_commit_inode(inode, 0);
2573	}
2574}
2575
2576void pnfs_error_mark_layout_for_return(struct inode *inode,
2577				       struct pnfs_layout_segment *lseg)
2578{
2579	struct pnfs_layout_range range = {
2580		.iomode = lseg->pls_range.iomode,
2581		.offset = 0,
2582		.length = NFS4_MAX_UINT64,
2583	};
2584
2585	pnfs_mark_layout_for_return(inode, &range);
2586}
2587EXPORT_SYMBOL_GPL(pnfs_error_mark_layout_for_return);
2588
2589static bool
2590pnfs_layout_can_be_returned(struct pnfs_layout_hdr *lo)
2591{
2592	return pnfs_layout_is_valid(lo) &&
2593		!test_bit(NFS_LAYOUT_INODE_FREEING, &lo->plh_flags) &&
2594		!test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags);
2595}
2596
2597static struct pnfs_layout_segment *
2598pnfs_find_first_lseg(struct pnfs_layout_hdr *lo,
2599		     const struct pnfs_layout_range *range,
2600		     enum pnfs_iomode iomode)
2601{
2602	struct pnfs_layout_segment *lseg;
2603
2604	list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
2605		if (!test_bit(NFS_LSEG_VALID, &lseg->pls_flags))
2606			continue;
2607		if (test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
2608			continue;
2609		if (lseg->pls_range.iomode != iomode && iomode != IOMODE_ANY)
2610			continue;
2611		if (pnfs_lseg_range_intersecting(&lseg->pls_range, range))
2612			return lseg;
2613	}
2614	return NULL;
2615}
2616
2617/* Find open file states whose mode matches that of the range */
2618static bool
2619pnfs_should_return_unused_layout(struct pnfs_layout_hdr *lo,
2620				 const struct pnfs_layout_range *range)
2621{
2622	struct list_head *head;
2623	struct nfs_open_context *ctx;
2624	fmode_t mode = 0;
2625
2626	if (!pnfs_layout_can_be_returned(lo) ||
2627	    !pnfs_find_first_lseg(lo, range, range->iomode))
2628		return false;
2629
2630	head = &NFS_I(lo->plh_inode)->open_files;
2631	list_for_each_entry_rcu(ctx, head, list) {
2632		if (ctx->state)
2633			mode |= ctx->state->state & (FMODE_READ|FMODE_WRITE);
2634	}
2635
2636	switch (range->iomode) {
2637	default:
2638		break;
2639	case IOMODE_READ:
2640		mode &= ~FMODE_WRITE;
2641		break;
2642	case IOMODE_RW:
2643		if (pnfs_find_first_lseg(lo, range, IOMODE_READ))
2644			mode &= ~FMODE_READ;
2645	}
2646	return mode == 0;
2647}
2648
2649static int pnfs_layout_return_unused_byserver(struct nfs_server *server,
2650					      void *data)
2651{
2652	const struct pnfs_layout_range *range = data;
2653	const struct cred *cred;
2654	struct pnfs_layout_hdr *lo;
2655	struct inode *inode;
2656	nfs4_stateid stateid;
2657	enum pnfs_iomode iomode;
2658
2659restart:
2660	rcu_read_lock();
2661	list_for_each_entry_rcu(lo, &server->layouts, plh_layouts) {
2662		inode = lo->plh_inode;
2663		if (!inode || !pnfs_layout_can_be_returned(lo) ||
2664		    test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
2665			continue;
2666		spin_lock(&inode->i_lock);
2667		if (!lo->plh_inode ||
2668		    !pnfs_should_return_unused_layout(lo, range)) {
2669			spin_unlock(&inode->i_lock);
2670			continue;
2671		}
2672		pnfs_get_layout_hdr(lo);
2673		pnfs_set_plh_return_info(lo, range->iomode, 0);
2674		if (pnfs_mark_matching_lsegs_return(lo, &lo->plh_return_segs,
2675						    range, 0) != 0 ||
2676		    !pnfs_prepare_layoutreturn(lo, &stateid, &cred, &iomode)) {
2677			spin_unlock(&inode->i_lock);
2678			rcu_read_unlock();
2679			pnfs_put_layout_hdr(lo);
2680			cond_resched();
2681			goto restart;
2682		}
2683		spin_unlock(&inode->i_lock);
2684		rcu_read_unlock();
2685		pnfs_send_layoutreturn(lo, &stateid, &cred, iomode, false);
 
2686		pnfs_put_layout_hdr(lo);
2687		cond_resched();
2688		goto restart;
2689	}
2690	rcu_read_unlock();
2691	return 0;
2692}
2693
2694void
2695pnfs_layout_return_unused_byclid(struct nfs_client *clp,
2696				 enum pnfs_iomode iomode)
2697{
2698	struct pnfs_layout_range range = {
2699		.iomode = iomode,
2700		.offset = 0,
2701		.length = NFS4_MAX_UINT64,
2702	};
2703
2704	nfs_client_for_each_server(clp, pnfs_layout_return_unused_byserver,
2705			&range);
2706}
2707
 
 
 
2708void
2709pnfs_generic_pg_check_layout(struct nfs_pageio_descriptor *pgio)
 
2710{
2711	if (pgio->pg_lseg == NULL ||
2712	    test_bit(NFS_LSEG_VALID, &pgio->pg_lseg->pls_flags))
 
2713		return;
2714	pnfs_put_lseg(pgio->pg_lseg);
2715	pgio->pg_lseg = NULL;
2716}
2717EXPORT_SYMBOL_GPL(pnfs_generic_pg_check_layout);
2718
2719/*
2720 * Check for any intersection between the request and the pgio->pg_lseg,
2721 * and if none, put this pgio->pg_lseg away.
2722 */
2723void
2724pnfs_generic_pg_check_range(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
2725{
2726	if (pgio->pg_lseg && !pnfs_lseg_request_intersecting(pgio->pg_lseg, req)) {
2727		pnfs_put_lseg(pgio->pg_lseg);
2728		pgio->pg_lseg = NULL;
2729	}
2730}
2731EXPORT_SYMBOL_GPL(pnfs_generic_pg_check_range);
2732
2733void
2734pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
2735{
2736	u64 rd_size;
2737
2738	pnfs_generic_pg_check_layout(pgio);
2739	pnfs_generic_pg_check_range(pgio, req);
2740	if (pgio->pg_lseg == NULL) {
2741		if (pgio->pg_dreq == NULL)
2742			rd_size = i_size_read(pgio->pg_inode) - req_offset(req);
2743		else
2744			rd_size = nfs_dreq_bytes_left(pgio->pg_dreq,
2745						      req_offset(req));
2746
2747		pgio->pg_lseg =
2748			pnfs_update_layout(pgio->pg_inode, nfs_req_openctx(req),
2749					   req_offset(req), rd_size,
2750					   IOMODE_READ, false,
2751					   nfs_io_gfp_mask());
2752		if (IS_ERR(pgio->pg_lseg)) {
2753			pgio->pg_error = PTR_ERR(pgio->pg_lseg);
2754			pgio->pg_lseg = NULL;
2755			return;
2756		}
2757	}
2758	/* If no lseg, fall back to read through mds */
2759	if (pgio->pg_lseg == NULL)
2760		nfs_pageio_reset_read_mds(pgio);
2761
2762}
2763EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_read);
2764
2765void
2766pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio,
2767			   struct nfs_page *req, u64 wb_size)
2768{
2769	pnfs_generic_pg_check_layout(pgio);
2770	pnfs_generic_pg_check_range(pgio, req);
2771	if (pgio->pg_lseg == NULL) {
2772		pgio->pg_lseg =
2773			pnfs_update_layout(pgio->pg_inode, nfs_req_openctx(req),
2774					   req_offset(req), wb_size, IOMODE_RW,
2775					   false, nfs_io_gfp_mask());
2776		if (IS_ERR(pgio->pg_lseg)) {
2777			pgio->pg_error = PTR_ERR(pgio->pg_lseg);
2778			pgio->pg_lseg = NULL;
2779			return;
2780		}
2781	}
2782	/* If no lseg, fall back to write through mds */
2783	if (pgio->pg_lseg == NULL)
2784		nfs_pageio_reset_write_mds(pgio);
2785}
2786EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_write);
2787
2788void
2789pnfs_generic_pg_cleanup(struct nfs_pageio_descriptor *desc)
2790{
2791	if (desc->pg_lseg) {
2792		pnfs_put_lseg(desc->pg_lseg);
2793		desc->pg_lseg = NULL;
2794	}
2795}
2796EXPORT_SYMBOL_GPL(pnfs_generic_pg_cleanup);
2797
2798/*
2799 * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
2800 * of bytes (maximum @req->wb_bytes) that can be coalesced.
2801 */
2802size_t
2803pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio,
2804		     struct nfs_page *prev, struct nfs_page *req)
2805{
2806	unsigned int size;
2807	u64 seg_end, req_start, seg_left;
2808
2809	size = nfs_generic_pg_test(pgio, prev, req);
2810	if (!size)
2811		return 0;
2812
2813	/*
2814	 * 'size' contains the number of bytes left in the current page (up
2815	 * to the original size asked for in @req->wb_bytes).
2816	 *
2817	 * Calculate how many bytes are left in the layout segment
2818	 * and if there are less bytes than 'size', return that instead.
2819	 *
2820	 * Please also note that 'end_offset' is actually the offset of the
2821	 * first byte that lies outside the pnfs_layout_range. FIXME?
2822	 *
2823	 */
2824	if (pgio->pg_lseg) {
2825		seg_end = pnfs_end_offset(pgio->pg_lseg->pls_range.offset,
2826				     pgio->pg_lseg->pls_range.length);
2827		req_start = req_offset(req);
2828
2829		/* start of request is past the last byte of this segment */
2830		if (req_start >= seg_end)
2831			return 0;
2832
2833		/* adjust 'size' iff there are fewer bytes left in the
2834		 * segment than what nfs_generic_pg_test returned */
2835		seg_left = seg_end - req_start;
2836		if (seg_left < size)
2837			size = (unsigned int)seg_left;
2838	}
2839
2840	return size;
2841}
2842EXPORT_SYMBOL_GPL(pnfs_generic_pg_test);
2843
2844int pnfs_write_done_resend_to_mds(struct nfs_pgio_header *hdr)
2845{
2846	struct nfs_pageio_descriptor pgio;
2847
2848	/* Resend all requests through the MDS */
2849	nfs_pageio_init_write(&pgio, hdr->inode, FLUSH_STABLE, true,
2850			      hdr->completion_ops);
2851	return nfs_pageio_resend(&pgio, hdr);
2852}
2853EXPORT_SYMBOL_GPL(pnfs_write_done_resend_to_mds);
2854
2855static void pnfs_ld_handle_write_error(struct nfs_pgio_header *hdr)
2856{
2857
2858	dprintk("pnfs write error = %d\n", hdr->pnfs_error);
2859	if (NFS_SERVER(hdr->inode)->pnfs_curr_ld->flags &
2860	    PNFS_LAYOUTRET_ON_ERROR) {
2861		pnfs_return_layout(hdr->inode);
2862	}
2863	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))
2864		hdr->task.tk_status = pnfs_write_done_resend_to_mds(hdr);
2865}
2866
2867/*
2868 * Called by non rpc-based layout drivers
2869 */
2870void pnfs_ld_write_done(struct nfs_pgio_header *hdr)
2871{
2872	if (likely(!hdr->pnfs_error)) {
2873		pnfs_set_layoutcommit(hdr->inode, hdr->lseg,
2874				hdr->mds_offset + hdr->res.count);
2875		hdr->mds_ops->rpc_call_done(&hdr->task, hdr);
2876	}
2877	trace_nfs4_pnfs_write(hdr, hdr->pnfs_error);
2878	if (unlikely(hdr->pnfs_error))
2879		pnfs_ld_handle_write_error(hdr);
2880	hdr->mds_ops->rpc_release(hdr);
2881}
2882EXPORT_SYMBOL_GPL(pnfs_ld_write_done);
2883
2884static void
2885pnfs_write_through_mds(struct nfs_pageio_descriptor *desc,
2886		struct nfs_pgio_header *hdr)
2887{
2888	struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
2889
2890	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2891		list_splice_tail_init(&hdr->pages, &mirror->pg_list);
2892		nfs_pageio_reset_write_mds(desc);
2893		mirror->pg_recoalesce = 1;
2894	}
2895	hdr->completion_ops->completion(hdr);
2896}
2897
2898static enum pnfs_try_status
2899pnfs_try_to_write_data(struct nfs_pgio_header *hdr,
2900			const struct rpc_call_ops *call_ops,
2901			struct pnfs_layout_segment *lseg,
2902			int how)
2903{
2904	struct inode *inode = hdr->inode;
2905	enum pnfs_try_status trypnfs;
2906	struct nfs_server *nfss = NFS_SERVER(inode);
2907
2908	hdr->mds_ops = call_ops;
2909
2910	dprintk("%s: Writing ino:%lu %u@%llu (how %d)\n", __func__,
2911		inode->i_ino, hdr->args.count, hdr->args.offset, how);
2912	trypnfs = nfss->pnfs_curr_ld->write_pagelist(hdr, how);
2913	if (trypnfs != PNFS_NOT_ATTEMPTED)
2914		nfs_inc_stats(inode, NFSIOS_PNFS_WRITE);
2915	dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
2916	return trypnfs;
2917}
2918
2919static void
2920pnfs_do_write(struct nfs_pageio_descriptor *desc,
2921	      struct nfs_pgio_header *hdr, int how)
2922{
2923	const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
2924	struct pnfs_layout_segment *lseg = desc->pg_lseg;
2925	enum pnfs_try_status trypnfs;
2926
2927	trypnfs = pnfs_try_to_write_data(hdr, call_ops, lseg, how);
2928	switch (trypnfs) {
2929	case PNFS_NOT_ATTEMPTED:
2930		pnfs_write_through_mds(desc, hdr);
2931		break;
2932	case PNFS_ATTEMPTED:
2933		break;
2934	case PNFS_TRY_AGAIN:
2935		/* cleanup hdr and prepare to redo pnfs */
2936		if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
2937			struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
2938			list_splice_init(&hdr->pages, &mirror->pg_list);
2939			mirror->pg_recoalesce = 1;
2940		}
2941		hdr->mds_ops->rpc_release(hdr);
2942	}
2943}
2944
2945static void pnfs_writehdr_free(struct nfs_pgio_header *hdr)
2946{
2947	pnfs_put_lseg(hdr->lseg);
2948	nfs_pgio_header_free(hdr);
2949}
2950
2951int
2952pnfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
2953{
2954	struct nfs_pgio_header *hdr;
2955	int ret;
2956
2957	hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
2958	if (!hdr) {
2959		desc->pg_error = -ENOMEM;
2960		return desc->pg_error;
2961	}
2962	nfs_pgheader_init(desc, hdr, pnfs_writehdr_free);
2963
2964	hdr->lseg = pnfs_get_lseg(desc->pg_lseg);
2965	ret = nfs_generic_pgio(desc, hdr);
2966	if (!ret)
2967		pnfs_do_write(desc, hdr, desc->pg_ioflags);
2968
2969	return ret;
2970}
2971EXPORT_SYMBOL_GPL(pnfs_generic_pg_writepages);
2972
2973int pnfs_read_done_resend_to_mds(struct nfs_pgio_header *hdr)
2974{
2975	struct nfs_pageio_descriptor pgio;
2976
2977	/* Resend all requests through the MDS */
2978	nfs_pageio_init_read(&pgio, hdr->inode, true, hdr->completion_ops);
2979	return nfs_pageio_resend(&pgio, hdr);
2980}
2981EXPORT_SYMBOL_GPL(pnfs_read_done_resend_to_mds);
2982
2983static void pnfs_ld_handle_read_error(struct nfs_pgio_header *hdr)
2984{
2985	dprintk("pnfs read error = %d\n", hdr->pnfs_error);
2986	if (NFS_SERVER(hdr->inode)->pnfs_curr_ld->flags &
2987	    PNFS_LAYOUTRET_ON_ERROR) {
2988		pnfs_return_layout(hdr->inode);
2989	}
2990	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))
2991		hdr->task.tk_status = pnfs_read_done_resend_to_mds(hdr);
2992}
2993
2994/*
2995 * Called by non rpc-based layout drivers
2996 */
2997void pnfs_ld_read_done(struct nfs_pgio_header *hdr)
2998{
2999	if (likely(!hdr->pnfs_error))
3000		hdr->mds_ops->rpc_call_done(&hdr->task, hdr);
3001	trace_nfs4_pnfs_read(hdr, hdr->pnfs_error);
3002	if (unlikely(hdr->pnfs_error))
3003		pnfs_ld_handle_read_error(hdr);
3004	hdr->mds_ops->rpc_release(hdr);
3005}
3006EXPORT_SYMBOL_GPL(pnfs_ld_read_done);
3007
3008static void
3009pnfs_read_through_mds(struct nfs_pageio_descriptor *desc,
3010		struct nfs_pgio_header *hdr)
3011{
3012	struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
3013
3014	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
3015		list_splice_tail_init(&hdr->pages, &mirror->pg_list);
3016		nfs_pageio_reset_read_mds(desc);
3017		mirror->pg_recoalesce = 1;
3018	}
3019	hdr->completion_ops->completion(hdr);
3020}
3021
3022/*
3023 * Call the appropriate parallel I/O subsystem read function.
3024 */
3025static enum pnfs_try_status
3026pnfs_try_to_read_data(struct nfs_pgio_header *hdr,
3027		       const struct rpc_call_ops *call_ops,
3028		       struct pnfs_layout_segment *lseg)
3029{
3030	struct inode *inode = hdr->inode;
3031	struct nfs_server *nfss = NFS_SERVER(inode);
3032	enum pnfs_try_status trypnfs;
3033
3034	hdr->mds_ops = call_ops;
3035
3036	dprintk("%s: Reading ino:%lu %u@%llu\n",
3037		__func__, inode->i_ino, hdr->args.count, hdr->args.offset);
3038
3039	trypnfs = nfss->pnfs_curr_ld->read_pagelist(hdr);
3040	if (trypnfs != PNFS_NOT_ATTEMPTED)
3041		nfs_inc_stats(inode, NFSIOS_PNFS_READ);
3042	dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
3043	return trypnfs;
3044}
3045
3046/* Resend all requests through pnfs. */
3047void pnfs_read_resend_pnfs(struct nfs_pgio_header *hdr,
3048			   unsigned int mirror_idx)
3049{
3050	struct nfs_pageio_descriptor pgio;
3051
3052	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
3053		/* Prevent deadlocks with layoutreturn! */
3054		pnfs_put_lseg(hdr->lseg);
3055		hdr->lseg = NULL;
3056
3057		nfs_pageio_init_read(&pgio, hdr->inode, false,
3058					hdr->completion_ops);
3059		pgio.pg_mirror_idx = mirror_idx;
3060		hdr->task.tk_status = nfs_pageio_resend(&pgio, hdr);
3061	}
3062}
3063EXPORT_SYMBOL_GPL(pnfs_read_resend_pnfs);
3064
3065static void
3066pnfs_do_read(struct nfs_pageio_descriptor *desc, struct nfs_pgio_header *hdr)
3067{
3068	const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
3069	struct pnfs_layout_segment *lseg = desc->pg_lseg;
3070	enum pnfs_try_status trypnfs;
3071
3072	trypnfs = pnfs_try_to_read_data(hdr, call_ops, lseg);
3073	switch (trypnfs) {
3074	case PNFS_NOT_ATTEMPTED:
3075		pnfs_read_through_mds(desc, hdr);
3076		break;
3077	case PNFS_ATTEMPTED:
3078		break;
3079	case PNFS_TRY_AGAIN:
3080		/* cleanup hdr and prepare to redo pnfs */
3081		if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
3082			struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
3083			list_splice_init(&hdr->pages, &mirror->pg_list);
3084			mirror->pg_recoalesce = 1;
3085		}
3086		hdr->mds_ops->rpc_release(hdr);
3087	}
3088}
3089
3090static void pnfs_readhdr_free(struct nfs_pgio_header *hdr)
3091{
3092	pnfs_put_lseg(hdr->lseg);
3093	nfs_pgio_header_free(hdr);
3094}
3095
3096int
3097pnfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc)
3098{
3099	struct nfs_pgio_header *hdr;
3100	int ret;
3101
3102	hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
3103	if (!hdr) {
3104		desc->pg_error = -ENOMEM;
3105		return desc->pg_error;
3106	}
3107	nfs_pgheader_init(desc, hdr, pnfs_readhdr_free);
3108	hdr->lseg = pnfs_get_lseg(desc->pg_lseg);
3109	ret = nfs_generic_pgio(desc, hdr);
3110	if (!ret)
3111		pnfs_do_read(desc, hdr);
3112	return ret;
3113}
3114EXPORT_SYMBOL_GPL(pnfs_generic_pg_readpages);
3115
3116static void pnfs_clear_layoutcommitting(struct inode *inode)
3117{
3118	unsigned long *bitlock = &NFS_I(inode)->flags;
3119
3120	clear_bit_unlock(NFS_INO_LAYOUTCOMMITTING, bitlock);
3121	smp_mb__after_atomic();
3122	wake_up_bit(bitlock, NFS_INO_LAYOUTCOMMITTING);
3123}
3124
3125/*
3126 * There can be multiple RW segments.
3127 */
3128static void pnfs_list_write_lseg(struct inode *inode, struct list_head *listp)
3129{
3130	struct pnfs_layout_segment *lseg;
3131
3132	list_for_each_entry(lseg, &NFS_I(inode)->layout->plh_segs, pls_list) {
3133		if (lseg->pls_range.iomode == IOMODE_RW &&
3134		    test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
3135			list_add(&lseg->pls_lc_list, listp);
3136	}
3137}
3138
3139static void pnfs_list_write_lseg_done(struct inode *inode, struct list_head *listp)
3140{
3141	struct pnfs_layout_segment *lseg, *tmp;
3142
3143	/* Matched by references in pnfs_set_layoutcommit */
3144	list_for_each_entry_safe(lseg, tmp, listp, pls_lc_list) {
3145		list_del_init(&lseg->pls_lc_list);
3146		pnfs_put_lseg(lseg);
3147	}
3148
3149	pnfs_clear_layoutcommitting(inode);
3150}
3151
3152void pnfs_set_lo_fail(struct pnfs_layout_segment *lseg)
3153{
3154	pnfs_layout_io_set_failed(lseg->pls_layout, lseg->pls_range.iomode);
3155}
3156EXPORT_SYMBOL_GPL(pnfs_set_lo_fail);
3157
3158void
3159pnfs_set_layoutcommit(struct inode *inode, struct pnfs_layout_segment *lseg,
3160		loff_t end_pos)
3161{
3162	struct nfs_inode *nfsi = NFS_I(inode);
3163	bool mark_as_dirty = false;
3164
3165	spin_lock(&inode->i_lock);
3166	if (!test_and_set_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags)) {
3167		nfsi->layout->plh_lwb = end_pos;
3168		mark_as_dirty = true;
3169		dprintk("%s: Set layoutcommit for inode %lu ",
3170			__func__, inode->i_ino);
3171	} else if (end_pos > nfsi->layout->plh_lwb)
3172		nfsi->layout->plh_lwb = end_pos;
3173	if (!test_and_set_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags)) {
3174		/* references matched in nfs4_layoutcommit_release */
3175		pnfs_get_lseg(lseg);
3176	}
3177	spin_unlock(&inode->i_lock);
3178	dprintk("%s: lseg %p end_pos %llu\n",
3179		__func__, lseg, nfsi->layout->plh_lwb);
3180
3181	/* if pnfs_layoutcommit_inode() runs between inode locks, the next one
3182	 * will be a noop because NFS_INO_LAYOUTCOMMIT will not be set */
3183	if (mark_as_dirty)
3184		mark_inode_dirty_sync(inode);
3185}
3186EXPORT_SYMBOL_GPL(pnfs_set_layoutcommit);
3187
3188void pnfs_cleanup_layoutcommit(struct nfs4_layoutcommit_data *data)
3189{
3190	struct nfs_server *nfss = NFS_SERVER(data->args.inode);
3191
3192	if (nfss->pnfs_curr_ld->cleanup_layoutcommit)
3193		nfss->pnfs_curr_ld->cleanup_layoutcommit(data);
3194	pnfs_list_write_lseg_done(data->args.inode, &data->lseg_list);
3195}
3196
3197/*
3198 * For the LAYOUT4_NFSV4_1_FILES layout type, NFS_DATA_SYNC WRITEs and
3199 * NFS_UNSTABLE WRITEs with a COMMIT to data servers must store enough
3200 * data to disk to allow the server to recover the data if it crashes.
3201 * LAYOUTCOMMIT is only needed when the NFL4_UFLG_COMMIT_THRU_MDS flag
3202 * is off, and a COMMIT is sent to a data server, or
3203 * if WRITEs to a data server return NFS_DATA_SYNC.
3204 */
3205int
3206pnfs_layoutcommit_inode(struct inode *inode, bool sync)
3207{
3208	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
3209	struct nfs4_layoutcommit_data *data;
3210	struct nfs_inode *nfsi = NFS_I(inode);
3211	loff_t end_pos;
3212	int status;
3213
3214	if (!pnfs_layoutcommit_outstanding(inode))
3215		return 0;
3216
3217	dprintk("--> %s inode %lu\n", __func__, inode->i_ino);
3218
3219	status = -EAGAIN;
3220	if (test_and_set_bit(NFS_INO_LAYOUTCOMMITTING, &nfsi->flags)) {
3221		if (!sync)
3222			goto out;
3223		status = wait_on_bit_lock_action(&nfsi->flags,
3224				NFS_INO_LAYOUTCOMMITTING,
3225				nfs_wait_bit_killable,
3226				TASK_KILLABLE|TASK_FREEZABLE_UNSAFE);
3227		if (status)
3228			goto out;
3229	}
3230
3231	status = -ENOMEM;
3232	/* Note kzalloc ensures data->res.seq_res.sr_slot == NULL */
3233	data = kzalloc(sizeof(*data), nfs_io_gfp_mask());
3234	if (!data)
3235		goto clear_layoutcommitting;
3236
3237	status = 0;
3238	spin_lock(&inode->i_lock);
3239	if (!test_and_clear_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags))
3240		goto out_unlock;
3241
3242	INIT_LIST_HEAD(&data->lseg_list);
3243	pnfs_list_write_lseg(inode, &data->lseg_list);
3244
3245	end_pos = nfsi->layout->plh_lwb;
3246
3247	nfs4_stateid_copy(&data->args.stateid, &nfsi->layout->plh_stateid);
3248	data->cred = get_cred(nfsi->layout->plh_lc_cred);
3249	spin_unlock(&inode->i_lock);
3250
3251	data->args.inode = inode;
3252	nfs_fattr_init(&data->fattr);
3253	data->args.bitmask = NFS_SERVER(inode)->cache_consistency_bitmask;
3254	data->res.fattr = &data->fattr;
3255	if (end_pos != 0)
3256		data->args.lastbytewritten = end_pos - 1;
3257	else
3258		data->args.lastbytewritten = U64_MAX;
3259	data->res.server = NFS_SERVER(inode);
3260
3261	if (ld->prepare_layoutcommit) {
3262		status = ld->prepare_layoutcommit(&data->args);
3263		if (status) {
3264			put_cred(data->cred);
3265			spin_lock(&inode->i_lock);
3266			set_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags);
3267			if (end_pos > nfsi->layout->plh_lwb)
3268				nfsi->layout->plh_lwb = end_pos;
3269			goto out_unlock;
3270		}
3271	}
3272
3273
3274	status = nfs4_proc_layoutcommit(data, sync);
3275out:
3276	if (status)
3277		mark_inode_dirty_sync(inode);
3278	dprintk("<-- %s status %d\n", __func__, status);
3279	return status;
3280out_unlock:
3281	spin_unlock(&inode->i_lock);
3282	kfree(data);
3283clear_layoutcommitting:
3284	pnfs_clear_layoutcommitting(inode);
3285	goto out;
3286}
3287EXPORT_SYMBOL_GPL(pnfs_layoutcommit_inode);
3288
3289int
3290pnfs_generic_sync(struct inode *inode, bool datasync)
3291{
3292	return pnfs_layoutcommit_inode(inode, true);
3293}
3294EXPORT_SYMBOL_GPL(pnfs_generic_sync);
3295
3296struct nfs4_threshold *pnfs_mdsthreshold_alloc(void)
3297{
3298	struct nfs4_threshold *thp;
3299
3300	thp = kzalloc(sizeof(*thp), nfs_io_gfp_mask());
3301	if (!thp) {
3302		dprintk("%s mdsthreshold allocation failed\n", __func__);
3303		return NULL;
3304	}
3305	return thp;
3306}
3307
3308#if IS_ENABLED(CONFIG_NFS_V4_2)
3309int
3310pnfs_report_layoutstat(struct inode *inode, gfp_t gfp_flags)
3311{
3312	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
3313	struct nfs_server *server = NFS_SERVER(inode);
3314	struct nfs_inode *nfsi = NFS_I(inode);
3315	struct nfs42_layoutstat_data *data;
3316	struct pnfs_layout_hdr *hdr;
3317	int status = 0;
3318
3319	if (!pnfs_enabled_sb(server) || !ld->prepare_layoutstats)
3320		goto out;
3321
3322	if (!nfs_server_capable(inode, NFS_CAP_LAYOUTSTATS))
3323		goto out;
3324
3325	if (test_and_set_bit(NFS_INO_LAYOUTSTATS, &nfsi->flags))
3326		goto out;
3327
3328	spin_lock(&inode->i_lock);
3329	if (!NFS_I(inode)->layout) {
3330		spin_unlock(&inode->i_lock);
3331		goto out_clear_layoutstats;
3332	}
3333	hdr = NFS_I(inode)->layout;
3334	pnfs_get_layout_hdr(hdr);
3335	spin_unlock(&inode->i_lock);
3336
3337	data = kzalloc(sizeof(*data), gfp_flags);
3338	if (!data) {
3339		status = -ENOMEM;
3340		goto out_put;
3341	}
3342
3343	data->args.fh = NFS_FH(inode);
3344	data->args.inode = inode;
3345	status = ld->prepare_layoutstats(&data->args);
3346	if (status)
3347		goto out_free;
3348
3349	status = nfs42_proc_layoutstats_generic(NFS_SERVER(inode), data);
3350
3351out:
3352	dprintk("%s returns %d\n", __func__, status);
3353	return status;
3354
3355out_free:
3356	kfree(data);
3357out_put:
3358	pnfs_put_layout_hdr(hdr);
3359out_clear_layoutstats:
3360	smp_mb__before_atomic();
3361	clear_bit(NFS_INO_LAYOUTSTATS, &nfsi->flags);
3362	smp_mb__after_atomic();
3363	goto out;
3364}
3365EXPORT_SYMBOL_GPL(pnfs_report_layoutstat);
3366#endif
3367
3368unsigned int layoutstats_timer;
3369module_param(layoutstats_timer, uint, 0644);
3370EXPORT_SYMBOL_GPL(layoutstats_timer);
v6.13.7
   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);
  64static int pnfs_layout_return_on_reboot(struct pnfs_layout_hdr *lo);
  65
  66/* Return the registered pnfs layout driver module matching given id */
  67static struct pnfs_layoutdriver_type *
  68find_pnfs_driver_locked(u32 id)
  69{
  70	struct pnfs_layoutdriver_type *local;
  71
  72	list_for_each_entry(local, &pnfs_modules_tbl, pnfs_tblid)
  73		if (local->id == id)
  74			goto out;
  75	local = NULL;
  76out:
  77	dprintk("%s: Searching for id %u, found %p\n", __func__, id, local);
  78	return local;
  79}
  80
  81static struct pnfs_layoutdriver_type *
  82find_pnfs_driver(u32 id)
  83{
  84	struct pnfs_layoutdriver_type *local;
  85
  86	spin_lock(&pnfs_spinlock);
  87	local = find_pnfs_driver_locked(id);
  88	if (local != NULL && !try_module_get(local->owner)) {
  89		dprintk("%s: Could not grab reference on module\n", __func__);
  90		local = NULL;
  91	}
  92	spin_unlock(&pnfs_spinlock);
  93	return local;
  94}
  95
  96const struct pnfs_layoutdriver_type *pnfs_find_layoutdriver(u32 id)
  97{
  98	return find_pnfs_driver(id);
  99}
 100
 101void pnfs_put_layoutdriver(const struct pnfs_layoutdriver_type *ld)
 102{
 103	if (ld)
 104		module_put(ld->owner);
 105}
 106
 107void
 108unset_pnfs_layoutdriver(struct nfs_server *nfss)
 109{
 110	if (nfss->pnfs_curr_ld) {
 111		if (nfss->pnfs_curr_ld->clear_layoutdriver)
 112			nfss->pnfs_curr_ld->clear_layoutdriver(nfss);
 113		/* Decrement the MDS count. Purge the deviceid cache if zero */
 114		if (atomic_dec_and_test(&nfss->nfs_client->cl_mds_count))
 115			nfs4_deviceid_purge_client(nfss->nfs_client);
 116		module_put(nfss->pnfs_curr_ld->owner);
 117	}
 118	nfss->pnfs_curr_ld = NULL;
 119}
 120
 121/*
 122 * When the server sends a list of layout types, we choose one in the order
 123 * given in the list below.
 124 *
 125 * FIXME: should this list be configurable in some fashion? module param?
 126 * 	  mount option? something else?
 127 */
 128static const u32 ld_prefs[] = {
 129	LAYOUT_SCSI,
 130	LAYOUT_BLOCK_VOLUME,
 131	LAYOUT_OSD2_OBJECTS,
 132	LAYOUT_FLEX_FILES,
 133	LAYOUT_NFSV4_1_FILES,
 134	0
 135};
 136
 137static int
 138ld_cmp(const void *e1, const void *e2)
 139{
 140	u32 ld1 = *((u32 *)e1);
 141	u32 ld2 = *((u32 *)e2);
 142	int i;
 143
 144	for (i = 0; ld_prefs[i] != 0; i++) {
 145		if (ld1 == ld_prefs[i])
 146			return -1;
 147
 148		if (ld2 == ld_prefs[i])
 149			return 1;
 150	}
 151	return 0;
 152}
 153
 154/*
 155 * Try to set the server's pnfs module to the pnfs layout type specified by id.
 156 * Currently only one pNFS layout driver per filesystem is supported.
 157 *
 158 * @ids array of layout types supported by MDS.
 159 */
 160void
 161set_pnfs_layoutdriver(struct nfs_server *server, const struct nfs_fh *mntfh,
 162		      struct nfs_fsinfo *fsinfo)
 163{
 164	struct pnfs_layoutdriver_type *ld_type = NULL;
 165	u32 id;
 166	int i;
 167
 168	if (fsinfo->nlayouttypes == 0)
 169		goto out_no_driver;
 170	if (!(server->nfs_client->cl_exchange_flags &
 171		 (EXCHGID4_FLAG_USE_NON_PNFS | EXCHGID4_FLAG_USE_PNFS_MDS))) {
 172		printk(KERN_ERR "NFS: %s: cl_exchange_flags 0x%x\n",
 173			__func__, server->nfs_client->cl_exchange_flags);
 174		goto out_no_driver;
 175	}
 176
 177	sort(fsinfo->layouttype, fsinfo->nlayouttypes,
 178		sizeof(*fsinfo->layouttype), ld_cmp, NULL);
 179
 180	for (i = 0; i < fsinfo->nlayouttypes; i++) {
 181		id = fsinfo->layouttype[i];
 182		ld_type = find_pnfs_driver(id);
 183		if (!ld_type) {
 184			request_module("%s-%u", LAYOUT_NFSV4_1_MODULE_PREFIX,
 185					id);
 186			ld_type = find_pnfs_driver(id);
 187		}
 188		if (ld_type)
 189			break;
 190	}
 191
 192	if (!ld_type) {
 193		dprintk("%s: No pNFS module found!\n", __func__);
 194		goto out_no_driver;
 195	}
 196
 197	server->pnfs_curr_ld = ld_type;
 198	if (ld_type->set_layoutdriver
 199	    && ld_type->set_layoutdriver(server, mntfh)) {
 200		printk(KERN_ERR "NFS: %s: Error initializing pNFS layout "
 201			"driver %u.\n", __func__, id);
 202		module_put(ld_type->owner);
 203		goto out_no_driver;
 204	}
 205	/* Bump the MDS count */
 206	atomic_inc(&server->nfs_client->cl_mds_count);
 207
 208	dprintk("%s: pNFS module for %u set\n", __func__, id);
 209	return;
 210
 211out_no_driver:
 212	dprintk("%s: Using NFSv4 I/O\n", __func__);
 213	server->pnfs_curr_ld = NULL;
 214}
 215
 216int
 217pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
 218{
 219	int status = -EINVAL;
 220	struct pnfs_layoutdriver_type *tmp;
 221
 222	if (ld_type->id == 0) {
 223		printk(KERN_ERR "NFS: %s id 0 is reserved\n", __func__);
 224		return status;
 225	}
 226	if (!ld_type->alloc_lseg || !ld_type->free_lseg) {
 227		printk(KERN_ERR "NFS: %s Layout driver must provide "
 228		       "alloc_lseg and free_lseg.\n", __func__);
 229		return status;
 230	}
 231
 232	spin_lock(&pnfs_spinlock);
 233	tmp = find_pnfs_driver_locked(ld_type->id);
 234	if (!tmp) {
 235		list_add(&ld_type->pnfs_tblid, &pnfs_modules_tbl);
 236		status = 0;
 237		dprintk("%s Registering id:%u name:%s\n", __func__, ld_type->id,
 238			ld_type->name);
 239	} else {
 240		printk(KERN_ERR "NFS: %s Module with id %d already loaded!\n",
 241			__func__, ld_type->id);
 242	}
 243	spin_unlock(&pnfs_spinlock);
 244
 245	return status;
 246}
 247EXPORT_SYMBOL_GPL(pnfs_register_layoutdriver);
 248
 249void
 250pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *ld_type)
 251{
 252	dprintk("%s Deregistering id:%u\n", __func__, ld_type->id);
 253	spin_lock(&pnfs_spinlock);
 254	list_del(&ld_type->pnfs_tblid);
 255	spin_unlock(&pnfs_spinlock);
 256}
 257EXPORT_SYMBOL_GPL(pnfs_unregister_layoutdriver);
 258
 259/*
 260 * pNFS client layout cache
 261 */
 262
 263/* Need to hold i_lock if caller does not already hold reference */
 264void
 265pnfs_get_layout_hdr(struct pnfs_layout_hdr *lo)
 266{
 267	refcount_inc(&lo->plh_refcount);
 268}
 269
 270static struct pnfs_layout_hdr *
 271pnfs_alloc_layout_hdr(struct inode *ino, gfp_t gfp_flags)
 272{
 273	struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
 274	return ld->alloc_layout_hdr(ino, gfp_flags);
 275}
 276
 277static void
 278pnfs_free_layout_hdr(struct pnfs_layout_hdr *lo)
 279{
 280	struct nfs_server *server = NFS_SERVER(lo->plh_inode);
 281	struct pnfs_layoutdriver_type *ld = server->pnfs_curr_ld;
 282
 283	if (test_and_clear_bit(NFS_LAYOUT_HASHED, &lo->plh_flags)) {
 284		struct nfs_client *clp = server->nfs_client;
 285
 286		spin_lock(&clp->cl_lock);
 287		list_del_rcu(&lo->plh_layouts);
 288		spin_unlock(&clp->cl_lock);
 289	}
 290	put_cred(lo->plh_lc_cred);
 291	return ld->free_layout_hdr(lo);
 292}
 293
 294static void
 295pnfs_detach_layout_hdr(struct pnfs_layout_hdr *lo)
 296{
 297	struct nfs_inode *nfsi = NFS_I(lo->plh_inode);
 298	dprintk("%s: freeing layout cache %p\n", __func__, lo);
 299	nfsi->layout = NULL;
 300	/* Reset MDS Threshold I/O counters */
 301	nfsi->write_io = 0;
 302	nfsi->read_io = 0;
 303}
 304
 305void
 306pnfs_put_layout_hdr(struct pnfs_layout_hdr *lo)
 307{
 308	struct inode *inode;
 309	unsigned long i_state;
 310
 311	if (!lo)
 312		return;
 313	inode = lo->plh_inode;
 314	pnfs_layoutreturn_before_put_layout_hdr(lo);
 315
 316	if (refcount_dec_and_lock(&lo->plh_refcount, &inode->i_lock)) {
 317		if (!list_empty(&lo->plh_segs))
 318			WARN_ONCE(1, "NFS: BUG unfreed layout segments.\n");
 319		pnfs_detach_layout_hdr(lo);
 320		i_state = inode->i_state;
 321		spin_unlock(&inode->i_lock);
 322		pnfs_free_layout_hdr(lo);
 323		/* Notify pnfs_destroy_layout_final() that we're done */
 324		if (i_state & (I_FREEING | I_CLEAR))
 325			wake_up_var(lo);
 326	}
 327}
 328
 329static struct inode *
 330pnfs_grab_inode_layout_hdr(struct pnfs_layout_hdr *lo)
 331{
 332	struct inode *inode = igrab(lo->plh_inode);
 333	if (inode)
 334		return inode;
 335	set_bit(NFS_LAYOUT_INODE_FREEING, &lo->plh_flags);
 336	return NULL;
 337}
 338
 339/*
 340 * Compare 2 layout stateid sequence ids, to see which is newer,
 341 * taking into account wraparound issues.
 342 */
 343static bool pnfs_seqid_is_newer(u32 s1, u32 s2)
 344{
 345	return (s32)(s1 - s2) > 0;
 346}
 347
 348static void pnfs_barrier_update(struct pnfs_layout_hdr *lo, u32 newseq)
 349{
 350	if (pnfs_seqid_is_newer(newseq, lo->plh_barrier) || !lo->plh_barrier)
 351		lo->plh_barrier = newseq;
 352}
 353
 354static void
 355pnfs_set_plh_return_info(struct pnfs_layout_hdr *lo, enum pnfs_iomode iomode,
 356			 u32 seq)
 357{
 358	if (lo->plh_return_iomode != 0 && lo->plh_return_iomode != iomode)
 359		iomode = IOMODE_ANY;
 360	lo->plh_return_iomode = iomode;
 361	set_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags);
 362	/*
 363	 * We must set lo->plh_return_seq to avoid livelocks with
 364	 * pnfs_layout_need_return()
 365	 */
 366	if (seq == 0)
 367		seq = be32_to_cpu(lo->plh_stateid.seqid);
 368	if (!lo->plh_return_seq || pnfs_seqid_is_newer(seq, lo->plh_return_seq))
 369		lo->plh_return_seq = seq;
 370	pnfs_barrier_update(lo, seq);
 371}
 372
 373static void
 374pnfs_clear_layoutreturn_info(struct pnfs_layout_hdr *lo)
 375{
 376	struct pnfs_layout_segment *lseg;
 377	lo->plh_return_iomode = 0;
 378	lo->plh_return_seq = 0;
 379	clear_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags);
 380	list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
 381		if (!test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
 382			continue;
 383		pnfs_set_plh_return_info(lo, lseg->pls_range.iomode, 0);
 384	}
 385}
 386
 387static void pnfs_clear_layoutreturn_waitbit(struct pnfs_layout_hdr *lo)
 388{
 389	clear_bit_unlock(NFS_LAYOUT_RETURN, &lo->plh_flags);
 390	clear_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags);
 391	smp_mb__after_atomic();
 392	wake_up_bit(&lo->plh_flags, NFS_LAYOUT_RETURN);
 393	rpc_wake_up(&NFS_SERVER(lo->plh_inode)->roc_rpcwaitq);
 394}
 395
 396static void
 397pnfs_clear_lseg_state(struct pnfs_layout_segment *lseg,
 398		struct list_head *free_me)
 399{
 400	clear_bit(NFS_LSEG_ROC, &lseg->pls_flags);
 401	clear_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
 402	if (test_and_clear_bit(NFS_LSEG_VALID, &lseg->pls_flags))
 403		pnfs_lseg_dec_and_remove_zero(lseg, free_me);
 404	if (test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
 405		pnfs_lseg_dec_and_remove_zero(lseg, free_me);
 406}
 407
 408/*
 409 * Update the seqid of a layout stateid after receiving
 410 * NFS4ERR_OLD_STATEID
 411 */
 412bool nfs4_layout_refresh_old_stateid(nfs4_stateid *dst,
 413		struct pnfs_layout_range *dst_range,
 414		struct inode *inode)
 415{
 416	struct pnfs_layout_hdr *lo;
 417	struct pnfs_layout_range range = {
 418		.iomode = IOMODE_ANY,
 419		.offset = 0,
 420		.length = NFS4_MAX_UINT64,
 421	};
 422	bool ret = false;
 423	LIST_HEAD(head);
 424	int err;
 425
 426	spin_lock(&inode->i_lock);
 427	lo = NFS_I(inode)->layout;
 428	if (lo &&  pnfs_layout_is_valid(lo) &&
 429	    nfs4_stateid_match_other(dst, &lo->plh_stateid)) {
 430		/* Is our call using the most recent seqid? If so, bump it */
 431		if (!nfs4_stateid_is_newer(&lo->plh_stateid, dst)) {
 432			nfs4_stateid_seqid_inc(dst);
 433			ret = true;
 434			goto out;
 435		}
 436		/* Try to update the seqid to the most recent */
 437		err = pnfs_mark_matching_lsegs_return(lo, &head, &range, 0);
 438		if (err != -EBUSY) {
 439			dst->seqid = lo->plh_stateid.seqid;
 440			*dst_range = range;
 441			ret = true;
 442		}
 443	}
 444out:
 445	spin_unlock(&inode->i_lock);
 446	pnfs_free_lseg_list(&head);
 447	return ret;
 448}
 449
 450/*
 451 * Mark a pnfs_layout_hdr and all associated layout segments as invalid
 452 *
 453 * In order to continue using the pnfs_layout_hdr, a full recovery
 454 * is required.
 455 * Note that caller must hold inode->i_lock.
 456 */
 457int
 458pnfs_mark_layout_stateid_invalid(struct pnfs_layout_hdr *lo,
 459		struct list_head *lseg_list)
 460{
 461	struct pnfs_layout_range range = {
 462		.iomode = IOMODE_ANY,
 463		.offset = 0,
 464		.length = NFS4_MAX_UINT64,
 465	};
 466	struct pnfs_layout_segment *lseg, *next;
 467
 468	set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
 469	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
 470		pnfs_clear_lseg_state(lseg, lseg_list);
 471	pnfs_clear_layoutreturn_info(lo);
 472	pnfs_free_returned_lsegs(lo, lseg_list, &range, 0);
 473	set_bit(NFS_LAYOUT_DRAIN, &lo->plh_flags);
 474	if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags) &&
 475	    !test_and_set_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags))
 476		pnfs_clear_layoutreturn_waitbit(lo);
 477	return !list_empty(&lo->plh_segs);
 478}
 479
 480static int pnfs_mark_layout_stateid_return(struct pnfs_layout_hdr *lo,
 481					   struct list_head *lseg_list,
 482					   enum pnfs_iomode iomode, u32 seq)
 483{
 484	struct pnfs_layout_range range = {
 485		.iomode = iomode,
 486		.length = NFS4_MAX_UINT64,
 487	};
 488
 489	return pnfs_mark_matching_lsegs_return(lo, lseg_list, &range, seq);
 490}
 491
 492static int
 493pnfs_iomode_to_fail_bit(u32 iomode)
 494{
 495	return iomode == IOMODE_RW ?
 496		NFS_LAYOUT_RW_FAILED : NFS_LAYOUT_RO_FAILED;
 497}
 498
 499static void
 500pnfs_layout_set_fail_bit(struct pnfs_layout_hdr *lo, int fail_bit)
 501{
 502	lo->plh_retry_timestamp = jiffies;
 503	if (!test_and_set_bit(fail_bit, &lo->plh_flags))
 504		refcount_inc(&lo->plh_refcount);
 505}
 506
 507static void
 508pnfs_layout_clear_fail_bit(struct pnfs_layout_hdr *lo, int fail_bit)
 509{
 510	if (test_and_clear_bit(fail_bit, &lo->plh_flags))
 511		refcount_dec(&lo->plh_refcount);
 512}
 513
 514static void
 515pnfs_layout_io_set_failed(struct pnfs_layout_hdr *lo, u32 iomode)
 516{
 517	struct inode *inode = lo->plh_inode;
 518	struct pnfs_layout_range range = {
 519		.iomode = iomode,
 520		.offset = 0,
 521		.length = NFS4_MAX_UINT64,
 522	};
 523	LIST_HEAD(head);
 524
 525	spin_lock(&inode->i_lock);
 526	pnfs_layout_set_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
 527	pnfs_mark_matching_lsegs_return(lo, &head, &range, 0);
 528	spin_unlock(&inode->i_lock);
 529	pnfs_free_lseg_list(&head);
 530	dprintk("%s Setting layout IOMODE_%s fail bit\n", __func__,
 531			iomode == IOMODE_RW ?  "RW" : "READ");
 532}
 533
 534static bool
 535pnfs_layout_io_test_failed(struct pnfs_layout_hdr *lo, u32 iomode)
 536{
 537	unsigned long start, end;
 538	int fail_bit = pnfs_iomode_to_fail_bit(iomode);
 539
 540	if (test_bit(fail_bit, &lo->plh_flags) == 0)
 541		return false;
 542	end = jiffies;
 543	start = end - PNFS_LAYOUTGET_RETRY_TIMEOUT;
 544	if (!time_in_range(lo->plh_retry_timestamp, start, end)) {
 545		/* It is time to retry the failed layoutgets */
 546		pnfs_layout_clear_fail_bit(lo, fail_bit);
 547		return false;
 548	}
 549	return true;
 550}
 551
 552static void
 553pnfs_init_lseg(struct pnfs_layout_hdr *lo, struct pnfs_layout_segment *lseg,
 554		const struct pnfs_layout_range *range,
 555		const nfs4_stateid *stateid)
 556{
 557	INIT_LIST_HEAD(&lseg->pls_list);
 558	INIT_LIST_HEAD(&lseg->pls_lc_list);
 559	INIT_LIST_HEAD(&lseg->pls_commits);
 560	refcount_set(&lseg->pls_refcount, 1);
 561	set_bit(NFS_LSEG_VALID, &lseg->pls_flags);
 562	lseg->pls_layout = lo;
 563	lseg->pls_range = *range;
 564	lseg->pls_seq = be32_to_cpu(stateid->seqid);
 565}
 566
 567static void pnfs_free_lseg(struct pnfs_layout_segment *lseg)
 568{
 569	if (lseg != NULL) {
 570		struct inode *inode = lseg->pls_layout->plh_inode;
 571		NFS_SERVER(inode)->pnfs_curr_ld->free_lseg(lseg);
 572	}
 573}
 574
 575static void
 576pnfs_layout_remove_lseg(struct pnfs_layout_hdr *lo,
 577		struct pnfs_layout_segment *lseg)
 578{
 579	WARN_ON(test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
 580	list_del_init(&lseg->pls_list);
 581	/* Matched by pnfs_get_layout_hdr in pnfs_layout_insert_lseg */
 582	refcount_dec(&lo->plh_refcount);
 583	if (test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
 584		return;
 585	if (list_empty(&lo->plh_segs) &&
 586	    !test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags) &&
 587	    !test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
 588		if (atomic_read(&lo->plh_outstanding) == 0)
 589			set_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
 590		clear_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
 591	}
 592}
 593
 594static bool
 595pnfs_cache_lseg_for_layoutreturn(struct pnfs_layout_hdr *lo,
 596		struct pnfs_layout_segment *lseg)
 597{
 598	if (test_and_clear_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags) &&
 599	    pnfs_layout_is_valid(lo)) {
 600		pnfs_set_plh_return_info(lo, lseg->pls_range.iomode, 0);
 601		list_move_tail(&lseg->pls_list, &lo->plh_return_segs);
 602		return true;
 603	}
 604	return false;
 605}
 606
 607void
 608pnfs_put_lseg(struct pnfs_layout_segment *lseg)
 609{
 610	struct pnfs_layout_hdr *lo;
 611	struct inode *inode;
 612
 613	if (!lseg)
 614		return;
 615
 616	dprintk("%s: lseg %p ref %d valid %d\n", __func__, lseg,
 617		refcount_read(&lseg->pls_refcount),
 618		test_bit(NFS_LSEG_VALID, &lseg->pls_flags));
 619
 620	lo = lseg->pls_layout;
 621	inode = lo->plh_inode;
 622
 623	if (refcount_dec_and_lock(&lseg->pls_refcount, &inode->i_lock)) {
 624		pnfs_get_layout_hdr(lo);
 625		pnfs_layout_remove_lseg(lo, lseg);
 626		if (pnfs_cache_lseg_for_layoutreturn(lo, lseg))
 627			lseg = NULL;
 628		spin_unlock(&inode->i_lock);
 629		pnfs_free_lseg(lseg);
 630		pnfs_put_layout_hdr(lo);
 631	}
 632}
 633EXPORT_SYMBOL_GPL(pnfs_put_lseg);
 634
 635/*
 636 * is l2 fully contained in l1?
 637 *   start1                             end1
 638 *   [----------------------------------)
 639 *           start2           end2
 640 *           [----------------)
 641 */
 642static bool
 643pnfs_lseg_range_contained(const struct pnfs_layout_range *l1,
 644		 const struct pnfs_layout_range *l2)
 645{
 646	u64 start1 = l1->offset;
 647	u64 end1 = pnfs_end_offset(start1, l1->length);
 648	u64 start2 = l2->offset;
 649	u64 end2 = pnfs_end_offset(start2, l2->length);
 650
 651	return (start1 <= start2) && (end1 >= end2);
 652}
 653
 654static bool pnfs_lseg_dec_and_remove_zero(struct pnfs_layout_segment *lseg,
 655		struct list_head *tmp_list)
 656{
 657	if (!refcount_dec_and_test(&lseg->pls_refcount))
 658		return false;
 659	pnfs_layout_remove_lseg(lseg->pls_layout, lseg);
 660	list_add(&lseg->pls_list, tmp_list);
 661	return true;
 662}
 663
 664/* Returns 1 if lseg is removed from list, 0 otherwise */
 665static int mark_lseg_invalid(struct pnfs_layout_segment *lseg,
 666			     struct list_head *tmp_list)
 667{
 668	int rv = 0;
 669
 670	if (test_and_clear_bit(NFS_LSEG_VALID, &lseg->pls_flags)) {
 671		/* Remove the reference keeping the lseg in the
 672		 * list.  It will now be removed when all
 673		 * outstanding io is finished.
 674		 */
 675		dprintk("%s: lseg %p ref %d\n", __func__, lseg,
 676			refcount_read(&lseg->pls_refcount));
 677		if (pnfs_lseg_dec_and_remove_zero(lseg, tmp_list))
 678			rv = 1;
 679	}
 680	return rv;
 681}
 682
 683static bool
 684pnfs_should_free_range(const struct pnfs_layout_range *lseg_range,
 685		 const struct pnfs_layout_range *recall_range)
 686{
 687	return (recall_range->iomode == IOMODE_ANY ||
 688		lseg_range->iomode == recall_range->iomode) &&
 689	       pnfs_lseg_range_intersecting(lseg_range, recall_range);
 690}
 691
 692static bool
 693pnfs_match_lseg_recall(const struct pnfs_layout_segment *lseg,
 694		const struct pnfs_layout_range *recall_range,
 695		u32 seq)
 696{
 697	if (seq != 0 && pnfs_seqid_is_newer(lseg->pls_seq, seq))
 698		return false;
 699	if (recall_range == NULL)
 700		return true;
 701	return pnfs_should_free_range(&lseg->pls_range, recall_range);
 702}
 703
 704/**
 705 * pnfs_mark_matching_lsegs_invalid - tear down lsegs or mark them for later
 706 * @lo: layout header containing the lsegs
 707 * @tmp_list: list head where doomed lsegs should go
 708 * @recall_range: optional recall range argument to match (may be NULL)
 709 * @seq: only invalidate lsegs obtained prior to this sequence (may be 0)
 710 *
 711 * Walk the list of lsegs in the layout header, and tear down any that should
 712 * be destroyed. If "recall_range" is specified then the segment must match
 713 * that range. If "seq" is non-zero, then only match segments that were handed
 714 * out at or before that sequence.
 715 *
 716 * Returns number of matching invalid lsegs remaining in list after scanning
 717 * it and purging them.
 718 */
 719int
 720pnfs_mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo,
 721			    struct list_head *tmp_list,
 722			    const struct pnfs_layout_range *recall_range,
 723			    u32 seq)
 724{
 725	struct pnfs_layout_segment *lseg, *next;
 726	struct nfs_server *server = NFS_SERVER(lo->plh_inode);
 727	int remaining = 0;
 728
 729	dprintk("%s:Begin lo %p\n", __func__, lo);
 730
 731	if (list_empty(&lo->plh_segs))
 732		return 0;
 733	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
 734		if (pnfs_match_lseg_recall(lseg, recall_range, seq)) {
 735			dprintk("%s: freeing lseg %p iomode %d seq %u "
 736				"offset %llu length %llu\n", __func__,
 737				lseg, lseg->pls_range.iomode, lseg->pls_seq,
 738				lseg->pls_range.offset, lseg->pls_range.length);
 739			if (mark_lseg_invalid(lseg, tmp_list))
 740				continue;
 741			remaining++;
 742			pnfs_lseg_cancel_io(server, lseg);
 743		}
 744	dprintk("%s:Return %i\n", __func__, remaining);
 745	return remaining;
 746}
 747
 748static void
 749pnfs_free_returned_lsegs(struct pnfs_layout_hdr *lo,
 750		struct list_head *free_me,
 751		const struct pnfs_layout_range *range,
 752		u32 seq)
 753{
 754	struct pnfs_layout_segment *lseg, *next;
 755
 756	list_for_each_entry_safe(lseg, next, &lo->plh_return_segs, pls_list) {
 757		if (pnfs_match_lseg_recall(lseg, range, seq))
 758			list_move_tail(&lseg->pls_list, free_me);
 759	}
 760}
 761
 762/* note free_me must contain lsegs from a single layout_hdr */
 763void
 764pnfs_free_lseg_list(struct list_head *free_me)
 765{
 766	struct pnfs_layout_segment *lseg, *tmp;
 767
 768	if (list_empty(free_me))
 769		return;
 770
 771	list_for_each_entry_safe(lseg, tmp, free_me, pls_list) {
 772		list_del(&lseg->pls_list);
 773		pnfs_free_lseg(lseg);
 774	}
 775}
 776
 777static struct pnfs_layout_hdr *__pnfs_destroy_layout(struct nfs_inode *nfsi)
 778{
 779	struct pnfs_layout_hdr *lo;
 780	LIST_HEAD(tmp_list);
 781
 782	spin_lock(&nfsi->vfs_inode.i_lock);
 783	lo = nfsi->layout;
 784	if (lo) {
 785		pnfs_get_layout_hdr(lo);
 786		pnfs_mark_layout_stateid_invalid(lo, &tmp_list);
 787		pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RO_FAILED);
 788		pnfs_layout_clear_fail_bit(lo, NFS_LAYOUT_RW_FAILED);
 789		spin_unlock(&nfsi->vfs_inode.i_lock);
 790		pnfs_free_lseg_list(&tmp_list);
 791		nfs_commit_inode(&nfsi->vfs_inode, 0);
 792		pnfs_put_layout_hdr(lo);
 793	} else
 794		spin_unlock(&nfsi->vfs_inode.i_lock);
 795	return lo;
 796}
 797
 798void pnfs_destroy_layout(struct nfs_inode *nfsi)
 799{
 800	__pnfs_destroy_layout(nfsi);
 801}
 802EXPORT_SYMBOL_GPL(pnfs_destroy_layout);
 803
 804static bool pnfs_layout_removed(struct nfs_inode *nfsi,
 805				struct pnfs_layout_hdr *lo)
 806{
 807	bool ret;
 808
 809	spin_lock(&nfsi->vfs_inode.i_lock);
 810	ret = nfsi->layout != lo;
 811	spin_unlock(&nfsi->vfs_inode.i_lock);
 812	return ret;
 813}
 814
 815void pnfs_destroy_layout_final(struct nfs_inode *nfsi)
 816{
 817	struct pnfs_layout_hdr *lo = __pnfs_destroy_layout(nfsi);
 818
 819	if (lo)
 820		wait_var_event(lo, pnfs_layout_removed(nfsi, lo));
 821}
 822
 823static bool
 824pnfs_layout_add_bulk_destroy_list(struct inode *inode,
 825		struct list_head *layout_list)
 826{
 827	struct pnfs_layout_hdr *lo;
 828	bool ret = false;
 829
 830	spin_lock(&inode->i_lock);
 831	lo = NFS_I(inode)->layout;
 832	if (lo != NULL && list_empty(&lo->plh_bulk_destroy)) {
 833		pnfs_get_layout_hdr(lo);
 834		list_add(&lo->plh_bulk_destroy, layout_list);
 835		ret = true;
 836	}
 837	spin_unlock(&inode->i_lock);
 838	return ret;
 839}
 840
 841/* Caller must hold rcu_read_lock and clp->cl_lock */
 842static int
 843pnfs_layout_bulk_destroy_byserver_locked(struct nfs_client *clp,
 844		struct nfs_server *server,
 845		struct list_head *layout_list)
 846	__must_hold(&clp->cl_lock)
 847	__must_hold(RCU)
 848{
 849	struct pnfs_layout_hdr *lo, *next;
 850	struct inode *inode;
 851
 852	list_for_each_entry_safe(lo, next, &server->layouts, plh_layouts) {
 853		if (test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags) ||
 854		    test_bit(NFS_LAYOUT_INODE_FREEING, &lo->plh_flags) ||
 855		    !list_empty(&lo->plh_bulk_destroy))
 856			continue;
 857		/* If the sb is being destroyed, just bail */
 858		if (!nfs_sb_active(server->super))
 859			break;
 860		inode = pnfs_grab_inode_layout_hdr(lo);
 861		if (inode != NULL) {
 
 
 862			if (pnfs_layout_add_bulk_destroy_list(inode,
 863						layout_list))
 864				continue;
 865			rcu_read_unlock();
 866			spin_unlock(&clp->cl_lock);
 867			iput(inode);
 868		} else {
 869			rcu_read_unlock();
 870			spin_unlock(&clp->cl_lock);
 871		}
 872		nfs_sb_deactive(server->super);
 873		spin_lock(&clp->cl_lock);
 874		rcu_read_lock();
 875		return -EAGAIN;
 876	}
 877	return 0;
 878}
 879
 880static int
 881pnfs_layout_free_bulk_destroy_list(struct list_head *layout_list,
 882				   enum pnfs_layout_destroy_mode mode)
 883{
 884	struct pnfs_layout_hdr *lo;
 885	struct inode *inode;
 886	LIST_HEAD(lseg_list);
 887	int ret = 0;
 888
 889	while (!list_empty(layout_list)) {
 890		lo = list_entry(layout_list->next, struct pnfs_layout_hdr,
 891				plh_bulk_destroy);
 892		dprintk("%s freeing layout for inode %lu\n", __func__,
 893			lo->plh_inode->i_ino);
 894		inode = lo->plh_inode;
 895
 896		pnfs_layoutcommit_inode(inode, false);
 897
 898		spin_lock(&inode->i_lock);
 899		list_del_init(&lo->plh_bulk_destroy);
 900		if (mode == PNFS_LAYOUT_FILE_BULK_RETURN) {
 901			pnfs_mark_layout_stateid_return(lo, &lseg_list,
 902							IOMODE_ANY, 0);
 903		} else if (pnfs_mark_layout_stateid_invalid(lo, &lseg_list)) {
 904			if (mode == PNFS_LAYOUT_BULK_RETURN)
 905				set_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
 906			ret = -EAGAIN;
 907		}
 908		spin_unlock(&inode->i_lock);
 909		pnfs_free_lseg_list(&lseg_list);
 910		/* Free all lsegs that are attached to commit buckets */
 911		nfs_commit_inode(inode, 0);
 912		pnfs_put_layout_hdr(lo);
 913		nfs_iput_and_deactive(inode);
 914	}
 915	return ret;
 916}
 917
 918int pnfs_layout_destroy_byfsid(struct nfs_client *clp, struct nfs_fsid *fsid,
 919			       enum pnfs_layout_destroy_mode mode)
 
 
 920{
 921	struct nfs_server *server;
 922	LIST_HEAD(layout_list);
 923
 924	spin_lock(&clp->cl_lock);
 925	rcu_read_lock();
 926restart:
 927	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 928		if (memcmp(&server->fsid, fsid, sizeof(*fsid)) != 0)
 929			continue;
 930		if (pnfs_layout_bulk_destroy_byserver_locked(clp,
 931				server,
 932				&layout_list) != 0)
 933			goto restart;
 934	}
 935	rcu_read_unlock();
 936	spin_unlock(&clp->cl_lock);
 937
 938	return pnfs_layout_free_bulk_destroy_list(&layout_list, mode);
 
 
 939}
 940
 941static void pnfs_layout_build_destroy_list_byclient(struct nfs_client *clp,
 942						    struct list_head *list)
 
 943{
 944	struct nfs_server *server;
 
 945
 946	spin_lock(&clp->cl_lock);
 947	rcu_read_lock();
 948restart:
 949	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 950		if (pnfs_layout_bulk_destroy_byserver_locked(clp, server,
 951							     list) != 0)
 
 952			goto restart;
 953	}
 954	rcu_read_unlock();
 955	spin_unlock(&clp->cl_lock);
 956}
 957
 958static int pnfs_layout_do_destroy_byclid(struct nfs_client *clp,
 959					 struct list_head *list,
 960					 enum pnfs_layout_destroy_mode mode)
 961{
 962	pnfs_layout_build_destroy_list_byclient(clp, list);
 963	return pnfs_layout_free_bulk_destroy_list(list, mode);
 964}
 965
 966int pnfs_layout_destroy_byclid(struct nfs_client *clp,
 967			       enum pnfs_layout_destroy_mode mode)
 968{
 969	LIST_HEAD(layout_list);
 970
 971	return pnfs_layout_do_destroy_byclid(clp, &layout_list, mode);
 972}
 973
 974/*
 975 * Called by the state manager to remove all layouts established under an
 976 * expired lease.
 977 */
 978void
 979pnfs_destroy_all_layouts(struct nfs_client *clp)
 980{
 981	nfs4_deviceid_mark_client_invalid(clp);
 982	nfs4_deviceid_purge_client(clp);
 983
 984	pnfs_layout_destroy_byclid(clp, PNFS_LAYOUT_INVALIDATE);
 985}
 986
 987static void pnfs_layout_build_recover_list_byclient(struct nfs_client *clp,
 988						    struct list_head *list)
 989{
 990	struct nfs_server *server;
 991
 992	spin_lock(&clp->cl_lock);
 993	rcu_read_lock();
 994restart:
 995	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
 996		if (!(server->caps & NFS_CAP_REBOOT_LAYOUTRETURN))
 997			continue;
 998		if (pnfs_layout_bulk_destroy_byserver_locked(clp, server,
 999							     list) != 0)
1000			goto restart;
1001	}
1002	rcu_read_unlock();
1003	spin_unlock(&clp->cl_lock);
1004}
1005
1006static int pnfs_layout_bulk_list_reboot(struct list_head *list)
1007{
1008	struct pnfs_layout_hdr *lo;
1009	struct nfs_server *server;
1010	int ret;
1011
1012	list_for_each_entry(lo, list, plh_bulk_destroy) {
1013		server = NFS_SERVER(lo->plh_inode);
1014		ret = pnfs_layout_return_on_reboot(lo);
1015		switch (ret) {
1016		case 0:
1017			continue;
1018		case -NFS4ERR_BAD_STATEID:
1019			server->caps &= ~NFS_CAP_REBOOT_LAYOUTRETURN;
1020			break;
1021		case -NFS4ERR_NO_GRACE:
1022			break;
1023		default:
1024			goto err;
1025		}
1026		break;
1027	}
1028	return 0;
1029err:
1030	return ret;
1031}
1032
1033int pnfs_layout_handle_reboot(struct nfs_client *clp)
1034{
1035	LIST_HEAD(list);
1036	int ret = 0, ret2;
1037
1038	pnfs_layout_build_recover_list_byclient(clp, &list);
1039	if (!list_empty(&list))
1040		ret = pnfs_layout_bulk_list_reboot(&list);
1041	ret2 = pnfs_layout_do_destroy_byclid(clp, &list,
1042					     PNFS_LAYOUT_INVALIDATE);
1043	if (!ret)
1044		ret = ret2;
1045	return (ret == 0) ?  0 : -EAGAIN;
1046}
1047
1048static void
1049pnfs_set_layout_cred(struct pnfs_layout_hdr *lo, const struct cred *cred)
1050{
1051	const struct cred *old;
1052
1053	if (cred && cred_fscmp(lo->plh_lc_cred, cred) != 0) {
1054		old = xchg(&lo->plh_lc_cred, get_cred(cred));
1055		put_cred(old);
1056	}
1057}
1058
1059/* update lo->plh_stateid with new if is more recent */
1060void
1061pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo, const nfs4_stateid *new,
1062			const struct cred *cred, bool update_barrier)
1063{
1064	u32 oldseq = be32_to_cpu(lo->plh_stateid.seqid);
1065	u32 newseq = be32_to_cpu(new->seqid);
1066
1067	if (!pnfs_layout_is_valid(lo)) {
1068		pnfs_set_layout_cred(lo, cred);
1069		nfs4_stateid_copy(&lo->plh_stateid, new);
1070		lo->plh_barrier = newseq;
1071		pnfs_clear_layoutreturn_info(lo);
1072		clear_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags);
1073		return;
1074	}
1075
1076	if (pnfs_seqid_is_newer(newseq, oldseq))
1077		nfs4_stateid_copy(&lo->plh_stateid, new);
1078
1079	if (update_barrier) {
1080		pnfs_barrier_update(lo, newseq);
1081		return;
1082	}
1083	/*
1084	 * Because of wraparound, we want to keep the barrier
1085	 * "close" to the current seqids. We really only want to
1086	 * get here from a layoutget call.
1087	 */
1088	if (atomic_read(&lo->plh_outstanding) == 1)
1089		 pnfs_barrier_update(lo, be32_to_cpu(lo->plh_stateid.seqid));
1090}
1091
1092static bool
1093pnfs_layout_stateid_blocked(const struct pnfs_layout_hdr *lo,
1094		const nfs4_stateid *stateid)
1095{
1096	u32 seqid = be32_to_cpu(stateid->seqid);
1097
1098	return lo->plh_barrier && pnfs_seqid_is_newer(lo->plh_barrier, seqid);
1099}
1100
1101/* lget is set to 1 if called from inside send_layoutget call chain */
1102static bool
1103pnfs_layoutgets_blocked(const struct pnfs_layout_hdr *lo)
1104{
1105	return lo->plh_block_lgets ||
1106		test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
1107}
1108
1109static struct nfs_server *
1110pnfs_find_server(struct inode *inode, struct nfs_open_context *ctx)
1111{
1112	struct nfs_server *server;
1113
1114	if (inode) {
1115		server = NFS_SERVER(inode);
1116	} else {
1117		struct dentry *parent_dir = dget_parent(ctx->dentry);
1118		server = NFS_SERVER(parent_dir->d_inode);
1119		dput(parent_dir);
1120	}
1121	return server;
1122}
1123
1124static void nfs4_free_pages(struct page **pages, size_t size)
1125{
1126	int i;
1127
1128	if (!pages)
1129		return;
1130
1131	for (i = 0; i < size; i++) {
1132		if (!pages[i])
1133			break;
1134		__free_page(pages[i]);
1135	}
1136	kfree(pages);
1137}
1138
1139static struct page **nfs4_alloc_pages(size_t size, gfp_t gfp_flags)
1140{
1141	struct page **pages;
1142	int i;
1143
1144	pages = kmalloc_array(size, sizeof(struct page *), gfp_flags);
1145	if (!pages) {
1146		dprintk("%s: can't alloc array of %zu pages\n", __func__, size);
1147		return NULL;
1148	}
1149
1150	for (i = 0; i < size; i++) {
1151		pages[i] = alloc_page(gfp_flags);
1152		if (!pages[i]) {
1153			dprintk("%s: failed to allocate page\n", __func__);
1154			nfs4_free_pages(pages, i);
1155			return NULL;
1156		}
1157	}
1158
1159	return pages;
1160}
1161
1162static struct nfs4_layoutget *
1163pnfs_alloc_init_layoutget_args(struct inode *ino,
1164	   struct nfs_open_context *ctx,
1165	   const nfs4_stateid *stateid,
1166	   const struct pnfs_layout_range *range,
1167	   gfp_t gfp_flags)
1168{
1169	struct nfs_server *server = pnfs_find_server(ino, ctx);
1170	size_t max_reply_sz = server->pnfs_curr_ld->max_layoutget_response;
1171	size_t max_pages = max_response_pages(server);
1172	struct nfs4_layoutget *lgp;
1173
1174	dprintk("--> %s\n", __func__);
1175
1176	lgp = kzalloc(sizeof(*lgp), gfp_flags);
1177	if (lgp == NULL)
1178		return NULL;
1179
1180	if (max_reply_sz) {
1181		size_t npages = (max_reply_sz + PAGE_SIZE - 1) >> PAGE_SHIFT;
1182		if (npages < max_pages)
1183			max_pages = npages;
1184	}
1185
1186	lgp->args.layout.pages = nfs4_alloc_pages(max_pages, gfp_flags);
1187	if (!lgp->args.layout.pages) {
1188		kfree(lgp);
1189		return NULL;
1190	}
1191	lgp->args.layout.pglen = max_pages * PAGE_SIZE;
1192	lgp->res.layoutp = &lgp->args.layout;
1193
1194	/* Don't confuse uninitialised result and success */
1195	lgp->res.status = -NFS4ERR_DELAY;
1196
1197	lgp->args.minlength = PAGE_SIZE;
1198	if (lgp->args.minlength > range->length)
1199		lgp->args.minlength = range->length;
1200	if (ino) {
1201		loff_t i_size = i_size_read(ino);
1202
1203		if (range->iomode == IOMODE_READ) {
1204			if (range->offset >= i_size)
1205				lgp->args.minlength = 0;
1206			else if (i_size - range->offset < lgp->args.minlength)
1207				lgp->args.minlength = i_size - range->offset;
1208		}
1209	}
1210	lgp->args.maxcount = PNFS_LAYOUT_MAXSIZE;
1211	pnfs_copy_range(&lgp->args.range, range);
1212	lgp->args.type = server->pnfs_curr_ld->id;
1213	lgp->args.inode = ino;
1214	lgp->args.ctx = get_nfs_open_context(ctx);
1215	nfs4_stateid_copy(&lgp->args.stateid, stateid);
1216	lgp->gfp_flags = gfp_flags;
1217	lgp->cred = ctx->cred;
1218	return lgp;
1219}
1220
1221void pnfs_layoutget_free(struct nfs4_layoutget *lgp)
1222{
1223	size_t max_pages = lgp->args.layout.pglen / PAGE_SIZE;
1224
1225	nfs4_free_pages(lgp->args.layout.pages, max_pages);
1226	pnfs_put_layout_hdr(lgp->lo);
1227	put_nfs_open_context(lgp->args.ctx);
1228	kfree(lgp);
1229}
1230
1231static void pnfs_clear_layoutcommit(struct inode *inode,
1232		struct list_head *head)
1233{
1234	struct nfs_inode *nfsi = NFS_I(inode);
1235	struct pnfs_layout_segment *lseg, *tmp;
1236
1237	if (!test_and_clear_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags))
1238		return;
1239	list_for_each_entry_safe(lseg, tmp, &nfsi->layout->plh_segs, pls_list) {
1240		if (!test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
1241			continue;
1242		pnfs_lseg_dec_and_remove_zero(lseg, head);
1243	}
1244}
1245
1246static void
1247pnfs_layoutreturn_retry_later_locked(struct pnfs_layout_hdr *lo,
1248				     const nfs4_stateid *arg_stateid,
1249				     const struct pnfs_layout_range *range)
1250{
1251	const struct pnfs_layout_segment *lseg;
1252	u32 seq = be32_to_cpu(arg_stateid->seqid);
1253
1254	if (pnfs_layout_is_valid(lo) &&
1255	    nfs4_stateid_match_other(&lo->plh_stateid, arg_stateid)) {
1256		list_for_each_entry(lseg, &lo->plh_return_segs, pls_list) {
1257			if (pnfs_seqid_is_newer(lseg->pls_seq, seq) ||
1258			    !pnfs_should_free_range(&lseg->pls_range, range))
1259				continue;
1260			pnfs_set_plh_return_info(lo, range->iomode, seq);
1261			break;
1262		}
1263	}
1264}
1265
1266void pnfs_layoutreturn_retry_later(struct pnfs_layout_hdr *lo,
1267				   const nfs4_stateid *arg_stateid,
1268				   const struct pnfs_layout_range *range)
1269{
1270	struct inode *inode = lo->plh_inode;
1271
1272	spin_lock(&inode->i_lock);
1273	pnfs_layoutreturn_retry_later_locked(lo, arg_stateid, range);
1274	pnfs_clear_layoutreturn_waitbit(lo);
1275	spin_unlock(&inode->i_lock);
1276}
1277
1278void pnfs_layoutreturn_free_lsegs(struct pnfs_layout_hdr *lo,
1279		const nfs4_stateid *arg_stateid,
1280		const struct pnfs_layout_range *range,
1281		const nfs4_stateid *stateid)
1282{
1283	struct inode *inode = lo->plh_inode;
1284	LIST_HEAD(freeme);
1285
1286	spin_lock(&inode->i_lock);
1287	if (!nfs4_stateid_match_other(&lo->plh_stateid, arg_stateid))
 
1288		goto out_unlock;
1289	if (stateid && pnfs_layout_is_valid(lo)) {
1290		u32 seq = be32_to_cpu(arg_stateid->seqid);
1291
1292		pnfs_mark_matching_lsegs_invalid(lo, &freeme, range, seq);
1293		pnfs_free_returned_lsegs(lo, &freeme, range, seq);
1294		pnfs_set_layout_stateid(lo, stateid, NULL, true);
1295	} else
1296		pnfs_mark_layout_stateid_invalid(lo, &freeme);
1297out_unlock:
1298	pnfs_clear_layoutreturn_waitbit(lo);
1299	spin_unlock(&inode->i_lock);
1300	pnfs_free_lseg_list(&freeme);
1301
1302}
1303
1304static bool
1305pnfs_prepare_layoutreturn(struct pnfs_layout_hdr *lo,
1306		nfs4_stateid *stateid,
1307		const struct cred **cred,
1308		enum pnfs_iomode *iomode)
1309{
1310	/* Serialise LAYOUTGET/LAYOUTRETURN */
1311	if (atomic_read(&lo->plh_outstanding) != 0 && lo->plh_return_seq == 0)
1312		return false;
1313	if (test_and_set_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags))
1314		return false;
1315	set_bit(NFS_LAYOUT_RETURN, &lo->plh_flags);
1316	pnfs_get_layout_hdr(lo);
1317	nfs4_stateid_copy(stateid, &lo->plh_stateid);
1318	*cred = get_cred(lo->plh_lc_cred);
1319	if (test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags)) {
1320		if (lo->plh_return_seq != 0)
1321			stateid->seqid = cpu_to_be32(lo->plh_return_seq);
1322		if (iomode != NULL)
1323			*iomode = lo->plh_return_iomode;
1324		pnfs_clear_layoutreturn_info(lo);
1325	} else if (iomode != NULL)
1326		*iomode = IOMODE_ANY;
1327	pnfs_barrier_update(lo, be32_to_cpu(stateid->seqid));
1328	return true;
1329}
1330
1331static void
1332pnfs_init_layoutreturn_args(struct nfs4_layoutreturn_args *args,
1333		struct pnfs_layout_hdr *lo,
1334		const nfs4_stateid *stateid,
1335		enum pnfs_iomode iomode)
1336{
1337	struct inode *inode = lo->plh_inode;
1338
1339	args->layout_type = NFS_SERVER(inode)->pnfs_curr_ld->id;
1340	args->inode = inode;
1341	args->range.iomode = iomode;
1342	args->range.offset = 0;
1343	args->range.length = NFS4_MAX_UINT64;
1344	args->layout = lo;
1345	nfs4_stateid_copy(&args->stateid, stateid);
1346}
1347
1348static int
1349pnfs_send_layoutreturn(struct pnfs_layout_hdr *lo,
1350		       const nfs4_stateid *stateid,
1351		       const struct cred **pcred,
1352		       enum pnfs_iomode iomode,
1353		       unsigned int flags)
1354{
1355	struct inode *ino = lo->plh_inode;
1356	struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
1357	struct nfs4_layoutreturn *lrp;
1358	const struct cred *cred = *pcred;
1359	int status = 0;
1360
1361	*pcred = NULL;
1362	lrp = kzalloc(sizeof(*lrp), nfs_io_gfp_mask());
1363	if (unlikely(lrp == NULL)) {
1364		status = -ENOMEM;
1365		spin_lock(&ino->i_lock);
1366		pnfs_clear_layoutreturn_waitbit(lo);
1367		spin_unlock(&ino->i_lock);
1368		put_cred(cred);
1369		pnfs_put_layout_hdr(lo);
1370		goto out;
1371	}
1372
1373	pnfs_init_layoutreturn_args(&lrp->args, lo, stateid, iomode);
1374	lrp->args.ld_private = &lrp->ld_private;
1375	lrp->clp = NFS_SERVER(ino)->nfs_client;
1376	lrp->cred = cred;
1377	if (ld->prepare_layoutreturn)
1378		ld->prepare_layoutreturn(&lrp->args);
1379
1380	status = nfs4_proc_layoutreturn(lrp, flags);
1381out:
1382	dprintk("<-- %s status: %d\n", __func__, status);
1383	return status;
1384}
1385
 
 
 
 
 
 
 
 
 
 
 
 
 
1386/* Return true if layoutreturn is needed */
1387static bool
1388pnfs_layout_need_return(struct pnfs_layout_hdr *lo)
1389{
1390	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
1391		return false;
1392	return pnfs_mark_layout_stateid_return(lo, &lo->plh_return_segs,
1393					       lo->plh_return_iomode,
1394					       lo->plh_return_seq) != EBUSY;
1395}
1396
1397static void pnfs_layoutreturn_before_put_layout_hdr(struct pnfs_layout_hdr *lo)
1398{
1399	struct inode *inode= lo->plh_inode;
1400
1401	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
1402		return;
1403	spin_lock(&inode->i_lock);
1404	if (pnfs_layout_need_return(lo)) {
1405		const struct cred *cred;
1406		nfs4_stateid stateid;
1407		enum pnfs_iomode iomode;
1408		bool send;
1409
1410		send = pnfs_prepare_layoutreturn(lo, &stateid, &cred, &iomode);
1411		spin_unlock(&inode->i_lock);
1412		if (send) {
1413			/* Send an async layoutreturn so we dont deadlock */
1414			pnfs_send_layoutreturn(lo, &stateid, &cred, iomode,
1415					       PNFS_FL_LAYOUTRETURN_ASYNC);
1416		}
1417	} else
1418		spin_unlock(&inode->i_lock);
1419}
1420
1421/*
1422 * Initiates a LAYOUTRETURN(FILE), and removes the pnfs_layout_hdr
1423 * when the layout segment list is empty.
1424 *
1425 * Note that a pnfs_layout_hdr can exist with an empty layout segment
1426 * list when LAYOUTGET has failed, or when LAYOUTGET succeeded, but the
1427 * deviceid is marked invalid.
1428 */
1429int
1430_pnfs_return_layout(struct inode *ino)
1431{
1432	struct pnfs_layout_hdr *lo = NULL;
1433	struct nfs_inode *nfsi = NFS_I(ino);
1434	struct pnfs_layout_range range = {
1435		.iomode		= IOMODE_ANY,
1436		.offset		= 0,
1437		.length		= NFS4_MAX_UINT64,
1438	};
1439	LIST_HEAD(tmp_list);
1440	const struct cred *cred;
1441	nfs4_stateid stateid;
1442	int status = 0;
1443	bool send, valid_layout;
1444
1445	dprintk("NFS: %s for inode %lu\n", __func__, ino->i_ino);
1446
1447	spin_lock(&ino->i_lock);
1448	lo = nfsi->layout;
1449	if (!lo) {
1450		spin_unlock(&ino->i_lock);
1451		dprintk("NFS: %s no layout to return\n", __func__);
1452		goto out;
1453	}
1454	/* Reference matched in nfs4_layoutreturn_release */
1455	pnfs_get_layout_hdr(lo);
1456	/* Is there an outstanding layoutreturn ? */
1457	if (test_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags)) {
1458		spin_unlock(&ino->i_lock);
1459		if (wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN,
1460					TASK_UNINTERRUPTIBLE))
1461			goto out_put_layout_hdr;
1462		spin_lock(&ino->i_lock);
1463	}
1464	valid_layout = pnfs_layout_is_valid(lo);
1465	pnfs_clear_layoutcommit(ino, &tmp_list);
1466	pnfs_mark_matching_lsegs_return(lo, &tmp_list, &range, 0);
1467
1468	if (NFS_SERVER(ino)->pnfs_curr_ld->return_range)
1469		NFS_SERVER(ino)->pnfs_curr_ld->return_range(lo, &range);
1470
1471	/* Don't send a LAYOUTRETURN if list was initially empty */
1472	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags) ||
1473			!valid_layout) {
1474		spin_unlock(&ino->i_lock);
1475		dprintk("NFS: %s no layout segments to return\n", __func__);
1476		goto out_wait_layoutreturn;
1477	}
1478
1479	send = pnfs_prepare_layoutreturn(lo, &stateid, &cred, NULL);
1480	spin_unlock(&ino->i_lock);
1481	if (send)
1482		status = pnfs_send_layoutreturn(lo, &stateid, &cred, IOMODE_ANY,
1483						0);
1484out_wait_layoutreturn:
1485	wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN, TASK_UNINTERRUPTIBLE);
1486out_put_layout_hdr:
1487	pnfs_free_lseg_list(&tmp_list);
1488	pnfs_put_layout_hdr(lo);
1489out:
1490	dprintk("<-- %s status: %d\n", __func__, status);
1491	return status;
1492}
1493
1494int
1495pnfs_commit_and_return_layout(struct inode *inode)
1496{
1497	struct pnfs_layout_hdr *lo;
1498	int ret;
1499
1500	spin_lock(&inode->i_lock);
1501	lo = NFS_I(inode)->layout;
1502	if (lo == NULL) {
1503		spin_unlock(&inode->i_lock);
1504		return 0;
1505	}
1506	pnfs_get_layout_hdr(lo);
1507	/* Block new layoutgets and read/write to ds */
1508	lo->plh_block_lgets++;
1509	spin_unlock(&inode->i_lock);
1510	filemap_fdatawait(inode->i_mapping);
1511	ret = pnfs_layoutcommit_inode(inode, true);
1512	if (ret == 0)
1513		ret = _pnfs_return_layout(inode);
1514	spin_lock(&inode->i_lock);
1515	lo->plh_block_lgets--;
1516	spin_unlock(&inode->i_lock);
1517	pnfs_put_layout_hdr(lo);
1518	return ret;
1519}
1520
1521static int pnfs_layout_return_on_reboot(struct pnfs_layout_hdr *lo)
1522{
1523	struct inode *inode = lo->plh_inode;
1524	const struct cred *cred;
1525
1526	spin_lock(&inode->i_lock);
1527	if (!pnfs_layout_is_valid(lo)) {
1528		spin_unlock(&inode->i_lock);
1529		return 0;
1530	}
1531	cred = get_cred(lo->plh_lc_cred);
1532	pnfs_get_layout_hdr(lo);
1533	spin_unlock(&inode->i_lock);
1534
1535	return pnfs_send_layoutreturn(lo, &zero_stateid, &cred, IOMODE_ANY,
1536				      PNFS_FL_LAYOUTRETURN_PRIVILEGED);
1537}
1538
1539bool pnfs_roc(struct inode *ino,
1540		struct nfs4_layoutreturn_args *args,
1541		struct nfs4_layoutreturn_res *res,
1542		const struct cred *cred)
1543{
1544	struct nfs_inode *nfsi = NFS_I(ino);
1545	struct nfs_open_context *ctx;
1546	struct nfs4_state *state;
1547	struct pnfs_layout_hdr *lo;
1548	struct pnfs_layout_segment *lseg, *next;
1549	const struct cred *lc_cred;
1550	nfs4_stateid stateid;
1551	enum pnfs_iomode iomode = 0;
1552	bool layoutreturn = false, roc = false;
1553	bool skip_read = false;
1554
1555	if (!nfs_have_layout(ino))
1556		return false;
1557retry:
1558	rcu_read_lock();
1559	spin_lock(&ino->i_lock);
1560	lo = nfsi->layout;
1561	if (!lo || !pnfs_layout_is_valid(lo) ||
1562	    test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
1563		lo = NULL;
1564		goto out_noroc;
1565	}
1566	pnfs_get_layout_hdr(lo);
1567	if (test_bit(NFS_LAYOUT_RETURN_LOCK, &lo->plh_flags)) {
1568		spin_unlock(&ino->i_lock);
1569		rcu_read_unlock();
1570		wait_on_bit(&lo->plh_flags, NFS_LAYOUT_RETURN,
1571				TASK_UNINTERRUPTIBLE);
1572		pnfs_put_layout_hdr(lo);
1573		goto retry;
1574	}
1575
1576	/* no roc if we hold a delegation */
1577	if (nfs4_check_delegation(ino, FMODE_READ)) {
1578		if (nfs4_check_delegation(ino, FMODE_WRITE))
1579			goto out_noroc;
1580		skip_read = true;
1581	}
1582
1583	list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
1584		state = ctx->state;
1585		if (state == NULL)
1586			continue;
1587		/* Don't return layout if there is open file state */
1588		if (state->state & FMODE_WRITE)
1589			goto out_noroc;
1590		if (state->state & FMODE_READ)
1591			skip_read = true;
1592	}
1593
1594
1595	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list) {
1596		if (skip_read && lseg->pls_range.iomode == IOMODE_READ)
1597			continue;
1598		/* If we are sending layoutreturn, invalidate all valid lsegs */
1599		if (!test_and_clear_bit(NFS_LSEG_ROC, &lseg->pls_flags))
1600			continue;
1601		/*
1602		 * Note: mark lseg for return so pnfs_layout_remove_lseg
1603		 * doesn't invalidate the layout for us.
1604		 */
1605		set_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
1606		if (!mark_lseg_invalid(lseg, &lo->plh_return_segs))
1607			continue;
1608		pnfs_set_plh_return_info(lo, lseg->pls_range.iomode, 0);
1609	}
1610
1611	if (!test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
1612		goto out_noroc;
1613
1614	/* ROC in two conditions:
1615	 * 1. there are ROC lsegs
1616	 * 2. we don't send layoutreturn
1617	 */
1618	/* lo ref dropped in pnfs_roc_release() */
1619	layoutreturn = pnfs_prepare_layoutreturn(lo, &stateid, &lc_cred, &iomode);
1620	/* If the creds don't match, we can't compound the layoutreturn */
1621	if (!layoutreturn || cred_fscmp(cred, lc_cred) != 0)
1622		goto out_noroc;
1623
1624	roc = layoutreturn;
1625	pnfs_init_layoutreturn_args(args, lo, &stateid, iomode);
1626	res->lrs_present = 0;
1627	layoutreturn = false;
1628	put_cred(lc_cred);
1629
1630out_noroc:
1631	spin_unlock(&ino->i_lock);
1632	rcu_read_unlock();
1633	pnfs_layoutcommit_inode(ino, true);
1634	if (roc) {
1635		struct pnfs_layoutdriver_type *ld = NFS_SERVER(ino)->pnfs_curr_ld;
1636		if (ld->prepare_layoutreturn)
1637			ld->prepare_layoutreturn(args);
1638		pnfs_put_layout_hdr(lo);
1639		return true;
1640	}
1641	if (layoutreturn)
1642		pnfs_send_layoutreturn(lo, &stateid, &lc_cred, iomode, 0);
1643	pnfs_put_layout_hdr(lo);
1644	return false;
1645}
1646
1647int pnfs_roc_done(struct rpc_task *task, struct nfs4_layoutreturn_args **argpp,
1648		  struct nfs4_layoutreturn_res **respp, int *ret)
1649{
1650	struct nfs4_layoutreturn_args *arg = *argpp;
1651	int retval = -EAGAIN;
1652
1653	if (!arg)
1654		return 0;
1655	/* Handle Layoutreturn errors */
1656	switch (*ret) {
1657	case 0:
1658		retval = 0;
1659		break;
1660	case -NFS4ERR_NOMATCHING_LAYOUT:
1661		/* Was there an RPC level error? If not, retry */
1662		if (task->tk_rpc_status == 0)
1663			break;
1664		/* If the call was not sent, let caller handle it */
1665		if (!RPC_WAS_SENT(task))
1666			return 0;
1667		/*
1668		 * Otherwise, assume the call succeeded and
1669		 * that we need to release the layout
1670		 */
1671		*ret = 0;
1672		(*respp)->lrs_present = 0;
1673		retval = 0;
1674		break;
1675	case -NFS4ERR_DELAY:
1676		/* Let the caller handle the retry */
1677		*ret = -NFS4ERR_NOMATCHING_LAYOUT;
1678		return 0;
1679	case -NFS4ERR_OLD_STATEID:
1680		if (!nfs4_layout_refresh_old_stateid(&arg->stateid,
1681						     &arg->range, arg->inode))
1682			break;
1683		*ret = -NFS4ERR_NOMATCHING_LAYOUT;
1684		return -EAGAIN;
1685	}
1686	*argpp = NULL;
1687	*respp = NULL;
1688	return retval;
1689}
1690
1691void pnfs_roc_release(struct nfs4_layoutreturn_args *args,
1692		      struct nfs4_layoutreturn_res *res, int ret)
 
1693{
1694	struct pnfs_layout_hdr *lo = args->layout;
1695	struct inode *inode = args->inode;
1696	const nfs4_stateid *res_stateid = NULL;
1697	struct nfs4_xdr_opaque_data *ld_private = args->ld_private;
1698
1699	switch (ret) {
1700	case -NFS4ERR_BADSESSION:
1701	case -NFS4ERR_DEADSESSION:
1702	case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1703	case -NFS4ERR_NOMATCHING_LAYOUT:
1704		spin_lock(&inode->i_lock);
1705		pnfs_layoutreturn_retry_later_locked(lo, &args->stateid,
1706						     &args->range);
 
1707		pnfs_clear_layoutreturn_waitbit(lo);
1708		spin_unlock(&inode->i_lock);
1709		break;
1710	case 0:
1711		if (res->lrs_present)
1712			res_stateid = &res->stateid;
1713		fallthrough;
1714	default:
1715		pnfs_layoutreturn_free_lsegs(lo, &args->stateid, &args->range,
1716					     res_stateid);
1717	}
1718	trace_nfs4_layoutreturn_on_close(args->inode, &args->stateid, ret);
1719	if (ld_private && ld_private->ops && ld_private->ops->free)
1720		ld_private->ops->free(ld_private);
1721	pnfs_put_layout_hdr(lo);
1722}
1723
1724bool pnfs_wait_on_layoutreturn(struct inode *ino, struct rpc_task *task)
1725{
1726	struct nfs_inode *nfsi = NFS_I(ino);
1727        struct pnfs_layout_hdr *lo;
1728        bool sleep = false;
1729
1730	/* we might not have grabbed lo reference. so need to check under
1731	 * i_lock */
1732        spin_lock(&ino->i_lock);
1733        lo = nfsi->layout;
1734        if (lo && test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
1735                rpc_sleep_on(&NFS_SERVER(ino)->roc_rpcwaitq, task, NULL);
1736                sleep = true;
1737	}
1738        spin_unlock(&ino->i_lock);
1739        return sleep;
1740}
1741
1742/*
1743 * Compare two layout segments for sorting into layout cache.
1744 * We want to preferentially return RW over RO layouts, so ensure those
1745 * are seen first.
1746 */
1747static s64
1748pnfs_lseg_range_cmp(const struct pnfs_layout_range *l1,
1749	   const struct pnfs_layout_range *l2)
1750{
1751	s64 d;
1752
1753	/* high offset > low offset */
1754	d = l1->offset - l2->offset;
1755	if (d)
1756		return d;
1757
1758	/* short length > long length */
1759	d = l2->length - l1->length;
1760	if (d)
1761		return d;
1762
1763	/* read > read/write */
1764	return (int)(l1->iomode == IOMODE_READ) - (int)(l2->iomode == IOMODE_READ);
1765}
1766
1767static bool
1768pnfs_lseg_range_is_after(const struct pnfs_layout_range *l1,
1769		const struct pnfs_layout_range *l2)
1770{
1771	return pnfs_lseg_range_cmp(l1, l2) > 0;
1772}
1773
1774static bool
1775pnfs_lseg_no_merge(struct pnfs_layout_segment *lseg,
1776		struct pnfs_layout_segment *old)
1777{
1778	return false;
1779}
1780
1781void
1782pnfs_generic_layout_insert_lseg(struct pnfs_layout_hdr *lo,
1783		   struct pnfs_layout_segment *lseg,
1784		   bool (*is_after)(const struct pnfs_layout_range *,
1785			   const struct pnfs_layout_range *),
1786		   bool (*do_merge)(struct pnfs_layout_segment *,
1787			   struct pnfs_layout_segment *),
1788		   struct list_head *free_me)
1789{
1790	struct pnfs_layout_segment *lp, *tmp;
1791
1792	dprintk("%s:Begin\n", __func__);
1793
1794	list_for_each_entry_safe(lp, tmp, &lo->plh_segs, pls_list) {
1795		if (test_bit(NFS_LSEG_VALID, &lp->pls_flags) == 0)
1796			continue;
1797		if (do_merge(lseg, lp)) {
1798			mark_lseg_invalid(lp, free_me);
1799			continue;
1800		}
1801		if (is_after(&lseg->pls_range, &lp->pls_range))
1802			continue;
1803		list_add_tail(&lseg->pls_list, &lp->pls_list);
1804		dprintk("%s: inserted lseg %p "
1805			"iomode %d offset %llu length %llu before "
1806			"lp %p iomode %d offset %llu length %llu\n",
1807			__func__, lseg, lseg->pls_range.iomode,
1808			lseg->pls_range.offset, lseg->pls_range.length,
1809			lp, lp->pls_range.iomode, lp->pls_range.offset,
1810			lp->pls_range.length);
1811		goto out;
1812	}
1813	list_add_tail(&lseg->pls_list, &lo->plh_segs);
1814	dprintk("%s: inserted lseg %p "
1815		"iomode %d offset %llu length %llu at tail\n",
1816		__func__, lseg, lseg->pls_range.iomode,
1817		lseg->pls_range.offset, lseg->pls_range.length);
1818out:
1819	pnfs_get_layout_hdr(lo);
1820
1821	dprintk("%s:Return\n", __func__);
1822}
1823EXPORT_SYMBOL_GPL(pnfs_generic_layout_insert_lseg);
1824
1825static void
1826pnfs_layout_insert_lseg(struct pnfs_layout_hdr *lo,
1827		   struct pnfs_layout_segment *lseg,
1828		   struct list_head *free_me)
1829{
1830	struct inode *inode = lo->plh_inode;
1831	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
1832
1833	if (ld->add_lseg != NULL)
1834		ld->add_lseg(lo, lseg, free_me);
1835	else
1836		pnfs_generic_layout_insert_lseg(lo, lseg,
1837				pnfs_lseg_range_is_after,
1838				pnfs_lseg_no_merge,
1839				free_me);
1840}
1841
1842static struct pnfs_layout_hdr *
1843alloc_init_layout_hdr(struct inode *ino,
1844		      struct nfs_open_context *ctx,
1845		      gfp_t gfp_flags)
1846{
1847	struct pnfs_layout_hdr *lo;
1848
1849	lo = pnfs_alloc_layout_hdr(ino, gfp_flags);
1850	if (!lo)
1851		return NULL;
1852	refcount_set(&lo->plh_refcount, 1);
1853	INIT_LIST_HEAD(&lo->plh_layouts);
1854	INIT_LIST_HEAD(&lo->plh_segs);
1855	INIT_LIST_HEAD(&lo->plh_return_segs);
1856	INIT_LIST_HEAD(&lo->plh_bulk_destroy);
1857	lo->plh_inode = ino;
1858	lo->plh_lc_cred = get_cred(ctx->cred);
1859	lo->plh_flags |= 1 << NFS_LAYOUT_INVALID_STID;
1860	return lo;
1861}
1862
1863static struct pnfs_layout_hdr *
1864pnfs_find_alloc_layout(struct inode *ino,
1865		       struct nfs_open_context *ctx,
1866		       gfp_t gfp_flags)
1867	__releases(&ino->i_lock)
1868	__acquires(&ino->i_lock)
1869{
1870	struct nfs_inode *nfsi = NFS_I(ino);
1871	struct pnfs_layout_hdr *new = NULL;
1872
1873	dprintk("%s Begin ino=%p layout=%p\n", __func__, ino, nfsi->layout);
1874
1875	if (nfsi->layout != NULL)
1876		goto out_existing;
1877	spin_unlock(&ino->i_lock);
1878	new = alloc_init_layout_hdr(ino, ctx, gfp_flags);
1879	spin_lock(&ino->i_lock);
1880
1881	if (likely(nfsi->layout == NULL)) {	/* Won the race? */
1882		nfsi->layout = new;
1883		return new;
1884	} else if (new != NULL)
1885		pnfs_free_layout_hdr(new);
1886out_existing:
1887	pnfs_get_layout_hdr(nfsi->layout);
1888	return nfsi->layout;
1889}
1890
1891/*
1892 * iomode matching rules:
1893 * iomode	lseg	strict match
1894 *                      iomode
1895 * -----	-----	------ -----
1896 * ANY		READ	N/A    true
1897 * ANY		RW	N/A    true
1898 * RW		READ	N/A    false
1899 * RW		RW	N/A    true
1900 * READ		READ	N/A    true
1901 * READ		RW	true   false
1902 * READ		RW	false  true
1903 */
1904static bool
1905pnfs_lseg_range_match(const struct pnfs_layout_range *ls_range,
1906		 const struct pnfs_layout_range *range,
1907		 bool strict_iomode)
1908{
1909	struct pnfs_layout_range range1;
1910
1911	if ((range->iomode == IOMODE_RW &&
1912	     ls_range->iomode != IOMODE_RW) ||
1913	    (range->iomode != ls_range->iomode &&
1914	     strict_iomode) ||
1915	    !pnfs_lseg_range_intersecting(ls_range, range))
1916		return false;
1917
1918	/* range1 covers only the first byte in the range */
1919	range1 = *range;
1920	range1.length = 1;
1921	return pnfs_lseg_range_contained(ls_range, &range1);
1922}
1923
1924/*
1925 * lookup range in layout
1926 */
1927static struct pnfs_layout_segment *
1928pnfs_find_lseg(struct pnfs_layout_hdr *lo,
1929		struct pnfs_layout_range *range,
1930		bool strict_iomode)
1931{
1932	struct pnfs_layout_segment *lseg, *ret = NULL;
1933
1934	dprintk("%s:Begin\n", __func__);
1935
1936	list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
1937		if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags) &&
1938		    pnfs_lseg_range_match(&lseg->pls_range, range,
1939					  strict_iomode)) {
1940			ret = pnfs_get_lseg(lseg);
1941			break;
1942		}
1943	}
1944
1945	dprintk("%s:Return lseg %p ref %d\n",
1946		__func__, ret, ret ? refcount_read(&ret->pls_refcount) : 0);
1947	return ret;
1948}
1949
1950/*
1951 * Use mdsthreshold hints set at each OPEN to determine if I/O should go
1952 * to the MDS or over pNFS
1953 *
1954 * The nfs_inode read_io and write_io fields are cumulative counters reset
1955 * when there are no layout segments. Note that in pnfs_update_layout iomode
1956 * is set to IOMODE_READ for a READ request, and set to IOMODE_RW for a
1957 * WRITE request.
1958 *
1959 * A return of true means use MDS I/O.
1960 *
1961 * From rfc 5661:
1962 * If a file's size is smaller than the file size threshold, data accesses
1963 * SHOULD be sent to the metadata server.  If an I/O request has a length that
1964 * is below the I/O size threshold, the I/O SHOULD be sent to the metadata
1965 * server.  If both file size and I/O size are provided, the client SHOULD
1966 * reach or exceed  both thresholds before sending its read or write
1967 * requests to the data server.
1968 */
1969static bool pnfs_within_mdsthreshold(struct nfs_open_context *ctx,
1970				     struct inode *ino, int iomode)
1971{
1972	struct nfs4_threshold *t = ctx->mdsthreshold;
1973	struct nfs_inode *nfsi = NFS_I(ino);
1974	loff_t fsize = i_size_read(ino);
1975	bool size = false, size_set = false, io = false, io_set = false, ret = false;
1976
1977	if (t == NULL)
1978		return ret;
1979
1980	dprintk("%s bm=0x%x rd_sz=%llu wr_sz=%llu rd_io=%llu wr_io=%llu\n",
1981		__func__, t->bm, t->rd_sz, t->wr_sz, t->rd_io_sz, t->wr_io_sz);
1982
1983	switch (iomode) {
1984	case IOMODE_READ:
1985		if (t->bm & THRESHOLD_RD) {
1986			dprintk("%s fsize %llu\n", __func__, fsize);
1987			size_set = true;
1988			if (fsize < t->rd_sz)
1989				size = true;
1990		}
1991		if (t->bm & THRESHOLD_RD_IO) {
1992			dprintk("%s nfsi->read_io %llu\n", __func__,
1993				nfsi->read_io);
1994			io_set = true;
1995			if (nfsi->read_io < t->rd_io_sz)
1996				io = true;
1997		}
1998		break;
1999	case IOMODE_RW:
2000		if (t->bm & THRESHOLD_WR) {
2001			dprintk("%s fsize %llu\n", __func__, fsize);
2002			size_set = true;
2003			if (fsize < t->wr_sz)
2004				size = true;
2005		}
2006		if (t->bm & THRESHOLD_WR_IO) {
2007			dprintk("%s nfsi->write_io %llu\n", __func__,
2008				nfsi->write_io);
2009			io_set = true;
2010			if (nfsi->write_io < t->wr_io_sz)
2011				io = true;
2012		}
2013		break;
2014	}
2015	if (size_set && io_set) {
2016		if (size && io)
2017			ret = true;
2018	} else if (size || io)
2019		ret = true;
2020
2021	dprintk("<-- %s size %d io %d ret %d\n", __func__, size, io, ret);
2022	return ret;
2023}
2024
2025static int pnfs_prepare_to_retry_layoutget(struct pnfs_layout_hdr *lo)
2026{
2027	/*
2028	 * send layoutcommit as it can hold up layoutreturn due to lseg
2029	 * reference
2030	 */
2031	pnfs_layoutcommit_inode(lo->plh_inode, false);
2032	return wait_on_bit_action(&lo->plh_flags, NFS_LAYOUT_RETURN,
2033				   nfs_wait_bit_killable,
2034				   TASK_KILLABLE|TASK_FREEZABLE_UNSAFE);
2035}
2036
2037static void nfs_layoutget_begin(struct pnfs_layout_hdr *lo)
2038{
2039	atomic_inc(&lo->plh_outstanding);
2040}
2041
2042static void nfs_layoutget_end(struct pnfs_layout_hdr *lo)
2043{
2044	if (atomic_dec_and_test(&lo->plh_outstanding) &&
2045	    test_and_clear_bit(NFS_LAYOUT_DRAIN, &lo->plh_flags))
2046		wake_up_bit(&lo->plh_flags, NFS_LAYOUT_DRAIN);
2047}
2048
2049static bool pnfs_is_first_layoutget(struct pnfs_layout_hdr *lo)
2050{
2051	return test_bit(NFS_LAYOUT_FIRST_LAYOUTGET, &lo->plh_flags);
2052}
2053
2054static void pnfs_clear_first_layoutget(struct pnfs_layout_hdr *lo)
2055{
2056	unsigned long *bitlock = &lo->plh_flags;
2057
2058	clear_bit_unlock(NFS_LAYOUT_FIRST_LAYOUTGET, bitlock);
2059	smp_mb__after_atomic();
2060	wake_up_bit(bitlock, NFS_LAYOUT_FIRST_LAYOUTGET);
2061}
2062
2063static void _add_to_server_list(struct pnfs_layout_hdr *lo,
2064				struct nfs_server *server)
2065{
2066	if (!test_and_set_bit(NFS_LAYOUT_HASHED, &lo->plh_flags)) {
2067		struct nfs_client *clp = server->nfs_client;
2068
2069		/* The lo must be on the clp list if there is any
2070		 * chance of a CB_LAYOUTRECALL(FILE) coming in.
2071		 */
2072		spin_lock(&clp->cl_lock);
2073		list_add_tail_rcu(&lo->plh_layouts, &server->layouts);
2074		spin_unlock(&clp->cl_lock);
2075	}
2076}
2077
2078/*
2079 * Layout segment is retreived from the server if not cached.
2080 * The appropriate layout segment is referenced and returned to the caller.
2081 */
2082struct pnfs_layout_segment *
2083pnfs_update_layout(struct inode *ino,
2084		   struct nfs_open_context *ctx,
2085		   loff_t pos,
2086		   u64 count,
2087		   enum pnfs_iomode iomode,
2088		   bool strict_iomode,
2089		   gfp_t gfp_flags)
2090{
2091	struct pnfs_layout_range arg = {
2092		.iomode = iomode,
2093		.offset = pos,
2094		.length = count,
2095	};
2096	unsigned pg_offset;
2097	struct nfs_server *server = NFS_SERVER(ino);
2098	struct nfs_client *clp = server->nfs_client;
2099	struct pnfs_layout_hdr *lo = NULL;
2100	struct pnfs_layout_segment *lseg = NULL;
2101	struct nfs4_layoutget *lgp;
2102	nfs4_stateid stateid;
2103	struct nfs4_exception exception = {
2104		.inode = ino,
2105	};
2106	unsigned long giveup = jiffies + (clp->cl_lease_time << 1);
2107	bool first;
2108
2109	if (!pnfs_enabled_sb(NFS_SERVER(ino))) {
2110		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2111				 PNFS_UPDATE_LAYOUT_NO_PNFS);
2112		goto out;
2113	}
2114
2115	if (pnfs_within_mdsthreshold(ctx, ino, iomode)) {
2116		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2117				 PNFS_UPDATE_LAYOUT_MDSTHRESH);
2118		goto out;
2119	}
2120
2121lookup_again:
2122	if (!nfs4_valid_open_stateid(ctx->state)) {
2123		trace_pnfs_update_layout(ino, pos, count,
2124					 iomode, lo, lseg,
2125					 PNFS_UPDATE_LAYOUT_INVALID_OPEN);
2126		lseg = ERR_PTR(-EIO);
2127		goto out;
2128	}
2129
2130	lseg = ERR_PTR(nfs4_client_recover_expired_lease(clp));
2131	if (IS_ERR(lseg))
2132		goto out;
2133	first = false;
2134	spin_lock(&ino->i_lock);
2135	lo = pnfs_find_alloc_layout(ino, ctx, gfp_flags);
2136	if (lo == NULL) {
2137		spin_unlock(&ino->i_lock);
2138		lseg = ERR_PTR(-ENOMEM);
2139		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2140				 PNFS_UPDATE_LAYOUT_NOMEM);
2141		goto out;
2142	}
2143
2144	/* Do we even need to bother with this? */
2145	if (test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
2146		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2147				 PNFS_UPDATE_LAYOUT_BULK_RECALL);
2148		dprintk("%s matches recall, use MDS\n", __func__);
2149		goto out_unlock;
2150	}
2151
2152	/* if LAYOUTGET already failed once we don't try again */
2153	if (pnfs_layout_io_test_failed(lo, iomode)) {
2154		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2155				 PNFS_UPDATE_LAYOUT_IO_TEST_FAIL);
2156		goto out_unlock;
2157	}
2158
2159	/*
2160	 * If the layout segment list is empty, but there are outstanding
2161	 * layoutget calls, then they might be subject to a layoutrecall.
2162	 */
2163	if (test_bit(NFS_LAYOUT_DRAIN, &lo->plh_flags) &&
2164	    atomic_read(&lo->plh_outstanding) != 0) {
2165		spin_unlock(&ino->i_lock);
2166		lseg = ERR_PTR(wait_on_bit(&lo->plh_flags, NFS_LAYOUT_DRAIN,
2167					   TASK_KILLABLE));
2168		if (IS_ERR(lseg))
2169			goto out_put_layout_hdr;
2170		pnfs_put_layout_hdr(lo);
2171		goto lookup_again;
2172	}
2173
2174	/*
2175	 * Because we free lsegs when sending LAYOUTRETURN, we need to wait
2176	 * for LAYOUTRETURN.
2177	 */
2178	if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) {
2179		spin_unlock(&ino->i_lock);
2180		dprintk("%s wait for layoutreturn\n", __func__);
2181		lseg = ERR_PTR(pnfs_prepare_to_retry_layoutget(lo));
2182		if (!IS_ERR(lseg)) {
2183			pnfs_put_layout_hdr(lo);
2184			dprintk("%s retrying\n", __func__);
2185			trace_pnfs_update_layout(ino, pos, count, iomode, lo,
2186						 lseg,
2187						 PNFS_UPDATE_LAYOUT_RETRY);
2188			goto lookup_again;
2189		}
2190		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2191					 PNFS_UPDATE_LAYOUT_RETURN);
2192		goto out_put_layout_hdr;
2193	}
2194
2195	lseg = pnfs_find_lseg(lo, &arg, strict_iomode);
2196	if (lseg) {
2197		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2198				PNFS_UPDATE_LAYOUT_FOUND_CACHED);
2199		goto out_unlock;
2200	}
2201
2202	/*
2203	 * Choose a stateid for the LAYOUTGET. If we don't have a layout
2204	 * stateid, or it has been invalidated, then we must use the open
2205	 * stateid.
2206	 */
2207	if (test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags)) {
2208		int status;
2209
2210		/*
2211		 * The first layoutget for the file. Need to serialize per
2212		 * RFC 5661 Errata 3208.
2213		 */
2214		if (test_and_set_bit(NFS_LAYOUT_FIRST_LAYOUTGET,
2215				     &lo->plh_flags)) {
2216			spin_unlock(&ino->i_lock);
2217			lseg = ERR_PTR(wait_on_bit(&lo->plh_flags,
2218						NFS_LAYOUT_FIRST_LAYOUTGET,
2219						TASK_KILLABLE));
2220			if (IS_ERR(lseg))
2221				goto out_put_layout_hdr;
2222			pnfs_put_layout_hdr(lo);
2223			dprintk("%s retrying\n", __func__);
2224			goto lookup_again;
2225		}
2226
2227		spin_unlock(&ino->i_lock);
2228		first = true;
2229		status = nfs4_select_rw_stateid(ctx->state,
2230					iomode == IOMODE_RW ? FMODE_WRITE : FMODE_READ,
2231					NULL, &stateid, NULL);
2232		if (status != 0) {
2233			lseg = ERR_PTR(status);
2234			trace_pnfs_update_layout(ino, pos, count,
2235					iomode, lo, lseg,
2236					PNFS_UPDATE_LAYOUT_INVALID_OPEN);
2237			nfs4_schedule_stateid_recovery(server, ctx->state);
2238			pnfs_clear_first_layoutget(lo);
2239			pnfs_put_layout_hdr(lo);
2240			goto lookup_again;
2241		}
2242		spin_lock(&ino->i_lock);
2243	} else {
2244		nfs4_stateid_copy(&stateid, &lo->plh_stateid);
2245	}
2246
2247	if (pnfs_layoutgets_blocked(lo)) {
2248		trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2249				PNFS_UPDATE_LAYOUT_BLOCKED);
2250		goto out_unlock;
2251	}
2252	nfs_layoutget_begin(lo);
2253	spin_unlock(&ino->i_lock);
2254
2255	_add_to_server_list(lo, server);
2256
2257	pg_offset = arg.offset & ~PAGE_MASK;
2258	if (pg_offset) {
2259		arg.offset -= pg_offset;
2260		arg.length += pg_offset;
2261	}
2262	if (arg.length != NFS4_MAX_UINT64)
2263		arg.length = PAGE_ALIGN(arg.length);
2264
2265	lgp = pnfs_alloc_init_layoutget_args(ino, ctx, &stateid, &arg, gfp_flags);
2266	if (!lgp) {
2267		lseg = ERR_PTR(-ENOMEM);
2268		trace_pnfs_update_layout(ino, pos, count, iomode, lo, NULL,
2269					 PNFS_UPDATE_LAYOUT_NOMEM);
2270		nfs_layoutget_end(lo);
2271		goto out_put_layout_hdr;
2272	}
2273
2274	lgp->lo = lo;
2275	pnfs_get_layout_hdr(lo);
2276
2277	lseg = nfs4_proc_layoutget(lgp, &exception);
2278	trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2279				 PNFS_UPDATE_LAYOUT_SEND_LAYOUTGET);
2280	nfs_layoutget_end(lo);
2281	if (IS_ERR(lseg)) {
2282		switch(PTR_ERR(lseg)) {
2283		case -EBUSY:
2284			if (time_after(jiffies, giveup))
2285				lseg = NULL;
2286			break;
2287		case -ERECALLCONFLICT:
2288		case -EAGAIN:
2289			break;
2290		case -ENODATA:
2291			/* The server returned NFS4ERR_LAYOUTUNAVAILABLE */
2292			pnfs_layout_set_fail_bit(
2293				lo, pnfs_iomode_to_fail_bit(iomode));
2294			lseg = NULL;
2295			goto out_put_layout_hdr;
2296		default:
2297			if (!nfs_error_is_fatal(PTR_ERR(lseg))) {
2298				pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
2299				lseg = NULL;
2300			}
2301			goto out_put_layout_hdr;
2302		}
2303		if (lseg) {
2304			if (!exception.retry)
2305				goto out_put_layout_hdr;
2306			if (first)
2307				pnfs_clear_first_layoutget(lo);
2308			trace_pnfs_update_layout(ino, pos, count,
2309				iomode, lo, lseg, PNFS_UPDATE_LAYOUT_RETRY);
2310			pnfs_put_layout_hdr(lo);
2311			goto lookup_again;
2312		}
2313	} else {
2314		pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
2315	}
2316
2317out_put_layout_hdr:
2318	if (first)
2319		pnfs_clear_first_layoutget(lo);
2320	trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
2321				 PNFS_UPDATE_LAYOUT_EXIT);
2322	pnfs_put_layout_hdr(lo);
2323out:
2324	dprintk("%s: inode %s/%llu pNFS layout segment %s for "
2325			"(%s, offset: %llu, length: %llu)\n",
2326			__func__, ino->i_sb->s_id,
2327			(unsigned long long)NFS_FILEID(ino),
2328			IS_ERR_OR_NULL(lseg) ? "not found" : "found",
2329			iomode==IOMODE_RW ?  "read/write" : "read-only",
2330			(unsigned long long)pos,
2331			(unsigned long long)count);
2332	return lseg;
2333out_unlock:
2334	spin_unlock(&ino->i_lock);
2335	goto out_put_layout_hdr;
2336}
2337EXPORT_SYMBOL_GPL(pnfs_update_layout);
2338
2339static bool
2340pnfs_sanity_check_layout_range(struct pnfs_layout_range *range)
2341{
2342	switch (range->iomode) {
2343	case IOMODE_READ:
2344	case IOMODE_RW:
2345		break;
2346	default:
2347		return false;
2348	}
2349	if (range->offset == NFS4_MAX_UINT64)
2350		return false;
2351	if (range->length == 0)
2352		return false;
2353	if (range->length != NFS4_MAX_UINT64 &&
2354	    range->length > NFS4_MAX_UINT64 - range->offset)
2355		return false;
2356	return true;
2357}
2358
2359static struct pnfs_layout_hdr *
2360_pnfs_grab_empty_layout(struct inode *ino, struct nfs_open_context *ctx)
2361{
2362	struct pnfs_layout_hdr *lo;
2363
2364	spin_lock(&ino->i_lock);
2365	lo = pnfs_find_alloc_layout(ino, ctx, nfs_io_gfp_mask());
2366	if (!lo)
2367		goto out_unlock;
2368	if (!test_bit(NFS_LAYOUT_INVALID_STID, &lo->plh_flags))
2369		goto out_unlock;
2370	if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags))
2371		goto out_unlock;
2372	if (pnfs_layoutgets_blocked(lo))
2373		goto out_unlock;
2374	if (test_and_set_bit(NFS_LAYOUT_FIRST_LAYOUTGET, &lo->plh_flags))
2375		goto out_unlock;
2376	nfs_layoutget_begin(lo);
2377	spin_unlock(&ino->i_lock);
2378	_add_to_server_list(lo, NFS_SERVER(ino));
2379	return lo;
2380
2381out_unlock:
2382	spin_unlock(&ino->i_lock);
2383	pnfs_put_layout_hdr(lo);
2384	return NULL;
2385}
2386
2387static void _lgopen_prepare_attached(struct nfs4_opendata *data,
2388				     struct nfs_open_context *ctx)
2389{
2390	struct inode *ino = data->dentry->d_inode;
2391	struct pnfs_layout_range rng = {
2392		.iomode = (data->o_arg.fmode & FMODE_WRITE) ?
2393			  IOMODE_RW: IOMODE_READ,
2394		.offset = 0,
2395		.length = NFS4_MAX_UINT64,
2396	};
2397	struct nfs4_layoutget *lgp;
2398	struct pnfs_layout_hdr *lo;
2399
2400	/* Heuristic: don't send layoutget if we have cached data */
2401	if (rng.iomode == IOMODE_READ &&
2402	   (i_size_read(ino) == 0 || ino->i_mapping->nrpages != 0))
2403		return;
2404
2405	lo = _pnfs_grab_empty_layout(ino, ctx);
2406	if (!lo)
2407		return;
2408	lgp = pnfs_alloc_init_layoutget_args(ino, ctx, &current_stateid, &rng,
2409					     nfs_io_gfp_mask());
2410	if (!lgp) {
2411		pnfs_clear_first_layoutget(lo);
2412		nfs_layoutget_end(lo);
2413		pnfs_put_layout_hdr(lo);
2414		return;
2415	}
2416	lgp->lo = lo;
2417	data->lgp = lgp;
2418	data->o_arg.lg_args = &lgp->args;
2419	data->o_res.lg_res = &lgp->res;
2420}
2421
2422static void _lgopen_prepare_floating(struct nfs4_opendata *data,
2423				     struct nfs_open_context *ctx)
2424{
2425	struct inode *ino = data->dentry->d_inode;
2426	struct pnfs_layout_range rng = {
2427		.iomode = (data->o_arg.fmode & FMODE_WRITE) ?
2428			  IOMODE_RW: IOMODE_READ,
2429		.offset = 0,
2430		.length = NFS4_MAX_UINT64,
2431	};
2432	struct nfs4_layoutget *lgp;
2433
2434	lgp = pnfs_alloc_init_layoutget_args(ino, ctx, &current_stateid, &rng,
2435					     nfs_io_gfp_mask());
2436	if (!lgp)
2437		return;
2438	data->lgp = lgp;
2439	data->o_arg.lg_args = &lgp->args;
2440	data->o_res.lg_res = &lgp->res;
2441}
2442
2443void pnfs_lgopen_prepare(struct nfs4_opendata *data,
2444			 struct nfs_open_context *ctx)
2445{
2446	struct nfs_server *server = NFS_SERVER(data->dir->d_inode);
2447
2448	if (!(pnfs_enabled_sb(server) &&
2449	      server->pnfs_curr_ld->flags & PNFS_LAYOUTGET_ON_OPEN))
2450		return;
2451	/* Could check on max_ops, but currently hardcoded high enough */
2452	if (!nfs_server_capable(data->dir->d_inode, NFS_CAP_LGOPEN))
2453		return;
2454	if (data->lgp)
2455		return;
2456	if (data->state)
2457		_lgopen_prepare_attached(data, ctx);
2458	else
2459		_lgopen_prepare_floating(data, ctx);
2460}
2461
2462void pnfs_parse_lgopen(struct inode *ino, struct nfs4_layoutget *lgp,
2463		       struct nfs_open_context *ctx)
2464{
2465	struct pnfs_layout_hdr *lo;
2466	struct pnfs_layout_segment *lseg;
2467	struct nfs_server *srv = NFS_SERVER(ino);
2468	u32 iomode;
2469
2470	if (!lgp)
2471		return;
2472	dprintk("%s: entered with status %i\n", __func__, lgp->res.status);
2473	if (lgp->res.status) {
2474		switch (lgp->res.status) {
2475		default:
2476			break;
2477		/*
2478		 * Halt lgopen attempts if the server doesn't recognise
2479		 * the "current stateid" value, the layout type, or the
2480		 * layoutget operation as being valid.
2481		 * Also if it complains about too many ops in the compound
2482		 * or of the request/reply being too big.
2483		 */
2484		case -NFS4ERR_BAD_STATEID:
2485		case -NFS4ERR_NOTSUPP:
2486		case -NFS4ERR_REP_TOO_BIG:
2487		case -NFS4ERR_REP_TOO_BIG_TO_CACHE:
2488		case -NFS4ERR_REQ_TOO_BIG:
2489		case -NFS4ERR_TOO_MANY_OPS:
2490		case -NFS4ERR_UNKNOWN_LAYOUTTYPE:
2491			srv->caps &= ~NFS_CAP_LGOPEN;
2492		}
2493		return;
2494	}
2495	if (!lgp->lo) {
2496		lo = _pnfs_grab_empty_layout(ino, ctx);
2497		if (!lo)
2498			return;
2499		lgp->lo = lo;
2500	} else
2501		lo = lgp->lo;
2502
2503	lseg = pnfs_layout_process(lgp);
2504	if (!IS_ERR(lseg)) {
2505		iomode = lgp->args.range.iomode;
2506		pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
2507		pnfs_put_lseg(lseg);
2508	}
2509}
2510
2511void nfs4_lgopen_release(struct nfs4_layoutget *lgp)
2512{
2513	if (lgp != NULL) {
2514		if (lgp->lo) {
2515			pnfs_clear_first_layoutget(lgp->lo);
2516			nfs_layoutget_end(lgp->lo);
2517		}
2518		pnfs_layoutget_free(lgp);
2519	}
2520}
2521
2522struct pnfs_layout_segment *
2523pnfs_layout_process(struct nfs4_layoutget *lgp)
2524{
2525	struct pnfs_layout_hdr *lo = lgp->lo;
2526	struct nfs4_layoutget_res *res = &lgp->res;
2527	struct pnfs_layout_segment *lseg;
2528	struct inode *ino = lo->plh_inode;
2529	LIST_HEAD(free_me);
2530
2531	if (!pnfs_sanity_check_layout_range(&res->range))
2532		return ERR_PTR(-EINVAL);
2533
2534	/* Inject layout blob into I/O device driver */
2535	lseg = NFS_SERVER(ino)->pnfs_curr_ld->alloc_lseg(lo, res, lgp->gfp_flags);
2536	if (IS_ERR_OR_NULL(lseg)) {
2537		if (!lseg)
2538			lseg = ERR_PTR(-ENOMEM);
2539
2540		dprintk("%s: Could not allocate layout: error %ld\n",
2541		       __func__, PTR_ERR(lseg));
2542		return lseg;
2543	}
2544
2545	pnfs_init_lseg(lo, lseg, &res->range, &res->stateid);
2546
2547	spin_lock(&ino->i_lock);
2548	if (pnfs_layoutgets_blocked(lo)) {
2549		dprintk("%s forget reply due to state\n", __func__);
2550		goto out_forget;
2551	}
2552
2553	if (test_bit(NFS_LAYOUT_DRAIN, &lo->plh_flags) &&
2554	    !pnfs_is_first_layoutget(lo))
2555		goto out_forget;
2556
2557	if (nfs4_stateid_match_other(&lo->plh_stateid, &res->stateid)) {
2558		/* existing state ID, make sure the sequence number matches. */
2559		if (pnfs_layout_stateid_blocked(lo, &res->stateid)) {
2560			if (!pnfs_layout_is_valid(lo))
2561				lo->plh_barrier = 0;
2562			dprintk("%s forget reply due to sequence\n", __func__);
2563			goto out_forget;
2564		}
2565		pnfs_set_layout_stateid(lo, &res->stateid, lgp->cred, false);
2566	} else if (pnfs_layout_is_valid(lo)) {
2567		/*
2568		 * We got an entirely new state ID.  Mark all segments for the
2569		 * inode invalid, and retry the layoutget
2570		 */
2571		struct pnfs_layout_range range = {
2572			.iomode = IOMODE_ANY,
2573			.length = NFS4_MAX_UINT64,
2574		};
2575		pnfs_mark_matching_lsegs_return(lo, &free_me, &range, 0);
2576		goto out_forget;
2577	} else {
2578		/* We have a completely new layout */
2579		pnfs_set_layout_stateid(lo, &res->stateid, lgp->cred, true);
2580	}
2581
2582	pnfs_get_lseg(lseg);
2583	pnfs_layout_insert_lseg(lo, lseg, &free_me);
2584
2585
2586	if (res->return_on_close)
2587		set_bit(NFS_LSEG_ROC, &lseg->pls_flags);
2588
2589	spin_unlock(&ino->i_lock);
2590	pnfs_free_lseg_list(&free_me);
2591	return lseg;
2592
2593out_forget:
2594	spin_unlock(&ino->i_lock);
2595	lseg->pls_layout = lo;
2596	NFS_SERVER(ino)->pnfs_curr_ld->free_lseg(lseg);
2597	return ERR_PTR(-EAGAIN);
2598}
2599
2600/**
2601 * pnfs_mark_matching_lsegs_return - Free or return matching layout segments
2602 * @lo: pointer to layout header
2603 * @tmp_list: list header to be used with pnfs_free_lseg_list()
2604 * @return_range: describe layout segment ranges to be returned
2605 * @seq: stateid seqid to match
2606 *
2607 * This function is mainly intended for use by layoutrecall. It attempts
2608 * to free the layout segment immediately, or else to mark it for return
2609 * as soon as its reference count drops to zero.
2610 *
2611 * Returns
2612 * - 0: a layoutreturn needs to be scheduled.
2613 * - EBUSY: there are layout segment that are still in use.
2614 * - ENOENT: there are no layout segments that need to be returned.
2615 */
2616int
2617pnfs_mark_matching_lsegs_return(struct pnfs_layout_hdr *lo,
2618				struct list_head *tmp_list,
2619				const struct pnfs_layout_range *return_range,
2620				u32 seq)
2621{
2622	struct pnfs_layout_segment *lseg, *next;
2623	struct nfs_server *server = NFS_SERVER(lo->plh_inode);
2624	int remaining = 0;
2625
2626	dprintk("%s:Begin lo %p\n", __func__, lo);
2627
2628	assert_spin_locked(&lo->plh_inode->i_lock);
2629
2630	if (test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
2631		tmp_list = &lo->plh_return_segs;
2632
2633	list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list)
2634		if (pnfs_match_lseg_recall(lseg, return_range, seq)) {
2635			dprintk("%s: marking lseg %p iomode %d "
2636				"offset %llu length %llu\n", __func__,
2637				lseg, lseg->pls_range.iomode,
2638				lseg->pls_range.offset,
2639				lseg->pls_range.length);
2640			if (test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
2641				tmp_list = &lo->plh_return_segs;
2642			if (mark_lseg_invalid(lseg, tmp_list))
2643				continue;
2644			remaining++;
2645			set_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags);
2646			pnfs_lseg_cancel_io(server, lseg);
2647		}
2648
2649	if (remaining) {
2650		pnfs_set_plh_return_info(lo, return_range->iomode, seq);
2651		return -EBUSY;
2652	}
2653
2654	if (!list_empty(&lo->plh_return_segs)) {
2655		pnfs_set_plh_return_info(lo, return_range->iomode, seq);
2656		return 0;
2657	}
2658
2659	return -ENOENT;
2660}
2661
2662static void
2663pnfs_mark_layout_for_return(struct inode *inode,
2664			    const struct pnfs_layout_range *range)
2665{
2666	struct pnfs_layout_hdr *lo;
2667	bool return_now = false;
2668
2669	spin_lock(&inode->i_lock);
2670	lo = NFS_I(inode)->layout;
2671	if (!pnfs_layout_is_valid(lo)) {
2672		spin_unlock(&inode->i_lock);
2673		return;
2674	}
2675	pnfs_set_plh_return_info(lo, range->iomode, 0);
2676	/*
2677	 * mark all matching lsegs so that we are sure to have no live
2678	 * segments at hand when sending layoutreturn. See pnfs_put_lseg()
2679	 * for how it works.
2680	 */
2681	if (pnfs_mark_matching_lsegs_return(lo, &lo->plh_return_segs, range, 0) != -EBUSY) {
2682		const struct cred *cred;
2683		nfs4_stateid stateid;
2684		enum pnfs_iomode iomode;
2685
2686		return_now = pnfs_prepare_layoutreturn(lo, &stateid, &cred, &iomode);
2687		spin_unlock(&inode->i_lock);
2688		if (return_now)
2689			pnfs_send_layoutreturn(lo, &stateid, &cred, iomode,
2690					       PNFS_FL_LAYOUTRETURN_ASYNC);
2691	} else {
2692		spin_unlock(&inode->i_lock);
2693		nfs_commit_inode(inode, 0);
2694	}
2695}
2696
2697void pnfs_error_mark_layout_for_return(struct inode *inode,
2698				       struct pnfs_layout_segment *lseg)
2699{
2700	struct pnfs_layout_range range = {
2701		.iomode = lseg->pls_range.iomode,
2702		.offset = 0,
2703		.length = NFS4_MAX_UINT64,
2704	};
2705
2706	pnfs_mark_layout_for_return(inode, &range);
2707}
2708EXPORT_SYMBOL_GPL(pnfs_error_mark_layout_for_return);
2709
2710static bool
2711pnfs_layout_can_be_returned(struct pnfs_layout_hdr *lo)
2712{
2713	return pnfs_layout_is_valid(lo) &&
2714		!test_bit(NFS_LAYOUT_INODE_FREEING, &lo->plh_flags) &&
2715		!test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags);
2716}
2717
2718static struct pnfs_layout_segment *
2719pnfs_find_first_lseg(struct pnfs_layout_hdr *lo,
2720		     const struct pnfs_layout_range *range,
2721		     enum pnfs_iomode iomode)
2722{
2723	struct pnfs_layout_segment *lseg;
2724
2725	list_for_each_entry(lseg, &lo->plh_segs, pls_list) {
2726		if (!test_bit(NFS_LSEG_VALID, &lseg->pls_flags))
2727			continue;
2728		if (test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags))
2729			continue;
2730		if (lseg->pls_range.iomode != iomode && iomode != IOMODE_ANY)
2731			continue;
2732		if (pnfs_lseg_range_intersecting(&lseg->pls_range, range))
2733			return lseg;
2734	}
2735	return NULL;
2736}
2737
2738/* Find open file states whose mode matches that of the range */
2739static bool
2740pnfs_should_return_unused_layout(struct pnfs_layout_hdr *lo,
2741				 const struct pnfs_layout_range *range)
2742{
2743	struct list_head *head;
2744	struct nfs_open_context *ctx;
2745	fmode_t mode = 0;
2746
2747	if (!pnfs_layout_can_be_returned(lo) ||
2748	    !pnfs_find_first_lseg(lo, range, range->iomode))
2749		return false;
2750
2751	head = &NFS_I(lo->plh_inode)->open_files;
2752	list_for_each_entry_rcu(ctx, head, list) {
2753		if (ctx->state)
2754			mode |= ctx->state->state & (FMODE_READ|FMODE_WRITE);
2755	}
2756
2757	switch (range->iomode) {
2758	default:
2759		break;
2760	case IOMODE_READ:
2761		mode &= ~FMODE_WRITE;
2762		break;
2763	case IOMODE_RW:
2764		if (pnfs_find_first_lseg(lo, range, IOMODE_READ))
2765			mode &= ~FMODE_READ;
2766	}
2767	return mode == 0;
2768}
2769
2770static int pnfs_layout_return_unused_byserver(struct nfs_server *server,
2771					      void *data)
2772{
2773	const struct pnfs_layout_range *range = data;
2774	const struct cred *cred;
2775	struct pnfs_layout_hdr *lo;
2776	struct inode *inode;
2777	nfs4_stateid stateid;
2778	enum pnfs_iomode iomode;
2779
2780restart:
2781	rcu_read_lock();
2782	list_for_each_entry_rcu(lo, &server->layouts, plh_layouts) {
2783		inode = lo->plh_inode;
2784		if (!inode || !pnfs_layout_can_be_returned(lo) ||
2785		    test_bit(NFS_LAYOUT_RETURN_REQUESTED, &lo->plh_flags))
2786			continue;
2787		spin_lock(&inode->i_lock);
2788		if (!lo->plh_inode ||
2789		    !pnfs_should_return_unused_layout(lo, range)) {
2790			spin_unlock(&inode->i_lock);
2791			continue;
2792		}
2793		pnfs_get_layout_hdr(lo);
2794		pnfs_set_plh_return_info(lo, range->iomode, 0);
2795		if (pnfs_mark_matching_lsegs_return(lo, &lo->plh_return_segs,
2796						    range, 0) != 0 ||
2797		    !pnfs_prepare_layoutreturn(lo, &stateid, &cred, &iomode)) {
2798			spin_unlock(&inode->i_lock);
2799			rcu_read_unlock();
2800			pnfs_put_layout_hdr(lo);
2801			cond_resched();
2802			goto restart;
2803		}
2804		spin_unlock(&inode->i_lock);
2805		rcu_read_unlock();
2806		pnfs_send_layoutreturn(lo, &stateid, &cred, iomode,
2807				       PNFS_FL_LAYOUTRETURN_ASYNC);
2808		pnfs_put_layout_hdr(lo);
2809		cond_resched();
2810		goto restart;
2811	}
2812	rcu_read_unlock();
2813	return 0;
2814}
2815
2816void
2817pnfs_layout_return_unused_byclid(struct nfs_client *clp,
2818				 enum pnfs_iomode iomode)
2819{
2820	struct pnfs_layout_range range = {
2821		.iomode = iomode,
2822		.offset = 0,
2823		.length = NFS4_MAX_UINT64,
2824	};
2825
2826	nfs_client_for_each_server(clp, pnfs_layout_return_unused_byserver,
2827			&range);
2828}
2829
2830/* Check if we have we have a valid layout but if there isn't an intersection
2831 * between the request and the pgio->pg_lseg, put this pgio->pg_lseg away.
2832 */
2833void
2834pnfs_generic_pg_check_layout(struct nfs_pageio_descriptor *pgio,
2835			     struct nfs_page *req)
2836{
2837	if (pgio->pg_lseg == NULL ||
2838	    (test_bit(NFS_LSEG_VALID, &pgio->pg_lseg->pls_flags) &&
2839	    pnfs_lseg_request_intersecting(pgio->pg_lseg, req)))
2840		return;
2841	pnfs_put_lseg(pgio->pg_lseg);
2842	pgio->pg_lseg = NULL;
2843}
2844EXPORT_SYMBOL_GPL(pnfs_generic_pg_check_layout);
2845
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2846void
2847pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
2848{
2849	u64 rd_size;
2850
2851	pnfs_generic_pg_check_layout(pgio, req);
 
2852	if (pgio->pg_lseg == NULL) {
2853		if (pgio->pg_dreq == NULL)
2854			rd_size = i_size_read(pgio->pg_inode) - req_offset(req);
2855		else
2856			rd_size = nfs_dreq_bytes_left(pgio->pg_dreq,
2857						      req_offset(req));
2858
2859		pgio->pg_lseg =
2860			pnfs_update_layout(pgio->pg_inode, nfs_req_openctx(req),
2861					   req_offset(req), rd_size,
2862					   IOMODE_READ, false,
2863					   nfs_io_gfp_mask());
2864		if (IS_ERR(pgio->pg_lseg)) {
2865			pgio->pg_error = PTR_ERR(pgio->pg_lseg);
2866			pgio->pg_lseg = NULL;
2867			return;
2868		}
2869	}
2870	/* If no lseg, fall back to read through mds */
2871	if (pgio->pg_lseg == NULL)
2872		nfs_pageio_reset_read_mds(pgio);
2873
2874}
2875EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_read);
2876
2877void
2878pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio,
2879			   struct nfs_page *req, u64 wb_size)
2880{
2881	pnfs_generic_pg_check_layout(pgio, req);
 
2882	if (pgio->pg_lseg == NULL) {
2883		pgio->pg_lseg =
2884			pnfs_update_layout(pgio->pg_inode, nfs_req_openctx(req),
2885					   req_offset(req), wb_size, IOMODE_RW,
2886					   false, nfs_io_gfp_mask());
2887		if (IS_ERR(pgio->pg_lseg)) {
2888			pgio->pg_error = PTR_ERR(pgio->pg_lseg);
2889			pgio->pg_lseg = NULL;
2890			return;
2891		}
2892	}
2893	/* If no lseg, fall back to write through mds */
2894	if (pgio->pg_lseg == NULL)
2895		nfs_pageio_reset_write_mds(pgio);
2896}
2897EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_write);
2898
2899void
2900pnfs_generic_pg_cleanup(struct nfs_pageio_descriptor *desc)
2901{
2902	if (desc->pg_lseg) {
2903		pnfs_put_lseg(desc->pg_lseg);
2904		desc->pg_lseg = NULL;
2905	}
2906}
2907EXPORT_SYMBOL_GPL(pnfs_generic_pg_cleanup);
2908
2909/*
2910 * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
2911 * of bytes (maximum @req->wb_bytes) that can be coalesced.
2912 */
2913size_t
2914pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio,
2915		     struct nfs_page *prev, struct nfs_page *req)
2916{
2917	unsigned int size;
2918	u64 seg_end, req_start, seg_left;
2919
2920	size = nfs_generic_pg_test(pgio, prev, req);
2921	if (!size)
2922		return 0;
2923
2924	/*
2925	 * 'size' contains the number of bytes left in the current page (up
2926	 * to the original size asked for in @req->wb_bytes).
2927	 *
2928	 * Calculate how many bytes are left in the layout segment
2929	 * and if there are less bytes than 'size', return that instead.
2930	 *
2931	 * Please also note that 'end_offset' is actually the offset of the
2932	 * first byte that lies outside the pnfs_layout_range. FIXME?
2933	 *
2934	 */
2935	if (pgio->pg_lseg) {
2936		seg_end = pnfs_end_offset(pgio->pg_lseg->pls_range.offset,
2937				     pgio->pg_lseg->pls_range.length);
2938		req_start = req_offset(req);
2939
2940		/* start of request is past the last byte of this segment */
2941		if (req_start >= seg_end)
2942			return 0;
2943
2944		/* adjust 'size' iff there are fewer bytes left in the
2945		 * segment than what nfs_generic_pg_test returned */
2946		seg_left = seg_end - req_start;
2947		if (seg_left < size)
2948			size = (unsigned int)seg_left;
2949	}
2950
2951	return size;
2952}
2953EXPORT_SYMBOL_GPL(pnfs_generic_pg_test);
2954
2955int pnfs_write_done_resend_to_mds(struct nfs_pgio_header *hdr)
2956{
2957	struct nfs_pageio_descriptor pgio;
2958
2959	/* Resend all requests through the MDS */
2960	nfs_pageio_init_write(&pgio, hdr->inode, FLUSH_STABLE, true,
2961			      hdr->completion_ops);
2962	return nfs_pageio_resend(&pgio, hdr);
2963}
2964EXPORT_SYMBOL_GPL(pnfs_write_done_resend_to_mds);
2965
2966static void pnfs_ld_handle_write_error(struct nfs_pgio_header *hdr)
2967{
2968
2969	dprintk("pnfs write error = %d\n", hdr->pnfs_error);
2970	if (NFS_SERVER(hdr->inode)->pnfs_curr_ld->flags &
2971	    PNFS_LAYOUTRET_ON_ERROR) {
2972		pnfs_return_layout(hdr->inode);
2973	}
2974	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))
2975		hdr->task.tk_status = pnfs_write_done_resend_to_mds(hdr);
2976}
2977
2978/*
2979 * Called by non rpc-based layout drivers
2980 */
2981void pnfs_ld_write_done(struct nfs_pgio_header *hdr)
2982{
2983	if (likely(!hdr->pnfs_error)) {
2984		pnfs_set_layoutcommit(hdr->inode, hdr->lseg,
2985				hdr->mds_offset + hdr->res.count);
2986		hdr->mds_ops->rpc_call_done(&hdr->task, hdr);
2987	}
2988	trace_nfs4_pnfs_write(hdr, hdr->pnfs_error);
2989	if (unlikely(hdr->pnfs_error))
2990		pnfs_ld_handle_write_error(hdr);
2991	hdr->mds_ops->rpc_release(hdr);
2992}
2993EXPORT_SYMBOL_GPL(pnfs_ld_write_done);
2994
2995static void
2996pnfs_write_through_mds(struct nfs_pageio_descriptor *desc,
2997		struct nfs_pgio_header *hdr)
2998{
2999	struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
3000
3001	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
3002		list_splice_tail_init(&hdr->pages, &mirror->pg_list);
3003		nfs_pageio_reset_write_mds(desc);
3004		mirror->pg_recoalesce = 1;
3005	}
3006	hdr->completion_ops->completion(hdr);
3007}
3008
3009static enum pnfs_try_status
3010pnfs_try_to_write_data(struct nfs_pgio_header *hdr,
3011			const struct rpc_call_ops *call_ops,
3012			struct pnfs_layout_segment *lseg,
3013			int how)
3014{
3015	struct inode *inode = hdr->inode;
3016	enum pnfs_try_status trypnfs;
3017	struct nfs_server *nfss = NFS_SERVER(inode);
3018
3019	hdr->mds_ops = call_ops;
3020
3021	dprintk("%s: Writing ino:%lu %u@%llu (how %d)\n", __func__,
3022		inode->i_ino, hdr->args.count, hdr->args.offset, how);
3023	trypnfs = nfss->pnfs_curr_ld->write_pagelist(hdr, how);
3024	if (trypnfs != PNFS_NOT_ATTEMPTED)
3025		nfs_inc_stats(inode, NFSIOS_PNFS_WRITE);
3026	dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
3027	return trypnfs;
3028}
3029
3030static void
3031pnfs_do_write(struct nfs_pageio_descriptor *desc,
3032	      struct nfs_pgio_header *hdr, int how)
3033{
3034	const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
3035	struct pnfs_layout_segment *lseg = desc->pg_lseg;
3036	enum pnfs_try_status trypnfs;
3037
3038	trypnfs = pnfs_try_to_write_data(hdr, call_ops, lseg, how);
3039	switch (trypnfs) {
3040	case PNFS_NOT_ATTEMPTED:
3041		pnfs_write_through_mds(desc, hdr);
3042		break;
3043	case PNFS_ATTEMPTED:
3044		break;
3045	case PNFS_TRY_AGAIN:
3046		/* cleanup hdr and prepare to redo pnfs */
3047		if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
3048			struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
3049			list_splice_init(&hdr->pages, &mirror->pg_list);
3050			mirror->pg_recoalesce = 1;
3051		}
3052		hdr->mds_ops->rpc_release(hdr);
3053	}
3054}
3055
3056static void pnfs_writehdr_free(struct nfs_pgio_header *hdr)
3057{
3058	pnfs_put_lseg(hdr->lseg);
3059	nfs_pgio_header_free(hdr);
3060}
3061
3062int
3063pnfs_generic_pg_writepages(struct nfs_pageio_descriptor *desc)
3064{
3065	struct nfs_pgio_header *hdr;
3066	int ret;
3067
3068	hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
3069	if (!hdr) {
3070		desc->pg_error = -ENOMEM;
3071		return desc->pg_error;
3072	}
3073	nfs_pgheader_init(desc, hdr, pnfs_writehdr_free);
3074
3075	hdr->lseg = pnfs_get_lseg(desc->pg_lseg);
3076	ret = nfs_generic_pgio(desc, hdr);
3077	if (!ret)
3078		pnfs_do_write(desc, hdr, desc->pg_ioflags);
3079
3080	return ret;
3081}
3082EXPORT_SYMBOL_GPL(pnfs_generic_pg_writepages);
3083
3084int pnfs_read_done_resend_to_mds(struct nfs_pgio_header *hdr)
3085{
3086	struct nfs_pageio_descriptor pgio;
3087
3088	/* Resend all requests through the MDS */
3089	nfs_pageio_init_read(&pgio, hdr->inode, true, hdr->completion_ops);
3090	return nfs_pageio_resend(&pgio, hdr);
3091}
3092EXPORT_SYMBOL_GPL(pnfs_read_done_resend_to_mds);
3093
3094static void pnfs_ld_handle_read_error(struct nfs_pgio_header *hdr)
3095{
3096	dprintk("pnfs read error = %d\n", hdr->pnfs_error);
3097	if (NFS_SERVER(hdr->inode)->pnfs_curr_ld->flags &
3098	    PNFS_LAYOUTRET_ON_ERROR) {
3099		pnfs_return_layout(hdr->inode);
3100	}
3101	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags))
3102		hdr->task.tk_status = pnfs_read_done_resend_to_mds(hdr);
3103}
3104
3105/*
3106 * Called by non rpc-based layout drivers
3107 */
3108void pnfs_ld_read_done(struct nfs_pgio_header *hdr)
3109{
3110	if (likely(!hdr->pnfs_error))
3111		hdr->mds_ops->rpc_call_done(&hdr->task, hdr);
3112	trace_nfs4_pnfs_read(hdr, hdr->pnfs_error);
3113	if (unlikely(hdr->pnfs_error))
3114		pnfs_ld_handle_read_error(hdr);
3115	hdr->mds_ops->rpc_release(hdr);
3116}
3117EXPORT_SYMBOL_GPL(pnfs_ld_read_done);
3118
3119static void
3120pnfs_read_through_mds(struct nfs_pageio_descriptor *desc,
3121		struct nfs_pgio_header *hdr)
3122{
3123	struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
3124
3125	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
3126		list_splice_tail_init(&hdr->pages, &mirror->pg_list);
3127		nfs_pageio_reset_read_mds(desc);
3128		mirror->pg_recoalesce = 1;
3129	}
3130	hdr->completion_ops->completion(hdr);
3131}
3132
3133/*
3134 * Call the appropriate parallel I/O subsystem read function.
3135 */
3136static enum pnfs_try_status
3137pnfs_try_to_read_data(struct nfs_pgio_header *hdr,
3138		       const struct rpc_call_ops *call_ops,
3139		       struct pnfs_layout_segment *lseg)
3140{
3141	struct inode *inode = hdr->inode;
3142	struct nfs_server *nfss = NFS_SERVER(inode);
3143	enum pnfs_try_status trypnfs;
3144
3145	hdr->mds_ops = call_ops;
3146
3147	dprintk("%s: Reading ino:%lu %u@%llu\n",
3148		__func__, inode->i_ino, hdr->args.count, hdr->args.offset);
3149
3150	trypnfs = nfss->pnfs_curr_ld->read_pagelist(hdr);
3151	if (trypnfs != PNFS_NOT_ATTEMPTED)
3152		nfs_inc_stats(inode, NFSIOS_PNFS_READ);
3153	dprintk("%s End (trypnfs:%d)\n", __func__, trypnfs);
3154	return trypnfs;
3155}
3156
3157/* Resend all requests through pnfs. */
3158void pnfs_read_resend_pnfs(struct nfs_pgio_header *hdr,
3159			   unsigned int mirror_idx)
3160{
3161	struct nfs_pageio_descriptor pgio;
3162
3163	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
3164		/* Prevent deadlocks with layoutreturn! */
3165		pnfs_put_lseg(hdr->lseg);
3166		hdr->lseg = NULL;
3167
3168		nfs_pageio_init_read(&pgio, hdr->inode, false,
3169					hdr->completion_ops);
3170		pgio.pg_mirror_idx = mirror_idx;
3171		hdr->task.tk_status = nfs_pageio_resend(&pgio, hdr);
3172	}
3173}
3174EXPORT_SYMBOL_GPL(pnfs_read_resend_pnfs);
3175
3176static void
3177pnfs_do_read(struct nfs_pageio_descriptor *desc, struct nfs_pgio_header *hdr)
3178{
3179	const struct rpc_call_ops *call_ops = desc->pg_rpc_callops;
3180	struct pnfs_layout_segment *lseg = desc->pg_lseg;
3181	enum pnfs_try_status trypnfs;
3182
3183	trypnfs = pnfs_try_to_read_data(hdr, call_ops, lseg);
3184	switch (trypnfs) {
3185	case PNFS_NOT_ATTEMPTED:
3186		pnfs_read_through_mds(desc, hdr);
3187		break;
3188	case PNFS_ATTEMPTED:
3189		break;
3190	case PNFS_TRY_AGAIN:
3191		/* cleanup hdr and prepare to redo pnfs */
3192		if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
3193			struct nfs_pgio_mirror *mirror = nfs_pgio_current_mirror(desc);
3194			list_splice_init(&hdr->pages, &mirror->pg_list);
3195			mirror->pg_recoalesce = 1;
3196		}
3197		hdr->mds_ops->rpc_release(hdr);
3198	}
3199}
3200
3201static void pnfs_readhdr_free(struct nfs_pgio_header *hdr)
3202{
3203	pnfs_put_lseg(hdr->lseg);
3204	nfs_pgio_header_free(hdr);
3205}
3206
3207int
3208pnfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc)
3209{
3210	struct nfs_pgio_header *hdr;
3211	int ret;
3212
3213	hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
3214	if (!hdr) {
3215		desc->pg_error = -ENOMEM;
3216		return desc->pg_error;
3217	}
3218	nfs_pgheader_init(desc, hdr, pnfs_readhdr_free);
3219	hdr->lseg = pnfs_get_lseg(desc->pg_lseg);
3220	ret = nfs_generic_pgio(desc, hdr);
3221	if (!ret)
3222		pnfs_do_read(desc, hdr);
3223	return ret;
3224}
3225EXPORT_SYMBOL_GPL(pnfs_generic_pg_readpages);
3226
3227static void pnfs_clear_layoutcommitting(struct inode *inode)
3228{
3229	unsigned long *bitlock = &NFS_I(inode)->flags;
3230
3231	clear_bit_unlock(NFS_INO_LAYOUTCOMMITTING, bitlock);
3232	smp_mb__after_atomic();
3233	wake_up_bit(bitlock, NFS_INO_LAYOUTCOMMITTING);
3234}
3235
3236/*
3237 * There can be multiple RW segments.
3238 */
3239static void pnfs_list_write_lseg(struct inode *inode, struct list_head *listp)
3240{
3241	struct pnfs_layout_segment *lseg;
3242
3243	list_for_each_entry(lseg, &NFS_I(inode)->layout->plh_segs, pls_list) {
3244		if (lseg->pls_range.iomode == IOMODE_RW &&
3245		    test_and_clear_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags))
3246			list_add(&lseg->pls_lc_list, listp);
3247	}
3248}
3249
3250static void pnfs_list_write_lseg_done(struct inode *inode, struct list_head *listp)
3251{
3252	struct pnfs_layout_segment *lseg, *tmp;
3253
3254	/* Matched by references in pnfs_set_layoutcommit */
3255	list_for_each_entry_safe(lseg, tmp, listp, pls_lc_list) {
3256		list_del_init(&lseg->pls_lc_list);
3257		pnfs_put_lseg(lseg);
3258	}
3259
3260	pnfs_clear_layoutcommitting(inode);
3261}
3262
3263void pnfs_set_lo_fail(struct pnfs_layout_segment *lseg)
3264{
3265	pnfs_layout_io_set_failed(lseg->pls_layout, lseg->pls_range.iomode);
3266}
3267EXPORT_SYMBOL_GPL(pnfs_set_lo_fail);
3268
3269void
3270pnfs_set_layoutcommit(struct inode *inode, struct pnfs_layout_segment *lseg,
3271		loff_t end_pos)
3272{
3273	struct nfs_inode *nfsi = NFS_I(inode);
3274	bool mark_as_dirty = false;
3275
3276	spin_lock(&inode->i_lock);
3277	if (!test_and_set_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags)) {
3278		nfsi->layout->plh_lwb = end_pos;
3279		mark_as_dirty = true;
3280		dprintk("%s: Set layoutcommit for inode %lu ",
3281			__func__, inode->i_ino);
3282	} else if (end_pos > nfsi->layout->plh_lwb)
3283		nfsi->layout->plh_lwb = end_pos;
3284	if (!test_and_set_bit(NFS_LSEG_LAYOUTCOMMIT, &lseg->pls_flags)) {
3285		/* references matched in nfs4_layoutcommit_release */
3286		pnfs_get_lseg(lseg);
3287	}
3288	spin_unlock(&inode->i_lock);
3289	dprintk("%s: lseg %p end_pos %llu\n",
3290		__func__, lseg, nfsi->layout->plh_lwb);
3291
3292	/* if pnfs_layoutcommit_inode() runs between inode locks, the next one
3293	 * will be a noop because NFS_INO_LAYOUTCOMMIT will not be set */
3294	if (mark_as_dirty)
3295		mark_inode_dirty_sync(inode);
3296}
3297EXPORT_SYMBOL_GPL(pnfs_set_layoutcommit);
3298
3299void pnfs_cleanup_layoutcommit(struct nfs4_layoutcommit_data *data)
3300{
3301	struct nfs_server *nfss = NFS_SERVER(data->args.inode);
3302
3303	if (nfss->pnfs_curr_ld->cleanup_layoutcommit)
3304		nfss->pnfs_curr_ld->cleanup_layoutcommit(data);
3305	pnfs_list_write_lseg_done(data->args.inode, &data->lseg_list);
3306}
3307
3308/*
3309 * For the LAYOUT4_NFSV4_1_FILES layout type, NFS_DATA_SYNC WRITEs and
3310 * NFS_UNSTABLE WRITEs with a COMMIT to data servers must store enough
3311 * data to disk to allow the server to recover the data if it crashes.
3312 * LAYOUTCOMMIT is only needed when the NFL4_UFLG_COMMIT_THRU_MDS flag
3313 * is off, and a COMMIT is sent to a data server, or
3314 * if WRITEs to a data server return NFS_DATA_SYNC.
3315 */
3316int
3317pnfs_layoutcommit_inode(struct inode *inode, bool sync)
3318{
3319	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
3320	struct nfs4_layoutcommit_data *data;
3321	struct nfs_inode *nfsi = NFS_I(inode);
3322	loff_t end_pos;
3323	int status;
3324
3325	if (!pnfs_layoutcommit_outstanding(inode))
3326		return 0;
3327
3328	dprintk("--> %s inode %lu\n", __func__, inode->i_ino);
3329
3330	status = -EAGAIN;
3331	if (test_and_set_bit(NFS_INO_LAYOUTCOMMITTING, &nfsi->flags)) {
3332		if (!sync)
3333			goto out;
3334		status = wait_on_bit_lock_action(&nfsi->flags,
3335				NFS_INO_LAYOUTCOMMITTING,
3336				nfs_wait_bit_killable,
3337				TASK_KILLABLE|TASK_FREEZABLE_UNSAFE);
3338		if (status)
3339			goto out;
3340	}
3341
3342	status = -ENOMEM;
3343	/* Note kzalloc ensures data->res.seq_res.sr_slot == NULL */
3344	data = kzalloc(sizeof(*data), nfs_io_gfp_mask());
3345	if (!data)
3346		goto clear_layoutcommitting;
3347
3348	status = 0;
3349	spin_lock(&inode->i_lock);
3350	if (!test_and_clear_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags))
3351		goto out_unlock;
3352
3353	INIT_LIST_HEAD(&data->lseg_list);
3354	pnfs_list_write_lseg(inode, &data->lseg_list);
3355
3356	end_pos = nfsi->layout->plh_lwb;
3357
3358	nfs4_stateid_copy(&data->args.stateid, &nfsi->layout->plh_stateid);
3359	data->cred = get_cred(nfsi->layout->plh_lc_cred);
3360	spin_unlock(&inode->i_lock);
3361
3362	data->args.inode = inode;
3363	nfs_fattr_init(&data->fattr);
3364	data->args.bitmask = NFS_SERVER(inode)->cache_consistency_bitmask;
3365	data->res.fattr = &data->fattr;
3366	if (end_pos != 0)
3367		data->args.lastbytewritten = end_pos - 1;
3368	else
3369		data->args.lastbytewritten = U64_MAX;
3370	data->res.server = NFS_SERVER(inode);
3371
3372	if (ld->prepare_layoutcommit) {
3373		status = ld->prepare_layoutcommit(&data->args);
3374		if (status) {
3375			put_cred(data->cred);
3376			spin_lock(&inode->i_lock);
3377			set_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags);
3378			if (end_pos > nfsi->layout->plh_lwb)
3379				nfsi->layout->plh_lwb = end_pos;
3380			goto out_unlock;
3381		}
3382	}
3383
3384
3385	status = nfs4_proc_layoutcommit(data, sync);
3386out:
3387	if (status)
3388		mark_inode_dirty_sync(inode);
3389	dprintk("<-- %s status %d\n", __func__, status);
3390	return status;
3391out_unlock:
3392	spin_unlock(&inode->i_lock);
3393	kfree(data);
3394clear_layoutcommitting:
3395	pnfs_clear_layoutcommitting(inode);
3396	goto out;
3397}
3398EXPORT_SYMBOL_GPL(pnfs_layoutcommit_inode);
3399
3400int
3401pnfs_generic_sync(struct inode *inode, bool datasync)
3402{
3403	return pnfs_layoutcommit_inode(inode, true);
3404}
3405EXPORT_SYMBOL_GPL(pnfs_generic_sync);
3406
3407struct nfs4_threshold *pnfs_mdsthreshold_alloc(void)
3408{
3409	struct nfs4_threshold *thp;
3410
3411	thp = kzalloc(sizeof(*thp), nfs_io_gfp_mask());
3412	if (!thp) {
3413		dprintk("%s mdsthreshold allocation failed\n", __func__);
3414		return NULL;
3415	}
3416	return thp;
3417}
3418
3419#if IS_ENABLED(CONFIG_NFS_V4_2)
3420int
3421pnfs_report_layoutstat(struct inode *inode, gfp_t gfp_flags)
3422{
3423	struct pnfs_layoutdriver_type *ld = NFS_SERVER(inode)->pnfs_curr_ld;
3424	struct nfs_server *server = NFS_SERVER(inode);
3425	struct nfs_inode *nfsi = NFS_I(inode);
3426	struct nfs42_layoutstat_data *data;
3427	struct pnfs_layout_hdr *hdr;
3428	int status = 0;
3429
3430	if (!pnfs_enabled_sb(server) || !ld->prepare_layoutstats)
3431		goto out;
3432
3433	if (!nfs_server_capable(inode, NFS_CAP_LAYOUTSTATS))
3434		goto out;
3435
3436	if (test_and_set_bit(NFS_INO_LAYOUTSTATS, &nfsi->flags))
3437		goto out;
3438
3439	spin_lock(&inode->i_lock);
3440	if (!NFS_I(inode)->layout) {
3441		spin_unlock(&inode->i_lock);
3442		goto out_clear_layoutstats;
3443	}
3444	hdr = NFS_I(inode)->layout;
3445	pnfs_get_layout_hdr(hdr);
3446	spin_unlock(&inode->i_lock);
3447
3448	data = kzalloc(sizeof(*data), gfp_flags);
3449	if (!data) {
3450		status = -ENOMEM;
3451		goto out_put;
3452	}
3453
3454	data->args.fh = NFS_FH(inode);
3455	data->args.inode = inode;
3456	status = ld->prepare_layoutstats(&data->args);
3457	if (status)
3458		goto out_free;
3459
3460	status = nfs42_proc_layoutstats_generic(NFS_SERVER(inode), data);
3461
3462out:
3463	dprintk("%s returns %d\n", __func__, status);
3464	return status;
3465
3466out_free:
3467	kfree(data);
3468out_put:
3469	pnfs_put_layout_hdr(hdr);
3470out_clear_layoutstats:
3471	smp_mb__before_atomic();
3472	clear_bit(NFS_INO_LAYOUTSTATS, &nfsi->flags);
3473	smp_mb__after_atomic();
3474	goto out;
3475}
3476EXPORT_SYMBOL_GPL(pnfs_report_layoutstat);
3477#endif
3478
3479unsigned int layoutstats_timer;
3480module_param(layoutstats_timer, uint, 0644);
3481EXPORT_SYMBOL_GPL(layoutstats_timer);