1/*
   2 *  Module for the pnfs nfs4 file layout driver.
   3 *  Defines all I/O and Policy interface operations, plus code
   4 *  to register itself with the pNFS client.
   5 *
   6 *  Copyright (c) 2002
   7 *  The Regents of the University of Michigan
   8 *  All Rights Reserved
   9 *
  10 *  Dean Hildebrand <dhildebz@umich.edu>
  11 *
  12 *  Permission is granted to use, copy, create derivative works, and
  13 *  redistribute this software and such derivative works for any purpose,
  14 *  so long as the name of the University of Michigan is not used in
  15 *  any advertising or publicity pertaining to the use or distribution
  16 *  of this software without specific, written prior authorization. If
  17 *  the above copyright notice or any other identification of the
  18 *  University of Michigan is included in any copy of any portion of
  19 *  this software, then the disclaimer below must also be included.
  20 *
  21 *  This software is provided as is, without representation or warranty
  22 *  of any kind either express or implied, including without limitation
  23 *  the implied warranties of merchantability, fitness for a particular
  24 *  purpose, or noninfringement.  The Regents of the University of
  25 *  Michigan shall not be liable for any damages, including special,
  26 *  indirect, incidental, or consequential damages, with respect to any
  27 *  claim arising out of or in connection with the use of the software,
  28 *  even if it has been or is hereafter advised of the possibility of
  29 *  such damages.
  30 */
  31
  32#include <linux/nfs_fs.h>
  33#include <linux/nfs_page.h>
  34#include <linux/module.h>
  35#include <linux/backing-dev.h>
  36
  37#include <linux/sunrpc/metrics.h>
  38
  39#include "../nfs4session.h"
  40#include "../internal.h"
  41#include "../delegation.h"
  42#include "filelayout.h"
  43#include "../nfs4trace.h"
  44
  45#define NFSDBG_FACILITY         NFSDBG_PNFS_LD
  46
  47MODULE_LICENSE("GPL");
  48MODULE_AUTHOR("Dean Hildebrand <dhildebz@umich.edu>");
  49MODULE_DESCRIPTION("The NFSv4 file layout driver");
  50
  51#define FILELAYOUT_POLL_RETRY_MAX     (15*HZ)
  52
  53static loff_t
  54filelayout_get_dense_offset(struct nfs4_filelayout_segment *flseg,
  55			    loff_t offset)
  56{
  57	u32 stripe_width = flseg->stripe_unit * flseg->dsaddr->stripe_count;
  58	u64 stripe_no;
  59	u32 rem;
  60
  61	offset -= flseg->pattern_offset;
  62	stripe_no = div_u64(offset, stripe_width);
  63	div_u64_rem(offset, flseg->stripe_unit, &rem);
  64
  65	return stripe_no * flseg->stripe_unit + rem;
  66}
  67
  68/* This function is used by the layout driver to calculate the
  69 * offset of the file on the dserver based on whether the
  70 * layout type is STRIPE_DENSE or STRIPE_SPARSE
  71 */
  72static loff_t
  73filelayout_get_dserver_offset(struct pnfs_layout_segment *lseg, loff_t offset)
  74{
  75	struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
  76
  77	switch (flseg->stripe_type) {
  78	case STRIPE_SPARSE:
  79		return offset;
  80
  81	case STRIPE_DENSE:
  82		return filelayout_get_dense_offset(flseg, offset);
  83	}
  84
  85	BUG();
  86}
  87
  88static void filelayout_reset_write(struct nfs_pgio_header *hdr)
  89{
  90	struct rpc_task *task = &hdr->task;
  91
  92	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
  93		dprintk("%s Reset task %5u for i/o through MDS "
  94			"(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
  95			hdr->task.tk_pid,
  96			hdr->inode->i_sb->s_id,
  97			(unsigned long long)NFS_FILEID(hdr->inode),
  98			hdr->args.count,
  99			(unsigned long long)hdr->args.offset);
 100
 101		task->tk_status = pnfs_write_done_resend_to_mds(hdr);
 102	}
 103}
 104
 105static void filelayout_reset_read(struct nfs_pgio_header *hdr)
 106{
 107	struct rpc_task *task = &hdr->task;
 108
 109	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
 110		dprintk("%s Reset task %5u for i/o through MDS "
 111			"(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
 112			hdr->task.tk_pid,
 113			hdr->inode->i_sb->s_id,
 114			(unsigned long long)NFS_FILEID(hdr->inode),
 115			hdr->args.count,
 116			(unsigned long long)hdr->args.offset);
 117
 118		task->tk_status = pnfs_read_done_resend_to_mds(hdr);
 119	}
 120}
 121
 122static int filelayout_async_handle_error(struct rpc_task *task,
 123					 struct nfs4_state *state,
 124					 struct nfs_client *clp,
 125					 struct pnfs_layout_segment *lseg)
 126{
 127	struct pnfs_layout_hdr *lo = lseg->pls_layout;
 128	struct inode *inode = lo->plh_inode;
 129	struct nfs_server *mds_server = NFS_SERVER(inode);
 130	struct nfs4_deviceid_node *devid = FILELAYOUT_DEVID_NODE(lseg);
 131	struct nfs_client *mds_client = mds_server->nfs_client;
 132	struct nfs4_slot_table *tbl = &clp->cl_session->fc_slot_table;
 133
 134	if (task->tk_status >= 0)
 135		return 0;
 136
 137	switch (task->tk_status) {
 138	/* MDS state errors */
 139	case -NFS4ERR_DELEG_REVOKED:
 140	case -NFS4ERR_ADMIN_REVOKED:
 141	case -NFS4ERR_BAD_STATEID:
 142	case -NFS4ERR_OPENMODE:
 143		if (state == NULL)
 144			break;
 145		if (nfs4_schedule_stateid_recovery(mds_server, state) < 0)
 146			goto out_bad_stateid;
 147		goto wait_on_recovery;
 148	case -NFS4ERR_EXPIRED:
 149		if (state != NULL) {
 150			if (nfs4_schedule_stateid_recovery(mds_server, state) < 0)
 151				goto out_bad_stateid;
 152		}
 153		nfs4_schedule_lease_recovery(mds_client);
 154		goto wait_on_recovery;
 155	/* DS session errors */
 156	case -NFS4ERR_BADSESSION:
 157	case -NFS4ERR_BADSLOT:
 158	case -NFS4ERR_BAD_HIGH_SLOT:
 159	case -NFS4ERR_DEADSESSION:
 160	case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
 161	case -NFS4ERR_SEQ_FALSE_RETRY:
 162	case -NFS4ERR_SEQ_MISORDERED:
 163		dprintk("%s ERROR %d, Reset session. Exchangeid "
 164			"flags 0x%x\n", __func__, task->tk_status,
 165			clp->cl_exchange_flags);
 166		nfs4_schedule_session_recovery(clp->cl_session, task->tk_status);
 167		break;
 168	case -NFS4ERR_DELAY:
 169	case -NFS4ERR_GRACE:
 170		rpc_delay(task, FILELAYOUT_POLL_RETRY_MAX);
 171		break;
 172	case -NFS4ERR_RETRY_UNCACHED_REP:
 173		break;
 174	/* Invalidate Layout errors */
 175	case -NFS4ERR_PNFS_NO_LAYOUT:
 176	case -ESTALE:           /* mapped NFS4ERR_STALE */
 177	case -EBADHANDLE:       /* mapped NFS4ERR_BADHANDLE */
 178	case -EISDIR:           /* mapped NFS4ERR_ISDIR */
 179	case -NFS4ERR_FHEXPIRED:
 180	case -NFS4ERR_WRONG_TYPE:
 181		dprintk("%s Invalid layout error %d\n", __func__,
 182			task->tk_status);
 183		/*
 184		 * Destroy layout so new i/o will get a new layout.
 185		 * Layout will not be destroyed until all current lseg
 186		 * references are put. Mark layout as invalid to resend failed
 187		 * i/o and all i/o waiting on the slot table to the MDS until
 188		 * layout is destroyed and a new valid layout is obtained.
 189		 */
 190		pnfs_destroy_layout(NFS_I(inode));
 191		rpc_wake_up(&tbl->slot_tbl_waitq);
 192		goto reset;
 193	/* RPC connection errors */
 194	case -ECONNREFUSED:
 195	case -EHOSTDOWN:
 196	case -EHOSTUNREACH:
 197	case -ENETUNREACH:
 198	case -EIO:
 199	case -ETIMEDOUT:
 200	case -EPIPE:
 201		dprintk("%s DS connection error %d\n", __func__,
 202			task->tk_status);
 203		nfs4_mark_deviceid_unavailable(devid);
 204		pnfs_error_mark_layout_for_return(inode, lseg);
 205		pnfs_set_lo_fail(lseg);
 206		rpc_wake_up(&tbl->slot_tbl_waitq);
 207		/* fall through */
 208	default:
 209reset:
 210		dprintk("%s Retry through MDS. Error %d\n", __func__,
 211			task->tk_status);
 212		return -NFS4ERR_RESET_TO_MDS;
 213	}
 214out:
 215	task->tk_status = 0;
 216	return -EAGAIN;
 217out_bad_stateid:
 218	task->tk_status = -EIO;
 219	return 0;
 220wait_on_recovery:
 221	rpc_sleep_on(&mds_client->cl_rpcwaitq, task, NULL);
 222	if (test_bit(NFS4CLNT_MANAGER_RUNNING, &mds_client->cl_state) == 0)
 223		rpc_wake_up_queued_task(&mds_client->cl_rpcwaitq, task);
 224	goto out;
 225}
 226
 227/* NFS_PROTO call done callback routines */
 228
 229static int filelayout_read_done_cb(struct rpc_task *task,
 230				struct nfs_pgio_header *hdr)
 231{
 232	int err;
 233
 234	trace_nfs4_pnfs_read(hdr, task->tk_status);
 235	err = filelayout_async_handle_error(task, hdr->args.context->state,
 236					    hdr->ds_clp, hdr->lseg);
 237
 238	switch (err) {
 239	case -NFS4ERR_RESET_TO_MDS:
 240		filelayout_reset_read(hdr);
 241		return task->tk_status;
 242	case -EAGAIN:
 243		rpc_restart_call_prepare(task);
 244		return -EAGAIN;
 245	}
 246
 247	return 0;
 248}
 249
 250/*
 251 * We reference the rpc_cred of the first WRITE that triggers the need for
 252 * a LAYOUTCOMMIT, and use it to send the layoutcommit compound.
 253 * rfc5661 is not clear about which credential should be used.
 254 */
 255static void
 256filelayout_set_layoutcommit(struct nfs_pgio_header *hdr)
 257{
 258	loff_t end_offs = 0;
 259
 260	if (FILELAYOUT_LSEG(hdr->lseg)->commit_through_mds ||
 261	    hdr->res.verf->committed == NFS_FILE_SYNC)
 262		return;
 263	if (hdr->res.verf->committed == NFS_DATA_SYNC)
 264		end_offs = hdr->mds_offset + (loff_t)hdr->res.count;
 265
 266	/* Note: if the write is unstable, don't set end_offs until commit */
 267	pnfs_set_layoutcommit(hdr->inode, hdr->lseg, end_offs);
 268	dprintk("%s inode %lu pls_end_pos %lu\n", __func__, hdr->inode->i_ino,
 269		(unsigned long) NFS_I(hdr->inode)->layout->plh_lwb);
 270}
 271
 272bool
 273filelayout_test_devid_unavailable(struct nfs4_deviceid_node *node)
 274{
 275	return filelayout_test_devid_invalid(node) ||
 276		nfs4_test_deviceid_unavailable(node);
 277}
 278
 279static bool
 280filelayout_reset_to_mds(struct pnfs_layout_segment *lseg)
 281{
 282	struct nfs4_deviceid_node *node = FILELAYOUT_DEVID_NODE(lseg);
 283
 284	return filelayout_test_devid_unavailable(node);
 285}
 286
 287/*
 288 * Call ops for the async read/write cases
 289 * In the case of dense layouts, the offset needs to be reset to its
 290 * original value.
 291 */
 292static void filelayout_read_prepare(struct rpc_task *task, void *data)
 293{
 294	struct nfs_pgio_header *hdr = data;
 295
 296	if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
 297		rpc_exit(task, -EIO);
 298		return;
 299	}
 300	if (filelayout_reset_to_mds(hdr->lseg)) {
 301		dprintk("%s task %u reset io to MDS\n", __func__, task->tk_pid);
 302		filelayout_reset_read(hdr);
 303		rpc_exit(task, 0);
 304		return;
 305	}
 306	hdr->pgio_done_cb = filelayout_read_done_cb;
 307
 308	if (nfs41_setup_sequence(hdr->ds_clp->cl_session,
 309			&hdr->args.seq_args,
 310			&hdr->res.seq_res,
 311			task))
 312		return;
 313	if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
 314			hdr->args.lock_context, FMODE_READ) == -EIO)
 315		rpc_exit(task, -EIO); /* lost lock, terminate I/O */
 316}
 317
 318static void filelayout_read_call_done(struct rpc_task *task, void *data)
 319{
 320	struct nfs_pgio_header *hdr = data;
 321
 322	dprintk("--> %s task->tk_status %d\n", __func__, task->tk_status);
 323
 324	if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
 325	    task->tk_status == 0) {
 326		nfs41_sequence_done(task, &hdr->res.seq_res);
 327		return;
 328	}
 329
 330	/* Note this may cause RPC to be resent */
 331	hdr->mds_ops->rpc_call_done(task, data);
 332}
 333
 334static void filelayout_read_count_stats(struct rpc_task *task, void *data)
 335{
 336	struct nfs_pgio_header *hdr = data;
 337
 338	rpc_count_iostats(task, NFS_SERVER(hdr->inode)->client->cl_metrics);
 339}
 340
 341static int filelayout_write_done_cb(struct rpc_task *task,
 342				struct nfs_pgio_header *hdr)
 343{
 344	int err;
 345
 346	trace_nfs4_pnfs_write(hdr, task->tk_status);
 347	err = filelayout_async_handle_error(task, hdr->args.context->state,
 348					    hdr->ds_clp, hdr->lseg);
 349
 350	switch (err) {
 351	case -NFS4ERR_RESET_TO_MDS:
 352		filelayout_reset_write(hdr);
 353		return task->tk_status;
 354	case -EAGAIN:
 355		rpc_restart_call_prepare(task);
 356		return -EAGAIN;
 357	}
 358
 359	filelayout_set_layoutcommit(hdr);
 360
 361	/* zero out the fattr */
 362	hdr->fattr.valid = 0;
 363	if (task->tk_status >= 0)
 364		nfs_writeback_update_inode(hdr);
 365
 366	return 0;
 367}
 368
 369static int filelayout_commit_done_cb(struct rpc_task *task,
 370				     struct nfs_commit_data *data)
 371{
 372	int err;
 373
 374	trace_nfs4_pnfs_commit_ds(data, task->tk_status);
 375	err = filelayout_async_handle_error(task, NULL, data->ds_clp,
 376					    data->lseg);
 377
 378	switch (err) {
 379	case -NFS4ERR_RESET_TO_MDS:
 380		pnfs_generic_prepare_to_resend_writes(data);
 381		return -EAGAIN;
 382	case -EAGAIN:
 383		rpc_restart_call_prepare(task);
 384		return -EAGAIN;
 385	}
 386
 387	pnfs_set_layoutcommit(data->inode, data->lseg, data->lwb);
 
 388
 389	return 0;
 390}
 391
 392static void filelayout_write_prepare(struct rpc_task *task, void *data)
 393{
 394	struct nfs_pgio_header *hdr = data;
 395
 396	if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
 397		rpc_exit(task, -EIO);
 398		return;
 399	}
 400	if (filelayout_reset_to_mds(hdr->lseg)) {
 401		dprintk("%s task %u reset io to MDS\n", __func__, task->tk_pid);
 402		filelayout_reset_write(hdr);
 403		rpc_exit(task, 0);
 404		return;
 405	}
 406	if (nfs41_setup_sequence(hdr->ds_clp->cl_session,
 407			&hdr->args.seq_args,
 408			&hdr->res.seq_res,
 409			task))
 410		return;
 411	if (nfs4_set_rw_stateid(&hdr->args.stateid, hdr->args.context,
 412			hdr->args.lock_context, FMODE_WRITE) == -EIO)
 413		rpc_exit(task, -EIO); /* lost lock, terminate I/O */
 414}
 415
 416static void filelayout_write_call_done(struct rpc_task *task, void *data)
 417{
 418	struct nfs_pgio_header *hdr = data;
 419
 420	if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
 421	    task->tk_status == 0) {
 422		nfs41_sequence_done(task, &hdr->res.seq_res);
 423		return;
 424	}
 425
 426	/* Note this may cause RPC to be resent */
 427	hdr->mds_ops->rpc_call_done(task, data);
 428}
 429
 430static void filelayout_write_count_stats(struct rpc_task *task, void *data)
 431{
 432	struct nfs_pgio_header *hdr = data;
 433
 434	rpc_count_iostats(task, NFS_SERVER(hdr->inode)->client->cl_metrics);
 435}
 436
 437static void filelayout_commit_prepare(struct rpc_task *task, void *data)
 438{
 439	struct nfs_commit_data *wdata = data;
 440
 441	nfs41_setup_sequence(wdata->ds_clp->cl_session,
 442			&wdata->args.seq_args,
 443			&wdata->res.seq_res,
 444			task);
 445}
 446
 447static void filelayout_commit_count_stats(struct rpc_task *task, void *data)
 448{
 449	struct nfs_commit_data *cdata = data;
 450
 451	rpc_count_iostats(task, NFS_SERVER(cdata->inode)->client->cl_metrics);
 452}
 453
 454static const struct rpc_call_ops filelayout_read_call_ops = {
 455	.rpc_call_prepare = filelayout_read_prepare,
 456	.rpc_call_done = filelayout_read_call_done,
 457	.rpc_count_stats = filelayout_read_count_stats,
 458	.rpc_release = pnfs_generic_rw_release,
 459};
 460
 461static const struct rpc_call_ops filelayout_write_call_ops = {
 462	.rpc_call_prepare = filelayout_write_prepare,
 463	.rpc_call_done = filelayout_write_call_done,
 464	.rpc_count_stats = filelayout_write_count_stats,
 465	.rpc_release = pnfs_generic_rw_release,
 466};
 467
 468static const struct rpc_call_ops filelayout_commit_call_ops = {
 469	.rpc_call_prepare = filelayout_commit_prepare,
 470	.rpc_call_done = pnfs_generic_write_commit_done,
 471	.rpc_count_stats = filelayout_commit_count_stats,
 472	.rpc_release = pnfs_generic_commit_release,
 473};
 474
 475static enum pnfs_try_status
 476filelayout_read_pagelist(struct nfs_pgio_header *hdr)
 477{
 478	struct pnfs_layout_segment *lseg = hdr->lseg;
 479	struct nfs4_pnfs_ds *ds;
 480	struct rpc_clnt *ds_clnt;
 481	loff_t offset = hdr->args.offset;
 482	u32 j, idx;
 483	struct nfs_fh *fh;
 484
 485	dprintk("--> %s ino %lu pgbase %u req %Zu@%llu\n",
 486		__func__, hdr->inode->i_ino,
 487		hdr->args.pgbase, (size_t)hdr->args.count, offset);
 488
 489	/* Retrieve the correct rpc_client for the byte range */
 490	j = nfs4_fl_calc_j_index(lseg, offset);
 491	idx = nfs4_fl_calc_ds_index(lseg, j);
 492	ds = nfs4_fl_prepare_ds(lseg, idx);
 493	if (!ds)
 494		return PNFS_NOT_ATTEMPTED;
 495
 496	ds_clnt = nfs4_find_or_create_ds_client(ds->ds_clp, hdr->inode);
 497	if (IS_ERR(ds_clnt))
 498		return PNFS_NOT_ATTEMPTED;
 499
 500	dprintk("%s USE DS: %s cl_count %d\n", __func__,
 501		ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count));
 502
 503	/* No multipath support. Use first DS */
 504	atomic_inc(&ds->ds_clp->cl_count);
 505	hdr->ds_clp = ds->ds_clp;
 506	hdr->ds_commit_idx = idx;
 507	fh = nfs4_fl_select_ds_fh(lseg, j);
 508	if (fh)
 509		hdr->args.fh = fh;
 510
 511	hdr->args.offset = filelayout_get_dserver_offset(lseg, offset);
 512	hdr->mds_offset = offset;
 513
 514	/* Perform an asynchronous read to ds */
 515	nfs_initiate_pgio(ds_clnt, hdr, hdr->cred,
 516			  NFS_PROTO(hdr->inode), &filelayout_read_call_ops,
 517			  0, RPC_TASK_SOFTCONN);
 518	return PNFS_ATTEMPTED;
 519}
 520
 521/* Perform async writes. */
 522static enum pnfs_try_status
 523filelayout_write_pagelist(struct nfs_pgio_header *hdr, int sync)
 524{
 525	struct pnfs_layout_segment *lseg = hdr->lseg;
 526	struct nfs4_pnfs_ds *ds;
 527	struct rpc_clnt *ds_clnt;
 528	loff_t offset = hdr->args.offset;
 529	u32 j, idx;
 530	struct nfs_fh *fh;
 531
 532	/* Retrieve the correct rpc_client for the byte range */
 533	j = nfs4_fl_calc_j_index(lseg, offset);
 534	idx = nfs4_fl_calc_ds_index(lseg, j);
 535	ds = nfs4_fl_prepare_ds(lseg, idx);
 536	if (!ds)
 537		return PNFS_NOT_ATTEMPTED;
 538
 539	ds_clnt = nfs4_find_or_create_ds_client(ds->ds_clp, hdr->inode);
 540	if (IS_ERR(ds_clnt))
 541		return PNFS_NOT_ATTEMPTED;
 542
 543	dprintk("%s ino %lu sync %d req %Zu@%llu DS: %s cl_count %d\n",
 544		__func__, hdr->inode->i_ino, sync, (size_t) hdr->args.count,
 545		offset, ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count));
 546
 547	hdr->pgio_done_cb = filelayout_write_done_cb;
 548	atomic_inc(&ds->ds_clp->cl_count);
 549	hdr->ds_clp = ds->ds_clp;
 550	hdr->ds_commit_idx = idx;
 551	fh = nfs4_fl_select_ds_fh(lseg, j);
 552	if (fh)
 553		hdr->args.fh = fh;
 554	hdr->args.offset = filelayout_get_dserver_offset(lseg, offset);
 555
 556	/* Perform an asynchronous write */
 557	nfs_initiate_pgio(ds_clnt, hdr, hdr->cred,
 558			  NFS_PROTO(hdr->inode), &filelayout_write_call_ops,
 559			  sync, RPC_TASK_SOFTCONN);
 560	return PNFS_ATTEMPTED;
 561}
 562
 563/*
 564 * filelayout_check_layout()
 565 *
 566 * Make sure layout segment parameters are sane WRT the device.
 567 * At this point no generic layer initialization of the lseg has occurred,
 568 * and nothing has been added to the layout_hdr cache.
 569 *
 570 */
 571static int
 572filelayout_check_layout(struct pnfs_layout_hdr *lo,
 573			struct nfs4_filelayout_segment *fl,
 574			struct nfs4_layoutget_res *lgr,
 575			struct nfs4_deviceid *id,
 576			gfp_t gfp_flags)
 577{
 578	struct nfs4_deviceid_node *d;
 579	struct nfs4_file_layout_dsaddr *dsaddr;
 580	int status = -EINVAL;
 581
 582	dprintk("--> %s\n", __func__);
 583
 584	/* FIXME: remove this check when layout segment support is added */
 585	if (lgr->range.offset != 0 ||
 586	    lgr->range.length != NFS4_MAX_UINT64) {
 587		dprintk("%s Only whole file layouts supported. Use MDS i/o\n",
 588			__func__);
 589		goto out;
 590	}
 591
 592	if (fl->pattern_offset > lgr->range.offset) {
 593		dprintk("%s pattern_offset %lld too large\n",
 594				__func__, fl->pattern_offset);
 595		goto out;
 596	}
 597
 598	if (!fl->stripe_unit) {
 599		dprintk("%s Invalid stripe unit (%u)\n",
 600			__func__, fl->stripe_unit);
 601		goto out;
 602	}
 603
 604	/* find and reference the deviceid */
 605	d = nfs4_find_get_deviceid(NFS_SERVER(lo->plh_inode), id,
 606			lo->plh_lc_cred, gfp_flags);
 607	if (d == NULL)
 608		goto out;
 609
 610	dsaddr = container_of(d, struct nfs4_file_layout_dsaddr, id_node);
 611	/* Found deviceid is unavailable */
 612	if (filelayout_test_devid_unavailable(&dsaddr->id_node))
 613		goto out_put;
 614
 615	fl->dsaddr = dsaddr;
 616
 617	if (fl->first_stripe_index >= dsaddr->stripe_count) {
 618		dprintk("%s Bad first_stripe_index %u\n",
 619				__func__, fl->first_stripe_index);
 620		goto out_put;
 621	}
 622
 623	if ((fl->stripe_type == STRIPE_SPARSE &&
 624	    fl->num_fh > 1 && fl->num_fh != dsaddr->ds_num) ||
 625	    (fl->stripe_type == STRIPE_DENSE &&
 626	    fl->num_fh != dsaddr->stripe_count)) {
 627		dprintk("%s num_fh %u not valid for given packing\n",
 628			__func__, fl->num_fh);
 629		goto out_put;
 630	}
 631
 632	status = 0;
 633out:
 634	dprintk("--> %s returns %d\n", __func__, status);
 635	return status;
 636out_put:
 637	nfs4_fl_put_deviceid(dsaddr);
 638	goto out;
 639}
 640
 641static void _filelayout_free_lseg(struct nfs4_filelayout_segment *fl)
 642{
 643	int i;
 644
 645	if (fl->fh_array) {
 646		for (i = 0; i < fl->num_fh; i++) {
 647			if (!fl->fh_array[i])
 648				break;
 649			kfree(fl->fh_array[i]);
 650		}
 651		kfree(fl->fh_array);
 652	}
 653	kfree(fl);
 654}
 655
 656static int
 657filelayout_decode_layout(struct pnfs_layout_hdr *flo,
 658			 struct nfs4_filelayout_segment *fl,
 659			 struct nfs4_layoutget_res *lgr,
 660			 struct nfs4_deviceid *id,
 661			 gfp_t gfp_flags)
 662{
 663	struct xdr_stream stream;
 664	struct xdr_buf buf;
 665	struct page *scratch;
 666	__be32 *p;
 667	uint32_t nfl_util;
 668	int i;
 669
 670	dprintk("%s: set_layout_map Begin\n", __func__);
 671
 672	scratch = alloc_page(gfp_flags);
 673	if (!scratch)
 674		return -ENOMEM;
 675
 676	xdr_init_decode_pages(&stream, &buf, lgr->layoutp->pages, lgr->layoutp->len);
 677	xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
 678
 679	/* 20 = ufl_util (4), first_stripe_index (4), pattern_offset (8),
 680	 * num_fh (4) */
 681	p = xdr_inline_decode(&stream, NFS4_DEVICEID4_SIZE + 20);
 682	if (unlikely(!p))
 683		goto out_err;
 684
 685	memcpy(id, p, sizeof(*id));
 686	p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
 687	nfs4_print_deviceid(id);
 688
 689	nfl_util = be32_to_cpup(p++);
 690	if (nfl_util & NFL4_UFLG_COMMIT_THRU_MDS)
 691		fl->commit_through_mds = 1;
 692	if (nfl_util & NFL4_UFLG_DENSE)
 693		fl->stripe_type = STRIPE_DENSE;
 694	else
 695		fl->stripe_type = STRIPE_SPARSE;
 696	fl->stripe_unit = nfl_util & ~NFL4_UFLG_MASK;
 697
 698	fl->first_stripe_index = be32_to_cpup(p++);
 699	p = xdr_decode_hyper(p, &fl->pattern_offset);
 700	fl->num_fh = be32_to_cpup(p++);
 701
 702	dprintk("%s: nfl_util 0x%X num_fh %u fsi %u po %llu\n",
 703		__func__, nfl_util, fl->num_fh, fl->first_stripe_index,
 704		fl->pattern_offset);
 705
 706	/* Note that a zero value for num_fh is legal for STRIPE_SPARSE.
 707	 * Futher checking is done in filelayout_check_layout */
 708	if (fl->num_fh >
 709	    max(NFS4_PNFS_MAX_STRIPE_CNT, NFS4_PNFS_MAX_MULTI_CNT))
 710		goto out_err;
 711
 712	if (fl->num_fh > 0) {
 713		fl->fh_array = kcalloc(fl->num_fh, sizeof(fl->fh_array[0]),
 714				       gfp_flags);
 715		if (!fl->fh_array)
 716			goto out_err;
 717	}
 718
 719	for (i = 0; i < fl->num_fh; i++) {
 720		/* Do we want to use a mempool here? */
 721		fl->fh_array[i] = kmalloc(sizeof(struct nfs_fh), gfp_flags);
 722		if (!fl->fh_array[i])
 723			goto out_err;
 724
 725		p = xdr_inline_decode(&stream, 4);
 726		if (unlikely(!p))
 727			goto out_err;
 728		fl->fh_array[i]->size = be32_to_cpup(p++);
 729		if (sizeof(struct nfs_fh) < fl->fh_array[i]->size) {
 730			printk(KERN_ERR "NFS: Too big fh %d received %d\n",
 731			       i, fl->fh_array[i]->size);
 732			goto out_err;
 733		}
 734
 735		p = xdr_inline_decode(&stream, fl->fh_array[i]->size);
 736		if (unlikely(!p))
 737			goto out_err;
 738		memcpy(fl->fh_array[i]->data, p, fl->fh_array[i]->size);
 739		dprintk("DEBUG: %s: fh len %d\n", __func__,
 740			fl->fh_array[i]->size);
 741	}
 742
 743	__free_page(scratch);
 744	return 0;
 745
 746out_err:
 747	__free_page(scratch);
 748	return -EIO;
 749}
 750
 751static void
 752filelayout_free_lseg(struct pnfs_layout_segment *lseg)
 753{
 754	struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
 755
 756	dprintk("--> %s\n", __func__);
 757	nfs4_fl_put_deviceid(fl->dsaddr);
 758	/* This assumes a single RW lseg */
 759	if (lseg->pls_range.iomode == IOMODE_RW) {
 760		struct nfs4_filelayout *flo;
 761
 762		flo = FILELAYOUT_FROM_HDR(lseg->pls_layout);
 763		flo->commit_info.nbuckets = 0;
 764		kfree(flo->commit_info.buckets);
 765		flo->commit_info.buckets = NULL;
 766	}
 767	_filelayout_free_lseg(fl);
 768}
 769
 770static int
 771filelayout_alloc_commit_info(struct pnfs_layout_segment *lseg,
 772			     struct nfs_commit_info *cinfo,
 773			     gfp_t gfp_flags)
 774{
 775	struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
 776	struct pnfs_commit_bucket *buckets;
 777	int size, i;
 778
 779	if (fl->commit_through_mds)
 780		return 0;
 781
 782	size = (fl->stripe_type == STRIPE_SPARSE) ?
 783		fl->dsaddr->ds_num : fl->dsaddr->stripe_count;
 784
 785	if (cinfo->ds->nbuckets >= size) {
 786		/* This assumes there is only one IOMODE_RW lseg.  What
 787		 * we really want to do is have a layout_hdr level
 788		 * dictionary of <multipath_list4, fh> keys, each
 789		 * associated with a struct list_head, populated by calls
 790		 * to filelayout_write_pagelist().
 791		 * */
 792		return 0;
 793	}
 794
 795	buckets = kcalloc(size, sizeof(struct pnfs_commit_bucket),
 796			  gfp_flags);
 797	if (!buckets)
 798		return -ENOMEM;
 799	for (i = 0; i < size; i++) {
 800		INIT_LIST_HEAD(&buckets[i].written);
 801		INIT_LIST_HEAD(&buckets[i].committing);
 802		/* mark direct verifier as unset */
 803		buckets[i].direct_verf.committed = NFS_INVALID_STABLE_HOW;
 804	}
 805
 806	spin_lock(&cinfo->inode->i_lock);
 807	if (cinfo->ds->nbuckets >= size)
 808		goto out;
 809	for (i = 0; i < cinfo->ds->nbuckets; i++) {
 810		list_splice(&cinfo->ds->buckets[i].written,
 811			    &buckets[i].written);
 812		list_splice(&cinfo->ds->buckets[i].committing,
 813			    &buckets[i].committing);
 814		buckets[i].direct_verf.committed =
 815			cinfo->ds->buckets[i].direct_verf.committed;
 816		buckets[i].wlseg = cinfo->ds->buckets[i].wlseg;
 817		buckets[i].clseg = cinfo->ds->buckets[i].clseg;
 818	}
 819	swap(cinfo->ds->buckets, buckets);
 820	cinfo->ds->nbuckets = size;
 821out:
 822	spin_unlock(&cinfo->inode->i_lock);
 823	kfree(buckets);
 824	return 0;
 825}
 826
 827static struct pnfs_layout_segment *
 828filelayout_alloc_lseg(struct pnfs_layout_hdr *layoutid,
 829		      struct nfs4_layoutget_res *lgr,
 830		      gfp_t gfp_flags)
 831{
 832	struct nfs4_filelayout_segment *fl;
 833	int rc;
 834	struct nfs4_deviceid id;
 835
 836	dprintk("--> %s\n", __func__);
 837	fl = kzalloc(sizeof(*fl), gfp_flags);
 838	if (!fl)
 839		return NULL;
 840
 841	rc = filelayout_decode_layout(layoutid, fl, lgr, &id, gfp_flags);
 842	if (rc != 0 || filelayout_check_layout(layoutid, fl, lgr, &id, gfp_flags)) {
 843		_filelayout_free_lseg(fl);
 844		return NULL;
 845	}
 846	return &fl->generic_hdr;
 847}
 848
 849/*
 850 * filelayout_pg_test(). Called by nfs_can_coalesce_requests()
 851 *
 852 * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
 853 * of bytes (maximum @req->wb_bytes) that can be coalesced.
 854 */
 855static size_t
 856filelayout_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
 857		   struct nfs_page *req)
 858{
 859	unsigned int size;
 860	u64 p_stripe, r_stripe;
 861	u32 stripe_offset;
 862	u64 segment_offset = pgio->pg_lseg->pls_range.offset;
 863	u32 stripe_unit = FILELAYOUT_LSEG(pgio->pg_lseg)->stripe_unit;
 864
 865	/* calls nfs_generic_pg_test */
 866	size = pnfs_generic_pg_test(pgio, prev, req);
 867	if (!size)
 868		return 0;
 869
 870	/* see if req and prev are in the same stripe */
 871	if (prev) {
 872		p_stripe = (u64)req_offset(prev) - segment_offset;
 873		r_stripe = (u64)req_offset(req) - segment_offset;
 874		do_div(p_stripe, stripe_unit);
 875		do_div(r_stripe, stripe_unit);
 876
 877		if (p_stripe != r_stripe)
 878			return 0;
 879	}
 880
 881	/* calculate remaining bytes in the current stripe */
 882	div_u64_rem((u64)req_offset(req) - segment_offset,
 883			stripe_unit,
 884			&stripe_offset);
 885	WARN_ON_ONCE(stripe_offset > stripe_unit);
 886	if (stripe_offset >= stripe_unit)
 887		return 0;
 888	return min(stripe_unit - (unsigned int)stripe_offset, size);
 889}
 890
 891static void
 892filelayout_pg_init_read(struct nfs_pageio_descriptor *pgio,
 893			struct nfs_page *req)
 894{
 895	if (!pgio->pg_lseg) {
 896		pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 897					   req->wb_context,
 898					   0,
 899					   NFS4_MAX_UINT64,
 900					   IOMODE_READ,
 901					   false,
 902					   GFP_KERNEL);
 903		if (IS_ERR(pgio->pg_lseg)) {
 904			pgio->pg_error = PTR_ERR(pgio->pg_lseg);
 905			pgio->pg_lseg = NULL;
 906			return;
 907		}
 908	}
 909	/* If no lseg, fall back to read through mds */
 910	if (pgio->pg_lseg == NULL)
 911		nfs_pageio_reset_read_mds(pgio);
 912}
 913
 914static void
 915filelayout_pg_init_write(struct nfs_pageio_descriptor *pgio,
 916			 struct nfs_page *req)
 917{
 918	struct nfs_commit_info cinfo;
 919	int status;
 920
 921	if (!pgio->pg_lseg) {
 922		pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
 923					   req->wb_context,
 924					   0,
 925					   NFS4_MAX_UINT64,
 926					   IOMODE_RW,
 927					   false,
 928					   GFP_NOFS);
 929		if (IS_ERR(pgio->pg_lseg)) {
 930			pgio->pg_error = PTR_ERR(pgio->pg_lseg);
 931			pgio->pg_lseg = NULL;
 932			return;
 933		}
 934	}
 935
 936	/* If no lseg, fall back to write through mds */
 937	if (pgio->pg_lseg == NULL)
 938		goto out_mds;
 939	nfs_init_cinfo(&cinfo, pgio->pg_inode, pgio->pg_dreq);
 940	status = filelayout_alloc_commit_info(pgio->pg_lseg, &cinfo, GFP_NOFS);
 941	if (status < 0) {
 942		pnfs_put_lseg(pgio->pg_lseg);
 943		pgio->pg_lseg = NULL;
 944		goto out_mds;
 945	}
 946	return;
 947out_mds:
 948	nfs_pageio_reset_write_mds(pgio);
 949}
 950
 951static const struct nfs_pageio_ops filelayout_pg_read_ops = {
 952	.pg_init = filelayout_pg_init_read,
 953	.pg_test = filelayout_pg_test,
 954	.pg_doio = pnfs_generic_pg_readpages,
 955	.pg_cleanup = pnfs_generic_pg_cleanup,
 956};
 957
 958static const struct nfs_pageio_ops filelayout_pg_write_ops = {
 959	.pg_init = filelayout_pg_init_write,
 960	.pg_test = filelayout_pg_test,
 961	.pg_doio = pnfs_generic_pg_writepages,
 962	.pg_cleanup = pnfs_generic_pg_cleanup,
 963};
 964
 965static u32 select_bucket_index(struct nfs4_filelayout_segment *fl, u32 j)
 966{
 967	if (fl->stripe_type == STRIPE_SPARSE)
 968		return nfs4_fl_calc_ds_index(&fl->generic_hdr, j);
 969	else
 970		return j;
 971}
 972
 973static void
 974filelayout_mark_request_commit(struct nfs_page *req,
 975			       struct pnfs_layout_segment *lseg,
 976			       struct nfs_commit_info *cinfo,
 977			       u32 ds_commit_idx)
 978
 979{
 980	struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
 981	u32 i, j;
 982
 983	if (fl->commit_through_mds) {
 984		nfs_request_add_commit_list(req, cinfo);
 985	} else {
 986		/* Note that we are calling nfs4_fl_calc_j_index on each page
 987		 * that ends up being committed to a data server.  An attractive
 988		 * alternative is to add a field to nfs_write_data and nfs_page
 989		 * to store the value calculated in filelayout_write_pagelist
 990		 * and just use that here.
 991		 */
 992		j = nfs4_fl_calc_j_index(lseg, req_offset(req));
 993		i = select_bucket_index(fl, j);
 994		pnfs_layout_mark_request_commit(req, lseg, cinfo, i);
 995	}
 996}
 997
 998static u32 calc_ds_index_from_commit(struct pnfs_layout_segment *lseg, u32 i)
 999{
1000	struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
1001
1002	if (flseg->stripe_type == STRIPE_SPARSE)
1003		return i;
1004	else
1005		return nfs4_fl_calc_ds_index(lseg, i);
1006}
1007
1008static struct nfs_fh *
1009select_ds_fh_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1010{
1011	struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
1012
1013	if (flseg->stripe_type == STRIPE_SPARSE) {
1014		if (flseg->num_fh == 1)
1015			i = 0;
1016		else if (flseg->num_fh == 0)
1017			/* Use the MDS OPEN fh set in nfs_read_rpcsetup */
1018			return NULL;
1019	}
1020	return flseg->fh_array[i];
1021}
1022
1023static int filelayout_initiate_commit(struct nfs_commit_data *data, int how)
1024{
1025	struct pnfs_layout_segment *lseg = data->lseg;
1026	struct nfs4_pnfs_ds *ds;
1027	struct rpc_clnt *ds_clnt;
1028	u32 idx;
1029	struct nfs_fh *fh;
1030
1031	idx = calc_ds_index_from_commit(lseg, data->ds_commit_index);
1032	ds = nfs4_fl_prepare_ds(lseg, idx);
1033	if (!ds)
1034		goto out_err;
1035
1036	ds_clnt = nfs4_find_or_create_ds_client(ds->ds_clp, data->inode);
1037	if (IS_ERR(ds_clnt))
1038		goto out_err;
1039
1040	dprintk("%s ino %lu, how %d cl_count %d\n", __func__,
1041		data->inode->i_ino, how, atomic_read(&ds->ds_clp->cl_count));
1042	data->commit_done_cb = filelayout_commit_done_cb;
1043	atomic_inc(&ds->ds_clp->cl_count);
1044	data->ds_clp = ds->ds_clp;
1045	fh = select_ds_fh_from_commit(lseg, data->ds_commit_index);
1046	if (fh)
1047		data->args.fh = fh;
1048	return nfs_initiate_commit(ds_clnt, data, NFS_PROTO(data->inode),
1049				   &filelayout_commit_call_ops, how,
1050				   RPC_TASK_SOFTCONN);
1051out_err:
1052	pnfs_generic_prepare_to_resend_writes(data);
1053	pnfs_generic_commit_release(data);
1054	return -EAGAIN;
1055}
1056
1057/* filelayout_search_commit_reqs - Search lists in @cinfo for the head reqest
1058 *				   for @page
1059 * @cinfo - commit info for current inode
1060 * @page - page to search for matching head request
1061 *
1062 * Returns a the head request if one is found, otherwise returns NULL.
1063 */
1064static struct nfs_page *
1065filelayout_search_commit_reqs(struct nfs_commit_info *cinfo, struct page *page)
1066{
1067	struct nfs_page *freq, *t;
1068	struct pnfs_commit_bucket *b;
1069	int i;
1070
1071	/* Linearly search the commit lists for each bucket until a matching
1072	 * request is found */
1073	for (i = 0, b = cinfo->ds->buckets; i < cinfo->ds->nbuckets; i++, b++) {
1074		list_for_each_entry_safe(freq, t, &b->written, wb_list) {
1075			if (freq->wb_page == page)
1076				return freq->wb_head;
1077		}
1078		list_for_each_entry_safe(freq, t, &b->committing, wb_list) {
1079			if (freq->wb_page == page)
1080				return freq->wb_head;
1081		}
1082	}
1083
1084	return NULL;
1085}
1086
1087static int
1088filelayout_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
1089			   int how, struct nfs_commit_info *cinfo)
1090{
1091	return pnfs_generic_commit_pagelist(inode, mds_pages, how, cinfo,
1092					    filelayout_initiate_commit);
1093}
1094
1095static struct nfs4_deviceid_node *
1096filelayout_alloc_deviceid_node(struct nfs_server *server,
1097		struct pnfs_device *pdev, gfp_t gfp_flags)
1098{
1099	struct nfs4_file_layout_dsaddr *dsaddr;
1100
1101	dsaddr = nfs4_fl_alloc_deviceid_node(server, pdev, gfp_flags);
1102	if (!dsaddr)
1103		return NULL;
1104	return &dsaddr->id_node;
1105}
1106
1107static void
1108filelayout_free_deviceid_node(struct nfs4_deviceid_node *d)
1109{
1110	nfs4_fl_free_deviceid(container_of(d, struct nfs4_file_layout_dsaddr, id_node));
1111}
1112
1113static struct pnfs_layout_hdr *
1114filelayout_alloc_layout_hdr(struct inode *inode, gfp_t gfp_flags)
1115{
1116	struct nfs4_filelayout *flo;
1117
1118	flo = kzalloc(sizeof(*flo), gfp_flags);
1119	return flo != NULL ? &flo->generic_hdr : NULL;
1120}
1121
1122static void
1123filelayout_free_layout_hdr(struct pnfs_layout_hdr *lo)
1124{
1125	kfree(FILELAYOUT_FROM_HDR(lo));
1126}
1127
1128static struct pnfs_ds_commit_info *
1129filelayout_get_ds_info(struct inode *inode)
1130{
1131	struct pnfs_layout_hdr *layout = NFS_I(inode)->layout;
1132
1133	if (layout == NULL)
1134		return NULL;
1135	else
1136		return &FILELAYOUT_FROM_HDR(layout)->commit_info;
1137}
1138
1139static struct pnfs_layoutdriver_type filelayout_type = {
1140	.id			= LAYOUT_NFSV4_1_FILES,
1141	.name			= "LAYOUT_NFSV4_1_FILES",
1142	.owner			= THIS_MODULE,
1143	.alloc_layout_hdr	= filelayout_alloc_layout_hdr,
1144	.free_layout_hdr	= filelayout_free_layout_hdr,
1145	.alloc_lseg		= filelayout_alloc_lseg,
1146	.free_lseg		= filelayout_free_lseg,
1147	.pg_read_ops		= &filelayout_pg_read_ops,
1148	.pg_write_ops		= &filelayout_pg_write_ops,
1149	.get_ds_info		= &filelayout_get_ds_info,
1150	.mark_request_commit	= filelayout_mark_request_commit,
1151	.clear_request_commit	= pnfs_generic_clear_request_commit,
1152	.scan_commit_lists	= pnfs_generic_scan_commit_lists,
1153	.recover_commit_reqs	= pnfs_generic_recover_commit_reqs,
1154	.search_commit_reqs	= filelayout_search_commit_reqs,
1155	.commit_pagelist	= filelayout_commit_pagelist,
1156	.read_pagelist		= filelayout_read_pagelist,
1157	.write_pagelist		= filelayout_write_pagelist,
1158	.alloc_deviceid_node	= filelayout_alloc_deviceid_node,
1159	.free_deviceid_node	= filelayout_free_deviceid_node,
1160	.sync			= pnfs_nfs_generic_sync,
1161};
1162
1163static int __init nfs4filelayout_init(void)
1164{
1165	printk(KERN_INFO "%s: NFSv4 File Layout Driver Registering...\n",
1166	       __func__);
1167	return pnfs_register_layoutdriver(&filelayout_type);
1168}
1169
1170static void __exit nfs4filelayout_exit(void)
1171{
1172	printk(KERN_INFO "%s: NFSv4 File Layout Driver Unregistering...\n",
1173	       __func__);
1174	pnfs_unregister_layoutdriver(&filelayout_type);
1175}
1176
1177MODULE_ALIAS("nfs-layouttype4-1");
1178
1179module_init(nfs4filelayout_init);
1180module_exit(nfs4filelayout_exit);