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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
36#include <linux/sunrpc/metrics.h>
37
38#include "internal.h"
39#include "delegation.h"
40#include "nfs4filelayout.h"
41
42#define NFSDBG_FACILITY NFSDBG_PNFS_LD
43
44MODULE_LICENSE("GPL");
45MODULE_AUTHOR("Dean Hildebrand <dhildebz@umich.edu>");
46MODULE_DESCRIPTION("The NFSv4 file layout driver");
47
48#define FILELAYOUT_POLL_RETRY_MAX (15*HZ)
49
50static loff_t
51filelayout_get_dense_offset(struct nfs4_filelayout_segment *flseg,
52 loff_t offset)
53{
54 u32 stripe_width = flseg->stripe_unit * flseg->dsaddr->stripe_count;
55 u64 stripe_no;
56 u32 rem;
57
58 offset -= flseg->pattern_offset;
59 stripe_no = div_u64(offset, stripe_width);
60 div_u64_rem(offset, flseg->stripe_unit, &rem);
61
62 return stripe_no * flseg->stripe_unit + rem;
63}
64
65/* This function is used by the layout driver to calculate the
66 * offset of the file on the dserver based on whether the
67 * layout type is STRIPE_DENSE or STRIPE_SPARSE
68 */
69static loff_t
70filelayout_get_dserver_offset(struct pnfs_layout_segment *lseg, loff_t offset)
71{
72 struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
73
74 switch (flseg->stripe_type) {
75 case STRIPE_SPARSE:
76 return offset;
77
78 case STRIPE_DENSE:
79 return filelayout_get_dense_offset(flseg, offset);
80 }
81
82 BUG();
83}
84
85static void filelayout_reset_write(struct nfs_write_data *data)
86{
87 struct nfs_pgio_header *hdr = data->header;
88 struct rpc_task *task = &data->task;
89
90 if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
91 dprintk("%s Reset task %5u for i/o through MDS "
92 "(req %s/%lld, %u bytes @ offset %llu)\n", __func__,
93 data->task.tk_pid,
94 hdr->inode->i_sb->s_id,
95 (long long)NFS_FILEID(hdr->inode),
96 data->args.count,
97 (unsigned long long)data->args.offset);
98
99 task->tk_status = pnfs_write_done_resend_to_mds(hdr->inode,
100 &hdr->pages,
101 hdr->completion_ops);
102 }
103}
104
105static void filelayout_reset_read(struct nfs_read_data *data)
106{
107 struct nfs_pgio_header *hdr = data->header;
108 struct rpc_task *task = &data->task;
109
110 if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
111 dprintk("%s Reset task %5u for i/o through MDS "
112 "(req %s/%lld, %u bytes @ offset %llu)\n", __func__,
113 data->task.tk_pid,
114 hdr->inode->i_sb->s_id,
115 (long long)NFS_FILEID(hdr->inode),
116 data->args.count,
117 (unsigned long long)data->args.offset);
118
119 task->tk_status = pnfs_read_done_resend_to_mds(hdr->inode,
120 &hdr->pages,
121 hdr->completion_ops);
122 }
123}
124
125static int filelayout_async_handle_error(struct rpc_task *task,
126 struct nfs4_state *state,
127 struct nfs_client *clp,
128 struct pnfs_layout_segment *lseg)
129{
130 struct inode *inode = lseg->pls_layout->plh_inode;
131 struct nfs_server *mds_server = NFS_SERVER(inode);
132 struct nfs4_deviceid_node *devid = FILELAYOUT_DEVID_NODE(lseg);
133 struct nfs_client *mds_client = mds_server->nfs_client;
134 struct nfs4_slot_table *tbl = &clp->cl_session->fc_slot_table;
135
136 if (task->tk_status >= 0)
137 return 0;
138
139 switch (task->tk_status) {
140 /* MDS state errors */
141 case -NFS4ERR_DELEG_REVOKED:
142 case -NFS4ERR_ADMIN_REVOKED:
143 case -NFS4ERR_BAD_STATEID:
144 if (state == NULL)
145 break;
146 nfs_remove_bad_delegation(state->inode);
147 case -NFS4ERR_OPENMODE:
148 if (state == NULL)
149 break;
150 nfs4_schedule_stateid_recovery(mds_server, state);
151 goto wait_on_recovery;
152 case -NFS4ERR_EXPIRED:
153 if (state != NULL)
154 nfs4_schedule_stateid_recovery(mds_server, state);
155 nfs4_schedule_lease_recovery(mds_client);
156 goto wait_on_recovery;
157 /* DS session errors */
158 case -NFS4ERR_BADSESSION:
159 case -NFS4ERR_BADSLOT:
160 case -NFS4ERR_BAD_HIGH_SLOT:
161 case -NFS4ERR_DEADSESSION:
162 case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
163 case -NFS4ERR_SEQ_FALSE_RETRY:
164 case -NFS4ERR_SEQ_MISORDERED:
165 dprintk("%s ERROR %d, Reset session. Exchangeid "
166 "flags 0x%x\n", __func__, task->tk_status,
167 clp->cl_exchange_flags);
168 nfs4_schedule_session_recovery(clp->cl_session, task->tk_status);
169 break;
170 case -NFS4ERR_DELAY:
171 case -NFS4ERR_GRACE:
172 case -EKEYEXPIRED:
173 rpc_delay(task, FILELAYOUT_POLL_RETRY_MAX);
174 break;
175 case -NFS4ERR_RETRY_UNCACHED_REP:
176 break;
177 /* Invalidate Layout errors */
178 case -NFS4ERR_PNFS_NO_LAYOUT:
179 case -ESTALE: /* mapped NFS4ERR_STALE */
180 case -EBADHANDLE: /* mapped NFS4ERR_BADHANDLE */
181 case -EISDIR: /* mapped NFS4ERR_ISDIR */
182 case -NFS4ERR_FHEXPIRED:
183 case -NFS4ERR_WRONG_TYPE:
184 dprintk("%s Invalid layout error %d\n", __func__,
185 task->tk_status);
186 /*
187 * Destroy layout so new i/o will get a new layout.
188 * Layout will not be destroyed until all current lseg
189 * references are put. Mark layout as invalid to resend failed
190 * i/o and all i/o waiting on the slot table to the MDS until
191 * layout is destroyed and a new valid layout is obtained.
192 */
193 set_bit(NFS_LAYOUT_INVALID,
194 &NFS_I(inode)->layout->plh_flags);
195 pnfs_destroy_layout(NFS_I(inode));
196 rpc_wake_up(&tbl->slot_tbl_waitq);
197 goto reset;
198 /* RPC connection errors */
199 case -ECONNREFUSED:
200 case -EHOSTDOWN:
201 case -EHOSTUNREACH:
202 case -ENETUNREACH:
203 case -EIO:
204 case -ETIMEDOUT:
205 case -EPIPE:
206 dprintk("%s DS connection error %d\n", __func__,
207 task->tk_status);
208 if (!filelayout_test_devid_invalid(devid))
209 _pnfs_return_layout(inode);
210 filelayout_mark_devid_invalid(devid);
211 rpc_wake_up(&tbl->slot_tbl_waitq);
212 nfs4_ds_disconnect(clp);
213 /* fall through */
214 default:
215reset:
216 dprintk("%s Retry through MDS. Error %d\n", __func__,
217 task->tk_status);
218 return -NFS4ERR_RESET_TO_MDS;
219 }
220out:
221 task->tk_status = 0;
222 return -EAGAIN;
223wait_on_recovery:
224 rpc_sleep_on(&mds_client->cl_rpcwaitq, task, NULL);
225 if (test_bit(NFS4CLNT_MANAGER_RUNNING, &mds_client->cl_state) == 0)
226 rpc_wake_up_queued_task(&mds_client->cl_rpcwaitq, task);
227 goto out;
228}
229
230/* NFS_PROTO call done callback routines */
231
232static int filelayout_read_done_cb(struct rpc_task *task,
233 struct nfs_read_data *data)
234{
235 struct nfs_pgio_header *hdr = data->header;
236 int err;
237
238 err = filelayout_async_handle_error(task, data->args.context->state,
239 data->ds_clp, hdr->lseg);
240
241 switch (err) {
242 case -NFS4ERR_RESET_TO_MDS:
243 filelayout_reset_read(data);
244 return task->tk_status;
245 case -EAGAIN:
246 rpc_restart_call_prepare(task);
247 return -EAGAIN;
248 }
249
250 return 0;
251}
252
253/*
254 * We reference the rpc_cred of the first WRITE that triggers the need for
255 * a LAYOUTCOMMIT, and use it to send the layoutcommit compound.
256 * rfc5661 is not clear about which credential should be used.
257 */
258static void
259filelayout_set_layoutcommit(struct nfs_write_data *wdata)
260{
261 struct nfs_pgio_header *hdr = wdata->header;
262
263 if (FILELAYOUT_LSEG(hdr->lseg)->commit_through_mds ||
264 wdata->res.verf->committed == NFS_FILE_SYNC)
265 return;
266
267 pnfs_set_layoutcommit(wdata);
268 dprintk("%s ionde %lu pls_end_pos %lu\n", __func__, hdr->inode->i_ino,
269 (unsigned long) NFS_I(hdr->inode)->layout->plh_lwb);
270}
271
272/*
273 * Call ops for the async read/write cases
274 * In the case of dense layouts, the offset needs to be reset to its
275 * original value.
276 */
277static void filelayout_read_prepare(struct rpc_task *task, void *data)
278{
279 struct nfs_read_data *rdata = data;
280
281 if (filelayout_reset_to_mds(rdata->header->lseg)) {
282 dprintk("%s task %u reset io to MDS\n", __func__, task->tk_pid);
283 filelayout_reset_read(rdata);
284 rpc_exit(task, 0);
285 return;
286 }
287 rdata->read_done_cb = filelayout_read_done_cb;
288
289 if (nfs41_setup_sequence(rdata->ds_clp->cl_session,
290 &rdata->args.seq_args, &rdata->res.seq_res,
291 task))
292 return;
293
294 rpc_call_start(task);
295}
296
297static void filelayout_read_call_done(struct rpc_task *task, void *data)
298{
299 struct nfs_read_data *rdata = data;
300
301 dprintk("--> %s task->tk_status %d\n", __func__, task->tk_status);
302
303 if (test_bit(NFS_IOHDR_REDO, &rdata->header->flags) &&
304 task->tk_status == 0)
305 return;
306
307 /* Note this may cause RPC to be resent */
308 rdata->header->mds_ops->rpc_call_done(task, data);
309}
310
311static void filelayout_read_count_stats(struct rpc_task *task, void *data)
312{
313 struct nfs_read_data *rdata = data;
314
315 rpc_count_iostats(task, NFS_SERVER(rdata->header->inode)->client->cl_metrics);
316}
317
318static void filelayout_read_release(void *data)
319{
320 struct nfs_read_data *rdata = data;
321
322 nfs_put_client(rdata->ds_clp);
323 rdata->header->mds_ops->rpc_release(data);
324}
325
326static int filelayout_write_done_cb(struct rpc_task *task,
327 struct nfs_write_data *data)
328{
329 struct nfs_pgio_header *hdr = data->header;
330 int err;
331
332 err = filelayout_async_handle_error(task, data->args.context->state,
333 data->ds_clp, hdr->lseg);
334
335 switch (err) {
336 case -NFS4ERR_RESET_TO_MDS:
337 filelayout_reset_write(data);
338 return task->tk_status;
339 case -EAGAIN:
340 rpc_restart_call_prepare(task);
341 return -EAGAIN;
342 }
343
344 filelayout_set_layoutcommit(data);
345 return 0;
346}
347
348/* Fake up some data that will cause nfs_commit_release to retry the writes. */
349static void prepare_to_resend_writes(struct nfs_commit_data *data)
350{
351 struct nfs_page *first = nfs_list_entry(data->pages.next);
352
353 data->task.tk_status = 0;
354 memcpy(data->verf.verifier, first->wb_verf.verifier,
355 sizeof(first->wb_verf.verifier));
356 data->verf.verifier[0]++; /* ensure verifier mismatch */
357}
358
359static int filelayout_commit_done_cb(struct rpc_task *task,
360 struct nfs_commit_data *data)
361{
362 int err;
363
364 err = filelayout_async_handle_error(task, NULL, data->ds_clp,
365 data->lseg);
366
367 switch (err) {
368 case -NFS4ERR_RESET_TO_MDS:
369 prepare_to_resend_writes(data);
370 return -EAGAIN;
371 case -EAGAIN:
372 rpc_restart_call_prepare(task);
373 return -EAGAIN;
374 }
375
376 return 0;
377}
378
379static void filelayout_write_prepare(struct rpc_task *task, void *data)
380{
381 struct nfs_write_data *wdata = data;
382
383 if (filelayout_reset_to_mds(wdata->header->lseg)) {
384 dprintk("%s task %u reset io to MDS\n", __func__, task->tk_pid);
385 filelayout_reset_write(wdata);
386 rpc_exit(task, 0);
387 return;
388 }
389 if (nfs41_setup_sequence(wdata->ds_clp->cl_session,
390 &wdata->args.seq_args, &wdata->res.seq_res,
391 task))
392 return;
393
394 rpc_call_start(task);
395}
396
397static void filelayout_write_call_done(struct rpc_task *task, void *data)
398{
399 struct nfs_write_data *wdata = data;
400
401 if (test_bit(NFS_IOHDR_REDO, &wdata->header->flags) &&
402 task->tk_status == 0)
403 return;
404
405 /* Note this may cause RPC to be resent */
406 wdata->header->mds_ops->rpc_call_done(task, data);
407}
408
409static void filelayout_write_count_stats(struct rpc_task *task, void *data)
410{
411 struct nfs_write_data *wdata = data;
412
413 rpc_count_iostats(task, NFS_SERVER(wdata->header->inode)->client->cl_metrics);
414}
415
416static void filelayout_write_release(void *data)
417{
418 struct nfs_write_data *wdata = data;
419
420 nfs_put_client(wdata->ds_clp);
421 wdata->header->mds_ops->rpc_release(data);
422}
423
424static void filelayout_commit_prepare(struct rpc_task *task, void *data)
425{
426 struct nfs_commit_data *wdata = data;
427
428 if (nfs41_setup_sequence(wdata->ds_clp->cl_session,
429 &wdata->args.seq_args, &wdata->res.seq_res,
430 task))
431 return;
432
433 rpc_call_start(task);
434}
435
436static void filelayout_write_commit_done(struct rpc_task *task, void *data)
437{
438 struct nfs_commit_data *wdata = data;
439
440 /* Note this may cause RPC to be resent */
441 wdata->mds_ops->rpc_call_done(task, data);
442}
443
444static void filelayout_commit_count_stats(struct rpc_task *task, void *data)
445{
446 struct nfs_commit_data *cdata = data;
447
448 rpc_count_iostats(task, NFS_SERVER(cdata->inode)->client->cl_metrics);
449}
450
451static void filelayout_commit_release(void *calldata)
452{
453 struct nfs_commit_data *data = calldata;
454
455 data->completion_ops->completion(data);
456 put_lseg(data->lseg);
457 nfs_put_client(data->ds_clp);
458 nfs_commitdata_release(data);
459}
460
461static const struct rpc_call_ops filelayout_read_call_ops = {
462 .rpc_call_prepare = filelayout_read_prepare,
463 .rpc_call_done = filelayout_read_call_done,
464 .rpc_count_stats = filelayout_read_count_stats,
465 .rpc_release = filelayout_read_release,
466};
467
468static const struct rpc_call_ops filelayout_write_call_ops = {
469 .rpc_call_prepare = filelayout_write_prepare,
470 .rpc_call_done = filelayout_write_call_done,
471 .rpc_count_stats = filelayout_write_count_stats,
472 .rpc_release = filelayout_write_release,
473};
474
475static const struct rpc_call_ops filelayout_commit_call_ops = {
476 .rpc_call_prepare = filelayout_commit_prepare,
477 .rpc_call_done = filelayout_write_commit_done,
478 .rpc_count_stats = filelayout_commit_count_stats,
479 .rpc_release = filelayout_commit_release,
480};
481
482static enum pnfs_try_status
483filelayout_read_pagelist(struct nfs_read_data *data)
484{
485 struct nfs_pgio_header *hdr = data->header;
486 struct pnfs_layout_segment *lseg = hdr->lseg;
487 struct nfs4_pnfs_ds *ds;
488 loff_t offset = data->args.offset;
489 u32 j, idx;
490 struct nfs_fh *fh;
491 int status;
492
493 dprintk("--> %s ino %lu pgbase %u req %Zu@%llu\n",
494 __func__, hdr->inode->i_ino,
495 data->args.pgbase, (size_t)data->args.count, offset);
496
497 /* Retrieve the correct rpc_client for the byte range */
498 j = nfs4_fl_calc_j_index(lseg, offset);
499 idx = nfs4_fl_calc_ds_index(lseg, j);
500 ds = nfs4_fl_prepare_ds(lseg, idx);
501 if (!ds)
502 return PNFS_NOT_ATTEMPTED;
503 dprintk("%s USE DS: %s cl_count %d\n", __func__,
504 ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count));
505
506 /* No multipath support. Use first DS */
507 atomic_inc(&ds->ds_clp->cl_count);
508 data->ds_clp = ds->ds_clp;
509 fh = nfs4_fl_select_ds_fh(lseg, j);
510 if (fh)
511 data->args.fh = fh;
512
513 data->args.offset = filelayout_get_dserver_offset(lseg, offset);
514 data->mds_offset = offset;
515
516 /* Perform an asynchronous read to ds */
517 status = nfs_initiate_read(ds->ds_clp->cl_rpcclient, data,
518 &filelayout_read_call_ops, RPC_TASK_SOFTCONN);
519 BUG_ON(status != 0);
520 return PNFS_ATTEMPTED;
521}
522
523/* Perform async writes. */
524static enum pnfs_try_status
525filelayout_write_pagelist(struct nfs_write_data *data, int sync)
526{
527 struct nfs_pgio_header *hdr = data->header;
528 struct pnfs_layout_segment *lseg = hdr->lseg;
529 struct nfs4_pnfs_ds *ds;
530 loff_t offset = data->args.offset;
531 u32 j, idx;
532 struct nfs_fh *fh;
533 int status;
534
535 /* Retrieve the correct rpc_client for the byte range */
536 j = nfs4_fl_calc_j_index(lseg, offset);
537 idx = nfs4_fl_calc_ds_index(lseg, j);
538 ds = nfs4_fl_prepare_ds(lseg, idx);
539 if (!ds)
540 return PNFS_NOT_ATTEMPTED;
541 dprintk("%s ino %lu sync %d req %Zu@%llu DS: %s cl_count %d\n",
542 __func__, hdr->inode->i_ino, sync, (size_t) data->args.count,
543 offset, ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count));
544
545 data->write_done_cb = filelayout_write_done_cb;
546 atomic_inc(&ds->ds_clp->cl_count);
547 data->ds_clp = ds->ds_clp;
548 fh = nfs4_fl_select_ds_fh(lseg, j);
549 if (fh)
550 data->args.fh = fh;
551 /*
552 * Get the file offset on the dserver. Set the write offset to
553 * this offset and save the original offset.
554 */
555 data->args.offset = filelayout_get_dserver_offset(lseg, offset);
556
557 /* Perform an asynchronous write */
558 status = nfs_initiate_write(ds->ds_clp->cl_rpcclient, data,
559 &filelayout_write_call_ops, sync,
560 RPC_TASK_SOFTCONN);
561 BUG_ON(status != 0);
562 return PNFS_ATTEMPTED;
563}
564
565/*
566 * filelayout_check_layout()
567 *
568 * Make sure layout segment parameters are sane WRT the device.
569 * At this point no generic layer initialization of the lseg has occurred,
570 * and nothing has been added to the layout_hdr cache.
571 *
572 */
573static int
574filelayout_check_layout(struct pnfs_layout_hdr *lo,
575 struct nfs4_filelayout_segment *fl,
576 struct nfs4_layoutget_res *lgr,
577 struct nfs4_deviceid *id,
578 gfp_t gfp_flags)
579{
580 struct nfs4_deviceid_node *d;
581 struct nfs4_file_layout_dsaddr *dsaddr;
582 int status = -EINVAL;
583 struct nfs_server *nfss = NFS_SERVER(lo->plh_inode);
584
585 dprintk("--> %s\n", __func__);
586
587 /* FIXME: remove this check when layout segment support is added */
588 if (lgr->range.offset != 0 ||
589 lgr->range.length != NFS4_MAX_UINT64) {
590 dprintk("%s Only whole file layouts supported. Use MDS i/o\n",
591 __func__);
592 goto out;
593 }
594
595 if (fl->pattern_offset > lgr->range.offset) {
596 dprintk("%s pattern_offset %lld too large\n",
597 __func__, fl->pattern_offset);
598 goto out;
599 }
600
601 if (!fl->stripe_unit || fl->stripe_unit % PAGE_SIZE) {
602 dprintk("%s Invalid stripe unit (%u)\n",
603 __func__, fl->stripe_unit);
604 goto out;
605 }
606
607 /* find and reference the deviceid */
608 d = nfs4_find_get_deviceid(NFS_SERVER(lo->plh_inode)->pnfs_curr_ld,
609 NFS_SERVER(lo->plh_inode)->nfs_client, id);
610 if (d == NULL) {
611 dsaddr = get_device_info(lo->plh_inode, id, gfp_flags);
612 if (dsaddr == NULL)
613 goto out;
614 } else
615 dsaddr = container_of(d, struct nfs4_file_layout_dsaddr, id_node);
616 /* Found deviceid is being reaped */
617 if (test_bit(NFS_DEVICEID_INVALID, &dsaddr->id_node.flags))
618 goto out_put;
619
620 fl->dsaddr = dsaddr;
621
622 if (fl->first_stripe_index >= dsaddr->stripe_count) {
623 dprintk("%s Bad first_stripe_index %u\n",
624 __func__, fl->first_stripe_index);
625 goto out_put;
626 }
627
628 if ((fl->stripe_type == STRIPE_SPARSE &&
629 fl->num_fh > 1 && fl->num_fh != dsaddr->ds_num) ||
630 (fl->stripe_type == STRIPE_DENSE &&
631 fl->num_fh != dsaddr->stripe_count)) {
632 dprintk("%s num_fh %u not valid for given packing\n",
633 __func__, fl->num_fh);
634 goto out_put;
635 }
636
637 if (fl->stripe_unit % nfss->rsize || fl->stripe_unit % nfss->wsize) {
638 dprintk("%s Stripe unit (%u) not aligned with rsize %u "
639 "wsize %u\n", __func__, fl->stripe_unit, nfss->rsize,
640 nfss->wsize);
641 }
642
643 status = 0;
644out:
645 dprintk("--> %s returns %d\n", __func__, status);
646 return status;
647out_put:
648 nfs4_fl_put_deviceid(dsaddr);
649 goto out;
650}
651
652static void filelayout_free_fh_array(struct nfs4_filelayout_segment *fl)
653{
654 int i;
655
656 for (i = 0; i < fl->num_fh; i++) {
657 if (!fl->fh_array[i])
658 break;
659 kfree(fl->fh_array[i]);
660 }
661 kfree(fl->fh_array);
662 fl->fh_array = NULL;
663}
664
665static void
666_filelayout_free_lseg(struct nfs4_filelayout_segment *fl)
667{
668 filelayout_free_fh_array(fl);
669 kfree(fl);
670}
671
672static int
673filelayout_decode_layout(struct pnfs_layout_hdr *flo,
674 struct nfs4_filelayout_segment *fl,
675 struct nfs4_layoutget_res *lgr,
676 struct nfs4_deviceid *id,
677 gfp_t gfp_flags)
678{
679 struct xdr_stream stream;
680 struct xdr_buf buf;
681 struct page *scratch;
682 __be32 *p;
683 uint32_t nfl_util;
684 int i;
685
686 dprintk("%s: set_layout_map Begin\n", __func__);
687
688 scratch = alloc_page(gfp_flags);
689 if (!scratch)
690 return -ENOMEM;
691
692 xdr_init_decode_pages(&stream, &buf, lgr->layoutp->pages, lgr->layoutp->len);
693 xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
694
695 /* 20 = ufl_util (4), first_stripe_index (4), pattern_offset (8),
696 * num_fh (4) */
697 p = xdr_inline_decode(&stream, NFS4_DEVICEID4_SIZE + 20);
698 if (unlikely(!p))
699 goto out_err;
700
701 memcpy(id, p, sizeof(*id));
702 p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
703 nfs4_print_deviceid(id);
704
705 nfl_util = be32_to_cpup(p++);
706 if (nfl_util & NFL4_UFLG_COMMIT_THRU_MDS)
707 fl->commit_through_mds = 1;
708 if (nfl_util & NFL4_UFLG_DENSE)
709 fl->stripe_type = STRIPE_DENSE;
710 else
711 fl->stripe_type = STRIPE_SPARSE;
712 fl->stripe_unit = nfl_util & ~NFL4_UFLG_MASK;
713
714 fl->first_stripe_index = be32_to_cpup(p++);
715 p = xdr_decode_hyper(p, &fl->pattern_offset);
716 fl->num_fh = be32_to_cpup(p++);
717
718 dprintk("%s: nfl_util 0x%X num_fh %u fsi %u po %llu\n",
719 __func__, nfl_util, fl->num_fh, fl->first_stripe_index,
720 fl->pattern_offset);
721
722 /* Note that a zero value for num_fh is legal for STRIPE_SPARSE.
723 * Futher checking is done in filelayout_check_layout */
724 if (fl->num_fh >
725 max(NFS4_PNFS_MAX_STRIPE_CNT, NFS4_PNFS_MAX_MULTI_CNT))
726 goto out_err;
727
728 if (fl->num_fh > 0) {
729 fl->fh_array = kzalloc(fl->num_fh * sizeof(struct nfs_fh *),
730 gfp_flags);
731 if (!fl->fh_array)
732 goto out_err;
733 }
734
735 for (i = 0; i < fl->num_fh; i++) {
736 /* Do we want to use a mempool here? */
737 fl->fh_array[i] = kmalloc(sizeof(struct nfs_fh), gfp_flags);
738 if (!fl->fh_array[i])
739 goto out_err_free;
740
741 p = xdr_inline_decode(&stream, 4);
742 if (unlikely(!p))
743 goto out_err_free;
744 fl->fh_array[i]->size = be32_to_cpup(p++);
745 if (sizeof(struct nfs_fh) < fl->fh_array[i]->size) {
746 printk(KERN_ERR "NFS: Too big fh %d received %d\n",
747 i, fl->fh_array[i]->size);
748 goto out_err_free;
749 }
750
751 p = xdr_inline_decode(&stream, fl->fh_array[i]->size);
752 if (unlikely(!p))
753 goto out_err_free;
754 memcpy(fl->fh_array[i]->data, p, fl->fh_array[i]->size);
755 dprintk("DEBUG: %s: fh len %d\n", __func__,
756 fl->fh_array[i]->size);
757 }
758
759 __free_page(scratch);
760 return 0;
761
762out_err_free:
763 filelayout_free_fh_array(fl);
764out_err:
765 __free_page(scratch);
766 return -EIO;
767}
768
769static void
770filelayout_free_lseg(struct pnfs_layout_segment *lseg)
771{
772 struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
773
774 dprintk("--> %s\n", __func__);
775 nfs4_fl_put_deviceid(fl->dsaddr);
776 /* This assumes a single RW lseg */
777 if (lseg->pls_range.iomode == IOMODE_RW) {
778 struct nfs4_filelayout *flo;
779
780 flo = FILELAYOUT_FROM_HDR(lseg->pls_layout);
781 flo->commit_info.nbuckets = 0;
782 kfree(flo->commit_info.buckets);
783 flo->commit_info.buckets = NULL;
784 }
785 _filelayout_free_lseg(fl);
786}
787
788static int
789filelayout_alloc_commit_info(struct pnfs_layout_segment *lseg,
790 struct nfs_commit_info *cinfo,
791 gfp_t gfp_flags)
792{
793 struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
794 struct pnfs_commit_bucket *buckets;
795 int size;
796
797 if (fl->commit_through_mds)
798 return 0;
799 if (cinfo->ds->nbuckets != 0) {
800 /* This assumes there is only one IOMODE_RW lseg. What
801 * we really want to do is have a layout_hdr level
802 * dictionary of <multipath_list4, fh> keys, each
803 * associated with a struct list_head, populated by calls
804 * to filelayout_write_pagelist().
805 * */
806 return 0;
807 }
808
809 size = (fl->stripe_type == STRIPE_SPARSE) ?
810 fl->dsaddr->ds_num : fl->dsaddr->stripe_count;
811
812 buckets = kcalloc(size, sizeof(struct pnfs_commit_bucket),
813 gfp_flags);
814 if (!buckets)
815 return -ENOMEM;
816 else {
817 int i;
818
819 spin_lock(cinfo->lock);
820 if (cinfo->ds->nbuckets != 0)
821 kfree(buckets);
822 else {
823 cinfo->ds->buckets = buckets;
824 cinfo->ds->nbuckets = size;
825 for (i = 0; i < size; i++) {
826 INIT_LIST_HEAD(&buckets[i].written);
827 INIT_LIST_HEAD(&buckets[i].committing);
828 }
829 }
830 spin_unlock(cinfo->lock);
831 return 0;
832 }
833}
834
835static struct pnfs_layout_segment *
836filelayout_alloc_lseg(struct pnfs_layout_hdr *layoutid,
837 struct nfs4_layoutget_res *lgr,
838 gfp_t gfp_flags)
839{
840 struct nfs4_filelayout_segment *fl;
841 int rc;
842 struct nfs4_deviceid id;
843
844 dprintk("--> %s\n", __func__);
845 fl = kzalloc(sizeof(*fl), gfp_flags);
846 if (!fl)
847 return NULL;
848
849 rc = filelayout_decode_layout(layoutid, fl, lgr, &id, gfp_flags);
850 if (rc != 0 || filelayout_check_layout(layoutid, fl, lgr, &id, gfp_flags)) {
851 _filelayout_free_lseg(fl);
852 return NULL;
853 }
854 return &fl->generic_hdr;
855}
856
857/*
858 * filelayout_pg_test(). Called by nfs_can_coalesce_requests()
859 *
860 * return true : coalesce page
861 * return false : don't coalesce page
862 */
863static bool
864filelayout_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
865 struct nfs_page *req)
866{
867 u64 p_stripe, r_stripe;
868 u32 stripe_unit;
869
870 if (!pnfs_generic_pg_test(pgio, prev, req) ||
871 !nfs_generic_pg_test(pgio, prev, req))
872 return false;
873
874 p_stripe = (u64)req_offset(prev);
875 r_stripe = (u64)req_offset(req);
876 stripe_unit = FILELAYOUT_LSEG(pgio->pg_lseg)->stripe_unit;
877
878 do_div(p_stripe, stripe_unit);
879 do_div(r_stripe, stripe_unit);
880
881 return (p_stripe == r_stripe);
882}
883
884static void
885filelayout_pg_init_read(struct nfs_pageio_descriptor *pgio,
886 struct nfs_page *req)
887{
888 BUG_ON(pgio->pg_lseg != NULL);
889
890 if (req->wb_offset != req->wb_pgbase) {
891 /*
892 * Handling unaligned pages is difficult, because have to
893 * somehow split a req in two in certain cases in the
894 * pg.test code. Avoid this by just not using pnfs
895 * in this case.
896 */
897 nfs_pageio_reset_read_mds(pgio);
898 return;
899 }
900 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
901 req->wb_context,
902 0,
903 NFS4_MAX_UINT64,
904 IOMODE_READ,
905 GFP_KERNEL);
906 /* If no lseg, fall back to read through mds */
907 if (pgio->pg_lseg == NULL)
908 nfs_pageio_reset_read_mds(pgio);
909}
910
911static void
912filelayout_pg_init_write(struct nfs_pageio_descriptor *pgio,
913 struct nfs_page *req)
914{
915 struct nfs_commit_info cinfo;
916 int status;
917
918 BUG_ON(pgio->pg_lseg != NULL);
919
920 if (req->wb_offset != req->wb_pgbase)
921 goto out_mds;
922 pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
923 req->wb_context,
924 0,
925 NFS4_MAX_UINT64,
926 IOMODE_RW,
927 GFP_NOFS);
928 /* If no lseg, fall back to write through mds */
929 if (pgio->pg_lseg == NULL)
930 goto out_mds;
931 nfs_init_cinfo(&cinfo, pgio->pg_inode, pgio->pg_dreq);
932 status = filelayout_alloc_commit_info(pgio->pg_lseg, &cinfo, GFP_NOFS);
933 if (status < 0) {
934 put_lseg(pgio->pg_lseg);
935 pgio->pg_lseg = NULL;
936 goto out_mds;
937 }
938 return;
939out_mds:
940 nfs_pageio_reset_write_mds(pgio);
941}
942
943static const struct nfs_pageio_ops filelayout_pg_read_ops = {
944 .pg_init = filelayout_pg_init_read,
945 .pg_test = filelayout_pg_test,
946 .pg_doio = pnfs_generic_pg_readpages,
947};
948
949static const struct nfs_pageio_ops filelayout_pg_write_ops = {
950 .pg_init = filelayout_pg_init_write,
951 .pg_test = filelayout_pg_test,
952 .pg_doio = pnfs_generic_pg_writepages,
953};
954
955static u32 select_bucket_index(struct nfs4_filelayout_segment *fl, u32 j)
956{
957 if (fl->stripe_type == STRIPE_SPARSE)
958 return nfs4_fl_calc_ds_index(&fl->generic_hdr, j);
959 else
960 return j;
961}
962
963/* The generic layer is about to remove the req from the commit list.
964 * If this will make the bucket empty, it will need to put the lseg reference.
965 */
966static void
967filelayout_clear_request_commit(struct nfs_page *req,
968 struct nfs_commit_info *cinfo)
969{
970 struct pnfs_layout_segment *freeme = NULL;
971
972 spin_lock(cinfo->lock);
973 if (!test_and_clear_bit(PG_COMMIT_TO_DS, &req->wb_flags))
974 goto out;
975 cinfo->ds->nwritten--;
976 if (list_is_singular(&req->wb_list)) {
977 struct pnfs_commit_bucket *bucket;
978
979 bucket = list_first_entry(&req->wb_list,
980 struct pnfs_commit_bucket,
981 written);
982 freeme = bucket->wlseg;
983 bucket->wlseg = NULL;
984 }
985out:
986 nfs_request_remove_commit_list(req, cinfo);
987 spin_unlock(cinfo->lock);
988 put_lseg(freeme);
989}
990
991static struct list_head *
992filelayout_choose_commit_list(struct nfs_page *req,
993 struct pnfs_layout_segment *lseg,
994 struct nfs_commit_info *cinfo)
995{
996 struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
997 u32 i, j;
998 struct list_head *list;
999 struct pnfs_commit_bucket *buckets;
1000
1001 if (fl->commit_through_mds)
1002 return &cinfo->mds->list;
1003
1004 /* Note that we are calling nfs4_fl_calc_j_index on each page
1005 * that ends up being committed to a data server. An attractive
1006 * alternative is to add a field to nfs_write_data and nfs_page
1007 * to store the value calculated in filelayout_write_pagelist
1008 * and just use that here.
1009 */
1010 j = nfs4_fl_calc_j_index(lseg, req_offset(req));
1011 i = select_bucket_index(fl, j);
1012 buckets = cinfo->ds->buckets;
1013 list = &buckets[i].written;
1014 if (list_empty(list)) {
1015 /* Non-empty buckets hold a reference on the lseg. That ref
1016 * is normally transferred to the COMMIT call and released
1017 * there. It could also be released if the last req is pulled
1018 * off due to a rewrite, in which case it will be done in
1019 * filelayout_clear_request_commit
1020 */
1021 buckets[i].wlseg = get_lseg(lseg);
1022 }
1023 set_bit(PG_COMMIT_TO_DS, &req->wb_flags);
1024 cinfo->ds->nwritten++;
1025 return list;
1026}
1027
1028static void
1029filelayout_mark_request_commit(struct nfs_page *req,
1030 struct pnfs_layout_segment *lseg,
1031 struct nfs_commit_info *cinfo)
1032{
1033 struct list_head *list;
1034
1035 list = filelayout_choose_commit_list(req, lseg, cinfo);
1036 nfs_request_add_commit_list(req, list, cinfo);
1037}
1038
1039static u32 calc_ds_index_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1040{
1041 struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
1042
1043 if (flseg->stripe_type == STRIPE_SPARSE)
1044 return i;
1045 else
1046 return nfs4_fl_calc_ds_index(lseg, i);
1047}
1048
1049static struct nfs_fh *
1050select_ds_fh_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1051{
1052 struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
1053
1054 if (flseg->stripe_type == STRIPE_SPARSE) {
1055 if (flseg->num_fh == 1)
1056 i = 0;
1057 else if (flseg->num_fh == 0)
1058 /* Use the MDS OPEN fh set in nfs_read_rpcsetup */
1059 return NULL;
1060 }
1061 return flseg->fh_array[i];
1062}
1063
1064static int filelayout_initiate_commit(struct nfs_commit_data *data, int how)
1065{
1066 struct pnfs_layout_segment *lseg = data->lseg;
1067 struct nfs4_pnfs_ds *ds;
1068 u32 idx;
1069 struct nfs_fh *fh;
1070
1071 idx = calc_ds_index_from_commit(lseg, data->ds_commit_index);
1072 ds = nfs4_fl_prepare_ds(lseg, idx);
1073 if (!ds) {
1074 prepare_to_resend_writes(data);
1075 filelayout_commit_release(data);
1076 return -EAGAIN;
1077 }
1078 dprintk("%s ino %lu, how %d cl_count %d\n", __func__,
1079 data->inode->i_ino, how, atomic_read(&ds->ds_clp->cl_count));
1080 data->commit_done_cb = filelayout_commit_done_cb;
1081 atomic_inc(&ds->ds_clp->cl_count);
1082 data->ds_clp = ds->ds_clp;
1083 fh = select_ds_fh_from_commit(lseg, data->ds_commit_index);
1084 if (fh)
1085 data->args.fh = fh;
1086 return nfs_initiate_commit(ds->ds_clp->cl_rpcclient, data,
1087 &filelayout_commit_call_ops, how,
1088 RPC_TASK_SOFTCONN);
1089}
1090
1091static int
1092transfer_commit_list(struct list_head *src, struct list_head *dst,
1093 struct nfs_commit_info *cinfo, int max)
1094{
1095 struct nfs_page *req, *tmp;
1096 int ret = 0;
1097
1098 list_for_each_entry_safe(req, tmp, src, wb_list) {
1099 if (!nfs_lock_request(req))
1100 continue;
1101 kref_get(&req->wb_kref);
1102 if (cond_resched_lock(cinfo->lock))
1103 list_safe_reset_next(req, tmp, wb_list);
1104 nfs_request_remove_commit_list(req, cinfo);
1105 clear_bit(PG_COMMIT_TO_DS, &req->wb_flags);
1106 nfs_list_add_request(req, dst);
1107 ret++;
1108 if ((ret == max) && !cinfo->dreq)
1109 break;
1110 }
1111 return ret;
1112}
1113
1114static int
1115filelayout_scan_ds_commit_list(struct pnfs_commit_bucket *bucket,
1116 struct nfs_commit_info *cinfo,
1117 int max)
1118{
1119 struct list_head *src = &bucket->written;
1120 struct list_head *dst = &bucket->committing;
1121 int ret;
1122
1123 ret = transfer_commit_list(src, dst, cinfo, max);
1124 if (ret) {
1125 cinfo->ds->nwritten -= ret;
1126 cinfo->ds->ncommitting += ret;
1127 bucket->clseg = bucket->wlseg;
1128 if (list_empty(src))
1129 bucket->wlseg = NULL;
1130 else
1131 get_lseg(bucket->clseg);
1132 }
1133 return ret;
1134}
1135
1136/* Move reqs from written to committing lists, returning count of number moved.
1137 * Note called with cinfo->lock held.
1138 */
1139static int filelayout_scan_commit_lists(struct nfs_commit_info *cinfo,
1140 int max)
1141{
1142 int i, rv = 0, cnt;
1143
1144 for (i = 0; i < cinfo->ds->nbuckets && max != 0; i++) {
1145 cnt = filelayout_scan_ds_commit_list(&cinfo->ds->buckets[i],
1146 cinfo, max);
1147 max -= cnt;
1148 rv += cnt;
1149 }
1150 return rv;
1151}
1152
1153/* Pull everything off the committing lists and dump into @dst */
1154static void filelayout_recover_commit_reqs(struct list_head *dst,
1155 struct nfs_commit_info *cinfo)
1156{
1157 struct pnfs_commit_bucket *b;
1158 int i;
1159
1160 /* NOTE cinfo->lock is NOT held, relying on fact that this is
1161 * only called on single thread per dreq.
1162 * Can't take the lock because need to do put_lseg
1163 */
1164 for (i = 0, b = cinfo->ds->buckets; i < cinfo->ds->nbuckets; i++, b++) {
1165 if (transfer_commit_list(&b->written, dst, cinfo, 0)) {
1166 BUG_ON(!list_empty(&b->written));
1167 put_lseg(b->wlseg);
1168 b->wlseg = NULL;
1169 }
1170 }
1171 cinfo->ds->nwritten = 0;
1172}
1173
1174static unsigned int
1175alloc_ds_commits(struct nfs_commit_info *cinfo, struct list_head *list)
1176{
1177 struct pnfs_ds_commit_info *fl_cinfo;
1178 struct pnfs_commit_bucket *bucket;
1179 struct nfs_commit_data *data;
1180 int i, j;
1181 unsigned int nreq = 0;
1182
1183 fl_cinfo = cinfo->ds;
1184 bucket = fl_cinfo->buckets;
1185 for (i = 0; i < fl_cinfo->nbuckets; i++, bucket++) {
1186 if (list_empty(&bucket->committing))
1187 continue;
1188 data = nfs_commitdata_alloc();
1189 if (!data)
1190 break;
1191 data->ds_commit_index = i;
1192 data->lseg = bucket->clseg;
1193 bucket->clseg = NULL;
1194 list_add(&data->pages, list);
1195 nreq++;
1196 }
1197
1198 /* Clean up on error */
1199 for (j = i; j < fl_cinfo->nbuckets; j++, bucket++) {
1200 if (list_empty(&bucket->committing))
1201 continue;
1202 nfs_retry_commit(&bucket->committing, bucket->clseg, cinfo);
1203 put_lseg(bucket->clseg);
1204 bucket->clseg = NULL;
1205 }
1206 /* Caller will clean up entries put on list */
1207 return nreq;
1208}
1209
1210/* This follows nfs_commit_list pretty closely */
1211static int
1212filelayout_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
1213 int how, struct nfs_commit_info *cinfo)
1214{
1215 struct nfs_commit_data *data, *tmp;
1216 LIST_HEAD(list);
1217 unsigned int nreq = 0;
1218
1219 if (!list_empty(mds_pages)) {
1220 data = nfs_commitdata_alloc();
1221 if (data != NULL) {
1222 data->lseg = NULL;
1223 list_add(&data->pages, &list);
1224 nreq++;
1225 } else
1226 nfs_retry_commit(mds_pages, NULL, cinfo);
1227 }
1228
1229 nreq += alloc_ds_commits(cinfo, &list);
1230
1231 if (nreq == 0) {
1232 cinfo->completion_ops->error_cleanup(NFS_I(inode));
1233 goto out;
1234 }
1235
1236 atomic_add(nreq, &cinfo->mds->rpcs_out);
1237
1238 list_for_each_entry_safe(data, tmp, &list, pages) {
1239 list_del_init(&data->pages);
1240 if (!data->lseg) {
1241 nfs_init_commit(data, mds_pages, NULL, cinfo);
1242 nfs_initiate_commit(NFS_CLIENT(inode), data,
1243 data->mds_ops, how, 0);
1244 } else {
1245 struct pnfs_commit_bucket *buckets;
1246
1247 buckets = cinfo->ds->buckets;
1248 nfs_init_commit(data, &buckets[data->ds_commit_index].committing, data->lseg, cinfo);
1249 filelayout_initiate_commit(data, how);
1250 }
1251 }
1252out:
1253 cinfo->ds->ncommitting = 0;
1254 return PNFS_ATTEMPTED;
1255}
1256
1257static void
1258filelayout_free_deveiceid_node(struct nfs4_deviceid_node *d)
1259{
1260 nfs4_fl_free_deviceid(container_of(d, struct nfs4_file_layout_dsaddr, id_node));
1261}
1262
1263static struct pnfs_layout_hdr *
1264filelayout_alloc_layout_hdr(struct inode *inode, gfp_t gfp_flags)
1265{
1266 struct nfs4_filelayout *flo;
1267
1268 flo = kzalloc(sizeof(*flo), gfp_flags);
1269 return &flo->generic_hdr;
1270}
1271
1272static void
1273filelayout_free_layout_hdr(struct pnfs_layout_hdr *lo)
1274{
1275 kfree(FILELAYOUT_FROM_HDR(lo));
1276}
1277
1278static struct pnfs_ds_commit_info *
1279filelayout_get_ds_info(struct inode *inode)
1280{
1281 struct pnfs_layout_hdr *layout = NFS_I(inode)->layout;
1282
1283 if (layout == NULL)
1284 return NULL;
1285 else
1286 return &FILELAYOUT_FROM_HDR(layout)->commit_info;
1287}
1288
1289static struct pnfs_layoutdriver_type filelayout_type = {
1290 .id = LAYOUT_NFSV4_1_FILES,
1291 .name = "LAYOUT_NFSV4_1_FILES",
1292 .owner = THIS_MODULE,
1293 .alloc_layout_hdr = filelayout_alloc_layout_hdr,
1294 .free_layout_hdr = filelayout_free_layout_hdr,
1295 .alloc_lseg = filelayout_alloc_lseg,
1296 .free_lseg = filelayout_free_lseg,
1297 .pg_read_ops = &filelayout_pg_read_ops,
1298 .pg_write_ops = &filelayout_pg_write_ops,
1299 .get_ds_info = &filelayout_get_ds_info,
1300 .mark_request_commit = filelayout_mark_request_commit,
1301 .clear_request_commit = filelayout_clear_request_commit,
1302 .scan_commit_lists = filelayout_scan_commit_lists,
1303 .recover_commit_reqs = filelayout_recover_commit_reqs,
1304 .commit_pagelist = filelayout_commit_pagelist,
1305 .read_pagelist = filelayout_read_pagelist,
1306 .write_pagelist = filelayout_write_pagelist,
1307 .free_deviceid_node = filelayout_free_deveiceid_node,
1308};
1309
1310static int __init nfs4filelayout_init(void)
1311{
1312 printk(KERN_INFO "%s: NFSv4 File Layout Driver Registering...\n",
1313 __func__);
1314 return pnfs_register_layoutdriver(&filelayout_type);
1315}
1316
1317static void __exit nfs4filelayout_exit(void)
1318{
1319 printk(KERN_INFO "%s: NFSv4 File Layout Driver Unregistering...\n",
1320 __func__);
1321 pnfs_unregister_layoutdriver(&filelayout_type);
1322}
1323
1324MODULE_ALIAS("nfs-layouttype4-1");
1325
1326module_init(nfs4filelayout_init);
1327module_exit(nfs4filelayout_exit);