usb: gadget: storage_common: Remove FSG specific definitions.
[platform/adaptation/renesas_rcar/renesas_kernel.git] / fs / nfs / nfs4filelayout.c
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
44 MODULE_LICENSE("GPL");
45 MODULE_AUTHOR("Dean Hildebrand <dhildebz@umich.edu>");
46 MODULE_DESCRIPTION("The NFSv4 file layout driver");
47
48 #define FILELAYOUT_POLL_RETRY_MAX     (15*HZ)
49
50 static loff_t
51 filelayout_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  */
69 static loff_t
70 filelayout_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
85 static 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
105 static 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
125 static 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                 pnfs_destroy_layout(NFS_I(inode));
194                 rpc_wake_up(&tbl->slot_tbl_waitq);
195                 goto reset;
196         /* RPC connection errors */
197         case -ECONNREFUSED:
198         case -EHOSTDOWN:
199         case -EHOSTUNREACH:
200         case -ENETUNREACH:
201         case -EIO:
202         case -ETIMEDOUT:
203         case -EPIPE:
204                 dprintk("%s DS connection error %d\n", __func__,
205                         task->tk_status);
206                 nfs4_mark_deviceid_unavailable(devid);
207                 clear_bit(NFS_INO_LAYOUTCOMMIT, &NFS_I(inode)->flags);
208                 _pnfs_return_layout(inode);
209                 rpc_wake_up(&tbl->slot_tbl_waitq);
210                 nfs4_ds_disconnect(clp);
211                 /* fall through */
212         default:
213 reset:
214                 dprintk("%s Retry through MDS. Error %d\n", __func__,
215                         task->tk_status);
216                 return -NFS4ERR_RESET_TO_MDS;
217         }
218 out:
219         task->tk_status = 0;
220         return -EAGAIN;
221 wait_on_recovery:
222         rpc_sleep_on(&mds_client->cl_rpcwaitq, task, NULL);
223         if (test_bit(NFS4CLNT_MANAGER_RUNNING, &mds_client->cl_state) == 0)
224                 rpc_wake_up_queued_task(&mds_client->cl_rpcwaitq, task);
225         goto out;
226 }
227
228 /* NFS_PROTO call done callback routines */
229
230 static int filelayout_read_done_cb(struct rpc_task *task,
231                                 struct nfs_read_data *data)
232 {
233         struct nfs_pgio_header *hdr = data->header;
234         int err;
235
236         err = filelayout_async_handle_error(task, data->args.context->state,
237                                             data->ds_clp, hdr->lseg);
238
239         switch (err) {
240         case -NFS4ERR_RESET_TO_MDS:
241                 filelayout_reset_read(data);
242                 return task->tk_status;
243         case -EAGAIN:
244                 rpc_restart_call_prepare(task);
245                 return -EAGAIN;
246         }
247
248         return 0;
249 }
250
251 /*
252  * We reference the rpc_cred of the first WRITE that triggers the need for
253  * a LAYOUTCOMMIT, and use it to send the layoutcommit compound.
254  * rfc5661 is not clear about which credential should be used.
255  */
256 static void
257 filelayout_set_layoutcommit(struct nfs_write_data *wdata)
258 {
259         struct nfs_pgio_header *hdr = wdata->header;
260
261         if (FILELAYOUT_LSEG(hdr->lseg)->commit_through_mds ||
262             wdata->res.verf->committed == NFS_FILE_SYNC)
263                 return;
264
265         pnfs_set_layoutcommit(wdata);
266         dprintk("%s ionde %lu pls_end_pos %lu\n", __func__, hdr->inode->i_ino,
267                 (unsigned long) NFS_I(hdr->inode)->layout->plh_lwb);
268 }
269
270 bool
271 filelayout_test_devid_unavailable(struct nfs4_deviceid_node *node)
272 {
273         return filelayout_test_devid_invalid(node) ||
274                 nfs4_test_deviceid_unavailable(node);
275 }
276
277 static bool
278 filelayout_reset_to_mds(struct pnfs_layout_segment *lseg)
279 {
280         struct nfs4_deviceid_node *node = FILELAYOUT_DEVID_NODE(lseg);
281
282         return filelayout_test_devid_unavailable(node);
283 }
284
285 /*
286  * Call ops for the async read/write cases
287  * In the case of dense layouts, the offset needs to be reset to its
288  * original value.
289  */
290 static void filelayout_read_prepare(struct rpc_task *task, void *data)
291 {
292         struct nfs_read_data *rdata = data;
293
294         if (filelayout_reset_to_mds(rdata->header->lseg)) {
295                 dprintk("%s task %u reset io to MDS\n", __func__, task->tk_pid);
296                 filelayout_reset_read(rdata);
297                 rpc_exit(task, 0);
298                 return;
299         }
300         rdata->read_done_cb = filelayout_read_done_cb;
301
302         if (nfs41_setup_sequence(rdata->ds_clp->cl_session,
303                                 &rdata->args.seq_args, &rdata->res.seq_res,
304                                 task))
305                 return;
306
307         rpc_call_start(task);
308 }
309
310 static void filelayout_read_call_done(struct rpc_task *task, void *data)
311 {
312         struct nfs_read_data *rdata = data;
313
314         dprintk("--> %s task->tk_status %d\n", __func__, task->tk_status);
315
316         if (test_bit(NFS_IOHDR_REDO, &rdata->header->flags) &&
317             task->tk_status == 0)
318                 return;
319
320         /* Note this may cause RPC to be resent */
321         rdata->header->mds_ops->rpc_call_done(task, data);
322 }
323
324 static void filelayout_read_count_stats(struct rpc_task *task, void *data)
325 {
326         struct nfs_read_data *rdata = data;
327
328         rpc_count_iostats(task, NFS_SERVER(rdata->header->inode)->client->cl_metrics);
329 }
330
331 static void filelayout_read_release(void *data)
332 {
333         struct nfs_read_data *rdata = data;
334
335         nfs_put_client(rdata->ds_clp);
336         rdata->header->mds_ops->rpc_release(data);
337 }
338
339 static int filelayout_write_done_cb(struct rpc_task *task,
340                                 struct nfs_write_data *data)
341 {
342         struct nfs_pgio_header *hdr = data->header;
343         int err;
344
345         err = filelayout_async_handle_error(task, data->args.context->state,
346                                             data->ds_clp, hdr->lseg);
347
348         switch (err) {
349         case -NFS4ERR_RESET_TO_MDS:
350                 filelayout_reset_write(data);
351                 return task->tk_status;
352         case -EAGAIN:
353                 rpc_restart_call_prepare(task);
354                 return -EAGAIN;
355         }
356
357         filelayout_set_layoutcommit(data);
358         return 0;
359 }
360
361 /* Fake up some data that will cause nfs_commit_release to retry the writes. */
362 static void prepare_to_resend_writes(struct nfs_commit_data *data)
363 {
364         struct nfs_page *first = nfs_list_entry(data->pages.next);
365
366         data->task.tk_status = 0;
367         memcpy(&data->verf.verifier, &first->wb_verf,
368                sizeof(data->verf.verifier));
369         data->verf.verifier.data[0]++; /* ensure verifier mismatch */
370 }
371
372 static int filelayout_commit_done_cb(struct rpc_task *task,
373                                      struct nfs_commit_data *data)
374 {
375         int err;
376
377         err = filelayout_async_handle_error(task, NULL, data->ds_clp,
378                                             data->lseg);
379
380         switch (err) {
381         case -NFS4ERR_RESET_TO_MDS:
382                 prepare_to_resend_writes(data);
383                 return -EAGAIN;
384         case -EAGAIN:
385                 rpc_restart_call_prepare(task);
386                 return -EAGAIN;
387         }
388
389         return 0;
390 }
391
392 static void filelayout_write_prepare(struct rpc_task *task, void *data)
393 {
394         struct nfs_write_data *wdata = data;
395
396         if (filelayout_reset_to_mds(wdata->header->lseg)) {
397                 dprintk("%s task %u reset io to MDS\n", __func__, task->tk_pid);
398                 filelayout_reset_write(wdata);
399                 rpc_exit(task, 0);
400                 return;
401         }
402         if (nfs41_setup_sequence(wdata->ds_clp->cl_session,
403                                 &wdata->args.seq_args, &wdata->res.seq_res,
404                                 task))
405                 return;
406
407         rpc_call_start(task);
408 }
409
410 static void filelayout_write_call_done(struct rpc_task *task, void *data)
411 {
412         struct nfs_write_data *wdata = data;
413
414         if (test_bit(NFS_IOHDR_REDO, &wdata->header->flags) &&
415             task->tk_status == 0)
416                 return;
417
418         /* Note this may cause RPC to be resent */
419         wdata->header->mds_ops->rpc_call_done(task, data);
420 }
421
422 static void filelayout_write_count_stats(struct rpc_task *task, void *data)
423 {
424         struct nfs_write_data *wdata = data;
425
426         rpc_count_iostats(task, NFS_SERVER(wdata->header->inode)->client->cl_metrics);
427 }
428
429 static void filelayout_write_release(void *data)
430 {
431         struct nfs_write_data *wdata = data;
432
433         nfs_put_client(wdata->ds_clp);
434         wdata->header->mds_ops->rpc_release(data);
435 }
436
437 static void filelayout_commit_prepare(struct rpc_task *task, void *data)
438 {
439         struct nfs_commit_data *wdata = data;
440
441         if (nfs41_setup_sequence(wdata->ds_clp->cl_session,
442                                 &wdata->args.seq_args, &wdata->res.seq_res,
443                                 task))
444                 return;
445
446         rpc_call_start(task);
447 }
448
449 static void filelayout_write_commit_done(struct rpc_task *task, void *data)
450 {
451         struct nfs_commit_data *wdata = data;
452
453         /* Note this may cause RPC to be resent */
454         wdata->mds_ops->rpc_call_done(task, data);
455 }
456
457 static void filelayout_commit_count_stats(struct rpc_task *task, void *data)
458 {
459         struct nfs_commit_data *cdata = data;
460
461         rpc_count_iostats(task, NFS_SERVER(cdata->inode)->client->cl_metrics);
462 }
463
464 static void filelayout_commit_release(void *calldata)
465 {
466         struct nfs_commit_data *data = calldata;
467
468         data->completion_ops->completion(data);
469         pnfs_put_lseg(data->lseg);
470         nfs_put_client(data->ds_clp);
471         nfs_commitdata_release(data);
472 }
473
474 static const struct rpc_call_ops filelayout_read_call_ops = {
475         .rpc_call_prepare = filelayout_read_prepare,
476         .rpc_call_done = filelayout_read_call_done,
477         .rpc_count_stats = filelayout_read_count_stats,
478         .rpc_release = filelayout_read_release,
479 };
480
481 static const struct rpc_call_ops filelayout_write_call_ops = {
482         .rpc_call_prepare = filelayout_write_prepare,
483         .rpc_call_done = filelayout_write_call_done,
484         .rpc_count_stats = filelayout_write_count_stats,
485         .rpc_release = filelayout_write_release,
486 };
487
488 static const struct rpc_call_ops filelayout_commit_call_ops = {
489         .rpc_call_prepare = filelayout_commit_prepare,
490         .rpc_call_done = filelayout_write_commit_done,
491         .rpc_count_stats = filelayout_commit_count_stats,
492         .rpc_release = filelayout_commit_release,
493 };
494
495 static enum pnfs_try_status
496 filelayout_read_pagelist(struct nfs_read_data *data)
497 {
498         struct nfs_pgio_header *hdr = data->header;
499         struct pnfs_layout_segment *lseg = hdr->lseg;
500         struct nfs4_pnfs_ds *ds;
501         loff_t offset = data->args.offset;
502         u32 j, idx;
503         struct nfs_fh *fh;
504         int status;
505
506         dprintk("--> %s ino %lu pgbase %u req %Zu@%llu\n",
507                 __func__, hdr->inode->i_ino,
508                 data->args.pgbase, (size_t)data->args.count, offset);
509
510         /* Retrieve the correct rpc_client for the byte range */
511         j = nfs4_fl_calc_j_index(lseg, offset);
512         idx = nfs4_fl_calc_ds_index(lseg, j);
513         ds = nfs4_fl_prepare_ds(lseg, idx);
514         if (!ds)
515                 return PNFS_NOT_ATTEMPTED;
516         dprintk("%s USE DS: %s cl_count %d\n", __func__,
517                 ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count));
518
519         /* No multipath support. Use first DS */
520         atomic_inc(&ds->ds_clp->cl_count);
521         data->ds_clp = ds->ds_clp;
522         fh = nfs4_fl_select_ds_fh(lseg, j);
523         if (fh)
524                 data->args.fh = fh;
525
526         data->args.offset = filelayout_get_dserver_offset(lseg, offset);
527         data->mds_offset = offset;
528
529         /* Perform an asynchronous read to ds */
530         status = nfs_initiate_read(ds->ds_clp->cl_rpcclient, data,
531                                   &filelayout_read_call_ops, RPC_TASK_SOFTCONN);
532         BUG_ON(status != 0);
533         return PNFS_ATTEMPTED;
534 }
535
536 /* Perform async writes. */
537 static enum pnfs_try_status
538 filelayout_write_pagelist(struct nfs_write_data *data, int sync)
539 {
540         struct nfs_pgio_header *hdr = data->header;
541         struct pnfs_layout_segment *lseg = hdr->lseg;
542         struct nfs4_pnfs_ds *ds;
543         loff_t offset = data->args.offset;
544         u32 j, idx;
545         struct nfs_fh *fh;
546         int status;
547
548         /* Retrieve the correct rpc_client for the byte range */
549         j = nfs4_fl_calc_j_index(lseg, offset);
550         idx = nfs4_fl_calc_ds_index(lseg, j);
551         ds = nfs4_fl_prepare_ds(lseg, idx);
552         if (!ds)
553                 return PNFS_NOT_ATTEMPTED;
554         dprintk("%s ino %lu sync %d req %Zu@%llu DS: %s cl_count %d\n",
555                 __func__, hdr->inode->i_ino, sync, (size_t) data->args.count,
556                 offset, ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count));
557
558         data->write_done_cb = filelayout_write_done_cb;
559         atomic_inc(&ds->ds_clp->cl_count);
560         data->ds_clp = ds->ds_clp;
561         fh = nfs4_fl_select_ds_fh(lseg, j);
562         if (fh)
563                 data->args.fh = fh;
564         /*
565          * Get the file offset on the dserver. Set the write offset to
566          * this offset and save the original offset.
567          */
568         data->args.offset = filelayout_get_dserver_offset(lseg, offset);
569
570         /* Perform an asynchronous write */
571         status = nfs_initiate_write(ds->ds_clp->cl_rpcclient, data,
572                                     &filelayout_write_call_ops, sync,
573                                     RPC_TASK_SOFTCONN);
574         BUG_ON(status != 0);
575         return PNFS_ATTEMPTED;
576 }
577
578 /*
579  * filelayout_check_layout()
580  *
581  * Make sure layout segment parameters are sane WRT the device.
582  * At this point no generic layer initialization of the lseg has occurred,
583  * and nothing has been added to the layout_hdr cache.
584  *
585  */
586 static int
587 filelayout_check_layout(struct pnfs_layout_hdr *lo,
588                         struct nfs4_filelayout_segment *fl,
589                         struct nfs4_layoutget_res *lgr,
590                         struct nfs4_deviceid *id,
591                         gfp_t gfp_flags)
592 {
593         struct nfs4_deviceid_node *d;
594         struct nfs4_file_layout_dsaddr *dsaddr;
595         int status = -EINVAL;
596         struct nfs_server *nfss = NFS_SERVER(lo->plh_inode);
597
598         dprintk("--> %s\n", __func__);
599
600         /* FIXME: remove this check when layout segment support is added */
601         if (lgr->range.offset != 0 ||
602             lgr->range.length != NFS4_MAX_UINT64) {
603                 dprintk("%s Only whole file layouts supported. Use MDS i/o\n",
604                         __func__);
605                 goto out;
606         }
607
608         if (fl->pattern_offset > lgr->range.offset) {
609                 dprintk("%s pattern_offset %lld too large\n",
610                                 __func__, fl->pattern_offset);
611                 goto out;
612         }
613
614         if (!fl->stripe_unit || fl->stripe_unit % PAGE_SIZE) {
615                 dprintk("%s Invalid stripe unit (%u)\n",
616                         __func__, fl->stripe_unit);
617                 goto out;
618         }
619
620         /* find and reference the deviceid */
621         d = nfs4_find_get_deviceid(NFS_SERVER(lo->plh_inode)->pnfs_curr_ld,
622                                    NFS_SERVER(lo->plh_inode)->nfs_client, id);
623         if (d == NULL) {
624                 dsaddr = filelayout_get_device_info(lo->plh_inode, id, gfp_flags);
625                 if (dsaddr == NULL)
626                         goto out;
627         } else
628                 dsaddr = container_of(d, struct nfs4_file_layout_dsaddr, id_node);
629         /* Found deviceid is unavailable */
630         if (filelayout_test_devid_unavailable(&dsaddr->id_node))
631                         goto out_put;
632
633         fl->dsaddr = dsaddr;
634
635         if (fl->first_stripe_index >= dsaddr->stripe_count) {
636                 dprintk("%s Bad first_stripe_index %u\n",
637                                 __func__, fl->first_stripe_index);
638                 goto out_put;
639         }
640
641         if ((fl->stripe_type == STRIPE_SPARSE &&
642             fl->num_fh > 1 && fl->num_fh != dsaddr->ds_num) ||
643             (fl->stripe_type == STRIPE_DENSE &&
644             fl->num_fh != dsaddr->stripe_count)) {
645                 dprintk("%s num_fh %u not valid for given packing\n",
646                         __func__, fl->num_fh);
647                 goto out_put;
648         }
649
650         if (fl->stripe_unit % nfss->rsize || fl->stripe_unit % nfss->wsize) {
651                 dprintk("%s Stripe unit (%u) not aligned with rsize %u "
652                         "wsize %u\n", __func__, fl->stripe_unit, nfss->rsize,
653                         nfss->wsize);
654         }
655
656         status = 0;
657 out:
658         dprintk("--> %s returns %d\n", __func__, status);
659         return status;
660 out_put:
661         nfs4_fl_put_deviceid(dsaddr);
662         goto out;
663 }
664
665 static void filelayout_free_fh_array(struct nfs4_filelayout_segment *fl)
666 {
667         int i;
668
669         for (i = 0; i < fl->num_fh; i++) {
670                 if (!fl->fh_array[i])
671                         break;
672                 kfree(fl->fh_array[i]);
673         }
674         kfree(fl->fh_array);
675         fl->fh_array = NULL;
676 }
677
678 static void
679 _filelayout_free_lseg(struct nfs4_filelayout_segment *fl)
680 {
681         filelayout_free_fh_array(fl);
682         kfree(fl);
683 }
684
685 static int
686 filelayout_decode_layout(struct pnfs_layout_hdr *flo,
687                          struct nfs4_filelayout_segment *fl,
688                          struct nfs4_layoutget_res *lgr,
689                          struct nfs4_deviceid *id,
690                          gfp_t gfp_flags)
691 {
692         struct xdr_stream stream;
693         struct xdr_buf buf;
694         struct page *scratch;
695         __be32 *p;
696         uint32_t nfl_util;
697         int i;
698
699         dprintk("%s: set_layout_map Begin\n", __func__);
700
701         scratch = alloc_page(gfp_flags);
702         if (!scratch)
703                 return -ENOMEM;
704
705         xdr_init_decode_pages(&stream, &buf, lgr->layoutp->pages, lgr->layoutp->len);
706         xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
707
708         /* 20 = ufl_util (4), first_stripe_index (4), pattern_offset (8),
709          * num_fh (4) */
710         p = xdr_inline_decode(&stream, NFS4_DEVICEID4_SIZE + 20);
711         if (unlikely(!p))
712                 goto out_err;
713
714         memcpy(id, p, sizeof(*id));
715         p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
716         nfs4_print_deviceid(id);
717
718         nfl_util = be32_to_cpup(p++);
719         if (nfl_util & NFL4_UFLG_COMMIT_THRU_MDS)
720                 fl->commit_through_mds = 1;
721         if (nfl_util & NFL4_UFLG_DENSE)
722                 fl->stripe_type = STRIPE_DENSE;
723         else
724                 fl->stripe_type = STRIPE_SPARSE;
725         fl->stripe_unit = nfl_util & ~NFL4_UFLG_MASK;
726
727         fl->first_stripe_index = be32_to_cpup(p++);
728         p = xdr_decode_hyper(p, &fl->pattern_offset);
729         fl->num_fh = be32_to_cpup(p++);
730
731         dprintk("%s: nfl_util 0x%X num_fh %u fsi %u po %llu\n",
732                 __func__, nfl_util, fl->num_fh, fl->first_stripe_index,
733                 fl->pattern_offset);
734
735         /* Note that a zero value for num_fh is legal for STRIPE_SPARSE.
736          * Futher checking is done in filelayout_check_layout */
737         if (fl->num_fh >
738             max(NFS4_PNFS_MAX_STRIPE_CNT, NFS4_PNFS_MAX_MULTI_CNT))
739                 goto out_err;
740
741         if (fl->num_fh > 0) {
742                 fl->fh_array = kzalloc(fl->num_fh * sizeof(struct nfs_fh *),
743                                        gfp_flags);
744                 if (!fl->fh_array)
745                         goto out_err;
746         }
747
748         for (i = 0; i < fl->num_fh; i++) {
749                 /* Do we want to use a mempool here? */
750                 fl->fh_array[i] = kmalloc(sizeof(struct nfs_fh), gfp_flags);
751                 if (!fl->fh_array[i])
752                         goto out_err_free;
753
754                 p = xdr_inline_decode(&stream, 4);
755                 if (unlikely(!p))
756                         goto out_err_free;
757                 fl->fh_array[i]->size = be32_to_cpup(p++);
758                 if (sizeof(struct nfs_fh) < fl->fh_array[i]->size) {
759                         printk(KERN_ERR "NFS: Too big fh %d received %d\n",
760                                i, fl->fh_array[i]->size);
761                         goto out_err_free;
762                 }
763
764                 p = xdr_inline_decode(&stream, fl->fh_array[i]->size);
765                 if (unlikely(!p))
766                         goto out_err_free;
767                 memcpy(fl->fh_array[i]->data, p, fl->fh_array[i]->size);
768                 dprintk("DEBUG: %s: fh len %d\n", __func__,
769                         fl->fh_array[i]->size);
770         }
771
772         __free_page(scratch);
773         return 0;
774
775 out_err_free:
776         filelayout_free_fh_array(fl);
777 out_err:
778         __free_page(scratch);
779         return -EIO;
780 }
781
782 static void
783 filelayout_free_lseg(struct pnfs_layout_segment *lseg)
784 {
785         struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
786
787         dprintk("--> %s\n", __func__);
788         nfs4_fl_put_deviceid(fl->dsaddr);
789         /* This assumes a single RW lseg */
790         if (lseg->pls_range.iomode == IOMODE_RW) {
791                 struct nfs4_filelayout *flo;
792
793                 flo = FILELAYOUT_FROM_HDR(lseg->pls_layout);
794                 flo->commit_info.nbuckets = 0;
795                 kfree(flo->commit_info.buckets);
796                 flo->commit_info.buckets = NULL;
797         }
798         _filelayout_free_lseg(fl);
799 }
800
801 static int
802 filelayout_alloc_commit_info(struct pnfs_layout_segment *lseg,
803                              struct nfs_commit_info *cinfo,
804                              gfp_t gfp_flags)
805 {
806         struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
807         struct pnfs_commit_bucket *buckets;
808         int size;
809
810         if (fl->commit_through_mds)
811                 return 0;
812         if (cinfo->ds->nbuckets != 0) {
813                 /* This assumes there is only one IOMODE_RW lseg.  What
814                  * we really want to do is have a layout_hdr level
815                  * dictionary of <multipath_list4, fh> keys, each
816                  * associated with a struct list_head, populated by calls
817                  * to filelayout_write_pagelist().
818                  * */
819                 return 0;
820         }
821
822         size = (fl->stripe_type == STRIPE_SPARSE) ?
823                 fl->dsaddr->ds_num : fl->dsaddr->stripe_count;
824
825         buckets = kcalloc(size, sizeof(struct pnfs_commit_bucket),
826                           gfp_flags);
827         if (!buckets)
828                 return -ENOMEM;
829         else {
830                 int i;
831
832                 spin_lock(cinfo->lock);
833                 if (cinfo->ds->nbuckets != 0)
834                         kfree(buckets);
835                 else {
836                         cinfo->ds->buckets = buckets;
837                         cinfo->ds->nbuckets = size;
838                         for (i = 0; i < size; i++) {
839                                 INIT_LIST_HEAD(&buckets[i].written);
840                                 INIT_LIST_HEAD(&buckets[i].committing);
841                         }
842                 }
843                 spin_unlock(cinfo->lock);
844                 return 0;
845         }
846 }
847
848 static struct pnfs_layout_segment *
849 filelayout_alloc_lseg(struct pnfs_layout_hdr *layoutid,
850                       struct nfs4_layoutget_res *lgr,
851                       gfp_t gfp_flags)
852 {
853         struct nfs4_filelayout_segment *fl;
854         int rc;
855         struct nfs4_deviceid id;
856
857         dprintk("--> %s\n", __func__);
858         fl = kzalloc(sizeof(*fl), gfp_flags);
859         if (!fl)
860                 return NULL;
861
862         rc = filelayout_decode_layout(layoutid, fl, lgr, &id, gfp_flags);
863         if (rc != 0 || filelayout_check_layout(layoutid, fl, lgr, &id, gfp_flags)) {
864                 _filelayout_free_lseg(fl);
865                 return NULL;
866         }
867         return &fl->generic_hdr;
868 }
869
870 /*
871  * filelayout_pg_test(). Called by nfs_can_coalesce_requests()
872  *
873  * return true  : coalesce page
874  * return false : don't coalesce page
875  */
876 static bool
877 filelayout_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
878                    struct nfs_page *req)
879 {
880         u64 p_stripe, r_stripe;
881         u32 stripe_unit;
882
883         if (!pnfs_generic_pg_test(pgio, prev, req) ||
884             !nfs_generic_pg_test(pgio, prev, req))
885                 return false;
886
887         p_stripe = (u64)req_offset(prev);
888         r_stripe = (u64)req_offset(req);
889         stripe_unit = FILELAYOUT_LSEG(pgio->pg_lseg)->stripe_unit;
890
891         do_div(p_stripe, stripe_unit);
892         do_div(r_stripe, stripe_unit);
893
894         return (p_stripe == r_stripe);
895 }
896
897 static void
898 filelayout_pg_init_read(struct nfs_pageio_descriptor *pgio,
899                         struct nfs_page *req)
900 {
901         BUG_ON(pgio->pg_lseg != NULL);
902
903         if (req->wb_offset != req->wb_pgbase) {
904                 /*
905                  * Handling unaligned pages is difficult, because have to
906                  * somehow split a req in two in certain cases in the
907                  * pg.test code.  Avoid this by just not using pnfs
908                  * in this case.
909                  */
910                 nfs_pageio_reset_read_mds(pgio);
911                 return;
912         }
913         pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
914                                            req->wb_context,
915                                            0,
916                                            NFS4_MAX_UINT64,
917                                            IOMODE_READ,
918                                            GFP_KERNEL);
919         /* If no lseg, fall back to read through mds */
920         if (pgio->pg_lseg == NULL)
921                 nfs_pageio_reset_read_mds(pgio);
922 }
923
924 static void
925 filelayout_pg_init_write(struct nfs_pageio_descriptor *pgio,
926                          struct nfs_page *req)
927 {
928         struct nfs_commit_info cinfo;
929         int status;
930
931         BUG_ON(pgio->pg_lseg != NULL);
932
933         if (req->wb_offset != req->wb_pgbase)
934                 goto out_mds;
935         pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
936                                            req->wb_context,
937                                            0,
938                                            NFS4_MAX_UINT64,
939                                            IOMODE_RW,
940                                            GFP_NOFS);
941         /* If no lseg, fall back to write through mds */
942         if (pgio->pg_lseg == NULL)
943                 goto out_mds;
944         nfs_init_cinfo(&cinfo, pgio->pg_inode, pgio->pg_dreq);
945         status = filelayout_alloc_commit_info(pgio->pg_lseg, &cinfo, GFP_NOFS);
946         if (status < 0) {
947                 pnfs_put_lseg(pgio->pg_lseg);
948                 pgio->pg_lseg = NULL;
949                 goto out_mds;
950         }
951         return;
952 out_mds:
953         nfs_pageio_reset_write_mds(pgio);
954 }
955
956 static const struct nfs_pageio_ops filelayout_pg_read_ops = {
957         .pg_init = filelayout_pg_init_read,
958         .pg_test = filelayout_pg_test,
959         .pg_doio = pnfs_generic_pg_readpages,
960 };
961
962 static const struct nfs_pageio_ops filelayout_pg_write_ops = {
963         .pg_init = filelayout_pg_init_write,
964         .pg_test = filelayout_pg_test,
965         .pg_doio = pnfs_generic_pg_writepages,
966 };
967
968 static u32 select_bucket_index(struct nfs4_filelayout_segment *fl, u32 j)
969 {
970         if (fl->stripe_type == STRIPE_SPARSE)
971                 return nfs4_fl_calc_ds_index(&fl->generic_hdr, j);
972         else
973                 return j;
974 }
975
976 /* The generic layer is about to remove the req from the commit list.
977  * If this will make the bucket empty, it will need to put the lseg reference.
978  */
979 static void
980 filelayout_clear_request_commit(struct nfs_page *req,
981                                 struct nfs_commit_info *cinfo)
982 {
983         struct pnfs_layout_segment *freeme = NULL;
984
985         spin_lock(cinfo->lock);
986         if (!test_and_clear_bit(PG_COMMIT_TO_DS, &req->wb_flags))
987                 goto out;
988         cinfo->ds->nwritten--;
989         if (list_is_singular(&req->wb_list)) {
990                 struct pnfs_commit_bucket *bucket;
991
992                 bucket = list_first_entry(&req->wb_list,
993                                           struct pnfs_commit_bucket,
994                                           written);
995                 freeme = bucket->wlseg;
996                 bucket->wlseg = NULL;
997         }
998 out:
999         nfs_request_remove_commit_list(req, cinfo);
1000         spin_unlock(cinfo->lock);
1001         pnfs_put_lseg(freeme);
1002 }
1003
1004 static struct list_head *
1005 filelayout_choose_commit_list(struct nfs_page *req,
1006                               struct pnfs_layout_segment *lseg,
1007                               struct nfs_commit_info *cinfo)
1008 {
1009         struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
1010         u32 i, j;
1011         struct list_head *list;
1012         struct pnfs_commit_bucket *buckets;
1013
1014         if (fl->commit_through_mds)
1015                 return &cinfo->mds->list;
1016
1017         /* Note that we are calling nfs4_fl_calc_j_index on each page
1018          * that ends up being committed to a data server.  An attractive
1019          * alternative is to add a field to nfs_write_data and nfs_page
1020          * to store the value calculated in filelayout_write_pagelist
1021          * and just use that here.
1022          */
1023         j = nfs4_fl_calc_j_index(lseg, req_offset(req));
1024         i = select_bucket_index(fl, j);
1025         buckets = cinfo->ds->buckets;
1026         list = &buckets[i].written;
1027         if (list_empty(list)) {
1028                 /* Non-empty buckets hold a reference on the lseg.  That ref
1029                  * is normally transferred to the COMMIT call and released
1030                  * there.  It could also be released if the last req is pulled
1031                  * off due to a rewrite, in which case it will be done in
1032                  * filelayout_clear_request_commit
1033                  */
1034                 buckets[i].wlseg = pnfs_get_lseg(lseg);
1035         }
1036         set_bit(PG_COMMIT_TO_DS, &req->wb_flags);
1037         cinfo->ds->nwritten++;
1038         return list;
1039 }
1040
1041 static void
1042 filelayout_mark_request_commit(struct nfs_page *req,
1043                                struct pnfs_layout_segment *lseg,
1044                                struct nfs_commit_info *cinfo)
1045 {
1046         struct list_head *list;
1047
1048         list = filelayout_choose_commit_list(req, lseg, cinfo);
1049         nfs_request_add_commit_list(req, list, cinfo);
1050 }
1051
1052 static u32 calc_ds_index_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1053 {
1054         struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
1055
1056         if (flseg->stripe_type == STRIPE_SPARSE)
1057                 return i;
1058         else
1059                 return nfs4_fl_calc_ds_index(lseg, i);
1060 }
1061
1062 static struct nfs_fh *
1063 select_ds_fh_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1064 {
1065         struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
1066
1067         if (flseg->stripe_type == STRIPE_SPARSE) {
1068                 if (flseg->num_fh == 1)
1069                         i = 0;
1070                 else if (flseg->num_fh == 0)
1071                         /* Use the MDS OPEN fh set in nfs_read_rpcsetup */
1072                         return NULL;
1073         }
1074         return flseg->fh_array[i];
1075 }
1076
1077 static int filelayout_initiate_commit(struct nfs_commit_data *data, int how)
1078 {
1079         struct pnfs_layout_segment *lseg = data->lseg;
1080         struct nfs4_pnfs_ds *ds;
1081         u32 idx;
1082         struct nfs_fh *fh;
1083
1084         idx = calc_ds_index_from_commit(lseg, data->ds_commit_index);
1085         ds = nfs4_fl_prepare_ds(lseg, idx);
1086         if (!ds) {
1087                 prepare_to_resend_writes(data);
1088                 filelayout_commit_release(data);
1089                 return -EAGAIN;
1090         }
1091         dprintk("%s ino %lu, how %d cl_count %d\n", __func__,
1092                 data->inode->i_ino, how, atomic_read(&ds->ds_clp->cl_count));
1093         data->commit_done_cb = filelayout_commit_done_cb;
1094         atomic_inc(&ds->ds_clp->cl_count);
1095         data->ds_clp = ds->ds_clp;
1096         fh = select_ds_fh_from_commit(lseg, data->ds_commit_index);
1097         if (fh)
1098                 data->args.fh = fh;
1099         return nfs_initiate_commit(ds->ds_clp->cl_rpcclient, data,
1100                                    &filelayout_commit_call_ops, how,
1101                                    RPC_TASK_SOFTCONN);
1102 }
1103
1104 static int
1105 transfer_commit_list(struct list_head *src, struct list_head *dst,
1106                      struct nfs_commit_info *cinfo, int max)
1107 {
1108         struct nfs_page *req, *tmp;
1109         int ret = 0;
1110
1111         list_for_each_entry_safe(req, tmp, src, wb_list) {
1112                 if (!nfs_lock_request(req))
1113                         continue;
1114                 kref_get(&req->wb_kref);
1115                 if (cond_resched_lock(cinfo->lock))
1116                         list_safe_reset_next(req, tmp, wb_list);
1117                 nfs_request_remove_commit_list(req, cinfo);
1118                 clear_bit(PG_COMMIT_TO_DS, &req->wb_flags);
1119                 nfs_list_add_request(req, dst);
1120                 ret++;
1121                 if ((ret == max) && !cinfo->dreq)
1122                         break;
1123         }
1124         return ret;
1125 }
1126
1127 static int
1128 filelayout_scan_ds_commit_list(struct pnfs_commit_bucket *bucket,
1129                                struct nfs_commit_info *cinfo,
1130                                int max)
1131 {
1132         struct list_head *src = &bucket->written;
1133         struct list_head *dst = &bucket->committing;
1134         int ret;
1135
1136         ret = transfer_commit_list(src, dst, cinfo, max);
1137         if (ret) {
1138                 cinfo->ds->nwritten -= ret;
1139                 cinfo->ds->ncommitting += ret;
1140                 bucket->clseg = bucket->wlseg;
1141                 if (list_empty(src))
1142                         bucket->wlseg = NULL;
1143                 else
1144                         pnfs_get_lseg(bucket->clseg);
1145         }
1146         return ret;
1147 }
1148
1149 /* Move reqs from written to committing lists, returning count of number moved.
1150  * Note called with cinfo->lock held.
1151  */
1152 static int filelayout_scan_commit_lists(struct nfs_commit_info *cinfo,
1153                                         int max)
1154 {
1155         int i, rv = 0, cnt;
1156
1157         for (i = 0; i < cinfo->ds->nbuckets && max != 0; i++) {
1158                 cnt = filelayout_scan_ds_commit_list(&cinfo->ds->buckets[i],
1159                                                      cinfo, max);
1160                 max -= cnt;
1161                 rv += cnt;
1162         }
1163         return rv;
1164 }
1165
1166 /* Pull everything off the committing lists and dump into @dst */
1167 static void filelayout_recover_commit_reqs(struct list_head *dst,
1168                                            struct nfs_commit_info *cinfo)
1169 {
1170         struct pnfs_commit_bucket *b;
1171         int i;
1172
1173         /* NOTE cinfo->lock is NOT held, relying on fact that this is
1174          * only called on single thread per dreq.
1175          * Can't take the lock because need to do pnfs_put_lseg
1176          */
1177         for (i = 0, b = cinfo->ds->buckets; i < cinfo->ds->nbuckets; i++, b++) {
1178                 if (transfer_commit_list(&b->written, dst, cinfo, 0)) {
1179                         BUG_ON(!list_empty(&b->written));
1180                         pnfs_put_lseg(b->wlseg);
1181                         b->wlseg = NULL;
1182                 }
1183         }
1184         cinfo->ds->nwritten = 0;
1185 }
1186
1187 static unsigned int
1188 alloc_ds_commits(struct nfs_commit_info *cinfo, struct list_head *list)
1189 {
1190         struct pnfs_ds_commit_info *fl_cinfo;
1191         struct pnfs_commit_bucket *bucket;
1192         struct nfs_commit_data *data;
1193         int i, j;
1194         unsigned int nreq = 0;
1195
1196         fl_cinfo = cinfo->ds;
1197         bucket = fl_cinfo->buckets;
1198         for (i = 0; i < fl_cinfo->nbuckets; i++, bucket++) {
1199                 if (list_empty(&bucket->committing))
1200                         continue;
1201                 data = nfs_commitdata_alloc();
1202                 if (!data)
1203                         break;
1204                 data->ds_commit_index = i;
1205                 data->lseg = bucket->clseg;
1206                 bucket->clseg = NULL;
1207                 list_add(&data->pages, list);
1208                 nreq++;
1209         }
1210
1211         /* Clean up on error */
1212         for (j = i; j < fl_cinfo->nbuckets; j++, bucket++) {
1213                 if (list_empty(&bucket->committing))
1214                         continue;
1215                 nfs_retry_commit(&bucket->committing, bucket->clseg, cinfo);
1216                 pnfs_put_lseg(bucket->clseg);
1217                 bucket->clseg = NULL;
1218         }
1219         /* Caller will clean up entries put on list */
1220         return nreq;
1221 }
1222
1223 /* This follows nfs_commit_list pretty closely */
1224 static int
1225 filelayout_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
1226                            int how, struct nfs_commit_info *cinfo)
1227 {
1228         struct nfs_commit_data *data, *tmp;
1229         LIST_HEAD(list);
1230         unsigned int nreq = 0;
1231
1232         if (!list_empty(mds_pages)) {
1233                 data = nfs_commitdata_alloc();
1234                 if (data != NULL) {
1235                         data->lseg = NULL;
1236                         list_add(&data->pages, &list);
1237                         nreq++;
1238                 } else
1239                         nfs_retry_commit(mds_pages, NULL, cinfo);
1240         }
1241
1242         nreq += alloc_ds_commits(cinfo, &list);
1243
1244         if (nreq == 0) {
1245                 cinfo->completion_ops->error_cleanup(NFS_I(inode));
1246                 goto out;
1247         }
1248
1249         atomic_add(nreq, &cinfo->mds->rpcs_out);
1250
1251         list_for_each_entry_safe(data, tmp, &list, pages) {
1252                 list_del_init(&data->pages);
1253                 if (!data->lseg) {
1254                         nfs_init_commit(data, mds_pages, NULL, cinfo);
1255                         nfs_initiate_commit(NFS_CLIENT(inode), data,
1256                                             data->mds_ops, how, 0);
1257                 } else {
1258                         struct pnfs_commit_bucket *buckets;
1259
1260                         buckets = cinfo->ds->buckets;
1261                         nfs_init_commit(data, &buckets[data->ds_commit_index].committing, data->lseg, cinfo);
1262                         filelayout_initiate_commit(data, how);
1263                 }
1264         }
1265 out:
1266         cinfo->ds->ncommitting = 0;
1267         return PNFS_ATTEMPTED;
1268 }
1269
1270 static void
1271 filelayout_free_deveiceid_node(struct nfs4_deviceid_node *d)
1272 {
1273         nfs4_fl_free_deviceid(container_of(d, struct nfs4_file_layout_dsaddr, id_node));
1274 }
1275
1276 static struct pnfs_layout_hdr *
1277 filelayout_alloc_layout_hdr(struct inode *inode, gfp_t gfp_flags)
1278 {
1279         struct nfs4_filelayout *flo;
1280
1281         flo = kzalloc(sizeof(*flo), gfp_flags);
1282         return &flo->generic_hdr;
1283 }
1284
1285 static void
1286 filelayout_free_layout_hdr(struct pnfs_layout_hdr *lo)
1287 {
1288         kfree(FILELAYOUT_FROM_HDR(lo));
1289 }
1290
1291 static struct pnfs_ds_commit_info *
1292 filelayout_get_ds_info(struct inode *inode)
1293 {
1294         struct pnfs_layout_hdr *layout = NFS_I(inode)->layout;
1295
1296         if (layout == NULL)
1297                 return NULL;
1298         else
1299                 return &FILELAYOUT_FROM_HDR(layout)->commit_info;
1300 }
1301
1302 static struct pnfs_layoutdriver_type filelayout_type = {
1303         .id                     = LAYOUT_NFSV4_1_FILES,
1304         .name                   = "LAYOUT_NFSV4_1_FILES",
1305         .owner                  = THIS_MODULE,
1306         .alloc_layout_hdr       = filelayout_alloc_layout_hdr,
1307         .free_layout_hdr        = filelayout_free_layout_hdr,
1308         .alloc_lseg             = filelayout_alloc_lseg,
1309         .free_lseg              = filelayout_free_lseg,
1310         .pg_read_ops            = &filelayout_pg_read_ops,
1311         .pg_write_ops           = &filelayout_pg_write_ops,
1312         .get_ds_info            = &filelayout_get_ds_info,
1313         .mark_request_commit    = filelayout_mark_request_commit,
1314         .clear_request_commit   = filelayout_clear_request_commit,
1315         .scan_commit_lists      = filelayout_scan_commit_lists,
1316         .recover_commit_reqs    = filelayout_recover_commit_reqs,
1317         .commit_pagelist        = filelayout_commit_pagelist,
1318         .read_pagelist          = filelayout_read_pagelist,
1319         .write_pagelist         = filelayout_write_pagelist,
1320         .free_deviceid_node     = filelayout_free_deveiceid_node,
1321 };
1322
1323 static int __init nfs4filelayout_init(void)
1324 {
1325         printk(KERN_INFO "%s: NFSv4 File Layout Driver Registering...\n",
1326                __func__);
1327         return pnfs_register_layoutdriver(&filelayout_type);
1328 }
1329
1330 static void __exit nfs4filelayout_exit(void)
1331 {
1332         printk(KERN_INFO "%s: NFSv4 File Layout Driver Unregistering...\n",
1333                __func__);
1334         pnfs_unregister_layoutdriver(&filelayout_type);
1335 }
1336
1337 MODULE_ALIAS("nfs-layouttype4-1");
1338
1339 module_init(nfs4filelayout_init);
1340 module_exit(nfs4filelayout_exit);