xref: /openbmc/linux/fs/nfs/filelayout/filelayout.c (revision d2999e1b)
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 "../nfs4session.h"
39 #include "../internal.h"
40 #include "../delegation.h"
41 #include "filelayout.h"
42 #include "../nfs4trace.h"
43 
44 #define NFSDBG_FACILITY         NFSDBG_PNFS_LD
45 
46 MODULE_LICENSE("GPL");
47 MODULE_AUTHOR("Dean Hildebrand <dhildebz@umich.edu>");
48 MODULE_DESCRIPTION("The NFSv4 file layout driver");
49 
50 #define FILELAYOUT_POLL_RETRY_MAX     (15*HZ)
51 
52 static loff_t
53 filelayout_get_dense_offset(struct nfs4_filelayout_segment *flseg,
54 			    loff_t offset)
55 {
56 	u32 stripe_width = flseg->stripe_unit * flseg->dsaddr->stripe_count;
57 	u64 stripe_no;
58 	u32 rem;
59 
60 	offset -= flseg->pattern_offset;
61 	stripe_no = div_u64(offset, stripe_width);
62 	div_u64_rem(offset, flseg->stripe_unit, &rem);
63 
64 	return stripe_no * flseg->stripe_unit + rem;
65 }
66 
67 /* This function is used by the layout driver to calculate the
68  * offset of the file on the dserver based on whether the
69  * layout type is STRIPE_DENSE or STRIPE_SPARSE
70  */
71 static loff_t
72 filelayout_get_dserver_offset(struct pnfs_layout_segment *lseg, loff_t offset)
73 {
74 	struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
75 
76 	switch (flseg->stripe_type) {
77 	case STRIPE_SPARSE:
78 		return offset;
79 
80 	case STRIPE_DENSE:
81 		return filelayout_get_dense_offset(flseg, offset);
82 	}
83 
84 	BUG();
85 }
86 
87 static void filelayout_reset_write(struct nfs_pgio_data *data)
88 {
89 	struct nfs_pgio_header *hdr = data->header;
90 	struct rpc_task *task = &data->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 			data->task.tk_pid,
96 			hdr->inode->i_sb->s_id,
97 			(unsigned long long)NFS_FILEID(hdr->inode),
98 			data->args.count,
99 			(unsigned long long)data->args.offset);
100 
101 		task->tk_status = pnfs_write_done_resend_to_mds(hdr->inode,
102 							&hdr->pages,
103 							hdr->completion_ops,
104 							hdr->dreq);
105 	}
106 }
107 
108 static void filelayout_reset_read(struct nfs_pgio_data *data)
109 {
110 	struct nfs_pgio_header *hdr = data->header;
111 	struct rpc_task *task = &data->task;
112 
113 	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
114 		dprintk("%s Reset task %5u for i/o through MDS "
115 			"(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
116 			data->task.tk_pid,
117 			hdr->inode->i_sb->s_id,
118 			(unsigned long long)NFS_FILEID(hdr->inode),
119 			data->args.count,
120 			(unsigned long long)data->args.offset);
121 
122 		task->tk_status = pnfs_read_done_resend_to_mds(hdr->inode,
123 							&hdr->pages,
124 							hdr->completion_ops,
125 							hdr->dreq);
126 	}
127 }
128 
129 static void filelayout_fenceme(struct inode *inode, struct pnfs_layout_hdr *lo)
130 {
131 	if (!test_and_clear_bit(NFS_LAYOUT_RETURN, &lo->plh_flags))
132 		return;
133 	pnfs_return_layout(inode);
134 }
135 
136 static int filelayout_async_handle_error(struct rpc_task *task,
137 					 struct nfs4_state *state,
138 					 struct nfs_client *clp,
139 					 struct pnfs_layout_segment *lseg)
140 {
141 	struct pnfs_layout_hdr *lo = lseg->pls_layout;
142 	struct inode *inode = lo->plh_inode;
143 	struct nfs_server *mds_server = NFS_SERVER(inode);
144 	struct nfs4_deviceid_node *devid = FILELAYOUT_DEVID_NODE(lseg);
145 	struct nfs_client *mds_client = mds_server->nfs_client;
146 	struct nfs4_slot_table *tbl = &clp->cl_session->fc_slot_table;
147 
148 	if (task->tk_status >= 0)
149 		return 0;
150 
151 	switch (task->tk_status) {
152 	/* MDS state errors */
153 	case -NFS4ERR_DELEG_REVOKED:
154 	case -NFS4ERR_ADMIN_REVOKED:
155 	case -NFS4ERR_BAD_STATEID:
156 		if (state == NULL)
157 			break;
158 		nfs_remove_bad_delegation(state->inode);
159 	case -NFS4ERR_OPENMODE:
160 		if (state == NULL)
161 			break;
162 		if (nfs4_schedule_stateid_recovery(mds_server, state) < 0)
163 			goto out_bad_stateid;
164 		goto wait_on_recovery;
165 	case -NFS4ERR_EXPIRED:
166 		if (state != NULL) {
167 			if (nfs4_schedule_stateid_recovery(mds_server, state) < 0)
168 				goto out_bad_stateid;
169 		}
170 		nfs4_schedule_lease_recovery(mds_client);
171 		goto wait_on_recovery;
172 	/* DS session errors */
173 	case -NFS4ERR_BADSESSION:
174 	case -NFS4ERR_BADSLOT:
175 	case -NFS4ERR_BAD_HIGH_SLOT:
176 	case -NFS4ERR_DEADSESSION:
177 	case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
178 	case -NFS4ERR_SEQ_FALSE_RETRY:
179 	case -NFS4ERR_SEQ_MISORDERED:
180 		dprintk("%s ERROR %d, Reset session. Exchangeid "
181 			"flags 0x%x\n", __func__, task->tk_status,
182 			clp->cl_exchange_flags);
183 		nfs4_schedule_session_recovery(clp->cl_session, task->tk_status);
184 		break;
185 	case -NFS4ERR_DELAY:
186 	case -NFS4ERR_GRACE:
187 		rpc_delay(task, FILELAYOUT_POLL_RETRY_MAX);
188 		break;
189 	case -NFS4ERR_RETRY_UNCACHED_REP:
190 		break;
191 	/* Invalidate Layout errors */
192 	case -NFS4ERR_PNFS_NO_LAYOUT:
193 	case -ESTALE:           /* mapped NFS4ERR_STALE */
194 	case -EBADHANDLE:       /* mapped NFS4ERR_BADHANDLE */
195 	case -EISDIR:           /* mapped NFS4ERR_ISDIR */
196 	case -NFS4ERR_FHEXPIRED:
197 	case -NFS4ERR_WRONG_TYPE:
198 		dprintk("%s Invalid layout error %d\n", __func__,
199 			task->tk_status);
200 		/*
201 		 * Destroy layout so new i/o will get a new layout.
202 		 * Layout will not be destroyed until all current lseg
203 		 * references are put. Mark layout as invalid to resend failed
204 		 * i/o and all i/o waiting on the slot table to the MDS until
205 		 * layout is destroyed and a new valid layout is obtained.
206 		 */
207 		pnfs_destroy_layout(NFS_I(inode));
208 		rpc_wake_up(&tbl->slot_tbl_waitq);
209 		goto reset;
210 	/* RPC connection errors */
211 	case -ECONNREFUSED:
212 	case -EHOSTDOWN:
213 	case -EHOSTUNREACH:
214 	case -ENETUNREACH:
215 	case -EIO:
216 	case -ETIMEDOUT:
217 	case -EPIPE:
218 		dprintk("%s DS connection error %d\n", __func__,
219 			task->tk_status);
220 		nfs4_mark_deviceid_unavailable(devid);
221 		set_bit(NFS_LAYOUT_RETURN, &lo->plh_flags);
222 		rpc_wake_up(&tbl->slot_tbl_waitq);
223 		/* fall through */
224 	default:
225 reset:
226 		dprintk("%s Retry through MDS. Error %d\n", __func__,
227 			task->tk_status);
228 		return -NFS4ERR_RESET_TO_MDS;
229 	}
230 out:
231 	task->tk_status = 0;
232 	return -EAGAIN;
233 out_bad_stateid:
234 	task->tk_status = -EIO;
235 	return 0;
236 wait_on_recovery:
237 	rpc_sleep_on(&mds_client->cl_rpcwaitq, task, NULL);
238 	if (test_bit(NFS4CLNT_MANAGER_RUNNING, &mds_client->cl_state) == 0)
239 		rpc_wake_up_queued_task(&mds_client->cl_rpcwaitq, task);
240 	goto out;
241 }
242 
243 /* NFS_PROTO call done callback routines */
244 
245 static int filelayout_read_done_cb(struct rpc_task *task,
246 				struct nfs_pgio_data *data)
247 {
248 	struct nfs_pgio_header *hdr = data->header;
249 	int err;
250 
251 	trace_nfs4_pnfs_read(data, task->tk_status);
252 	err = filelayout_async_handle_error(task, data->args.context->state,
253 					    data->ds_clp, hdr->lseg);
254 
255 	switch (err) {
256 	case -NFS4ERR_RESET_TO_MDS:
257 		filelayout_reset_read(data);
258 		return task->tk_status;
259 	case -EAGAIN:
260 		rpc_restart_call_prepare(task);
261 		return -EAGAIN;
262 	}
263 
264 	return 0;
265 }
266 
267 /*
268  * We reference the rpc_cred of the first WRITE that triggers the need for
269  * a LAYOUTCOMMIT, and use it to send the layoutcommit compound.
270  * rfc5661 is not clear about which credential should be used.
271  */
272 static void
273 filelayout_set_layoutcommit(struct nfs_pgio_data *wdata)
274 {
275 	struct nfs_pgio_header *hdr = wdata->header;
276 
277 	if (FILELAYOUT_LSEG(hdr->lseg)->commit_through_mds ||
278 	    wdata->res.verf->committed == NFS_FILE_SYNC)
279 		return;
280 
281 	pnfs_set_layoutcommit(wdata);
282 	dprintk("%s inode %lu pls_end_pos %lu\n", __func__, hdr->inode->i_ino,
283 		(unsigned long) NFS_I(hdr->inode)->layout->plh_lwb);
284 }
285 
286 bool
287 filelayout_test_devid_unavailable(struct nfs4_deviceid_node *node)
288 {
289 	return filelayout_test_devid_invalid(node) ||
290 		nfs4_test_deviceid_unavailable(node);
291 }
292 
293 static bool
294 filelayout_reset_to_mds(struct pnfs_layout_segment *lseg)
295 {
296 	struct nfs4_deviceid_node *node = FILELAYOUT_DEVID_NODE(lseg);
297 
298 	return filelayout_test_devid_unavailable(node);
299 }
300 
301 /*
302  * Call ops for the async read/write cases
303  * In the case of dense layouts, the offset needs to be reset to its
304  * original value.
305  */
306 static void filelayout_read_prepare(struct rpc_task *task, void *data)
307 {
308 	struct nfs_pgio_data *rdata = data;
309 
310 	if (unlikely(test_bit(NFS_CONTEXT_BAD, &rdata->args.context->flags))) {
311 		rpc_exit(task, -EIO);
312 		return;
313 	}
314 	if (filelayout_reset_to_mds(rdata->header->lseg)) {
315 		dprintk("%s task %u reset io to MDS\n", __func__, task->tk_pid);
316 		filelayout_reset_read(rdata);
317 		rpc_exit(task, 0);
318 		return;
319 	}
320 	rdata->pgio_done_cb = filelayout_read_done_cb;
321 
322 	if (nfs41_setup_sequence(rdata->ds_clp->cl_session,
323 			&rdata->args.seq_args,
324 			&rdata->res.seq_res,
325 			task))
326 		return;
327 	if (nfs4_set_rw_stateid(&rdata->args.stateid, rdata->args.context,
328 			rdata->args.lock_context, FMODE_READ) == -EIO)
329 		rpc_exit(task, -EIO); /* lost lock, terminate I/O */
330 }
331 
332 static void filelayout_read_call_done(struct rpc_task *task, void *data)
333 {
334 	struct nfs_pgio_data *rdata = data;
335 
336 	dprintk("--> %s task->tk_status %d\n", __func__, task->tk_status);
337 
338 	if (test_bit(NFS_IOHDR_REDO, &rdata->header->flags) &&
339 	    task->tk_status == 0) {
340 		nfs41_sequence_done(task, &rdata->res.seq_res);
341 		return;
342 	}
343 
344 	/* Note this may cause RPC to be resent */
345 	rdata->header->mds_ops->rpc_call_done(task, data);
346 }
347 
348 static void filelayout_read_count_stats(struct rpc_task *task, void *data)
349 {
350 	struct nfs_pgio_data *rdata = data;
351 
352 	rpc_count_iostats(task, NFS_SERVER(rdata->header->inode)->client->cl_metrics);
353 }
354 
355 static void filelayout_read_release(void *data)
356 {
357 	struct nfs_pgio_data *rdata = data;
358 	struct pnfs_layout_hdr *lo = rdata->header->lseg->pls_layout;
359 
360 	filelayout_fenceme(lo->plh_inode, lo);
361 	nfs_put_client(rdata->ds_clp);
362 	rdata->header->mds_ops->rpc_release(data);
363 }
364 
365 static int filelayout_write_done_cb(struct rpc_task *task,
366 				struct nfs_pgio_data *data)
367 {
368 	struct nfs_pgio_header *hdr = data->header;
369 	int err;
370 
371 	trace_nfs4_pnfs_write(data, task->tk_status);
372 	err = filelayout_async_handle_error(task, data->args.context->state,
373 					    data->ds_clp, hdr->lseg);
374 
375 	switch (err) {
376 	case -NFS4ERR_RESET_TO_MDS:
377 		filelayout_reset_write(data);
378 		return task->tk_status;
379 	case -EAGAIN:
380 		rpc_restart_call_prepare(task);
381 		return -EAGAIN;
382 	}
383 
384 	filelayout_set_layoutcommit(data);
385 	return 0;
386 }
387 
388 /* Fake up some data that will cause nfs_commit_release to retry the writes. */
389 static void prepare_to_resend_writes(struct nfs_commit_data *data)
390 {
391 	struct nfs_page *first = nfs_list_entry(data->pages.next);
392 
393 	data->task.tk_status = 0;
394 	memcpy(&data->verf.verifier, &first->wb_verf,
395 	       sizeof(data->verf.verifier));
396 	data->verf.verifier.data[0]++; /* ensure verifier mismatch */
397 }
398 
399 static int filelayout_commit_done_cb(struct rpc_task *task,
400 				     struct nfs_commit_data *data)
401 {
402 	int err;
403 
404 	trace_nfs4_pnfs_commit_ds(data, task->tk_status);
405 	err = filelayout_async_handle_error(task, NULL, data->ds_clp,
406 					    data->lseg);
407 
408 	switch (err) {
409 	case -NFS4ERR_RESET_TO_MDS:
410 		prepare_to_resend_writes(data);
411 		return -EAGAIN;
412 	case -EAGAIN:
413 		rpc_restart_call_prepare(task);
414 		return -EAGAIN;
415 	}
416 
417 	return 0;
418 }
419 
420 static void filelayout_write_prepare(struct rpc_task *task, void *data)
421 {
422 	struct nfs_pgio_data *wdata = data;
423 
424 	if (unlikely(test_bit(NFS_CONTEXT_BAD, &wdata->args.context->flags))) {
425 		rpc_exit(task, -EIO);
426 		return;
427 	}
428 	if (filelayout_reset_to_mds(wdata->header->lseg)) {
429 		dprintk("%s task %u reset io to MDS\n", __func__, task->tk_pid);
430 		filelayout_reset_write(wdata);
431 		rpc_exit(task, 0);
432 		return;
433 	}
434 	if (nfs41_setup_sequence(wdata->ds_clp->cl_session,
435 			&wdata->args.seq_args,
436 			&wdata->res.seq_res,
437 			task))
438 		return;
439 	if (nfs4_set_rw_stateid(&wdata->args.stateid, wdata->args.context,
440 			wdata->args.lock_context, FMODE_WRITE) == -EIO)
441 		rpc_exit(task, -EIO); /* lost lock, terminate I/O */
442 }
443 
444 static void filelayout_write_call_done(struct rpc_task *task, void *data)
445 {
446 	struct nfs_pgio_data *wdata = data;
447 
448 	if (test_bit(NFS_IOHDR_REDO, &wdata->header->flags) &&
449 	    task->tk_status == 0) {
450 		nfs41_sequence_done(task, &wdata->res.seq_res);
451 		return;
452 	}
453 
454 	/* Note this may cause RPC to be resent */
455 	wdata->header->mds_ops->rpc_call_done(task, data);
456 }
457 
458 static void filelayout_write_count_stats(struct rpc_task *task, void *data)
459 {
460 	struct nfs_pgio_data *wdata = data;
461 
462 	rpc_count_iostats(task, NFS_SERVER(wdata->header->inode)->client->cl_metrics);
463 }
464 
465 static void filelayout_write_release(void *data)
466 {
467 	struct nfs_pgio_data *wdata = data;
468 	struct pnfs_layout_hdr *lo = wdata->header->lseg->pls_layout;
469 
470 	filelayout_fenceme(lo->plh_inode, lo);
471 	nfs_put_client(wdata->ds_clp);
472 	wdata->header->mds_ops->rpc_release(data);
473 }
474 
475 static void filelayout_commit_prepare(struct rpc_task *task, void *data)
476 {
477 	struct nfs_commit_data *wdata = data;
478 
479 	nfs41_setup_sequence(wdata->ds_clp->cl_session,
480 			&wdata->args.seq_args,
481 			&wdata->res.seq_res,
482 			task);
483 }
484 
485 static void filelayout_write_commit_done(struct rpc_task *task, void *data)
486 {
487 	struct nfs_commit_data *wdata = data;
488 
489 	/* Note this may cause RPC to be resent */
490 	wdata->mds_ops->rpc_call_done(task, data);
491 }
492 
493 static void filelayout_commit_count_stats(struct rpc_task *task, void *data)
494 {
495 	struct nfs_commit_data *cdata = data;
496 
497 	rpc_count_iostats(task, NFS_SERVER(cdata->inode)->client->cl_metrics);
498 }
499 
500 static void filelayout_commit_release(void *calldata)
501 {
502 	struct nfs_commit_data *data = calldata;
503 
504 	data->completion_ops->completion(data);
505 	pnfs_put_lseg(data->lseg);
506 	nfs_put_client(data->ds_clp);
507 	nfs_commitdata_release(data);
508 }
509 
510 static const struct rpc_call_ops filelayout_read_call_ops = {
511 	.rpc_call_prepare = filelayout_read_prepare,
512 	.rpc_call_done = filelayout_read_call_done,
513 	.rpc_count_stats = filelayout_read_count_stats,
514 	.rpc_release = filelayout_read_release,
515 };
516 
517 static const struct rpc_call_ops filelayout_write_call_ops = {
518 	.rpc_call_prepare = filelayout_write_prepare,
519 	.rpc_call_done = filelayout_write_call_done,
520 	.rpc_count_stats = filelayout_write_count_stats,
521 	.rpc_release = filelayout_write_release,
522 };
523 
524 static const struct rpc_call_ops filelayout_commit_call_ops = {
525 	.rpc_call_prepare = filelayout_commit_prepare,
526 	.rpc_call_done = filelayout_write_commit_done,
527 	.rpc_count_stats = filelayout_commit_count_stats,
528 	.rpc_release = filelayout_commit_release,
529 };
530 
531 static enum pnfs_try_status
532 filelayout_read_pagelist(struct nfs_pgio_data *data)
533 {
534 	struct nfs_pgio_header *hdr = data->header;
535 	struct pnfs_layout_segment *lseg = hdr->lseg;
536 	struct nfs4_pnfs_ds *ds;
537 	struct rpc_clnt *ds_clnt;
538 	loff_t offset = data->args.offset;
539 	u32 j, idx;
540 	struct nfs_fh *fh;
541 
542 	dprintk("--> %s ino %lu pgbase %u req %Zu@%llu\n",
543 		__func__, hdr->inode->i_ino,
544 		data->args.pgbase, (size_t)data->args.count, offset);
545 
546 	/* Retrieve the correct rpc_client for the byte range */
547 	j = nfs4_fl_calc_j_index(lseg, offset);
548 	idx = nfs4_fl_calc_ds_index(lseg, j);
549 	ds = nfs4_fl_prepare_ds(lseg, idx);
550 	if (!ds)
551 		return PNFS_NOT_ATTEMPTED;
552 
553 	ds_clnt = nfs4_find_or_create_ds_client(ds->ds_clp, hdr->inode);
554 	if (IS_ERR(ds_clnt))
555 		return PNFS_NOT_ATTEMPTED;
556 
557 	dprintk("%s USE DS: %s cl_count %d\n", __func__,
558 		ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count));
559 
560 	/* No multipath support. Use first DS */
561 	atomic_inc(&ds->ds_clp->cl_count);
562 	data->ds_clp = ds->ds_clp;
563 	data->ds_idx = idx;
564 	fh = nfs4_fl_select_ds_fh(lseg, j);
565 	if (fh)
566 		data->args.fh = fh;
567 
568 	data->args.offset = filelayout_get_dserver_offset(lseg, offset);
569 	data->mds_offset = offset;
570 
571 	/* Perform an asynchronous read to ds */
572 	nfs_initiate_pgio(ds_clnt, data,
573 			    &filelayout_read_call_ops, 0, RPC_TASK_SOFTCONN);
574 	return PNFS_ATTEMPTED;
575 }
576 
577 /* Perform async writes. */
578 static enum pnfs_try_status
579 filelayout_write_pagelist(struct nfs_pgio_data *data, int sync)
580 {
581 	struct nfs_pgio_header *hdr = data->header;
582 	struct pnfs_layout_segment *lseg = hdr->lseg;
583 	struct nfs4_pnfs_ds *ds;
584 	struct rpc_clnt *ds_clnt;
585 	loff_t offset = data->args.offset;
586 	u32 j, idx;
587 	struct nfs_fh *fh;
588 
589 	/* Retrieve the correct rpc_client for the byte range */
590 	j = nfs4_fl_calc_j_index(lseg, offset);
591 	idx = nfs4_fl_calc_ds_index(lseg, j);
592 	ds = nfs4_fl_prepare_ds(lseg, idx);
593 	if (!ds)
594 		return PNFS_NOT_ATTEMPTED;
595 
596 	ds_clnt = nfs4_find_or_create_ds_client(ds->ds_clp, hdr->inode);
597 	if (IS_ERR(ds_clnt))
598 		return PNFS_NOT_ATTEMPTED;
599 
600 	dprintk("%s ino %lu sync %d req %Zu@%llu DS: %s cl_count %d\n",
601 		__func__, hdr->inode->i_ino, sync, (size_t) data->args.count,
602 		offset, ds->ds_remotestr, atomic_read(&ds->ds_clp->cl_count));
603 
604 	data->pgio_done_cb = filelayout_write_done_cb;
605 	atomic_inc(&ds->ds_clp->cl_count);
606 	data->ds_clp = ds->ds_clp;
607 	data->ds_idx = idx;
608 	fh = nfs4_fl_select_ds_fh(lseg, j);
609 	if (fh)
610 		data->args.fh = fh;
611 
612 	data->args.offset = filelayout_get_dserver_offset(lseg, offset);
613 
614 	/* Perform an asynchronous write */
615 	nfs_initiate_pgio(ds_clnt, data,
616 				    &filelayout_write_call_ops, sync,
617 				    RPC_TASK_SOFTCONN);
618 	return PNFS_ATTEMPTED;
619 }
620 
621 /*
622  * filelayout_check_layout()
623  *
624  * Make sure layout segment parameters are sane WRT the device.
625  * At this point no generic layer initialization of the lseg has occurred,
626  * and nothing has been added to the layout_hdr cache.
627  *
628  */
629 static int
630 filelayout_check_layout(struct pnfs_layout_hdr *lo,
631 			struct nfs4_filelayout_segment *fl,
632 			struct nfs4_layoutget_res *lgr,
633 			struct nfs4_deviceid *id,
634 			gfp_t gfp_flags)
635 {
636 	struct nfs4_deviceid_node *d;
637 	struct nfs4_file_layout_dsaddr *dsaddr;
638 	int status = -EINVAL;
639 
640 	dprintk("--> %s\n", __func__);
641 
642 	/* FIXME: remove this check when layout segment support is added */
643 	if (lgr->range.offset != 0 ||
644 	    lgr->range.length != NFS4_MAX_UINT64) {
645 		dprintk("%s Only whole file layouts supported. Use MDS i/o\n",
646 			__func__);
647 		goto out;
648 	}
649 
650 	if (fl->pattern_offset > lgr->range.offset) {
651 		dprintk("%s pattern_offset %lld too large\n",
652 				__func__, fl->pattern_offset);
653 		goto out;
654 	}
655 
656 	if (!fl->stripe_unit) {
657 		dprintk("%s Invalid stripe unit (%u)\n",
658 			__func__, fl->stripe_unit);
659 		goto out;
660 	}
661 
662 	/* find and reference the deviceid */
663 	d = nfs4_find_get_deviceid(NFS_SERVER(lo->plh_inode)->pnfs_curr_ld,
664 				   NFS_SERVER(lo->plh_inode)->nfs_client, id);
665 	if (d == NULL) {
666 		dsaddr = filelayout_get_device_info(lo->plh_inode, id,
667 				lo->plh_lc_cred, gfp_flags);
668 		if (dsaddr == NULL)
669 			goto out;
670 	} else
671 		dsaddr = container_of(d, struct nfs4_file_layout_dsaddr, id_node);
672 	/* Found deviceid is unavailable */
673 	if (filelayout_test_devid_unavailable(&dsaddr->id_node))
674 			goto out_put;
675 
676 	fl->dsaddr = dsaddr;
677 
678 	if (fl->first_stripe_index >= dsaddr->stripe_count) {
679 		dprintk("%s Bad first_stripe_index %u\n",
680 				__func__, fl->first_stripe_index);
681 		goto out_put;
682 	}
683 
684 	if ((fl->stripe_type == STRIPE_SPARSE &&
685 	    fl->num_fh > 1 && fl->num_fh != dsaddr->ds_num) ||
686 	    (fl->stripe_type == STRIPE_DENSE &&
687 	    fl->num_fh != dsaddr->stripe_count)) {
688 		dprintk("%s num_fh %u not valid for given packing\n",
689 			__func__, fl->num_fh);
690 		goto out_put;
691 	}
692 
693 	status = 0;
694 out:
695 	dprintk("--> %s returns %d\n", __func__, status);
696 	return status;
697 out_put:
698 	nfs4_fl_put_deviceid(dsaddr);
699 	goto out;
700 }
701 
702 static void filelayout_free_fh_array(struct nfs4_filelayout_segment *fl)
703 {
704 	int i;
705 
706 	for (i = 0; i < fl->num_fh; i++) {
707 		if (!fl->fh_array[i])
708 			break;
709 		kfree(fl->fh_array[i]);
710 	}
711 	kfree(fl->fh_array);
712 	fl->fh_array = NULL;
713 }
714 
715 static void
716 _filelayout_free_lseg(struct nfs4_filelayout_segment *fl)
717 {
718 	filelayout_free_fh_array(fl);
719 	kfree(fl);
720 }
721 
722 static int
723 filelayout_decode_layout(struct pnfs_layout_hdr *flo,
724 			 struct nfs4_filelayout_segment *fl,
725 			 struct nfs4_layoutget_res *lgr,
726 			 struct nfs4_deviceid *id,
727 			 gfp_t gfp_flags)
728 {
729 	struct xdr_stream stream;
730 	struct xdr_buf buf;
731 	struct page *scratch;
732 	__be32 *p;
733 	uint32_t nfl_util;
734 	int i;
735 
736 	dprintk("%s: set_layout_map Begin\n", __func__);
737 
738 	scratch = alloc_page(gfp_flags);
739 	if (!scratch)
740 		return -ENOMEM;
741 
742 	xdr_init_decode_pages(&stream, &buf, lgr->layoutp->pages, lgr->layoutp->len);
743 	xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
744 
745 	/* 20 = ufl_util (4), first_stripe_index (4), pattern_offset (8),
746 	 * num_fh (4) */
747 	p = xdr_inline_decode(&stream, NFS4_DEVICEID4_SIZE + 20);
748 	if (unlikely(!p))
749 		goto out_err;
750 
751 	memcpy(id, p, sizeof(*id));
752 	p += XDR_QUADLEN(NFS4_DEVICEID4_SIZE);
753 	nfs4_print_deviceid(id);
754 
755 	nfl_util = be32_to_cpup(p++);
756 	if (nfl_util & NFL4_UFLG_COMMIT_THRU_MDS)
757 		fl->commit_through_mds = 1;
758 	if (nfl_util & NFL4_UFLG_DENSE)
759 		fl->stripe_type = STRIPE_DENSE;
760 	else
761 		fl->stripe_type = STRIPE_SPARSE;
762 	fl->stripe_unit = nfl_util & ~NFL4_UFLG_MASK;
763 
764 	fl->first_stripe_index = be32_to_cpup(p++);
765 	p = xdr_decode_hyper(p, &fl->pattern_offset);
766 	fl->num_fh = be32_to_cpup(p++);
767 
768 	dprintk("%s: nfl_util 0x%X num_fh %u fsi %u po %llu\n",
769 		__func__, nfl_util, fl->num_fh, fl->first_stripe_index,
770 		fl->pattern_offset);
771 
772 	/* Note that a zero value for num_fh is legal for STRIPE_SPARSE.
773 	 * Futher checking is done in filelayout_check_layout */
774 	if (fl->num_fh >
775 	    max(NFS4_PNFS_MAX_STRIPE_CNT, NFS4_PNFS_MAX_MULTI_CNT))
776 		goto out_err;
777 
778 	if (fl->num_fh > 0) {
779 		fl->fh_array = kcalloc(fl->num_fh, sizeof(fl->fh_array[0]),
780 				       gfp_flags);
781 		if (!fl->fh_array)
782 			goto out_err;
783 	}
784 
785 	for (i = 0; i < fl->num_fh; i++) {
786 		/* Do we want to use a mempool here? */
787 		fl->fh_array[i] = kmalloc(sizeof(struct nfs_fh), gfp_flags);
788 		if (!fl->fh_array[i])
789 			goto out_err_free;
790 
791 		p = xdr_inline_decode(&stream, 4);
792 		if (unlikely(!p))
793 			goto out_err_free;
794 		fl->fh_array[i]->size = be32_to_cpup(p++);
795 		if (sizeof(struct nfs_fh) < fl->fh_array[i]->size) {
796 			printk(KERN_ERR "NFS: Too big fh %d received %d\n",
797 			       i, fl->fh_array[i]->size);
798 			goto out_err_free;
799 		}
800 
801 		p = xdr_inline_decode(&stream, fl->fh_array[i]->size);
802 		if (unlikely(!p))
803 			goto out_err_free;
804 		memcpy(fl->fh_array[i]->data, p, fl->fh_array[i]->size);
805 		dprintk("DEBUG: %s: fh len %d\n", __func__,
806 			fl->fh_array[i]->size);
807 	}
808 
809 	__free_page(scratch);
810 	return 0;
811 
812 out_err_free:
813 	filelayout_free_fh_array(fl);
814 out_err:
815 	__free_page(scratch);
816 	return -EIO;
817 }
818 
819 static void
820 filelayout_free_lseg(struct pnfs_layout_segment *lseg)
821 {
822 	struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
823 
824 	dprintk("--> %s\n", __func__);
825 	nfs4_fl_put_deviceid(fl->dsaddr);
826 	/* This assumes a single RW lseg */
827 	if (lseg->pls_range.iomode == IOMODE_RW) {
828 		struct nfs4_filelayout *flo;
829 
830 		flo = FILELAYOUT_FROM_HDR(lseg->pls_layout);
831 		flo->commit_info.nbuckets = 0;
832 		kfree(flo->commit_info.buckets);
833 		flo->commit_info.buckets = NULL;
834 	}
835 	_filelayout_free_lseg(fl);
836 }
837 
838 static int
839 filelayout_alloc_commit_info(struct pnfs_layout_segment *lseg,
840 			     struct nfs_commit_info *cinfo,
841 			     gfp_t gfp_flags)
842 {
843 	struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
844 	struct pnfs_commit_bucket *buckets;
845 	int size, i;
846 
847 	if (fl->commit_through_mds)
848 		return 0;
849 
850 	size = (fl->stripe_type == STRIPE_SPARSE) ?
851 		fl->dsaddr->ds_num : fl->dsaddr->stripe_count;
852 
853 	if (cinfo->ds->nbuckets >= size) {
854 		/* This assumes there is only one IOMODE_RW lseg.  What
855 		 * we really want to do is have a layout_hdr level
856 		 * dictionary of <multipath_list4, fh> keys, each
857 		 * associated with a struct list_head, populated by calls
858 		 * to filelayout_write_pagelist().
859 		 * */
860 		return 0;
861 	}
862 
863 	buckets = kcalloc(size, sizeof(struct pnfs_commit_bucket),
864 			  gfp_flags);
865 	if (!buckets)
866 		return -ENOMEM;
867 	for (i = 0; i < size; i++) {
868 		INIT_LIST_HEAD(&buckets[i].written);
869 		INIT_LIST_HEAD(&buckets[i].committing);
870 		/* mark direct verifier as unset */
871 		buckets[i].direct_verf.committed = NFS_INVALID_STABLE_HOW;
872 	}
873 
874 	spin_lock(cinfo->lock);
875 	if (cinfo->ds->nbuckets >= size)
876 		goto out;
877 	for (i = 0; i < cinfo->ds->nbuckets; i++) {
878 		list_splice(&cinfo->ds->buckets[i].written,
879 			    &buckets[i].written);
880 		list_splice(&cinfo->ds->buckets[i].committing,
881 			    &buckets[i].committing);
882 		buckets[i].direct_verf.committed =
883 			cinfo->ds->buckets[i].direct_verf.committed;
884 		buckets[i].wlseg = cinfo->ds->buckets[i].wlseg;
885 		buckets[i].clseg = cinfo->ds->buckets[i].clseg;
886 	}
887 	swap(cinfo->ds->buckets, buckets);
888 	cinfo->ds->nbuckets = size;
889 out:
890 	spin_unlock(cinfo->lock);
891 	kfree(buckets);
892 	return 0;
893 }
894 
895 static struct pnfs_layout_segment *
896 filelayout_alloc_lseg(struct pnfs_layout_hdr *layoutid,
897 		      struct nfs4_layoutget_res *lgr,
898 		      gfp_t gfp_flags)
899 {
900 	struct nfs4_filelayout_segment *fl;
901 	int rc;
902 	struct nfs4_deviceid id;
903 
904 	dprintk("--> %s\n", __func__);
905 	fl = kzalloc(sizeof(*fl), gfp_flags);
906 	if (!fl)
907 		return NULL;
908 
909 	rc = filelayout_decode_layout(layoutid, fl, lgr, &id, gfp_flags);
910 	if (rc != 0 || filelayout_check_layout(layoutid, fl, lgr, &id, gfp_flags)) {
911 		_filelayout_free_lseg(fl);
912 		return NULL;
913 	}
914 	return &fl->generic_hdr;
915 }
916 
917 /*
918  * filelayout_pg_test(). Called by nfs_can_coalesce_requests()
919  *
920  * Return 0 if @req cannot be coalesced into @pgio, otherwise return the number
921  * of bytes (maximum @req->wb_bytes) that can be coalesced.
922  */
923 static size_t
924 filelayout_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
925 		   struct nfs_page *req)
926 {
927 	unsigned int size;
928 	u64 p_stripe, r_stripe;
929 	u32 stripe_offset;
930 	u64 segment_offset = pgio->pg_lseg->pls_range.offset;
931 	u32 stripe_unit = FILELAYOUT_LSEG(pgio->pg_lseg)->stripe_unit;
932 
933 	/* calls nfs_generic_pg_test */
934 	size = pnfs_generic_pg_test(pgio, prev, req);
935 	if (!size)
936 		return 0;
937 
938 	/* see if req and prev are in the same stripe */
939 	if (prev) {
940 		p_stripe = (u64)req_offset(prev) - segment_offset;
941 		r_stripe = (u64)req_offset(req) - segment_offset;
942 		do_div(p_stripe, stripe_unit);
943 		do_div(r_stripe, stripe_unit);
944 
945 		if (p_stripe != r_stripe)
946 			return 0;
947 	}
948 
949 	/* calculate remaining bytes in the current stripe */
950 	div_u64_rem((u64)req_offset(req) - segment_offset,
951 			stripe_unit,
952 			&stripe_offset);
953 	WARN_ON_ONCE(stripe_offset > stripe_unit);
954 	if (stripe_offset >= stripe_unit)
955 		return 0;
956 	return min(stripe_unit - (unsigned int)stripe_offset, size);
957 }
958 
959 static void
960 filelayout_pg_init_read(struct nfs_pageio_descriptor *pgio,
961 			struct nfs_page *req)
962 {
963 	if (!pgio->pg_lseg)
964 		pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
965 					   req->wb_context,
966 					   0,
967 					   NFS4_MAX_UINT64,
968 					   IOMODE_READ,
969 					   GFP_KERNEL);
970 	/* If no lseg, fall back to read through mds */
971 	if (pgio->pg_lseg == NULL)
972 		nfs_pageio_reset_read_mds(pgio);
973 }
974 
975 static void
976 filelayout_pg_init_write(struct nfs_pageio_descriptor *pgio,
977 			 struct nfs_page *req)
978 {
979 	struct nfs_commit_info cinfo;
980 	int status;
981 
982 	if (!pgio->pg_lseg)
983 		pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
984 					   req->wb_context,
985 					   0,
986 					   NFS4_MAX_UINT64,
987 					   IOMODE_RW,
988 					   GFP_NOFS);
989 	/* If no lseg, fall back to write through mds */
990 	if (pgio->pg_lseg == NULL)
991 		goto out_mds;
992 	nfs_init_cinfo(&cinfo, pgio->pg_inode, pgio->pg_dreq);
993 	status = filelayout_alloc_commit_info(pgio->pg_lseg, &cinfo, GFP_NOFS);
994 	if (status < 0) {
995 		pnfs_put_lseg(pgio->pg_lseg);
996 		pgio->pg_lseg = NULL;
997 		goto out_mds;
998 	}
999 	return;
1000 out_mds:
1001 	nfs_pageio_reset_write_mds(pgio);
1002 }
1003 
1004 static const struct nfs_pageio_ops filelayout_pg_read_ops = {
1005 	.pg_init = filelayout_pg_init_read,
1006 	.pg_test = filelayout_pg_test,
1007 	.pg_doio = pnfs_generic_pg_readpages,
1008 };
1009 
1010 static const struct nfs_pageio_ops filelayout_pg_write_ops = {
1011 	.pg_init = filelayout_pg_init_write,
1012 	.pg_test = filelayout_pg_test,
1013 	.pg_doio = pnfs_generic_pg_writepages,
1014 };
1015 
1016 static u32 select_bucket_index(struct nfs4_filelayout_segment *fl, u32 j)
1017 {
1018 	if (fl->stripe_type == STRIPE_SPARSE)
1019 		return nfs4_fl_calc_ds_index(&fl->generic_hdr, j);
1020 	else
1021 		return j;
1022 }
1023 
1024 /* The generic layer is about to remove the req from the commit list.
1025  * If this will make the bucket empty, it will need to put the lseg reference.
1026  */
1027 static void
1028 filelayout_clear_request_commit(struct nfs_page *req,
1029 				struct nfs_commit_info *cinfo)
1030 {
1031 	struct pnfs_layout_segment *freeme = NULL;
1032 
1033 	spin_lock(cinfo->lock);
1034 	if (!test_and_clear_bit(PG_COMMIT_TO_DS, &req->wb_flags))
1035 		goto out;
1036 	cinfo->ds->nwritten--;
1037 	if (list_is_singular(&req->wb_list)) {
1038 		struct pnfs_commit_bucket *bucket;
1039 
1040 		bucket = list_first_entry(&req->wb_list,
1041 					  struct pnfs_commit_bucket,
1042 					  written);
1043 		freeme = bucket->wlseg;
1044 		bucket->wlseg = NULL;
1045 	}
1046 out:
1047 	nfs_request_remove_commit_list(req, cinfo);
1048 	spin_unlock(cinfo->lock);
1049 	pnfs_put_lseg(freeme);
1050 }
1051 
1052 static struct list_head *
1053 filelayout_choose_commit_list(struct nfs_page *req,
1054 			      struct pnfs_layout_segment *lseg,
1055 			      struct nfs_commit_info *cinfo)
1056 {
1057 	struct nfs4_filelayout_segment *fl = FILELAYOUT_LSEG(lseg);
1058 	u32 i, j;
1059 	struct list_head *list;
1060 	struct pnfs_commit_bucket *buckets;
1061 
1062 	if (fl->commit_through_mds)
1063 		return &cinfo->mds->list;
1064 
1065 	/* Note that we are calling nfs4_fl_calc_j_index on each page
1066 	 * that ends up being committed to a data server.  An attractive
1067 	 * alternative is to add a field to nfs_write_data and nfs_page
1068 	 * to store the value calculated in filelayout_write_pagelist
1069 	 * and just use that here.
1070 	 */
1071 	j = nfs4_fl_calc_j_index(lseg, req_offset(req));
1072 	i = select_bucket_index(fl, j);
1073 	spin_lock(cinfo->lock);
1074 	buckets = cinfo->ds->buckets;
1075 	list = &buckets[i].written;
1076 	if (list_empty(list)) {
1077 		/* Non-empty buckets hold a reference on the lseg.  That ref
1078 		 * is normally transferred to the COMMIT call and released
1079 		 * there.  It could also be released if the last req is pulled
1080 		 * off due to a rewrite, in which case it will be done in
1081 		 * filelayout_clear_request_commit
1082 		 */
1083 		buckets[i].wlseg = pnfs_get_lseg(lseg);
1084 	}
1085 	set_bit(PG_COMMIT_TO_DS, &req->wb_flags);
1086 	cinfo->ds->nwritten++;
1087 	spin_unlock(cinfo->lock);
1088 	return list;
1089 }
1090 
1091 static void
1092 filelayout_mark_request_commit(struct nfs_page *req,
1093 			       struct pnfs_layout_segment *lseg,
1094 			       struct nfs_commit_info *cinfo)
1095 {
1096 	struct list_head *list;
1097 
1098 	list = filelayout_choose_commit_list(req, lseg, cinfo);
1099 	nfs_request_add_commit_list(req, list, cinfo);
1100 }
1101 
1102 static u32 calc_ds_index_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1103 {
1104 	struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
1105 
1106 	if (flseg->stripe_type == STRIPE_SPARSE)
1107 		return i;
1108 	else
1109 		return nfs4_fl_calc_ds_index(lseg, i);
1110 }
1111 
1112 static struct nfs_fh *
1113 select_ds_fh_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1114 {
1115 	struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
1116 
1117 	if (flseg->stripe_type == STRIPE_SPARSE) {
1118 		if (flseg->num_fh == 1)
1119 			i = 0;
1120 		else if (flseg->num_fh == 0)
1121 			/* Use the MDS OPEN fh set in nfs_read_rpcsetup */
1122 			return NULL;
1123 	}
1124 	return flseg->fh_array[i];
1125 }
1126 
1127 static int filelayout_initiate_commit(struct nfs_commit_data *data, int how)
1128 {
1129 	struct pnfs_layout_segment *lseg = data->lseg;
1130 	struct nfs4_pnfs_ds *ds;
1131 	struct rpc_clnt *ds_clnt;
1132 	u32 idx;
1133 	struct nfs_fh *fh;
1134 
1135 	idx = calc_ds_index_from_commit(lseg, data->ds_commit_index);
1136 	ds = nfs4_fl_prepare_ds(lseg, idx);
1137 	if (!ds)
1138 		goto out_err;
1139 
1140 	ds_clnt = nfs4_find_or_create_ds_client(ds->ds_clp, data->inode);
1141 	if (IS_ERR(ds_clnt))
1142 		goto out_err;
1143 
1144 	dprintk("%s ino %lu, how %d cl_count %d\n", __func__,
1145 		data->inode->i_ino, how, atomic_read(&ds->ds_clp->cl_count));
1146 	data->commit_done_cb = filelayout_commit_done_cb;
1147 	atomic_inc(&ds->ds_clp->cl_count);
1148 	data->ds_clp = ds->ds_clp;
1149 	fh = select_ds_fh_from_commit(lseg, data->ds_commit_index);
1150 	if (fh)
1151 		data->args.fh = fh;
1152 	return nfs_initiate_commit(ds_clnt, data,
1153 				   &filelayout_commit_call_ops, how,
1154 				   RPC_TASK_SOFTCONN);
1155 out_err:
1156 	prepare_to_resend_writes(data);
1157 	filelayout_commit_release(data);
1158 	return -EAGAIN;
1159 }
1160 
1161 static int
1162 transfer_commit_list(struct list_head *src, struct list_head *dst,
1163 		     struct nfs_commit_info *cinfo, int max)
1164 {
1165 	struct nfs_page *req, *tmp;
1166 	int ret = 0;
1167 
1168 	list_for_each_entry_safe(req, tmp, src, wb_list) {
1169 		if (!nfs_lock_request(req))
1170 			continue;
1171 		kref_get(&req->wb_kref);
1172 		if (cond_resched_lock(cinfo->lock))
1173 			list_safe_reset_next(req, tmp, wb_list);
1174 		nfs_request_remove_commit_list(req, cinfo);
1175 		clear_bit(PG_COMMIT_TO_DS, &req->wb_flags);
1176 		nfs_list_add_request(req, dst);
1177 		ret++;
1178 		if ((ret == max) && !cinfo->dreq)
1179 			break;
1180 	}
1181 	return ret;
1182 }
1183 
1184 /* Note called with cinfo->lock held. */
1185 static int
1186 filelayout_scan_ds_commit_list(struct pnfs_commit_bucket *bucket,
1187 			       struct nfs_commit_info *cinfo,
1188 			       int max)
1189 {
1190 	struct list_head *src = &bucket->written;
1191 	struct list_head *dst = &bucket->committing;
1192 	int ret;
1193 
1194 	ret = transfer_commit_list(src, dst, cinfo, max);
1195 	if (ret) {
1196 		cinfo->ds->nwritten -= ret;
1197 		cinfo->ds->ncommitting += ret;
1198 		bucket->clseg = bucket->wlseg;
1199 		if (list_empty(src))
1200 			bucket->wlseg = NULL;
1201 		else
1202 			pnfs_get_lseg(bucket->clseg);
1203 	}
1204 	return ret;
1205 }
1206 
1207 /* Move reqs from written to committing lists, returning count of number moved.
1208  * Note called with cinfo->lock held.
1209  */
1210 static int filelayout_scan_commit_lists(struct nfs_commit_info *cinfo,
1211 					int max)
1212 {
1213 	int i, rv = 0, cnt;
1214 
1215 	for (i = 0; i < cinfo->ds->nbuckets && max != 0; i++) {
1216 		cnt = filelayout_scan_ds_commit_list(&cinfo->ds->buckets[i],
1217 						     cinfo, max);
1218 		max -= cnt;
1219 		rv += cnt;
1220 	}
1221 	return rv;
1222 }
1223 
1224 /* Pull everything off the committing lists and dump into @dst */
1225 static void filelayout_recover_commit_reqs(struct list_head *dst,
1226 					   struct nfs_commit_info *cinfo)
1227 {
1228 	struct pnfs_commit_bucket *b;
1229 	struct pnfs_layout_segment *freeme;
1230 	int i;
1231 
1232 restart:
1233 	spin_lock(cinfo->lock);
1234 	for (i = 0, b = cinfo->ds->buckets; i < cinfo->ds->nbuckets; i++, b++) {
1235 		if (transfer_commit_list(&b->written, dst, cinfo, 0)) {
1236 			freeme = b->wlseg;
1237 			b->wlseg = NULL;
1238 			spin_unlock(cinfo->lock);
1239 			pnfs_put_lseg(freeme);
1240 			goto restart;
1241 		}
1242 	}
1243 	cinfo->ds->nwritten = 0;
1244 	spin_unlock(cinfo->lock);
1245 }
1246 
1247 static unsigned int
1248 alloc_ds_commits(struct nfs_commit_info *cinfo, struct list_head *list)
1249 {
1250 	struct pnfs_ds_commit_info *fl_cinfo;
1251 	struct pnfs_commit_bucket *bucket;
1252 	struct nfs_commit_data *data;
1253 	int i, j;
1254 	unsigned int nreq = 0;
1255 	struct pnfs_layout_segment *freeme;
1256 
1257 	fl_cinfo = cinfo->ds;
1258 	bucket = fl_cinfo->buckets;
1259 	for (i = 0; i < fl_cinfo->nbuckets; i++, bucket++) {
1260 		if (list_empty(&bucket->committing))
1261 			continue;
1262 		data = nfs_commitdata_alloc();
1263 		if (!data)
1264 			break;
1265 		data->ds_commit_index = i;
1266 		spin_lock(cinfo->lock);
1267 		data->lseg = bucket->clseg;
1268 		bucket->clseg = NULL;
1269 		spin_unlock(cinfo->lock);
1270 		list_add(&data->pages, list);
1271 		nreq++;
1272 	}
1273 
1274 	/* Clean up on error */
1275 	for (j = i; j < fl_cinfo->nbuckets; j++, bucket++) {
1276 		if (list_empty(&bucket->committing))
1277 			continue;
1278 		nfs_retry_commit(&bucket->committing, bucket->clseg, cinfo);
1279 		spin_lock(cinfo->lock);
1280 		freeme = bucket->clseg;
1281 		bucket->clseg = NULL;
1282 		spin_unlock(cinfo->lock);
1283 		pnfs_put_lseg(freeme);
1284 	}
1285 	/* Caller will clean up entries put on list */
1286 	return nreq;
1287 }
1288 
1289 /* This follows nfs_commit_list pretty closely */
1290 static int
1291 filelayout_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
1292 			   int how, struct nfs_commit_info *cinfo)
1293 {
1294 	struct nfs_commit_data *data, *tmp;
1295 	LIST_HEAD(list);
1296 	unsigned int nreq = 0;
1297 
1298 	if (!list_empty(mds_pages)) {
1299 		data = nfs_commitdata_alloc();
1300 		if (data != NULL) {
1301 			data->lseg = NULL;
1302 			list_add(&data->pages, &list);
1303 			nreq++;
1304 		} else
1305 			nfs_retry_commit(mds_pages, NULL, cinfo);
1306 	}
1307 
1308 	nreq += alloc_ds_commits(cinfo, &list);
1309 
1310 	if (nreq == 0) {
1311 		cinfo->completion_ops->error_cleanup(NFS_I(inode));
1312 		goto out;
1313 	}
1314 
1315 	atomic_add(nreq, &cinfo->mds->rpcs_out);
1316 
1317 	list_for_each_entry_safe(data, tmp, &list, pages) {
1318 		list_del_init(&data->pages);
1319 		if (!data->lseg) {
1320 			nfs_init_commit(data, mds_pages, NULL, cinfo);
1321 			nfs_initiate_commit(NFS_CLIENT(inode), data,
1322 					    data->mds_ops, how, 0);
1323 		} else {
1324 			struct pnfs_commit_bucket *buckets;
1325 
1326 			buckets = cinfo->ds->buckets;
1327 			nfs_init_commit(data, &buckets[data->ds_commit_index].committing, data->lseg, cinfo);
1328 			filelayout_initiate_commit(data, how);
1329 		}
1330 	}
1331 out:
1332 	cinfo->ds->ncommitting = 0;
1333 	return PNFS_ATTEMPTED;
1334 }
1335 
1336 static void
1337 filelayout_free_deveiceid_node(struct nfs4_deviceid_node *d)
1338 {
1339 	nfs4_fl_free_deviceid(container_of(d, struct nfs4_file_layout_dsaddr, id_node));
1340 }
1341 
1342 static struct pnfs_layout_hdr *
1343 filelayout_alloc_layout_hdr(struct inode *inode, gfp_t gfp_flags)
1344 {
1345 	struct nfs4_filelayout *flo;
1346 
1347 	flo = kzalloc(sizeof(*flo), gfp_flags);
1348 	return flo != NULL ? &flo->generic_hdr : NULL;
1349 }
1350 
1351 static void
1352 filelayout_free_layout_hdr(struct pnfs_layout_hdr *lo)
1353 {
1354 	kfree(FILELAYOUT_FROM_HDR(lo));
1355 }
1356 
1357 static struct pnfs_ds_commit_info *
1358 filelayout_get_ds_info(struct inode *inode)
1359 {
1360 	struct pnfs_layout_hdr *layout = NFS_I(inode)->layout;
1361 
1362 	if (layout == NULL)
1363 		return NULL;
1364 	else
1365 		return &FILELAYOUT_FROM_HDR(layout)->commit_info;
1366 }
1367 
1368 static struct pnfs_layoutdriver_type filelayout_type = {
1369 	.id			= LAYOUT_NFSV4_1_FILES,
1370 	.name			= "LAYOUT_NFSV4_1_FILES",
1371 	.owner			= THIS_MODULE,
1372 	.alloc_layout_hdr	= filelayout_alloc_layout_hdr,
1373 	.free_layout_hdr	= filelayout_free_layout_hdr,
1374 	.alloc_lseg		= filelayout_alloc_lseg,
1375 	.free_lseg		= filelayout_free_lseg,
1376 	.pg_read_ops		= &filelayout_pg_read_ops,
1377 	.pg_write_ops		= &filelayout_pg_write_ops,
1378 	.get_ds_info		= &filelayout_get_ds_info,
1379 	.mark_request_commit	= filelayout_mark_request_commit,
1380 	.clear_request_commit	= filelayout_clear_request_commit,
1381 	.scan_commit_lists	= filelayout_scan_commit_lists,
1382 	.recover_commit_reqs	= filelayout_recover_commit_reqs,
1383 	.commit_pagelist	= filelayout_commit_pagelist,
1384 	.read_pagelist		= filelayout_read_pagelist,
1385 	.write_pagelist		= filelayout_write_pagelist,
1386 	.free_deviceid_node	= filelayout_free_deveiceid_node,
1387 };
1388 
1389 static int __init nfs4filelayout_init(void)
1390 {
1391 	printk(KERN_INFO "%s: NFSv4 File Layout Driver Registering...\n",
1392 	       __func__);
1393 	return pnfs_register_layoutdriver(&filelayout_type);
1394 }
1395 
1396 static void __exit nfs4filelayout_exit(void)
1397 {
1398 	printk(KERN_INFO "%s: NFSv4 File Layout Driver Unregistering...\n",
1399 	       __func__);
1400 	pnfs_unregister_layoutdriver(&filelayout_type);
1401 }
1402 
1403 MODULE_ALIAS("nfs-layouttype4-1");
1404 
1405 module_init(nfs4filelayout_init);
1406 module_exit(nfs4filelayout_exit);
1407