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