1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Device operations for the pnfs nfs4 file layout driver.
4 *
5 * Copyright (c) 2014, Primary Data, Inc. All rights reserved.
6 *
7 * Tao Peng <bergwolf@primarydata.com>
8 */
9
10#include <linux/nfs_fs.h>
11#include <linux/vmalloc.h>
12#include <linux/module.h>
13#include <linux/sunrpc/addr.h>
14
15#include "../internal.h"
16#include "../nfs4session.h"
17#include "flexfilelayout.h"
18
19#define NFSDBG_FACILITY		NFSDBG_PNFS_LD
20
21static unsigned int dataserver_timeo = NFS_DEF_TCP_TIMEO;
22static unsigned int dataserver_retrans;
23
24static bool ff_layout_has_available_ds(struct pnfs_layout_segment *lseg);
25
26void nfs4_ff_layout_put_deviceid(struct nfs4_ff_layout_ds *mirror_ds)
27{
28	if (!IS_ERR_OR_NULL(mirror_ds))
29		nfs4_put_deviceid_node(&mirror_ds->id_node);
30}
31
32void nfs4_ff_layout_free_deviceid(struct nfs4_ff_layout_ds *mirror_ds)
33{
34	nfs4_print_deviceid(&mirror_ds->id_node.deviceid);
35	nfs4_pnfs_ds_put(mirror_ds->ds);
36	kfree(mirror_ds->ds_versions);
37	kfree_rcu(mirror_ds, id_node.rcu);
38}
39
40/* Decode opaque device data and construct new_ds using it */
41struct nfs4_ff_layout_ds *
42nfs4_ff_alloc_deviceid_node(struct nfs_server *server, struct pnfs_device *pdev,
43			    gfp_t gfp_flags)
44{
45	struct xdr_stream stream;
46	struct xdr_buf buf;
47	struct page *scratch;
48	struct list_head dsaddrs;
49	struct nfs4_pnfs_ds_addr *da;
50	struct nfs4_ff_layout_ds *new_ds = NULL;
51	struct nfs4_ff_ds_version *ds_versions = NULL;
52	u32 mp_count;
53	u32 version_count;
54	__be32 *p;
55	int i, ret = -ENOMEM;
56
57	/* set up xdr stream */
58	scratch = alloc_page(gfp_flags);
59	if (!scratch)
60		goto out_err;
61
62	new_ds = kzalloc(sizeof(struct nfs4_ff_layout_ds), gfp_flags);
63	if (!new_ds)
64		goto out_scratch;
65
66	nfs4_init_deviceid_node(&new_ds->id_node,
67				server,
68				&pdev->dev_id);
69	INIT_LIST_HEAD(&dsaddrs);
70
71	xdr_init_decode_pages(&stream, &buf, pdev->pages, pdev->pglen);
72	xdr_set_scratch_page(&stream, scratch);
73
74	/* multipath count */
75	p = xdr_inline_decode(&stream, 4);
76	if (unlikely(!p))
77		goto out_err_drain_dsaddrs;
78	mp_count = be32_to_cpup(p);
79	dprintk("%s: multipath ds count %d\n", __func__, mp_count);
80
81	for (i = 0; i < mp_count; i++) {
82		/* multipath ds */
83		da = nfs4_decode_mp_ds_addr(server->nfs_client->cl_net,
84					    &stream, gfp_flags);
85		if (da)
86			list_add_tail(&da->da_node, &dsaddrs);
87	}
88	if (list_empty(&dsaddrs)) {
89		dprintk("%s: no suitable DS addresses found\n",
90			__func__);
91		ret = -ENOMEDIUM;
92		goto out_err_drain_dsaddrs;
93	}
94
95	/* version count */
96	p = xdr_inline_decode(&stream, 4);
97	if (unlikely(!p))
98		goto out_err_drain_dsaddrs;
99	version_count = be32_to_cpup(p);
100	dprintk("%s: version count %d\n", __func__, version_count);
101
102	ds_versions = kcalloc(version_count,
103			      sizeof(struct nfs4_ff_ds_version),
104			      gfp_flags);
105	if (!ds_versions)
106		goto out_scratch;
107
108	for (i = 0; i < version_count; i++) {
109		/* 20 = version(4) + minor_version(4) + rsize(4) + wsize(4) +
110		 * tightly_coupled(4) */
111		p = xdr_inline_decode(&stream, 20);
112		if (unlikely(!p))
113			goto out_err_drain_dsaddrs;
114		ds_versions[i].version = be32_to_cpup(p++);
115		ds_versions[i].minor_version = be32_to_cpup(p++);
116		ds_versions[i].rsize = nfs_io_size(be32_to_cpup(p++),
117						   server->nfs_client->cl_proto);
118		ds_versions[i].wsize = nfs_io_size(be32_to_cpup(p++),
119						   server->nfs_client->cl_proto);
120		ds_versions[i].tightly_coupled = be32_to_cpup(p);
121
122		if (ds_versions[i].rsize > NFS_MAX_FILE_IO_SIZE)
123			ds_versions[i].rsize = NFS_MAX_FILE_IO_SIZE;
124		if (ds_versions[i].wsize > NFS_MAX_FILE_IO_SIZE)
125			ds_versions[i].wsize = NFS_MAX_FILE_IO_SIZE;
126
127		/*
128		 * check for valid major/minor combination.
129		 * currently we support dataserver which talk:
130		 *   v3, v4.0, v4.1, v4.2
131		 */
132		if (!((ds_versions[i].version == 3 && ds_versions[i].minor_version == 0) ||
133			(ds_versions[i].version == 4 && ds_versions[i].minor_version < 3))) {
134			dprintk("%s: [%d] unsupported ds version %d-%d\n", __func__,
135				i, ds_versions[i].version,
136				ds_versions[i].minor_version);
137			ret = -EPROTONOSUPPORT;
138			goto out_err_drain_dsaddrs;
139		}
140
141		dprintk("%s: [%d] vers %u minor_ver %u rsize %u wsize %u coupled %d\n",
142			__func__, i, ds_versions[i].version,
143			ds_versions[i].minor_version,
144			ds_versions[i].rsize,
145			ds_versions[i].wsize,
146			ds_versions[i].tightly_coupled);
147	}
148
149	new_ds->ds_versions = ds_versions;
150	new_ds->ds_versions_cnt = version_count;
151
152	new_ds->ds = nfs4_pnfs_ds_add(&dsaddrs, gfp_flags);
153	if (!new_ds->ds)
154		goto out_err_drain_dsaddrs;
155
156	/* If DS was already in cache, free ds addrs */
157	while (!list_empty(&dsaddrs)) {
158		da = list_first_entry(&dsaddrs,
159				      struct nfs4_pnfs_ds_addr,
160				      da_node);
161		list_del_init(&da->da_node);
162		kfree(da->da_remotestr);
163		kfree(da);
164	}
165
166	__free_page(scratch);
167	return new_ds;
168
169out_err_drain_dsaddrs:
170	while (!list_empty(&dsaddrs)) {
171		da = list_first_entry(&dsaddrs, struct nfs4_pnfs_ds_addr,
172				      da_node);
173		list_del_init(&da->da_node);
174		kfree(da->da_remotestr);
175		kfree(da);
176	}
177
178	kfree(ds_versions);
179out_scratch:
180	__free_page(scratch);
181out_err:
182	kfree(new_ds);
183
184	dprintk("%s ERROR: returning %d\n", __func__, ret);
185	return NULL;
186}
187
188static void extend_ds_error(struct nfs4_ff_layout_ds_err *err,
189			    u64 offset, u64 length)
190{
191	u64 end;
192
193	end = max_t(u64, pnfs_end_offset(err->offset, err->length),
194		    pnfs_end_offset(offset, length));
195	err->offset = min_t(u64, err->offset, offset);
196	err->length = end - err->offset;
197}
198
199static int
200ff_ds_error_match(const struct nfs4_ff_layout_ds_err *e1,
201		const struct nfs4_ff_layout_ds_err *e2)
202{
203	int ret;
204
205	if (e1->opnum != e2->opnum)
206		return e1->opnum < e2->opnum ? -1 : 1;
207	if (e1->status != e2->status)
208		return e1->status < e2->status ? -1 : 1;
209	ret = memcmp(e1->stateid.data, e2->stateid.data,
210			sizeof(e1->stateid.data));
211	if (ret != 0)
212		return ret;
213	ret = memcmp(&e1->deviceid, &e2->deviceid, sizeof(e1->deviceid));
214	if (ret != 0)
215		return ret;
216	if (pnfs_end_offset(e1->offset, e1->length) < e2->offset)
217		return -1;
218	if (e1->offset > pnfs_end_offset(e2->offset, e2->length))
219		return 1;
220	/* If ranges overlap or are contiguous, they are the same */
221	return 0;
222}
223
224static void
225ff_layout_add_ds_error_locked(struct nfs4_flexfile_layout *flo,
226			      struct nfs4_ff_layout_ds_err *dserr)
227{
228	struct nfs4_ff_layout_ds_err *err, *tmp;
229	struct list_head *head = &flo->error_list;
230	int match;
231
232	/* Do insertion sort w/ merges */
233	list_for_each_entry_safe(err, tmp, &flo->error_list, list) {
234		match = ff_ds_error_match(err, dserr);
235		if (match < 0)
236			continue;
237		if (match > 0) {
238			/* Add entry "dserr" _before_ entry "err" */
239			head = &err->list;
240			break;
241		}
242		/* Entries match, so merge "err" into "dserr" */
243		extend_ds_error(dserr, err->offset, err->length);
244		list_replace(&err->list, &dserr->list);
245		kfree(err);
246		return;
247	}
248
249	list_add_tail(&dserr->list, head);
250}
251
252int ff_layout_track_ds_error(struct nfs4_flexfile_layout *flo,
253			     struct nfs4_ff_layout_mirror *mirror, u64 offset,
254			     u64 length, int status, enum nfs_opnum4 opnum,
255			     gfp_t gfp_flags)
256{
257	struct nfs4_ff_layout_ds_err *dserr;
258
259	if (status == 0)
260		return 0;
261
262	if (IS_ERR_OR_NULL(mirror->mirror_ds))
263		return -EINVAL;
264
265	dserr = kmalloc(sizeof(*dserr), gfp_flags);
266	if (!dserr)
267		return -ENOMEM;
268
269	INIT_LIST_HEAD(&dserr->list);
270	dserr->offset = offset;
271	dserr->length = length;
272	dserr->status = status;
273	dserr->opnum = opnum;
274	nfs4_stateid_copy(&dserr->stateid, &mirror->stateid);
275	memcpy(&dserr->deviceid, &mirror->mirror_ds->id_node.deviceid,
276	       NFS4_DEVICEID4_SIZE);
277
278	spin_lock(&flo->generic_hdr.plh_inode->i_lock);
279	ff_layout_add_ds_error_locked(flo, dserr);
280	spin_unlock(&flo->generic_hdr.plh_inode->i_lock);
281	return 0;
282}
283
284static const struct cred *
285ff_layout_get_mirror_cred(struct nfs4_ff_layout_mirror *mirror, u32 iomode)
286{
287	const struct cred *cred, __rcu **pcred;
288
289	if (iomode == IOMODE_READ)
290		pcred = &mirror->ro_cred;
291	else
292		pcred = &mirror->rw_cred;
293
294	rcu_read_lock();
295	do {
296		cred = rcu_dereference(*pcred);
297		if (!cred)
298			break;
299
300		cred = get_cred_rcu(cred);
301	} while(!cred);
302	rcu_read_unlock();
303	return cred;
304}
305
306struct nfs_fh *
307nfs4_ff_layout_select_ds_fh(struct nfs4_ff_layout_mirror *mirror)
308{
309	/* FIXME: For now assume there is only 1 version available for the DS */
310	return &mirror->fh_versions[0];
311}
312
313void
314nfs4_ff_layout_select_ds_stateid(const struct nfs4_ff_layout_mirror *mirror,
315		nfs4_stateid *stateid)
316{
317	if (nfs4_ff_layout_ds_version(mirror) == 4)
318		nfs4_stateid_copy(stateid, &mirror->stateid);
319}
320
321static bool
322ff_layout_init_mirror_ds(struct pnfs_layout_hdr *lo,
323			 struct nfs4_ff_layout_mirror *mirror)
324{
325	if (mirror == NULL)
326		goto outerr;
327	if (mirror->mirror_ds == NULL) {
328		struct nfs4_deviceid_node *node;
329		struct nfs4_ff_layout_ds *mirror_ds = ERR_PTR(-ENODEV);
330
331		node = nfs4_find_get_deviceid(NFS_SERVER(lo->plh_inode),
332				&mirror->devid, lo->plh_lc_cred,
333				GFP_KERNEL);
334		if (node)
335			mirror_ds = FF_LAYOUT_MIRROR_DS(node);
336
337		/* check for race with another call to this function */
338		if (cmpxchg(&mirror->mirror_ds, NULL, mirror_ds) &&
339		    mirror_ds != ERR_PTR(-ENODEV))
340			nfs4_put_deviceid_node(node);
341	}
342
343	if (IS_ERR(mirror->mirror_ds))
344		goto outerr;
345
346	return true;
347outerr:
348	return false;
349}
350
351/**
352 * nfs4_ff_layout_prepare_ds - prepare a DS connection for an RPC call
353 * @lseg: the layout segment we're operating on
354 * @mirror: layout mirror describing the DS to use
355 * @fail_return: return layout on connect failure?
356 *
357 * Try to prepare a DS connection to accept an RPC call. This involves
358 * selecting a mirror to use and connecting the client to it if it's not
359 * already connected.
360 *
361 * Since we only need a single functioning mirror to satisfy a read, we don't
362 * want to return the layout if there is one. For writes though, any down
363 * mirror should result in a LAYOUTRETURN. @fail_return is how we distinguish
364 * between the two cases.
365 *
366 * Returns a pointer to a connected DS object on success or NULL on failure.
367 */
368struct nfs4_pnfs_ds *
369nfs4_ff_layout_prepare_ds(struct pnfs_layout_segment *lseg,
370			  struct nfs4_ff_layout_mirror *mirror,
371			  bool fail_return)
372{
373	struct nfs4_pnfs_ds *ds = NULL;
374	struct inode *ino = lseg->pls_layout->plh_inode;
375	struct nfs_server *s = NFS_SERVER(ino);
376	unsigned int max_payload;
377	int status;
378
379	if (!ff_layout_init_mirror_ds(lseg->pls_layout, mirror))
380		goto noconnect;
381
382	ds = mirror->mirror_ds->ds;
383	if (READ_ONCE(ds->ds_clp))
384		goto out;
385	/* matching smp_wmb() in _nfs4_pnfs_v3/4_ds_connect */
386	smp_rmb();
387
388	/* FIXME: For now we assume the server sent only one version of NFS
389	 * to use for the DS.
390	 */
391	status = nfs4_pnfs_ds_connect(s, ds, &mirror->mirror_ds->id_node,
392			     dataserver_timeo, dataserver_retrans,
393			     mirror->mirror_ds->ds_versions[0].version,
394			     mirror->mirror_ds->ds_versions[0].minor_version);
395
396	/* connect success, check rsize/wsize limit */
397	if (!status) {
398		max_payload =
399			nfs_block_size(rpc_max_payload(ds->ds_clp->cl_rpcclient),
400				       NULL);
401		if (mirror->mirror_ds->ds_versions[0].rsize > max_payload)
402			mirror->mirror_ds->ds_versions[0].rsize = max_payload;
403		if (mirror->mirror_ds->ds_versions[0].wsize > max_payload)
404			mirror->mirror_ds->ds_versions[0].wsize = max_payload;
405		goto out;
406	}
407noconnect:
408	ff_layout_track_ds_error(FF_LAYOUT_FROM_HDR(lseg->pls_layout),
409				 mirror, lseg->pls_range.offset,
410				 lseg->pls_range.length, NFS4ERR_NXIO,
411				 OP_ILLEGAL, GFP_NOIO);
412	ff_layout_send_layouterror(lseg);
413	if (fail_return || !ff_layout_has_available_ds(lseg))
414		pnfs_error_mark_layout_for_return(ino, lseg);
415	ds = NULL;
416out:
417	return ds;
418}
419
420const struct cred *
421ff_layout_get_ds_cred(struct nfs4_ff_layout_mirror *mirror,
422		      const struct pnfs_layout_range *range,
423		      const struct cred *mdscred)
424{
425	const struct cred *cred;
426
427	if (mirror && !mirror->mirror_ds->ds_versions[0].tightly_coupled) {
428		cred = ff_layout_get_mirror_cred(mirror, range->iomode);
429		if (!cred)
430			cred = get_cred(mdscred);
431	} else {
432		cred = get_cred(mdscred);
433	}
434	return cred;
435}
436
437/**
438 * nfs4_ff_find_or_create_ds_client - Find or create a DS rpc client
439 * @mirror: pointer to the mirror
440 * @ds_clp: nfs_client for the DS
441 * @inode: pointer to inode
442 *
443 * Find or create a DS rpc client with th MDS server rpc client auth flavor
444 * in the nfs_client cl_ds_clients list.
445 */
446struct rpc_clnt *
447nfs4_ff_find_or_create_ds_client(struct nfs4_ff_layout_mirror *mirror,
448				 struct nfs_client *ds_clp, struct inode *inode)
449{
450	switch (mirror->mirror_ds->ds_versions[0].version) {
451	case 3:
452		/* For NFSv3 DS, flavor is set when creating DS connections */
453		return ds_clp->cl_rpcclient;
454	case 4:
455		return nfs4_find_or_create_ds_client(ds_clp, inode);
456	default:
457		BUG();
458	}
459}
460
461void ff_layout_free_ds_ioerr(struct list_head *head)
462{
463	struct nfs4_ff_layout_ds_err *err;
464
465	while (!list_empty(head)) {
466		err = list_first_entry(head,
467				struct nfs4_ff_layout_ds_err,
468				list);
469		list_del(&err->list);
470		kfree(err);
471	}
472}
473
474/* called with inode i_lock held */
475int ff_layout_encode_ds_ioerr(struct xdr_stream *xdr, const struct list_head *head)
476{
477	struct nfs4_ff_layout_ds_err *err;
478	__be32 *p;
479
480	list_for_each_entry(err, head, list) {
481		/* offset(8) + length(8) + stateid(NFS4_STATEID_SIZE)
482		 * + array length + deviceid(NFS4_DEVICEID4_SIZE)
483		 * + status(4) + opnum(4)
484		 */
485		p = xdr_reserve_space(xdr,
486				28 + NFS4_STATEID_SIZE + NFS4_DEVICEID4_SIZE);
487		if (unlikely(!p))
488			return -ENOBUFS;
489		p = xdr_encode_hyper(p, err->offset);
490		p = xdr_encode_hyper(p, err->length);
491		p = xdr_encode_opaque_fixed(p, &err->stateid,
492					    NFS4_STATEID_SIZE);
493		/* Encode 1 error */
494		*p++ = cpu_to_be32(1);
495		p = xdr_encode_opaque_fixed(p, &err->deviceid,
496					    NFS4_DEVICEID4_SIZE);
497		*p++ = cpu_to_be32(err->status);
498		*p++ = cpu_to_be32(err->opnum);
499		dprintk("%s: offset %llu length %llu status %d op %d\n",
500			__func__, err->offset, err->length, err->status,
501			err->opnum);
502	}
503
504	return 0;
505}
506
507static
508unsigned int do_layout_fetch_ds_ioerr(struct pnfs_layout_hdr *lo,
509				      const struct pnfs_layout_range *range,
510				      struct list_head *head,
511				      unsigned int maxnum)
512{
513	struct nfs4_flexfile_layout *flo = FF_LAYOUT_FROM_HDR(lo);
514	struct inode *inode = lo->plh_inode;
515	struct nfs4_ff_layout_ds_err *err, *n;
516	unsigned int ret = 0;
517
518	spin_lock(&inode->i_lock);
519	list_for_each_entry_safe(err, n, &flo->error_list, list) {
520		if (!pnfs_is_range_intersecting(err->offset,
521				pnfs_end_offset(err->offset, err->length),
522				range->offset,
523				pnfs_end_offset(range->offset, range->length)))
524			continue;
525		if (!maxnum)
526			break;
527		list_move(&err->list, head);
528		maxnum--;
529		ret++;
530	}
531	spin_unlock(&inode->i_lock);
532	return ret;
533}
534
535unsigned int ff_layout_fetch_ds_ioerr(struct pnfs_layout_hdr *lo,
536				      const struct pnfs_layout_range *range,
537				      struct list_head *head,
538				      unsigned int maxnum)
539{
540	unsigned int ret;
541
542	ret = do_layout_fetch_ds_ioerr(lo, range, head, maxnum);
543	/* If we're over the max, discard all remaining entries */
544	if (ret == maxnum) {
545		LIST_HEAD(discard);
546		do_layout_fetch_ds_ioerr(lo, range, &discard, -1);
547		ff_layout_free_ds_ioerr(&discard);
548	}
549	return ret;
550}
551
552static bool ff_read_layout_has_available_ds(struct pnfs_layout_segment *lseg)
553{
554	struct nfs4_ff_layout_mirror *mirror;
555	struct nfs4_deviceid_node *devid;
556	u32 idx;
557
558	for (idx = 0; idx < FF_LAYOUT_MIRROR_COUNT(lseg); idx++) {
559		mirror = FF_LAYOUT_COMP(lseg, idx);
560		if (mirror) {
561			if (!mirror->mirror_ds)
562				return true;
563			if (IS_ERR(mirror->mirror_ds))
564				continue;
565			devid = &mirror->mirror_ds->id_node;
566			if (!nfs4_test_deviceid_unavailable(devid))
567				return true;
568		}
569	}
570
571	return false;
572}
573
574static bool ff_rw_layout_has_available_ds(struct pnfs_layout_segment *lseg)
575{
576	struct nfs4_ff_layout_mirror *mirror;
577	struct nfs4_deviceid_node *devid;
578	u32 idx;
579
580	for (idx = 0; idx < FF_LAYOUT_MIRROR_COUNT(lseg); idx++) {
581		mirror = FF_LAYOUT_COMP(lseg, idx);
582		if (!mirror || IS_ERR(mirror->mirror_ds))
583			return false;
584		if (!mirror->mirror_ds)
585			continue;
586		devid = &mirror->mirror_ds->id_node;
587		if (nfs4_test_deviceid_unavailable(devid))
588			return false;
589	}
590
591	return FF_LAYOUT_MIRROR_COUNT(lseg) != 0;
592}
593
594static bool ff_layout_has_available_ds(struct pnfs_layout_segment *lseg)
595{
596	if (lseg->pls_range.iomode == IOMODE_READ)
597		return  ff_read_layout_has_available_ds(lseg);
598	/* Note: RW layout needs all mirrors available */
599	return ff_rw_layout_has_available_ds(lseg);
600}
601
602bool ff_layout_avoid_mds_available_ds(struct pnfs_layout_segment *lseg)
603{
604	return ff_layout_no_fallback_to_mds(lseg) ||
605	       ff_layout_has_available_ds(lseg);
606}
607
608bool ff_layout_avoid_read_on_rw(struct pnfs_layout_segment *lseg)
609{
610	return lseg->pls_range.iomode == IOMODE_RW &&
611	       ff_layout_no_read_on_rw(lseg);
612}
613
614module_param(dataserver_retrans, uint, 0644);
615MODULE_PARM_DESC(dataserver_retrans, "The  number of times the NFSv4.1 client "
616			"retries a request before it attempts further "
617			" recovery  action.");
618module_param(dataserver_timeo, uint, 0644);
619MODULE_PARM_DESC(dataserver_timeo, "The time (in tenths of a second) the "
620			"NFSv4.1  client  waits for a response from a "
621			" data server before it retries an NFS request.");
622