1 /*
2  * Device operations for the pnfs nfs4 file layout driver.
3  *
4  * Copyright (c) 2014, Primary Data, Inc. All rights reserved.
5  *
6  * Tao Peng <bergwolf@primarydata.com>
7  */
8 
9 #include <linux/nfs_fs.h>
10 #include <linux/vmalloc.h>
11 #include <linux/module.h>
12 #include <linux/sunrpc/addr.h>
13 
14 #include "../internal.h"
15 #include "../nfs4session.h"
16 #include "flexfilelayout.h"
17 
18 #define NFSDBG_FACILITY		NFSDBG_PNFS_LD
19 
20 static unsigned int dataserver_timeo = NFS4_DEF_DS_TIMEO;
21 static unsigned int dataserver_retrans = NFS4_DEF_DS_RETRANS;
22 
23 void nfs4_ff_layout_put_deviceid(struct nfs4_ff_layout_ds *mirror_ds)
24 {
25 	if (mirror_ds)
26 		nfs4_put_deviceid_node(&mirror_ds->id_node);
27 }
28 
29 void nfs4_ff_layout_free_deviceid(struct nfs4_ff_layout_ds *mirror_ds)
30 {
31 	nfs4_print_deviceid(&mirror_ds->id_node.deviceid);
32 	nfs4_pnfs_ds_put(mirror_ds->ds);
33 	kfree_rcu(mirror_ds, id_node.rcu);
34 }
35 
36 /* Decode opaque device data and construct new_ds using it */
37 struct nfs4_ff_layout_ds *
38 nfs4_ff_alloc_deviceid_node(struct nfs_server *server, struct pnfs_device *pdev,
39 			    gfp_t gfp_flags)
40 {
41 	struct xdr_stream stream;
42 	struct xdr_buf buf;
43 	struct page *scratch;
44 	struct list_head dsaddrs;
45 	struct nfs4_pnfs_ds_addr *da;
46 	struct nfs4_ff_layout_ds *new_ds = NULL;
47 	struct nfs4_ff_ds_version *ds_versions = NULL;
48 	u32 mp_count;
49 	u32 version_count;
50 	__be32 *p;
51 	int i, ret = -ENOMEM;
52 
53 	/* set up xdr stream */
54 	scratch = alloc_page(gfp_flags);
55 	if (!scratch)
56 		goto out_err;
57 
58 	new_ds = kzalloc(sizeof(struct nfs4_ff_layout_ds), gfp_flags);
59 	if (!new_ds)
60 		goto out_scratch;
61 
62 	nfs4_init_deviceid_node(&new_ds->id_node,
63 				server,
64 				&pdev->dev_id);
65 	INIT_LIST_HEAD(&dsaddrs);
66 
67 	xdr_init_decode_pages(&stream, &buf, pdev->pages, pdev->pglen);
68 	xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
69 
70 	/* multipath count */
71 	p = xdr_inline_decode(&stream, 4);
72 	if (unlikely(!p))
73 		goto out_err_drain_dsaddrs;
74 	mp_count = be32_to_cpup(p);
75 	dprintk("%s: multipath ds count %d\n", __func__, mp_count);
76 
77 	for (i = 0; i < mp_count; i++) {
78 		/* multipath ds */
79 		da = nfs4_decode_mp_ds_addr(server->nfs_client->cl_net,
80 					    &stream, gfp_flags);
81 		if (da)
82 			list_add_tail(&da->da_node, &dsaddrs);
83 	}
84 	if (list_empty(&dsaddrs)) {
85 		dprintk("%s: no suitable DS addresses found\n",
86 			__func__);
87 		ret = -ENOMEDIUM;
88 		goto out_err_drain_dsaddrs;
89 	}
90 
91 	/* version count */
92 	p = xdr_inline_decode(&stream, 4);
93 	if (unlikely(!p))
94 		goto out_err_drain_dsaddrs;
95 	version_count = be32_to_cpup(p);
96 	dprintk("%s: version count %d\n", __func__, version_count);
97 
98 	ds_versions = kzalloc(version_count * sizeof(struct nfs4_ff_ds_version),
99 			      gfp_flags);
100 	if (!ds_versions)
101 		goto out_scratch;
102 
103 	for (i = 0; i < version_count; i++) {
104 		/* 20 = version(4) + minor_version(4) + rsize(4) + wsize(4) +
105 		 * tightly_coupled(4) */
106 		p = xdr_inline_decode(&stream, 20);
107 		if (unlikely(!p))
108 			goto out_err_drain_dsaddrs;
109 		ds_versions[i].version = be32_to_cpup(p++);
110 		ds_versions[i].minor_version = be32_to_cpup(p++);
111 		ds_versions[i].rsize = nfs_block_size(be32_to_cpup(p++), NULL);
112 		ds_versions[i].wsize = nfs_block_size(be32_to_cpup(p++), NULL);
113 		ds_versions[i].tightly_coupled = be32_to_cpup(p);
114 
115 		if (ds_versions[i].rsize > NFS_MAX_FILE_IO_SIZE)
116 			ds_versions[i].rsize = NFS_MAX_FILE_IO_SIZE;
117 		if (ds_versions[i].wsize > NFS_MAX_FILE_IO_SIZE)
118 			ds_versions[i].wsize = NFS_MAX_FILE_IO_SIZE;
119 
120 		if (ds_versions[i].version != 3 || ds_versions[i].minor_version != 0) {
121 			dprintk("%s: [%d] unsupported ds version %d-%d\n", __func__,
122 				i, ds_versions[i].version,
123 				ds_versions[i].minor_version);
124 			ret = -EPROTONOSUPPORT;
125 			goto out_err_drain_dsaddrs;
126 		}
127 
128 		dprintk("%s: [%d] vers %u minor_ver %u rsize %u wsize %u coupled %d\n",
129 			__func__, i, ds_versions[i].version,
130 			ds_versions[i].minor_version,
131 			ds_versions[i].rsize,
132 			ds_versions[i].wsize,
133 			ds_versions[i].tightly_coupled);
134 	}
135 
136 	new_ds->ds_versions = ds_versions;
137 	new_ds->ds_versions_cnt = version_count;
138 
139 	new_ds->ds = nfs4_pnfs_ds_add(&dsaddrs, gfp_flags);
140 	if (!new_ds->ds)
141 		goto out_err_drain_dsaddrs;
142 
143 	/* If DS was already in cache, free ds addrs */
144 	while (!list_empty(&dsaddrs)) {
145 		da = list_first_entry(&dsaddrs,
146 				      struct nfs4_pnfs_ds_addr,
147 				      da_node);
148 		list_del_init(&da->da_node);
149 		kfree(da->da_remotestr);
150 		kfree(da);
151 	}
152 
153 	__free_page(scratch);
154 	return new_ds;
155 
156 out_err_drain_dsaddrs:
157 	while (!list_empty(&dsaddrs)) {
158 		da = list_first_entry(&dsaddrs, struct nfs4_pnfs_ds_addr,
159 				      da_node);
160 		list_del_init(&da->da_node);
161 		kfree(da->da_remotestr);
162 		kfree(da);
163 	}
164 
165 	kfree(ds_versions);
166 out_scratch:
167 	__free_page(scratch);
168 out_err:
169 	kfree(new_ds);
170 
171 	dprintk("%s ERROR: returning %d\n", __func__, ret);
172 	return NULL;
173 }
174 
175 static void ff_layout_mark_devid_invalid(struct pnfs_layout_segment *lseg,
176 		struct nfs4_deviceid_node *devid)
177 {
178 	nfs4_mark_deviceid_unavailable(devid);
179 	if (!ff_layout_has_available_ds(lseg))
180 		pnfs_error_mark_layout_for_return(lseg->pls_layout->plh_inode,
181 				lseg);
182 }
183 
184 static bool ff_layout_mirror_valid(struct pnfs_layout_segment *lseg,
185 		struct nfs4_ff_layout_mirror *mirror)
186 {
187 	if (mirror == NULL || mirror->mirror_ds == NULL) {
188 		pnfs_error_mark_layout_for_return(lseg->pls_layout->plh_inode,
189 					lseg);
190 		return false;
191 	}
192 	if (mirror->mirror_ds->ds == NULL) {
193 		struct nfs4_deviceid_node *devid;
194 		devid = &mirror->mirror_ds->id_node;
195 		ff_layout_mark_devid_invalid(lseg, devid);
196 		return false;
197 	}
198 	return true;
199 }
200 
201 static u64
202 end_offset(u64 start, u64 len)
203 {
204 	u64 end;
205 
206 	end = start + len;
207 	return end >= start ? end : NFS4_MAX_UINT64;
208 }
209 
210 static void extend_ds_error(struct nfs4_ff_layout_ds_err *err,
211 			    u64 offset, u64 length)
212 {
213 	u64 end;
214 
215 	end = max_t(u64, end_offset(err->offset, err->length),
216 		    end_offset(offset, length));
217 	err->offset = min_t(u64, err->offset, offset);
218 	err->length = end - err->offset;
219 }
220 
221 static int
222 ff_ds_error_match(const struct nfs4_ff_layout_ds_err *e1,
223 		const struct nfs4_ff_layout_ds_err *e2)
224 {
225 	int ret;
226 
227 	if (e1->opnum != e2->opnum)
228 		return e1->opnum < e2->opnum ? -1 : 1;
229 	if (e1->status != e2->status)
230 		return e1->status < e2->status ? -1 : 1;
231 	ret = memcmp(&e1->stateid, &e2->stateid, sizeof(e1->stateid));
232 	if (ret != 0)
233 		return ret;
234 	ret = memcmp(&e1->deviceid, &e2->deviceid, sizeof(e1->deviceid));
235 	if (ret != 0)
236 		return ret;
237 	if (end_offset(e1->offset, e1->length) < e2->offset)
238 		return -1;
239 	if (e1->offset > end_offset(e2->offset, e2->length))
240 		return 1;
241 	/* If ranges overlap or are contiguous, they are the same */
242 	return 0;
243 }
244 
245 static void
246 ff_layout_add_ds_error_locked(struct nfs4_flexfile_layout *flo,
247 			      struct nfs4_ff_layout_ds_err *dserr)
248 {
249 	struct nfs4_ff_layout_ds_err *err, *tmp;
250 	struct list_head *head = &flo->error_list;
251 	int match;
252 
253 	/* Do insertion sort w/ merges */
254 	list_for_each_entry_safe(err, tmp, &flo->error_list, list) {
255 		match = ff_ds_error_match(err, dserr);
256 		if (match < 0)
257 			continue;
258 		if (match > 0) {
259 			/* Add entry "dserr" _before_ entry "err" */
260 			head = &err->list;
261 			break;
262 		}
263 		/* Entries match, so merge "err" into "dserr" */
264 		extend_ds_error(dserr, err->offset, err->length);
265 		list_del(&err->list);
266 		kfree(err);
267 	}
268 
269 	list_add_tail(&dserr->list, head);
270 }
271 
272 int ff_layout_track_ds_error(struct nfs4_flexfile_layout *flo,
273 			     struct nfs4_ff_layout_mirror *mirror, u64 offset,
274 			     u64 length, int status, enum nfs_opnum4 opnum,
275 			     gfp_t gfp_flags)
276 {
277 	struct nfs4_ff_layout_ds_err *dserr;
278 
279 	if (status == 0)
280 		return 0;
281 
282 	if (mirror->mirror_ds == NULL)
283 		return -EINVAL;
284 
285 	dserr = kmalloc(sizeof(*dserr), gfp_flags);
286 	if (!dserr)
287 		return -ENOMEM;
288 
289 	INIT_LIST_HEAD(&dserr->list);
290 	dserr->offset = offset;
291 	dserr->length = length;
292 	dserr->status = status;
293 	dserr->opnum = opnum;
294 	nfs4_stateid_copy(&dserr->stateid, &mirror->stateid);
295 	memcpy(&dserr->deviceid, &mirror->mirror_ds->id_node.deviceid,
296 	       NFS4_DEVICEID4_SIZE);
297 
298 	spin_lock(&flo->generic_hdr.plh_inode->i_lock);
299 	ff_layout_add_ds_error_locked(flo, dserr);
300 	spin_unlock(&flo->generic_hdr.plh_inode->i_lock);
301 
302 	return 0;
303 }
304 
305 /* currently we only support AUTH_NONE and AUTH_SYS */
306 static rpc_authflavor_t
307 nfs4_ff_layout_choose_authflavor(struct nfs4_ff_layout_mirror *mirror)
308 {
309 	if (mirror->uid == (u32)-1)
310 		return RPC_AUTH_NULL;
311 	return RPC_AUTH_UNIX;
312 }
313 
314 /* fetch cred for NFSv3 DS */
315 static int ff_layout_update_mirror_cred(struct nfs4_ff_layout_mirror *mirror,
316 				      struct nfs4_pnfs_ds *ds)
317 {
318 	if (ds->ds_clp && !mirror->cred &&
319 	    mirror->mirror_ds->ds_versions[0].version == 3) {
320 		struct rpc_auth *auth = ds->ds_clp->cl_rpcclient->cl_auth;
321 		struct rpc_cred *cred;
322 		struct auth_cred acred = {
323 			.uid = make_kuid(&init_user_ns, mirror->uid),
324 			.gid = make_kgid(&init_user_ns, mirror->gid),
325 		};
326 
327 		/* AUTH_NULL ignores acred */
328 		cred = auth->au_ops->lookup_cred(auth, &acred, 0);
329 		if (IS_ERR(cred)) {
330 			dprintk("%s: lookup_cred failed with %ld\n",
331 				__func__, PTR_ERR(cred));
332 			return PTR_ERR(cred);
333 		} else {
334 			if (cmpxchg(&mirror->cred, NULL, cred))
335 				put_rpccred(cred);
336 		}
337 	}
338 	return 0;
339 }
340 
341 struct nfs_fh *
342 nfs4_ff_layout_select_ds_fh(struct pnfs_layout_segment *lseg, u32 mirror_idx)
343 {
344 	struct nfs4_ff_layout_mirror *mirror = FF_LAYOUT_COMP(lseg, mirror_idx);
345 	struct nfs_fh *fh = NULL;
346 
347 	if (!ff_layout_mirror_valid(lseg, mirror)) {
348 		pr_err_ratelimited("NFS: %s: No data server for mirror offset index %d\n",
349 			__func__, mirror_idx);
350 		goto out;
351 	}
352 
353 	/* FIXME: For now assume there is only 1 version available for the DS */
354 	fh = &mirror->fh_versions[0];
355 out:
356 	return fh;
357 }
358 
359 /* Upon return, either ds is connected, or ds is NULL */
360 struct nfs4_pnfs_ds *
361 nfs4_ff_layout_prepare_ds(struct pnfs_layout_segment *lseg, u32 ds_idx,
362 			  bool fail_return)
363 {
364 	struct nfs4_ff_layout_mirror *mirror = FF_LAYOUT_COMP(lseg, ds_idx);
365 	struct nfs4_pnfs_ds *ds = NULL;
366 	struct nfs4_deviceid_node *devid;
367 	struct inode *ino = lseg->pls_layout->plh_inode;
368 	struct nfs_server *s = NFS_SERVER(ino);
369 	unsigned int max_payload;
370 	rpc_authflavor_t flavor;
371 
372 	if (!ff_layout_mirror_valid(lseg, mirror)) {
373 		pr_err_ratelimited("NFS: %s: No data server for offset index %d\n",
374 			__func__, ds_idx);
375 		goto out;
376 	}
377 
378 	devid = &mirror->mirror_ds->id_node;
379 	if (ff_layout_test_devid_unavailable(devid))
380 		goto out;
381 
382 	ds = mirror->mirror_ds->ds;
383 	/* matching smp_wmb() in _nfs4_pnfs_v3/4_ds_connect */
384 	smp_rmb();
385 	if (ds->ds_clp)
386 		goto out_update_creds;
387 
388 	flavor = nfs4_ff_layout_choose_authflavor(mirror);
389 
390 	/* FIXME: For now we assume the server sent only one version of NFS
391 	 * to use for the DS.
392 	 */
393 	nfs4_pnfs_ds_connect(s, ds, devid, dataserver_timeo,
394 			     dataserver_retrans,
395 			     mirror->mirror_ds->ds_versions[0].version,
396 			     mirror->mirror_ds->ds_versions[0].minor_version,
397 			     flavor);
398 
399 	/* connect success, check rsize/wsize limit */
400 	if (ds->ds_clp) {
401 		max_payload =
402 			nfs_block_size(rpc_max_payload(ds->ds_clp->cl_rpcclient),
403 				       NULL);
404 		if (mirror->mirror_ds->ds_versions[0].rsize > max_payload)
405 			mirror->mirror_ds->ds_versions[0].rsize = max_payload;
406 		if (mirror->mirror_ds->ds_versions[0].wsize > max_payload)
407 			mirror->mirror_ds->ds_versions[0].wsize = max_payload;
408 	} else {
409 		ff_layout_track_ds_error(FF_LAYOUT_FROM_HDR(lseg->pls_layout),
410 					 mirror, lseg->pls_range.offset,
411 					 lseg->pls_range.length, NFS4ERR_NXIO,
412 					 OP_ILLEGAL, GFP_NOIO);
413 		if (!fail_return) {
414 			if (ff_layout_has_available_ds(lseg))
415 				set_bit(NFS_LAYOUT_RETURN_REQUESTED,
416 					&lseg->pls_layout->plh_flags);
417 			else
418 				pnfs_error_mark_layout_for_return(ino, lseg);
419 		} else
420 			pnfs_error_mark_layout_for_return(ino, lseg);
421 		ds = NULL;
422 		goto out;
423 	}
424 out_update_creds:
425 	if (ff_layout_update_mirror_cred(mirror, ds))
426 		ds = NULL;
427 out:
428 	return ds;
429 }
430 
431 struct rpc_cred *
432 ff_layout_get_ds_cred(struct pnfs_layout_segment *lseg, u32 ds_idx,
433 		      struct rpc_cred *mdscred)
434 {
435 	struct nfs4_ff_layout_mirror *mirror = FF_LAYOUT_COMP(lseg, ds_idx);
436 	struct rpc_cred *cred = ERR_PTR(-EINVAL);
437 
438 	if (!nfs4_ff_layout_prepare_ds(lseg, ds_idx, true))
439 		goto out;
440 
441 	if (mirror && mirror->cred)
442 		cred = mirror->cred;
443 	else
444 		cred = mdscred;
445 out:
446 	return cred;
447 }
448 
449 /**
450 * Find or create a DS rpc client with th MDS server rpc client auth flavor
451 * in the nfs_client cl_ds_clients list.
452 */
453 struct rpc_clnt *
454 nfs4_ff_find_or_create_ds_client(struct pnfs_layout_segment *lseg, u32 ds_idx,
455 				 struct nfs_client *ds_clp, struct inode *inode)
456 {
457 	struct nfs4_ff_layout_mirror *mirror = FF_LAYOUT_COMP(lseg, ds_idx);
458 
459 	switch (mirror->mirror_ds->ds_versions[0].version) {
460 	case 3:
461 		/* For NFSv3 DS, flavor is set when creating DS connections */
462 		return ds_clp->cl_rpcclient;
463 	case 4:
464 		return nfs4_find_or_create_ds_client(ds_clp, inode);
465 	default:
466 		BUG();
467 	}
468 }
469 
470 static bool is_range_intersecting(u64 offset1, u64 length1,
471 				  u64 offset2, u64 length2)
472 {
473 	u64 end1 = end_offset(offset1, length1);
474 	u64 end2 = end_offset(offset2, length2);
475 
476 	return (end1 == NFS4_MAX_UINT64 || end1 > offset2) &&
477 	       (end2 == NFS4_MAX_UINT64 || end2 > offset1);
478 }
479 
480 /* called with inode i_lock held */
481 int ff_layout_encode_ds_ioerr(struct nfs4_flexfile_layout *flo,
482 			      struct xdr_stream *xdr, int *count,
483 			      const struct pnfs_layout_range *range)
484 {
485 	struct nfs4_ff_layout_ds_err *err, *n;
486 	__be32 *p;
487 
488 	list_for_each_entry_safe(err, n, &flo->error_list, list) {
489 		if (!is_range_intersecting(err->offset, err->length,
490 					   range->offset, range->length))
491 			continue;
492 		/* offset(8) + length(8) + stateid(NFS4_STATEID_SIZE)
493 		 * + array length + deviceid(NFS4_DEVICEID4_SIZE)
494 		 * + status(4) + opnum(4)
495 		 */
496 		p = xdr_reserve_space(xdr,
497 				28 + NFS4_STATEID_SIZE + NFS4_DEVICEID4_SIZE);
498 		if (unlikely(!p))
499 			return -ENOBUFS;
500 		p = xdr_encode_hyper(p, err->offset);
501 		p = xdr_encode_hyper(p, err->length);
502 		p = xdr_encode_opaque_fixed(p, &err->stateid,
503 					    NFS4_STATEID_SIZE);
504 		/* Encode 1 error */
505 		*p++ = cpu_to_be32(1);
506 		p = xdr_encode_opaque_fixed(p, &err->deviceid,
507 					    NFS4_DEVICEID4_SIZE);
508 		*p++ = cpu_to_be32(err->status);
509 		*p++ = cpu_to_be32(err->opnum);
510 		*count += 1;
511 		list_del(&err->list);
512 		dprintk("%s: offset %llu length %llu status %d op %d count %d\n",
513 			__func__, err->offset, err->length, err->status,
514 			err->opnum, *count);
515 		kfree(err);
516 	}
517 
518 	return 0;
519 }
520 
521 static bool ff_read_layout_has_available_ds(struct pnfs_layout_segment *lseg)
522 {
523 	struct nfs4_ff_layout_mirror *mirror;
524 	struct nfs4_deviceid_node *devid;
525 	u32 idx;
526 
527 	for (idx = 0; idx < FF_LAYOUT_MIRROR_COUNT(lseg); idx++) {
528 		mirror = FF_LAYOUT_COMP(lseg, idx);
529 		if (mirror && mirror->mirror_ds) {
530 			devid = &mirror->mirror_ds->id_node;
531 			if (!ff_layout_test_devid_unavailable(devid))
532 				return true;
533 		}
534 	}
535 
536 	return false;
537 }
538 
539 static bool ff_rw_layout_has_available_ds(struct pnfs_layout_segment *lseg)
540 {
541 	struct nfs4_ff_layout_mirror *mirror;
542 	struct nfs4_deviceid_node *devid;
543 	u32 idx;
544 
545 	for (idx = 0; idx < FF_LAYOUT_MIRROR_COUNT(lseg); idx++) {
546 		mirror = FF_LAYOUT_COMP(lseg, idx);
547 		if (!mirror || !mirror->mirror_ds)
548 			return false;
549 		devid = &mirror->mirror_ds->id_node;
550 		if (ff_layout_test_devid_unavailable(devid))
551 			return false;
552 	}
553 
554 	return FF_LAYOUT_MIRROR_COUNT(lseg) != 0;
555 }
556 
557 bool ff_layout_has_available_ds(struct pnfs_layout_segment *lseg)
558 {
559 	if (lseg->pls_range.iomode == IOMODE_READ)
560 		return  ff_read_layout_has_available_ds(lseg);
561 	/* Note: RW layout needs all mirrors available */
562 	return ff_rw_layout_has_available_ds(lseg);
563 }
564 
565 module_param(dataserver_retrans, uint, 0644);
566 MODULE_PARM_DESC(dataserver_retrans, "The  number of times the NFSv4.1 client "
567 			"retries a request before it attempts further "
568 			" recovery  action.");
569 module_param(dataserver_timeo, uint, 0644);
570 MODULE_PARM_DESC(dataserver_timeo, "The time (in tenths of a second) the "
571 			"NFSv4.1  client  waits for a response from a "
572 			" data server before it retries an NFS request.");
573