xref: /openbmc/linux/fs/nfs/callback_proc.c (revision 3805e6a1)
1 /*
2  * linux/fs/nfs/callback_proc.c
3  *
4  * Copyright (C) 2004 Trond Myklebust
5  *
6  * NFSv4 callback procedures
7  */
8 #include <linux/nfs4.h>
9 #include <linux/nfs_fs.h>
10 #include <linux/slab.h>
11 #include <linux/rcupdate.h>
12 #include "nfs4_fs.h"
13 #include "callback.h"
14 #include "delegation.h"
15 #include "internal.h"
16 #include "pnfs.h"
17 #include "nfs4session.h"
18 #include "nfs4trace.h"
19 
20 #define NFSDBG_FACILITY NFSDBG_CALLBACK
21 
22 __be32 nfs4_callback_getattr(struct cb_getattrargs *args,
23 			     struct cb_getattrres *res,
24 			     struct cb_process_state *cps)
25 {
26 	struct nfs_delegation *delegation;
27 	struct nfs_inode *nfsi;
28 	struct inode *inode;
29 
30 	res->status = htonl(NFS4ERR_OP_NOT_IN_SESSION);
31 	if (!cps->clp) /* Always set for v4.0. Set in cb_sequence for v4.1 */
32 		goto out;
33 
34 	res->bitmap[0] = res->bitmap[1] = 0;
35 	res->status = htonl(NFS4ERR_BADHANDLE);
36 
37 	dprintk_rcu("NFS: GETATTR callback request from %s\n",
38 		rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR));
39 
40 	inode = nfs_delegation_find_inode(cps->clp, &args->fh);
41 	if (inode == NULL) {
42 		trace_nfs4_cb_getattr(cps->clp, &args->fh, NULL,
43 				-ntohl(res->status));
44 		goto out;
45 	}
46 	nfsi = NFS_I(inode);
47 	rcu_read_lock();
48 	delegation = rcu_dereference(nfsi->delegation);
49 	if (delegation == NULL || (delegation->type & FMODE_WRITE) == 0)
50 		goto out_iput;
51 	res->size = i_size_read(inode);
52 	res->change_attr = delegation->change_attr;
53 	if (nfsi->nrequests != 0)
54 		res->change_attr++;
55 	res->ctime = inode->i_ctime;
56 	res->mtime = inode->i_mtime;
57 	res->bitmap[0] = (FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE) &
58 		args->bitmap[0];
59 	res->bitmap[1] = (FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY) &
60 		args->bitmap[1];
61 	res->status = 0;
62 out_iput:
63 	rcu_read_unlock();
64 	trace_nfs4_cb_getattr(cps->clp, &args->fh, inode, -ntohl(res->status));
65 	iput(inode);
66 out:
67 	dprintk("%s: exit with status = %d\n", __func__, ntohl(res->status));
68 	return res->status;
69 }
70 
71 __be32 nfs4_callback_recall(struct cb_recallargs *args, void *dummy,
72 			    struct cb_process_state *cps)
73 {
74 	struct inode *inode;
75 	__be32 res;
76 
77 	res = htonl(NFS4ERR_OP_NOT_IN_SESSION);
78 	if (!cps->clp) /* Always set for v4.0. Set in cb_sequence for v4.1 */
79 		goto out;
80 
81 	dprintk_rcu("NFS: RECALL callback request from %s\n",
82 		rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR));
83 
84 	res = htonl(NFS4ERR_BADHANDLE);
85 	inode = nfs_delegation_find_inode(cps->clp, &args->fh);
86 	if (inode == NULL) {
87 		trace_nfs4_cb_recall(cps->clp, &args->fh, NULL,
88 				&args->stateid, -ntohl(res));
89 		goto out;
90 	}
91 	/* Set up a helper thread to actually return the delegation */
92 	switch (nfs_async_inode_return_delegation(inode, &args->stateid)) {
93 	case 0:
94 		res = 0;
95 		break;
96 	case -ENOENT:
97 		res = htonl(NFS4ERR_BAD_STATEID);
98 		break;
99 	default:
100 		res = htonl(NFS4ERR_RESOURCE);
101 	}
102 	trace_nfs4_cb_recall(cps->clp, &args->fh, inode,
103 			&args->stateid, -ntohl(res));
104 	iput(inode);
105 out:
106 	dprintk("%s: exit with status = %d\n", __func__, ntohl(res));
107 	return res;
108 }
109 
110 #if defined(CONFIG_NFS_V4_1)
111 
112 /*
113  * Lookup a layout by filehandle.
114  *
115  * Note: gets a refcount on the layout hdr and on its respective inode.
116  * Caller must put the layout hdr and the inode.
117  *
118  * TODO: keep track of all layouts (and delegations) in a hash table
119  * hashed by filehandle.
120  */
121 static struct pnfs_layout_hdr * get_layout_by_fh_locked(struct nfs_client *clp,
122 		struct nfs_fh *fh, nfs4_stateid *stateid)
123 {
124 	struct nfs_server *server;
125 	struct inode *ino;
126 	struct pnfs_layout_hdr *lo;
127 
128 	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
129 		list_for_each_entry(lo, &server->layouts, plh_layouts) {
130 			if (!nfs4_stateid_match_other(&lo->plh_stateid, stateid))
131 				continue;
132 			if (nfs_compare_fh(fh, &NFS_I(lo->plh_inode)->fh))
133 				continue;
134 			ino = igrab(lo->plh_inode);
135 			if (!ino)
136 				break;
137 			spin_lock(&ino->i_lock);
138 			/* Is this layout in the process of being freed? */
139 			if (NFS_I(ino)->layout != lo) {
140 				spin_unlock(&ino->i_lock);
141 				iput(ino);
142 				break;
143 			}
144 			pnfs_get_layout_hdr(lo);
145 			spin_unlock(&ino->i_lock);
146 			return lo;
147 		}
148 	}
149 
150 	return NULL;
151 }
152 
153 static struct pnfs_layout_hdr * get_layout_by_fh(struct nfs_client *clp,
154 		struct nfs_fh *fh, nfs4_stateid *stateid)
155 {
156 	struct pnfs_layout_hdr *lo;
157 
158 	spin_lock(&clp->cl_lock);
159 	rcu_read_lock();
160 	lo = get_layout_by_fh_locked(clp, fh, stateid);
161 	rcu_read_unlock();
162 	spin_unlock(&clp->cl_lock);
163 
164 	return lo;
165 }
166 
167 /*
168  * Enforce RFC5661 section 12.5.5.2.1. (Layout Recall and Return Sequencing)
169  */
170 static bool pnfs_check_stateid_sequence(struct pnfs_layout_hdr *lo,
171 					const nfs4_stateid *new)
172 {
173 	u32 oldseq, newseq;
174 
175 	oldseq = be32_to_cpu(lo->plh_stateid.seqid);
176 	newseq = be32_to_cpu(new->seqid);
177 
178 	if (newseq > oldseq + 1)
179 		return false;
180 	return true;
181 }
182 
183 static u32 initiate_file_draining(struct nfs_client *clp,
184 				  struct cb_layoutrecallargs *args)
185 {
186 	struct inode *ino;
187 	struct pnfs_layout_hdr *lo;
188 	u32 rv = NFS4ERR_NOMATCHING_LAYOUT;
189 	LIST_HEAD(free_me_list);
190 
191 	lo = get_layout_by_fh(clp, &args->cbl_fh, &args->cbl_stateid);
192 	if (!lo) {
193 		trace_nfs4_cb_layoutrecall_file(clp, &args->cbl_fh, NULL,
194 				&args->cbl_stateid, -rv);
195 		goto out;
196 	}
197 
198 	ino = lo->plh_inode;
199 
200 	spin_lock(&ino->i_lock);
201 	if (!pnfs_check_stateid_sequence(lo, &args->cbl_stateid)) {
202 		rv = NFS4ERR_DELAY;
203 		goto unlock;
204 	}
205 	pnfs_set_layout_stateid(lo, &args->cbl_stateid, true);
206 	spin_unlock(&ino->i_lock);
207 
208 	pnfs_layoutcommit_inode(ino, false);
209 
210 	spin_lock(&ino->i_lock);
211 	/*
212 	 * Enforce RFC5661 Section 12.5.5.2.1.5 (Bulk Recall and Return)
213 	 */
214 	if (test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags)) {
215 		rv = NFS4ERR_DELAY;
216 		goto unlock;
217 	}
218 
219 	if (pnfs_mark_matching_lsegs_return(lo, &free_me_list,
220 				&args->cbl_range,
221 				be32_to_cpu(args->cbl_stateid.seqid))) {
222 		rv = NFS4_OK;
223 		goto unlock;
224 	}
225 
226 	if (NFS_SERVER(ino)->pnfs_curr_ld->return_range) {
227 		NFS_SERVER(ino)->pnfs_curr_ld->return_range(lo,
228 			&args->cbl_range);
229 	}
230 	pnfs_mark_layout_returned_if_empty(lo);
231 unlock:
232 	spin_unlock(&ino->i_lock);
233 	pnfs_free_lseg_list(&free_me_list);
234 	/* Free all lsegs that are attached to commit buckets */
235 	nfs_commit_inode(ino, 0);
236 	pnfs_put_layout_hdr(lo);
237 	trace_nfs4_cb_layoutrecall_file(clp, &args->cbl_fh, ino,
238 			&args->cbl_stateid, -rv);
239 	iput(ino);
240 out:
241 	return rv;
242 }
243 
244 static u32 initiate_bulk_draining(struct nfs_client *clp,
245 				  struct cb_layoutrecallargs *args)
246 {
247 	int stat;
248 
249 	if (args->cbl_recall_type == RETURN_FSID)
250 		stat = pnfs_destroy_layouts_byfsid(clp, &args->cbl_fsid, true);
251 	else
252 		stat = pnfs_destroy_layouts_byclid(clp, true);
253 	if (stat != 0)
254 		return NFS4ERR_DELAY;
255 	return NFS4ERR_NOMATCHING_LAYOUT;
256 }
257 
258 static u32 do_callback_layoutrecall(struct nfs_client *clp,
259 				    struct cb_layoutrecallargs *args)
260 {
261 	u32 res;
262 
263 	dprintk("%s enter, type=%i\n", __func__, args->cbl_recall_type);
264 	if (args->cbl_recall_type == RETURN_FILE)
265 		res = initiate_file_draining(clp, args);
266 	else
267 		res = initiate_bulk_draining(clp, args);
268 	dprintk("%s returning %i\n", __func__, res);
269 	return res;
270 
271 }
272 
273 __be32 nfs4_callback_layoutrecall(struct cb_layoutrecallargs *args,
274 				  void *dummy, struct cb_process_state *cps)
275 {
276 	u32 res;
277 
278 	dprintk("%s: -->\n", __func__);
279 
280 	if (cps->clp)
281 		res = do_callback_layoutrecall(cps->clp, args);
282 	else
283 		res = NFS4ERR_OP_NOT_IN_SESSION;
284 
285 	dprintk("%s: exit with status = %d\n", __func__, res);
286 	return cpu_to_be32(res);
287 }
288 
289 static void pnfs_recall_all_layouts(struct nfs_client *clp)
290 {
291 	struct cb_layoutrecallargs args;
292 
293 	/* Pretend we got a CB_LAYOUTRECALL(ALL) */
294 	memset(&args, 0, sizeof(args));
295 	args.cbl_recall_type = RETURN_ALL;
296 	/* FIXME we ignore errors, what should we do? */
297 	do_callback_layoutrecall(clp, &args);
298 }
299 
300 __be32 nfs4_callback_devicenotify(struct cb_devicenotifyargs *args,
301 				  void *dummy, struct cb_process_state *cps)
302 {
303 	int i;
304 	__be32 res = 0;
305 	struct nfs_client *clp = cps->clp;
306 	struct nfs_server *server = NULL;
307 
308 	dprintk("%s: -->\n", __func__);
309 
310 	if (!clp) {
311 		res = cpu_to_be32(NFS4ERR_OP_NOT_IN_SESSION);
312 		goto out;
313 	}
314 
315 	for (i = 0; i < args->ndevs; i++) {
316 		struct cb_devicenotifyitem *dev = &args->devs[i];
317 
318 		if (!server ||
319 		    server->pnfs_curr_ld->id != dev->cbd_layout_type) {
320 			rcu_read_lock();
321 			list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
322 				if (server->pnfs_curr_ld &&
323 				    server->pnfs_curr_ld->id == dev->cbd_layout_type) {
324 					rcu_read_unlock();
325 					goto found;
326 				}
327 			rcu_read_unlock();
328 			dprintk("%s: layout type %u not found\n",
329 				__func__, dev->cbd_layout_type);
330 			continue;
331 		}
332 
333 	found:
334 		nfs4_delete_deviceid(server->pnfs_curr_ld, clp, &dev->cbd_dev_id);
335 	}
336 
337 out:
338 	kfree(args->devs);
339 	dprintk("%s: exit with status = %u\n",
340 		__func__, be32_to_cpu(res));
341 	return res;
342 }
343 
344 /*
345  * Validate the sequenceID sent by the server.
346  * Return success if the sequenceID is one more than what we last saw on
347  * this slot, accounting for wraparound.  Increments the slot's sequence.
348  *
349  * We don't yet implement a duplicate request cache, instead we set the
350  * back channel ca_maxresponsesize_cached to zero. This is OK for now
351  * since we only currently implement idempotent callbacks anyway.
352  *
353  * We have a single slot backchannel at this time, so we don't bother
354  * checking the used_slots bit array on the table.  The lower layer guarantees
355  * a single outstanding callback request at a time.
356  */
357 static __be32
358 validate_seqid(const struct nfs4_slot_table *tbl, const struct nfs4_slot *slot,
359 		const struct cb_sequenceargs * args)
360 {
361 	dprintk("%s enter. slotid %u seqid %u, slot table seqid: %u\n",
362 		__func__, args->csa_slotid, args->csa_sequenceid, slot->seq_nr);
363 
364 	if (args->csa_slotid > tbl->server_highest_slotid)
365 		return htonl(NFS4ERR_BADSLOT);
366 
367 	/* Replay */
368 	if (args->csa_sequenceid == slot->seq_nr) {
369 		dprintk("%s seqid %u is a replay\n",
370 			__func__, args->csa_sequenceid);
371 		if (nfs4_test_locked_slot(tbl, slot->slot_nr))
372 			return htonl(NFS4ERR_DELAY);
373 		/* Signal process_op to set this error on next op */
374 		if (args->csa_cachethis == 0)
375 			return htonl(NFS4ERR_RETRY_UNCACHED_REP);
376 
377 		/* Liar! We never allowed you to set csa_cachethis != 0 */
378 		return htonl(NFS4ERR_SEQ_FALSE_RETRY);
379 	}
380 
381 	/* Wraparound */
382 	if (unlikely(slot->seq_nr == 0xFFFFFFFFU)) {
383 		if (args->csa_sequenceid == 1)
384 			return htonl(NFS4_OK);
385 	} else if (likely(args->csa_sequenceid == slot->seq_nr + 1))
386 		return htonl(NFS4_OK);
387 
388 	/* Misordered request */
389 	return htonl(NFS4ERR_SEQ_MISORDERED);
390 }
391 
392 /*
393  * For each referring call triple, check the session's slot table for
394  * a match.  If the slot is in use and the sequence numbers match, the
395  * client is still waiting for a response to the original request.
396  */
397 static bool referring_call_exists(struct nfs_client *clp,
398 				  uint32_t nrclists,
399 				  struct referring_call_list *rclists)
400 {
401 	bool status = 0;
402 	int i, j;
403 	struct nfs4_session *session;
404 	struct nfs4_slot_table *tbl;
405 	struct referring_call_list *rclist;
406 	struct referring_call *ref;
407 
408 	/*
409 	 * XXX When client trunking is implemented, this becomes
410 	 * a session lookup from within the loop
411 	 */
412 	session = clp->cl_session;
413 	tbl = &session->fc_slot_table;
414 
415 	for (i = 0; i < nrclists; i++) {
416 		rclist = &rclists[i];
417 		if (memcmp(session->sess_id.data,
418 			   rclist->rcl_sessionid.data,
419 			   NFS4_MAX_SESSIONID_LEN) != 0)
420 			continue;
421 
422 		for (j = 0; j < rclist->rcl_nrefcalls; j++) {
423 			ref = &rclist->rcl_refcalls[j];
424 
425 			dprintk("%s: sessionid %x:%x:%x:%x sequenceid %u "
426 				"slotid %u\n", __func__,
427 				((u32 *)&rclist->rcl_sessionid.data)[0],
428 				((u32 *)&rclist->rcl_sessionid.data)[1],
429 				((u32 *)&rclist->rcl_sessionid.data)[2],
430 				((u32 *)&rclist->rcl_sessionid.data)[3],
431 				ref->rc_sequenceid, ref->rc_slotid);
432 
433 			spin_lock(&tbl->slot_tbl_lock);
434 			status = (test_bit(ref->rc_slotid, tbl->used_slots) &&
435 				  tbl->slots[ref->rc_slotid].seq_nr ==
436 					ref->rc_sequenceid);
437 			spin_unlock(&tbl->slot_tbl_lock);
438 			if (status)
439 				goto out;
440 		}
441 	}
442 
443 out:
444 	return status;
445 }
446 
447 __be32 nfs4_callback_sequence(struct cb_sequenceargs *args,
448 			      struct cb_sequenceres *res,
449 			      struct cb_process_state *cps)
450 {
451 	struct nfs4_slot_table *tbl;
452 	struct nfs4_slot *slot;
453 	struct nfs_client *clp;
454 	int i;
455 	__be32 status = htonl(NFS4ERR_BADSESSION);
456 
457 	clp = nfs4_find_client_sessionid(cps->net, args->csa_addr,
458 					 &args->csa_sessionid, cps->minorversion);
459 	if (clp == NULL)
460 		goto out;
461 
462 	if (!(clp->cl_session->flags & SESSION4_BACK_CHAN))
463 		goto out;
464 
465 	tbl = &clp->cl_session->bc_slot_table;
466 	slot = tbl->slots + args->csa_slotid;
467 
468 	/* Set up res before grabbing the spinlock */
469 	memcpy(&res->csr_sessionid, &args->csa_sessionid,
470 	       sizeof(res->csr_sessionid));
471 	res->csr_sequenceid = args->csa_sequenceid;
472 	res->csr_slotid = args->csa_slotid;
473 
474 	spin_lock(&tbl->slot_tbl_lock);
475 	/* state manager is resetting the session */
476 	if (test_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state)) {
477 		status = htonl(NFS4ERR_DELAY);
478 		/* Return NFS4ERR_BADSESSION if we're draining the session
479 		 * in order to reset it.
480 		 */
481 		if (test_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state))
482 			status = htonl(NFS4ERR_BADSESSION);
483 		goto out_unlock;
484 	}
485 
486 	status = htonl(NFS4ERR_BADSLOT);
487 	slot = nfs4_lookup_slot(tbl, args->csa_slotid);
488 	if (IS_ERR(slot))
489 		goto out_unlock;
490 
491 	res->csr_highestslotid = tbl->server_highest_slotid;
492 	res->csr_target_highestslotid = tbl->target_highest_slotid;
493 
494 	status = validate_seqid(tbl, slot, args);
495 	if (status)
496 		goto out_unlock;
497 	if (!nfs4_try_to_lock_slot(tbl, slot)) {
498 		status = htonl(NFS4ERR_DELAY);
499 		goto out_unlock;
500 	}
501 	cps->slot = slot;
502 
503 	/* The ca_maxresponsesize_cached is 0 with no DRC */
504 	if (args->csa_cachethis != 0) {
505 		status = htonl(NFS4ERR_REP_TOO_BIG_TO_CACHE);
506 		goto out_unlock;
507 	}
508 
509 	/*
510 	 * Check for pending referring calls.  If a match is found, a
511 	 * related callback was received before the response to the original
512 	 * call.
513 	 */
514 	if (referring_call_exists(clp, args->csa_nrclists, args->csa_rclists)) {
515 		status = htonl(NFS4ERR_DELAY);
516 		goto out_unlock;
517 	}
518 
519 	/*
520 	 * RFC5661 20.9.3
521 	 * If CB_SEQUENCE returns an error, then the state of the slot
522 	 * (sequence ID, cached reply) MUST NOT change.
523 	 */
524 	slot->seq_nr = args->csa_sequenceid;
525 out_unlock:
526 	spin_unlock(&tbl->slot_tbl_lock);
527 
528 out:
529 	cps->clp = clp; /* put in nfs4_callback_compound */
530 	for (i = 0; i < args->csa_nrclists; i++)
531 		kfree(args->csa_rclists[i].rcl_refcalls);
532 	kfree(args->csa_rclists);
533 
534 	if (status == htonl(NFS4ERR_RETRY_UNCACHED_REP)) {
535 		cps->drc_status = status;
536 		status = 0;
537 	} else
538 		res->csr_status = status;
539 
540 	trace_nfs4_cb_sequence(args, res, status);
541 	dprintk("%s: exit with status = %d res->csr_status %d\n", __func__,
542 		ntohl(status), ntohl(res->csr_status));
543 	return status;
544 }
545 
546 static bool
547 validate_bitmap_values(unsigned long mask)
548 {
549 	return (mask & ~RCA4_TYPE_MASK_ALL) == 0;
550 }
551 
552 __be32 nfs4_callback_recallany(struct cb_recallanyargs *args, void *dummy,
553 			       struct cb_process_state *cps)
554 {
555 	__be32 status;
556 	fmode_t flags = 0;
557 
558 	status = cpu_to_be32(NFS4ERR_OP_NOT_IN_SESSION);
559 	if (!cps->clp) /* set in cb_sequence */
560 		goto out;
561 
562 	dprintk_rcu("NFS: RECALL_ANY callback request from %s\n",
563 		rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR));
564 
565 	status = cpu_to_be32(NFS4ERR_INVAL);
566 	if (!validate_bitmap_values(args->craa_type_mask))
567 		goto out;
568 
569 	status = cpu_to_be32(NFS4_OK);
570 	if (test_bit(RCA4_TYPE_MASK_RDATA_DLG, (const unsigned long *)
571 		     &args->craa_type_mask))
572 		flags = FMODE_READ;
573 	if (test_bit(RCA4_TYPE_MASK_WDATA_DLG, (const unsigned long *)
574 		     &args->craa_type_mask))
575 		flags |= FMODE_WRITE;
576 	if (test_bit(RCA4_TYPE_MASK_FILE_LAYOUT, (const unsigned long *)
577 		     &args->craa_type_mask))
578 		pnfs_recall_all_layouts(cps->clp);
579 	if (flags)
580 		nfs_expire_unused_delegation_types(cps->clp, flags);
581 out:
582 	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
583 	return status;
584 }
585 
586 /* Reduce the fore channel's max_slots to the target value */
587 __be32 nfs4_callback_recallslot(struct cb_recallslotargs *args, void *dummy,
588 				struct cb_process_state *cps)
589 {
590 	struct nfs4_slot_table *fc_tbl;
591 	__be32 status;
592 
593 	status = htonl(NFS4ERR_OP_NOT_IN_SESSION);
594 	if (!cps->clp) /* set in cb_sequence */
595 		goto out;
596 
597 	dprintk_rcu("NFS: CB_RECALL_SLOT request from %s target highest slotid %u\n",
598 		rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR),
599 		args->crsa_target_highest_slotid);
600 
601 	fc_tbl = &cps->clp->cl_session->fc_slot_table;
602 
603 	status = htonl(NFS4_OK);
604 
605 	nfs41_set_target_slotid(fc_tbl, args->crsa_target_highest_slotid);
606 	nfs41_notify_server(cps->clp);
607 out:
608 	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
609 	return status;
610 }
611 #endif /* CONFIG_NFS_V4_1 */
612