xref: /openbmc/linux/fs/nfs/callback_proc.c (revision 73eb94a0)
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 
18 #ifdef NFS_DEBUG
19 #define NFSDBG_FACILITY NFSDBG_CALLBACK
20 #endif
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 		goto out;
43 	nfsi = NFS_I(inode);
44 	rcu_read_lock();
45 	delegation = rcu_dereference(nfsi->delegation);
46 	if (delegation == NULL || (delegation->type & FMODE_WRITE) == 0)
47 		goto out_iput;
48 	res->size = i_size_read(inode);
49 	res->change_attr = delegation->change_attr;
50 	if (nfsi->npages != 0)
51 		res->change_attr++;
52 	res->ctime = inode->i_ctime;
53 	res->mtime = inode->i_mtime;
54 	res->bitmap[0] = (FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE) &
55 		args->bitmap[0];
56 	res->bitmap[1] = (FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY) &
57 		args->bitmap[1];
58 	res->status = 0;
59 out_iput:
60 	rcu_read_unlock();
61 	iput(inode);
62 out:
63 	dprintk("%s: exit with status = %d\n", __func__, ntohl(res->status));
64 	return res->status;
65 }
66 
67 __be32 nfs4_callback_recall(struct cb_recallargs *args, void *dummy,
68 			    struct cb_process_state *cps)
69 {
70 	struct inode *inode;
71 	__be32 res;
72 
73 	res = htonl(NFS4ERR_OP_NOT_IN_SESSION);
74 	if (!cps->clp) /* Always set for v4.0. Set in cb_sequence for v4.1 */
75 		goto out;
76 
77 	dprintk_rcu("NFS: RECALL callback request from %s\n",
78 		rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR));
79 
80 	res = htonl(NFS4ERR_BADHANDLE);
81 	inode = nfs_delegation_find_inode(cps->clp, &args->fh);
82 	if (inode == NULL)
83 		goto out;
84 	/* Set up a helper thread to actually return the delegation */
85 	switch (nfs_async_inode_return_delegation(inode, &args->stateid)) {
86 	case 0:
87 		res = 0;
88 		break;
89 	case -ENOENT:
90 		res = htonl(NFS4ERR_BAD_STATEID);
91 		break;
92 	default:
93 		res = htonl(NFS4ERR_RESOURCE);
94 	}
95 	iput(inode);
96 out:
97 	dprintk("%s: exit with status = %d\n", __func__, ntohl(res));
98 	return res;
99 }
100 
101 #if defined(CONFIG_NFS_V4_1)
102 
103 /*
104  * Lookup a layout by filehandle.
105  *
106  * Note: gets a refcount on the layout hdr and on its respective inode.
107  * Caller must put the layout hdr and the inode.
108  *
109  * TODO: keep track of all layouts (and delegations) in a hash table
110  * hashed by filehandle.
111  */
112 static struct pnfs_layout_hdr * get_layout_by_fh_locked(struct nfs_client *clp, struct nfs_fh *fh)
113 {
114 	struct nfs_server *server;
115 	struct inode *ino;
116 	struct pnfs_layout_hdr *lo;
117 
118 	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
119 		list_for_each_entry(lo, &server->layouts, plh_layouts) {
120 			if (nfs_compare_fh(fh, &NFS_I(lo->plh_inode)->fh))
121 				continue;
122 			ino = igrab(lo->plh_inode);
123 			if (!ino)
124 				continue;
125 			get_layout_hdr(lo);
126 			return lo;
127 		}
128 	}
129 
130 	return NULL;
131 }
132 
133 static struct pnfs_layout_hdr * get_layout_by_fh(struct nfs_client *clp, struct nfs_fh *fh)
134 {
135 	struct pnfs_layout_hdr *lo;
136 
137 	spin_lock(&clp->cl_lock);
138 	rcu_read_lock();
139 	lo = get_layout_by_fh_locked(clp, fh);
140 	rcu_read_unlock();
141 	spin_unlock(&clp->cl_lock);
142 
143 	return lo;
144 }
145 
146 static u32 initiate_file_draining(struct nfs_client *clp,
147 				  struct cb_layoutrecallargs *args)
148 {
149 	struct inode *ino;
150 	struct pnfs_layout_hdr *lo;
151 	u32 rv = NFS4ERR_NOMATCHING_LAYOUT;
152 	LIST_HEAD(free_me_list);
153 
154 	lo = get_layout_by_fh(clp, &args->cbl_fh);
155 	if (!lo)
156 		return NFS4ERR_NOMATCHING_LAYOUT;
157 
158 	ino = lo->plh_inode;
159 	spin_lock(&ino->i_lock);
160 	if (test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags) ||
161 	    mark_matching_lsegs_invalid(lo, &free_me_list,
162 					&args->cbl_range))
163 		rv = NFS4ERR_DELAY;
164 	else
165 		rv = NFS4ERR_NOMATCHING_LAYOUT;
166 	pnfs_set_layout_stateid(lo, &args->cbl_stateid, true);
167 	spin_unlock(&ino->i_lock);
168 	pnfs_free_lseg_list(&free_me_list);
169 	put_layout_hdr(lo);
170 	iput(ino);
171 	return rv;
172 }
173 
174 static u32 initiate_bulk_draining(struct nfs_client *clp,
175 				  struct cb_layoutrecallargs *args)
176 {
177 	struct nfs_server *server;
178 	struct pnfs_layout_hdr *lo;
179 	struct inode *ino;
180 	u32 rv = NFS4ERR_NOMATCHING_LAYOUT;
181 	struct pnfs_layout_hdr *tmp;
182 	LIST_HEAD(recall_list);
183 	LIST_HEAD(free_me_list);
184 	struct pnfs_layout_range range = {
185 		.iomode = IOMODE_ANY,
186 		.offset = 0,
187 		.length = NFS4_MAX_UINT64,
188 	};
189 
190 	spin_lock(&clp->cl_lock);
191 	rcu_read_lock();
192 	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
193 		if ((args->cbl_recall_type == RETURN_FSID) &&
194 		    memcmp(&server->fsid, &args->cbl_fsid,
195 			   sizeof(struct nfs_fsid)))
196 			continue;
197 
198 		list_for_each_entry(lo, &server->layouts, plh_layouts) {
199 			if (!igrab(lo->plh_inode))
200 				continue;
201 			get_layout_hdr(lo);
202 			BUG_ON(!list_empty(&lo->plh_bulk_recall));
203 			list_add(&lo->plh_bulk_recall, &recall_list);
204 		}
205 	}
206 	rcu_read_unlock();
207 	spin_unlock(&clp->cl_lock);
208 
209 	list_for_each_entry_safe(lo, tmp,
210 				 &recall_list, plh_bulk_recall) {
211 		ino = lo->plh_inode;
212 		spin_lock(&ino->i_lock);
213 		set_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags);
214 		if (mark_matching_lsegs_invalid(lo, &free_me_list, &range))
215 			rv = NFS4ERR_DELAY;
216 		list_del_init(&lo->plh_bulk_recall);
217 		spin_unlock(&ino->i_lock);
218 		pnfs_free_lseg_list(&free_me_list);
219 		put_layout_hdr(lo);
220 		iput(ino);
221 	}
222 	return rv;
223 }
224 
225 static u32 do_callback_layoutrecall(struct nfs_client *clp,
226 				    struct cb_layoutrecallargs *args)
227 {
228 	u32 res;
229 
230 	dprintk("%s enter, type=%i\n", __func__, args->cbl_recall_type);
231 	if (args->cbl_recall_type == RETURN_FILE)
232 		res = initiate_file_draining(clp, args);
233 	else
234 		res = initiate_bulk_draining(clp, args);
235 	dprintk("%s returning %i\n", __func__, res);
236 	return res;
237 
238 }
239 
240 __be32 nfs4_callback_layoutrecall(struct cb_layoutrecallargs *args,
241 				  void *dummy, struct cb_process_state *cps)
242 {
243 	u32 res;
244 
245 	dprintk("%s: -->\n", __func__);
246 
247 	if (cps->clp)
248 		res = do_callback_layoutrecall(cps->clp, args);
249 	else
250 		res = NFS4ERR_OP_NOT_IN_SESSION;
251 
252 	dprintk("%s: exit with status = %d\n", __func__, res);
253 	return cpu_to_be32(res);
254 }
255 
256 static void pnfs_recall_all_layouts(struct nfs_client *clp)
257 {
258 	struct cb_layoutrecallargs args;
259 
260 	/* Pretend we got a CB_LAYOUTRECALL(ALL) */
261 	memset(&args, 0, sizeof(args));
262 	args.cbl_recall_type = RETURN_ALL;
263 	/* FIXME we ignore errors, what should we do? */
264 	do_callback_layoutrecall(clp, &args);
265 }
266 
267 __be32 nfs4_callback_devicenotify(struct cb_devicenotifyargs *args,
268 				  void *dummy, struct cb_process_state *cps)
269 {
270 	int i;
271 	__be32 res = 0;
272 	struct nfs_client *clp = cps->clp;
273 	struct nfs_server *server = NULL;
274 
275 	dprintk("%s: -->\n", __func__);
276 
277 	if (!clp) {
278 		res = cpu_to_be32(NFS4ERR_OP_NOT_IN_SESSION);
279 		goto out;
280 	}
281 
282 	for (i = 0; i < args->ndevs; i++) {
283 		struct cb_devicenotifyitem *dev = &args->devs[i];
284 
285 		if (!server ||
286 		    server->pnfs_curr_ld->id != dev->cbd_layout_type) {
287 			rcu_read_lock();
288 			list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
289 				if (server->pnfs_curr_ld &&
290 				    server->pnfs_curr_ld->id == dev->cbd_layout_type) {
291 					rcu_read_unlock();
292 					goto found;
293 				}
294 			rcu_read_unlock();
295 			dprintk("%s: layout type %u not found\n",
296 				__func__, dev->cbd_layout_type);
297 			continue;
298 		}
299 
300 	found:
301 		if (dev->cbd_notify_type == NOTIFY_DEVICEID4_CHANGE)
302 			dprintk("%s: NOTIFY_DEVICEID4_CHANGE not supported, "
303 				"deleting instead\n", __func__);
304 		nfs4_delete_deviceid(server->pnfs_curr_ld, clp, &dev->cbd_dev_id);
305 	}
306 
307 out:
308 	kfree(args->devs);
309 	dprintk("%s: exit with status = %u\n",
310 		__func__, be32_to_cpu(res));
311 	return res;
312 }
313 
314 /*
315  * Validate the sequenceID sent by the server.
316  * Return success if the sequenceID is one more than what we last saw on
317  * this slot, accounting for wraparound.  Increments the slot's sequence.
318  *
319  * We don't yet implement a duplicate request cache, instead we set the
320  * back channel ca_maxresponsesize_cached to zero. This is OK for now
321  * since we only currently implement idempotent callbacks anyway.
322  *
323  * We have a single slot backchannel at this time, so we don't bother
324  * checking the used_slots bit array on the table.  The lower layer guarantees
325  * a single outstanding callback request at a time.
326  */
327 static __be32
328 validate_seqid(struct nfs4_slot_table *tbl, struct cb_sequenceargs * args)
329 {
330 	struct nfs4_slot *slot;
331 
332 	dprintk("%s enter. slotid %d seqid %d\n",
333 		__func__, args->csa_slotid, args->csa_sequenceid);
334 
335 	if (args->csa_slotid >= NFS41_BC_MAX_CALLBACKS)
336 		return htonl(NFS4ERR_BADSLOT);
337 
338 	slot = tbl->slots + args->csa_slotid;
339 	dprintk("%s slot table seqid: %d\n", __func__, slot->seq_nr);
340 
341 	/* Normal */
342 	if (likely(args->csa_sequenceid == slot->seq_nr + 1)) {
343 		slot->seq_nr++;
344 		goto out_ok;
345 	}
346 
347 	/* Replay */
348 	if (args->csa_sequenceid == slot->seq_nr) {
349 		dprintk("%s seqid %d is a replay\n",
350 			__func__, args->csa_sequenceid);
351 		/* Signal process_op to set this error on next op */
352 		if (args->csa_cachethis == 0)
353 			return htonl(NFS4ERR_RETRY_UNCACHED_REP);
354 
355 		/* The ca_maxresponsesize_cached is 0 with no DRC */
356 		else if (args->csa_cachethis == 1)
357 			return htonl(NFS4ERR_REP_TOO_BIG_TO_CACHE);
358 	}
359 
360 	/* Wraparound */
361 	if (args->csa_sequenceid == 1 && (slot->seq_nr + 1) == 0) {
362 		slot->seq_nr = 1;
363 		goto out_ok;
364 	}
365 
366 	/* Misordered request */
367 	return htonl(NFS4ERR_SEQ_MISORDERED);
368 out_ok:
369 	tbl->highest_used_slotid = args->csa_slotid;
370 	return htonl(NFS4_OK);
371 }
372 
373 /*
374  * For each referring call triple, check the session's slot table for
375  * a match.  If the slot is in use and the sequence numbers match, the
376  * client is still waiting for a response to the original request.
377  */
378 static bool referring_call_exists(struct nfs_client *clp,
379 				  uint32_t nrclists,
380 				  struct referring_call_list *rclists)
381 {
382 	bool status = 0;
383 	int i, j;
384 	struct nfs4_session *session;
385 	struct nfs4_slot_table *tbl;
386 	struct referring_call_list *rclist;
387 	struct referring_call *ref;
388 
389 	/*
390 	 * XXX When client trunking is implemented, this becomes
391 	 * a session lookup from within the loop
392 	 */
393 	session = clp->cl_session;
394 	tbl = &session->fc_slot_table;
395 
396 	for (i = 0; i < nrclists; i++) {
397 		rclist = &rclists[i];
398 		if (memcmp(session->sess_id.data,
399 			   rclist->rcl_sessionid.data,
400 			   NFS4_MAX_SESSIONID_LEN) != 0)
401 			continue;
402 
403 		for (j = 0; j < rclist->rcl_nrefcalls; j++) {
404 			ref = &rclist->rcl_refcalls[j];
405 
406 			dprintk("%s: sessionid %x:%x:%x:%x sequenceid %u "
407 				"slotid %u\n", __func__,
408 				((u32 *)&rclist->rcl_sessionid.data)[0],
409 				((u32 *)&rclist->rcl_sessionid.data)[1],
410 				((u32 *)&rclist->rcl_sessionid.data)[2],
411 				((u32 *)&rclist->rcl_sessionid.data)[3],
412 				ref->rc_sequenceid, ref->rc_slotid);
413 
414 			spin_lock(&tbl->slot_tbl_lock);
415 			status = (test_bit(ref->rc_slotid, tbl->used_slots) &&
416 				  tbl->slots[ref->rc_slotid].seq_nr ==
417 					ref->rc_sequenceid);
418 			spin_unlock(&tbl->slot_tbl_lock);
419 			if (status)
420 				goto out;
421 		}
422 	}
423 
424 out:
425 	return status;
426 }
427 
428 __be32 nfs4_callback_sequence(struct cb_sequenceargs *args,
429 			      struct cb_sequenceres *res,
430 			      struct cb_process_state *cps)
431 {
432 	struct nfs4_slot_table *tbl;
433 	struct nfs_client *clp;
434 	int i;
435 	__be32 status = htonl(NFS4ERR_BADSESSION);
436 
437 	clp = nfs4_find_client_sessionid(cps->net, args->csa_addr, &args->csa_sessionid);
438 	if (clp == NULL)
439 		goto out;
440 
441 	tbl = &clp->cl_session->bc_slot_table;
442 
443 	spin_lock(&tbl->slot_tbl_lock);
444 	/* state manager is resetting the session */
445 	if (test_bit(NFS4_SESSION_DRAINING, &clp->cl_session->session_state)) {
446 		spin_unlock(&tbl->slot_tbl_lock);
447 		status = htonl(NFS4ERR_DELAY);
448 		/* Return NFS4ERR_BADSESSION if we're draining the session
449 		 * in order to reset it.
450 		 */
451 		if (test_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state))
452 			status = htonl(NFS4ERR_BADSESSION);
453 		goto out;
454 	}
455 
456 	status = validate_seqid(&clp->cl_session->bc_slot_table, args);
457 	spin_unlock(&tbl->slot_tbl_lock);
458 	if (status)
459 		goto out;
460 
461 	cps->slotid = args->csa_slotid;
462 
463 	/*
464 	 * Check for pending referring calls.  If a match is found, a
465 	 * related callback was received before the response to the original
466 	 * call.
467 	 */
468 	if (referring_call_exists(clp, args->csa_nrclists, args->csa_rclists)) {
469 		status = htonl(NFS4ERR_DELAY);
470 		goto out;
471 	}
472 
473 	memcpy(&res->csr_sessionid, &args->csa_sessionid,
474 	       sizeof(res->csr_sessionid));
475 	res->csr_sequenceid = args->csa_sequenceid;
476 	res->csr_slotid = args->csa_slotid;
477 	res->csr_highestslotid = NFS41_BC_MAX_CALLBACKS - 1;
478 	res->csr_target_highestslotid = NFS41_BC_MAX_CALLBACKS - 1;
479 
480 out:
481 	cps->clp = clp; /* put in nfs4_callback_compound */
482 	for (i = 0; i < args->csa_nrclists; i++)
483 		kfree(args->csa_rclists[i].rcl_refcalls);
484 	kfree(args->csa_rclists);
485 
486 	if (status == htonl(NFS4ERR_RETRY_UNCACHED_REP)) {
487 		cps->drc_status = status;
488 		status = 0;
489 	} else
490 		res->csr_status = status;
491 
492 	dprintk("%s: exit with status = %d res->csr_status %d\n", __func__,
493 		ntohl(status), ntohl(res->csr_status));
494 	return status;
495 }
496 
497 static bool
498 validate_bitmap_values(unsigned long mask)
499 {
500 	return (mask & ~RCA4_TYPE_MASK_ALL) == 0;
501 }
502 
503 __be32 nfs4_callback_recallany(struct cb_recallanyargs *args, void *dummy,
504 			       struct cb_process_state *cps)
505 {
506 	__be32 status;
507 	fmode_t flags = 0;
508 
509 	status = cpu_to_be32(NFS4ERR_OP_NOT_IN_SESSION);
510 	if (!cps->clp) /* set in cb_sequence */
511 		goto out;
512 
513 	dprintk_rcu("NFS: RECALL_ANY callback request from %s\n",
514 		rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR));
515 
516 	status = cpu_to_be32(NFS4ERR_INVAL);
517 	if (!validate_bitmap_values(args->craa_type_mask))
518 		goto out;
519 
520 	status = cpu_to_be32(NFS4_OK);
521 	if (test_bit(RCA4_TYPE_MASK_RDATA_DLG, (const unsigned long *)
522 		     &args->craa_type_mask))
523 		flags = FMODE_READ;
524 	if (test_bit(RCA4_TYPE_MASK_WDATA_DLG, (const unsigned long *)
525 		     &args->craa_type_mask))
526 		flags |= FMODE_WRITE;
527 	if (test_bit(RCA4_TYPE_MASK_FILE_LAYOUT, (const unsigned long *)
528 		     &args->craa_type_mask))
529 		pnfs_recall_all_layouts(cps->clp);
530 	if (flags)
531 		nfs_expire_all_delegation_types(cps->clp, flags);
532 out:
533 	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
534 	return status;
535 }
536 
537 /* Reduce the fore channel's max_slots to the target value */
538 __be32 nfs4_callback_recallslot(struct cb_recallslotargs *args, void *dummy,
539 				struct cb_process_state *cps)
540 {
541 	struct nfs4_slot_table *fc_tbl;
542 	__be32 status;
543 
544 	status = htonl(NFS4ERR_OP_NOT_IN_SESSION);
545 	if (!cps->clp) /* set in cb_sequence */
546 		goto out;
547 
548 	dprintk_rcu("NFS: CB_RECALL_SLOT request from %s target max slots %d\n",
549 		rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR),
550 		args->crsa_target_max_slots);
551 
552 	fc_tbl = &cps->clp->cl_session->fc_slot_table;
553 
554 	status = htonl(NFS4ERR_BAD_HIGH_SLOT);
555 	if (args->crsa_target_max_slots > fc_tbl->max_slots ||
556 	    args->crsa_target_max_slots < 1)
557 		goto out;
558 
559 	status = htonl(NFS4_OK);
560 	if (args->crsa_target_max_slots == fc_tbl->max_slots)
561 		goto out;
562 
563 	fc_tbl->target_max_slots = args->crsa_target_max_slots;
564 	nfs41_handle_recall_slot(cps->clp);
565 out:
566 	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
567 	return status;
568 }
569 #endif /* CONFIG_NFS_V4_1 */
570