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#ifdef NFS_DEBUG
21#define NFSDBG_FACILITY NFSDBG_CALLBACK
22#endif
23
24__be32 nfs4_callback_getattr(struct cb_getattrargs *args,
25			     struct cb_getattrres *res,
26			     struct cb_process_state *cps)
27{
28	struct nfs_delegation *delegation;
29	struct nfs_inode *nfsi;
30	struct inode *inode;
31
32	res->status = htonl(NFS4ERR_OP_NOT_IN_SESSION);
33	if (!cps->clp) /* Always set for v4.0. Set in cb_sequence for v4.1 */
34		goto out;
35
36	res->bitmap[0] = res->bitmap[1] = 0;
37	res->status = htonl(NFS4ERR_BADHANDLE);
38
39	dprintk_rcu("NFS: GETATTR callback request from %s\n",
40		rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR));
41
42	inode = nfs_delegation_find_inode(cps->clp, &args->fh);
43	if (inode == NULL)
44		goto out;
45	nfsi = NFS_I(inode);
46	rcu_read_lock();
47	delegation = rcu_dereference(nfsi->delegation);
48	if (delegation == NULL || (delegation->type & FMODE_WRITE) == 0)
49		goto out_iput;
50	res->size = i_size_read(inode);
51	res->change_attr = delegation->change_attr;
52	if (nfsi->nrequests != 0)
53		res->change_attr++;
54	res->ctime = inode->i_ctime;
55	res->mtime = inode->i_mtime;
56	res->bitmap[0] = (FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE) &
57		args->bitmap[0];
58	res->bitmap[1] = (FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY) &
59		args->bitmap[1];
60	res->status = 0;
61out_iput:
62	rcu_read_unlock();
63	iput(inode);
64out:
65	dprintk("%s: exit with status = %d\n", __func__, ntohl(res->status));
66	return res->status;
67}
68
69__be32 nfs4_callback_recall(struct cb_recallargs *args, void *dummy,
70			    struct cb_process_state *cps)
71{
72	struct inode *inode;
73	__be32 res;
74
75	res = htonl(NFS4ERR_OP_NOT_IN_SESSION);
76	if (!cps->clp) /* Always set for v4.0. Set in cb_sequence for v4.1 */
77		goto out;
78
79	dprintk_rcu("NFS: RECALL callback request from %s\n",
80		rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR));
81
82	res = htonl(NFS4ERR_BADHANDLE);
83	inode = nfs_delegation_find_inode(cps->clp, &args->fh);
84	if (inode == NULL)
85		goto out;
86	/* Set up a helper thread to actually return the delegation */
87	switch (nfs_async_inode_return_delegation(inode, &args->stateid)) {
88	case 0:
89		res = 0;
90		break;
91	case -ENOENT:
92		res = htonl(NFS4ERR_BAD_STATEID);
93		break;
94	default:
95		res = htonl(NFS4ERR_RESOURCE);
96	}
97	trace_nfs4_recall_delegation(inode, -ntohl(res));
98	iput(inode);
99out:
100	dprintk("%s: exit with status = %d\n", __func__, ntohl(res));
101	return res;
102}
103
104#if defined(CONFIG_NFS_V4_1)
105
106/*
107 * Lookup a layout by filehandle.
108 *
109 * Note: gets a refcount on the layout hdr and on its respective inode.
110 * Caller must put the layout hdr and the inode.
111 *
112 * TODO: keep track of all layouts (and delegations) in a hash table
113 * hashed by filehandle.
114 */
115static struct pnfs_layout_hdr * get_layout_by_fh_locked(struct nfs_client *clp,
116		struct nfs_fh *fh, nfs4_stateid *stateid)
117{
118	struct nfs_server *server;
119	struct inode *ino;
120	struct pnfs_layout_hdr *lo;
121
122	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
123		list_for_each_entry(lo, &server->layouts, plh_layouts) {
124			if (!nfs4_stateid_match_other(&lo->plh_stateid, stateid))
125				continue;
126			if (nfs_compare_fh(fh, &NFS_I(lo->plh_inode)->fh))
127				continue;
128			ino = igrab(lo->plh_inode);
129			if (!ino)
130				break;
131			spin_lock(&ino->i_lock);
132			/* Is this layout in the process of being freed? */
133			if (NFS_I(ino)->layout != lo) {
134				spin_unlock(&ino->i_lock);
135				iput(ino);
136				break;
137			}
138			pnfs_get_layout_hdr(lo);
139			spin_unlock(&ino->i_lock);
140			return lo;
141		}
142	}
143
144	return NULL;
145}
146
147static struct pnfs_layout_hdr * get_layout_by_fh(struct nfs_client *clp,
148		struct nfs_fh *fh, nfs4_stateid *stateid)
149{
150	struct pnfs_layout_hdr *lo;
151
152	spin_lock(&clp->cl_lock);
153	rcu_read_lock();
154	lo = get_layout_by_fh_locked(clp, fh, stateid);
155	rcu_read_unlock();
156	spin_unlock(&clp->cl_lock);
157
158	return lo;
159}
160
161static u32 initiate_file_draining(struct nfs_client *clp,
162				  struct cb_layoutrecallargs *args)
163{
164	struct inode *ino;
165	struct pnfs_layout_hdr *lo;
166	u32 rv = NFS4ERR_NOMATCHING_LAYOUT;
167	LIST_HEAD(free_me_list);
168
169	lo = get_layout_by_fh(clp, &args->cbl_fh, &args->cbl_stateid);
170	if (!lo)
171		goto out;
172
173	ino = lo->plh_inode;
174
175	spin_lock(&ino->i_lock);
176	pnfs_set_layout_stateid(lo, &args->cbl_stateid, true);
177	spin_unlock(&ino->i_lock);
178
179	pnfs_layoutcommit_inode(ino, false);
180
181	spin_lock(&ino->i_lock);
182	if (test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags) ||
183	    pnfs_mark_matching_lsegs_invalid(lo, &free_me_list,
184					&args->cbl_range)) {
185		rv = NFS4ERR_DELAY;
186		goto unlock;
187	}
188
189	if (NFS_SERVER(ino)->pnfs_curr_ld->return_range) {
190		NFS_SERVER(ino)->pnfs_curr_ld->return_range(lo,
191			&args->cbl_range);
192	}
193unlock:
194	spin_unlock(&ino->i_lock);
195	pnfs_free_lseg_list(&free_me_list);
196	pnfs_put_layout_hdr(lo);
197	iput(ino);
198out:
199	return rv;
200}
201
202static u32 initiate_bulk_draining(struct nfs_client *clp,
203				  struct cb_layoutrecallargs *args)
204{
205	int stat;
206
207	if (args->cbl_recall_type == RETURN_FSID)
208		stat = pnfs_destroy_layouts_byfsid(clp, &args->cbl_fsid, true);
209	else
210		stat = pnfs_destroy_layouts_byclid(clp, true);
211	if (stat != 0)
212		return NFS4ERR_DELAY;
213	return NFS4ERR_NOMATCHING_LAYOUT;
214}
215
216static u32 do_callback_layoutrecall(struct nfs_client *clp,
217				    struct cb_layoutrecallargs *args)
218{
219	u32 res;
220
221	dprintk("%s enter, type=%i\n", __func__, args->cbl_recall_type);
222	if (args->cbl_recall_type == RETURN_FILE)
223		res = initiate_file_draining(clp, args);
224	else
225		res = initiate_bulk_draining(clp, args);
226	dprintk("%s returning %i\n", __func__, res);
227	return res;
228
229}
230
231__be32 nfs4_callback_layoutrecall(struct cb_layoutrecallargs *args,
232				  void *dummy, struct cb_process_state *cps)
233{
234	u32 res;
235
236	dprintk("%s: -->\n", __func__);
237
238	if (cps->clp)
239		res = do_callback_layoutrecall(cps->clp, args);
240	else
241		res = NFS4ERR_OP_NOT_IN_SESSION;
242
243	dprintk("%s: exit with status = %d\n", __func__, res);
244	return cpu_to_be32(res);
245}
246
247static void pnfs_recall_all_layouts(struct nfs_client *clp)
248{
249	struct cb_layoutrecallargs args;
250
251	/* Pretend we got a CB_LAYOUTRECALL(ALL) */
252	memset(&args, 0, sizeof(args));
253	args.cbl_recall_type = RETURN_ALL;
254	/* FIXME we ignore errors, what should we do? */
255	do_callback_layoutrecall(clp, &args);
256}
257
258__be32 nfs4_callback_devicenotify(struct cb_devicenotifyargs *args,
259				  void *dummy, struct cb_process_state *cps)
260{
261	int i;
262	__be32 res = 0;
263	struct nfs_client *clp = cps->clp;
264	struct nfs_server *server = NULL;
265
266	dprintk("%s: -->\n", __func__);
267
268	if (!clp) {
269		res = cpu_to_be32(NFS4ERR_OP_NOT_IN_SESSION);
270		goto out;
271	}
272
273	for (i = 0; i < args->ndevs; i++) {
274		struct cb_devicenotifyitem *dev = &args->devs[i];
275
276		if (!server ||
277		    server->pnfs_curr_ld->id != dev->cbd_layout_type) {
278			rcu_read_lock();
279			list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
280				if (server->pnfs_curr_ld &&
281				    server->pnfs_curr_ld->id == dev->cbd_layout_type) {
282					rcu_read_unlock();
283					goto found;
284				}
285			rcu_read_unlock();
286			dprintk("%s: layout type %u not found\n",
287				__func__, dev->cbd_layout_type);
288			continue;
289		}
290
291	found:
292		nfs4_delete_deviceid(server->pnfs_curr_ld, clp, &dev->cbd_dev_id);
293	}
294
295out:
296	kfree(args->devs);
297	dprintk("%s: exit with status = %u\n",
298		__func__, be32_to_cpu(res));
299	return res;
300}
301
302/*
303 * Validate the sequenceID sent by the server.
304 * Return success if the sequenceID is one more than what we last saw on
305 * this slot, accounting for wraparound.  Increments the slot's sequence.
306 *
307 * We don't yet implement a duplicate request cache, instead we set the
308 * back channel ca_maxresponsesize_cached to zero. This is OK for now
309 * since we only currently implement idempotent callbacks anyway.
310 *
311 * We have a single slot backchannel at this time, so we don't bother
312 * checking the used_slots bit array on the table.  The lower layer guarantees
313 * a single outstanding callback request at a time.
314 */
315static __be32
316validate_seqid(struct nfs4_slot_table *tbl, struct cb_sequenceargs * args)
317{
318	struct nfs4_slot *slot;
319
320	dprintk("%s enter. slotid %u seqid %u\n",
321		__func__, args->csa_slotid, args->csa_sequenceid);
322
323	if (args->csa_slotid >= NFS41_BC_MAX_CALLBACKS)
324		return htonl(NFS4ERR_BADSLOT);
325
326	slot = tbl->slots + args->csa_slotid;
327	dprintk("%s slot table seqid: %u\n", __func__, slot->seq_nr);
328
329	/* Normal */
330	if (likely(args->csa_sequenceid == slot->seq_nr + 1)) {
331		slot->seq_nr++;
332		goto out_ok;
333	}
334
335	/* Replay */
336	if (args->csa_sequenceid == slot->seq_nr) {
337		dprintk("%s seqid %u is a replay\n",
338			__func__, args->csa_sequenceid);
339		/* Signal process_op to set this error on next op */
340		if (args->csa_cachethis == 0)
341			return htonl(NFS4ERR_RETRY_UNCACHED_REP);
342
343		/* The ca_maxresponsesize_cached is 0 with no DRC */
344		else if (args->csa_cachethis == 1)
345			return htonl(NFS4ERR_REP_TOO_BIG_TO_CACHE);
346	}
347
348	/* Wraparound */
349	if (args->csa_sequenceid == 1 && (slot->seq_nr + 1) == 0) {
350		slot->seq_nr = 1;
351		goto out_ok;
352	}
353
354	/* Misordered request */
355	return htonl(NFS4ERR_SEQ_MISORDERED);
356out_ok:
357	tbl->highest_used_slotid = args->csa_slotid;
358	return htonl(NFS4_OK);
359}
360
361/*
362 * For each referring call triple, check the session's slot table for
363 * a match.  If the slot is in use and the sequence numbers match, the
364 * client is still waiting for a response to the original request.
365 */
366static bool referring_call_exists(struct nfs_client *clp,
367				  uint32_t nrclists,
368				  struct referring_call_list *rclists)
369{
370	bool status = 0;
371	int i, j;
372	struct nfs4_session *session;
373	struct nfs4_slot_table *tbl;
374	struct referring_call_list *rclist;
375	struct referring_call *ref;
376
377	/*
378	 * XXX When client trunking is implemented, this becomes
379	 * a session lookup from within the loop
380	 */
381	session = clp->cl_session;
382	tbl = &session->fc_slot_table;
383
384	for (i = 0; i < nrclists; i++) {
385		rclist = &rclists[i];
386		if (memcmp(session->sess_id.data,
387			   rclist->rcl_sessionid.data,
388			   NFS4_MAX_SESSIONID_LEN) != 0)
389			continue;
390
391		for (j = 0; j < rclist->rcl_nrefcalls; j++) {
392			ref = &rclist->rcl_refcalls[j];
393
394			dprintk("%s: sessionid %x:%x:%x:%x sequenceid %u "
395				"slotid %u\n", __func__,
396				((u32 *)&rclist->rcl_sessionid.data)[0],
397				((u32 *)&rclist->rcl_sessionid.data)[1],
398				((u32 *)&rclist->rcl_sessionid.data)[2],
399				((u32 *)&rclist->rcl_sessionid.data)[3],
400				ref->rc_sequenceid, ref->rc_slotid);
401
402			spin_lock(&tbl->slot_tbl_lock);
403			status = (test_bit(ref->rc_slotid, tbl->used_slots) &&
404				  tbl->slots[ref->rc_slotid].seq_nr ==
405					ref->rc_sequenceid);
406			spin_unlock(&tbl->slot_tbl_lock);
407			if (status)
408				goto out;
409		}
410	}
411
412out:
413	return status;
414}
415
416__be32 nfs4_callback_sequence(struct cb_sequenceargs *args,
417			      struct cb_sequenceres *res,
418			      struct cb_process_state *cps)
419{
420	struct nfs4_slot_table *tbl;
421	struct nfs_client *clp;
422	int i;
423	__be32 status = htonl(NFS4ERR_BADSESSION);
424
425	clp = nfs4_find_client_sessionid(cps->net, args->csa_addr,
426					 &args->csa_sessionid, cps->minorversion);
427	if (clp == NULL)
428		goto out;
429
430	if (!(clp->cl_session->flags & SESSION4_BACK_CHAN))
431		goto out;
432	tbl = &clp->cl_session->bc_slot_table;
433
434	spin_lock(&tbl->slot_tbl_lock);
435	/* state manager is resetting the session */
436	if (test_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state)) {
437		spin_unlock(&tbl->slot_tbl_lock);
438		status = htonl(NFS4ERR_DELAY);
439		/* Return NFS4ERR_BADSESSION if we're draining the session
440		 * in order to reset it.
441		 */
442		if (test_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state))
443			status = htonl(NFS4ERR_BADSESSION);
444		goto out;
445	}
446
447	status = validate_seqid(&clp->cl_session->bc_slot_table, args);
448	spin_unlock(&tbl->slot_tbl_lock);
449	if (status)
450		goto out;
451
452	cps->slotid = args->csa_slotid;
453
454	/*
455	 * Check for pending referring calls.  If a match is found, a
456	 * related callback was received before the response to the original
457	 * call.
458	 */
459	if (referring_call_exists(clp, args->csa_nrclists, args->csa_rclists)) {
460		status = htonl(NFS4ERR_DELAY);
461		goto out;
462	}
463
464	memcpy(&res->csr_sessionid, &args->csa_sessionid,
465	       sizeof(res->csr_sessionid));
466	res->csr_sequenceid = args->csa_sequenceid;
467	res->csr_slotid = args->csa_slotid;
468	res->csr_highestslotid = NFS41_BC_MAX_CALLBACKS - 1;
469	res->csr_target_highestslotid = NFS41_BC_MAX_CALLBACKS - 1;
470
471out:
472	cps->clp = clp; /* put in nfs4_callback_compound */
473	for (i = 0; i < args->csa_nrclists; i++)
474		kfree(args->csa_rclists[i].rcl_refcalls);
475	kfree(args->csa_rclists);
476
477	if (status == htonl(NFS4ERR_RETRY_UNCACHED_REP)) {
478		cps->drc_status = status;
479		status = 0;
480	} else
481		res->csr_status = status;
482
483	trace_nfs4_cb_sequence(args, res, status);
484	dprintk("%s: exit with status = %d res->csr_status %d\n", __func__,
485		ntohl(status), ntohl(res->csr_status));
486	return status;
487}
488
489static bool
490validate_bitmap_values(unsigned long mask)
491{
492	return (mask & ~RCA4_TYPE_MASK_ALL) == 0;
493}
494
495__be32 nfs4_callback_recallany(struct cb_recallanyargs *args, void *dummy,
496			       struct cb_process_state *cps)
497{
498	__be32 status;
499	fmode_t flags = 0;
500
501	status = cpu_to_be32(NFS4ERR_OP_NOT_IN_SESSION);
502	if (!cps->clp) /* set in cb_sequence */
503		goto out;
504
505	dprintk_rcu("NFS: RECALL_ANY callback request from %s\n",
506		rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR));
507
508	status = cpu_to_be32(NFS4ERR_INVAL);
509	if (!validate_bitmap_values(args->craa_type_mask))
510		goto out;
511
512	status = cpu_to_be32(NFS4_OK);
513	if (test_bit(RCA4_TYPE_MASK_RDATA_DLG, (const unsigned long *)
514		     &args->craa_type_mask))
515		flags = FMODE_READ;
516	if (test_bit(RCA4_TYPE_MASK_WDATA_DLG, (const unsigned long *)
517		     &args->craa_type_mask))
518		flags |= FMODE_WRITE;
519	if (test_bit(RCA4_TYPE_MASK_FILE_LAYOUT, (const unsigned long *)
520		     &args->craa_type_mask))
521		pnfs_recall_all_layouts(cps->clp);
522	if (flags)
523		nfs_expire_unused_delegation_types(cps->clp, flags);
524out:
525	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
526	return status;
527}
528
529/* Reduce the fore channel's max_slots to the target value */
530__be32 nfs4_callback_recallslot(struct cb_recallslotargs *args, void *dummy,
531				struct cb_process_state *cps)
532{
533	struct nfs4_slot_table *fc_tbl;
534	__be32 status;
535
536	status = htonl(NFS4ERR_OP_NOT_IN_SESSION);
537	if (!cps->clp) /* set in cb_sequence */
538		goto out;
539
540	dprintk_rcu("NFS: CB_RECALL_SLOT request from %s target highest slotid %u\n",
541		rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR),
542		args->crsa_target_highest_slotid);
543
544	fc_tbl = &cps->clp->cl_session->fc_slot_table;
545
546	status = htonl(NFS4_OK);
547
548	nfs41_set_target_slotid(fc_tbl, args->crsa_target_highest_slotid);
549	nfs41_server_notify_target_slotid_update(cps->clp);
550out:
551	dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
552	return status;
553}
554#endif /* CONFIG_NFS_V4_1 */
555