NFS: Fix a potential busy wait in nfs_page_group_lock
[linux-2.6-block.git] / fs / nfs / callback_proc.c
CommitLineData
1da177e4
LT
1/*
2 * linux/fs/nfs/callback_proc.c
3 *
4 * Copyright (C) 2004 Trond Myklebust
5 *
6 * NFSv4 callback procedures
7 */
1da177e4
LT
8#include <linux/nfs4.h>
9#include <linux/nfs_fs.h>
5a0e3ad6 10#include <linux/slab.h>
2446ab60 11#include <linux/rcupdate.h>
4ce79717 12#include "nfs4_fs.h"
1da177e4
LT
13#include "callback.h"
14#include "delegation.h"
24c8dbbb 15#include "internal.h"
43f1b3da 16#include "pnfs.h"
73e39aaa 17#include "nfs4session.h"
ca8acf8d 18#include "nfs4trace.h"
1da177e4 19
1d98fe67 20#ifdef NFS_DEBUG
1da177e4 21#define NFSDBG_FACILITY NFSDBG_CALLBACK
1d98fe67 22#endif
c36fca52
AA
23
24__be32 nfs4_callback_getattr(struct cb_getattrargs *args,
25 struct cb_getattrres *res,
26 struct cb_process_state *cps)
1da177e4 27{
1da177e4
LT
28 struct nfs_delegation *delegation;
29 struct nfs_inode *nfsi;
30 struct inode *inode;
1d98fe67 31
c36fca52
AA
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
1da177e4
LT
36 res->bitmap[0] = res->bitmap[1] = 0;
37 res->status = htonl(NFS4ERR_BADHANDLE);
1d98fe67 38
2446ab60 39 dprintk_rcu("NFS: GETATTR callback request from %s\n",
c36fca52 40 rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR));
1d98fe67 41
c36fca52 42 inode = nfs_delegation_find_inode(cps->clp, &args->fh);
1da177e4 43 if (inode == NULL)
c36fca52 44 goto out;
1da177e4 45 nfsi = NFS_I(inode);
761fe93c
TM
46 rcu_read_lock();
47 delegation = rcu_dereference(nfsi->delegation);
1da177e4
LT
48 if (delegation == NULL || (delegation->type & FMODE_WRITE) == 0)
49 goto out_iput;
50 res->size = i_size_read(inode);
beb2a5ec
TM
51 res->change_attr = delegation->change_attr;
52 if (nfsi->npages != 0)
53 res->change_attr++;
1da177e4
LT
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:
761fe93c 62 rcu_read_unlock();
1da177e4 63 iput(inode);
1da177e4 64out:
3110ff80 65 dprintk("%s: exit with status = %d\n", __func__, ntohl(res->status));
1da177e4
LT
66 return res->status;
67}
68
c36fca52
AA
69__be32 nfs4_callback_recall(struct cb_recallargs *args, void *dummy,
70 struct cb_process_state *cps)
1da177e4 71{
1da177e4 72 struct inode *inode;
e6f684f6 73 __be32 res;
1da177e4 74
c36fca52
AA
75 res = htonl(NFS4ERR_OP_NOT_IN_SESSION);
76 if (!cps->clp) /* Always set for v4.0. Set in cb_sequence for v4.1 */
1da177e4 77 goto out;
1d98fe67 78
2446ab60 79 dprintk_rcu("NFS: RECALL callback request from %s\n",
c36fca52
AA
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:
8e663f0e 92 res = htonl(NFS4ERR_BAD_STATEID);
c36fca52
AA
93 break;
94 default:
95 res = htonl(NFS4ERR_RESOURCE);
96 }
ca8acf8d 97 trace_nfs4_recall_delegation(inode, -ntohl(res));
c36fca52 98 iput(inode);
1da177e4 99out:
3110ff80 100 dprintk("%s: exit with status = %d\n", __func__, ntohl(res));
1da177e4
LT
101 return res;
102}
d49433e1
BH
103
104#if defined(CONFIG_NFS_V4_1)
105
d36b7cf7
BH
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 */
27999f25
TM
115static struct pnfs_layout_hdr * get_layout_by_fh_locked(struct nfs_client *clp,
116 struct nfs_fh *fh, nfs4_stateid *stateid)
43f1b3da 117{
6382a441 118 struct nfs_server *server;
43f1b3da 119 struct inode *ino;
d36b7cf7 120 struct pnfs_layout_hdr *lo;
43f1b3da 121
6382a441
WAA
122 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
123 list_for_each_entry(lo, &server->layouts, plh_layouts) {
27999f25
TM
124 if (!nfs4_stateid_match_other(&lo->plh_stateid, stateid))
125 continue;
d36b7cf7 126 if (nfs_compare_fh(fh, &NFS_I(lo->plh_inode)->fh))
6382a441
WAA
127 continue;
128 ino = igrab(lo->plh_inode);
129 if (!ino)
9a7fe9e8 130 break;
9c626381
TM
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);
9a7fe9e8 136 break;
9c626381 137 }
70c3bd2b 138 pnfs_get_layout_hdr(lo);
9c626381 139 spin_unlock(&ino->i_lock);
d36b7cf7 140 return lo;
6382a441 141 }
43f1b3da 142 }
d36b7cf7
BH
143
144 return NULL;
145}
146
27999f25
TM
147static struct pnfs_layout_hdr * get_layout_by_fh(struct nfs_client *clp,
148 struct nfs_fh *fh, nfs4_stateid *stateid)
d36b7cf7
BH
149{
150 struct pnfs_layout_hdr *lo;
151
152 spin_lock(&clp->cl_lock);
153 rcu_read_lock();
27999f25 154 lo = get_layout_by_fh_locked(clp, fh, stateid);
6382a441 155 rcu_read_unlock();
43f1b3da 156 spin_unlock(&clp->cl_lock);
6382a441 157
d36b7cf7
BH
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
27999f25 169 lo = get_layout_by_fh(clp, &args->cbl_fh, &args->cbl_stateid);
d36b7cf7 170 if (!lo)
27999f25 171 goto out;
43f1b3da 172
d36b7cf7 173 ino = lo->plh_inode;
43f1b3da
FI
174 spin_lock(&ino->i_lock);
175 if (test_bit(NFS_LAYOUT_BULK_RECALL, &lo->plh_flags) ||
49a85061 176 pnfs_mark_matching_lsegs_invalid(lo, &free_me_list,
778b5502 177 &args->cbl_range))
43f1b3da
FI
178 rv = NFS4ERR_DELAY;
179 else
180 rv = NFS4ERR_NOMATCHING_LAYOUT;
181 pnfs_set_layout_stateid(lo, &args->cbl_stateid, true);
182 spin_unlock(&ino->i_lock);
183 pnfs_free_lseg_list(&free_me_list);
70c3bd2b 184 pnfs_put_layout_hdr(lo);
43f1b3da 185 iput(ino);
27999f25 186out:
43f1b3da
FI
187 return rv;
188}
189
190static u32 initiate_bulk_draining(struct nfs_client *clp,
191 struct cb_layoutrecallargs *args)
192{
fd9a8d71 193 int stat;
6382a441 194
fd9a8d71
TM
195 if (args->cbl_recall_type == RETURN_FSID)
196 stat = pnfs_destroy_layouts_byfsid(clp, &args->cbl_fsid, true);
197 else
198 stat = pnfs_destroy_layouts_byclid(clp, true);
199 if (stat != 0)
200 return NFS4ERR_DELAY;
201 return NFS4ERR_NOMATCHING_LAYOUT;
43f1b3da
FI
202}
203
204static u32 do_callback_layoutrecall(struct nfs_client *clp,
205 struct cb_layoutrecallargs *args)
206{
0cb3284b 207 u32 res;
43f1b3da
FI
208
209 dprintk("%s enter, type=%i\n", __func__, args->cbl_recall_type);
43f1b3da
FI
210 if (args->cbl_recall_type == RETURN_FILE)
211 res = initiate_file_draining(clp, args);
212 else
213 res = initiate_bulk_draining(clp, args);
43f1b3da
FI
214 dprintk("%s returning %i\n", __func__, res);
215 return res;
216
217}
218
f2a62561
FI
219__be32 nfs4_callback_layoutrecall(struct cb_layoutrecallargs *args,
220 void *dummy, struct cb_process_state *cps)
221{
43f1b3da
FI
222 u32 res;
223
224 dprintk("%s: -->\n", __func__);
225
226 if (cps->clp)
227 res = do_callback_layoutrecall(cps->clp, args);
228 else
229 res = NFS4ERR_OP_NOT_IN_SESSION;
230
231 dprintk("%s: exit with status = %d\n", __func__, res);
232 return cpu_to_be32(res);
f2a62561
FI
233}
234
36840370
AB
235static void pnfs_recall_all_layouts(struct nfs_client *clp)
236{
237 struct cb_layoutrecallargs args;
238
239 /* Pretend we got a CB_LAYOUTRECALL(ALL) */
240 memset(&args, 0, sizeof(args));
241 args.cbl_recall_type = RETURN_ALL;
242 /* FIXME we ignore errors, what should we do? */
243 do_callback_layoutrecall(clp, &args);
244}
245
1be5683b
ME
246__be32 nfs4_callback_devicenotify(struct cb_devicenotifyargs *args,
247 void *dummy, struct cb_process_state *cps)
248{
249 int i;
250 __be32 res = 0;
251 struct nfs_client *clp = cps->clp;
252 struct nfs_server *server = NULL;
253
254 dprintk("%s: -->\n", __func__);
255
256 if (!clp) {
257 res = cpu_to_be32(NFS4ERR_OP_NOT_IN_SESSION);
258 goto out;
259 }
260
261 for (i = 0; i < args->ndevs; i++) {
262 struct cb_devicenotifyitem *dev = &args->devs[i];
263
264 if (!server ||
265 server->pnfs_curr_ld->id != dev->cbd_layout_type) {
266 rcu_read_lock();
267 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
268 if (server->pnfs_curr_ld &&
269 server->pnfs_curr_ld->id == dev->cbd_layout_type) {
270 rcu_read_unlock();
271 goto found;
272 }
273 rcu_read_unlock();
274 dprintk("%s: layout type %u not found\n",
275 __func__, dev->cbd_layout_type);
276 continue;
277 }
278
279 found:
280 if (dev->cbd_notify_type == NOTIFY_DEVICEID4_CHANGE)
281 dprintk("%s: NOTIFY_DEVICEID4_CHANGE not supported, "
282 "deleting instead\n", __func__);
35c8bb54 283 nfs4_delete_deviceid(server->pnfs_curr_ld, clp, &dev->cbd_dev_id);
1be5683b
ME
284 }
285
286out:
287 kfree(args->devs);
288 dprintk("%s: exit with status = %u\n",
289 __func__, be32_to_cpu(res));
290 return res;
291}
292
68f3f901
RL
293/*
294 * Validate the sequenceID sent by the server.
295 * Return success if the sequenceID is one more than what we last saw on
296 * this slot, accounting for wraparound. Increments the slot's sequence.
297 *
4911096f
AA
298 * We don't yet implement a duplicate request cache, instead we set the
299 * back channel ca_maxresponsesize_cached to zero. This is OK for now
68f3f901
RL
300 * since we only currently implement idempotent callbacks anyway.
301 *
302 * We have a single slot backchannel at this time, so we don't bother
303 * checking the used_slots bit array on the table. The lower layer guarantees
304 * a single outstanding callback request at a time.
305 */
9733f0d9 306static __be32
b2f28bd7 307validate_seqid(struct nfs4_slot_table *tbl, struct cb_sequenceargs * args)
68f3f901
RL
308{
309 struct nfs4_slot *slot;
310
e8d92382 311 dprintk("%s enter. slotid %u seqid %u\n",
b2f28bd7 312 __func__, args->csa_slotid, args->csa_sequenceid);
68f3f901 313
61f2e510 314 if (args->csa_slotid >= NFS41_BC_MAX_CALLBACKS)
68f3f901
RL
315 return htonl(NFS4ERR_BADSLOT);
316
b2f28bd7 317 slot = tbl->slots + args->csa_slotid;
e8d92382 318 dprintk("%s slot table seqid: %u\n", __func__, slot->seq_nr);
68f3f901
RL
319
320 /* Normal */
b2f28bd7 321 if (likely(args->csa_sequenceid == slot->seq_nr + 1)) {
68f3f901 322 slot->seq_nr++;
55a67399 323 goto out_ok;
68f3f901
RL
324 }
325
326 /* Replay */
b2f28bd7 327 if (args->csa_sequenceid == slot->seq_nr) {
e8d92382 328 dprintk("%s seqid %u is a replay\n",
b2f28bd7 329 __func__, args->csa_sequenceid);
4911096f
AA
330 /* Signal process_op to set this error on next op */
331 if (args->csa_cachethis == 0)
332 return htonl(NFS4ERR_RETRY_UNCACHED_REP);
333
334 /* The ca_maxresponsesize_cached is 0 with no DRC */
335 else if (args->csa_cachethis == 1)
336 return htonl(NFS4ERR_REP_TOO_BIG_TO_CACHE);
68f3f901
RL
337 }
338
339 /* Wraparound */
b2f28bd7 340 if (args->csa_sequenceid == 1 && (slot->seq_nr + 1) == 0) {
68f3f901 341 slot->seq_nr = 1;
55a67399 342 goto out_ok;
68f3f901
RL
343 }
344
345 /* Misordered request */
346 return htonl(NFS4ERR_SEQ_MISORDERED);
55a67399
TM
347out_ok:
348 tbl->highest_used_slotid = args->csa_slotid;
349 return htonl(NFS4_OK);
68f3f901
RL
350}
351
a7989c3e
MS
352/*
353 * For each referring call triple, check the session's slot table for
354 * a match. If the slot is in use and the sequence numbers match, the
355 * client is still waiting for a response to the original request.
356 */
357static bool referring_call_exists(struct nfs_client *clp,
358 uint32_t nrclists,
359 struct referring_call_list *rclists)
360{
361 bool status = 0;
362 int i, j;
363 struct nfs4_session *session;
364 struct nfs4_slot_table *tbl;
365 struct referring_call_list *rclist;
366 struct referring_call *ref;
367
368 /*
369 * XXX When client trunking is implemented, this becomes
370 * a session lookup from within the loop
371 */
372 session = clp->cl_session;
373 tbl = &session->fc_slot_table;
374
375 for (i = 0; i < nrclists; i++) {
376 rclist = &rclists[i];
377 if (memcmp(session->sess_id.data,
378 rclist->rcl_sessionid.data,
379 NFS4_MAX_SESSIONID_LEN) != 0)
380 continue;
381
382 for (j = 0; j < rclist->rcl_nrefcalls; j++) {
383 ref = &rclist->rcl_refcalls[j];
384
385 dprintk("%s: sessionid %x:%x:%x:%x sequenceid %u "
386 "slotid %u\n", __func__,
387 ((u32 *)&rclist->rcl_sessionid.data)[0],
388 ((u32 *)&rclist->rcl_sessionid.data)[1],
389 ((u32 *)&rclist->rcl_sessionid.data)[2],
390 ((u32 *)&rclist->rcl_sessionid.data)[3],
391 ref->rc_sequenceid, ref->rc_slotid);
392
393 spin_lock(&tbl->slot_tbl_lock);
394 status = (test_bit(ref->rc_slotid, tbl->used_slots) &&
395 tbl->slots[ref->rc_slotid].seq_nr ==
396 ref->rc_sequenceid);
397 spin_unlock(&tbl->slot_tbl_lock);
398 if (status)
399 goto out;
400 }
401 }
402
403out:
404 return status;
405}
406
9733f0d9 407__be32 nfs4_callback_sequence(struct cb_sequenceargs *args,
c36fca52
AA
408 struct cb_sequenceres *res,
409 struct cb_process_state *cps)
d49433e1 410{
55a67399 411 struct nfs4_slot_table *tbl;
68f3f901 412 struct nfs_client *clp;
9733f0d9 413 int i;
778be232 414 __be32 status = htonl(NFS4ERR_BADSESSION);
d49433e1 415
459de2ed
BS
416 clp = nfs4_find_client_sessionid(cps->net, args->csa_addr,
417 &args->csa_sessionid, cps->minorversion);
68f3f901
RL
418 if (clp == NULL)
419 goto out;
420
55a67399
TM
421 tbl = &clp->cl_session->bc_slot_table;
422
423 spin_lock(&tbl->slot_tbl_lock);
42acd021 424 /* state manager is resetting the session */
774d5f14 425 if (test_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state)) {
55a67399
TM
426 spin_unlock(&tbl->slot_tbl_lock);
427 status = htonl(NFS4ERR_DELAY);
910ac68a
TM
428 /* Return NFS4ERR_BADSESSION if we're draining the session
429 * in order to reset it.
430 */
431 if (test_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state))
432 status = htonl(NFS4ERR_BADSESSION);
42acd021
AA
433 goto out;
434 }
435
b2f28bd7 436 status = validate_seqid(&clp->cl_session->bc_slot_table, args);
55a67399 437 spin_unlock(&tbl->slot_tbl_lock);
68f3f901 438 if (status)
c36fca52 439 goto out;
68f3f901 440
55a67399
TM
441 cps->slotid = args->csa_slotid;
442
72ce2b3c
MS
443 /*
444 * Check for pending referring calls. If a match is found, a
445 * related callback was received before the response to the original
446 * call.
447 */
448 if (referring_call_exists(clp, args->csa_nrclists, args->csa_rclists)) {
449 status = htonl(NFS4ERR_DELAY);
c36fca52 450 goto out;
72ce2b3c
MS
451 }
452
d49433e1
BH
453 memcpy(&res->csr_sessionid, &args->csa_sessionid,
454 sizeof(res->csr_sessionid));
455 res->csr_sequenceid = args->csa_sequenceid;
456 res->csr_slotid = args->csa_slotid;
457 res->csr_highestslotid = NFS41_BC_MAX_CALLBACKS - 1;
458 res->csr_target_highestslotid = NFS41_BC_MAX_CALLBACKS - 1;
459
68f3f901 460out:
2c4cdf8f 461 cps->clp = clp; /* put in nfs4_callback_compound */
72ce2b3c
MS
462 for (i = 0; i < args->csa_nrclists; i++)
463 kfree(args->csa_rclists[i].rcl_refcalls);
464 kfree(args->csa_rclists);
465
c36fca52
AA
466 if (status == htonl(NFS4ERR_RETRY_UNCACHED_REP)) {
467 cps->drc_status = status;
468 status = 0;
469 } else
4911096f 470 res->csr_status = status;
c36fca52 471
2f92ae34 472 trace_nfs4_cb_sequence(args, res, status);
4911096f
AA
473 dprintk("%s: exit with status = %d res->csr_status %d\n", __func__,
474 ntohl(status), ntohl(res->csr_status));
475 return status;
d49433e1
BH
476}
477
36840370
AB
478static bool
479validate_bitmap_values(unsigned long mask)
480{
481 return (mask & ~RCA4_TYPE_MASK_ALL) == 0;
482}
483
c36fca52
AA
484__be32 nfs4_callback_recallany(struct cb_recallanyargs *args, void *dummy,
485 struct cb_process_state *cps)
31f09607 486{
9733f0d9 487 __be32 status;
31f09607
AB
488 fmode_t flags = 0;
489
36840370 490 status = cpu_to_be32(NFS4ERR_OP_NOT_IN_SESSION);
c36fca52 491 if (!cps->clp) /* set in cb_sequence */
31f09607
AB
492 goto out;
493
2446ab60 494 dprintk_rcu("NFS: RECALL_ANY callback request from %s\n",
c36fca52 495 rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR));
31f09607 496
36840370
AB
497 status = cpu_to_be32(NFS4ERR_INVAL);
498 if (!validate_bitmap_values(args->craa_type_mask))
499 goto out;
500
501 status = cpu_to_be32(NFS4_OK);
31f09607
AB
502 if (test_bit(RCA4_TYPE_MASK_RDATA_DLG, (const unsigned long *)
503 &args->craa_type_mask))
504 flags = FMODE_READ;
505 if (test_bit(RCA4_TYPE_MASK_WDATA_DLG, (const unsigned long *)
506 &args->craa_type_mask))
507 flags |= FMODE_WRITE;
36840370
AB
508 if (test_bit(RCA4_TYPE_MASK_FILE_LAYOUT, (const unsigned long *)
509 &args->craa_type_mask))
510 pnfs_recall_all_layouts(cps->clp);
31f09607 511 if (flags)
826e0013 512 nfs_expire_unused_delegation_types(cps->clp, flags);
31f09607
AB
513out:
514 dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
515 return status;
516}
b9efa1b2
AA
517
518/* Reduce the fore channel's max_slots to the target value */
c36fca52
AA
519__be32 nfs4_callback_recallslot(struct cb_recallslotargs *args, void *dummy,
520 struct cb_process_state *cps)
b9efa1b2 521{
b9efa1b2 522 struct nfs4_slot_table *fc_tbl;
9733f0d9 523 __be32 status;
b9efa1b2
AA
524
525 status = htonl(NFS4ERR_OP_NOT_IN_SESSION);
c36fca52 526 if (!cps->clp) /* set in cb_sequence */
b9efa1b2
AA
527 goto out;
528
e8d92382 529 dprintk_rcu("NFS: CB_RECALL_SLOT request from %s target highest slotid %u\n",
c36fca52 530 rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR),
d5fb4ce3 531 args->crsa_target_highest_slotid);
b9efa1b2 532
c36fca52 533 fc_tbl = &cps->clp->cl_session->fc_slot_table;
b9efa1b2 534
bae0ac0e 535 status = htonl(NFS4_OK);
b9efa1b2 536
d5fb4ce3 537 nfs41_set_target_slotid(fc_tbl, args->crsa_target_highest_slotid);
ac074835 538 nfs41_server_notify_target_slotid_update(cps->clp);
b9efa1b2
AA
539out:
540 dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
541 return status;
542}
d49433e1 543#endif /* CONFIG_NFS_V4_1 */