blob: cf883c7ae053322626b8aa3c5b18861cd81f0085 [file] [log] [blame]
Trond Myklebust73e39aa2012-11-26 12:49:34 -05001/*
2 * fs/nfs/nfs4session.c
3 *
4 * Copyright (c) 2012 Trond Myklebust <Trond.Myklebust@netapp.com>
5 *
6 */
7#include <linux/kernel.h>
8#include <linux/errno.h>
9#include <linux/string.h>
10#include <linux/printk.h>
11#include <linux/slab.h>
12#include <linux/sunrpc/sched.h>
13#include <linux/sunrpc/bc_xprt.h>
14#include <linux/nfs.h>
15#include <linux/nfs4.h>
16#include <linux/nfs_fs.h>
17#include <linux/module.h>
18
19#include "nfs4_fs.h"
20#include "internal.h"
21#include "nfs4session.h"
22#include "callback.h"
23
24#define NFSDBG_FACILITY NFSDBG_STATE
25
Chuck Lever744aa522013-08-09 12:48:53 -040026static void nfs4_init_slot_table(struct nfs4_slot_table *tbl, const char *queue)
27{
28 tbl->highest_used_slotid = NFS4_NO_SLOT;
29 spin_lock_init(&tbl->slot_tbl_lock);
30 rpc_init_priority_wait_queue(&tbl->slot_tbl_waitq, queue);
31 init_completion(&tbl->complete);
32}
33
Trond Myklebust73e39aa2012-11-26 12:49:34 -050034/*
35 * nfs4_shrink_slot_table - free retired slots from the slot table
36 */
37static void nfs4_shrink_slot_table(struct nfs4_slot_table *tbl, u32 newsize)
38{
39 struct nfs4_slot **p;
40 if (newsize >= tbl->max_slots)
41 return;
42
43 p = &tbl->slots;
44 while (newsize--)
45 p = &(*p)->next;
46 while (*p) {
47 struct nfs4_slot *slot = *p;
48
49 *p = slot->next;
50 kfree(slot);
51 tbl->max_slots--;
52 }
53}
54
Chuck Lever9d330592013-08-09 12:48:44 -040055/**
56 * nfs4_slot_tbl_drain_complete - wake waiters when drain is complete
57 * @tbl - controlling slot table
58 *
59 */
60void nfs4_slot_tbl_drain_complete(struct nfs4_slot_table *tbl)
61{
62 if (nfs4_slot_tbl_draining(tbl))
63 complete(&tbl->complete);
64}
65
Trond Myklebust73e39aa2012-11-26 12:49:34 -050066/*
67 * nfs4_free_slot - free a slot and efficiently update slot table.
68 *
69 * freeing a slot is trivially done by clearing its respective bit
70 * in the bitmap.
71 * If the freed slotid equals highest_used_slotid we want to update it
72 * so that the server would be able to size down the slot table if needed,
73 * otherwise we know that the highest_used_slotid is still in use.
74 * When updating highest_used_slotid there may be "holes" in the bitmap
75 * so we need to scan down from highest_used_slotid to 0 looking for the now
76 * highest slotid in use.
77 * If none found, highest_used_slotid is set to NFS4_NO_SLOT.
78 *
79 * Must be called while holding tbl->slot_tbl_lock
80 */
81void nfs4_free_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot)
82{
83 u32 slotid = slot->slot_nr;
84
85 /* clear used bit in bitmap */
86 __clear_bit(slotid, tbl->used_slots);
87
88 /* update highest_used_slotid when it is freed */
89 if (slotid == tbl->highest_used_slotid) {
90 u32 new_max = find_last_bit(tbl->used_slots, slotid);
91 if (new_max < slotid)
92 tbl->highest_used_slotid = new_max;
93 else {
94 tbl->highest_used_slotid = NFS4_NO_SLOT;
Andy Adamson774d5f12013-05-20 14:13:50 -040095 nfs4_slot_tbl_drain_complete(tbl);
Trond Myklebust73e39aa2012-11-26 12:49:34 -050096 }
97 }
Chuck Levere8d92382013-08-09 12:47:51 -040098 dprintk("%s: slotid %u highest_used_slotid %u\n", __func__,
Trond Myklebust73e39aa2012-11-26 12:49:34 -050099 slotid, tbl->highest_used_slotid);
100}
101
102static struct nfs4_slot *nfs4_new_slot(struct nfs4_slot_table *tbl,
103 u32 slotid, u32 seq_init, gfp_t gfp_mask)
104{
105 struct nfs4_slot *slot;
106
107 slot = kzalloc(sizeof(*slot), gfp_mask);
108 if (slot) {
109 slot->table = tbl;
110 slot->slot_nr = slotid;
111 slot->seq_nr = seq_init;
112 }
113 return slot;
114}
115
116static struct nfs4_slot *nfs4_find_or_create_slot(struct nfs4_slot_table *tbl,
117 u32 slotid, u32 seq_init, gfp_t gfp_mask)
118{
119 struct nfs4_slot **p, *slot;
120
121 p = &tbl->slots;
122 for (;;) {
123 if (*p == NULL) {
124 *p = nfs4_new_slot(tbl, tbl->max_slots,
125 seq_init, gfp_mask);
126 if (*p == NULL)
127 break;
128 tbl->max_slots++;
129 }
130 slot = *p;
131 if (slot->slot_nr == slotid)
132 return slot;
133 p = &slot->next;
134 }
135 return ERR_PTR(-ENOMEM);
136}
137
138/*
139 * nfs4_alloc_slot - efficiently look for a free slot
140 *
141 * nfs4_alloc_slot looks for an unset bit in the used_slots bitmap.
142 * If found, we mark the slot as used, update the highest_used_slotid,
143 * and respectively set up the sequence operation args.
144 *
145 * Note: must be called with under the slot_tbl_lock.
146 */
147struct nfs4_slot *nfs4_alloc_slot(struct nfs4_slot_table *tbl)
148{
149 struct nfs4_slot *ret = ERR_PTR(-EBUSY);
150 u32 slotid;
151
152 dprintk("--> %s used_slots=%04lx highest_used=%u max_slots=%u\n",
153 __func__, tbl->used_slots[0], tbl->highest_used_slotid,
154 tbl->max_slotid + 1);
155 slotid = find_first_zero_bit(tbl->used_slots, tbl->max_slotid + 1);
156 if (slotid > tbl->max_slotid)
157 goto out;
158 ret = nfs4_find_or_create_slot(tbl, slotid, 1, GFP_NOWAIT);
159 if (IS_ERR(ret))
160 goto out;
161 __set_bit(slotid, tbl->used_slots);
162 if (slotid > tbl->highest_used_slotid ||
163 tbl->highest_used_slotid == NFS4_NO_SLOT)
164 tbl->highest_used_slotid = slotid;
Trond Myklebust73e39aa2012-11-26 12:49:34 -0500165 ret->generation = tbl->generation;
166
167out:
Chuck Levere8d92382013-08-09 12:47:51 -0400168 dprintk("<-- %s used_slots=%04lx highest_used=%u slotid=%u\n",
Trond Myklebust73e39aa2012-11-26 12:49:34 -0500169 __func__, tbl->used_slots[0], tbl->highest_used_slotid,
Chuck Levere8d92382013-08-09 12:47:51 -0400170 !IS_ERR(ret) ? ret->slot_nr : NFS4_NO_SLOT);
Trond Myklebust73e39aa2012-11-26 12:49:34 -0500171 return ret;
172}
173
174static int nfs4_grow_slot_table(struct nfs4_slot_table *tbl,
175 u32 max_reqs, u32 ivalue)
176{
177 if (max_reqs <= tbl->max_slots)
178 return 0;
179 if (!IS_ERR(nfs4_find_or_create_slot(tbl, max_reqs - 1, ivalue, GFP_NOFS)))
180 return 0;
181 return -ENOMEM;
182}
183
184static void nfs4_reset_slot_table(struct nfs4_slot_table *tbl,
185 u32 server_highest_slotid,
186 u32 ivalue)
187{
188 struct nfs4_slot **p;
189
190 nfs4_shrink_slot_table(tbl, server_highest_slotid + 1);
191 p = &tbl->slots;
192 while (*p) {
193 (*p)->seq_nr = ivalue;
Trond Myklebustac20d162012-12-15 15:36:07 -0500194 (*p)->interrupted = 0;
Trond Myklebust73e39aa2012-11-26 12:49:34 -0500195 p = &(*p)->next;
196 }
197 tbl->highest_used_slotid = NFS4_NO_SLOT;
198 tbl->target_highest_slotid = server_highest_slotid;
199 tbl->server_highest_slotid = server_highest_slotid;
Trond Myklebust1fa80642012-12-02 13:54:59 -0500200 tbl->d_target_highest_slotid = 0;
201 tbl->d2_target_highest_slotid = 0;
Trond Myklebust73e39aa2012-11-26 12:49:34 -0500202 tbl->max_slotid = server_highest_slotid;
203}
204
205/*
206 * (re)Initialise a slot table
207 */
208static int nfs4_realloc_slot_table(struct nfs4_slot_table *tbl,
209 u32 max_reqs, u32 ivalue)
210{
211 int ret;
212
Chuck Levere8d92382013-08-09 12:47:51 -0400213 dprintk("--> %s: max_reqs=%u, tbl->max_slots %u\n", __func__,
Trond Myklebust73e39aa2012-11-26 12:49:34 -0500214 max_reqs, tbl->max_slots);
215
216 if (max_reqs > NFS4_MAX_SLOT_TABLE)
217 max_reqs = NFS4_MAX_SLOT_TABLE;
218
219 ret = nfs4_grow_slot_table(tbl, max_reqs, ivalue);
220 if (ret)
221 goto out;
222
223 spin_lock(&tbl->slot_tbl_lock);
224 nfs4_reset_slot_table(tbl, max_reqs - 1, ivalue);
225 spin_unlock(&tbl->slot_tbl_lock);
226
Chuck Levere8d92382013-08-09 12:47:51 -0400227 dprintk("%s: tbl=%p slots=%p max_slots=%u\n", __func__,
Trond Myklebust73e39aa2012-11-26 12:49:34 -0500228 tbl, tbl->slots, tbl->max_slots);
229out:
230 dprintk("<-- %s: return %d\n", __func__, ret);
231 return ret;
232}
233
Chuck Lever744aa522013-08-09 12:48:53 -0400234/**
Chuck Levereb2a1cd2013-08-09 12:49:02 -0400235 * nfs4_release_slot_table - release resources attached to a slot table
236 * @tbl: slot table to shut down
237 *
238 */
239void nfs4_release_slot_table(struct nfs4_slot_table *tbl)
240{
241 nfs4_shrink_slot_table(tbl, 0);
242}
243
244/**
Chuck Lever744aa522013-08-09 12:48:53 -0400245 * nfs4_setup_slot_table - prepare a stand-alone slot table for use
246 * @tbl: slot table to set up
247 * @max_reqs: maximum number of requests allowed
248 * @queue: name to give RPC wait queue
249 *
250 * Returns zero on success, or a negative errno.
251 */
252int nfs4_setup_slot_table(struct nfs4_slot_table *tbl, unsigned int max_reqs,
253 const char *queue)
254{
255 nfs4_init_slot_table(tbl, queue);
256 return nfs4_realloc_slot_table(tbl, max_reqs, 0);
257}
258
Trond Myklebustb75ad4c2012-11-29 17:27:47 -0500259static bool nfs41_assign_slot(struct rpc_task *task, void *pslot)
260{
261 struct nfs4_sequence_args *args = task->tk_msg.rpc_argp;
262 struct nfs4_sequence_res *res = task->tk_msg.rpc_resp;
263 struct nfs4_slot *slot = pslot;
264 struct nfs4_slot_table *tbl = slot->table;
265
Andy Adamson774d5f12013-05-20 14:13:50 -0400266 if (nfs4_slot_tbl_draining(tbl) && !args->sa_privileged)
Trond Myklebustb75ad4c2012-11-29 17:27:47 -0500267 return false;
Trond Myklebustb75ad4c2012-11-29 17:27:47 -0500268 slot->generation = tbl->generation;
269 args->sa_slot = slot;
Trond Myklebust8e63b6a2012-12-15 15:21:52 -0500270 res->sr_timestamp = jiffies;
Trond Myklebustb75ad4c2012-11-29 17:27:47 -0500271 res->sr_slot = slot;
272 res->sr_status_flags = 0;
273 res->sr_status = 1;
274 return true;
275}
276
277static bool __nfs41_wake_and_assign_slot(struct nfs4_slot_table *tbl,
278 struct nfs4_slot *slot)
279{
280 if (rpc_wake_up_first(&tbl->slot_tbl_waitq, nfs41_assign_slot, slot))
281 return true;
282 return false;
283}
284
285bool nfs41_wake_and_assign_slot(struct nfs4_slot_table *tbl,
286 struct nfs4_slot *slot)
287{
288 if (slot->slot_nr > tbl->max_slotid)
289 return false;
290 return __nfs41_wake_and_assign_slot(tbl, slot);
291}
292
293static bool nfs41_try_wake_next_slot_table_entry(struct nfs4_slot_table *tbl)
294{
295 struct nfs4_slot *slot = nfs4_alloc_slot(tbl);
296 if (!IS_ERR(slot)) {
297 bool ret = __nfs41_wake_and_assign_slot(tbl, slot);
298 if (ret)
299 return ret;
300 nfs4_free_slot(tbl, slot);
301 }
302 return false;
303}
304
305void nfs41_wake_slot_table(struct nfs4_slot_table *tbl)
306{
307 for (;;) {
308 if (!nfs41_try_wake_next_slot_table_entry(tbl))
309 break;
310 }
311}
312
Chuck Lever1cec16a2013-09-04 12:26:03 -0400313#if defined(CONFIG_NFS_V4_1)
314
Trond Myklebustb0ef9642012-12-11 12:10:14 -0500315static void nfs41_set_max_slotid_locked(struct nfs4_slot_table *tbl,
316 u32 target_highest_slotid)
317{
318 u32 max_slotid;
319
320 max_slotid = min(NFS4_MAX_SLOT_TABLE - 1, target_highest_slotid);
321 if (max_slotid > tbl->server_highest_slotid)
322 max_slotid = tbl->server_highest_slotid;
323 if (max_slotid > tbl->target_highest_slotid)
324 max_slotid = tbl->target_highest_slotid;
325 tbl->max_slotid = max_slotid;
326 nfs41_wake_slot_table(tbl);
327}
328
Trond Myklebust73e39aa2012-11-26 12:49:34 -0500329/* Update the client's idea of target_highest_slotid */
330static void nfs41_set_target_slotid_locked(struct nfs4_slot_table *tbl,
331 u32 target_highest_slotid)
332{
Trond Myklebust73e39aa2012-11-26 12:49:34 -0500333 if (tbl->target_highest_slotid == target_highest_slotid)
334 return;
335 tbl->target_highest_slotid = target_highest_slotid;
336 tbl->generation++;
Trond Myklebust73e39aa2012-11-26 12:49:34 -0500337}
338
339void nfs41_set_target_slotid(struct nfs4_slot_table *tbl,
340 u32 target_highest_slotid)
341{
342 spin_lock(&tbl->slot_tbl_lock);
343 nfs41_set_target_slotid_locked(tbl, target_highest_slotid);
Trond Myklebust1fa80642012-12-02 13:54:59 -0500344 tbl->d_target_highest_slotid = 0;
345 tbl->d2_target_highest_slotid = 0;
Trond Myklebustb0ef9642012-12-11 12:10:14 -0500346 nfs41_set_max_slotid_locked(tbl, target_highest_slotid);
Trond Myklebust73e39aa2012-11-26 12:49:34 -0500347 spin_unlock(&tbl->slot_tbl_lock);
348}
349
350static void nfs41_set_server_slotid_locked(struct nfs4_slot_table *tbl,
351 u32 highest_slotid)
352{
353 if (tbl->server_highest_slotid == highest_slotid)
354 return;
355 if (tbl->highest_used_slotid > highest_slotid)
356 return;
357 /* Deallocate slots */
358 nfs4_shrink_slot_table(tbl, highest_slotid + 1);
359 tbl->server_highest_slotid = highest_slotid;
360}
361
Trond Myklebust1fa80642012-12-02 13:54:59 -0500362static s32 nfs41_derivative_target_slotid(s32 s1, s32 s2)
363{
364 s1 -= s2;
365 if (s1 == 0)
366 return 0;
367 if (s1 < 0)
368 return (s1 - 1) >> 1;
369 return (s1 + 1) >> 1;
370}
371
372static int nfs41_sign_s32(s32 s1)
373{
374 if (s1 > 0)
375 return 1;
376 if (s1 < 0)
377 return -1;
378 return 0;
379}
380
381static bool nfs41_same_sign_or_zero_s32(s32 s1, s32 s2)
382{
383 if (!s1 || !s2)
384 return true;
385 return nfs41_sign_s32(s1) == nfs41_sign_s32(s2);
386}
387
388/* Try to eliminate outliers by checking for sharp changes in the
389 * derivatives and second derivatives
390 */
391static bool nfs41_is_outlier_target_slotid(struct nfs4_slot_table *tbl,
392 u32 new_target)
393{
394 s32 d_target, d2_target;
395 bool ret = true;
396
397 d_target = nfs41_derivative_target_slotid(new_target,
398 tbl->target_highest_slotid);
399 d2_target = nfs41_derivative_target_slotid(d_target,
400 tbl->d_target_highest_slotid);
401 /* Is first derivative same sign? */
402 if (nfs41_same_sign_or_zero_s32(d_target, tbl->d_target_highest_slotid))
403 ret = false;
404 /* Is second derivative same sign? */
405 if (nfs41_same_sign_or_zero_s32(d2_target, tbl->d2_target_highest_slotid))
406 ret = false;
407 tbl->d_target_highest_slotid = d_target;
408 tbl->d2_target_highest_slotid = d2_target;
409 return ret;
410}
411
Trond Myklebust73e39aa2012-11-26 12:49:34 -0500412void nfs41_update_target_slotid(struct nfs4_slot_table *tbl,
413 struct nfs4_slot *slot,
414 struct nfs4_sequence_res *res)
415{
416 spin_lock(&tbl->slot_tbl_lock);
Trond Myklebust1fa80642012-12-02 13:54:59 -0500417 if (!nfs41_is_outlier_target_slotid(tbl, res->sr_target_highest_slotid))
418 nfs41_set_target_slotid_locked(tbl, res->sr_target_highest_slotid);
419 if (tbl->generation == slot->generation)
420 nfs41_set_server_slotid_locked(tbl, res->sr_highest_slotid);
Trond Myklebustb0ef9642012-12-11 12:10:14 -0500421 nfs41_set_max_slotid_locked(tbl, res->sr_target_highest_slotid);
Trond Myklebust73e39aa2012-11-26 12:49:34 -0500422 spin_unlock(&tbl->slot_tbl_lock);
423}
424
Chuck Levereb2a1cd2013-08-09 12:49:02 -0400425static void nfs4_destroy_session_slot_tables(struct nfs4_session *session)
Chuck Lever9d330592013-08-09 12:48:44 -0400426{
Chuck Levereb2a1cd2013-08-09 12:49:02 -0400427 nfs4_release_slot_table(&session->fc_slot_table);
428 nfs4_release_slot_table(&session->bc_slot_table);
Chuck Lever9d330592013-08-09 12:48:44 -0400429}
430
Trond Myklebust73e39aa2012-11-26 12:49:34 -0500431/*
432 * Initialize or reset the forechannel and backchannel tables
433 */
434int nfs4_setup_session_slot_tables(struct nfs4_session *ses)
435{
436 struct nfs4_slot_table *tbl;
437 int status;
438
439 dprintk("--> %s\n", __func__);
440 /* Fore channel */
441 tbl = &ses->fc_slot_table;
442 tbl->session = ses;
443 status = nfs4_realloc_slot_table(tbl, ses->fc_attrs.max_reqs, 1);
444 if (status) /* -ENOMEM */
445 return status;
446 /* Back channel */
447 tbl = &ses->bc_slot_table;
448 tbl->session = ses;
449 status = nfs4_realloc_slot_table(tbl, ses->bc_attrs.max_reqs, 0);
450 if (status && tbl->slots == NULL)
451 /* Fore and back channel share a connection so get
452 * both slot tables or neither */
Chuck Levereb2a1cd2013-08-09 12:49:02 -0400453 nfs4_destroy_session_slot_tables(ses);
Trond Myklebust73e39aa2012-11-26 12:49:34 -0500454 return status;
455}
456
457struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp)
458{
459 struct nfs4_session *session;
Trond Myklebust73e39aa2012-11-26 12:49:34 -0500460
461 session = kzalloc(sizeof(struct nfs4_session), GFP_NOFS);
462 if (!session)
463 return NULL;
464
Chuck Lever744aa522013-08-09 12:48:53 -0400465 nfs4_init_slot_table(&session->fc_slot_table, "ForeChannel Slot table");
466 nfs4_init_slot_table(&session->bc_slot_table, "BackChannel Slot table");
Trond Myklebust73e39aa2012-11-26 12:49:34 -0500467 session->session_state = 1<<NFS4_SESSION_INITING;
468
469 session->clp = clp;
470 return session;
471}
472
473void nfs4_destroy_session(struct nfs4_session *session)
474{
475 struct rpc_xprt *xprt;
476 struct rpc_cred *cred;
477
Chuck Lever73d8bde2013-07-24 12:28:37 -0400478 cred = nfs4_get_clid_cred(session->clp);
Trond Myklebust73e39aa2012-11-26 12:49:34 -0500479 nfs4_proc_destroy_session(session, cred);
480 if (cred)
481 put_rpccred(cred);
482
483 rcu_read_lock();
484 xprt = rcu_dereference(session->clp->cl_rpcclient->cl_xprt);
485 rcu_read_unlock();
486 dprintk("%s Destroy backchannel for xprt %p\n",
487 __func__, xprt);
488 xprt_destroy_backchannel(xprt, NFS41_BC_MIN_CALLBACKS);
Chuck Levereb2a1cd2013-08-09 12:49:02 -0400489 nfs4_destroy_session_slot_tables(session);
Trond Myklebust73e39aa2012-11-26 12:49:34 -0500490 kfree(session);
491}
492
493/*
494 * With sessions, the client is not marked ready until after a
495 * successful EXCHANGE_ID and CREATE_SESSION.
496 *
497 * Map errors cl_cons_state errors to EPROTONOSUPPORT to indicate
498 * other versions of NFS can be tried.
499 */
500static int nfs41_check_session_ready(struct nfs_client *clp)
501{
502 int ret;
503
504 if (clp->cl_cons_state == NFS_CS_SESSION_INITING) {
505 ret = nfs4_client_recover_expired_lease(clp);
506 if (ret)
507 return ret;
508 }
509 if (clp->cl_cons_state < NFS_CS_READY)
510 return -EPROTONOSUPPORT;
511 smp_rmb();
512 return 0;
513}
514
Andy Adamson18aad3d2013-06-26 12:21:49 -0400515int nfs4_init_session(struct nfs_client *clp)
Trond Myklebust73e39aa2012-11-26 12:49:34 -0500516{
Trond Myklebust73e39aa2012-11-26 12:49:34 -0500517 if (!nfs4_has_session(clp))
518 return 0;
519
Andy Adamson18aad3d2013-06-26 12:21:49 -0400520 clear_bit(NFS4_SESSION_INITING, &clp->cl_session->session_state);
Trond Myklebust73e39aa2012-11-26 12:49:34 -0500521 return nfs41_check_session_ready(clp);
522}
523
524int nfs4_init_ds_session(struct nfs_client *clp, unsigned long lease_time)
525{
526 struct nfs4_session *session = clp->cl_session;
527 int ret;
528
529 spin_lock(&clp->cl_lock);
530 if (test_and_clear_bit(NFS4_SESSION_INITING, &session->session_state)) {
531 /*
532 * Do not set NFS_CS_CHECK_LEASE_TIME instead set the
533 * DS lease to be equal to the MDS lease.
534 */
535 clp->cl_lease_time = lease_time;
536 clp->cl_last_renewal = jiffies;
537 }
538 spin_unlock(&clp->cl_lock);
539
540 ret = nfs41_check_session_ready(clp);
541 if (ret)
542 return ret;
543 /* Test for the DS role */
544 if (!is_ds_client(clp))
545 return -ENODEV;
546 return 0;
547}
548EXPORT_SYMBOL_GPL(nfs4_init_ds_session);
549
Chuck Lever9d330592013-08-09 12:48:44 -0400550#endif /* defined(CONFIG_NFS_V4_1) */