1 /*-
2 * Copyright (c) 2008 Isilon Inc http://www.isilon.com/
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 * SUCH DAMAGE.
24 */
25
26 #include <sys/cdefs.h>
27 __FBSDID("$FreeBSD$");
28
29 #include <sys/param.h>
30 #include <sys/systm.h>
31 #include <sys/sysproto.h>
32 #include <sys/kernel.h>
33 #include <sys/sysctl.h>
34 #include <sys/vnode.h>
35 #include <sys/malloc.h>
36 #include <sys/mount.h>
37 #include <sys/mbuf.h>
38 #include <sys/sbuf.h>
39
40 #include <rpc/rpc.h>
41 #include <nfs/nfs_fha.h>
42
43 static MALLOC_DEFINE(M_NFS_FHA, "NFS FHA", "NFS FHA");
44
45 /*
46 * XXX need to commonize definitions between old and new NFS code. Define
47 * this here so we don't include one nfsproto.h over the other.
48 */
49 #define NFS_PROG 100003
50
51 void
fha_init(struct fha_params * softc)52 fha_init(struct fha_params *softc)
53 {
54 char tmpstr[128];
55 int i;
56
57 for (i = 0; i < FHA_HASH_SIZE; i++)
58 mtx_init(&softc->fha_hash[i].mtx, "fhalock", NULL, MTX_DEF);
59
60 /*
61 * Set the default tuning parameters.
62 */
63 softc->ctls.enable = FHA_DEF_ENABLE;
64 softc->ctls.bin_shift = FHA_DEF_BIN_SHIFT;
65 softc->ctls.max_nfsds_per_fh = FHA_DEF_MAX_NFSDS_PER_FH;
66 softc->ctls.max_reqs_per_nfsd = FHA_DEF_MAX_REQS_PER_NFSD;
67
68 /*
69 * Allow the user to override the defaults at boot time with
70 * tunables.
71 */
72 snprintf(tmpstr, sizeof(tmpstr), "vfs.%s.fha.enable",
73 softc->server_name);
74 TUNABLE_INT_FETCH(tmpstr, &softc->ctls.enable);
75 snprintf(tmpstr, sizeof(tmpstr), "vfs.%s.fha.bin_shift",
76 softc->server_name);
77 TUNABLE_INT_FETCH(tmpstr, &softc->ctls.bin_shift);
78 snprintf(tmpstr, sizeof(tmpstr), "vfs.%s.fha.max_nfsds_per_fh",
79 softc->server_name);
80 TUNABLE_INT_FETCH(tmpstr, &softc->ctls.max_nfsds_per_fh);
81 snprintf(tmpstr, sizeof(tmpstr), "vfs.%s.fha.max_reqs_per_nfsd",
82 softc->server_name);
83 TUNABLE_INT_FETCH(tmpstr, &softc->ctls.max_reqs_per_nfsd);
84
85 /*
86 * Add sysctls so the user can change the tuning parameters at
87 * runtime.
88 */
89 SYSCTL_ADD_UINT(&softc->sysctl_ctx, SYSCTL_CHILDREN(softc->sysctl_tree),
90 OID_AUTO, "enable", CTLFLAG_RW,
91 &softc->ctls.enable, 0, "Enable NFS File Handle Affinity (FHA)");
92
93 SYSCTL_ADD_UINT(&softc->sysctl_ctx, SYSCTL_CHILDREN(softc->sysctl_tree),
94 OID_AUTO, "bin_shift", CTLFLAG_RW,
95 &softc->ctls.bin_shift, 0, "For FHA reads, no two requests will "
96 "contend if they're 2^(bin_shift) bytes apart");
97
98 SYSCTL_ADD_UINT(&softc->sysctl_ctx, SYSCTL_CHILDREN(softc->sysctl_tree),
99 OID_AUTO, "max_nfsds_per_fh", CTLFLAG_RW,
100 &softc->ctls.max_nfsds_per_fh, 0, "Maximum nfsd threads that "
101 "should be working on requests for the same file handle");
102
103 SYSCTL_ADD_UINT(&softc->sysctl_ctx, SYSCTL_CHILDREN(softc->sysctl_tree),
104 OID_AUTO, "max_reqs_per_nfsd", CTLFLAG_RW,
105 &softc->ctls.max_reqs_per_nfsd, 0, "Maximum requests that "
106 "single nfsd thread should be working on at any time");
107
108 SYSCTL_ADD_OID(&softc->sysctl_ctx, SYSCTL_CHILDREN(softc->sysctl_tree),
109 OID_AUTO, "fhe_stats", CTLTYPE_STRING | CTLFLAG_RD, 0, 0,
110 softc->callbacks.fhe_stats_sysctl, "A", "");
111
112 }
113
114 void
fha_uninit(struct fha_params * softc)115 fha_uninit(struct fha_params *softc)
116 {
117 int i;
118
119 sysctl_ctx_free(&softc->sysctl_ctx);
120 for (i = 0; i < FHA_HASH_SIZE; i++)
121 mtx_destroy(&softc->fha_hash[i].mtx);
122 }
123
124 /*
125 * This just specifies that offsets should obey affinity when within
126 * the same 1Mbyte (1<<20) chunk for the file (reads only for now).
127 */
128 static void
fha_extract_info(struct svc_req * req,struct fha_info * i,struct fha_callbacks * cb)129 fha_extract_info(struct svc_req *req, struct fha_info *i,
130 struct fha_callbacks *cb)
131 {
132 struct mbuf *md;
133 caddr_t dpos;
134 static u_int64_t random_fh = 0;
135 int error;
136 int v3 = (req->rq_vers == 3);
137 rpcproc_t procnum;
138
139 /*
140 * We start off with a random fh. If we get a reasonable
141 * procnum, we set the fh. If there's a concept of offset
142 * that we're interested in, we set that.
143 */
144 i->fh = ++random_fh;
145 i->offset = 0;
146 i->locktype = LK_EXCLUSIVE;
147
148 /*
149 * Extract the procnum and convert to v3 form if necessary,
150 * taking care to deal with out-of-range procnums. Caller will
151 * ensure that rq_vers is either 2 or 3.
152 */
153 procnum = req->rq_proc;
154 if (!v3) {
155 rpcproc_t tmp_procnum;
156
157 tmp_procnum = cb->get_procnum(procnum);
158 if (tmp_procnum == -1)
159 goto out;
160 procnum = tmp_procnum;
161 }
162
163 /*
164 * We do affinity for most. However, we divide a realm of affinity
165 * by file offset so as to allow for concurrent random access. We
166 * only do this for reads today, but this may change when IFS supports
167 * efficient concurrent writes.
168 */
169 if (cb->no_offset(procnum))
170 goto out;
171
172 error = cb->realign(&req->rq_args, M_NOWAIT);
173 if (error)
174 goto out;
175 md = req->rq_args;
176 dpos = mtod(md, caddr_t);
177
178 /* Grab the filehandle. */
179 error = cb->get_fh(&i->fh, v3, &md, &dpos);
180 if (error)
181 goto out;
182
183 /* Content ourselves with zero offset for all but reads. */
184 if (cb->is_read(procnum) || cb->is_write(procnum))
185 cb->get_offset(&md, &dpos, v3, i);
186
187 out:
188 cb->set_locktype(procnum, i);
189 }
190
191 static struct fha_hash_entry *
fha_hash_entry_new(u_int64_t fh)192 fha_hash_entry_new(u_int64_t fh)
193 {
194 struct fha_hash_entry *e;
195
196 e = malloc(sizeof(*e), M_NFS_FHA, M_WAITOK);
197 e->fh = fh;
198 e->num_rw = 0;
199 e->num_exclusive = 0;
200 e->num_threads = 0;
201 LIST_INIT(&e->threads);
202
203 return (e);
204 }
205
206 static void
fha_hash_entry_destroy(struct fha_hash_entry * e)207 fha_hash_entry_destroy(struct fha_hash_entry *e)
208 {
209
210 mtx_assert(e->mtx, MA_OWNED);
211 KASSERT(e->num_rw == 0,
212 ("%d reqs on destroyed fhe %p", e->num_rw, e));
213 KASSERT(e->num_exclusive == 0,
214 ("%d exclusive reqs on destroyed fhe %p", e->num_exclusive, e));
215 KASSERT(e->num_threads == 0,
216 ("%d threads on destroyed fhe %p", e->num_threads, e));
217 free(e, M_NFS_FHA);
218 }
219
220 static void
fha_hash_entry_remove(struct fha_hash_entry * e)221 fha_hash_entry_remove(struct fha_hash_entry *e)
222 {
223
224 mtx_assert(e->mtx, MA_OWNED);
225 LIST_REMOVE(e, link);
226 fha_hash_entry_destroy(e);
227 }
228
229 static struct fha_hash_entry *
fha_hash_entry_lookup(struct fha_params * softc,u_int64_t fh)230 fha_hash_entry_lookup(struct fha_params *softc, u_int64_t fh)
231 {
232 SVCPOOL *pool;
233 struct fha_hash_slot *fhs;
234 struct fha_hash_entry *fhe, *new_fhe;
235
236 pool = *softc->pool;
237 fhs = &softc->fha_hash[fh % FHA_HASH_SIZE];
238 new_fhe = fha_hash_entry_new(fh);
239 new_fhe->mtx = &fhs->mtx;
240 mtx_lock(&fhs->mtx);
241 LIST_FOREACH(fhe, &fhs->list, link)
242 if (fhe->fh == fh)
243 break;
244 if (!fhe) {
245 fhe = new_fhe;
246 LIST_INSERT_HEAD(&fhs->list, fhe, link);
247 } else
248 fha_hash_entry_destroy(new_fhe);
249 return (fhe);
250 }
251
252 static void
fha_hash_entry_add_thread(struct fha_hash_entry * fhe,SVCTHREAD * thread)253 fha_hash_entry_add_thread(struct fha_hash_entry *fhe, SVCTHREAD *thread)
254 {
255
256 mtx_assert(fhe->mtx, MA_OWNED);
257 thread->st_p2 = 0;
258 LIST_INSERT_HEAD(&fhe->threads, thread, st_alink);
259 fhe->num_threads++;
260 }
261
262 static void
fha_hash_entry_remove_thread(struct fha_hash_entry * fhe,SVCTHREAD * thread)263 fha_hash_entry_remove_thread(struct fha_hash_entry *fhe, SVCTHREAD *thread)
264 {
265
266 mtx_assert(fhe->mtx, MA_OWNED);
267 KASSERT(thread->st_p2 == 0,
268 ("%d reqs on removed thread %p", thread->st_p2, thread));
269 LIST_REMOVE(thread, st_alink);
270 fhe->num_threads--;
271 }
272
273 /*
274 * Account for an ongoing operation associated with this file.
275 */
276 static void
fha_hash_entry_add_op(struct fha_hash_entry * fhe,int locktype,int count)277 fha_hash_entry_add_op(struct fha_hash_entry *fhe, int locktype, int count)
278 {
279
280 mtx_assert(fhe->mtx, MA_OWNED);
281 if (LK_EXCLUSIVE == locktype)
282 fhe->num_exclusive += count;
283 else
284 fhe->num_rw += count;
285 }
286
287 /*
288 * Get the service thread currently associated with the fhe that is
289 * appropriate to handle this operation.
290 */
291 static SVCTHREAD *
fha_hash_entry_choose_thread(struct fha_params * softc,struct fha_hash_entry * fhe,struct fha_info * i,SVCTHREAD * this_thread)292 fha_hash_entry_choose_thread(struct fha_params *softc,
293 struct fha_hash_entry *fhe, struct fha_info *i, SVCTHREAD *this_thread)
294 {
295 SVCTHREAD *thread, *min_thread = NULL;
296 SVCPOOL *pool;
297 int req_count, min_count = 0;
298 off_t offset1, offset2;
299
300 pool = *softc->pool;
301
302 LIST_FOREACH(thread, &fhe->threads, st_alink) {
303 req_count = thread->st_p2;
304
305 /* If there are any writes in progress, use the first thread. */
306 if (fhe->num_exclusive) {
307 #if 0
308 ITRACE_CURPROC(ITRACE_NFS, ITRACE_INFO,
309 "fha: %p(%d)w", thread, req_count);
310 #endif
311 return (thread);
312 }
313
314 /*
315 * Check for read locality, making sure that we won't
316 * exceed our per-thread load limit in the process.
317 */
318 offset1 = i->offset;
319 offset2 = thread->st_p3;
320
321 if (((offset1 >= offset2)
322 && ((offset1 - offset2) < (1 << softc->ctls.bin_shift)))
323 || ((offset2 > offset1)
324 && ((offset2 - offset1) < (1 << softc->ctls.bin_shift)))) {
325 if ((softc->ctls.max_reqs_per_nfsd == 0) ||
326 (req_count < softc->ctls.max_reqs_per_nfsd)) {
327 #if 0
328 ITRACE_CURPROC(ITRACE_NFS, ITRACE_INFO,
329 "fha: %p(%d)r", thread, req_count);
330 #endif
331 return (thread);
332 }
333 }
334
335 /*
336 * We don't have a locality match, so skip this thread,
337 * but keep track of the most attractive thread in case
338 * we need to come back to it later.
339 */
340 #if 0
341 ITRACE_CURPROC(ITRACE_NFS, ITRACE_INFO,
342 "fha: %p(%d)s off1 %llu off2 %llu", thread,
343 req_count, offset1, offset2);
344 #endif
345 if ((min_thread == NULL) || (req_count < min_count)) {
346 min_count = req_count;
347 min_thread = thread;
348 }
349 }
350
351 /*
352 * We didn't find a good match yet. See if we can add
353 * a new thread to this file handle entry's thread list.
354 */
355 if ((softc->ctls.max_nfsds_per_fh == 0) ||
356 (fhe->num_threads < softc->ctls.max_nfsds_per_fh)) {
357 thread = this_thread;
358 #if 0
359 ITRACE_CURPROC(ITRACE_NFS, ITRACE_INFO,
360 "fha: %p(%d)t", thread, thread->st_p2);
361 #endif
362 fha_hash_entry_add_thread(fhe, thread);
363 } else {
364 /*
365 * We don't want to use any more threads for this file, so
366 * go back to the most attractive nfsd we're already using.
367 */
368 thread = min_thread;
369 }
370
371 return (thread);
372 }
373
374 /*
375 * After getting a request, try to assign it to some thread. Usually we
376 * handle it ourselves.
377 */
378 SVCTHREAD *
fha_assign(SVCTHREAD * this_thread,struct svc_req * req,struct fha_params * softc)379 fha_assign(SVCTHREAD *this_thread, struct svc_req *req,
380 struct fha_params *softc)
381 {
382 SVCTHREAD *thread;
383 struct fha_info i;
384 struct fha_hash_entry *fhe;
385 struct fha_callbacks *cb;
386
387 cb = &softc->callbacks;
388
389 /* Check to see whether we're enabled. */
390 if (softc->ctls.enable == 0)
391 goto thist;
392
393 /*
394 * Only do placement if this is an NFS request.
395 */
396 if (req->rq_prog != NFS_PROG)
397 goto thist;
398
399 if (req->rq_vers != 2 && req->rq_vers != 3)
400 goto thist;
401
402 fha_extract_info(req, &i, cb);
403
404 /*
405 * We save the offset associated with this request for later
406 * nfsd matching.
407 */
408 fhe = fha_hash_entry_lookup(softc, i.fh);
409 req->rq_p1 = fhe;
410 req->rq_p2 = i.locktype;
411 req->rq_p3 = i.offset;
412
413 /*
414 * Choose a thread, taking into consideration locality, thread load,
415 * and the number of threads already working on this file.
416 */
417 thread = fha_hash_entry_choose_thread(softc, fhe, &i, this_thread);
418 KASSERT(thread, ("fha_assign: NULL thread!"));
419 fha_hash_entry_add_op(fhe, i.locktype, 1);
420 thread->st_p2++;
421 thread->st_p3 = i.offset;
422
423 /*
424 * Grab the pool lock here to not let chosen thread go away before
425 * the new request inserted to its queue while we drop fhe lock.
426 */
427 mtx_lock(&thread->st_lock);
428 mtx_unlock(fhe->mtx);
429
430 return (thread);
431 thist:
432 req->rq_p1 = NULL;
433 mtx_lock(&this_thread->st_lock);
434 return (this_thread);
435 }
436
437 /*
438 * Called when we're done with an operation. The request has already
439 * been de-queued.
440 */
441 void
fha_nd_complete(SVCTHREAD * thread,struct svc_req * req)442 fha_nd_complete(SVCTHREAD *thread, struct svc_req *req)
443 {
444 struct fha_hash_entry *fhe = req->rq_p1;
445 struct mtx *mtx;
446
447 /*
448 * This may be called for reqs that didn't go through
449 * fha_assign (e.g. extra NULL ops used for RPCSEC_GSS.
450 */
451 if (!fhe)
452 return;
453
454 mtx = fhe->mtx;
455 mtx_lock(mtx);
456 fha_hash_entry_add_op(fhe, req->rq_p2, -1);
457 thread->st_p2--;
458 KASSERT(thread->st_p2 >= 0, ("Negative request count %d on %p",
459 thread->st_p2, thread));
460 if (thread->st_p2 == 0) {
461 fha_hash_entry_remove_thread(fhe, thread);
462 if (0 == fhe->num_rw + fhe->num_exclusive)
463 fha_hash_entry_remove(fhe);
464 }
465 mtx_unlock(mtx);
466 }
467
468 int
fhe_stats_sysctl(SYSCTL_HANDLER_ARGS,struct fha_params * softc)469 fhe_stats_sysctl(SYSCTL_HANDLER_ARGS, struct fha_params *softc)
470 {
471 int error, i;
472 struct sbuf sb;
473 struct fha_hash_entry *fhe;
474 bool_t first, hfirst;
475 SVCTHREAD *thread;
476 SVCPOOL *pool;
477
478 sbuf_new(&sb, NULL, 65536, SBUF_FIXEDLEN);
479
480 pool = NULL;
481
482 if (!*softc->pool) {
483 sbuf_printf(&sb, "NFSD not running\n");
484 goto out;
485 }
486 pool = *softc->pool;
487
488 for (i = 0; i < FHA_HASH_SIZE; i++)
489 if (!LIST_EMPTY(&softc->fha_hash[i].list))
490 break;
491
492 if (i == FHA_HASH_SIZE) {
493 sbuf_printf(&sb, "No file handle entries.\n");
494 goto out;
495 }
496
497 hfirst = TRUE;
498 for (; i < FHA_HASH_SIZE; i++) {
499 mtx_lock(&softc->fha_hash[i].mtx);
500 if (LIST_EMPTY(&softc->fha_hash[i].list)) {
501 mtx_unlock(&softc->fha_hash[i].mtx);
502 continue;
503 }
504 sbuf_printf(&sb, "%shash %d: {\n", hfirst ? "" : ", ", i);
505 first = TRUE;
506 LIST_FOREACH(fhe, &softc->fha_hash[i].list, link) {
507 sbuf_printf(&sb, "%sfhe %p: {\n", first ? " " : ", ", fhe);
508
509 sbuf_printf(&sb, " fh: %ju\n", (uintmax_t) fhe->fh);
510 sbuf_printf(&sb, " num_rw/exclusive: %d/%d\n",
511 fhe->num_rw, fhe->num_exclusive);
512 sbuf_printf(&sb, " num_threads: %d\n", fhe->num_threads);
513
514 LIST_FOREACH(thread, &fhe->threads, st_alink) {
515 sbuf_printf(&sb, " thread %p offset %ju "
516 "reqs %d\n", thread,
517 thread->st_p3, thread->st_p2);
518 }
519
520 sbuf_printf(&sb, " }");
521 first = FALSE;
522 }
523 sbuf_printf(&sb, "\n}");
524 mtx_unlock(&softc->fha_hash[i].mtx);
525 hfirst = FALSE;
526 }
527
528 out:
529 sbuf_trim(&sb);
530 sbuf_finish(&sb);
531 error = sysctl_handle_string(oidp, sbuf_data(&sb), sbuf_len(&sb), req);
532 sbuf_delete(&sb);
533 return (error);
534 }
535