spi: respect the maximum segment size of DMA device
[cascardo/linux.git] / fs / nfs / flexfilelayout / flexfilelayoutdev.c
1 /*
2  * Device operations for the pnfs nfs4 file layout driver.
3  *
4  * Copyright (c) 2014, Primary Data, Inc. All rights reserved.
5  *
6  * Tao Peng <bergwolf@primarydata.com>
7  */
8
9 #include <linux/nfs_fs.h>
10 #include <linux/vmalloc.h>
11 #include <linux/module.h>
12 #include <linux/sunrpc/addr.h>
13
14 #include "../internal.h"
15 #include "../nfs4session.h"
16 #include "flexfilelayout.h"
17
18 #define NFSDBG_FACILITY         NFSDBG_PNFS_LD
19
20 static unsigned int dataserver_timeo = NFS4_DEF_DS_TIMEO;
21 static unsigned int dataserver_retrans = NFS4_DEF_DS_RETRANS;
22
23 void nfs4_ff_layout_put_deviceid(struct nfs4_ff_layout_ds *mirror_ds)
24 {
25         if (mirror_ds)
26                 nfs4_put_deviceid_node(&mirror_ds->id_node);
27 }
28
29 void nfs4_ff_layout_free_deviceid(struct nfs4_ff_layout_ds *mirror_ds)
30 {
31         nfs4_print_deviceid(&mirror_ds->id_node.deviceid);
32         nfs4_pnfs_ds_put(mirror_ds->ds);
33         kfree_rcu(mirror_ds, id_node.rcu);
34 }
35
36 /* Decode opaque device data and construct new_ds using it */
37 struct nfs4_ff_layout_ds *
38 nfs4_ff_alloc_deviceid_node(struct nfs_server *server, struct pnfs_device *pdev,
39                             gfp_t gfp_flags)
40 {
41         struct xdr_stream stream;
42         struct xdr_buf buf;
43         struct page *scratch;
44         struct list_head dsaddrs;
45         struct nfs4_pnfs_ds_addr *da;
46         struct nfs4_ff_layout_ds *new_ds = NULL;
47         struct nfs4_ff_ds_version *ds_versions = NULL;
48         u32 mp_count;
49         u32 version_count;
50         __be32 *p;
51         int i, ret = -ENOMEM;
52
53         /* set up xdr stream */
54         scratch = alloc_page(gfp_flags);
55         if (!scratch)
56                 goto out_err;
57
58         new_ds = kzalloc(sizeof(struct nfs4_ff_layout_ds), gfp_flags);
59         if (!new_ds)
60                 goto out_scratch;
61
62         nfs4_init_deviceid_node(&new_ds->id_node,
63                                 server,
64                                 &pdev->dev_id);
65         INIT_LIST_HEAD(&dsaddrs);
66
67         xdr_init_decode_pages(&stream, &buf, pdev->pages, pdev->pglen);
68         xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
69
70         /* multipath count */
71         p = xdr_inline_decode(&stream, 4);
72         if (unlikely(!p))
73                 goto out_err_drain_dsaddrs;
74         mp_count = be32_to_cpup(p);
75         dprintk("%s: multipath ds count %d\n", __func__, mp_count);
76
77         for (i = 0; i < mp_count; i++) {
78                 /* multipath ds */
79                 da = nfs4_decode_mp_ds_addr(server->nfs_client->cl_net,
80                                             &stream, gfp_flags);
81                 if (da)
82                         list_add_tail(&da->da_node, &dsaddrs);
83         }
84         if (list_empty(&dsaddrs)) {
85                 dprintk("%s: no suitable DS addresses found\n",
86                         __func__);
87                 ret = -ENOMEDIUM;
88                 goto out_err_drain_dsaddrs;
89         }
90
91         /* version count */
92         p = xdr_inline_decode(&stream, 4);
93         if (unlikely(!p))
94                 goto out_err_drain_dsaddrs;
95         version_count = be32_to_cpup(p);
96         dprintk("%s: version count %d\n", __func__, version_count);
97
98         ds_versions = kzalloc(version_count * sizeof(struct nfs4_ff_ds_version),
99                               gfp_flags);
100         if (!ds_versions)
101                 goto out_scratch;
102
103         for (i = 0; i < version_count; i++) {
104                 /* 20 = version(4) + minor_version(4) + rsize(4) + wsize(4) +
105                  * tightly_coupled(4) */
106                 p = xdr_inline_decode(&stream, 20);
107                 if (unlikely(!p))
108                         goto out_err_drain_dsaddrs;
109                 ds_versions[i].version = be32_to_cpup(p++);
110                 ds_versions[i].minor_version = be32_to_cpup(p++);
111                 ds_versions[i].rsize = nfs_block_size(be32_to_cpup(p++), NULL);
112                 ds_versions[i].wsize = nfs_block_size(be32_to_cpup(p++), NULL);
113                 ds_versions[i].tightly_coupled = be32_to_cpup(p);
114
115                 if (ds_versions[i].rsize > NFS_MAX_FILE_IO_SIZE)
116                         ds_versions[i].rsize = NFS_MAX_FILE_IO_SIZE;
117                 if (ds_versions[i].wsize > NFS_MAX_FILE_IO_SIZE)
118                         ds_versions[i].wsize = NFS_MAX_FILE_IO_SIZE;
119
120                 if (ds_versions[i].version != 3 || ds_versions[i].minor_version != 0) {
121                         dprintk("%s: [%d] unsupported ds version %d-%d\n", __func__,
122                                 i, ds_versions[i].version,
123                                 ds_versions[i].minor_version);
124                         ret = -EPROTONOSUPPORT;
125                         goto out_err_drain_dsaddrs;
126                 }
127
128                 dprintk("%s: [%d] vers %u minor_ver %u rsize %u wsize %u coupled %d\n",
129                         __func__, i, ds_versions[i].version,
130                         ds_versions[i].minor_version,
131                         ds_versions[i].rsize,
132                         ds_versions[i].wsize,
133                         ds_versions[i].tightly_coupled);
134         }
135
136         new_ds->ds_versions = ds_versions;
137         new_ds->ds_versions_cnt = version_count;
138
139         new_ds->ds = nfs4_pnfs_ds_add(&dsaddrs, gfp_flags);
140         if (!new_ds->ds)
141                 goto out_err_drain_dsaddrs;
142
143         /* If DS was already in cache, free ds addrs */
144         while (!list_empty(&dsaddrs)) {
145                 da = list_first_entry(&dsaddrs,
146                                       struct nfs4_pnfs_ds_addr,
147                                       da_node);
148                 list_del_init(&da->da_node);
149                 kfree(da->da_remotestr);
150                 kfree(da);
151         }
152
153         __free_page(scratch);
154         return new_ds;
155
156 out_err_drain_dsaddrs:
157         while (!list_empty(&dsaddrs)) {
158                 da = list_first_entry(&dsaddrs, struct nfs4_pnfs_ds_addr,
159                                       da_node);
160                 list_del_init(&da->da_node);
161                 kfree(da->da_remotestr);
162                 kfree(da);
163         }
164
165         kfree(ds_versions);
166 out_scratch:
167         __free_page(scratch);
168 out_err:
169         kfree(new_ds);
170
171         dprintk("%s ERROR: returning %d\n", __func__, ret);
172         return NULL;
173 }
174
175 static void ff_layout_mark_devid_invalid(struct pnfs_layout_segment *lseg,
176                 struct nfs4_deviceid_node *devid)
177 {
178         nfs4_mark_deviceid_unavailable(devid);
179         if (!ff_layout_has_available_ds(lseg))
180                 pnfs_error_mark_layout_for_return(lseg->pls_layout->plh_inode,
181                                 lseg);
182 }
183
184 static bool ff_layout_mirror_valid(struct pnfs_layout_segment *lseg,
185                 struct nfs4_ff_layout_mirror *mirror)
186 {
187         if (mirror == NULL || mirror->mirror_ds == NULL) {
188                 pnfs_error_mark_layout_for_return(lseg->pls_layout->plh_inode,
189                                         lseg);
190                 return false;
191         }
192         if (mirror->mirror_ds->ds == NULL) {
193                 struct nfs4_deviceid_node *devid;
194                 devid = &mirror->mirror_ds->id_node;
195                 ff_layout_mark_devid_invalid(lseg, devid);
196                 return false;
197         }
198         return true;
199 }
200
201 static u64
202 end_offset(u64 start, u64 len)
203 {
204         u64 end;
205
206         end = start + len;
207         return end >= start ? end : NFS4_MAX_UINT64;
208 }
209
210 static void extend_ds_error(struct nfs4_ff_layout_ds_err *err,
211                             u64 offset, u64 length)
212 {
213         u64 end;
214
215         end = max_t(u64, end_offset(err->offset, err->length),
216                     end_offset(offset, length));
217         err->offset = min_t(u64, err->offset, offset);
218         err->length = end - err->offset;
219 }
220
221 static int
222 ff_ds_error_match(const struct nfs4_ff_layout_ds_err *e1,
223                 const struct nfs4_ff_layout_ds_err *e2)
224 {
225         int ret;
226
227         if (e1->opnum != e2->opnum)
228                 return e1->opnum < e2->opnum ? -1 : 1;
229         if (e1->status != e2->status)
230                 return e1->status < e2->status ? -1 : 1;
231         ret = memcmp(&e1->stateid, &e2->stateid, sizeof(e1->stateid));
232         if (ret != 0)
233                 return ret;
234         ret = memcmp(&e1->deviceid, &e2->deviceid, sizeof(e1->deviceid));
235         if (ret != 0)
236                 return ret;
237         if (end_offset(e1->offset, e1->length) < e2->offset)
238                 return -1;
239         if (e1->offset > end_offset(e2->offset, e2->length))
240                 return 1;
241         /* If ranges overlap or are contiguous, they are the same */
242         return 0;
243 }
244
245 static void
246 ff_layout_add_ds_error_locked(struct nfs4_flexfile_layout *flo,
247                               struct nfs4_ff_layout_ds_err *dserr)
248 {
249         struct nfs4_ff_layout_ds_err *err, *tmp;
250         struct list_head *head = &flo->error_list;
251         int match;
252
253         /* Do insertion sort w/ merges */
254         list_for_each_entry_safe(err, tmp, &flo->error_list, list) {
255                 match = ff_ds_error_match(err, dserr);
256                 if (match < 0)
257                         continue;
258                 if (match > 0) {
259                         /* Add entry "dserr" _before_ entry "err" */
260                         head = &err->list;
261                         break;
262                 }
263                 /* Entries match, so merge "err" into "dserr" */
264                 extend_ds_error(dserr, err->offset, err->length);
265                 list_del(&err->list);
266                 kfree(err);
267         }
268
269         list_add_tail(&dserr->list, head);
270 }
271
272 int ff_layout_track_ds_error(struct nfs4_flexfile_layout *flo,
273                              struct nfs4_ff_layout_mirror *mirror, u64 offset,
274                              u64 length, int status, enum nfs_opnum4 opnum,
275                              gfp_t gfp_flags)
276 {
277         struct nfs4_ff_layout_ds_err *dserr;
278
279         if (status == 0)
280                 return 0;
281
282         if (mirror->mirror_ds == NULL)
283                 return -EINVAL;
284
285         dserr = kmalloc(sizeof(*dserr), gfp_flags);
286         if (!dserr)
287                 return -ENOMEM;
288
289         INIT_LIST_HEAD(&dserr->list);
290         dserr->offset = offset;
291         dserr->length = length;
292         dserr->status = status;
293         dserr->opnum = opnum;
294         nfs4_stateid_copy(&dserr->stateid, &mirror->stateid);
295         memcpy(&dserr->deviceid, &mirror->mirror_ds->id_node.deviceid,
296                NFS4_DEVICEID4_SIZE);
297
298         spin_lock(&flo->generic_hdr.plh_inode->i_lock);
299         ff_layout_add_ds_error_locked(flo, dserr);
300         spin_unlock(&flo->generic_hdr.plh_inode->i_lock);
301
302         return 0;
303 }
304
305 /* currently we only support AUTH_NONE and AUTH_SYS */
306 static rpc_authflavor_t
307 nfs4_ff_layout_choose_authflavor(struct nfs4_ff_layout_mirror *mirror)
308 {
309         if (mirror->uid == (u32)-1)
310                 return RPC_AUTH_NULL;
311         return RPC_AUTH_UNIX;
312 }
313
314 /* fetch cred for NFSv3 DS */
315 static int ff_layout_update_mirror_cred(struct nfs4_ff_layout_mirror *mirror,
316                                       struct nfs4_pnfs_ds *ds)
317 {
318         if (ds->ds_clp && !mirror->cred &&
319             mirror->mirror_ds->ds_versions[0].version == 3) {
320                 struct rpc_auth *auth = ds->ds_clp->cl_rpcclient->cl_auth;
321                 struct rpc_cred *cred;
322                 struct auth_cred acred = {
323                         .uid = make_kuid(&init_user_ns, mirror->uid),
324                         .gid = make_kgid(&init_user_ns, mirror->gid),
325                 };
326
327                 /* AUTH_NULL ignores acred */
328                 cred = auth->au_ops->lookup_cred(auth, &acred, 0);
329                 if (IS_ERR(cred)) {
330                         dprintk("%s: lookup_cred failed with %ld\n",
331                                 __func__, PTR_ERR(cred));
332                         return PTR_ERR(cred);
333                 } else {
334                         if (cmpxchg(&mirror->cred, NULL, cred))
335                                 put_rpccred(cred);
336                 }
337         }
338         return 0;
339 }
340
341 struct nfs_fh *
342 nfs4_ff_layout_select_ds_fh(struct pnfs_layout_segment *lseg, u32 mirror_idx)
343 {
344         struct nfs4_ff_layout_mirror *mirror = FF_LAYOUT_COMP(lseg, mirror_idx);
345         struct nfs_fh *fh = NULL;
346
347         if (!ff_layout_mirror_valid(lseg, mirror)) {
348                 pr_err_ratelimited("NFS: %s: No data server for mirror offset index %d\n",
349                         __func__, mirror_idx);
350                 goto out;
351         }
352
353         /* FIXME: For now assume there is only 1 version available for the DS */
354         fh = &mirror->fh_versions[0];
355 out:
356         return fh;
357 }
358
359 /* Upon return, either ds is connected, or ds is NULL */
360 struct nfs4_pnfs_ds *
361 nfs4_ff_layout_prepare_ds(struct pnfs_layout_segment *lseg, u32 ds_idx,
362                           bool fail_return)
363 {
364         struct nfs4_ff_layout_mirror *mirror = FF_LAYOUT_COMP(lseg, ds_idx);
365         struct nfs4_pnfs_ds *ds = NULL;
366         struct nfs4_deviceid_node *devid;
367         struct inode *ino = lseg->pls_layout->plh_inode;
368         struct nfs_server *s = NFS_SERVER(ino);
369         unsigned int max_payload;
370         rpc_authflavor_t flavor;
371
372         if (!ff_layout_mirror_valid(lseg, mirror)) {
373                 pr_err_ratelimited("NFS: %s: No data server for offset index %d\n",
374                         __func__, ds_idx);
375                 goto out;
376         }
377
378         devid = &mirror->mirror_ds->id_node;
379         if (ff_layout_test_devid_unavailable(devid))
380                 goto out;
381
382         ds = mirror->mirror_ds->ds;
383         /* matching smp_wmb() in _nfs4_pnfs_v3/4_ds_connect */
384         smp_rmb();
385         if (ds->ds_clp)
386                 goto out_update_creds;
387
388         flavor = nfs4_ff_layout_choose_authflavor(mirror);
389
390         /* FIXME: For now we assume the server sent only one version of NFS
391          * to use for the DS.
392          */
393         nfs4_pnfs_ds_connect(s, ds, devid, dataserver_timeo,
394                              dataserver_retrans,
395                              mirror->mirror_ds->ds_versions[0].version,
396                              mirror->mirror_ds->ds_versions[0].minor_version,
397                              flavor);
398
399         /* connect success, check rsize/wsize limit */
400         if (ds->ds_clp) {
401                 max_payload =
402                         nfs_block_size(rpc_max_payload(ds->ds_clp->cl_rpcclient),
403                                        NULL);
404                 if (mirror->mirror_ds->ds_versions[0].rsize > max_payload)
405                         mirror->mirror_ds->ds_versions[0].rsize = max_payload;
406                 if (mirror->mirror_ds->ds_versions[0].wsize > max_payload)
407                         mirror->mirror_ds->ds_versions[0].wsize = max_payload;
408         } else {
409                 ff_layout_track_ds_error(FF_LAYOUT_FROM_HDR(lseg->pls_layout),
410                                          mirror, lseg->pls_range.offset,
411                                          lseg->pls_range.length, NFS4ERR_NXIO,
412                                          OP_ILLEGAL, GFP_NOIO);
413                 if (!fail_return) {
414                         if (ff_layout_has_available_ds(lseg))
415                                 set_bit(NFS_LAYOUT_RETURN_BEFORE_CLOSE,
416                                         &lseg->pls_layout->plh_flags);
417                         else
418                                 pnfs_error_mark_layout_for_return(ino, lseg);
419                 } else
420                         pnfs_error_mark_layout_for_return(ino, lseg);
421         }
422 out_update_creds:
423         if (ff_layout_update_mirror_cred(mirror, ds))
424                 ds = NULL;
425 out:
426         return ds;
427 }
428
429 struct rpc_cred *
430 ff_layout_get_ds_cred(struct pnfs_layout_segment *lseg, u32 ds_idx,
431                       struct rpc_cred *mdscred)
432 {
433         struct nfs4_ff_layout_mirror *mirror = FF_LAYOUT_COMP(lseg, ds_idx);
434         struct rpc_cred *cred = ERR_PTR(-EINVAL);
435
436         if (!nfs4_ff_layout_prepare_ds(lseg, ds_idx, true))
437                 goto out;
438
439         if (mirror && mirror->cred)
440                 cred = mirror->cred;
441         else
442                 cred = mdscred;
443 out:
444         return cred;
445 }
446
447 /**
448 * Find or create a DS rpc client with th MDS server rpc client auth flavor
449 * in the nfs_client cl_ds_clients list.
450 */
451 struct rpc_clnt *
452 nfs4_ff_find_or_create_ds_client(struct pnfs_layout_segment *lseg, u32 ds_idx,
453                                  struct nfs_client *ds_clp, struct inode *inode)
454 {
455         struct nfs4_ff_layout_mirror *mirror = FF_LAYOUT_COMP(lseg, ds_idx);
456
457         switch (mirror->mirror_ds->ds_versions[0].version) {
458         case 3:
459                 /* For NFSv3 DS, flavor is set when creating DS connections */
460                 return ds_clp->cl_rpcclient;
461         case 4:
462                 return nfs4_find_or_create_ds_client(ds_clp, inode);
463         default:
464                 BUG();
465         }
466 }
467
468 static bool is_range_intersecting(u64 offset1, u64 length1,
469                                   u64 offset2, u64 length2)
470 {
471         u64 end1 = end_offset(offset1, length1);
472         u64 end2 = end_offset(offset2, length2);
473
474         return (end1 == NFS4_MAX_UINT64 || end1 > offset2) &&
475                (end2 == NFS4_MAX_UINT64 || end2 > offset1);
476 }
477
478 /* called with inode i_lock held */
479 int ff_layout_encode_ds_ioerr(struct nfs4_flexfile_layout *flo,
480                               struct xdr_stream *xdr, int *count,
481                               const struct pnfs_layout_range *range)
482 {
483         struct nfs4_ff_layout_ds_err *err, *n;
484         __be32 *p;
485
486         list_for_each_entry_safe(err, n, &flo->error_list, list) {
487                 if (!is_range_intersecting(err->offset, err->length,
488                                            range->offset, range->length))
489                         continue;
490                 /* offset(8) + length(8) + stateid(NFS4_STATEID_SIZE)
491                  * + array length + deviceid(NFS4_DEVICEID4_SIZE)
492                  * + status(4) + opnum(4)
493                  */
494                 p = xdr_reserve_space(xdr,
495                                 28 + NFS4_STATEID_SIZE + NFS4_DEVICEID4_SIZE);
496                 if (unlikely(!p))
497                         return -ENOBUFS;
498                 p = xdr_encode_hyper(p, err->offset);
499                 p = xdr_encode_hyper(p, err->length);
500                 p = xdr_encode_opaque_fixed(p, &err->stateid,
501                                             NFS4_STATEID_SIZE);
502                 /* Encode 1 error */
503                 *p++ = cpu_to_be32(1);
504                 p = xdr_encode_opaque_fixed(p, &err->deviceid,
505                                             NFS4_DEVICEID4_SIZE);
506                 *p++ = cpu_to_be32(err->status);
507                 *p++ = cpu_to_be32(err->opnum);
508                 *count += 1;
509                 list_del(&err->list);
510                 dprintk("%s: offset %llu length %llu status %d op %d count %d\n",
511                         __func__, err->offset, err->length, err->status,
512                         err->opnum, *count);
513                 kfree(err);
514         }
515
516         return 0;
517 }
518
519 static bool ff_read_layout_has_available_ds(struct pnfs_layout_segment *lseg)
520 {
521         struct nfs4_ff_layout_mirror *mirror;
522         struct nfs4_deviceid_node *devid;
523         u32 idx;
524
525         for (idx = 0; idx < FF_LAYOUT_MIRROR_COUNT(lseg); idx++) {
526                 mirror = FF_LAYOUT_COMP(lseg, idx);
527                 if (mirror && mirror->mirror_ds) {
528                         devid = &mirror->mirror_ds->id_node;
529                         if (!ff_layout_test_devid_unavailable(devid))
530                                 return true;
531                 }
532         }
533
534         return false;
535 }
536
537 static bool ff_rw_layout_has_available_ds(struct pnfs_layout_segment *lseg)
538 {
539         struct nfs4_ff_layout_mirror *mirror;
540         struct nfs4_deviceid_node *devid;
541         u32 idx;
542
543         for (idx = 0; idx < FF_LAYOUT_MIRROR_COUNT(lseg); idx++) {
544                 mirror = FF_LAYOUT_COMP(lseg, idx);
545                 if (!mirror || !mirror->mirror_ds)
546                         return false;
547                 devid = &mirror->mirror_ds->id_node;
548                 if (ff_layout_test_devid_unavailable(devid))
549                         return false;
550         }
551
552         return FF_LAYOUT_MIRROR_COUNT(lseg) != 0;
553 }
554
555 bool ff_layout_has_available_ds(struct pnfs_layout_segment *lseg)
556 {
557         if (lseg->pls_range.iomode == IOMODE_READ)
558                 return  ff_read_layout_has_available_ds(lseg);
559         /* Note: RW layout needs all mirrors available */
560         return ff_rw_layout_has_available_ds(lseg);
561 }
562
563 module_param(dataserver_retrans, uint, 0644);
564 MODULE_PARM_DESC(dataserver_retrans, "The  number of times the NFSv4.1 client "
565                         "retries a request before it attempts further "
566                         " recovery  action.");
567 module_param(dataserver_timeo, uint, 0644);
568 MODULE_PARM_DESC(dataserver_timeo, "The time (in tenths of a second) the "
569                         "NFSv4.1  client  waits for a response from a "
570                         " data server before it retries an NFS request.");