Commit | Line | Data |
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85e174ba RL |
1 | /* |
2 | * pNFS functions to call and manage layout drivers. | |
3 | * | |
4 | * Copyright (c) 2002 [year of first publication] | |
5 | * The Regents of the University of Michigan | |
6 | * All Rights Reserved | |
7 | * | |
8 | * Dean Hildebrand <dhildebz@umich.edu> | |
9 | * | |
10 | * Permission is granted to use, copy, create derivative works, and | |
11 | * redistribute this software and such derivative works for any purpose, | |
12 | * so long as the name of the University of Michigan is not used in | |
13 | * any advertising or publicity pertaining to the use or distribution | |
14 | * of this software without specific, written prior authorization. If | |
15 | * the above copyright notice or any other identification of the | |
16 | * University of Michigan is included in any copy of any portion of | |
17 | * this software, then the disclaimer below must also be included. | |
18 | * | |
19 | * This software is provided as is, without representation or warranty | |
20 | * of any kind either express or implied, including without limitation | |
21 | * the implied warranties of merchantability, fitness for a particular | |
22 | * purpose, or noninfringement. The Regents of the University of | |
23 | * Michigan shall not be liable for any damages, including special, | |
24 | * indirect, incidental, or consequential damages, with respect to any | |
25 | * claim arising out of or in connection with the use of the software, | |
26 | * even if it has been or is hereafter advised of the possibility of | |
27 | * such damages. | |
28 | */ | |
29 | ||
30 | #include <linux/nfs_fs.h> | |
974cec8c | 31 | #include "internal.h" |
85e174ba RL |
32 | #include "pnfs.h" |
33 | ||
34 | #define NFSDBG_FACILITY NFSDBG_PNFS | |
35 | ||
02c35fca FI |
36 | /* Locking: |
37 | * | |
38 | * pnfs_spinlock: | |
39 | * protects pnfs_modules_tbl. | |
40 | */ | |
41 | static DEFINE_SPINLOCK(pnfs_spinlock); | |
42 | ||
43 | /* | |
44 | * pnfs_modules_tbl holds all pnfs modules | |
45 | */ | |
46 | static LIST_HEAD(pnfs_modules_tbl); | |
47 | ||
48 | /* Return the registered pnfs layout driver module matching given id */ | |
49 | static struct pnfs_layoutdriver_type * | |
50 | find_pnfs_driver_locked(u32 id) | |
51 | { | |
52 | struct pnfs_layoutdriver_type *local; | |
53 | ||
54 | list_for_each_entry(local, &pnfs_modules_tbl, pnfs_tblid) | |
55 | if (local->id == id) | |
56 | goto out; | |
57 | local = NULL; | |
58 | out: | |
59 | dprintk("%s: Searching for id %u, found %p\n", __func__, id, local); | |
60 | return local; | |
61 | } | |
62 | ||
85e174ba RL |
63 | static struct pnfs_layoutdriver_type * |
64 | find_pnfs_driver(u32 id) | |
65 | { | |
02c35fca FI |
66 | struct pnfs_layoutdriver_type *local; |
67 | ||
68 | spin_lock(&pnfs_spinlock); | |
69 | local = find_pnfs_driver_locked(id); | |
70 | spin_unlock(&pnfs_spinlock); | |
71 | return local; | |
85e174ba RL |
72 | } |
73 | ||
74 | void | |
75 | unset_pnfs_layoutdriver(struct nfs_server *nfss) | |
76 | { | |
02c35fca | 77 | if (nfss->pnfs_curr_ld) { |
1c787096 | 78 | nfss->pnfs_curr_ld->clear_layoutdriver(nfss); |
02c35fca FI |
79 | module_put(nfss->pnfs_curr_ld->owner); |
80 | } | |
85e174ba RL |
81 | nfss->pnfs_curr_ld = NULL; |
82 | } | |
83 | ||
84 | /* | |
85 | * Try to set the server's pnfs module to the pnfs layout type specified by id. | |
86 | * Currently only one pNFS layout driver per filesystem is supported. | |
87 | * | |
88 | * @id layout type. Zero (illegal layout type) indicates pNFS not in use. | |
89 | */ | |
90 | void | |
91 | set_pnfs_layoutdriver(struct nfs_server *server, u32 id) | |
92 | { | |
93 | struct pnfs_layoutdriver_type *ld_type = NULL; | |
94 | ||
95 | if (id == 0) | |
96 | goto out_no_driver; | |
97 | if (!(server->nfs_client->cl_exchange_flags & | |
98 | (EXCHGID4_FLAG_USE_NON_PNFS | EXCHGID4_FLAG_USE_PNFS_MDS))) { | |
99 | printk(KERN_ERR "%s: id %u cl_exchange_flags 0x%x\n", __func__, | |
100 | id, server->nfs_client->cl_exchange_flags); | |
101 | goto out_no_driver; | |
102 | } | |
103 | ld_type = find_pnfs_driver(id); | |
104 | if (!ld_type) { | |
105 | request_module("%s-%u", LAYOUT_NFSV4_1_MODULE_PREFIX, id); | |
106 | ld_type = find_pnfs_driver(id); | |
107 | if (!ld_type) { | |
108 | dprintk("%s: No pNFS module found for %u.\n", | |
109 | __func__, id); | |
110 | goto out_no_driver; | |
111 | } | |
112 | } | |
02c35fca FI |
113 | if (!try_module_get(ld_type->owner)) { |
114 | dprintk("%s: Could not grab reference on module\n", __func__); | |
115 | goto out_no_driver; | |
116 | } | |
85e174ba | 117 | server->pnfs_curr_ld = ld_type; |
1c787096 | 118 | if (ld_type->set_layoutdriver(server)) { |
02c35fca FI |
119 | printk(KERN_ERR |
120 | "%s: Error initializing mount point for layout driver %u.\n", | |
121 | __func__, id); | |
122 | module_put(ld_type->owner); | |
123 | goto out_no_driver; | |
124 | } | |
85e174ba RL |
125 | dprintk("%s: pNFS module for %u set\n", __func__, id); |
126 | return; | |
127 | ||
128 | out_no_driver: | |
129 | dprintk("%s: Using NFSv4 I/O\n", __func__); | |
130 | server->pnfs_curr_ld = NULL; | |
131 | } | |
02c35fca FI |
132 | |
133 | int | |
134 | pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *ld_type) | |
135 | { | |
136 | int status = -EINVAL; | |
137 | struct pnfs_layoutdriver_type *tmp; | |
138 | ||
139 | if (ld_type->id == 0) { | |
140 | printk(KERN_ERR "%s id 0 is reserved\n", __func__); | |
141 | return status; | |
142 | } | |
b1f69b75 AA |
143 | if (!ld_type->alloc_lseg || !ld_type->free_lseg) { |
144 | printk(KERN_ERR "%s Layout driver must provide " | |
145 | "alloc_lseg and free_lseg.\n", __func__); | |
146 | return status; | |
147 | } | |
02c35fca FI |
148 | |
149 | spin_lock(&pnfs_spinlock); | |
150 | tmp = find_pnfs_driver_locked(ld_type->id); | |
151 | if (!tmp) { | |
152 | list_add(&ld_type->pnfs_tblid, &pnfs_modules_tbl); | |
153 | status = 0; | |
154 | dprintk("%s Registering id:%u name:%s\n", __func__, ld_type->id, | |
155 | ld_type->name); | |
156 | } else { | |
157 | printk(KERN_ERR "%s Module with id %d already loaded!\n", | |
158 | __func__, ld_type->id); | |
159 | } | |
160 | spin_unlock(&pnfs_spinlock); | |
161 | ||
162 | return status; | |
163 | } | |
164 | EXPORT_SYMBOL_GPL(pnfs_register_layoutdriver); | |
165 | ||
166 | void | |
167 | pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *ld_type) | |
168 | { | |
169 | dprintk("%s Deregistering id:%u\n", __func__, ld_type->id); | |
170 | spin_lock(&pnfs_spinlock); | |
171 | list_del(&ld_type->pnfs_tblid); | |
172 | spin_unlock(&pnfs_spinlock); | |
173 | } | |
174 | EXPORT_SYMBOL_GPL(pnfs_unregister_layoutdriver); | |
e5e94017 | 175 | |
b1f69b75 AA |
176 | /* |
177 | * pNFS client layout cache | |
178 | */ | |
179 | ||
e5e94017 BH |
180 | static void |
181 | get_layout_hdr_locked(struct pnfs_layout_hdr *lo) | |
182 | { | |
183 | assert_spin_locked(&lo->inode->i_lock); | |
184 | lo->refcount++; | |
185 | } | |
186 | ||
187 | static void | |
188 | put_layout_hdr_locked(struct pnfs_layout_hdr *lo) | |
189 | { | |
190 | assert_spin_locked(&lo->inode->i_lock); | |
191 | BUG_ON(lo->refcount == 0); | |
192 | ||
193 | lo->refcount--; | |
194 | if (!lo->refcount) { | |
195 | dprintk("%s: freeing layout cache %p\n", __func__, lo); | |
974cec8c | 196 | BUG_ON(!list_empty(&lo->layouts)); |
e5e94017 BH |
197 | NFS_I(lo->inode)->layout = NULL; |
198 | kfree(lo); | |
199 | } | |
200 | } | |
201 | ||
b1f69b75 | 202 | void |
974cec8c AA |
203 | put_layout_hdr(struct inode *inode) |
204 | { | |
205 | spin_lock(&inode->i_lock); | |
206 | put_layout_hdr_locked(NFS_I(inode)->layout); | |
207 | spin_unlock(&inode->i_lock); | |
208 | } | |
209 | ||
210 | static void | |
211 | init_lseg(struct pnfs_layout_hdr *lo, struct pnfs_layout_segment *lseg) | |
212 | { | |
213 | INIT_LIST_HEAD(&lseg->fi_list); | |
214 | kref_init(&lseg->kref); | |
215 | lseg->layout = lo; | |
216 | } | |
217 | ||
218 | /* Called without i_lock held, as the free_lseg call may sleep */ | |
219 | static void | |
220 | destroy_lseg(struct kref *kref) | |
221 | { | |
222 | struct pnfs_layout_segment *lseg = | |
223 | container_of(kref, struct pnfs_layout_segment, kref); | |
224 | struct inode *ino = lseg->layout->inode; | |
225 | ||
226 | dprintk("--> %s\n", __func__); | |
b1f69b75 | 227 | NFS_SERVER(ino)->pnfs_curr_ld->free_lseg(lseg); |
52fabd73 | 228 | /* Matched by get_layout_hdr in pnfs_insert_layout */ |
974cec8c AA |
229 | put_layout_hdr(ino); |
230 | } | |
231 | ||
232 | static void | |
233 | put_lseg(struct pnfs_layout_segment *lseg) | |
234 | { | |
235 | if (!lseg) | |
236 | return; | |
237 | ||
238 | dprintk("%s: lseg %p ref %d\n", __func__, lseg, | |
239 | atomic_read(&lseg->kref.refcount)); | |
240 | kref_put(&lseg->kref, destroy_lseg); | |
241 | } | |
242 | ||
243 | static void | |
244 | pnfs_clear_lseg_list(struct pnfs_layout_hdr *lo, struct list_head *tmp_list) | |
245 | { | |
246 | struct pnfs_layout_segment *lseg, *next; | |
247 | struct nfs_client *clp; | |
248 | ||
249 | dprintk("%s:Begin lo %p\n", __func__, lo); | |
250 | ||
251 | assert_spin_locked(&lo->inode->i_lock); | |
252 | list_for_each_entry_safe(lseg, next, &lo->segs, fi_list) { | |
253 | dprintk("%s: freeing lseg %p\n", __func__, lseg); | |
254 | list_move(&lseg->fi_list, tmp_list); | |
255 | } | |
256 | clp = NFS_SERVER(lo->inode)->nfs_client; | |
257 | spin_lock(&clp->cl_lock); | |
258 | /* List does not take a reference, so no need for put here */ | |
259 | list_del_init(&lo->layouts); | |
260 | spin_unlock(&clp->cl_lock); | |
b1f69b75 AA |
261 | write_seqlock(&lo->seqlock); |
262 | clear_bit(NFS_LAYOUT_STATEID_SET, &lo->state); | |
263 | write_sequnlock(&lo->seqlock); | |
974cec8c AA |
264 | |
265 | dprintk("%s:Return\n", __func__); | |
266 | } | |
267 | ||
268 | static void | |
269 | pnfs_free_lseg_list(struct list_head *tmp_list) | |
270 | { | |
271 | struct pnfs_layout_segment *lseg; | |
272 | ||
273 | while (!list_empty(tmp_list)) { | |
274 | lseg = list_entry(tmp_list->next, struct pnfs_layout_segment, | |
275 | fi_list); | |
276 | dprintk("%s calling put_lseg on %p\n", __func__, lseg); | |
277 | list_del(&lseg->fi_list); | |
278 | put_lseg(lseg); | |
279 | } | |
280 | } | |
281 | ||
e5e94017 BH |
282 | void |
283 | pnfs_destroy_layout(struct nfs_inode *nfsi) | |
284 | { | |
285 | struct pnfs_layout_hdr *lo; | |
974cec8c | 286 | LIST_HEAD(tmp_list); |
e5e94017 BH |
287 | |
288 | spin_lock(&nfsi->vfs_inode.i_lock); | |
289 | lo = nfsi->layout; | |
290 | if (lo) { | |
974cec8c | 291 | pnfs_clear_lseg_list(lo, &tmp_list); |
e5e94017 BH |
292 | /* Matched by refcount set to 1 in alloc_init_layout_hdr */ |
293 | put_layout_hdr_locked(lo); | |
294 | } | |
295 | spin_unlock(&nfsi->vfs_inode.i_lock); | |
974cec8c AA |
296 | pnfs_free_lseg_list(&tmp_list); |
297 | } | |
298 | ||
299 | /* | |
300 | * Called by the state manger to remove all layouts established under an | |
301 | * expired lease. | |
302 | */ | |
303 | void | |
304 | pnfs_destroy_all_layouts(struct nfs_client *clp) | |
305 | { | |
306 | struct pnfs_layout_hdr *lo; | |
307 | LIST_HEAD(tmp_list); | |
308 | ||
309 | spin_lock(&clp->cl_lock); | |
310 | list_splice_init(&clp->cl_layouts, &tmp_list); | |
311 | spin_unlock(&clp->cl_lock); | |
312 | ||
313 | while (!list_empty(&tmp_list)) { | |
314 | lo = list_entry(tmp_list.next, struct pnfs_layout_hdr, | |
315 | layouts); | |
316 | dprintk("%s freeing layout for inode %lu\n", __func__, | |
317 | lo->inode->i_ino); | |
318 | pnfs_destroy_layout(NFS_I(lo->inode)); | |
319 | } | |
e5e94017 BH |
320 | } |
321 | ||
b1f69b75 AA |
322 | /* update lo->stateid with new if is more recent |
323 | * | |
324 | * lo->stateid could be the open stateid, in which case we just use what given. | |
325 | */ | |
326 | static void | |
327 | pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo, | |
328 | const nfs4_stateid *new) | |
329 | { | |
330 | nfs4_stateid *old = &lo->stateid; | |
331 | bool overwrite = false; | |
332 | ||
333 | write_seqlock(&lo->seqlock); | |
334 | if (!test_bit(NFS_LAYOUT_STATEID_SET, &lo->state) || | |
335 | memcmp(old->stateid.other, new->stateid.other, sizeof(new->stateid.other))) | |
336 | overwrite = true; | |
337 | else { | |
338 | u32 oldseq, newseq; | |
339 | ||
340 | oldseq = be32_to_cpu(old->stateid.seqid); | |
341 | newseq = be32_to_cpu(new->stateid.seqid); | |
342 | if ((int)(newseq - oldseq) > 0) | |
343 | overwrite = true; | |
344 | } | |
345 | if (overwrite) | |
346 | memcpy(&old->stateid, &new->stateid, sizeof(new->stateid)); | |
347 | write_sequnlock(&lo->seqlock); | |
348 | } | |
349 | ||
350 | static void | |
351 | pnfs_layout_from_open_stateid(struct pnfs_layout_hdr *lo, | |
352 | struct nfs4_state *state) | |
353 | { | |
354 | int seq; | |
355 | ||
356 | dprintk("--> %s\n", __func__); | |
357 | write_seqlock(&lo->seqlock); | |
358 | do { | |
359 | seq = read_seqbegin(&state->seqlock); | |
360 | memcpy(lo->stateid.data, state->stateid.data, | |
361 | sizeof(state->stateid.data)); | |
362 | } while (read_seqretry(&state->seqlock, seq)); | |
363 | set_bit(NFS_LAYOUT_STATEID_SET, &lo->state); | |
364 | write_sequnlock(&lo->seqlock); | |
365 | dprintk("<-- %s\n", __func__); | |
366 | } | |
367 | ||
368 | void | |
369 | pnfs_get_layout_stateid(nfs4_stateid *dst, struct pnfs_layout_hdr *lo, | |
370 | struct nfs4_state *open_state) | |
371 | { | |
372 | int seq; | |
974cec8c | 373 | |
b1f69b75 AA |
374 | dprintk("--> %s\n", __func__); |
375 | do { | |
376 | seq = read_seqbegin(&lo->seqlock); | |
377 | if (!test_bit(NFS_LAYOUT_STATEID_SET, &lo->state)) { | |
378 | /* This will trigger retry of the read */ | |
379 | pnfs_layout_from_open_stateid(lo, open_state); | |
380 | } else | |
381 | memcpy(dst->data, lo->stateid.data, | |
382 | sizeof(lo->stateid.data)); | |
383 | } while (read_seqretry(&lo->seqlock, seq)); | |
384 | dprintk("<-- %s\n", __func__); | |
385 | } | |
386 | ||
387 | /* | |
388 | * Get layout from server. | |
389 | * for now, assume that whole file layouts are requested. | |
390 | * arg->offset: 0 | |
391 | * arg->length: all ones | |
392 | */ | |
e5e94017 BH |
393 | static struct pnfs_layout_segment * |
394 | send_layoutget(struct pnfs_layout_hdr *lo, | |
395 | struct nfs_open_context *ctx, | |
396 | u32 iomode) | |
397 | { | |
398 | struct inode *ino = lo->inode; | |
b1f69b75 AA |
399 | struct nfs_server *server = NFS_SERVER(ino); |
400 | struct nfs4_layoutget *lgp; | |
401 | struct pnfs_layout_segment *lseg = NULL; | |
402 | ||
403 | dprintk("--> %s\n", __func__); | |
e5e94017 | 404 | |
b1f69b75 AA |
405 | BUG_ON(ctx == NULL); |
406 | lgp = kzalloc(sizeof(*lgp), GFP_KERNEL); | |
407 | if (lgp == NULL) { | |
408 | put_layout_hdr(lo->inode); | |
409 | return NULL; | |
410 | } | |
411 | lgp->args.minlength = NFS4_MAX_UINT64; | |
412 | lgp->args.maxcount = PNFS_LAYOUT_MAXSIZE; | |
413 | lgp->args.range.iomode = iomode; | |
414 | lgp->args.range.offset = 0; | |
415 | lgp->args.range.length = NFS4_MAX_UINT64; | |
416 | lgp->args.type = server->pnfs_curr_ld->id; | |
417 | lgp->args.inode = ino; | |
418 | lgp->args.ctx = get_nfs_open_context(ctx); | |
419 | lgp->lsegpp = &lseg; | |
420 | ||
421 | /* Synchronously retrieve layout information from server and | |
422 | * store in lseg. | |
423 | */ | |
424 | nfs4_proc_layoutget(lgp); | |
974cec8c | 425 | if (!lseg) { |
b1f69b75 | 426 | /* remember that LAYOUTGET failed and suspend trying */ |
974cec8c | 427 | set_bit(lo_fail_bit(iomode), &lo->state); |
974cec8c | 428 | } |
974cec8c AA |
429 | return lseg; |
430 | } | |
431 | ||
b1f69b75 AA |
432 | /* |
433 | * Compare two layout segments for sorting into layout cache. | |
434 | * We want to preferentially return RW over RO layouts, so ensure those | |
435 | * are seen first. | |
436 | */ | |
437 | static s64 | |
438 | cmp_layout(u32 iomode1, u32 iomode2) | |
439 | { | |
440 | /* read > read/write */ | |
441 | return (int)(iomode2 == IOMODE_READ) - (int)(iomode1 == IOMODE_READ); | |
442 | } | |
443 | ||
974cec8c AA |
444 | static void |
445 | pnfs_insert_layout(struct pnfs_layout_hdr *lo, | |
446 | struct pnfs_layout_segment *lseg) | |
447 | { | |
b1f69b75 AA |
448 | struct pnfs_layout_segment *lp; |
449 | int found = 0; | |
450 | ||
974cec8c AA |
451 | dprintk("%s:Begin\n", __func__); |
452 | ||
453 | assert_spin_locked(&lo->inode->i_lock); | |
454 | if (list_empty(&lo->segs)) { | |
455 | struct nfs_client *clp = NFS_SERVER(lo->inode)->nfs_client; | |
456 | ||
457 | spin_lock(&clp->cl_lock); | |
458 | BUG_ON(!list_empty(&lo->layouts)); | |
459 | list_add_tail(&lo->layouts, &clp->cl_layouts); | |
460 | spin_unlock(&clp->cl_lock); | |
461 | } | |
b1f69b75 AA |
462 | list_for_each_entry(lp, &lo->segs, fi_list) { |
463 | if (cmp_layout(lp->range.iomode, lseg->range.iomode) > 0) | |
464 | continue; | |
465 | list_add_tail(&lseg->fi_list, &lp->fi_list); | |
466 | dprintk("%s: inserted lseg %p " | |
467 | "iomode %d offset %llu length %llu before " | |
468 | "lp %p iomode %d offset %llu length %llu\n", | |
469 | __func__, lseg, lseg->range.iomode, | |
470 | lseg->range.offset, lseg->range.length, | |
471 | lp, lp->range.iomode, lp->range.offset, | |
472 | lp->range.length); | |
473 | found = 1; | |
474 | break; | |
475 | } | |
476 | if (!found) { | |
974cec8c | 477 | list_add_tail(&lseg->fi_list, &lo->segs); |
b1f69b75 AA |
478 | dprintk("%s: inserted lseg %p " |
479 | "iomode %d offset %llu length %llu at tail\n", | |
480 | __func__, lseg, lseg->range.iomode, | |
481 | lseg->range.offset, lseg->range.length); | |
974cec8c | 482 | } |
b1f69b75 | 483 | get_layout_hdr_locked(lo); |
974cec8c AA |
484 | |
485 | dprintk("%s:Return\n", __func__); | |
e5e94017 BH |
486 | } |
487 | ||
488 | static struct pnfs_layout_hdr * | |
489 | alloc_init_layout_hdr(struct inode *ino) | |
490 | { | |
491 | struct pnfs_layout_hdr *lo; | |
492 | ||
493 | lo = kzalloc(sizeof(struct pnfs_layout_hdr), GFP_KERNEL); | |
494 | if (!lo) | |
495 | return NULL; | |
496 | lo->refcount = 1; | |
974cec8c AA |
497 | INIT_LIST_HEAD(&lo->layouts); |
498 | INIT_LIST_HEAD(&lo->segs); | |
b1f69b75 | 499 | seqlock_init(&lo->seqlock); |
e5e94017 BH |
500 | lo->inode = ino; |
501 | return lo; | |
502 | } | |
503 | ||
504 | static struct pnfs_layout_hdr * | |
505 | pnfs_find_alloc_layout(struct inode *ino) | |
506 | { | |
507 | struct nfs_inode *nfsi = NFS_I(ino); | |
508 | struct pnfs_layout_hdr *new = NULL; | |
509 | ||
510 | dprintk("%s Begin ino=%p layout=%p\n", __func__, ino, nfsi->layout); | |
511 | ||
512 | assert_spin_locked(&ino->i_lock); | |
513 | if (nfsi->layout) | |
514 | return nfsi->layout; | |
515 | ||
516 | spin_unlock(&ino->i_lock); | |
517 | new = alloc_init_layout_hdr(ino); | |
518 | spin_lock(&ino->i_lock); | |
519 | ||
520 | if (likely(nfsi->layout == NULL)) /* Won the race? */ | |
521 | nfsi->layout = new; | |
522 | else | |
523 | kfree(new); | |
524 | return nfsi->layout; | |
525 | } | |
526 | ||
b1f69b75 AA |
527 | /* |
528 | * iomode matching rules: | |
529 | * iomode lseg match | |
530 | * ----- ----- ----- | |
531 | * ANY READ true | |
532 | * ANY RW true | |
533 | * RW READ false | |
534 | * RW RW true | |
535 | * READ READ true | |
536 | * READ RW true | |
537 | */ | |
538 | static int | |
539 | is_matching_lseg(struct pnfs_layout_segment *lseg, u32 iomode) | |
540 | { | |
541 | return (iomode != IOMODE_RW || lseg->range.iomode == IOMODE_RW); | |
542 | } | |
543 | ||
544 | /* | |
545 | * lookup range in layout | |
546 | */ | |
e5e94017 BH |
547 | static struct pnfs_layout_segment * |
548 | pnfs_has_layout(struct pnfs_layout_hdr *lo, u32 iomode) | |
549 | { | |
b1f69b75 AA |
550 | struct pnfs_layout_segment *lseg, *ret = NULL; |
551 | ||
552 | dprintk("%s:Begin\n", __func__); | |
553 | ||
554 | assert_spin_locked(&lo->inode->i_lock); | |
555 | list_for_each_entry(lseg, &lo->segs, fi_list) { | |
556 | if (is_matching_lseg(lseg, iomode)) { | |
557 | ret = lseg; | |
558 | break; | |
559 | } | |
560 | if (cmp_layout(iomode, lseg->range.iomode) > 0) | |
561 | break; | |
562 | } | |
563 | ||
564 | dprintk("%s:Return lseg %p ref %d\n", | |
565 | __func__, ret, ret ? atomic_read(&ret->kref.refcount) : 0); | |
566 | return ret; | |
e5e94017 BH |
567 | } |
568 | ||
569 | /* | |
570 | * Layout segment is retreived from the server if not cached. | |
571 | * The appropriate layout segment is referenced and returned to the caller. | |
572 | */ | |
573 | struct pnfs_layout_segment * | |
574 | pnfs_update_layout(struct inode *ino, | |
575 | struct nfs_open_context *ctx, | |
576 | enum pnfs_iomode iomode) | |
577 | { | |
578 | struct nfs_inode *nfsi = NFS_I(ino); | |
579 | struct pnfs_layout_hdr *lo; | |
580 | struct pnfs_layout_segment *lseg = NULL; | |
581 | ||
582 | if (!pnfs_enabled_sb(NFS_SERVER(ino))) | |
583 | return NULL; | |
584 | spin_lock(&ino->i_lock); | |
585 | lo = pnfs_find_alloc_layout(ino); | |
586 | if (lo == NULL) { | |
587 | dprintk("%s ERROR: can't get pnfs_layout_hdr\n", __func__); | |
588 | goto out_unlock; | |
589 | } | |
590 | ||
591 | /* Check to see if the layout for the given range already exists */ | |
592 | lseg = pnfs_has_layout(lo, iomode); | |
593 | if (lseg) { | |
594 | dprintk("%s: Using cached lseg %p for iomode %d)\n", | |
595 | __func__, lseg, iomode); | |
596 | goto out_unlock; | |
597 | } | |
598 | ||
599 | /* if LAYOUTGET already failed once we don't try again */ | |
600 | if (test_bit(lo_fail_bit(iomode), &nfsi->layout->state)) | |
601 | goto out_unlock; | |
602 | ||
b1f69b75 | 603 | get_layout_hdr_locked(lo); /* Matched in nfs4_layoutget_release */ |
e5e94017 BH |
604 | spin_unlock(&ino->i_lock); |
605 | ||
606 | lseg = send_layoutget(lo, ctx, iomode); | |
607 | out: | |
608 | dprintk("%s end, state 0x%lx lseg %p\n", __func__, | |
609 | nfsi->layout->state, lseg); | |
610 | return lseg; | |
611 | out_unlock: | |
612 | spin_unlock(&ino->i_lock); | |
613 | goto out; | |
614 | } | |
b1f69b75 AA |
615 | |
616 | int | |
617 | pnfs_layout_process(struct nfs4_layoutget *lgp) | |
618 | { | |
619 | struct pnfs_layout_hdr *lo = NFS_I(lgp->args.inode)->layout; | |
620 | struct nfs4_layoutget_res *res = &lgp->res; | |
621 | struct pnfs_layout_segment *lseg; | |
622 | struct inode *ino = lo->inode; | |
623 | int status = 0; | |
624 | ||
625 | /* Inject layout blob into I/O device driver */ | |
626 | lseg = NFS_SERVER(ino)->pnfs_curr_ld->alloc_lseg(lo, res); | |
627 | if (!lseg || IS_ERR(lseg)) { | |
628 | if (!lseg) | |
629 | status = -ENOMEM; | |
630 | else | |
631 | status = PTR_ERR(lseg); | |
632 | dprintk("%s: Could not allocate layout: error %d\n", | |
633 | __func__, status); | |
634 | goto out; | |
635 | } | |
636 | ||
637 | spin_lock(&ino->i_lock); | |
638 | init_lseg(lo, lseg); | |
639 | lseg->range = res->range; | |
640 | *lgp->lsegpp = lseg; | |
641 | pnfs_insert_layout(lo, lseg); | |
642 | ||
643 | /* Done processing layoutget. Set the layout stateid */ | |
644 | pnfs_set_layout_stateid(lo, &res->stateid); | |
645 | spin_unlock(&ino->i_lock); | |
646 | out: | |
647 | return status; | |
648 | } | |
649 | ||
650 | /* | |
651 | * Device ID cache. Currently supports one layout type per struct nfs_client. | |
652 | * Add layout type to the lookup key to expand to support multiple types. | |
653 | */ | |
654 | int | |
655 | pnfs_alloc_init_deviceid_cache(struct nfs_client *clp, | |
656 | void (*free_callback)(struct pnfs_deviceid_node *)) | |
657 | { | |
658 | struct pnfs_deviceid_cache *c; | |
659 | ||
660 | c = kzalloc(sizeof(struct pnfs_deviceid_cache), GFP_KERNEL); | |
661 | if (!c) | |
662 | return -ENOMEM; | |
663 | spin_lock(&clp->cl_lock); | |
664 | if (clp->cl_devid_cache != NULL) { | |
665 | atomic_inc(&clp->cl_devid_cache->dc_ref); | |
666 | dprintk("%s [kref [%d]]\n", __func__, | |
667 | atomic_read(&clp->cl_devid_cache->dc_ref)); | |
668 | kfree(c); | |
669 | } else { | |
670 | /* kzalloc initializes hlists */ | |
671 | spin_lock_init(&c->dc_lock); | |
672 | atomic_set(&c->dc_ref, 1); | |
673 | c->dc_free_callback = free_callback; | |
674 | clp->cl_devid_cache = c; | |
675 | dprintk("%s [new]\n", __func__); | |
676 | } | |
677 | spin_unlock(&clp->cl_lock); | |
678 | return 0; | |
679 | } | |
680 | EXPORT_SYMBOL_GPL(pnfs_alloc_init_deviceid_cache); | |
681 | ||
682 | /* | |
683 | * Called from pnfs_layoutdriver_type->free_lseg | |
684 | * last layout segment reference frees deviceid | |
685 | */ | |
686 | void | |
687 | pnfs_put_deviceid(struct pnfs_deviceid_cache *c, | |
688 | struct pnfs_deviceid_node *devid) | |
689 | { | |
690 | struct nfs4_deviceid *id = &devid->de_id; | |
691 | struct pnfs_deviceid_node *d; | |
692 | struct hlist_node *n; | |
693 | long h = nfs4_deviceid_hash(id); | |
694 | ||
695 | dprintk("%s [%d]\n", __func__, atomic_read(&devid->de_ref)); | |
696 | if (!atomic_dec_and_lock(&devid->de_ref, &c->dc_lock)) | |
697 | return; | |
698 | ||
699 | hlist_for_each_entry_rcu(d, n, &c->dc_deviceids[h], de_node) | |
700 | if (!memcmp(&d->de_id, id, sizeof(*id))) { | |
701 | hlist_del_rcu(&d->de_node); | |
702 | spin_unlock(&c->dc_lock); | |
703 | synchronize_rcu(); | |
704 | c->dc_free_callback(devid); | |
705 | return; | |
706 | } | |
707 | spin_unlock(&c->dc_lock); | |
708 | /* Why wasn't it found in the list? */ | |
709 | BUG(); | |
710 | } | |
711 | EXPORT_SYMBOL_GPL(pnfs_put_deviceid); | |
712 | ||
713 | /* Find and reference a deviceid */ | |
714 | struct pnfs_deviceid_node * | |
715 | pnfs_find_get_deviceid(struct pnfs_deviceid_cache *c, struct nfs4_deviceid *id) | |
716 | { | |
717 | struct pnfs_deviceid_node *d; | |
718 | struct hlist_node *n; | |
719 | long hash = nfs4_deviceid_hash(id); | |
720 | ||
721 | dprintk("--> %s hash %ld\n", __func__, hash); | |
722 | rcu_read_lock(); | |
723 | hlist_for_each_entry_rcu(d, n, &c->dc_deviceids[hash], de_node) { | |
724 | if (!memcmp(&d->de_id, id, sizeof(*id))) { | |
725 | if (!atomic_inc_not_zero(&d->de_ref)) { | |
726 | goto fail; | |
727 | } else { | |
728 | rcu_read_unlock(); | |
729 | return d; | |
730 | } | |
731 | } | |
732 | } | |
733 | fail: | |
734 | rcu_read_unlock(); | |
735 | return NULL; | |
736 | } | |
737 | EXPORT_SYMBOL_GPL(pnfs_find_get_deviceid); | |
738 | ||
739 | /* | |
740 | * Add a deviceid to the cache. | |
741 | * GETDEVICEINFOs for same deviceid can race. If deviceid is found, discard new | |
742 | */ | |
743 | struct pnfs_deviceid_node * | |
744 | pnfs_add_deviceid(struct pnfs_deviceid_cache *c, struct pnfs_deviceid_node *new) | |
745 | { | |
746 | struct pnfs_deviceid_node *d; | |
747 | long hash = nfs4_deviceid_hash(&new->de_id); | |
748 | ||
749 | dprintk("--> %s hash %ld\n", __func__, hash); | |
750 | spin_lock(&c->dc_lock); | |
751 | d = pnfs_find_get_deviceid(c, &new->de_id); | |
752 | if (d) { | |
753 | spin_unlock(&c->dc_lock); | |
754 | dprintk("%s [discard]\n", __func__); | |
755 | c->dc_free_callback(new); | |
756 | return d; | |
757 | } | |
758 | INIT_HLIST_NODE(&new->de_node); | |
759 | atomic_set(&new->de_ref, 1); | |
760 | hlist_add_head_rcu(&new->de_node, &c->dc_deviceids[hash]); | |
761 | spin_unlock(&c->dc_lock); | |
762 | dprintk("%s [new]\n", __func__); | |
763 | return new; | |
764 | } | |
765 | EXPORT_SYMBOL_GPL(pnfs_add_deviceid); | |
766 | ||
767 | void | |
768 | pnfs_put_deviceid_cache(struct nfs_client *clp) | |
769 | { | |
770 | struct pnfs_deviceid_cache *local = clp->cl_devid_cache; | |
771 | ||
772 | dprintk("--> %s cl_devid_cache %p\n", __func__, clp->cl_devid_cache); | |
773 | if (atomic_dec_and_lock(&local->dc_ref, &clp->cl_lock)) { | |
774 | int i; | |
775 | /* Verify cache is empty */ | |
776 | for (i = 0; i < NFS4_DEVICE_ID_HASH_SIZE; i++) | |
777 | BUG_ON(!hlist_empty(&local->dc_deviceids[i])); | |
778 | clp->cl_devid_cache = NULL; | |
779 | spin_unlock(&clp->cl_lock); | |
780 | kfree(local); | |
781 | } | |
782 | } | |
783 | EXPORT_SYMBOL_GPL(pnfs_put_deviceid_cache); |