1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * The NFSD open file cache. |
4 | * |
5 | * (c) 2015 - Jeff Layton <jeff.layton@primarydata.com> |
6 | * |
7 | * An nfsd_file object is a per-file collection of open state that binds |
8 | * together: |
9 | * - a struct file * |
10 | * - a user credential |
11 | * - a network namespace |
12 | * - a read-ahead context |
13 | * - monitoring for writeback errors |
14 | * |
15 | * nfsd_file objects are reference-counted. Consumers acquire a new |
16 | * object via the nfsd_file_acquire API. They manage their interest in |
17 | * the acquired object, and hence the object's reference count, via |
18 | * nfsd_file_get and nfsd_file_put. There are two varieties of nfsd_file |
19 | * object: |
20 | * |
21 | * * non-garbage-collected: When a consumer wants to precisely control |
22 | * the lifetime of a file's open state, it acquires a non-garbage- |
23 | * collected nfsd_file. The final nfsd_file_put releases the open |
24 | * state immediately. |
25 | * |
26 | * * garbage-collected: When a consumer does not control the lifetime |
27 | * of open state, it acquires a garbage-collected nfsd_file. The |
28 | * final nfsd_file_put allows the open state to linger for a period |
29 | * during which it may be re-used. |
30 | */ |
31 | |
32 | #include <linux/hash.h> |
33 | #include <linux/slab.h> |
34 | #include <linux/file.h> |
35 | #include <linux/pagemap.h> |
36 | #include <linux/sched.h> |
37 | #include <linux/list_lru.h> |
38 | #include <linux/fsnotify_backend.h> |
39 | #include <linux/fsnotify.h> |
40 | #include <linux/seq_file.h> |
41 | #include <linux/rhashtable.h> |
42 | |
43 | #include "vfs.h" |
44 | #include "nfsd.h" |
45 | #include "nfsfh.h" |
46 | #include "netns.h" |
47 | #include "filecache.h" |
48 | #include "trace.h" |
49 | |
50 | #define NFSD_LAUNDRETTE_DELAY (2 * HZ) |
51 | |
52 | #define NFSD_FILE_CACHE_UP (0) |
53 | |
54 | /* We only care about NFSD_MAY_READ/WRITE for this cache */ |
55 | #define NFSD_FILE_MAY_MASK (NFSD_MAY_READ|NFSD_MAY_WRITE) |
56 | |
57 | static DEFINE_PER_CPU(unsigned long, nfsd_file_cache_hits); |
58 | static DEFINE_PER_CPU(unsigned long, nfsd_file_acquisitions); |
59 | static DEFINE_PER_CPU(unsigned long, nfsd_file_releases); |
60 | static DEFINE_PER_CPU(unsigned long, nfsd_file_total_age); |
61 | static DEFINE_PER_CPU(unsigned long, nfsd_file_evictions); |
62 | |
63 | struct nfsd_fcache_disposal { |
64 | struct work_struct work; |
65 | spinlock_t lock; |
66 | struct list_head freeme; |
67 | }; |
68 | |
69 | static struct workqueue_struct *nfsd_filecache_wq __read_mostly; |
70 | |
71 | static struct kmem_cache *nfsd_file_slab; |
72 | static struct kmem_cache *nfsd_file_mark_slab; |
73 | static struct list_lru nfsd_file_lru; |
74 | static unsigned long nfsd_file_flags; |
75 | static struct fsnotify_group *nfsd_file_fsnotify_group; |
76 | static struct delayed_work nfsd_filecache_laundrette; |
77 | static struct rhltable nfsd_file_rhltable |
78 | ____cacheline_aligned_in_smp; |
79 | |
80 | static bool |
81 | nfsd_match_cred(const struct cred *c1, const struct cred *c2) |
82 | { |
83 | int i; |
84 | |
85 | if (!uid_eq(left: c1->fsuid, right: c2->fsuid)) |
86 | return false; |
87 | if (!gid_eq(left: c1->fsgid, right: c2->fsgid)) |
88 | return false; |
89 | if (c1->group_info == NULL || c2->group_info == NULL) |
90 | return c1->group_info == c2->group_info; |
91 | if (c1->group_info->ngroups != c2->group_info->ngroups) |
92 | return false; |
93 | for (i = 0; i < c1->group_info->ngroups; i++) { |
94 | if (!gid_eq(left: c1->group_info->gid[i], right: c2->group_info->gid[i])) |
95 | return false; |
96 | } |
97 | return true; |
98 | } |
99 | |
100 | static const struct rhashtable_params nfsd_file_rhash_params = { |
101 | .key_len = sizeof_field(struct nfsd_file, nf_inode), |
102 | .key_offset = offsetof(struct nfsd_file, nf_inode), |
103 | .head_offset = offsetof(struct nfsd_file, nf_rlist), |
104 | |
105 | /* |
106 | * Start with a single page hash table to reduce resizing churn |
107 | * on light workloads. |
108 | */ |
109 | .min_size = 256, |
110 | .automatic_shrinking = true, |
111 | }; |
112 | |
113 | static void |
114 | nfsd_file_schedule_laundrette(void) |
115 | { |
116 | if (test_bit(NFSD_FILE_CACHE_UP, &nfsd_file_flags)) |
117 | queue_delayed_work(wq: system_wq, dwork: &nfsd_filecache_laundrette, |
118 | NFSD_LAUNDRETTE_DELAY); |
119 | } |
120 | |
121 | static void |
122 | nfsd_file_slab_free(struct rcu_head *rcu) |
123 | { |
124 | struct nfsd_file *nf = container_of(rcu, struct nfsd_file, nf_rcu); |
125 | |
126 | put_cred(cred: nf->nf_cred); |
127 | kmem_cache_free(s: nfsd_file_slab, objp: nf); |
128 | } |
129 | |
130 | static void |
131 | nfsd_file_mark_free(struct fsnotify_mark *mark) |
132 | { |
133 | struct nfsd_file_mark *nfm = container_of(mark, struct nfsd_file_mark, |
134 | nfm_mark); |
135 | |
136 | kmem_cache_free(s: nfsd_file_mark_slab, objp: nfm); |
137 | } |
138 | |
139 | static struct nfsd_file_mark * |
140 | nfsd_file_mark_get(struct nfsd_file_mark *nfm) |
141 | { |
142 | if (!refcount_inc_not_zero(r: &nfm->nfm_ref)) |
143 | return NULL; |
144 | return nfm; |
145 | } |
146 | |
147 | static void |
148 | nfsd_file_mark_put(struct nfsd_file_mark *nfm) |
149 | { |
150 | if (refcount_dec_and_test(r: &nfm->nfm_ref)) { |
151 | fsnotify_destroy_mark(mark: &nfm->nfm_mark, group: nfsd_file_fsnotify_group); |
152 | fsnotify_put_mark(mark: &nfm->nfm_mark); |
153 | } |
154 | } |
155 | |
156 | static struct nfsd_file_mark * |
157 | nfsd_file_mark_find_or_create(struct nfsd_file *nf, struct inode *inode) |
158 | { |
159 | int err; |
160 | struct fsnotify_mark *mark; |
161 | struct nfsd_file_mark *nfm = NULL, *new; |
162 | |
163 | do { |
164 | fsnotify_group_lock(group: nfsd_file_fsnotify_group); |
165 | mark = fsnotify_find_mark(connp: &inode->i_fsnotify_marks, |
166 | group: nfsd_file_fsnotify_group); |
167 | if (mark) { |
168 | nfm = nfsd_file_mark_get(container_of(mark, |
169 | struct nfsd_file_mark, |
170 | nfm_mark)); |
171 | fsnotify_group_unlock(group: nfsd_file_fsnotify_group); |
172 | if (nfm) { |
173 | fsnotify_put_mark(mark); |
174 | break; |
175 | } |
176 | /* Avoid soft lockup race with nfsd_file_mark_put() */ |
177 | fsnotify_destroy_mark(mark, group: nfsd_file_fsnotify_group); |
178 | fsnotify_put_mark(mark); |
179 | } else { |
180 | fsnotify_group_unlock(group: nfsd_file_fsnotify_group); |
181 | } |
182 | |
183 | /* allocate a new nfm */ |
184 | new = kmem_cache_alloc(cachep: nfsd_file_mark_slab, GFP_KERNEL); |
185 | if (!new) |
186 | return NULL; |
187 | fsnotify_init_mark(mark: &new->nfm_mark, group: nfsd_file_fsnotify_group); |
188 | new->nfm_mark.mask = FS_ATTRIB|FS_DELETE_SELF; |
189 | refcount_set(r: &new->nfm_ref, n: 1); |
190 | |
191 | err = fsnotify_add_inode_mark(mark: &new->nfm_mark, inode, add_flags: 0); |
192 | |
193 | /* |
194 | * If the add was successful, then return the object. |
195 | * Otherwise, we need to put the reference we hold on the |
196 | * nfm_mark. The fsnotify code will take a reference and put |
197 | * it on failure, so we can't just free it directly. It's also |
198 | * not safe to call fsnotify_destroy_mark on it as the |
199 | * mark->group will be NULL. Thus, we can't let the nfm_ref |
200 | * counter drive the destruction at this point. |
201 | */ |
202 | if (likely(!err)) |
203 | nfm = new; |
204 | else |
205 | fsnotify_put_mark(mark: &new->nfm_mark); |
206 | } while (unlikely(err == -EEXIST)); |
207 | |
208 | return nfm; |
209 | } |
210 | |
211 | static struct nfsd_file * |
212 | nfsd_file_alloc(struct net *net, struct inode *inode, unsigned char need, |
213 | bool want_gc) |
214 | { |
215 | struct nfsd_file *nf; |
216 | |
217 | nf = kmem_cache_alloc(cachep: nfsd_file_slab, GFP_KERNEL); |
218 | if (unlikely(!nf)) |
219 | return NULL; |
220 | |
221 | INIT_LIST_HEAD(list: &nf->nf_lru); |
222 | nf->nf_birthtime = ktime_get(); |
223 | nf->nf_file = NULL; |
224 | nf->nf_cred = get_current_cred(); |
225 | nf->nf_net = net; |
226 | nf->nf_flags = want_gc ? |
227 | BIT(NFSD_FILE_HASHED) | BIT(NFSD_FILE_PENDING) | BIT(NFSD_FILE_GC) : |
228 | BIT(NFSD_FILE_HASHED) | BIT(NFSD_FILE_PENDING); |
229 | nf->nf_inode = inode; |
230 | refcount_set(r: &nf->nf_ref, n: 1); |
231 | nf->nf_may = need; |
232 | nf->nf_mark = NULL; |
233 | return nf; |
234 | } |
235 | |
236 | /** |
237 | * nfsd_file_check_write_error - check for writeback errors on a file |
238 | * @nf: nfsd_file to check for writeback errors |
239 | * |
240 | * Check whether a nfsd_file has an unseen error. Reset the write |
241 | * verifier if so. |
242 | */ |
243 | static void |
244 | nfsd_file_check_write_error(struct nfsd_file *nf) |
245 | { |
246 | struct file *file = nf->nf_file; |
247 | |
248 | if ((file->f_mode & FMODE_WRITE) && |
249 | filemap_check_wb_err(mapping: file->f_mapping, READ_ONCE(file->f_wb_err))) |
250 | nfsd_reset_write_verifier(nn: net_generic(net: nf->nf_net, id: nfsd_net_id)); |
251 | } |
252 | |
253 | static void |
254 | nfsd_file_hash_remove(struct nfsd_file *nf) |
255 | { |
256 | trace_nfsd_file_unhash(nf); |
257 | rhltable_remove(hlt: &nfsd_file_rhltable, list: &nf->nf_rlist, |
258 | params: nfsd_file_rhash_params); |
259 | } |
260 | |
261 | static bool |
262 | nfsd_file_unhash(struct nfsd_file *nf) |
263 | { |
264 | if (test_and_clear_bit(NFSD_FILE_HASHED, addr: &nf->nf_flags)) { |
265 | nfsd_file_hash_remove(nf); |
266 | return true; |
267 | } |
268 | return false; |
269 | } |
270 | |
271 | static void |
272 | nfsd_file_free(struct nfsd_file *nf) |
273 | { |
274 | s64 age = ktime_to_ms(ktime_sub(ktime_get(), nf->nf_birthtime)); |
275 | |
276 | trace_nfsd_file_free(nf); |
277 | |
278 | this_cpu_inc(nfsd_file_releases); |
279 | this_cpu_add(nfsd_file_total_age, age); |
280 | |
281 | nfsd_file_unhash(nf); |
282 | if (nf->nf_mark) |
283 | nfsd_file_mark_put(nfm: nf->nf_mark); |
284 | if (nf->nf_file) { |
285 | nfsd_file_check_write_error(nf); |
286 | filp_close(nf->nf_file, NULL); |
287 | } |
288 | |
289 | /* |
290 | * If this item is still linked via nf_lru, that's a bug. |
291 | * WARN and leak it to preserve system stability. |
292 | */ |
293 | if (WARN_ON_ONCE(!list_empty(&nf->nf_lru))) |
294 | return; |
295 | |
296 | call_rcu(head: &nf->nf_rcu, func: nfsd_file_slab_free); |
297 | } |
298 | |
299 | static bool |
300 | nfsd_file_check_writeback(struct nfsd_file *nf) |
301 | { |
302 | struct file *file = nf->nf_file; |
303 | struct address_space *mapping; |
304 | |
305 | /* File not open for write? */ |
306 | if (!(file->f_mode & FMODE_WRITE)) |
307 | return false; |
308 | |
309 | /* |
310 | * Some filesystems (e.g. NFS) flush all dirty data on close. |
311 | * On others, there is no need to wait for writeback. |
312 | */ |
313 | if (!(file_inode(f: file)->i_sb->s_export_op->flags & EXPORT_OP_FLUSH_ON_CLOSE)) |
314 | return false; |
315 | |
316 | mapping = file->f_mapping; |
317 | return mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) || |
318 | mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK); |
319 | } |
320 | |
321 | |
322 | static bool nfsd_file_lru_add(struct nfsd_file *nf) |
323 | { |
324 | set_bit(NFSD_FILE_REFERENCED, addr: &nf->nf_flags); |
325 | if (list_lru_add(lru: &nfsd_file_lru, item: &nf->nf_lru)) { |
326 | trace_nfsd_file_lru_add(nf); |
327 | return true; |
328 | } |
329 | return false; |
330 | } |
331 | |
332 | static bool nfsd_file_lru_remove(struct nfsd_file *nf) |
333 | { |
334 | if (list_lru_del(lru: &nfsd_file_lru, item: &nf->nf_lru)) { |
335 | trace_nfsd_file_lru_del(nf); |
336 | return true; |
337 | } |
338 | return false; |
339 | } |
340 | |
341 | struct nfsd_file * |
342 | nfsd_file_get(struct nfsd_file *nf) |
343 | { |
344 | if (nf && refcount_inc_not_zero(r: &nf->nf_ref)) |
345 | return nf; |
346 | return NULL; |
347 | } |
348 | |
349 | /** |
350 | * nfsd_file_put - put the reference to a nfsd_file |
351 | * @nf: nfsd_file of which to put the reference |
352 | * |
353 | * Put a reference to a nfsd_file. In the non-GC case, we just put the |
354 | * reference immediately. In the GC case, if the reference would be |
355 | * the last one, the put it on the LRU instead to be cleaned up later. |
356 | */ |
357 | void |
358 | nfsd_file_put(struct nfsd_file *nf) |
359 | { |
360 | might_sleep(); |
361 | trace_nfsd_file_put(nf); |
362 | |
363 | if (test_bit(NFSD_FILE_GC, &nf->nf_flags) && |
364 | test_bit(NFSD_FILE_HASHED, &nf->nf_flags)) { |
365 | /* |
366 | * If this is the last reference (nf_ref == 1), then try to |
367 | * transfer it to the LRU. |
368 | */ |
369 | if (refcount_dec_not_one(r: &nf->nf_ref)) |
370 | return; |
371 | |
372 | /* Try to add it to the LRU. If that fails, decrement. */ |
373 | if (nfsd_file_lru_add(nf)) { |
374 | /* If it's still hashed, we're done */ |
375 | if (test_bit(NFSD_FILE_HASHED, &nf->nf_flags)) { |
376 | nfsd_file_schedule_laundrette(); |
377 | return; |
378 | } |
379 | |
380 | /* |
381 | * We're racing with unhashing, so try to remove it from |
382 | * the LRU. If removal fails, then someone else already |
383 | * has our reference. |
384 | */ |
385 | if (!nfsd_file_lru_remove(nf)) |
386 | return; |
387 | } |
388 | } |
389 | if (refcount_dec_and_test(r: &nf->nf_ref)) |
390 | nfsd_file_free(nf); |
391 | } |
392 | |
393 | static void |
394 | nfsd_file_dispose_list(struct list_head *dispose) |
395 | { |
396 | struct nfsd_file *nf; |
397 | |
398 | while (!list_empty(head: dispose)) { |
399 | nf = list_first_entry(dispose, struct nfsd_file, nf_lru); |
400 | list_del_init(entry: &nf->nf_lru); |
401 | nfsd_file_free(nf); |
402 | } |
403 | } |
404 | |
405 | /** |
406 | * nfsd_file_dispose_list_delayed - move list of dead files to net's freeme list |
407 | * @dispose: list of nfsd_files to be disposed |
408 | * |
409 | * Transfers each file to the "freeme" list for its nfsd_net, to eventually |
410 | * be disposed of by the per-net garbage collector. |
411 | */ |
412 | static void |
413 | nfsd_file_dispose_list_delayed(struct list_head *dispose) |
414 | { |
415 | while(!list_empty(head: dispose)) { |
416 | struct nfsd_file *nf = list_first_entry(dispose, |
417 | struct nfsd_file, nf_lru); |
418 | struct nfsd_net *nn = net_generic(net: nf->nf_net, id: nfsd_net_id); |
419 | struct nfsd_fcache_disposal *l = nn->fcache_disposal; |
420 | |
421 | spin_lock(lock: &l->lock); |
422 | list_move_tail(list: &nf->nf_lru, head: &l->freeme); |
423 | spin_unlock(lock: &l->lock); |
424 | queue_work(wq: nfsd_filecache_wq, work: &l->work); |
425 | } |
426 | } |
427 | |
428 | /** |
429 | * nfsd_file_lru_cb - Examine an entry on the LRU list |
430 | * @item: LRU entry to examine |
431 | * @lru: controlling LRU |
432 | * @lock: LRU list lock (unused) |
433 | * @arg: dispose list |
434 | * |
435 | * Return values: |
436 | * %LRU_REMOVED: @item was removed from the LRU |
437 | * %LRU_ROTATE: @item is to be moved to the LRU tail |
438 | * %LRU_SKIP: @item cannot be evicted |
439 | */ |
440 | static enum lru_status |
441 | nfsd_file_lru_cb(struct list_head *item, struct list_lru_one *lru, |
442 | spinlock_t *lock, void *arg) |
443 | __releases(lock) |
444 | __acquires(lock) |
445 | { |
446 | struct list_head *head = arg; |
447 | struct nfsd_file *nf = list_entry(item, struct nfsd_file, nf_lru); |
448 | |
449 | /* We should only be dealing with GC entries here */ |
450 | WARN_ON_ONCE(!test_bit(NFSD_FILE_GC, &nf->nf_flags)); |
451 | |
452 | /* |
453 | * Don't throw out files that are still undergoing I/O or |
454 | * that have uncleared errors pending. |
455 | */ |
456 | if (nfsd_file_check_writeback(nf)) { |
457 | trace_nfsd_file_gc_writeback(nf); |
458 | return LRU_SKIP; |
459 | } |
460 | |
461 | /* If it was recently added to the list, skip it */ |
462 | if (test_and_clear_bit(NFSD_FILE_REFERENCED, addr: &nf->nf_flags)) { |
463 | trace_nfsd_file_gc_referenced(nf); |
464 | return LRU_ROTATE; |
465 | } |
466 | |
467 | /* |
468 | * Put the reference held on behalf of the LRU. If it wasn't the last |
469 | * one, then just remove it from the LRU and ignore it. |
470 | */ |
471 | if (!refcount_dec_and_test(r: &nf->nf_ref)) { |
472 | trace_nfsd_file_gc_in_use(nf); |
473 | list_lru_isolate(list: lru, item: &nf->nf_lru); |
474 | return LRU_REMOVED; |
475 | } |
476 | |
477 | /* Refcount went to zero. Unhash it and queue it to the dispose list */ |
478 | nfsd_file_unhash(nf); |
479 | list_lru_isolate_move(list: lru, item: &nf->nf_lru, head); |
480 | this_cpu_inc(nfsd_file_evictions); |
481 | trace_nfsd_file_gc_disposed(nf); |
482 | return LRU_REMOVED; |
483 | } |
484 | |
485 | static void |
486 | nfsd_file_gc(void) |
487 | { |
488 | LIST_HEAD(dispose); |
489 | unsigned long ret; |
490 | |
491 | ret = list_lru_walk(lru: &nfsd_file_lru, isolate: nfsd_file_lru_cb, |
492 | cb_arg: &dispose, nr_to_walk: list_lru_count(lru: &nfsd_file_lru)); |
493 | trace_nfsd_file_gc_removed(removed: ret, remaining: list_lru_count(lru: &nfsd_file_lru)); |
494 | nfsd_file_dispose_list_delayed(dispose: &dispose); |
495 | } |
496 | |
497 | static void |
498 | nfsd_file_gc_worker(struct work_struct *work) |
499 | { |
500 | nfsd_file_gc(); |
501 | if (list_lru_count(lru: &nfsd_file_lru)) |
502 | nfsd_file_schedule_laundrette(); |
503 | } |
504 | |
505 | static unsigned long |
506 | nfsd_file_lru_count(struct shrinker *s, struct shrink_control *sc) |
507 | { |
508 | return list_lru_count(lru: &nfsd_file_lru); |
509 | } |
510 | |
511 | static unsigned long |
512 | nfsd_file_lru_scan(struct shrinker *s, struct shrink_control *sc) |
513 | { |
514 | LIST_HEAD(dispose); |
515 | unsigned long ret; |
516 | |
517 | ret = list_lru_shrink_walk(lru: &nfsd_file_lru, sc, |
518 | isolate: nfsd_file_lru_cb, cb_arg: &dispose); |
519 | trace_nfsd_file_shrinker_removed(removed: ret, remaining: list_lru_count(lru: &nfsd_file_lru)); |
520 | nfsd_file_dispose_list_delayed(dispose: &dispose); |
521 | return ret; |
522 | } |
523 | |
524 | static struct shrinker *nfsd_file_shrinker; |
525 | |
526 | /** |
527 | * nfsd_file_cond_queue - conditionally unhash and queue a nfsd_file |
528 | * @nf: nfsd_file to attempt to queue |
529 | * @dispose: private list to queue successfully-put objects |
530 | * |
531 | * Unhash an nfsd_file, try to get a reference to it, and then put that |
532 | * reference. If it's the last reference, queue it to the dispose list. |
533 | */ |
534 | static void |
535 | nfsd_file_cond_queue(struct nfsd_file *nf, struct list_head *dispose) |
536 | __must_hold(RCU) |
537 | { |
538 | int decrement = 1; |
539 | |
540 | /* If we raced with someone else unhashing, ignore it */ |
541 | if (!nfsd_file_unhash(nf)) |
542 | return; |
543 | |
544 | /* If we can't get a reference, ignore it */ |
545 | if (!nfsd_file_get(nf)) |
546 | return; |
547 | |
548 | /* Extra decrement if we remove from the LRU */ |
549 | if (nfsd_file_lru_remove(nf)) |
550 | ++decrement; |
551 | |
552 | /* If refcount goes to 0, then put on the dispose list */ |
553 | if (refcount_sub_and_test(i: decrement, r: &nf->nf_ref)) { |
554 | list_add(new: &nf->nf_lru, head: dispose); |
555 | trace_nfsd_file_closing(nf); |
556 | } |
557 | } |
558 | |
559 | /** |
560 | * nfsd_file_queue_for_close: try to close out any open nfsd_files for an inode |
561 | * @inode: inode on which to close out nfsd_files |
562 | * @dispose: list on which to gather nfsd_files to close out |
563 | * |
564 | * An nfsd_file represents a struct file being held open on behalf of nfsd. |
565 | * An open file however can block other activity (such as leases), or cause |
566 | * undesirable behavior (e.g. spurious silly-renames when reexporting NFS). |
567 | * |
568 | * This function is intended to find open nfsd_files when this sort of |
569 | * conflicting access occurs and then attempt to close those files out. |
570 | * |
571 | * Populates the dispose list with entries that have already had their |
572 | * refcounts go to zero. The actual free of an nfsd_file can be expensive, |
573 | * so we leave it up to the caller whether it wants to wait or not. |
574 | */ |
575 | static void |
576 | nfsd_file_queue_for_close(struct inode *inode, struct list_head *dispose) |
577 | { |
578 | struct rhlist_head *tmp, *list; |
579 | struct nfsd_file *nf; |
580 | |
581 | rcu_read_lock(); |
582 | list = rhltable_lookup(hlt: &nfsd_file_rhltable, key: &inode, |
583 | params: nfsd_file_rhash_params); |
584 | rhl_for_each_entry_rcu(nf, tmp, list, nf_rlist) { |
585 | if (!test_bit(NFSD_FILE_GC, &nf->nf_flags)) |
586 | continue; |
587 | nfsd_file_cond_queue(nf, dispose); |
588 | } |
589 | rcu_read_unlock(); |
590 | } |
591 | |
592 | /** |
593 | * nfsd_file_close_inode - attempt a delayed close of a nfsd_file |
594 | * @inode: inode of the file to attempt to remove |
595 | * |
596 | * Close out any open nfsd_files that can be reaped for @inode. The |
597 | * actual freeing is deferred to the dispose_list_delayed infrastructure. |
598 | * |
599 | * This is used by the fsnotify callbacks and setlease notifier. |
600 | */ |
601 | static void |
602 | nfsd_file_close_inode(struct inode *inode) |
603 | { |
604 | LIST_HEAD(dispose); |
605 | |
606 | nfsd_file_queue_for_close(inode, dispose: &dispose); |
607 | nfsd_file_dispose_list_delayed(dispose: &dispose); |
608 | } |
609 | |
610 | /** |
611 | * nfsd_file_close_inode_sync - attempt to forcibly close a nfsd_file |
612 | * @inode: inode of the file to attempt to remove |
613 | * |
614 | * Close out any open nfsd_files that can be reaped for @inode. The |
615 | * nfsd_files are closed out synchronously. |
616 | * |
617 | * This is called from nfsd_rename and nfsd_unlink to avoid silly-renames |
618 | * when reexporting NFS. |
619 | */ |
620 | void |
621 | nfsd_file_close_inode_sync(struct inode *inode) |
622 | { |
623 | struct nfsd_file *nf; |
624 | LIST_HEAD(dispose); |
625 | |
626 | trace_nfsd_file_close(inode); |
627 | |
628 | nfsd_file_queue_for_close(inode, dispose: &dispose); |
629 | while (!list_empty(head: &dispose)) { |
630 | nf = list_first_entry(&dispose, struct nfsd_file, nf_lru); |
631 | list_del_init(entry: &nf->nf_lru); |
632 | nfsd_file_free(nf); |
633 | } |
634 | flush_delayed_fput(); |
635 | } |
636 | |
637 | /** |
638 | * nfsd_file_delayed_close - close unused nfsd_files |
639 | * @work: dummy |
640 | * |
641 | * Scrape the freeme list for this nfsd_net, and then dispose of them |
642 | * all. |
643 | */ |
644 | static void |
645 | nfsd_file_delayed_close(struct work_struct *work) |
646 | { |
647 | LIST_HEAD(head); |
648 | struct nfsd_fcache_disposal *l = container_of(work, |
649 | struct nfsd_fcache_disposal, work); |
650 | |
651 | spin_lock(lock: &l->lock); |
652 | list_splice_init(list: &l->freeme, head: &head); |
653 | spin_unlock(lock: &l->lock); |
654 | |
655 | nfsd_file_dispose_list(dispose: &head); |
656 | } |
657 | |
658 | static int |
659 | nfsd_file_lease_notifier_call(struct notifier_block *nb, unsigned long arg, |
660 | void *data) |
661 | { |
662 | struct file_lock *fl = data; |
663 | |
664 | /* Only close files for F_SETLEASE leases */ |
665 | if (fl->fl_flags & FL_LEASE) |
666 | nfsd_file_close_inode(inode: file_inode(f: fl->fl_file)); |
667 | return 0; |
668 | } |
669 | |
670 | static struct notifier_block nfsd_file_lease_notifier = { |
671 | .notifier_call = nfsd_file_lease_notifier_call, |
672 | }; |
673 | |
674 | static int |
675 | nfsd_file_fsnotify_handle_event(struct fsnotify_mark *mark, u32 mask, |
676 | struct inode *inode, struct inode *dir, |
677 | const struct qstr *name, u32 cookie) |
678 | { |
679 | if (WARN_ON_ONCE(!inode)) |
680 | return 0; |
681 | |
682 | trace_nfsd_file_fsnotify_handle_event(inode, mask); |
683 | |
684 | /* Should be no marks on non-regular files */ |
685 | if (!S_ISREG(inode->i_mode)) { |
686 | WARN_ON_ONCE(1); |
687 | return 0; |
688 | } |
689 | |
690 | /* don't close files if this was not the last link */ |
691 | if (mask & FS_ATTRIB) { |
692 | if (inode->i_nlink) |
693 | return 0; |
694 | } |
695 | |
696 | nfsd_file_close_inode(inode); |
697 | return 0; |
698 | } |
699 | |
700 | |
701 | static const struct fsnotify_ops nfsd_file_fsnotify_ops = { |
702 | .handle_inode_event = nfsd_file_fsnotify_handle_event, |
703 | .free_mark = nfsd_file_mark_free, |
704 | }; |
705 | |
706 | int |
707 | nfsd_file_cache_init(void) |
708 | { |
709 | int ret; |
710 | |
711 | lockdep_assert_held(&nfsd_mutex); |
712 | if (test_and_set_bit(NFSD_FILE_CACHE_UP, addr: &nfsd_file_flags) == 1) |
713 | return 0; |
714 | |
715 | ret = rhltable_init(hlt: &nfsd_file_rhltable, params: &nfsd_file_rhash_params); |
716 | if (ret) |
717 | return ret; |
718 | |
719 | ret = -ENOMEM; |
720 | nfsd_filecache_wq = alloc_workqueue(fmt: "nfsd_filecache" , flags: 0, max_active: 0); |
721 | if (!nfsd_filecache_wq) |
722 | goto out; |
723 | |
724 | nfsd_file_slab = kmem_cache_create(name: "nfsd_file" , |
725 | size: sizeof(struct nfsd_file), align: 0, flags: 0, NULL); |
726 | if (!nfsd_file_slab) { |
727 | pr_err("nfsd: unable to create nfsd_file_slab\n" ); |
728 | goto out_err; |
729 | } |
730 | |
731 | nfsd_file_mark_slab = kmem_cache_create(name: "nfsd_file_mark" , |
732 | size: sizeof(struct nfsd_file_mark), align: 0, flags: 0, NULL); |
733 | if (!nfsd_file_mark_slab) { |
734 | pr_err("nfsd: unable to create nfsd_file_mark_slab\n" ); |
735 | goto out_err; |
736 | } |
737 | |
738 | |
739 | ret = list_lru_init(&nfsd_file_lru); |
740 | if (ret) { |
741 | pr_err("nfsd: failed to init nfsd_file_lru: %d\n" , ret); |
742 | goto out_err; |
743 | } |
744 | |
745 | nfsd_file_shrinker = shrinker_alloc(flags: 0, fmt: "nfsd-filecache" ); |
746 | if (!nfsd_file_shrinker) { |
747 | ret = -ENOMEM; |
748 | pr_err("nfsd: failed to allocate nfsd_file_shrinker\n" ); |
749 | goto out_lru; |
750 | } |
751 | |
752 | nfsd_file_shrinker->count_objects = nfsd_file_lru_count; |
753 | nfsd_file_shrinker->scan_objects = nfsd_file_lru_scan; |
754 | nfsd_file_shrinker->seeks = 1; |
755 | |
756 | shrinker_register(shrinker: nfsd_file_shrinker); |
757 | |
758 | ret = lease_register_notifier(&nfsd_file_lease_notifier); |
759 | if (ret) { |
760 | pr_err("nfsd: unable to register lease notifier: %d\n" , ret); |
761 | goto out_shrinker; |
762 | } |
763 | |
764 | nfsd_file_fsnotify_group = fsnotify_alloc_group(ops: &nfsd_file_fsnotify_ops, |
765 | FSNOTIFY_GROUP_NOFS); |
766 | if (IS_ERR(ptr: nfsd_file_fsnotify_group)) { |
767 | pr_err("nfsd: unable to create fsnotify group: %ld\n" , |
768 | PTR_ERR(nfsd_file_fsnotify_group)); |
769 | ret = PTR_ERR(ptr: nfsd_file_fsnotify_group); |
770 | nfsd_file_fsnotify_group = NULL; |
771 | goto out_notifier; |
772 | } |
773 | |
774 | INIT_DELAYED_WORK(&nfsd_filecache_laundrette, nfsd_file_gc_worker); |
775 | out: |
776 | return ret; |
777 | out_notifier: |
778 | lease_unregister_notifier(&nfsd_file_lease_notifier); |
779 | out_shrinker: |
780 | shrinker_free(shrinker: nfsd_file_shrinker); |
781 | out_lru: |
782 | list_lru_destroy(lru: &nfsd_file_lru); |
783 | out_err: |
784 | kmem_cache_destroy(s: nfsd_file_slab); |
785 | nfsd_file_slab = NULL; |
786 | kmem_cache_destroy(s: nfsd_file_mark_slab); |
787 | nfsd_file_mark_slab = NULL; |
788 | destroy_workqueue(wq: nfsd_filecache_wq); |
789 | nfsd_filecache_wq = NULL; |
790 | rhltable_destroy(hlt: &nfsd_file_rhltable); |
791 | goto out; |
792 | } |
793 | |
794 | /** |
795 | * __nfsd_file_cache_purge: clean out the cache for shutdown |
796 | * @net: net-namespace to shut down the cache (may be NULL) |
797 | * |
798 | * Walk the nfsd_file cache and close out any that match @net. If @net is NULL, |
799 | * then close out everything. Called when an nfsd instance is being shut down, |
800 | * and when the exports table is flushed. |
801 | */ |
802 | static void |
803 | __nfsd_file_cache_purge(struct net *net) |
804 | { |
805 | struct rhashtable_iter iter; |
806 | struct nfsd_file *nf; |
807 | LIST_HEAD(dispose); |
808 | |
809 | rhltable_walk_enter(hlt: &nfsd_file_rhltable, iter: &iter); |
810 | do { |
811 | rhashtable_walk_start(iter: &iter); |
812 | |
813 | nf = rhashtable_walk_next(iter: &iter); |
814 | while (!IS_ERR_OR_NULL(ptr: nf)) { |
815 | if (!net || nf->nf_net == net) |
816 | nfsd_file_cond_queue(nf, dispose: &dispose); |
817 | nf = rhashtable_walk_next(iter: &iter); |
818 | } |
819 | |
820 | rhashtable_walk_stop(iter: &iter); |
821 | } while (nf == ERR_PTR(error: -EAGAIN)); |
822 | rhashtable_walk_exit(iter: &iter); |
823 | |
824 | nfsd_file_dispose_list(dispose: &dispose); |
825 | } |
826 | |
827 | static struct nfsd_fcache_disposal * |
828 | nfsd_alloc_fcache_disposal(void) |
829 | { |
830 | struct nfsd_fcache_disposal *l; |
831 | |
832 | l = kmalloc(size: sizeof(*l), GFP_KERNEL); |
833 | if (!l) |
834 | return NULL; |
835 | INIT_WORK(&l->work, nfsd_file_delayed_close); |
836 | spin_lock_init(&l->lock); |
837 | INIT_LIST_HEAD(list: &l->freeme); |
838 | return l; |
839 | } |
840 | |
841 | static void |
842 | nfsd_free_fcache_disposal(struct nfsd_fcache_disposal *l) |
843 | { |
844 | cancel_work_sync(work: &l->work); |
845 | nfsd_file_dispose_list(dispose: &l->freeme); |
846 | kfree(objp: l); |
847 | } |
848 | |
849 | static void |
850 | nfsd_free_fcache_disposal_net(struct net *net) |
851 | { |
852 | struct nfsd_net *nn = net_generic(net, id: nfsd_net_id); |
853 | struct nfsd_fcache_disposal *l = nn->fcache_disposal; |
854 | |
855 | nfsd_free_fcache_disposal(l); |
856 | } |
857 | |
858 | int |
859 | nfsd_file_cache_start_net(struct net *net) |
860 | { |
861 | struct nfsd_net *nn = net_generic(net, id: nfsd_net_id); |
862 | |
863 | nn->fcache_disposal = nfsd_alloc_fcache_disposal(); |
864 | return nn->fcache_disposal ? 0 : -ENOMEM; |
865 | } |
866 | |
867 | /** |
868 | * nfsd_file_cache_purge - Remove all cache items associated with @net |
869 | * @net: target net namespace |
870 | * |
871 | */ |
872 | void |
873 | nfsd_file_cache_purge(struct net *net) |
874 | { |
875 | lockdep_assert_held(&nfsd_mutex); |
876 | if (test_bit(NFSD_FILE_CACHE_UP, &nfsd_file_flags) == 1) |
877 | __nfsd_file_cache_purge(net); |
878 | } |
879 | |
880 | void |
881 | nfsd_file_cache_shutdown_net(struct net *net) |
882 | { |
883 | nfsd_file_cache_purge(net); |
884 | nfsd_free_fcache_disposal_net(net); |
885 | } |
886 | |
887 | void |
888 | nfsd_file_cache_shutdown(void) |
889 | { |
890 | int i; |
891 | |
892 | lockdep_assert_held(&nfsd_mutex); |
893 | if (test_and_clear_bit(NFSD_FILE_CACHE_UP, addr: &nfsd_file_flags) == 0) |
894 | return; |
895 | |
896 | lease_unregister_notifier(&nfsd_file_lease_notifier); |
897 | shrinker_free(shrinker: nfsd_file_shrinker); |
898 | /* |
899 | * make sure all callers of nfsd_file_lru_cb are done before |
900 | * calling nfsd_file_cache_purge |
901 | */ |
902 | cancel_delayed_work_sync(dwork: &nfsd_filecache_laundrette); |
903 | __nfsd_file_cache_purge(NULL); |
904 | list_lru_destroy(lru: &nfsd_file_lru); |
905 | rcu_barrier(); |
906 | fsnotify_put_group(group: nfsd_file_fsnotify_group); |
907 | nfsd_file_fsnotify_group = NULL; |
908 | kmem_cache_destroy(s: nfsd_file_slab); |
909 | nfsd_file_slab = NULL; |
910 | fsnotify_wait_marks_destroyed(); |
911 | kmem_cache_destroy(s: nfsd_file_mark_slab); |
912 | nfsd_file_mark_slab = NULL; |
913 | destroy_workqueue(wq: nfsd_filecache_wq); |
914 | nfsd_filecache_wq = NULL; |
915 | rhltable_destroy(hlt: &nfsd_file_rhltable); |
916 | |
917 | for_each_possible_cpu(i) { |
918 | per_cpu(nfsd_file_cache_hits, i) = 0; |
919 | per_cpu(nfsd_file_acquisitions, i) = 0; |
920 | per_cpu(nfsd_file_releases, i) = 0; |
921 | per_cpu(nfsd_file_total_age, i) = 0; |
922 | per_cpu(nfsd_file_evictions, i) = 0; |
923 | } |
924 | } |
925 | |
926 | static struct nfsd_file * |
927 | nfsd_file_lookup_locked(const struct net *net, const struct cred *cred, |
928 | struct inode *inode, unsigned char need, |
929 | bool want_gc) |
930 | { |
931 | struct rhlist_head *tmp, *list; |
932 | struct nfsd_file *nf; |
933 | |
934 | list = rhltable_lookup(hlt: &nfsd_file_rhltable, key: &inode, |
935 | params: nfsd_file_rhash_params); |
936 | rhl_for_each_entry_rcu(nf, tmp, list, nf_rlist) { |
937 | if (nf->nf_may != need) |
938 | continue; |
939 | if (nf->nf_net != net) |
940 | continue; |
941 | if (!nfsd_match_cred(c1: nf->nf_cred, c2: cred)) |
942 | continue; |
943 | if (test_bit(NFSD_FILE_GC, &nf->nf_flags) != want_gc) |
944 | continue; |
945 | if (test_bit(NFSD_FILE_HASHED, &nf->nf_flags) == 0) |
946 | continue; |
947 | |
948 | if (!nfsd_file_get(nf)) |
949 | continue; |
950 | return nf; |
951 | } |
952 | return NULL; |
953 | } |
954 | |
955 | /** |
956 | * nfsd_file_is_cached - are there any cached open files for this inode? |
957 | * @inode: inode to check |
958 | * |
959 | * The lookup matches inodes in all net namespaces and is atomic wrt |
960 | * nfsd_file_acquire(). |
961 | * |
962 | * Return values: |
963 | * %true: filecache contains at least one file matching this inode |
964 | * %false: filecache contains no files matching this inode |
965 | */ |
966 | bool |
967 | nfsd_file_is_cached(struct inode *inode) |
968 | { |
969 | struct rhlist_head *tmp, *list; |
970 | struct nfsd_file *nf; |
971 | bool ret = false; |
972 | |
973 | rcu_read_lock(); |
974 | list = rhltable_lookup(hlt: &nfsd_file_rhltable, key: &inode, |
975 | params: nfsd_file_rhash_params); |
976 | rhl_for_each_entry_rcu(nf, tmp, list, nf_rlist) |
977 | if (test_bit(NFSD_FILE_GC, &nf->nf_flags)) { |
978 | ret = true; |
979 | break; |
980 | } |
981 | rcu_read_unlock(); |
982 | |
983 | trace_nfsd_file_is_cached(inode, found: (int)ret); |
984 | return ret; |
985 | } |
986 | |
987 | static __be32 |
988 | nfsd_file_do_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp, |
989 | unsigned int may_flags, struct file *file, |
990 | struct nfsd_file **pnf, bool want_gc) |
991 | { |
992 | unsigned char need = may_flags & NFSD_FILE_MAY_MASK; |
993 | struct net *net = SVC_NET(rqstp); |
994 | struct nfsd_file *new, *nf; |
995 | bool stale_retry = true; |
996 | bool open_retry = true; |
997 | struct inode *inode; |
998 | __be32 status; |
999 | int ret; |
1000 | |
1001 | retry: |
1002 | status = fh_verify(rqstp, fhp, S_IFREG, |
1003 | may_flags|NFSD_MAY_OWNER_OVERRIDE); |
1004 | if (status != nfs_ok) |
1005 | return status; |
1006 | inode = d_inode(dentry: fhp->fh_dentry); |
1007 | |
1008 | rcu_read_lock(); |
1009 | nf = nfsd_file_lookup_locked(net, current_cred(), inode, need, want_gc); |
1010 | rcu_read_unlock(); |
1011 | |
1012 | if (nf) { |
1013 | /* |
1014 | * If the nf is on the LRU then it holds an extra reference |
1015 | * that must be put if it's removed. It had better not be |
1016 | * the last one however, since we should hold another. |
1017 | */ |
1018 | if (nfsd_file_lru_remove(nf)) |
1019 | WARN_ON_ONCE(refcount_dec_and_test(&nf->nf_ref)); |
1020 | goto wait_for_construction; |
1021 | } |
1022 | |
1023 | new = nfsd_file_alloc(net, inode, need, want_gc); |
1024 | if (!new) { |
1025 | status = nfserr_jukebox; |
1026 | goto out; |
1027 | } |
1028 | |
1029 | rcu_read_lock(); |
1030 | spin_lock(lock: &inode->i_lock); |
1031 | nf = nfsd_file_lookup_locked(net, current_cred(), inode, need, want_gc); |
1032 | if (unlikely(nf)) { |
1033 | spin_unlock(lock: &inode->i_lock); |
1034 | rcu_read_unlock(); |
1035 | nfsd_file_slab_free(rcu: &new->nf_rcu); |
1036 | goto wait_for_construction; |
1037 | } |
1038 | nf = new; |
1039 | ret = rhltable_insert(hlt: &nfsd_file_rhltable, list: &nf->nf_rlist, |
1040 | params: nfsd_file_rhash_params); |
1041 | spin_unlock(lock: &inode->i_lock); |
1042 | rcu_read_unlock(); |
1043 | if (likely(ret == 0)) |
1044 | goto open_file; |
1045 | |
1046 | if (ret == -EEXIST) |
1047 | goto retry; |
1048 | trace_nfsd_file_insert_err(rqstp, inode, may_flags, error: ret); |
1049 | status = nfserr_jukebox; |
1050 | goto construction_err; |
1051 | |
1052 | wait_for_construction: |
1053 | wait_on_bit(word: &nf->nf_flags, NFSD_FILE_PENDING, TASK_UNINTERRUPTIBLE); |
1054 | |
1055 | /* Did construction of this file fail? */ |
1056 | if (!test_bit(NFSD_FILE_HASHED, &nf->nf_flags)) { |
1057 | trace_nfsd_file_cons_err(rqstp, inode, may_flags, nf); |
1058 | if (!open_retry) { |
1059 | status = nfserr_jukebox; |
1060 | goto construction_err; |
1061 | } |
1062 | open_retry = false; |
1063 | fh_put(fhp); |
1064 | goto retry; |
1065 | } |
1066 | this_cpu_inc(nfsd_file_cache_hits); |
1067 | |
1068 | status = nfserrno(errno: nfsd_open_break_lease(file_inode(f: nf->nf_file), may_flags)); |
1069 | if (status != nfs_ok) { |
1070 | nfsd_file_put(nf); |
1071 | nf = NULL; |
1072 | } |
1073 | |
1074 | out: |
1075 | if (status == nfs_ok) { |
1076 | this_cpu_inc(nfsd_file_acquisitions); |
1077 | nfsd_file_check_write_error(nf); |
1078 | *pnf = nf; |
1079 | } |
1080 | trace_nfsd_file_acquire(rqstp, inode, may_flags, nf, status); |
1081 | return status; |
1082 | |
1083 | open_file: |
1084 | trace_nfsd_file_alloc(nf); |
1085 | nf->nf_mark = nfsd_file_mark_find_or_create(nf, inode); |
1086 | if (nf->nf_mark) { |
1087 | if (file) { |
1088 | get_file(f: file); |
1089 | nf->nf_file = file; |
1090 | status = nfs_ok; |
1091 | trace_nfsd_file_opened(nf, status); |
1092 | } else { |
1093 | ret = nfsd_open_verified(rqstp, fhp, may_flags, |
1094 | filp: &nf->nf_file); |
1095 | if (ret == -EOPENSTALE && stale_retry) { |
1096 | stale_retry = false; |
1097 | nfsd_file_unhash(nf); |
1098 | clear_and_wake_up_bit(NFSD_FILE_PENDING, |
1099 | word: &nf->nf_flags); |
1100 | if (refcount_dec_and_test(r: &nf->nf_ref)) |
1101 | nfsd_file_free(nf); |
1102 | nf = NULL; |
1103 | fh_put(fhp); |
1104 | goto retry; |
1105 | } |
1106 | status = nfserrno(errno: ret); |
1107 | trace_nfsd_file_open(nf, status); |
1108 | } |
1109 | } else |
1110 | status = nfserr_jukebox; |
1111 | /* |
1112 | * If construction failed, or we raced with a call to unlink() |
1113 | * then unhash. |
1114 | */ |
1115 | if (status != nfs_ok || inode->i_nlink == 0) |
1116 | nfsd_file_unhash(nf); |
1117 | clear_and_wake_up_bit(NFSD_FILE_PENDING, word: &nf->nf_flags); |
1118 | if (status == nfs_ok) |
1119 | goto out; |
1120 | |
1121 | construction_err: |
1122 | if (refcount_dec_and_test(r: &nf->nf_ref)) |
1123 | nfsd_file_free(nf); |
1124 | nf = NULL; |
1125 | goto out; |
1126 | } |
1127 | |
1128 | /** |
1129 | * nfsd_file_acquire_gc - Get a struct nfsd_file with an open file |
1130 | * @rqstp: the RPC transaction being executed |
1131 | * @fhp: the NFS filehandle of the file to be opened |
1132 | * @may_flags: NFSD_MAY_ settings for the file |
1133 | * @pnf: OUT: new or found "struct nfsd_file" object |
1134 | * |
1135 | * The nfsd_file object returned by this API is reference-counted |
1136 | * and garbage-collected. The object is retained for a few |
1137 | * seconds after the final nfsd_file_put() in case the caller |
1138 | * wants to re-use it. |
1139 | * |
1140 | * Return values: |
1141 | * %nfs_ok - @pnf points to an nfsd_file with its reference |
1142 | * count boosted. |
1143 | * |
1144 | * On error, an nfsstat value in network byte order is returned. |
1145 | */ |
1146 | __be32 |
1147 | nfsd_file_acquire_gc(struct svc_rqst *rqstp, struct svc_fh *fhp, |
1148 | unsigned int may_flags, struct nfsd_file **pnf) |
1149 | { |
1150 | return nfsd_file_do_acquire(rqstp, fhp, may_flags, NULL, pnf, want_gc: true); |
1151 | } |
1152 | |
1153 | /** |
1154 | * nfsd_file_acquire - Get a struct nfsd_file with an open file |
1155 | * @rqstp: the RPC transaction being executed |
1156 | * @fhp: the NFS filehandle of the file to be opened |
1157 | * @may_flags: NFSD_MAY_ settings for the file |
1158 | * @pnf: OUT: new or found "struct nfsd_file" object |
1159 | * |
1160 | * The nfsd_file_object returned by this API is reference-counted |
1161 | * but not garbage-collected. The object is unhashed after the |
1162 | * final nfsd_file_put(). |
1163 | * |
1164 | * Return values: |
1165 | * %nfs_ok - @pnf points to an nfsd_file with its reference |
1166 | * count boosted. |
1167 | * |
1168 | * On error, an nfsstat value in network byte order is returned. |
1169 | */ |
1170 | __be32 |
1171 | nfsd_file_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp, |
1172 | unsigned int may_flags, struct nfsd_file **pnf) |
1173 | { |
1174 | return nfsd_file_do_acquire(rqstp, fhp, may_flags, NULL, pnf, want_gc: false); |
1175 | } |
1176 | |
1177 | /** |
1178 | * nfsd_file_acquire_opened - Get a struct nfsd_file using existing open file |
1179 | * @rqstp: the RPC transaction being executed |
1180 | * @fhp: the NFS filehandle of the file just created |
1181 | * @may_flags: NFSD_MAY_ settings for the file |
1182 | * @file: cached, already-open file (may be NULL) |
1183 | * @pnf: OUT: new or found "struct nfsd_file" object |
1184 | * |
1185 | * Acquire a nfsd_file object that is not GC'ed. If one doesn't already exist, |
1186 | * and @file is non-NULL, use it to instantiate a new nfsd_file instead of |
1187 | * opening a new one. |
1188 | * |
1189 | * Return values: |
1190 | * %nfs_ok - @pnf points to an nfsd_file with its reference |
1191 | * count boosted. |
1192 | * |
1193 | * On error, an nfsstat value in network byte order is returned. |
1194 | */ |
1195 | __be32 |
1196 | nfsd_file_acquire_opened(struct svc_rqst *rqstp, struct svc_fh *fhp, |
1197 | unsigned int may_flags, struct file *file, |
1198 | struct nfsd_file **pnf) |
1199 | { |
1200 | return nfsd_file_do_acquire(rqstp, fhp, may_flags, file, pnf, want_gc: false); |
1201 | } |
1202 | |
1203 | /* |
1204 | * Note that fields may be added, removed or reordered in the future. Programs |
1205 | * scraping this file for info should test the labels to ensure they're |
1206 | * getting the correct field. |
1207 | */ |
1208 | int nfsd_file_cache_stats_show(struct seq_file *m, void *v) |
1209 | { |
1210 | unsigned long releases = 0, evictions = 0; |
1211 | unsigned long hits = 0, acquisitions = 0; |
1212 | unsigned int i, count = 0, buckets = 0; |
1213 | unsigned long lru = 0, total_age = 0; |
1214 | |
1215 | /* Serialize with server shutdown */ |
1216 | mutex_lock(&nfsd_mutex); |
1217 | if (test_bit(NFSD_FILE_CACHE_UP, &nfsd_file_flags) == 1) { |
1218 | struct bucket_table *tbl; |
1219 | struct rhashtable *ht; |
1220 | |
1221 | lru = list_lru_count(lru: &nfsd_file_lru); |
1222 | |
1223 | rcu_read_lock(); |
1224 | ht = &nfsd_file_rhltable.ht; |
1225 | count = atomic_read(v: &ht->nelems); |
1226 | tbl = rht_dereference_rcu(ht->tbl, ht); |
1227 | buckets = tbl->size; |
1228 | rcu_read_unlock(); |
1229 | } |
1230 | mutex_unlock(lock: &nfsd_mutex); |
1231 | |
1232 | for_each_possible_cpu(i) { |
1233 | hits += per_cpu(nfsd_file_cache_hits, i); |
1234 | acquisitions += per_cpu(nfsd_file_acquisitions, i); |
1235 | releases += per_cpu(nfsd_file_releases, i); |
1236 | total_age += per_cpu(nfsd_file_total_age, i); |
1237 | evictions += per_cpu(nfsd_file_evictions, i); |
1238 | } |
1239 | |
1240 | seq_printf(m, fmt: "total inodes: %u\n" , count); |
1241 | seq_printf(m, fmt: "hash buckets: %u\n" , buckets); |
1242 | seq_printf(m, fmt: "lru entries: %lu\n" , lru); |
1243 | seq_printf(m, fmt: "cache hits: %lu\n" , hits); |
1244 | seq_printf(m, fmt: "acquisitions: %lu\n" , acquisitions); |
1245 | seq_printf(m, fmt: "releases: %lu\n" , releases); |
1246 | seq_printf(m, fmt: "evictions: %lu\n" , evictions); |
1247 | if (releases) |
1248 | seq_printf(m, fmt: "mean age (ms): %ld\n" , total_age / releases); |
1249 | else |
1250 | seq_printf(m, fmt: "mean age (ms): -\n" ); |
1251 | return 0; |
1252 | } |
1253 | |