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Commit | Line | Data |
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65294c1f JL |
1 | /* |
2 | * Open file cache. | |
3 | * | |
4 | * (c) 2015 - Jeff Layton <jeff.layton@primarydata.com> | |
5 | */ | |
6 | ||
7 | #include <linux/hash.h> | |
8 | #include <linux/slab.h> | |
65294c1f JL |
9 | #include <linux/file.h> |
10 | #include <linux/sched.h> | |
11 | #include <linux/list_lru.h> | |
12 | #include <linux/fsnotify_backend.h> | |
13 | #include <linux/fsnotify.h> | |
14 | #include <linux/seq_file.h> | |
15 | ||
16 | #include "vfs.h" | |
17 | #include "nfsd.h" | |
18 | #include "nfsfh.h" | |
5e113224 | 19 | #include "netns.h" |
65294c1f JL |
20 | #include "filecache.h" |
21 | #include "trace.h" | |
22 | ||
23 | #define NFSDDBG_FACILITY NFSDDBG_FH | |
24 | ||
25 | /* FIXME: dynamically size this for the machine somehow? */ | |
26 | #define NFSD_FILE_HASH_BITS 12 | |
27 | #define NFSD_FILE_HASH_SIZE (1 << NFSD_FILE_HASH_BITS) | |
28 | #define NFSD_LAUNDRETTE_DELAY (2 * HZ) | |
29 | ||
65294c1f JL |
30 | #define NFSD_FILE_SHUTDOWN (1) |
31 | #define NFSD_FILE_LRU_THRESHOLD (4096UL) | |
32 | #define NFSD_FILE_LRU_LIMIT (NFSD_FILE_LRU_THRESHOLD << 2) | |
33 | ||
34 | /* We only care about NFSD_MAY_READ/WRITE for this cache */ | |
35 | #define NFSD_FILE_MAY_MASK (NFSD_MAY_READ|NFSD_MAY_WRITE) | |
36 | ||
37 | struct nfsd_fcache_bucket { | |
38 | struct hlist_head nfb_head; | |
39 | spinlock_t nfb_lock; | |
40 | unsigned int nfb_count; | |
41 | unsigned int nfb_maxcount; | |
42 | }; | |
43 | ||
44 | static DEFINE_PER_CPU(unsigned long, nfsd_file_cache_hits); | |
45 | ||
9542e6a6 TM |
46 | struct nfsd_fcache_disposal { |
47 | struct list_head list; | |
48 | struct work_struct work; | |
49 | struct net *net; | |
50 | spinlock_t lock; | |
51 | struct list_head freeme; | |
52 | struct rcu_head rcu; | |
53 | }; | |
54 | ||
55 | struct workqueue_struct *nfsd_filecache_wq __read_mostly; | |
56 | ||
65294c1f JL |
57 | static struct kmem_cache *nfsd_file_slab; |
58 | static struct kmem_cache *nfsd_file_mark_slab; | |
59 | static struct nfsd_fcache_bucket *nfsd_file_hashtbl; | |
60 | static struct list_lru nfsd_file_lru; | |
61 | static long nfsd_file_lru_flags; | |
62 | static struct fsnotify_group *nfsd_file_fsnotify_group; | |
63 | static atomic_long_t nfsd_filecache_count; | |
64 | static struct delayed_work nfsd_filecache_laundrette; | |
9542e6a6 TM |
65 | static DEFINE_SPINLOCK(laundrette_lock); |
66 | static LIST_HEAD(laundrettes); | |
65294c1f | 67 | |
9542e6a6 | 68 | static void nfsd_file_gc(void); |
65294c1f JL |
69 | |
70 | static void | |
9542e6a6 | 71 | nfsd_file_schedule_laundrette(void) |
65294c1f JL |
72 | { |
73 | long count = atomic_long_read(&nfsd_filecache_count); | |
74 | ||
75 | if (count == 0 || test_bit(NFSD_FILE_SHUTDOWN, &nfsd_file_lru_flags)) | |
76 | return; | |
77 | ||
9542e6a6 TM |
78 | queue_delayed_work(system_wq, &nfsd_filecache_laundrette, |
79 | NFSD_LAUNDRETTE_DELAY); | |
65294c1f JL |
80 | } |
81 | ||
82 | static void | |
83 | nfsd_file_slab_free(struct rcu_head *rcu) | |
84 | { | |
85 | struct nfsd_file *nf = container_of(rcu, struct nfsd_file, nf_rcu); | |
86 | ||
87 | put_cred(nf->nf_cred); | |
88 | kmem_cache_free(nfsd_file_slab, nf); | |
89 | } | |
90 | ||
91 | static void | |
92 | nfsd_file_mark_free(struct fsnotify_mark *mark) | |
93 | { | |
94 | struct nfsd_file_mark *nfm = container_of(mark, struct nfsd_file_mark, | |
95 | nfm_mark); | |
96 | ||
97 | kmem_cache_free(nfsd_file_mark_slab, nfm); | |
98 | } | |
99 | ||
100 | static struct nfsd_file_mark * | |
101 | nfsd_file_mark_get(struct nfsd_file_mark *nfm) | |
102 | { | |
103 | if (!atomic_inc_not_zero(&nfm->nfm_ref)) | |
104 | return NULL; | |
105 | return nfm; | |
106 | } | |
107 | ||
108 | static void | |
109 | nfsd_file_mark_put(struct nfsd_file_mark *nfm) | |
110 | { | |
111 | if (atomic_dec_and_test(&nfm->nfm_ref)) { | |
112 | ||
113 | fsnotify_destroy_mark(&nfm->nfm_mark, nfsd_file_fsnotify_group); | |
114 | fsnotify_put_mark(&nfm->nfm_mark); | |
115 | } | |
116 | } | |
117 | ||
118 | static struct nfsd_file_mark * | |
119 | nfsd_file_mark_find_or_create(struct nfsd_file *nf) | |
120 | { | |
121 | int err; | |
122 | struct fsnotify_mark *mark; | |
123 | struct nfsd_file_mark *nfm = NULL, *new; | |
124 | struct inode *inode = nf->nf_inode; | |
125 | ||
126 | do { | |
127 | mutex_lock(&nfsd_file_fsnotify_group->mark_mutex); | |
128 | mark = fsnotify_find_mark(&inode->i_fsnotify_marks, | |
129 | nfsd_file_fsnotify_group); | |
130 | if (mark) { | |
131 | nfm = nfsd_file_mark_get(container_of(mark, | |
132 | struct nfsd_file_mark, | |
133 | nfm_mark)); | |
134 | mutex_unlock(&nfsd_file_fsnotify_group->mark_mutex); | |
135 | fsnotify_put_mark(mark); | |
136 | if (likely(nfm)) | |
137 | break; | |
138 | } else | |
139 | mutex_unlock(&nfsd_file_fsnotify_group->mark_mutex); | |
140 | ||
141 | /* allocate a new nfm */ | |
142 | new = kmem_cache_alloc(nfsd_file_mark_slab, GFP_KERNEL); | |
143 | if (!new) | |
144 | return NULL; | |
145 | fsnotify_init_mark(&new->nfm_mark, nfsd_file_fsnotify_group); | |
146 | new->nfm_mark.mask = FS_ATTRIB|FS_DELETE_SELF; | |
147 | atomic_set(&new->nfm_ref, 1); | |
148 | ||
149 | err = fsnotify_add_inode_mark(&new->nfm_mark, inode, 0); | |
150 | ||
151 | /* | |
152 | * If the add was successful, then return the object. | |
153 | * Otherwise, we need to put the reference we hold on the | |
154 | * nfm_mark. The fsnotify code will take a reference and put | |
155 | * it on failure, so we can't just free it directly. It's also | |
156 | * not safe to call fsnotify_destroy_mark on it as the | |
157 | * mark->group will be NULL. Thus, we can't let the nfm_ref | |
158 | * counter drive the destruction at this point. | |
159 | */ | |
160 | if (likely(!err)) | |
161 | nfm = new; | |
162 | else | |
163 | fsnotify_put_mark(&new->nfm_mark); | |
164 | } while (unlikely(err == -EEXIST)); | |
165 | ||
166 | return nfm; | |
167 | } | |
168 | ||
169 | static struct nfsd_file * | |
5e113224 TM |
170 | nfsd_file_alloc(struct inode *inode, unsigned int may, unsigned int hashval, |
171 | struct net *net) | |
65294c1f JL |
172 | { |
173 | struct nfsd_file *nf; | |
174 | ||
175 | nf = kmem_cache_alloc(nfsd_file_slab, GFP_KERNEL); | |
176 | if (nf) { | |
177 | INIT_HLIST_NODE(&nf->nf_node); | |
178 | INIT_LIST_HEAD(&nf->nf_lru); | |
179 | nf->nf_file = NULL; | |
180 | nf->nf_cred = get_current_cred(); | |
5e113224 | 181 | nf->nf_net = net; |
65294c1f JL |
182 | nf->nf_flags = 0; |
183 | nf->nf_inode = inode; | |
184 | nf->nf_hashval = hashval; | |
185 | atomic_set(&nf->nf_ref, 1); | |
186 | nf->nf_may = may & NFSD_FILE_MAY_MASK; | |
187 | if (may & NFSD_MAY_NOT_BREAK_LEASE) { | |
188 | if (may & NFSD_MAY_WRITE) | |
189 | __set_bit(NFSD_FILE_BREAK_WRITE, &nf->nf_flags); | |
190 | if (may & NFSD_MAY_READ) | |
191 | __set_bit(NFSD_FILE_BREAK_READ, &nf->nf_flags); | |
192 | } | |
193 | nf->nf_mark = NULL; | |
194 | trace_nfsd_file_alloc(nf); | |
195 | } | |
196 | return nf; | |
197 | } | |
198 | ||
199 | static bool | |
200 | nfsd_file_free(struct nfsd_file *nf) | |
201 | { | |
202 | bool flush = false; | |
203 | ||
204 | trace_nfsd_file_put_final(nf); | |
205 | if (nf->nf_mark) | |
206 | nfsd_file_mark_put(nf->nf_mark); | |
207 | if (nf->nf_file) { | |
208 | get_file(nf->nf_file); | |
209 | filp_close(nf->nf_file, NULL); | |
210 | fput(nf->nf_file); | |
211 | flush = true; | |
212 | } | |
213 | call_rcu(&nf->nf_rcu, nfsd_file_slab_free); | |
214 | return flush; | |
215 | } | |
216 | ||
055b24a8 TM |
217 | static bool |
218 | nfsd_file_check_writeback(struct nfsd_file *nf) | |
219 | { | |
220 | struct file *file = nf->nf_file; | |
221 | struct address_space *mapping; | |
222 | ||
223 | if (!file || !(file->f_mode & FMODE_WRITE)) | |
224 | return false; | |
225 | mapping = file->f_mapping; | |
226 | return mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) || | |
227 | mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK); | |
228 | } | |
229 | ||
230 | static int | |
231 | nfsd_file_check_write_error(struct nfsd_file *nf) | |
232 | { | |
233 | struct file *file = nf->nf_file; | |
234 | ||
235 | if (!file || !(file->f_mode & FMODE_WRITE)) | |
236 | return 0; | |
237 | return filemap_check_wb_err(file->f_mapping, READ_ONCE(file->f_wb_err)); | |
238 | } | |
239 | ||
65294c1f JL |
240 | static void |
241 | nfsd_file_do_unhash(struct nfsd_file *nf) | |
242 | { | |
243 | lockdep_assert_held(&nfsd_file_hashtbl[nf->nf_hashval].nfb_lock); | |
244 | ||
245 | trace_nfsd_file_unhash(nf); | |
246 | ||
055b24a8 TM |
247 | if (nfsd_file_check_write_error(nf)) |
248 | nfsd_reset_boot_verifier(net_generic(nf->nf_net, nfsd_net_id)); | |
65294c1f JL |
249 | --nfsd_file_hashtbl[nf->nf_hashval].nfb_count; |
250 | hlist_del_rcu(&nf->nf_node); | |
65294c1f JL |
251 | atomic_long_dec(&nfsd_filecache_count); |
252 | } | |
253 | ||
254 | static bool | |
255 | nfsd_file_unhash(struct nfsd_file *nf) | |
256 | { | |
257 | if (test_and_clear_bit(NFSD_FILE_HASHED, &nf->nf_flags)) { | |
258 | nfsd_file_do_unhash(nf); | |
36ebbdb9 TM |
259 | if (!list_empty(&nf->nf_lru)) |
260 | list_lru_del(&nfsd_file_lru, &nf->nf_lru); | |
65294c1f JL |
261 | return true; |
262 | } | |
263 | return false; | |
264 | } | |
265 | ||
266 | /* | |
267 | * Return true if the file was unhashed. | |
268 | */ | |
269 | static bool | |
270 | nfsd_file_unhash_and_release_locked(struct nfsd_file *nf, struct list_head *dispose) | |
271 | { | |
272 | lockdep_assert_held(&nfsd_file_hashtbl[nf->nf_hashval].nfb_lock); | |
273 | ||
274 | trace_nfsd_file_unhash_and_release_locked(nf); | |
275 | if (!nfsd_file_unhash(nf)) | |
276 | return false; | |
277 | /* keep final reference for nfsd_file_lru_dispose */ | |
278 | if (atomic_add_unless(&nf->nf_ref, -1, 1)) | |
279 | return true; | |
280 | ||
281 | list_add(&nf->nf_lru, dispose); | |
282 | return true; | |
283 | } | |
284 | ||
b6669305 | 285 | static void |
65294c1f JL |
286 | nfsd_file_put_noref(struct nfsd_file *nf) |
287 | { | |
65294c1f JL |
288 | trace_nfsd_file_put(nf); |
289 | ||
b6669305 | 290 | if (atomic_dec_and_test(&nf->nf_ref)) { |
65294c1f JL |
291 | WARN_ON(test_bit(NFSD_FILE_HASHED, &nf->nf_flags)); |
292 | nfsd_file_free(nf); | |
293 | } | |
65294c1f JL |
294 | } |
295 | ||
296 | void | |
297 | nfsd_file_put(struct nfsd_file *nf) | |
298 | { | |
b6669305 | 299 | bool is_hashed; |
65294c1f JL |
300 | |
301 | set_bit(NFSD_FILE_REFERENCED, &nf->nf_flags); | |
b6669305 TM |
302 | if (atomic_read(&nf->nf_ref) > 2 || !nf->nf_file) { |
303 | nfsd_file_put_noref(nf); | |
304 | return; | |
305 | } | |
306 | ||
307 | filemap_flush(nf->nf_file->f_mapping); | |
308 | is_hashed = test_bit(NFSD_FILE_HASHED, &nf->nf_flags) != 0; | |
309 | nfsd_file_put_noref(nf); | |
310 | if (is_hashed) | |
9542e6a6 TM |
311 | nfsd_file_schedule_laundrette(); |
312 | if (atomic_long_read(&nfsd_filecache_count) >= NFSD_FILE_LRU_LIMIT) | |
313 | nfsd_file_gc(); | |
65294c1f JL |
314 | } |
315 | ||
316 | struct nfsd_file * | |
317 | nfsd_file_get(struct nfsd_file *nf) | |
318 | { | |
319 | if (likely(atomic_inc_not_zero(&nf->nf_ref))) | |
320 | return nf; | |
321 | return NULL; | |
322 | } | |
323 | ||
324 | static void | |
325 | nfsd_file_dispose_list(struct list_head *dispose) | |
326 | { | |
327 | struct nfsd_file *nf; | |
328 | ||
329 | while(!list_empty(dispose)) { | |
330 | nf = list_first_entry(dispose, struct nfsd_file, nf_lru); | |
331 | list_del(&nf->nf_lru); | |
332 | nfsd_file_put_noref(nf); | |
333 | } | |
334 | } | |
335 | ||
336 | static void | |
337 | nfsd_file_dispose_list_sync(struct list_head *dispose) | |
338 | { | |
339 | bool flush = false; | |
340 | struct nfsd_file *nf; | |
341 | ||
342 | while(!list_empty(dispose)) { | |
343 | nf = list_first_entry(dispose, struct nfsd_file, nf_lru); | |
344 | list_del(&nf->nf_lru); | |
345 | if (!atomic_dec_and_test(&nf->nf_ref)) | |
346 | continue; | |
347 | if (nfsd_file_free(nf)) | |
348 | flush = true; | |
349 | } | |
350 | if (flush) | |
351 | flush_delayed_fput(); | |
352 | } | |
353 | ||
9542e6a6 TM |
354 | static void |
355 | nfsd_file_list_remove_disposal(struct list_head *dst, | |
356 | struct nfsd_fcache_disposal *l) | |
357 | { | |
358 | spin_lock(&l->lock); | |
359 | list_splice_init(&l->freeme, dst); | |
360 | spin_unlock(&l->lock); | |
361 | } | |
362 | ||
363 | static void | |
364 | nfsd_file_list_add_disposal(struct list_head *files, struct net *net) | |
365 | { | |
366 | struct nfsd_fcache_disposal *l; | |
367 | ||
368 | rcu_read_lock(); | |
369 | list_for_each_entry_rcu(l, &laundrettes, list) { | |
370 | if (l->net == net) { | |
371 | spin_lock(&l->lock); | |
372 | list_splice_tail_init(files, &l->freeme); | |
373 | spin_unlock(&l->lock); | |
374 | queue_work(nfsd_filecache_wq, &l->work); | |
375 | break; | |
376 | } | |
377 | } | |
378 | rcu_read_unlock(); | |
379 | } | |
380 | ||
381 | static void | |
382 | nfsd_file_list_add_pernet(struct list_head *dst, struct list_head *src, | |
383 | struct net *net) | |
384 | { | |
385 | struct nfsd_file *nf, *tmp; | |
386 | ||
387 | list_for_each_entry_safe(nf, tmp, src, nf_lru) { | |
388 | if (nf->nf_net == net) | |
389 | list_move_tail(&nf->nf_lru, dst); | |
390 | } | |
391 | } | |
392 | ||
393 | static void | |
394 | nfsd_file_dispose_list_delayed(struct list_head *dispose) | |
395 | { | |
396 | LIST_HEAD(list); | |
397 | struct nfsd_file *nf; | |
398 | ||
399 | while(!list_empty(dispose)) { | |
400 | nf = list_first_entry(dispose, struct nfsd_file, nf_lru); | |
401 | nfsd_file_list_add_pernet(&list, dispose, nf->nf_net); | |
402 | nfsd_file_list_add_disposal(&list, nf->nf_net); | |
403 | } | |
404 | } | |
405 | ||
65294c1f JL |
406 | /* |
407 | * Note this can deadlock with nfsd_file_cache_purge. | |
408 | */ | |
409 | static enum lru_status | |
410 | nfsd_file_lru_cb(struct list_head *item, struct list_lru_one *lru, | |
411 | spinlock_t *lock, void *arg) | |
412 | __releases(lock) | |
413 | __acquires(lock) | |
414 | { | |
415 | struct list_head *head = arg; | |
416 | struct nfsd_file *nf = list_entry(item, struct nfsd_file, nf_lru); | |
417 | ||
418 | /* | |
419 | * Do a lockless refcount check. The hashtable holds one reference, so | |
420 | * we look to see if anything else has a reference, or if any have | |
421 | * been put since the shrinker last ran. Those don't get unhashed and | |
422 | * released. | |
423 | * | |
424 | * Note that in the put path, we set the flag and then decrement the | |
425 | * counter. Here we check the counter and then test and clear the flag. | |
426 | * That order is deliberate to ensure that we can do this locklessly. | |
427 | */ | |
428 | if (atomic_read(&nf->nf_ref) > 1) | |
429 | goto out_skip; | |
055b24a8 TM |
430 | |
431 | /* | |
432 | * Don't throw out files that are still undergoing I/O or | |
433 | * that have uncleared errors pending. | |
434 | */ | |
435 | if (nfsd_file_check_writeback(nf)) | |
436 | goto out_skip; | |
437 | ||
65294c1f | 438 | if (test_and_clear_bit(NFSD_FILE_REFERENCED, &nf->nf_flags)) |
bd6e1cec | 439 | goto out_skip; |
65294c1f JL |
440 | |
441 | if (!test_and_clear_bit(NFSD_FILE_HASHED, &nf->nf_flags)) | |
442 | goto out_skip; | |
443 | ||
444 | list_lru_isolate_move(lru, &nf->nf_lru, head); | |
445 | return LRU_REMOVED; | |
65294c1f JL |
446 | out_skip: |
447 | return LRU_SKIP; | |
448 | } | |
449 | ||
9542e6a6 TM |
450 | static unsigned long |
451 | nfsd_file_lru_walk_list(struct shrink_control *sc) | |
65294c1f | 452 | { |
9542e6a6 | 453 | LIST_HEAD(head); |
36ebbdb9 | 454 | struct nfsd_file *nf; |
9542e6a6 | 455 | unsigned long ret; |
36ebbdb9 | 456 | |
9542e6a6 TM |
457 | if (sc) |
458 | ret = list_lru_shrink_walk(&nfsd_file_lru, sc, | |
459 | nfsd_file_lru_cb, &head); | |
460 | else | |
461 | ret = list_lru_walk(&nfsd_file_lru, | |
462 | nfsd_file_lru_cb, | |
463 | &head, LONG_MAX); | |
464 | list_for_each_entry(nf, &head, nf_lru) { | |
65294c1f JL |
465 | spin_lock(&nfsd_file_hashtbl[nf->nf_hashval].nfb_lock); |
466 | nfsd_file_do_unhash(nf); | |
467 | spin_unlock(&nfsd_file_hashtbl[nf->nf_hashval].nfb_lock); | |
65294c1f | 468 | } |
9542e6a6 TM |
469 | nfsd_file_dispose_list_delayed(&head); |
470 | return ret; | |
471 | } | |
472 | ||
473 | static void | |
474 | nfsd_file_gc(void) | |
475 | { | |
476 | nfsd_file_lru_walk_list(NULL); | |
477 | } | |
478 | ||
479 | static void | |
480 | nfsd_file_gc_worker(struct work_struct *work) | |
481 | { | |
482 | nfsd_file_gc(); | |
483 | nfsd_file_schedule_laundrette(); | |
65294c1f JL |
484 | } |
485 | ||
486 | static unsigned long | |
487 | nfsd_file_lru_count(struct shrinker *s, struct shrink_control *sc) | |
488 | { | |
489 | return list_lru_count(&nfsd_file_lru); | |
490 | } | |
491 | ||
492 | static unsigned long | |
493 | nfsd_file_lru_scan(struct shrinker *s, struct shrink_control *sc) | |
494 | { | |
9542e6a6 | 495 | return nfsd_file_lru_walk_list(sc); |
65294c1f JL |
496 | } |
497 | ||
498 | static struct shrinker nfsd_file_shrinker = { | |
499 | .scan_objects = nfsd_file_lru_scan, | |
500 | .count_objects = nfsd_file_lru_count, | |
501 | .seeks = 1, | |
502 | }; | |
503 | ||
504 | static void | |
505 | __nfsd_file_close_inode(struct inode *inode, unsigned int hashval, | |
506 | struct list_head *dispose) | |
507 | { | |
508 | struct nfsd_file *nf; | |
509 | struct hlist_node *tmp; | |
510 | ||
511 | spin_lock(&nfsd_file_hashtbl[hashval].nfb_lock); | |
512 | hlist_for_each_entry_safe(nf, tmp, &nfsd_file_hashtbl[hashval].nfb_head, nf_node) { | |
513 | if (inode == nf->nf_inode) | |
514 | nfsd_file_unhash_and_release_locked(nf, dispose); | |
515 | } | |
516 | spin_unlock(&nfsd_file_hashtbl[hashval].nfb_lock); | |
517 | } | |
518 | ||
519 | /** | |
520 | * nfsd_file_close_inode_sync - attempt to forcibly close a nfsd_file | |
521 | * @inode: inode of the file to attempt to remove | |
522 | * | |
523 | * Walk the whole hash bucket, looking for any files that correspond to "inode". | |
524 | * If any do, then unhash them and put the hashtable reference to them and | |
525 | * destroy any that had their last reference put. Also ensure that any of the | |
526 | * fputs also have their final __fput done as well. | |
527 | */ | |
528 | void | |
529 | nfsd_file_close_inode_sync(struct inode *inode) | |
530 | { | |
531 | unsigned int hashval = (unsigned int)hash_long(inode->i_ino, | |
532 | NFSD_FILE_HASH_BITS); | |
533 | LIST_HEAD(dispose); | |
534 | ||
535 | __nfsd_file_close_inode(inode, hashval, &dispose); | |
536 | trace_nfsd_file_close_inode_sync(inode, hashval, !list_empty(&dispose)); | |
537 | nfsd_file_dispose_list_sync(&dispose); | |
538 | } | |
539 | ||
540 | /** | |
541 | * nfsd_file_close_inode_sync - attempt to forcibly close a nfsd_file | |
542 | * @inode: inode of the file to attempt to remove | |
543 | * | |
544 | * Walk the whole hash bucket, looking for any files that correspond to "inode". | |
545 | * If any do, then unhash them and put the hashtable reference to them and | |
546 | * destroy any that had their last reference put. | |
547 | */ | |
548 | static void | |
549 | nfsd_file_close_inode(struct inode *inode) | |
550 | { | |
551 | unsigned int hashval = (unsigned int)hash_long(inode->i_ino, | |
552 | NFSD_FILE_HASH_BITS); | |
553 | LIST_HEAD(dispose); | |
554 | ||
555 | __nfsd_file_close_inode(inode, hashval, &dispose); | |
556 | trace_nfsd_file_close_inode(inode, hashval, !list_empty(&dispose)); | |
9542e6a6 | 557 | nfsd_file_dispose_list_delayed(&dispose); |
65294c1f JL |
558 | } |
559 | ||
560 | /** | |
561 | * nfsd_file_delayed_close - close unused nfsd_files | |
562 | * @work: dummy | |
563 | * | |
564 | * Walk the LRU list and close any entries that have not been used since | |
565 | * the last scan. | |
566 | * | |
567 | * Note this can deadlock with nfsd_file_cache_purge. | |
568 | */ | |
569 | static void | |
570 | nfsd_file_delayed_close(struct work_struct *work) | |
571 | { | |
572 | LIST_HEAD(head); | |
9542e6a6 TM |
573 | struct nfsd_fcache_disposal *l = container_of(work, |
574 | struct nfsd_fcache_disposal, work); | |
65294c1f | 575 | |
9542e6a6 TM |
576 | nfsd_file_list_remove_disposal(&head, l); |
577 | nfsd_file_dispose_list(&head); | |
65294c1f JL |
578 | } |
579 | ||
580 | static int | |
581 | nfsd_file_lease_notifier_call(struct notifier_block *nb, unsigned long arg, | |
582 | void *data) | |
583 | { | |
584 | struct file_lock *fl = data; | |
585 | ||
586 | /* Only close files for F_SETLEASE leases */ | |
587 | if (fl->fl_flags & FL_LEASE) | |
588 | nfsd_file_close_inode_sync(file_inode(fl->fl_file)); | |
589 | return 0; | |
590 | } | |
591 | ||
592 | static struct notifier_block nfsd_file_lease_notifier = { | |
593 | .notifier_call = nfsd_file_lease_notifier_call, | |
594 | }; | |
595 | ||
596 | static int | |
597 | nfsd_file_fsnotify_handle_event(struct fsnotify_group *group, | |
598 | struct inode *inode, | |
599 | u32 mask, const void *data, int data_type, | |
600 | const struct qstr *file_name, u32 cookie, | |
601 | struct fsnotify_iter_info *iter_info) | |
602 | { | |
603 | trace_nfsd_file_fsnotify_handle_event(inode, mask); | |
604 | ||
605 | /* Should be no marks on non-regular files */ | |
606 | if (!S_ISREG(inode->i_mode)) { | |
607 | WARN_ON_ONCE(1); | |
608 | return 0; | |
609 | } | |
610 | ||
611 | /* don't close files if this was not the last link */ | |
612 | if (mask & FS_ATTRIB) { | |
613 | if (inode->i_nlink) | |
614 | return 0; | |
615 | } | |
616 | ||
617 | nfsd_file_close_inode(inode); | |
618 | return 0; | |
619 | } | |
620 | ||
621 | ||
622 | static const struct fsnotify_ops nfsd_file_fsnotify_ops = { | |
623 | .handle_event = nfsd_file_fsnotify_handle_event, | |
624 | .free_mark = nfsd_file_mark_free, | |
625 | }; | |
626 | ||
627 | int | |
628 | nfsd_file_cache_init(void) | |
629 | { | |
630 | int ret = -ENOMEM; | |
631 | unsigned int i; | |
632 | ||
633 | clear_bit(NFSD_FILE_SHUTDOWN, &nfsd_file_lru_flags); | |
634 | ||
635 | if (nfsd_file_hashtbl) | |
636 | return 0; | |
637 | ||
9542e6a6 TM |
638 | nfsd_filecache_wq = alloc_workqueue("nfsd_filecache", 0, 0); |
639 | if (!nfsd_filecache_wq) | |
640 | goto out; | |
641 | ||
65294c1f JL |
642 | nfsd_file_hashtbl = kcalloc(NFSD_FILE_HASH_SIZE, |
643 | sizeof(*nfsd_file_hashtbl), GFP_KERNEL); | |
644 | if (!nfsd_file_hashtbl) { | |
645 | pr_err("nfsd: unable to allocate nfsd_file_hashtbl\n"); | |
646 | goto out_err; | |
647 | } | |
648 | ||
649 | nfsd_file_slab = kmem_cache_create("nfsd_file", | |
650 | sizeof(struct nfsd_file), 0, 0, NULL); | |
651 | if (!nfsd_file_slab) { | |
652 | pr_err("nfsd: unable to create nfsd_file_slab\n"); | |
653 | goto out_err; | |
654 | } | |
655 | ||
656 | nfsd_file_mark_slab = kmem_cache_create("nfsd_file_mark", | |
657 | sizeof(struct nfsd_file_mark), 0, 0, NULL); | |
658 | if (!nfsd_file_mark_slab) { | |
659 | pr_err("nfsd: unable to create nfsd_file_mark_slab\n"); | |
660 | goto out_err; | |
661 | } | |
662 | ||
663 | ||
664 | ret = list_lru_init(&nfsd_file_lru); | |
665 | if (ret) { | |
666 | pr_err("nfsd: failed to init nfsd_file_lru: %d\n", ret); | |
667 | goto out_err; | |
668 | } | |
669 | ||
670 | ret = register_shrinker(&nfsd_file_shrinker); | |
671 | if (ret) { | |
672 | pr_err("nfsd: failed to register nfsd_file_shrinker: %d\n", ret); | |
673 | goto out_lru; | |
674 | } | |
675 | ||
676 | ret = lease_register_notifier(&nfsd_file_lease_notifier); | |
677 | if (ret) { | |
678 | pr_err("nfsd: unable to register lease notifier: %d\n", ret); | |
679 | goto out_shrinker; | |
680 | } | |
681 | ||
682 | nfsd_file_fsnotify_group = fsnotify_alloc_group(&nfsd_file_fsnotify_ops); | |
683 | if (IS_ERR(nfsd_file_fsnotify_group)) { | |
684 | pr_err("nfsd: unable to create fsnotify group: %ld\n", | |
685 | PTR_ERR(nfsd_file_fsnotify_group)); | |
686 | nfsd_file_fsnotify_group = NULL; | |
687 | goto out_notifier; | |
688 | } | |
689 | ||
690 | for (i = 0; i < NFSD_FILE_HASH_SIZE; i++) { | |
691 | INIT_HLIST_HEAD(&nfsd_file_hashtbl[i].nfb_head); | |
692 | spin_lock_init(&nfsd_file_hashtbl[i].nfb_lock); | |
693 | } | |
694 | ||
9542e6a6 | 695 | INIT_DELAYED_WORK(&nfsd_filecache_laundrette, nfsd_file_gc_worker); |
65294c1f JL |
696 | out: |
697 | return ret; | |
698 | out_notifier: | |
699 | lease_unregister_notifier(&nfsd_file_lease_notifier); | |
700 | out_shrinker: | |
701 | unregister_shrinker(&nfsd_file_shrinker); | |
702 | out_lru: | |
703 | list_lru_destroy(&nfsd_file_lru); | |
704 | out_err: | |
705 | kmem_cache_destroy(nfsd_file_slab); | |
706 | nfsd_file_slab = NULL; | |
707 | kmem_cache_destroy(nfsd_file_mark_slab); | |
708 | nfsd_file_mark_slab = NULL; | |
709 | kfree(nfsd_file_hashtbl); | |
710 | nfsd_file_hashtbl = NULL; | |
9542e6a6 TM |
711 | destroy_workqueue(nfsd_filecache_wq); |
712 | nfsd_filecache_wq = NULL; | |
65294c1f JL |
713 | goto out; |
714 | } | |
715 | ||
716 | /* | |
717 | * Note this can deadlock with nfsd_file_lru_cb. | |
718 | */ | |
719 | void | |
5e113224 | 720 | nfsd_file_cache_purge(struct net *net) |
65294c1f JL |
721 | { |
722 | unsigned int i; | |
723 | struct nfsd_file *nf; | |
5e113224 | 724 | struct hlist_node *next; |
65294c1f JL |
725 | LIST_HEAD(dispose); |
726 | bool del; | |
727 | ||
728 | if (!nfsd_file_hashtbl) | |
729 | return; | |
730 | ||
731 | for (i = 0; i < NFSD_FILE_HASH_SIZE; i++) { | |
5e113224 TM |
732 | struct nfsd_fcache_bucket *nfb = &nfsd_file_hashtbl[i]; |
733 | ||
734 | spin_lock(&nfb->nfb_lock); | |
735 | hlist_for_each_entry_safe(nf, next, &nfb->nfb_head, nf_node) { | |
736 | if (net && nf->nf_net != net) | |
737 | continue; | |
65294c1f JL |
738 | del = nfsd_file_unhash_and_release_locked(nf, &dispose); |
739 | ||
740 | /* | |
741 | * Deadlock detected! Something marked this entry as | |
742 | * unhased, but hasn't removed it from the hash list. | |
743 | */ | |
744 | WARN_ON_ONCE(!del); | |
745 | } | |
5e113224 | 746 | spin_unlock(&nfb->nfb_lock); |
65294c1f JL |
747 | nfsd_file_dispose_list(&dispose); |
748 | } | |
749 | } | |
750 | ||
9542e6a6 TM |
751 | static struct nfsd_fcache_disposal * |
752 | nfsd_alloc_fcache_disposal(struct net *net) | |
753 | { | |
754 | struct nfsd_fcache_disposal *l; | |
755 | ||
756 | l = kmalloc(sizeof(*l), GFP_KERNEL); | |
757 | if (!l) | |
758 | return NULL; | |
759 | INIT_WORK(&l->work, nfsd_file_delayed_close); | |
760 | l->net = net; | |
761 | spin_lock_init(&l->lock); | |
762 | INIT_LIST_HEAD(&l->freeme); | |
763 | return l; | |
764 | } | |
765 | ||
766 | static void | |
767 | nfsd_free_fcache_disposal(struct nfsd_fcache_disposal *l) | |
768 | { | |
769 | rcu_assign_pointer(l->net, NULL); | |
770 | cancel_work_sync(&l->work); | |
771 | nfsd_file_dispose_list(&l->freeme); | |
772 | kfree_rcu(l, rcu); | |
773 | } | |
774 | ||
775 | static void | |
776 | nfsd_add_fcache_disposal(struct nfsd_fcache_disposal *l) | |
777 | { | |
778 | spin_lock(&laundrette_lock); | |
779 | list_add_tail_rcu(&l->list, &laundrettes); | |
780 | spin_unlock(&laundrette_lock); | |
781 | } | |
782 | ||
783 | static void | |
784 | nfsd_del_fcache_disposal(struct nfsd_fcache_disposal *l) | |
785 | { | |
786 | spin_lock(&laundrette_lock); | |
787 | list_del_rcu(&l->list); | |
788 | spin_unlock(&laundrette_lock); | |
789 | } | |
790 | ||
791 | static int | |
792 | nfsd_alloc_fcache_disposal_net(struct net *net) | |
793 | { | |
794 | struct nfsd_fcache_disposal *l; | |
795 | ||
796 | l = nfsd_alloc_fcache_disposal(net); | |
797 | if (!l) | |
798 | return -ENOMEM; | |
799 | nfsd_add_fcache_disposal(l); | |
800 | return 0; | |
801 | } | |
802 | ||
803 | static void | |
804 | nfsd_free_fcache_disposal_net(struct net *net) | |
805 | { | |
806 | struct nfsd_fcache_disposal *l; | |
807 | ||
808 | rcu_read_lock(); | |
809 | list_for_each_entry_rcu(l, &laundrettes, list) { | |
810 | if (l->net != net) | |
811 | continue; | |
812 | nfsd_del_fcache_disposal(l); | |
813 | rcu_read_unlock(); | |
814 | nfsd_free_fcache_disposal(l); | |
815 | return; | |
816 | } | |
817 | rcu_read_unlock(); | |
818 | } | |
819 | ||
820 | int | |
821 | nfsd_file_cache_start_net(struct net *net) | |
822 | { | |
823 | return nfsd_alloc_fcache_disposal_net(net); | |
824 | } | |
825 | ||
826 | void | |
827 | nfsd_file_cache_shutdown_net(struct net *net) | |
828 | { | |
829 | nfsd_file_cache_purge(net); | |
830 | nfsd_free_fcache_disposal_net(net); | |
831 | } | |
832 | ||
65294c1f JL |
833 | void |
834 | nfsd_file_cache_shutdown(void) | |
835 | { | |
65294c1f JL |
836 | set_bit(NFSD_FILE_SHUTDOWN, &nfsd_file_lru_flags); |
837 | ||
838 | lease_unregister_notifier(&nfsd_file_lease_notifier); | |
839 | unregister_shrinker(&nfsd_file_shrinker); | |
840 | /* | |
841 | * make sure all callers of nfsd_file_lru_cb are done before | |
842 | * calling nfsd_file_cache_purge | |
843 | */ | |
844 | cancel_delayed_work_sync(&nfsd_filecache_laundrette); | |
5e113224 | 845 | nfsd_file_cache_purge(NULL); |
65294c1f JL |
846 | list_lru_destroy(&nfsd_file_lru); |
847 | rcu_barrier(); | |
848 | fsnotify_put_group(nfsd_file_fsnotify_group); | |
849 | nfsd_file_fsnotify_group = NULL; | |
850 | kmem_cache_destroy(nfsd_file_slab); | |
851 | nfsd_file_slab = NULL; | |
852 | fsnotify_wait_marks_destroyed(); | |
853 | kmem_cache_destroy(nfsd_file_mark_slab); | |
854 | nfsd_file_mark_slab = NULL; | |
855 | kfree(nfsd_file_hashtbl); | |
856 | nfsd_file_hashtbl = NULL; | |
9542e6a6 TM |
857 | destroy_workqueue(nfsd_filecache_wq); |
858 | nfsd_filecache_wq = NULL; | |
65294c1f JL |
859 | } |
860 | ||
861 | static bool | |
862 | nfsd_match_cred(const struct cred *c1, const struct cred *c2) | |
863 | { | |
864 | int i; | |
865 | ||
866 | if (!uid_eq(c1->fsuid, c2->fsuid)) | |
867 | return false; | |
868 | if (!gid_eq(c1->fsgid, c2->fsgid)) | |
869 | return false; | |
870 | if (c1->group_info == NULL || c2->group_info == NULL) | |
871 | return c1->group_info == c2->group_info; | |
872 | if (c1->group_info->ngroups != c2->group_info->ngroups) | |
873 | return false; | |
874 | for (i = 0; i < c1->group_info->ngroups; i++) { | |
875 | if (!gid_eq(c1->group_info->gid[i], c2->group_info->gid[i])) | |
876 | return false; | |
877 | } | |
878 | return true; | |
879 | } | |
880 | ||
881 | static struct nfsd_file * | |
882 | nfsd_file_find_locked(struct inode *inode, unsigned int may_flags, | |
5e113224 | 883 | unsigned int hashval, struct net *net) |
65294c1f JL |
884 | { |
885 | struct nfsd_file *nf; | |
886 | unsigned char need = may_flags & NFSD_FILE_MAY_MASK; | |
887 | ||
888 | hlist_for_each_entry_rcu(nf, &nfsd_file_hashtbl[hashval].nfb_head, | |
889 | nf_node) { | |
890 | if ((need & nf->nf_may) != need) | |
891 | continue; | |
892 | if (nf->nf_inode != inode) | |
893 | continue; | |
5e113224 TM |
894 | if (nf->nf_net != net) |
895 | continue; | |
65294c1f JL |
896 | if (!nfsd_match_cred(nf->nf_cred, current_cred())) |
897 | continue; | |
898 | if (nfsd_file_get(nf) != NULL) | |
899 | return nf; | |
900 | } | |
901 | return NULL; | |
902 | } | |
903 | ||
904 | /** | |
905 | * nfsd_file_is_cached - are there any cached open files for this fh? | |
906 | * @inode: inode of the file to check | |
907 | * | |
908 | * Scan the hashtable for open files that match this fh. Returns true if there | |
909 | * are any, and false if not. | |
910 | */ | |
911 | bool | |
912 | nfsd_file_is_cached(struct inode *inode) | |
913 | { | |
914 | bool ret = false; | |
915 | struct nfsd_file *nf; | |
916 | unsigned int hashval; | |
917 | ||
918 | hashval = (unsigned int)hash_long(inode->i_ino, NFSD_FILE_HASH_BITS); | |
919 | ||
920 | rcu_read_lock(); | |
921 | hlist_for_each_entry_rcu(nf, &nfsd_file_hashtbl[hashval].nfb_head, | |
922 | nf_node) { | |
923 | if (inode == nf->nf_inode) { | |
924 | ret = true; | |
925 | break; | |
926 | } | |
927 | } | |
928 | rcu_read_unlock(); | |
929 | trace_nfsd_file_is_cached(inode, hashval, (int)ret); | |
930 | return ret; | |
931 | } | |
932 | ||
933 | __be32 | |
934 | nfsd_file_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp, | |
935 | unsigned int may_flags, struct nfsd_file **pnf) | |
936 | { | |
937 | __be32 status; | |
5e113224 | 938 | struct net *net = SVC_NET(rqstp); |
65294c1f JL |
939 | struct nfsd_file *nf, *new; |
940 | struct inode *inode; | |
941 | unsigned int hashval; | |
28c7d86b | 942 | bool retry = true; |
65294c1f JL |
943 | |
944 | /* FIXME: skip this if fh_dentry is already set? */ | |
945 | status = fh_verify(rqstp, fhp, S_IFREG, | |
946 | may_flags|NFSD_MAY_OWNER_OVERRIDE); | |
947 | if (status != nfs_ok) | |
948 | return status; | |
949 | ||
950 | inode = d_inode(fhp->fh_dentry); | |
951 | hashval = (unsigned int)hash_long(inode->i_ino, NFSD_FILE_HASH_BITS); | |
952 | retry: | |
953 | rcu_read_lock(); | |
5e113224 | 954 | nf = nfsd_file_find_locked(inode, may_flags, hashval, net); |
65294c1f JL |
955 | rcu_read_unlock(); |
956 | if (nf) | |
957 | goto wait_for_construction; | |
958 | ||
5e113224 | 959 | new = nfsd_file_alloc(inode, may_flags, hashval, net); |
65294c1f JL |
960 | if (!new) { |
961 | trace_nfsd_file_acquire(rqstp, hashval, inode, may_flags, | |
962 | NULL, nfserr_jukebox); | |
963 | return nfserr_jukebox; | |
964 | } | |
965 | ||
966 | spin_lock(&nfsd_file_hashtbl[hashval].nfb_lock); | |
5e113224 | 967 | nf = nfsd_file_find_locked(inode, may_flags, hashval, net); |
65294c1f JL |
968 | if (nf == NULL) |
969 | goto open_file; | |
970 | spin_unlock(&nfsd_file_hashtbl[hashval].nfb_lock); | |
971 | nfsd_file_slab_free(&new->nf_rcu); | |
972 | ||
973 | wait_for_construction: | |
974 | wait_on_bit(&nf->nf_flags, NFSD_FILE_PENDING, TASK_UNINTERRUPTIBLE); | |
975 | ||
976 | /* Did construction of this file fail? */ | |
977 | if (!test_bit(NFSD_FILE_HASHED, &nf->nf_flags)) { | |
28c7d86b TM |
978 | if (!retry) { |
979 | status = nfserr_jukebox; | |
980 | goto out; | |
981 | } | |
982 | retry = false; | |
65294c1f JL |
983 | nfsd_file_put_noref(nf); |
984 | goto retry; | |
985 | } | |
986 | ||
987 | this_cpu_inc(nfsd_file_cache_hits); | |
988 | ||
989 | if (!(may_flags & NFSD_MAY_NOT_BREAK_LEASE)) { | |
990 | bool write = (may_flags & NFSD_MAY_WRITE); | |
991 | ||
992 | if (test_bit(NFSD_FILE_BREAK_READ, &nf->nf_flags) || | |
993 | (test_bit(NFSD_FILE_BREAK_WRITE, &nf->nf_flags) && write)) { | |
994 | status = nfserrno(nfsd_open_break_lease( | |
995 | file_inode(nf->nf_file), may_flags)); | |
996 | if (status == nfs_ok) { | |
997 | clear_bit(NFSD_FILE_BREAK_READ, &nf->nf_flags); | |
998 | if (write) | |
999 | clear_bit(NFSD_FILE_BREAK_WRITE, | |
1000 | &nf->nf_flags); | |
1001 | } | |
1002 | } | |
1003 | } | |
1004 | out: | |
1005 | if (status == nfs_ok) { | |
1006 | *pnf = nf; | |
1007 | } else { | |
1008 | nfsd_file_put(nf); | |
1009 | nf = NULL; | |
1010 | } | |
1011 | ||
1012 | trace_nfsd_file_acquire(rqstp, hashval, inode, may_flags, nf, status); | |
1013 | return status; | |
1014 | open_file: | |
1015 | nf = new; | |
1016 | /* Take reference for the hashtable */ | |
1017 | atomic_inc(&nf->nf_ref); | |
1018 | __set_bit(NFSD_FILE_HASHED, &nf->nf_flags); | |
1019 | __set_bit(NFSD_FILE_PENDING, &nf->nf_flags); | |
1020 | list_lru_add(&nfsd_file_lru, &nf->nf_lru); | |
1021 | hlist_add_head_rcu(&nf->nf_node, &nfsd_file_hashtbl[hashval].nfb_head); | |
1022 | ++nfsd_file_hashtbl[hashval].nfb_count; | |
1023 | nfsd_file_hashtbl[hashval].nfb_maxcount = max(nfsd_file_hashtbl[hashval].nfb_maxcount, | |
1024 | nfsd_file_hashtbl[hashval].nfb_count); | |
1025 | spin_unlock(&nfsd_file_hashtbl[hashval].nfb_lock); | |
9542e6a6 TM |
1026 | if (atomic_long_inc_return(&nfsd_filecache_count) >= NFSD_FILE_LRU_THRESHOLD) |
1027 | nfsd_file_gc(); | |
65294c1f JL |
1028 | |
1029 | nf->nf_mark = nfsd_file_mark_find_or_create(nf); | |
1030 | if (nf->nf_mark) | |
1031 | status = nfsd_open_verified(rqstp, fhp, S_IFREG, | |
1032 | may_flags, &nf->nf_file); | |
1033 | else | |
1034 | status = nfserr_jukebox; | |
1035 | /* | |
1036 | * If construction failed, or we raced with a call to unlink() | |
1037 | * then unhash. | |
1038 | */ | |
1039 | if (status != nfs_ok || inode->i_nlink == 0) { | |
1040 | bool do_free; | |
1041 | spin_lock(&nfsd_file_hashtbl[hashval].nfb_lock); | |
1042 | do_free = nfsd_file_unhash(nf); | |
1043 | spin_unlock(&nfsd_file_hashtbl[hashval].nfb_lock); | |
1044 | if (do_free) | |
1045 | nfsd_file_put_noref(nf); | |
1046 | } | |
1047 | clear_bit_unlock(NFSD_FILE_PENDING, &nf->nf_flags); | |
1048 | smp_mb__after_atomic(); | |
1049 | wake_up_bit(&nf->nf_flags, NFSD_FILE_PENDING); | |
1050 | goto out; | |
1051 | } | |
1052 | ||
1053 | /* | |
1054 | * Note that fields may be added, removed or reordered in the future. Programs | |
1055 | * scraping this file for info should test the labels to ensure they're | |
1056 | * getting the correct field. | |
1057 | */ | |
1058 | static int nfsd_file_cache_stats_show(struct seq_file *m, void *v) | |
1059 | { | |
1060 | unsigned int i, count = 0, longest = 0; | |
1061 | unsigned long hits = 0; | |
1062 | ||
1063 | /* | |
1064 | * No need for spinlocks here since we're not terribly interested in | |
1065 | * accuracy. We do take the nfsd_mutex simply to ensure that we | |
1066 | * don't end up racing with server shutdown | |
1067 | */ | |
1068 | mutex_lock(&nfsd_mutex); | |
1069 | if (nfsd_file_hashtbl) { | |
1070 | for (i = 0; i < NFSD_FILE_HASH_SIZE; i++) { | |
1071 | count += nfsd_file_hashtbl[i].nfb_count; | |
1072 | longest = max(longest, nfsd_file_hashtbl[i].nfb_count); | |
1073 | } | |
1074 | } | |
1075 | mutex_unlock(&nfsd_mutex); | |
1076 | ||
1077 | for_each_possible_cpu(i) | |
1078 | hits += per_cpu(nfsd_file_cache_hits, i); | |
1079 | ||
1080 | seq_printf(m, "total entries: %u\n", count); | |
1081 | seq_printf(m, "longest chain: %u\n", longest); | |
1082 | seq_printf(m, "cache hits: %lu\n", hits); | |
1083 | return 0; | |
1084 | } | |
1085 | ||
1086 | int nfsd_file_cache_stats_open(struct inode *inode, struct file *file) | |
1087 | { | |
1088 | return single_open(file, nfsd_file_cache_stats_show, NULL); | |
1089 | } |