1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /* Internal definitions for network filesystem support
3  *
4  * Copyright (C) 2021 Red Hat, Inc. All Rights Reserved.
5  * Written by David Howells (dhowells@redhat.com)
6  */
7 
8 #include <linux/slab.h>
9 #include <linux/seq_file.h>
10 #include <linux/folio_queue.h>
11 #include <linux/netfs.h>
12 #include <linux/fscache.h>
13 #include <linux/fscache-cache.h>
14 #include <trace/events/netfs.h>
15 #include <trace/events/fscache.h>
16 
17 #ifdef pr_fmt
18 #undef pr_fmt
19 #endif
20 
21 #define pr_fmt(fmt) "netfs: " fmt
22 
23 /*
24  * buffered_read.c
25  */
26 void netfs_cache_read_terminated(void *priv, ssize_t transferred_or_error);
27 int netfs_prefetch_for_write(struct file *file, struct folio *folio,
28 			     size_t offset, size_t len);
29 
30 /*
31  * main.c
32  */
33 extern unsigned int netfs_debug;
34 extern struct list_head netfs_io_requests;
35 extern spinlock_t netfs_proc_lock;
36 extern mempool_t netfs_request_pool;
37 extern mempool_t netfs_subrequest_pool;
38 
39 #ifdef CONFIG_PROC_FS
40 static inline void netfs_proc_add_rreq(struct netfs_io_request *rreq)
41 {
42 	spin_lock(&netfs_proc_lock);
43 	list_add_tail_rcu(&rreq->proc_link, &netfs_io_requests);
44 	spin_unlock(&netfs_proc_lock);
45 }
46 static inline void netfs_proc_del_rreq(struct netfs_io_request *rreq)
47 {
48 	if (!list_empty(&rreq->proc_link)) {
49 		spin_lock(&netfs_proc_lock);
50 		list_del_rcu(&rreq->proc_link);
51 		spin_unlock(&netfs_proc_lock);
52 	}
53 }
54 #else
55 static inline void netfs_proc_add_rreq(struct netfs_io_request *rreq) {}
56 static inline void netfs_proc_del_rreq(struct netfs_io_request *rreq) {}
57 #endif
58 
59 /*
60  * misc.c
61  */
62 struct folio_queue *netfs_buffer_make_space(struct netfs_io_request *rreq,
63 					    enum netfs_folioq_trace trace);
64 void netfs_reset_iter(struct netfs_io_subrequest *subreq);
65 void netfs_wake_collector(struct netfs_io_request *rreq);
66 void netfs_subreq_clear_in_progress(struct netfs_io_subrequest *subreq);
67 void netfs_wait_for_in_progress_stream(struct netfs_io_request *rreq,
68 				       struct netfs_io_stream *stream);
69 ssize_t netfs_wait_for_read(struct netfs_io_request *rreq);
70 ssize_t netfs_wait_for_write(struct netfs_io_request *rreq);
71 void netfs_wait_for_paused_read(struct netfs_io_request *rreq);
72 void netfs_wait_for_paused_write(struct netfs_io_request *rreq);
73 
74 /*
75  * objects.c
76  */
77 struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
78 					     struct file *file,
79 					     loff_t start, size_t len,
80 					     enum netfs_io_origin origin);
81 void netfs_get_request(struct netfs_io_request *rreq, enum netfs_rreq_ref_trace what);
82 void netfs_clear_subrequests(struct netfs_io_request *rreq);
83 void netfs_put_request(struct netfs_io_request *rreq, enum netfs_rreq_ref_trace what);
84 struct netfs_io_subrequest *netfs_alloc_subrequest(struct netfs_io_request *rreq);
85 
86 static inline void netfs_see_request(struct netfs_io_request *rreq,
87 				     enum netfs_rreq_ref_trace what)
88 {
89 	trace_netfs_rreq_ref(rreq->debug_id, refcount_read(&rreq->ref), what);
90 }
91 
92 static inline void netfs_see_subrequest(struct netfs_io_subrequest *subreq,
93 					enum netfs_sreq_ref_trace what)
94 {
95 	trace_netfs_sreq_ref(subreq->rreq->debug_id, subreq->debug_index,
96 			     refcount_read(&subreq->ref), what);
97 }
98 
99 /*
100  * read_collect.c
101  */
102 bool netfs_read_collection(struct netfs_io_request *rreq);
103 void netfs_read_collection_worker(struct work_struct *work);
104 void netfs_cache_read_terminated(void *priv, ssize_t transferred_or_error);
105 
106 /*
107  * read_pgpriv2.c
108  */
109 void netfs_pgpriv2_copy_to_cache(struct netfs_io_request *rreq, struct folio *folio);
110 void netfs_pgpriv2_end_copy_to_cache(struct netfs_io_request *rreq);
111 bool netfs_pgpriv2_unlock_copied_folios(struct netfs_io_request *wreq);
112 
113 /*
114  * read_retry.c
115  */
116 void netfs_retry_reads(struct netfs_io_request *rreq);
117 void netfs_unlock_abandoned_read_pages(struct netfs_io_request *rreq);
118 
119 /*
120  * stats.c
121  */
122 #ifdef CONFIG_NETFS_STATS
123 extern atomic_t netfs_n_rh_dio_read;
124 extern atomic_t netfs_n_rh_readahead;
125 extern atomic_t netfs_n_rh_read_folio;
126 extern atomic_t netfs_n_rh_read_single;
127 extern atomic_t netfs_n_rh_rreq;
128 extern atomic_t netfs_n_rh_sreq;
129 extern atomic_t netfs_n_rh_download;
130 extern atomic_t netfs_n_rh_download_done;
131 extern atomic_t netfs_n_rh_download_failed;
132 extern atomic_t netfs_n_rh_download_instead;
133 extern atomic_t netfs_n_rh_read;
134 extern atomic_t netfs_n_rh_read_done;
135 extern atomic_t netfs_n_rh_read_failed;
136 extern atomic_t netfs_n_rh_zero;
137 extern atomic_t netfs_n_rh_short_read;
138 extern atomic_t netfs_n_rh_write;
139 extern atomic_t netfs_n_rh_write_begin;
140 extern atomic_t netfs_n_rh_write_done;
141 extern atomic_t netfs_n_rh_write_failed;
142 extern atomic_t netfs_n_rh_write_zskip;
143 extern atomic_t netfs_n_rh_retry_read_req;
144 extern atomic_t netfs_n_rh_retry_read_subreq;
145 extern atomic_t netfs_n_wh_buffered_write;
146 extern atomic_t netfs_n_wh_writethrough;
147 extern atomic_t netfs_n_wh_dio_write;
148 extern atomic_t netfs_n_wh_writepages;
149 extern atomic_t netfs_n_wh_copy_to_cache;
150 extern atomic_t netfs_n_wh_wstream_conflict;
151 extern atomic_t netfs_n_wh_upload;
152 extern atomic_t netfs_n_wh_upload_done;
153 extern atomic_t netfs_n_wh_upload_failed;
154 extern atomic_t netfs_n_wh_write;
155 extern atomic_t netfs_n_wh_write_done;
156 extern atomic_t netfs_n_wh_write_failed;
157 extern atomic_t netfs_n_wh_retry_write_req;
158 extern atomic_t netfs_n_wh_retry_write_subreq;
159 extern atomic_t netfs_n_wb_lock_skip;
160 extern atomic_t netfs_n_wb_lock_wait;
161 extern atomic_t netfs_n_folioq;
162 
163 int netfs_stats_show(struct seq_file *m, void *v);
164 
165 static inline void netfs_stat(atomic_t *stat)
166 {
167 	atomic_inc(stat);
168 }
169 
170 static inline void netfs_stat_d(atomic_t *stat)
171 {
172 	atomic_dec(stat);
173 }
174 
175 #else
176 #define netfs_stat(x) do {} while(0)
177 #define netfs_stat_d(x) do {} while(0)
178 #endif
179 
180 /*
181  * write_collect.c
182  */
183 int netfs_folio_written_back(struct folio *folio);
184 bool netfs_write_collection(struct netfs_io_request *wreq);
185 void netfs_write_collection_worker(struct work_struct *work);
186 
187 /*
188  * write_issue.c
189  */
190 struct netfs_io_request *netfs_create_write_req(struct address_space *mapping,
191 						struct file *file,
192 						loff_t start,
193 						enum netfs_io_origin origin);
194 void netfs_reissue_write(struct netfs_io_stream *stream,
195 			 struct netfs_io_subrequest *subreq,
196 			 struct iov_iter *source);
197 void netfs_issue_write(struct netfs_io_request *wreq,
198 		       struct netfs_io_stream *stream);
199 size_t netfs_advance_write(struct netfs_io_request *wreq,
200 			   struct netfs_io_stream *stream,
201 			   loff_t start, size_t len, bool to_eof);
202 struct netfs_io_request *netfs_begin_writethrough(struct kiocb *iocb, size_t len);
203 int netfs_advance_writethrough(struct netfs_io_request *wreq, struct writeback_control *wbc,
204 			       struct folio *folio, size_t copied, bool to_page_end,
205 			       struct folio **writethrough_cache);
206 ssize_t netfs_end_writethrough(struct netfs_io_request *wreq, struct writeback_control *wbc,
207 			       struct folio *writethrough_cache);
208 int netfs_unbuffered_write(struct netfs_io_request *wreq, bool may_wait, size_t len);
209 
210 /*
211  * write_retry.c
212  */
213 void netfs_retry_writes(struct netfs_io_request *wreq);
214 
215 /*
216  * Miscellaneous functions.
217  */
218 static inline bool netfs_is_cache_enabled(struct netfs_inode *ctx)
219 {
220 #if IS_ENABLED(CONFIG_FSCACHE)
221 	struct fscache_cookie *cookie = ctx->cache;
222 
223 	return fscache_cookie_valid(cookie) && cookie->cache_priv &&
224 		fscache_cookie_enabled(cookie);
225 #else
226 	return false;
227 #endif
228 }
229 
230 /*
231  * Get a ref on a netfs group attached to a dirty page (e.g. a ceph snap).
232  */
233 static inline struct netfs_group *netfs_get_group(struct netfs_group *netfs_group)
234 {
235 	if (netfs_group && netfs_group != NETFS_FOLIO_COPY_TO_CACHE)
236 		refcount_inc(&netfs_group->ref);
237 	return netfs_group;
238 }
239 
240 /*
241  * Dispose of a netfs group attached to a dirty page (e.g. a ceph snap).
242  */
243 static inline void netfs_put_group(struct netfs_group *netfs_group)
244 {
245 	if (netfs_group &&
246 	    netfs_group != NETFS_FOLIO_COPY_TO_CACHE &&
247 	    refcount_dec_and_test(&netfs_group->ref))
248 		netfs_group->free(netfs_group);
249 }
250 
251 /*
252  * Dispose of a netfs group attached to a dirty page (e.g. a ceph snap).
253  */
254 static inline void netfs_put_group_many(struct netfs_group *netfs_group, int nr)
255 {
256 	if (netfs_group &&
257 	    netfs_group != NETFS_FOLIO_COPY_TO_CACHE &&
258 	    refcount_sub_and_test(nr, &netfs_group->ref))
259 		netfs_group->free(netfs_group);
260 }
261 
262 /*
263  * Clear and wake up a NETFS_RREQ_* flag bit on a request.
264  */
265 static inline void netfs_wake_rreq_flag(struct netfs_io_request *rreq,
266 					unsigned int rreq_flag,
267 					enum netfs_rreq_trace trace)
268 {
269 	if (test_bit(rreq_flag, &rreq->flags)) {
270 		trace_netfs_rreq(rreq, trace);
271 		clear_bit_unlock(rreq_flag, &rreq->flags);
272 		smp_mb__after_atomic(); /* Set flag before task state */
273 		wake_up(&rreq->waitq);
274 	}
275 }
276 
277 /*
278  * fscache-cache.c
279  */
280 #ifdef CONFIG_PROC_FS
281 extern const struct seq_operations fscache_caches_seq_ops;
282 #endif
283 bool fscache_begin_cache_access(struct fscache_cache *cache, enum fscache_access_trace why);
284 void fscache_end_cache_access(struct fscache_cache *cache, enum fscache_access_trace why);
285 struct fscache_cache *fscache_lookup_cache(const char *name, bool is_cache);
286 void fscache_put_cache(struct fscache_cache *cache, enum fscache_cache_trace where);
287 
288 static inline enum fscache_cache_state fscache_cache_state(const struct fscache_cache *cache)
289 {
290 	return smp_load_acquire(&cache->state);
291 }
292 
293 static inline bool fscache_cache_is_live(const struct fscache_cache *cache)
294 {
295 	return fscache_cache_state(cache) == FSCACHE_CACHE_IS_ACTIVE;
296 }
297 
298 static inline void fscache_set_cache_state(struct fscache_cache *cache,
299 					   enum fscache_cache_state new_state)
300 {
301 	smp_store_release(&cache->state, new_state);
302 
303 }
304 
305 static inline bool fscache_set_cache_state_maybe(struct fscache_cache *cache,
306 						 enum fscache_cache_state old_state,
307 						 enum fscache_cache_state new_state)
308 {
309 	return try_cmpxchg_release(&cache->state, &old_state, new_state);
310 }
311 
312 /*
313  * fscache-cookie.c
314  */
315 extern struct kmem_cache *fscache_cookie_jar;
316 #ifdef CONFIG_PROC_FS
317 extern const struct seq_operations fscache_cookies_seq_ops;
318 #endif
319 extern struct timer_list fscache_cookie_lru_timer;
320 
321 extern void fscache_print_cookie(struct fscache_cookie *cookie, char prefix);
322 extern bool fscache_begin_cookie_access(struct fscache_cookie *cookie,
323 					enum fscache_access_trace why);
324 
325 static inline void fscache_see_cookie(struct fscache_cookie *cookie,
326 				      enum fscache_cookie_trace where)
327 {
328 	trace_fscache_cookie(cookie->debug_id, refcount_read(&cookie->ref),
329 			     where);
330 }
331 
332 /*
333  * fscache-main.c
334  */
335 extern unsigned int fscache_hash(unsigned int salt, const void *data, size_t len);
336 #ifdef CONFIG_FSCACHE
337 int __init fscache_init(void);
338 void __exit fscache_exit(void);
339 #else
340 static inline int fscache_init(void) { return 0; }
341 static inline void fscache_exit(void) {}
342 #endif
343 
344 /*
345  * fscache-proc.c
346  */
347 #ifdef CONFIG_PROC_FS
348 extern int __init fscache_proc_init(void);
349 extern void fscache_proc_cleanup(void);
350 #else
351 #define fscache_proc_init()	(0)
352 #define fscache_proc_cleanup()	do {} while (0)
353 #endif
354 
355 /*
356  * fscache-stats.c
357  */
358 #ifdef CONFIG_FSCACHE_STATS
359 extern atomic_t fscache_n_volumes;
360 extern atomic_t fscache_n_volumes_collision;
361 extern atomic_t fscache_n_volumes_nomem;
362 extern atomic_t fscache_n_cookies;
363 extern atomic_t fscache_n_cookies_lru;
364 extern atomic_t fscache_n_cookies_lru_expired;
365 extern atomic_t fscache_n_cookies_lru_removed;
366 extern atomic_t fscache_n_cookies_lru_dropped;
367 
368 extern atomic_t fscache_n_acquires;
369 extern atomic_t fscache_n_acquires_ok;
370 extern atomic_t fscache_n_acquires_oom;
371 
372 extern atomic_t fscache_n_invalidates;
373 
374 extern atomic_t fscache_n_relinquishes;
375 extern atomic_t fscache_n_relinquishes_retire;
376 extern atomic_t fscache_n_relinquishes_dropped;
377 
378 extern atomic_t fscache_n_resizes;
379 extern atomic_t fscache_n_resizes_null;
380 
381 static inline void fscache_stat(atomic_t *stat)
382 {
383 	atomic_inc(stat);
384 }
385 
386 static inline void fscache_stat_d(atomic_t *stat)
387 {
388 	atomic_dec(stat);
389 }
390 
391 #define __fscache_stat(stat) (stat)
392 
393 int fscache_stats_show(struct seq_file *m);
394 #else
395 
396 #define __fscache_stat(stat) (NULL)
397 #define fscache_stat(stat) do {} while (0)
398 #define fscache_stat_d(stat) do {} while (0)
399 
400 static inline int fscache_stats_show(struct seq_file *m) { return 0; }
401 #endif
402 
403 /*
404  * fscache-volume.c
405  */
406 #ifdef CONFIG_PROC_FS
407 extern const struct seq_operations fscache_volumes_seq_ops;
408 #endif
409 
410 struct fscache_volume *fscache_get_volume(struct fscache_volume *volume,
411 					  enum fscache_volume_trace where);
412 bool fscache_begin_volume_access(struct fscache_volume *volume,
413 				 struct fscache_cookie *cookie,
414 				 enum fscache_access_trace why);
415 void fscache_create_volume(struct fscache_volume *volume, bool wait);
416 
417 /*****************************************************************************/
418 /*
419  * debug tracing
420  */
421 #define dbgprintk(FMT, ...) \
422 	printk("[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
423 
424 #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
425 #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
426 #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
427 
428 #ifdef __KDEBUG
429 #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
430 #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
431 #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
432 
433 #elif defined(CONFIG_NETFS_DEBUG)
434 #define _enter(FMT, ...)			\
435 do {						\
436 	if (netfs_debug)			\
437 		kenter(FMT, ##__VA_ARGS__);	\
438 } while (0)
439 
440 #define _leave(FMT, ...)			\
441 do {						\
442 	if (netfs_debug)			\
443 		kleave(FMT, ##__VA_ARGS__);	\
444 } while (0)
445 
446 #define _debug(FMT, ...)			\
447 do {						\
448 	if (netfs_debug)			\
449 		kdebug(FMT, ##__VA_ARGS__);	\
450 } while (0)
451 
452 #else
453 #define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
454 #define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
455 #define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
456 #endif
457 
458 /*
459  * assertions
460  */
461 #if 1 /* defined(__KDEBUGALL) */
462 
463 #define ASSERT(X)							\
464 do {									\
465 	if (unlikely(!(X))) {						\
466 		pr_err("\n");					\
467 		pr_err("Assertion failed\n");	\
468 		BUG();							\
469 	}								\
470 } while (0)
471 
472 #define ASSERTCMP(X, OP, Y)						\
473 do {									\
474 	if (unlikely(!((X) OP (Y)))) {					\
475 		pr_err("\n");					\
476 		pr_err("Assertion failed\n");	\
477 		pr_err("%lx " #OP " %lx is false\n",		\
478 		       (unsigned long)(X), (unsigned long)(Y));		\
479 		BUG();							\
480 	}								\
481 } while (0)
482 
483 #define ASSERTIF(C, X)							\
484 do {									\
485 	if (unlikely((C) && !(X))) {					\
486 		pr_err("\n");					\
487 		pr_err("Assertion failed\n");	\
488 		BUG();							\
489 	}								\
490 } while (0)
491 
492 #define ASSERTIFCMP(C, X, OP, Y)					\
493 do {									\
494 	if (unlikely((C) && !((X) OP (Y)))) {				\
495 		pr_err("\n");					\
496 		pr_err("Assertion failed\n");	\
497 		pr_err("%lx " #OP " %lx is false\n",		\
498 		       (unsigned long)(X), (unsigned long)(Y));		\
499 		BUG();							\
500 	}								\
501 } while (0)
502 
503 #else
504 
505 #define ASSERT(X)			do {} while (0)
506 #define ASSERTCMP(X, OP, Y)		do {} while (0)
507 #define ASSERTIF(C, X)			do {} while (0)
508 #define ASSERTIFCMP(C, X, OP, Y)	do {} while (0)
509 
510 #endif /* assert or not */
511