xref: /linux/fs/netfs/internal.h (revision 69bf14300b50631e7c2271289d347bbd1b19a06c)
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_queue_read(struct netfs_io_request *rreq,
27 		      struct netfs_io_subrequest *subreq);
28 void netfs_cache_read_terminated(void *priv, ssize_t transferred_or_error);
29 int netfs_prefetch_for_write(struct file *file, struct folio *folio,
30 			     size_t offset, size_t len);
31 
32 /*
33  * buffered_write.c
34  */
35 void netfs_update_i_size(struct netfs_inode *ctx, struct inode *inode,
36 			 loff_t pos, size_t copied);
37 
38 /*
39  * main.c
40  */
41 extern unsigned int netfs_debug;
42 extern struct list_head netfs_io_requests;
43 extern spinlock_t netfs_proc_lock;
44 extern mempool_t netfs_request_pool;
45 extern mempool_t netfs_subrequest_pool;
46 extern mempool_t netfs_folioq_pool;
47 
48 #ifdef CONFIG_PROC_FS
49 static inline void netfs_proc_add_rreq(struct netfs_io_request *rreq)
50 {
51 	spin_lock(&netfs_proc_lock);
52 	list_add_tail_rcu(&rreq->proc_link, &netfs_io_requests);
53 	spin_unlock(&netfs_proc_lock);
54 }
55 static inline void netfs_proc_del_rreq(struct netfs_io_request *rreq)
56 {
57 	if (!list_empty(&rreq->proc_link)) {
58 		spin_lock(&netfs_proc_lock);
59 		list_del_rcu(&rreq->proc_link);
60 		spin_unlock(&netfs_proc_lock);
61 	}
62 }
63 #else
64 static inline void netfs_proc_add_rreq(struct netfs_io_request *rreq) {}
65 static inline void netfs_proc_del_rreq(struct netfs_io_request *rreq) {}
66 #endif
67 
68 /*
69  * misc.c
70  */
71 struct folio_queue *netfs_buffer_make_space(struct netfs_io_request *rreq,
72 					    enum netfs_folioq_trace trace);
73 void netfs_reset_iter(struct netfs_io_subrequest *subreq);
74 void netfs_wake_collector(struct netfs_io_request *rreq);
75 void netfs_subreq_clear_in_progress(struct netfs_io_subrequest *subreq);
76 void netfs_wait_for_in_progress_stream(struct netfs_io_request *rreq,
77 				       struct netfs_io_stream *stream);
78 ssize_t netfs_wait_for_read(struct netfs_io_request *rreq);
79 ssize_t netfs_wait_for_write(struct netfs_io_request *rreq);
80 void netfs_wait_for_paused_read(struct netfs_io_request *rreq);
81 void netfs_wait_for_paused_write(struct netfs_io_request *rreq);
82 void netfs_wait_for_put_ra_refs(struct netfs_io_request *rreq);
83 int netfs_clear_stale_pre_isize(struct inode *inode, uoff_t from,
84 				uoff_t to, bool nowait);
85 
86 /*
87  * objects.c
88  */
89 struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
90 					     struct file *file,
91 					     loff_t start, size_t len,
92 					     enum netfs_io_origin origin);
93 void netfs_get_request(struct netfs_io_request *rreq, enum netfs_rreq_ref_trace what);
94 void netfs_clear_subrequests(struct netfs_io_request *rreq);
95 void netfs_put_request(struct netfs_io_request *rreq, enum netfs_rreq_ref_trace what);
96 void netfs_put_failed_request(struct netfs_io_request *rreq);
97 struct netfs_io_subrequest *netfs_alloc_subrequest(struct netfs_io_request *rreq);
98 
99 static inline void netfs_see_request(struct netfs_io_request *rreq,
100 				     enum netfs_rreq_ref_trace what)
101 {
102 	trace_netfs_rreq_ref(rreq->debug_id, refcount_read(&rreq->ref), what);
103 }
104 
105 static inline void netfs_see_subrequest(struct netfs_io_subrequest *subreq,
106 					enum netfs_sreq_ref_trace what)
107 {
108 	trace_netfs_sreq_ref(subreq->rreq->debug_id, subreq->debug_index,
109 			     refcount_read(&subreq->ref), what);
110 }
111 
112 /*
113  * read_collect.c
114  */
115 void netfs_cancel_copy_to_cache(struct netfs_io_request *rreq, struct folio *folio);
116 void netfs_read_set_unlock_at(struct netfs_io_request *rreq);
117 bool netfs_read_collection(struct netfs_io_request *rreq);
118 void netfs_read_collection_worker(struct work_struct *work);
119 void netfs_cancel_read(struct netfs_io_subrequest *subreq, int error);
120 void netfs_cache_read_terminated(void *priv, ssize_t transferred_or_error);
121 
122 /*
123  * read_pgpriv2.c
124  */
125 void netfs_pgpriv2_copy_to_cache(struct netfs_io_request *rreq, struct folio *folio);
126 void netfs_pgpriv2_end_copy_to_cache(struct netfs_io_request *rreq);
127 bool netfs_pgpriv2_unlock_copied_folios(struct netfs_io_request *wreq);
128 
129 /*
130  * read_retry.c
131  */
132 void netfs_retry_reads(struct netfs_io_request *rreq);
133 void netfs_unlock_abandoned_read_pages(struct netfs_io_request *rreq);
134 
135 /*
136  * stats.c
137  */
138 #ifdef CONFIG_NETFS_STATS
139 extern atomic_t netfs_n_rh_dio_read;
140 extern atomic_t netfs_n_rh_readahead;
141 extern atomic_t netfs_n_rh_read_folio;
142 extern atomic_t netfs_n_rh_read_single;
143 extern atomic_t netfs_n_rh_rreq;
144 extern atomic_t netfs_n_rh_sreq;
145 extern atomic_t netfs_n_rh_download;
146 extern atomic_t netfs_n_rh_download_done;
147 extern atomic_t netfs_n_rh_download_failed;
148 extern atomic_t netfs_n_rh_download_instead;
149 extern atomic_t netfs_n_rh_read;
150 extern atomic_t netfs_n_rh_read_done;
151 extern atomic_t netfs_n_rh_read_failed;
152 extern atomic_t netfs_n_rh_zero;
153 extern atomic_t netfs_n_rh_short_read;
154 extern atomic_t netfs_n_rh_write;
155 extern atomic_t netfs_n_rh_write_begin;
156 extern atomic_t netfs_n_rh_write_done;
157 extern atomic_t netfs_n_rh_write_failed;
158 extern atomic_t netfs_n_rh_write_zskip;
159 extern atomic_t netfs_n_rh_retry_read_req;
160 extern atomic_t netfs_n_rh_retry_read_subreq;
161 extern atomic_t netfs_n_wh_buffered_write;
162 extern atomic_t netfs_n_wh_writethrough;
163 extern atomic_t netfs_n_wh_dio_write;
164 extern atomic_t netfs_n_wh_writepages;
165 extern atomic_t netfs_n_wh_copy_to_cache;
166 extern atomic_t netfs_n_wh_wstream_conflict;
167 extern atomic_t netfs_n_wh_upload;
168 extern atomic_t netfs_n_wh_upload_done;
169 extern atomic_t netfs_n_wh_upload_failed;
170 extern atomic_t netfs_n_wh_write;
171 extern atomic_t netfs_n_wh_write_done;
172 extern atomic_t netfs_n_wh_write_failed;
173 extern atomic_t netfs_n_wh_retry_write_req;
174 extern atomic_t netfs_n_wh_retry_write_subreq;
175 extern atomic_t netfs_n_wb_lock_skip;
176 extern atomic_t netfs_n_wb_lock_wait;
177 extern atomic_t netfs_n_folioq;
178 
179 int netfs_stats_show(struct seq_file *m, void *v);
180 
181 static inline void netfs_stat(atomic_t *stat)
182 {
183 	atomic_inc(stat);
184 }
185 
186 static inline void netfs_stat_d(atomic_t *stat)
187 {
188 	atomic_dec(stat);
189 }
190 
191 #else
192 #define netfs_stat(x) do {} while(0)
193 #define netfs_stat_d(x) do {} while(0)
194 #endif
195 
196 /*
197  * write_collect.c
198  */
199 int netfs_folio_written_back(struct folio *folio);
200 bool netfs_write_collection(struct netfs_io_request *wreq);
201 void netfs_write_collection_worker(struct work_struct *work);
202 
203 /*
204  * write_issue.c
205  */
206 struct netfs_io_request *netfs_create_write_req(struct address_space *mapping,
207 						struct file *file,
208 						loff_t start,
209 						enum netfs_io_origin origin);
210 void netfs_prepare_write(struct netfs_io_request *wreq,
211 			 struct netfs_io_stream *stream,
212 			 loff_t start);
213 void netfs_reissue_write(struct netfs_io_stream *stream,
214 			 struct netfs_io_subrequest *subreq,
215 			 struct iov_iter *source);
216 void netfs_issue_write(struct netfs_io_request *wreq,
217 		       struct netfs_io_stream *stream);
218 size_t netfs_advance_write(struct netfs_io_request *wreq,
219 			   struct netfs_io_stream *stream,
220 			   loff_t start, size_t len, bool to_eof);
221 struct netfs_io_request *netfs_begin_writethrough(struct kiocb *iocb, size_t len);
222 int netfs_advance_writethrough(struct netfs_io_request *wreq, struct writeback_control *wbc,
223 			       struct folio *folio, size_t copied, bool to_page_end,
224 			       struct folio **writethrough_cache);
225 ssize_t netfs_end_writethrough(struct netfs_io_request *wreq, struct writeback_control *wbc,
226 			       struct folio *writethrough_cache);
227 
228 /*
229  * write_retry.c
230  */
231 void netfs_retry_writes(struct netfs_io_request *wreq);
232 
233 /*
234  * Miscellaneous functions.
235  */
236 static inline bool netfs_is_cache_enabled(struct netfs_inode *ctx)
237 {
238 #if IS_ENABLED(CONFIG_FSCACHE)
239 	struct fscache_cookie *cookie = ctx->cache;
240 
241 	return fscache_cookie_valid(cookie) && cookie->cache_priv &&
242 		fscache_cookie_enabled(cookie);
243 #else
244 	return false;
245 #endif
246 }
247 
248 static inline bool netfs_is_cache_maybe_enabled(struct netfs_inode *ctx)
249 {
250 #if IS_ENABLED(CONFIG_FSCACHE)
251 	struct fscache_cookie *cookie = ctx->cache;
252 
253 	return fscache_cookie_valid(cookie) &&
254 		test_bit(FSCACHE_COOKIE_IS_CACHING, &cookie->flags);
255 #else
256 	return false;
257 #endif
258 }
259 
260 /*
261  * Get a ref on a netfs group attached to a dirty page (e.g. a ceph snap).
262  */
263 static inline struct netfs_group *netfs_get_group(struct netfs_group *netfs_group)
264 {
265 	if (netfs_group && netfs_group != NETFS_FOLIO_COPY_TO_CACHE)
266 		refcount_inc(&netfs_group->ref);
267 	return netfs_group;
268 }
269 
270 /*
271  * Dispose of a netfs group attached to a dirty page (e.g. a ceph snap).
272  */
273 static inline void netfs_put_group(struct netfs_group *netfs_group)
274 {
275 	if (netfs_group &&
276 	    netfs_group != NETFS_FOLIO_COPY_TO_CACHE &&
277 	    refcount_dec_and_test(&netfs_group->ref))
278 		netfs_group->free(netfs_group);
279 }
280 
281 /*
282  * Dispose of a netfs group attached to a dirty page (e.g. a ceph snap).
283  */
284 static inline void netfs_put_group_many(struct netfs_group *netfs_group, int nr)
285 {
286 	if (netfs_group &&
287 	    netfs_group != NETFS_FOLIO_COPY_TO_CACHE &&
288 	    refcount_sub_and_test(nr, &netfs_group->ref))
289 		netfs_group->free(netfs_group);
290 }
291 
292 /*
293  * Clear and wake up a NETFS_RREQ_* flag bit on a request.
294  */
295 static inline void netfs_wake_rreq_flag(struct netfs_io_request *rreq,
296 					unsigned int rreq_flag,
297 					enum netfs_rreq_trace trace)
298 {
299 	if (test_bit(rreq_flag, &rreq->flags)) {
300 		clear_bit_unlock(rreq_flag, &rreq->flags);
301 		smp_mb__after_atomic(); /* Set flag before task state */
302 		trace_netfs_rreq(rreq, trace);
303 		wake_up(&rreq->waitq);
304 	}
305 }
306 
307 /*
308  * Test the NETFS_RREQ_IN_PROGRESS flag, inserting an appropriate barrier.
309  */
310 static inline bool netfs_check_rreq_in_progress(const struct netfs_io_request *rreq)
311 {
312 	/* Order read of flags before read of anything else, such as error. */
313 	return test_bit_acquire(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
314 }
315 
316 /*
317  * Test the NETFS_SREQ_IN_PROGRESS flag, inserting an appropriate barrier.
318  */
319 static inline bool netfs_check_subreq_in_progress(const struct netfs_io_subrequest *subreq)
320 {
321 	/* Order read of flags before read of anything else, such as error. */
322 	return test_bit_acquire(NETFS_SREQ_IN_PROGRESS, &subreq->flags);
323 }
324 
325 /*
326  * fscache-cache.c
327  */
328 #ifdef CONFIG_PROC_FS
329 extern const struct seq_operations fscache_caches_seq_ops;
330 #endif
331 bool fscache_begin_cache_access(struct fscache_cache *cache, enum fscache_access_trace why);
332 void fscache_end_cache_access(struct fscache_cache *cache, enum fscache_access_trace why);
333 struct fscache_cache *fscache_lookup_cache(const char *name, bool is_cache);
334 void fscache_put_cache(struct fscache_cache *cache, enum fscache_cache_trace where);
335 
336 static inline enum fscache_cache_state fscache_cache_state(const struct fscache_cache *cache)
337 {
338 	return smp_load_acquire(&cache->state);
339 }
340 
341 static inline bool fscache_cache_is_live(const struct fscache_cache *cache)
342 {
343 	return fscache_cache_state(cache) == FSCACHE_CACHE_IS_ACTIVE;
344 }
345 
346 static inline void fscache_set_cache_state(struct fscache_cache *cache,
347 					   enum fscache_cache_state new_state)
348 {
349 	smp_store_release(&cache->state, new_state);
350 
351 }
352 
353 static inline bool fscache_set_cache_state_maybe(struct fscache_cache *cache,
354 						 enum fscache_cache_state old_state,
355 						 enum fscache_cache_state new_state)
356 {
357 	return try_cmpxchg_release(&cache->state, &old_state, new_state);
358 }
359 
360 /*
361  * fscache-cookie.c
362  */
363 extern struct kmem_cache *fscache_cookie_jar;
364 #ifdef CONFIG_PROC_FS
365 extern const struct seq_operations fscache_cookies_seq_ops;
366 #endif
367 extern struct timer_list fscache_cookie_lru_timer;
368 
369 extern void fscache_print_cookie(struct fscache_cookie *cookie, char prefix);
370 extern bool fscache_begin_cookie_access(struct fscache_cookie *cookie,
371 					enum fscache_access_trace why);
372 
373 static inline void fscache_see_cookie(struct fscache_cookie *cookie,
374 				      enum fscache_cookie_trace where)
375 {
376 	trace_fscache_cookie(cookie->debug_id, refcount_read(&cookie->ref),
377 			     where);
378 }
379 
380 /*
381  * fscache-main.c
382  */
383 extern unsigned int fscache_hash(unsigned int salt, const void *data, size_t len);
384 #ifdef CONFIG_FSCACHE
385 int __init fscache_init(void);
386 void __exit fscache_exit(void);
387 #else
388 static inline int fscache_init(void) { return 0; }
389 static inline void fscache_exit(void) {}
390 #endif
391 
392 /*
393  * fscache-proc.c
394  */
395 #ifdef CONFIG_PROC_FS
396 extern int __init fscache_proc_init(void);
397 extern void fscache_proc_cleanup(void);
398 #else
399 #define fscache_proc_init()	(0)
400 #define fscache_proc_cleanup()	do {} while (0)
401 #endif
402 
403 /*
404  * fscache-stats.c
405  */
406 #ifdef CONFIG_FSCACHE_STATS
407 extern atomic_t fscache_n_volumes;
408 extern atomic_t fscache_n_volumes_collision;
409 extern atomic_t fscache_n_volumes_nomem;
410 extern atomic_t fscache_n_cookies;
411 extern atomic_t fscache_n_cookies_lru;
412 extern atomic_t fscache_n_cookies_lru_expired;
413 extern atomic_t fscache_n_cookies_lru_removed;
414 extern atomic_t fscache_n_cookies_lru_dropped;
415 
416 extern atomic_t fscache_n_acquires;
417 extern atomic_t fscache_n_acquires_ok;
418 extern atomic_t fscache_n_acquires_oom;
419 
420 extern atomic_t fscache_n_invalidates;
421 
422 extern atomic_t fscache_n_relinquishes;
423 extern atomic_t fscache_n_relinquishes_retire;
424 extern atomic_t fscache_n_relinquishes_dropped;
425 
426 extern atomic_t fscache_n_resizes;
427 extern atomic_t fscache_n_resizes_null;
428 
429 static inline void fscache_stat(atomic_t *stat)
430 {
431 	atomic_inc(stat);
432 }
433 
434 static inline void fscache_stat_d(atomic_t *stat)
435 {
436 	atomic_dec(stat);
437 }
438 
439 #define __fscache_stat(stat) (stat)
440 
441 int fscache_stats_show(struct seq_file *m);
442 #else
443 
444 #define __fscache_stat(stat) (NULL)
445 #define fscache_stat(stat) do {} while (0)
446 #define fscache_stat_d(stat) do {} while (0)
447 
448 static inline int fscache_stats_show(struct seq_file *m) { return 0; }
449 #endif
450 
451 /*
452  * fscache-volume.c
453  */
454 #ifdef CONFIG_PROC_FS
455 extern const struct seq_operations fscache_volumes_seq_ops;
456 #endif
457 
458 struct fscache_volume *fscache_get_volume(struct fscache_volume *volume,
459 					  enum fscache_volume_trace where);
460 bool fscache_begin_volume_access(struct fscache_volume *volume,
461 				 struct fscache_cookie *cookie,
462 				 enum fscache_access_trace why);
463 void fscache_create_volume(struct fscache_volume *volume, bool wait);
464 
465 /*****************************************************************************/
466 /*
467  * debug tracing
468  */
469 #define dbgprintk(FMT, ...) \
470 	printk("[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
471 
472 #define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
473 #define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
474 #define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
475 
476 #ifdef __KDEBUG
477 #define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
478 #define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
479 #define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
480 
481 #elif defined(CONFIG_NETFS_DEBUG)
482 #define _enter(FMT, ...)			\
483 do {						\
484 	if (netfs_debug)			\
485 		kenter(FMT, ##__VA_ARGS__);	\
486 } while (0)
487 
488 #define _leave(FMT, ...)			\
489 do {						\
490 	if (netfs_debug)			\
491 		kleave(FMT, ##__VA_ARGS__);	\
492 } while (0)
493 
494 #define _debug(FMT, ...)			\
495 do {						\
496 	if (netfs_debug)			\
497 		kdebug(FMT, ##__VA_ARGS__);	\
498 } while (0)
499 
500 #else
501 #define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
502 #define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
503 #define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
504 #endif
505 
506 /*
507  * assertions
508  */
509 #if 1 /* defined(__KDEBUGALL) */
510 
511 #define ASSERT(X)							\
512 do {									\
513 	if (unlikely(!(X))) {						\
514 		pr_err("\n");					\
515 		pr_err("Assertion failed\n");	\
516 		BUG();							\
517 	}								\
518 } while (0)
519 
520 #define ASSERTCMP(X, OP, Y)						\
521 do {									\
522 	if (unlikely(!((X) OP (Y)))) {					\
523 		pr_err("\n");					\
524 		pr_err("Assertion failed\n");	\
525 		pr_err("%lx " #OP " %lx is false\n",		\
526 		       (unsigned long)(X), (unsigned long)(Y));		\
527 		BUG();							\
528 	}								\
529 } while (0)
530 
531 #define ASSERTIF(C, X)							\
532 do {									\
533 	if (unlikely((C) && !(X))) {					\
534 		pr_err("\n");					\
535 		pr_err("Assertion failed\n");	\
536 		BUG();							\
537 	}								\
538 } while (0)
539 
540 #define ASSERTIFCMP(C, X, OP, Y)					\
541 do {									\
542 	if (unlikely((C) && !((X) OP (Y)))) {				\
543 		pr_err("\n");					\
544 		pr_err("Assertion failed\n");	\
545 		pr_err("%lx " #OP " %lx is false\n",		\
546 		       (unsigned long)(X), (unsigned long)(Y));		\
547 		BUG();							\
548 	}								\
549 } while (0)
550 
551 #else
552 
553 #define ASSERT(X)			do {} while (0)
554 #define ASSERTCMP(X, OP, Y)		do {} while (0)
555 #define ASSERTIF(C, X)			do {} while (0)
556 #define ASSERTIFCMP(C, X, OP, Y)	do {} while (0)
557 
558 #endif /* assert or not */
559