internal.h

  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 */
 26void netfs_cache_read_terminated(void *priv, ssize_t transferred_or_error);
 27int netfs_prefetch_for_write(struct file *file, struct folio *folio,
 28			     size_t offset, size_t len);
 29
 30/*
 31 * buffered_write.c
 32 */
 33void netfs_update_i_size(struct netfs_inode *ctx, struct inode *inode,
 34			 loff_t pos, size_t copied);
 35
 36/*
 37 * main.c
 38 */
 39extern unsigned int netfs_debug;
 40extern struct list_head netfs_io_requests;
 41extern spinlock_t netfs_proc_lock;
 42extern mempool_t netfs_request_pool;
 43extern mempool_t netfs_subrequest_pool;
 44
 45#ifdef CONFIG_PROC_FS
 46static inline void netfs_proc_add_rreq(struct netfs_io_request *rreq)
 47{
 48	spin_lock(&netfs_proc_lock);
 49	list_add_tail_rcu(&rreq->proc_link, &netfs_io_requests);
 50	spin_unlock(&netfs_proc_lock);
 51}
 52static inline void netfs_proc_del_rreq(struct netfs_io_request *rreq)
 53{
 54	if (!list_empty(&rreq->proc_link)) {
 55		spin_lock(&netfs_proc_lock);
 56		list_del_rcu(&rreq->proc_link);
 57		spin_unlock(&netfs_proc_lock);
 58	}
 59}
 60#else
 61static inline void netfs_proc_add_rreq(struct netfs_io_request *rreq) {}
 62static inline void netfs_proc_del_rreq(struct netfs_io_request *rreq) {}
 63#endif
 64
 65/*
 66 * misc.c
 67 */
 68struct folio_queue *netfs_buffer_make_space(struct netfs_io_request *rreq,
 69					    enum netfs_folioq_trace trace);
 70void netfs_reset_iter(struct netfs_io_subrequest *subreq);
 71void netfs_wake_collector(struct netfs_io_request *rreq);
 72void netfs_subreq_clear_in_progress(struct netfs_io_subrequest *subreq);
 73void netfs_wait_for_in_progress_stream(struct netfs_io_request *rreq,
 74				       struct netfs_io_stream *stream);
 75ssize_t netfs_wait_for_read(struct netfs_io_request *rreq);
 76ssize_t netfs_wait_for_write(struct netfs_io_request *rreq);
 77void netfs_wait_for_paused_read(struct netfs_io_request *rreq);
 78void netfs_wait_for_paused_write(struct netfs_io_request *rreq);
 79
 80/*
 81 * objects.c
 82 */
 83struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
 84					     struct file *file,
 85					     loff_t start, size_t len,
 86					     enum netfs_io_origin origin);
 87void netfs_get_request(struct netfs_io_request *rreq, enum netfs_rreq_ref_trace what);
 88void netfs_clear_subrequests(struct netfs_io_request *rreq);
 89void netfs_put_request(struct netfs_io_request *rreq, enum netfs_rreq_ref_trace what);
 90void netfs_put_failed_request(struct netfs_io_request *rreq);
 91struct netfs_io_subrequest *netfs_alloc_subrequest(struct netfs_io_request *rreq);
 92
 93static inline void netfs_see_request(struct netfs_io_request *rreq,
 94				     enum netfs_rreq_ref_trace what)
 95{
 96	trace_netfs_rreq_ref(rreq->debug_id, refcount_read(&rreq->ref), what);
 97}
 98
 99static inline void netfs_see_subrequest(struct netfs_io_subrequest *subreq,
100					enum netfs_sreq_ref_trace what)
101{
102	trace_netfs_sreq_ref(subreq->rreq->debug_id, subreq->debug_index,
103			     refcount_read(&subreq->ref), what);
104}
105
106/*
107 * read_collect.c
108 */
109bool netfs_read_collection(struct netfs_io_request *rreq);
110void netfs_read_collection_worker(struct work_struct *work);
111void netfs_cache_read_terminated(void *priv, ssize_t transferred_or_error);
112
113/*
114 * read_pgpriv2.c
115 */
116void netfs_pgpriv2_copy_to_cache(struct netfs_io_request *rreq, struct folio *folio);
117void netfs_pgpriv2_end_copy_to_cache(struct netfs_io_request *rreq);
118bool netfs_pgpriv2_unlock_copied_folios(struct netfs_io_request *wreq);
119
120/*
121 * read_retry.c
122 */
123void netfs_retry_reads(struct netfs_io_request *rreq);
124void netfs_unlock_abandoned_read_pages(struct netfs_io_request *rreq);
125
126/*
127 * stats.c
128 */
129#ifdef CONFIG_NETFS_STATS
130extern atomic_t netfs_n_rh_dio_read;
131extern atomic_t netfs_n_rh_readahead;
132extern atomic_t netfs_n_rh_read_folio;
133extern atomic_t netfs_n_rh_read_single;
134extern atomic_t netfs_n_rh_rreq;
135extern atomic_t netfs_n_rh_sreq;
136extern atomic_t netfs_n_rh_download;
137extern atomic_t netfs_n_rh_download_done;
138extern atomic_t netfs_n_rh_download_failed;
139extern atomic_t netfs_n_rh_download_instead;
140extern atomic_t netfs_n_rh_read;
141extern atomic_t netfs_n_rh_read_done;
142extern atomic_t netfs_n_rh_read_failed;
143extern atomic_t netfs_n_rh_zero;
144extern atomic_t netfs_n_rh_short_read;
145extern atomic_t netfs_n_rh_write;
146extern atomic_t netfs_n_rh_write_begin;
147extern atomic_t netfs_n_rh_write_done;
148extern atomic_t netfs_n_rh_write_failed;
149extern atomic_t netfs_n_rh_write_zskip;
150extern atomic_t netfs_n_rh_retry_read_req;
151extern atomic_t netfs_n_rh_retry_read_subreq;
152extern atomic_t netfs_n_wh_buffered_write;
153extern atomic_t netfs_n_wh_writethrough;
154extern atomic_t netfs_n_wh_dio_write;
155extern atomic_t netfs_n_wh_writepages;
156extern atomic_t netfs_n_wh_copy_to_cache;
157extern atomic_t netfs_n_wh_wstream_conflict;
158extern atomic_t netfs_n_wh_upload;
159extern atomic_t netfs_n_wh_upload_done;
160extern atomic_t netfs_n_wh_upload_failed;
161extern atomic_t netfs_n_wh_write;
162extern atomic_t netfs_n_wh_write_done;
163extern atomic_t netfs_n_wh_write_failed;
164extern atomic_t netfs_n_wh_retry_write_req;
165extern atomic_t netfs_n_wh_retry_write_subreq;
166extern atomic_t netfs_n_wb_lock_skip;
167extern atomic_t netfs_n_wb_lock_wait;
168extern atomic_t netfs_n_folioq;
169
170int netfs_stats_show(struct seq_file *m, void *v);
171
172static inline void netfs_stat(atomic_t *stat)
173{
174	atomic_inc(stat);
175}
176
177static inline void netfs_stat_d(atomic_t *stat)
178{
179	atomic_dec(stat);
180}
181
182#else
183#define netfs_stat(x) do {} while(0)
184#define netfs_stat_d(x) do {} while(0)
185#endif
186
187/*
188 * write_collect.c
189 */
190int netfs_folio_written_back(struct folio *folio);
191bool netfs_write_collection(struct netfs_io_request *wreq);
192void netfs_write_collection_worker(struct work_struct *work);
193
194/*
195 * write_issue.c
196 */
197struct netfs_io_request *netfs_create_write_req(struct address_space *mapping,
198						struct file *file,
199						loff_t start,
200						enum netfs_io_origin origin);
201void netfs_prepare_write(struct netfs_io_request *wreq,
202			 struct netfs_io_stream *stream,
203			 loff_t start);
204void netfs_reissue_write(struct netfs_io_stream *stream,
205			 struct netfs_io_subrequest *subreq,
206			 struct iov_iter *source);
207void netfs_issue_write(struct netfs_io_request *wreq,
208		       struct netfs_io_stream *stream);
209size_t netfs_advance_write(struct netfs_io_request *wreq,
210			   struct netfs_io_stream *stream,
211			   loff_t start, size_t len, bool to_eof);
212struct netfs_io_request *netfs_begin_writethrough(struct kiocb *iocb, size_t len);
213int netfs_advance_writethrough(struct netfs_io_request *wreq, struct writeback_control *wbc,
214			       struct folio *folio, size_t copied, bool to_page_end,
215			       struct folio **writethrough_cache);
216ssize_t netfs_end_writethrough(struct netfs_io_request *wreq, struct writeback_control *wbc,
217			       struct folio *writethrough_cache);
218
219/*
220 * write_retry.c
221 */
222void netfs_retry_writes(struct netfs_io_request *wreq);
223
224/*
225 * Miscellaneous functions.
226 */
227static inline bool netfs_is_cache_enabled(struct netfs_inode *ctx)
228{
229#if IS_ENABLED(CONFIG_FSCACHE)
230	struct fscache_cookie *cookie = ctx->cache;
231
232	return fscache_cookie_valid(cookie) && cookie->cache_priv &&
233		fscache_cookie_enabled(cookie);
234#else
235	return false;
236#endif
237}
238
239/*
240 * Get a ref on a netfs group attached to a dirty page (e.g. a ceph snap).
241 */
242static inline struct netfs_group *netfs_get_group(struct netfs_group *netfs_group)
243{
244	if (netfs_group && netfs_group != NETFS_FOLIO_COPY_TO_CACHE)
245		refcount_inc(&netfs_group->ref);
246	return netfs_group;
247}
248
249/*
250 * Dispose of a netfs group attached to a dirty page (e.g. a ceph snap).
251 */
252static inline void netfs_put_group(struct netfs_group *netfs_group)
253{
254	if (netfs_group &&
255	    netfs_group != NETFS_FOLIO_COPY_TO_CACHE &&
256	    refcount_dec_and_test(&netfs_group->ref))
257		netfs_group->free(netfs_group);
258}
259
260/*
261 * Dispose of a netfs group attached to a dirty page (e.g. a ceph snap).
262 */
263static inline void netfs_put_group_many(struct netfs_group *netfs_group, int nr)
264{
265	if (netfs_group &&
266	    netfs_group != NETFS_FOLIO_COPY_TO_CACHE &&
267	    refcount_sub_and_test(nr, &netfs_group->ref))
268		netfs_group->free(netfs_group);
269}
270
271/*
272 * Clear and wake up a NETFS_RREQ_* flag bit on a request.
273 */
274static inline void netfs_wake_rreq_flag(struct netfs_io_request *rreq,
275					unsigned int rreq_flag,
276					enum netfs_rreq_trace trace)
277{
278	if (test_bit(rreq_flag, &rreq->flags)) {
279		clear_bit_unlock(rreq_flag, &rreq->flags);
280		smp_mb__after_atomic(); /* Set flag before task state */
281		trace_netfs_rreq(rreq, trace);
282		wake_up(&rreq->waitq);
283	}
284}
285
286/*
287 * Test the NETFS_RREQ_IN_PROGRESS flag, inserting an appropriate barrier.
288 */
289static inline bool netfs_check_rreq_in_progress(const struct netfs_io_request *rreq)
290{
291	/* Order read of flags before read of anything else, such as error. */
292	return test_bit_acquire(NETFS_RREQ_IN_PROGRESS, &rreq->flags);
293}
294
295/*
296 * Test the NETFS_SREQ_IN_PROGRESS flag, inserting an appropriate barrier.
297 */
298static inline bool netfs_check_subreq_in_progress(const struct netfs_io_subrequest *subreq)
299{
300	/* Order read of flags before read of anything else, such as error. */
301	return test_bit_acquire(NETFS_SREQ_IN_PROGRESS, &subreq->flags);
302}
303
304/*
305 * fscache-cache.c
306 */
307#ifdef CONFIG_PROC_FS
308extern const struct seq_operations fscache_caches_seq_ops;
309#endif
310bool fscache_begin_cache_access(struct fscache_cache *cache, enum fscache_access_trace why);
311void fscache_end_cache_access(struct fscache_cache *cache, enum fscache_access_trace why);
312struct fscache_cache *fscache_lookup_cache(const char *name, bool is_cache);
313void fscache_put_cache(struct fscache_cache *cache, enum fscache_cache_trace where);
314
315static inline enum fscache_cache_state fscache_cache_state(const struct fscache_cache *cache)
316{
317	return smp_load_acquire(&cache->state);
318}
319
320static inline bool fscache_cache_is_live(const struct fscache_cache *cache)
321{
322	return fscache_cache_state(cache) == FSCACHE_CACHE_IS_ACTIVE;
323}
324
325static inline void fscache_set_cache_state(struct fscache_cache *cache,
326					   enum fscache_cache_state new_state)
327{
328	smp_store_release(&cache->state, new_state);
329
330}
331
332static inline bool fscache_set_cache_state_maybe(struct fscache_cache *cache,
333						 enum fscache_cache_state old_state,
334						 enum fscache_cache_state new_state)
335{
336	return try_cmpxchg_release(&cache->state, &old_state, new_state);
337}
338
339/*
340 * fscache-cookie.c
341 */
342extern struct kmem_cache *fscache_cookie_jar;
343#ifdef CONFIG_PROC_FS
344extern const struct seq_operations fscache_cookies_seq_ops;
345#endif
346extern struct timer_list fscache_cookie_lru_timer;
347
348extern void fscache_print_cookie(struct fscache_cookie *cookie, char prefix);
349extern bool fscache_begin_cookie_access(struct fscache_cookie *cookie,
350					enum fscache_access_trace why);
351
352static inline void fscache_see_cookie(struct fscache_cookie *cookie,
353				      enum fscache_cookie_trace where)
354{
355	trace_fscache_cookie(cookie->debug_id, refcount_read(&cookie->ref),
356			     where);
357}
358
359/*
360 * fscache-main.c
361 */
362extern unsigned int fscache_hash(unsigned int salt, const void *data, size_t len);
363#ifdef CONFIG_FSCACHE
364int __init fscache_init(void);
365void __exit fscache_exit(void);
366#else
367static inline int fscache_init(void) { return 0; }
368static inline void fscache_exit(void) {}
369#endif
370
371/*
372 * fscache-proc.c
373 */
374#ifdef CONFIG_PROC_FS
375extern int __init fscache_proc_init(void);
376extern void fscache_proc_cleanup(void);
377#else
378#define fscache_proc_init()	(0)
379#define fscache_proc_cleanup()	do {} while (0)
380#endif
381
382/*
383 * fscache-stats.c
384 */
385#ifdef CONFIG_FSCACHE_STATS
386extern atomic_t fscache_n_volumes;
387extern atomic_t fscache_n_volumes_collision;
388extern atomic_t fscache_n_volumes_nomem;
389extern atomic_t fscache_n_cookies;
390extern atomic_t fscache_n_cookies_lru;
391extern atomic_t fscache_n_cookies_lru_expired;
392extern atomic_t fscache_n_cookies_lru_removed;
393extern atomic_t fscache_n_cookies_lru_dropped;
394
395extern atomic_t fscache_n_acquires;
396extern atomic_t fscache_n_acquires_ok;
397extern atomic_t fscache_n_acquires_oom;
398
399extern atomic_t fscache_n_invalidates;
400
401extern atomic_t fscache_n_relinquishes;
402extern atomic_t fscache_n_relinquishes_retire;
403extern atomic_t fscache_n_relinquishes_dropped;
404
405extern atomic_t fscache_n_resizes;
406extern atomic_t fscache_n_resizes_null;
407
408static inline void fscache_stat(atomic_t *stat)
409{
410	atomic_inc(stat);
411}
412
413static inline void fscache_stat_d(atomic_t *stat)
414{
415	atomic_dec(stat);
416}
417
418#define __fscache_stat(stat) (stat)
419
420int fscache_stats_show(struct seq_file *m);
421#else
422
423#define __fscache_stat(stat) (NULL)
424#define fscache_stat(stat) do {} while (0)
425#define fscache_stat_d(stat) do {} while (0)
426
427static inline int fscache_stats_show(struct seq_file *m) { return 0; }
428#endif
429
430/*
431 * fscache-volume.c
432 */
433#ifdef CONFIG_PROC_FS
434extern const struct seq_operations fscache_volumes_seq_ops;
435#endif
436
437struct fscache_volume *fscache_get_volume(struct fscache_volume *volume,
438					  enum fscache_volume_trace where);
439bool fscache_begin_volume_access(struct fscache_volume *volume,
440				 struct fscache_cookie *cookie,
441				 enum fscache_access_trace why);
442void fscache_create_volume(struct fscache_volume *volume, bool wait);
443
444/*****************************************************************************/
445/*
446 * debug tracing
447 */
448#define dbgprintk(FMT, ...) \
449	printk("[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
450
451#define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
452#define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
453#define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
454
455#ifdef __KDEBUG
456#define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
457#define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
458#define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
459
460#elif defined(CONFIG_NETFS_DEBUG)
461#define _enter(FMT, ...)			\
462do {						\
463	if (netfs_debug)			\
464		kenter(FMT, ##__VA_ARGS__);	\
465} while (0)
466
467#define _leave(FMT, ...)			\
468do {						\
469	if (netfs_debug)			\
470		kleave(FMT, ##__VA_ARGS__);	\
471} while (0)
472
473#define _debug(FMT, ...)			\
474do {						\
475	if (netfs_debug)			\
476		kdebug(FMT, ##__VA_ARGS__);	\
477} while (0)
478
479#else
480#define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
481#define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
482#define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
483#endif
484
485/*
486 * assertions
487 */
488#if 1 /* defined(__KDEBUGALL) */
489
490#define ASSERT(X)							\
491do {									\
492	if (unlikely(!(X))) {						\
493		pr_err("\n");					\
494		pr_err("Assertion failed\n");	\
495		BUG();							\
496	}								\
497} while (0)
498
499#define ASSERTCMP(X, OP, Y)						\
500do {									\
501	if (unlikely(!((X) OP (Y)))) {					\
502		pr_err("\n");					\
503		pr_err("Assertion failed\n");	\
504		pr_err("%lx " #OP " %lx is false\n",		\
505		       (unsigned long)(X), (unsigned long)(Y));		\
506		BUG();							\
507	}								\
508} while (0)
509
510#define ASSERTIF(C, X)							\
511do {									\
512	if (unlikely((C) && !(X))) {					\
513		pr_err("\n");					\
514		pr_err("Assertion failed\n");	\
515		BUG();							\
516	}								\
517} while (0)
518
519#define ASSERTIFCMP(C, X, OP, Y)					\
520do {									\
521	if (unlikely((C) && !((X) OP (Y)))) {				\
522		pr_err("\n");					\
523		pr_err("Assertion failed\n");	\
524		pr_err("%lx " #OP " %lx is false\n",		\
525		       (unsigned long)(X), (unsigned long)(Y));		\
526		BUG();							\
527	}								\
528} while (0)
529
530#else
531
532#define ASSERT(X)			do {} while (0)
533#define ASSERTCMP(X, OP, Y)		do {} while (0)
534#define ASSERTIF(C, X)			do {} while (0)
535#define ASSERTIFCMP(C, X, OP, Y)	do {} while (0)
536
537#endif /* assert or not */