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  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 */
 26int netfs_prefetch_for_write(struct file *file, struct folio *folio,
 27			     size_t offset, size_t len);
 28
 29/*
 30 * main.c
 31 */
 32extern unsigned int netfs_debug;
 33extern struct list_head netfs_io_requests;
 34extern spinlock_t netfs_proc_lock;
 35extern mempool_t netfs_request_pool;
 36extern mempool_t netfs_subrequest_pool;
 37
 38#ifdef CONFIG_PROC_FS
 39static inline void netfs_proc_add_rreq(struct netfs_io_request *rreq)
 40{
 41	spin_lock(&netfs_proc_lock);
 42	list_add_tail_rcu(&rreq->proc_link, &netfs_io_requests);
 43	spin_unlock(&netfs_proc_lock);
 44}
 45static inline void netfs_proc_del_rreq(struct netfs_io_request *rreq)
 46{
 47	if (!list_empty(&rreq->proc_link)) {
 48		spin_lock(&netfs_proc_lock);
 49		list_del_rcu(&rreq->proc_link);
 50		spin_unlock(&netfs_proc_lock);
 51	}
 52}
 53#else
 54static inline void netfs_proc_add_rreq(struct netfs_io_request *rreq) {}
 55static inline void netfs_proc_del_rreq(struct netfs_io_request *rreq) {}
 56#endif
 57
 58/*
 59 * misc.c
 60 */
 61struct folio_queue *netfs_buffer_make_space(struct netfs_io_request *rreq);
 62int netfs_buffer_append_folio(struct netfs_io_request *rreq, struct folio *folio,
 63			      bool needs_put);
 64struct folio_queue *netfs_delete_buffer_head(struct netfs_io_request *wreq);
 65void netfs_clear_buffer(struct netfs_io_request *rreq);
 66void netfs_reset_iter(struct netfs_io_subrequest *subreq);
 67
 68/*
 69 * objects.c
 70 */
 71struct netfs_io_request *netfs_alloc_request(struct address_space *mapping,
 72					     struct file *file,
 73					     loff_t start, size_t len,
 74					     enum netfs_io_origin origin);
 75void netfs_get_request(struct netfs_io_request *rreq, enum netfs_rreq_ref_trace what);
 76void netfs_clear_subrequests(struct netfs_io_request *rreq, bool was_async);
 77void netfs_put_request(struct netfs_io_request *rreq, bool was_async,
 78		       enum netfs_rreq_ref_trace what);
 79struct netfs_io_subrequest *netfs_alloc_subrequest(struct netfs_io_request *rreq);
 80
 81static inline void netfs_see_request(struct netfs_io_request *rreq,
 82				     enum netfs_rreq_ref_trace what)
 83{
 84	trace_netfs_rreq_ref(rreq->debug_id, refcount_read(&rreq->ref), what);
 85}
 86
 87/*
 88 * read_collect.c
 89 */
 90void netfs_read_termination_worker(struct work_struct *work);
 91void netfs_rreq_terminated(struct netfs_io_request *rreq, bool was_async);
 92
 93/*
 94 * read_pgpriv2.c
 95 */
 96void netfs_pgpriv2_mark_copy_to_cache(struct netfs_io_subrequest *subreq,
 97				      struct netfs_io_request *rreq,
 98				      struct folio_queue *folioq,
 99				      int slot);
100void netfs_pgpriv2_write_to_the_cache(struct netfs_io_request *rreq);
101bool netfs_pgpriv2_unlock_copied_folios(struct netfs_io_request *wreq);
102
103/*
104 * read_retry.c
105 */
106void netfs_retry_reads(struct netfs_io_request *rreq);
107void netfs_unlock_abandoned_read_pages(struct netfs_io_request *rreq);
108
109/*
110 * stats.c
111 */
112#ifdef CONFIG_NETFS_STATS
113extern atomic_t netfs_n_rh_dio_read;
114extern atomic_t netfs_n_rh_readahead;
115extern atomic_t netfs_n_rh_read_folio;
116extern atomic_t netfs_n_rh_rreq;
117extern atomic_t netfs_n_rh_sreq;
118extern atomic_t netfs_n_rh_download;
119extern atomic_t netfs_n_rh_download_done;
120extern atomic_t netfs_n_rh_download_failed;
121extern atomic_t netfs_n_rh_download_instead;
122extern atomic_t netfs_n_rh_read;
123extern atomic_t netfs_n_rh_read_done;
124extern atomic_t netfs_n_rh_read_failed;
125extern atomic_t netfs_n_rh_zero;
126extern atomic_t netfs_n_rh_short_read;
127extern atomic_t netfs_n_rh_write;
128extern atomic_t netfs_n_rh_write_begin;
129extern atomic_t netfs_n_rh_write_done;
130extern atomic_t netfs_n_rh_write_failed;
131extern atomic_t netfs_n_rh_write_zskip;
132extern atomic_t netfs_n_wh_buffered_write;
133extern atomic_t netfs_n_wh_writethrough;
134extern atomic_t netfs_n_wh_dio_write;
135extern atomic_t netfs_n_wh_writepages;
136extern atomic_t netfs_n_wh_copy_to_cache;
137extern atomic_t netfs_n_wh_wstream_conflict;
138extern atomic_t netfs_n_wh_upload;
139extern atomic_t netfs_n_wh_upload_done;
140extern atomic_t netfs_n_wh_upload_failed;
141extern atomic_t netfs_n_wh_write;
142extern atomic_t netfs_n_wh_write_done;
143extern atomic_t netfs_n_wh_write_failed;
144extern atomic_t netfs_n_wb_lock_skip;
145extern atomic_t netfs_n_wb_lock_wait;
146extern atomic_t netfs_n_folioq;
147
148int netfs_stats_show(struct seq_file *m, void *v);
149
150static inline void netfs_stat(atomic_t *stat)
151{
152	atomic_inc(stat);
153}
154
155static inline void netfs_stat_d(atomic_t *stat)
156{
157	atomic_dec(stat);
158}
159
160#else
161#define netfs_stat(x) do {} while(0)
162#define netfs_stat_d(x) do {} while(0)
163#endif
164
165/*
166 * write_collect.c
167 */
168int netfs_folio_written_back(struct folio *folio);
169void netfs_write_collection_worker(struct work_struct *work);
170void netfs_wake_write_collector(struct netfs_io_request *wreq, bool was_async);
171
172/*
173 * write_issue.c
174 */
175struct netfs_io_request *netfs_create_write_req(struct address_space *mapping,
176						struct file *file,
177						loff_t start,
178						enum netfs_io_origin origin);
179void netfs_reissue_write(struct netfs_io_stream *stream,
180			 struct netfs_io_subrequest *subreq,
181			 struct iov_iter *source);
182void netfs_issue_write(struct netfs_io_request *wreq,
183		       struct netfs_io_stream *stream);
184int netfs_advance_write(struct netfs_io_request *wreq,
185			struct netfs_io_stream *stream,
186			loff_t start, size_t len, bool to_eof);
187struct netfs_io_request *netfs_begin_writethrough(struct kiocb *iocb, size_t len);
188int netfs_advance_writethrough(struct netfs_io_request *wreq, struct writeback_control *wbc,
189			       struct folio *folio, size_t copied, bool to_page_end,
190			       struct folio **writethrough_cache);
191int netfs_end_writethrough(struct netfs_io_request *wreq, struct writeback_control *wbc,
192			   struct folio *writethrough_cache);
193int netfs_unbuffered_write(struct netfs_io_request *wreq, bool may_wait, size_t len);
194
195/*
196 * Miscellaneous functions.
197 */
198static inline bool netfs_is_cache_enabled(struct netfs_inode *ctx)
199{
200#if IS_ENABLED(CONFIG_FSCACHE)
201	struct fscache_cookie *cookie = ctx->cache;
202
203	return fscache_cookie_valid(cookie) && cookie->cache_priv &&
204		fscache_cookie_enabled(cookie);
205#else
206	return false;
207#endif
208}
209
210/*
211 * Get a ref on a netfs group attached to a dirty page (e.g. a ceph snap).
212 */
213static inline struct netfs_group *netfs_get_group(struct netfs_group *netfs_group)
214{
215	if (netfs_group && netfs_group != NETFS_FOLIO_COPY_TO_CACHE)
216		refcount_inc(&netfs_group->ref);
217	return netfs_group;
218}
219
220/*
221 * Dispose of a netfs group attached to a dirty page (e.g. a ceph snap).
222 */
223static inline void netfs_put_group(struct netfs_group *netfs_group)
224{
225	if (netfs_group &&
226	    netfs_group != NETFS_FOLIO_COPY_TO_CACHE &&
227	    refcount_dec_and_test(&netfs_group->ref))
228		netfs_group->free(netfs_group);
229}
230
231/*
232 * Dispose of a netfs group attached to a dirty page (e.g. a ceph snap).
233 */
234static inline void netfs_put_group_many(struct netfs_group *netfs_group, int nr)
235{
236	if (netfs_group &&
237	    netfs_group != NETFS_FOLIO_COPY_TO_CACHE &&
238	    refcount_sub_and_test(nr, &netfs_group->ref))
239		netfs_group->free(netfs_group);
240}
241
242/*
243 * fscache-cache.c
244 */
245#ifdef CONFIG_PROC_FS
246extern const struct seq_operations fscache_caches_seq_ops;
247#endif
248bool fscache_begin_cache_access(struct fscache_cache *cache, enum fscache_access_trace why);
249void fscache_end_cache_access(struct fscache_cache *cache, enum fscache_access_trace why);
250struct fscache_cache *fscache_lookup_cache(const char *name, bool is_cache);
251void fscache_put_cache(struct fscache_cache *cache, enum fscache_cache_trace where);
252
253static inline enum fscache_cache_state fscache_cache_state(const struct fscache_cache *cache)
254{
255	return smp_load_acquire(&cache->state);
256}
257
258static inline bool fscache_cache_is_live(const struct fscache_cache *cache)
259{
260	return fscache_cache_state(cache) == FSCACHE_CACHE_IS_ACTIVE;
261}
262
263static inline void fscache_set_cache_state(struct fscache_cache *cache,
264					   enum fscache_cache_state new_state)
265{
266	smp_store_release(&cache->state, new_state);
267
268}
269
270static inline bool fscache_set_cache_state_maybe(struct fscache_cache *cache,
271						 enum fscache_cache_state old_state,
272						 enum fscache_cache_state new_state)
273{
274	return try_cmpxchg_release(&cache->state, &old_state, new_state);
275}
276
277/*
278 * fscache-cookie.c
279 */
280extern struct kmem_cache *fscache_cookie_jar;
281#ifdef CONFIG_PROC_FS
282extern const struct seq_operations fscache_cookies_seq_ops;
283#endif
284extern struct timer_list fscache_cookie_lru_timer;
285
286extern void fscache_print_cookie(struct fscache_cookie *cookie, char prefix);
287extern bool fscache_begin_cookie_access(struct fscache_cookie *cookie,
288					enum fscache_access_trace why);
289
290static inline void fscache_see_cookie(struct fscache_cookie *cookie,
291				      enum fscache_cookie_trace where)
292{
293	trace_fscache_cookie(cookie->debug_id, refcount_read(&cookie->ref),
294			     where);
295}
296
297/*
298 * fscache-main.c
299 */
300extern unsigned int fscache_hash(unsigned int salt, const void *data, size_t len);
301#ifdef CONFIG_FSCACHE
302int __init fscache_init(void);
303void __exit fscache_exit(void);
304#else
305static inline int fscache_init(void) { return 0; }
306static inline void fscache_exit(void) {}
307#endif
308
309/*
310 * fscache-proc.c
311 */
312#ifdef CONFIG_PROC_FS
313extern int __init fscache_proc_init(void);
314extern void fscache_proc_cleanup(void);
315#else
316#define fscache_proc_init()	(0)
317#define fscache_proc_cleanup()	do {} while (0)
318#endif
319
320/*
321 * fscache-stats.c
322 */
323#ifdef CONFIG_FSCACHE_STATS
324extern atomic_t fscache_n_volumes;
325extern atomic_t fscache_n_volumes_collision;
326extern atomic_t fscache_n_volumes_nomem;
327extern atomic_t fscache_n_cookies;
328extern atomic_t fscache_n_cookies_lru;
329extern atomic_t fscache_n_cookies_lru_expired;
330extern atomic_t fscache_n_cookies_lru_removed;
331extern atomic_t fscache_n_cookies_lru_dropped;
332
333extern atomic_t fscache_n_acquires;
334extern atomic_t fscache_n_acquires_ok;
335extern atomic_t fscache_n_acquires_oom;
336
337extern atomic_t fscache_n_invalidates;
338
339extern atomic_t fscache_n_relinquishes;
340extern atomic_t fscache_n_relinquishes_retire;
341extern atomic_t fscache_n_relinquishes_dropped;
342
343extern atomic_t fscache_n_resizes;
344extern atomic_t fscache_n_resizes_null;
345
346static inline void fscache_stat(atomic_t *stat)
347{
348	atomic_inc(stat);
349}
350
351static inline void fscache_stat_d(atomic_t *stat)
352{
353	atomic_dec(stat);
354}
355
356#define __fscache_stat(stat) (stat)
357
358int fscache_stats_show(struct seq_file *m);
359#else
360
361#define __fscache_stat(stat) (NULL)
362#define fscache_stat(stat) do {} while (0)
363#define fscache_stat_d(stat) do {} while (0)
364
365static inline int fscache_stats_show(struct seq_file *m) { return 0; }
366#endif
367
368/*
369 * fscache-volume.c
370 */
371#ifdef CONFIG_PROC_FS
372extern const struct seq_operations fscache_volumes_seq_ops;
373#endif
374
375struct fscache_volume *fscache_get_volume(struct fscache_volume *volume,
376					  enum fscache_volume_trace where);
377bool fscache_begin_volume_access(struct fscache_volume *volume,
378				 struct fscache_cookie *cookie,
379				 enum fscache_access_trace why);
380void fscache_create_volume(struct fscache_volume *volume, bool wait);
381
382/*****************************************************************************/
383/*
384 * debug tracing
385 */
386#define dbgprintk(FMT, ...) \
387	printk("[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
388
389#define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
390#define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
391#define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
392
393#ifdef __KDEBUG
394#define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
395#define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
396#define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
397
398#elif defined(CONFIG_NETFS_DEBUG)
399#define _enter(FMT, ...)			\
400do {						\
401	if (netfs_debug)			\
402		kenter(FMT, ##__VA_ARGS__);	\
403} while (0)
404
405#define _leave(FMT, ...)			\
406do {						\
407	if (netfs_debug)			\
408		kleave(FMT, ##__VA_ARGS__);	\
409} while (0)
410
411#define _debug(FMT, ...)			\
412do {						\
413	if (netfs_debug)			\
414		kdebug(FMT, ##__VA_ARGS__);	\
415} while (0)
416
417#else
418#define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
419#define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
420#define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
421#endif
422
423/*
424 * assertions
425 */
426#if 1 /* defined(__KDEBUGALL) */
427
428#define ASSERT(X)							\
429do {									\
430	if (unlikely(!(X))) {						\
431		pr_err("\n");					\
432		pr_err("Assertion failed\n");	\
433		BUG();							\
434	}								\
435} while (0)
436
437#define ASSERTCMP(X, OP, Y)						\
438do {									\
439	if (unlikely(!((X) OP (Y)))) {					\
440		pr_err("\n");					\
441		pr_err("Assertion failed\n");	\
442		pr_err("%lx " #OP " %lx is false\n",		\
443		       (unsigned long)(X), (unsigned long)(Y));		\
444		BUG();							\
445	}								\
446} while (0)
447
448#define ASSERTIF(C, X)							\
449do {									\
450	if (unlikely((C) && !(X))) {					\
451		pr_err("\n");					\
452		pr_err("Assertion failed\n");	\
453		BUG();							\
454	}								\
455} while (0)
456
457#define ASSERTIFCMP(C, X, OP, Y)					\
458do {									\
459	if (unlikely((C) && !((X) OP (Y)))) {				\
460		pr_err("\n");					\
461		pr_err("Assertion failed\n");	\
462		pr_err("%lx " #OP " %lx is false\n",		\
463		       (unsigned long)(X), (unsigned long)(Y));		\
464		BUG();							\
465	}								\
466} while (0)
467
468#else
469
470#define ASSERT(X)			do {} while (0)
471#define ASSERTCMP(X, OP, Y)		do {} while (0)
472#define ASSERTIF(C, X)			do {} while (0)
473#define ASSERTIFCMP(C, X, OP, Y)	do {} while (0)
474
475#endif /* assert or not */