1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /* Network filesystem support services.
3 *
4 * Copyright (C) 2021 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 *
7 * See:
8 *
9 * Documentation/filesystems/netfs_library.rst
10 *
11 * for a description of the network filesystem interface declared here.
12 */
13
14 #ifndef _LINUX_NETFS_H
15 #define _LINUX_NETFS_H
16
17 #include <linux/workqueue.h>
18 #include <linux/fs.h>
19 #include <linux/pagemap.h>
20 #include <linux/uio.h>
21 #include <linux/rolling_buffer.h>
22
23 enum netfs_sreq_ref_trace;
24 typedef struct mempool_s mempool_t;
25 struct folio_queue;
26
27 /**
28 * folio_start_private_2 - Start an fscache write on a folio. [DEPRECATED]
29 * @folio: The folio.
30 *
31 * Call this function before writing a folio to a local cache. Starting a
32 * second write before the first one finishes is not allowed.
33 *
34 * Note that this should no longer be used.
35 */
folio_start_private_2(struct folio * folio)36 static inline void folio_start_private_2(struct folio *folio)
37 {
38 VM_BUG_ON_FOLIO(folio_test_private_2(folio), folio);
39 folio_get(folio);
40 folio_set_private_2(folio);
41 }
42
43 enum netfs_io_source {
44 NETFS_SOURCE_UNKNOWN,
45 NETFS_FILL_WITH_ZEROES,
46 NETFS_DOWNLOAD_FROM_SERVER,
47 NETFS_READ_FROM_CACHE,
48 NETFS_INVALID_READ,
49 NETFS_UPLOAD_TO_SERVER,
50 NETFS_WRITE_TO_CACHE,
51 } __mode(byte);
52
53 typedef void (*netfs_io_terminated_t)(void *priv, ssize_t transferred_or_error);
54
55 /*
56 * Per-inode context. This wraps the VFS inode.
57 */
58 struct netfs_inode {
59 struct inode inode; /* The VFS inode */
60 const struct netfs_request_ops *ops;
61 #if IS_ENABLED(CONFIG_FSCACHE)
62 struct fscache_cookie *cache;
63 #endif
64 struct mutex wb_lock; /* Writeback serialisation */
65 loff_t remote_i_size; /* Size of the remote file */
66 loff_t zero_point; /* Size after which we assume there's no data
67 * on the server */
68 atomic_t io_count; /* Number of outstanding reqs */
69 unsigned long flags;
70 #define NETFS_ICTX_ODIRECT 0 /* The file has DIO in progress */
71 #define NETFS_ICTX_UNBUFFERED 1 /* I/O should not use the pagecache */
72 #define NETFS_ICTX_MODIFIED_ATTR 3 /* Indicate change in mtime/ctime */
73 #define NETFS_ICTX_SINGLE_NO_UPLOAD 4 /* Monolithic payload, cache but no upload */
74 };
75
76 /*
77 * A netfs group - for instance a ceph snap. This is marked on dirty pages and
78 * pages marked with a group must be flushed before they can be written under
79 * the domain of another group.
80 */
81 struct netfs_group {
82 refcount_t ref;
83 void (*free)(struct netfs_group *netfs_group);
84 };
85
86 /*
87 * Information about a dirty page (attached only if necessary).
88 * folio->private
89 */
90 struct netfs_folio {
91 struct netfs_group *netfs_group; /* Filesystem's grouping marker (or NULL). */
92 unsigned int dirty_offset; /* Write-streaming dirty data offset */
93 unsigned int dirty_len; /* Write-streaming dirty data length */
94 };
95 #define NETFS_FOLIO_INFO 0x1UL /* OR'd with folio->private. */
96 #define NETFS_FOLIO_COPY_TO_CACHE ((struct netfs_group *)0x356UL) /* Write to the cache only */
97
netfs_is_folio_info(const void * priv)98 static inline bool netfs_is_folio_info(const void *priv)
99 {
100 return (unsigned long)priv & NETFS_FOLIO_INFO;
101 }
102
__netfs_folio_info(const void * priv)103 static inline struct netfs_folio *__netfs_folio_info(const void *priv)
104 {
105 if (netfs_is_folio_info(priv))
106 return (struct netfs_folio *)((unsigned long)priv & ~NETFS_FOLIO_INFO);
107 return NULL;
108 }
109
netfs_folio_info(struct folio * folio)110 static inline struct netfs_folio *netfs_folio_info(struct folio *folio)
111 {
112 return __netfs_folio_info(folio_get_private(folio));
113 }
114
netfs_folio_group(struct folio * folio)115 static inline struct netfs_group *netfs_folio_group(struct folio *folio)
116 {
117 struct netfs_folio *finfo;
118 void *priv = folio_get_private(folio);
119
120 finfo = netfs_folio_info(folio);
121 if (finfo)
122 return finfo->netfs_group;
123 return priv;
124 }
125
126 /*
127 * Stream of I/O subrequests going to a particular destination, such as the
128 * server or the local cache. This is mainly intended for writing where we may
129 * have to write to multiple destinations concurrently.
130 */
131 struct netfs_io_stream {
132 /* Submission tracking */
133 struct netfs_io_subrequest *construct; /* Op being constructed */
134 size_t sreq_max_len; /* Maximum size of a subrequest */
135 unsigned int sreq_max_segs; /* 0 or max number of segments in an iterator */
136 unsigned int submit_off; /* Folio offset we're submitting from */
137 unsigned int submit_len; /* Amount of data left to submit */
138 unsigned int submit_extendable_to; /* Amount I/O can be rounded up to */
139 void (*prepare_write)(struct netfs_io_subrequest *subreq);
140 void (*issue_write)(struct netfs_io_subrequest *subreq);
141 /* Collection tracking */
142 struct list_head subrequests; /* Contributory I/O operations */
143 struct netfs_io_subrequest *front; /* Op being collected */
144 unsigned long long collected_to; /* Position we've collected results to */
145 size_t transferred; /* The amount transferred from this stream */
146 unsigned short error; /* Aggregate error for the stream */
147 enum netfs_io_source source; /* Where to read from/write to */
148 unsigned char stream_nr; /* Index of stream in parent table */
149 bool avail; /* T if stream is available */
150 bool active; /* T if stream is active */
151 bool need_retry; /* T if this stream needs retrying */
152 bool failed; /* T if this stream failed */
153 };
154
155 /*
156 * Resources required to do operations on a cache.
157 */
158 struct netfs_cache_resources {
159 const struct netfs_cache_ops *ops;
160 void *cache_priv;
161 void *cache_priv2;
162 unsigned int debug_id; /* Cookie debug ID */
163 unsigned int inval_counter; /* object->inval_counter at begin_op */
164 };
165
166 /*
167 * Descriptor for a single component subrequest. Each operation represents an
168 * individual read/write from/to a server, a cache, a journal, etc..
169 *
170 * The buffer iterator is persistent for the life of the subrequest struct and
171 * the pages it points to can be relied on to exist for the duration.
172 */
173 struct netfs_io_subrequest {
174 struct netfs_io_request *rreq; /* Supervising I/O request */
175 struct work_struct work;
176 struct list_head rreq_link; /* Link in rreq->subrequests */
177 struct iov_iter io_iter; /* Iterator for this subrequest */
178 unsigned long long start; /* Where to start the I/O */
179 size_t len; /* Size of the I/O */
180 size_t transferred; /* Amount of data transferred */
181 refcount_t ref;
182 short error; /* 0 or error that occurred */
183 unsigned short debug_index; /* Index in list (for debugging output) */
184 unsigned int nr_segs; /* Number of segs in io_iter */
185 u8 retry_count; /* The number of retries (0 on initial pass) */
186 enum netfs_io_source source; /* Where to read from/write to */
187 unsigned char stream_nr; /* I/O stream this belongs to */
188 unsigned long flags;
189 #define NETFS_SREQ_COPY_TO_CACHE 0 /* Set if should copy the data to the cache */
190 #define NETFS_SREQ_CLEAR_TAIL 1 /* Set if the rest of the read should be cleared */
191 #define NETFS_SREQ_MADE_PROGRESS 4 /* Set if we transferred at least some data */
192 #define NETFS_SREQ_ONDEMAND 5 /* Set if it's from on-demand read mode */
193 #define NETFS_SREQ_BOUNDARY 6 /* Set if ends on hard boundary (eg. ceph object) */
194 #define NETFS_SREQ_HIT_EOF 7 /* Set if short due to EOF */
195 #define NETFS_SREQ_IN_PROGRESS 8 /* Unlocked when the subrequest completes */
196 #define NETFS_SREQ_NEED_RETRY 9 /* Set if the filesystem requests a retry */
197 #define NETFS_SREQ_FAILED 10 /* Set if the subreq failed unretryably */
198 };
199
200 enum netfs_io_origin {
201 NETFS_READAHEAD, /* This read was triggered by readahead */
202 NETFS_READPAGE, /* This read is a synchronous read */
203 NETFS_READ_GAPS, /* This read is a synchronous read to fill gaps */
204 NETFS_READ_SINGLE, /* This read should be treated as a single object */
205 NETFS_READ_FOR_WRITE, /* This read is to prepare a write */
206 NETFS_UNBUFFERED_READ, /* This is an unbuffered read */
207 NETFS_DIO_READ, /* This is a direct I/O read */
208 NETFS_WRITEBACK, /* This write was triggered by writepages */
209 NETFS_WRITEBACK_SINGLE, /* This monolithic write was triggered by writepages */
210 NETFS_WRITETHROUGH, /* This write was made by netfs_perform_write() */
211 NETFS_UNBUFFERED_WRITE, /* This is an unbuffered write */
212 NETFS_DIO_WRITE, /* This is a direct I/O write */
213 NETFS_PGPRIV2_COPY_TO_CACHE, /* [DEPRECATED] This is writing read data to the cache */
214 nr__netfs_io_origin
215 } __mode(byte);
216
217 /*
218 * Descriptor for an I/O helper request. This is used to make multiple I/O
219 * operations to a variety of data stores and then stitch the result together.
220 */
221 struct netfs_io_request {
222 union {
223 struct work_struct cleanup_work; /* Deferred cleanup work */
224 struct rcu_head rcu;
225 };
226 struct work_struct work; /* Result collector work */
227 struct inode *inode; /* The file being accessed */
228 struct address_space *mapping; /* The mapping being accessed */
229 struct kiocb *iocb; /* AIO completion vector */
230 struct netfs_cache_resources cache_resources;
231 struct netfs_io_request *copy_to_cache; /* Request to write just-read data to the cache */
232 #ifdef CONFIG_PROC_FS
233 struct list_head proc_link; /* Link in netfs_iorequests */
234 #endif
235 struct netfs_io_stream io_streams[2]; /* Streams of parallel I/O operations */
236 #define NR_IO_STREAMS 2 //wreq->nr_io_streams
237 struct netfs_group *group; /* Writeback group being written back */
238 struct rolling_buffer buffer; /* Unencrypted buffer */
239 #define NETFS_ROLLBUF_PUT_MARK ROLLBUF_MARK_1
240 #define NETFS_ROLLBUF_PAGECACHE_MARK ROLLBUF_MARK_2
241 wait_queue_head_t waitq; /* Processor waiter */
242 void *netfs_priv; /* Private data for the netfs */
243 void *netfs_priv2; /* Private data for the netfs */
244 struct bio_vec *direct_bv; /* DIO buffer list (when handling iovec-iter) */
245 unsigned long long submitted; /* Amount submitted for I/O so far */
246 unsigned long long len; /* Length of the request */
247 size_t transferred; /* Amount to be indicated as transferred */
248 long error; /* 0 or error that occurred */
249 unsigned long long i_size; /* Size of the file */
250 unsigned long long start; /* Start position */
251 atomic64_t issued_to; /* Write issuer folio cursor */
252 unsigned long long collected_to; /* Point we've collected to */
253 unsigned long long cleaned_to; /* Position we've cleaned folios to */
254 unsigned long long abandon_to; /* Position to abandon folios to */
255 pgoff_t no_unlock_folio; /* Don't unlock this folio after read */
256 unsigned int direct_bv_count; /* Number of elements in direct_bv[] */
257 unsigned int debug_id;
258 unsigned int rsize; /* Maximum read size (0 for none) */
259 unsigned int wsize; /* Maximum write size (0 for none) */
260 atomic_t subreq_counter; /* Next subreq->debug_index */
261 unsigned int nr_group_rel; /* Number of refs to release on ->group */
262 spinlock_t lock; /* Lock for queuing subreqs */
263 unsigned char front_folio_order; /* Order (size) of front folio */
264 enum netfs_io_origin origin; /* Origin of the request */
265 bool direct_bv_unpin; /* T if direct_bv[] must be unpinned */
266 refcount_t ref;
267 unsigned long flags;
268 #define NETFS_RREQ_IN_PROGRESS 0 /* Unlocked when the request completes (has ref) */
269 #define NETFS_RREQ_ALL_QUEUED 1 /* All subreqs are now queued */
270 #define NETFS_RREQ_PAUSE 2 /* Pause subrequest generation */
271 #define NETFS_RREQ_FAILED 3 /* The request failed */
272 #define NETFS_RREQ_RETRYING 4 /* Set if we're in the retry path */
273 #define NETFS_RREQ_SHORT_TRANSFER 5 /* Set if we have a short transfer */
274 #define NETFS_RREQ_OFFLOAD_COLLECTION 8 /* Offload collection to workqueue */
275 #define NETFS_RREQ_NO_UNLOCK_FOLIO 9 /* Don't unlock no_unlock_folio on completion */
276 #define NETFS_RREQ_FOLIO_COPY_TO_CACHE 10 /* Copy current folio to cache from read */
277 #define NETFS_RREQ_UPLOAD_TO_SERVER 11 /* Need to write to the server */
278 #define NETFS_RREQ_USE_IO_ITER 12 /* Use ->io_iter rather than ->i_pages */
279 #define NETFS_RREQ_USE_PGPRIV2 31 /* [DEPRECATED] Use PG_private_2 to mark
280 * write to cache on read */
281 const struct netfs_request_ops *netfs_ops;
282 };
283
284 /*
285 * Operations the network filesystem can/must provide to the helpers.
286 */
287 struct netfs_request_ops {
288 mempool_t *request_pool;
289 mempool_t *subrequest_pool;
290 int (*init_request)(struct netfs_io_request *rreq, struct file *file);
291 void (*free_request)(struct netfs_io_request *rreq);
292 void (*free_subrequest)(struct netfs_io_subrequest *rreq);
293
294 /* Read request handling */
295 void (*expand_readahead)(struct netfs_io_request *rreq);
296 int (*prepare_read)(struct netfs_io_subrequest *subreq);
297 void (*issue_read)(struct netfs_io_subrequest *subreq);
298 bool (*is_still_valid)(struct netfs_io_request *rreq);
299 int (*check_write_begin)(struct file *file, loff_t pos, unsigned len,
300 struct folio **foliop, void **_fsdata);
301 void (*done)(struct netfs_io_request *rreq);
302
303 /* Modification handling */
304 void (*update_i_size)(struct inode *inode, loff_t i_size);
305 void (*post_modify)(struct inode *inode);
306
307 /* Write request handling */
308 void (*begin_writeback)(struct netfs_io_request *wreq);
309 void (*prepare_write)(struct netfs_io_subrequest *subreq);
310 void (*issue_write)(struct netfs_io_subrequest *subreq);
311 void (*retry_request)(struct netfs_io_request *wreq, struct netfs_io_stream *stream);
312 void (*invalidate_cache)(struct netfs_io_request *wreq);
313 };
314
315 /*
316 * How to handle reading from a hole.
317 */
318 enum netfs_read_from_hole {
319 NETFS_READ_HOLE_IGNORE,
320 NETFS_READ_HOLE_FAIL,
321 };
322
323 /*
324 * Table of operations for access to a cache.
325 */
326 struct netfs_cache_ops {
327 /* End an operation */
328 void (*end_operation)(struct netfs_cache_resources *cres);
329
330 /* Read data from the cache */
331 int (*read)(struct netfs_cache_resources *cres,
332 loff_t start_pos,
333 struct iov_iter *iter,
334 enum netfs_read_from_hole read_hole,
335 netfs_io_terminated_t term_func,
336 void *term_func_priv);
337
338 /* Write data to the cache */
339 int (*write)(struct netfs_cache_resources *cres,
340 loff_t start_pos,
341 struct iov_iter *iter,
342 netfs_io_terminated_t term_func,
343 void *term_func_priv);
344
345 /* Write data to the cache from a netfs subrequest. */
346 void (*issue_write)(struct netfs_io_subrequest *subreq);
347
348 /* Expand readahead request */
349 void (*expand_readahead)(struct netfs_cache_resources *cres,
350 unsigned long long *_start,
351 unsigned long long *_len,
352 unsigned long long i_size);
353
354 /* Prepare a read operation, shortening it to a cached/uncached
355 * boundary as appropriate.
356 */
357 enum netfs_io_source (*prepare_read)(struct netfs_io_subrequest *subreq,
358 unsigned long long i_size);
359
360 /* Prepare a write subrequest, working out if we're allowed to do it
361 * and finding out the maximum amount of data to gather before
362 * attempting to submit. If we're not permitted to do it, the
363 * subrequest should be marked failed.
364 */
365 void (*prepare_write_subreq)(struct netfs_io_subrequest *subreq);
366
367 /* Prepare a write operation, working out what part of the write we can
368 * actually do.
369 */
370 int (*prepare_write)(struct netfs_cache_resources *cres,
371 loff_t *_start, size_t *_len, size_t upper_len,
372 loff_t i_size, bool no_space_allocated_yet);
373
374 /* Prepare an on-demand read operation, shortening it to a cached/uncached
375 * boundary as appropriate.
376 */
377 enum netfs_io_source (*prepare_ondemand_read)(struct netfs_cache_resources *cres,
378 loff_t start, size_t *_len,
379 loff_t i_size,
380 unsigned long *_flags, ino_t ino);
381
382 /* Query the occupancy of the cache in a region, returning where the
383 * next chunk of data starts and how long it is.
384 */
385 int (*query_occupancy)(struct netfs_cache_resources *cres,
386 loff_t start, size_t len, size_t granularity,
387 loff_t *_data_start, size_t *_data_len);
388 };
389
390 /* High-level read API. */
391 ssize_t netfs_unbuffered_read_iter_locked(struct kiocb *iocb, struct iov_iter *iter);
392 ssize_t netfs_unbuffered_read_iter(struct kiocb *iocb, struct iov_iter *iter);
393 ssize_t netfs_buffered_read_iter(struct kiocb *iocb, struct iov_iter *iter);
394 ssize_t netfs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter);
395
396 /* High-level write API */
397 ssize_t netfs_perform_write(struct kiocb *iocb, struct iov_iter *iter,
398 struct netfs_group *netfs_group);
399 ssize_t netfs_buffered_write_iter_locked(struct kiocb *iocb, struct iov_iter *from,
400 struct netfs_group *netfs_group);
401 ssize_t netfs_unbuffered_write_iter(struct kiocb *iocb, struct iov_iter *from);
402 ssize_t netfs_unbuffered_write_iter_locked(struct kiocb *iocb, struct iov_iter *iter,
403 struct netfs_group *netfs_group);
404 ssize_t netfs_file_write_iter(struct kiocb *iocb, struct iov_iter *from);
405
406 /* Single, monolithic object read/write API. */
407 void netfs_single_mark_inode_dirty(struct inode *inode);
408 ssize_t netfs_read_single(struct inode *inode, struct file *file, struct iov_iter *iter);
409 int netfs_writeback_single(struct address_space *mapping,
410 struct writeback_control *wbc,
411 struct iov_iter *iter);
412
413 /* Address operations API */
414 struct readahead_control;
415 void netfs_readahead(struct readahead_control *);
416 int netfs_read_folio(struct file *, struct folio *);
417 int netfs_write_begin(struct netfs_inode *, struct file *,
418 struct address_space *, loff_t pos, unsigned int len,
419 struct folio **, void **fsdata);
420 int netfs_writepages(struct address_space *mapping,
421 struct writeback_control *wbc);
422 bool netfs_dirty_folio(struct address_space *mapping, struct folio *folio);
423 int netfs_unpin_writeback(struct inode *inode, struct writeback_control *wbc);
424 void netfs_clear_inode_writeback(struct inode *inode, const void *aux);
425 void netfs_invalidate_folio(struct folio *folio, size_t offset, size_t length);
426 bool netfs_release_folio(struct folio *folio, gfp_t gfp);
427
428 /* VMA operations API. */
429 vm_fault_t netfs_page_mkwrite(struct vm_fault *vmf, struct netfs_group *netfs_group);
430
431 /* (Sub)request management API. */
432 void netfs_read_subreq_progress(struct netfs_io_subrequest *subreq);
433 void netfs_read_subreq_terminated(struct netfs_io_subrequest *subreq);
434 void netfs_get_subrequest(struct netfs_io_subrequest *subreq,
435 enum netfs_sreq_ref_trace what);
436 void netfs_put_subrequest(struct netfs_io_subrequest *subreq,
437 enum netfs_sreq_ref_trace what);
438 ssize_t netfs_extract_user_iter(struct iov_iter *orig, size_t orig_len,
439 struct iov_iter *new,
440 iov_iter_extraction_t extraction_flags);
441 size_t netfs_limit_iter(const struct iov_iter *iter, size_t start_offset,
442 size_t max_size, size_t max_segs);
443 void netfs_prepare_write_failed(struct netfs_io_subrequest *subreq);
444 void netfs_write_subrequest_terminated(void *_op, ssize_t transferred_or_error);
445 void netfs_queue_write_request(struct netfs_io_subrequest *subreq);
446
447 int netfs_start_io_read(struct inode *inode);
448 void netfs_end_io_read(struct inode *inode);
449 int netfs_start_io_write(struct inode *inode);
450 void netfs_end_io_write(struct inode *inode);
451 int netfs_start_io_direct(struct inode *inode);
452 void netfs_end_io_direct(struct inode *inode);
453
454 /* Miscellaneous APIs. */
455 struct folio_queue *netfs_folioq_alloc(unsigned int rreq_id, gfp_t gfp,
456 unsigned int trace /*enum netfs_folioq_trace*/);
457 void netfs_folioq_free(struct folio_queue *folioq,
458 unsigned int trace /*enum netfs_trace_folioq*/);
459
460 /* Buffer wrangling helpers API. */
461 int netfs_alloc_folioq_buffer(struct address_space *mapping,
462 struct folio_queue **_buffer,
463 size_t *_cur_size, ssize_t size, gfp_t gfp);
464 void netfs_free_folioq_buffer(struct folio_queue *fq);
465
466 /**
467 * netfs_inode - Get the netfs inode context from the inode
468 * @inode: The inode to query
469 *
470 * Get the netfs lib inode context from the network filesystem's inode. The
471 * context struct is expected to directly follow on from the VFS inode struct.
472 */
netfs_inode(struct inode * inode)473 static inline struct netfs_inode *netfs_inode(struct inode *inode)
474 {
475 return container_of(inode, struct netfs_inode, inode);
476 }
477
478 /**
479 * netfs_inode_init - Initialise a netfslib inode context
480 * @ctx: The netfs inode to initialise
481 * @ops: The netfs's operations list
482 * @use_zero_point: True to use the zero_point read optimisation
483 *
484 * Initialise the netfs library context struct. This is expected to follow on
485 * directly from the VFS inode struct.
486 */
netfs_inode_init(struct netfs_inode * ctx,const struct netfs_request_ops * ops,bool use_zero_point)487 static inline void netfs_inode_init(struct netfs_inode *ctx,
488 const struct netfs_request_ops *ops,
489 bool use_zero_point)
490 {
491 ctx->ops = ops;
492 ctx->remote_i_size = i_size_read(&ctx->inode);
493 ctx->zero_point = LLONG_MAX;
494 ctx->flags = 0;
495 atomic_set(&ctx->io_count, 0);
496 #if IS_ENABLED(CONFIG_FSCACHE)
497 ctx->cache = NULL;
498 #endif
499 mutex_init(&ctx->wb_lock);
500 /* ->releasepage() drives zero_point */
501 if (use_zero_point) {
502 ctx->zero_point = ctx->remote_i_size;
503 mapping_set_release_always(ctx->inode.i_mapping);
504 }
505 }
506
507 /**
508 * netfs_resize_file - Note that a file got resized
509 * @ctx: The netfs inode being resized
510 * @new_i_size: The new file size
511 * @changed_on_server: The change was applied to the server
512 *
513 * Inform the netfs lib that a file got resized so that it can adjust its state.
514 */
netfs_resize_file(struct netfs_inode * ctx,loff_t new_i_size,bool changed_on_server)515 static inline void netfs_resize_file(struct netfs_inode *ctx, loff_t new_i_size,
516 bool changed_on_server)
517 {
518 if (changed_on_server)
519 ctx->remote_i_size = new_i_size;
520 if (new_i_size < ctx->zero_point)
521 ctx->zero_point = new_i_size;
522 }
523
524 /**
525 * netfs_i_cookie - Get the cache cookie from the inode
526 * @ctx: The netfs inode to query
527 *
528 * Get the caching cookie (if enabled) from the network filesystem's inode.
529 */
netfs_i_cookie(struct netfs_inode * ctx)530 static inline struct fscache_cookie *netfs_i_cookie(struct netfs_inode *ctx)
531 {
532 #if IS_ENABLED(CONFIG_FSCACHE)
533 return ctx->cache;
534 #else
535 return NULL;
536 #endif
537 }
538
539 /**
540 * netfs_wait_for_outstanding_io - Wait for outstanding I/O to complete
541 * @inode: The netfs inode to wait on
542 *
543 * Wait for outstanding I/O requests of any type to complete. This is intended
544 * to be called from inode eviction routines. This makes sure that any
545 * resources held by those requests are cleaned up before we let the inode get
546 * cleaned up.
547 */
netfs_wait_for_outstanding_io(struct inode * inode)548 static inline void netfs_wait_for_outstanding_io(struct inode *inode)
549 {
550 struct netfs_inode *ictx = netfs_inode(inode);
551
552 wait_var_event(&ictx->io_count, atomic_read(&ictx->io_count) == 0);
553 }
554
555 #endif /* _LINUX_NETFS_H */
556