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 NETFS_INVALID_WRITE,
52 } __mode(byte);
53
54 typedef void (*netfs_io_terminated_t)(void *priv, ssize_t transferred_or_error,
55 bool was_async);
56
57 /*
58 * Per-inode context. This wraps the VFS inode.
59 */
60 struct netfs_inode {
61 struct inode inode; /* The VFS inode */
62 const struct netfs_request_ops *ops;
63 #if IS_ENABLED(CONFIG_FSCACHE)
64 struct fscache_cookie *cache;
65 #endif
66 struct mutex wb_lock; /* Writeback serialisation */
67 loff_t remote_i_size; /* Size of the remote file */
68 loff_t zero_point; /* Size after which we assume there's no data
69 * on the server */
70 atomic_t io_count; /* Number of outstanding reqs */
71 unsigned long flags;
72 #define NETFS_ICTX_ODIRECT 0 /* The file has DIO in progress */
73 #define NETFS_ICTX_UNBUFFERED 1 /* I/O should not use the pagecache */
74 #define NETFS_ICTX_WRITETHROUGH 2 /* Write-through caching */
75 #define NETFS_ICTX_MODIFIED_ATTR 3 /* Indicate change in mtime/ctime */
76 #define NETFS_ICTX_SINGLE_NO_UPLOAD 4 /* Monolithic payload, cache but no upload */
77 };
78
79 /*
80 * A netfs group - for instance a ceph snap. This is marked on dirty pages and
81 * pages marked with a group must be flushed before they can be written under
82 * the domain of another group.
83 */
84 struct netfs_group {
85 refcount_t ref;
86 void (*free)(struct netfs_group *netfs_group);
87 };
88
89 /*
90 * Information about a dirty page (attached only if necessary).
91 * folio->private
92 */
93 struct netfs_folio {
94 struct netfs_group *netfs_group; /* Filesystem's grouping marker (or NULL). */
95 unsigned int dirty_offset; /* Write-streaming dirty data offset */
96 unsigned int dirty_len; /* Write-streaming dirty data length */
97 };
98 #define NETFS_FOLIO_INFO 0x1UL /* OR'd with folio->private. */
99 #define NETFS_FOLIO_COPY_TO_CACHE ((struct netfs_group *)0x356UL) /* Write to the cache only */
100
netfs_is_folio_info(const void * priv)101 static inline bool netfs_is_folio_info(const void *priv)
102 {
103 return (unsigned long)priv & NETFS_FOLIO_INFO;
104 }
105
__netfs_folio_info(const void * priv)106 static inline struct netfs_folio *__netfs_folio_info(const void *priv)
107 {
108 if (netfs_is_folio_info(priv))
109 return (struct netfs_folio *)((unsigned long)priv & ~NETFS_FOLIO_INFO);
110 return NULL;
111 }
112
netfs_folio_info(struct folio * folio)113 static inline struct netfs_folio *netfs_folio_info(struct folio *folio)
114 {
115 return __netfs_folio_info(folio_get_private(folio));
116 }
117
netfs_folio_group(struct folio * folio)118 static inline struct netfs_group *netfs_folio_group(struct folio *folio)
119 {
120 struct netfs_folio *finfo;
121 void *priv = folio_get_private(folio);
122
123 finfo = netfs_folio_info(folio);
124 if (finfo)
125 return finfo->netfs_group;
126 return priv;
127 }
128
129 /*
130 * Stream of I/O subrequests going to a particular destination, such as the
131 * server or the local cache. This is mainly intended for writing where we may
132 * have to write to multiple destinations concurrently.
133 */
134 struct netfs_io_stream {
135 /* Submission tracking */
136 struct netfs_io_subrequest *construct; /* Op being constructed */
137 size_t sreq_max_len; /* Maximum size of a subrequest */
138 unsigned int sreq_max_segs; /* 0 or max number of segments in an iterator */
139 unsigned int submit_off; /* Folio offset we're submitting from */
140 unsigned int submit_len; /* Amount of data left to submit */
141 unsigned int submit_extendable_to; /* Amount I/O can be rounded up to */
142 void (*prepare_write)(struct netfs_io_subrequest *subreq);
143 void (*issue_write)(struct netfs_io_subrequest *subreq);
144 /* Collection tracking */
145 struct list_head subrequests; /* Contributory I/O operations */
146 struct netfs_io_subrequest *front; /* Op being collected */
147 unsigned long long collected_to; /* Position we've collected results to */
148 size_t transferred; /* The amount transferred from this stream */
149 enum netfs_io_source source; /* Where to read from/write to */
150 unsigned short error; /* Aggregate error for the stream */
151 unsigned char stream_nr; /* Index of stream in parent table */
152 bool avail; /* T if stream is available */
153 bool active; /* T if stream is active */
154 bool need_retry; /* T if this stream needs retrying */
155 bool failed; /* T if this stream failed */
156 };
157
158 /*
159 * Resources required to do operations on a cache.
160 */
161 struct netfs_cache_resources {
162 const struct netfs_cache_ops *ops;
163 void *cache_priv;
164 void *cache_priv2;
165 unsigned int debug_id; /* Cookie debug ID */
166 unsigned int inval_counter; /* object->inval_counter at begin_op */
167 };
168
169 /*
170 * Descriptor for a single component subrequest. Each operation represents an
171 * individual read/write from/to a server, a cache, a journal, etc..
172 *
173 * The buffer iterator is persistent for the life of the subrequest struct and
174 * the pages it points to can be relied on to exist for the duration.
175 */
176 struct netfs_io_subrequest {
177 struct netfs_io_request *rreq; /* Supervising I/O request */
178 struct work_struct work;
179 struct list_head rreq_link; /* Link in rreq->subrequests */
180 struct iov_iter io_iter; /* Iterator for this subrequest */
181 unsigned long long start; /* Where to start the I/O */
182 size_t len; /* Size of the I/O */
183 size_t transferred; /* Amount of data transferred */
184 refcount_t ref;
185 short error; /* 0 or error that occurred */
186 unsigned short debug_index; /* Index in list (for debugging output) */
187 unsigned int nr_segs; /* Number of segs in io_iter */
188 u8 retry_count; /* The number of retries (0 on initial pass) */
189 enum netfs_io_source source; /* Where to read from/write to */
190 unsigned char stream_nr; /* I/O stream this belongs to */
191 unsigned long flags;
192 #define NETFS_SREQ_COPY_TO_CACHE 0 /* Set if should copy the data to the cache */
193 #define NETFS_SREQ_CLEAR_TAIL 1 /* Set if the rest of the read should be cleared */
194 #define NETFS_SREQ_SEEK_DATA_READ 3 /* Set if ->read() should SEEK_DATA first */
195 #define NETFS_SREQ_MADE_PROGRESS 4 /* Set if we transferred at least some data */
196 #define NETFS_SREQ_ONDEMAND 5 /* Set if it's from on-demand read mode */
197 #define NETFS_SREQ_BOUNDARY 6 /* Set if ends on hard boundary (eg. ceph object) */
198 #define NETFS_SREQ_HIT_EOF 7 /* Set if short due to EOF */
199 #define NETFS_SREQ_IN_PROGRESS 8 /* Unlocked when the subrequest completes */
200 #define NETFS_SREQ_NEED_RETRY 9 /* Set if the filesystem requests a retry */
201 #define NETFS_SREQ_FAILED 10 /* Set if the subreq failed unretryably */
202 };
203
204 enum netfs_io_origin {
205 NETFS_READAHEAD, /* This read was triggered by readahead */
206 NETFS_READPAGE, /* This read is a synchronous read */
207 NETFS_READ_GAPS, /* This read is a synchronous read to fill gaps */
208 NETFS_READ_SINGLE, /* This read should be treated as a single object */
209 NETFS_READ_FOR_WRITE, /* This read is to prepare a write */
210 NETFS_DIO_READ, /* This is a direct I/O read */
211 NETFS_WRITEBACK, /* This write was triggered by writepages */
212 NETFS_WRITEBACK_SINGLE, /* This monolithic write was triggered by writepages */
213 NETFS_WRITETHROUGH, /* This write was made by netfs_perform_write() */
214 NETFS_UNBUFFERED_WRITE, /* This is an unbuffered write */
215 NETFS_DIO_WRITE, /* This is a direct I/O write */
216 NETFS_PGPRIV2_COPY_TO_CACHE, /* [DEPRECATED] This is writing read data to the cache */
217 nr__netfs_io_origin
218 } __mode(byte);
219
220 /*
221 * Descriptor for an I/O helper request. This is used to make multiple I/O
222 * operations to a variety of data stores and then stitch the result together.
223 */
224 struct netfs_io_request {
225 union {
226 struct work_struct work;
227 struct rcu_head rcu;
228 };
229 struct inode *inode; /* The file being accessed */
230 struct address_space *mapping; /* The mapping being accessed */
231 struct kiocb *iocb; /* AIO completion vector */
232 struct netfs_cache_resources cache_resources;
233 struct netfs_io_request *copy_to_cache; /* Request to write just-read data to the cache */
234 struct readahead_control *ractl; /* Readahead descriptor */
235 struct list_head proc_link; /* Link in netfs_iorequests */
236 struct netfs_io_stream io_streams[2]; /* Streams of parallel I/O operations */
237 #define NR_IO_STREAMS 2 //wreq->nr_io_streams
238 struct netfs_group *group; /* Writeback group being written back */
239 struct rolling_buffer buffer; /* Unencrypted buffer */
240 #define NETFS_ROLLBUF_PUT_MARK ROLLBUF_MARK_1
241 #define NETFS_ROLLBUF_PAGECACHE_MARK ROLLBUF_MARK_2
242 wait_queue_head_t waitq; /* Processor waiter */
243 void *netfs_priv; /* Private data for the netfs */
244 void *netfs_priv2; /* Private data for the netfs */
245 struct bio_vec *direct_bv; /* DIO buffer list (when handling iovec-iter) */
246 unsigned int direct_bv_count; /* Number of elements in direct_bv[] */
247 unsigned int debug_id;
248 unsigned int rsize; /* Maximum read size (0 for none) */
249 unsigned int wsize; /* Maximum write size (0 for none) */
250 atomic_t subreq_counter; /* Next subreq->debug_index */
251 unsigned int nr_group_rel; /* Number of refs to release on ->group */
252 spinlock_t lock; /* Lock for queuing subreqs */
253 unsigned long long submitted; /* Amount submitted for I/O so far */
254 unsigned long long len; /* Length of the request */
255 size_t transferred; /* Amount to be indicated as transferred */
256 long error; /* 0 or error that occurred */
257 enum netfs_io_origin origin; /* Origin of the request */
258 bool direct_bv_unpin; /* T if direct_bv[] must be unpinned */
259 unsigned long long i_size; /* Size of the file */
260 unsigned long long start; /* Start position */
261 atomic64_t issued_to; /* Write issuer folio cursor */
262 unsigned long long collected_to; /* Point we've collected to */
263 unsigned long long cleaned_to; /* Position we've cleaned folios to */
264 unsigned long long abandon_to; /* Position to abandon folios to */
265 pgoff_t no_unlock_folio; /* Don't unlock this folio after read */
266 unsigned char front_folio_order; /* Order (size) of front folio */
267 refcount_t ref;
268 unsigned long flags;
269 #define NETFS_RREQ_OFFLOAD_COLLECTION 0 /* Offload collection to workqueue */
270 #define NETFS_RREQ_NO_UNLOCK_FOLIO 2 /* Don't unlock no_unlock_folio on completion */
271 #define NETFS_RREQ_DONT_UNLOCK_FOLIOS 3 /* Don't unlock the folios on completion */
272 #define NETFS_RREQ_FAILED 4 /* The request failed */
273 #define NETFS_RREQ_IN_PROGRESS 5 /* Unlocked when the request completes */
274 #define NETFS_RREQ_FOLIO_COPY_TO_CACHE 6 /* Copy current folio to cache from read */
275 #define NETFS_RREQ_UPLOAD_TO_SERVER 8 /* Need to write to the server */
276 #define NETFS_RREQ_NONBLOCK 9 /* Don't block if possible (O_NONBLOCK) */
277 #define NETFS_RREQ_BLOCKED 10 /* We blocked */
278 #define NETFS_RREQ_PAUSE 11 /* Pause subrequest generation */
279 #define NETFS_RREQ_USE_IO_ITER 12 /* Use ->io_iter rather than ->i_pages */
280 #define NETFS_RREQ_ALL_QUEUED 13 /* All subreqs are now queued */
281 #define NETFS_RREQ_RETRYING 14 /* Set if we're in the retry path */
282 #define NETFS_RREQ_USE_PGPRIV2 31 /* [DEPRECATED] Use PG_private_2 to mark
283 * write to cache on read */
284 const struct netfs_request_ops *netfs_ops;
285 void (*cleanup)(struct netfs_io_request *req);
286 };
287
288 /*
289 * Operations the network filesystem can/must provide to the helpers.
290 */
291 struct netfs_request_ops {
292 mempool_t *request_pool;
293 mempool_t *subrequest_pool;
294 int (*init_request)(struct netfs_io_request *rreq, struct file *file);
295 void (*free_request)(struct netfs_io_request *rreq);
296 void (*free_subrequest)(struct netfs_io_subrequest *rreq);
297
298 /* Read request handling */
299 void (*expand_readahead)(struct netfs_io_request *rreq);
300 int (*prepare_read)(struct netfs_io_subrequest *subreq);
301 void (*issue_read)(struct netfs_io_subrequest *subreq);
302 bool (*is_still_valid)(struct netfs_io_request *rreq);
303 int (*check_write_begin)(struct file *file, loff_t pos, unsigned len,
304 struct folio **foliop, void **_fsdata);
305 void (*done)(struct netfs_io_request *rreq);
306
307 /* Modification handling */
308 void (*update_i_size)(struct inode *inode, loff_t i_size);
309 void (*post_modify)(struct inode *inode);
310
311 /* Write request handling */
312 void (*begin_writeback)(struct netfs_io_request *wreq);
313 void (*prepare_write)(struct netfs_io_subrequest *subreq);
314 void (*issue_write)(struct netfs_io_subrequest *subreq);
315 void (*retry_request)(struct netfs_io_request *wreq, struct netfs_io_stream *stream);
316 void (*invalidate_cache)(struct netfs_io_request *wreq);
317 };
318
319 /*
320 * How to handle reading from a hole.
321 */
322 enum netfs_read_from_hole {
323 NETFS_READ_HOLE_IGNORE,
324 NETFS_READ_HOLE_CLEAR,
325 NETFS_READ_HOLE_FAIL,
326 };
327
328 /*
329 * Table of operations for access to a cache.
330 */
331 struct netfs_cache_ops {
332 /* End an operation */
333 void (*end_operation)(struct netfs_cache_resources *cres);
334
335 /* Read data from the cache */
336 int (*read)(struct netfs_cache_resources *cres,
337 loff_t start_pos,
338 struct iov_iter *iter,
339 enum netfs_read_from_hole read_hole,
340 netfs_io_terminated_t term_func,
341 void *term_func_priv);
342
343 /* Write data to the cache */
344 int (*write)(struct netfs_cache_resources *cres,
345 loff_t start_pos,
346 struct iov_iter *iter,
347 netfs_io_terminated_t term_func,
348 void *term_func_priv);
349
350 /* Write data to the cache from a netfs subrequest. */
351 void (*issue_write)(struct netfs_io_subrequest *subreq);
352
353 /* Expand readahead request */
354 void (*expand_readahead)(struct netfs_cache_resources *cres,
355 unsigned long long *_start,
356 unsigned long long *_len,
357 unsigned long long i_size);
358
359 /* Prepare a read operation, shortening it to a cached/uncached
360 * boundary as appropriate.
361 */
362 enum netfs_io_source (*prepare_read)(struct netfs_io_subrequest *subreq,
363 unsigned long long i_size);
364
365 /* Prepare a write subrequest, working out if we're allowed to do it
366 * and finding out the maximum amount of data to gather before
367 * attempting to submit. If we're not permitted to do it, the
368 * subrequest should be marked failed.
369 */
370 void (*prepare_write_subreq)(struct netfs_io_subrequest *subreq);
371
372 /* Prepare a write operation, working out what part of the write we can
373 * actually do.
374 */
375 int (*prepare_write)(struct netfs_cache_resources *cres,
376 loff_t *_start, size_t *_len, size_t upper_len,
377 loff_t i_size, bool no_space_allocated_yet);
378
379 /* Prepare an on-demand read operation, shortening it to a cached/uncached
380 * boundary as appropriate.
381 */
382 enum netfs_io_source (*prepare_ondemand_read)(struct netfs_cache_resources *cres,
383 loff_t start, size_t *_len,
384 loff_t i_size,
385 unsigned long *_flags, ino_t ino);
386
387 /* Query the occupancy of the cache in a region, returning where the
388 * next chunk of data starts and how long it is.
389 */
390 int (*query_occupancy)(struct netfs_cache_resources *cres,
391 loff_t start, size_t len, size_t granularity,
392 loff_t *_data_start, size_t *_data_len);
393 };
394
395 /* High-level read API. */
396 ssize_t netfs_unbuffered_read_iter_locked(struct kiocb *iocb, struct iov_iter *iter);
397 ssize_t netfs_unbuffered_read_iter(struct kiocb *iocb, struct iov_iter *iter);
398 ssize_t netfs_buffered_read_iter(struct kiocb *iocb, struct iov_iter *iter);
399 ssize_t netfs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter);
400
401 /* High-level write API */
402 ssize_t netfs_perform_write(struct kiocb *iocb, struct iov_iter *iter,
403 struct netfs_group *netfs_group);
404 ssize_t netfs_buffered_write_iter_locked(struct kiocb *iocb, struct iov_iter *from,
405 struct netfs_group *netfs_group);
406 ssize_t netfs_unbuffered_write_iter(struct kiocb *iocb, struct iov_iter *from);
407 ssize_t netfs_unbuffered_write_iter_locked(struct kiocb *iocb, struct iov_iter *iter,
408 struct netfs_group *netfs_group);
409 ssize_t netfs_file_write_iter(struct kiocb *iocb, struct iov_iter *from);
410
411 /* Single, monolithic object read/write API. */
412 void netfs_single_mark_inode_dirty(struct inode *inode);
413 ssize_t netfs_read_single(struct inode *inode, struct file *file, struct iov_iter *iter);
414 int netfs_writeback_single(struct address_space *mapping,
415 struct writeback_control *wbc,
416 struct iov_iter *iter);
417
418 /* Address operations API */
419 struct readahead_control;
420 void netfs_readahead(struct readahead_control *);
421 int netfs_read_folio(struct file *, struct folio *);
422 int netfs_write_begin(struct netfs_inode *, struct file *,
423 struct address_space *, loff_t pos, unsigned int len,
424 struct folio **, void **fsdata);
425 int netfs_writepages(struct address_space *mapping,
426 struct writeback_control *wbc);
427 bool netfs_dirty_folio(struct address_space *mapping, struct folio *folio);
428 int netfs_unpin_writeback(struct inode *inode, struct writeback_control *wbc);
429 void netfs_clear_inode_writeback(struct inode *inode, const void *aux);
430 void netfs_invalidate_folio(struct folio *folio, size_t offset, size_t length);
431 bool netfs_release_folio(struct folio *folio, gfp_t gfp);
432
433 /* VMA operations API. */
434 vm_fault_t netfs_page_mkwrite(struct vm_fault *vmf, struct netfs_group *netfs_group);
435
436 /* (Sub)request management API. */
437 void netfs_read_subreq_progress(struct netfs_io_subrequest *subreq);
438 void netfs_read_subreq_terminated(struct netfs_io_subrequest *subreq);
439 void netfs_get_subrequest(struct netfs_io_subrequest *subreq,
440 enum netfs_sreq_ref_trace what);
441 void netfs_put_subrequest(struct netfs_io_subrequest *subreq,
442 bool was_async, enum netfs_sreq_ref_trace what);
443 ssize_t netfs_extract_user_iter(struct iov_iter *orig, size_t orig_len,
444 struct iov_iter *new,
445 iov_iter_extraction_t extraction_flags);
446 size_t netfs_limit_iter(const struct iov_iter *iter, size_t start_offset,
447 size_t max_size, size_t max_segs);
448 void netfs_prepare_write_failed(struct netfs_io_subrequest *subreq);
449 void netfs_write_subrequest_terminated(void *_op, ssize_t transferred_or_error,
450 bool was_async);
451 void netfs_queue_write_request(struct netfs_io_subrequest *subreq);
452
453 int netfs_start_io_read(struct inode *inode);
454 void netfs_end_io_read(struct inode *inode);
455 int netfs_start_io_write(struct inode *inode);
456 void netfs_end_io_write(struct inode *inode);
457 int netfs_start_io_direct(struct inode *inode);
458 void netfs_end_io_direct(struct inode *inode);
459
460 /* Miscellaneous APIs. */
461 struct folio_queue *netfs_folioq_alloc(unsigned int rreq_id, gfp_t gfp,
462 unsigned int trace /*enum netfs_folioq_trace*/);
463 void netfs_folioq_free(struct folio_queue *folioq,
464 unsigned int trace /*enum netfs_trace_folioq*/);
465
466 /* Buffer wrangling helpers API. */
467 int netfs_alloc_folioq_buffer(struct address_space *mapping,
468 struct folio_queue **_buffer,
469 size_t *_cur_size, ssize_t size, gfp_t gfp);
470 void netfs_free_folioq_buffer(struct folio_queue *fq);
471
472 /**
473 * netfs_inode - Get the netfs inode context from the inode
474 * @inode: The inode to query
475 *
476 * Get the netfs lib inode context from the network filesystem's inode. The
477 * context struct is expected to directly follow on from the VFS inode struct.
478 */
netfs_inode(struct inode * inode)479 static inline struct netfs_inode *netfs_inode(struct inode *inode)
480 {
481 return container_of(inode, struct netfs_inode, inode);
482 }
483
484 /**
485 * netfs_inode_init - Initialise a netfslib inode context
486 * @ctx: The netfs inode to initialise
487 * @ops: The netfs's operations list
488 * @use_zero_point: True to use the zero_point read optimisation
489 *
490 * Initialise the netfs library context struct. This is expected to follow on
491 * directly from the VFS inode struct.
492 */
netfs_inode_init(struct netfs_inode * ctx,const struct netfs_request_ops * ops,bool use_zero_point)493 static inline void netfs_inode_init(struct netfs_inode *ctx,
494 const struct netfs_request_ops *ops,
495 bool use_zero_point)
496 {
497 ctx->ops = ops;
498 ctx->remote_i_size = i_size_read(&ctx->inode);
499 ctx->zero_point = LLONG_MAX;
500 ctx->flags = 0;
501 atomic_set(&ctx->io_count, 0);
502 #if IS_ENABLED(CONFIG_FSCACHE)
503 ctx->cache = NULL;
504 #endif
505 mutex_init(&ctx->wb_lock);
506 /* ->releasepage() drives zero_point */
507 if (use_zero_point) {
508 ctx->zero_point = ctx->remote_i_size;
509 mapping_set_release_always(ctx->inode.i_mapping);
510 }
511 }
512
513 /**
514 * netfs_resize_file - Note that a file got resized
515 * @ctx: The netfs inode being resized
516 * @new_i_size: The new file size
517 * @changed_on_server: The change was applied to the server
518 *
519 * Inform the netfs lib that a file got resized so that it can adjust its state.
520 */
netfs_resize_file(struct netfs_inode * ctx,loff_t new_i_size,bool changed_on_server)521 static inline void netfs_resize_file(struct netfs_inode *ctx, loff_t new_i_size,
522 bool changed_on_server)
523 {
524 if (changed_on_server)
525 ctx->remote_i_size = new_i_size;
526 if (new_i_size < ctx->zero_point)
527 ctx->zero_point = new_i_size;
528 }
529
530 /**
531 * netfs_i_cookie - Get the cache cookie from the inode
532 * @ctx: The netfs inode to query
533 *
534 * Get the caching cookie (if enabled) from the network filesystem's inode.
535 */
netfs_i_cookie(struct netfs_inode * ctx)536 static inline struct fscache_cookie *netfs_i_cookie(struct netfs_inode *ctx)
537 {
538 #if IS_ENABLED(CONFIG_FSCACHE)
539 return ctx->cache;
540 #else
541 return NULL;
542 #endif
543 }
544
545 /**
546 * netfs_wait_for_outstanding_io - Wait for outstanding I/O to complete
547 * @inode: The netfs inode to wait on
548 *
549 * Wait for outstanding I/O requests of any type to complete. This is intended
550 * to be called from inode eviction routines. This makes sure that any
551 * resources held by those requests are cleaned up before we let the inode get
552 * cleaned up.
553 */
netfs_wait_for_outstanding_io(struct inode * inode)554 static inline void netfs_wait_for_outstanding_io(struct inode *inode)
555 {
556 struct netfs_inode *ictx = netfs_inode(inode);
557
558 wait_var_event(&ictx->io_count, atomic_read(&ictx->io_count) == 0);
559 }
560
561 #endif /* _LINUX_NETFS_H */
562