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