1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | #ifndef _LINUX_FS_H |
3 | #define _LINUX_FS_H |
4 | |
5 | #include <linux/linkage.h> |
6 | #include <linux/wait_bit.h> |
7 | #include <linux/kdev_t.h> |
8 | #include <linux/dcache.h> |
9 | #include <linux/path.h> |
10 | #include <linux/stat.h> |
11 | #include <linux/cache.h> |
12 | #include <linux/list.h> |
13 | #include <linux/list_lru.h> |
14 | #include <linux/llist.h> |
15 | #include <linux/radix-tree.h> |
16 | #include <linux/xarray.h> |
17 | #include <linux/rbtree.h> |
18 | #include <linux/init.h> |
19 | #include <linux/pid.h> |
20 | #include <linux/bug.h> |
21 | #include <linux/mutex.h> |
22 | #include <linux/rwsem.h> |
23 | #include <linux/mm_types.h> |
24 | #include <linux/capability.h> |
25 | #include <linux/semaphore.h> |
26 | #include <linux/fcntl.h> |
27 | #include <linux/rculist_bl.h> |
28 | #include <linux/atomic.h> |
29 | #include <linux/shrinker.h> |
30 | #include <linux/migrate_mode.h> |
31 | #include <linux/uidgid.h> |
32 | #include <linux/lockdep.h> |
33 | #include <linux/percpu-rwsem.h> |
34 | #include <linux/workqueue.h> |
35 | #include <linux/delayed_call.h> |
36 | #include <linux/uuid.h> |
37 | #include <linux/errseq.h> |
38 | #include <linux/ioprio.h> |
39 | #include <linux/fs_types.h> |
40 | #include <linux/build_bug.h> |
41 | #include <linux/stddef.h> |
42 | #include <linux/mount.h> |
43 | #include <linux/cred.h> |
44 | #include <linux/mnt_idmapping.h> |
45 | #include <linux/slab.h> |
46 | |
47 | #include <asm/byteorder.h> |
48 | #include <uapi/linux/fs.h> |
49 | |
50 | struct backing_dev_info; |
51 | struct bdi_writeback; |
52 | struct bio; |
53 | struct io_comp_batch; |
54 | struct export_operations; |
55 | struct fiemap_extent_info; |
56 | struct hd_geometry; |
57 | struct iovec; |
58 | struct kiocb; |
59 | struct kobject; |
60 | struct pipe_inode_info; |
61 | struct poll_table_struct; |
62 | struct kstatfs; |
63 | struct vm_area_struct; |
64 | struct vfsmount; |
65 | struct cred; |
66 | struct swap_info_struct; |
67 | struct seq_file; |
68 | struct workqueue_struct; |
69 | struct iov_iter; |
70 | struct fscrypt_inode_info; |
71 | struct fscrypt_operations; |
72 | struct fsverity_info; |
73 | struct fsverity_operations; |
74 | struct fs_context; |
75 | struct fs_parameter_spec; |
76 | struct fileattr; |
77 | struct iomap_ops; |
78 | |
79 | extern void __init inode_init(void); |
80 | extern void __init inode_init_early(void); |
81 | extern void __init files_init(void); |
82 | extern void __init files_maxfiles_init(void); |
83 | |
84 | extern unsigned long get_max_files(void); |
85 | extern unsigned int sysctl_nr_open; |
86 | |
87 | typedef __kernel_rwf_t rwf_t; |
88 | |
89 | struct buffer_head; |
90 | typedef int (get_block_t)(struct inode *inode, sector_t iblock, |
91 | struct buffer_head *bh_result, int create); |
92 | typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset, |
93 | ssize_t bytes, void *private); |
94 | |
95 | #define MAY_EXEC 0x00000001 |
96 | #define MAY_WRITE 0x00000002 |
97 | #define MAY_READ 0x00000004 |
98 | #define MAY_APPEND 0x00000008 |
99 | #define MAY_ACCESS 0x00000010 |
100 | #define MAY_OPEN 0x00000020 |
101 | #define MAY_CHDIR 0x00000040 |
102 | /* called from RCU mode, don't block */ |
103 | #define MAY_NOT_BLOCK 0x00000080 |
104 | |
105 | /* |
106 | * flags in file.f_mode. Note that FMODE_READ and FMODE_WRITE must correspond |
107 | * to O_WRONLY and O_RDWR via the strange trick in do_dentry_open() |
108 | */ |
109 | |
110 | /* file is open for reading */ |
111 | #define FMODE_READ ((__force fmode_t)0x1) |
112 | /* file is open for writing */ |
113 | #define FMODE_WRITE ((__force fmode_t)0x2) |
114 | /* file is seekable */ |
115 | #define FMODE_LSEEK ((__force fmode_t)0x4) |
116 | /* file can be accessed using pread */ |
117 | #define FMODE_PREAD ((__force fmode_t)0x8) |
118 | /* file can be accessed using pwrite */ |
119 | #define FMODE_PWRITE ((__force fmode_t)0x10) |
120 | /* File is opened for execution with sys_execve / sys_uselib */ |
121 | #define FMODE_EXEC ((__force fmode_t)0x20) |
122 | /* 32bit hashes as llseek() offset (for directories) */ |
123 | #define FMODE_32BITHASH ((__force fmode_t)0x200) |
124 | /* 64bit hashes as llseek() offset (for directories) */ |
125 | #define FMODE_64BITHASH ((__force fmode_t)0x400) |
126 | |
127 | /* |
128 | * Don't update ctime and mtime. |
129 | * |
130 | * Currently a special hack for the XFS open_by_handle ioctl, but we'll |
131 | * hopefully graduate it to a proper O_CMTIME flag supported by open(2) soon. |
132 | */ |
133 | #define FMODE_NOCMTIME ((__force fmode_t)0x800) |
134 | |
135 | /* Expect random access pattern */ |
136 | #define FMODE_RANDOM ((__force fmode_t)0x1000) |
137 | |
138 | /* File is huge (eg. /dev/mem): treat loff_t as unsigned */ |
139 | #define FMODE_UNSIGNED_OFFSET ((__force fmode_t)0x2000) |
140 | |
141 | /* File is opened with O_PATH; almost nothing can be done with it */ |
142 | #define FMODE_PATH ((__force fmode_t)0x4000) |
143 | |
144 | /* File needs atomic accesses to f_pos */ |
145 | #define FMODE_ATOMIC_POS ((__force fmode_t)0x8000) |
146 | /* Write access to underlying fs */ |
147 | #define FMODE_WRITER ((__force fmode_t)0x10000) |
148 | /* Has read method(s) */ |
149 | #define FMODE_CAN_READ ((__force fmode_t)0x20000) |
150 | /* Has write method(s) */ |
151 | #define FMODE_CAN_WRITE ((__force fmode_t)0x40000) |
152 | |
153 | #define FMODE_OPENED ((__force fmode_t)0x80000) |
154 | #define FMODE_CREATED ((__force fmode_t)0x100000) |
155 | |
156 | /* File is stream-like */ |
157 | #define FMODE_STREAM ((__force fmode_t)0x200000) |
158 | |
159 | /* File supports DIRECT IO */ |
160 | #define FMODE_CAN_ODIRECT ((__force fmode_t)0x400000) |
161 | |
162 | #define FMODE_NOREUSE ((__force fmode_t)0x800000) |
163 | |
164 | /* File supports non-exclusive O_DIRECT writes from multiple threads */ |
165 | #define FMODE_DIO_PARALLEL_WRITE ((__force fmode_t)0x1000000) |
166 | |
167 | /* File is embedded in backing_file object */ |
168 | #define FMODE_BACKING ((__force fmode_t)0x2000000) |
169 | |
170 | /* File was opened by fanotify and shouldn't generate fanotify events */ |
171 | #define FMODE_NONOTIFY ((__force fmode_t)0x4000000) |
172 | |
173 | /* File is capable of returning -EAGAIN if I/O will block */ |
174 | #define FMODE_NOWAIT ((__force fmode_t)0x8000000) |
175 | |
176 | /* File represents mount that needs unmounting */ |
177 | #define FMODE_NEED_UNMOUNT ((__force fmode_t)0x10000000) |
178 | |
179 | /* File does not contribute to nr_files count */ |
180 | #define FMODE_NOACCOUNT ((__force fmode_t)0x20000000) |
181 | |
182 | /* File supports async buffered reads */ |
183 | #define FMODE_BUF_RASYNC ((__force fmode_t)0x40000000) |
184 | |
185 | /* File supports async nowait buffered writes */ |
186 | #define FMODE_BUF_WASYNC ((__force fmode_t)0x80000000) |
187 | |
188 | /* |
189 | * Attribute flags. These should be or-ed together to figure out what |
190 | * has been changed! |
191 | */ |
192 | #define ATTR_MODE (1 << 0) |
193 | #define ATTR_UID (1 << 1) |
194 | #define ATTR_GID (1 << 2) |
195 | #define ATTR_SIZE (1 << 3) |
196 | #define ATTR_ATIME (1 << 4) |
197 | #define ATTR_MTIME (1 << 5) |
198 | #define ATTR_CTIME (1 << 6) |
199 | #define ATTR_ATIME_SET (1 << 7) |
200 | #define ATTR_MTIME_SET (1 << 8) |
201 | #define ATTR_FORCE (1 << 9) /* Not a change, but a change it */ |
202 | #define ATTR_KILL_SUID (1 << 11) |
203 | #define ATTR_KILL_SGID (1 << 12) |
204 | #define ATTR_FILE (1 << 13) |
205 | #define ATTR_KILL_PRIV (1 << 14) |
206 | #define ATTR_OPEN (1 << 15) /* Truncating from open(O_TRUNC) */ |
207 | #define ATTR_TIMES_SET (1 << 16) |
208 | #define ATTR_TOUCH (1 << 17) |
209 | |
210 | /* |
211 | * Whiteout is represented by a char device. The following constants define the |
212 | * mode and device number to use. |
213 | */ |
214 | #define WHITEOUT_MODE 0 |
215 | #define WHITEOUT_DEV 0 |
216 | |
217 | /* |
218 | * This is the Inode Attributes structure, used for notify_change(). It |
219 | * uses the above definitions as flags, to know which values have changed. |
220 | * Also, in this manner, a Filesystem can look at only the values it cares |
221 | * about. Basically, these are the attributes that the VFS layer can |
222 | * request to change from the FS layer. |
223 | * |
224 | * Derek Atkins <warlord@MIT.EDU> 94-10-20 |
225 | */ |
226 | struct iattr { |
227 | unsigned int ia_valid; |
228 | umode_t ia_mode; |
229 | /* |
230 | * The two anonymous unions wrap structures with the same member. |
231 | * |
232 | * Filesystems raising FS_ALLOW_IDMAP need to use ia_vfs{g,u}id which |
233 | * are a dedicated type requiring the filesystem to use the dedicated |
234 | * helpers. Other filesystem can continue to use ia_{g,u}id until they |
235 | * have been ported. |
236 | * |
237 | * They always contain the same value. In other words FS_ALLOW_IDMAP |
238 | * pass down the same value on idmapped mounts as they would on regular |
239 | * mounts. |
240 | */ |
241 | union { |
242 | kuid_t ia_uid; |
243 | vfsuid_t ia_vfsuid; |
244 | }; |
245 | union { |
246 | kgid_t ia_gid; |
247 | vfsgid_t ia_vfsgid; |
248 | }; |
249 | loff_t ia_size; |
250 | struct timespec64 ia_atime; |
251 | struct timespec64 ia_mtime; |
252 | struct timespec64 ia_ctime; |
253 | |
254 | /* |
255 | * Not an attribute, but an auxiliary info for filesystems wanting to |
256 | * implement an ftruncate() like method. NOTE: filesystem should |
257 | * check for (ia_valid & ATTR_FILE), and not for (ia_file != NULL). |
258 | */ |
259 | struct file *ia_file; |
260 | }; |
261 | |
262 | /* |
263 | * Includes for diskquotas. |
264 | */ |
265 | #include <linux/quota.h> |
266 | |
267 | /* |
268 | * Maximum number of layers of fs stack. Needs to be limited to |
269 | * prevent kernel stack overflow |
270 | */ |
271 | #define FILESYSTEM_MAX_STACK_DEPTH 2 |
272 | |
273 | /** |
274 | * enum positive_aop_returns - aop return codes with specific semantics |
275 | * |
276 | * @AOP_WRITEPAGE_ACTIVATE: Informs the caller that page writeback has |
277 | * completed, that the page is still locked, and |
278 | * should be considered active. The VM uses this hint |
279 | * to return the page to the active list -- it won't |
280 | * be a candidate for writeback again in the near |
281 | * future. Other callers must be careful to unlock |
282 | * the page if they get this return. Returned by |
283 | * writepage(); |
284 | * |
285 | * @AOP_TRUNCATED_PAGE: The AOP method that was handed a locked page has |
286 | * unlocked it and the page might have been truncated. |
287 | * The caller should back up to acquiring a new page and |
288 | * trying again. The aop will be taking reasonable |
289 | * precautions not to livelock. If the caller held a page |
290 | * reference, it should drop it before retrying. Returned |
291 | * by read_folio(). |
292 | * |
293 | * address_space_operation functions return these large constants to indicate |
294 | * special semantics to the caller. These are much larger than the bytes in a |
295 | * page to allow for functions that return the number of bytes operated on in a |
296 | * given page. |
297 | */ |
298 | |
299 | enum positive_aop_returns { |
300 | AOP_WRITEPAGE_ACTIVATE = 0x80000, |
301 | AOP_TRUNCATED_PAGE = 0x80001, |
302 | }; |
303 | |
304 | /* |
305 | * oh the beauties of C type declarations. |
306 | */ |
307 | struct page; |
308 | struct address_space; |
309 | struct writeback_control; |
310 | struct readahead_control; |
311 | |
312 | /* |
313 | * Write life time hint values. |
314 | * Stored in struct inode as u8. |
315 | */ |
316 | enum rw_hint { |
317 | WRITE_LIFE_NOT_SET = 0, |
318 | WRITE_LIFE_NONE = RWH_WRITE_LIFE_NONE, |
319 | WRITE_LIFE_SHORT = RWH_WRITE_LIFE_SHORT, |
320 | WRITE_LIFE_MEDIUM = RWH_WRITE_LIFE_MEDIUM, |
321 | WRITE_LIFE_LONG = RWH_WRITE_LIFE_LONG, |
322 | WRITE_LIFE_EXTREME = RWH_WRITE_LIFE_EXTREME, |
323 | }; |
324 | |
325 | /* Match RWF_* bits to IOCB bits */ |
326 | #define IOCB_HIPRI (__force int) RWF_HIPRI |
327 | #define IOCB_DSYNC (__force int) RWF_DSYNC |
328 | #define IOCB_SYNC (__force int) RWF_SYNC |
329 | #define IOCB_NOWAIT (__force int) RWF_NOWAIT |
330 | #define IOCB_APPEND (__force int) RWF_APPEND |
331 | |
332 | /* non-RWF related bits - start at 16 */ |
333 | #define IOCB_EVENTFD (1 << 16) |
334 | #define IOCB_DIRECT (1 << 17) |
335 | #define IOCB_WRITE (1 << 18) |
336 | /* iocb->ki_waitq is valid */ |
337 | #define IOCB_WAITQ (1 << 19) |
338 | #define IOCB_NOIO (1 << 20) |
339 | /* can use bio alloc cache */ |
340 | #define IOCB_ALLOC_CACHE (1 << 21) |
341 | /* |
342 | * IOCB_DIO_CALLER_COMP can be set by the iocb owner, to indicate that the |
343 | * iocb completion can be passed back to the owner for execution from a safe |
344 | * context rather than needing to be punted through a workqueue. If this |
345 | * flag is set, the bio completion handling may set iocb->dio_complete to a |
346 | * handler function and iocb->private to context information for that handler. |
347 | * The issuer should call the handler with that context information from task |
348 | * context to complete the processing of the iocb. Note that while this |
349 | * provides a task context for the dio_complete() callback, it should only be |
350 | * used on the completion side for non-IO generating completions. It's fine to |
351 | * call blocking functions from this callback, but they should not wait for |
352 | * unrelated IO (like cache flushing, new IO generation, etc). |
353 | */ |
354 | #define IOCB_DIO_CALLER_COMP (1 << 22) |
355 | |
356 | /* for use in trace events */ |
357 | #define TRACE_IOCB_STRINGS \ |
358 | { IOCB_HIPRI, "HIPRI" }, \ |
359 | { IOCB_DSYNC, "DSYNC" }, \ |
360 | { IOCB_SYNC, "SYNC" }, \ |
361 | { IOCB_NOWAIT, "NOWAIT" }, \ |
362 | { IOCB_APPEND, "APPEND" }, \ |
363 | { IOCB_EVENTFD, "EVENTFD"}, \ |
364 | { IOCB_DIRECT, "DIRECT" }, \ |
365 | { IOCB_WRITE, "WRITE" }, \ |
366 | { IOCB_WAITQ, "WAITQ" }, \ |
367 | { IOCB_NOIO, "NOIO" }, \ |
368 | { IOCB_ALLOC_CACHE, "ALLOC_CACHE" }, \ |
369 | { IOCB_DIO_CALLER_COMP, "CALLER_COMP" } |
370 | |
371 | struct kiocb { |
372 | struct file *ki_filp; |
373 | loff_t ki_pos; |
374 | void (*ki_complete)(struct kiocb *iocb, long ret); |
375 | void *private; |
376 | int ki_flags; |
377 | u16 ki_ioprio; /* See linux/ioprio.h */ |
378 | union { |
379 | /* |
380 | * Only used for async buffered reads, where it denotes the |
381 | * page waitqueue associated with completing the read. Valid |
382 | * IFF IOCB_WAITQ is set. |
383 | */ |
384 | struct wait_page_queue *ki_waitq; |
385 | /* |
386 | * Can be used for O_DIRECT IO, where the completion handling |
387 | * is punted back to the issuer of the IO. May only be set |
388 | * if IOCB_DIO_CALLER_COMP is set by the issuer, and the issuer |
389 | * must then check for presence of this handler when ki_complete |
390 | * is invoked. The data passed in to this handler must be |
391 | * assigned to ->private when dio_complete is assigned. |
392 | */ |
393 | ssize_t (*dio_complete)(void *data); |
394 | }; |
395 | }; |
396 | |
397 | static inline bool is_sync_kiocb(struct kiocb *kiocb) |
398 | { |
399 | return kiocb->ki_complete == NULL; |
400 | } |
401 | |
402 | struct address_space_operations { |
403 | int (*writepage)(struct page *page, struct writeback_control *wbc); |
404 | int (*read_folio)(struct file *, struct folio *); |
405 | |
406 | /* Write back some dirty pages from this mapping. */ |
407 | int (*writepages)(struct address_space *, struct writeback_control *); |
408 | |
409 | /* Mark a folio dirty. Return true if this dirtied it */ |
410 | bool (*dirty_folio)(struct address_space *, struct folio *); |
411 | |
412 | void (*readahead)(struct readahead_control *); |
413 | |
414 | int (*write_begin)(struct file *, struct address_space *mapping, |
415 | loff_t pos, unsigned len, |
416 | struct page **pagep, void **fsdata); |
417 | int (*write_end)(struct file *, struct address_space *mapping, |
418 | loff_t pos, unsigned len, unsigned copied, |
419 | struct page *page, void *fsdata); |
420 | |
421 | /* Unfortunately this kludge is needed for FIBMAP. Don't use it */ |
422 | sector_t (*bmap)(struct address_space *, sector_t); |
423 | void (*invalidate_folio) (struct folio *, size_t offset, size_t len); |
424 | bool (*release_folio)(struct folio *, gfp_t); |
425 | void (*free_folio)(struct folio *folio); |
426 | ssize_t (*direct_IO)(struct kiocb *, struct iov_iter *iter); |
427 | /* |
428 | * migrate the contents of a folio to the specified target. If |
429 | * migrate_mode is MIGRATE_ASYNC, it must not block. |
430 | */ |
431 | int (*migrate_folio)(struct address_space *, struct folio *dst, |
432 | struct folio *src, enum migrate_mode); |
433 | int (*launder_folio)(struct folio *); |
434 | bool (*is_partially_uptodate) (struct folio *, size_t from, |
435 | size_t count); |
436 | void (*is_dirty_writeback) (struct folio *, bool *dirty, bool *wb); |
437 | int (*error_remove_page)(struct address_space *, struct page *); |
438 | |
439 | /* swapfile support */ |
440 | int (*swap_activate)(struct swap_info_struct *sis, struct file *file, |
441 | sector_t *span); |
442 | void (*swap_deactivate)(struct file *file); |
443 | int (*swap_rw)(struct kiocb *iocb, struct iov_iter *iter); |
444 | }; |
445 | |
446 | extern const struct address_space_operations empty_aops; |
447 | |
448 | /** |
449 | * struct address_space - Contents of a cacheable, mappable object. |
450 | * @host: Owner, either the inode or the block_device. |
451 | * @i_pages: Cached pages. |
452 | * @invalidate_lock: Guards coherency between page cache contents and |
453 | * file offset->disk block mappings in the filesystem during invalidates. |
454 | * It is also used to block modification of page cache contents through |
455 | * memory mappings. |
456 | * @gfp_mask: Memory allocation flags to use for allocating pages. |
457 | * @i_mmap_writable: Number of VM_SHARED, VM_MAYWRITE mappings. |
458 | * @nr_thps: Number of THPs in the pagecache (non-shmem only). |
459 | * @i_mmap: Tree of private and shared mappings. |
460 | * @i_mmap_rwsem: Protects @i_mmap and @i_mmap_writable. |
461 | * @nrpages: Number of page entries, protected by the i_pages lock. |
462 | * @writeback_index: Writeback starts here. |
463 | * @a_ops: Methods. |
464 | * @flags: Error bits and flags (AS_*). |
465 | * @wb_err: The most recent error which has occurred. |
466 | * @private_lock: For use by the owner of the address_space. |
467 | * @private_list: For use by the owner of the address_space. |
468 | * @private_data: For use by the owner of the address_space. |
469 | */ |
470 | struct address_space { |
471 | struct inode *host; |
472 | struct xarray i_pages; |
473 | struct rw_semaphore invalidate_lock; |
474 | gfp_t gfp_mask; |
475 | atomic_t i_mmap_writable; |
476 | #ifdef CONFIG_READ_ONLY_THP_FOR_FS |
477 | /* number of thp, only for non-shmem files */ |
478 | atomic_t nr_thps; |
479 | #endif |
480 | struct rb_root_cached i_mmap; |
481 | unsigned long nrpages; |
482 | pgoff_t writeback_index; |
483 | const struct address_space_operations *a_ops; |
484 | unsigned long flags; |
485 | struct rw_semaphore i_mmap_rwsem; |
486 | errseq_t wb_err; |
487 | spinlock_t private_lock; |
488 | struct list_head private_list; |
489 | void *private_data; |
490 | } __attribute__((aligned(sizeof(long)))) __randomize_layout; |
491 | /* |
492 | * On most architectures that alignment is already the case; but |
493 | * must be enforced here for CRIS, to let the least significant bit |
494 | * of struct page's "mapping" pointer be used for PAGE_MAPPING_ANON. |
495 | */ |
496 | |
497 | /* XArray tags, for tagging dirty and writeback pages in the pagecache. */ |
498 | #define PAGECACHE_TAG_DIRTY XA_MARK_0 |
499 | #define PAGECACHE_TAG_WRITEBACK XA_MARK_1 |
500 | #define PAGECACHE_TAG_TOWRITE XA_MARK_2 |
501 | |
502 | /* |
503 | * Returns true if any of the pages in the mapping are marked with the tag. |
504 | */ |
505 | static inline bool mapping_tagged(struct address_space *mapping, xa_mark_t tag) |
506 | { |
507 | return xa_marked(xa: &mapping->i_pages, mark: tag); |
508 | } |
509 | |
510 | static inline void i_mmap_lock_write(struct address_space *mapping) |
511 | { |
512 | down_write(sem: &mapping->i_mmap_rwsem); |
513 | } |
514 | |
515 | static inline int i_mmap_trylock_write(struct address_space *mapping) |
516 | { |
517 | return down_write_trylock(sem: &mapping->i_mmap_rwsem); |
518 | } |
519 | |
520 | static inline void i_mmap_unlock_write(struct address_space *mapping) |
521 | { |
522 | up_write(sem: &mapping->i_mmap_rwsem); |
523 | } |
524 | |
525 | static inline int i_mmap_trylock_read(struct address_space *mapping) |
526 | { |
527 | return down_read_trylock(sem: &mapping->i_mmap_rwsem); |
528 | } |
529 | |
530 | static inline void i_mmap_lock_read(struct address_space *mapping) |
531 | { |
532 | down_read(sem: &mapping->i_mmap_rwsem); |
533 | } |
534 | |
535 | static inline void i_mmap_unlock_read(struct address_space *mapping) |
536 | { |
537 | up_read(sem: &mapping->i_mmap_rwsem); |
538 | } |
539 | |
540 | static inline void i_mmap_assert_locked(struct address_space *mapping) |
541 | { |
542 | lockdep_assert_held(&mapping->i_mmap_rwsem); |
543 | } |
544 | |
545 | static inline void i_mmap_assert_write_locked(struct address_space *mapping) |
546 | { |
547 | lockdep_assert_held_write(&mapping->i_mmap_rwsem); |
548 | } |
549 | |
550 | /* |
551 | * Might pages of this file be mapped into userspace? |
552 | */ |
553 | static inline int mapping_mapped(struct address_space *mapping) |
554 | { |
555 | return !RB_EMPTY_ROOT(&mapping->i_mmap.rb_root); |
556 | } |
557 | |
558 | /* |
559 | * Might pages of this file have been modified in userspace? |
560 | * Note that i_mmap_writable counts all VM_SHARED, VM_MAYWRITE vmas: do_mmap |
561 | * marks vma as VM_SHARED if it is shared, and the file was opened for |
562 | * writing i.e. vma may be mprotected writable even if now readonly. |
563 | * |
564 | * If i_mmap_writable is negative, no new writable mappings are allowed. You |
565 | * can only deny writable mappings, if none exists right now. |
566 | */ |
567 | static inline int mapping_writably_mapped(struct address_space *mapping) |
568 | { |
569 | return atomic_read(v: &mapping->i_mmap_writable) > 0; |
570 | } |
571 | |
572 | static inline int mapping_map_writable(struct address_space *mapping) |
573 | { |
574 | return atomic_inc_unless_negative(v: &mapping->i_mmap_writable) ? |
575 | 0 : -EPERM; |
576 | } |
577 | |
578 | static inline void mapping_unmap_writable(struct address_space *mapping) |
579 | { |
580 | atomic_dec(v: &mapping->i_mmap_writable); |
581 | } |
582 | |
583 | static inline int mapping_deny_writable(struct address_space *mapping) |
584 | { |
585 | return atomic_dec_unless_positive(v: &mapping->i_mmap_writable) ? |
586 | 0 : -EBUSY; |
587 | } |
588 | |
589 | static inline void mapping_allow_writable(struct address_space *mapping) |
590 | { |
591 | atomic_inc(v: &mapping->i_mmap_writable); |
592 | } |
593 | |
594 | /* |
595 | * Use sequence counter to get consistent i_size on 32-bit processors. |
596 | */ |
597 | #if BITS_PER_LONG==32 && defined(CONFIG_SMP) |
598 | #include <linux/seqlock.h> |
599 | #define __NEED_I_SIZE_ORDERED |
600 | #define i_size_ordered_init(inode) seqcount_init(&inode->i_size_seqcount) |
601 | #else |
602 | #define i_size_ordered_init(inode) do { } while (0) |
603 | #endif |
604 | |
605 | struct posix_acl; |
606 | #define ACL_NOT_CACHED ((void *)(-1)) |
607 | /* |
608 | * ACL_DONT_CACHE is for stacked filesystems, that rely on underlying fs to |
609 | * cache the ACL. This also means that ->get_inode_acl() can be called in RCU |
610 | * mode with the LOOKUP_RCU flag. |
611 | */ |
612 | #define ACL_DONT_CACHE ((void *)(-3)) |
613 | |
614 | static inline struct posix_acl * |
615 | uncached_acl_sentinel(struct task_struct *task) |
616 | { |
617 | return (void *)task + 1; |
618 | } |
619 | |
620 | static inline bool |
621 | is_uncached_acl(struct posix_acl *acl) |
622 | { |
623 | return (long)acl & 1; |
624 | } |
625 | |
626 | #define IOP_FASTPERM 0x0001 |
627 | #define IOP_LOOKUP 0x0002 |
628 | #define IOP_NOFOLLOW 0x0004 |
629 | #define IOP_XATTR 0x0008 |
630 | #define IOP_DEFAULT_READLINK 0x0010 |
631 | |
632 | struct fsnotify_mark_connector; |
633 | |
634 | /* |
635 | * Keep mostly read-only and often accessed (especially for |
636 | * the RCU path lookup and 'stat' data) fields at the beginning |
637 | * of the 'struct inode' |
638 | */ |
639 | struct inode { |
640 | umode_t i_mode; |
641 | unsigned short i_opflags; |
642 | kuid_t i_uid; |
643 | kgid_t i_gid; |
644 | unsigned int i_flags; |
645 | |
646 | #ifdef CONFIG_FS_POSIX_ACL |
647 | struct posix_acl *i_acl; |
648 | struct posix_acl *i_default_acl; |
649 | #endif |
650 | |
651 | const struct inode_operations *i_op; |
652 | struct super_block *i_sb; |
653 | struct address_space *i_mapping; |
654 | |
655 | #ifdef CONFIG_SECURITY |
656 | void *i_security; |
657 | #endif |
658 | |
659 | /* Stat data, not accessed from path walking */ |
660 | unsigned long i_ino; |
661 | /* |
662 | * Filesystems may only read i_nlink directly. They shall use the |
663 | * following functions for modification: |
664 | * |
665 | * (set|clear|inc|drop)_nlink |
666 | * inode_(inc|dec)_link_count |
667 | */ |
668 | union { |
669 | const unsigned int i_nlink; |
670 | unsigned int __i_nlink; |
671 | }; |
672 | dev_t i_rdev; |
673 | loff_t i_size; |
674 | struct timespec64 __i_atime; |
675 | struct timespec64 __i_mtime; |
676 | struct timespec64 __i_ctime; /* use inode_*_ctime accessors! */ |
677 | spinlock_t i_lock; /* i_blocks, i_bytes, maybe i_size */ |
678 | unsigned short i_bytes; |
679 | u8 i_blkbits; |
680 | u8 i_write_hint; |
681 | blkcnt_t i_blocks; |
682 | |
683 | #ifdef __NEED_I_SIZE_ORDERED |
684 | seqcount_t i_size_seqcount; |
685 | #endif |
686 | |
687 | /* Misc */ |
688 | unsigned long i_state; |
689 | struct rw_semaphore i_rwsem; |
690 | |
691 | unsigned long dirtied_when; /* jiffies of first dirtying */ |
692 | unsigned long dirtied_time_when; |
693 | |
694 | struct hlist_node i_hash; |
695 | struct list_head i_io_list; /* backing dev IO list */ |
696 | #ifdef CONFIG_CGROUP_WRITEBACK |
697 | struct bdi_writeback *i_wb; /* the associated cgroup wb */ |
698 | |
699 | /* foreign inode detection, see wbc_detach_inode() */ |
700 | int i_wb_frn_winner; |
701 | u16 i_wb_frn_avg_time; |
702 | u16 i_wb_frn_history; |
703 | #endif |
704 | struct list_head i_lru; /* inode LRU list */ |
705 | struct list_head i_sb_list; |
706 | struct list_head i_wb_list; /* backing dev writeback list */ |
707 | union { |
708 | struct hlist_head i_dentry; |
709 | struct rcu_head i_rcu; |
710 | }; |
711 | atomic64_t i_version; |
712 | atomic64_t i_sequence; /* see futex */ |
713 | atomic_t i_count; |
714 | atomic_t i_dio_count; |
715 | atomic_t i_writecount; |
716 | #if defined(CONFIG_IMA) || defined(CONFIG_FILE_LOCKING) |
717 | atomic_t i_readcount; /* struct files open RO */ |
718 | #endif |
719 | union { |
720 | const struct file_operations *i_fop; /* former ->i_op->default_file_ops */ |
721 | void (*free_inode)(struct inode *); |
722 | }; |
723 | struct file_lock_context *i_flctx; |
724 | struct address_space i_data; |
725 | struct list_head i_devices; |
726 | union { |
727 | struct pipe_inode_info *i_pipe; |
728 | struct cdev *i_cdev; |
729 | char *i_link; |
730 | unsigned i_dir_seq; |
731 | }; |
732 | |
733 | __u32 i_generation; |
734 | |
735 | #ifdef CONFIG_FSNOTIFY |
736 | __u32 i_fsnotify_mask; /* all events this inode cares about */ |
737 | struct fsnotify_mark_connector __rcu *i_fsnotify_marks; |
738 | #endif |
739 | |
740 | #ifdef CONFIG_FS_ENCRYPTION |
741 | struct fscrypt_inode_info *i_crypt_info; |
742 | #endif |
743 | |
744 | #ifdef CONFIG_FS_VERITY |
745 | struct fsverity_info *i_verity_info; |
746 | #endif |
747 | |
748 | void *i_private; /* fs or device private pointer */ |
749 | } __randomize_layout; |
750 | |
751 | struct timespec64 timestamp_truncate(struct timespec64 t, struct inode *inode); |
752 | |
753 | static inline unsigned int i_blocksize(const struct inode *node) |
754 | { |
755 | return (1 << node->i_blkbits); |
756 | } |
757 | |
758 | static inline int inode_unhashed(struct inode *inode) |
759 | { |
760 | return hlist_unhashed(h: &inode->i_hash); |
761 | } |
762 | |
763 | /* |
764 | * __mark_inode_dirty expects inodes to be hashed. Since we don't |
765 | * want special inodes in the fileset inode space, we make them |
766 | * appear hashed, but do not put on any lists. hlist_del() |
767 | * will work fine and require no locking. |
768 | */ |
769 | static inline void inode_fake_hash(struct inode *inode) |
770 | { |
771 | hlist_add_fake(n: &inode->i_hash); |
772 | } |
773 | |
774 | /* |
775 | * inode->i_mutex nesting subclasses for the lock validator: |
776 | * |
777 | * 0: the object of the current VFS operation |
778 | * 1: parent |
779 | * 2: child/target |
780 | * 3: xattr |
781 | * 4: second non-directory |
782 | * 5: second parent (when locking independent directories in rename) |
783 | * |
784 | * I_MUTEX_NONDIR2 is for certain operations (such as rename) which lock two |
785 | * non-directories at once. |
786 | * |
787 | * The locking order between these classes is |
788 | * parent[2] -> child -> grandchild -> normal -> xattr -> second non-directory |
789 | */ |
790 | enum inode_i_mutex_lock_class |
791 | { |
792 | I_MUTEX_NORMAL, |
793 | I_MUTEX_PARENT, |
794 | I_MUTEX_CHILD, |
795 | I_MUTEX_XATTR, |
796 | I_MUTEX_NONDIR2, |
797 | I_MUTEX_PARENT2, |
798 | }; |
799 | |
800 | static inline void inode_lock(struct inode *inode) |
801 | { |
802 | down_write(sem: &inode->i_rwsem); |
803 | } |
804 | |
805 | static inline void inode_unlock(struct inode *inode) |
806 | { |
807 | up_write(sem: &inode->i_rwsem); |
808 | } |
809 | |
810 | static inline void inode_lock_shared(struct inode *inode) |
811 | { |
812 | down_read(sem: &inode->i_rwsem); |
813 | } |
814 | |
815 | static inline void inode_unlock_shared(struct inode *inode) |
816 | { |
817 | up_read(sem: &inode->i_rwsem); |
818 | } |
819 | |
820 | static inline int inode_trylock(struct inode *inode) |
821 | { |
822 | return down_write_trylock(sem: &inode->i_rwsem); |
823 | } |
824 | |
825 | static inline int inode_trylock_shared(struct inode *inode) |
826 | { |
827 | return down_read_trylock(sem: &inode->i_rwsem); |
828 | } |
829 | |
830 | static inline int inode_is_locked(struct inode *inode) |
831 | { |
832 | return rwsem_is_locked(sem: &inode->i_rwsem); |
833 | } |
834 | |
835 | static inline void inode_lock_nested(struct inode *inode, unsigned subclass) |
836 | { |
837 | down_write_nested(sem: &inode->i_rwsem, subclass); |
838 | } |
839 | |
840 | static inline void inode_lock_shared_nested(struct inode *inode, unsigned subclass) |
841 | { |
842 | down_read_nested(sem: &inode->i_rwsem, subclass); |
843 | } |
844 | |
845 | static inline void filemap_invalidate_lock(struct address_space *mapping) |
846 | { |
847 | down_write(sem: &mapping->invalidate_lock); |
848 | } |
849 | |
850 | static inline void filemap_invalidate_unlock(struct address_space *mapping) |
851 | { |
852 | up_write(sem: &mapping->invalidate_lock); |
853 | } |
854 | |
855 | static inline void filemap_invalidate_lock_shared(struct address_space *mapping) |
856 | { |
857 | down_read(sem: &mapping->invalidate_lock); |
858 | } |
859 | |
860 | static inline int filemap_invalidate_trylock_shared( |
861 | struct address_space *mapping) |
862 | { |
863 | return down_read_trylock(sem: &mapping->invalidate_lock); |
864 | } |
865 | |
866 | static inline void filemap_invalidate_unlock_shared( |
867 | struct address_space *mapping) |
868 | { |
869 | up_read(sem: &mapping->invalidate_lock); |
870 | } |
871 | |
872 | void lock_two_nondirectories(struct inode *, struct inode*); |
873 | void unlock_two_nondirectories(struct inode *, struct inode*); |
874 | |
875 | void filemap_invalidate_lock_two(struct address_space *mapping1, |
876 | struct address_space *mapping2); |
877 | void filemap_invalidate_unlock_two(struct address_space *mapping1, |
878 | struct address_space *mapping2); |
879 | |
880 | |
881 | /* |
882 | * NOTE: in a 32bit arch with a preemptable kernel and |
883 | * an UP compile the i_size_read/write must be atomic |
884 | * with respect to the local cpu (unlike with preempt disabled), |
885 | * but they don't need to be atomic with respect to other cpus like in |
886 | * true SMP (so they need either to either locally disable irq around |
887 | * the read or for example on x86 they can be still implemented as a |
888 | * cmpxchg8b without the need of the lock prefix). For SMP compiles |
889 | * and 64bit archs it makes no difference if preempt is enabled or not. |
890 | */ |
891 | static inline loff_t i_size_read(const struct inode *inode) |
892 | { |
893 | #if BITS_PER_LONG==32 && defined(CONFIG_SMP) |
894 | loff_t i_size; |
895 | unsigned int seq; |
896 | |
897 | do { |
898 | seq = read_seqcount_begin(&inode->i_size_seqcount); |
899 | i_size = inode->i_size; |
900 | } while (read_seqcount_retry(&inode->i_size_seqcount, seq)); |
901 | return i_size; |
902 | #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION) |
903 | loff_t i_size; |
904 | |
905 | preempt_disable(); |
906 | i_size = inode->i_size; |
907 | preempt_enable(); |
908 | return i_size; |
909 | #else |
910 | return inode->i_size; |
911 | #endif |
912 | } |
913 | |
914 | /* |
915 | * NOTE: unlike i_size_read(), i_size_write() does need locking around it |
916 | * (normally i_mutex), otherwise on 32bit/SMP an update of i_size_seqcount |
917 | * can be lost, resulting in subsequent i_size_read() calls spinning forever. |
918 | */ |
919 | static inline void i_size_write(struct inode *inode, loff_t i_size) |
920 | { |
921 | #if BITS_PER_LONG==32 && defined(CONFIG_SMP) |
922 | preempt_disable(); |
923 | write_seqcount_begin(&inode->i_size_seqcount); |
924 | inode->i_size = i_size; |
925 | write_seqcount_end(&inode->i_size_seqcount); |
926 | preempt_enable(); |
927 | #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION) |
928 | preempt_disable(); |
929 | inode->i_size = i_size; |
930 | preempt_enable(); |
931 | #else |
932 | inode->i_size = i_size; |
933 | #endif |
934 | } |
935 | |
936 | static inline unsigned iminor(const struct inode *inode) |
937 | { |
938 | return MINOR(inode->i_rdev); |
939 | } |
940 | |
941 | static inline unsigned imajor(const struct inode *inode) |
942 | { |
943 | return MAJOR(inode->i_rdev); |
944 | } |
945 | |
946 | struct fown_struct { |
947 | rwlock_t lock; /* protects pid, uid, euid fields */ |
948 | struct pid *pid; /* pid or -pgrp where SIGIO should be sent */ |
949 | enum pid_type pid_type; /* Kind of process group SIGIO should be sent to */ |
950 | kuid_t uid, euid; /* uid/euid of process setting the owner */ |
951 | int signum; /* posix.1b rt signal to be delivered on IO */ |
952 | }; |
953 | |
954 | /** |
955 | * struct file_ra_state - Track a file's readahead state. |
956 | * @start: Where the most recent readahead started. |
957 | * @size: Number of pages read in the most recent readahead. |
958 | * @async_size: Numer of pages that were/are not needed immediately |
959 | * and so were/are genuinely "ahead". Start next readahead when |
960 | * the first of these pages is accessed. |
961 | * @ra_pages: Maximum size of a readahead request, copied from the bdi. |
962 | * @mmap_miss: How many mmap accesses missed in the page cache. |
963 | * @prev_pos: The last byte in the most recent read request. |
964 | * |
965 | * When this structure is passed to ->readahead(), the "most recent" |
966 | * readahead means the current readahead. |
967 | */ |
968 | struct file_ra_state { |
969 | pgoff_t start; |
970 | unsigned int size; |
971 | unsigned int async_size; |
972 | unsigned int ra_pages; |
973 | unsigned int mmap_miss; |
974 | loff_t prev_pos; |
975 | }; |
976 | |
977 | /* |
978 | * Check if @index falls in the readahead windows. |
979 | */ |
980 | static inline int ra_has_index(struct file_ra_state *ra, pgoff_t index) |
981 | { |
982 | return (index >= ra->start && |
983 | index < ra->start + ra->size); |
984 | } |
985 | |
986 | /* |
987 | * f_{lock,count,pos_lock} members can be highly contended and share |
988 | * the same cacheline. f_{lock,mode} are very frequently used together |
989 | * and so share the same cacheline as well. The read-mostly |
990 | * f_{path,inode,op} are kept on a separate cacheline. |
991 | */ |
992 | struct file { |
993 | union { |
994 | struct llist_node f_llist; |
995 | struct rcu_head f_rcuhead; |
996 | unsigned int f_iocb_flags; |
997 | }; |
998 | |
999 | /* |
1000 | * Protects f_ep, f_flags. |
1001 | * Must not be taken from IRQ context. |
1002 | */ |
1003 | spinlock_t f_lock; |
1004 | fmode_t f_mode; |
1005 | atomic_long_t f_count; |
1006 | struct mutex f_pos_lock; |
1007 | loff_t f_pos; |
1008 | unsigned int f_flags; |
1009 | struct fown_struct f_owner; |
1010 | const struct cred *f_cred; |
1011 | struct file_ra_state f_ra; |
1012 | struct path f_path; |
1013 | struct inode *f_inode; /* cached value */ |
1014 | const struct file_operations *f_op; |
1015 | |
1016 | u64 f_version; |
1017 | #ifdef CONFIG_SECURITY |
1018 | void *f_security; |
1019 | #endif |
1020 | /* needed for tty driver, and maybe others */ |
1021 | void *private_data; |
1022 | |
1023 | #ifdef CONFIG_EPOLL |
1024 | /* Used by fs/eventpoll.c to link all the hooks to this file */ |
1025 | struct hlist_head *f_ep; |
1026 | #endif /* #ifdef CONFIG_EPOLL */ |
1027 | struct address_space *f_mapping; |
1028 | errseq_t f_wb_err; |
1029 | errseq_t f_sb_err; /* for syncfs */ |
1030 | } __randomize_layout |
1031 | __attribute__((aligned(4))); /* lest something weird decides that 2 is OK */ |
1032 | |
1033 | struct file_handle { |
1034 | __u32 handle_bytes; |
1035 | int handle_type; |
1036 | /* file identifier */ |
1037 | unsigned char f_handle[]; |
1038 | }; |
1039 | |
1040 | static inline struct file *get_file(struct file *f) |
1041 | { |
1042 | atomic_long_inc(v: &f->f_count); |
1043 | return f; |
1044 | } |
1045 | |
1046 | struct file *get_file_rcu(struct file __rcu **f); |
1047 | struct file *get_file_active(struct file **f); |
1048 | |
1049 | #define file_count(x) atomic_long_read(&(x)->f_count) |
1050 | |
1051 | #define MAX_NON_LFS ((1UL<<31) - 1) |
1052 | |
1053 | /* Page cache limit. The filesystems should put that into their s_maxbytes |
1054 | limits, otherwise bad things can happen in VM. */ |
1055 | #if BITS_PER_LONG==32 |
1056 | #define MAX_LFS_FILESIZE ((loff_t)ULONG_MAX << PAGE_SHIFT) |
1057 | #elif BITS_PER_LONG==64 |
1058 | #define MAX_LFS_FILESIZE ((loff_t)LLONG_MAX) |
1059 | #endif |
1060 | |
1061 | /* legacy typedef, should eventually be removed */ |
1062 | typedef void *fl_owner_t; |
1063 | |
1064 | struct file_lock; |
1065 | |
1066 | /* The following constant reflects the upper bound of the file/locking space */ |
1067 | #ifndef OFFSET_MAX |
1068 | #define OFFSET_MAX type_max(loff_t) |
1069 | #define OFFT_OFFSET_MAX type_max(off_t) |
1070 | #endif |
1071 | |
1072 | extern void send_sigio(struct fown_struct *fown, int fd, int band); |
1073 | |
1074 | static inline struct inode *file_inode(const struct file *f) |
1075 | { |
1076 | return f->f_inode; |
1077 | } |
1078 | |
1079 | static inline struct dentry *file_dentry(const struct file *file) |
1080 | { |
1081 | return d_real(dentry: file->f_path.dentry, inode: file_inode(f: file)); |
1082 | } |
1083 | |
1084 | struct fasync_struct { |
1085 | rwlock_t fa_lock; |
1086 | int magic; |
1087 | int fa_fd; |
1088 | struct fasync_struct *fa_next; /* singly linked list */ |
1089 | struct file *fa_file; |
1090 | struct rcu_head fa_rcu; |
1091 | }; |
1092 | |
1093 | #define FASYNC_MAGIC 0x4601 |
1094 | |
1095 | /* SMP safe fasync helpers: */ |
1096 | extern int fasync_helper(int, struct file *, int, struct fasync_struct **); |
1097 | extern struct fasync_struct *fasync_insert_entry(int, struct file *, struct fasync_struct **, struct fasync_struct *); |
1098 | extern int fasync_remove_entry(struct file *, struct fasync_struct **); |
1099 | extern struct fasync_struct *fasync_alloc(void); |
1100 | extern void fasync_free(struct fasync_struct *); |
1101 | |
1102 | /* can be called from interrupts */ |
1103 | extern void kill_fasync(struct fasync_struct **, int, int); |
1104 | |
1105 | extern void __f_setown(struct file *filp, struct pid *, enum pid_type, int force); |
1106 | extern int f_setown(struct file *filp, int who, int force); |
1107 | extern void f_delown(struct file *filp); |
1108 | extern pid_t f_getown(struct file *filp); |
1109 | extern int send_sigurg(struct fown_struct *fown); |
1110 | |
1111 | /* |
1112 | * sb->s_flags. Note that these mirror the equivalent MS_* flags where |
1113 | * represented in both. |
1114 | */ |
1115 | #define SB_RDONLY BIT(0) /* Mount read-only */ |
1116 | #define SB_NOSUID BIT(1) /* Ignore suid and sgid bits */ |
1117 | #define SB_NODEV BIT(2) /* Disallow access to device special files */ |
1118 | #define SB_NOEXEC BIT(3) /* Disallow program execution */ |
1119 | #define SB_SYNCHRONOUS BIT(4) /* Writes are synced at once */ |
1120 | #define SB_MANDLOCK BIT(6) /* Allow mandatory locks on an FS */ |
1121 | #define SB_DIRSYNC BIT(7) /* Directory modifications are synchronous */ |
1122 | #define SB_NOATIME BIT(10) /* Do not update access times. */ |
1123 | #define SB_NODIRATIME BIT(11) /* Do not update directory access times */ |
1124 | #define SB_SILENT BIT(15) |
1125 | #define SB_POSIXACL BIT(16) /* Supports POSIX ACLs */ |
1126 | #define SB_INLINECRYPT BIT(17) /* Use blk-crypto for encrypted files */ |
1127 | #define SB_KERNMOUNT BIT(22) /* this is a kern_mount call */ |
1128 | #define SB_I_VERSION BIT(23) /* Update inode I_version field */ |
1129 | #define SB_LAZYTIME BIT(25) /* Update the on-disk [acm]times lazily */ |
1130 | |
1131 | /* These sb flags are internal to the kernel */ |
1132 | #define SB_DEAD BIT(21) |
1133 | #define SB_DYING BIT(24) |
1134 | #define SB_SUBMOUNT BIT(26) |
1135 | #define SB_FORCE BIT(27) |
1136 | #define SB_NOSEC BIT(28) |
1137 | #define SB_BORN BIT(29) |
1138 | #define SB_ACTIVE BIT(30) |
1139 | #define SB_NOUSER BIT(31) |
1140 | |
1141 | /* These flags relate to encoding and casefolding */ |
1142 | #define SB_ENC_STRICT_MODE_FL (1 << 0) |
1143 | |
1144 | #define sb_has_strict_encoding(sb) \ |
1145 | (sb->s_encoding_flags & SB_ENC_STRICT_MODE_FL) |
1146 | |
1147 | /* |
1148 | * Umount options |
1149 | */ |
1150 | |
1151 | #define MNT_FORCE 0x00000001 /* Attempt to forcibily umount */ |
1152 | #define MNT_DETACH 0x00000002 /* Just detach from the tree */ |
1153 | #define MNT_EXPIRE 0x00000004 /* Mark for expiry */ |
1154 | #define UMOUNT_NOFOLLOW 0x00000008 /* Don't follow symlink on umount */ |
1155 | #define UMOUNT_UNUSED 0x80000000 /* Flag guaranteed to be unused */ |
1156 | |
1157 | /* sb->s_iflags */ |
1158 | #define SB_I_CGROUPWB 0x00000001 /* cgroup-aware writeback enabled */ |
1159 | #define SB_I_NOEXEC 0x00000002 /* Ignore executables on this fs */ |
1160 | #define SB_I_NODEV 0x00000004 /* Ignore devices on this fs */ |
1161 | #define SB_I_STABLE_WRITES 0x00000008 /* don't modify blks until WB is done */ |
1162 | |
1163 | /* sb->s_iflags to limit user namespace mounts */ |
1164 | #define SB_I_USERNS_VISIBLE 0x00000010 /* fstype already mounted */ |
1165 | #define SB_I_IMA_UNVERIFIABLE_SIGNATURE 0x00000020 |
1166 | #define SB_I_UNTRUSTED_MOUNTER 0x00000040 |
1167 | |
1168 | #define SB_I_SKIP_SYNC 0x00000100 /* Skip superblock at global sync */ |
1169 | #define SB_I_PERSB_BDI 0x00000200 /* has a per-sb bdi */ |
1170 | #define SB_I_TS_EXPIRY_WARNED 0x00000400 /* warned about timestamp range expiry */ |
1171 | #define SB_I_RETIRED 0x00000800 /* superblock shouldn't be reused */ |
1172 | #define SB_I_NOUMASK 0x00001000 /* VFS does not apply umask */ |
1173 | |
1174 | /* Possible states of 'frozen' field */ |
1175 | enum { |
1176 | SB_UNFROZEN = 0, /* FS is unfrozen */ |
1177 | SB_FREEZE_WRITE = 1, /* Writes, dir ops, ioctls frozen */ |
1178 | SB_FREEZE_PAGEFAULT = 2, /* Page faults stopped as well */ |
1179 | SB_FREEZE_FS = 3, /* For internal FS use (e.g. to stop |
1180 | * internal threads if needed) */ |
1181 | SB_FREEZE_COMPLETE = 4, /* ->freeze_fs finished successfully */ |
1182 | }; |
1183 | |
1184 | #define SB_FREEZE_LEVELS (SB_FREEZE_COMPLETE - 1) |
1185 | |
1186 | struct sb_writers { |
1187 | unsigned short frozen; /* Is sb frozen? */ |
1188 | unsigned short freeze_holders; /* Who froze fs? */ |
1189 | struct percpu_rw_semaphore rw_sem[SB_FREEZE_LEVELS]; |
1190 | }; |
1191 | |
1192 | struct super_block { |
1193 | struct list_head s_list; /* Keep this first */ |
1194 | dev_t s_dev; /* search index; _not_ kdev_t */ |
1195 | unsigned char s_blocksize_bits; |
1196 | unsigned long s_blocksize; |
1197 | loff_t s_maxbytes; /* Max file size */ |
1198 | struct file_system_type *s_type; |
1199 | const struct super_operations *s_op; |
1200 | const struct dquot_operations *dq_op; |
1201 | const struct quotactl_ops *s_qcop; |
1202 | const struct export_operations *s_export_op; |
1203 | unsigned long s_flags; |
1204 | unsigned long s_iflags; /* internal SB_I_* flags */ |
1205 | unsigned long s_magic; |
1206 | struct dentry *s_root; |
1207 | struct rw_semaphore s_umount; |
1208 | int s_count; |
1209 | atomic_t s_active; |
1210 | #ifdef CONFIG_SECURITY |
1211 | void *s_security; |
1212 | #endif |
1213 | const struct xattr_handler * const *s_xattr; |
1214 | #ifdef CONFIG_FS_ENCRYPTION |
1215 | const struct fscrypt_operations *s_cop; |
1216 | struct fscrypt_keyring *s_master_keys; /* master crypto keys in use */ |
1217 | #endif |
1218 | #ifdef CONFIG_FS_VERITY |
1219 | const struct fsverity_operations *s_vop; |
1220 | #endif |
1221 | #if IS_ENABLED(CONFIG_UNICODE) |
1222 | struct unicode_map *s_encoding; |
1223 | __u16 s_encoding_flags; |
1224 | #endif |
1225 | struct hlist_bl_head s_roots; /* alternate root dentries for NFS */ |
1226 | struct list_head s_mounts; /* list of mounts; _not_ for fs use */ |
1227 | struct block_device *s_bdev; |
1228 | struct bdev_handle *s_bdev_handle; |
1229 | struct backing_dev_info *s_bdi; |
1230 | struct mtd_info *s_mtd; |
1231 | struct hlist_node s_instances; |
1232 | unsigned int s_quota_types; /* Bitmask of supported quota types */ |
1233 | struct quota_info s_dquot; /* Diskquota specific options */ |
1234 | |
1235 | struct sb_writers s_writers; |
1236 | |
1237 | /* |
1238 | * Keep s_fs_info, s_time_gran, s_fsnotify_mask, and |
1239 | * s_fsnotify_marks together for cache efficiency. They are frequently |
1240 | * accessed and rarely modified. |
1241 | */ |
1242 | void *s_fs_info; /* Filesystem private info */ |
1243 | |
1244 | /* Granularity of c/m/atime in ns (cannot be worse than a second) */ |
1245 | u32 s_time_gran; |
1246 | /* Time limits for c/m/atime in seconds */ |
1247 | time64_t s_time_min; |
1248 | time64_t s_time_max; |
1249 | #ifdef CONFIG_FSNOTIFY |
1250 | __u32 s_fsnotify_mask; |
1251 | struct fsnotify_mark_connector __rcu *s_fsnotify_marks; |
1252 | #endif |
1253 | |
1254 | char s_id[32]; /* Informational name */ |
1255 | uuid_t s_uuid; /* UUID */ |
1256 | |
1257 | unsigned int s_max_links; |
1258 | |
1259 | /* |
1260 | * The next field is for VFS *only*. No filesystems have any business |
1261 | * even looking at it. You had been warned. |
1262 | */ |
1263 | struct mutex s_vfs_rename_mutex; /* Kludge */ |
1264 | |
1265 | /* |
1266 | * Filesystem subtype. If non-empty the filesystem type field |
1267 | * in /proc/mounts will be "type.subtype" |
1268 | */ |
1269 | const char *s_subtype; |
1270 | |
1271 | const struct dentry_operations *s_d_op; /* default d_op for dentries */ |
1272 | |
1273 | struct shrinker *s_shrink; /* per-sb shrinker handle */ |
1274 | |
1275 | /* Number of inodes with nlink == 0 but still referenced */ |
1276 | atomic_long_t s_remove_count; |
1277 | |
1278 | /* |
1279 | * Number of inode/mount/sb objects that are being watched, note that |
1280 | * inodes objects are currently double-accounted. |
1281 | */ |
1282 | atomic_long_t s_fsnotify_connectors; |
1283 | |
1284 | /* Read-only state of the superblock is being changed */ |
1285 | int s_readonly_remount; |
1286 | |
1287 | /* per-sb errseq_t for reporting writeback errors via syncfs */ |
1288 | errseq_t s_wb_err; |
1289 | |
1290 | /* AIO completions deferred from interrupt context */ |
1291 | struct workqueue_struct *s_dio_done_wq; |
1292 | struct hlist_head s_pins; |
1293 | |
1294 | /* |
1295 | * Owning user namespace and default context in which to |
1296 | * interpret filesystem uids, gids, quotas, device nodes, |
1297 | * xattrs and security labels. |
1298 | */ |
1299 | struct user_namespace *s_user_ns; |
1300 | |
1301 | /* |
1302 | * The list_lru structure is essentially just a pointer to a table |
1303 | * of per-node lru lists, each of which has its own spinlock. |
1304 | * There is no need to put them into separate cachelines. |
1305 | */ |
1306 | struct list_lru s_dentry_lru; |
1307 | struct list_lru s_inode_lru; |
1308 | struct rcu_head rcu; |
1309 | struct work_struct destroy_work; |
1310 | |
1311 | struct mutex s_sync_lock; /* sync serialisation lock */ |
1312 | |
1313 | /* |
1314 | * Indicates how deep in a filesystem stack this SB is |
1315 | */ |
1316 | int s_stack_depth; |
1317 | |
1318 | /* s_inode_list_lock protects s_inodes */ |
1319 | spinlock_t s_inode_list_lock ____cacheline_aligned_in_smp; |
1320 | struct list_head s_inodes; /* all inodes */ |
1321 | |
1322 | spinlock_t s_inode_wblist_lock; |
1323 | struct list_head s_inodes_wb; /* writeback inodes */ |
1324 | } __randomize_layout; |
1325 | |
1326 | static inline struct user_namespace *i_user_ns(const struct inode *inode) |
1327 | { |
1328 | return inode->i_sb->s_user_ns; |
1329 | } |
1330 | |
1331 | /* Helper functions so that in most cases filesystems will |
1332 | * not need to deal directly with kuid_t and kgid_t and can |
1333 | * instead deal with the raw numeric values that are stored |
1334 | * in the filesystem. |
1335 | */ |
1336 | static inline uid_t i_uid_read(const struct inode *inode) |
1337 | { |
1338 | return from_kuid(to: i_user_ns(inode), uid: inode->i_uid); |
1339 | } |
1340 | |
1341 | static inline gid_t i_gid_read(const struct inode *inode) |
1342 | { |
1343 | return from_kgid(to: i_user_ns(inode), gid: inode->i_gid); |
1344 | } |
1345 | |
1346 | static inline void i_uid_write(struct inode *inode, uid_t uid) |
1347 | { |
1348 | inode->i_uid = make_kuid(from: i_user_ns(inode), uid); |
1349 | } |
1350 | |
1351 | static inline void i_gid_write(struct inode *inode, gid_t gid) |
1352 | { |
1353 | inode->i_gid = make_kgid(from: i_user_ns(inode), gid); |
1354 | } |
1355 | |
1356 | /** |
1357 | * i_uid_into_vfsuid - map an inode's i_uid down according to an idmapping |
1358 | * @idmap: idmap of the mount the inode was found from |
1359 | * @inode: inode to map |
1360 | * |
1361 | * Return: whe inode's i_uid mapped down according to @idmap. |
1362 | * If the inode's i_uid has no mapping INVALID_VFSUID is returned. |
1363 | */ |
1364 | static inline vfsuid_t i_uid_into_vfsuid(struct mnt_idmap *idmap, |
1365 | const struct inode *inode) |
1366 | { |
1367 | return make_vfsuid(idmap, fs_userns: i_user_ns(inode), kuid: inode->i_uid); |
1368 | } |
1369 | |
1370 | /** |
1371 | * i_uid_needs_update - check whether inode's i_uid needs to be updated |
1372 | * @idmap: idmap of the mount the inode was found from |
1373 | * @attr: the new attributes of @inode |
1374 | * @inode: the inode to update |
1375 | * |
1376 | * Check whether the $inode's i_uid field needs to be updated taking idmapped |
1377 | * mounts into account if the filesystem supports it. |
1378 | * |
1379 | * Return: true if @inode's i_uid field needs to be updated, false if not. |
1380 | */ |
1381 | static inline bool i_uid_needs_update(struct mnt_idmap *idmap, |
1382 | const struct iattr *attr, |
1383 | const struct inode *inode) |
1384 | { |
1385 | return ((attr->ia_valid & ATTR_UID) && |
1386 | !vfsuid_eq(left: attr->ia_vfsuid, |
1387 | right: i_uid_into_vfsuid(idmap, inode))); |
1388 | } |
1389 | |
1390 | /** |
1391 | * i_uid_update - update @inode's i_uid field |
1392 | * @idmap: idmap of the mount the inode was found from |
1393 | * @attr: the new attributes of @inode |
1394 | * @inode: the inode to update |
1395 | * |
1396 | * Safely update @inode's i_uid field translating the vfsuid of any idmapped |
1397 | * mount into the filesystem kuid. |
1398 | */ |
1399 | static inline void i_uid_update(struct mnt_idmap *idmap, |
1400 | const struct iattr *attr, |
1401 | struct inode *inode) |
1402 | { |
1403 | if (attr->ia_valid & ATTR_UID) |
1404 | inode->i_uid = from_vfsuid(idmap, fs_userns: i_user_ns(inode), |
1405 | vfsuid: attr->ia_vfsuid); |
1406 | } |
1407 | |
1408 | /** |
1409 | * i_gid_into_vfsgid - map an inode's i_gid down according to an idmapping |
1410 | * @idmap: idmap of the mount the inode was found from |
1411 | * @inode: inode to map |
1412 | * |
1413 | * Return: the inode's i_gid mapped down according to @idmap. |
1414 | * If the inode's i_gid has no mapping INVALID_VFSGID is returned. |
1415 | */ |
1416 | static inline vfsgid_t i_gid_into_vfsgid(struct mnt_idmap *idmap, |
1417 | const struct inode *inode) |
1418 | { |
1419 | return make_vfsgid(idmap, fs_userns: i_user_ns(inode), kgid: inode->i_gid); |
1420 | } |
1421 | |
1422 | /** |
1423 | * i_gid_needs_update - check whether inode's i_gid needs to be updated |
1424 | * @idmap: idmap of the mount the inode was found from |
1425 | * @attr: the new attributes of @inode |
1426 | * @inode: the inode to update |
1427 | * |
1428 | * Check whether the $inode's i_gid field needs to be updated taking idmapped |
1429 | * mounts into account if the filesystem supports it. |
1430 | * |
1431 | * Return: true if @inode's i_gid field needs to be updated, false if not. |
1432 | */ |
1433 | static inline bool i_gid_needs_update(struct mnt_idmap *idmap, |
1434 | const struct iattr *attr, |
1435 | const struct inode *inode) |
1436 | { |
1437 | return ((attr->ia_valid & ATTR_GID) && |
1438 | !vfsgid_eq(left: attr->ia_vfsgid, |
1439 | right: i_gid_into_vfsgid(idmap, inode))); |
1440 | } |
1441 | |
1442 | /** |
1443 | * i_gid_update - update @inode's i_gid field |
1444 | * @idmap: idmap of the mount the inode was found from |
1445 | * @attr: the new attributes of @inode |
1446 | * @inode: the inode to update |
1447 | * |
1448 | * Safely update @inode's i_gid field translating the vfsgid of any idmapped |
1449 | * mount into the filesystem kgid. |
1450 | */ |
1451 | static inline void i_gid_update(struct mnt_idmap *idmap, |
1452 | const struct iattr *attr, |
1453 | struct inode *inode) |
1454 | { |
1455 | if (attr->ia_valid & ATTR_GID) |
1456 | inode->i_gid = from_vfsgid(idmap, fs_userns: i_user_ns(inode), |
1457 | vfsgid: attr->ia_vfsgid); |
1458 | } |
1459 | |
1460 | /** |
1461 | * inode_fsuid_set - initialize inode's i_uid field with callers fsuid |
1462 | * @inode: inode to initialize |
1463 | * @idmap: idmap of the mount the inode was found from |
1464 | * |
1465 | * Initialize the i_uid field of @inode. If the inode was found/created via |
1466 | * an idmapped mount map the caller's fsuid according to @idmap. |
1467 | */ |
1468 | static inline void inode_fsuid_set(struct inode *inode, |
1469 | struct mnt_idmap *idmap) |
1470 | { |
1471 | inode->i_uid = mapped_fsuid(idmap, fs_userns: i_user_ns(inode)); |
1472 | } |
1473 | |
1474 | /** |
1475 | * inode_fsgid_set - initialize inode's i_gid field with callers fsgid |
1476 | * @inode: inode to initialize |
1477 | * @idmap: idmap of the mount the inode was found from |
1478 | * |
1479 | * Initialize the i_gid field of @inode. If the inode was found/created via |
1480 | * an idmapped mount map the caller's fsgid according to @idmap. |
1481 | */ |
1482 | static inline void inode_fsgid_set(struct inode *inode, |
1483 | struct mnt_idmap *idmap) |
1484 | { |
1485 | inode->i_gid = mapped_fsgid(idmap, fs_userns: i_user_ns(inode)); |
1486 | } |
1487 | |
1488 | /** |
1489 | * fsuidgid_has_mapping() - check whether caller's fsuid/fsgid is mapped |
1490 | * @sb: the superblock we want a mapping in |
1491 | * @idmap: idmap of the relevant mount |
1492 | * |
1493 | * Check whether the caller's fsuid and fsgid have a valid mapping in the |
1494 | * s_user_ns of the superblock @sb. If the caller is on an idmapped mount map |
1495 | * the caller's fsuid and fsgid according to the @idmap first. |
1496 | * |
1497 | * Return: true if fsuid and fsgid is mapped, false if not. |
1498 | */ |
1499 | static inline bool fsuidgid_has_mapping(struct super_block *sb, |
1500 | struct mnt_idmap *idmap) |
1501 | { |
1502 | struct user_namespace *fs_userns = sb->s_user_ns; |
1503 | kuid_t kuid; |
1504 | kgid_t kgid; |
1505 | |
1506 | kuid = mapped_fsuid(idmap, fs_userns); |
1507 | if (!uid_valid(uid: kuid)) |
1508 | return false; |
1509 | kgid = mapped_fsgid(idmap, fs_userns); |
1510 | if (!gid_valid(gid: kgid)) |
1511 | return false; |
1512 | return kuid_has_mapping(ns: fs_userns, uid: kuid) && |
1513 | kgid_has_mapping(ns: fs_userns, gid: kgid); |
1514 | } |
1515 | |
1516 | struct timespec64 current_time(struct inode *inode); |
1517 | struct timespec64 inode_set_ctime_current(struct inode *inode); |
1518 | |
1519 | static inline time64_t inode_get_atime_sec(const struct inode *inode) |
1520 | { |
1521 | return inode->__i_atime.tv_sec; |
1522 | } |
1523 | |
1524 | static inline long inode_get_atime_nsec(const struct inode *inode) |
1525 | { |
1526 | return inode->__i_atime.tv_nsec; |
1527 | } |
1528 | |
1529 | static inline struct timespec64 inode_get_atime(const struct inode *inode) |
1530 | { |
1531 | return inode->__i_atime; |
1532 | } |
1533 | |
1534 | static inline struct timespec64 inode_set_atime_to_ts(struct inode *inode, |
1535 | struct timespec64 ts) |
1536 | { |
1537 | inode->__i_atime = ts; |
1538 | return ts; |
1539 | } |
1540 | |
1541 | static inline struct timespec64 inode_set_atime(struct inode *inode, |
1542 | time64_t sec, long nsec) |
1543 | { |
1544 | struct timespec64 ts = { .tv_sec = sec, |
1545 | .tv_nsec = nsec }; |
1546 | return inode_set_atime_to_ts(inode, ts); |
1547 | } |
1548 | |
1549 | static inline time64_t inode_get_mtime_sec(const struct inode *inode) |
1550 | { |
1551 | return inode->__i_mtime.tv_sec; |
1552 | } |
1553 | |
1554 | static inline long inode_get_mtime_nsec(const struct inode *inode) |
1555 | { |
1556 | return inode->__i_mtime.tv_nsec; |
1557 | } |
1558 | |
1559 | static inline struct timespec64 inode_get_mtime(const struct inode *inode) |
1560 | { |
1561 | return inode->__i_mtime; |
1562 | } |
1563 | |
1564 | static inline struct timespec64 inode_set_mtime_to_ts(struct inode *inode, |
1565 | struct timespec64 ts) |
1566 | { |
1567 | inode->__i_mtime = ts; |
1568 | return ts; |
1569 | } |
1570 | |
1571 | static inline struct timespec64 inode_set_mtime(struct inode *inode, |
1572 | time64_t sec, long nsec) |
1573 | { |
1574 | struct timespec64 ts = { .tv_sec = sec, |
1575 | .tv_nsec = nsec }; |
1576 | return inode_set_mtime_to_ts(inode, ts); |
1577 | } |
1578 | |
1579 | static inline time64_t inode_get_ctime_sec(const struct inode *inode) |
1580 | { |
1581 | return inode->__i_ctime.tv_sec; |
1582 | } |
1583 | |
1584 | static inline long inode_get_ctime_nsec(const struct inode *inode) |
1585 | { |
1586 | return inode->__i_ctime.tv_nsec; |
1587 | } |
1588 | |
1589 | static inline struct timespec64 inode_get_ctime(const struct inode *inode) |
1590 | { |
1591 | return inode->__i_ctime; |
1592 | } |
1593 | |
1594 | static inline struct timespec64 inode_set_ctime_to_ts(struct inode *inode, |
1595 | struct timespec64 ts) |
1596 | { |
1597 | inode->__i_ctime = ts; |
1598 | return ts; |
1599 | } |
1600 | |
1601 | /** |
1602 | * inode_set_ctime - set the ctime in the inode |
1603 | * @inode: inode in which to set the ctime |
1604 | * @sec: tv_sec value to set |
1605 | * @nsec: tv_nsec value to set |
1606 | * |
1607 | * Set the ctime in @inode to { @sec, @nsec } |
1608 | */ |
1609 | static inline struct timespec64 inode_set_ctime(struct inode *inode, |
1610 | time64_t sec, long nsec) |
1611 | { |
1612 | struct timespec64 ts = { .tv_sec = sec, |
1613 | .tv_nsec = nsec }; |
1614 | |
1615 | return inode_set_ctime_to_ts(inode, ts); |
1616 | } |
1617 | |
1618 | struct timespec64 simple_inode_init_ts(struct inode *inode); |
1619 | |
1620 | /* |
1621 | * Snapshotting support. |
1622 | */ |
1623 | |
1624 | /* |
1625 | * These are internal functions, please use sb_start_{write,pagefault,intwrite} |
1626 | * instead. |
1627 | */ |
1628 | static inline void __sb_end_write(struct super_block *sb, int level) |
1629 | { |
1630 | percpu_up_read(sem: sb->s_writers.rw_sem + level-1); |
1631 | } |
1632 | |
1633 | static inline void __sb_start_write(struct super_block *sb, int level) |
1634 | { |
1635 | percpu_down_read(sem: sb->s_writers.rw_sem + level - 1); |
1636 | } |
1637 | |
1638 | static inline bool __sb_start_write_trylock(struct super_block *sb, int level) |
1639 | { |
1640 | return percpu_down_read_trylock(sem: sb->s_writers.rw_sem + level - 1); |
1641 | } |
1642 | |
1643 | #define __sb_writers_acquired(sb, lev) \ |
1644 | percpu_rwsem_acquire(&(sb)->s_writers.rw_sem[(lev)-1], 1, _THIS_IP_) |
1645 | #define __sb_writers_release(sb, lev) \ |
1646 | percpu_rwsem_release(&(sb)->s_writers.rw_sem[(lev)-1], 1, _THIS_IP_) |
1647 | |
1648 | static inline bool sb_write_started(const struct super_block *sb) |
1649 | { |
1650 | return lockdep_is_held_type(sb->s_writers.rw_sem + SB_FREEZE_WRITE - 1, 1); |
1651 | } |
1652 | |
1653 | /** |
1654 | * sb_end_write - drop write access to a superblock |
1655 | * @sb: the super we wrote to |
1656 | * |
1657 | * Decrement number of writers to the filesystem. Wake up possible waiters |
1658 | * wanting to freeze the filesystem. |
1659 | */ |
1660 | static inline void sb_end_write(struct super_block *sb) |
1661 | { |
1662 | __sb_end_write(sb, level: SB_FREEZE_WRITE); |
1663 | } |
1664 | |
1665 | /** |
1666 | * sb_end_pagefault - drop write access to a superblock from a page fault |
1667 | * @sb: the super we wrote to |
1668 | * |
1669 | * Decrement number of processes handling write page fault to the filesystem. |
1670 | * Wake up possible waiters wanting to freeze the filesystem. |
1671 | */ |
1672 | static inline void sb_end_pagefault(struct super_block *sb) |
1673 | { |
1674 | __sb_end_write(sb, level: SB_FREEZE_PAGEFAULT); |
1675 | } |
1676 | |
1677 | /** |
1678 | * sb_end_intwrite - drop write access to a superblock for internal fs purposes |
1679 | * @sb: the super we wrote to |
1680 | * |
1681 | * Decrement fs-internal number of writers to the filesystem. Wake up possible |
1682 | * waiters wanting to freeze the filesystem. |
1683 | */ |
1684 | static inline void sb_end_intwrite(struct super_block *sb) |
1685 | { |
1686 | __sb_end_write(sb, level: SB_FREEZE_FS); |
1687 | } |
1688 | |
1689 | /** |
1690 | * sb_start_write - get write access to a superblock |
1691 | * @sb: the super we write to |
1692 | * |
1693 | * When a process wants to write data or metadata to a file system (i.e. dirty |
1694 | * a page or an inode), it should embed the operation in a sb_start_write() - |
1695 | * sb_end_write() pair to get exclusion against file system freezing. This |
1696 | * function increments number of writers preventing freezing. If the file |
1697 | * system is already frozen, the function waits until the file system is |
1698 | * thawed. |
1699 | * |
1700 | * Since freeze protection behaves as a lock, users have to preserve |
1701 | * ordering of freeze protection and other filesystem locks. Generally, |
1702 | * freeze protection should be the outermost lock. In particular, we have: |
1703 | * |
1704 | * sb_start_write |
1705 | * -> i_mutex (write path, truncate, directory ops, ...) |
1706 | * -> s_umount (freeze_super, thaw_super) |
1707 | */ |
1708 | static inline void sb_start_write(struct super_block *sb) |
1709 | { |
1710 | __sb_start_write(sb, level: SB_FREEZE_WRITE); |
1711 | } |
1712 | |
1713 | static inline bool sb_start_write_trylock(struct super_block *sb) |
1714 | { |
1715 | return __sb_start_write_trylock(sb, level: SB_FREEZE_WRITE); |
1716 | } |
1717 | |
1718 | /** |
1719 | * sb_start_pagefault - get write access to a superblock from a page fault |
1720 | * @sb: the super we write to |
1721 | * |
1722 | * When a process starts handling write page fault, it should embed the |
1723 | * operation into sb_start_pagefault() - sb_end_pagefault() pair to get |
1724 | * exclusion against file system freezing. This is needed since the page fault |
1725 | * is going to dirty a page. This function increments number of running page |
1726 | * faults preventing freezing. If the file system is already frozen, the |
1727 | * function waits until the file system is thawed. |
1728 | * |
1729 | * Since page fault freeze protection behaves as a lock, users have to preserve |
1730 | * ordering of freeze protection and other filesystem locks. It is advised to |
1731 | * put sb_start_pagefault() close to mmap_lock in lock ordering. Page fault |
1732 | * handling code implies lock dependency: |
1733 | * |
1734 | * mmap_lock |
1735 | * -> sb_start_pagefault |
1736 | */ |
1737 | static inline void sb_start_pagefault(struct super_block *sb) |
1738 | { |
1739 | __sb_start_write(sb, level: SB_FREEZE_PAGEFAULT); |
1740 | } |
1741 | |
1742 | /** |
1743 | * sb_start_intwrite - get write access to a superblock for internal fs purposes |
1744 | * @sb: the super we write to |
1745 | * |
1746 | * This is the third level of protection against filesystem freezing. It is |
1747 | * free for use by a filesystem. The only requirement is that it must rank |
1748 | * below sb_start_pagefault. |
1749 | * |
1750 | * For example filesystem can call sb_start_intwrite() when starting a |
1751 | * transaction which somewhat eases handling of freezing for internal sources |
1752 | * of filesystem changes (internal fs threads, discarding preallocation on file |
1753 | * close, etc.). |
1754 | */ |
1755 | static inline void sb_start_intwrite(struct super_block *sb) |
1756 | { |
1757 | __sb_start_write(sb, level: SB_FREEZE_FS); |
1758 | } |
1759 | |
1760 | static inline bool sb_start_intwrite_trylock(struct super_block *sb) |
1761 | { |
1762 | return __sb_start_write_trylock(sb, level: SB_FREEZE_FS); |
1763 | } |
1764 | |
1765 | bool inode_owner_or_capable(struct mnt_idmap *idmap, |
1766 | const struct inode *inode); |
1767 | |
1768 | /* |
1769 | * VFS helper functions.. |
1770 | */ |
1771 | int vfs_create(struct mnt_idmap *, struct inode *, |
1772 | struct dentry *, umode_t, bool); |
1773 | int vfs_mkdir(struct mnt_idmap *, struct inode *, |
1774 | struct dentry *, umode_t); |
1775 | int vfs_mknod(struct mnt_idmap *, struct inode *, struct dentry *, |
1776 | umode_t, dev_t); |
1777 | int vfs_symlink(struct mnt_idmap *, struct inode *, |
1778 | struct dentry *, const char *); |
1779 | int vfs_link(struct dentry *, struct mnt_idmap *, struct inode *, |
1780 | struct dentry *, struct inode **); |
1781 | int vfs_rmdir(struct mnt_idmap *, struct inode *, struct dentry *); |
1782 | int vfs_unlink(struct mnt_idmap *, struct inode *, struct dentry *, |
1783 | struct inode **); |
1784 | |
1785 | /** |
1786 | * struct renamedata - contains all information required for renaming |
1787 | * @old_mnt_idmap: idmap of the old mount the inode was found from |
1788 | * @old_dir: parent of source |
1789 | * @old_dentry: source |
1790 | * @new_mnt_idmap: idmap of the new mount the inode was found from |
1791 | * @new_dir: parent of destination |
1792 | * @new_dentry: destination |
1793 | * @delegated_inode: returns an inode needing a delegation break |
1794 | * @flags: rename flags |
1795 | */ |
1796 | struct renamedata { |
1797 | struct mnt_idmap *old_mnt_idmap; |
1798 | struct inode *old_dir; |
1799 | struct dentry *old_dentry; |
1800 | struct mnt_idmap *new_mnt_idmap; |
1801 | struct inode *new_dir; |
1802 | struct dentry *new_dentry; |
1803 | struct inode **delegated_inode; |
1804 | unsigned int flags; |
1805 | } __randomize_layout; |
1806 | |
1807 | int vfs_rename(struct renamedata *); |
1808 | |
1809 | static inline int vfs_whiteout(struct mnt_idmap *idmap, |
1810 | struct inode *dir, struct dentry *dentry) |
1811 | { |
1812 | return vfs_mknod(idmap, dir, dentry, S_IFCHR | WHITEOUT_MODE, |
1813 | WHITEOUT_DEV); |
1814 | } |
1815 | |
1816 | struct file *kernel_tmpfile_open(struct mnt_idmap *idmap, |
1817 | const struct path *parentpath, |
1818 | umode_t mode, int open_flag, |
1819 | const struct cred *cred); |
1820 | struct file *kernel_file_open(const struct path *path, int flags, |
1821 | struct inode *inode, const struct cred *cred); |
1822 | |
1823 | int vfs_mkobj(struct dentry *, umode_t, |
1824 | int (*f)(struct dentry *, umode_t, void *), |
1825 | void *); |
1826 | |
1827 | int vfs_fchown(struct file *file, uid_t user, gid_t group); |
1828 | int vfs_fchmod(struct file *file, umode_t mode); |
1829 | int vfs_utimes(const struct path *path, struct timespec64 *times); |
1830 | |
1831 | extern long vfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg); |
1832 | |
1833 | #ifdef CONFIG_COMPAT |
1834 | extern long compat_ptr_ioctl(struct file *file, unsigned int cmd, |
1835 | unsigned long arg); |
1836 | #else |
1837 | #define compat_ptr_ioctl NULL |
1838 | #endif |
1839 | |
1840 | /* |
1841 | * VFS file helper functions. |
1842 | */ |
1843 | void inode_init_owner(struct mnt_idmap *idmap, struct inode *inode, |
1844 | const struct inode *dir, umode_t mode); |
1845 | extern bool may_open_dev(const struct path *path); |
1846 | umode_t mode_strip_sgid(struct mnt_idmap *idmap, |
1847 | const struct inode *dir, umode_t mode); |
1848 | |
1849 | /* |
1850 | * This is the "filldir" function type, used by readdir() to let |
1851 | * the kernel specify what kind of dirent layout it wants to have. |
1852 | * This allows the kernel to read directories into kernel space or |
1853 | * to have different dirent layouts depending on the binary type. |
1854 | * Return 'true' to keep going and 'false' if there are no more entries. |
1855 | */ |
1856 | struct dir_context; |
1857 | typedef bool (*filldir_t)(struct dir_context *, const char *, int, loff_t, u64, |
1858 | unsigned); |
1859 | |
1860 | struct dir_context { |
1861 | filldir_t actor; |
1862 | loff_t pos; |
1863 | }; |
1864 | |
1865 | /* |
1866 | * These flags let !MMU mmap() govern direct device mapping vs immediate |
1867 | * copying more easily for MAP_PRIVATE, especially for ROM filesystems. |
1868 | * |
1869 | * NOMMU_MAP_COPY: Copy can be mapped (MAP_PRIVATE) |
1870 | * NOMMU_MAP_DIRECT: Can be mapped directly (MAP_SHARED) |
1871 | * NOMMU_MAP_READ: Can be mapped for reading |
1872 | * NOMMU_MAP_WRITE: Can be mapped for writing |
1873 | * NOMMU_MAP_EXEC: Can be mapped for execution |
1874 | */ |
1875 | #define NOMMU_MAP_COPY 0x00000001 |
1876 | #define NOMMU_MAP_DIRECT 0x00000008 |
1877 | #define NOMMU_MAP_READ VM_MAYREAD |
1878 | #define NOMMU_MAP_WRITE VM_MAYWRITE |
1879 | #define NOMMU_MAP_EXEC VM_MAYEXEC |
1880 | |
1881 | #define NOMMU_VMFLAGS \ |
1882 | (NOMMU_MAP_READ | NOMMU_MAP_WRITE | NOMMU_MAP_EXEC) |
1883 | |
1884 | /* |
1885 | * These flags control the behavior of the remap_file_range function pointer. |
1886 | * If it is called with len == 0 that means "remap to end of source file". |
1887 | * See Documentation/filesystems/vfs.rst for more details about this call. |
1888 | * |
1889 | * REMAP_FILE_DEDUP: only remap if contents identical (i.e. deduplicate) |
1890 | * REMAP_FILE_CAN_SHORTEN: caller can handle a shortened request |
1891 | */ |
1892 | #define REMAP_FILE_DEDUP (1 << 0) |
1893 | #define REMAP_FILE_CAN_SHORTEN (1 << 1) |
1894 | |
1895 | /* |
1896 | * These flags signal that the caller is ok with altering various aspects of |
1897 | * the behavior of the remap operation. The changes must be made by the |
1898 | * implementation; the vfs remap helper functions can take advantage of them. |
1899 | * Flags in this category exist to preserve the quirky behavior of the hoisted |
1900 | * btrfs clone/dedupe ioctls. |
1901 | */ |
1902 | #define REMAP_FILE_ADVISORY (REMAP_FILE_CAN_SHORTEN) |
1903 | |
1904 | /* |
1905 | * These flags control the behavior of vfs_copy_file_range(). |
1906 | * They are not available to the user via syscall. |
1907 | * |
1908 | * COPY_FILE_SPLICE: call splice direct instead of fs clone/copy ops |
1909 | */ |
1910 | #define COPY_FILE_SPLICE (1 << 0) |
1911 | |
1912 | struct iov_iter; |
1913 | struct io_uring_cmd; |
1914 | struct offset_ctx; |
1915 | |
1916 | struct file_operations { |
1917 | struct module *owner; |
1918 | loff_t (*llseek) (struct file *, loff_t, int); |
1919 | ssize_t (*read) (struct file *, char __user *, size_t, loff_t *); |
1920 | ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *); |
1921 | ssize_t (*read_iter) (struct kiocb *, struct iov_iter *); |
1922 | ssize_t (*write_iter) (struct kiocb *, struct iov_iter *); |
1923 | int (*iopoll)(struct kiocb *kiocb, struct io_comp_batch *, |
1924 | unsigned int flags); |
1925 | int (*iterate_shared) (struct file *, struct dir_context *); |
1926 | __poll_t (*poll) (struct file *, struct poll_table_struct *); |
1927 | long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long); |
1928 | long (*compat_ioctl) (struct file *, unsigned int, unsigned long); |
1929 | int (*mmap) (struct file *, struct vm_area_struct *); |
1930 | unsigned long mmap_supported_flags; |
1931 | int (*open) (struct inode *, struct file *); |
1932 | int (*flush) (struct file *, fl_owner_t id); |
1933 | int (*release) (struct inode *, struct file *); |
1934 | int (*fsync) (struct file *, loff_t, loff_t, int datasync); |
1935 | int (*fasync) (int, struct file *, int); |
1936 | int (*lock) (struct file *, int, struct file_lock *); |
1937 | unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long); |
1938 | int (*check_flags)(int); |
1939 | int (*flock) (struct file *, int, struct file_lock *); |
1940 | ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int); |
1941 | ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int); |
1942 | void (*splice_eof)(struct file *file); |
1943 | int (*setlease)(struct file *, int, struct file_lock **, void **); |
1944 | long (*fallocate)(struct file *file, int mode, loff_t offset, |
1945 | loff_t len); |
1946 | void (*show_fdinfo)(struct seq_file *m, struct file *f); |
1947 | #ifndef CONFIG_MMU |
1948 | unsigned (*mmap_capabilities)(struct file *); |
1949 | #endif |
1950 | ssize_t (*copy_file_range)(struct file *, loff_t, struct file *, |
1951 | loff_t, size_t, unsigned int); |
1952 | loff_t (*remap_file_range)(struct file *file_in, loff_t pos_in, |
1953 | struct file *file_out, loff_t pos_out, |
1954 | loff_t len, unsigned int remap_flags); |
1955 | int (*fadvise)(struct file *, loff_t, loff_t, int); |
1956 | int (*uring_cmd)(struct io_uring_cmd *ioucmd, unsigned int issue_flags); |
1957 | int (*uring_cmd_iopoll)(struct io_uring_cmd *, struct io_comp_batch *, |
1958 | unsigned int poll_flags); |
1959 | } __randomize_layout; |
1960 | |
1961 | /* Wrap a directory iterator that needs exclusive inode access */ |
1962 | int wrap_directory_iterator(struct file *, struct dir_context *, |
1963 | int (*) (struct file *, struct dir_context *)); |
1964 | #define WRAP_DIR_ITER(x) \ |
1965 | static int shared_##x(struct file *file , struct dir_context *ctx) \ |
1966 | { return wrap_directory_iterator(file, ctx, x); } |
1967 | |
1968 | struct inode_operations { |
1969 | struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int); |
1970 | const char * (*get_link) (struct dentry *, struct inode *, struct delayed_call *); |
1971 | int (*permission) (struct mnt_idmap *, struct inode *, int); |
1972 | struct posix_acl * (*get_inode_acl)(struct inode *, int, bool); |
1973 | |
1974 | int (*readlink) (struct dentry *, char __user *,int); |
1975 | |
1976 | int (*create) (struct mnt_idmap *, struct inode *,struct dentry *, |
1977 | umode_t, bool); |
1978 | int (*link) (struct dentry *,struct inode *,struct dentry *); |
1979 | int (*unlink) (struct inode *,struct dentry *); |
1980 | int (*symlink) (struct mnt_idmap *, struct inode *,struct dentry *, |
1981 | const char *); |
1982 | int (*mkdir) (struct mnt_idmap *, struct inode *,struct dentry *, |
1983 | umode_t); |
1984 | int (*rmdir) (struct inode *,struct dentry *); |
1985 | int (*mknod) (struct mnt_idmap *, struct inode *,struct dentry *, |
1986 | umode_t,dev_t); |
1987 | int (*rename) (struct mnt_idmap *, struct inode *, struct dentry *, |
1988 | struct inode *, struct dentry *, unsigned int); |
1989 | int (*setattr) (struct mnt_idmap *, struct dentry *, struct iattr *); |
1990 | int (*getattr) (struct mnt_idmap *, const struct path *, |
1991 | struct kstat *, u32, unsigned int); |
1992 | ssize_t (*listxattr) (struct dentry *, char *, size_t); |
1993 | int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start, |
1994 | u64 len); |
1995 | int (*update_time)(struct inode *, int); |
1996 | int (*atomic_open)(struct inode *, struct dentry *, |
1997 | struct file *, unsigned open_flag, |
1998 | umode_t create_mode); |
1999 | int (*tmpfile) (struct mnt_idmap *, struct inode *, |
2000 | struct file *, umode_t); |
2001 | struct posix_acl *(*get_acl)(struct mnt_idmap *, struct dentry *, |
2002 | int); |
2003 | int (*set_acl)(struct mnt_idmap *, struct dentry *, |
2004 | struct posix_acl *, int); |
2005 | int (*fileattr_set)(struct mnt_idmap *idmap, |
2006 | struct dentry *dentry, struct fileattr *fa); |
2007 | int (*fileattr_get)(struct dentry *dentry, struct fileattr *fa); |
2008 | struct offset_ctx *(*get_offset_ctx)(struct inode *inode); |
2009 | } ____cacheline_aligned; |
2010 | |
2011 | static inline ssize_t call_read_iter(struct file *file, struct kiocb *kio, |
2012 | struct iov_iter *iter) |
2013 | { |
2014 | return file->f_op->read_iter(kio, iter); |
2015 | } |
2016 | |
2017 | static inline ssize_t call_write_iter(struct file *file, struct kiocb *kio, |
2018 | struct iov_iter *iter) |
2019 | { |
2020 | return file->f_op->write_iter(kio, iter); |
2021 | } |
2022 | |
2023 | static inline int call_mmap(struct file *file, struct vm_area_struct *vma) |
2024 | { |
2025 | return file->f_op->mmap(file, vma); |
2026 | } |
2027 | |
2028 | extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *); |
2029 | extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *); |
2030 | extern ssize_t vfs_copy_file_range(struct file *, loff_t , struct file *, |
2031 | loff_t, size_t, unsigned int); |
2032 | extern ssize_t generic_copy_file_range(struct file *file_in, loff_t pos_in, |
2033 | struct file *file_out, loff_t pos_out, |
2034 | size_t len, unsigned int flags); |
2035 | int __generic_remap_file_range_prep(struct file *file_in, loff_t pos_in, |
2036 | struct file *file_out, loff_t pos_out, |
2037 | loff_t *len, unsigned int remap_flags, |
2038 | const struct iomap_ops *dax_read_ops); |
2039 | int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in, |
2040 | struct file *file_out, loff_t pos_out, |
2041 | loff_t *count, unsigned int remap_flags); |
2042 | extern loff_t do_clone_file_range(struct file *file_in, loff_t pos_in, |
2043 | struct file *file_out, loff_t pos_out, |
2044 | loff_t len, unsigned int remap_flags); |
2045 | extern loff_t vfs_clone_file_range(struct file *file_in, loff_t pos_in, |
2046 | struct file *file_out, loff_t pos_out, |
2047 | loff_t len, unsigned int remap_flags); |
2048 | extern int vfs_dedupe_file_range(struct file *file, |
2049 | struct file_dedupe_range *same); |
2050 | extern loff_t vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos, |
2051 | struct file *dst_file, loff_t dst_pos, |
2052 | loff_t len, unsigned int remap_flags); |
2053 | |
2054 | enum freeze_holder { |
2055 | FREEZE_HOLDER_KERNEL = (1U << 0), |
2056 | FREEZE_HOLDER_USERSPACE = (1U << 1), |
2057 | }; |
2058 | |
2059 | struct super_operations { |
2060 | struct inode *(*alloc_inode)(struct super_block *sb); |
2061 | void (*destroy_inode)(struct inode *); |
2062 | void (*free_inode)(struct inode *); |
2063 | |
2064 | void (*dirty_inode) (struct inode *, int flags); |
2065 | int (*write_inode) (struct inode *, struct writeback_control *wbc); |
2066 | int (*drop_inode) (struct inode *); |
2067 | void (*evict_inode) (struct inode *); |
2068 | void (*put_super) (struct super_block *); |
2069 | int (*sync_fs)(struct super_block *sb, int wait); |
2070 | int (*freeze_super) (struct super_block *, enum freeze_holder who); |
2071 | int (*freeze_fs) (struct super_block *); |
2072 | int (*thaw_super) (struct super_block *, enum freeze_holder who); |
2073 | int (*unfreeze_fs) (struct super_block *); |
2074 | int (*statfs) (struct dentry *, struct kstatfs *); |
2075 | int (*remount_fs) (struct super_block *, int *, char *); |
2076 | void (*umount_begin) (struct super_block *); |
2077 | |
2078 | int (*show_options)(struct seq_file *, struct dentry *); |
2079 | int (*show_devname)(struct seq_file *, struct dentry *); |
2080 | int (*show_path)(struct seq_file *, struct dentry *); |
2081 | int (*show_stats)(struct seq_file *, struct dentry *); |
2082 | #ifdef CONFIG_QUOTA |
2083 | ssize_t (*quota_read)(struct super_block *, int, char *, size_t, loff_t); |
2084 | ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t); |
2085 | struct dquot **(*get_dquots)(struct inode *); |
2086 | #endif |
2087 | long (*nr_cached_objects)(struct super_block *, |
2088 | struct shrink_control *); |
2089 | long (*free_cached_objects)(struct super_block *, |
2090 | struct shrink_control *); |
2091 | void (*shutdown)(struct super_block *sb); |
2092 | }; |
2093 | |
2094 | /* |
2095 | * Inode flags - they have no relation to superblock flags now |
2096 | */ |
2097 | #define S_SYNC (1 << 0) /* Writes are synced at once */ |
2098 | #define S_NOATIME (1 << 1) /* Do not update access times */ |
2099 | #define S_APPEND (1 << 2) /* Append-only file */ |
2100 | #define S_IMMUTABLE (1 << 3) /* Immutable file */ |
2101 | #define S_DEAD (1 << 4) /* removed, but still open directory */ |
2102 | #define S_NOQUOTA (1 << 5) /* Inode is not counted to quota */ |
2103 | #define S_DIRSYNC (1 << 6) /* Directory modifications are synchronous */ |
2104 | #define S_NOCMTIME (1 << 7) /* Do not update file c/mtime */ |
2105 | #define S_SWAPFILE (1 << 8) /* Do not truncate: swapon got its bmaps */ |
2106 | #define S_PRIVATE (1 << 9) /* Inode is fs-internal */ |
2107 | #define S_IMA (1 << 10) /* Inode has an associated IMA struct */ |
2108 | #define S_AUTOMOUNT (1 << 11) /* Automount/referral quasi-directory */ |
2109 | #define S_NOSEC (1 << 12) /* no suid or xattr security attributes */ |
2110 | #ifdef CONFIG_FS_DAX |
2111 | #define S_DAX (1 << 13) /* Direct Access, avoiding the page cache */ |
2112 | #else |
2113 | #define S_DAX 0 /* Make all the DAX code disappear */ |
2114 | #endif |
2115 | #define S_ENCRYPTED (1 << 14) /* Encrypted file (using fs/crypto/) */ |
2116 | #define S_CASEFOLD (1 << 15) /* Casefolded file */ |
2117 | #define S_VERITY (1 << 16) /* Verity file (using fs/verity/) */ |
2118 | #define S_KERNEL_FILE (1 << 17) /* File is in use by the kernel (eg. fs/cachefiles) */ |
2119 | |
2120 | /* |
2121 | * Note that nosuid etc flags are inode-specific: setting some file-system |
2122 | * flags just means all the inodes inherit those flags by default. It might be |
2123 | * possible to override it selectively if you really wanted to with some |
2124 | * ioctl() that is not currently implemented. |
2125 | * |
2126 | * Exception: SB_RDONLY is always applied to the entire file system. |
2127 | * |
2128 | * Unfortunately, it is possible to change a filesystems flags with it mounted |
2129 | * with files in use. This means that all of the inodes will not have their |
2130 | * i_flags updated. Hence, i_flags no longer inherit the superblock mount |
2131 | * flags, so these have to be checked separately. -- rmk@arm.uk.linux.org |
2132 | */ |
2133 | #define __IS_FLG(inode, flg) ((inode)->i_sb->s_flags & (flg)) |
2134 | |
2135 | static inline bool sb_rdonly(const struct super_block *sb) { return sb->s_flags & SB_RDONLY; } |
2136 | #define IS_RDONLY(inode) sb_rdonly((inode)->i_sb) |
2137 | #define IS_SYNC(inode) (__IS_FLG(inode, SB_SYNCHRONOUS) || \ |
2138 | ((inode)->i_flags & S_SYNC)) |
2139 | #define IS_DIRSYNC(inode) (__IS_FLG(inode, SB_SYNCHRONOUS|SB_DIRSYNC) || \ |
2140 | ((inode)->i_flags & (S_SYNC|S_DIRSYNC))) |
2141 | #define IS_MANDLOCK(inode) __IS_FLG(inode, SB_MANDLOCK) |
2142 | #define IS_NOATIME(inode) __IS_FLG(inode, SB_RDONLY|SB_NOATIME) |
2143 | #define IS_I_VERSION(inode) __IS_FLG(inode, SB_I_VERSION) |
2144 | |
2145 | #define IS_NOQUOTA(inode) ((inode)->i_flags & S_NOQUOTA) |
2146 | #define IS_APPEND(inode) ((inode)->i_flags & S_APPEND) |
2147 | #define IS_IMMUTABLE(inode) ((inode)->i_flags & S_IMMUTABLE) |
2148 | |
2149 | #ifdef CONFIG_FS_POSIX_ACL |
2150 | #define IS_POSIXACL(inode) __IS_FLG(inode, SB_POSIXACL) |
2151 | #else |
2152 | #define IS_POSIXACL(inode) 0 |
2153 | #endif |
2154 | |
2155 | #define IS_DEADDIR(inode) ((inode)->i_flags & S_DEAD) |
2156 | #define IS_NOCMTIME(inode) ((inode)->i_flags & S_NOCMTIME) |
2157 | #define IS_SWAPFILE(inode) ((inode)->i_flags & S_SWAPFILE) |
2158 | #define IS_PRIVATE(inode) ((inode)->i_flags & S_PRIVATE) |
2159 | #define IS_IMA(inode) ((inode)->i_flags & S_IMA) |
2160 | #define IS_AUTOMOUNT(inode) ((inode)->i_flags & S_AUTOMOUNT) |
2161 | #define IS_NOSEC(inode) ((inode)->i_flags & S_NOSEC) |
2162 | #define IS_DAX(inode) ((inode)->i_flags & S_DAX) |
2163 | #define IS_ENCRYPTED(inode) ((inode)->i_flags & S_ENCRYPTED) |
2164 | #define IS_CASEFOLDED(inode) ((inode)->i_flags & S_CASEFOLD) |
2165 | #define IS_VERITY(inode) ((inode)->i_flags & S_VERITY) |
2166 | |
2167 | #define IS_WHITEOUT(inode) (S_ISCHR(inode->i_mode) && \ |
2168 | (inode)->i_rdev == WHITEOUT_DEV) |
2169 | |
2170 | static inline bool HAS_UNMAPPED_ID(struct mnt_idmap *idmap, |
2171 | struct inode *inode) |
2172 | { |
2173 | return !vfsuid_valid(uid: i_uid_into_vfsuid(idmap, inode)) || |
2174 | !vfsgid_valid(gid: i_gid_into_vfsgid(idmap, inode)); |
2175 | } |
2176 | |
2177 | static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp) |
2178 | { |
2179 | *kiocb = (struct kiocb) { |
2180 | .ki_filp = filp, |
2181 | .ki_flags = filp->f_iocb_flags, |
2182 | .ki_ioprio = get_current_ioprio(), |
2183 | }; |
2184 | } |
2185 | |
2186 | static inline void kiocb_clone(struct kiocb *kiocb, struct kiocb *kiocb_src, |
2187 | struct file *filp) |
2188 | { |
2189 | *kiocb = (struct kiocb) { |
2190 | .ki_filp = filp, |
2191 | .ki_flags = kiocb_src->ki_flags, |
2192 | .ki_ioprio = kiocb_src->ki_ioprio, |
2193 | .ki_pos = kiocb_src->ki_pos, |
2194 | }; |
2195 | } |
2196 | |
2197 | /* |
2198 | * Inode state bits. Protected by inode->i_lock |
2199 | * |
2200 | * Four bits determine the dirty state of the inode: I_DIRTY_SYNC, |
2201 | * I_DIRTY_DATASYNC, I_DIRTY_PAGES, and I_DIRTY_TIME. |
2202 | * |
2203 | * Four bits define the lifetime of an inode. Initially, inodes are I_NEW, |
2204 | * until that flag is cleared. I_WILL_FREE, I_FREEING and I_CLEAR are set at |
2205 | * various stages of removing an inode. |
2206 | * |
2207 | * Two bits are used for locking and completion notification, I_NEW and I_SYNC. |
2208 | * |
2209 | * I_DIRTY_SYNC Inode is dirty, but doesn't have to be written on |
2210 | * fdatasync() (unless I_DIRTY_DATASYNC is also set). |
2211 | * Timestamp updates are the usual cause. |
2212 | * I_DIRTY_DATASYNC Data-related inode changes pending. We keep track of |
2213 | * these changes separately from I_DIRTY_SYNC so that we |
2214 | * don't have to write inode on fdatasync() when only |
2215 | * e.g. the timestamps have changed. |
2216 | * I_DIRTY_PAGES Inode has dirty pages. Inode itself may be clean. |
2217 | * I_DIRTY_TIME The inode itself has dirty timestamps, and the |
2218 | * lazytime mount option is enabled. We keep track of this |
2219 | * separately from I_DIRTY_SYNC in order to implement |
2220 | * lazytime. This gets cleared if I_DIRTY_INODE |
2221 | * (I_DIRTY_SYNC and/or I_DIRTY_DATASYNC) gets set. But |
2222 | * I_DIRTY_TIME can still be set if I_DIRTY_SYNC is already |
2223 | * in place because writeback might already be in progress |
2224 | * and we don't want to lose the time update |
2225 | * I_NEW Serves as both a mutex and completion notification. |
2226 | * New inodes set I_NEW. If two processes both create |
2227 | * the same inode, one of them will release its inode and |
2228 | * wait for I_NEW to be released before returning. |
2229 | * Inodes in I_WILL_FREE, I_FREEING or I_CLEAR state can |
2230 | * also cause waiting on I_NEW, without I_NEW actually |
2231 | * being set. find_inode() uses this to prevent returning |
2232 | * nearly-dead inodes. |
2233 | * I_WILL_FREE Must be set when calling write_inode_now() if i_count |
2234 | * is zero. I_FREEING must be set when I_WILL_FREE is |
2235 | * cleared. |
2236 | * I_FREEING Set when inode is about to be freed but still has dirty |
2237 | * pages or buffers attached or the inode itself is still |
2238 | * dirty. |
2239 | * I_CLEAR Added by clear_inode(). In this state the inode is |
2240 | * clean and can be destroyed. Inode keeps I_FREEING. |
2241 | * |
2242 | * Inodes that are I_WILL_FREE, I_FREEING or I_CLEAR are |
2243 | * prohibited for many purposes. iget() must wait for |
2244 | * the inode to be completely released, then create it |
2245 | * anew. Other functions will just ignore such inodes, |
2246 | * if appropriate. I_NEW is used for waiting. |
2247 | * |
2248 | * I_SYNC Writeback of inode is running. The bit is set during |
2249 | * data writeback, and cleared with a wakeup on the bit |
2250 | * address once it is done. The bit is also used to pin |
2251 | * the inode in memory for flusher thread. |
2252 | * |
2253 | * I_REFERENCED Marks the inode as recently references on the LRU list. |
2254 | * |
2255 | * I_DIO_WAKEUP Never set. Only used as a key for wait_on_bit(). |
2256 | * |
2257 | * I_WB_SWITCH Cgroup bdi_writeback switching in progress. Used to |
2258 | * synchronize competing switching instances and to tell |
2259 | * wb stat updates to grab the i_pages lock. See |
2260 | * inode_switch_wbs_work_fn() for details. |
2261 | * |
2262 | * I_OVL_INUSE Used by overlayfs to get exclusive ownership on upper |
2263 | * and work dirs among overlayfs mounts. |
2264 | * |
2265 | * I_CREATING New object's inode in the middle of setting up. |
2266 | * |
2267 | * I_DONTCACHE Evict inode as soon as it is not used anymore. |
2268 | * |
2269 | * I_SYNC_QUEUED Inode is queued in b_io or b_more_io writeback lists. |
2270 | * Used to detect that mark_inode_dirty() should not move |
2271 | * inode between dirty lists. |
2272 | * |
2273 | * I_PINNING_FSCACHE_WB Inode is pinning an fscache object for writeback. |
2274 | * |
2275 | * Q: What is the difference between I_WILL_FREE and I_FREEING? |
2276 | */ |
2277 | #define I_DIRTY_SYNC (1 << 0) |
2278 | #define I_DIRTY_DATASYNC (1 << 1) |
2279 | #define I_DIRTY_PAGES (1 << 2) |
2280 | #define __I_NEW 3 |
2281 | #define I_NEW (1 << __I_NEW) |
2282 | #define I_WILL_FREE (1 << 4) |
2283 | #define I_FREEING (1 << 5) |
2284 | #define I_CLEAR (1 << 6) |
2285 | #define __I_SYNC 7 |
2286 | #define I_SYNC (1 << __I_SYNC) |
2287 | #define I_REFERENCED (1 << 8) |
2288 | #define __I_DIO_WAKEUP 9 |
2289 | #define I_DIO_WAKEUP (1 << __I_DIO_WAKEUP) |
2290 | #define I_LINKABLE (1 << 10) |
2291 | #define I_DIRTY_TIME (1 << 11) |
2292 | #define I_WB_SWITCH (1 << 13) |
2293 | #define I_OVL_INUSE (1 << 14) |
2294 | #define I_CREATING (1 << 15) |
2295 | #define I_DONTCACHE (1 << 16) |
2296 | #define I_SYNC_QUEUED (1 << 17) |
2297 | #define I_PINNING_FSCACHE_WB (1 << 18) |
2298 | |
2299 | #define I_DIRTY_INODE (I_DIRTY_SYNC | I_DIRTY_DATASYNC) |
2300 | #define I_DIRTY (I_DIRTY_INODE | I_DIRTY_PAGES) |
2301 | #define I_DIRTY_ALL (I_DIRTY | I_DIRTY_TIME) |
2302 | |
2303 | extern void __mark_inode_dirty(struct inode *, int); |
2304 | static inline void mark_inode_dirty(struct inode *inode) |
2305 | { |
2306 | __mark_inode_dirty(inode, I_DIRTY); |
2307 | } |
2308 | |
2309 | static inline void mark_inode_dirty_sync(struct inode *inode) |
2310 | { |
2311 | __mark_inode_dirty(inode, I_DIRTY_SYNC); |
2312 | } |
2313 | |
2314 | /* |
2315 | * Returns true if the given inode itself only has dirty timestamps (its pages |
2316 | * may still be dirty) and isn't currently being allocated or freed. |
2317 | * Filesystems should call this if when writing an inode when lazytime is |
2318 | * enabled, they want to opportunistically write the timestamps of other inodes |
2319 | * located very nearby on-disk, e.g. in the same inode block. This returns true |
2320 | * if the given inode is in need of such an opportunistic update. Requires |
2321 | * i_lock, or at least later re-checking under i_lock. |
2322 | */ |
2323 | static inline bool inode_is_dirtytime_only(struct inode *inode) |
2324 | { |
2325 | return (inode->i_state & (I_DIRTY_TIME | I_NEW | |
2326 | I_FREEING | I_WILL_FREE)) == I_DIRTY_TIME; |
2327 | } |
2328 | |
2329 | extern void inc_nlink(struct inode *inode); |
2330 | extern void drop_nlink(struct inode *inode); |
2331 | extern void clear_nlink(struct inode *inode); |
2332 | extern void set_nlink(struct inode *inode, unsigned int nlink); |
2333 | |
2334 | static inline void inode_inc_link_count(struct inode *inode) |
2335 | { |
2336 | inc_nlink(inode); |
2337 | mark_inode_dirty(inode); |
2338 | } |
2339 | |
2340 | static inline void inode_dec_link_count(struct inode *inode) |
2341 | { |
2342 | drop_nlink(inode); |
2343 | mark_inode_dirty(inode); |
2344 | } |
2345 | |
2346 | enum file_time_flags { |
2347 | S_ATIME = 1, |
2348 | S_MTIME = 2, |
2349 | S_CTIME = 4, |
2350 | S_VERSION = 8, |
2351 | }; |
2352 | |
2353 | extern bool atime_needs_update(const struct path *, struct inode *); |
2354 | extern void touch_atime(const struct path *); |
2355 | int inode_update_time(struct inode *inode, int flags); |
2356 | |
2357 | static inline void file_accessed(struct file *file) |
2358 | { |
2359 | if (!(file->f_flags & O_NOATIME)) |
2360 | touch_atime(&file->f_path); |
2361 | } |
2362 | |
2363 | extern int file_modified(struct file *file); |
2364 | int kiocb_modified(struct kiocb *iocb); |
2365 | |
2366 | int sync_inode_metadata(struct inode *inode, int wait); |
2367 | |
2368 | struct file_system_type { |
2369 | const char *name; |
2370 | int fs_flags; |
2371 | #define FS_REQUIRES_DEV 1 |
2372 | #define FS_BINARY_MOUNTDATA 2 |
2373 | #define FS_HAS_SUBTYPE 4 |
2374 | #define FS_USERNS_MOUNT 8 /* Can be mounted by userns root */ |
2375 | #define FS_DISALLOW_NOTIFY_PERM 16 /* Disable fanotify permission events */ |
2376 | #define FS_ALLOW_IDMAP 32 /* FS has been updated to handle vfs idmappings. */ |
2377 | #define FS_RENAME_DOES_D_MOVE 32768 /* FS will handle d_move() during rename() internally. */ |
2378 | int (*init_fs_context)(struct fs_context *); |
2379 | const struct fs_parameter_spec *parameters; |
2380 | struct dentry *(*mount) (struct file_system_type *, int, |
2381 | const char *, void *); |
2382 | void (*kill_sb) (struct super_block *); |
2383 | struct module *owner; |
2384 | struct file_system_type * next; |
2385 | struct hlist_head fs_supers; |
2386 | |
2387 | struct lock_class_key s_lock_key; |
2388 | struct lock_class_key s_umount_key; |
2389 | struct lock_class_key s_vfs_rename_key; |
2390 | struct lock_class_key s_writers_key[SB_FREEZE_LEVELS]; |
2391 | |
2392 | struct lock_class_key i_lock_key; |
2393 | struct lock_class_key i_mutex_key; |
2394 | struct lock_class_key invalidate_lock_key; |
2395 | struct lock_class_key i_mutex_dir_key; |
2396 | }; |
2397 | |
2398 | #define MODULE_ALIAS_FS(NAME) MODULE_ALIAS("fs-" NAME) |
2399 | |
2400 | extern struct dentry *mount_bdev(struct file_system_type *fs_type, |
2401 | int flags, const char *dev_name, void *data, |
2402 | int (*fill_super)(struct super_block *, void *, int)); |
2403 | extern struct dentry *mount_single(struct file_system_type *fs_type, |
2404 | int flags, void *data, |
2405 | int (*fill_super)(struct super_block *, void *, int)); |
2406 | extern struct dentry *mount_nodev(struct file_system_type *fs_type, |
2407 | int flags, void *data, |
2408 | int (*fill_super)(struct super_block *, void *, int)); |
2409 | extern struct dentry *mount_subtree(struct vfsmount *mnt, const char *path); |
2410 | void retire_super(struct super_block *sb); |
2411 | void generic_shutdown_super(struct super_block *sb); |
2412 | void kill_block_super(struct super_block *sb); |
2413 | void kill_anon_super(struct super_block *sb); |
2414 | void kill_litter_super(struct super_block *sb); |
2415 | void deactivate_super(struct super_block *sb); |
2416 | void deactivate_locked_super(struct super_block *sb); |
2417 | int set_anon_super(struct super_block *s, void *data); |
2418 | int set_anon_super_fc(struct super_block *s, struct fs_context *fc); |
2419 | int get_anon_bdev(dev_t *); |
2420 | void free_anon_bdev(dev_t); |
2421 | struct super_block *sget_fc(struct fs_context *fc, |
2422 | int (*test)(struct super_block *, struct fs_context *), |
2423 | int (*set)(struct super_block *, struct fs_context *)); |
2424 | struct super_block *sget(struct file_system_type *type, |
2425 | int (*test)(struct super_block *,void *), |
2426 | int (*set)(struct super_block *,void *), |
2427 | int flags, void *data); |
2428 | struct super_block *sget_dev(struct fs_context *fc, dev_t dev); |
2429 | |
2430 | /* Alas, no aliases. Too much hassle with bringing module.h everywhere */ |
2431 | #define fops_get(fops) \ |
2432 | (((fops) && try_module_get((fops)->owner) ? (fops) : NULL)) |
2433 | #define fops_put(fops) \ |
2434 | do { if (fops) module_put((fops)->owner); } while(0) |
2435 | /* |
2436 | * This one is to be used *ONLY* from ->open() instances. |
2437 | * fops must be non-NULL, pinned down *and* module dependencies |
2438 | * should be sufficient to pin the caller down as well. |
2439 | */ |
2440 | #define replace_fops(f, fops) \ |
2441 | do { \ |
2442 | struct file *__file = (f); \ |
2443 | fops_put(__file->f_op); \ |
2444 | BUG_ON(!(__file->f_op = (fops))); \ |
2445 | } while(0) |
2446 | |
2447 | extern int register_filesystem(struct file_system_type *); |
2448 | extern int unregister_filesystem(struct file_system_type *); |
2449 | extern int vfs_statfs(const struct path *, struct kstatfs *); |
2450 | extern int user_statfs(const char __user *, struct kstatfs *); |
2451 | extern int fd_statfs(int, struct kstatfs *); |
2452 | int freeze_super(struct super_block *super, enum freeze_holder who); |
2453 | int thaw_super(struct super_block *super, enum freeze_holder who); |
2454 | extern __printf(2, 3) |
2455 | int super_setup_bdi_name(struct super_block *sb, char *fmt, ...); |
2456 | extern int super_setup_bdi(struct super_block *sb); |
2457 | |
2458 | extern int current_umask(void); |
2459 | |
2460 | extern void ihold(struct inode * inode); |
2461 | extern void iput(struct inode *); |
2462 | int inode_update_timestamps(struct inode *inode, int flags); |
2463 | int generic_update_time(struct inode *, int); |
2464 | |
2465 | /* /sys/fs */ |
2466 | extern struct kobject *fs_kobj; |
2467 | |
2468 | #define MAX_RW_COUNT (INT_MAX & PAGE_MASK) |
2469 | |
2470 | /* fs/open.c */ |
2471 | struct audit_names; |
2472 | struct filename { |
2473 | const char *name; /* pointer to actual string */ |
2474 | const __user char *uptr; /* original userland pointer */ |
2475 | atomic_t refcnt; |
2476 | struct audit_names *aname; |
2477 | const char iname[]; |
2478 | }; |
2479 | static_assert(offsetof(struct filename, iname) % sizeof(long) == 0); |
2480 | |
2481 | static inline struct mnt_idmap *file_mnt_idmap(const struct file *file) |
2482 | { |
2483 | return mnt_idmap(mnt: file->f_path.mnt); |
2484 | } |
2485 | |
2486 | /** |
2487 | * is_idmapped_mnt - check whether a mount is mapped |
2488 | * @mnt: the mount to check |
2489 | * |
2490 | * If @mnt has an non @nop_mnt_idmap attached to it then @mnt is mapped. |
2491 | * |
2492 | * Return: true if mount is mapped, false if not. |
2493 | */ |
2494 | static inline bool is_idmapped_mnt(const struct vfsmount *mnt) |
2495 | { |
2496 | return mnt_idmap(mnt) != &nop_mnt_idmap; |
2497 | } |
2498 | |
2499 | extern long vfs_truncate(const struct path *, loff_t); |
2500 | int do_truncate(struct mnt_idmap *, struct dentry *, loff_t start, |
2501 | unsigned int time_attrs, struct file *filp); |
2502 | extern int vfs_fallocate(struct file *file, int mode, loff_t offset, |
2503 | loff_t len); |
2504 | extern long do_sys_open(int dfd, const char __user *filename, int flags, |
2505 | umode_t mode); |
2506 | extern struct file *file_open_name(struct filename *, int, umode_t); |
2507 | extern struct file *filp_open(const char *, int, umode_t); |
2508 | extern struct file *file_open_root(const struct path *, |
2509 | const char *, int, umode_t); |
2510 | static inline struct file *file_open_root_mnt(struct vfsmount *mnt, |
2511 | const char *name, int flags, umode_t mode) |
2512 | { |
2513 | return file_open_root(&(struct path){.mnt = mnt, .dentry = mnt->mnt_root}, |
2514 | name, flags, mode); |
2515 | } |
2516 | struct file *dentry_open(const struct path *path, int flags, |
2517 | const struct cred *creds); |
2518 | struct file *dentry_create(const struct path *path, int flags, umode_t mode, |
2519 | const struct cred *cred); |
2520 | struct file *backing_file_open(const struct path *user_path, int flags, |
2521 | const struct path *real_path, |
2522 | const struct cred *cred); |
2523 | struct path *backing_file_user_path(struct file *f); |
2524 | |
2525 | /* |
2526 | * file_user_path - get the path to display for memory mapped file |
2527 | * |
2528 | * When mmapping a file on a stackable filesystem (e.g., overlayfs), the file |
2529 | * stored in ->vm_file is a backing file whose f_inode is on the underlying |
2530 | * filesystem. When the mapped file path is displayed to user (e.g. via |
2531 | * /proc/<pid>/maps), this helper should be used to get the path to display |
2532 | * to the user, which is the path of the fd that user has requested to map. |
2533 | */ |
2534 | static inline const struct path *file_user_path(struct file *f) |
2535 | { |
2536 | if (unlikely(f->f_mode & FMODE_BACKING)) |
2537 | return backing_file_user_path(f); |
2538 | return &f->f_path; |
2539 | } |
2540 | |
2541 | static inline struct file *file_clone_open(struct file *file) |
2542 | { |
2543 | return dentry_open(path: &file->f_path, flags: file->f_flags, creds: file->f_cred); |
2544 | } |
2545 | extern int filp_close(struct file *, fl_owner_t id); |
2546 | |
2547 | extern struct filename *getname_flags(const char __user *, int, int *); |
2548 | extern struct filename *getname_uflags(const char __user *, int); |
2549 | extern struct filename *getname(const char __user *); |
2550 | extern struct filename *getname_kernel(const char *); |
2551 | extern void putname(struct filename *name); |
2552 | |
2553 | extern int finish_open(struct file *file, struct dentry *dentry, |
2554 | int (*open)(struct inode *, struct file *)); |
2555 | extern int finish_no_open(struct file *file, struct dentry *dentry); |
2556 | |
2557 | /* Helper for the simple case when original dentry is used */ |
2558 | static inline int finish_open_simple(struct file *file, int error) |
2559 | { |
2560 | if (error) |
2561 | return error; |
2562 | |
2563 | return finish_open(file, dentry: file->f_path.dentry, NULL); |
2564 | } |
2565 | |
2566 | /* fs/dcache.c */ |
2567 | extern void __init vfs_caches_init_early(void); |
2568 | extern void __init vfs_caches_init(void); |
2569 | |
2570 | extern struct kmem_cache *names_cachep; |
2571 | |
2572 | #define __getname() kmem_cache_alloc(names_cachep, GFP_KERNEL) |
2573 | #define __putname(name) kmem_cache_free(names_cachep, (void *)(name)) |
2574 | |
2575 | extern struct super_block *blockdev_superblock; |
2576 | static inline bool sb_is_blkdev_sb(struct super_block *sb) |
2577 | { |
2578 | return IS_ENABLED(CONFIG_BLOCK) && sb == blockdev_superblock; |
2579 | } |
2580 | |
2581 | void emergency_thaw_all(void); |
2582 | extern int sync_filesystem(struct super_block *); |
2583 | extern const struct file_operations def_blk_fops; |
2584 | extern const struct file_operations def_chr_fops; |
2585 | |
2586 | /* fs/char_dev.c */ |
2587 | #define CHRDEV_MAJOR_MAX 512 |
2588 | /* Marks the bottom of the first segment of free char majors */ |
2589 | #define CHRDEV_MAJOR_DYN_END 234 |
2590 | /* Marks the top and bottom of the second segment of free char majors */ |
2591 | #define CHRDEV_MAJOR_DYN_EXT_START 511 |
2592 | #define CHRDEV_MAJOR_DYN_EXT_END 384 |
2593 | |
2594 | extern int alloc_chrdev_region(dev_t *, unsigned, unsigned, const char *); |
2595 | extern int register_chrdev_region(dev_t, unsigned, const char *); |
2596 | extern int __register_chrdev(unsigned int major, unsigned int baseminor, |
2597 | unsigned int count, const char *name, |
2598 | const struct file_operations *fops); |
2599 | extern void __unregister_chrdev(unsigned int major, unsigned int baseminor, |
2600 | unsigned int count, const char *name); |
2601 | extern void unregister_chrdev_region(dev_t, unsigned); |
2602 | extern void chrdev_show(struct seq_file *,off_t); |
2603 | |
2604 | static inline int register_chrdev(unsigned int major, const char *name, |
2605 | const struct file_operations *fops) |
2606 | { |
2607 | return __register_chrdev(major, baseminor: 0, count: 256, name, fops); |
2608 | } |
2609 | |
2610 | static inline void unregister_chrdev(unsigned int major, const char *name) |
2611 | { |
2612 | __unregister_chrdev(major, baseminor: 0, count: 256, name); |
2613 | } |
2614 | |
2615 | extern void init_special_inode(struct inode *, umode_t, dev_t); |
2616 | |
2617 | /* Invalid inode operations -- fs/bad_inode.c */ |
2618 | extern void make_bad_inode(struct inode *); |
2619 | extern bool is_bad_inode(struct inode *); |
2620 | |
2621 | extern int __must_check file_fdatawait_range(struct file *file, loff_t lstart, |
2622 | loff_t lend); |
2623 | extern int __must_check file_check_and_advance_wb_err(struct file *file); |
2624 | extern int __must_check file_write_and_wait_range(struct file *file, |
2625 | loff_t start, loff_t end); |
2626 | |
2627 | static inline int file_write_and_wait(struct file *file) |
2628 | { |
2629 | return file_write_and_wait_range(file, start: 0, LLONG_MAX); |
2630 | } |
2631 | |
2632 | extern int vfs_fsync_range(struct file *file, loff_t start, loff_t end, |
2633 | int datasync); |
2634 | extern int vfs_fsync(struct file *file, int datasync); |
2635 | |
2636 | extern int sync_file_range(struct file *file, loff_t offset, loff_t nbytes, |
2637 | unsigned int flags); |
2638 | |
2639 | static inline bool iocb_is_dsync(const struct kiocb *iocb) |
2640 | { |
2641 | return (iocb->ki_flags & IOCB_DSYNC) || |
2642 | IS_SYNC(iocb->ki_filp->f_mapping->host); |
2643 | } |
2644 | |
2645 | /* |
2646 | * Sync the bytes written if this was a synchronous write. Expect ki_pos |
2647 | * to already be updated for the write, and will return either the amount |
2648 | * of bytes passed in, or an error if syncing the file failed. |
2649 | */ |
2650 | static inline ssize_t generic_write_sync(struct kiocb *iocb, ssize_t count) |
2651 | { |
2652 | if (iocb_is_dsync(iocb)) { |
2653 | int ret = vfs_fsync_range(file: iocb->ki_filp, |
2654 | start: iocb->ki_pos - count, end: iocb->ki_pos - 1, |
2655 | datasync: (iocb->ki_flags & IOCB_SYNC) ? 0 : 1); |
2656 | if (ret) |
2657 | return ret; |
2658 | } |
2659 | |
2660 | return count; |
2661 | } |
2662 | |
2663 | extern void emergency_sync(void); |
2664 | extern void emergency_remount(void); |
2665 | |
2666 | #ifdef CONFIG_BLOCK |
2667 | extern int bmap(struct inode *inode, sector_t *block); |
2668 | #else |
2669 | static inline int bmap(struct inode *inode, sector_t *block) |
2670 | { |
2671 | return -EINVAL; |
2672 | } |
2673 | #endif |
2674 | |
2675 | int notify_change(struct mnt_idmap *, struct dentry *, |
2676 | struct iattr *, struct inode **); |
2677 | int inode_permission(struct mnt_idmap *, struct inode *, int); |
2678 | int generic_permission(struct mnt_idmap *, struct inode *, int); |
2679 | static inline int file_permission(struct file *file, int mask) |
2680 | { |
2681 | return inode_permission(file_mnt_idmap(file), |
2682 | file_inode(f: file), mask); |
2683 | } |
2684 | static inline int path_permission(const struct path *path, int mask) |
2685 | { |
2686 | return inode_permission(mnt_idmap(mnt: path->mnt), |
2687 | d_inode(dentry: path->dentry), mask); |
2688 | } |
2689 | int __check_sticky(struct mnt_idmap *idmap, struct inode *dir, |
2690 | struct inode *inode); |
2691 | |
2692 | static inline bool execute_ok(struct inode *inode) |
2693 | { |
2694 | return (inode->i_mode & S_IXUGO) || S_ISDIR(inode->i_mode); |
2695 | } |
2696 | |
2697 | static inline bool inode_wrong_type(const struct inode *inode, umode_t mode) |
2698 | { |
2699 | return (inode->i_mode ^ mode) & S_IFMT; |
2700 | } |
2701 | |
2702 | /** |
2703 | * file_start_write - get write access to a superblock for regular file io |
2704 | * @file: the file we want to write to |
2705 | * |
2706 | * This is a variant of sb_start_write() which is a noop on non-regualr file. |
2707 | * Should be matched with a call to file_end_write(). |
2708 | */ |
2709 | static inline void file_start_write(struct file *file) |
2710 | { |
2711 | if (!S_ISREG(file_inode(file)->i_mode)) |
2712 | return; |
2713 | sb_start_write(sb: file_inode(f: file)->i_sb); |
2714 | } |
2715 | |
2716 | static inline bool file_start_write_trylock(struct file *file) |
2717 | { |
2718 | if (!S_ISREG(file_inode(file)->i_mode)) |
2719 | return true; |
2720 | return sb_start_write_trylock(sb: file_inode(f: file)->i_sb); |
2721 | } |
2722 | |
2723 | /** |
2724 | * file_end_write - drop write access to a superblock of a regular file |
2725 | * @file: the file we wrote to |
2726 | * |
2727 | * Should be matched with a call to file_start_write(). |
2728 | */ |
2729 | static inline void file_end_write(struct file *file) |
2730 | { |
2731 | if (!S_ISREG(file_inode(file)->i_mode)) |
2732 | return; |
2733 | sb_end_write(sb: file_inode(f: file)->i_sb); |
2734 | } |
2735 | |
2736 | /** |
2737 | * kiocb_start_write - get write access to a superblock for async file io |
2738 | * @iocb: the io context we want to submit the write with |
2739 | * |
2740 | * This is a variant of sb_start_write() for async io submission. |
2741 | * Should be matched with a call to kiocb_end_write(). |
2742 | */ |
2743 | static inline void kiocb_start_write(struct kiocb *iocb) |
2744 | { |
2745 | struct inode *inode = file_inode(f: iocb->ki_filp); |
2746 | |
2747 | sb_start_write(sb: inode->i_sb); |
2748 | /* |
2749 | * Fool lockdep by telling it the lock got released so that it |
2750 | * doesn't complain about the held lock when we return to userspace. |
2751 | */ |
2752 | __sb_writers_release(inode->i_sb, SB_FREEZE_WRITE); |
2753 | } |
2754 | |
2755 | /** |
2756 | * kiocb_end_write - drop write access to a superblock after async file io |
2757 | * @iocb: the io context we sumbitted the write with |
2758 | * |
2759 | * Should be matched with a call to kiocb_start_write(). |
2760 | */ |
2761 | static inline void kiocb_end_write(struct kiocb *iocb) |
2762 | { |
2763 | struct inode *inode = file_inode(f: iocb->ki_filp); |
2764 | |
2765 | /* |
2766 | * Tell lockdep we inherited freeze protection from submission thread. |
2767 | */ |
2768 | __sb_writers_acquired(inode->i_sb, SB_FREEZE_WRITE); |
2769 | sb_end_write(sb: inode->i_sb); |
2770 | } |
2771 | |
2772 | /* |
2773 | * This is used for regular files where some users -- especially the |
2774 | * currently executed binary in a process, previously handled via |
2775 | * VM_DENYWRITE -- cannot handle concurrent write (and maybe mmap |
2776 | * read-write shared) accesses. |
2777 | * |
2778 | * get_write_access() gets write permission for a file. |
2779 | * put_write_access() releases this write permission. |
2780 | * deny_write_access() denies write access to a file. |
2781 | * allow_write_access() re-enables write access to a file. |
2782 | * |
2783 | * The i_writecount field of an inode can have the following values: |
2784 | * 0: no write access, no denied write access |
2785 | * < 0: (-i_writecount) users that denied write access to the file. |
2786 | * > 0: (i_writecount) users that have write access to the file. |
2787 | * |
2788 | * Normally we operate on that counter with atomic_{inc,dec} and it's safe |
2789 | * except for the cases where we don't hold i_writecount yet. Then we need to |
2790 | * use {get,deny}_write_access() - these functions check the sign and refuse |
2791 | * to do the change if sign is wrong. |
2792 | */ |
2793 | static inline int get_write_access(struct inode *inode) |
2794 | { |
2795 | return atomic_inc_unless_negative(v: &inode->i_writecount) ? 0 : -ETXTBSY; |
2796 | } |
2797 | static inline int deny_write_access(struct file *file) |
2798 | { |
2799 | struct inode *inode = file_inode(f: file); |
2800 | return atomic_dec_unless_positive(v: &inode->i_writecount) ? 0 : -ETXTBSY; |
2801 | } |
2802 | static inline void put_write_access(struct inode * inode) |
2803 | { |
2804 | atomic_dec(v: &inode->i_writecount); |
2805 | } |
2806 | static inline void allow_write_access(struct file *file) |
2807 | { |
2808 | if (file) |
2809 | atomic_inc(v: &file_inode(f: file)->i_writecount); |
2810 | } |
2811 | static inline bool inode_is_open_for_write(const struct inode *inode) |
2812 | { |
2813 | return atomic_read(v: &inode->i_writecount) > 0; |
2814 | } |
2815 | |
2816 | #if defined(CONFIG_IMA) || defined(CONFIG_FILE_LOCKING) |
2817 | static inline void i_readcount_dec(struct inode *inode) |
2818 | { |
2819 | BUG_ON(atomic_dec_return(&inode->i_readcount) < 0); |
2820 | } |
2821 | static inline void i_readcount_inc(struct inode *inode) |
2822 | { |
2823 | atomic_inc(v: &inode->i_readcount); |
2824 | } |
2825 | #else |
2826 | static inline void i_readcount_dec(struct inode *inode) |
2827 | { |
2828 | return; |
2829 | } |
2830 | static inline void i_readcount_inc(struct inode *inode) |
2831 | { |
2832 | return; |
2833 | } |
2834 | #endif |
2835 | extern int do_pipe_flags(int *, int); |
2836 | |
2837 | extern ssize_t kernel_read(struct file *, void *, size_t, loff_t *); |
2838 | ssize_t __kernel_read(struct file *file, void *buf, size_t count, loff_t *pos); |
2839 | extern ssize_t kernel_write(struct file *, const void *, size_t, loff_t *); |
2840 | extern ssize_t __kernel_write(struct file *, const void *, size_t, loff_t *); |
2841 | extern struct file * open_exec(const char *); |
2842 | |
2843 | /* fs/dcache.c -- generic fs support functions */ |
2844 | extern bool is_subdir(struct dentry *, struct dentry *); |
2845 | extern bool path_is_under(const struct path *, const struct path *); |
2846 | |
2847 | extern char *file_path(struct file *, char *, int); |
2848 | |
2849 | #include <linux/err.h> |
2850 | |
2851 | /* needed for stackable file system support */ |
2852 | extern loff_t default_llseek(struct file *file, loff_t offset, int whence); |
2853 | |
2854 | extern loff_t vfs_llseek(struct file *file, loff_t offset, int whence); |
2855 | |
2856 | extern int inode_init_always(struct super_block *, struct inode *); |
2857 | extern void inode_init_once(struct inode *); |
2858 | extern void address_space_init_once(struct address_space *mapping); |
2859 | extern struct inode * igrab(struct inode *); |
2860 | extern ino_t iunique(struct super_block *, ino_t); |
2861 | extern int inode_needs_sync(struct inode *inode); |
2862 | extern int generic_delete_inode(struct inode *inode); |
2863 | static inline int generic_drop_inode(struct inode *inode) |
2864 | { |
2865 | return !inode->i_nlink || inode_unhashed(inode); |
2866 | } |
2867 | extern void d_mark_dontcache(struct inode *inode); |
2868 | |
2869 | extern struct inode *ilookup5_nowait(struct super_block *sb, |
2870 | unsigned long hashval, int (*test)(struct inode *, void *), |
2871 | void *data); |
2872 | extern struct inode *ilookup5(struct super_block *sb, unsigned long hashval, |
2873 | int (*test)(struct inode *, void *), void *data); |
2874 | extern struct inode *ilookup(struct super_block *sb, unsigned long ino); |
2875 | |
2876 | extern struct inode *inode_insert5(struct inode *inode, unsigned long hashval, |
2877 | int (*test)(struct inode *, void *), |
2878 | int (*set)(struct inode *, void *), |
2879 | void *data); |
2880 | extern struct inode * iget5_locked(struct super_block *, unsigned long, int (*test)(struct inode *, void *), int (*set)(struct inode *, void *), void *); |
2881 | extern struct inode * iget_locked(struct super_block *, unsigned long); |
2882 | extern struct inode *find_inode_nowait(struct super_block *, |
2883 | unsigned long, |
2884 | int (*match)(struct inode *, |
2885 | unsigned long, void *), |
2886 | void *data); |
2887 | extern struct inode *find_inode_rcu(struct super_block *, unsigned long, |
2888 | int (*)(struct inode *, void *), void *); |
2889 | extern struct inode *find_inode_by_ino_rcu(struct super_block *, unsigned long); |
2890 | extern int insert_inode_locked4(struct inode *, unsigned long, int (*test)(struct inode *, void *), void *); |
2891 | extern int insert_inode_locked(struct inode *); |
2892 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
2893 | extern void lockdep_annotate_inode_mutex_key(struct inode *inode); |
2894 | #else |
2895 | static inline void lockdep_annotate_inode_mutex_key(struct inode *inode) { }; |
2896 | #endif |
2897 | extern void unlock_new_inode(struct inode *); |
2898 | extern void discard_new_inode(struct inode *); |
2899 | extern unsigned int get_next_ino(void); |
2900 | extern void evict_inodes(struct super_block *sb); |
2901 | void dump_mapping(const struct address_space *); |
2902 | |
2903 | /* |
2904 | * Userspace may rely on the inode number being non-zero. For example, glibc |
2905 | * simply ignores files with zero i_ino in unlink() and other places. |
2906 | * |
2907 | * As an additional complication, if userspace was compiled with |
2908 | * _FILE_OFFSET_BITS=32 on a 64-bit kernel we'll only end up reading out the |
2909 | * lower 32 bits, so we need to check that those aren't zero explicitly. With |
2910 | * _FILE_OFFSET_BITS=64, this may cause some harmless false-negatives, but |
2911 | * better safe than sorry. |
2912 | */ |
2913 | static inline bool is_zero_ino(ino_t ino) |
2914 | { |
2915 | return (u32)ino == 0; |
2916 | } |
2917 | |
2918 | extern void __iget(struct inode * inode); |
2919 | extern void iget_failed(struct inode *); |
2920 | extern void clear_inode(struct inode *); |
2921 | extern void __destroy_inode(struct inode *); |
2922 | extern struct inode *new_inode_pseudo(struct super_block *sb); |
2923 | extern struct inode *new_inode(struct super_block *sb); |
2924 | extern void free_inode_nonrcu(struct inode *inode); |
2925 | extern int setattr_should_drop_suidgid(struct mnt_idmap *, struct inode *); |
2926 | extern int file_remove_privs(struct file *); |
2927 | int setattr_should_drop_sgid(struct mnt_idmap *idmap, |
2928 | const struct inode *inode); |
2929 | |
2930 | /* |
2931 | * This must be used for allocating filesystems specific inodes to set |
2932 | * up the inode reclaim context correctly. |
2933 | */ |
2934 | static inline void * |
2935 | alloc_inode_sb(struct super_block *sb, struct kmem_cache *cache, gfp_t gfp) |
2936 | { |
2937 | return kmem_cache_alloc_lru(s: cache, lru: &sb->s_inode_lru, gfpflags: gfp); |
2938 | } |
2939 | |
2940 | extern void __insert_inode_hash(struct inode *, unsigned long hashval); |
2941 | static inline void insert_inode_hash(struct inode *inode) |
2942 | { |
2943 | __insert_inode_hash(inode, hashval: inode->i_ino); |
2944 | } |
2945 | |
2946 | extern void __remove_inode_hash(struct inode *); |
2947 | static inline void remove_inode_hash(struct inode *inode) |
2948 | { |
2949 | if (!inode_unhashed(inode) && !hlist_fake(h: &inode->i_hash)) |
2950 | __remove_inode_hash(inode); |
2951 | } |
2952 | |
2953 | extern void inode_sb_list_add(struct inode *inode); |
2954 | extern void inode_add_lru(struct inode *inode); |
2955 | |
2956 | extern int sb_set_blocksize(struct super_block *, int); |
2957 | extern int sb_min_blocksize(struct super_block *, int); |
2958 | |
2959 | extern int generic_file_mmap(struct file *, struct vm_area_struct *); |
2960 | extern int generic_file_readonly_mmap(struct file *, struct vm_area_struct *); |
2961 | extern ssize_t generic_write_checks(struct kiocb *, struct iov_iter *); |
2962 | int generic_write_checks_count(struct kiocb *iocb, loff_t *count); |
2963 | extern int generic_write_check_limits(struct file *file, loff_t pos, |
2964 | loff_t *count); |
2965 | extern int generic_file_rw_checks(struct file *file_in, struct file *file_out); |
2966 | ssize_t filemap_read(struct kiocb *iocb, struct iov_iter *to, |
2967 | ssize_t already_read); |
2968 | extern ssize_t generic_file_read_iter(struct kiocb *, struct iov_iter *); |
2969 | extern ssize_t __generic_file_write_iter(struct kiocb *, struct iov_iter *); |
2970 | extern ssize_t generic_file_write_iter(struct kiocb *, struct iov_iter *); |
2971 | extern ssize_t generic_file_direct_write(struct kiocb *, struct iov_iter *); |
2972 | ssize_t generic_perform_write(struct kiocb *, struct iov_iter *); |
2973 | ssize_t direct_write_fallback(struct kiocb *iocb, struct iov_iter *iter, |
2974 | ssize_t direct_written, ssize_t buffered_written); |
2975 | |
2976 | ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos, |
2977 | rwf_t flags); |
2978 | ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos, |
2979 | rwf_t flags); |
2980 | ssize_t vfs_iocb_iter_read(struct file *file, struct kiocb *iocb, |
2981 | struct iov_iter *iter); |
2982 | ssize_t vfs_iocb_iter_write(struct file *file, struct kiocb *iocb, |
2983 | struct iov_iter *iter); |
2984 | |
2985 | /* fs/splice.c */ |
2986 | ssize_t filemap_splice_read(struct file *in, loff_t *ppos, |
2987 | struct pipe_inode_info *pipe, |
2988 | size_t len, unsigned int flags); |
2989 | ssize_t copy_splice_read(struct file *in, loff_t *ppos, |
2990 | struct pipe_inode_info *pipe, |
2991 | size_t len, unsigned int flags); |
2992 | extern ssize_t iter_file_splice_write(struct pipe_inode_info *, |
2993 | struct file *, loff_t *, size_t, unsigned int); |
2994 | extern long do_splice_direct(struct file *in, loff_t *ppos, struct file *out, |
2995 | loff_t *opos, size_t len, unsigned int flags); |
2996 | |
2997 | |
2998 | extern void |
2999 | file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping); |
3000 | extern loff_t noop_llseek(struct file *file, loff_t offset, int whence); |
3001 | #define no_llseek NULL |
3002 | extern loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize); |
3003 | extern loff_t generic_file_llseek(struct file *file, loff_t offset, int whence); |
3004 | extern loff_t generic_file_llseek_size(struct file *file, loff_t offset, |
3005 | int whence, loff_t maxsize, loff_t eof); |
3006 | extern loff_t fixed_size_llseek(struct file *file, loff_t offset, |
3007 | int whence, loff_t size); |
3008 | extern loff_t no_seek_end_llseek_size(struct file *, loff_t, int, loff_t); |
3009 | extern loff_t no_seek_end_llseek(struct file *, loff_t, int); |
3010 | int rw_verify_area(int, struct file *, const loff_t *, size_t); |
3011 | extern int generic_file_open(struct inode * inode, struct file * filp); |
3012 | extern int nonseekable_open(struct inode * inode, struct file * filp); |
3013 | extern int stream_open(struct inode * inode, struct file * filp); |
3014 | |
3015 | #ifdef CONFIG_BLOCK |
3016 | typedef void (dio_submit_t)(struct bio *bio, struct inode *inode, |
3017 | loff_t file_offset); |
3018 | |
3019 | enum { |
3020 | /* need locking between buffered and direct access */ |
3021 | DIO_LOCKING = 0x01, |
3022 | |
3023 | /* filesystem does not support filling holes */ |
3024 | DIO_SKIP_HOLES = 0x02, |
3025 | }; |
3026 | |
3027 | ssize_t __blockdev_direct_IO(struct kiocb *iocb, struct inode *inode, |
3028 | struct block_device *bdev, struct iov_iter *iter, |
3029 | get_block_t get_block, |
3030 | dio_iodone_t end_io, |
3031 | int flags); |
3032 | |
3033 | static inline ssize_t blockdev_direct_IO(struct kiocb *iocb, |
3034 | struct inode *inode, |
3035 | struct iov_iter *iter, |
3036 | get_block_t get_block) |
3037 | { |
3038 | return __blockdev_direct_IO(iocb, inode, bdev: inode->i_sb->s_bdev, iter, |
3039 | get_block, NULL, flags: DIO_LOCKING | DIO_SKIP_HOLES); |
3040 | } |
3041 | #endif |
3042 | |
3043 | void inode_dio_wait(struct inode *inode); |
3044 | |
3045 | /** |
3046 | * inode_dio_begin - signal start of a direct I/O requests |
3047 | * @inode: inode the direct I/O happens on |
3048 | * |
3049 | * This is called once we've finished processing a direct I/O request, |
3050 | * and is used to wake up callers waiting for direct I/O to be quiesced. |
3051 | */ |
3052 | static inline void inode_dio_begin(struct inode *inode) |
3053 | { |
3054 | atomic_inc(v: &inode->i_dio_count); |
3055 | } |
3056 | |
3057 | /** |
3058 | * inode_dio_end - signal finish of a direct I/O requests |
3059 | * @inode: inode the direct I/O happens on |
3060 | * |
3061 | * This is called once we've finished processing a direct I/O request, |
3062 | * and is used to wake up callers waiting for direct I/O to be quiesced. |
3063 | */ |
3064 | static inline void inode_dio_end(struct inode *inode) |
3065 | { |
3066 | if (atomic_dec_and_test(v: &inode->i_dio_count)) |
3067 | wake_up_bit(word: &inode->i_state, __I_DIO_WAKEUP); |
3068 | } |
3069 | |
3070 | extern void inode_set_flags(struct inode *inode, unsigned int flags, |
3071 | unsigned int mask); |
3072 | |
3073 | extern const struct file_operations generic_ro_fops; |
3074 | |
3075 | #define special_file(m) (S_ISCHR(m)||S_ISBLK(m)||S_ISFIFO(m)||S_ISSOCK(m)) |
3076 | |
3077 | extern int readlink_copy(char __user *, int, const char *); |
3078 | extern int page_readlink(struct dentry *, char __user *, int); |
3079 | extern const char *page_get_link(struct dentry *, struct inode *, |
3080 | struct delayed_call *); |
3081 | extern void page_put_link(void *); |
3082 | extern int page_symlink(struct inode *inode, const char *symname, int len); |
3083 | extern const struct inode_operations page_symlink_inode_operations; |
3084 | extern void kfree_link(void *); |
3085 | void generic_fillattr(struct mnt_idmap *, u32, struct inode *, struct kstat *); |
3086 | void generic_fill_statx_attr(struct inode *inode, struct kstat *stat); |
3087 | extern int vfs_getattr_nosec(const struct path *, struct kstat *, u32, unsigned int); |
3088 | extern int vfs_getattr(const struct path *, struct kstat *, u32, unsigned int); |
3089 | void __inode_add_bytes(struct inode *inode, loff_t bytes); |
3090 | void inode_add_bytes(struct inode *inode, loff_t bytes); |
3091 | void __inode_sub_bytes(struct inode *inode, loff_t bytes); |
3092 | void inode_sub_bytes(struct inode *inode, loff_t bytes); |
3093 | static inline loff_t __inode_get_bytes(struct inode *inode) |
3094 | { |
3095 | return (((loff_t)inode->i_blocks) << 9) + inode->i_bytes; |
3096 | } |
3097 | loff_t inode_get_bytes(struct inode *inode); |
3098 | void inode_set_bytes(struct inode *inode, loff_t bytes); |
3099 | const char *simple_get_link(struct dentry *, struct inode *, |
3100 | struct delayed_call *); |
3101 | extern const struct inode_operations simple_symlink_inode_operations; |
3102 | |
3103 | extern int iterate_dir(struct file *, struct dir_context *); |
3104 | |
3105 | int vfs_fstatat(int dfd, const char __user *filename, struct kstat *stat, |
3106 | int flags); |
3107 | int vfs_fstat(int fd, struct kstat *stat); |
3108 | |
3109 | static inline int vfs_stat(const char __user *filename, struct kstat *stat) |
3110 | { |
3111 | return vfs_fstatat(AT_FDCWD, filename, stat, flags: 0); |
3112 | } |
3113 | static inline int vfs_lstat(const char __user *name, struct kstat *stat) |
3114 | { |
3115 | return vfs_fstatat(AT_FDCWD, filename: name, stat, AT_SYMLINK_NOFOLLOW); |
3116 | } |
3117 | |
3118 | extern const char *vfs_get_link(struct dentry *, struct delayed_call *); |
3119 | extern int vfs_readlink(struct dentry *, char __user *, int); |
3120 | |
3121 | extern struct file_system_type *get_filesystem(struct file_system_type *fs); |
3122 | extern void put_filesystem(struct file_system_type *fs); |
3123 | extern struct file_system_type *get_fs_type(const char *name); |
3124 | extern struct super_block *get_active_super(struct block_device *bdev); |
3125 | extern void drop_super(struct super_block *sb); |
3126 | extern void drop_super_exclusive(struct super_block *sb); |
3127 | extern void iterate_supers(void (*)(struct super_block *, void *), void *); |
3128 | extern void iterate_supers_type(struct file_system_type *, |
3129 | void (*)(struct super_block *, void *), void *); |
3130 | |
3131 | extern int dcache_dir_open(struct inode *, struct file *); |
3132 | extern int dcache_dir_close(struct inode *, struct file *); |
3133 | extern loff_t dcache_dir_lseek(struct file *, loff_t, int); |
3134 | extern int dcache_readdir(struct file *, struct dir_context *); |
3135 | extern int simple_setattr(struct mnt_idmap *, struct dentry *, |
3136 | struct iattr *); |
3137 | extern int simple_getattr(struct mnt_idmap *, const struct path *, |
3138 | struct kstat *, u32, unsigned int); |
3139 | extern int simple_statfs(struct dentry *, struct kstatfs *); |
3140 | extern int simple_open(struct inode *inode, struct file *file); |
3141 | extern int simple_link(struct dentry *, struct inode *, struct dentry *); |
3142 | extern int simple_unlink(struct inode *, struct dentry *); |
3143 | extern int simple_rmdir(struct inode *, struct dentry *); |
3144 | void simple_rename_timestamp(struct inode *old_dir, struct dentry *old_dentry, |
3145 | struct inode *new_dir, struct dentry *new_dentry); |
3146 | extern int simple_rename_exchange(struct inode *old_dir, struct dentry *old_dentry, |
3147 | struct inode *new_dir, struct dentry *new_dentry); |
3148 | extern int simple_rename(struct mnt_idmap *, struct inode *, |
3149 | struct dentry *, struct inode *, struct dentry *, |
3150 | unsigned int); |
3151 | extern void simple_recursive_removal(struct dentry *, |
3152 | void (*callback)(struct dentry *)); |
3153 | extern int noop_fsync(struct file *, loff_t, loff_t, int); |
3154 | extern ssize_t noop_direct_IO(struct kiocb *iocb, struct iov_iter *iter); |
3155 | extern int simple_empty(struct dentry *); |
3156 | extern int simple_write_begin(struct file *file, struct address_space *mapping, |
3157 | loff_t pos, unsigned len, |
3158 | struct page **pagep, void **fsdata); |
3159 | extern const struct address_space_operations ram_aops; |
3160 | extern int always_delete_dentry(const struct dentry *); |
3161 | extern struct inode *alloc_anon_inode(struct super_block *); |
3162 | extern int simple_nosetlease(struct file *, int, struct file_lock **, void **); |
3163 | extern const struct dentry_operations simple_dentry_operations; |
3164 | |
3165 | extern struct dentry *simple_lookup(struct inode *, struct dentry *, unsigned int flags); |
3166 | extern ssize_t generic_read_dir(struct file *, char __user *, size_t, loff_t *); |
3167 | extern const struct file_operations simple_dir_operations; |
3168 | extern const struct inode_operations simple_dir_inode_operations; |
3169 | extern void make_empty_dir_inode(struct inode *inode); |
3170 | extern bool is_empty_dir_inode(struct inode *inode); |
3171 | struct tree_descr { const char *name; const struct file_operations *ops; int mode; }; |
3172 | struct dentry *d_alloc_name(struct dentry *, const char *); |
3173 | extern int simple_fill_super(struct super_block *, unsigned long, |
3174 | const struct tree_descr *); |
3175 | extern int simple_pin_fs(struct file_system_type *, struct vfsmount **mount, int *count); |
3176 | extern void simple_release_fs(struct vfsmount **mount, int *count); |
3177 | |
3178 | extern ssize_t simple_read_from_buffer(void __user *to, size_t count, |
3179 | loff_t *ppos, const void *from, size_t available); |
3180 | extern ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos, |
3181 | const void __user *from, size_t count); |
3182 | |
3183 | struct offset_ctx { |
3184 | struct xarray xa; |
3185 | u32 next_offset; |
3186 | }; |
3187 | |
3188 | void simple_offset_init(struct offset_ctx *octx); |
3189 | int simple_offset_add(struct offset_ctx *octx, struct dentry *dentry); |
3190 | void simple_offset_remove(struct offset_ctx *octx, struct dentry *dentry); |
3191 | int simple_offset_rename_exchange(struct inode *old_dir, |
3192 | struct dentry *old_dentry, |
3193 | struct inode *new_dir, |
3194 | struct dentry *new_dentry); |
3195 | void simple_offset_destroy(struct offset_ctx *octx); |
3196 | |
3197 | extern const struct file_operations simple_offset_dir_operations; |
3198 | |
3199 | extern int __generic_file_fsync(struct file *, loff_t, loff_t, int); |
3200 | extern int generic_file_fsync(struct file *, loff_t, loff_t, int); |
3201 | |
3202 | extern int generic_check_addressable(unsigned, u64); |
3203 | |
3204 | extern void generic_set_encrypted_ci_d_ops(struct dentry *dentry); |
3205 | |
3206 | int may_setattr(struct mnt_idmap *idmap, struct inode *inode, |
3207 | unsigned int ia_valid); |
3208 | int setattr_prepare(struct mnt_idmap *, struct dentry *, struct iattr *); |
3209 | extern int inode_newsize_ok(const struct inode *, loff_t offset); |
3210 | void setattr_copy(struct mnt_idmap *, struct inode *inode, |
3211 | const struct iattr *attr); |
3212 | |
3213 | extern int file_update_time(struct file *file); |
3214 | |
3215 | static inline bool vma_is_dax(const struct vm_area_struct *vma) |
3216 | { |
3217 | return vma->vm_file && IS_DAX(vma->vm_file->f_mapping->host); |
3218 | } |
3219 | |
3220 | static inline bool vma_is_fsdax(struct vm_area_struct *vma) |
3221 | { |
3222 | struct inode *inode; |
3223 | |
3224 | if (!IS_ENABLED(CONFIG_FS_DAX) || !vma->vm_file) |
3225 | return false; |
3226 | if (!vma_is_dax(vma)) |
3227 | return false; |
3228 | inode = file_inode(f: vma->vm_file); |
3229 | if (S_ISCHR(inode->i_mode)) |
3230 | return false; /* device-dax */ |
3231 | return true; |
3232 | } |
3233 | |
3234 | static inline int iocb_flags(struct file *file) |
3235 | { |
3236 | int res = 0; |
3237 | if (file->f_flags & O_APPEND) |
3238 | res |= IOCB_APPEND; |
3239 | if (file->f_flags & O_DIRECT) |
3240 | res |= IOCB_DIRECT; |
3241 | if (file->f_flags & O_DSYNC) |
3242 | res |= IOCB_DSYNC; |
3243 | if (file->f_flags & __O_SYNC) |
3244 | res |= IOCB_SYNC; |
3245 | return res; |
3246 | } |
3247 | |
3248 | static inline int kiocb_set_rw_flags(struct kiocb *ki, rwf_t flags) |
3249 | { |
3250 | int kiocb_flags = 0; |
3251 | |
3252 | /* make sure there's no overlap between RWF and private IOCB flags */ |
3253 | BUILD_BUG_ON((__force int) RWF_SUPPORTED & IOCB_EVENTFD); |
3254 | |
3255 | if (!flags) |
3256 | return 0; |
3257 | if (unlikely(flags & ~RWF_SUPPORTED)) |
3258 | return -EOPNOTSUPP; |
3259 | |
3260 | if (flags & RWF_NOWAIT) { |
3261 | if (!(ki->ki_filp->f_mode & FMODE_NOWAIT)) |
3262 | return -EOPNOTSUPP; |
3263 | kiocb_flags |= IOCB_NOIO; |
3264 | } |
3265 | kiocb_flags |= (__force int) (flags & RWF_SUPPORTED); |
3266 | if (flags & RWF_SYNC) |
3267 | kiocb_flags |= IOCB_DSYNC; |
3268 | |
3269 | ki->ki_flags |= kiocb_flags; |
3270 | return 0; |
3271 | } |
3272 | |
3273 | static inline ino_t parent_ino(struct dentry *dentry) |
3274 | { |
3275 | ino_t res; |
3276 | |
3277 | /* |
3278 | * Don't strictly need d_lock here? If the parent ino could change |
3279 | * then surely we'd have a deeper race in the caller? |
3280 | */ |
3281 | spin_lock(lock: &dentry->d_lock); |
3282 | res = dentry->d_parent->d_inode->i_ino; |
3283 | spin_unlock(lock: &dentry->d_lock); |
3284 | return res; |
3285 | } |
3286 | |
3287 | /* Transaction based IO helpers */ |
3288 | |
3289 | /* |
3290 | * An argresp is stored in an allocated page and holds the |
3291 | * size of the argument or response, along with its content |
3292 | */ |
3293 | struct simple_transaction_argresp { |
3294 | ssize_t size; |
3295 | char data[]; |
3296 | }; |
3297 | |
3298 | #define SIMPLE_TRANSACTION_LIMIT (PAGE_SIZE - sizeof(struct simple_transaction_argresp)) |
3299 | |
3300 | char *simple_transaction_get(struct file *file, const char __user *buf, |
3301 | size_t size); |
3302 | ssize_t simple_transaction_read(struct file *file, char __user *buf, |
3303 | size_t size, loff_t *pos); |
3304 | int simple_transaction_release(struct inode *inode, struct file *file); |
3305 | |
3306 | void simple_transaction_set(struct file *file, size_t n); |
3307 | |
3308 | /* |
3309 | * simple attribute files |
3310 | * |
3311 | * These attributes behave similar to those in sysfs: |
3312 | * |
3313 | * Writing to an attribute immediately sets a value, an open file can be |
3314 | * written to multiple times. |
3315 | * |
3316 | * Reading from an attribute creates a buffer from the value that might get |
3317 | * read with multiple read calls. When the attribute has been read |
3318 | * completely, no further read calls are possible until the file is opened |
3319 | * again. |
3320 | * |
3321 | * All attributes contain a text representation of a numeric value |
3322 | * that are accessed with the get() and set() functions. |
3323 | */ |
3324 | #define DEFINE_SIMPLE_ATTRIBUTE_XSIGNED(__fops, __get, __set, __fmt, __is_signed) \ |
3325 | static int __fops ## _open(struct inode *inode, struct file *file) \ |
3326 | { \ |
3327 | __simple_attr_check_format(__fmt, 0ull); \ |
3328 | return simple_attr_open(inode, file, __get, __set, __fmt); \ |
3329 | } \ |
3330 | static const struct file_operations __fops = { \ |
3331 | .owner = THIS_MODULE, \ |
3332 | .open = __fops ## _open, \ |
3333 | .release = simple_attr_release, \ |
3334 | .read = simple_attr_read, \ |
3335 | .write = (__is_signed) ? simple_attr_write_signed : simple_attr_write, \ |
3336 | .llseek = generic_file_llseek, \ |
3337 | } |
3338 | |
3339 | #define DEFINE_SIMPLE_ATTRIBUTE(__fops, __get, __set, __fmt) \ |
3340 | DEFINE_SIMPLE_ATTRIBUTE_XSIGNED(__fops, __get, __set, __fmt, false) |
3341 | |
3342 | #define DEFINE_SIMPLE_ATTRIBUTE_SIGNED(__fops, __get, __set, __fmt) \ |
3343 | DEFINE_SIMPLE_ATTRIBUTE_XSIGNED(__fops, __get, __set, __fmt, true) |
3344 | |
3345 | static inline __printf(1, 2) |
3346 | void __simple_attr_check_format(const char *fmt, ...) |
3347 | { |
3348 | /* don't do anything, just let the compiler check the arguments; */ |
3349 | } |
3350 | |
3351 | int simple_attr_open(struct inode *inode, struct file *file, |
3352 | int (*get)(void *, u64 *), int (*set)(void *, u64), |
3353 | const char *fmt); |
3354 | int simple_attr_release(struct inode *inode, struct file *file); |
3355 | ssize_t simple_attr_read(struct file *file, char __user *buf, |
3356 | size_t len, loff_t *ppos); |
3357 | ssize_t simple_attr_write(struct file *file, const char __user *buf, |
3358 | size_t len, loff_t *ppos); |
3359 | ssize_t simple_attr_write_signed(struct file *file, const char __user *buf, |
3360 | size_t len, loff_t *ppos); |
3361 | |
3362 | struct ctl_table; |
3363 | int __init list_bdev_fs_names(char *buf, size_t size); |
3364 | |
3365 | #define __FMODE_EXEC ((__force int) FMODE_EXEC) |
3366 | #define __FMODE_NONOTIFY ((__force int) FMODE_NONOTIFY) |
3367 | |
3368 | #define ACC_MODE(x) ("\004\002\006\006"[(x)&O_ACCMODE]) |
3369 | #define OPEN_FMODE(flag) ((__force fmode_t)(((flag + 1) & O_ACCMODE) | \ |
3370 | (flag & __FMODE_NONOTIFY))) |
3371 | |
3372 | static inline bool is_sxid(umode_t mode) |
3373 | { |
3374 | return mode & (S_ISUID | S_ISGID); |
3375 | } |
3376 | |
3377 | static inline int check_sticky(struct mnt_idmap *idmap, |
3378 | struct inode *dir, struct inode *inode) |
3379 | { |
3380 | if (!(dir->i_mode & S_ISVTX)) |
3381 | return 0; |
3382 | |
3383 | return __check_sticky(idmap, dir, inode); |
3384 | } |
3385 | |
3386 | static inline void inode_has_no_xattr(struct inode *inode) |
3387 | { |
3388 | if (!is_sxid(mode: inode->i_mode) && (inode->i_sb->s_flags & SB_NOSEC)) |
3389 | inode->i_flags |= S_NOSEC; |
3390 | } |
3391 | |
3392 | static inline bool is_root_inode(struct inode *inode) |
3393 | { |
3394 | return inode == inode->i_sb->s_root->d_inode; |
3395 | } |
3396 | |
3397 | static inline bool dir_emit(struct dir_context *ctx, |
3398 | const char *name, int namelen, |
3399 | u64 ino, unsigned type) |
3400 | { |
3401 | return ctx->actor(ctx, name, namelen, ctx->pos, ino, type); |
3402 | } |
3403 | static inline bool dir_emit_dot(struct file *file, struct dir_context *ctx) |
3404 | { |
3405 | return ctx->actor(ctx, "." , 1, ctx->pos, |
3406 | file->f_path.dentry->d_inode->i_ino, DT_DIR); |
3407 | } |
3408 | static inline bool dir_emit_dotdot(struct file *file, struct dir_context *ctx) |
3409 | { |
3410 | return ctx->actor(ctx, ".." , 2, ctx->pos, |
3411 | parent_ino(dentry: file->f_path.dentry), DT_DIR); |
3412 | } |
3413 | static inline bool dir_emit_dots(struct file *file, struct dir_context *ctx) |
3414 | { |
3415 | if (ctx->pos == 0) { |
3416 | if (!dir_emit_dot(file, ctx)) |
3417 | return false; |
3418 | ctx->pos = 1; |
3419 | } |
3420 | if (ctx->pos == 1) { |
3421 | if (!dir_emit_dotdot(file, ctx)) |
3422 | return false; |
3423 | ctx->pos = 2; |
3424 | } |
3425 | return true; |
3426 | } |
3427 | static inline bool dir_relax(struct inode *inode) |
3428 | { |
3429 | inode_unlock(inode); |
3430 | inode_lock(inode); |
3431 | return !IS_DEADDIR(inode); |
3432 | } |
3433 | |
3434 | static inline bool dir_relax_shared(struct inode *inode) |
3435 | { |
3436 | inode_unlock_shared(inode); |
3437 | inode_lock_shared(inode); |
3438 | return !IS_DEADDIR(inode); |
3439 | } |
3440 | |
3441 | extern bool path_noexec(const struct path *path); |
3442 | extern void inode_nohighmem(struct inode *inode); |
3443 | |
3444 | /* mm/fadvise.c */ |
3445 | extern int vfs_fadvise(struct file *file, loff_t offset, loff_t len, |
3446 | int advice); |
3447 | extern int generic_fadvise(struct file *file, loff_t offset, loff_t len, |
3448 | int advice); |
3449 | |
3450 | #endif /* _LINUX_FS_H */ |
3451 | |