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_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 /* File is opened with O_NDELAY (only set for block devices) */
123 #define FMODE_NDELAY		((__force fmode_t)0x40)
124 /* File is opened with O_EXCL (only set for block devices) */
125 #define FMODE_EXCL		((__force fmode_t)0x80)
126 /* File is opened using open(.., 3, ..) and is writeable only for ioctls
127    (specialy hack for floppy.c) */
128 #define FMODE_WRITE_IOCTL	((__force fmode_t)0x100)
129 /* 32bit hashes as llseek() offset (for directories) */
130 #define FMODE_32BITHASH         ((__force fmode_t)0x200)
131 /* 64bit hashes as llseek() offset (for directories) */
132 #define FMODE_64BITHASH         ((__force fmode_t)0x400)
133 
134 /*
135  * Don't update ctime and mtime.
136  *
137  * Currently a special hack for the XFS open_by_handle ioctl, but we'll
138  * hopefully graduate it to a proper O_CMTIME flag supported by open(2) soon.
139  */
140 #define FMODE_NOCMTIME		((__force fmode_t)0x800)
141 
142 /* Expect random access pattern */
143 #define FMODE_RANDOM		((__force fmode_t)0x1000)
144 
145 /* File is huge (eg. /dev/mem): treat loff_t as unsigned */
146 #define FMODE_UNSIGNED_OFFSET	((__force fmode_t)0x2000)
147 
148 /* File is opened with O_PATH; almost nothing can be done with it */
149 #define FMODE_PATH		((__force fmode_t)0x4000)
150 
151 /* File needs atomic accesses to f_pos */
152 #define FMODE_ATOMIC_POS	((__force fmode_t)0x8000)
153 /* Write access to underlying fs */
154 #define FMODE_WRITER		((__force fmode_t)0x10000)
155 /* Has read method(s) */
156 #define FMODE_CAN_READ          ((__force fmode_t)0x20000)
157 /* Has write method(s) */
158 #define FMODE_CAN_WRITE         ((__force fmode_t)0x40000)
159 
160 #define FMODE_OPENED		((__force fmode_t)0x80000)
161 #define FMODE_CREATED		((__force fmode_t)0x100000)
162 
163 /* File is stream-like */
164 #define FMODE_STREAM		((__force fmode_t)0x200000)
165 
166 /* File supports DIRECT IO */
167 #define	FMODE_CAN_ODIRECT	((__force fmode_t)0x400000)
168 
169 #define	FMODE_NOREUSE		((__force fmode_t)0x800000)
170 
171 /* File was opened by fanotify and shouldn't generate fanotify events */
172 #define FMODE_NONOTIFY		((__force fmode_t)0x4000000)
173 
174 /* File is capable of returning -EAGAIN if I/O will block */
175 #define FMODE_NOWAIT		((__force fmode_t)0x8000000)
176 
177 /* File represents mount that needs unmounting */
178 #define FMODE_NEED_UNMOUNT	((__force fmode_t)0x10000000)
179 
180 /* File does not contribute to nr_files count */
181 #define FMODE_NOACCOUNT		((__force fmode_t)0x20000000)
182 
183 /* File supports async buffered reads */
184 #define FMODE_BUF_RASYNC	((__force fmode_t)0x40000000)
185 
186 /* File supports async nowait buffered writes */
187 #define FMODE_BUF_WASYNC	((__force fmode_t)0x80000000)
188 
189 /*
190  * Attribute flags.  These should be or-ed together to figure out what
191  * has been changed!
192  */
193 #define ATTR_MODE	(1 << 0)
194 #define ATTR_UID	(1 << 1)
195 #define ATTR_GID	(1 << 2)
196 #define ATTR_SIZE	(1 << 3)
197 #define ATTR_ATIME	(1 << 4)
198 #define ATTR_MTIME	(1 << 5)
199 #define ATTR_CTIME	(1 << 6)
200 #define ATTR_ATIME_SET	(1 << 7)
201 #define ATTR_MTIME_SET	(1 << 8)
202 #define ATTR_FORCE	(1 << 9) /* Not a change, but a change it */
203 #define ATTR_KILL_SUID	(1 << 11)
204 #define ATTR_KILL_SGID	(1 << 12)
205 #define ATTR_FILE	(1 << 13)
206 #define ATTR_KILL_PRIV	(1 << 14)
207 #define ATTR_OPEN	(1 << 15) /* Truncating from open(O_TRUNC) */
208 #define ATTR_TIMES_SET	(1 << 16)
209 #define ATTR_TOUCH	(1 << 17)
210 
211 /*
212  * Whiteout is represented by a char device.  The following constants define the
213  * mode and device number to use.
214  */
215 #define WHITEOUT_MODE 0
216 #define WHITEOUT_DEV 0
217 
218 /*
219  * This is the Inode Attributes structure, used for notify_change().  It
220  * uses the above definitions as flags, to know which values have changed.
221  * Also, in this manner, a Filesystem can look at only the values it cares
222  * about.  Basically, these are the attributes that the VFS layer can
223  * request to change from the FS layer.
224  *
225  * Derek Atkins <warlord@MIT.EDU> 94-10-20
226  */
227 struct iattr {
228 	unsigned int	ia_valid;
229 	umode_t		ia_mode;
230 	/*
231 	 * The two anonymous unions wrap structures with the same member.
232 	 *
233 	 * Filesystems raising FS_ALLOW_IDMAP need to use ia_vfs{g,u}id which
234 	 * are a dedicated type requiring the filesystem to use the dedicated
235 	 * helpers. Other filesystem can continue to use ia_{g,u}id until they
236 	 * have been ported.
237 	 *
238 	 * They always contain the same value. In other words FS_ALLOW_IDMAP
239 	 * pass down the same value on idmapped mounts as they would on regular
240 	 * mounts.
241 	 */
242 	union {
243 		kuid_t		ia_uid;
244 		vfsuid_t	ia_vfsuid;
245 	};
246 	union {
247 		kgid_t		ia_gid;
248 		vfsgid_t	ia_vfsgid;
249 	};
250 	loff_t		ia_size;
251 	struct timespec64 ia_atime;
252 	struct timespec64 ia_mtime;
253 	struct timespec64 ia_ctime;
254 
255 	/*
256 	 * Not an attribute, but an auxiliary info for filesystems wanting to
257 	 * implement an ftruncate() like method.  NOTE: filesystem should
258 	 * check for (ia_valid & ATTR_FILE), and not for (ia_file != NULL).
259 	 */
260 	struct file	*ia_file;
261 };
262 
263 /*
264  * Includes for diskquotas.
265  */
266 #include <linux/quota.h>
267 
268 /*
269  * Maximum number of layers of fs stack.  Needs to be limited to
270  * prevent kernel stack overflow
271  */
272 #define FILESYSTEM_MAX_STACK_DEPTH 2
273 
274 /**
275  * enum positive_aop_returns - aop return codes with specific semantics
276  *
277  * @AOP_WRITEPAGE_ACTIVATE: Informs the caller that page writeback has
278  * 			    completed, that the page is still locked, and
279  * 			    should be considered active.  The VM uses this hint
280  * 			    to return the page to the active list -- it won't
281  * 			    be a candidate for writeback again in the near
282  * 			    future.  Other callers must be careful to unlock
283  * 			    the page if they get this return.  Returned by
284  * 			    writepage();
285  *
286  * @AOP_TRUNCATED_PAGE: The AOP method that was handed a locked page has
287  *  			unlocked it and the page might have been truncated.
288  *  			The caller should back up to acquiring a new page and
289  *  			trying again.  The aop will be taking reasonable
290  *  			precautions not to livelock.  If the caller held a page
291  *  			reference, it should drop it before retrying.  Returned
292  *  			by read_folio().
293  *
294  * address_space_operation functions return these large constants to indicate
295  * special semantics to the caller.  These are much larger than the bytes in a
296  * page to allow for functions that return the number of bytes operated on in a
297  * given page.
298  */
299 
300 enum positive_aop_returns {
301 	AOP_WRITEPAGE_ACTIVATE	= 0x80000,
302 	AOP_TRUNCATED_PAGE	= 0x80001,
303 };
304 
305 /*
306  * oh the beauties of C type declarations.
307  */
308 struct page;
309 struct address_space;
310 struct writeback_control;
311 struct readahead_control;
312 
313 /*
314  * Write life time hint values.
315  * Stored in struct inode as u8.
316  */
317 enum rw_hint {
318 	WRITE_LIFE_NOT_SET	= 0,
319 	WRITE_LIFE_NONE		= RWH_WRITE_LIFE_NONE,
320 	WRITE_LIFE_SHORT	= RWH_WRITE_LIFE_SHORT,
321 	WRITE_LIFE_MEDIUM	= RWH_WRITE_LIFE_MEDIUM,
322 	WRITE_LIFE_LONG		= RWH_WRITE_LIFE_LONG,
323 	WRITE_LIFE_EXTREME	= RWH_WRITE_LIFE_EXTREME,
324 };
325 
326 /* Match RWF_* bits to IOCB bits */
327 #define IOCB_HIPRI		(__force int) RWF_HIPRI
328 #define IOCB_DSYNC		(__force int) RWF_DSYNC
329 #define IOCB_SYNC		(__force int) RWF_SYNC
330 #define IOCB_NOWAIT		(__force int) RWF_NOWAIT
331 #define IOCB_APPEND		(__force int) RWF_APPEND
332 
333 /* non-RWF related bits - start at 16 */
334 #define IOCB_EVENTFD		(1 << 16)
335 #define IOCB_DIRECT		(1 << 17)
336 #define IOCB_WRITE		(1 << 18)
337 /* iocb->ki_waitq is valid */
338 #define IOCB_WAITQ		(1 << 19)
339 #define IOCB_NOIO		(1 << 20)
340 /* can use bio alloc cache */
341 #define IOCB_ALLOC_CACHE	(1 << 21)
342 
343 struct kiocb {
344 	struct file		*ki_filp;
345 	loff_t			ki_pos;
346 	void (*ki_complete)(struct kiocb *iocb, long ret);
347 	void			*private;
348 	int			ki_flags;
349 	u16			ki_ioprio; /* See linux/ioprio.h */
350 	struct wait_page_queue	*ki_waitq; /* for async buffered IO */
351 };
352 
is_sync_kiocb(struct kiocb * kiocb)353 static inline bool is_sync_kiocb(struct kiocb *kiocb)
354 {
355 	return kiocb->ki_complete == NULL;
356 }
357 
358 struct address_space_operations {
359 	int (*writepage)(struct page *page, struct writeback_control *wbc);
360 	int (*read_folio)(struct file *, struct folio *);
361 
362 	/* Write back some dirty pages from this mapping. */
363 	int (*writepages)(struct address_space *, struct writeback_control *);
364 
365 	/* Mark a folio dirty.  Return true if this dirtied it */
366 	bool (*dirty_folio)(struct address_space *, struct folio *);
367 
368 	void (*readahead)(struct readahead_control *);
369 
370 	int (*write_begin)(struct file *, struct address_space *mapping,
371 				loff_t pos, unsigned len,
372 				struct page **pagep, void **fsdata);
373 	int (*write_end)(struct file *, struct address_space *mapping,
374 				loff_t pos, unsigned len, unsigned copied,
375 				struct page *page, void *fsdata);
376 
377 	/* Unfortunately this kludge is needed for FIBMAP. Don't use it */
378 	sector_t (*bmap)(struct address_space *, sector_t);
379 	void (*invalidate_folio) (struct folio *, size_t offset, size_t len);
380 	bool (*release_folio)(struct folio *, gfp_t);
381 	void (*free_folio)(struct folio *folio);
382 	ssize_t (*direct_IO)(struct kiocb *, struct iov_iter *iter);
383 	/*
384 	 * migrate the contents of a folio to the specified target. If
385 	 * migrate_mode is MIGRATE_ASYNC, it must not block.
386 	 */
387 	int (*migrate_folio)(struct address_space *, struct folio *dst,
388 			struct folio *src, enum migrate_mode);
389 	int (*launder_folio)(struct folio *);
390 	bool (*is_partially_uptodate) (struct folio *, size_t from,
391 			size_t count);
392 	void (*is_dirty_writeback) (struct folio *, bool *dirty, bool *wb);
393 	int (*error_remove_page)(struct address_space *, struct page *);
394 
395 	/* swapfile support */
396 	int (*swap_activate)(struct swap_info_struct *sis, struct file *file,
397 				sector_t *span);
398 	void (*swap_deactivate)(struct file *file);
399 	int (*swap_rw)(struct kiocb *iocb, struct iov_iter *iter);
400 };
401 
402 extern const struct address_space_operations empty_aops;
403 
404 /**
405  * struct address_space - Contents of a cacheable, mappable object.
406  * @host: Owner, either the inode or the block_device.
407  * @i_pages: Cached pages.
408  * @invalidate_lock: Guards coherency between page cache contents and
409  *   file offset->disk block mappings in the filesystem during invalidates.
410  *   It is also used to block modification of page cache contents through
411  *   memory mappings.
412  * @gfp_mask: Memory allocation flags to use for allocating pages.
413  * @i_mmap_writable: Number of VM_SHARED mappings.
414  * @nr_thps: Number of THPs in the pagecache (non-shmem only).
415  * @i_mmap: Tree of private and shared mappings.
416  * @i_mmap_rwsem: Protects @i_mmap and @i_mmap_writable.
417  * @nrpages: Number of page entries, protected by the i_pages lock.
418  * @writeback_index: Writeback starts here.
419  * @a_ops: Methods.
420  * @flags: Error bits and flags (AS_*).
421  * @wb_err: The most recent error which has occurred.
422  * @private_lock: For use by the owner of the address_space.
423  * @private_list: For use by the owner of the address_space.
424  * @private_data: For use by the owner of the address_space.
425  */
426 struct address_space {
427 	struct inode		*host;
428 	struct xarray		i_pages;
429 	struct rw_semaphore	invalidate_lock;
430 	gfp_t			gfp_mask;
431 	atomic_t		i_mmap_writable;
432 #ifdef CONFIG_READ_ONLY_THP_FOR_FS
433 	/* number of thp, only for non-shmem files */
434 	atomic_t		nr_thps;
435 #endif
436 	struct rb_root_cached	i_mmap;
437 	struct rw_semaphore	i_mmap_rwsem;
438 	unsigned long		nrpages;
439 	pgoff_t			writeback_index;
440 	const struct address_space_operations *a_ops;
441 	unsigned long		flags;
442 	errseq_t		wb_err;
443 	spinlock_t		private_lock;
444 	struct list_head	private_list;
445 	void			*private_data;
446 } __attribute__((aligned(sizeof(long)))) __randomize_layout;
447 	/*
448 	 * On most architectures that alignment is already the case; but
449 	 * must be enforced here for CRIS, to let the least significant bit
450 	 * of struct page's "mapping" pointer be used for PAGE_MAPPING_ANON.
451 	 */
452 
453 /* XArray tags, for tagging dirty and writeback pages in the pagecache. */
454 #define PAGECACHE_TAG_DIRTY	XA_MARK_0
455 #define PAGECACHE_TAG_WRITEBACK	XA_MARK_1
456 #define PAGECACHE_TAG_TOWRITE	XA_MARK_2
457 
458 /*
459  * Returns true if any of the pages in the mapping are marked with the tag.
460  */
mapping_tagged(struct address_space * mapping,xa_mark_t tag)461 static inline bool mapping_tagged(struct address_space *mapping, xa_mark_t tag)
462 {
463 	return xa_marked(&mapping->i_pages, tag);
464 }
465 
i_mmap_lock_write(struct address_space * mapping)466 static inline void i_mmap_lock_write(struct address_space *mapping)
467 {
468 	down_write(&mapping->i_mmap_rwsem);
469 }
470 
i_mmap_trylock_write(struct address_space * mapping)471 static inline int i_mmap_trylock_write(struct address_space *mapping)
472 {
473 	return down_write_trylock(&mapping->i_mmap_rwsem);
474 }
475 
i_mmap_unlock_write(struct address_space * mapping)476 static inline void i_mmap_unlock_write(struct address_space *mapping)
477 {
478 	up_write(&mapping->i_mmap_rwsem);
479 }
480 
i_mmap_trylock_read(struct address_space * mapping)481 static inline int i_mmap_trylock_read(struct address_space *mapping)
482 {
483 	return down_read_trylock(&mapping->i_mmap_rwsem);
484 }
485 
i_mmap_lock_read(struct address_space * mapping)486 static inline void i_mmap_lock_read(struct address_space *mapping)
487 {
488 	down_read(&mapping->i_mmap_rwsem);
489 }
490 
i_mmap_unlock_read(struct address_space * mapping)491 static inline void i_mmap_unlock_read(struct address_space *mapping)
492 {
493 	up_read(&mapping->i_mmap_rwsem);
494 }
495 
i_mmap_assert_locked(struct address_space * mapping)496 static inline void i_mmap_assert_locked(struct address_space *mapping)
497 {
498 	lockdep_assert_held(&mapping->i_mmap_rwsem);
499 }
500 
i_mmap_assert_write_locked(struct address_space * mapping)501 static inline void i_mmap_assert_write_locked(struct address_space *mapping)
502 {
503 	lockdep_assert_held_write(&mapping->i_mmap_rwsem);
504 }
505 
506 /*
507  * Might pages of this file be mapped into userspace?
508  */
mapping_mapped(struct address_space * mapping)509 static inline int mapping_mapped(struct address_space *mapping)
510 {
511 	return	!RB_EMPTY_ROOT(&mapping->i_mmap.rb_root);
512 }
513 
514 /*
515  * Might pages of this file have been modified in userspace?
516  * Note that i_mmap_writable counts all VM_SHARED vmas: do_mmap
517  * marks vma as VM_SHARED if it is shared, and the file was opened for
518  * writing i.e. vma may be mprotected writable even if now readonly.
519  *
520  * If i_mmap_writable is negative, no new writable mappings are allowed. You
521  * can only deny writable mappings, if none exists right now.
522  */
mapping_writably_mapped(struct address_space * mapping)523 static inline int mapping_writably_mapped(struct address_space *mapping)
524 {
525 	return atomic_read(&mapping->i_mmap_writable) > 0;
526 }
527 
mapping_map_writable(struct address_space * mapping)528 static inline int mapping_map_writable(struct address_space *mapping)
529 {
530 	return atomic_inc_unless_negative(&mapping->i_mmap_writable) ?
531 		0 : -EPERM;
532 }
533 
mapping_unmap_writable(struct address_space * mapping)534 static inline void mapping_unmap_writable(struct address_space *mapping)
535 {
536 	atomic_dec(&mapping->i_mmap_writable);
537 }
538 
mapping_deny_writable(struct address_space * mapping)539 static inline int mapping_deny_writable(struct address_space *mapping)
540 {
541 	return atomic_dec_unless_positive(&mapping->i_mmap_writable) ?
542 		0 : -EBUSY;
543 }
544 
mapping_allow_writable(struct address_space * mapping)545 static inline void mapping_allow_writable(struct address_space *mapping)
546 {
547 	atomic_inc(&mapping->i_mmap_writable);
548 }
549 
550 /*
551  * Use sequence counter to get consistent i_size on 32-bit processors.
552  */
553 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
554 #include <linux/seqlock.h>
555 #define __NEED_I_SIZE_ORDERED
556 #define i_size_ordered_init(inode) seqcount_init(&inode->i_size_seqcount)
557 #else
558 #define i_size_ordered_init(inode) do { } while (0)
559 #endif
560 
561 struct posix_acl;
562 #define ACL_NOT_CACHED ((void *)(-1))
563 /*
564  * ACL_DONT_CACHE is for stacked filesystems, that rely on underlying fs to
565  * cache the ACL.  This also means that ->get_inode_acl() can be called in RCU
566  * mode with the LOOKUP_RCU flag.
567  */
568 #define ACL_DONT_CACHE ((void *)(-3))
569 
570 static inline struct posix_acl *
uncached_acl_sentinel(struct task_struct * task)571 uncached_acl_sentinel(struct task_struct *task)
572 {
573 	return (void *)task + 1;
574 }
575 
576 static inline bool
is_uncached_acl(struct posix_acl * acl)577 is_uncached_acl(struct posix_acl *acl)
578 {
579 	return (long)acl & 1;
580 }
581 
582 #define IOP_FASTPERM	0x0001
583 #define IOP_LOOKUP	0x0002
584 #define IOP_NOFOLLOW	0x0004
585 #define IOP_XATTR	0x0008
586 #define IOP_DEFAULT_READLINK	0x0010
587 
588 struct fsnotify_mark_connector;
589 
590 /*
591  * Keep mostly read-only and often accessed (especially for
592  * the RCU path lookup and 'stat' data) fields at the beginning
593  * of the 'struct inode'
594  */
595 struct inode {
596 	umode_t			i_mode;
597 	unsigned short		i_opflags;
598 	kuid_t			i_uid;
599 	kgid_t			i_gid;
600 	unsigned int		i_flags;
601 
602 #ifdef CONFIG_FS_POSIX_ACL
603 	struct posix_acl	*i_acl;
604 	struct posix_acl	*i_default_acl;
605 #endif
606 
607 	const struct inode_operations	*i_op;
608 	struct super_block	*i_sb;
609 	struct address_space	*i_mapping;
610 
611 #ifdef CONFIG_SECURITY
612 	void			*i_security;
613 #endif
614 
615 	/* Stat data, not accessed from path walking */
616 	unsigned long		i_ino;
617 	/*
618 	 * Filesystems may only read i_nlink directly.  They shall use the
619 	 * following functions for modification:
620 	 *
621 	 *    (set|clear|inc|drop)_nlink
622 	 *    inode_(inc|dec)_link_count
623 	 */
624 	union {
625 		const unsigned int i_nlink;
626 		unsigned int __i_nlink;
627 	};
628 	dev_t			i_rdev;
629 	loff_t			i_size;
630 	struct timespec64	i_atime;
631 	struct timespec64	i_mtime;
632 	struct timespec64	i_ctime;
633 	spinlock_t		i_lock;	/* i_blocks, i_bytes, maybe i_size */
634 	unsigned short          i_bytes;
635 	u8			i_blkbits;
636 	u8			i_write_hint;
637 	blkcnt_t		i_blocks;
638 
639 #ifdef __NEED_I_SIZE_ORDERED
640 	seqcount_t		i_size_seqcount;
641 #endif
642 
643 	/* Misc */
644 	unsigned long		i_state;
645 	struct rw_semaphore	i_rwsem;
646 
647 	unsigned long		dirtied_when;	/* jiffies of first dirtying */
648 	unsigned long		dirtied_time_when;
649 
650 	struct hlist_node	i_hash;
651 	struct list_head	i_io_list;	/* backing dev IO list */
652 #ifdef CONFIG_CGROUP_WRITEBACK
653 	struct bdi_writeback	*i_wb;		/* the associated cgroup wb */
654 
655 	/* foreign inode detection, see wbc_detach_inode() */
656 	int			i_wb_frn_winner;
657 	u16			i_wb_frn_avg_time;
658 	u16			i_wb_frn_history;
659 #endif
660 	struct list_head	i_lru;		/* inode LRU list */
661 	struct list_head	i_sb_list;
662 	struct list_head	i_wb_list;	/* backing dev writeback list */
663 	union {
664 		struct hlist_head	i_dentry;
665 		struct rcu_head		i_rcu;
666 	};
667 	atomic64_t		i_version;
668 	atomic64_t		i_sequence; /* see futex */
669 	atomic_t		i_count;
670 	atomic_t		i_dio_count;
671 	atomic_t		i_writecount;
672 #if defined(CONFIG_IMA) || defined(CONFIG_FILE_LOCKING)
673 	atomic_t		i_readcount; /* struct files open RO */
674 #endif
675 	union {
676 		const struct file_operations	*i_fop;	/* former ->i_op->default_file_ops */
677 		void (*free_inode)(struct inode *);
678 	};
679 	struct file_lock_context	*i_flctx;
680 	struct address_space	i_data;
681 	struct list_head	i_devices;
682 	union {
683 		struct pipe_inode_info	*i_pipe;
684 		struct cdev		*i_cdev;
685 		char			*i_link;
686 		unsigned		i_dir_seq;
687 	};
688 
689 	__u32			i_generation;
690 
691 #ifdef CONFIG_FSNOTIFY
692 	__u32			i_fsnotify_mask; /* all events this inode cares about */
693 	struct fsnotify_mark_connector __rcu	*i_fsnotify_marks;
694 #endif
695 
696 #ifdef CONFIG_FS_ENCRYPTION
697 	struct fscrypt_info	*i_crypt_info;
698 #endif
699 
700 #ifdef CONFIG_FS_VERITY
701 	struct fsverity_info	*i_verity_info;
702 #endif
703 
704 	void			*i_private; /* fs or device private pointer */
705 } __randomize_layout;
706 
707 struct timespec64 timestamp_truncate(struct timespec64 t, struct inode *inode);
708 
i_blocksize(const struct inode * node)709 static inline unsigned int i_blocksize(const struct inode *node)
710 {
711 	return (1 << node->i_blkbits);
712 }
713 
inode_unhashed(struct inode * inode)714 static inline int inode_unhashed(struct inode *inode)
715 {
716 	return hlist_unhashed(&inode->i_hash);
717 }
718 
719 /*
720  * __mark_inode_dirty expects inodes to be hashed.  Since we don't
721  * want special inodes in the fileset inode space, we make them
722  * appear hashed, but do not put on any lists.  hlist_del()
723  * will work fine and require no locking.
724  */
inode_fake_hash(struct inode * inode)725 static inline void inode_fake_hash(struct inode *inode)
726 {
727 	hlist_add_fake(&inode->i_hash);
728 }
729 
730 /*
731  * inode->i_mutex nesting subclasses for the lock validator:
732  *
733  * 0: the object of the current VFS operation
734  * 1: parent
735  * 2: child/target
736  * 3: xattr
737  * 4: second non-directory
738  * 5: second parent (when locking independent directories in rename)
739  *
740  * I_MUTEX_NONDIR2 is for certain operations (such as rename) which lock two
741  * non-directories at once.
742  *
743  * The locking order between these classes is
744  * parent[2] -> child -> grandchild -> normal -> xattr -> second non-directory
745  */
746 enum inode_i_mutex_lock_class
747 {
748 	I_MUTEX_NORMAL,
749 	I_MUTEX_PARENT,
750 	I_MUTEX_CHILD,
751 	I_MUTEX_XATTR,
752 	I_MUTEX_NONDIR2,
753 	I_MUTEX_PARENT2,
754 };
755 
inode_lock(struct inode * inode)756 static inline void inode_lock(struct inode *inode)
757 {
758 	down_write(&inode->i_rwsem);
759 }
760 
inode_unlock(struct inode * inode)761 static inline void inode_unlock(struct inode *inode)
762 {
763 	up_write(&inode->i_rwsem);
764 }
765 
inode_lock_shared(struct inode * inode)766 static inline void inode_lock_shared(struct inode *inode)
767 {
768 	down_read(&inode->i_rwsem);
769 }
770 
inode_unlock_shared(struct inode * inode)771 static inline void inode_unlock_shared(struct inode *inode)
772 {
773 	up_read(&inode->i_rwsem);
774 }
775 
inode_trylock(struct inode * inode)776 static inline int inode_trylock(struct inode *inode)
777 {
778 	return down_write_trylock(&inode->i_rwsem);
779 }
780 
inode_trylock_shared(struct inode * inode)781 static inline int inode_trylock_shared(struct inode *inode)
782 {
783 	return down_read_trylock(&inode->i_rwsem);
784 }
785 
inode_is_locked(struct inode * inode)786 static inline int inode_is_locked(struct inode *inode)
787 {
788 	return rwsem_is_locked(&inode->i_rwsem);
789 }
790 
inode_lock_nested(struct inode * inode,unsigned subclass)791 static inline void inode_lock_nested(struct inode *inode, unsigned subclass)
792 {
793 	down_write_nested(&inode->i_rwsem, subclass);
794 }
795 
inode_lock_shared_nested(struct inode * inode,unsigned subclass)796 static inline void inode_lock_shared_nested(struct inode *inode, unsigned subclass)
797 {
798 	down_read_nested(&inode->i_rwsem, subclass);
799 }
800 
filemap_invalidate_lock(struct address_space * mapping)801 static inline void filemap_invalidate_lock(struct address_space *mapping)
802 {
803 	down_write(&mapping->invalidate_lock);
804 }
805 
filemap_invalidate_unlock(struct address_space * mapping)806 static inline void filemap_invalidate_unlock(struct address_space *mapping)
807 {
808 	up_write(&mapping->invalidate_lock);
809 }
810 
filemap_invalidate_lock_shared(struct address_space * mapping)811 static inline void filemap_invalidate_lock_shared(struct address_space *mapping)
812 {
813 	down_read(&mapping->invalidate_lock);
814 }
815 
filemap_invalidate_trylock_shared(struct address_space * mapping)816 static inline int filemap_invalidate_trylock_shared(
817 					struct address_space *mapping)
818 {
819 	return down_read_trylock(&mapping->invalidate_lock);
820 }
821 
filemap_invalidate_unlock_shared(struct address_space * mapping)822 static inline void filemap_invalidate_unlock_shared(
823 					struct address_space *mapping)
824 {
825 	up_read(&mapping->invalidate_lock);
826 }
827 
828 void lock_two_nondirectories(struct inode *, struct inode*);
829 void unlock_two_nondirectories(struct inode *, struct inode*);
830 
831 void filemap_invalidate_lock_two(struct address_space *mapping1,
832 				 struct address_space *mapping2);
833 void filemap_invalidate_unlock_two(struct address_space *mapping1,
834 				   struct address_space *mapping2);
835 
836 
837 /*
838  * NOTE: in a 32bit arch with a preemptable kernel and
839  * an UP compile the i_size_read/write must be atomic
840  * with respect to the local cpu (unlike with preempt disabled),
841  * but they don't need to be atomic with respect to other cpus like in
842  * true SMP (so they need either to either locally disable irq around
843  * the read or for example on x86 they can be still implemented as a
844  * cmpxchg8b without the need of the lock prefix). For SMP compiles
845  * and 64bit archs it makes no difference if preempt is enabled or not.
846  */
i_size_read(const struct inode * inode)847 static inline loff_t i_size_read(const struct inode *inode)
848 {
849 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
850 	loff_t i_size;
851 	unsigned int seq;
852 
853 	do {
854 		seq = read_seqcount_begin(&inode->i_size_seqcount);
855 		i_size = inode->i_size;
856 	} while (read_seqcount_retry(&inode->i_size_seqcount, seq));
857 	return i_size;
858 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION)
859 	loff_t i_size;
860 
861 	preempt_disable();
862 	i_size = inode->i_size;
863 	preempt_enable();
864 	return i_size;
865 #else
866 	return inode->i_size;
867 #endif
868 }
869 
870 /*
871  * NOTE: unlike i_size_read(), i_size_write() does need locking around it
872  * (normally i_mutex), otherwise on 32bit/SMP an update of i_size_seqcount
873  * can be lost, resulting in subsequent i_size_read() calls spinning forever.
874  */
i_size_write(struct inode * inode,loff_t i_size)875 static inline void i_size_write(struct inode *inode, loff_t i_size)
876 {
877 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
878 	preempt_disable();
879 	write_seqcount_begin(&inode->i_size_seqcount);
880 	inode->i_size = i_size;
881 	write_seqcount_end(&inode->i_size_seqcount);
882 	preempt_enable();
883 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION)
884 	preempt_disable();
885 	inode->i_size = i_size;
886 	preempt_enable();
887 #else
888 	inode->i_size = i_size;
889 #endif
890 }
891 
iminor(const struct inode * inode)892 static inline unsigned iminor(const struct inode *inode)
893 {
894 	return MINOR(inode->i_rdev);
895 }
896 
imajor(const struct inode * inode)897 static inline unsigned imajor(const struct inode *inode)
898 {
899 	return MAJOR(inode->i_rdev);
900 }
901 
902 struct fown_struct {
903 	rwlock_t lock;          /* protects pid, uid, euid fields */
904 	struct pid *pid;	/* pid or -pgrp where SIGIO should be sent */
905 	enum pid_type pid_type;	/* Kind of process group SIGIO should be sent to */
906 	kuid_t uid, euid;	/* uid/euid of process setting the owner */
907 	int signum;		/* posix.1b rt signal to be delivered on IO */
908 };
909 
910 /**
911  * struct file_ra_state - Track a file's readahead state.
912  * @start: Where the most recent readahead started.
913  * @size: Number of pages read in the most recent readahead.
914  * @async_size: Numer of pages that were/are not needed immediately
915  *      and so were/are genuinely "ahead".  Start next readahead when
916  *      the first of these pages is accessed.
917  * @ra_pages: Maximum size of a readahead request, copied from the bdi.
918  * @mmap_miss: How many mmap accesses missed in the page cache.
919  * @prev_pos: The last byte in the most recent read request.
920  *
921  * When this structure is passed to ->readahead(), the "most recent"
922  * readahead means the current readahead.
923  */
924 struct file_ra_state {
925 	pgoff_t start;
926 	unsigned int size;
927 	unsigned int async_size;
928 	unsigned int ra_pages;
929 	unsigned int mmap_miss;
930 	loff_t prev_pos;
931 };
932 
933 /*
934  * Check if @index falls in the readahead windows.
935  */
ra_has_index(struct file_ra_state * ra,pgoff_t index)936 static inline int ra_has_index(struct file_ra_state *ra, pgoff_t index)
937 {
938 	return (index >= ra->start &&
939 		index <  ra->start + ra->size);
940 }
941 
942 struct file {
943 	union {
944 		struct llist_node	f_llist;
945 		struct rcu_head 	f_rcuhead;
946 		unsigned int 		f_iocb_flags;
947 	};
948 	struct path		f_path;
949 	struct inode		*f_inode;	/* cached value */
950 	const struct file_operations	*f_op;
951 
952 	/*
953 	 * Protects f_ep, f_flags.
954 	 * Must not be taken from IRQ context.
955 	 */
956 	spinlock_t		f_lock;
957 	atomic_long_t		f_count;
958 	unsigned int 		f_flags;
959 	fmode_t			f_mode;
960 	struct mutex		f_pos_lock;
961 	loff_t			f_pos;
962 	struct fown_struct	f_owner;
963 	const struct cred	*f_cred;
964 	struct file_ra_state	f_ra;
965 
966 	u64			f_version;
967 #ifdef CONFIG_SECURITY
968 	void			*f_security;
969 #endif
970 	/* needed for tty driver, and maybe others */
971 	void			*private_data;
972 
973 #ifdef CONFIG_EPOLL
974 	/* Used by fs/eventpoll.c to link all the hooks to this file */
975 	struct hlist_head	*f_ep;
976 #endif /* #ifdef CONFIG_EPOLL */
977 	struct address_space	*f_mapping;
978 	errseq_t		f_wb_err;
979 	errseq_t		f_sb_err; /* for syncfs */
980 } __randomize_layout
981   __attribute__((aligned(4)));	/* lest something weird decides that 2 is OK */
982 
983 struct file_handle {
984 	__u32 handle_bytes;
985 	int handle_type;
986 	/* file identifier */
987 	unsigned char f_handle[];
988 };
989 
get_file(struct file * f)990 static inline struct file *get_file(struct file *f)
991 {
992 	atomic_long_inc(&f->f_count);
993 	return f;
994 }
995 #define get_file_rcu(x) atomic_long_inc_not_zero(&(x)->f_count)
996 #define file_count(x)	atomic_long_read(&(x)->f_count)
997 
998 #define	MAX_NON_LFS	((1UL<<31) - 1)
999 
1000 /* Page cache limit. The filesystems should put that into their s_maxbytes
1001    limits, otherwise bad things can happen in VM. */
1002 #if BITS_PER_LONG==32
1003 #define MAX_LFS_FILESIZE	((loff_t)ULONG_MAX << PAGE_SHIFT)
1004 #elif BITS_PER_LONG==64
1005 #define MAX_LFS_FILESIZE 	((loff_t)LLONG_MAX)
1006 #endif
1007 
1008 /* legacy typedef, should eventually be removed */
1009 typedef void *fl_owner_t;
1010 
1011 struct file_lock;
1012 
1013 /* The following constant reflects the upper bound of the file/locking space */
1014 #ifndef OFFSET_MAX
1015 #define OFFSET_MAX	type_max(loff_t)
1016 #define OFFT_OFFSET_MAX	type_max(off_t)
1017 #endif
1018 
1019 extern void send_sigio(struct fown_struct *fown, int fd, int band);
1020 
file_inode(const struct file * f)1021 static inline struct inode *file_inode(const struct file *f)
1022 {
1023 	return f->f_inode;
1024 }
1025 
file_dentry(const struct file * file)1026 static inline struct dentry *file_dentry(const struct file *file)
1027 {
1028 	return d_real(file->f_path.dentry, file_inode(file));
1029 }
1030 
1031 struct fasync_struct {
1032 	rwlock_t		fa_lock;
1033 	int			magic;
1034 	int			fa_fd;
1035 	struct fasync_struct	*fa_next; /* singly linked list */
1036 	struct file		*fa_file;
1037 	struct rcu_head		fa_rcu;
1038 };
1039 
1040 #define FASYNC_MAGIC 0x4601
1041 
1042 /* SMP safe fasync helpers: */
1043 extern int fasync_helper(int, struct file *, int, struct fasync_struct **);
1044 extern struct fasync_struct *fasync_insert_entry(int, struct file *, struct fasync_struct **, struct fasync_struct *);
1045 extern int fasync_remove_entry(struct file *, struct fasync_struct **);
1046 extern struct fasync_struct *fasync_alloc(void);
1047 extern void fasync_free(struct fasync_struct *);
1048 
1049 /* can be called from interrupts */
1050 extern void kill_fasync(struct fasync_struct **, int, int);
1051 
1052 extern void __f_setown(struct file *filp, struct pid *, enum pid_type, int force);
1053 extern int f_setown(struct file *filp, unsigned long arg, int force);
1054 extern void f_delown(struct file *filp);
1055 extern pid_t f_getown(struct file *filp);
1056 extern int send_sigurg(struct fown_struct *fown);
1057 
1058 /*
1059  * sb->s_flags.  Note that these mirror the equivalent MS_* flags where
1060  * represented in both.
1061  */
1062 #define SB_RDONLY	 1	/* Mount read-only */
1063 #define SB_NOSUID	 2	/* Ignore suid and sgid bits */
1064 #define SB_NODEV	 4	/* Disallow access to device special files */
1065 #define SB_NOEXEC	 8	/* Disallow program execution */
1066 #define SB_SYNCHRONOUS	16	/* Writes are synced at once */
1067 #define SB_MANDLOCK	64	/* Allow mandatory locks on an FS */
1068 #define SB_DIRSYNC	128	/* Directory modifications are synchronous */
1069 #define SB_NOATIME	1024	/* Do not update access times. */
1070 #define SB_NODIRATIME	2048	/* Do not update directory access times */
1071 #define SB_SILENT	32768
1072 #define SB_POSIXACL	(1<<16)	/* VFS does not apply the umask */
1073 #define SB_INLINECRYPT	(1<<17)	/* Use blk-crypto for encrypted files */
1074 #define SB_KERNMOUNT	(1<<22) /* this is a kern_mount call */
1075 #define SB_I_VERSION	(1<<23) /* Update inode I_version field */
1076 #define SB_LAZYTIME	(1<<25) /* Update the on-disk [acm]times lazily */
1077 
1078 /* These sb flags are internal to the kernel */
1079 #define SB_SUBMOUNT     (1<<26)
1080 #define SB_FORCE    	(1<<27)
1081 #define SB_NOSEC	(1<<28)
1082 #define SB_BORN		(1<<29)
1083 #define SB_ACTIVE	(1<<30)
1084 #define SB_NOUSER	(1<<31)
1085 
1086 /* These flags relate to encoding and casefolding */
1087 #define SB_ENC_STRICT_MODE_FL	(1 << 0)
1088 
1089 #define sb_has_strict_encoding(sb) \
1090 	(sb->s_encoding_flags & SB_ENC_STRICT_MODE_FL)
1091 
1092 /*
1093  *	Umount options
1094  */
1095 
1096 #define MNT_FORCE	0x00000001	/* Attempt to forcibily umount */
1097 #define MNT_DETACH	0x00000002	/* Just detach from the tree */
1098 #define MNT_EXPIRE	0x00000004	/* Mark for expiry */
1099 #define UMOUNT_NOFOLLOW	0x00000008	/* Don't follow symlink on umount */
1100 #define UMOUNT_UNUSED	0x80000000	/* Flag guaranteed to be unused */
1101 
1102 /* sb->s_iflags */
1103 #define SB_I_CGROUPWB	0x00000001	/* cgroup-aware writeback enabled */
1104 #define SB_I_NOEXEC	0x00000002	/* Ignore executables on this fs */
1105 #define SB_I_NODEV	0x00000004	/* Ignore devices on this fs */
1106 #define SB_I_STABLE_WRITES 0x00000008	/* don't modify blks until WB is done */
1107 
1108 /* sb->s_iflags to limit user namespace mounts */
1109 #define SB_I_USERNS_VISIBLE		0x00000010 /* fstype already mounted */
1110 #define SB_I_IMA_UNVERIFIABLE_SIGNATURE	0x00000020
1111 #define SB_I_UNTRUSTED_MOUNTER		0x00000040
1112 
1113 #define SB_I_SKIP_SYNC	0x00000100	/* Skip superblock at global sync */
1114 #define SB_I_PERSB_BDI	0x00000200	/* has a per-sb bdi */
1115 #define SB_I_TS_EXPIRY_WARNED 0x00000400 /* warned about timestamp range expiry */
1116 #define SB_I_RETIRED	0x00000800	/* superblock shouldn't be reused */
1117 
1118 /* Possible states of 'frozen' field */
1119 enum {
1120 	SB_UNFROZEN = 0,		/* FS is unfrozen */
1121 	SB_FREEZE_WRITE	= 1,		/* Writes, dir ops, ioctls frozen */
1122 	SB_FREEZE_PAGEFAULT = 2,	/* Page faults stopped as well */
1123 	SB_FREEZE_FS = 3,		/* For internal FS use (e.g. to stop
1124 					 * internal threads if needed) */
1125 	SB_FREEZE_COMPLETE = 4,		/* ->freeze_fs finished successfully */
1126 };
1127 
1128 #define SB_FREEZE_LEVELS (SB_FREEZE_COMPLETE - 1)
1129 
1130 struct sb_writers {
1131 	int				frozen;		/* Is sb frozen? */
1132 	wait_queue_head_t		wait_unfrozen;	/* wait for thaw */
1133 	struct percpu_rw_semaphore	rw_sem[SB_FREEZE_LEVELS];
1134 };
1135 
1136 struct super_block {
1137 	struct list_head	s_list;		/* Keep this first */
1138 	dev_t			s_dev;		/* search index; _not_ kdev_t */
1139 	unsigned char		s_blocksize_bits;
1140 	unsigned long		s_blocksize;
1141 	loff_t			s_maxbytes;	/* Max file size */
1142 	struct file_system_type	*s_type;
1143 	const struct super_operations	*s_op;
1144 	const struct dquot_operations	*dq_op;
1145 	const struct quotactl_ops	*s_qcop;
1146 	const struct export_operations *s_export_op;
1147 	unsigned long		s_flags;
1148 	unsigned long		s_iflags;	/* internal SB_I_* flags */
1149 	unsigned long		s_magic;
1150 	struct dentry		*s_root;
1151 	struct rw_semaphore	s_umount;
1152 	int			s_count;
1153 	atomic_t		s_active;
1154 #ifdef CONFIG_SECURITY
1155 	void                    *s_security;
1156 #endif
1157 	const struct xattr_handler **s_xattr;
1158 #ifdef CONFIG_FS_ENCRYPTION
1159 	const struct fscrypt_operations	*s_cop;
1160 	struct fscrypt_keyring	*s_master_keys; /* master crypto keys in use */
1161 #endif
1162 #ifdef CONFIG_FS_VERITY
1163 	const struct fsverity_operations *s_vop;
1164 #endif
1165 #if IS_ENABLED(CONFIG_UNICODE)
1166 	struct unicode_map *s_encoding;
1167 	__u16 s_encoding_flags;
1168 #endif
1169 	struct hlist_bl_head	s_roots;	/* alternate root dentries for NFS */
1170 	struct list_head	s_mounts;	/* list of mounts; _not_ for fs use */
1171 	struct block_device	*s_bdev;
1172 	struct backing_dev_info *s_bdi;
1173 	struct mtd_info		*s_mtd;
1174 	struct hlist_node	s_instances;
1175 	unsigned int		s_quota_types;	/* Bitmask of supported quota types */
1176 	struct quota_info	s_dquot;	/* Diskquota specific options */
1177 
1178 	struct sb_writers	s_writers;
1179 
1180 	/*
1181 	 * Keep s_fs_info, s_time_gran, s_fsnotify_mask, and
1182 	 * s_fsnotify_marks together for cache efficiency. They are frequently
1183 	 * accessed and rarely modified.
1184 	 */
1185 	void			*s_fs_info;	/* Filesystem private info */
1186 
1187 	/* Granularity of c/m/atime in ns (cannot be worse than a second) */
1188 	u32			s_time_gran;
1189 	/* Time limits for c/m/atime in seconds */
1190 	time64_t		   s_time_min;
1191 	time64_t		   s_time_max;
1192 #ifdef CONFIG_FSNOTIFY
1193 	__u32			s_fsnotify_mask;
1194 	struct fsnotify_mark_connector __rcu	*s_fsnotify_marks;
1195 #endif
1196 
1197 	char			s_id[32];	/* Informational name */
1198 	uuid_t			s_uuid;		/* UUID */
1199 
1200 	unsigned int		s_max_links;
1201 	fmode_t			s_mode;
1202 
1203 	/*
1204 	 * The next field is for VFS *only*. No filesystems have any business
1205 	 * even looking at it. You had been warned.
1206 	 */
1207 	struct mutex s_vfs_rename_mutex;	/* Kludge */
1208 
1209 	/*
1210 	 * Filesystem subtype.  If non-empty the filesystem type field
1211 	 * in /proc/mounts will be "type.subtype"
1212 	 */
1213 	const char *s_subtype;
1214 
1215 	const struct dentry_operations *s_d_op; /* default d_op for dentries */
1216 
1217 	struct shrinker s_shrink;	/* per-sb shrinker handle */
1218 
1219 	/* Number of inodes with nlink == 0 but still referenced */
1220 	atomic_long_t s_remove_count;
1221 
1222 	/*
1223 	 * Number of inode/mount/sb objects that are being watched, note that
1224 	 * inodes objects are currently double-accounted.
1225 	 */
1226 	atomic_long_t s_fsnotify_connectors;
1227 
1228 	/* Being remounted read-only */
1229 	int s_readonly_remount;
1230 
1231 	/* per-sb errseq_t for reporting writeback errors via syncfs */
1232 	errseq_t s_wb_err;
1233 
1234 	/* AIO completions deferred from interrupt context */
1235 	struct workqueue_struct *s_dio_done_wq;
1236 	struct hlist_head s_pins;
1237 
1238 	/*
1239 	 * Owning user namespace and default context in which to
1240 	 * interpret filesystem uids, gids, quotas, device nodes,
1241 	 * xattrs and security labels.
1242 	 */
1243 	struct user_namespace *s_user_ns;
1244 
1245 	/*
1246 	 * The list_lru structure is essentially just a pointer to a table
1247 	 * of per-node lru lists, each of which has its own spinlock.
1248 	 * There is no need to put them into separate cachelines.
1249 	 */
1250 	struct list_lru		s_dentry_lru;
1251 	struct list_lru		s_inode_lru;
1252 	struct rcu_head		rcu;
1253 	struct work_struct	destroy_work;
1254 
1255 	struct mutex		s_sync_lock;	/* sync serialisation lock */
1256 
1257 	/*
1258 	 * Indicates how deep in a filesystem stack this SB is
1259 	 */
1260 	int s_stack_depth;
1261 
1262 	/* s_inode_list_lock protects s_inodes */
1263 	spinlock_t		s_inode_list_lock ____cacheline_aligned_in_smp;
1264 	struct list_head	s_inodes;	/* all inodes */
1265 
1266 	spinlock_t		s_inode_wblist_lock;
1267 	struct list_head	s_inodes_wb;	/* writeback inodes */
1268 } __randomize_layout;
1269 
i_user_ns(const struct inode * inode)1270 static inline struct user_namespace *i_user_ns(const struct inode *inode)
1271 {
1272 	return inode->i_sb->s_user_ns;
1273 }
1274 
1275 /* Helper functions so that in most cases filesystems will
1276  * not need to deal directly with kuid_t and kgid_t and can
1277  * instead deal with the raw numeric values that are stored
1278  * in the filesystem.
1279  */
i_uid_read(const struct inode * inode)1280 static inline uid_t i_uid_read(const struct inode *inode)
1281 {
1282 	return from_kuid(i_user_ns(inode), inode->i_uid);
1283 }
1284 
i_gid_read(const struct inode * inode)1285 static inline gid_t i_gid_read(const struct inode *inode)
1286 {
1287 	return from_kgid(i_user_ns(inode), inode->i_gid);
1288 }
1289 
i_uid_write(struct inode * inode,uid_t uid)1290 static inline void i_uid_write(struct inode *inode, uid_t uid)
1291 {
1292 	inode->i_uid = make_kuid(i_user_ns(inode), uid);
1293 }
1294 
i_gid_write(struct inode * inode,gid_t gid)1295 static inline void i_gid_write(struct inode *inode, gid_t gid)
1296 {
1297 	inode->i_gid = make_kgid(i_user_ns(inode), gid);
1298 }
1299 
1300 /**
1301  * i_uid_into_vfsuid - map an inode's i_uid down according to an idmapping
1302  * @idmap: idmap of the mount the inode was found from
1303  * @inode: inode to map
1304  *
1305  * Return: whe inode's i_uid mapped down according to @idmap.
1306  * If the inode's i_uid has no mapping INVALID_VFSUID is returned.
1307  */
i_uid_into_vfsuid(struct mnt_idmap * idmap,const struct inode * inode)1308 static inline vfsuid_t i_uid_into_vfsuid(struct mnt_idmap *idmap,
1309 					 const struct inode *inode)
1310 {
1311 	return make_vfsuid(idmap, i_user_ns(inode), inode->i_uid);
1312 }
1313 
1314 /**
1315  * i_uid_needs_update - check whether inode's i_uid needs to be updated
1316  * @idmap: idmap of the mount the inode was found from
1317  * @attr: the new attributes of @inode
1318  * @inode: the inode to update
1319  *
1320  * Check whether the $inode's i_uid field needs to be updated taking idmapped
1321  * mounts into account if the filesystem supports it.
1322  *
1323  * Return: true if @inode's i_uid field needs to be updated, false if not.
1324  */
i_uid_needs_update(struct mnt_idmap * idmap,const struct iattr * attr,const struct inode * inode)1325 static inline bool i_uid_needs_update(struct mnt_idmap *idmap,
1326 				      const struct iattr *attr,
1327 				      const struct inode *inode)
1328 {
1329 	return ((attr->ia_valid & ATTR_UID) &&
1330 		!vfsuid_eq(attr->ia_vfsuid,
1331 			   i_uid_into_vfsuid(idmap, inode)));
1332 }
1333 
1334 /**
1335  * i_uid_update - update @inode's i_uid field
1336  * @idmap: idmap of the mount the inode was found from
1337  * @attr: the new attributes of @inode
1338  * @inode: the inode to update
1339  *
1340  * Safely update @inode's i_uid field translating the vfsuid of any idmapped
1341  * mount into the filesystem kuid.
1342  */
i_uid_update(struct mnt_idmap * idmap,const struct iattr * attr,struct inode * inode)1343 static inline void i_uid_update(struct mnt_idmap *idmap,
1344 				const struct iattr *attr,
1345 				struct inode *inode)
1346 {
1347 	if (attr->ia_valid & ATTR_UID)
1348 		inode->i_uid = from_vfsuid(idmap, i_user_ns(inode),
1349 					   attr->ia_vfsuid);
1350 }
1351 
1352 /**
1353  * i_gid_into_vfsgid - map an inode's i_gid down according to an idmapping
1354  * @idmap: idmap of the mount the inode was found from
1355  * @inode: inode to map
1356  *
1357  * Return: the inode's i_gid mapped down according to @idmap.
1358  * If the inode's i_gid has no mapping INVALID_VFSGID is returned.
1359  */
i_gid_into_vfsgid(struct mnt_idmap * idmap,const struct inode * inode)1360 static inline vfsgid_t i_gid_into_vfsgid(struct mnt_idmap *idmap,
1361 					 const struct inode *inode)
1362 {
1363 	return make_vfsgid(idmap, i_user_ns(inode), inode->i_gid);
1364 }
1365 
1366 /**
1367  * i_gid_needs_update - check whether inode's i_gid needs to be updated
1368  * @idmap: idmap of the mount the inode was found from
1369  * @attr: the new attributes of @inode
1370  * @inode: the inode to update
1371  *
1372  * Check whether the $inode's i_gid field needs to be updated taking idmapped
1373  * mounts into account if the filesystem supports it.
1374  *
1375  * Return: true if @inode's i_gid field needs to be updated, false if not.
1376  */
i_gid_needs_update(struct mnt_idmap * idmap,const struct iattr * attr,const struct inode * inode)1377 static inline bool i_gid_needs_update(struct mnt_idmap *idmap,
1378 				      const struct iattr *attr,
1379 				      const struct inode *inode)
1380 {
1381 	return ((attr->ia_valid & ATTR_GID) &&
1382 		!vfsgid_eq(attr->ia_vfsgid,
1383 			   i_gid_into_vfsgid(idmap, inode)));
1384 }
1385 
1386 /**
1387  * i_gid_update - update @inode's i_gid field
1388  * @idmap: idmap of the mount the inode was found from
1389  * @attr: the new attributes of @inode
1390  * @inode: the inode to update
1391  *
1392  * Safely update @inode's i_gid field translating the vfsgid of any idmapped
1393  * mount into the filesystem kgid.
1394  */
i_gid_update(struct mnt_idmap * idmap,const struct iattr * attr,struct inode * inode)1395 static inline void i_gid_update(struct mnt_idmap *idmap,
1396 				const struct iattr *attr,
1397 				struct inode *inode)
1398 {
1399 	if (attr->ia_valid & ATTR_GID)
1400 		inode->i_gid = from_vfsgid(idmap, i_user_ns(inode),
1401 					   attr->ia_vfsgid);
1402 }
1403 
1404 /**
1405  * inode_fsuid_set - initialize inode's i_uid field with callers fsuid
1406  * @inode: inode to initialize
1407  * @idmap: idmap of the mount the inode was found from
1408  *
1409  * Initialize the i_uid field of @inode. If the inode was found/created via
1410  * an idmapped mount map the caller's fsuid according to @idmap.
1411  */
inode_fsuid_set(struct inode * inode,struct mnt_idmap * idmap)1412 static inline void inode_fsuid_set(struct inode *inode,
1413 				   struct mnt_idmap *idmap)
1414 {
1415 	inode->i_uid = mapped_fsuid(idmap, i_user_ns(inode));
1416 }
1417 
1418 /**
1419  * inode_fsgid_set - initialize inode's i_gid field with callers fsgid
1420  * @inode: inode to initialize
1421  * @idmap: idmap of the mount the inode was found from
1422  *
1423  * Initialize the i_gid field of @inode. If the inode was found/created via
1424  * an idmapped mount map the caller's fsgid according to @idmap.
1425  */
inode_fsgid_set(struct inode * inode,struct mnt_idmap * idmap)1426 static inline void inode_fsgid_set(struct inode *inode,
1427 				   struct mnt_idmap *idmap)
1428 {
1429 	inode->i_gid = mapped_fsgid(idmap, i_user_ns(inode));
1430 }
1431 
1432 /**
1433  * fsuidgid_has_mapping() - check whether caller's fsuid/fsgid is mapped
1434  * @sb: the superblock we want a mapping in
1435  * @idmap: idmap of the relevant mount
1436  *
1437  * Check whether the caller's fsuid and fsgid have a valid mapping in the
1438  * s_user_ns of the superblock @sb. If the caller is on an idmapped mount map
1439  * the caller's fsuid and fsgid according to the @idmap first.
1440  *
1441  * Return: true if fsuid and fsgid is mapped, false if not.
1442  */
fsuidgid_has_mapping(struct super_block * sb,struct mnt_idmap * idmap)1443 static inline bool fsuidgid_has_mapping(struct super_block *sb,
1444 					struct mnt_idmap *idmap)
1445 {
1446 	struct user_namespace *fs_userns = sb->s_user_ns;
1447 	kuid_t kuid;
1448 	kgid_t kgid;
1449 
1450 	kuid = mapped_fsuid(idmap, fs_userns);
1451 	if (!uid_valid(kuid))
1452 		return false;
1453 	kgid = mapped_fsgid(idmap, fs_userns);
1454 	if (!gid_valid(kgid))
1455 		return false;
1456 	return kuid_has_mapping(fs_userns, kuid) &&
1457 	       kgid_has_mapping(fs_userns, kgid);
1458 }
1459 
1460 extern struct timespec64 current_time(struct inode *inode);
1461 
1462 /*
1463  * Snapshotting support.
1464  */
1465 
1466 /*
1467  * These are internal functions, please use sb_start_{write,pagefault,intwrite}
1468  * instead.
1469  */
__sb_end_write(struct super_block * sb,int level)1470 static inline void __sb_end_write(struct super_block *sb, int level)
1471 {
1472 	percpu_up_read(sb->s_writers.rw_sem + level-1);
1473 }
1474 
__sb_start_write(struct super_block * sb,int level)1475 static inline void __sb_start_write(struct super_block *sb, int level)
1476 {
1477 	percpu_down_read(sb->s_writers.rw_sem + level - 1);
1478 }
1479 
__sb_start_write_trylock(struct super_block * sb,int level)1480 static inline bool __sb_start_write_trylock(struct super_block *sb, int level)
1481 {
1482 	return percpu_down_read_trylock(sb->s_writers.rw_sem + level - 1);
1483 }
1484 
1485 #define __sb_writers_acquired(sb, lev)	\
1486 	percpu_rwsem_acquire(&(sb)->s_writers.rw_sem[(lev)-1], 1, _THIS_IP_)
1487 #define __sb_writers_release(sb, lev)	\
1488 	percpu_rwsem_release(&(sb)->s_writers.rw_sem[(lev)-1], 1, _THIS_IP_)
1489 
sb_write_started(const struct super_block * sb)1490 static inline bool sb_write_started(const struct super_block *sb)
1491 {
1492 	return lockdep_is_held_type(sb->s_writers.rw_sem + SB_FREEZE_WRITE - 1, 1);
1493 }
1494 
1495 /**
1496  * sb_end_write - drop write access to a superblock
1497  * @sb: the super we wrote to
1498  *
1499  * Decrement number of writers to the filesystem. Wake up possible waiters
1500  * wanting to freeze the filesystem.
1501  */
sb_end_write(struct super_block * sb)1502 static inline void sb_end_write(struct super_block *sb)
1503 {
1504 	__sb_end_write(sb, SB_FREEZE_WRITE);
1505 }
1506 
1507 /**
1508  * sb_end_pagefault - drop write access to a superblock from a page fault
1509  * @sb: the super we wrote to
1510  *
1511  * Decrement number of processes handling write page fault to the filesystem.
1512  * Wake up possible waiters wanting to freeze the filesystem.
1513  */
sb_end_pagefault(struct super_block * sb)1514 static inline void sb_end_pagefault(struct super_block *sb)
1515 {
1516 	__sb_end_write(sb, SB_FREEZE_PAGEFAULT);
1517 }
1518 
1519 /**
1520  * sb_end_intwrite - drop write access to a superblock for internal fs purposes
1521  * @sb: the super we wrote to
1522  *
1523  * Decrement fs-internal number of writers to the filesystem.  Wake up possible
1524  * waiters wanting to freeze the filesystem.
1525  */
sb_end_intwrite(struct super_block * sb)1526 static inline void sb_end_intwrite(struct super_block *sb)
1527 {
1528 	__sb_end_write(sb, SB_FREEZE_FS);
1529 }
1530 
1531 /**
1532  * sb_start_write - get write access to a superblock
1533  * @sb: the super we write to
1534  *
1535  * When a process wants to write data or metadata to a file system (i.e. dirty
1536  * a page or an inode), it should embed the operation in a sb_start_write() -
1537  * sb_end_write() pair to get exclusion against file system freezing. This
1538  * function increments number of writers preventing freezing. If the file
1539  * system is already frozen, the function waits until the file system is
1540  * thawed.
1541  *
1542  * Since freeze protection behaves as a lock, users have to preserve
1543  * ordering of freeze protection and other filesystem locks. Generally,
1544  * freeze protection should be the outermost lock. In particular, we have:
1545  *
1546  * sb_start_write
1547  *   -> i_mutex			(write path, truncate, directory ops, ...)
1548  *   -> s_umount		(freeze_super, thaw_super)
1549  */
sb_start_write(struct super_block * sb)1550 static inline void sb_start_write(struct super_block *sb)
1551 {
1552 	__sb_start_write(sb, SB_FREEZE_WRITE);
1553 }
1554 
sb_start_write_trylock(struct super_block * sb)1555 static inline bool sb_start_write_trylock(struct super_block *sb)
1556 {
1557 	return __sb_start_write_trylock(sb, SB_FREEZE_WRITE);
1558 }
1559 
1560 /**
1561  * sb_start_pagefault - get write access to a superblock from a page fault
1562  * @sb: the super we write to
1563  *
1564  * When a process starts handling write page fault, it should embed the
1565  * operation into sb_start_pagefault() - sb_end_pagefault() pair to get
1566  * exclusion against file system freezing. This is needed since the page fault
1567  * is going to dirty a page. This function increments number of running page
1568  * faults preventing freezing. If the file system is already frozen, the
1569  * function waits until the file system is thawed.
1570  *
1571  * Since page fault freeze protection behaves as a lock, users have to preserve
1572  * ordering of freeze protection and other filesystem locks. It is advised to
1573  * put sb_start_pagefault() close to mmap_lock in lock ordering. Page fault
1574  * handling code implies lock dependency:
1575  *
1576  * mmap_lock
1577  *   -> sb_start_pagefault
1578  */
sb_start_pagefault(struct super_block * sb)1579 static inline void sb_start_pagefault(struct super_block *sb)
1580 {
1581 	__sb_start_write(sb, SB_FREEZE_PAGEFAULT);
1582 }
1583 
1584 /**
1585  * sb_start_intwrite - get write access to a superblock for internal fs purposes
1586  * @sb: the super we write to
1587  *
1588  * This is the third level of protection against filesystem freezing. It is
1589  * free for use by a filesystem. The only requirement is that it must rank
1590  * below sb_start_pagefault.
1591  *
1592  * For example filesystem can call sb_start_intwrite() when starting a
1593  * transaction which somewhat eases handling of freezing for internal sources
1594  * of filesystem changes (internal fs threads, discarding preallocation on file
1595  * close, etc.).
1596  */
sb_start_intwrite(struct super_block * sb)1597 static inline void sb_start_intwrite(struct super_block *sb)
1598 {
1599 	__sb_start_write(sb, SB_FREEZE_FS);
1600 }
1601 
sb_start_intwrite_trylock(struct super_block * sb)1602 static inline bool sb_start_intwrite_trylock(struct super_block *sb)
1603 {
1604 	return __sb_start_write_trylock(sb, SB_FREEZE_FS);
1605 }
1606 
1607 bool inode_owner_or_capable(struct mnt_idmap *idmap,
1608 			    const struct inode *inode);
1609 
1610 /*
1611  * VFS helper functions..
1612  */
1613 int vfs_create(struct mnt_idmap *, struct inode *,
1614 	       struct dentry *, umode_t, bool);
1615 int vfs_mkdir(struct mnt_idmap *, struct inode *,
1616 	      struct dentry *, umode_t);
1617 int vfs_mknod(struct mnt_idmap *, struct inode *, struct dentry *,
1618               umode_t, dev_t);
1619 int vfs_symlink(struct mnt_idmap *, struct inode *,
1620 		struct dentry *, const char *);
1621 int vfs_link(struct dentry *, struct mnt_idmap *, struct inode *,
1622 	     struct dentry *, struct inode **);
1623 int vfs_rmdir(struct mnt_idmap *, struct inode *, struct dentry *);
1624 int vfs_unlink(struct mnt_idmap *, struct inode *, struct dentry *,
1625 	       struct inode **);
1626 
1627 /**
1628  * struct renamedata - contains all information required for renaming
1629  * @old_mnt_idmap:     idmap of the old mount the inode was found from
1630  * @old_dir:           parent of source
1631  * @old_dentry:                source
1632  * @new_mnt_idmap:     idmap of the new mount the inode was found from
1633  * @new_dir:           parent of destination
1634  * @new_dentry:                destination
1635  * @delegated_inode:   returns an inode needing a delegation break
1636  * @flags:             rename flags
1637  */
1638 struct renamedata {
1639 	struct mnt_idmap *old_mnt_idmap;
1640 	struct inode *old_dir;
1641 	struct dentry *old_dentry;
1642 	struct mnt_idmap *new_mnt_idmap;
1643 	struct inode *new_dir;
1644 	struct dentry *new_dentry;
1645 	struct inode **delegated_inode;
1646 	unsigned int flags;
1647 } __randomize_layout;
1648 
1649 int vfs_rename(struct renamedata *);
1650 
vfs_whiteout(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry)1651 static inline int vfs_whiteout(struct mnt_idmap *idmap,
1652 			       struct inode *dir, struct dentry *dentry)
1653 {
1654 	return vfs_mknod(idmap, dir, dentry, S_IFCHR | WHITEOUT_MODE,
1655 			 WHITEOUT_DEV);
1656 }
1657 
1658 struct file *vfs_tmpfile_open(struct mnt_idmap *idmap,
1659 			const struct path *parentpath,
1660 			umode_t mode, int open_flag, const struct cred *cred);
1661 
1662 int vfs_mkobj(struct dentry *, umode_t,
1663 		int (*f)(struct dentry *, umode_t, void *),
1664 		void *);
1665 
1666 int vfs_fchown(struct file *file, uid_t user, gid_t group);
1667 int vfs_fchmod(struct file *file, umode_t mode);
1668 int vfs_utimes(const struct path *path, struct timespec64 *times);
1669 
1670 extern long vfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
1671 
1672 #ifdef CONFIG_COMPAT
1673 extern long compat_ptr_ioctl(struct file *file, unsigned int cmd,
1674 					unsigned long arg);
1675 #else
1676 #define compat_ptr_ioctl NULL
1677 #endif
1678 
1679 /*
1680  * VFS file helper functions.
1681  */
1682 void inode_init_owner(struct mnt_idmap *idmap, struct inode *inode,
1683 		      const struct inode *dir, umode_t mode);
1684 extern bool may_open_dev(const struct path *path);
1685 umode_t mode_strip_sgid(struct mnt_idmap *idmap,
1686 			const struct inode *dir, umode_t mode);
1687 
1688 /*
1689  * This is the "filldir" function type, used by readdir() to let
1690  * the kernel specify what kind of dirent layout it wants to have.
1691  * This allows the kernel to read directories into kernel space or
1692  * to have different dirent layouts depending on the binary type.
1693  * Return 'true' to keep going and 'false' if there are no more entries.
1694  */
1695 struct dir_context;
1696 typedef bool (*filldir_t)(struct dir_context *, const char *, int, loff_t, u64,
1697 			 unsigned);
1698 
1699 struct dir_context {
1700 	filldir_t actor;
1701 	loff_t pos;
1702 };
1703 
1704 /*
1705  * These flags let !MMU mmap() govern direct device mapping vs immediate
1706  * copying more easily for MAP_PRIVATE, especially for ROM filesystems.
1707  *
1708  * NOMMU_MAP_COPY:	Copy can be mapped (MAP_PRIVATE)
1709  * NOMMU_MAP_DIRECT:	Can be mapped directly (MAP_SHARED)
1710  * NOMMU_MAP_READ:	Can be mapped for reading
1711  * NOMMU_MAP_WRITE:	Can be mapped for writing
1712  * NOMMU_MAP_EXEC:	Can be mapped for execution
1713  */
1714 #define NOMMU_MAP_COPY		0x00000001
1715 #define NOMMU_MAP_DIRECT	0x00000008
1716 #define NOMMU_MAP_READ		VM_MAYREAD
1717 #define NOMMU_MAP_WRITE		VM_MAYWRITE
1718 #define NOMMU_MAP_EXEC		VM_MAYEXEC
1719 
1720 #define NOMMU_VMFLAGS \
1721 	(NOMMU_MAP_READ | NOMMU_MAP_WRITE | NOMMU_MAP_EXEC)
1722 
1723 /*
1724  * These flags control the behavior of the remap_file_range function pointer.
1725  * If it is called with len == 0 that means "remap to end of source file".
1726  * See Documentation/filesystems/vfs.rst for more details about this call.
1727  *
1728  * REMAP_FILE_DEDUP: only remap if contents identical (i.e. deduplicate)
1729  * REMAP_FILE_CAN_SHORTEN: caller can handle a shortened request
1730  */
1731 #define REMAP_FILE_DEDUP		(1 << 0)
1732 #define REMAP_FILE_CAN_SHORTEN		(1 << 1)
1733 
1734 /*
1735  * These flags signal that the caller is ok with altering various aspects of
1736  * the behavior of the remap operation.  The changes must be made by the
1737  * implementation; the vfs remap helper functions can take advantage of them.
1738  * Flags in this category exist to preserve the quirky behavior of the hoisted
1739  * btrfs clone/dedupe ioctls.
1740  */
1741 #define REMAP_FILE_ADVISORY		(REMAP_FILE_CAN_SHORTEN)
1742 
1743 /*
1744  * These flags control the behavior of vfs_copy_file_range().
1745  * They are not available to the user via syscall.
1746  *
1747  * COPY_FILE_SPLICE: call splice direct instead of fs clone/copy ops
1748  */
1749 #define COPY_FILE_SPLICE		(1 << 0)
1750 
1751 struct iov_iter;
1752 struct io_uring_cmd;
1753 
1754 struct file_operations {
1755 	struct module *owner;
1756 	loff_t (*llseek) (struct file *, loff_t, int);
1757 	ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
1758 	ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
1759 	ssize_t (*read_iter) (struct kiocb *, struct iov_iter *);
1760 	ssize_t (*write_iter) (struct kiocb *, struct iov_iter *);
1761 	int (*iopoll)(struct kiocb *kiocb, struct io_comp_batch *,
1762 			unsigned int flags);
1763 	int (*iterate) (struct file *, struct dir_context *);
1764 	int (*iterate_shared) (struct file *, struct dir_context *);
1765 	__poll_t (*poll) (struct file *, struct poll_table_struct *);
1766 	long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
1767 	long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
1768 	int (*mmap) (struct file *, struct vm_area_struct *);
1769 	unsigned long mmap_supported_flags;
1770 	int (*open) (struct inode *, struct file *);
1771 	int (*flush) (struct file *, fl_owner_t id);
1772 	int (*release) (struct inode *, struct file *);
1773 	int (*fsync) (struct file *, loff_t, loff_t, int datasync);
1774 	int (*fasync) (int, struct file *, int);
1775 	int (*lock) (struct file *, int, struct file_lock *);
1776 	ssize_t (*sendpage) (struct file *, struct page *, int, size_t, loff_t *, int);
1777 	unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
1778 	int (*check_flags)(int);
1779 	int (*flock) (struct file *, int, struct file_lock *);
1780 	ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int);
1781 	ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int);
1782 	int (*setlease)(struct file *, long, struct file_lock **, void **);
1783 	long (*fallocate)(struct file *file, int mode, loff_t offset,
1784 			  loff_t len);
1785 	void (*show_fdinfo)(struct seq_file *m, struct file *f);
1786 #ifndef CONFIG_MMU
1787 	unsigned (*mmap_capabilities)(struct file *);
1788 #endif
1789 	ssize_t (*copy_file_range)(struct file *, loff_t, struct file *,
1790 			loff_t, size_t, unsigned int);
1791 	loff_t (*remap_file_range)(struct file *file_in, loff_t pos_in,
1792 				   struct file *file_out, loff_t pos_out,
1793 				   loff_t len, unsigned int remap_flags);
1794 	int (*fadvise)(struct file *, loff_t, loff_t, int);
1795 	int (*uring_cmd)(struct io_uring_cmd *ioucmd, unsigned int issue_flags);
1796 	int (*uring_cmd_iopoll)(struct io_uring_cmd *, struct io_comp_batch *,
1797 				unsigned int poll_flags);
1798 } __randomize_layout;
1799 
1800 struct inode_operations {
1801 	struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int);
1802 	const char * (*get_link) (struct dentry *, struct inode *, struct delayed_call *);
1803 	int (*permission) (struct mnt_idmap *, struct inode *, int);
1804 	struct posix_acl * (*get_inode_acl)(struct inode *, int, bool);
1805 
1806 	int (*readlink) (struct dentry *, char __user *,int);
1807 
1808 	int (*create) (struct mnt_idmap *, struct inode *,struct dentry *,
1809 		       umode_t, bool);
1810 	int (*link) (struct dentry *,struct inode *,struct dentry *);
1811 	int (*unlink) (struct inode *,struct dentry *);
1812 	int (*symlink) (struct mnt_idmap *, struct inode *,struct dentry *,
1813 			const char *);
1814 	int (*mkdir) (struct mnt_idmap *, struct inode *,struct dentry *,
1815 		      umode_t);
1816 	int (*rmdir) (struct inode *,struct dentry *);
1817 	int (*mknod) (struct mnt_idmap *, struct inode *,struct dentry *,
1818 		      umode_t,dev_t);
1819 	int (*rename) (struct mnt_idmap *, struct inode *, struct dentry *,
1820 			struct inode *, struct dentry *, unsigned int);
1821 	int (*setattr) (struct mnt_idmap *, struct dentry *, struct iattr *);
1822 	int (*getattr) (struct mnt_idmap *, const struct path *,
1823 			struct kstat *, u32, unsigned int);
1824 	ssize_t (*listxattr) (struct dentry *, char *, size_t);
1825 	int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start,
1826 		      u64 len);
1827 	int (*update_time)(struct inode *, struct timespec64 *, int);
1828 	int (*atomic_open)(struct inode *, struct dentry *,
1829 			   struct file *, unsigned open_flag,
1830 			   umode_t create_mode);
1831 	int (*tmpfile) (struct mnt_idmap *, struct inode *,
1832 			struct file *, umode_t);
1833 	struct posix_acl *(*get_acl)(struct mnt_idmap *, struct dentry *,
1834 				     int);
1835 	int (*set_acl)(struct mnt_idmap *, struct dentry *,
1836 		       struct posix_acl *, int);
1837 	int (*fileattr_set)(struct mnt_idmap *idmap,
1838 			    struct dentry *dentry, struct fileattr *fa);
1839 	int (*fileattr_get)(struct dentry *dentry, struct fileattr *fa);
1840 } ____cacheline_aligned;
1841 
call_read_iter(struct file * file,struct kiocb * kio,struct iov_iter * iter)1842 static inline ssize_t call_read_iter(struct file *file, struct kiocb *kio,
1843 				     struct iov_iter *iter)
1844 {
1845 	return file->f_op->read_iter(kio, iter);
1846 }
1847 
call_write_iter(struct file * file,struct kiocb * kio,struct iov_iter * iter)1848 static inline ssize_t call_write_iter(struct file *file, struct kiocb *kio,
1849 				      struct iov_iter *iter)
1850 {
1851 	return file->f_op->write_iter(kio, iter);
1852 }
1853 
call_mmap(struct file * file,struct vm_area_struct * vma)1854 static inline int call_mmap(struct file *file, struct vm_area_struct *vma)
1855 {
1856 	return file->f_op->mmap(file, vma);
1857 }
1858 
1859 extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *);
1860 extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *);
1861 extern ssize_t vfs_copy_file_range(struct file *, loff_t , struct file *,
1862 				   loff_t, size_t, unsigned int);
1863 extern ssize_t generic_copy_file_range(struct file *file_in, loff_t pos_in,
1864 				       struct file *file_out, loff_t pos_out,
1865 				       size_t len, unsigned int flags);
1866 int __generic_remap_file_range_prep(struct file *file_in, loff_t pos_in,
1867 				    struct file *file_out, loff_t pos_out,
1868 				    loff_t *len, unsigned int remap_flags,
1869 				    const struct iomap_ops *dax_read_ops);
1870 int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in,
1871 				  struct file *file_out, loff_t pos_out,
1872 				  loff_t *count, unsigned int remap_flags);
1873 extern loff_t do_clone_file_range(struct file *file_in, loff_t pos_in,
1874 				  struct file *file_out, loff_t pos_out,
1875 				  loff_t len, unsigned int remap_flags);
1876 extern loff_t vfs_clone_file_range(struct file *file_in, loff_t pos_in,
1877 				   struct file *file_out, loff_t pos_out,
1878 				   loff_t len, unsigned int remap_flags);
1879 extern int vfs_dedupe_file_range(struct file *file,
1880 				 struct file_dedupe_range *same);
1881 extern loff_t vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos,
1882 					struct file *dst_file, loff_t dst_pos,
1883 					loff_t len, unsigned int remap_flags);
1884 
1885 
1886 struct super_operations {
1887    	struct inode *(*alloc_inode)(struct super_block *sb);
1888 	void (*destroy_inode)(struct inode *);
1889 	void (*free_inode)(struct inode *);
1890 
1891    	void (*dirty_inode) (struct inode *, int flags);
1892 	int (*write_inode) (struct inode *, struct writeback_control *wbc);
1893 	int (*drop_inode) (struct inode *);
1894 	void (*evict_inode) (struct inode *);
1895 	void (*put_super) (struct super_block *);
1896 	int (*sync_fs)(struct super_block *sb, int wait);
1897 	int (*freeze_super) (struct super_block *);
1898 	int (*freeze_fs) (struct super_block *);
1899 	int (*thaw_super) (struct super_block *);
1900 	int (*unfreeze_fs) (struct super_block *);
1901 	int (*statfs) (struct dentry *, struct kstatfs *);
1902 	int (*remount_fs) (struct super_block *, int *, char *);
1903 	void (*umount_begin) (struct super_block *);
1904 
1905 	int (*show_options)(struct seq_file *, struct dentry *);
1906 	int (*show_devname)(struct seq_file *, struct dentry *);
1907 	int (*show_path)(struct seq_file *, struct dentry *);
1908 	int (*show_stats)(struct seq_file *, struct dentry *);
1909 #ifdef CONFIG_QUOTA
1910 	ssize_t (*quota_read)(struct super_block *, int, char *, size_t, loff_t);
1911 	ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t);
1912 	struct dquot **(*get_dquots)(struct inode *);
1913 #endif
1914 	long (*nr_cached_objects)(struct super_block *,
1915 				  struct shrink_control *);
1916 	long (*free_cached_objects)(struct super_block *,
1917 				    struct shrink_control *);
1918 };
1919 
1920 /*
1921  * Inode flags - they have no relation to superblock flags now
1922  */
1923 #define S_SYNC		(1 << 0)  /* Writes are synced at once */
1924 #define S_NOATIME	(1 << 1)  /* Do not update access times */
1925 #define S_APPEND	(1 << 2)  /* Append-only file */
1926 #define S_IMMUTABLE	(1 << 3)  /* Immutable file */
1927 #define S_DEAD		(1 << 4)  /* removed, but still open directory */
1928 #define S_NOQUOTA	(1 << 5)  /* Inode is not counted to quota */
1929 #define S_DIRSYNC	(1 << 6)  /* Directory modifications are synchronous */
1930 #define S_NOCMTIME	(1 << 7)  /* Do not update file c/mtime */
1931 #define S_SWAPFILE	(1 << 8)  /* Do not truncate: swapon got its bmaps */
1932 #define S_PRIVATE	(1 << 9)  /* Inode is fs-internal */
1933 #define S_IMA		(1 << 10) /* Inode has an associated IMA struct */
1934 #define S_AUTOMOUNT	(1 << 11) /* Automount/referral quasi-directory */
1935 #define S_NOSEC		(1 << 12) /* no suid or xattr security attributes */
1936 #ifdef CONFIG_FS_DAX
1937 #define S_DAX		(1 << 13) /* Direct Access, avoiding the page cache */
1938 #else
1939 #define S_DAX		0	  /* Make all the DAX code disappear */
1940 #endif
1941 #define S_ENCRYPTED	(1 << 14) /* Encrypted file (using fs/crypto/) */
1942 #define S_CASEFOLD	(1 << 15) /* Casefolded file */
1943 #define S_VERITY	(1 << 16) /* Verity file (using fs/verity/) */
1944 #define S_KERNEL_FILE	(1 << 17) /* File is in use by the kernel (eg. fs/cachefiles) */
1945 
1946 /*
1947  * Note that nosuid etc flags are inode-specific: setting some file-system
1948  * flags just means all the inodes inherit those flags by default. It might be
1949  * possible to override it selectively if you really wanted to with some
1950  * ioctl() that is not currently implemented.
1951  *
1952  * Exception: SB_RDONLY is always applied to the entire file system.
1953  *
1954  * Unfortunately, it is possible to change a filesystems flags with it mounted
1955  * with files in use.  This means that all of the inodes will not have their
1956  * i_flags updated.  Hence, i_flags no longer inherit the superblock mount
1957  * flags, so these have to be checked separately. -- rmk@arm.uk.linux.org
1958  */
1959 #define __IS_FLG(inode, flg)	((inode)->i_sb->s_flags & (flg))
1960 
sb_rdonly(const struct super_block * sb)1961 static inline bool sb_rdonly(const struct super_block *sb) { return sb->s_flags & SB_RDONLY; }
1962 #define IS_RDONLY(inode)	sb_rdonly((inode)->i_sb)
1963 #define IS_SYNC(inode)		(__IS_FLG(inode, SB_SYNCHRONOUS) || \
1964 					((inode)->i_flags & S_SYNC))
1965 #define IS_DIRSYNC(inode)	(__IS_FLG(inode, SB_SYNCHRONOUS|SB_DIRSYNC) || \
1966 					((inode)->i_flags & (S_SYNC|S_DIRSYNC)))
1967 #define IS_MANDLOCK(inode)	__IS_FLG(inode, SB_MANDLOCK)
1968 #define IS_NOATIME(inode)	__IS_FLG(inode, SB_RDONLY|SB_NOATIME)
1969 #define IS_I_VERSION(inode)	__IS_FLG(inode, SB_I_VERSION)
1970 
1971 #define IS_NOQUOTA(inode)	((inode)->i_flags & S_NOQUOTA)
1972 #define IS_APPEND(inode)	((inode)->i_flags & S_APPEND)
1973 #define IS_IMMUTABLE(inode)	((inode)->i_flags & S_IMMUTABLE)
1974 #define IS_POSIXACL(inode)	__IS_FLG(inode, SB_POSIXACL)
1975 
1976 #define IS_DEADDIR(inode)	((inode)->i_flags & S_DEAD)
1977 #define IS_NOCMTIME(inode)	((inode)->i_flags & S_NOCMTIME)
1978 #define IS_SWAPFILE(inode)	((inode)->i_flags & S_SWAPFILE)
1979 #define IS_PRIVATE(inode)	((inode)->i_flags & S_PRIVATE)
1980 #define IS_IMA(inode)		((inode)->i_flags & S_IMA)
1981 #define IS_AUTOMOUNT(inode)	((inode)->i_flags & S_AUTOMOUNT)
1982 #define IS_NOSEC(inode)		((inode)->i_flags & S_NOSEC)
1983 #define IS_DAX(inode)		((inode)->i_flags & S_DAX)
1984 #define IS_ENCRYPTED(inode)	((inode)->i_flags & S_ENCRYPTED)
1985 #define IS_CASEFOLDED(inode)	((inode)->i_flags & S_CASEFOLD)
1986 #define IS_VERITY(inode)	((inode)->i_flags & S_VERITY)
1987 
1988 #define IS_WHITEOUT(inode)	(S_ISCHR(inode->i_mode) && \
1989 				 (inode)->i_rdev == WHITEOUT_DEV)
1990 
HAS_UNMAPPED_ID(struct mnt_idmap * idmap,struct inode * inode)1991 static inline bool HAS_UNMAPPED_ID(struct mnt_idmap *idmap,
1992 				   struct inode *inode)
1993 {
1994 	return !vfsuid_valid(i_uid_into_vfsuid(idmap, inode)) ||
1995 	       !vfsgid_valid(i_gid_into_vfsgid(idmap, inode));
1996 }
1997 
init_sync_kiocb(struct kiocb * kiocb,struct file * filp)1998 static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp)
1999 {
2000 	*kiocb = (struct kiocb) {
2001 		.ki_filp = filp,
2002 		.ki_flags = filp->f_iocb_flags,
2003 		.ki_ioprio = get_current_ioprio(),
2004 	};
2005 }
2006 
kiocb_clone(struct kiocb * kiocb,struct kiocb * kiocb_src,struct file * filp)2007 static inline void kiocb_clone(struct kiocb *kiocb, struct kiocb *kiocb_src,
2008 			       struct file *filp)
2009 {
2010 	*kiocb = (struct kiocb) {
2011 		.ki_filp = filp,
2012 		.ki_flags = kiocb_src->ki_flags,
2013 		.ki_ioprio = kiocb_src->ki_ioprio,
2014 		.ki_pos = kiocb_src->ki_pos,
2015 	};
2016 }
2017 
2018 /*
2019  * Inode state bits.  Protected by inode->i_lock
2020  *
2021  * Four bits determine the dirty state of the inode: I_DIRTY_SYNC,
2022  * I_DIRTY_DATASYNC, I_DIRTY_PAGES, and I_DIRTY_TIME.
2023  *
2024  * Four bits define the lifetime of an inode.  Initially, inodes are I_NEW,
2025  * until that flag is cleared.  I_WILL_FREE, I_FREEING and I_CLEAR are set at
2026  * various stages of removing an inode.
2027  *
2028  * Two bits are used for locking and completion notification, I_NEW and I_SYNC.
2029  *
2030  * I_DIRTY_SYNC		Inode is dirty, but doesn't have to be written on
2031  *			fdatasync() (unless I_DIRTY_DATASYNC is also set).
2032  *			Timestamp updates are the usual cause.
2033  * I_DIRTY_DATASYNC	Data-related inode changes pending.  We keep track of
2034  *			these changes separately from I_DIRTY_SYNC so that we
2035  *			don't have to write inode on fdatasync() when only
2036  *			e.g. the timestamps have changed.
2037  * I_DIRTY_PAGES	Inode has dirty pages.  Inode itself may be clean.
2038  * I_DIRTY_TIME		The inode itself has dirty timestamps, and the
2039  *			lazytime mount option is enabled.  We keep track of this
2040  *			separately from I_DIRTY_SYNC in order to implement
2041  *			lazytime.  This gets cleared if I_DIRTY_INODE
2042  *			(I_DIRTY_SYNC and/or I_DIRTY_DATASYNC) gets set. But
2043  *			I_DIRTY_TIME can still be set if I_DIRTY_SYNC is already
2044  *			in place because writeback might already be in progress
2045  *			and we don't want to lose the time update
2046  * I_NEW		Serves as both a mutex and completion notification.
2047  *			New inodes set I_NEW.  If two processes both create
2048  *			the same inode, one of them will release its inode and
2049  *			wait for I_NEW to be released before returning.
2050  *			Inodes in I_WILL_FREE, I_FREEING or I_CLEAR state can
2051  *			also cause waiting on I_NEW, without I_NEW actually
2052  *			being set.  find_inode() uses this to prevent returning
2053  *			nearly-dead inodes.
2054  * I_WILL_FREE		Must be set when calling write_inode_now() if i_count
2055  *			is zero.  I_FREEING must be set when I_WILL_FREE is
2056  *			cleared.
2057  * I_FREEING		Set when inode is about to be freed but still has dirty
2058  *			pages or buffers attached or the inode itself is still
2059  *			dirty.
2060  * I_CLEAR		Added by clear_inode().  In this state the inode is
2061  *			clean and can be destroyed.  Inode keeps I_FREEING.
2062  *
2063  *			Inodes that are I_WILL_FREE, I_FREEING or I_CLEAR are
2064  *			prohibited for many purposes.  iget() must wait for
2065  *			the inode to be completely released, then create it
2066  *			anew.  Other functions will just ignore such inodes,
2067  *			if appropriate.  I_NEW is used for waiting.
2068  *
2069  * I_SYNC		Writeback of inode is running. The bit is set during
2070  *			data writeback, and cleared with a wakeup on the bit
2071  *			address once it is done. The bit is also used to pin
2072  *			the inode in memory for flusher thread.
2073  *
2074  * I_REFERENCED		Marks the inode as recently references on the LRU list.
2075  *
2076  * I_DIO_WAKEUP		Never set.  Only used as a key for wait_on_bit().
2077  *
2078  * I_WB_SWITCH		Cgroup bdi_writeback switching in progress.  Used to
2079  *			synchronize competing switching instances and to tell
2080  *			wb stat updates to grab the i_pages lock.  See
2081  *			inode_switch_wbs_work_fn() for details.
2082  *
2083  * I_OVL_INUSE		Used by overlayfs to get exclusive ownership on upper
2084  *			and work dirs among overlayfs mounts.
2085  *
2086  * I_CREATING		New object's inode in the middle of setting up.
2087  *
2088  * I_DONTCACHE		Evict inode as soon as it is not used anymore.
2089  *
2090  * I_SYNC_QUEUED	Inode is queued in b_io or b_more_io writeback lists.
2091  *			Used to detect that mark_inode_dirty() should not move
2092  * 			inode between dirty lists.
2093  *
2094  * I_PINNING_FSCACHE_WB	Inode is pinning an fscache object for writeback.
2095  *
2096  * Q: What is the difference between I_WILL_FREE and I_FREEING?
2097  */
2098 #define I_DIRTY_SYNC		(1 << 0)
2099 #define I_DIRTY_DATASYNC	(1 << 1)
2100 #define I_DIRTY_PAGES		(1 << 2)
2101 #define __I_NEW			3
2102 #define I_NEW			(1 << __I_NEW)
2103 #define I_WILL_FREE		(1 << 4)
2104 #define I_FREEING		(1 << 5)
2105 #define I_CLEAR			(1 << 6)
2106 #define __I_SYNC		7
2107 #define I_SYNC			(1 << __I_SYNC)
2108 #define I_REFERENCED		(1 << 8)
2109 #define __I_DIO_WAKEUP		9
2110 #define I_DIO_WAKEUP		(1 << __I_DIO_WAKEUP)
2111 #define I_LINKABLE		(1 << 10)
2112 #define I_DIRTY_TIME		(1 << 11)
2113 #define I_WB_SWITCH		(1 << 13)
2114 #define I_OVL_INUSE		(1 << 14)
2115 #define I_CREATING		(1 << 15)
2116 #define I_DONTCACHE		(1 << 16)
2117 #define I_SYNC_QUEUED		(1 << 17)
2118 #define I_PINNING_FSCACHE_WB	(1 << 18)
2119 
2120 #define I_DIRTY_INODE (I_DIRTY_SYNC | I_DIRTY_DATASYNC)
2121 #define I_DIRTY (I_DIRTY_INODE | I_DIRTY_PAGES)
2122 #define I_DIRTY_ALL (I_DIRTY | I_DIRTY_TIME)
2123 
2124 extern void __mark_inode_dirty(struct inode *, int);
mark_inode_dirty(struct inode * inode)2125 static inline void mark_inode_dirty(struct inode *inode)
2126 {
2127 	__mark_inode_dirty(inode, I_DIRTY);
2128 }
2129 
mark_inode_dirty_sync(struct inode * inode)2130 static inline void mark_inode_dirty_sync(struct inode *inode)
2131 {
2132 	__mark_inode_dirty(inode, I_DIRTY_SYNC);
2133 }
2134 
2135 /*
2136  * Returns true if the given inode itself only has dirty timestamps (its pages
2137  * may still be dirty) and isn't currently being allocated or freed.
2138  * Filesystems should call this if when writing an inode when lazytime is
2139  * enabled, they want to opportunistically write the timestamps of other inodes
2140  * located very nearby on-disk, e.g. in the same inode block.  This returns true
2141  * if the given inode is in need of such an opportunistic update.  Requires
2142  * i_lock, or at least later re-checking under i_lock.
2143  */
inode_is_dirtytime_only(struct inode * inode)2144 static inline bool inode_is_dirtytime_only(struct inode *inode)
2145 {
2146 	return (inode->i_state & (I_DIRTY_TIME | I_NEW |
2147 				  I_FREEING | I_WILL_FREE)) == I_DIRTY_TIME;
2148 }
2149 
2150 extern void inc_nlink(struct inode *inode);
2151 extern void drop_nlink(struct inode *inode);
2152 extern void clear_nlink(struct inode *inode);
2153 extern void set_nlink(struct inode *inode, unsigned int nlink);
2154 
inode_inc_link_count(struct inode * inode)2155 static inline void inode_inc_link_count(struct inode *inode)
2156 {
2157 	inc_nlink(inode);
2158 	mark_inode_dirty(inode);
2159 }
2160 
inode_dec_link_count(struct inode * inode)2161 static inline void inode_dec_link_count(struct inode *inode)
2162 {
2163 	drop_nlink(inode);
2164 	mark_inode_dirty(inode);
2165 }
2166 
2167 enum file_time_flags {
2168 	S_ATIME = 1,
2169 	S_MTIME = 2,
2170 	S_CTIME = 4,
2171 	S_VERSION = 8,
2172 };
2173 
2174 extern bool atime_needs_update(const struct path *, struct inode *);
2175 extern void touch_atime(const struct path *);
2176 int inode_update_time(struct inode *inode, struct timespec64 *time, int flags);
2177 
file_accessed(struct file * file)2178 static inline void file_accessed(struct file *file)
2179 {
2180 	if (!(file->f_flags & O_NOATIME))
2181 		touch_atime(&file->f_path);
2182 }
2183 
2184 extern int file_modified(struct file *file);
2185 int kiocb_modified(struct kiocb *iocb);
2186 
2187 int sync_inode_metadata(struct inode *inode, int wait);
2188 
2189 struct file_system_type {
2190 	const char *name;
2191 	int fs_flags;
2192 #define FS_REQUIRES_DEV		1
2193 #define FS_BINARY_MOUNTDATA	2
2194 #define FS_HAS_SUBTYPE		4
2195 #define FS_USERNS_MOUNT		8	/* Can be mounted by userns root */
2196 #define FS_DISALLOW_NOTIFY_PERM	16	/* Disable fanotify permission events */
2197 #define FS_ALLOW_IDMAP         32      /* FS has been updated to handle vfs idmappings. */
2198 #define FS_RENAME_DOES_D_MOVE	32768	/* FS will handle d_move() during rename() internally. */
2199 	int (*init_fs_context)(struct fs_context *);
2200 	const struct fs_parameter_spec *parameters;
2201 	struct dentry *(*mount) (struct file_system_type *, int,
2202 		       const char *, void *);
2203 	void (*kill_sb) (struct super_block *);
2204 	struct module *owner;
2205 	struct file_system_type * next;
2206 	struct hlist_head fs_supers;
2207 
2208 	struct lock_class_key s_lock_key;
2209 	struct lock_class_key s_umount_key;
2210 	struct lock_class_key s_vfs_rename_key;
2211 	struct lock_class_key s_writers_key[SB_FREEZE_LEVELS];
2212 
2213 	struct lock_class_key i_lock_key;
2214 	struct lock_class_key i_mutex_key;
2215 	struct lock_class_key invalidate_lock_key;
2216 	struct lock_class_key i_mutex_dir_key;
2217 };
2218 
2219 #define MODULE_ALIAS_FS(NAME) MODULE_ALIAS("fs-" NAME)
2220 
2221 extern struct dentry *mount_bdev(struct file_system_type *fs_type,
2222 	int flags, const char *dev_name, void *data,
2223 	int (*fill_super)(struct super_block *, void *, int));
2224 extern struct dentry *mount_single(struct file_system_type *fs_type,
2225 	int flags, void *data,
2226 	int (*fill_super)(struct super_block *, void *, int));
2227 extern struct dentry *mount_nodev(struct file_system_type *fs_type,
2228 	int flags, void *data,
2229 	int (*fill_super)(struct super_block *, void *, int));
2230 extern struct dentry *mount_subtree(struct vfsmount *mnt, const char *path);
2231 void retire_super(struct super_block *sb);
2232 void generic_shutdown_super(struct super_block *sb);
2233 void kill_block_super(struct super_block *sb);
2234 void kill_anon_super(struct super_block *sb);
2235 void kill_litter_super(struct super_block *sb);
2236 void deactivate_super(struct super_block *sb);
2237 void deactivate_locked_super(struct super_block *sb);
2238 int set_anon_super(struct super_block *s, void *data);
2239 int set_anon_super_fc(struct super_block *s, struct fs_context *fc);
2240 int get_anon_bdev(dev_t *);
2241 void free_anon_bdev(dev_t);
2242 struct super_block *sget_fc(struct fs_context *fc,
2243 			    int (*test)(struct super_block *, struct fs_context *),
2244 			    int (*set)(struct super_block *, struct fs_context *));
2245 struct super_block *sget(struct file_system_type *type,
2246 			int (*test)(struct super_block *,void *),
2247 			int (*set)(struct super_block *,void *),
2248 			int flags, void *data);
2249 
2250 /* Alas, no aliases. Too much hassle with bringing module.h everywhere */
2251 #define fops_get(fops) \
2252 	(((fops) && try_module_get((fops)->owner) ? (fops) : NULL))
2253 #define fops_put(fops) \
2254 	do { if (fops) module_put((fops)->owner); } while(0)
2255 /*
2256  * This one is to be used *ONLY* from ->open() instances.
2257  * fops must be non-NULL, pinned down *and* module dependencies
2258  * should be sufficient to pin the caller down as well.
2259  */
2260 #define replace_fops(f, fops) \
2261 	do {	\
2262 		struct file *__file = (f); \
2263 		fops_put(__file->f_op); \
2264 		BUG_ON(!(__file->f_op = (fops))); \
2265 	} while(0)
2266 
2267 extern int register_filesystem(struct file_system_type *);
2268 extern int unregister_filesystem(struct file_system_type *);
2269 extern int vfs_statfs(const struct path *, struct kstatfs *);
2270 extern int user_statfs(const char __user *, struct kstatfs *);
2271 extern int fd_statfs(int, struct kstatfs *);
2272 extern int freeze_super(struct super_block *super);
2273 extern int thaw_super(struct super_block *super);
2274 extern __printf(2, 3)
2275 int super_setup_bdi_name(struct super_block *sb, char *fmt, ...);
2276 extern int super_setup_bdi(struct super_block *sb);
2277 
2278 extern int current_umask(void);
2279 
2280 extern void ihold(struct inode * inode);
2281 extern void iput(struct inode *);
2282 extern int generic_update_time(struct inode *, struct timespec64 *, int);
2283 
2284 /* /sys/fs */
2285 extern struct kobject *fs_kobj;
2286 
2287 #define MAX_RW_COUNT (INT_MAX & PAGE_MASK)
2288 
2289 /* fs/open.c */
2290 struct audit_names;
2291 struct filename {
2292 	const char		*name;	/* pointer to actual string */
2293 	const __user char	*uptr;	/* original userland pointer */
2294 	int			refcnt;
2295 	struct audit_names	*aname;
2296 	const char		iname[];
2297 };
2298 static_assert(offsetof(struct filename, iname) % sizeof(long) == 0);
2299 
file_mnt_idmap(struct file * file)2300 static inline struct mnt_idmap *file_mnt_idmap(struct file *file)
2301 {
2302 	return mnt_idmap(file->f_path.mnt);
2303 }
2304 
2305 /**
2306  * is_idmapped_mnt - check whether a mount is mapped
2307  * @mnt: the mount to check
2308  *
2309  * If @mnt has an non @nop_mnt_idmap attached to it then @mnt is mapped.
2310  *
2311  * Return: true if mount is mapped, false if not.
2312  */
is_idmapped_mnt(const struct vfsmount * mnt)2313 static inline bool is_idmapped_mnt(const struct vfsmount *mnt)
2314 {
2315 	return mnt_idmap(mnt) != &nop_mnt_idmap;
2316 }
2317 
2318 extern long vfs_truncate(const struct path *, loff_t);
2319 int do_truncate(struct mnt_idmap *, struct dentry *, loff_t start,
2320 		unsigned int time_attrs, struct file *filp);
2321 extern int vfs_fallocate(struct file *file, int mode, loff_t offset,
2322 			loff_t len);
2323 extern long do_sys_open(int dfd, const char __user *filename, int flags,
2324 			umode_t mode);
2325 extern struct file *file_open_name(struct filename *, int, umode_t);
2326 extern struct file *filp_open(const char *, int, umode_t);
2327 extern struct file *file_open_root(const struct path *,
2328 				   const char *, int, umode_t);
file_open_root_mnt(struct vfsmount * mnt,const char * name,int flags,umode_t mode)2329 static inline struct file *file_open_root_mnt(struct vfsmount *mnt,
2330 				   const char *name, int flags, umode_t mode)
2331 {
2332 	return file_open_root(&(struct path){.mnt = mnt, .dentry = mnt->mnt_root},
2333 			      name, flags, mode);
2334 }
2335 extern struct file * dentry_open(const struct path *, int, const struct cred *);
2336 extern struct file *dentry_create(const struct path *path, int flags,
2337 				  umode_t mode, const struct cred *cred);
2338 extern struct file * open_with_fake_path(const struct path *, int,
2339 					 struct inode*, const struct cred *);
file_clone_open(struct file * file)2340 static inline struct file *file_clone_open(struct file *file)
2341 {
2342 	return dentry_open(&file->f_path, file->f_flags, file->f_cred);
2343 }
2344 extern int filp_close(struct file *, fl_owner_t id);
2345 
2346 extern struct filename *getname_flags(const char __user *, int, int *);
2347 extern struct filename *getname_uflags(const char __user *, int);
2348 extern struct filename *getname(const char __user *);
2349 extern struct filename *getname_kernel(const char *);
2350 extern void putname(struct filename *name);
2351 
2352 extern int finish_open(struct file *file, struct dentry *dentry,
2353 			int (*open)(struct inode *, struct file *));
2354 extern int finish_no_open(struct file *file, struct dentry *dentry);
2355 
2356 /* Helper for the simple case when original dentry is used */
finish_open_simple(struct file * file,int error)2357 static inline int finish_open_simple(struct file *file, int error)
2358 {
2359 	if (error)
2360 		return error;
2361 
2362 	return finish_open(file, file->f_path.dentry, NULL);
2363 }
2364 
2365 /* fs/dcache.c */
2366 extern void __init vfs_caches_init_early(void);
2367 extern void __init vfs_caches_init(void);
2368 
2369 extern struct kmem_cache *names_cachep;
2370 
2371 #define __getname()		kmem_cache_alloc(names_cachep, GFP_KERNEL)
2372 #define __putname(name)		kmem_cache_free(names_cachep, (void *)(name))
2373 
2374 extern struct super_block *blockdev_superblock;
sb_is_blkdev_sb(struct super_block * sb)2375 static inline bool sb_is_blkdev_sb(struct super_block *sb)
2376 {
2377 	return IS_ENABLED(CONFIG_BLOCK) && sb == blockdev_superblock;
2378 }
2379 
2380 void emergency_thaw_all(void);
2381 extern int sync_filesystem(struct super_block *);
2382 extern const struct file_operations def_blk_fops;
2383 extern const struct file_operations def_chr_fops;
2384 
2385 /* fs/char_dev.c */
2386 #define CHRDEV_MAJOR_MAX 512
2387 /* Marks the bottom of the first segment of free char majors */
2388 #define CHRDEV_MAJOR_DYN_END 234
2389 /* Marks the top and bottom of the second segment of free char majors */
2390 #define CHRDEV_MAJOR_DYN_EXT_START 511
2391 #define CHRDEV_MAJOR_DYN_EXT_END 384
2392 
2393 extern int alloc_chrdev_region(dev_t *, unsigned, unsigned, const char *);
2394 extern int register_chrdev_region(dev_t, unsigned, const char *);
2395 extern int __register_chrdev(unsigned int major, unsigned int baseminor,
2396 			     unsigned int count, const char *name,
2397 			     const struct file_operations *fops);
2398 extern void __unregister_chrdev(unsigned int major, unsigned int baseminor,
2399 				unsigned int count, const char *name);
2400 extern void unregister_chrdev_region(dev_t, unsigned);
2401 extern void chrdev_show(struct seq_file *,off_t);
2402 
register_chrdev(unsigned int major,const char * name,const struct file_operations * fops)2403 static inline int register_chrdev(unsigned int major, const char *name,
2404 				  const struct file_operations *fops)
2405 {
2406 	return __register_chrdev(major, 0, 256, name, fops);
2407 }
2408 
unregister_chrdev(unsigned int major,const char * name)2409 static inline void unregister_chrdev(unsigned int major, const char *name)
2410 {
2411 	__unregister_chrdev(major, 0, 256, name);
2412 }
2413 
2414 extern void init_special_inode(struct inode *, umode_t, dev_t);
2415 
2416 /* Invalid inode operations -- fs/bad_inode.c */
2417 extern void make_bad_inode(struct inode *);
2418 extern bool is_bad_inode(struct inode *);
2419 
2420 extern int __must_check file_fdatawait_range(struct file *file, loff_t lstart,
2421 						loff_t lend);
2422 extern int __must_check file_check_and_advance_wb_err(struct file *file);
2423 extern int __must_check file_write_and_wait_range(struct file *file,
2424 						loff_t start, loff_t end);
2425 
file_write_and_wait(struct file * file)2426 static inline int file_write_and_wait(struct file *file)
2427 {
2428 	return file_write_and_wait_range(file, 0, LLONG_MAX);
2429 }
2430 
2431 extern int vfs_fsync_range(struct file *file, loff_t start, loff_t end,
2432 			   int datasync);
2433 extern int vfs_fsync(struct file *file, int datasync);
2434 
2435 extern int sync_file_range(struct file *file, loff_t offset, loff_t nbytes,
2436 				unsigned int flags);
2437 
iocb_is_dsync(const struct kiocb * iocb)2438 static inline bool iocb_is_dsync(const struct kiocb *iocb)
2439 {
2440 	return (iocb->ki_flags & IOCB_DSYNC) ||
2441 		IS_SYNC(iocb->ki_filp->f_mapping->host);
2442 }
2443 
2444 /*
2445  * Sync the bytes written if this was a synchronous write.  Expect ki_pos
2446  * to already be updated for the write, and will return either the amount
2447  * of bytes passed in, or an error if syncing the file failed.
2448  */
generic_write_sync(struct kiocb * iocb,ssize_t count)2449 static inline ssize_t generic_write_sync(struct kiocb *iocb, ssize_t count)
2450 {
2451 	if (iocb_is_dsync(iocb)) {
2452 		int ret = vfs_fsync_range(iocb->ki_filp,
2453 				iocb->ki_pos - count, iocb->ki_pos - 1,
2454 				(iocb->ki_flags & IOCB_SYNC) ? 0 : 1);
2455 		if (ret)
2456 			return ret;
2457 	}
2458 
2459 	return count;
2460 }
2461 
2462 extern void emergency_sync(void);
2463 extern void emergency_remount(void);
2464 
2465 #ifdef CONFIG_BLOCK
2466 extern int bmap(struct inode *inode, sector_t *block);
2467 #else
bmap(struct inode * inode,sector_t * block)2468 static inline int bmap(struct inode *inode,  sector_t *block)
2469 {
2470 	return -EINVAL;
2471 }
2472 #endif
2473 
2474 int notify_change(struct mnt_idmap *, struct dentry *,
2475 		  struct iattr *, struct inode **);
2476 int inode_permission(struct mnt_idmap *, struct inode *, int);
2477 int generic_permission(struct mnt_idmap *, struct inode *, int);
file_permission(struct file * file,int mask)2478 static inline int file_permission(struct file *file, int mask)
2479 {
2480 	return inode_permission(file_mnt_idmap(file),
2481 				file_inode(file), mask);
2482 }
path_permission(const struct path * path,int mask)2483 static inline int path_permission(const struct path *path, int mask)
2484 {
2485 	return inode_permission(mnt_idmap(path->mnt),
2486 				d_inode(path->dentry), mask);
2487 }
2488 int __check_sticky(struct mnt_idmap *idmap, struct inode *dir,
2489 		   struct inode *inode);
2490 
execute_ok(struct inode * inode)2491 static inline bool execute_ok(struct inode *inode)
2492 {
2493 	return (inode->i_mode & S_IXUGO) || S_ISDIR(inode->i_mode);
2494 }
2495 
inode_wrong_type(const struct inode * inode,umode_t mode)2496 static inline bool inode_wrong_type(const struct inode *inode, umode_t mode)
2497 {
2498 	return (inode->i_mode ^ mode) & S_IFMT;
2499 }
2500 
file_start_write(struct file * file)2501 static inline void file_start_write(struct file *file)
2502 {
2503 	if (!S_ISREG(file_inode(file)->i_mode))
2504 		return;
2505 	sb_start_write(file_inode(file)->i_sb);
2506 }
2507 
file_start_write_trylock(struct file * file)2508 static inline bool file_start_write_trylock(struct file *file)
2509 {
2510 	if (!S_ISREG(file_inode(file)->i_mode))
2511 		return true;
2512 	return sb_start_write_trylock(file_inode(file)->i_sb);
2513 }
2514 
file_end_write(struct file * file)2515 static inline void file_end_write(struct file *file)
2516 {
2517 	if (!S_ISREG(file_inode(file)->i_mode))
2518 		return;
2519 	__sb_end_write(file_inode(file)->i_sb, SB_FREEZE_WRITE);
2520 }
2521 
2522 /*
2523  * This is used for regular files where some users -- especially the
2524  * currently executed binary in a process, previously handled via
2525  * VM_DENYWRITE -- cannot handle concurrent write (and maybe mmap
2526  * read-write shared) accesses.
2527  *
2528  * get_write_access() gets write permission for a file.
2529  * put_write_access() releases this write permission.
2530  * deny_write_access() denies write access to a file.
2531  * allow_write_access() re-enables write access to a file.
2532  *
2533  * The i_writecount field of an inode can have the following values:
2534  * 0: no write access, no denied write access
2535  * < 0: (-i_writecount) users that denied write access to the file.
2536  * > 0: (i_writecount) users that have write access to the file.
2537  *
2538  * Normally we operate on that counter with atomic_{inc,dec} and it's safe
2539  * except for the cases where we don't hold i_writecount yet. Then we need to
2540  * use {get,deny}_write_access() - these functions check the sign and refuse
2541  * to do the change if sign is wrong.
2542  */
get_write_access(struct inode * inode)2543 static inline int get_write_access(struct inode *inode)
2544 {
2545 	return atomic_inc_unless_negative(&inode->i_writecount) ? 0 : -ETXTBSY;
2546 }
deny_write_access(struct file * file)2547 static inline int deny_write_access(struct file *file)
2548 {
2549 	struct inode *inode = file_inode(file);
2550 	return atomic_dec_unless_positive(&inode->i_writecount) ? 0 : -ETXTBSY;
2551 }
put_write_access(struct inode * inode)2552 static inline void put_write_access(struct inode * inode)
2553 {
2554 	atomic_dec(&inode->i_writecount);
2555 }
allow_write_access(struct file * file)2556 static inline void allow_write_access(struct file *file)
2557 {
2558 	if (file)
2559 		atomic_inc(&file_inode(file)->i_writecount);
2560 }
inode_is_open_for_write(const struct inode * inode)2561 static inline bool inode_is_open_for_write(const struct inode *inode)
2562 {
2563 	return atomic_read(&inode->i_writecount) > 0;
2564 }
2565 
2566 #if defined(CONFIG_IMA) || defined(CONFIG_FILE_LOCKING)
i_readcount_dec(struct inode * inode)2567 static inline void i_readcount_dec(struct inode *inode)
2568 {
2569 	BUG_ON(!atomic_read(&inode->i_readcount));
2570 	atomic_dec(&inode->i_readcount);
2571 }
i_readcount_inc(struct inode * inode)2572 static inline void i_readcount_inc(struct inode *inode)
2573 {
2574 	atomic_inc(&inode->i_readcount);
2575 }
2576 #else
i_readcount_dec(struct inode * inode)2577 static inline void i_readcount_dec(struct inode *inode)
2578 {
2579 	return;
2580 }
i_readcount_inc(struct inode * inode)2581 static inline void i_readcount_inc(struct inode *inode)
2582 {
2583 	return;
2584 }
2585 #endif
2586 extern int do_pipe_flags(int *, int);
2587 
2588 extern ssize_t kernel_read(struct file *, void *, size_t, loff_t *);
2589 ssize_t __kernel_read(struct file *file, void *buf, size_t count, loff_t *pos);
2590 extern ssize_t kernel_write(struct file *, const void *, size_t, loff_t *);
2591 extern ssize_t __kernel_write(struct file *, const void *, size_t, loff_t *);
2592 extern struct file * open_exec(const char *);
2593 
2594 /* fs/dcache.c -- generic fs support functions */
2595 extern bool is_subdir(struct dentry *, struct dentry *);
2596 extern bool path_is_under(const struct path *, const struct path *);
2597 
2598 extern char *file_path(struct file *, char *, int);
2599 
2600 #include <linux/err.h>
2601 
2602 /* needed for stackable file system support */
2603 extern loff_t default_llseek(struct file *file, loff_t offset, int whence);
2604 
2605 extern loff_t vfs_llseek(struct file *file, loff_t offset, int whence);
2606 
2607 extern int inode_init_always(struct super_block *, struct inode *);
2608 extern void inode_init_once(struct inode *);
2609 extern void address_space_init_once(struct address_space *mapping);
2610 extern struct inode * igrab(struct inode *);
2611 extern ino_t iunique(struct super_block *, ino_t);
2612 extern int inode_needs_sync(struct inode *inode);
2613 extern int generic_delete_inode(struct inode *inode);
generic_drop_inode(struct inode * inode)2614 static inline int generic_drop_inode(struct inode *inode)
2615 {
2616 	return !inode->i_nlink || inode_unhashed(inode);
2617 }
2618 extern void d_mark_dontcache(struct inode *inode);
2619 
2620 extern struct inode *ilookup5_nowait(struct super_block *sb,
2621 		unsigned long hashval, int (*test)(struct inode *, void *),
2622 		void *data);
2623 extern struct inode *ilookup5(struct super_block *sb, unsigned long hashval,
2624 		int (*test)(struct inode *, void *), void *data);
2625 extern struct inode *ilookup(struct super_block *sb, unsigned long ino);
2626 
2627 extern struct inode *inode_insert5(struct inode *inode, unsigned long hashval,
2628 		int (*test)(struct inode *, void *),
2629 		int (*set)(struct inode *, void *),
2630 		void *data);
2631 extern struct inode * iget5_locked(struct super_block *, unsigned long, int (*test)(struct inode *, void *), int (*set)(struct inode *, void *), void *);
2632 extern struct inode * iget_locked(struct super_block *, unsigned long);
2633 extern struct inode *find_inode_nowait(struct super_block *,
2634 				       unsigned long,
2635 				       int (*match)(struct inode *,
2636 						    unsigned long, void *),
2637 				       void *data);
2638 extern struct inode *find_inode_rcu(struct super_block *, unsigned long,
2639 				    int (*)(struct inode *, void *), void *);
2640 extern struct inode *find_inode_by_ino_rcu(struct super_block *, unsigned long);
2641 extern int insert_inode_locked4(struct inode *, unsigned long, int (*test)(struct inode *, void *), void *);
2642 extern int insert_inode_locked(struct inode *);
2643 #ifdef CONFIG_DEBUG_LOCK_ALLOC
2644 extern void lockdep_annotate_inode_mutex_key(struct inode *inode);
2645 #else
lockdep_annotate_inode_mutex_key(struct inode * inode)2646 static inline void lockdep_annotate_inode_mutex_key(struct inode *inode) { };
2647 #endif
2648 extern void unlock_new_inode(struct inode *);
2649 extern void discard_new_inode(struct inode *);
2650 extern unsigned int get_next_ino(void);
2651 extern void evict_inodes(struct super_block *sb);
2652 void dump_mapping(const struct address_space *);
2653 
2654 /*
2655  * Userspace may rely on the the inode number being non-zero. For example, glibc
2656  * simply ignores files with zero i_ino in unlink() and other places.
2657  *
2658  * As an additional complication, if userspace was compiled with
2659  * _FILE_OFFSET_BITS=32 on a 64-bit kernel we'll only end up reading out the
2660  * lower 32 bits, so we need to check that those aren't zero explicitly. With
2661  * _FILE_OFFSET_BITS=64, this may cause some harmless false-negatives, but
2662  * better safe than sorry.
2663  */
is_zero_ino(ino_t ino)2664 static inline bool is_zero_ino(ino_t ino)
2665 {
2666 	return (u32)ino == 0;
2667 }
2668 
2669 extern void __iget(struct inode * inode);
2670 extern void iget_failed(struct inode *);
2671 extern void clear_inode(struct inode *);
2672 extern void __destroy_inode(struct inode *);
2673 extern struct inode *new_inode_pseudo(struct super_block *sb);
2674 extern struct inode *new_inode(struct super_block *sb);
2675 extern void free_inode_nonrcu(struct inode *inode);
2676 extern int setattr_should_drop_suidgid(struct mnt_idmap *, struct inode *);
2677 extern int file_remove_privs(struct file *);
2678 
2679 /*
2680  * This must be used for allocating filesystems specific inodes to set
2681  * up the inode reclaim context correctly.
2682  */
2683 static inline void *
alloc_inode_sb(struct super_block * sb,struct kmem_cache * cache,gfp_t gfp)2684 alloc_inode_sb(struct super_block *sb, struct kmem_cache *cache, gfp_t gfp)
2685 {
2686 	return kmem_cache_alloc_lru(cache, &sb->s_inode_lru, gfp);
2687 }
2688 
2689 extern void __insert_inode_hash(struct inode *, unsigned long hashval);
insert_inode_hash(struct inode * inode)2690 static inline void insert_inode_hash(struct inode *inode)
2691 {
2692 	__insert_inode_hash(inode, inode->i_ino);
2693 }
2694 
2695 extern void __remove_inode_hash(struct inode *);
remove_inode_hash(struct inode * inode)2696 static inline void remove_inode_hash(struct inode *inode)
2697 {
2698 	if (!inode_unhashed(inode) && !hlist_fake(&inode->i_hash))
2699 		__remove_inode_hash(inode);
2700 }
2701 
2702 extern void inode_sb_list_add(struct inode *inode);
2703 extern void inode_add_lru(struct inode *inode);
2704 
2705 extern int sb_set_blocksize(struct super_block *, int);
2706 extern int sb_min_blocksize(struct super_block *, int);
2707 
2708 extern int generic_file_mmap(struct file *, struct vm_area_struct *);
2709 extern int generic_file_readonly_mmap(struct file *, struct vm_area_struct *);
2710 extern ssize_t generic_write_checks(struct kiocb *, struct iov_iter *);
2711 int generic_write_checks_count(struct kiocb *iocb, loff_t *count);
2712 extern int generic_write_check_limits(struct file *file, loff_t pos,
2713 		loff_t *count);
2714 extern int generic_file_rw_checks(struct file *file_in, struct file *file_out);
2715 ssize_t filemap_read(struct kiocb *iocb, struct iov_iter *to,
2716 		ssize_t already_read);
2717 extern ssize_t generic_file_read_iter(struct kiocb *, struct iov_iter *);
2718 extern ssize_t __generic_file_write_iter(struct kiocb *, struct iov_iter *);
2719 extern ssize_t generic_file_write_iter(struct kiocb *, struct iov_iter *);
2720 extern ssize_t generic_file_direct_write(struct kiocb *, struct iov_iter *);
2721 ssize_t generic_perform_write(struct kiocb *, struct iov_iter *);
2722 
2723 ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos,
2724 		rwf_t flags);
2725 ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos,
2726 		rwf_t flags);
2727 ssize_t vfs_iocb_iter_read(struct file *file, struct kiocb *iocb,
2728 			   struct iov_iter *iter);
2729 ssize_t vfs_iocb_iter_write(struct file *file, struct kiocb *iocb,
2730 			    struct iov_iter *iter);
2731 
2732 /* fs/splice.c */
2733 ssize_t filemap_splice_read(struct file *in, loff_t *ppos,
2734 			    struct pipe_inode_info *pipe,
2735 			    size_t len, unsigned int flags);
2736 ssize_t direct_splice_read(struct file *in, loff_t *ppos,
2737 			   struct pipe_inode_info *pipe,
2738 			   size_t len, unsigned int flags);
2739 extern ssize_t generic_file_splice_read(struct file *, loff_t *,
2740 		struct pipe_inode_info *, size_t, unsigned int);
2741 extern ssize_t iter_file_splice_write(struct pipe_inode_info *,
2742 		struct file *, loff_t *, size_t, unsigned int);
2743 extern ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe,
2744 		struct file *out, loff_t *, size_t len, unsigned int flags);
2745 extern long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
2746 		loff_t *opos, size_t len, unsigned int flags);
2747 
2748 
2749 extern void
2750 file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping);
2751 extern loff_t noop_llseek(struct file *file, loff_t offset, int whence);
2752 #define no_llseek NULL
2753 extern loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize);
2754 extern loff_t generic_file_llseek(struct file *file, loff_t offset, int whence);
2755 extern loff_t generic_file_llseek_size(struct file *file, loff_t offset,
2756 		int whence, loff_t maxsize, loff_t eof);
2757 extern loff_t fixed_size_llseek(struct file *file, loff_t offset,
2758 		int whence, loff_t size);
2759 extern loff_t no_seek_end_llseek_size(struct file *, loff_t, int, loff_t);
2760 extern loff_t no_seek_end_llseek(struct file *, loff_t, int);
2761 int rw_verify_area(int, struct file *, const loff_t *, size_t);
2762 extern int generic_file_open(struct inode * inode, struct file * filp);
2763 extern int nonseekable_open(struct inode * inode, struct file * filp);
2764 extern int stream_open(struct inode * inode, struct file * filp);
2765 
2766 #ifdef CONFIG_BLOCK
2767 typedef void (dio_submit_t)(struct bio *bio, struct inode *inode,
2768 			    loff_t file_offset);
2769 
2770 enum {
2771 	/* need locking between buffered and direct access */
2772 	DIO_LOCKING	= 0x01,
2773 
2774 	/* filesystem does not support filling holes */
2775 	DIO_SKIP_HOLES	= 0x02,
2776 };
2777 
2778 ssize_t __blockdev_direct_IO(struct kiocb *iocb, struct inode *inode,
2779 			     struct block_device *bdev, struct iov_iter *iter,
2780 			     get_block_t get_block,
2781 			     dio_iodone_t end_io, dio_submit_t submit_io,
2782 			     int flags);
2783 
blockdev_direct_IO(struct kiocb * iocb,struct inode * inode,struct iov_iter * iter,get_block_t get_block)2784 static inline ssize_t blockdev_direct_IO(struct kiocb *iocb,
2785 					 struct inode *inode,
2786 					 struct iov_iter *iter,
2787 					 get_block_t get_block)
2788 {
2789 	return __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev, iter,
2790 			get_block, NULL, NULL, DIO_LOCKING | DIO_SKIP_HOLES);
2791 }
2792 #endif
2793 
2794 void inode_dio_wait(struct inode *inode);
2795 
2796 /**
2797  * inode_dio_begin - signal start of a direct I/O requests
2798  * @inode: inode the direct I/O happens on
2799  *
2800  * This is called once we've finished processing a direct I/O request,
2801  * and is used to wake up callers waiting for direct I/O to be quiesced.
2802  */
inode_dio_begin(struct inode * inode)2803 static inline void inode_dio_begin(struct inode *inode)
2804 {
2805 	atomic_inc(&inode->i_dio_count);
2806 }
2807 
2808 /**
2809  * inode_dio_end - signal finish of a direct I/O requests
2810  * @inode: inode the direct I/O happens on
2811  *
2812  * This is called once we've finished processing a direct I/O request,
2813  * and is used to wake up callers waiting for direct I/O to be quiesced.
2814  */
inode_dio_end(struct inode * inode)2815 static inline void inode_dio_end(struct inode *inode)
2816 {
2817 	if (atomic_dec_and_test(&inode->i_dio_count))
2818 		wake_up_bit(&inode->i_state, __I_DIO_WAKEUP);
2819 }
2820 
2821 /*
2822  * Warn about a page cache invalidation failure diring a direct I/O write.
2823  */
2824 void dio_warn_stale_pagecache(struct file *filp);
2825 
2826 extern void inode_set_flags(struct inode *inode, unsigned int flags,
2827 			    unsigned int mask);
2828 
2829 extern const struct file_operations generic_ro_fops;
2830 
2831 #define special_file(m) (S_ISCHR(m)||S_ISBLK(m)||S_ISFIFO(m)||S_ISSOCK(m))
2832 
2833 extern int readlink_copy(char __user *, int, const char *);
2834 extern int page_readlink(struct dentry *, char __user *, int);
2835 extern const char *page_get_link(struct dentry *, struct inode *,
2836 				 struct delayed_call *);
2837 extern void page_put_link(void *);
2838 extern int page_symlink(struct inode *inode, const char *symname, int len);
2839 extern const struct inode_operations page_symlink_inode_operations;
2840 extern void kfree_link(void *);
2841 void generic_fillattr(struct mnt_idmap *, struct inode *, struct kstat *);
2842 void generic_fill_statx_attr(struct inode *inode, struct kstat *stat);
2843 extern int vfs_getattr_nosec(const struct path *, struct kstat *, u32, unsigned int);
2844 extern int vfs_getattr(const struct path *, struct kstat *, u32, unsigned int);
2845 void __inode_add_bytes(struct inode *inode, loff_t bytes);
2846 void inode_add_bytes(struct inode *inode, loff_t bytes);
2847 void __inode_sub_bytes(struct inode *inode, loff_t bytes);
2848 void inode_sub_bytes(struct inode *inode, loff_t bytes);
__inode_get_bytes(struct inode * inode)2849 static inline loff_t __inode_get_bytes(struct inode *inode)
2850 {
2851 	return (((loff_t)inode->i_blocks) << 9) + inode->i_bytes;
2852 }
2853 loff_t inode_get_bytes(struct inode *inode);
2854 void inode_set_bytes(struct inode *inode, loff_t bytes);
2855 const char *simple_get_link(struct dentry *, struct inode *,
2856 			    struct delayed_call *);
2857 extern const struct inode_operations simple_symlink_inode_operations;
2858 
2859 extern int iterate_dir(struct file *, struct dir_context *);
2860 
2861 int vfs_fstatat(int dfd, const char __user *filename, struct kstat *stat,
2862 		int flags);
2863 int vfs_fstat(int fd, struct kstat *stat);
2864 
vfs_stat(const char __user * filename,struct kstat * stat)2865 static inline int vfs_stat(const char __user *filename, struct kstat *stat)
2866 {
2867 	return vfs_fstatat(AT_FDCWD, filename, stat, 0);
2868 }
vfs_lstat(const char __user * name,struct kstat * stat)2869 static inline int vfs_lstat(const char __user *name, struct kstat *stat)
2870 {
2871 	return vfs_fstatat(AT_FDCWD, name, stat, AT_SYMLINK_NOFOLLOW);
2872 }
2873 
2874 extern const char *vfs_get_link(struct dentry *, struct delayed_call *);
2875 extern int vfs_readlink(struct dentry *, char __user *, int);
2876 
2877 extern struct file_system_type *get_filesystem(struct file_system_type *fs);
2878 extern void put_filesystem(struct file_system_type *fs);
2879 extern struct file_system_type *get_fs_type(const char *name);
2880 extern struct super_block *get_super(struct block_device *);
2881 extern struct super_block *get_active_super(struct block_device *bdev);
2882 extern void drop_super(struct super_block *sb);
2883 extern void drop_super_exclusive(struct super_block *sb);
2884 extern void iterate_supers(void (*)(struct super_block *, void *), void *);
2885 extern void iterate_supers_type(struct file_system_type *,
2886 			        void (*)(struct super_block *, void *), void *);
2887 
2888 extern int dcache_dir_open(struct inode *, struct file *);
2889 extern int dcache_dir_close(struct inode *, struct file *);
2890 extern loff_t dcache_dir_lseek(struct file *, loff_t, int);
2891 extern int dcache_readdir(struct file *, struct dir_context *);
2892 extern int simple_setattr(struct mnt_idmap *, struct dentry *,
2893 			  struct iattr *);
2894 extern int simple_getattr(struct mnt_idmap *, const struct path *,
2895 			  struct kstat *, u32, unsigned int);
2896 extern int simple_statfs(struct dentry *, struct kstatfs *);
2897 extern int simple_open(struct inode *inode, struct file *file);
2898 extern int simple_link(struct dentry *, struct inode *, struct dentry *);
2899 extern int simple_unlink(struct inode *, struct dentry *);
2900 extern int simple_rmdir(struct inode *, struct dentry *);
2901 extern int simple_rename_exchange(struct inode *old_dir, struct dentry *old_dentry,
2902 				  struct inode *new_dir, struct dentry *new_dentry);
2903 extern int simple_rename(struct mnt_idmap *, struct inode *,
2904 			 struct dentry *, struct inode *, struct dentry *,
2905 			 unsigned int);
2906 extern void simple_recursive_removal(struct dentry *,
2907                               void (*callback)(struct dentry *));
2908 extern int noop_fsync(struct file *, loff_t, loff_t, int);
2909 extern ssize_t noop_direct_IO(struct kiocb *iocb, struct iov_iter *iter);
2910 extern int simple_empty(struct dentry *);
2911 extern int simple_write_begin(struct file *file, struct address_space *mapping,
2912 			loff_t pos, unsigned len,
2913 			struct page **pagep, void **fsdata);
2914 extern const struct address_space_operations ram_aops;
2915 extern int always_delete_dentry(const struct dentry *);
2916 extern struct inode *alloc_anon_inode(struct super_block *);
2917 extern int simple_nosetlease(struct file *, long, struct file_lock **, void **);
2918 extern const struct dentry_operations simple_dentry_operations;
2919 
2920 extern struct dentry *simple_lookup(struct inode *, struct dentry *, unsigned int flags);
2921 extern ssize_t generic_read_dir(struct file *, char __user *, size_t, loff_t *);
2922 extern const struct file_operations simple_dir_operations;
2923 extern const struct inode_operations simple_dir_inode_operations;
2924 extern void make_empty_dir_inode(struct inode *inode);
2925 extern bool is_empty_dir_inode(struct inode *inode);
2926 struct tree_descr { const char *name; const struct file_operations *ops; int mode; };
2927 struct dentry *d_alloc_name(struct dentry *, const char *);
2928 extern int simple_fill_super(struct super_block *, unsigned long,
2929 			     const struct tree_descr *);
2930 extern int simple_pin_fs(struct file_system_type *, struct vfsmount **mount, int *count);
2931 extern void simple_release_fs(struct vfsmount **mount, int *count);
2932 
2933 extern ssize_t simple_read_from_buffer(void __user *to, size_t count,
2934 			loff_t *ppos, const void *from, size_t available);
2935 extern ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos,
2936 		const void __user *from, size_t count);
2937 
2938 extern int __generic_file_fsync(struct file *, loff_t, loff_t, int);
2939 extern int generic_file_fsync(struct file *, loff_t, loff_t, int);
2940 
2941 extern int generic_check_addressable(unsigned, u64);
2942 
2943 extern void generic_set_encrypted_ci_d_ops(struct dentry *dentry);
2944 
2945 int may_setattr(struct mnt_idmap *idmap, struct inode *inode,
2946 		unsigned int ia_valid);
2947 int setattr_prepare(struct mnt_idmap *, struct dentry *, struct iattr *);
2948 extern int inode_newsize_ok(const struct inode *, loff_t offset);
2949 void setattr_copy(struct mnt_idmap *, struct inode *inode,
2950 		  const struct iattr *attr);
2951 
2952 extern int file_update_time(struct file *file);
2953 
vma_is_dax(const struct vm_area_struct * vma)2954 static inline bool vma_is_dax(const struct vm_area_struct *vma)
2955 {
2956 	return vma->vm_file && IS_DAX(vma->vm_file->f_mapping->host);
2957 }
2958 
vma_is_fsdax(struct vm_area_struct * vma)2959 static inline bool vma_is_fsdax(struct vm_area_struct *vma)
2960 {
2961 	struct inode *inode;
2962 
2963 	if (!IS_ENABLED(CONFIG_FS_DAX) || !vma->vm_file)
2964 		return false;
2965 	if (!vma_is_dax(vma))
2966 		return false;
2967 	inode = file_inode(vma->vm_file);
2968 	if (S_ISCHR(inode->i_mode))
2969 		return false; /* device-dax */
2970 	return true;
2971 }
2972 
iocb_flags(struct file * file)2973 static inline int iocb_flags(struct file *file)
2974 {
2975 	int res = 0;
2976 	if (file->f_flags & O_APPEND)
2977 		res |= IOCB_APPEND;
2978 	if (file->f_flags & O_DIRECT)
2979 		res |= IOCB_DIRECT;
2980 	if (file->f_flags & O_DSYNC)
2981 		res |= IOCB_DSYNC;
2982 	if (file->f_flags & __O_SYNC)
2983 		res |= IOCB_SYNC;
2984 	return res;
2985 }
2986 
kiocb_set_rw_flags(struct kiocb * ki,rwf_t flags)2987 static inline int kiocb_set_rw_flags(struct kiocb *ki, rwf_t flags)
2988 {
2989 	int kiocb_flags = 0;
2990 
2991 	/* make sure there's no overlap between RWF and private IOCB flags */
2992 	BUILD_BUG_ON((__force int) RWF_SUPPORTED & IOCB_EVENTFD);
2993 
2994 	if (!flags)
2995 		return 0;
2996 	if (unlikely(flags & ~RWF_SUPPORTED))
2997 		return -EOPNOTSUPP;
2998 
2999 	if (flags & RWF_NOWAIT) {
3000 		if (!(ki->ki_filp->f_mode & FMODE_NOWAIT))
3001 			return -EOPNOTSUPP;
3002 		kiocb_flags |= IOCB_NOIO;
3003 	}
3004 	kiocb_flags |= (__force int) (flags & RWF_SUPPORTED);
3005 	if (flags & RWF_SYNC)
3006 		kiocb_flags |= IOCB_DSYNC;
3007 
3008 	ki->ki_flags |= kiocb_flags;
3009 	return 0;
3010 }
3011 
parent_ino(struct dentry * dentry)3012 static inline ino_t parent_ino(struct dentry *dentry)
3013 {
3014 	ino_t res;
3015 
3016 	/*
3017 	 * Don't strictly need d_lock here? If the parent ino could change
3018 	 * then surely we'd have a deeper race in the caller?
3019 	 */
3020 	spin_lock(&dentry->d_lock);
3021 	res = dentry->d_parent->d_inode->i_ino;
3022 	spin_unlock(&dentry->d_lock);
3023 	return res;
3024 }
3025 
3026 /* Transaction based IO helpers */
3027 
3028 /*
3029  * An argresp is stored in an allocated page and holds the
3030  * size of the argument or response, along with its content
3031  */
3032 struct simple_transaction_argresp {
3033 	ssize_t size;
3034 	char data[];
3035 };
3036 
3037 #define SIMPLE_TRANSACTION_LIMIT (PAGE_SIZE - sizeof(struct simple_transaction_argresp))
3038 
3039 char *simple_transaction_get(struct file *file, const char __user *buf,
3040 				size_t size);
3041 ssize_t simple_transaction_read(struct file *file, char __user *buf,
3042 				size_t size, loff_t *pos);
3043 int simple_transaction_release(struct inode *inode, struct file *file);
3044 
3045 void simple_transaction_set(struct file *file, size_t n);
3046 
3047 /*
3048  * simple attribute files
3049  *
3050  * These attributes behave similar to those in sysfs:
3051  *
3052  * Writing to an attribute immediately sets a value, an open file can be
3053  * written to multiple times.
3054  *
3055  * Reading from an attribute creates a buffer from the value that might get
3056  * read with multiple read calls. When the attribute has been read
3057  * completely, no further read calls are possible until the file is opened
3058  * again.
3059  *
3060  * All attributes contain a text representation of a numeric value
3061  * that are accessed with the get() and set() functions.
3062  */
3063 #define DEFINE_SIMPLE_ATTRIBUTE_XSIGNED(__fops, __get, __set, __fmt, __is_signed)	\
3064 static int __fops ## _open(struct inode *inode, struct file *file)	\
3065 {									\
3066 	__simple_attr_check_format(__fmt, 0ull);			\
3067 	return simple_attr_open(inode, file, __get, __set, __fmt);	\
3068 }									\
3069 static const struct file_operations __fops = {				\
3070 	.owner	 = THIS_MODULE,						\
3071 	.open	 = __fops ## _open,					\
3072 	.release = simple_attr_release,					\
3073 	.read	 = simple_attr_read,					\
3074 	.write	 = (__is_signed) ? simple_attr_write_signed : simple_attr_write,	\
3075 	.llseek	 = generic_file_llseek,					\
3076 }
3077 
3078 #define DEFINE_SIMPLE_ATTRIBUTE(__fops, __get, __set, __fmt)		\
3079 	DEFINE_SIMPLE_ATTRIBUTE_XSIGNED(__fops, __get, __set, __fmt, false)
3080 
3081 #define DEFINE_SIMPLE_ATTRIBUTE_SIGNED(__fops, __get, __set, __fmt)	\
3082 	DEFINE_SIMPLE_ATTRIBUTE_XSIGNED(__fops, __get, __set, __fmt, true)
3083 
3084 static inline __printf(1, 2)
__simple_attr_check_format(const char * fmt,...)3085 void __simple_attr_check_format(const char *fmt, ...)
3086 {
3087 	/* don't do anything, just let the compiler check the arguments; */
3088 }
3089 
3090 int simple_attr_open(struct inode *inode, struct file *file,
3091 		     int (*get)(void *, u64 *), int (*set)(void *, u64),
3092 		     const char *fmt);
3093 int simple_attr_release(struct inode *inode, struct file *file);
3094 ssize_t simple_attr_read(struct file *file, char __user *buf,
3095 			 size_t len, loff_t *ppos);
3096 ssize_t simple_attr_write(struct file *file, const char __user *buf,
3097 			  size_t len, loff_t *ppos);
3098 ssize_t simple_attr_write_signed(struct file *file, const char __user *buf,
3099 				 size_t len, loff_t *ppos);
3100 
3101 struct ctl_table;
3102 int __init list_bdev_fs_names(char *buf, size_t size);
3103 
3104 #define __FMODE_EXEC		((__force int) FMODE_EXEC)
3105 #define __FMODE_NONOTIFY	((__force int) FMODE_NONOTIFY)
3106 
3107 #define ACC_MODE(x) ("\004\002\006\006"[(x)&O_ACCMODE])
3108 #define OPEN_FMODE(flag) ((__force fmode_t)(((flag + 1) & O_ACCMODE) | \
3109 					    (flag & __FMODE_NONOTIFY)))
3110 
is_sxid(umode_t mode)3111 static inline bool is_sxid(umode_t mode)
3112 {
3113 	return mode & (S_ISUID | S_ISGID);
3114 }
3115 
check_sticky(struct mnt_idmap * idmap,struct inode * dir,struct inode * inode)3116 static inline int check_sticky(struct mnt_idmap *idmap,
3117 			       struct inode *dir, struct inode *inode)
3118 {
3119 	if (!(dir->i_mode & S_ISVTX))
3120 		return 0;
3121 
3122 	return __check_sticky(idmap, dir, inode);
3123 }
3124 
inode_has_no_xattr(struct inode * inode)3125 static inline void inode_has_no_xattr(struct inode *inode)
3126 {
3127 	if (!is_sxid(inode->i_mode) && (inode->i_sb->s_flags & SB_NOSEC))
3128 		inode->i_flags |= S_NOSEC;
3129 }
3130 
is_root_inode(struct inode * inode)3131 static inline bool is_root_inode(struct inode *inode)
3132 {
3133 	return inode == inode->i_sb->s_root->d_inode;
3134 }
3135 
dir_emit(struct dir_context * ctx,const char * name,int namelen,u64 ino,unsigned type)3136 static inline bool dir_emit(struct dir_context *ctx,
3137 			    const char *name, int namelen,
3138 			    u64 ino, unsigned type)
3139 {
3140 	return ctx->actor(ctx, name, namelen, ctx->pos, ino, type);
3141 }
dir_emit_dot(struct file * file,struct dir_context * ctx)3142 static inline bool dir_emit_dot(struct file *file, struct dir_context *ctx)
3143 {
3144 	return ctx->actor(ctx, ".", 1, ctx->pos,
3145 			  file->f_path.dentry->d_inode->i_ino, DT_DIR);
3146 }
dir_emit_dotdot(struct file * file,struct dir_context * ctx)3147 static inline bool dir_emit_dotdot(struct file *file, struct dir_context *ctx)
3148 {
3149 	return ctx->actor(ctx, "..", 2, ctx->pos,
3150 			  parent_ino(file->f_path.dentry), DT_DIR);
3151 }
dir_emit_dots(struct file * file,struct dir_context * ctx)3152 static inline bool dir_emit_dots(struct file *file, struct dir_context *ctx)
3153 {
3154 	if (ctx->pos == 0) {
3155 		if (!dir_emit_dot(file, ctx))
3156 			return false;
3157 		ctx->pos = 1;
3158 	}
3159 	if (ctx->pos == 1) {
3160 		if (!dir_emit_dotdot(file, ctx))
3161 			return false;
3162 		ctx->pos = 2;
3163 	}
3164 	return true;
3165 }
dir_relax(struct inode * inode)3166 static inline bool dir_relax(struct inode *inode)
3167 {
3168 	inode_unlock(inode);
3169 	inode_lock(inode);
3170 	return !IS_DEADDIR(inode);
3171 }
3172 
dir_relax_shared(struct inode * inode)3173 static inline bool dir_relax_shared(struct inode *inode)
3174 {
3175 	inode_unlock_shared(inode);
3176 	inode_lock_shared(inode);
3177 	return !IS_DEADDIR(inode);
3178 }
3179 
3180 extern bool path_noexec(const struct path *path);
3181 extern void inode_nohighmem(struct inode *inode);
3182 
3183 /* mm/fadvise.c */
3184 extern int vfs_fadvise(struct file *file, loff_t offset, loff_t len,
3185 		       int advice);
3186 extern int generic_fadvise(struct file *file, loff_t offset, loff_t len,
3187 			   int advice);
3188 
3189 #endif /* _LINUX_FS_H */
3190