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#include <linux/maple_tree.h>
47#include <linux/rw_hint.h>
48
49#include <asm/byteorder.h>
50#include <uapi/linux/fs.h>
51
52struct backing_dev_info;
53struct bdi_writeback;
54struct bio;
55struct io_comp_batch;
56struct export_operations;
57struct fiemap_extent_info;
58struct hd_geometry;
59struct iovec;
60struct kiocb;
61struct kobject;
62struct pipe_inode_info;
63struct poll_table_struct;
64struct kstatfs;
65struct vm_area_struct;
66struct vfsmount;
67struct cred;
68struct swap_info_struct;
69struct seq_file;
70struct workqueue_struct;
71struct iov_iter;
72struct fscrypt_inode_info;
73struct fscrypt_operations;
74struct fsverity_info;
75struct fsverity_operations;
76struct fs_context;
77struct fs_parameter_spec;
78struct fileattr;
79struct iomap_ops;
80
81extern void __init inode_init(void);
82extern void __init inode_init_early(void);
83extern void __init files_init(void);
84extern void __init files_maxfiles_init(void);
85
86extern unsigned long get_max_files(void);
87extern unsigned int sysctl_nr_open;
88
89typedef __kernel_rwf_t rwf_t;
90
91struct buffer_head;
92typedef int (get_block_t)(struct inode *inode, sector_t iblock,
93 struct buffer_head *bh_result, int create);
94typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset,
95 ssize_t bytes, void *private);
96
97#define MAY_EXEC 0x00000001
98#define MAY_WRITE 0x00000002
99#define MAY_READ 0x00000004
100#define MAY_APPEND 0x00000008
101#define MAY_ACCESS 0x00000010
102#define MAY_OPEN 0x00000020
103#define MAY_CHDIR 0x00000040
104/* called from RCU mode, don't block */
105#define MAY_NOT_BLOCK 0x00000080
106
107/*
108 * flags in file.f_mode. Note that FMODE_READ and FMODE_WRITE must correspond
109 * to O_WRONLY and O_RDWR via the strange trick in do_dentry_open()
110 */
111
112/* file is open for reading */
113#define FMODE_READ ((__force fmode_t)0x1)
114/* file is open for writing */
115#define FMODE_WRITE ((__force fmode_t)0x2)
116/* file is seekable */
117#define FMODE_LSEEK ((__force fmode_t)0x4)
118/* file can be accessed using pread */
119#define FMODE_PREAD ((__force fmode_t)0x8)
120/* file can be accessed using pwrite */
121#define FMODE_PWRITE ((__force fmode_t)0x10)
122/* File is opened for execution with sys_execve / sys_uselib */
123#define FMODE_EXEC ((__force fmode_t)0x20)
124/* File writes are restricted (block device specific) */
125#define FMODE_WRITE_RESTRICTED ((__force fmode_t)0x40)
126/* 32bit hashes as llseek() offset (for directories) */
127#define FMODE_32BITHASH ((__force fmode_t)0x200)
128/* 64bit hashes as llseek() offset (for directories) */
129#define FMODE_64BITHASH ((__force fmode_t)0x400)
130
131/*
132 * Don't update ctime and mtime.
133 *
134 * Currently a special hack for the XFS open_by_handle ioctl, but we'll
135 * hopefully graduate it to a proper O_CMTIME flag supported by open(2) soon.
136 */
137#define FMODE_NOCMTIME ((__force fmode_t)0x800)
138
139/* Expect random access pattern */
140#define FMODE_RANDOM ((__force fmode_t)0x1000)
141
142/* File is huge (eg. /dev/mem): treat loff_t as unsigned */
143#define FMODE_UNSIGNED_OFFSET ((__force fmode_t)0x2000)
144
145/* File is opened with O_PATH; almost nothing can be done with it */
146#define FMODE_PATH ((__force fmode_t)0x4000)
147
148/* File needs atomic accesses to f_pos */
149#define FMODE_ATOMIC_POS ((__force fmode_t)0x8000)
150/* Write access to underlying fs */
151#define FMODE_WRITER ((__force fmode_t)0x10000)
152/* Has read method(s) */
153#define FMODE_CAN_READ ((__force fmode_t)0x20000)
154/* Has write method(s) */
155#define FMODE_CAN_WRITE ((__force fmode_t)0x40000)
156
157#define FMODE_OPENED ((__force fmode_t)0x80000)
158#define FMODE_CREATED ((__force fmode_t)0x100000)
159
160/* File is stream-like */
161#define FMODE_STREAM ((__force fmode_t)0x200000)
162
163/* File supports DIRECT IO */
164#define FMODE_CAN_ODIRECT ((__force fmode_t)0x400000)
165
166#define FMODE_NOREUSE ((__force fmode_t)0x800000)
167
168/* File supports non-exclusive O_DIRECT writes from multiple threads */
169#define FMODE_DIO_PARALLEL_WRITE ((__force fmode_t)0x1000000)
170
171/* File is embedded in backing_file object */
172#define FMODE_BACKING ((__force fmode_t)0x2000000)
173
174/* File was opened by fanotify and shouldn't generate fanotify events */
175#define FMODE_NONOTIFY ((__force fmode_t)0x4000000)
176
177/* File is capable of returning -EAGAIN if I/O will block */
178#define FMODE_NOWAIT ((__force fmode_t)0x8000000)
179
180/* File represents mount that needs unmounting */
181#define FMODE_NEED_UNMOUNT ((__force fmode_t)0x10000000)
182
183/* File does not contribute to nr_files count */
184#define FMODE_NOACCOUNT ((__force fmode_t)0x20000000)
185
186/* File supports async buffered reads */
187#define FMODE_BUF_RASYNC ((__force fmode_t)0x40000000)
188
189/* File supports async nowait buffered writes */
190#define FMODE_BUF_WASYNC ((__force fmode_t)0x80000000)
191
192/*
193 * Attribute flags. These should be or-ed together to figure out what
194 * has been changed!
195 */
196#define ATTR_MODE (1 << 0)
197#define ATTR_UID (1 << 1)
198#define ATTR_GID (1 << 2)
199#define ATTR_SIZE (1 << 3)
200#define ATTR_ATIME (1 << 4)
201#define ATTR_MTIME (1 << 5)
202#define ATTR_CTIME (1 << 6)
203#define ATTR_ATIME_SET (1 << 7)
204#define ATTR_MTIME_SET (1 << 8)
205#define ATTR_FORCE (1 << 9) /* Not a change, but a change it */
206#define ATTR_KILL_SUID (1 << 11)
207#define ATTR_KILL_SGID (1 << 12)
208#define ATTR_FILE (1 << 13)
209#define ATTR_KILL_PRIV (1 << 14)
210#define ATTR_OPEN (1 << 15) /* Truncating from open(O_TRUNC) */
211#define ATTR_TIMES_SET (1 << 16)
212#define ATTR_TOUCH (1 << 17)
213
214/*
215 * Whiteout is represented by a char device. The following constants define the
216 * mode and device number to use.
217 */
218#define WHITEOUT_MODE 0
219#define WHITEOUT_DEV 0
220
221/*
222 * This is the Inode Attributes structure, used for notify_change(). It
223 * uses the above definitions as flags, to know which values have changed.
224 * Also, in this manner, a Filesystem can look at only the values it cares
225 * about. Basically, these are the attributes that the VFS layer can
226 * request to change from the FS layer.
227 *
228 * Derek Atkins <warlord@MIT.EDU> 94-10-20
229 */
230struct iattr {
231 unsigned int ia_valid;
232 umode_t ia_mode;
233 /*
234 * The two anonymous unions wrap structures with the same member.
235 *
236 * Filesystems raising FS_ALLOW_IDMAP need to use ia_vfs{g,u}id which
237 * are a dedicated type requiring the filesystem to use the dedicated
238 * helpers. Other filesystem can continue to use ia_{g,u}id until they
239 * have been ported.
240 *
241 * They always contain the same value. In other words FS_ALLOW_IDMAP
242 * pass down the same value on idmapped mounts as they would on regular
243 * mounts.
244 */
245 union {
246 kuid_t ia_uid;
247 vfsuid_t ia_vfsuid;
248 };
249 union {
250 kgid_t ia_gid;
251 vfsgid_t ia_vfsgid;
252 };
253 loff_t ia_size;
254 struct timespec64 ia_atime;
255 struct timespec64 ia_mtime;
256 struct timespec64 ia_ctime;
257
258 /*
259 * Not an attribute, but an auxiliary info for filesystems wanting to
260 * implement an ftruncate() like method. NOTE: filesystem should
261 * check for (ia_valid & ATTR_FILE), and not for (ia_file != NULL).
262 */
263 struct file *ia_file;
264};
265
266/*
267 * Includes for diskquotas.
268 */
269#include <linux/quota.h>
270
271/*
272 * Maximum number of layers of fs stack. Needs to be limited to
273 * prevent kernel stack overflow
274 */
275#define FILESYSTEM_MAX_STACK_DEPTH 2
276
277/**
278 * enum positive_aop_returns - aop return codes with specific semantics
279 *
280 * @AOP_WRITEPAGE_ACTIVATE: Informs the caller that page writeback has
281 * completed, that the page is still locked, and
282 * should be considered active. The VM uses this hint
283 * to return the page to the active list -- it won't
284 * be a candidate for writeback again in the near
285 * future. Other callers must be careful to unlock
286 * the page if they get this return. Returned by
287 * writepage();
288 *
289 * @AOP_TRUNCATED_PAGE: The AOP method that was handed a locked page has
290 * unlocked it and the page might have been truncated.
291 * The caller should back up to acquiring a new page and
292 * trying again. The aop will be taking reasonable
293 * precautions not to livelock. If the caller held a page
294 * reference, it should drop it before retrying. Returned
295 * by read_folio().
296 *
297 * address_space_operation functions return these large constants to indicate
298 * special semantics to the caller. These are much larger than the bytes in a
299 * page to allow for functions that return the number of bytes operated on in a
300 * given page.
301 */
302
303enum positive_aop_returns {
304 AOP_WRITEPAGE_ACTIVATE = 0x80000,
305 AOP_TRUNCATED_PAGE = 0x80001,
306};
307
308/*
309 * oh the beauties of C type declarations.
310 */
311struct page;
312struct address_space;
313struct writeback_control;
314struct readahead_control;
315
316/* Match RWF_* bits to IOCB bits */
317#define IOCB_HIPRI (__force int) RWF_HIPRI
318#define IOCB_DSYNC (__force int) RWF_DSYNC
319#define IOCB_SYNC (__force int) RWF_SYNC
320#define IOCB_NOWAIT (__force int) RWF_NOWAIT
321#define IOCB_APPEND (__force int) RWF_APPEND
322
323/* non-RWF related bits - start at 16 */
324#define IOCB_EVENTFD (1 << 16)
325#define IOCB_DIRECT (1 << 17)
326#define IOCB_WRITE (1 << 18)
327/* iocb->ki_waitq is valid */
328#define IOCB_WAITQ (1 << 19)
329#define IOCB_NOIO (1 << 20)
330/* can use bio alloc cache */
331#define IOCB_ALLOC_CACHE (1 << 21)
332/*
333 * IOCB_DIO_CALLER_COMP can be set by the iocb owner, to indicate that the
334 * iocb completion can be passed back to the owner for execution from a safe
335 * context rather than needing to be punted through a workqueue. If this
336 * flag is set, the bio completion handling may set iocb->dio_complete to a
337 * handler function and iocb->private to context information for that handler.
338 * The issuer should call the handler with that context information from task
339 * context to complete the processing of the iocb. Note that while this
340 * provides a task context for the dio_complete() callback, it should only be
341 * used on the completion side for non-IO generating completions. It's fine to
342 * call blocking functions from this callback, but they should not wait for
343 * unrelated IO (like cache flushing, new IO generation, etc).
344 */
345#define IOCB_DIO_CALLER_COMP (1 << 22)
346/* kiocb is a read or write operation submitted by fs/aio.c. */
347#define IOCB_AIO_RW (1 << 23)
348
349/* for use in trace events */
350#define TRACE_IOCB_STRINGS \
351 { IOCB_HIPRI, "HIPRI" }, \
352 { IOCB_DSYNC, "DSYNC" }, \
353 { IOCB_SYNC, "SYNC" }, \
354 { IOCB_NOWAIT, "NOWAIT" }, \
355 { IOCB_APPEND, "APPEND" }, \
356 { IOCB_EVENTFD, "EVENTFD"}, \
357 { IOCB_DIRECT, "DIRECT" }, \
358 { IOCB_WRITE, "WRITE" }, \
359 { IOCB_WAITQ, "WAITQ" }, \
360 { IOCB_NOIO, "NOIO" }, \
361 { IOCB_ALLOC_CACHE, "ALLOC_CACHE" }, \
362 { IOCB_DIO_CALLER_COMP, "CALLER_COMP" }
363
364struct kiocb {
365 struct file *ki_filp;
366 loff_t ki_pos;
367 void (*ki_complete)(struct kiocb *iocb, long ret);
368 void *private;
369 int ki_flags;
370 u16 ki_ioprio; /* See linux/ioprio.h */
371 union {
372 /*
373 * Only used for async buffered reads, where it denotes the
374 * page waitqueue associated with completing the read. Valid
375 * IFF IOCB_WAITQ is set.
376 */
377 struct wait_page_queue *ki_waitq;
378 /*
379 * Can be used for O_DIRECT IO, where the completion handling
380 * is punted back to the issuer of the IO. May only be set
381 * if IOCB_DIO_CALLER_COMP is set by the issuer, and the issuer
382 * must then check for presence of this handler when ki_complete
383 * is invoked. The data passed in to this handler must be
384 * assigned to ->private when dio_complete is assigned.
385 */
386 ssize_t (*dio_complete)(void *data);
387 };
388};
389
390static inline bool is_sync_kiocb(struct kiocb *kiocb)
391{
392 return kiocb->ki_complete == NULL;
393}
394
395struct address_space_operations {
396 int (*writepage)(struct page *page, struct writeback_control *wbc);
397 int (*read_folio)(struct file *, struct folio *);
398
399 /* Write back some dirty pages from this mapping. */
400 int (*writepages)(struct address_space *, struct writeback_control *);
401
402 /* Mark a folio dirty. Return true if this dirtied it */
403 bool (*dirty_folio)(struct address_space *, struct folio *);
404
405 void (*readahead)(struct readahead_control *);
406
407 int (*write_begin)(struct file *, struct address_space *mapping,
408 loff_t pos, unsigned len,
409 struct page **pagep, void **fsdata);
410 int (*write_end)(struct file *, struct address_space *mapping,
411 loff_t pos, unsigned len, unsigned copied,
412 struct page *page, void *fsdata);
413
414 /* Unfortunately this kludge is needed for FIBMAP. Don't use it */
415 sector_t (*bmap)(struct address_space *, sector_t);
416 void (*invalidate_folio) (struct folio *, size_t offset, size_t len);
417 bool (*release_folio)(struct folio *, gfp_t);
418 void (*free_folio)(struct folio *folio);
419 ssize_t (*direct_IO)(struct kiocb *, struct iov_iter *iter);
420 /*
421 * migrate the contents of a folio to the specified target. If
422 * migrate_mode is MIGRATE_ASYNC, it must not block.
423 */
424 int (*migrate_folio)(struct address_space *, struct folio *dst,
425 struct folio *src, enum migrate_mode);
426 int (*launder_folio)(struct folio *);
427 bool (*is_partially_uptodate) (struct folio *, size_t from,
428 size_t count);
429 void (*is_dirty_writeback) (struct folio *, bool *dirty, bool *wb);
430 int (*error_remove_folio)(struct address_space *, struct folio *);
431
432 /* swapfile support */
433 int (*swap_activate)(struct swap_info_struct *sis, struct file *file,
434 sector_t *span);
435 void (*swap_deactivate)(struct file *file);
436 int (*swap_rw)(struct kiocb *iocb, struct iov_iter *iter);
437};
438
439extern const struct address_space_operations empty_aops;
440
441/**
442 * struct address_space - Contents of a cacheable, mappable object.
443 * @host: Owner, either the inode or the block_device.
444 * @i_pages: Cached pages.
445 * @invalidate_lock: Guards coherency between page cache contents and
446 * file offset->disk block mappings in the filesystem during invalidates.
447 * It is also used to block modification of page cache contents through
448 * memory mappings.
449 * @gfp_mask: Memory allocation flags to use for allocating pages.
450 * @i_mmap_writable: Number of VM_SHARED, VM_MAYWRITE mappings.
451 * @nr_thps: Number of THPs in the pagecache (non-shmem only).
452 * @i_mmap: Tree of private and shared mappings.
453 * @i_mmap_rwsem: Protects @i_mmap and @i_mmap_writable.
454 * @nrpages: Number of page entries, protected by the i_pages lock.
455 * @writeback_index: Writeback starts here.
456 * @a_ops: Methods.
457 * @flags: Error bits and flags (AS_*).
458 * @wb_err: The most recent error which has occurred.
459 * @i_private_lock: For use by the owner of the address_space.
460 * @i_private_list: For use by the owner of the address_space.
461 * @i_private_data: For use by the owner of the address_space.
462 */
463struct address_space {
464 struct inode *host;
465 struct xarray i_pages;
466 struct rw_semaphore invalidate_lock;
467 gfp_t gfp_mask;
468 atomic_t i_mmap_writable;
469#ifdef CONFIG_READ_ONLY_THP_FOR_FS
470 /* number of thp, only for non-shmem files */
471 atomic_t nr_thps;
472#endif
473 struct rb_root_cached i_mmap;
474 unsigned long nrpages;
475 pgoff_t writeback_index;
476 const struct address_space_operations *a_ops;
477 unsigned long flags;
478 errseq_t wb_err;
479 spinlock_t i_private_lock;
480 struct list_head i_private_list;
481 struct rw_semaphore i_mmap_rwsem;
482 void * i_private_data;
483} __attribute__((aligned(sizeof(long)))) __randomize_layout;
484 /*
485 * On most architectures that alignment is already the case; but
486 * must be enforced here for CRIS, to let the least significant bit
487 * of struct page's "mapping" pointer be used for PAGE_MAPPING_ANON.
488 */
489
490/* XArray tags, for tagging dirty and writeback pages in the pagecache. */
491#define PAGECACHE_TAG_DIRTY XA_MARK_0
492#define PAGECACHE_TAG_WRITEBACK XA_MARK_1
493#define PAGECACHE_TAG_TOWRITE XA_MARK_2
494
495/*
496 * Returns true if any of the pages in the mapping are marked with the tag.
497 */
498static inline bool mapping_tagged(struct address_space *mapping, xa_mark_t tag)
499{
500 return xa_marked(xa: &mapping->i_pages, mark: tag);
501}
502
503static inline void i_mmap_lock_write(struct address_space *mapping)
504{
505 down_write(sem: &mapping->i_mmap_rwsem);
506}
507
508static inline int i_mmap_trylock_write(struct address_space *mapping)
509{
510 return down_write_trylock(sem: &mapping->i_mmap_rwsem);
511}
512
513static inline void i_mmap_unlock_write(struct address_space *mapping)
514{
515 up_write(sem: &mapping->i_mmap_rwsem);
516}
517
518static inline int i_mmap_trylock_read(struct address_space *mapping)
519{
520 return down_read_trylock(sem: &mapping->i_mmap_rwsem);
521}
522
523static inline void i_mmap_lock_read(struct address_space *mapping)
524{
525 down_read(sem: &mapping->i_mmap_rwsem);
526}
527
528static inline void i_mmap_unlock_read(struct address_space *mapping)
529{
530 up_read(sem: &mapping->i_mmap_rwsem);
531}
532
533static inline void i_mmap_assert_locked(struct address_space *mapping)
534{
535 lockdep_assert_held(&mapping->i_mmap_rwsem);
536}
537
538static inline void i_mmap_assert_write_locked(struct address_space *mapping)
539{
540 lockdep_assert_held_write(&mapping->i_mmap_rwsem);
541}
542
543/*
544 * Might pages of this file be mapped into userspace?
545 */
546static inline int mapping_mapped(struct address_space *mapping)
547{
548 return !RB_EMPTY_ROOT(&mapping->i_mmap.rb_root);
549}
550
551/*
552 * Might pages of this file have been modified in userspace?
553 * Note that i_mmap_writable counts all VM_SHARED, VM_MAYWRITE vmas: do_mmap
554 * marks vma as VM_SHARED if it is shared, and the file was opened for
555 * writing i.e. vma may be mprotected writable even if now readonly.
556 *
557 * If i_mmap_writable is negative, no new writable mappings are allowed. You
558 * can only deny writable mappings, if none exists right now.
559 */
560static inline int mapping_writably_mapped(struct address_space *mapping)
561{
562 return atomic_read(v: &mapping->i_mmap_writable) > 0;
563}
564
565static inline int mapping_map_writable(struct address_space *mapping)
566{
567 return atomic_inc_unless_negative(v: &mapping->i_mmap_writable) ?
568 0 : -EPERM;
569}
570
571static inline void mapping_unmap_writable(struct address_space *mapping)
572{
573 atomic_dec(v: &mapping->i_mmap_writable);
574}
575
576static inline int mapping_deny_writable(struct address_space *mapping)
577{
578 return atomic_dec_unless_positive(v: &mapping->i_mmap_writable) ?
579 0 : -EBUSY;
580}
581
582static inline void mapping_allow_writable(struct address_space *mapping)
583{
584 atomic_inc(v: &mapping->i_mmap_writable);
585}
586
587/*
588 * Use sequence counter to get consistent i_size on 32-bit processors.
589 */
590#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
591#include <linux/seqlock.h>
592#define __NEED_I_SIZE_ORDERED
593#define i_size_ordered_init(inode) seqcount_init(&inode->i_size_seqcount)
594#else
595#define i_size_ordered_init(inode) do { } while (0)
596#endif
597
598struct posix_acl;
599#define ACL_NOT_CACHED ((void *)(-1))
600/*
601 * ACL_DONT_CACHE is for stacked filesystems, that rely on underlying fs to
602 * cache the ACL. This also means that ->get_inode_acl() can be called in RCU
603 * mode with the LOOKUP_RCU flag.
604 */
605#define ACL_DONT_CACHE ((void *)(-3))
606
607static inline struct posix_acl *
608uncached_acl_sentinel(struct task_struct *task)
609{
610 return (void *)task + 1;
611}
612
613static inline bool
614is_uncached_acl(struct posix_acl *acl)
615{
616 return (long)acl & 1;
617}
618
619#define IOP_FASTPERM 0x0001
620#define IOP_LOOKUP 0x0002
621#define IOP_NOFOLLOW 0x0004
622#define IOP_XATTR 0x0008
623#define IOP_DEFAULT_READLINK 0x0010
624
625struct fsnotify_mark_connector;
626
627/*
628 * Keep mostly read-only and often accessed (especially for
629 * the RCU path lookup and 'stat' data) fields at the beginning
630 * of the 'struct inode'
631 */
632struct inode {
633 umode_t i_mode;
634 unsigned short i_opflags;
635 kuid_t i_uid;
636 kgid_t i_gid;
637 unsigned int i_flags;
638
639#ifdef CONFIG_FS_POSIX_ACL
640 struct posix_acl *i_acl;
641 struct posix_acl *i_default_acl;
642#endif
643
644 const struct inode_operations *i_op;
645 struct super_block *i_sb;
646 struct address_space *i_mapping;
647
648#ifdef CONFIG_SECURITY
649 void *i_security;
650#endif
651
652 /* Stat data, not accessed from path walking */
653 unsigned long i_ino;
654 /*
655 * Filesystems may only read i_nlink directly. They shall use the
656 * following functions for modification:
657 *
658 * (set|clear|inc|drop)_nlink
659 * inode_(inc|dec)_link_count
660 */
661 union {
662 const unsigned int i_nlink;
663 unsigned int __i_nlink;
664 };
665 dev_t i_rdev;
666 loff_t i_size;
667 struct timespec64 __i_atime;
668 struct timespec64 __i_mtime;
669 struct timespec64 __i_ctime; /* use inode_*_ctime accessors! */
670 spinlock_t i_lock; /* i_blocks, i_bytes, maybe i_size */
671 unsigned short i_bytes;
672 u8 i_blkbits;
673 enum rw_hint i_write_hint;
674 blkcnt_t i_blocks;
675
676#ifdef __NEED_I_SIZE_ORDERED
677 seqcount_t i_size_seqcount;
678#endif
679
680 /* Misc */
681 unsigned long i_state;
682 struct rw_semaphore i_rwsem;
683
684 unsigned long dirtied_when; /* jiffies of first dirtying */
685 unsigned long dirtied_time_when;
686
687 struct hlist_node i_hash;
688 struct list_head i_io_list; /* backing dev IO list */
689#ifdef CONFIG_CGROUP_WRITEBACK
690 struct bdi_writeback *i_wb; /* the associated cgroup wb */
691
692 /* foreign inode detection, see wbc_detach_inode() */
693 int i_wb_frn_winner;
694 u16 i_wb_frn_avg_time;
695 u16 i_wb_frn_history;
696#endif
697 struct list_head i_lru; /* inode LRU list */
698 struct list_head i_sb_list;
699 struct list_head i_wb_list; /* backing dev writeback list */
700 union {
701 struct hlist_head i_dentry;
702 struct rcu_head i_rcu;
703 };
704 atomic64_t i_version;
705 atomic64_t i_sequence; /* see futex */
706 atomic_t i_count;
707 atomic_t i_dio_count;
708 atomic_t i_writecount;
709#if defined(CONFIG_IMA) || defined(CONFIG_FILE_LOCKING)
710 atomic_t i_readcount; /* struct files open RO */
711#endif
712 union {
713 const struct file_operations *i_fop; /* former ->i_op->default_file_ops */
714 void (*free_inode)(struct inode *);
715 };
716 struct file_lock_context *i_flctx;
717 struct address_space i_data;
718 struct list_head i_devices;
719 union {
720 struct pipe_inode_info *i_pipe;
721 struct cdev *i_cdev;
722 char *i_link;
723 unsigned i_dir_seq;
724 };
725
726 __u32 i_generation;
727
728#ifdef CONFIG_FSNOTIFY
729 __u32 i_fsnotify_mask; /* all events this inode cares about */
730 struct fsnotify_mark_connector __rcu *i_fsnotify_marks;
731#endif
732
733#ifdef CONFIG_FS_ENCRYPTION
734 struct fscrypt_inode_info *i_crypt_info;
735#endif
736
737#ifdef CONFIG_FS_VERITY
738 struct fsverity_info *i_verity_info;
739#endif
740
741 void *i_private; /* fs or device private pointer */
742} __randomize_layout;
743
744struct timespec64 timestamp_truncate(struct timespec64 t, struct inode *inode);
745
746static inline unsigned int i_blocksize(const struct inode *node)
747{
748 return (1 << node->i_blkbits);
749}
750
751static inline int inode_unhashed(struct inode *inode)
752{
753 return hlist_unhashed(h: &inode->i_hash);
754}
755
756/*
757 * __mark_inode_dirty expects inodes to be hashed. Since we don't
758 * want special inodes in the fileset inode space, we make them
759 * appear hashed, but do not put on any lists. hlist_del()
760 * will work fine and require no locking.
761 */
762static inline void inode_fake_hash(struct inode *inode)
763{
764 hlist_add_fake(n: &inode->i_hash);
765}
766
767/*
768 * inode->i_mutex nesting subclasses for the lock validator:
769 *
770 * 0: the object of the current VFS operation
771 * 1: parent
772 * 2: child/target
773 * 3: xattr
774 * 4: second non-directory
775 * 5: second parent (when locking independent directories in rename)
776 *
777 * I_MUTEX_NONDIR2 is for certain operations (such as rename) which lock two
778 * non-directories at once.
779 *
780 * The locking order between these classes is
781 * parent[2] -> child -> grandchild -> normal -> xattr -> second non-directory
782 */
783enum inode_i_mutex_lock_class
784{
785 I_MUTEX_NORMAL,
786 I_MUTEX_PARENT,
787 I_MUTEX_CHILD,
788 I_MUTEX_XATTR,
789 I_MUTEX_NONDIR2,
790 I_MUTEX_PARENT2,
791};
792
793static inline void inode_lock(struct inode *inode)
794{
795 down_write(sem: &inode->i_rwsem);
796}
797
798static inline void inode_unlock(struct inode *inode)
799{
800 up_write(sem: &inode->i_rwsem);
801}
802
803static inline void inode_lock_shared(struct inode *inode)
804{
805 down_read(sem: &inode->i_rwsem);
806}
807
808static inline void inode_unlock_shared(struct inode *inode)
809{
810 up_read(sem: &inode->i_rwsem);
811}
812
813static inline int inode_trylock(struct inode *inode)
814{
815 return down_write_trylock(sem: &inode->i_rwsem);
816}
817
818static inline int inode_trylock_shared(struct inode *inode)
819{
820 return down_read_trylock(sem: &inode->i_rwsem);
821}
822
823static inline int inode_is_locked(struct inode *inode)
824{
825 return rwsem_is_locked(sem: &inode->i_rwsem);
826}
827
828static inline void inode_lock_nested(struct inode *inode, unsigned subclass)
829{
830 down_write_nested(sem: &inode->i_rwsem, subclass);
831}
832
833static inline void inode_lock_shared_nested(struct inode *inode, unsigned subclass)
834{
835 down_read_nested(sem: &inode->i_rwsem, subclass);
836}
837
838static inline void filemap_invalidate_lock(struct address_space *mapping)
839{
840 down_write(sem: &mapping->invalidate_lock);
841}
842
843static inline void filemap_invalidate_unlock(struct address_space *mapping)
844{
845 up_write(sem: &mapping->invalidate_lock);
846}
847
848static inline void filemap_invalidate_lock_shared(struct address_space *mapping)
849{
850 down_read(sem: &mapping->invalidate_lock);
851}
852
853static inline int filemap_invalidate_trylock_shared(
854 struct address_space *mapping)
855{
856 return down_read_trylock(sem: &mapping->invalidate_lock);
857}
858
859static inline void filemap_invalidate_unlock_shared(
860 struct address_space *mapping)
861{
862 up_read(sem: &mapping->invalidate_lock);
863}
864
865void lock_two_nondirectories(struct inode *, struct inode*);
866void unlock_two_nondirectories(struct inode *, struct inode*);
867
868void filemap_invalidate_lock_two(struct address_space *mapping1,
869 struct address_space *mapping2);
870void filemap_invalidate_unlock_two(struct address_space *mapping1,
871 struct address_space *mapping2);
872
873
874/*
875 * NOTE: in a 32bit arch with a preemptable kernel and
876 * an UP compile the i_size_read/write must be atomic
877 * with respect to the local cpu (unlike with preempt disabled),
878 * but they don't need to be atomic with respect to other cpus like in
879 * true SMP (so they need either to either locally disable irq around
880 * the read or for example on x86 they can be still implemented as a
881 * cmpxchg8b without the need of the lock prefix). For SMP compiles
882 * and 64bit archs it makes no difference if preempt is enabled or not.
883 */
884static inline loff_t i_size_read(const struct inode *inode)
885{
886#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
887 loff_t i_size;
888 unsigned int seq;
889
890 do {
891 seq = read_seqcount_begin(&inode->i_size_seqcount);
892 i_size = inode->i_size;
893 } while (read_seqcount_retry(&inode->i_size_seqcount, seq));
894 return i_size;
895#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION)
896 loff_t i_size;
897
898 preempt_disable();
899 i_size = inode->i_size;
900 preempt_enable();
901 return i_size;
902#else
903 /* Pairs with smp_store_release() in i_size_write() */
904 return smp_load_acquire(&inode->i_size);
905#endif
906}
907
908/*
909 * NOTE: unlike i_size_read(), i_size_write() does need locking around it
910 * (normally i_mutex), otherwise on 32bit/SMP an update of i_size_seqcount
911 * can be lost, resulting in subsequent i_size_read() calls spinning forever.
912 */
913static inline void i_size_write(struct inode *inode, loff_t i_size)
914{
915#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
916 preempt_disable();
917 write_seqcount_begin(&inode->i_size_seqcount);
918 inode->i_size = i_size;
919 write_seqcount_end(&inode->i_size_seqcount);
920 preempt_enable();
921#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION)
922 preempt_disable();
923 inode->i_size = i_size;
924 preempt_enable();
925#else
926 /*
927 * Pairs with smp_load_acquire() in i_size_read() to ensure
928 * changes related to inode size (such as page contents) are
929 * visible before we see the changed inode size.
930 */
931 smp_store_release(&inode->i_size, i_size);
932#endif
933}
934
935static inline unsigned iminor(const struct inode *inode)
936{
937 return MINOR(inode->i_rdev);
938}
939
940static inline unsigned imajor(const struct inode *inode)
941{
942 return MAJOR(inode->i_rdev);
943}
944
945struct fown_struct {
946 rwlock_t lock; /* protects pid, uid, euid fields */
947 struct pid *pid; /* pid or -pgrp where SIGIO should be sent */
948 enum pid_type pid_type; /* Kind of process group SIGIO should be sent to */
949 kuid_t uid, euid; /* uid/euid of process setting the owner */
950 int signum; /* posix.1b rt signal to be delivered on IO */
951};
952
953/**
954 * struct file_ra_state - Track a file's readahead state.
955 * @start: Where the most recent readahead started.
956 * @size: Number of pages read in the most recent readahead.
957 * @async_size: Numer of pages that were/are not needed immediately
958 * and so were/are genuinely "ahead". Start next readahead when
959 * the first of these pages is accessed.
960 * @ra_pages: Maximum size of a readahead request, copied from the bdi.
961 * @mmap_miss: How many mmap accesses missed in the page cache.
962 * @prev_pos: The last byte in the most recent read request.
963 *
964 * When this structure is passed to ->readahead(), the "most recent"
965 * readahead means the current readahead.
966 */
967struct file_ra_state {
968 pgoff_t start;
969 unsigned int size;
970 unsigned int async_size;
971 unsigned int ra_pages;
972 unsigned int mmap_miss;
973 loff_t prev_pos;
974};
975
976/*
977 * Check if @index falls in the readahead windows.
978 */
979static inline int ra_has_index(struct file_ra_state *ra, pgoff_t index)
980{
981 return (index >= ra->start &&
982 index < ra->start + ra->size);
983}
984
985/*
986 * f_{lock,count,pos_lock} members can be highly contended and share
987 * the same cacheline. f_{lock,mode} are very frequently used together
988 * and so share the same cacheline as well. The read-mostly
989 * f_{path,inode,op} are kept on a separate cacheline.
990 */
991struct file {
992 union {
993 /* fput() uses task work when closing and freeing file (default). */
994 struct callback_head f_task_work;
995 /* fput() must use workqueue (most kernel threads). */
996 struct llist_node f_llist;
997 unsigned int f_iocb_flags;
998 };
999
1000 /*
1001 * Protects f_ep, f_flags.
1002 * Must not be taken from IRQ context.
1003 */
1004 spinlock_t f_lock;
1005 fmode_t f_mode;
1006 atomic_long_t f_count;
1007 struct mutex f_pos_lock;
1008 loff_t f_pos;
1009 unsigned int f_flags;
1010 struct fown_struct f_owner;
1011 const struct cred *f_cred;
1012 struct file_ra_state f_ra;
1013 struct path f_path;
1014 struct inode *f_inode; /* cached value */
1015 const struct file_operations *f_op;
1016
1017 u64 f_version;
1018#ifdef CONFIG_SECURITY
1019 void *f_security;
1020#endif
1021 /* needed for tty driver, and maybe others */
1022 void *private_data;
1023
1024#ifdef CONFIG_EPOLL
1025 /* Used by fs/eventpoll.c to link all the hooks to this file */
1026 struct hlist_head *f_ep;
1027#endif /* #ifdef CONFIG_EPOLL */
1028 struct address_space *f_mapping;
1029 errseq_t f_wb_err;
1030 errseq_t f_sb_err; /* for syncfs */
1031} __randomize_layout
1032 __attribute__((aligned(4))); /* lest something weird decides that 2 is OK */
1033
1034struct file_handle {
1035 __u32 handle_bytes;
1036 int handle_type;
1037 /* file identifier */
1038 unsigned char f_handle[];
1039};
1040
1041static inline struct file *get_file(struct file *f)
1042{
1043 atomic_long_inc(v: &f->f_count);
1044 return f;
1045}
1046
1047struct file *get_file_rcu(struct file __rcu **f);
1048struct file *get_file_active(struct file **f);
1049
1050#define file_count(x) atomic_long_read(&(x)->f_count)
1051
1052#define MAX_NON_LFS ((1UL<<31) - 1)
1053
1054/* Page cache limit. The filesystems should put that into their s_maxbytes
1055 limits, otherwise bad things can happen in VM. */
1056#if BITS_PER_LONG==32
1057#define MAX_LFS_FILESIZE ((loff_t)ULONG_MAX << PAGE_SHIFT)
1058#elif BITS_PER_LONG==64
1059#define MAX_LFS_FILESIZE ((loff_t)LLONG_MAX)
1060#endif
1061
1062/* legacy typedef, should eventually be removed */
1063typedef void *fl_owner_t;
1064
1065struct file_lock;
1066struct file_lease;
1067
1068/* The following constant reflects the upper bound of the file/locking space */
1069#ifndef OFFSET_MAX
1070#define OFFSET_MAX type_max(loff_t)
1071#define OFFT_OFFSET_MAX type_max(off_t)
1072#endif
1073
1074extern void send_sigio(struct fown_struct *fown, int fd, int band);
1075
1076static inline struct inode *file_inode(const struct file *f)
1077{
1078 return f->f_inode;
1079}
1080
1081/*
1082 * file_dentry() is a relic from the days that overlayfs was using files with a
1083 * "fake" path, meaning, f_path on overlayfs and f_inode on underlying fs.
1084 * In those days, file_dentry() was needed to get the underlying fs dentry that
1085 * matches f_inode.
1086 * Files with "fake" path should not exist nowadays, so use an assertion to make
1087 * sure that file_dentry() was not papering over filesystem bugs.
1088 */
1089static inline struct dentry *file_dentry(const struct file *file)
1090{
1091 struct dentry *dentry = file->f_path.dentry;
1092
1093 WARN_ON_ONCE(d_inode(dentry) != file_inode(file));
1094 return dentry;
1095}
1096
1097struct fasync_struct {
1098 rwlock_t fa_lock;
1099 int magic;
1100 int fa_fd;
1101 struct fasync_struct *fa_next; /* singly linked list */
1102 struct file *fa_file;
1103 struct rcu_head fa_rcu;
1104};
1105
1106#define FASYNC_MAGIC 0x4601
1107
1108/* SMP safe fasync helpers: */
1109extern int fasync_helper(int, struct file *, int, struct fasync_struct **);
1110extern struct fasync_struct *fasync_insert_entry(int, struct file *, struct fasync_struct **, struct fasync_struct *);
1111extern int fasync_remove_entry(struct file *, struct fasync_struct **);
1112extern struct fasync_struct *fasync_alloc(void);
1113extern void fasync_free(struct fasync_struct *);
1114
1115/* can be called from interrupts */
1116extern void kill_fasync(struct fasync_struct **, int, int);
1117
1118extern void __f_setown(struct file *filp, struct pid *, enum pid_type, int force);
1119extern int f_setown(struct file *filp, int who, int force);
1120extern void f_delown(struct file *filp);
1121extern pid_t f_getown(struct file *filp);
1122extern int send_sigurg(struct fown_struct *fown);
1123
1124/*
1125 * sb->s_flags. Note that these mirror the equivalent MS_* flags where
1126 * represented in both.
1127 */
1128#define SB_RDONLY BIT(0) /* Mount read-only */
1129#define SB_NOSUID BIT(1) /* Ignore suid and sgid bits */
1130#define SB_NODEV BIT(2) /* Disallow access to device special files */
1131#define SB_NOEXEC BIT(3) /* Disallow program execution */
1132#define SB_SYNCHRONOUS BIT(4) /* Writes are synced at once */
1133#define SB_MANDLOCK BIT(6) /* Allow mandatory locks on an FS */
1134#define SB_DIRSYNC BIT(7) /* Directory modifications are synchronous */
1135#define SB_NOATIME BIT(10) /* Do not update access times. */
1136#define SB_NODIRATIME BIT(11) /* Do not update directory access times */
1137#define SB_SILENT BIT(15)
1138#define SB_POSIXACL BIT(16) /* Supports POSIX ACLs */
1139#define SB_INLINECRYPT BIT(17) /* Use blk-crypto for encrypted files */
1140#define SB_KERNMOUNT BIT(22) /* this is a kern_mount call */
1141#define SB_I_VERSION BIT(23) /* Update inode I_version field */
1142#define SB_LAZYTIME BIT(25) /* Update the on-disk [acm]times lazily */
1143
1144/* These sb flags are internal to the kernel */
1145#define SB_DEAD BIT(21)
1146#define SB_DYING BIT(24)
1147#define SB_SUBMOUNT BIT(26)
1148#define SB_FORCE BIT(27)
1149#define SB_NOSEC BIT(28)
1150#define SB_BORN BIT(29)
1151#define SB_ACTIVE BIT(30)
1152#define SB_NOUSER BIT(31)
1153
1154/* These flags relate to encoding and casefolding */
1155#define SB_ENC_STRICT_MODE_FL (1 << 0)
1156
1157#define sb_has_strict_encoding(sb) \
1158 (sb->s_encoding_flags & SB_ENC_STRICT_MODE_FL)
1159
1160/*
1161 * Umount options
1162 */
1163
1164#define MNT_FORCE 0x00000001 /* Attempt to forcibily umount */
1165#define MNT_DETACH 0x00000002 /* Just detach from the tree */
1166#define MNT_EXPIRE 0x00000004 /* Mark for expiry */
1167#define UMOUNT_NOFOLLOW 0x00000008 /* Don't follow symlink on umount */
1168#define UMOUNT_UNUSED 0x80000000 /* Flag guaranteed to be unused */
1169
1170/* sb->s_iflags */
1171#define SB_I_CGROUPWB 0x00000001 /* cgroup-aware writeback enabled */
1172#define SB_I_NOEXEC 0x00000002 /* Ignore executables on this fs */
1173#define SB_I_NODEV 0x00000004 /* Ignore devices on this fs */
1174#define SB_I_STABLE_WRITES 0x00000008 /* don't modify blks until WB is done */
1175
1176/* sb->s_iflags to limit user namespace mounts */
1177#define SB_I_USERNS_VISIBLE 0x00000010 /* fstype already mounted */
1178#define SB_I_IMA_UNVERIFIABLE_SIGNATURE 0x00000020
1179#define SB_I_UNTRUSTED_MOUNTER 0x00000040
1180#define SB_I_EVM_UNSUPPORTED 0x00000080
1181
1182#define SB_I_SKIP_SYNC 0x00000100 /* Skip superblock at global sync */
1183#define SB_I_PERSB_BDI 0x00000200 /* has a per-sb bdi */
1184#define SB_I_TS_EXPIRY_WARNED 0x00000400 /* warned about timestamp range expiry */
1185#define SB_I_RETIRED 0x00000800 /* superblock shouldn't be reused */
1186#define SB_I_NOUMASK 0x00001000 /* VFS does not apply umask */
1187
1188/* Possible states of 'frozen' field */
1189enum {
1190 SB_UNFROZEN = 0, /* FS is unfrozen */
1191 SB_FREEZE_WRITE = 1, /* Writes, dir ops, ioctls frozen */
1192 SB_FREEZE_PAGEFAULT = 2, /* Page faults stopped as well */
1193 SB_FREEZE_FS = 3, /* For internal FS use (e.g. to stop
1194 * internal threads if needed) */
1195 SB_FREEZE_COMPLETE = 4, /* ->freeze_fs finished successfully */
1196};
1197
1198#define SB_FREEZE_LEVELS (SB_FREEZE_COMPLETE - 1)
1199
1200struct sb_writers {
1201 unsigned short frozen; /* Is sb frozen? */
1202 int freeze_kcount; /* How many kernel freeze requests? */
1203 int freeze_ucount; /* How many userspace freeze requests? */
1204 struct percpu_rw_semaphore rw_sem[SB_FREEZE_LEVELS];
1205};
1206
1207struct super_block {
1208 struct list_head s_list; /* Keep this first */
1209 dev_t s_dev; /* search index; _not_ kdev_t */
1210 unsigned char s_blocksize_bits;
1211 unsigned long s_blocksize;
1212 loff_t s_maxbytes; /* Max file size */
1213 struct file_system_type *s_type;
1214 const struct super_operations *s_op;
1215 const struct dquot_operations *dq_op;
1216 const struct quotactl_ops *s_qcop;
1217 const struct export_operations *s_export_op;
1218 unsigned long s_flags;
1219 unsigned long s_iflags; /* internal SB_I_* flags */
1220 unsigned long s_magic;
1221 struct dentry *s_root;
1222 struct rw_semaphore s_umount;
1223 int s_count;
1224 atomic_t s_active;
1225#ifdef CONFIG_SECURITY
1226 void *s_security;
1227#endif
1228 const struct xattr_handler * const *s_xattr;
1229#ifdef CONFIG_FS_ENCRYPTION
1230 const struct fscrypt_operations *s_cop;
1231 struct fscrypt_keyring *s_master_keys; /* master crypto keys in use */
1232#endif
1233#ifdef CONFIG_FS_VERITY
1234 const struct fsverity_operations *s_vop;
1235#endif
1236#if IS_ENABLED(CONFIG_UNICODE)
1237 struct unicode_map *s_encoding;
1238 __u16 s_encoding_flags;
1239#endif
1240 struct hlist_bl_head s_roots; /* alternate root dentries for NFS */
1241 struct list_head s_mounts; /* list of mounts; _not_ for fs use */
1242 struct block_device *s_bdev; /* can go away once we use an accessor for @s_bdev_file */
1243 struct file *s_bdev_file;
1244 struct backing_dev_info *s_bdi;
1245 struct mtd_info *s_mtd;
1246 struct hlist_node s_instances;
1247 unsigned int s_quota_types; /* Bitmask of supported quota types */
1248 struct quota_info s_dquot; /* Diskquota specific options */
1249
1250 struct sb_writers s_writers;
1251
1252 /*
1253 * Keep s_fs_info, s_time_gran, s_fsnotify_mask, and
1254 * s_fsnotify_marks together for cache efficiency. They are frequently
1255 * accessed and rarely modified.
1256 */
1257 void *s_fs_info; /* Filesystem private info */
1258
1259 /* Granularity of c/m/atime in ns (cannot be worse than a second) */
1260 u32 s_time_gran;
1261 /* Time limits for c/m/atime in seconds */
1262 time64_t s_time_min;
1263 time64_t s_time_max;
1264#ifdef CONFIG_FSNOTIFY
1265 __u32 s_fsnotify_mask;
1266 struct fsnotify_mark_connector __rcu *s_fsnotify_marks;
1267#endif
1268
1269 /*
1270 * q: why are s_id and s_sysfs_name not the same? both are human
1271 * readable strings that identify the filesystem
1272 * a: s_id is allowed to change at runtime; it's used in log messages,
1273 * and we want to when a device starts out as single device (s_id is dev
1274 * name) but then a device is hot added and we have to switch to
1275 * identifying it by UUID
1276 * but s_sysfs_name is a handle for programmatic access, and can't
1277 * change at runtime
1278 */
1279 char s_id[32]; /* Informational name */
1280 uuid_t s_uuid; /* UUID */
1281 u8 s_uuid_len; /* Default 16, possibly smaller for weird filesystems */
1282
1283 /* if set, fs shows up under sysfs at /sys/fs/$FSTYP/s_sysfs_name */
1284 char s_sysfs_name[UUID_STRING_LEN + 1];
1285
1286 unsigned int s_max_links;
1287
1288 /*
1289 * The next field is for VFS *only*. No filesystems have any business
1290 * even looking at it. You had been warned.
1291 */
1292 struct mutex s_vfs_rename_mutex; /* Kludge */
1293
1294 /*
1295 * Filesystem subtype. If non-empty the filesystem type field
1296 * in /proc/mounts will be "type.subtype"
1297 */
1298 const char *s_subtype;
1299
1300 const struct dentry_operations *s_d_op; /* default d_op for dentries */
1301
1302 struct shrinker *s_shrink; /* per-sb shrinker handle */
1303
1304 /* Number of inodes with nlink == 0 but still referenced */
1305 atomic_long_t s_remove_count;
1306
1307 /*
1308 * Number of inode/mount/sb objects that are being watched, note that
1309 * inodes objects are currently double-accounted.
1310 */
1311 atomic_long_t s_fsnotify_connectors;
1312
1313 /* Read-only state of the superblock is being changed */
1314 int s_readonly_remount;
1315
1316 /* per-sb errseq_t for reporting writeback errors via syncfs */
1317 errseq_t s_wb_err;
1318
1319 /* AIO completions deferred from interrupt context */
1320 struct workqueue_struct *s_dio_done_wq;
1321 struct hlist_head s_pins;
1322
1323 /*
1324 * Owning user namespace and default context in which to
1325 * interpret filesystem uids, gids, quotas, device nodes,
1326 * xattrs and security labels.
1327 */
1328 struct user_namespace *s_user_ns;
1329
1330 /*
1331 * The list_lru structure is essentially just a pointer to a table
1332 * of per-node lru lists, each of which has its own spinlock.
1333 * There is no need to put them into separate cachelines.
1334 */
1335 struct list_lru s_dentry_lru;
1336 struct list_lru s_inode_lru;
1337 struct rcu_head rcu;
1338 struct work_struct destroy_work;
1339
1340 struct mutex s_sync_lock; /* sync serialisation lock */
1341
1342 /*
1343 * Indicates how deep in a filesystem stack this SB is
1344 */
1345 int s_stack_depth;
1346
1347 /* s_inode_list_lock protects s_inodes */
1348 spinlock_t s_inode_list_lock ____cacheline_aligned_in_smp;
1349 struct list_head s_inodes; /* all inodes */
1350
1351 spinlock_t s_inode_wblist_lock;
1352 struct list_head s_inodes_wb; /* writeback inodes */
1353} __randomize_layout;
1354
1355static inline struct user_namespace *i_user_ns(const struct inode *inode)
1356{
1357 return inode->i_sb->s_user_ns;
1358}
1359
1360/* Helper functions so that in most cases filesystems will
1361 * not need to deal directly with kuid_t and kgid_t and can
1362 * instead deal with the raw numeric values that are stored
1363 * in the filesystem.
1364 */
1365static inline uid_t i_uid_read(const struct inode *inode)
1366{
1367 return from_kuid(to: i_user_ns(inode), uid: inode->i_uid);
1368}
1369
1370static inline gid_t i_gid_read(const struct inode *inode)
1371{
1372 return from_kgid(to: i_user_ns(inode), gid: inode->i_gid);
1373}
1374
1375static inline void i_uid_write(struct inode *inode, uid_t uid)
1376{
1377 inode->i_uid = make_kuid(from: i_user_ns(inode), uid);
1378}
1379
1380static inline void i_gid_write(struct inode *inode, gid_t gid)
1381{
1382 inode->i_gid = make_kgid(from: i_user_ns(inode), gid);
1383}
1384
1385/**
1386 * i_uid_into_vfsuid - map an inode's i_uid down according to an idmapping
1387 * @idmap: idmap of the mount the inode was found from
1388 * @inode: inode to map
1389 *
1390 * Return: whe inode's i_uid mapped down according to @idmap.
1391 * If the inode's i_uid has no mapping INVALID_VFSUID is returned.
1392 */
1393static inline vfsuid_t i_uid_into_vfsuid(struct mnt_idmap *idmap,
1394 const struct inode *inode)
1395{
1396 return make_vfsuid(idmap, fs_userns: i_user_ns(inode), kuid: inode->i_uid);
1397}
1398
1399/**
1400 * i_uid_needs_update - check whether inode's i_uid needs to be updated
1401 * @idmap: idmap of the mount the inode was found from
1402 * @attr: the new attributes of @inode
1403 * @inode: the inode to update
1404 *
1405 * Check whether the $inode's i_uid field needs to be updated taking idmapped
1406 * mounts into account if the filesystem supports it.
1407 *
1408 * Return: true if @inode's i_uid field needs to be updated, false if not.
1409 */
1410static inline bool i_uid_needs_update(struct mnt_idmap *idmap,
1411 const struct iattr *attr,
1412 const struct inode *inode)
1413{
1414 return ((attr->ia_valid & ATTR_UID) &&
1415 !vfsuid_eq(left: attr->ia_vfsuid,
1416 right: i_uid_into_vfsuid(idmap, inode)));
1417}
1418
1419/**
1420 * i_uid_update - update @inode's i_uid field
1421 * @idmap: idmap of the mount the inode was found from
1422 * @attr: the new attributes of @inode
1423 * @inode: the inode to update
1424 *
1425 * Safely update @inode's i_uid field translating the vfsuid of any idmapped
1426 * mount into the filesystem kuid.
1427 */
1428static inline void i_uid_update(struct mnt_idmap *idmap,
1429 const struct iattr *attr,
1430 struct inode *inode)
1431{
1432 if (attr->ia_valid & ATTR_UID)
1433 inode->i_uid = from_vfsuid(idmap, fs_userns: i_user_ns(inode),
1434 vfsuid: attr->ia_vfsuid);
1435}
1436
1437/**
1438 * i_gid_into_vfsgid - map an inode's i_gid down according to an idmapping
1439 * @idmap: idmap of the mount the inode was found from
1440 * @inode: inode to map
1441 *
1442 * Return: the inode's i_gid mapped down according to @idmap.
1443 * If the inode's i_gid has no mapping INVALID_VFSGID is returned.
1444 */
1445static inline vfsgid_t i_gid_into_vfsgid(struct mnt_idmap *idmap,
1446 const struct inode *inode)
1447{
1448 return make_vfsgid(idmap, fs_userns: i_user_ns(inode), kgid: inode->i_gid);
1449}
1450
1451/**
1452 * i_gid_needs_update - check whether inode's i_gid needs to be updated
1453 * @idmap: idmap of the mount the inode was found from
1454 * @attr: the new attributes of @inode
1455 * @inode: the inode to update
1456 *
1457 * Check whether the $inode's i_gid field needs to be updated taking idmapped
1458 * mounts into account if the filesystem supports it.
1459 *
1460 * Return: true if @inode's i_gid field needs to be updated, false if not.
1461 */
1462static inline bool i_gid_needs_update(struct mnt_idmap *idmap,
1463 const struct iattr *attr,
1464 const struct inode *inode)
1465{
1466 return ((attr->ia_valid & ATTR_GID) &&
1467 !vfsgid_eq(left: attr->ia_vfsgid,
1468 right: i_gid_into_vfsgid(idmap, inode)));
1469}
1470
1471/**
1472 * i_gid_update - update @inode's i_gid field
1473 * @idmap: idmap of the mount the inode was found from
1474 * @attr: the new attributes of @inode
1475 * @inode: the inode to update
1476 *
1477 * Safely update @inode's i_gid field translating the vfsgid of any idmapped
1478 * mount into the filesystem kgid.
1479 */
1480static inline void i_gid_update(struct mnt_idmap *idmap,
1481 const struct iattr *attr,
1482 struct inode *inode)
1483{
1484 if (attr->ia_valid & ATTR_GID)
1485 inode->i_gid = from_vfsgid(idmap, fs_userns: i_user_ns(inode),
1486 vfsgid: attr->ia_vfsgid);
1487}
1488
1489/**
1490 * inode_fsuid_set - initialize inode's i_uid field with callers fsuid
1491 * @inode: inode to initialize
1492 * @idmap: idmap of the mount the inode was found from
1493 *
1494 * Initialize the i_uid field of @inode. If the inode was found/created via
1495 * an idmapped mount map the caller's fsuid according to @idmap.
1496 */
1497static inline void inode_fsuid_set(struct inode *inode,
1498 struct mnt_idmap *idmap)
1499{
1500 inode->i_uid = mapped_fsuid(idmap, fs_userns: i_user_ns(inode));
1501}
1502
1503/**
1504 * inode_fsgid_set - initialize inode's i_gid field with callers fsgid
1505 * @inode: inode to initialize
1506 * @idmap: idmap of the mount the inode was found from
1507 *
1508 * Initialize the i_gid field of @inode. If the inode was found/created via
1509 * an idmapped mount map the caller's fsgid according to @idmap.
1510 */
1511static inline void inode_fsgid_set(struct inode *inode,
1512 struct mnt_idmap *idmap)
1513{
1514 inode->i_gid = mapped_fsgid(idmap, fs_userns: i_user_ns(inode));
1515}
1516
1517/**
1518 * fsuidgid_has_mapping() - check whether caller's fsuid/fsgid is mapped
1519 * @sb: the superblock we want a mapping in
1520 * @idmap: idmap of the relevant mount
1521 *
1522 * Check whether the caller's fsuid and fsgid have a valid mapping in the
1523 * s_user_ns of the superblock @sb. If the caller is on an idmapped mount map
1524 * the caller's fsuid and fsgid according to the @idmap first.
1525 *
1526 * Return: true if fsuid and fsgid is mapped, false if not.
1527 */
1528static inline bool fsuidgid_has_mapping(struct super_block *sb,
1529 struct mnt_idmap *idmap)
1530{
1531 struct user_namespace *fs_userns = sb->s_user_ns;
1532 kuid_t kuid;
1533 kgid_t kgid;
1534
1535 kuid = mapped_fsuid(idmap, fs_userns);
1536 if (!uid_valid(uid: kuid))
1537 return false;
1538 kgid = mapped_fsgid(idmap, fs_userns);
1539 if (!gid_valid(gid: kgid))
1540 return false;
1541 return kuid_has_mapping(ns: fs_userns, uid: kuid) &&
1542 kgid_has_mapping(ns: fs_userns, gid: kgid);
1543}
1544
1545struct timespec64 current_time(struct inode *inode);
1546struct timespec64 inode_set_ctime_current(struct inode *inode);
1547
1548static inline time64_t inode_get_atime_sec(const struct inode *inode)
1549{
1550 return inode->__i_atime.tv_sec;
1551}
1552
1553static inline long inode_get_atime_nsec(const struct inode *inode)
1554{
1555 return inode->__i_atime.tv_nsec;
1556}
1557
1558static inline struct timespec64 inode_get_atime(const struct inode *inode)
1559{
1560 return inode->__i_atime;
1561}
1562
1563static inline struct timespec64 inode_set_atime_to_ts(struct inode *inode,
1564 struct timespec64 ts)
1565{
1566 inode->__i_atime = ts;
1567 return ts;
1568}
1569
1570static inline struct timespec64 inode_set_atime(struct inode *inode,
1571 time64_t sec, long nsec)
1572{
1573 struct timespec64 ts = { .tv_sec = sec,
1574 .tv_nsec = nsec };
1575 return inode_set_atime_to_ts(inode, ts);
1576}
1577
1578static inline time64_t inode_get_mtime_sec(const struct inode *inode)
1579{
1580 return inode->__i_mtime.tv_sec;
1581}
1582
1583static inline long inode_get_mtime_nsec(const struct inode *inode)
1584{
1585 return inode->__i_mtime.tv_nsec;
1586}
1587
1588static inline struct timespec64 inode_get_mtime(const struct inode *inode)
1589{
1590 return inode->__i_mtime;
1591}
1592
1593static inline struct timespec64 inode_set_mtime_to_ts(struct inode *inode,
1594 struct timespec64 ts)
1595{
1596 inode->__i_mtime = ts;
1597 return ts;
1598}
1599
1600static inline struct timespec64 inode_set_mtime(struct inode *inode,
1601 time64_t sec, long nsec)
1602{
1603 struct timespec64 ts = { .tv_sec = sec,
1604 .tv_nsec = nsec };
1605 return inode_set_mtime_to_ts(inode, ts);
1606}
1607
1608static inline time64_t inode_get_ctime_sec(const struct inode *inode)
1609{
1610 return inode->__i_ctime.tv_sec;
1611}
1612
1613static inline long inode_get_ctime_nsec(const struct inode *inode)
1614{
1615 return inode->__i_ctime.tv_nsec;
1616}
1617
1618static inline struct timespec64 inode_get_ctime(const struct inode *inode)
1619{
1620 return inode->__i_ctime;
1621}
1622
1623static inline struct timespec64 inode_set_ctime_to_ts(struct inode *inode,
1624 struct timespec64 ts)
1625{
1626 inode->__i_ctime = ts;
1627 return ts;
1628}
1629
1630/**
1631 * inode_set_ctime - set the ctime in the inode
1632 * @inode: inode in which to set the ctime
1633 * @sec: tv_sec value to set
1634 * @nsec: tv_nsec value to set
1635 *
1636 * Set the ctime in @inode to { @sec, @nsec }
1637 */
1638static inline struct timespec64 inode_set_ctime(struct inode *inode,
1639 time64_t sec, long nsec)
1640{
1641 struct timespec64 ts = { .tv_sec = sec,
1642 .tv_nsec = nsec };
1643
1644 return inode_set_ctime_to_ts(inode, ts);
1645}
1646
1647struct timespec64 simple_inode_init_ts(struct inode *inode);
1648
1649/*
1650 * Snapshotting support.
1651 */
1652
1653/*
1654 * These are internal functions, please use sb_start_{write,pagefault,intwrite}
1655 * instead.
1656 */
1657static inline void __sb_end_write(struct super_block *sb, int level)
1658{
1659 percpu_up_read(sem: sb->s_writers.rw_sem + level-1);
1660}
1661
1662static inline void __sb_start_write(struct super_block *sb, int level)
1663{
1664 percpu_down_read(sem: sb->s_writers.rw_sem + level - 1);
1665}
1666
1667static inline bool __sb_start_write_trylock(struct super_block *sb, int level)
1668{
1669 return percpu_down_read_trylock(sem: sb->s_writers.rw_sem + level - 1);
1670}
1671
1672#define __sb_writers_acquired(sb, lev) \
1673 percpu_rwsem_acquire(&(sb)->s_writers.rw_sem[(lev)-1], 1, _THIS_IP_)
1674#define __sb_writers_release(sb, lev) \
1675 percpu_rwsem_release(&(sb)->s_writers.rw_sem[(lev)-1], 1, _THIS_IP_)
1676
1677/**
1678 * __sb_write_started - check if sb freeze level is held
1679 * @sb: the super we write to
1680 * @level: the freeze level
1681 *
1682 * * > 0 - sb freeze level is held
1683 * * 0 - sb freeze level is not held
1684 * * < 0 - !CONFIG_LOCKDEP/LOCK_STATE_UNKNOWN
1685 */
1686static inline int __sb_write_started(const struct super_block *sb, int level)
1687{
1688 return lockdep_is_held_type(sb->s_writers.rw_sem + level - 1, 1);
1689}
1690
1691/**
1692 * sb_write_started - check if SB_FREEZE_WRITE is held
1693 * @sb: the super we write to
1694 *
1695 * May be false positive with !CONFIG_LOCKDEP/LOCK_STATE_UNKNOWN.
1696 */
1697static inline bool sb_write_started(const struct super_block *sb)
1698{
1699 return __sb_write_started(sb, level: SB_FREEZE_WRITE);
1700}
1701
1702/**
1703 * sb_write_not_started - check if SB_FREEZE_WRITE is not held
1704 * @sb: the super we write to
1705 *
1706 * May be false positive with !CONFIG_LOCKDEP/LOCK_STATE_UNKNOWN.
1707 */
1708static inline bool sb_write_not_started(const struct super_block *sb)
1709{
1710 return __sb_write_started(sb, level: SB_FREEZE_WRITE) <= 0;
1711}
1712
1713/**
1714 * file_write_started - check if SB_FREEZE_WRITE is held
1715 * @file: the file we write to
1716 *
1717 * May be false positive with !CONFIG_LOCKDEP/LOCK_STATE_UNKNOWN.
1718 * May be false positive with !S_ISREG, because file_start_write() has
1719 * no effect on !S_ISREG.
1720 */
1721static inline bool file_write_started(const struct file *file)
1722{
1723 if (!S_ISREG(file_inode(file)->i_mode))
1724 return true;
1725 return sb_write_started(sb: file_inode(f: file)->i_sb);
1726}
1727
1728/**
1729 * file_write_not_started - check if SB_FREEZE_WRITE is not held
1730 * @file: the file we write to
1731 *
1732 * May be false positive with !CONFIG_LOCKDEP/LOCK_STATE_UNKNOWN.
1733 * May be false positive with !S_ISREG, because file_start_write() has
1734 * no effect on !S_ISREG.
1735 */
1736static inline bool file_write_not_started(const struct file *file)
1737{
1738 if (!S_ISREG(file_inode(file)->i_mode))
1739 return true;
1740 return sb_write_not_started(sb: file_inode(f: file)->i_sb);
1741}
1742
1743/**
1744 * sb_end_write - drop write access to a superblock
1745 * @sb: the super we wrote to
1746 *
1747 * Decrement number of writers to the filesystem. Wake up possible waiters
1748 * wanting to freeze the filesystem.
1749 */
1750static inline void sb_end_write(struct super_block *sb)
1751{
1752 __sb_end_write(sb, level: SB_FREEZE_WRITE);
1753}
1754
1755/**
1756 * sb_end_pagefault - drop write access to a superblock from a page fault
1757 * @sb: the super we wrote to
1758 *
1759 * Decrement number of processes handling write page fault to the filesystem.
1760 * Wake up possible waiters wanting to freeze the filesystem.
1761 */
1762static inline void sb_end_pagefault(struct super_block *sb)
1763{
1764 __sb_end_write(sb, level: SB_FREEZE_PAGEFAULT);
1765}
1766
1767/**
1768 * sb_end_intwrite - drop write access to a superblock for internal fs purposes
1769 * @sb: the super we wrote to
1770 *
1771 * Decrement fs-internal number of writers to the filesystem. Wake up possible
1772 * waiters wanting to freeze the filesystem.
1773 */
1774static inline void sb_end_intwrite(struct super_block *sb)
1775{
1776 __sb_end_write(sb, level: SB_FREEZE_FS);
1777}
1778
1779/**
1780 * sb_start_write - get write access to a superblock
1781 * @sb: the super we write to
1782 *
1783 * When a process wants to write data or metadata to a file system (i.e. dirty
1784 * a page or an inode), it should embed the operation in a sb_start_write() -
1785 * sb_end_write() pair to get exclusion against file system freezing. This
1786 * function increments number of writers preventing freezing. If the file
1787 * system is already frozen, the function waits until the file system is
1788 * thawed.
1789 *
1790 * Since freeze protection behaves as a lock, users have to preserve
1791 * ordering of freeze protection and other filesystem locks. Generally,
1792 * freeze protection should be the outermost lock. In particular, we have:
1793 *
1794 * sb_start_write
1795 * -> i_mutex (write path, truncate, directory ops, ...)
1796 * -> s_umount (freeze_super, thaw_super)
1797 */
1798static inline void sb_start_write(struct super_block *sb)
1799{
1800 __sb_start_write(sb, level: SB_FREEZE_WRITE);
1801}
1802
1803static inline bool sb_start_write_trylock(struct super_block *sb)
1804{
1805 return __sb_start_write_trylock(sb, level: SB_FREEZE_WRITE);
1806}
1807
1808/**
1809 * sb_start_pagefault - get write access to a superblock from a page fault
1810 * @sb: the super we write to
1811 *
1812 * When a process starts handling write page fault, it should embed the
1813 * operation into sb_start_pagefault() - sb_end_pagefault() pair to get
1814 * exclusion against file system freezing. This is needed since the page fault
1815 * is going to dirty a page. This function increments number of running page
1816 * faults preventing freezing. If the file system is already frozen, the
1817 * function waits until the file system is thawed.
1818 *
1819 * Since page fault freeze protection behaves as a lock, users have to preserve
1820 * ordering of freeze protection and other filesystem locks. It is advised to
1821 * put sb_start_pagefault() close to mmap_lock in lock ordering. Page fault
1822 * handling code implies lock dependency:
1823 *
1824 * mmap_lock
1825 * -> sb_start_pagefault
1826 */
1827static inline void sb_start_pagefault(struct super_block *sb)
1828{
1829 __sb_start_write(sb, level: SB_FREEZE_PAGEFAULT);
1830}
1831
1832/**
1833 * sb_start_intwrite - get write access to a superblock for internal fs purposes
1834 * @sb: the super we write to
1835 *
1836 * This is the third level of protection against filesystem freezing. It is
1837 * free for use by a filesystem. The only requirement is that it must rank
1838 * below sb_start_pagefault.
1839 *
1840 * For example filesystem can call sb_start_intwrite() when starting a
1841 * transaction which somewhat eases handling of freezing for internal sources
1842 * of filesystem changes (internal fs threads, discarding preallocation on file
1843 * close, etc.).
1844 */
1845static inline void sb_start_intwrite(struct super_block *sb)
1846{
1847 __sb_start_write(sb, level: SB_FREEZE_FS);
1848}
1849
1850static inline bool sb_start_intwrite_trylock(struct super_block *sb)
1851{
1852 return __sb_start_write_trylock(sb, level: SB_FREEZE_FS);
1853}
1854
1855bool inode_owner_or_capable(struct mnt_idmap *idmap,
1856 const struct inode *inode);
1857
1858/*
1859 * VFS helper functions..
1860 */
1861int vfs_create(struct mnt_idmap *, struct inode *,
1862 struct dentry *, umode_t, bool);
1863int vfs_mkdir(struct mnt_idmap *, struct inode *,
1864 struct dentry *, umode_t);
1865int vfs_mknod(struct mnt_idmap *, struct inode *, struct dentry *,
1866 umode_t, dev_t);
1867int vfs_symlink(struct mnt_idmap *, struct inode *,
1868 struct dentry *, const char *);
1869int vfs_link(struct dentry *, struct mnt_idmap *, struct inode *,
1870 struct dentry *, struct inode **);
1871int vfs_rmdir(struct mnt_idmap *, struct inode *, struct dentry *);
1872int vfs_unlink(struct mnt_idmap *, struct inode *, struct dentry *,
1873 struct inode **);
1874
1875/**
1876 * struct renamedata - contains all information required for renaming
1877 * @old_mnt_idmap: idmap of the old mount the inode was found from
1878 * @old_dir: parent of source
1879 * @old_dentry: source
1880 * @new_mnt_idmap: idmap of the new mount the inode was found from
1881 * @new_dir: parent of destination
1882 * @new_dentry: destination
1883 * @delegated_inode: returns an inode needing a delegation break
1884 * @flags: rename flags
1885 */
1886struct renamedata {
1887 struct mnt_idmap *old_mnt_idmap;
1888 struct inode *old_dir;
1889 struct dentry *old_dentry;
1890 struct mnt_idmap *new_mnt_idmap;
1891 struct inode *new_dir;
1892 struct dentry *new_dentry;
1893 struct inode **delegated_inode;
1894 unsigned int flags;
1895} __randomize_layout;
1896
1897int vfs_rename(struct renamedata *);
1898
1899static inline int vfs_whiteout(struct mnt_idmap *idmap,
1900 struct inode *dir, struct dentry *dentry)
1901{
1902 return vfs_mknod(idmap, dir, dentry, S_IFCHR | WHITEOUT_MODE,
1903 WHITEOUT_DEV);
1904}
1905
1906struct file *kernel_tmpfile_open(struct mnt_idmap *idmap,
1907 const struct path *parentpath,
1908 umode_t mode, int open_flag,
1909 const struct cred *cred);
1910struct file *kernel_file_open(const struct path *path, int flags,
1911 struct inode *inode, const struct cred *cred);
1912
1913int vfs_mkobj(struct dentry *, umode_t,
1914 int (*f)(struct dentry *, umode_t, void *),
1915 void *);
1916
1917int vfs_fchown(struct file *file, uid_t user, gid_t group);
1918int vfs_fchmod(struct file *file, umode_t mode);
1919int vfs_utimes(const struct path *path, struct timespec64 *times);
1920
1921extern long vfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
1922
1923#ifdef CONFIG_COMPAT
1924extern long compat_ptr_ioctl(struct file *file, unsigned int cmd,
1925 unsigned long arg);
1926#else
1927#define compat_ptr_ioctl NULL
1928#endif
1929
1930/*
1931 * VFS file helper functions.
1932 */
1933void inode_init_owner(struct mnt_idmap *idmap, struct inode *inode,
1934 const struct inode *dir, umode_t mode);
1935extern bool may_open_dev(const struct path *path);
1936umode_t mode_strip_sgid(struct mnt_idmap *idmap,
1937 const struct inode *dir, umode_t mode);
1938
1939/*
1940 * This is the "filldir" function type, used by readdir() to let
1941 * the kernel specify what kind of dirent layout it wants to have.
1942 * This allows the kernel to read directories into kernel space or
1943 * to have different dirent layouts depending on the binary type.
1944 * Return 'true' to keep going and 'false' if there are no more entries.
1945 */
1946struct dir_context;
1947typedef bool (*filldir_t)(struct dir_context *, const char *, int, loff_t, u64,
1948 unsigned);
1949
1950struct dir_context {
1951 filldir_t actor;
1952 loff_t pos;
1953};
1954
1955/*
1956 * These flags let !MMU mmap() govern direct device mapping vs immediate
1957 * copying more easily for MAP_PRIVATE, especially for ROM filesystems.
1958 *
1959 * NOMMU_MAP_COPY: Copy can be mapped (MAP_PRIVATE)
1960 * NOMMU_MAP_DIRECT: Can be mapped directly (MAP_SHARED)
1961 * NOMMU_MAP_READ: Can be mapped for reading
1962 * NOMMU_MAP_WRITE: Can be mapped for writing
1963 * NOMMU_MAP_EXEC: Can be mapped for execution
1964 */
1965#define NOMMU_MAP_COPY 0x00000001
1966#define NOMMU_MAP_DIRECT 0x00000008
1967#define NOMMU_MAP_READ VM_MAYREAD
1968#define NOMMU_MAP_WRITE VM_MAYWRITE
1969#define NOMMU_MAP_EXEC VM_MAYEXEC
1970
1971#define NOMMU_VMFLAGS \
1972 (NOMMU_MAP_READ | NOMMU_MAP_WRITE | NOMMU_MAP_EXEC)
1973
1974/*
1975 * These flags control the behavior of the remap_file_range function pointer.
1976 * If it is called with len == 0 that means "remap to end of source file".
1977 * See Documentation/filesystems/vfs.rst for more details about this call.
1978 *
1979 * REMAP_FILE_DEDUP: only remap if contents identical (i.e. deduplicate)
1980 * REMAP_FILE_CAN_SHORTEN: caller can handle a shortened request
1981 */
1982#define REMAP_FILE_DEDUP (1 << 0)
1983#define REMAP_FILE_CAN_SHORTEN (1 << 1)
1984
1985/*
1986 * These flags signal that the caller is ok with altering various aspects of
1987 * the behavior of the remap operation. The changes must be made by the
1988 * implementation; the vfs remap helper functions can take advantage of them.
1989 * Flags in this category exist to preserve the quirky behavior of the hoisted
1990 * btrfs clone/dedupe ioctls.
1991 */
1992#define REMAP_FILE_ADVISORY (REMAP_FILE_CAN_SHORTEN)
1993
1994/*
1995 * These flags control the behavior of vfs_copy_file_range().
1996 * They are not available to the user via syscall.
1997 *
1998 * COPY_FILE_SPLICE: call splice direct instead of fs clone/copy ops
1999 */
2000#define COPY_FILE_SPLICE (1 << 0)
2001
2002struct iov_iter;
2003struct io_uring_cmd;
2004struct offset_ctx;
2005
2006struct file_operations {
2007 struct module *owner;
2008 loff_t (*llseek) (struct file *, loff_t, int);
2009 ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
2010 ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
2011 ssize_t (*read_iter) (struct kiocb *, struct iov_iter *);
2012 ssize_t (*write_iter) (struct kiocb *, struct iov_iter *);
2013 int (*iopoll)(struct kiocb *kiocb, struct io_comp_batch *,
2014 unsigned int flags);
2015 int (*iterate_shared) (struct file *, struct dir_context *);
2016 __poll_t (*poll) (struct file *, struct poll_table_struct *);
2017 long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
2018 long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
2019 int (*mmap) (struct file *, struct vm_area_struct *);
2020 unsigned long mmap_supported_flags;
2021 int (*open) (struct inode *, struct file *);
2022 int (*flush) (struct file *, fl_owner_t id);
2023 int (*release) (struct inode *, struct file *);
2024 int (*fsync) (struct file *, loff_t, loff_t, int datasync);
2025 int (*fasync) (int, struct file *, int);
2026 int (*lock) (struct file *, int, struct file_lock *);
2027 unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
2028 int (*check_flags)(int);
2029 int (*flock) (struct file *, int, struct file_lock *);
2030 ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int);
2031 ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int);
2032 void (*splice_eof)(struct file *file);
2033 int (*setlease)(struct file *, int, struct file_lease **, void **);
2034 long (*fallocate)(struct file *file, int mode, loff_t offset,
2035 loff_t len);
2036 void (*show_fdinfo)(struct seq_file *m, struct file *f);
2037#ifndef CONFIG_MMU
2038 unsigned (*mmap_capabilities)(struct file *);
2039#endif
2040 ssize_t (*copy_file_range)(struct file *, loff_t, struct file *,
2041 loff_t, size_t, unsigned int);
2042 loff_t (*remap_file_range)(struct file *file_in, loff_t pos_in,
2043 struct file *file_out, loff_t pos_out,
2044 loff_t len, unsigned int remap_flags);
2045 int (*fadvise)(struct file *, loff_t, loff_t, int);
2046 int (*uring_cmd)(struct io_uring_cmd *ioucmd, unsigned int issue_flags);
2047 int (*uring_cmd_iopoll)(struct io_uring_cmd *, struct io_comp_batch *,
2048 unsigned int poll_flags);
2049} __randomize_layout;
2050
2051/* Wrap a directory iterator that needs exclusive inode access */
2052int wrap_directory_iterator(struct file *, struct dir_context *,
2053 int (*) (struct file *, struct dir_context *));
2054#define WRAP_DIR_ITER(x) \
2055 static int shared_##x(struct file *file , struct dir_context *ctx) \
2056 { return wrap_directory_iterator(file, ctx, x); }
2057
2058struct inode_operations {
2059 struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int);
2060 const char * (*get_link) (struct dentry *, struct inode *, struct delayed_call *);
2061 int (*permission) (struct mnt_idmap *, struct inode *, int);
2062 struct posix_acl * (*get_inode_acl)(struct inode *, int, bool);
2063
2064 int (*readlink) (struct dentry *, char __user *,int);
2065
2066 int (*create) (struct mnt_idmap *, struct inode *,struct dentry *,
2067 umode_t, bool);
2068 int (*link) (struct dentry *,struct inode *,struct dentry *);
2069 int (*unlink) (struct inode *,struct dentry *);
2070 int (*symlink) (struct mnt_idmap *, struct inode *,struct dentry *,
2071 const char *);
2072 int (*mkdir) (struct mnt_idmap *, struct inode *,struct dentry *,
2073 umode_t);
2074 int (*rmdir) (struct inode *,struct dentry *);
2075 int (*mknod) (struct mnt_idmap *, struct inode *,struct dentry *,
2076 umode_t,dev_t);
2077 int (*rename) (struct mnt_idmap *, struct inode *, struct dentry *,
2078 struct inode *, struct dentry *, unsigned int);
2079 int (*setattr) (struct mnt_idmap *, struct dentry *, struct iattr *);
2080 int (*getattr) (struct mnt_idmap *, const struct path *,
2081 struct kstat *, u32, unsigned int);
2082 ssize_t (*listxattr) (struct dentry *, char *, size_t);
2083 int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start,
2084 u64 len);
2085 int (*update_time)(struct inode *, int);
2086 int (*atomic_open)(struct inode *, struct dentry *,
2087 struct file *, unsigned open_flag,
2088 umode_t create_mode);
2089 int (*tmpfile) (struct mnt_idmap *, struct inode *,
2090 struct file *, umode_t);
2091 struct posix_acl *(*get_acl)(struct mnt_idmap *, struct dentry *,
2092 int);
2093 int (*set_acl)(struct mnt_idmap *, struct dentry *,
2094 struct posix_acl *, int);
2095 int (*fileattr_set)(struct mnt_idmap *idmap,
2096 struct dentry *dentry, struct fileattr *fa);
2097 int (*fileattr_get)(struct dentry *dentry, struct fileattr *fa);
2098 struct offset_ctx *(*get_offset_ctx)(struct inode *inode);
2099} ____cacheline_aligned;
2100
2101static inline ssize_t call_read_iter(struct file *file, struct kiocb *kio,
2102 struct iov_iter *iter)
2103{
2104 return file->f_op->read_iter(kio, iter);
2105}
2106
2107static inline ssize_t call_write_iter(struct file *file, struct kiocb *kio,
2108 struct iov_iter *iter)
2109{
2110 return file->f_op->write_iter(kio, iter);
2111}
2112
2113static inline int call_mmap(struct file *file, struct vm_area_struct *vma)
2114{
2115 return file->f_op->mmap(file, vma);
2116}
2117
2118extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *);
2119extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *);
2120extern ssize_t vfs_copy_file_range(struct file *, loff_t , struct file *,
2121 loff_t, size_t, unsigned int);
2122int __generic_remap_file_range_prep(struct file *file_in, loff_t pos_in,
2123 struct file *file_out, loff_t pos_out,
2124 loff_t *len, unsigned int remap_flags,
2125 const struct iomap_ops *dax_read_ops);
2126int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in,
2127 struct file *file_out, loff_t pos_out,
2128 loff_t *count, unsigned int remap_flags);
2129extern loff_t vfs_clone_file_range(struct file *file_in, loff_t pos_in,
2130 struct file *file_out, loff_t pos_out,
2131 loff_t len, unsigned int remap_flags);
2132extern int vfs_dedupe_file_range(struct file *file,
2133 struct file_dedupe_range *same);
2134extern loff_t vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos,
2135 struct file *dst_file, loff_t dst_pos,
2136 loff_t len, unsigned int remap_flags);
2137
2138/**
2139 * enum freeze_holder - holder of the freeze
2140 * @FREEZE_HOLDER_KERNEL: kernel wants to freeze or thaw filesystem
2141 * @FREEZE_HOLDER_USERSPACE: userspace wants to freeze or thaw filesystem
2142 * @FREEZE_MAY_NEST: whether nesting freeze and thaw requests is allowed
2143 *
2144 * Indicate who the owner of the freeze or thaw request is and whether
2145 * the freeze needs to be exclusive or can nest.
2146 * Without @FREEZE_MAY_NEST, multiple freeze and thaw requests from the
2147 * same holder aren't allowed. It is however allowed to hold a single
2148 * @FREEZE_HOLDER_USERSPACE and a single @FREEZE_HOLDER_KERNEL freeze at
2149 * the same time. This is relied upon by some filesystems during online
2150 * repair or similar.
2151 */
2152enum freeze_holder {
2153 FREEZE_HOLDER_KERNEL = (1U << 0),
2154 FREEZE_HOLDER_USERSPACE = (1U << 1),
2155 FREEZE_MAY_NEST = (1U << 2),
2156};
2157
2158struct super_operations {
2159 struct inode *(*alloc_inode)(struct super_block *sb);
2160 void (*destroy_inode)(struct inode *);
2161 void (*free_inode)(struct inode *);
2162
2163 void (*dirty_inode) (struct inode *, int flags);
2164 int (*write_inode) (struct inode *, struct writeback_control *wbc);
2165 int (*drop_inode) (struct inode *);
2166 void (*evict_inode) (struct inode *);
2167 void (*put_super) (struct super_block *);
2168 int (*sync_fs)(struct super_block *sb, int wait);
2169 int (*freeze_super) (struct super_block *, enum freeze_holder who);
2170 int (*freeze_fs) (struct super_block *);
2171 int (*thaw_super) (struct super_block *, enum freeze_holder who);
2172 int (*unfreeze_fs) (struct super_block *);
2173 int (*statfs) (struct dentry *, struct kstatfs *);
2174 int (*remount_fs) (struct super_block *, int *, char *);
2175 void (*umount_begin) (struct super_block *);
2176
2177 int (*show_options)(struct seq_file *, struct dentry *);
2178 int (*show_devname)(struct seq_file *, struct dentry *);
2179 int (*show_path)(struct seq_file *, struct dentry *);
2180 int (*show_stats)(struct seq_file *, struct dentry *);
2181#ifdef CONFIG_QUOTA
2182 ssize_t (*quota_read)(struct super_block *, int, char *, size_t, loff_t);
2183 ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t);
2184 struct dquot __rcu **(*get_dquots)(struct inode *);
2185#endif
2186 long (*nr_cached_objects)(struct super_block *,
2187 struct shrink_control *);
2188 long (*free_cached_objects)(struct super_block *,
2189 struct shrink_control *);
2190 void (*shutdown)(struct super_block *sb);
2191};
2192
2193/*
2194 * Inode flags - they have no relation to superblock flags now
2195 */
2196#define S_SYNC (1 << 0) /* Writes are synced at once */
2197#define S_NOATIME (1 << 1) /* Do not update access times */
2198#define S_APPEND (1 << 2) /* Append-only file */
2199#define S_IMMUTABLE (1 << 3) /* Immutable file */
2200#define S_DEAD (1 << 4) /* removed, but still open directory */
2201#define S_NOQUOTA (1 << 5) /* Inode is not counted to quota */
2202#define S_DIRSYNC (1 << 6) /* Directory modifications are synchronous */
2203#define S_NOCMTIME (1 << 7) /* Do not update file c/mtime */
2204#define S_SWAPFILE (1 << 8) /* Do not truncate: swapon got its bmaps */
2205#define S_PRIVATE (1 << 9) /* Inode is fs-internal */
2206#define S_IMA (1 << 10) /* Inode has an associated IMA struct */
2207#define S_AUTOMOUNT (1 << 11) /* Automount/referral quasi-directory */
2208#define S_NOSEC (1 << 12) /* no suid or xattr security attributes */
2209#ifdef CONFIG_FS_DAX
2210#define S_DAX (1 << 13) /* Direct Access, avoiding the page cache */
2211#else
2212#define S_DAX 0 /* Make all the DAX code disappear */
2213#endif
2214#define S_ENCRYPTED (1 << 14) /* Encrypted file (using fs/crypto/) */
2215#define S_CASEFOLD (1 << 15) /* Casefolded file */
2216#define S_VERITY (1 << 16) /* Verity file (using fs/verity/) */
2217#define S_KERNEL_FILE (1 << 17) /* File is in use by the kernel (eg. fs/cachefiles) */
2218
2219/*
2220 * Note that nosuid etc flags are inode-specific: setting some file-system
2221 * flags just means all the inodes inherit those flags by default. It might be
2222 * possible to override it selectively if you really wanted to with some
2223 * ioctl() that is not currently implemented.
2224 *
2225 * Exception: SB_RDONLY is always applied to the entire file system.
2226 *
2227 * Unfortunately, it is possible to change a filesystems flags with it mounted
2228 * with files in use. This means that all of the inodes will not have their
2229 * i_flags updated. Hence, i_flags no longer inherit the superblock mount
2230 * flags, so these have to be checked separately. -- rmk@arm.uk.linux.org
2231 */
2232#define __IS_FLG(inode, flg) ((inode)->i_sb->s_flags & (flg))
2233
2234static inline bool sb_rdonly(const struct super_block *sb) { return sb->s_flags & SB_RDONLY; }
2235#define IS_RDONLY(inode) sb_rdonly((inode)->i_sb)
2236#define IS_SYNC(inode) (__IS_FLG(inode, SB_SYNCHRONOUS) || \
2237 ((inode)->i_flags & S_SYNC))
2238#define IS_DIRSYNC(inode) (__IS_FLG(inode, SB_SYNCHRONOUS|SB_DIRSYNC) || \
2239 ((inode)->i_flags & (S_SYNC|S_DIRSYNC)))
2240#define IS_MANDLOCK(inode) __IS_FLG(inode, SB_MANDLOCK)
2241#define IS_NOATIME(inode) __IS_FLG(inode, SB_RDONLY|SB_NOATIME)
2242#define IS_I_VERSION(inode) __IS_FLG(inode, SB_I_VERSION)
2243
2244#define IS_NOQUOTA(inode) ((inode)->i_flags & S_NOQUOTA)
2245#define IS_APPEND(inode) ((inode)->i_flags & S_APPEND)
2246#define IS_IMMUTABLE(inode) ((inode)->i_flags & S_IMMUTABLE)
2247
2248#ifdef CONFIG_FS_POSIX_ACL
2249#define IS_POSIXACL(inode) __IS_FLG(inode, SB_POSIXACL)
2250#else
2251#define IS_POSIXACL(inode) 0
2252#endif
2253
2254#define IS_DEADDIR(inode) ((inode)->i_flags & S_DEAD)
2255#define IS_NOCMTIME(inode) ((inode)->i_flags & S_NOCMTIME)
2256#define IS_SWAPFILE(inode) ((inode)->i_flags & S_SWAPFILE)
2257#define IS_PRIVATE(inode) ((inode)->i_flags & S_PRIVATE)
2258#define IS_IMA(inode) ((inode)->i_flags & S_IMA)
2259#define IS_AUTOMOUNT(inode) ((inode)->i_flags & S_AUTOMOUNT)
2260#define IS_NOSEC(inode) ((inode)->i_flags & S_NOSEC)
2261#define IS_DAX(inode) ((inode)->i_flags & S_DAX)
2262#define IS_ENCRYPTED(inode) ((inode)->i_flags & S_ENCRYPTED)
2263#define IS_CASEFOLDED(inode) ((inode)->i_flags & S_CASEFOLD)
2264#define IS_VERITY(inode) ((inode)->i_flags & S_VERITY)
2265
2266#define IS_WHITEOUT(inode) (S_ISCHR(inode->i_mode) && \
2267 (inode)->i_rdev == WHITEOUT_DEV)
2268
2269static inline bool HAS_UNMAPPED_ID(struct mnt_idmap *idmap,
2270 struct inode *inode)
2271{
2272 return !vfsuid_valid(uid: i_uid_into_vfsuid(idmap, inode)) ||
2273 !vfsgid_valid(gid: i_gid_into_vfsgid(idmap, inode));
2274}
2275
2276static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp)
2277{
2278 *kiocb = (struct kiocb) {
2279 .ki_filp = filp,
2280 .ki_flags = filp->f_iocb_flags,
2281 .ki_ioprio = get_current_ioprio(),
2282 };
2283}
2284
2285static inline void kiocb_clone(struct kiocb *kiocb, struct kiocb *kiocb_src,
2286 struct file *filp)
2287{
2288 *kiocb = (struct kiocb) {
2289 .ki_filp = filp,
2290 .ki_flags = kiocb_src->ki_flags,
2291 .ki_ioprio = kiocb_src->ki_ioprio,
2292 .ki_pos = kiocb_src->ki_pos,
2293 };
2294}
2295
2296/*
2297 * Inode state bits. Protected by inode->i_lock
2298 *
2299 * Four bits determine the dirty state of the inode: I_DIRTY_SYNC,
2300 * I_DIRTY_DATASYNC, I_DIRTY_PAGES, and I_DIRTY_TIME.
2301 *
2302 * Four bits define the lifetime of an inode. Initially, inodes are I_NEW,
2303 * until that flag is cleared. I_WILL_FREE, I_FREEING and I_CLEAR are set at
2304 * various stages of removing an inode.
2305 *
2306 * Two bits are used for locking and completion notification, I_NEW and I_SYNC.
2307 *
2308 * I_DIRTY_SYNC Inode is dirty, but doesn't have to be written on
2309 * fdatasync() (unless I_DIRTY_DATASYNC is also set).
2310 * Timestamp updates are the usual cause.
2311 * I_DIRTY_DATASYNC Data-related inode changes pending. We keep track of
2312 * these changes separately from I_DIRTY_SYNC so that we
2313 * don't have to write inode on fdatasync() when only
2314 * e.g. the timestamps have changed.
2315 * I_DIRTY_PAGES Inode has dirty pages. Inode itself may be clean.
2316 * I_DIRTY_TIME The inode itself has dirty timestamps, and the
2317 * lazytime mount option is enabled. We keep track of this
2318 * separately from I_DIRTY_SYNC in order to implement
2319 * lazytime. This gets cleared if I_DIRTY_INODE
2320 * (I_DIRTY_SYNC and/or I_DIRTY_DATASYNC) gets set. But
2321 * I_DIRTY_TIME can still be set if I_DIRTY_SYNC is already
2322 * in place because writeback might already be in progress
2323 * and we don't want to lose the time update
2324 * I_NEW Serves as both a mutex and completion notification.
2325 * New inodes set I_NEW. If two processes both create
2326 * the same inode, one of them will release its inode and
2327 * wait for I_NEW to be released before returning.
2328 * Inodes in I_WILL_FREE, I_FREEING or I_CLEAR state can
2329 * also cause waiting on I_NEW, without I_NEW actually
2330 * being set. find_inode() uses this to prevent returning
2331 * nearly-dead inodes.
2332 * I_WILL_FREE Must be set when calling write_inode_now() if i_count
2333 * is zero. I_FREEING must be set when I_WILL_FREE is
2334 * cleared.
2335 * I_FREEING Set when inode is about to be freed but still has dirty
2336 * pages or buffers attached or the inode itself is still
2337 * dirty.
2338 * I_CLEAR Added by clear_inode(). In this state the inode is
2339 * clean and can be destroyed. Inode keeps I_FREEING.
2340 *
2341 * Inodes that are I_WILL_FREE, I_FREEING or I_CLEAR are
2342 * prohibited for many purposes. iget() must wait for
2343 * the inode to be completely released, then create it
2344 * anew. Other functions will just ignore such inodes,
2345 * if appropriate. I_NEW is used for waiting.
2346 *
2347 * I_SYNC Writeback of inode is running. The bit is set during
2348 * data writeback, and cleared with a wakeup on the bit
2349 * address once it is done. The bit is also used to pin
2350 * the inode in memory for flusher thread.
2351 *
2352 * I_REFERENCED Marks the inode as recently references on the LRU list.
2353 *
2354 * I_DIO_WAKEUP Never set. Only used as a key for wait_on_bit().
2355 *
2356 * I_WB_SWITCH Cgroup bdi_writeback switching in progress. Used to
2357 * synchronize competing switching instances and to tell
2358 * wb stat updates to grab the i_pages lock. See
2359 * inode_switch_wbs_work_fn() for details.
2360 *
2361 * I_OVL_INUSE Used by overlayfs to get exclusive ownership on upper
2362 * and work dirs among overlayfs mounts.
2363 *
2364 * I_CREATING New object's inode in the middle of setting up.
2365 *
2366 * I_DONTCACHE Evict inode as soon as it is not used anymore.
2367 *
2368 * I_SYNC_QUEUED Inode is queued in b_io or b_more_io writeback lists.
2369 * Used to detect that mark_inode_dirty() should not move
2370 * inode between dirty lists.
2371 *
2372 * I_PINNING_FSCACHE_WB Inode is pinning an fscache object for writeback.
2373 *
2374 * Q: What is the difference between I_WILL_FREE and I_FREEING?
2375 */
2376#define I_DIRTY_SYNC (1 << 0)
2377#define I_DIRTY_DATASYNC (1 << 1)
2378#define I_DIRTY_PAGES (1 << 2)
2379#define __I_NEW 3
2380#define I_NEW (1 << __I_NEW)
2381#define I_WILL_FREE (1 << 4)
2382#define I_FREEING (1 << 5)
2383#define I_CLEAR (1 << 6)
2384#define __I_SYNC 7
2385#define I_SYNC (1 << __I_SYNC)
2386#define I_REFERENCED (1 << 8)
2387#define __I_DIO_WAKEUP 9
2388#define I_DIO_WAKEUP (1 << __I_DIO_WAKEUP)
2389#define I_LINKABLE (1 << 10)
2390#define I_DIRTY_TIME (1 << 11)
2391#define I_WB_SWITCH (1 << 13)
2392#define I_OVL_INUSE (1 << 14)
2393#define I_CREATING (1 << 15)
2394#define I_DONTCACHE (1 << 16)
2395#define I_SYNC_QUEUED (1 << 17)
2396#define I_PINNING_NETFS_WB (1 << 18)
2397
2398#define I_DIRTY_INODE (I_DIRTY_SYNC | I_DIRTY_DATASYNC)
2399#define I_DIRTY (I_DIRTY_INODE | I_DIRTY_PAGES)
2400#define I_DIRTY_ALL (I_DIRTY | I_DIRTY_TIME)
2401
2402extern void __mark_inode_dirty(struct inode *, int);
2403static inline void mark_inode_dirty(struct inode *inode)
2404{
2405 __mark_inode_dirty(inode, I_DIRTY);
2406}
2407
2408static inline void mark_inode_dirty_sync(struct inode *inode)
2409{
2410 __mark_inode_dirty(inode, I_DIRTY_SYNC);
2411}
2412
2413/*
2414 * Returns true if the given inode itself only has dirty timestamps (its pages
2415 * may still be dirty) and isn't currently being allocated or freed.
2416 * Filesystems should call this if when writing an inode when lazytime is
2417 * enabled, they want to opportunistically write the timestamps of other inodes
2418 * located very nearby on-disk, e.g. in the same inode block. This returns true
2419 * if the given inode is in need of such an opportunistic update. Requires
2420 * i_lock, or at least later re-checking under i_lock.
2421 */
2422static inline bool inode_is_dirtytime_only(struct inode *inode)
2423{
2424 return (inode->i_state & (I_DIRTY_TIME | I_NEW |
2425 I_FREEING | I_WILL_FREE)) == I_DIRTY_TIME;
2426}
2427
2428extern void inc_nlink(struct inode *inode);
2429extern void drop_nlink(struct inode *inode);
2430extern void clear_nlink(struct inode *inode);
2431extern void set_nlink(struct inode *inode, unsigned int nlink);
2432
2433static inline void inode_inc_link_count(struct inode *inode)
2434{
2435 inc_nlink(inode);
2436 mark_inode_dirty(inode);
2437}
2438
2439static inline void inode_dec_link_count(struct inode *inode)
2440{
2441 drop_nlink(inode);
2442 mark_inode_dirty(inode);
2443}
2444
2445enum file_time_flags {
2446 S_ATIME = 1,
2447 S_MTIME = 2,
2448 S_CTIME = 4,
2449 S_VERSION = 8,
2450};
2451
2452extern bool atime_needs_update(const struct path *, struct inode *);
2453extern void touch_atime(const struct path *);
2454int inode_update_time(struct inode *inode, int flags);
2455
2456static inline void file_accessed(struct file *file)
2457{
2458 if (!(file->f_flags & O_NOATIME))
2459 touch_atime(&file->f_path);
2460}
2461
2462extern int file_modified(struct file *file);
2463int kiocb_modified(struct kiocb *iocb);
2464
2465int sync_inode_metadata(struct inode *inode, int wait);
2466
2467struct file_system_type {
2468 const char *name;
2469 int fs_flags;
2470#define FS_REQUIRES_DEV 1
2471#define FS_BINARY_MOUNTDATA 2
2472#define FS_HAS_SUBTYPE 4
2473#define FS_USERNS_MOUNT 8 /* Can be mounted by userns root */
2474#define FS_DISALLOW_NOTIFY_PERM 16 /* Disable fanotify permission events */
2475#define FS_ALLOW_IDMAP 32 /* FS has been updated to handle vfs idmappings. */
2476#define FS_RENAME_DOES_D_MOVE 32768 /* FS will handle d_move() during rename() internally. */
2477 int (*init_fs_context)(struct fs_context *);
2478 const struct fs_parameter_spec *parameters;
2479 struct dentry *(*mount) (struct file_system_type *, int,
2480 const char *, void *);
2481 void (*kill_sb) (struct super_block *);
2482 struct module *owner;
2483 struct file_system_type * next;
2484 struct hlist_head fs_supers;
2485
2486 struct lock_class_key s_lock_key;
2487 struct lock_class_key s_umount_key;
2488 struct lock_class_key s_vfs_rename_key;
2489 struct lock_class_key s_writers_key[SB_FREEZE_LEVELS];
2490
2491 struct lock_class_key i_lock_key;
2492 struct lock_class_key i_mutex_key;
2493 struct lock_class_key invalidate_lock_key;
2494 struct lock_class_key i_mutex_dir_key;
2495};
2496
2497#define MODULE_ALIAS_FS(NAME) MODULE_ALIAS("fs-" NAME)
2498
2499extern struct dentry *mount_bdev(struct file_system_type *fs_type,
2500 int flags, const char *dev_name, void *data,
2501 int (*fill_super)(struct super_block *, void *, int));
2502extern struct dentry *mount_single(struct file_system_type *fs_type,
2503 int flags, void *data,
2504 int (*fill_super)(struct super_block *, void *, int));
2505extern struct dentry *mount_nodev(struct file_system_type *fs_type,
2506 int flags, void *data,
2507 int (*fill_super)(struct super_block *, void *, int));
2508extern struct dentry *mount_subtree(struct vfsmount *mnt, const char *path);
2509void retire_super(struct super_block *sb);
2510void generic_shutdown_super(struct super_block *sb);
2511void kill_block_super(struct super_block *sb);
2512void kill_anon_super(struct super_block *sb);
2513void kill_litter_super(struct super_block *sb);
2514void deactivate_super(struct super_block *sb);
2515void deactivate_locked_super(struct super_block *sb);
2516int set_anon_super(struct super_block *s, void *data);
2517int set_anon_super_fc(struct super_block *s, struct fs_context *fc);
2518int get_anon_bdev(dev_t *);
2519void free_anon_bdev(dev_t);
2520struct super_block *sget_fc(struct fs_context *fc,
2521 int (*test)(struct super_block *, struct fs_context *),
2522 int (*set)(struct super_block *, struct fs_context *));
2523struct super_block *sget(struct file_system_type *type,
2524 int (*test)(struct super_block *,void *),
2525 int (*set)(struct super_block *,void *),
2526 int flags, void *data);
2527struct super_block *sget_dev(struct fs_context *fc, dev_t dev);
2528
2529/* Alas, no aliases. Too much hassle with bringing module.h everywhere */
2530#define fops_get(fops) \
2531 (((fops) && try_module_get((fops)->owner) ? (fops) : NULL))
2532#define fops_put(fops) \
2533 do { if (fops) module_put((fops)->owner); } while(0)
2534/*
2535 * This one is to be used *ONLY* from ->open() instances.
2536 * fops must be non-NULL, pinned down *and* module dependencies
2537 * should be sufficient to pin the caller down as well.
2538 */
2539#define replace_fops(f, fops) \
2540 do { \
2541 struct file *__file = (f); \
2542 fops_put(__file->f_op); \
2543 BUG_ON(!(__file->f_op = (fops))); \
2544 } while(0)
2545
2546extern int register_filesystem(struct file_system_type *);
2547extern int unregister_filesystem(struct file_system_type *);
2548extern int vfs_statfs(const struct path *, struct kstatfs *);
2549extern int user_statfs(const char __user *, struct kstatfs *);
2550extern int fd_statfs(int, struct kstatfs *);
2551int freeze_super(struct super_block *super, enum freeze_holder who);
2552int thaw_super(struct super_block *super, enum freeze_holder who);
2553extern __printf(2, 3)
2554int super_setup_bdi_name(struct super_block *sb, char *fmt, ...);
2555extern int super_setup_bdi(struct super_block *sb);
2556
2557static inline void super_set_uuid(struct super_block *sb, const u8 *uuid, unsigned len)
2558{
2559 if (WARN_ON(len > sizeof(sb->s_uuid)))
2560 len = sizeof(sb->s_uuid);
2561 sb->s_uuid_len = len;
2562 memcpy(&sb->s_uuid, uuid, len);
2563}
2564
2565/* set sb sysfs name based on sb->s_bdev */
2566static inline void super_set_sysfs_name_bdev(struct super_block *sb)
2567{
2568 snprintf(buf: sb->s_sysfs_name, size: sizeof(sb->s_sysfs_name), fmt: "%pg", sb->s_bdev);
2569}
2570
2571/* set sb sysfs name based on sb->s_uuid */
2572static inline void super_set_sysfs_name_uuid(struct super_block *sb)
2573{
2574 WARN_ON(sb->s_uuid_len != sizeof(sb->s_uuid));
2575 snprintf(buf: sb->s_sysfs_name, size: sizeof(sb->s_sysfs_name), fmt: "%pU", sb->s_uuid.b);
2576}
2577
2578/* set sb sysfs name based on sb->s_id */
2579static inline void super_set_sysfs_name_id(struct super_block *sb)
2580{
2581 strscpy(sb->s_sysfs_name, sb->s_id, sizeof(sb->s_sysfs_name));
2582}
2583
2584/* try to use something standard before you use this */
2585__printf(2, 3)
2586static inline void super_set_sysfs_name_generic(struct super_block *sb, const char *fmt, ...)
2587{
2588 va_list args;
2589
2590 va_start(args, fmt);
2591 vsnprintf(buf: sb->s_sysfs_name, size: sizeof(sb->s_sysfs_name), fmt, args);
2592 va_end(args);
2593}
2594
2595extern int current_umask(void);
2596
2597extern void ihold(struct inode * inode);
2598extern void iput(struct inode *);
2599int inode_update_timestamps(struct inode *inode, int flags);
2600int generic_update_time(struct inode *, int);
2601
2602/* /sys/fs */
2603extern struct kobject *fs_kobj;
2604
2605#define MAX_RW_COUNT (INT_MAX & PAGE_MASK)
2606
2607/* fs/open.c */
2608struct audit_names;
2609struct filename {
2610 const char *name; /* pointer to actual string */
2611 const __user char *uptr; /* original userland pointer */
2612 atomic_t refcnt;
2613 struct audit_names *aname;
2614 const char iname[];
2615};
2616static_assert(offsetof(struct filename, iname) % sizeof(long) == 0);
2617
2618static inline struct mnt_idmap *file_mnt_idmap(const struct file *file)
2619{
2620 return mnt_idmap(mnt: file->f_path.mnt);
2621}
2622
2623/**
2624 * is_idmapped_mnt - check whether a mount is mapped
2625 * @mnt: the mount to check
2626 *
2627 * If @mnt has an non @nop_mnt_idmap attached to it then @mnt is mapped.
2628 *
2629 * Return: true if mount is mapped, false if not.
2630 */
2631static inline bool is_idmapped_mnt(const struct vfsmount *mnt)
2632{
2633 return mnt_idmap(mnt) != &nop_mnt_idmap;
2634}
2635
2636extern long vfs_truncate(const struct path *, loff_t);
2637int do_truncate(struct mnt_idmap *, struct dentry *, loff_t start,
2638 unsigned int time_attrs, struct file *filp);
2639extern int vfs_fallocate(struct file *file, int mode, loff_t offset,
2640 loff_t len);
2641extern long do_sys_open(int dfd, const char __user *filename, int flags,
2642 umode_t mode);
2643extern struct file *file_open_name(struct filename *, int, umode_t);
2644extern struct file *filp_open(const char *, int, umode_t);
2645extern struct file *file_open_root(const struct path *,
2646 const char *, int, umode_t);
2647static inline struct file *file_open_root_mnt(struct vfsmount *mnt,
2648 const char *name, int flags, umode_t mode)
2649{
2650 return file_open_root(&(struct path){.mnt = mnt, .dentry = mnt->mnt_root},
2651 name, flags, mode);
2652}
2653struct file *dentry_open(const struct path *path, int flags,
2654 const struct cred *creds);
2655struct file *dentry_create(const struct path *path, int flags, umode_t mode,
2656 const struct cred *cred);
2657struct path *backing_file_user_path(struct file *f);
2658
2659/*
2660 * When mmapping a file on a stackable filesystem (e.g., overlayfs), the file
2661 * stored in ->vm_file is a backing file whose f_inode is on the underlying
2662 * filesystem. When the mapped file path and inode number are displayed to
2663 * user (e.g. via /proc/<pid>/maps), these helpers should be used to get the
2664 * path and inode number to display to the user, which is the path of the fd
2665 * that user has requested to map and the inode number that would be returned
2666 * by fstat() on that same fd.
2667 */
2668/* Get the path to display in /proc/<pid>/maps */
2669static inline const struct path *file_user_path(struct file *f)
2670{
2671 if (unlikely(f->f_mode & FMODE_BACKING))
2672 return backing_file_user_path(f);
2673 return &f->f_path;
2674}
2675/* Get the inode whose inode number to display in /proc/<pid>/maps */
2676static inline const struct inode *file_user_inode(struct file *f)
2677{
2678 if (unlikely(f->f_mode & FMODE_BACKING))
2679 return d_inode(dentry: backing_file_user_path(f)->dentry);
2680 return file_inode(f);
2681}
2682
2683static inline struct file *file_clone_open(struct file *file)
2684{
2685 return dentry_open(path: &file->f_path, flags: file->f_flags, creds: file->f_cred);
2686}
2687extern int filp_close(struct file *, fl_owner_t id);
2688
2689extern struct filename *getname_flags(const char __user *, int, int *);
2690extern struct filename *getname_uflags(const char __user *, int);
2691extern struct filename *getname(const char __user *);
2692extern struct filename *getname_kernel(const char *);
2693extern void putname(struct filename *name);
2694
2695extern int finish_open(struct file *file, struct dentry *dentry,
2696 int (*open)(struct inode *, struct file *));
2697extern int finish_no_open(struct file *file, struct dentry *dentry);
2698
2699/* Helper for the simple case when original dentry is used */
2700static inline int finish_open_simple(struct file *file, int error)
2701{
2702 if (error)
2703 return error;
2704
2705 return finish_open(file, dentry: file->f_path.dentry, NULL);
2706}
2707
2708/* fs/dcache.c */
2709extern void __init vfs_caches_init_early(void);
2710extern void __init vfs_caches_init(void);
2711
2712extern struct kmem_cache *names_cachep;
2713
2714#define __getname() kmem_cache_alloc(names_cachep, GFP_KERNEL)
2715#define __putname(name) kmem_cache_free(names_cachep, (void *)(name))
2716
2717extern struct super_block *blockdev_superblock;
2718static inline bool sb_is_blkdev_sb(struct super_block *sb)
2719{
2720 return IS_ENABLED(CONFIG_BLOCK) && sb == blockdev_superblock;
2721}
2722
2723void emergency_thaw_all(void);
2724extern int sync_filesystem(struct super_block *);
2725extern const struct file_operations def_blk_fops;
2726extern const struct file_operations def_chr_fops;
2727
2728/* fs/char_dev.c */
2729#define CHRDEV_MAJOR_MAX 512
2730/* Marks the bottom of the first segment of free char majors */
2731#define CHRDEV_MAJOR_DYN_END 234
2732/* Marks the top and bottom of the second segment of free char majors */
2733#define CHRDEV_MAJOR_DYN_EXT_START 511
2734#define CHRDEV_MAJOR_DYN_EXT_END 384
2735
2736extern int alloc_chrdev_region(dev_t *, unsigned, unsigned, const char *);
2737extern int register_chrdev_region(dev_t, unsigned, const char *);
2738extern int __register_chrdev(unsigned int major, unsigned int baseminor,
2739 unsigned int count, const char *name,
2740 const struct file_operations *fops);
2741extern void __unregister_chrdev(unsigned int major, unsigned int baseminor,
2742 unsigned int count, const char *name);
2743extern void unregister_chrdev_region(dev_t, unsigned);
2744extern void chrdev_show(struct seq_file *,off_t);
2745
2746static inline int register_chrdev(unsigned int major, const char *name,
2747 const struct file_operations *fops)
2748{
2749 return __register_chrdev(major, baseminor: 0, count: 256, name, fops);
2750}
2751
2752static inline void unregister_chrdev(unsigned int major, const char *name)
2753{
2754 __unregister_chrdev(major, baseminor: 0, count: 256, name);
2755}
2756
2757extern void init_special_inode(struct inode *, umode_t, dev_t);
2758
2759/* Invalid inode operations -- fs/bad_inode.c */
2760extern void make_bad_inode(struct inode *);
2761extern bool is_bad_inode(struct inode *);
2762
2763extern int __must_check file_fdatawait_range(struct file *file, loff_t lstart,
2764 loff_t lend);
2765extern int __must_check file_check_and_advance_wb_err(struct file *file);
2766extern int __must_check file_write_and_wait_range(struct file *file,
2767 loff_t start, loff_t end);
2768
2769static inline int file_write_and_wait(struct file *file)
2770{
2771 return file_write_and_wait_range(file, start: 0, LLONG_MAX);
2772}
2773
2774extern int vfs_fsync_range(struct file *file, loff_t start, loff_t end,
2775 int datasync);
2776extern int vfs_fsync(struct file *file, int datasync);
2777
2778extern int sync_file_range(struct file *file, loff_t offset, loff_t nbytes,
2779 unsigned int flags);
2780
2781static inline bool iocb_is_dsync(const struct kiocb *iocb)
2782{
2783 return (iocb->ki_flags & IOCB_DSYNC) ||
2784 IS_SYNC(iocb->ki_filp->f_mapping->host);
2785}
2786
2787/*
2788 * Sync the bytes written if this was a synchronous write. Expect ki_pos
2789 * to already be updated for the write, and will return either the amount
2790 * of bytes passed in, or an error if syncing the file failed.
2791 */
2792static inline ssize_t generic_write_sync(struct kiocb *iocb, ssize_t count)
2793{
2794 if (iocb_is_dsync(iocb)) {
2795 int ret = vfs_fsync_range(file: iocb->ki_filp,
2796 start: iocb->ki_pos - count, end: iocb->ki_pos - 1,
2797 datasync: (iocb->ki_flags & IOCB_SYNC) ? 0 : 1);
2798 if (ret)
2799 return ret;
2800 }
2801
2802 return count;
2803}
2804
2805extern void emergency_sync(void);
2806extern void emergency_remount(void);
2807
2808#ifdef CONFIG_BLOCK
2809extern int bmap(struct inode *inode, sector_t *block);
2810#else
2811static inline int bmap(struct inode *inode, sector_t *block)
2812{
2813 return -EINVAL;
2814}
2815#endif
2816
2817int notify_change(struct mnt_idmap *, struct dentry *,
2818 struct iattr *, struct inode **);
2819int inode_permission(struct mnt_idmap *, struct inode *, int);
2820int generic_permission(struct mnt_idmap *, struct inode *, int);
2821static inline int file_permission(struct file *file, int mask)
2822{
2823 return inode_permission(file_mnt_idmap(file),
2824 file_inode(f: file), mask);
2825}
2826static inline int path_permission(const struct path *path, int mask)
2827{
2828 return inode_permission(mnt_idmap(mnt: path->mnt),
2829 d_inode(dentry: path->dentry), mask);
2830}
2831int __check_sticky(struct mnt_idmap *idmap, struct inode *dir,
2832 struct inode *inode);
2833
2834static inline bool execute_ok(struct inode *inode)
2835{
2836 return (inode->i_mode & S_IXUGO) || S_ISDIR(inode->i_mode);
2837}
2838
2839static inline bool inode_wrong_type(const struct inode *inode, umode_t mode)
2840{
2841 return (inode->i_mode ^ mode) & S_IFMT;
2842}
2843
2844/**
2845 * file_start_write - get write access to a superblock for regular file io
2846 * @file: the file we want to write to
2847 *
2848 * This is a variant of sb_start_write() which is a noop on non-regualr file.
2849 * Should be matched with a call to file_end_write().
2850 */
2851static inline void file_start_write(struct file *file)
2852{
2853 if (!S_ISREG(file_inode(file)->i_mode))
2854 return;
2855 sb_start_write(sb: file_inode(f: file)->i_sb);
2856}
2857
2858static inline bool file_start_write_trylock(struct file *file)
2859{
2860 if (!S_ISREG(file_inode(file)->i_mode))
2861 return true;
2862 return sb_start_write_trylock(sb: file_inode(f: file)->i_sb);
2863}
2864
2865/**
2866 * file_end_write - drop write access to a superblock of a regular file
2867 * @file: the file we wrote to
2868 *
2869 * Should be matched with a call to file_start_write().
2870 */
2871static inline void file_end_write(struct file *file)
2872{
2873 if (!S_ISREG(file_inode(file)->i_mode))
2874 return;
2875 sb_end_write(sb: file_inode(f: file)->i_sb);
2876}
2877
2878/**
2879 * kiocb_start_write - get write access to a superblock for async file io
2880 * @iocb: the io context we want to submit the write with
2881 *
2882 * This is a variant of sb_start_write() for async io submission.
2883 * Should be matched with a call to kiocb_end_write().
2884 */
2885static inline void kiocb_start_write(struct kiocb *iocb)
2886{
2887 struct inode *inode = file_inode(f: iocb->ki_filp);
2888
2889 sb_start_write(sb: inode->i_sb);
2890 /*
2891 * Fool lockdep by telling it the lock got released so that it
2892 * doesn't complain about the held lock when we return to userspace.
2893 */
2894 __sb_writers_release(inode->i_sb, SB_FREEZE_WRITE);
2895}
2896
2897/**
2898 * kiocb_end_write - drop write access to a superblock after async file io
2899 * @iocb: the io context we sumbitted the write with
2900 *
2901 * Should be matched with a call to kiocb_start_write().
2902 */
2903static inline void kiocb_end_write(struct kiocb *iocb)
2904{
2905 struct inode *inode = file_inode(f: iocb->ki_filp);
2906
2907 /*
2908 * Tell lockdep we inherited freeze protection from submission thread.
2909 */
2910 __sb_writers_acquired(inode->i_sb, SB_FREEZE_WRITE);
2911 sb_end_write(sb: inode->i_sb);
2912}
2913
2914/*
2915 * This is used for regular files where some users -- especially the
2916 * currently executed binary in a process, previously handled via
2917 * VM_DENYWRITE -- cannot handle concurrent write (and maybe mmap
2918 * read-write shared) accesses.
2919 *
2920 * get_write_access() gets write permission for a file.
2921 * put_write_access() releases this write permission.
2922 * deny_write_access() denies write access to a file.
2923 * allow_write_access() re-enables write access to a file.
2924 *
2925 * The i_writecount field of an inode can have the following values:
2926 * 0: no write access, no denied write access
2927 * < 0: (-i_writecount) users that denied write access to the file.
2928 * > 0: (i_writecount) users that have write access to the file.
2929 *
2930 * Normally we operate on that counter with atomic_{inc,dec} and it's safe
2931 * except for the cases where we don't hold i_writecount yet. Then we need to
2932 * use {get,deny}_write_access() - these functions check the sign and refuse
2933 * to do the change if sign is wrong.
2934 */
2935static inline int get_write_access(struct inode *inode)
2936{
2937 return atomic_inc_unless_negative(v: &inode->i_writecount) ? 0 : -ETXTBSY;
2938}
2939static inline int deny_write_access(struct file *file)
2940{
2941 struct inode *inode = file_inode(f: file);
2942 return atomic_dec_unless_positive(v: &inode->i_writecount) ? 0 : -ETXTBSY;
2943}
2944static inline void put_write_access(struct inode * inode)
2945{
2946 atomic_dec(v: &inode->i_writecount);
2947}
2948static inline void allow_write_access(struct file *file)
2949{
2950 if (file)
2951 atomic_inc(v: &file_inode(f: file)->i_writecount);
2952}
2953static inline bool inode_is_open_for_write(const struct inode *inode)
2954{
2955 return atomic_read(v: &inode->i_writecount) > 0;
2956}
2957
2958#if defined(CONFIG_IMA) || defined(CONFIG_FILE_LOCKING)
2959static inline void i_readcount_dec(struct inode *inode)
2960{
2961 BUG_ON(atomic_dec_return(&inode->i_readcount) < 0);
2962}
2963static inline void i_readcount_inc(struct inode *inode)
2964{
2965 atomic_inc(v: &inode->i_readcount);
2966}
2967#else
2968static inline void i_readcount_dec(struct inode *inode)
2969{
2970 return;
2971}
2972static inline void i_readcount_inc(struct inode *inode)
2973{
2974 return;
2975}
2976#endif
2977extern int do_pipe_flags(int *, int);
2978
2979extern ssize_t kernel_read(struct file *, void *, size_t, loff_t *);
2980ssize_t __kernel_read(struct file *file, void *buf, size_t count, loff_t *pos);
2981extern ssize_t kernel_write(struct file *, const void *, size_t, loff_t *);
2982extern ssize_t __kernel_write(struct file *, const void *, size_t, loff_t *);
2983extern struct file * open_exec(const char *);
2984
2985/* fs/dcache.c -- generic fs support functions */
2986extern bool is_subdir(struct dentry *, struct dentry *);
2987extern bool path_is_under(const struct path *, const struct path *);
2988
2989extern char *file_path(struct file *, char *, int);
2990
2991/**
2992 * is_dot_dotdot - returns true only if @name is "." or ".."
2993 * @name: file name to check
2994 * @len: length of file name, in bytes
2995 */
2996static inline bool is_dot_dotdot(const char *name, size_t len)
2997{
2998 return len && unlikely(name[0] == '.') &&
2999 (len == 1 || (len == 2 && name[1] == '.'));
3000}
3001
3002#include <linux/err.h>
3003
3004/* needed for stackable file system support */
3005extern loff_t default_llseek(struct file *file, loff_t offset, int whence);
3006
3007extern loff_t vfs_llseek(struct file *file, loff_t offset, int whence);
3008
3009extern int inode_init_always(struct super_block *, struct inode *);
3010extern void inode_init_once(struct inode *);
3011extern void address_space_init_once(struct address_space *mapping);
3012extern struct inode * igrab(struct inode *);
3013extern ino_t iunique(struct super_block *, ino_t);
3014extern int inode_needs_sync(struct inode *inode);
3015extern int generic_delete_inode(struct inode *inode);
3016static inline int generic_drop_inode(struct inode *inode)
3017{
3018 return !inode->i_nlink || inode_unhashed(inode);
3019}
3020extern void d_mark_dontcache(struct inode *inode);
3021
3022extern struct inode *ilookup5_nowait(struct super_block *sb,
3023 unsigned long hashval, int (*test)(struct inode *, void *),
3024 void *data);
3025extern struct inode *ilookup5(struct super_block *sb, unsigned long hashval,
3026 int (*test)(struct inode *, void *), void *data);
3027extern struct inode *ilookup(struct super_block *sb, unsigned long ino);
3028
3029extern struct inode *inode_insert5(struct inode *inode, unsigned long hashval,
3030 int (*test)(struct inode *, void *),
3031 int (*set)(struct inode *, void *),
3032 void *data);
3033extern struct inode * iget5_locked(struct super_block *, unsigned long, int (*test)(struct inode *, void *), int (*set)(struct inode *, void *), void *);
3034extern struct inode * iget_locked(struct super_block *, unsigned long);
3035extern struct inode *find_inode_nowait(struct super_block *,
3036 unsigned long,
3037 int (*match)(struct inode *,
3038 unsigned long, void *),
3039 void *data);
3040extern struct inode *find_inode_rcu(struct super_block *, unsigned long,
3041 int (*)(struct inode *, void *), void *);
3042extern struct inode *find_inode_by_ino_rcu(struct super_block *, unsigned long);
3043extern int insert_inode_locked4(struct inode *, unsigned long, int (*test)(struct inode *, void *), void *);
3044extern int insert_inode_locked(struct inode *);
3045#ifdef CONFIG_DEBUG_LOCK_ALLOC
3046extern void lockdep_annotate_inode_mutex_key(struct inode *inode);
3047#else
3048static inline void lockdep_annotate_inode_mutex_key(struct inode *inode) { };
3049#endif
3050extern void unlock_new_inode(struct inode *);
3051extern void discard_new_inode(struct inode *);
3052extern unsigned int get_next_ino(void);
3053extern void evict_inodes(struct super_block *sb);
3054void dump_mapping(const struct address_space *);
3055
3056/*
3057 * Userspace may rely on the inode number being non-zero. For example, glibc
3058 * simply ignores files with zero i_ino in unlink() and other places.
3059 *
3060 * As an additional complication, if userspace was compiled with
3061 * _FILE_OFFSET_BITS=32 on a 64-bit kernel we'll only end up reading out the
3062 * lower 32 bits, so we need to check that those aren't zero explicitly. With
3063 * _FILE_OFFSET_BITS=64, this may cause some harmless false-negatives, but
3064 * better safe than sorry.
3065 */
3066static inline bool is_zero_ino(ino_t ino)
3067{
3068 return (u32)ino == 0;
3069}
3070
3071extern void __iget(struct inode * inode);
3072extern void iget_failed(struct inode *);
3073extern void clear_inode(struct inode *);
3074extern void __destroy_inode(struct inode *);
3075extern struct inode *new_inode_pseudo(struct super_block *sb);
3076extern struct inode *new_inode(struct super_block *sb);
3077extern void free_inode_nonrcu(struct inode *inode);
3078extern int setattr_should_drop_suidgid(struct mnt_idmap *, struct inode *);
3079extern int file_remove_privs_flags(struct file *file, unsigned int flags);
3080extern int file_remove_privs(struct file *);
3081int setattr_should_drop_sgid(struct mnt_idmap *idmap,
3082 const struct inode *inode);
3083
3084/*
3085 * This must be used for allocating filesystems specific inodes to set
3086 * up the inode reclaim context correctly.
3087 */
3088static inline void *
3089alloc_inode_sb(struct super_block *sb, struct kmem_cache *cache, gfp_t gfp)
3090{
3091 return kmem_cache_alloc_lru(s: cache, lru: &sb->s_inode_lru, gfpflags: gfp);
3092}
3093
3094extern void __insert_inode_hash(struct inode *, unsigned long hashval);
3095static inline void insert_inode_hash(struct inode *inode)
3096{
3097 __insert_inode_hash(inode, hashval: inode->i_ino);
3098}
3099
3100extern void __remove_inode_hash(struct inode *);
3101static inline void remove_inode_hash(struct inode *inode)
3102{
3103 if (!inode_unhashed(inode) && !hlist_fake(h: &inode->i_hash))
3104 __remove_inode_hash(inode);
3105}
3106
3107extern void inode_sb_list_add(struct inode *inode);
3108extern void inode_add_lru(struct inode *inode);
3109
3110extern int sb_set_blocksize(struct super_block *, int);
3111extern int sb_min_blocksize(struct super_block *, int);
3112
3113extern int generic_file_mmap(struct file *, struct vm_area_struct *);
3114extern int generic_file_readonly_mmap(struct file *, struct vm_area_struct *);
3115extern ssize_t generic_write_checks(struct kiocb *, struct iov_iter *);
3116int generic_write_checks_count(struct kiocb *iocb, loff_t *count);
3117extern int generic_write_check_limits(struct file *file, loff_t pos,
3118 loff_t *count);
3119extern int generic_file_rw_checks(struct file *file_in, struct file *file_out);
3120ssize_t filemap_read(struct kiocb *iocb, struct iov_iter *to,
3121 ssize_t already_read);
3122extern ssize_t generic_file_read_iter(struct kiocb *, struct iov_iter *);
3123extern ssize_t __generic_file_write_iter(struct kiocb *, struct iov_iter *);
3124extern ssize_t generic_file_write_iter(struct kiocb *, struct iov_iter *);
3125extern ssize_t generic_file_direct_write(struct kiocb *, struct iov_iter *);
3126ssize_t generic_perform_write(struct kiocb *, struct iov_iter *);
3127ssize_t direct_write_fallback(struct kiocb *iocb, struct iov_iter *iter,
3128 ssize_t direct_written, ssize_t buffered_written);
3129
3130ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos,
3131 rwf_t flags);
3132ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos,
3133 rwf_t flags);
3134ssize_t vfs_iocb_iter_read(struct file *file, struct kiocb *iocb,
3135 struct iov_iter *iter);
3136ssize_t vfs_iocb_iter_write(struct file *file, struct kiocb *iocb,
3137 struct iov_iter *iter);
3138
3139/* fs/splice.c */
3140ssize_t filemap_splice_read(struct file *in, loff_t *ppos,
3141 struct pipe_inode_info *pipe,
3142 size_t len, unsigned int flags);
3143ssize_t copy_splice_read(struct file *in, loff_t *ppos,
3144 struct pipe_inode_info *pipe,
3145 size_t len, unsigned int flags);
3146extern ssize_t iter_file_splice_write(struct pipe_inode_info *,
3147 struct file *, loff_t *, size_t, unsigned int);
3148
3149
3150extern void
3151file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping);
3152extern loff_t noop_llseek(struct file *file, loff_t offset, int whence);
3153#define no_llseek NULL
3154extern loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize);
3155extern loff_t generic_file_llseek(struct file *file, loff_t offset, int whence);
3156extern loff_t generic_file_llseek_size(struct file *file, loff_t offset,
3157 int whence, loff_t maxsize, loff_t eof);
3158extern loff_t fixed_size_llseek(struct file *file, loff_t offset,
3159 int whence, loff_t size);
3160extern loff_t no_seek_end_llseek_size(struct file *, loff_t, int, loff_t);
3161extern loff_t no_seek_end_llseek(struct file *, loff_t, int);
3162int rw_verify_area(int, struct file *, const loff_t *, size_t);
3163extern int generic_file_open(struct inode * inode, struct file * filp);
3164extern int nonseekable_open(struct inode * inode, struct file * filp);
3165extern int stream_open(struct inode * inode, struct file * filp);
3166
3167#ifdef CONFIG_BLOCK
3168typedef void (dio_submit_t)(struct bio *bio, struct inode *inode,
3169 loff_t file_offset);
3170
3171enum {
3172 /* need locking between buffered and direct access */
3173 DIO_LOCKING = 0x01,
3174
3175 /* filesystem does not support filling holes */
3176 DIO_SKIP_HOLES = 0x02,
3177};
3178
3179ssize_t __blockdev_direct_IO(struct kiocb *iocb, struct inode *inode,
3180 struct block_device *bdev, struct iov_iter *iter,
3181 get_block_t get_block,
3182 dio_iodone_t end_io,
3183 int flags);
3184
3185static inline ssize_t blockdev_direct_IO(struct kiocb *iocb,
3186 struct inode *inode,
3187 struct iov_iter *iter,
3188 get_block_t get_block)
3189{
3190 return __blockdev_direct_IO(iocb, inode, bdev: inode->i_sb->s_bdev, iter,
3191 get_block, NULL, flags: DIO_LOCKING | DIO_SKIP_HOLES);
3192}
3193#endif
3194
3195void inode_dio_wait(struct inode *inode);
3196
3197/**
3198 * inode_dio_begin - signal start of a direct I/O requests
3199 * @inode: inode the direct I/O happens on
3200 *
3201 * This is called once we've finished processing a direct I/O request,
3202 * and is used to wake up callers waiting for direct I/O to be quiesced.
3203 */
3204static inline void inode_dio_begin(struct inode *inode)
3205{
3206 atomic_inc(v: &inode->i_dio_count);
3207}
3208
3209/**
3210 * inode_dio_end - signal finish of a direct I/O requests
3211 * @inode: inode the direct I/O happens on
3212 *
3213 * This is called once we've finished processing a direct I/O request,
3214 * and is used to wake up callers waiting for direct I/O to be quiesced.
3215 */
3216static inline void inode_dio_end(struct inode *inode)
3217{
3218 if (atomic_dec_and_test(v: &inode->i_dio_count))
3219 wake_up_bit(word: &inode->i_state, __I_DIO_WAKEUP);
3220}
3221
3222extern void inode_set_flags(struct inode *inode, unsigned int flags,
3223 unsigned int mask);
3224
3225extern const struct file_operations generic_ro_fops;
3226
3227#define special_file(m) (S_ISCHR(m)||S_ISBLK(m)||S_ISFIFO(m)||S_ISSOCK(m))
3228
3229extern int readlink_copy(char __user *, int, const char *);
3230extern int page_readlink(struct dentry *, char __user *, int);
3231extern const char *page_get_link(struct dentry *, struct inode *,
3232 struct delayed_call *);
3233extern void page_put_link(void *);
3234extern int page_symlink(struct inode *inode, const char *symname, int len);
3235extern const struct inode_operations page_symlink_inode_operations;
3236extern void kfree_link(void *);
3237void generic_fillattr(struct mnt_idmap *, u32, struct inode *, struct kstat *);
3238void generic_fill_statx_attr(struct inode *inode, struct kstat *stat);
3239extern int vfs_getattr_nosec(const struct path *, struct kstat *, u32, unsigned int);
3240extern int vfs_getattr(const struct path *, struct kstat *, u32, unsigned int);
3241void __inode_add_bytes(struct inode *inode, loff_t bytes);
3242void inode_add_bytes(struct inode *inode, loff_t bytes);
3243void __inode_sub_bytes(struct inode *inode, loff_t bytes);
3244void inode_sub_bytes(struct inode *inode, loff_t bytes);
3245static inline loff_t __inode_get_bytes(struct inode *inode)
3246{
3247 return (((loff_t)inode->i_blocks) << 9) + inode->i_bytes;
3248}
3249loff_t inode_get_bytes(struct inode *inode);
3250void inode_set_bytes(struct inode *inode, loff_t bytes);
3251const char *simple_get_link(struct dentry *, struct inode *,
3252 struct delayed_call *);
3253extern const struct inode_operations simple_symlink_inode_operations;
3254
3255extern int iterate_dir(struct file *, struct dir_context *);
3256
3257int vfs_fstatat(int dfd, const char __user *filename, struct kstat *stat,
3258 int flags);
3259int vfs_fstat(int fd, struct kstat *stat);
3260
3261static inline int vfs_stat(const char __user *filename, struct kstat *stat)
3262{
3263 return vfs_fstatat(AT_FDCWD, filename, stat, flags: 0);
3264}
3265static inline int vfs_lstat(const char __user *name, struct kstat *stat)
3266{
3267 return vfs_fstatat(AT_FDCWD, filename: name, stat, AT_SYMLINK_NOFOLLOW);
3268}
3269
3270extern const char *vfs_get_link(struct dentry *, struct delayed_call *);
3271extern int vfs_readlink(struct dentry *, char __user *, int);
3272
3273extern struct file_system_type *get_filesystem(struct file_system_type *fs);
3274extern void put_filesystem(struct file_system_type *fs);
3275extern struct file_system_type *get_fs_type(const char *name);
3276extern void drop_super(struct super_block *sb);
3277extern void drop_super_exclusive(struct super_block *sb);
3278extern void iterate_supers(void (*)(struct super_block *, void *), void *);
3279extern void iterate_supers_type(struct file_system_type *,
3280 void (*)(struct super_block *, void *), void *);
3281
3282extern int dcache_dir_open(struct inode *, struct file *);
3283extern int dcache_dir_close(struct inode *, struct file *);
3284extern loff_t dcache_dir_lseek(struct file *, loff_t, int);
3285extern int dcache_readdir(struct file *, struct dir_context *);
3286extern int simple_setattr(struct mnt_idmap *, struct dentry *,
3287 struct iattr *);
3288extern int simple_getattr(struct mnt_idmap *, const struct path *,
3289 struct kstat *, u32, unsigned int);
3290extern int simple_statfs(struct dentry *, struct kstatfs *);
3291extern int simple_open(struct inode *inode, struct file *file);
3292extern int simple_link(struct dentry *, struct inode *, struct dentry *);
3293extern int simple_unlink(struct inode *, struct dentry *);
3294extern int simple_rmdir(struct inode *, struct dentry *);
3295void simple_rename_timestamp(struct inode *old_dir, struct dentry *old_dentry,
3296 struct inode *new_dir, struct dentry *new_dentry);
3297extern int simple_rename_exchange(struct inode *old_dir, struct dentry *old_dentry,
3298 struct inode *new_dir, struct dentry *new_dentry);
3299extern int simple_rename(struct mnt_idmap *, struct inode *,
3300 struct dentry *, struct inode *, struct dentry *,
3301 unsigned int);
3302extern void simple_recursive_removal(struct dentry *,
3303 void (*callback)(struct dentry *));
3304extern int noop_fsync(struct file *, loff_t, loff_t, int);
3305extern ssize_t noop_direct_IO(struct kiocb *iocb, struct iov_iter *iter);
3306extern int simple_empty(struct dentry *);
3307extern int simple_write_begin(struct file *file, struct address_space *mapping,
3308 loff_t pos, unsigned len,
3309 struct page **pagep, void **fsdata);
3310extern const struct address_space_operations ram_aops;
3311extern int always_delete_dentry(const struct dentry *);
3312extern struct inode *alloc_anon_inode(struct super_block *);
3313extern int simple_nosetlease(struct file *, int, struct file_lease **, void **);
3314extern const struct dentry_operations simple_dentry_operations;
3315
3316extern struct dentry *simple_lookup(struct inode *, struct dentry *, unsigned int flags);
3317extern ssize_t generic_read_dir(struct file *, char __user *, size_t, loff_t *);
3318extern const struct file_operations simple_dir_operations;
3319extern const struct inode_operations simple_dir_inode_operations;
3320extern void make_empty_dir_inode(struct inode *inode);
3321extern bool is_empty_dir_inode(struct inode *inode);
3322struct tree_descr { const char *name; const struct file_operations *ops; int mode; };
3323struct dentry *d_alloc_name(struct dentry *, const char *);
3324extern int simple_fill_super(struct super_block *, unsigned long,
3325 const struct tree_descr *);
3326extern int simple_pin_fs(struct file_system_type *, struct vfsmount **mount, int *count);
3327extern void simple_release_fs(struct vfsmount **mount, int *count);
3328
3329extern ssize_t simple_read_from_buffer(void __user *to, size_t count,
3330 loff_t *ppos, const void *from, size_t available);
3331extern ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos,
3332 const void __user *from, size_t count);
3333
3334struct offset_ctx {
3335 struct maple_tree mt;
3336 unsigned long next_offset;
3337};
3338
3339void simple_offset_init(struct offset_ctx *octx);
3340int simple_offset_add(struct offset_ctx *octx, struct dentry *dentry);
3341void simple_offset_remove(struct offset_ctx *octx, struct dentry *dentry);
3342int simple_offset_empty(struct dentry *dentry);
3343int simple_offset_rename_exchange(struct inode *old_dir,
3344 struct dentry *old_dentry,
3345 struct inode *new_dir,
3346 struct dentry *new_dentry);
3347void simple_offset_destroy(struct offset_ctx *octx);
3348
3349extern const struct file_operations simple_offset_dir_operations;
3350
3351extern int __generic_file_fsync(struct file *, loff_t, loff_t, int);
3352extern int generic_file_fsync(struct file *, loff_t, loff_t, int);
3353
3354extern int generic_check_addressable(unsigned, u64);
3355
3356extern void generic_set_sb_d_ops(struct super_block *sb);
3357
3358static inline bool sb_has_encoding(const struct super_block *sb)
3359{
3360#if IS_ENABLED(CONFIG_UNICODE)
3361 return !!sb->s_encoding;
3362#else
3363 return false;
3364#endif
3365}
3366
3367int may_setattr(struct mnt_idmap *idmap, struct inode *inode,
3368 unsigned int ia_valid);
3369int setattr_prepare(struct mnt_idmap *, struct dentry *, struct iattr *);
3370extern int inode_newsize_ok(const struct inode *, loff_t offset);
3371void setattr_copy(struct mnt_idmap *, struct inode *inode,
3372 const struct iattr *attr);
3373
3374extern int file_update_time(struct file *file);
3375
3376static inline bool vma_is_dax(const struct vm_area_struct *vma)
3377{
3378 return vma->vm_file && IS_DAX(vma->vm_file->f_mapping->host);
3379}
3380
3381static inline bool vma_is_fsdax(struct vm_area_struct *vma)
3382{
3383 struct inode *inode;
3384
3385 if (!IS_ENABLED(CONFIG_FS_DAX) || !vma->vm_file)
3386 return false;
3387 if (!vma_is_dax(vma))
3388 return false;
3389 inode = file_inode(f: vma->vm_file);
3390 if (S_ISCHR(inode->i_mode))
3391 return false; /* device-dax */
3392 return true;
3393}
3394
3395static inline int iocb_flags(struct file *file)
3396{
3397 int res = 0;
3398 if (file->f_flags & O_APPEND)
3399 res |= IOCB_APPEND;
3400 if (file->f_flags & O_DIRECT)
3401 res |= IOCB_DIRECT;
3402 if (file->f_flags & O_DSYNC)
3403 res |= IOCB_DSYNC;
3404 if (file->f_flags & __O_SYNC)
3405 res |= IOCB_SYNC;
3406 return res;
3407}
3408
3409static inline int kiocb_set_rw_flags(struct kiocb *ki, rwf_t flags)
3410{
3411 int kiocb_flags = 0;
3412
3413 /* make sure there's no overlap between RWF and private IOCB flags */
3414 BUILD_BUG_ON((__force int) RWF_SUPPORTED & IOCB_EVENTFD);
3415
3416 if (!flags)
3417 return 0;
3418 if (unlikely(flags & ~RWF_SUPPORTED))
3419 return -EOPNOTSUPP;
3420 if (unlikely((flags & RWF_APPEND) && (flags & RWF_NOAPPEND)))
3421 return -EINVAL;
3422
3423 if (flags & RWF_NOWAIT) {
3424 if (!(ki->ki_filp->f_mode & FMODE_NOWAIT))
3425 return -EOPNOTSUPP;
3426 kiocb_flags |= IOCB_NOIO;
3427 }
3428 kiocb_flags |= (__force int) (flags & RWF_SUPPORTED);
3429 if (flags & RWF_SYNC)
3430 kiocb_flags |= IOCB_DSYNC;
3431
3432 if ((flags & RWF_NOAPPEND) && (ki->ki_flags & IOCB_APPEND)) {
3433 if (IS_APPEND(file_inode(ki->ki_filp)))
3434 return -EPERM;
3435 ki->ki_flags &= ~IOCB_APPEND;
3436 }
3437
3438 ki->ki_flags |= kiocb_flags;
3439 return 0;
3440}
3441
3442static inline ino_t parent_ino(struct dentry *dentry)
3443{
3444 ino_t res;
3445
3446 /*
3447 * Don't strictly need d_lock here? If the parent ino could change
3448 * then surely we'd have a deeper race in the caller?
3449 */
3450 spin_lock(lock: &dentry->d_lock);
3451 res = dentry->d_parent->d_inode->i_ino;
3452 spin_unlock(lock: &dentry->d_lock);
3453 return res;
3454}
3455
3456/* Transaction based IO helpers */
3457
3458/*
3459 * An argresp is stored in an allocated page and holds the
3460 * size of the argument or response, along with its content
3461 */
3462struct simple_transaction_argresp {
3463 ssize_t size;
3464 char data[];
3465};
3466
3467#define SIMPLE_TRANSACTION_LIMIT (PAGE_SIZE - sizeof(struct simple_transaction_argresp))
3468
3469char *simple_transaction_get(struct file *file, const char __user *buf,
3470 size_t size);
3471ssize_t simple_transaction_read(struct file *file, char __user *buf,
3472 size_t size, loff_t *pos);
3473int simple_transaction_release(struct inode *inode, struct file *file);
3474
3475void simple_transaction_set(struct file *file, size_t n);
3476
3477/*
3478 * simple attribute files
3479 *
3480 * These attributes behave similar to those in sysfs:
3481 *
3482 * Writing to an attribute immediately sets a value, an open file can be
3483 * written to multiple times.
3484 *
3485 * Reading from an attribute creates a buffer from the value that might get
3486 * read with multiple read calls. When the attribute has been read
3487 * completely, no further read calls are possible until the file is opened
3488 * again.
3489 *
3490 * All attributes contain a text representation of a numeric value
3491 * that are accessed with the get() and set() functions.
3492 */
3493#define DEFINE_SIMPLE_ATTRIBUTE_XSIGNED(__fops, __get, __set, __fmt, __is_signed) \
3494static int __fops ## _open(struct inode *inode, struct file *file) \
3495{ \
3496 __simple_attr_check_format(__fmt, 0ull); \
3497 return simple_attr_open(inode, file, __get, __set, __fmt); \
3498} \
3499static const struct file_operations __fops = { \
3500 .owner = THIS_MODULE, \
3501 .open = __fops ## _open, \
3502 .release = simple_attr_release, \
3503 .read = simple_attr_read, \
3504 .write = (__is_signed) ? simple_attr_write_signed : simple_attr_write, \
3505 .llseek = generic_file_llseek, \
3506}
3507
3508#define DEFINE_SIMPLE_ATTRIBUTE(__fops, __get, __set, __fmt) \
3509 DEFINE_SIMPLE_ATTRIBUTE_XSIGNED(__fops, __get, __set, __fmt, false)
3510
3511#define DEFINE_SIMPLE_ATTRIBUTE_SIGNED(__fops, __get, __set, __fmt) \
3512 DEFINE_SIMPLE_ATTRIBUTE_XSIGNED(__fops, __get, __set, __fmt, true)
3513
3514static inline __printf(1, 2)
3515void __simple_attr_check_format(const char *fmt, ...)
3516{
3517 /* don't do anything, just let the compiler check the arguments; */
3518}
3519
3520int simple_attr_open(struct inode *inode, struct file *file,
3521 int (*get)(void *, u64 *), int (*set)(void *, u64),
3522 const char *fmt);
3523int simple_attr_release(struct inode *inode, struct file *file);
3524ssize_t simple_attr_read(struct file *file, char __user *buf,
3525 size_t len, loff_t *ppos);
3526ssize_t simple_attr_write(struct file *file, const char __user *buf,
3527 size_t len, loff_t *ppos);
3528ssize_t simple_attr_write_signed(struct file *file, const char __user *buf,
3529 size_t len, loff_t *ppos);
3530
3531struct ctl_table;
3532int __init list_bdev_fs_names(char *buf, size_t size);
3533
3534#define __FMODE_EXEC ((__force int) FMODE_EXEC)
3535#define __FMODE_NONOTIFY ((__force int) FMODE_NONOTIFY)
3536
3537#define ACC_MODE(x) ("\004\002\006\006"[(x)&O_ACCMODE])
3538#define OPEN_FMODE(flag) ((__force fmode_t)(((flag + 1) & O_ACCMODE) | \
3539 (flag & __FMODE_NONOTIFY)))
3540
3541static inline bool is_sxid(umode_t mode)
3542{
3543 return mode & (S_ISUID | S_ISGID);
3544}
3545
3546static inline int check_sticky(struct mnt_idmap *idmap,
3547 struct inode *dir, struct inode *inode)
3548{
3549 if (!(dir->i_mode & S_ISVTX))
3550 return 0;
3551
3552 return __check_sticky(idmap, dir, inode);
3553}
3554
3555static inline void inode_has_no_xattr(struct inode *inode)
3556{
3557 if (!is_sxid(mode: inode->i_mode) && (inode->i_sb->s_flags & SB_NOSEC))
3558 inode->i_flags |= S_NOSEC;
3559}
3560
3561static inline bool is_root_inode(struct inode *inode)
3562{
3563 return inode == inode->i_sb->s_root->d_inode;
3564}
3565
3566static inline bool dir_emit(struct dir_context *ctx,
3567 const char *name, int namelen,
3568 u64 ino, unsigned type)
3569{
3570 return ctx->actor(ctx, name, namelen, ctx->pos, ino, type);
3571}
3572static inline bool dir_emit_dot(struct file *file, struct dir_context *ctx)
3573{
3574 return ctx->actor(ctx, ".", 1, ctx->pos,
3575 file->f_path.dentry->d_inode->i_ino, DT_DIR);
3576}
3577static inline bool dir_emit_dotdot(struct file *file, struct dir_context *ctx)
3578{
3579 return ctx->actor(ctx, "..", 2, ctx->pos,
3580 parent_ino(dentry: file->f_path.dentry), DT_DIR);
3581}
3582static inline bool dir_emit_dots(struct file *file, struct dir_context *ctx)
3583{
3584 if (ctx->pos == 0) {
3585 if (!dir_emit_dot(file, ctx))
3586 return false;
3587 ctx->pos = 1;
3588 }
3589 if (ctx->pos == 1) {
3590 if (!dir_emit_dotdot(file, ctx))
3591 return false;
3592 ctx->pos = 2;
3593 }
3594 return true;
3595}
3596static inline bool dir_relax(struct inode *inode)
3597{
3598 inode_unlock(inode);
3599 inode_lock(inode);
3600 return !IS_DEADDIR(inode);
3601}
3602
3603static inline bool dir_relax_shared(struct inode *inode)
3604{
3605 inode_unlock_shared(inode);
3606 inode_lock_shared(inode);
3607 return !IS_DEADDIR(inode);
3608}
3609
3610extern bool path_noexec(const struct path *path);
3611extern void inode_nohighmem(struct inode *inode);
3612
3613/* mm/fadvise.c */
3614extern int vfs_fadvise(struct file *file, loff_t offset, loff_t len,
3615 int advice);
3616extern int generic_fadvise(struct file *file, loff_t offset, loff_t len,
3617 int advice);
3618
3619#endif /* _LINUX_FS_H */
3620

source code of linux/include/linux/fs.h