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TOMOYO Linux Cross Reference
Linux/include/linux/fs.h

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  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/fiemap.h>
 28 #include <linux/rculist_bl.h>
 29 #include <linux/atomic.h>
 30 #include <linux/shrinker.h>
 31 #include <linux/migrate_mode.h>
 32 #include <linux/uidgid.h>
 33 #include <linux/lockdep.h>
 34 #include <linux/percpu-rwsem.h>
 35 #include <linux/workqueue.h>
 36 #include <linux/delayed_call.h>
 37 #include <linux/uuid.h>
 38 #include <linux/errseq.h>
 39 #include <linux/ioprio.h>
 40 #include <linux/fs_types.h>
 41 #include <linux/build_bug.h>
 42 #include <linux/stddef.h>
 43 
 44 #include <asm/byteorder.h>
 45 #include <uapi/linux/fs.h>
 46 
 47 struct backing_dev_info;
 48 struct bdi_writeback;
 49 struct bio;
 50 struct export_operations;
 51 struct hd_geometry;
 52 struct iovec;
 53 struct kiocb;
 54 struct kobject;
 55 struct pipe_inode_info;
 56 struct poll_table_struct;
 57 struct kstatfs;
 58 struct vm_area_struct;
 59 struct vfsmount;
 60 struct cred;
 61 struct swap_info_struct;
 62 struct seq_file;
 63 struct workqueue_struct;
 64 struct iov_iter;
 65 struct fscrypt_info;
 66 struct fscrypt_operations;
 67 struct fs_context;
 68 struct fs_parameter_description;
 69 
 70 extern void __init inode_init(void);
 71 extern void __init inode_init_early(void);
 72 extern void __init files_init(void);
 73 extern void __init files_maxfiles_init(void);
 74 
 75 extern struct files_stat_struct files_stat;
 76 extern unsigned long get_max_files(void);
 77 extern unsigned int sysctl_nr_open;
 78 extern struct inodes_stat_t inodes_stat;
 79 extern int leases_enable, lease_break_time;
 80 extern int sysctl_protected_symlinks;
 81 extern int sysctl_protected_hardlinks;
 82 extern int sysctl_protected_fifos;
 83 extern int sysctl_protected_regular;
 84 
 85 typedef __kernel_rwf_t rwf_t;
 86 
 87 struct buffer_head;
 88 typedef int (get_block_t)(struct inode *inode, sector_t iblock,
 89                         struct buffer_head *bh_result, int create);
 90 typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset,
 91                         ssize_t bytes, void *private);
 92 
 93 #define MAY_EXEC                0x00000001
 94 #define MAY_WRITE               0x00000002
 95 #define MAY_READ                0x00000004
 96 #define MAY_APPEND              0x00000008
 97 #define MAY_ACCESS              0x00000010
 98 #define MAY_OPEN                0x00000020
 99 #define MAY_CHDIR               0x00000040
100 /* called from RCU mode, don't block */
101 #define MAY_NOT_BLOCK           0x00000080
102 
103 /*
104  * flags in file.f_mode.  Note that FMODE_READ and FMODE_WRITE must correspond
105  * to O_WRONLY and O_RDWR via the strange trick in do_dentry_open()
106  */
107 
108 /* file is open for reading */
109 #define FMODE_READ              ((__force fmode_t)0x1)
110 /* file is open for writing */
111 #define FMODE_WRITE             ((__force fmode_t)0x2)
112 /* file is seekable */
113 #define FMODE_LSEEK             ((__force fmode_t)0x4)
114 /* file can be accessed using pread */
115 #define FMODE_PREAD             ((__force fmode_t)0x8)
116 /* file can be accessed using pwrite */
117 #define FMODE_PWRITE            ((__force fmode_t)0x10)
118 /* File is opened for execution with sys_execve / sys_uselib */
119 #define FMODE_EXEC              ((__force fmode_t)0x20)
120 /* File is opened with O_NDELAY (only set for block devices) */
121 #define FMODE_NDELAY            ((__force fmode_t)0x40)
122 /* File is opened with O_EXCL (only set for block devices) */
123 #define FMODE_EXCL              ((__force fmode_t)0x80)
124 /* File is opened using open(.., 3, ..) and is writeable only for ioctls
125    (specialy hack for floppy.c) */
126 #define FMODE_WRITE_IOCTL       ((__force fmode_t)0x100)
127 /* 32bit hashes as llseek() offset (for directories) */
128 #define FMODE_32BITHASH         ((__force fmode_t)0x200)
129 /* 64bit hashes as llseek() offset (for directories) */
130 #define FMODE_64BITHASH         ((__force fmode_t)0x400)
131 
132 /*
133  * Don't update ctime and mtime.
134  *
135  * Currently a special hack for the XFS open_by_handle ioctl, but we'll
136  * hopefully graduate it to a proper O_CMTIME flag supported by open(2) soon.
137  */
138 #define FMODE_NOCMTIME          ((__force fmode_t)0x800)
139 
140 /* Expect random access pattern */
141 #define FMODE_RANDOM            ((__force fmode_t)0x1000)
142 
143 /* File is huge (eg. /dev/kmem): treat loff_t as unsigned */
144 #define FMODE_UNSIGNED_OFFSET   ((__force fmode_t)0x2000)
145 
146 /* File is opened with O_PATH; almost nothing can be done with it */
147 #define FMODE_PATH              ((__force fmode_t)0x4000)
148 
149 /* File needs atomic accesses to f_pos */
150 #define FMODE_ATOMIC_POS        ((__force fmode_t)0x8000)
151 /* Write access to underlying fs */
152 #define FMODE_WRITER            ((__force fmode_t)0x10000)
153 /* Has read method(s) */
154 #define FMODE_CAN_READ          ((__force fmode_t)0x20000)
155 /* Has write method(s) */
156 #define FMODE_CAN_WRITE         ((__force fmode_t)0x40000)
157 
158 #define FMODE_OPENED            ((__force fmode_t)0x80000)
159 #define FMODE_CREATED           ((__force fmode_t)0x100000)
160 
161 /* File is stream-like */
162 #define FMODE_STREAM            ((__force fmode_t)0x200000)
163 
164 /* File was opened by fanotify and shouldn't generate fanotify events */
165 #define FMODE_NONOTIFY          ((__force fmode_t)0x4000000)
166 
167 /* File is capable of returning -EAGAIN if I/O will block */
168 #define FMODE_NOWAIT            ((__force fmode_t)0x8000000)
169 
170 /* File represents mount that needs unmounting */
171 #define FMODE_NEED_UNMOUNT      ((__force fmode_t)0x10000000)
172 
173 /* File does not contribute to nr_files count */
174 #define FMODE_NOACCOUNT         ((__force fmode_t)0x20000000)
175 
176 /*
177  * Flag for rw_copy_check_uvector and compat_rw_copy_check_uvector
178  * that indicates that they should check the contents of the iovec are
179  * valid, but not check the memory that the iovec elements
180  * points too.
181  */
182 #define CHECK_IOVEC_ONLY -1
183 
184 /*
185  * Attribute flags.  These should be or-ed together to figure out what
186  * has been changed!
187  */
188 #define ATTR_MODE       (1 << 0)
189 #define ATTR_UID        (1 << 1)
190 #define ATTR_GID        (1 << 2)
191 #define ATTR_SIZE       (1 << 3)
192 #define ATTR_ATIME      (1 << 4)
193 #define ATTR_MTIME      (1 << 5)
194 #define ATTR_CTIME      (1 << 6)
195 #define ATTR_ATIME_SET  (1 << 7)
196 #define ATTR_MTIME_SET  (1 << 8)
197 #define ATTR_FORCE      (1 << 9) /* Not a change, but a change it */
198 #define ATTR_KILL_SUID  (1 << 11)
199 #define ATTR_KILL_SGID  (1 << 12)
200 #define ATTR_FILE       (1 << 13)
201 #define ATTR_KILL_PRIV  (1 << 14)
202 #define ATTR_OPEN       (1 << 15) /* Truncating from open(O_TRUNC) */
203 #define ATTR_TIMES_SET  (1 << 16)
204 #define ATTR_TOUCH      (1 << 17)
205 
206 /*
207  * Whiteout is represented by a char device.  The following constants define the
208  * mode and device number to use.
209  */
210 #define WHITEOUT_MODE 0
211 #define WHITEOUT_DEV 0
212 
213 /*
214  * This is the Inode Attributes structure, used for notify_change().  It
215  * uses the above definitions as flags, to know which values have changed.
216  * Also, in this manner, a Filesystem can look at only the values it cares
217  * about.  Basically, these are the attributes that the VFS layer can
218  * request to change from the FS layer.
219  *
220  * Derek Atkins <warlord@MIT.EDU> 94-10-20
221  */
222 struct iattr {
223         unsigned int    ia_valid;
224         umode_t         ia_mode;
225         kuid_t          ia_uid;
226         kgid_t          ia_gid;
227         loff_t          ia_size;
228         struct timespec64 ia_atime;
229         struct timespec64 ia_mtime;
230         struct timespec64 ia_ctime;
231 
232         /*
233          * Not an attribute, but an auxiliary info for filesystems wanting to
234          * implement an ftruncate() like method.  NOTE: filesystem should
235          * check for (ia_valid & ATTR_FILE), and not for (ia_file != NULL).
236          */
237         struct file     *ia_file;
238 };
239 
240 /*
241  * Includes for diskquotas.
242  */
243 #include <linux/quota.h>
244 
245 /*
246  * Maximum number of layers of fs stack.  Needs to be limited to
247  * prevent kernel stack overflow
248  */
249 #define FILESYSTEM_MAX_STACK_DEPTH 2
250 
251 /** 
252  * enum positive_aop_returns - aop return codes with specific semantics
253  *
254  * @AOP_WRITEPAGE_ACTIVATE: Informs the caller that page writeback has
255  *                          completed, that the page is still locked, and
256  *                          should be considered active.  The VM uses this hint
257  *                          to return the page to the active list -- it won't
258  *                          be a candidate for writeback again in the near
259  *                          future.  Other callers must be careful to unlock
260  *                          the page if they get this return.  Returned by
261  *                          writepage(); 
262  *
263  * @AOP_TRUNCATED_PAGE: The AOP method that was handed a locked page has
264  *                      unlocked it and the page might have been truncated.
265  *                      The caller should back up to acquiring a new page and
266  *                      trying again.  The aop will be taking reasonable
267  *                      precautions not to livelock.  If the caller held a page
268  *                      reference, it should drop it before retrying.  Returned
269  *                      by readpage().
270  *
271  * address_space_operation functions return these large constants to indicate
272  * special semantics to the caller.  These are much larger than the bytes in a
273  * page to allow for functions that return the number of bytes operated on in a
274  * given page.
275  */
276 
277 enum positive_aop_returns {
278         AOP_WRITEPAGE_ACTIVATE  = 0x80000,
279         AOP_TRUNCATED_PAGE      = 0x80001,
280 };
281 
282 #define AOP_FLAG_CONT_EXPAND            0x0001 /* called from cont_expand */
283 #define AOP_FLAG_NOFS                   0x0002 /* used by filesystem to direct
284                                                 * helper code (eg buffer layer)
285                                                 * to clear GFP_FS from alloc */
286 
287 /*
288  * oh the beauties of C type declarations.
289  */
290 struct page;
291 struct address_space;
292 struct writeback_control;
293 
294 /*
295  * Write life time hint values.
296  * Stored in struct inode as u8.
297  */
298 enum rw_hint {
299         WRITE_LIFE_NOT_SET      = 0,
300         WRITE_LIFE_NONE         = RWH_WRITE_LIFE_NONE,
301         WRITE_LIFE_SHORT        = RWH_WRITE_LIFE_SHORT,
302         WRITE_LIFE_MEDIUM       = RWH_WRITE_LIFE_MEDIUM,
303         WRITE_LIFE_LONG         = RWH_WRITE_LIFE_LONG,
304         WRITE_LIFE_EXTREME      = RWH_WRITE_LIFE_EXTREME,
305 };
306 
307 #define IOCB_EVENTFD            (1 << 0)
308 #define IOCB_APPEND             (1 << 1)
309 #define IOCB_DIRECT             (1 << 2)
310 #define IOCB_HIPRI              (1 << 3)
311 #define IOCB_DSYNC              (1 << 4)
312 #define IOCB_SYNC               (1 << 5)
313 #define IOCB_WRITE              (1 << 6)
314 #define IOCB_NOWAIT             (1 << 7)
315 
316 struct kiocb {
317         struct file             *ki_filp;
318 
319         /* The 'ki_filp' pointer is shared in a union for aio */
320         randomized_struct_fields_start
321 
322         loff_t                  ki_pos;
323         void (*ki_complete)(struct kiocb *iocb, long ret, long ret2);
324         void                    *private;
325         int                     ki_flags;
326         u16                     ki_hint;
327         u16                     ki_ioprio; /* See linux/ioprio.h */
328         unsigned int            ki_cookie; /* for ->iopoll */
329 
330         randomized_struct_fields_end
331 };
332 
333 static inline bool is_sync_kiocb(struct kiocb *kiocb)
334 {
335         return kiocb->ki_complete == NULL;
336 }
337 
338 /*
339  * "descriptor" for what we're up to with a read.
340  * This allows us to use the same read code yet
341  * have multiple different users of the data that
342  * we read from a file.
343  *
344  * The simplest case just copies the data to user
345  * mode.
346  */
347 typedef struct {
348         size_t written;
349         size_t count;
350         union {
351                 char __user *buf;
352                 void *data;
353         } arg;
354         int error;
355 } read_descriptor_t;
356 
357 typedef int (*read_actor_t)(read_descriptor_t *, struct page *,
358                 unsigned long, unsigned long);
359 
360 struct address_space_operations {
361         int (*writepage)(struct page *page, struct writeback_control *wbc);
362         int (*readpage)(struct file *, struct page *);
363 
364         /* Write back some dirty pages from this mapping. */
365         int (*writepages)(struct address_space *, struct writeback_control *);
366 
367         /* Set a page dirty.  Return true if this dirtied it */
368         int (*set_page_dirty)(struct page *page);
369 
370         /*
371          * Reads in the requested pages. Unlike ->readpage(), this is
372          * PURELY used for read-ahead!.
373          */
374         int (*readpages)(struct file *filp, struct address_space *mapping,
375                         struct list_head *pages, unsigned nr_pages);
376 
377         int (*write_begin)(struct file *, struct address_space *mapping,
378                                 loff_t pos, unsigned len, unsigned flags,
379                                 struct page **pagep, void **fsdata);
380         int (*write_end)(struct file *, struct address_space *mapping,
381                                 loff_t pos, unsigned len, unsigned copied,
382                                 struct page *page, void *fsdata);
383 
384         /* Unfortunately this kludge is needed for FIBMAP. Don't use it */
385         sector_t (*bmap)(struct address_space *, sector_t);
386         void (*invalidatepage) (struct page *, unsigned int, unsigned int);
387         int (*releasepage) (struct page *, gfp_t);
388         void (*freepage)(struct page *);
389         ssize_t (*direct_IO)(struct kiocb *, struct iov_iter *iter);
390         /*
391          * migrate the contents of a page to the specified target. If
392          * migrate_mode is MIGRATE_ASYNC, it must not block.
393          */
394         int (*migratepage) (struct address_space *,
395                         struct page *, struct page *, enum migrate_mode);
396         bool (*isolate_page)(struct page *, isolate_mode_t);
397         void (*putback_page)(struct page *);
398         int (*launder_page) (struct page *);
399         int (*is_partially_uptodate) (struct page *, unsigned long,
400                                         unsigned long);
401         void (*is_dirty_writeback) (struct page *, bool *, bool *);
402         int (*error_remove_page)(struct address_space *, struct page *);
403 
404         /* swapfile support */
405         int (*swap_activate)(struct swap_info_struct *sis, struct file *file,
406                                 sector_t *span);
407         void (*swap_deactivate)(struct file *file);
408 };
409 
410 extern const struct address_space_operations empty_aops;
411 
412 /*
413  * pagecache_write_begin/pagecache_write_end must be used by general code
414  * to write into the pagecache.
415  */
416 int pagecache_write_begin(struct file *, struct address_space *mapping,
417                                 loff_t pos, unsigned len, unsigned flags,
418                                 struct page **pagep, void **fsdata);
419 
420 int pagecache_write_end(struct file *, struct address_space *mapping,
421                                 loff_t pos, unsigned len, unsigned copied,
422                                 struct page *page, void *fsdata);
423 
424 /**
425  * struct address_space - Contents of a cacheable, mappable object.
426  * @host: Owner, either the inode or the block_device.
427  * @i_pages: Cached pages.
428  * @gfp_mask: Memory allocation flags to use for allocating pages.
429  * @i_mmap_writable: Number of VM_SHARED mappings.
430  * @i_mmap: Tree of private and shared mappings.
431  * @i_mmap_rwsem: Protects @i_mmap and @i_mmap_writable.
432  * @nrpages: Number of page entries, protected by the i_pages lock.
433  * @nrexceptional: Shadow or DAX entries, protected by the i_pages lock.
434  * @writeback_index: Writeback starts here.
435  * @a_ops: Methods.
436  * @flags: Error bits and flags (AS_*).
437  * @wb_err: The most recent error which has occurred.
438  * @private_lock: For use by the owner of the address_space.
439  * @private_list: For use by the owner of the address_space.
440  * @private_data: For use by the owner of the address_space.
441  */
442 struct address_space {
443         struct inode            *host;
444         struct xarray           i_pages;
445         gfp_t                   gfp_mask;
446         atomic_t                i_mmap_writable;
447         struct rb_root_cached   i_mmap;
448         struct rw_semaphore     i_mmap_rwsem;
449         unsigned long           nrpages;
450         unsigned long           nrexceptional;
451         pgoff_t                 writeback_index;
452         const struct address_space_operations *a_ops;
453         unsigned long           flags;
454         errseq_t                wb_err;
455         spinlock_t              private_lock;
456         struct list_head        private_list;
457         void                    *private_data;
458 } __attribute__((aligned(sizeof(long)))) __randomize_layout;
459         /*
460          * On most architectures that alignment is already the case; but
461          * must be enforced here for CRIS, to let the least significant bit
462          * of struct page's "mapping" pointer be used for PAGE_MAPPING_ANON.
463          */
464 struct request_queue;
465 
466 struct block_device {
467         dev_t                   bd_dev;  /* not a kdev_t - it's a search key */
468         int                     bd_openers;
469         struct inode *          bd_inode;       /* will die */
470         struct super_block *    bd_super;
471         struct mutex            bd_mutex;       /* open/close mutex */
472         void *                  bd_claiming;
473         void *                  bd_holder;
474         int                     bd_holders;
475         bool                    bd_write_holder;
476 #ifdef CONFIG_SYSFS
477         struct list_head        bd_holder_disks;
478 #endif
479         struct block_device *   bd_contains;
480         unsigned                bd_block_size;
481         u8                      bd_partno;
482         struct hd_struct *      bd_part;
483         /* number of times partitions within this device have been opened. */
484         unsigned                bd_part_count;
485         int                     bd_invalidated;
486         struct gendisk *        bd_disk;
487         struct request_queue *  bd_queue;
488         struct backing_dev_info *bd_bdi;
489         struct list_head        bd_list;
490         /*
491          * Private data.  You must have bd_claim'ed the block_device
492          * to use this.  NOTE:  bd_claim allows an owner to claim
493          * the same device multiple times, the owner must take special
494          * care to not mess up bd_private for that case.
495          */
496         unsigned long           bd_private;
497 
498         /* The counter of freeze processes */
499         int                     bd_fsfreeze_count;
500         /* Mutex for freeze */
501         struct mutex            bd_fsfreeze_mutex;
502 } __randomize_layout;
503 
504 /* XArray tags, for tagging dirty and writeback pages in the pagecache. */
505 #define PAGECACHE_TAG_DIRTY     XA_MARK_0
506 #define PAGECACHE_TAG_WRITEBACK XA_MARK_1
507 #define PAGECACHE_TAG_TOWRITE   XA_MARK_2
508 
509 /*
510  * Returns true if any of the pages in the mapping are marked with the tag.
511  */
512 static inline bool mapping_tagged(struct address_space *mapping, xa_mark_t tag)
513 {
514         return xa_marked(&mapping->i_pages, tag);
515 }
516 
517 static inline void i_mmap_lock_write(struct address_space *mapping)
518 {
519         down_write(&mapping->i_mmap_rwsem);
520 }
521 
522 static inline void i_mmap_unlock_write(struct address_space *mapping)
523 {
524         up_write(&mapping->i_mmap_rwsem);
525 }
526 
527 static inline void i_mmap_lock_read(struct address_space *mapping)
528 {
529         down_read(&mapping->i_mmap_rwsem);
530 }
531 
532 static inline void i_mmap_unlock_read(struct address_space *mapping)
533 {
534         up_read(&mapping->i_mmap_rwsem);
535 }
536 
537 /*
538  * Might pages of this file be mapped into userspace?
539  */
540 static inline int mapping_mapped(struct address_space *mapping)
541 {
542         return  !RB_EMPTY_ROOT(&mapping->i_mmap.rb_root);
543 }
544 
545 /*
546  * Might pages of this file have been modified in userspace?
547  * Note that i_mmap_writable counts all VM_SHARED vmas: do_mmap_pgoff
548  * marks vma as VM_SHARED if it is shared, and the file was opened for
549  * writing i.e. vma may be mprotected writable even if now readonly.
550  *
551  * If i_mmap_writable is negative, no new writable mappings are allowed. You
552  * can only deny writable mappings, if none exists right now.
553  */
554 static inline int mapping_writably_mapped(struct address_space *mapping)
555 {
556         return atomic_read(&mapping->i_mmap_writable) > 0;
557 }
558 
559 static inline int mapping_map_writable(struct address_space *mapping)
560 {
561         return atomic_inc_unless_negative(&mapping->i_mmap_writable) ?
562                 0 : -EPERM;
563 }
564 
565 static inline void mapping_unmap_writable(struct address_space *mapping)
566 {
567         atomic_dec(&mapping->i_mmap_writable);
568 }
569 
570 static inline int mapping_deny_writable(struct address_space *mapping)
571 {
572         return atomic_dec_unless_positive(&mapping->i_mmap_writable) ?
573                 0 : -EBUSY;
574 }
575 
576 static inline void mapping_allow_writable(struct address_space *mapping)
577 {
578         atomic_inc(&mapping->i_mmap_writable);
579 }
580 
581 /*
582  * Use sequence counter to get consistent i_size on 32-bit processors.
583  */
584 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
585 #include <linux/seqlock.h>
586 #define __NEED_I_SIZE_ORDERED
587 #define i_size_ordered_init(inode) seqcount_init(&inode->i_size_seqcount)
588 #else
589 #define i_size_ordered_init(inode) do { } while (0)
590 #endif
591 
592 struct posix_acl;
593 #define ACL_NOT_CACHED ((void *)(-1))
594 #define ACL_DONT_CACHE ((void *)(-3))
595 
596 static inline struct posix_acl *
597 uncached_acl_sentinel(struct task_struct *task)
598 {
599         return (void *)task + 1;
600 }
601 
602 static inline bool
603 is_uncached_acl(struct posix_acl *acl)
604 {
605         return (long)acl & 1;
606 }
607 
608 #define IOP_FASTPERM    0x0001
609 #define IOP_LOOKUP      0x0002
610 #define IOP_NOFOLLOW    0x0004
611 #define IOP_XATTR       0x0008
612 #define IOP_DEFAULT_READLINK    0x0010
613 
614 struct fsnotify_mark_connector;
615 
616 /*
617  * Keep mostly read-only and often accessed (especially for
618  * the RCU path lookup and 'stat' data) fields at the beginning
619  * of the 'struct inode'
620  */
621 struct inode {
622         umode_t                 i_mode;
623         unsigned short          i_opflags;
624         kuid_t                  i_uid;
625         kgid_t                  i_gid;
626         unsigned int            i_flags;
627 
628 #ifdef CONFIG_FS_POSIX_ACL
629         struct posix_acl        *i_acl;
630         struct posix_acl        *i_default_acl;
631 #endif
632 
633         const struct inode_operations   *i_op;
634         struct super_block      *i_sb;
635         struct address_space    *i_mapping;
636 
637 #ifdef CONFIG_SECURITY
638         void                    *i_security;
639 #endif
640 
641         /* Stat data, not accessed from path walking */
642         unsigned long           i_ino;
643         /*
644          * Filesystems may only read i_nlink directly.  They shall use the
645          * following functions for modification:
646          *
647          *    (set|clear|inc|drop)_nlink
648          *    inode_(inc|dec)_link_count
649          */
650         union {
651                 const unsigned int i_nlink;
652                 unsigned int __i_nlink;
653         };
654         dev_t                   i_rdev;
655         loff_t                  i_size;
656         struct timespec64       i_atime;
657         struct timespec64       i_mtime;
658         struct timespec64       i_ctime;
659         spinlock_t              i_lock; /* i_blocks, i_bytes, maybe i_size */
660         unsigned short          i_bytes;
661         u8                      i_blkbits;
662         u8                      i_write_hint;
663         blkcnt_t                i_blocks;
664 
665 #ifdef __NEED_I_SIZE_ORDERED
666         seqcount_t              i_size_seqcount;
667 #endif
668 
669         /* Misc */
670         unsigned long           i_state;
671         struct rw_semaphore     i_rwsem;
672 
673         unsigned long           dirtied_when;   /* jiffies of first dirtying */
674         unsigned long           dirtied_time_when;
675 
676         struct hlist_node       i_hash;
677         struct list_head        i_io_list;      /* backing dev IO list */
678 #ifdef CONFIG_CGROUP_WRITEBACK
679         struct bdi_writeback    *i_wb;          /* the associated cgroup wb */
680 
681         /* foreign inode detection, see wbc_detach_inode() */
682         int                     i_wb_frn_winner;
683         u16                     i_wb_frn_avg_time;
684         u16                     i_wb_frn_history;
685 #endif
686         struct list_head        i_lru;          /* inode LRU list */
687         struct list_head        i_sb_list;
688         struct list_head        i_wb_list;      /* backing dev writeback list */
689         union {
690                 struct hlist_head       i_dentry;
691                 struct rcu_head         i_rcu;
692         };
693         atomic64_t              i_version;
694         atomic_t                i_count;
695         atomic_t                i_dio_count;
696         atomic_t                i_writecount;
697 #ifdef CONFIG_IMA
698         atomic_t                i_readcount; /* struct files open RO */
699 #endif
700         union {
701                 const struct file_operations    *i_fop; /* former ->i_op->default_file_ops */
702                 void (*free_inode)(struct inode *);
703         };
704         struct file_lock_context        *i_flctx;
705         struct address_space    i_data;
706         struct list_head        i_devices;
707         union {
708                 struct pipe_inode_info  *i_pipe;
709                 struct block_device     *i_bdev;
710                 struct cdev             *i_cdev;
711                 char                    *i_link;
712                 unsigned                i_dir_seq;
713         };
714 
715         __u32                   i_generation;
716 
717 #ifdef CONFIG_FSNOTIFY
718         __u32                   i_fsnotify_mask; /* all events this inode cares about */
719         struct fsnotify_mark_connector __rcu    *i_fsnotify_marks;
720 #endif
721 
722 #ifdef CONFIG_FS_ENCRYPTION
723         struct fscrypt_info     *i_crypt_info;
724 #endif
725 
726         void                    *i_private; /* fs or device private pointer */
727 } __randomize_layout;
728 
729 static inline unsigned int i_blocksize(const struct inode *node)
730 {
731         return (1 << node->i_blkbits);
732 }
733 
734 static inline int inode_unhashed(struct inode *inode)
735 {
736         return hlist_unhashed(&inode->i_hash);
737 }
738 
739 /*
740  * __mark_inode_dirty expects inodes to be hashed.  Since we don't
741  * want special inodes in the fileset inode space, we make them
742  * appear hashed, but do not put on any lists.  hlist_del()
743  * will work fine and require no locking.
744  */
745 static inline void inode_fake_hash(struct inode *inode)
746 {
747         hlist_add_fake(&inode->i_hash);
748 }
749 
750 /*
751  * inode->i_mutex nesting subclasses for the lock validator:
752  *
753  * 0: the object of the current VFS operation
754  * 1: parent
755  * 2: child/target
756  * 3: xattr
757  * 4: second non-directory
758  * 5: second parent (when locking independent directories in rename)
759  *
760  * I_MUTEX_NONDIR2 is for certain operations (such as rename) which lock two
761  * non-directories at once.
762  *
763  * The locking order between these classes is
764  * parent[2] -> child -> grandchild -> normal -> xattr -> second non-directory
765  */
766 enum inode_i_mutex_lock_class
767 {
768         I_MUTEX_NORMAL,
769         I_MUTEX_PARENT,
770         I_MUTEX_CHILD,
771         I_MUTEX_XATTR,
772         I_MUTEX_NONDIR2,
773         I_MUTEX_PARENT2,
774 };
775 
776 static inline void inode_lock(struct inode *inode)
777 {
778         down_write(&inode->i_rwsem);
779 }
780 
781 static inline void inode_unlock(struct inode *inode)
782 {
783         up_write(&inode->i_rwsem);
784 }
785 
786 static inline void inode_lock_shared(struct inode *inode)
787 {
788         down_read(&inode->i_rwsem);
789 }
790 
791 static inline void inode_unlock_shared(struct inode *inode)
792 {
793         up_read(&inode->i_rwsem);
794 }
795 
796 static inline int inode_trylock(struct inode *inode)
797 {
798         return down_write_trylock(&inode->i_rwsem);
799 }
800 
801 static inline int inode_trylock_shared(struct inode *inode)
802 {
803         return down_read_trylock(&inode->i_rwsem);
804 }
805 
806 static inline int inode_is_locked(struct inode *inode)
807 {
808         return rwsem_is_locked(&inode->i_rwsem);
809 }
810 
811 static inline void inode_lock_nested(struct inode *inode, unsigned subclass)
812 {
813         down_write_nested(&inode->i_rwsem, subclass);
814 }
815 
816 static inline void inode_lock_shared_nested(struct inode *inode, unsigned subclass)
817 {
818         down_read_nested(&inode->i_rwsem, subclass);
819 }
820 
821 void lock_two_nondirectories(struct inode *, struct inode*);
822 void unlock_two_nondirectories(struct inode *, struct inode*);
823 
824 /*
825  * NOTE: in a 32bit arch with a preemptable kernel and
826  * an UP compile the i_size_read/write must be atomic
827  * with respect to the local cpu (unlike with preempt disabled),
828  * but they don't need to be atomic with respect to other cpus like in
829  * true SMP (so they need either to either locally disable irq around
830  * the read or for example on x86 they can be still implemented as a
831  * cmpxchg8b without the need of the lock prefix). For SMP compiles
832  * and 64bit archs it makes no difference if preempt is enabled or not.
833  */
834 static inline loff_t i_size_read(const struct inode *inode)
835 {
836 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
837         loff_t i_size;
838         unsigned int seq;
839 
840         do {
841                 seq = read_seqcount_begin(&inode->i_size_seqcount);
842                 i_size = inode->i_size;
843         } while (read_seqcount_retry(&inode->i_size_seqcount, seq));
844         return i_size;
845 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
846         loff_t i_size;
847 
848         preempt_disable();
849         i_size = inode->i_size;
850         preempt_enable();
851         return i_size;
852 #else
853         return inode->i_size;
854 #endif
855 }
856 
857 /*
858  * NOTE: unlike i_size_read(), i_size_write() does need locking around it
859  * (normally i_mutex), otherwise on 32bit/SMP an update of i_size_seqcount
860  * can be lost, resulting in subsequent i_size_read() calls spinning forever.
861  */
862 static inline void i_size_write(struct inode *inode, loff_t i_size)
863 {
864 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
865         preempt_disable();
866         write_seqcount_begin(&inode->i_size_seqcount);
867         inode->i_size = i_size;
868         write_seqcount_end(&inode->i_size_seqcount);
869         preempt_enable();
870 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
871         preempt_disable();
872         inode->i_size = i_size;
873         preempt_enable();
874 #else
875         inode->i_size = i_size;
876 #endif
877 }
878 
879 static inline unsigned iminor(const struct inode *inode)
880 {
881         return MINOR(inode->i_rdev);
882 }
883 
884 static inline unsigned imajor(const struct inode *inode)
885 {
886         return MAJOR(inode->i_rdev);
887 }
888 
889 extern struct block_device *I_BDEV(struct inode *inode);
890 
891 struct fown_struct {
892         rwlock_t lock;          /* protects pid, uid, euid fields */
893         struct pid *pid;        /* pid or -pgrp where SIGIO should be sent */
894         enum pid_type pid_type; /* Kind of process group SIGIO should be sent to */
895         kuid_t uid, euid;       /* uid/euid of process setting the owner */
896         int signum;             /* posix.1b rt signal to be delivered on IO */
897 };
898 
899 /*
900  * Track a single file's readahead state
901  */
902 struct file_ra_state {
903         pgoff_t start;                  /* where readahead started */
904         unsigned int size;              /* # of readahead pages */
905         unsigned int async_size;        /* do asynchronous readahead when
906                                            there are only # of pages ahead */
907 
908         unsigned int ra_pages;          /* Maximum readahead window */
909         unsigned int mmap_miss;         /* Cache miss stat for mmap accesses */
910         loff_t prev_pos;                /* Cache last read() position */
911 };
912 
913 /*
914  * Check if @index falls in the readahead windows.
915  */
916 static inline int ra_has_index(struct file_ra_state *ra, pgoff_t index)
917 {
918         return (index >= ra->start &&
919                 index <  ra->start + ra->size);
920 }
921 
922 struct file {
923         union {
924                 struct llist_node       fu_llist;
925                 struct rcu_head         fu_rcuhead;
926         } f_u;
927         struct path             f_path;
928         struct inode            *f_inode;       /* cached value */
929         const struct file_operations    *f_op;
930 
931         /*
932          * Protects f_ep_links, f_flags.
933          * Must not be taken from IRQ context.
934          */
935         spinlock_t              f_lock;
936         enum rw_hint            f_write_hint;
937         atomic_long_t           f_count;
938         unsigned int            f_flags;
939         fmode_t                 f_mode;
940         struct mutex            f_pos_lock;
941         loff_t                  f_pos;
942         struct fown_struct      f_owner;
943         const struct cred       *f_cred;
944         struct file_ra_state    f_ra;
945 
946         u64                     f_version;
947 #ifdef CONFIG_SECURITY
948         void                    *f_security;
949 #endif
950         /* needed for tty driver, and maybe others */
951         void                    *private_data;
952 
953 #ifdef CONFIG_EPOLL
954         /* Used by fs/eventpoll.c to link all the hooks to this file */
955         struct list_head        f_ep_links;
956         struct list_head        f_tfile_llink;
957 #endif /* #ifdef CONFIG_EPOLL */
958         struct address_space    *f_mapping;
959         errseq_t                f_wb_err;
960 } __randomize_layout
961   __attribute__((aligned(4)));  /* lest something weird decides that 2 is OK */
962 
963 struct file_handle {
964         __u32 handle_bytes;
965         int handle_type;
966         /* file identifier */
967         unsigned char f_handle[0];
968 };
969 
970 static inline struct file *get_file(struct file *f)
971 {
972         atomic_long_inc(&f->f_count);
973         return f;
974 }
975 #define get_file_rcu_many(x, cnt)       \
976         atomic_long_add_unless(&(x)->f_count, (cnt), 0)
977 #define get_file_rcu(x) get_file_rcu_many((x), 1)
978 #define file_count(x)   atomic_long_read(&(x)->f_count)
979 
980 #define MAX_NON_LFS     ((1UL<<31) - 1)
981 
982 /* Page cache limit. The filesystems should put that into their s_maxbytes 
983    limits, otherwise bad things can happen in VM. */ 
984 #if BITS_PER_LONG==32
985 #define MAX_LFS_FILESIZE        ((loff_t)ULONG_MAX << PAGE_SHIFT)
986 #elif BITS_PER_LONG==64
987 #define MAX_LFS_FILESIZE        ((loff_t)LLONG_MAX)
988 #endif
989 
990 #define FL_POSIX        1
991 #define FL_FLOCK        2
992 #define FL_DELEG        4       /* NFSv4 delegation */
993 #define FL_ACCESS       8       /* not trying to lock, just looking */
994 #define FL_EXISTS       16      /* when unlocking, test for existence */
995 #define FL_LEASE        32      /* lease held on this file */
996 #define FL_CLOSE        64      /* unlock on close */
997 #define FL_SLEEP        128     /* A blocking lock */
998 #define FL_DOWNGRADE_PENDING    256 /* Lease is being downgraded */
999 #define FL_UNLOCK_PENDING       512 /* Lease is being broken */
1000 #define FL_OFDLCK       1024    /* lock is "owned" by struct file */
1001 #define FL_LAYOUT       2048    /* outstanding pNFS layout */
1002 
1003 #define FL_CLOSE_POSIX (FL_POSIX | FL_CLOSE)
1004 
1005 /*
1006  * Special return value from posix_lock_file() and vfs_lock_file() for
1007  * asynchronous locking.
1008  */
1009 #define FILE_LOCK_DEFERRED 1
1010 
1011 /* legacy typedef, should eventually be removed */
1012 typedef void *fl_owner_t;
1013 
1014 struct file_lock;
1015 
1016 struct file_lock_operations {
1017         void (*fl_copy_lock)(struct file_lock *, struct file_lock *);
1018         void (*fl_release_private)(struct file_lock *);
1019 };
1020 
1021 struct lock_manager_operations {
1022         int (*lm_compare_owner)(struct file_lock *, struct file_lock *);
1023         unsigned long (*lm_owner_key)(struct file_lock *);
1024         fl_owner_t (*lm_get_owner)(fl_owner_t);
1025         void (*lm_put_owner)(fl_owner_t);
1026         void (*lm_notify)(struct file_lock *);  /* unblock callback */
1027         int (*lm_grant)(struct file_lock *, int);
1028         bool (*lm_break)(struct file_lock *);
1029         int (*lm_change)(struct file_lock *, int, struct list_head *);
1030         void (*lm_setup)(struct file_lock *, void **);
1031 };
1032 
1033 struct lock_manager {
1034         struct list_head list;
1035         /*
1036          * NFSv4 and up also want opens blocked during the grace period;
1037          * NLM doesn't care:
1038          */
1039         bool block_opens;
1040 };
1041 
1042 struct net;
1043 void locks_start_grace(struct net *, struct lock_manager *);
1044 void locks_end_grace(struct lock_manager *);
1045 bool locks_in_grace(struct net *);
1046 bool opens_in_grace(struct net *);
1047 
1048 /* that will die - we need it for nfs_lock_info */
1049 #include <linux/nfs_fs_i.h>
1050 
1051 /*
1052  * struct file_lock represents a generic "file lock". It's used to represent
1053  * POSIX byte range locks, BSD (flock) locks, and leases. It's important to
1054  * note that the same struct is used to represent both a request for a lock and
1055  * the lock itself, but the same object is never used for both.
1056  *
1057  * FIXME: should we create a separate "struct lock_request" to help distinguish
1058  * these two uses?
1059  *
1060  * The varous i_flctx lists are ordered by:
1061  *
1062  * 1) lock owner
1063  * 2) lock range start
1064  * 3) lock range end
1065  *
1066  * Obviously, the last two criteria only matter for POSIX locks.
1067  */
1068 struct file_lock {
1069         struct file_lock *fl_blocker;   /* The lock, that is blocking us */
1070         struct list_head fl_list;       /* link into file_lock_context */
1071         struct hlist_node fl_link;      /* node in global lists */
1072         struct list_head fl_blocked_requests;   /* list of requests with
1073                                                  * ->fl_blocker pointing here
1074                                                  */
1075         struct list_head fl_blocked_member;     /* node in
1076                                                  * ->fl_blocker->fl_blocked_requests
1077                                                  */
1078         fl_owner_t fl_owner;
1079         unsigned int fl_flags;
1080         unsigned char fl_type;
1081         unsigned int fl_pid;
1082         int fl_link_cpu;                /* what cpu's list is this on? */
1083         wait_queue_head_t fl_wait;
1084         struct file *fl_file;
1085         loff_t fl_start;
1086         loff_t fl_end;
1087 
1088         struct fasync_struct *  fl_fasync; /* for lease break notifications */
1089         /* for lease breaks: */
1090         unsigned long fl_break_time;
1091         unsigned long fl_downgrade_time;
1092 
1093         const struct file_lock_operations *fl_ops;      /* Callbacks for filesystems */
1094         const struct lock_manager_operations *fl_lmops; /* Callbacks for lockmanagers */
1095         union {
1096                 struct nfs_lock_info    nfs_fl;
1097                 struct nfs4_lock_info   nfs4_fl;
1098                 struct {
1099                         struct list_head link;  /* link in AFS vnode's pending_locks list */
1100                         int state;              /* state of grant or error if -ve */
1101                         unsigned int    debug_id;
1102                 } afs;
1103         } fl_u;
1104 } __randomize_layout;
1105 
1106 struct file_lock_context {
1107         spinlock_t              flc_lock;
1108         struct list_head        flc_flock;
1109         struct list_head        flc_posix;
1110         struct list_head        flc_lease;
1111 };
1112 
1113 /* The following constant reflects the upper bound of the file/locking space */
1114 #ifndef OFFSET_MAX
1115 #define INT_LIMIT(x)    (~((x)1 << (sizeof(x)*8 - 1)))
1116 #define OFFSET_MAX      INT_LIMIT(loff_t)
1117 #define OFFT_OFFSET_MAX INT_LIMIT(off_t)
1118 #endif
1119 
1120 extern void send_sigio(struct fown_struct *fown, int fd, int band);
1121 
1122 #define locks_inode(f) file_inode(f)
1123 
1124 #ifdef CONFIG_FILE_LOCKING
1125 extern int fcntl_getlk(struct file *, unsigned int, struct flock *);
1126 extern int fcntl_setlk(unsigned int, struct file *, unsigned int,
1127                         struct flock *);
1128 
1129 #if BITS_PER_LONG == 32
1130 extern int fcntl_getlk64(struct file *, unsigned int, struct flock64 *);
1131 extern int fcntl_setlk64(unsigned int, struct file *, unsigned int,
1132                         struct flock64 *);
1133 #endif
1134 
1135 extern int fcntl_setlease(unsigned int fd, struct file *filp, long arg);
1136 extern int fcntl_getlease(struct file *filp);
1137 
1138 /* fs/locks.c */
1139 void locks_free_lock_context(struct inode *inode);
1140 void locks_free_lock(struct file_lock *fl);
1141 extern void locks_init_lock(struct file_lock *);
1142 extern struct file_lock * locks_alloc_lock(void);
1143 extern void locks_copy_lock(struct file_lock *, struct file_lock *);
1144 extern void locks_copy_conflock(struct file_lock *, struct file_lock *);
1145 extern void locks_remove_posix(struct file *, fl_owner_t);
1146 extern void locks_remove_file(struct file *);
1147 extern void locks_release_private(struct file_lock *);
1148 extern void posix_test_lock(struct file *, struct file_lock *);
1149 extern int posix_lock_file(struct file *, struct file_lock *, struct file_lock *);
1150 extern int locks_delete_block(struct file_lock *);
1151 extern int vfs_test_lock(struct file *, struct file_lock *);
1152 extern int vfs_lock_file(struct file *, unsigned int, struct file_lock *, struct file_lock *);
1153 extern int vfs_cancel_lock(struct file *filp, struct file_lock *fl);
1154 extern int locks_lock_inode_wait(struct inode *inode, struct file_lock *fl);
1155 extern int __break_lease(struct inode *inode, unsigned int flags, unsigned int type);
1156 extern void lease_get_mtime(struct inode *, struct timespec64 *time);
1157 extern int generic_setlease(struct file *, long, struct file_lock **, void **priv);
1158 extern int vfs_setlease(struct file *, long, struct file_lock **, void **);
1159 extern int lease_modify(struct file_lock *, int, struct list_head *);
1160 struct files_struct;
1161 extern void show_fd_locks(struct seq_file *f,
1162                          struct file *filp, struct files_struct *files);
1163 #else /* !CONFIG_FILE_LOCKING */
1164 static inline int fcntl_getlk(struct file *file, unsigned int cmd,
1165                               struct flock __user *user)
1166 {
1167         return -EINVAL;
1168 }
1169 
1170 static inline int fcntl_setlk(unsigned int fd, struct file *file,
1171                               unsigned int cmd, struct flock __user *user)
1172 {
1173         return -EACCES;
1174 }
1175 
1176 #if BITS_PER_LONG == 32
1177 static inline int fcntl_getlk64(struct file *file, unsigned int cmd,
1178                                 struct flock64 __user *user)
1179 {
1180         return -EINVAL;
1181 }
1182 
1183 static inline int fcntl_setlk64(unsigned int fd, struct file *file,
1184                                 unsigned int cmd, struct flock64 __user *user)
1185 {
1186         return -EACCES;
1187 }
1188 #endif
1189 static inline int fcntl_setlease(unsigned int fd, struct file *filp, long arg)
1190 {
1191         return -EINVAL;
1192 }
1193 
1194 static inline int fcntl_getlease(struct file *filp)
1195 {
1196         return F_UNLCK;
1197 }
1198 
1199 static inline void
1200 locks_free_lock_context(struct inode *inode)
1201 {
1202 }
1203 
1204 static inline void locks_init_lock(struct file_lock *fl)
1205 {
1206         return;
1207 }
1208 
1209 static inline void locks_copy_conflock(struct file_lock *new, struct file_lock *fl)
1210 {
1211         return;
1212 }
1213 
1214 static inline void locks_copy_lock(struct file_lock *new, struct file_lock *fl)
1215 {
1216         return;
1217 }
1218 
1219 static inline void locks_remove_posix(struct file *filp, fl_owner_t owner)
1220 {
1221         return;
1222 }
1223 
1224 static inline void locks_remove_file(struct file *filp)
1225 {
1226         return;
1227 }
1228 
1229 static inline void posix_test_lock(struct file *filp, struct file_lock *fl)
1230 {
1231         return;
1232 }
1233 
1234 static inline int posix_lock_file(struct file *filp, struct file_lock *fl,
1235                                   struct file_lock *conflock)
1236 {
1237         return -ENOLCK;
1238 }
1239 
1240 static inline int locks_delete_block(struct file_lock *waiter)
1241 {
1242         return -ENOENT;
1243 }
1244 
1245 static inline int vfs_test_lock(struct file *filp, struct file_lock *fl)
1246 {
1247         return 0;
1248 }
1249 
1250 static inline int vfs_lock_file(struct file *filp, unsigned int cmd,
1251                                 struct file_lock *fl, struct file_lock *conf)
1252 {
1253         return -ENOLCK;
1254 }
1255 
1256 static inline int vfs_cancel_lock(struct file *filp, struct file_lock *fl)
1257 {
1258         return 0;
1259 }
1260 
1261 static inline int locks_lock_inode_wait(struct inode *inode, struct file_lock *fl)
1262 {
1263         return -ENOLCK;
1264 }
1265 
1266 static inline int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
1267 {
1268         return 0;
1269 }
1270 
1271 static inline void lease_get_mtime(struct inode *inode,
1272                                    struct timespec64 *time)
1273 {
1274         return;
1275 }
1276 
1277 static inline int generic_setlease(struct file *filp, long arg,
1278                                     struct file_lock **flp, void **priv)
1279 {
1280         return -EINVAL;
1281 }
1282 
1283 static inline int vfs_setlease(struct file *filp, long arg,
1284                                struct file_lock **lease, void **priv)
1285 {
1286         return -EINVAL;
1287 }
1288 
1289 static inline int lease_modify(struct file_lock *fl, int arg,
1290                                struct list_head *dispose)
1291 {
1292         return -EINVAL;
1293 }
1294 
1295 struct files_struct;
1296 static inline void show_fd_locks(struct seq_file *f,
1297                         struct file *filp, struct files_struct *files) {}
1298 #endif /* !CONFIG_FILE_LOCKING */
1299 
1300 static inline struct inode *file_inode(const struct file *f)
1301 {
1302         return f->f_inode;
1303 }
1304 
1305 static inline struct dentry *file_dentry(const struct file *file)
1306 {
1307         return d_real(file->f_path.dentry, file_inode(file));
1308 }
1309 
1310 static inline int locks_lock_file_wait(struct file *filp, struct file_lock *fl)
1311 {
1312         return locks_lock_inode_wait(locks_inode(filp), fl);
1313 }
1314 
1315 struct fasync_struct {
1316         rwlock_t                fa_lock;
1317         int                     magic;
1318         int                     fa_fd;
1319         struct fasync_struct    *fa_next; /* singly linked list */
1320         struct file             *fa_file;
1321         struct rcu_head         fa_rcu;
1322 };
1323 
1324 #define FASYNC_MAGIC 0x4601
1325 
1326 /* SMP safe fasync helpers: */
1327 extern int fasync_helper(int, struct file *, int, struct fasync_struct **);
1328 extern struct fasync_struct *fasync_insert_entry(int, struct file *, struct fasync_struct **, struct fasync_struct *);
1329 extern int fasync_remove_entry(struct file *, struct fasync_struct **);
1330 extern struct fasync_struct *fasync_alloc(void);
1331 extern void fasync_free(struct fasync_struct *);
1332 
1333 /* can be called from interrupts */
1334 extern void kill_fasync(struct fasync_struct **, int, int);
1335 
1336 extern void __f_setown(struct file *filp, struct pid *, enum pid_type, int force);
1337 extern int f_setown(struct file *filp, unsigned long arg, int force);
1338 extern void f_delown(struct file *filp);
1339 extern pid_t f_getown(struct file *filp);
1340 extern int send_sigurg(struct fown_struct *fown);
1341 
1342 /*
1343  * sb->s_flags.  Note that these mirror the equivalent MS_* flags where
1344  * represented in both.
1345  */
1346 #define SB_RDONLY        1      /* Mount read-only */
1347 #define SB_NOSUID        2      /* Ignore suid and sgid bits */
1348 #define SB_NODEV         4      /* Disallow access to device special files */
1349 #define SB_NOEXEC        8      /* Disallow program execution */
1350 #define SB_SYNCHRONOUS  16      /* Writes are synced at once */
1351 #define SB_MANDLOCK     64      /* Allow mandatory locks on an FS */
1352 #define SB_DIRSYNC      128     /* Directory modifications are synchronous */
1353 #define SB_NOATIME      1024    /* Do not update access times. */
1354 #define SB_NODIRATIME   2048    /* Do not update directory access times */
1355 #define SB_SILENT       32768
1356 #define SB_POSIXACL     (1<<16) /* VFS does not apply the umask */
1357 #define SB_KERNMOUNT    (1<<22) /* this is a kern_mount call */
1358 #define SB_I_VERSION    (1<<23) /* Update inode I_version field */
1359 #define SB_LAZYTIME     (1<<25) /* Update the on-disk [acm]times lazily */
1360 
1361 /* These sb flags are internal to the kernel */
1362 #define SB_SUBMOUNT     (1<<26)
1363 #define SB_FORCE        (1<<27)
1364 #define SB_NOSEC        (1<<28)
1365 #define SB_BORN         (1<<29)
1366 #define SB_ACTIVE       (1<<30)
1367 #define SB_NOUSER       (1<<31)
1368 
1369 /*
1370  *      Umount options
1371  */
1372 
1373 #define MNT_FORCE       0x00000001      /* Attempt to forcibily umount */
1374 #define MNT_DETACH      0x00000002      /* Just detach from the tree */
1375 #define MNT_EXPIRE      0x00000004      /* Mark for expiry */
1376 #define UMOUNT_NOFOLLOW 0x00000008      /* Don't follow symlink on umount */
1377 #define UMOUNT_UNUSED   0x80000000      /* Flag guaranteed to be unused */
1378 
1379 /* sb->s_iflags */
1380 #define SB_I_CGROUPWB   0x00000001      /* cgroup-aware writeback enabled */
1381 #define SB_I_NOEXEC     0x00000002      /* Ignore executables on this fs */
1382 #define SB_I_NODEV      0x00000004      /* Ignore devices on this fs */
1383 #define SB_I_MULTIROOT  0x00000008      /* Multiple roots to the dentry tree */
1384 
1385 /* sb->s_iflags to limit user namespace mounts */
1386 #define SB_I_USERNS_VISIBLE             0x00000010 /* fstype already mounted */
1387 #define SB_I_IMA_UNVERIFIABLE_SIGNATURE 0x00000020
1388 #define SB_I_UNTRUSTED_MOUNTER          0x00000040
1389 
1390 /* Possible states of 'frozen' field */
1391 enum {
1392         SB_UNFROZEN = 0,                /* FS is unfrozen */
1393         SB_FREEZE_WRITE = 1,            /* Writes, dir ops, ioctls frozen */
1394         SB_FREEZE_PAGEFAULT = 2,        /* Page faults stopped as well */
1395         SB_FREEZE_FS = 3,               /* For internal FS use (e.g. to stop
1396                                          * internal threads if needed) */
1397         SB_FREEZE_COMPLETE = 4,         /* ->freeze_fs finished successfully */
1398 };
1399 
1400 #define SB_FREEZE_LEVELS (SB_FREEZE_COMPLETE - 1)
1401 
1402 struct sb_writers {
1403         int                             frozen;         /* Is sb frozen? */
1404         wait_queue_head_t               wait_unfrozen;  /* for get_super_thawed() */
1405         struct percpu_rw_semaphore      rw_sem[SB_FREEZE_LEVELS];
1406 };
1407 
1408 struct super_block {
1409         struct list_head        s_list;         /* Keep this first */
1410         dev_t                   s_dev;          /* search index; _not_ kdev_t */
1411         unsigned char           s_blocksize_bits;
1412         unsigned long           s_blocksize;
1413         loff_t                  s_maxbytes;     /* Max file size */
1414         struct file_system_type *s_type;
1415         const struct super_operations   *s_op;
1416         const struct dquot_operations   *dq_op;
1417         const struct quotactl_ops       *s_qcop;
1418         const struct export_operations *s_export_op;
1419         unsigned long           s_flags;
1420         unsigned long           s_iflags;       /* internal SB_I_* flags */
1421         unsigned long           s_magic;
1422         struct dentry           *s_root;
1423         struct rw_semaphore     s_umount;
1424         int                     s_count;
1425         atomic_t                s_active;
1426 #ifdef CONFIG_SECURITY
1427         void                    *s_security;
1428 #endif
1429         const struct xattr_handler **s_xattr;
1430 #ifdef CONFIG_FS_ENCRYPTION
1431         const struct fscrypt_operations *s_cop;
1432 #endif
1433         struct hlist_bl_head    s_roots;        /* alternate root dentries for NFS */
1434         struct list_head        s_mounts;       /* list of mounts; _not_ for fs use */
1435         struct block_device     *s_bdev;
1436         struct backing_dev_info *s_bdi;
1437         struct mtd_info         *s_mtd;
1438         struct hlist_node       s_instances;
1439         unsigned int            s_quota_types;  /* Bitmask of supported quota types */
1440         struct quota_info       s_dquot;        /* Diskquota specific options */
1441 
1442         struct sb_writers       s_writers;
1443 
1444         /*
1445          * Keep s_fs_info, s_time_gran, s_fsnotify_mask, and
1446          * s_fsnotify_marks together for cache efficiency. They are frequently
1447          * accessed and rarely modified.
1448          */
1449         void                    *s_fs_info;     /* Filesystem private info */
1450 
1451         /* Granularity of c/m/atime in ns (cannot be worse than a second) */
1452         u32                     s_time_gran;
1453 #ifdef CONFIG_FSNOTIFY
1454         __u32                   s_fsnotify_mask;
1455         struct fsnotify_mark_connector __rcu    *s_fsnotify_marks;
1456 #endif
1457 
1458         char                    s_id[32];       /* Informational name */
1459         uuid_t                  s_uuid;         /* UUID */
1460 
1461         unsigned int            s_max_links;
1462         fmode_t                 s_mode;
1463 
1464         /*
1465          * The next field is for VFS *only*. No filesystems have any business
1466          * even looking at it. You had been warned.
1467          */
1468         struct mutex s_vfs_rename_mutex;        /* Kludge */
1469 
1470         /*
1471          * Filesystem subtype.  If non-empty the filesystem type field
1472          * in /proc/mounts will be "type.subtype"
1473          */
1474         const char *s_subtype;
1475 
1476         const struct dentry_operations *s_d_op; /* default d_op for dentries */
1477 
1478         /*
1479          * Saved pool identifier for cleancache (-1 means none)
1480          */
1481         int cleancache_poolid;
1482 
1483         struct shrinker s_shrink;       /* per-sb shrinker handle */
1484 
1485         /* Number of inodes with nlink == 0 but still referenced */
1486         atomic_long_t s_remove_count;
1487 
1488         /* Pending fsnotify inode refs */
1489         atomic_long_t s_fsnotify_inode_refs;
1490 
1491         /* Being remounted read-only */
1492         int s_readonly_remount;
1493 
1494         /* AIO completions deferred from interrupt context */
1495         struct workqueue_struct *s_dio_done_wq;
1496         struct hlist_head s_pins;
1497 
1498         /*
1499          * Owning user namespace and default context in which to
1500          * interpret filesystem uids, gids, quotas, device nodes,
1501          * xattrs and security labels.
1502          */
1503         struct user_namespace *s_user_ns;
1504 
1505         /*
1506          * The list_lru structure is essentially just a pointer to a table
1507          * of per-node lru lists, each of which has its own spinlock.
1508          * There is no need to put them into separate cachelines.
1509          */
1510         struct list_lru         s_dentry_lru;
1511         struct list_lru         s_inode_lru;
1512         struct rcu_head         rcu;
1513         struct work_struct      destroy_work;
1514 
1515         struct mutex            s_sync_lock;    /* sync serialisation lock */
1516 
1517         /*
1518          * Indicates how deep in a filesystem stack this SB is
1519          */
1520         int s_stack_depth;
1521 
1522         /* s_inode_list_lock protects s_inodes */
1523         spinlock_t              s_inode_list_lock ____cacheline_aligned_in_smp;
1524         struct list_head        s_inodes;       /* all inodes */
1525 
1526         spinlock_t              s_inode_wblist_lock;
1527         struct list_head        s_inodes_wb;    /* writeback inodes */
1528 } __randomize_layout;
1529 
1530 /* Helper functions so that in most cases filesystems will
1531  * not need to deal directly with kuid_t and kgid_t and can
1532  * instead deal with the raw numeric values that are stored
1533  * in the filesystem.
1534  */
1535 static inline uid_t i_uid_read(const struct inode *inode)
1536 {
1537         return from_kuid(inode->i_sb->s_user_ns, inode->i_uid);
1538 }
1539 
1540 static inline gid_t i_gid_read(const struct inode *inode)
1541 {
1542         return from_kgid(inode->i_sb->s_user_ns, inode->i_gid);
1543 }
1544 
1545 static inline void i_uid_write(struct inode *inode, uid_t uid)
1546 {
1547         inode->i_uid = make_kuid(inode->i_sb->s_user_ns, uid);
1548 }
1549 
1550 static inline void i_gid_write(struct inode *inode, gid_t gid)
1551 {
1552         inode->i_gid = make_kgid(inode->i_sb->s_user_ns, gid);
1553 }
1554 
1555 extern struct timespec64 timespec64_trunc(struct timespec64 t, unsigned gran);
1556 extern struct timespec64 current_time(struct inode *inode);
1557 
1558 /*
1559  * Snapshotting support.
1560  */
1561 
1562 void __sb_end_write(struct super_block *sb, int level);
1563 int __sb_start_write(struct super_block *sb, int level, bool wait);
1564 
1565 #define __sb_writers_acquired(sb, lev)  \
1566         percpu_rwsem_acquire(&(sb)->s_writers.rw_sem[(lev)-1], 1, _THIS_IP_)
1567 #define __sb_writers_release(sb, lev)   \
1568         percpu_rwsem_release(&(sb)->s_writers.rw_sem[(lev)-1], 1, _THIS_IP_)
1569 
1570 /**
1571  * sb_end_write - drop write access to a superblock
1572  * @sb: the super we wrote to
1573  *
1574  * Decrement number of writers to the filesystem. Wake up possible waiters
1575  * wanting to freeze the filesystem.
1576  */
1577 static inline void sb_end_write(struct super_block *sb)
1578 {
1579         __sb_end_write(sb, SB_FREEZE_WRITE);
1580 }
1581 
1582 /**
1583  * sb_end_pagefault - drop write access to a superblock from a page fault
1584  * @sb: the super we wrote to
1585  *
1586  * Decrement number of processes handling write page fault to the filesystem.
1587  * Wake up possible waiters wanting to freeze the filesystem.
1588  */
1589 static inline void sb_end_pagefault(struct super_block *sb)
1590 {
1591         __sb_end_write(sb, SB_FREEZE_PAGEFAULT);
1592 }
1593 
1594 /**
1595  * sb_end_intwrite - drop write access to a superblock for internal fs purposes
1596  * @sb: the super we wrote to
1597  *
1598  * Decrement fs-internal number of writers to the filesystem.  Wake up possible
1599  * waiters wanting to freeze the filesystem.
1600  */
1601 static inline void sb_end_intwrite(struct super_block *sb)
1602 {
1603         __sb_end_write(sb, SB_FREEZE_FS);
1604 }
1605 
1606 /**
1607  * sb_start_write - get write access to a superblock
1608  * @sb: the super we write to
1609  *
1610  * When a process wants to write data or metadata to a file system (i.e. dirty
1611  * a page or an inode), it should embed the operation in a sb_start_write() -
1612  * sb_end_write() pair to get exclusion against file system freezing. This
1613  * function increments number of writers preventing freezing. If the file
1614  * system is already frozen, the function waits until the file system is
1615  * thawed.
1616  *
1617  * Since freeze protection behaves as a lock, users have to preserve
1618  * ordering of freeze protection and other filesystem locks. Generally,
1619  * freeze protection should be the outermost lock. In particular, we have:
1620  *
1621  * sb_start_write
1622  *   -> i_mutex                 (write path, truncate, directory ops, ...)
1623  *   -> s_umount                (freeze_super, thaw_super)
1624  */
1625 static inline void sb_start_write(struct super_block *sb)
1626 {
1627         __sb_start_write(sb, SB_FREEZE_WRITE, true);
1628 }
1629 
1630 static inline int sb_start_write_trylock(struct super_block *sb)
1631 {
1632         return __sb_start_write(sb, SB_FREEZE_WRITE, false);
1633 }
1634 
1635 /**
1636  * sb_start_pagefault - get write access to a superblock from a page fault
1637  * @sb: the super we write to
1638  *
1639  * When a process starts handling write page fault, it should embed the
1640  * operation into sb_start_pagefault() - sb_end_pagefault() pair to get
1641  * exclusion against file system freezing. This is needed since the page fault
1642  * is going to dirty a page. This function increments number of running page
1643  * faults preventing freezing. If the file system is already frozen, the
1644  * function waits until the file system is thawed.
1645  *
1646  * Since page fault freeze protection behaves as a lock, users have to preserve
1647  * ordering of freeze protection and other filesystem locks. It is advised to
1648  * put sb_start_pagefault() close to mmap_sem in lock ordering. Page fault
1649  * handling code implies lock dependency:
1650  *
1651  * mmap_sem
1652  *   -> sb_start_pagefault
1653  */
1654 static inline void sb_start_pagefault(struct super_block *sb)
1655 {
1656         __sb_start_write(sb, SB_FREEZE_PAGEFAULT, true);
1657 }
1658 
1659 /*
1660  * sb_start_intwrite - get write access to a superblock for internal fs purposes
1661  * @sb: the super we write to
1662  *
1663  * This is the third level of protection against filesystem freezing. It is
1664  * free for use by a filesystem. The only requirement is that it must rank
1665  * below sb_start_pagefault.
1666  *
1667  * For example filesystem can call sb_start_intwrite() when starting a
1668  * transaction which somewhat eases handling of freezing for internal sources
1669  * of filesystem changes (internal fs threads, discarding preallocation on file
1670  * close, etc.).
1671  */
1672 static inline void sb_start_intwrite(struct super_block *sb)
1673 {
1674         __sb_start_write(sb, SB_FREEZE_FS, true);
1675 }
1676 
1677 static inline int sb_start_intwrite_trylock(struct super_block *sb)
1678 {
1679         return __sb_start_write(sb, SB_FREEZE_FS, false);
1680 }
1681 
1682 
1683 extern bool inode_owner_or_capable(const struct inode *inode);
1684 
1685 /*
1686  * VFS helper functions..
1687  */
1688 extern int vfs_create(struct inode *, struct dentry *, umode_t, bool);
1689 extern int vfs_mkdir(struct inode *, struct dentry *, umode_t);
1690 extern int vfs_mknod(struct inode *, struct dentry *, umode_t, dev_t);
1691 extern int vfs_symlink(struct inode *, struct dentry *, const char *);
1692 extern int vfs_link(struct dentry *, struct inode *, struct dentry *, struct inode **);
1693 extern int vfs_rmdir(struct inode *, struct dentry *);
1694 extern int vfs_unlink(struct inode *, struct dentry *, struct inode **);
1695 extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *, struct inode **, unsigned int);
1696 extern int vfs_whiteout(struct inode *, struct dentry *);
1697 
1698 extern struct dentry *vfs_tmpfile(struct dentry *dentry, umode_t mode,
1699                                   int open_flag);
1700 
1701 int vfs_mkobj(struct dentry *, umode_t,
1702                 int (*f)(struct dentry *, umode_t, void *),
1703                 void *);
1704 
1705 extern long vfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
1706 
1707 /*
1708  * VFS file helper functions.
1709  */
1710 extern void inode_init_owner(struct inode *inode, const struct inode *dir,
1711                         umode_t mode);
1712 extern bool may_open_dev(const struct path *path);
1713 /*
1714  * VFS FS_IOC_FIEMAP helper definitions.
1715  */
1716 struct fiemap_extent_info {
1717         unsigned int fi_flags;          /* Flags as passed from user */
1718         unsigned int fi_extents_mapped; /* Number of mapped extents */
1719         unsigned int fi_extents_max;    /* Size of fiemap_extent array */
1720         struct fiemap_extent __user *fi_extents_start; /* Start of
1721                                                         fiemap_extent array */
1722 };
1723 int fiemap_fill_next_extent(struct fiemap_extent_info *info, u64 logical,
1724                             u64 phys, u64 len, u32 flags);
1725 int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags);
1726 
1727 /*
1728  * This is the "filldir" function type, used by readdir() to let
1729  * the kernel specify what kind of dirent layout it wants to have.
1730  * This allows the kernel to read directories into kernel space or
1731  * to have different dirent layouts depending on the binary type.
1732  */
1733 struct dir_context;
1734 typedef int (*filldir_t)(struct dir_context *, const char *, int, loff_t, u64,
1735                          unsigned);
1736 
1737 struct dir_context {
1738         filldir_t actor;
1739         loff_t pos;
1740 };
1741 
1742 struct block_device_operations;
1743 
1744 /* These macros are for out of kernel modules to test that
1745  * the kernel supports the unlocked_ioctl and compat_ioctl
1746  * fields in struct file_operations. */
1747 #define HAVE_COMPAT_IOCTL 1
1748 #define HAVE_UNLOCKED_IOCTL 1
1749 
1750 /*
1751  * These flags let !MMU mmap() govern direct device mapping vs immediate
1752  * copying more easily for MAP_PRIVATE, especially for ROM filesystems.
1753  *
1754  * NOMMU_MAP_COPY:      Copy can be mapped (MAP_PRIVATE)
1755  * NOMMU_MAP_DIRECT:    Can be mapped directly (MAP_SHARED)
1756  * NOMMU_MAP_READ:      Can be mapped for reading
1757  * NOMMU_MAP_WRITE:     Can be mapped for writing
1758  * NOMMU_MAP_EXEC:      Can be mapped for execution
1759  */
1760 #define NOMMU_MAP_COPY          0x00000001
1761 #define NOMMU_MAP_DIRECT        0x00000008
1762 #define NOMMU_MAP_READ          VM_MAYREAD
1763 #define NOMMU_MAP_WRITE         VM_MAYWRITE
1764 #define NOMMU_MAP_EXEC          VM_MAYEXEC
1765 
1766 #define NOMMU_VMFLAGS \
1767         (NOMMU_MAP_READ | NOMMU_MAP_WRITE | NOMMU_MAP_EXEC)
1768 
1769 /*
1770  * These flags control the behavior of the remap_file_range function pointer.
1771  * If it is called with len == 0 that means "remap to end of source file".
1772  * See Documentation/filesystems/vfs.txt for more details about this call.
1773  *
1774  * REMAP_FILE_DEDUP: only remap if contents identical (i.e. deduplicate)
1775  * REMAP_FILE_CAN_SHORTEN: caller can handle a shortened request
1776  */
1777 #define REMAP_FILE_DEDUP                (1 << 0)
1778 #define REMAP_FILE_CAN_SHORTEN          (1 << 1)
1779 
1780 /*
1781  * These flags signal that the caller is ok with altering various aspects of
1782  * the behavior of the remap operation.  The changes must be made by the
1783  * implementation; the vfs remap helper functions can take advantage of them.
1784  * Flags in this category exist to preserve the quirky behavior of the hoisted
1785  * btrfs clone/dedupe ioctls.
1786  */
1787 #define REMAP_FILE_ADVISORY             (REMAP_FILE_CAN_SHORTEN)
1788 
1789 struct iov_iter;
1790 
1791 struct file_operations {
1792         struct module *owner;
1793         loff_t (*llseek) (struct file *, loff_t, int);
1794         ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
1795         ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
1796         ssize_t (*read_iter) (struct kiocb *, struct iov_iter *);
1797         ssize_t (*write_iter) (struct kiocb *, struct iov_iter *);
1798         int (*iopoll)(struct kiocb *kiocb, bool spin);
1799         int (*iterate) (struct file *, struct dir_context *);
1800         int (*iterate_shared) (struct file *, struct dir_context *);
1801         __poll_t (*poll) (struct file *, struct poll_table_struct *);
1802         long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
1803         long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
1804         int (*mmap) (struct file *, struct vm_area_struct *);
1805         unsigned long mmap_supported_flags;
1806         int (*open) (struct inode *, struct file *);
1807         int (*flush) (struct file *, fl_owner_t id);
1808         int (*release) (struct inode *, struct file *);
1809         int (*fsync) (struct file *, loff_t, loff_t, int datasync);
1810         int (*fasync) (int, struct file *, int);
1811         int (*lock) (struct file *, int, struct file_lock *);
1812         ssize_t (*sendpage) (struct file *, struct page *, int, size_t, loff_t *, int);
1813         unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
1814         int (*check_flags)(int);
1815         int (*flock) (struct file *, int, struct file_lock *);
1816         ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int);
1817         ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int);
1818         int (*setlease)(struct file *, long, struct file_lock **, void **);
1819         long (*fallocate)(struct file *file, int mode, loff_t offset,
1820                           loff_t len);
1821         void (*show_fdinfo)(struct seq_file *m, struct file *f);
1822 #ifndef CONFIG_MMU
1823         unsigned (*mmap_capabilities)(struct file *);
1824 #endif
1825         ssize_t (*copy_file_range)(struct file *, loff_t, struct file *,
1826                         loff_t, size_t, unsigned int);
1827         loff_t (*remap_file_range)(struct file *file_in, loff_t pos_in,
1828                                    struct file *file_out, loff_t pos_out,
1829                                    loff_t len, unsigned int remap_flags);
1830         int (*fadvise)(struct file *, loff_t, loff_t, int);
1831 } __randomize_layout;
1832 
1833 struct inode_operations {
1834         struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int);
1835         const char * (*get_link) (struct dentry *, struct inode *, struct delayed_call *);
1836         int (*permission) (struct inode *, int);
1837         struct posix_acl * (*get_acl)(struct inode *, int);
1838 
1839         int (*readlink) (struct dentry *, char __user *,int);
1840 
1841         int (*create) (struct inode *,struct dentry *, umode_t, bool);
1842         int (*link) (struct dentry *,struct inode *,struct dentry *);
1843         int (*unlink) (struct inode *,struct dentry *);
1844         int (*symlink) (struct inode *,struct dentry *,const char *);
1845         int (*mkdir) (struct inode *,struct dentry *,umode_t);
1846         int (*rmdir) (struct inode *,struct dentry *);
1847         int (*mknod) (struct inode *,struct dentry *,umode_t,dev_t);
1848         int (*rename) (struct inode *, struct dentry *,
1849                         struct inode *, struct dentry *, unsigned int);
1850         int (*setattr) (struct dentry *, struct iattr *);
1851         int (*getattr) (const struct path *, struct kstat *, u32, unsigned int);
1852         ssize_t (*listxattr) (struct dentry *, char *, size_t);
1853         int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start,
1854                       u64 len);
1855         int (*update_time)(struct inode *, struct timespec64 *, int);
1856         int (*atomic_open)(struct inode *, struct dentry *,
1857                            struct file *, unsigned open_flag,
1858                            umode_t create_mode);
1859         int (*tmpfile) (struct inode *, struct dentry *, umode_t);
1860         int (*set_acl)(struct inode *, struct posix_acl *, int);
1861 } ____cacheline_aligned;
1862 
1863 static inline ssize_t call_read_iter(struct file *file, struct kiocb *kio,
1864                                      struct iov_iter *iter)
1865 {
1866         return file->f_op->read_iter(kio, iter);
1867 }
1868 
1869 static inline ssize_t call_write_iter(struct file *file, struct kiocb *kio,
1870                                       struct iov_iter *iter)
1871 {
1872         return file->f_op->write_iter(kio, iter);
1873 }
1874 
1875 static inline int call_mmap(struct file *file, struct vm_area_struct *vma)
1876 {
1877         return file->f_op->mmap(file, vma);
1878 }
1879 
1880 ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
1881                               unsigned long nr_segs, unsigned long fast_segs,
1882                               struct iovec *fast_pointer,
1883                               struct iovec **ret_pointer);
1884 
1885 extern ssize_t __vfs_read(struct file *, char __user *, size_t, loff_t *);
1886 extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *);
1887 extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *);
1888 extern ssize_t vfs_readv(struct file *, const struct iovec __user *,
1889                 unsigned long, loff_t *, rwf_t);
1890 extern ssize_t vfs_copy_file_range(struct file *, loff_t , struct file *,
1891                                    loff_t, size_t, unsigned int);
1892 extern int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in,
1893                                          struct file *file_out, loff_t pos_out,
1894                                          loff_t *count,
1895                                          unsigned int remap_flags);
1896 extern loff_t do_clone_file_range(struct file *file_in, loff_t pos_in,
1897                                   struct file *file_out, loff_t pos_out,
1898                                   loff_t len, unsigned int remap_flags);
1899 extern loff_t vfs_clone_file_range(struct file *file_in, loff_t pos_in,
1900                                    struct file *file_out, loff_t pos_out,
1901                                    loff_t len, unsigned int remap_flags);
1902 extern int vfs_dedupe_file_range(struct file *file,
1903                                  struct file_dedupe_range *same);
1904 extern loff_t vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos,
1905                                         struct file *dst_file, loff_t dst_pos,
1906                                         loff_t len, unsigned int remap_flags);
1907 
1908 
1909 struct super_operations {
1910         struct inode *(*alloc_inode)(struct super_block *sb);
1911         void (*destroy_inode)(struct inode *);
1912         void (*free_inode)(struct inode *);
1913 
1914         void (*dirty_inode) (struct inode *, int flags);
1915         int (*write_inode) (struct inode *, struct writeback_control *wbc);
1916         int (*drop_inode) (struct inode *);
1917         void (*evict_inode) (struct inode *);
1918         void (*put_super) (struct super_block *);
1919         int (*sync_fs)(struct super_block *sb, int wait);
1920         int (*freeze_super) (struct super_block *);
1921         int (*freeze_fs) (struct super_block *);
1922         int (*thaw_super) (struct super_block *);
1923         int (*unfreeze_fs) (struct super_block *);
1924         int (*statfs) (struct dentry *, struct kstatfs *);
1925         int (*remount_fs) (struct super_block *, int *, char *);
1926         void (*umount_begin) (struct super_block *);
1927 
1928         int (*show_options)(struct seq_file *, struct dentry *);
1929         int (*show_devname)(struct seq_file *, struct dentry *);
1930         int (*show_path)(struct seq_file *, struct dentry *);
1931         int (*show_stats)(struct seq_file *, struct dentry *);
1932 #ifdef CONFIG_QUOTA
1933         ssize_t (*quota_read)(struct super_block *, int, char *, size_t, loff_t);
1934         ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t);
1935         struct dquot **(*get_dquots)(struct inode *);
1936 #endif
1937         int (*bdev_try_to_free_page)(struct super_block*, struct page*, gfp_t);
1938         long (*nr_cached_objects)(struct super_block *,
1939                                   struct shrink_control *);
1940         long (*free_cached_objects)(struct super_block *,
1941                                     struct shrink_control *);
1942 };
1943 
1944 /*
1945  * Inode flags - they have no relation to superblock flags now
1946  */
1947 #define S_SYNC          1       /* Writes are synced at once */
1948 #define S_NOATIME       2       /* Do not update access times */
1949 #define S_APPEND        4       /* Append-only file */
1950 #define S_IMMUTABLE     8       /* Immutable file */
1951 #define S_DEAD          16      /* removed, but still open directory */
1952 #define S_NOQUOTA       32      /* Inode is not counted to quota */
1953 #define S_DIRSYNC       64      /* Directory modifications are synchronous */
1954 #define S_NOCMTIME      128     /* Do not update file c/mtime */
1955 #define S_SWAPFILE      256     /* Do not truncate: swapon got its bmaps */
1956 #define S_PRIVATE       512     /* Inode is fs-internal */
1957 #define S_IMA           1024    /* Inode has an associated IMA struct */
1958 #define S_AUTOMOUNT     2048    /* Automount/referral quasi-directory */
1959 #define S_NOSEC         4096    /* no suid or xattr security attributes */
1960 #ifdef CONFIG_FS_DAX
1961 #define S_DAX           8192    /* Direct Access, avoiding the page cache */
1962 #else
1963 #define S_DAX           0       /* Make all the DAX code disappear */
1964 #endif
1965 #define S_ENCRYPTED     16384   /* Encrypted file (using fs/crypto/) */
1966 #define S_CASEFOLD      32768   /* Casefolded file */
1967 
1968 /*
1969  * Note that nosuid etc flags are inode-specific: setting some file-system
1970  * flags just means all the inodes inherit those flags by default. It might be
1971  * possible to override it selectively if you really wanted to with some
1972  * ioctl() that is not currently implemented.
1973  *
1974  * Exception: SB_RDONLY is always applied to the entire file system.
1975  *
1976  * Unfortunately, it is possible to change a filesystems flags with it mounted
1977  * with files in use.  This means that all of the inodes will not have their
1978  * i_flags updated.  Hence, i_flags no longer inherit the superblock mount
1979  * flags, so these have to be checked separately. -- rmk@arm.uk.linux.org
1980  */
1981 #define __IS_FLG(inode, flg)    ((inode)->i_sb->s_flags & (flg))
1982 
1983 static inline bool sb_rdonly(const struct super_block *sb) { return sb->s_flags & SB_RDONLY; }
1984 #define IS_RDONLY(inode)        sb_rdonly((inode)->i_sb)
1985 #define IS_SYNC(inode)          (__IS_FLG(inode, SB_SYNCHRONOUS) || \
1986                                         ((inode)->i_flags & S_SYNC))
1987 #define IS_DIRSYNC(inode)       (__IS_FLG(inode, SB_SYNCHRONOUS|SB_DIRSYNC) || \
1988                                         ((inode)->i_flags & (S_SYNC|S_DIRSYNC)))
1989 #define IS_MANDLOCK(inode)      __IS_FLG(inode, SB_MANDLOCK)
1990 #define IS_NOATIME(inode)       __IS_FLG(inode, SB_RDONLY|SB_NOATIME)
1991 #define IS_I_VERSION(inode)     __IS_FLG(inode, SB_I_VERSION)
1992 
1993 #define IS_NOQUOTA(inode)       ((inode)->i_flags & S_NOQUOTA)
1994 #define IS_APPEND(inode)        ((inode)->i_flags & S_APPEND)
1995 #define IS_IMMUTABLE(inode)     ((inode)->i_flags & S_IMMUTABLE)
1996 #define IS_POSIXACL(inode)      __IS_FLG(inode, SB_POSIXACL)
1997 
1998 #define IS_DEADDIR(inode)       ((inode)->i_flags & S_DEAD)
1999 #define IS_NOCMTIME(inode)      ((inode)->i_flags & S_NOCMTIME)
2000 #define IS_SWAPFILE(inode)      ((inode)->i_flags & S_SWAPFILE)
2001 #define IS_PRIVATE(inode)       ((inode)->i_flags & S_PRIVATE)
2002 #define IS_IMA(inode)           ((inode)->i_flags & S_IMA)
2003 #define IS_AUTOMOUNT(inode)     ((inode)->i_flags & S_AUTOMOUNT)
2004 #define IS_NOSEC(inode)         ((inode)->i_flags & S_NOSEC)
2005 #define IS_DAX(inode)           ((inode)->i_flags & S_DAX)
2006 #define IS_ENCRYPTED(inode)     ((inode)->i_flags & S_ENCRYPTED)
2007 #define IS_CASEFOLDED(inode)    ((inode)->i_flags & S_CASEFOLD)
2008 
2009 #define IS_WHITEOUT(inode)      (S_ISCHR(inode->i_mode) && \
2010                                  (inode)->i_rdev == WHITEOUT_DEV)
2011 
2012 static inline bool HAS_UNMAPPED_ID(struct inode *inode)
2013 {
2014         return !uid_valid(inode->i_uid) || !gid_valid(inode->i_gid);
2015 }
2016 
2017 static inline enum rw_hint file_write_hint(struct file *file)
2018 {
2019         if (file->f_write_hint != WRITE_LIFE_NOT_SET)
2020                 return file->f_write_hint;
2021 
2022         return file_inode(file)->i_write_hint;
2023 }
2024 
2025 static inline int iocb_flags(struct file *file);
2026 
2027 static inline u16 ki_hint_validate(enum rw_hint hint)
2028 {
2029         typeof(((struct kiocb *)0)->ki_hint) max_hint = -1;
2030 
2031         if (hint <= max_hint)
2032                 return hint;
2033         return 0;
2034 }
2035 
2036 static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp)
2037 {
2038         *kiocb = (struct kiocb) {
2039                 .ki_filp = filp,
2040                 .ki_flags = iocb_flags(filp),
2041                 .ki_hint = ki_hint_validate(file_write_hint(filp)),
2042                 .ki_ioprio = get_current_ioprio(),
2043         };
2044 }
2045 
2046 /*
2047  * Inode state bits.  Protected by inode->i_lock
2048  *
2049  * Three bits determine the dirty state of the inode, I_DIRTY_SYNC,
2050  * I_DIRTY_DATASYNC and I_DIRTY_PAGES.
2051  *
2052  * Four bits define the lifetime of an inode.  Initially, inodes are I_NEW,
2053  * until that flag is cleared.  I_WILL_FREE, I_FREEING and I_CLEAR are set at
2054  * various stages of removing an inode.
2055  *
2056  * Two bits are used for locking and completion notification, I_NEW and I_SYNC.
2057  *
2058  * I_DIRTY_SYNC         Inode is dirty, but doesn't have to be written on
2059  *                      fdatasync().  i_atime is the usual cause.
2060  * I_DIRTY_DATASYNC     Data-related inode changes pending. We keep track of
2061  *                      these changes separately from I_DIRTY_SYNC so that we
2062  *                      don't have to write inode on fdatasync() when only
2063  *                      mtime has changed in it.
2064  * I_DIRTY_PAGES        Inode has dirty pages.  Inode itself may be clean.
2065  * I_NEW                Serves as both a mutex and completion notification.
2066  *                      New inodes set I_NEW.  If two processes both create
2067  *                      the same inode, one of them will release its inode and
2068  *                      wait for I_NEW to be released before returning.
2069  *                      Inodes in I_WILL_FREE, I_FREEING or I_CLEAR state can
2070  *                      also cause waiting on I_NEW, without I_NEW actually
2071  *                      being set.  find_inode() uses this to prevent returning
2072  *                      nearly-dead inodes.
2073  * I_WILL_FREE          Must be set when calling write_inode_now() if i_count
2074  *                      is zero.  I_FREEING must be set when I_WILL_FREE is
2075  *                      cleared.
2076  * I_FREEING            Set when inode is about to be freed but still has dirty
2077  *                      pages or buffers attached or the inode itself is still
2078  *                      dirty.
2079  * I_CLEAR              Added by clear_inode().  In this state the inode is
2080  *                      clean and can be destroyed.  Inode keeps I_FREEING.
2081  *
2082  *                      Inodes that are I_WILL_FREE, I_FREEING or I_CLEAR are
2083  *                      prohibited for many purposes.  iget() must wait for
2084  *                      the inode to be completely released, then create it
2085  *                      anew.  Other functions will just ignore such inodes,
2086  *                      if appropriate.  I_NEW is used for waiting.
2087  *
2088  * I_SYNC               Writeback of inode is running. The bit is set during
2089  *                      data writeback, and cleared with a wakeup on the bit
2090  *                      address once it is done. The bit is also used to pin
2091  *                      the inode in memory for flusher thread.
2092  *
2093  * I_REFERENCED         Marks the inode as recently references on the LRU list.
2094  *
2095  * I_DIO_WAKEUP         Never set.  Only used as a key for wait_on_bit().
2096  *
2097  * I_WB_SWITCH          Cgroup bdi_writeback switching in progress.  Used to
2098  *                      synchronize competing switching instances and to tell
2099  *                      wb stat updates to grab the i_pages lock.  See
2100  *                      inode_switch_wbs_work_fn() for details.
2101  *
2102  * I_OVL_INUSE          Used by overlayfs to get exclusive ownership on upper
2103  *                      and work dirs among overlayfs mounts.
2104  *
2105  * I_CREATING           New object's inode in the middle of setting up.
2106  *
2107  * Q: What is the difference between I_WILL_FREE and I_FREEING?
2108  */
2109 #define I_DIRTY_SYNC            (1 << 0)
2110 #define I_DIRTY_DATASYNC        (1 << 1)
2111 #define I_DIRTY_PAGES           (1 << 2)
2112 #define __I_NEW                 3
2113 #define I_NEW                   (1 << __I_NEW)
2114 #define I_WILL_FREE             (1 << 4)
2115 #define I_FREEING               (1 << 5)
2116 #define I_CLEAR                 (1 << 6)
2117 #define __I_SYNC                7
2118 #define I_SYNC                  (1 << __I_SYNC)
2119 #define I_REFERENCED            (1 << 8)
2120 #define __I_DIO_WAKEUP          9
2121 #define I_DIO_WAKEUP            (1 << __I_DIO_WAKEUP)
2122 #define I_LINKABLE              (1 << 10)
2123 #define I_DIRTY_TIME            (1 << 11)
2124 #define __I_DIRTY_TIME_EXPIRED  12
2125 #define I_DIRTY_TIME_EXPIRED    (1 << __I_DIRTY_TIME_EXPIRED)
2126 #define I_WB_SWITCH             (1 << 13)
2127 #define I_OVL_INUSE             (1 << 14)
2128 #define I_CREATING              (1 << 15)
2129 
2130 #define I_DIRTY_INODE (I_DIRTY_SYNC | I_DIRTY_DATASYNC)
2131 #define I_DIRTY (I_DIRTY_INODE | I_DIRTY_PAGES)
2132 #define I_DIRTY_ALL (I_DIRTY | I_DIRTY_TIME)
2133 
2134 extern void __mark_inode_dirty(struct inode *, int);
2135 static inline void mark_inode_dirty(struct inode *inode)
2136 {
2137         __mark_inode_dirty(inode, I_DIRTY);
2138 }
2139 
2140 static inline void mark_inode_dirty_sync(struct inode *inode)
2141 {
2142         __mark_inode_dirty(inode, I_DIRTY_SYNC);
2143 }
2144 
2145 extern void inc_nlink(struct inode *inode);
2146 extern void drop_nlink(struct inode *inode);
2147 extern void clear_nlink(struct inode *inode);
2148 extern void set_nlink(struct inode *inode, unsigned int nlink);
2149 
2150 static inline void inode_inc_link_count(struct inode *inode)
2151 {
2152         inc_nlink(inode);
2153         mark_inode_dirty(inode);
2154 }
2155 
2156 static inline void inode_dec_link_count(struct inode *inode)
2157 {
2158         drop_nlink(inode);
2159         mark_inode_dirty(inode);
2160 }
2161 
2162 enum file_time_flags {
2163         S_ATIME = 1,
2164         S_MTIME = 2,
2165         S_CTIME = 4,
2166         S_VERSION = 8,
2167 };
2168 
2169 extern bool atime_needs_update(const struct path *, struct inode *);
2170 extern void touch_atime(const struct path *);
2171 static inline void file_accessed(struct file *file)
2172 {
2173         if (!(file->f_flags & O_NOATIME))
2174                 touch_atime(&file->f_path);
2175 }
2176 
2177 int sync_inode(struct inode *inode, struct writeback_control *wbc);
2178 int sync_inode_metadata(struct inode *inode, int wait);
2179 
2180 struct file_system_type {
2181         const char *name;
2182         int fs_flags;
2183 #define FS_REQUIRES_DEV         1 
2184 #define FS_BINARY_MOUNTDATA     2
2185 #define FS_HAS_SUBTYPE          4
2186 #define FS_USERNS_MOUNT         8       /* Can be mounted by userns root */
2187 #define FS_RENAME_DOES_D_MOVE   32768   /* FS will handle d_move() during rename() internally. */
2188         int (*init_fs_context)(struct fs_context *);
2189         const struct fs_parameter_description *parameters;
2190         struct dentry *(*mount) (struct file_system_type *, int,
2191                        const char *, void *);
2192         void (*kill_sb) (struct super_block *);
2193         struct module *owner;
2194         struct file_system_type * next;
2195         struct hlist_head fs_supers;
2196 
2197         struct lock_class_key s_lock_key;
2198         struct lock_class_key s_umount_key;
2199         struct lock_class_key s_vfs_rename_key;
2200         struct lock_class_key s_writers_key[SB_FREEZE_LEVELS];
2201 
2202         struct lock_class_key i_lock_key;
2203         struct lock_class_key i_mutex_key;
2204         struct lock_class_key i_mutex_dir_key;
2205 };
2206 
2207 #define MODULE_ALIAS_FS(NAME) MODULE_ALIAS("fs-" NAME)
2208 
2209 extern struct dentry *mount_ns(struct file_system_type *fs_type,
2210         int flags, void *data, void *ns, struct user_namespace *user_ns,
2211         int (*fill_super)(struct super_block *, void *, int));
2212 #ifdef CONFIG_BLOCK
2213 extern struct dentry *mount_bdev(struct file_system_type *fs_type,
2214         int flags, const char *dev_name, void *data,
2215         int (*fill_super)(struct super_block *, void *, int));
2216 #else
2217 static inline struct dentry *mount_bdev(struct file_system_type *fs_type,
2218         int flags, const char *dev_name, void *data,
2219         int (*fill_super)(struct super_block *, void *, int))
2220 {
2221         return ERR_PTR(-ENODEV);
2222 }
2223 #endif
2224 extern struct dentry *mount_single(struct file_system_type *fs_type,
2225         int flags, void *data,
2226         int (*fill_super)(struct super_block *, void *, int));
2227 extern struct dentry *mount_nodev(struct file_system_type *fs_type,
2228         int flags, void *data,
2229         int (*fill_super)(struct super_block *, void *, int));
2230 extern struct dentry *mount_subtree(struct vfsmount *mnt, const char *path);
2231 void generic_shutdown_super(struct super_block *sb);
2232 #ifdef CONFIG_BLOCK
2233 void kill_block_super(struct super_block *sb);
2234 #else
2235 static inline void kill_block_super(struct super_block *sb)
2236 {
2237         BUG();
2238 }
2239 #endif
2240 void kill_anon_super(struct super_block *sb);
2241 void kill_litter_super(struct super_block *sb);
2242 void deactivate_super(struct super_block *sb);
2243 void deactivate_locked_super(struct super_block *sb);
2244 int set_anon_super(struct super_block *s, void *data);
2245 int set_anon_super_fc(struct super_block *s, struct fs_context *fc);
2246 int get_anon_bdev(dev_t *);
2247 void free_anon_bdev(dev_t);
2248 struct super_block *sget_fc(struct fs_context *fc,
2249                             int (*test)(struct super_block *, struct fs_context *),
2250                             int (*set)(struct super_block *, struct fs_context *));
2251 struct super_block *sget_userns(struct file_system_type *type,
2252                         int (*test)(struct super_block *,void *),
2253                         int (*set)(struct super_block *,void *),
2254                         int flags, struct user_namespace *user_ns,
2255                         void *data);
2256 struct super_block *sget(struct file_system_type *type,
2257                         int (*test)(struct super_block *,void *),
2258                         int (*set)(struct super_block *,void *),
2259                         int flags, void *data);
2260 extern struct dentry *mount_pseudo_xattr(struct file_system_type *, char *,
2261                                          const struct super_operations *ops,
2262                                          const struct xattr_handler **xattr,
2263                                          const struct dentry_operations *dops,
2264                                          unsigned long);
2265 
2266 static inline struct dentry *
2267 mount_pseudo(struct file_system_type *fs_type, char *name,
2268              const struct super_operations *ops,
2269              const struct dentry_operations *dops, unsigned long magic)
2270 {
2271         return mount_pseudo_xattr(fs_type, name, ops, NULL, dops, magic);
2272 }
2273 
2274 /* Alas, no aliases. Too much hassle with bringing module.h everywhere */
2275 #define fops_get(fops) \
2276         (((fops) && try_module_get((fops)->owner) ? (fops) : NULL))
2277 #define fops_put(fops) \
2278         do { if (fops) module_put((fops)->owner); } while(0)
2279 /*
2280  * This one is to be used *ONLY* from ->open() instances.
2281  * fops must be non-NULL, pinned down *and* module dependencies
2282  * should be sufficient to pin the caller down as well.
2283  */
2284 #define replace_fops(f, fops) \
2285         do {    \
2286                 struct file *__file = (f); \
2287                 fops_put(__file->f_op); \
2288                 BUG_ON(!(__file->f_op = (fops))); \
2289         } while(0)
2290 
2291 extern int register_filesystem(struct file_system_type *);
2292 extern int unregister_filesystem(struct file_system_type *);
2293 extern struct vfsmount *kern_mount(struct file_system_type *);
2294 extern void kern_unmount(struct vfsmount *mnt);
2295 extern int may_umount_tree(struct vfsmount *);
2296 extern int may_umount(struct vfsmount *);
2297 extern long do_mount(const char *, const char __user *,
2298                      const char *, unsigned long, void *);
2299 extern struct vfsmount *collect_mounts(const struct path *);
2300 extern void drop_collected_mounts(struct vfsmount *);
2301 extern int iterate_mounts(int (*)(struct vfsmount *, void *), void *,
2302                           struct vfsmount *);
2303 extern int vfs_statfs(const struct path *, struct kstatfs *);
2304 extern int user_statfs(const char __user *, struct kstatfs *);
2305 extern int fd_statfs(int, struct kstatfs *);
2306 extern int freeze_super(struct super_block *super);
2307 extern int thaw_super(struct super_block *super);
2308 extern bool our_mnt(struct vfsmount *mnt);
2309 extern __printf(2, 3)
2310 int super_setup_bdi_name(struct super_block *sb, char *fmt, ...);
2311 extern int super_setup_bdi(struct super_block *sb);
2312 
2313 extern int current_umask(void);
2314 
2315 extern void ihold(struct inode * inode);
2316 extern void iput(struct inode *);
2317 extern int generic_update_time(struct inode *, struct timespec64 *, int);
2318 
2319 /* /sys/fs */
2320 extern struct kobject *fs_kobj;
2321 
2322 #define MAX_RW_COUNT (INT_MAX & PAGE_MASK)
2323 
2324 #ifdef CONFIG_MANDATORY_FILE_LOCKING
2325 extern int locks_mandatory_locked(struct file *);
2326 extern int locks_mandatory_area(struct inode *, struct file *, loff_t, loff_t, unsigned char);
2327 
2328 /*
2329  * Candidates for mandatory locking have the setgid bit set
2330  * but no group execute bit -  an otherwise meaningless combination.
2331  */
2332 
2333 static inline int __mandatory_lock(struct inode *ino)
2334 {
2335         return (ino->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID;
2336 }
2337 
2338 /*
2339  * ... and these candidates should be on SB_MANDLOCK mounted fs,
2340  * otherwise these will be advisory locks
2341  */
2342 
2343 static inline int mandatory_lock(struct inode *ino)
2344 {
2345         return IS_MANDLOCK(ino) && __mandatory_lock(ino);
2346 }
2347 
2348 static inline int locks_verify_locked(struct file *file)
2349 {
2350         if (mandatory_lock(locks_inode(file)))
2351                 return locks_mandatory_locked(file);
2352         return 0;
2353 }
2354 
2355 static inline int locks_verify_truncate(struct inode *inode,
2356                                     struct file *f,
2357                                     loff_t size)
2358 {
2359         if (!inode->i_flctx || !mandatory_lock(inode))
2360                 return 0;
2361 
2362         if (size < inode->i_size) {
2363                 return locks_mandatory_area(inode, f, size, inode->i_size - 1,
2364                                 F_WRLCK);
2365         } else {
2366                 return locks_mandatory_area(inode, f, inode->i_size, size - 1,
2367                                 F_WRLCK);
2368         }
2369 }
2370 
2371 #else /* !CONFIG_MANDATORY_FILE_LOCKING */
2372 
2373 static inline int locks_mandatory_locked(struct file *file)
2374 {
2375         return 0;
2376 }
2377 
2378 static inline int locks_mandatory_area(struct inode *inode, struct file *filp,
2379                                        loff_t start, loff_t end, unsigned char type)
2380 {
2381         return 0;
2382 }
2383 
2384 static inline int __mandatory_lock(struct inode *inode)
2385 {
2386         return 0;
2387 }
2388 
2389 static inline int mandatory_lock(struct inode *inode)
2390 {
2391         return 0;
2392 }
2393 
2394 static inline int locks_verify_locked(struct file *file)
2395 {
2396         return 0;
2397 }
2398 
2399 static inline int locks_verify_truncate(struct inode *inode, struct file *filp,
2400                                         size_t size)
2401 {
2402         return 0;
2403 }
2404 
2405 #endif /* CONFIG_MANDATORY_FILE_LOCKING */
2406 
2407 
2408 #ifdef CONFIG_FILE_LOCKING
2409 static inline int break_lease(struct inode *inode, unsigned int mode)
2410 {
2411         /*
2412          * Since this check is lockless, we must ensure that any refcounts
2413          * taken are done before checking i_flctx->flc_lease. Otherwise, we
2414          * could end up racing with tasks trying to set a new lease on this
2415          * file.
2416          */
2417         smp_mb();
2418         if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease))
2419                 return __break_lease(inode, mode, FL_LEASE);
2420         return 0;
2421 }
2422 
2423 static inline int break_deleg(struct inode *inode, unsigned int mode)
2424 {
2425         /*
2426          * Since this check is lockless, we must ensure that any refcounts
2427          * taken are done before checking i_flctx->flc_lease. Otherwise, we
2428          * could end up racing with tasks trying to set a new lease on this
2429          * file.
2430          */
2431         smp_mb();
2432         if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease))
2433                 return __break_lease(inode, mode, FL_DELEG);
2434         return 0;
2435 }
2436 
2437 static inline int try_break_deleg(struct inode *inode, struct inode **delegated_inode)
2438 {
2439         int ret;
2440 
2441         ret = break_deleg(inode, O_WRONLY|O_NONBLOCK);
2442         if (ret == -EWOULDBLOCK && delegated_inode) {
2443                 *delegated_inode = inode;
2444                 ihold(inode);
2445         }
2446         return ret;
2447 }
2448 
2449 static inline int break_deleg_wait(struct inode **delegated_inode)
2450 {
2451         int ret;
2452 
2453         ret = break_deleg(*delegated_inode, O_WRONLY);
2454         iput(*delegated_inode);
2455         *delegated_inode = NULL;
2456         return ret;
2457 }
2458 
2459 static inline int break_layout(struct inode *inode, bool wait)
2460 {
2461         smp_mb();
2462         if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease))
2463                 return __break_lease(inode,
2464                                 wait ? O_WRONLY : O_WRONLY | O_NONBLOCK,
2465                                 FL_LAYOUT);
2466         return 0;
2467 }
2468 
2469 #else /* !CONFIG_FILE_LOCKING */
2470 static inline int break_lease(struct inode *inode, unsigned int mode)
2471 {
2472         return 0;
2473 }
2474 
2475 static inline int break_deleg(struct inode *inode, unsigned int mode)
2476 {
2477         return 0;
2478 }
2479 
2480 static inline int try_break_deleg(struct inode *inode, struct inode **delegated_inode)
2481 {
2482         return 0;
2483 }
2484 
2485 static inline int break_deleg_wait(struct inode **delegated_inode)
2486 {
2487         BUG();
2488         return 0;
2489 }
2490 
2491 static inline int break_layout(struct inode *inode, bool wait)
2492 {
2493         return 0;
2494 }
2495 
2496 #endif /* CONFIG_FILE_LOCKING */
2497 
2498 /* fs/open.c */
2499 struct audit_names;
2500 struct filename {
2501         const char              *name;  /* pointer to actual string */
2502         const __user char       *uptr;  /* original userland pointer */
2503         int                     refcnt;
2504         struct audit_names      *aname;
2505         const char              iname[];
2506 };
2507 static_assert(offsetof(struct filename, iname) % sizeof(long) == 0);
2508 
2509 extern long vfs_truncate(const struct path *, loff_t);
2510 extern int do_truncate(struct dentry *, loff_t start, unsigned int time_attrs,
2511                        struct file *filp);
2512 extern int vfs_fallocate(struct file *file, int mode, loff_t offset,
2513                         loff_t len);
2514 extern long do_sys_open(int dfd, const char __user *filename, int flags,
2515                         umode_t mode);
2516 extern struct file *file_open_name(struct filename *, int, umode_t);
2517 extern struct file *filp_open(const char *, int, umode_t);
2518 extern struct file *file_open_root(struct dentry *, struct vfsmount *,
2519                                    const char *, int, umode_t);
2520 extern struct file * dentry_open(const struct path *, int, const struct cred *);
2521 extern struct file * open_with_fake_path(const struct path *, int,
2522                                          struct inode*, const struct cred *);
2523 static inline struct file *file_clone_open(struct file *file)
2524 {
2525         return dentry_open(&file->f_path, file->f_flags, file->f_cred);
2526 }
2527 extern int filp_close(struct file *, fl_owner_t id);
2528 
2529 extern struct filename *getname_flags(const char __user *, int, int *);
2530 extern struct filename *getname(const char __user *);
2531 extern struct filename *getname_kernel(const char *);
2532 extern void putname(struct filename *name);
2533 
2534 extern int finish_open(struct file *file, struct dentry *dentry,
2535                         int (*open)(struct inode *, struct file *));
2536 extern int finish_no_open(struct file *file, struct dentry *dentry);
2537 
2538 /* fs/ioctl.c */
2539 
2540 extern int ioctl_preallocate(struct file *filp, void __user *argp);
2541 
2542 /* fs/dcache.c */
2543 extern void __init vfs_caches_init_early(void);
2544 extern void __init vfs_caches_init(void);
2545 
2546 extern struct kmem_cache *names_cachep;
2547 
2548 #define __getname()             kmem_cache_alloc(names_cachep, GFP_KERNEL)
2549 #define __putname(name)         kmem_cache_free(names_cachep, (void *)(name))
2550 
2551 #ifdef CONFIG_BLOCK
2552 extern int register_blkdev(unsigned int, const char *);
2553 extern void unregister_blkdev(unsigned int, const char *);
2554 extern void bdev_unhash_inode(dev_t dev);
2555 extern struct block_device *bdget(dev_t);
2556 extern struct block_device *bdgrab(struct block_device *bdev);
2557 extern void bd_set_size(struct block_device *, loff_t size);
2558 extern void bd_forget(struct inode *inode);
2559 extern void bdput(struct block_device *);
2560 extern void invalidate_bdev(struct block_device *);
2561 extern void iterate_bdevs(void (*)(struct block_device *, void *), void *);
2562 extern int sync_blockdev(struct block_device *bdev);
2563 extern void kill_bdev(struct block_device *);
2564 extern struct super_block *freeze_bdev(struct block_device *);
2565 extern void emergency_thaw_all(void);
2566 extern void emergency_thaw_bdev(struct super_block *sb);
2567 extern int thaw_bdev(struct block_device *bdev, struct super_block *sb);
2568 extern int fsync_bdev(struct block_device *);
2569 
2570 extern struct super_block *blockdev_superblock;
2571 
2572 static inline bool sb_is_blkdev_sb(struct super_block *sb)
2573 {
2574         return sb == blockdev_superblock;
2575 }
2576 #else
2577 static inline void bd_forget(struct inode *inode) {}
2578 static inline int sync_blockdev(struct block_device *bdev) { return 0; }
2579 static inline void kill_bdev(struct block_device *bdev) {}
2580 static inline void invalidate_bdev(struct block_device *bdev) {}
2581 
2582 static inline struct super_block *freeze_bdev(struct block_device *sb)
2583 {
2584         return NULL;
2585 }
2586 
2587 static inline int thaw_bdev(struct block_device *bdev, struct super_block *sb)
2588 {
2589         return 0;
2590 }
2591 
2592 static inline int emergency_thaw_bdev(struct super_block *sb)
2593 {
2594         return 0;
2595 }
2596 
2597 static inline void iterate_bdevs(void (*f)(struct block_device *, void *), void *arg)
2598 {
2599 }
2600 
2601 static inline bool sb_is_blkdev_sb(struct super_block *sb)
2602 {
2603         return false;
2604 }
2605 #endif
2606 extern int sync_filesystem(struct super_block *);
2607 extern const struct file_operations def_blk_fops;
2608 extern const struct file_operations def_chr_fops;
2609 #ifdef CONFIG_BLOCK
2610 extern int ioctl_by_bdev(struct block_device *, unsigned, unsigned long);
2611 extern int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long);
2612 extern long compat_blkdev_ioctl(struct file *, unsigned, unsigned long);
2613 extern int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder);
2614 extern struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
2615                                                void *holder);
2616 extern struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode,
2617                                               void *holder);
2618 extern struct block_device *bd_start_claiming(struct block_device *bdev,
2619                                               void *holder);
2620 extern void bd_finish_claiming(struct block_device *bdev,
2621                                struct block_device *whole, void *holder);
2622 extern void bd_abort_claiming(struct block_device *bdev,
2623                               struct block_device *whole, void *holder);
2624 extern void blkdev_put(struct block_device *bdev, fmode_t mode);
2625 extern int __blkdev_reread_part(struct block_device *bdev);
2626 extern int blkdev_reread_part(struct block_device *bdev);
2627 
2628 #ifdef CONFIG_SYSFS
2629 extern int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);
2630 extern void bd_unlink_disk_holder(struct block_device *bdev,
2631                                   struct gendisk *disk);
2632 #else
2633 static inline int bd_link_disk_holder(struct block_device *bdev,
2634                                       struct gendisk *disk)
2635 {
2636         return 0;
2637 }
2638 static inline void bd_unlink_disk_holder(struct block_device *bdev,
2639                                          struct gendisk *disk)
2640 {
2641 }
2642 #endif
2643 #endif
2644 
2645 /* fs/char_dev.c */
2646 #define CHRDEV_MAJOR_MAX 512
2647 /* Marks the bottom of the first segment of free char majors */
2648 #define CHRDEV_MAJOR_DYN_END 234
2649 /* Marks the top and bottom of the second segment of free char majors */
2650 #define CHRDEV_MAJOR_DYN_EXT_START 511
2651 #define CHRDEV_MAJOR_DYN_EXT_END 384
2652 
2653 extern int alloc_chrdev_region(dev_t *, unsigned, unsigned, const char *);
2654 extern int register_chrdev_region(dev_t, unsigned, const char *);
2655 extern int __register_chrdev(unsigned int major, unsigned int baseminor,
2656                              unsigned int count, const char *name,
2657                              const struct file_operations *fops);
2658 extern void __unregister_chrdev(unsigned int major, unsigned int baseminor,
2659                                 unsigned int count, const char *name);
2660 extern void unregister_chrdev_region(dev_t, unsigned);
2661 extern void chrdev_show(struct seq_file *,off_t);
2662 
2663 static inline int register_chrdev(unsigned int major, const char *name,
2664                                   const struct file_operations *fops)
2665 {
2666         return __register_chrdev(major, 0, 256, name, fops);
2667 }
2668 
2669 static inline void unregister_chrdev(unsigned int major, const char *name)
2670 {
2671         __unregister_chrdev(major, 0, 256, name);
2672 }
2673 
2674 /* fs/block_dev.c */
2675 #define BDEVNAME_SIZE   32      /* Largest string for a blockdev identifier */
2676 #define BDEVT_SIZE      10      /* Largest string for MAJ:MIN for blkdev */
2677 
2678 #ifdef CONFIG_BLOCK
2679 #define BLKDEV_MAJOR_MAX        512
2680 extern const char *__bdevname(dev_t, char *buffer);
2681 extern const char *bdevname(struct block_device *bdev, char *buffer);
2682 extern struct block_device *lookup_bdev(const char *);
2683 extern void blkdev_show(struct seq_file *,off_t);
2684 
2685 #else
2686 #define BLKDEV_MAJOR_MAX        0
2687 #endif
2688 
2689 extern void init_special_inode(struct inode *, umode_t, dev_t);
2690 
2691 /* Invalid inode operations -- fs/bad_inode.c */
2692 extern void make_bad_inode(struct inode *);
2693 extern bool is_bad_inode(struct inode *);
2694 
2695 #ifdef CONFIG_BLOCK
2696 extern void check_disk_size_change(struct gendisk *disk,
2697                 struct block_device *bdev, bool verbose);
2698 extern int revalidate_disk(struct gendisk *);
2699 extern int check_disk_change(struct block_device *);
2700 extern int __invalidate_device(struct block_device *, bool);
2701 extern int invalidate_partition(struct gendisk *, int);
2702 #endif
2703 unsigned long invalidate_mapping_pages(struct address_space *mapping,
2704                                         pgoff_t start, pgoff_t end);
2705 
2706 static inline void invalidate_remote_inode(struct inode *inode)
2707 {
2708         if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2709             S_ISLNK(inode->i_mode))
2710                 invalidate_mapping_pages(inode->i_mapping, 0, -1);
2711 }
2712 extern int invalidate_inode_pages2(struct address_space *mapping);
2713 extern int invalidate_inode_pages2_range(struct address_space *mapping,
2714                                          pgoff_t start, pgoff_t end);
2715 extern int write_inode_now(struct inode *, int);
2716 extern int filemap_fdatawrite(struct address_space *);
2717 extern int filemap_flush(struct address_space *);
2718 extern int filemap_fdatawait_keep_errors(struct address_space *mapping);
2719 extern int filemap_fdatawait_range(struct address_space *, loff_t lstart,
2720                                    loff_t lend);
2721 extern int filemap_fdatawait_range_keep_errors(struct address_space *mapping,
2722                 loff_t start_byte, loff_t end_byte);
2723 
2724 static inline int filemap_fdatawait(struct address_space *mapping)
2725 {
2726         return filemap_fdatawait_range(mapping, 0, LLONG_MAX);
2727 }
2728 
2729 extern bool filemap_range_has_page(struct address_space *, loff_t lstart,
2730                                   loff_t lend);
2731 extern int filemap_write_and_wait(struct address_space *mapping);
2732 extern int filemap_write_and_wait_range(struct address_space *mapping,
2733                                         loff_t lstart, loff_t lend);
2734 extern int __filemap_fdatawrite_range(struct address_space *mapping,
2735                                 loff_t start, loff_t end, int sync_mode);
2736 extern int filemap_fdatawrite_range(struct address_space *mapping,
2737                                 loff_t start, loff_t end);
2738 extern int filemap_check_errors(struct address_space *mapping);
2739 extern void __filemap_set_wb_err(struct address_space *mapping, int err);
2740 
2741 extern int __must_check file_fdatawait_range(struct file *file, loff_t lstart,
2742                                                 loff_t lend);
2743 extern int __must_check file_check_and_advance_wb_err(struct file *file);
2744 extern int __must_check file_write_and_wait_range(struct file *file,
2745                                                 loff_t start, loff_t end);
2746 
2747 static inline int file_write_and_wait(struct file *file)
2748 {
2749         return file_write_and_wait_range(file, 0, LLONG_MAX);
2750 }
2751 
2752 /**
2753  * filemap_set_wb_err - set a writeback error on an address_space
2754  * @mapping: mapping in which to set writeback error
2755  * @err: error to be set in mapping
2756  *
2757  * When writeback fails in some way, we must record that error so that
2758  * userspace can be informed when fsync and the like are called.  We endeavor
2759  * to report errors on any file that was open at the time of the error.  Some
2760  * internal callers also need to know when writeback errors have occurred.
2761  *
2762  * When a writeback error occurs, most filesystems will want to call
2763  * filemap_set_wb_err to record the error in the mapping so that it will be
2764  * automatically reported whenever fsync is called on the file.
2765  */
2766 static inline void filemap_set_wb_err(struct address_space *mapping, int err)
2767 {
2768         /* Fastpath for common case of no error */
2769         if (unlikely(err))
2770                 __filemap_set_wb_err(mapping, err);
2771 }
2772 
2773 /**
2774  * filemap_check_wb_error - has an error occurred since the mark was sampled?
2775  * @mapping: mapping to check for writeback errors
2776  * @since: previously-sampled errseq_t
2777  *
2778  * Grab the errseq_t value from the mapping, and see if it has changed "since"
2779  * the given value was sampled.
2780  *
2781  * If it has then report the latest error set, otherwise return 0.
2782  */
2783 static inline int filemap_check_wb_err(struct address_space *mapping,
2784                                         errseq_t since)
2785 {
2786         return errseq_check(&mapping->wb_err, since);
2787 }
2788 
2789 /**
2790  * filemap_sample_wb_err - sample the current errseq_t to test for later errors
2791  * @mapping: mapping to be sampled
2792  *
2793  * Writeback errors are always reported relative to a particular sample point
2794  * in the past. This function provides those sample points.
2795  */
2796 static inline errseq_t filemap_sample_wb_err(struct address_space *mapping)
2797 {
2798         return errseq_sample(&mapping->wb_err);
2799 }
2800 
2801 extern int vfs_fsync_range(struct file *file, loff_t start, loff_t end,
2802                            int datasync);
2803 extern int vfs_fsync(struct file *file, int datasync);
2804 
2805 extern int sync_file_range(struct file *file, loff_t offset, loff_t nbytes,
2806                                 unsigned int flags);
2807 
2808 /*
2809  * Sync the bytes written if this was a synchronous write.  Expect ki_pos
2810  * to already be updated for the write, and will return either the amount
2811  * of bytes passed in, or an error if syncing the file failed.
2812  */
2813 static inline ssize_t generic_write_sync(struct kiocb *iocb, ssize_t count)
2814 {
2815         if (iocb->ki_flags & IOCB_DSYNC) {
2816                 int ret = vfs_fsync_range(iocb->ki_filp,
2817                                 iocb->ki_pos - count, iocb->ki_pos - 1,
2818                                 (iocb->ki_flags & IOCB_SYNC) ? 0 : 1);
2819                 if (ret)
2820                         return ret;
2821         }
2822 
2823         return count;
2824 }
2825 
2826 extern void emergency_sync(void);
2827 extern void emergency_remount(void);
2828 #ifdef CONFIG_BLOCK
2829 extern sector_t bmap(struct inode *, sector_t);
2830 #endif
2831 extern int notify_change(struct dentry *, struct iattr *, struct inode **);
2832 extern int inode_permission(struct inode *, int);
2833 extern int generic_permission(struct inode *, int);
2834 extern int __check_sticky(struct inode *dir, struct inode *inode);
2835 
2836 static inline bool execute_ok(struct inode *inode)
2837 {
2838         return (inode->i_mode & S_IXUGO) || S_ISDIR(inode->i_mode);
2839 }
2840 
2841 static inline void file_start_write(struct file *file)
2842 {
2843         if (!S_ISREG(file_inode(file)->i_mode))
2844                 return;
2845         __sb_start_write(file_inode(file)->i_sb, SB_FREEZE_WRITE, true);
2846 }
2847 
2848 static inline bool file_start_write_trylock(struct file *file)
2849 {
2850         if (!S_ISREG(file_inode(file)->i_mode))
2851                 return true;
2852         return __sb_start_write(file_inode(file)->i_sb, SB_FREEZE_WRITE, false);
2853 }
2854 
2855 static inline void file_end_write(struct file *file)
2856 {
2857         if (!S_ISREG(file_inode(file)->i_mode))
2858                 return;
2859         __sb_end_write(file_inode(file)->i_sb, SB_FREEZE_WRITE);
2860 }
2861 
2862 /*
2863  * get_write_access() gets write permission for a file.
2864  * put_write_access() releases this write permission.
2865  * This is used for regular files.
2866  * We cannot support write (and maybe mmap read-write shared) accesses and
2867  * MAP_DENYWRITE mmappings simultaneously. The i_writecount field of an inode
2868  * can have the following values:
2869  * 0: no writers, no VM_DENYWRITE mappings
2870  * < 0: (-i_writecount) vm_area_structs with VM_DENYWRITE set exist
2871  * > 0: (i_writecount) users are writing to the file.
2872  *
2873  * Normally we operate on that counter with atomic_{inc,dec} and it's safe
2874  * except for the cases where we don't hold i_writecount yet. Then we need to
2875  * use {get,deny}_write_access() - these functions check the sign and refuse
2876  * to do the change if sign is wrong.
2877  */
2878 static inline int get_write_access(struct inode *inode)
2879 {
2880         return atomic_inc_unless_negative(&inode->i_writecount) ? 0 : -ETXTBSY;
2881 }
2882 static inline int deny_write_access(struct file *file)
2883 {
2884         struct inode *inode = file_inode(file);
2885         return atomic_dec_unless_positive(&inode->i_writecount) ? 0 : -ETXTBSY;
2886 }
2887 static inline void put_write_access(struct inode * inode)
2888 {
2889         atomic_dec(&inode->i_writecount);
2890 }
2891 static inline void allow_write_access(struct file *file)
2892 {
2893         if (file)
2894                 atomic_inc(&file_inode(file)->i_writecount);
2895 }
2896 static inline bool inode_is_open_for_write(const struct inode *inode)
2897 {
2898         return atomic_read(&inode->i_writecount) > 0;
2899 }
2900 
2901 #ifdef CONFIG_IMA
2902 static inline void i_readcount_dec(struct inode *inode)
2903 {
2904         BUG_ON(!atomic_read(&inode->i_readcount));
2905         atomic_dec(&inode->i_readcount);
2906 }
2907 static inline void i_readcount_inc(struct inode *inode)
2908 {
2909         atomic_inc(&inode->i_readcount);
2910 }
2911 #else
2912 static inline void i_readcount_dec(struct inode *inode)
2913 {
2914         return;
2915 }
2916 static inline void i_readcount_inc(struct inode *inode)
2917 {
2918         return;
2919 }
2920 #endif
2921 extern int do_pipe_flags(int *, int);
2922 
2923 #define __kernel_read_file_id(id) \
2924         id(UNKNOWN, unknown)            \
2925         id(FIRMWARE, firmware)          \
2926         id(FIRMWARE_PREALLOC_BUFFER, firmware)  \
2927         id(MODULE, kernel-module)               \
2928         id(KEXEC_IMAGE, kexec-image)            \
2929         id(KEXEC_INITRAMFS, kexec-initramfs)    \
2930         id(POLICY, security-policy)             \
2931         id(X509_CERTIFICATE, x509-certificate)  \
2932         id(MAX_ID, )
2933 
2934 #define __fid_enumify(ENUM, dummy) READING_ ## ENUM,
2935 #define __fid_stringify(dummy, str) #str,
2936 
2937 enum kernel_read_file_id {
2938         __kernel_read_file_id(__fid_enumify)
2939 };
2940 
2941 static const char * const kernel_read_file_str[] = {
2942         __kernel_read_file_id(__fid_stringify)
2943 };
2944 
2945 static inline const char *kernel_read_file_id_str(enum kernel_read_file_id id)
2946 {
2947         if ((unsigned)id >= READING_MAX_ID)
2948                 return kernel_read_file_str[READING_UNKNOWN];
2949 
2950         return kernel_read_file_str[id];
2951 }
2952 
2953 extern int kernel_read_file(struct file *, void **, loff_t *, loff_t,
2954                             enum kernel_read_file_id);
2955 extern int kernel_read_file_from_path(const char *, void **, loff_t *, loff_t,
2956                                       enum kernel_read_file_id);
2957 extern int kernel_read_file_from_fd(int, void **, loff_t *, loff_t,
2958                                     enum kernel_read_file_id);
2959 extern ssize_t kernel_read(struct file *, void *, size_t, loff_t *);
2960 extern ssize_t kernel_write(struct file *, const void *, size_t, loff_t *);
2961 extern ssize_t __kernel_write(struct file *, const void *, size_t, loff_t *);
2962 extern struct file * open_exec(const char *);
2963  
2964 /* fs/dcache.c -- generic fs support functions */
2965 extern bool is_subdir(struct dentry *, struct dentry *);
2966 extern bool path_is_under(const struct path *, const struct path *);
2967 
2968 extern char *file_path(struct file *, char *, int);
2969 
2970 #include <linux/err.h>
2971 
2972 /* needed for stackable file system support */
2973 extern loff_t default_llseek(struct file *file, loff_t offset, int whence);
2974 
2975 extern loff_t vfs_llseek(struct file *file, loff_t offset, int whence);
2976 
2977 extern int inode_init_always(struct super_block *, struct inode *);
2978 extern void inode_init_once(struct inode *);
2979 extern void address_space_init_once(struct address_space *mapping);
2980 extern struct inode * igrab(struct inode *);
2981 extern ino_t iunique(struct super_block *, ino_t);
2982 extern int inode_needs_sync(struct inode *inode);
2983 extern int generic_delete_inode(struct inode *inode);
2984 static inline int generic_drop_inode(struct inode *inode)
2985 {
2986         return !inode->i_nlink || inode_unhashed(inode);
2987 }
2988 
2989 extern struct inode *ilookup5_nowait(struct super_block *sb,
2990                 unsigned long hashval, int (*test)(struct inode *, void *),
2991                 void *data);
2992 extern struct inode *ilookup5(struct super_block *sb, unsigned long hashval,
2993                 int (*test)(struct inode *, void *), void *data);
2994 extern struct inode *ilookup(struct super_block *sb, unsigned long ino);
2995 
2996 extern struct inode *inode_insert5(struct inode *inode, unsigned long hashval,
2997                 int (*test)(struct inode *, void *),
2998                 int (*set)(struct inode *, void *),
2999                 void *data);
3000 extern struct inode * iget5_locked(struct super_block *, unsigned long, int (*test)(struct inode *, void *), int (*set)(struct inode *, void *), void *);
3001 extern struct inode * iget_locked(struct super_block *, unsigned long);
3002 extern struct inode *find_inode_nowait(struct super_block *,
3003                                        unsigned long,
3004                                        int (*match)(struct inode *,
3005                                                     unsigned long, void *),
3006                                        void *data);
3007 extern int insert_inode_locked4(struct inode *, unsigned long, int (*test)(struct inode *, void *), void *);
3008 extern int insert_inode_locked(struct inode *);
3009 #ifdef CONFIG_DEBUG_LOCK_ALLOC
3010 extern void lockdep_annotate_inode_mutex_key(struct inode *inode);
3011 #else
3012 static inline void lockdep_annotate_inode_mutex_key(struct inode *inode) { };
3013 #endif
3014 extern void unlock_new_inode(struct inode *);
3015 extern void discard_new_inode(struct inode *);
3016 extern unsigned int get_next_ino(void);
3017 extern void evict_inodes(struct super_block *sb);
3018 
3019 extern void __iget(struct inode * inode);
3020 extern void iget_failed(struct inode *);
3021 extern void clear_inode(struct inode *);
3022 extern void __destroy_inode(struct inode *);
3023 extern struct inode *new_inode_pseudo(struct super_block *sb);
3024 extern struct inode *new_inode(struct super_block *sb);
3025 extern void free_inode_nonrcu(struct inode *inode);
3026 extern int should_remove_suid(struct dentry *);
3027 extern int file_remove_privs(struct file *);
3028 
3029 extern void __insert_inode_hash(struct inode *, unsigned long hashval);
3030 static inline void insert_inode_hash(struct inode *inode)
3031 {
3032         __insert_inode_hash(inode, inode->i_ino);
3033 }
3034 
3035 extern void __remove_inode_hash(struct inode *);
3036 static inline void remove_inode_hash(struct inode *inode)
3037 {
3038         if (!inode_unhashed(inode) && !hlist_fake(&inode->i_hash))
3039                 __remove_inode_hash(inode);
3040 }
3041 
3042 extern void inode_sb_list_add(struct inode *inode);
3043 
3044 #ifdef CONFIG_BLOCK
3045 extern int bdev_read_only(struct block_device *);
3046 #endif
3047 extern int set_blocksize(struct block_device *, int);
3048 extern int sb_set_blocksize(struct super_block *, int);
3049 extern int sb_min_blocksize(struct super_block *, int);
3050 
3051 extern int generic_file_mmap(struct file *, struct vm_area_struct *);
3052 extern int generic_file_readonly_mmap(struct file *, struct vm_area_struct *);
3053 extern ssize_t generic_write_checks(struct kiocb *, struct iov_iter *);
3054 extern int generic_remap_checks(struct file *file_in, loff_t pos_in,
3055                                 struct file *file_out, loff_t pos_out,
3056                                 loff_t *count, unsigned int remap_flags);
3057 extern ssize_t generic_file_read_iter(struct kiocb *, struct iov_iter *);
3058 extern ssize_t __generic_file_write_iter(struct kiocb *, struct iov_iter *);
3059 extern ssize_t generic_file_write_iter(struct kiocb *, struct iov_iter *);
3060 extern ssize_t generic_file_direct_write(struct kiocb *, struct iov_iter *);
3061 extern ssize_t generic_perform_write(struct file *, struct iov_iter *, loff_t);
3062 
3063 ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos,
3064                 rwf_t flags);
3065 ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos,
3066                 rwf_t flags);
3067 
3068 /* fs/block_dev.c */
3069 extern ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to);
3070 extern ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from);
3071 extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
3072                         int datasync);
3073 extern void block_sync_page(struct page *page);
3074 
3075 /* fs/splice.c */
3076 extern ssize_t generic_file_splice_read(struct file *, loff_t *,
3077                 struct pipe_inode_info *, size_t, unsigned int);
3078 extern ssize_t iter_file_splice_write(struct pipe_inode_info *,
3079                 struct file *, loff_t *, size_t, unsigned int);
3080 extern ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe,
3081                 struct file *out, loff_t *, size_t len, unsigned int flags);
3082 extern long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
3083                 loff_t *opos, size_t len, unsigned int flags);
3084 
3085 
3086 extern void
3087 file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping);
3088 extern loff_t noop_llseek(struct file *file, loff_t offset, int whence);
3089 extern loff_t no_llseek(struct file *file, loff_t offset, int whence);
3090 extern loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize);
3091 extern loff_t generic_file_llseek(struct file *file, loff_t offset, int whence);
3092 extern loff_t generic_file_llseek_size(struct file *file, loff_t offset,
3093                 int whence, loff_t maxsize, loff_t eof);
3094 extern loff_t fixed_size_llseek(struct file *file, loff_t offset,
3095                 int whence, loff_t size);
3096 extern loff_t no_seek_end_llseek_size(struct file *, loff_t, int, loff_t);
3097 extern loff_t no_seek_end_llseek(struct file *, loff_t, int);
3098 extern int generic_file_open(struct inode * inode, struct file * filp);
3099 extern int nonseekable_open(struct inode * inode, struct file * filp);
3100 extern int stream_open(struct inode * inode, struct file * filp);
3101 
3102 #ifdef CONFIG_BLOCK
3103 typedef void (dio_submit_t)(struct bio *bio, struct inode *inode,
3104                             loff_t file_offset);
3105 
3106 enum {
3107         /* need locking between buffered and direct access */
3108         DIO_LOCKING     = 0x01,
3109 
3110         /* filesystem does not support filling holes */
3111         DIO_SKIP_HOLES  = 0x02,
3112 };
3113 
3114 void dio_end_io(struct bio *bio);
3115 void dio_warn_stale_pagecache(struct file *filp);
3116 
3117 ssize_t __blockdev_direct_IO(struct kiocb *iocb, struct inode *inode,
3118                              struct block_device *bdev, struct iov_iter *iter,
3119                              get_block_t get_block,
3120                              dio_iodone_t end_io, dio_submit_t submit_io,
3121                              int flags);
3122 
3123 static inline ssize_t blockdev_direct_IO(struct kiocb *iocb,
3124                                          struct inode *inode,
3125                                          struct iov_iter *iter,
3126                                          get_block_t get_block)
3127 {
3128         return __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev, iter,
3129                         get_block, NULL, NULL, DIO_LOCKING | DIO_SKIP_HOLES);
3130 }
3131 #endif
3132 
3133 void inode_dio_wait(struct inode *inode);
3134 
3135 /*
3136  * inode_dio_begin - signal start of a direct I/O requests
3137  * @inode: inode the direct I/O happens on
3138  *
3139  * This is called once we've finished processing a direct I/O request,
3140  * and is used to wake up callers waiting for direct I/O to be quiesced.
3141  */
3142 static inline void inode_dio_begin(struct inode *inode)
3143 {
3144         atomic_inc(&inode->i_dio_count);
3145 }
3146 
3147 /*
3148  * inode_dio_end - signal finish of a direct I/O requests
3149  * @inode: inode the direct I/O happens on
3150  *
3151  * This is called once we've finished processing a direct I/O request,
3152  * and is used to wake up callers waiting for direct I/O to be quiesced.
3153  */
3154 static inline void inode_dio_end(struct inode *inode)
3155 {
3156         if (atomic_dec_and_test(&inode->i_dio_count))
3157                 wake_up_bit(&inode->i_state, __I_DIO_WAKEUP);
3158 }
3159 
3160 extern void inode_set_flags(struct inode *inode, unsigned int flags,
3161                             unsigned int mask);
3162 
3163 extern const struct file_operations generic_ro_fops;
3164 
3165 #define special_file(m) (S_ISCHR(m)||S_ISBLK(m)||S_ISFIFO(m)||S_ISSOCK(m))
3166 
3167 extern int readlink_copy(char __user *, int, const char *);
3168 extern int page_readlink(struct dentry *, char __user *, int);
3169 extern const char *page_get_link(struct dentry *, struct inode *,
3170                                  struct delayed_call *);
3171 extern void page_put_link(void *);
3172 extern int __page_symlink(struct inode *inode, const char *symname, int len,
3173                 int nofs);
3174 extern int page_symlink(struct inode *inode, const char *symname, int len);
3175 extern const struct inode_operations page_symlink_inode_operations;
3176 extern void kfree_link(void *);
3177 extern void generic_fillattr(struct inode *, struct kstat *);
3178 extern int vfs_getattr_nosec(const struct path *, struct kstat *, u32, unsigned int);
3179 extern int vfs_getattr(const struct path *, struct kstat *, u32, unsigned int);
3180 void __inode_add_bytes(struct inode *inode, loff_t bytes);
3181 void inode_add_bytes(struct inode *inode, loff_t bytes);
3182 void __inode_sub_bytes(struct inode *inode, loff_t bytes);
3183 void inode_sub_bytes(struct inode *inode, loff_t bytes);
3184 static inline loff_t __inode_get_bytes(struct inode *inode)
3185 {
3186         return (((loff_t)inode->i_blocks) << 9) + inode->i_bytes;
3187 }
3188 loff_t inode_get_bytes(struct inode *inode);
3189 void inode_set_bytes(struct inode *inode, loff_t bytes);
3190 const char *simple_get_link(struct dentry *, struct inode *,
3191                             struct delayed_call *);
3192 extern const struct inode_operations simple_symlink_inode_operations;
3193 
3194 extern int iterate_dir(struct file *, struct dir_context *);
3195 
3196 extern int vfs_statx(int, const char __user *, int, struct kstat *, u32);
3197 extern int vfs_statx_fd(unsigned int, struct kstat *, u32, unsigned int);
3198 
3199 static inline int vfs_stat(const char __user *filename, struct kstat *stat)
3200 {
3201         return vfs_statx(AT_FDCWD, filename, AT_NO_AUTOMOUNT,
3202                          stat, STATX_BASIC_STATS);
3203 }
3204 static inline int vfs_lstat(const char __user *name, struct kstat *stat)
3205 {
3206         return vfs_statx(AT_FDCWD, name, AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT,
3207                          stat, STATX_BASIC_STATS);
3208 }
3209 static inline int vfs_fstatat(int dfd, const char __user *filename,
3210                               struct kstat *stat, int flags)
3211 {
3212         return vfs_statx(dfd, filename, flags | AT_NO_AUTOMOUNT,
3213                          stat, STATX_BASIC_STATS);
3214 }
3215 static inline int vfs_fstat(int fd, struct kstat *stat)
3216 {
3217         return vfs_statx_fd(fd, stat, STATX_BASIC_STATS, 0);
3218 }
3219 
3220 
3221 extern const char *vfs_get_link(struct dentry *, struct delayed_call *);
3222 extern int vfs_readlink(struct dentry *, char __user *, int);
3223 
3224 extern int __generic_block_fiemap(struct inode *inode,
3225                                   struct fiemap_extent_info *fieinfo,
3226                                   loff_t start, loff_t len,
3227                                   get_block_t *get_block);
3228 extern int generic_block_fiemap(struct inode *inode,
3229                                 struct fiemap_extent_info *fieinfo, u64 start,
3230                                 u64 len, get_block_t *get_block);
3231 
3232 extern struct file_system_type *get_filesystem(struct file_system_type *fs);
3233 extern void put_filesystem(struct file_system_type *fs);
3234 extern struct file_system_type *get_fs_type(const char *name);
3235 extern struct super_block *get_super(struct block_device *);
3236 extern struct super_block *get_super_thawed(struct block_device *);
3237 extern struct super_block *get_super_exclusive_thawed(struct block_device *bdev);
3238 extern struct super_block *get_active_super(struct block_device *bdev);
3239 extern void drop_super(struct super_block *sb);
3240 extern void drop_super_exclusive(struct super_block *sb);
3241 extern void iterate_supers(void (*)(struct super_block *, void *), void *);
3242 extern void iterate_supers_type(struct file_system_type *,
3243                                 void (*)(struct super_block *, void *), void *);
3244 
3245 extern int dcache_dir_open(struct inode *, struct file *);
3246 extern int dcache_dir_close(struct inode *, struct file *);
3247 extern loff_t dcache_dir_lseek(struct file *, loff_t, int);
3248 extern int dcache_readdir(struct file *, struct dir_context *);
3249 extern int simple_setattr(struct dentry *, struct iattr *);
3250 extern int simple_getattr(const struct path *, struct kstat *, u32, unsigned int);
3251 extern int simple_statfs(struct dentry *, struct kstatfs *);
3252 extern int simple_open(struct inode *inode, struct file *file);
3253 extern int simple_link(struct dentry *, struct inode *, struct dentry *);
3254 extern int simple_unlink(struct inode *, struct dentry *);
3255 extern int simple_rmdir(struct inode *, struct dentry *);
3256 extern int simple_rename(struct inode *, struct dentry *,
3257                          struct inode *, struct dentry *, unsigned int);
3258 extern int noop_fsync(struct file *, loff_t, loff_t, int);
3259 extern int noop_set_page_dirty(struct page *page);
3260 extern void noop_invalidatepage(struct page *page, unsigned int offset,
3261                 unsigned int length);
3262 extern ssize_t noop_direct_IO(struct kiocb *iocb, struct iov_iter *iter);
3263 extern int simple_empty(struct dentry *);
3264 extern int simple_readpage(struct file *file, struct page *page);
3265 extern int simple_write_begin(struct file *file, struct address_space *mapping,
3266                         loff_t pos, unsigned len, unsigned flags,
3267                         struct page **pagep, void **fsdata);
3268 extern int simple_write_end(struct file *file, struct address_space *mapping,
3269                         loff_t pos, unsigned len, unsigned copied,
3270                         struct page *page, void *fsdata);
3271 extern int always_delete_dentry(const struct dentry *);
3272 extern struct inode *alloc_anon_inode(struct super_block *);
3273 extern int simple_nosetlease(struct file *, long, struct file_lock **, void **);
3274 extern const struct dentry_operations simple_dentry_operations;
3275 
3276 extern struct dentry *simple_lookup(struct inode *, struct dentry *, unsigned int flags);
3277 extern ssize_t generic_read_dir(struct file *, char __user *, size_t, loff_t *);
3278 extern const struct file_operations simple_dir_operations;
3279 extern const struct inode_operations simple_dir_inode_operations;
3280 extern void make_empty_dir_inode(struct inode *inode);
3281 extern bool is_empty_dir_inode(struct inode *inode);
3282 struct tree_descr { const char *name; const struct file_operations *ops; int mode; };
3283 struct dentry *d_alloc_name(struct dentry *, const char *);
3284 extern int simple_fill_super(struct super_block *, unsigned long,
3285                              const struct tree_descr *);
3286 extern int simple_pin_fs(struct file_system_type *, struct vfsmount **mount, int *count);
3287 extern void simple_release_fs(struct vfsmount **mount, int *count);
3288 
3289 extern ssize_t simple_read_from_buffer(void __user *to, size_t count,
3290                         loff_t *ppos, const void *from, size_t available);
3291 extern ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos,
3292                 const void __user *from, size_t count);
3293 
3294 extern int __generic_file_fsync(struct file *, loff_t, loff_t, int);
3295 extern int generic_file_fsync(struct file *, loff_t, loff_t, int);
3296 
3297 extern int generic_check_addressable(unsigned, u64);
3298 
3299 #ifdef CONFIG_MIGRATION
3300 extern int buffer_migrate_page(struct address_space *,
3301                                 struct page *, struct page *,
3302                                 enum migrate_mode);
3303 extern int buffer_migrate_page_norefs(struct address_space *,
3304                                 struct page *, struct page *,
3305                                 enum migrate_mode);
3306 #else
3307 #define buffer_migrate_page NULL
3308 #define buffer_migrate_page_norefs NULL
3309 #endif
3310 
3311 extern int setattr_prepare(struct dentry *, struct iattr *);
3312 extern int inode_newsize_ok(const struct inode *, loff_t offset);
3313 extern void setattr_copy(struct inode *inode, const struct iattr *attr);
3314 
3315 extern int file_update_time(struct file *file);
3316 
3317 static inline bool io_is_direct(struct file *filp)
3318 {
3319         return (filp->f_flags & O_DIRECT) || IS_DAX(filp->f_mapping->host);
3320 }
3321 
3322 static inline bool vma_is_dax(struct vm_area_struct *vma)
3323 {
3324         return vma->vm_file && IS_DAX(vma->vm_file->f_mapping->host);
3325 }
3326 
3327 static inline bool vma_is_fsdax(struct vm_area_struct *vma)
3328 {
3329         struct inode *inode;
3330 
3331         if (!vma->vm_file)
3332                 return false;
3333         if (!vma_is_dax(vma))
3334                 return false;
3335         inode = file_inode(vma->vm_file);
3336         if (S_ISCHR(inode->i_mode))
3337                 return false; /* device-dax */
3338         return true;
3339 }
3340 
3341 static inline int iocb_flags(struct file *file)
3342 {
3343         int res = 0;
3344         if (file->f_flags & O_APPEND)
3345                 res |= IOCB_APPEND;
3346         if (io_is_direct(file))
3347                 res |= IOCB_DIRECT;
3348         if ((file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host))
3349                 res |= IOCB_DSYNC;
3350         if (file->f_flags & __O_SYNC)
3351                 res |= IOCB_SYNC;
3352         return res;
3353 }
3354 
3355 static inline int kiocb_set_rw_flags(struct kiocb *ki, rwf_t flags)
3356 {
3357         if (unlikely(flags & ~RWF_SUPPORTED))
3358                 return -EOPNOTSUPP;
3359 
3360         if (flags & RWF_NOWAIT) {
3361                 if (!(ki->ki_filp->f_mode & FMODE_NOWAIT))
3362                         return -EOPNOTSUPP;
3363                 ki->ki_flags |= IOCB_NOWAIT;
3364         }
3365         if (flags & RWF_HIPRI)
3366                 ki->ki_flags |= IOCB_HIPRI;
3367         if (flags & RWF_DSYNC)
3368                 ki->ki_flags |= IOCB_DSYNC;
3369         if (flags & RWF_SYNC)
3370                 ki->ki_flags |= (IOCB_DSYNC | IOCB_SYNC);
3371         if (flags & RWF_APPEND)
3372                 ki->ki_flags |= IOCB_APPEND;
3373         return 0;
3374 }
3375 
3376 static inline ino_t parent_ino(struct dentry *dentry)
3377 {
3378         ino_t res;
3379 
3380         /*
3381          * Don't strictly need d_lock here? If the parent ino could change
3382          * then surely we'd have a deeper race in the caller?
3383          */
3384         spin_lock(&dentry->d_lock);
3385         res = dentry->d_parent->d_inode->i_ino;
3386         spin_unlock(&dentry->d_lock);
3387         return res;
3388 }
3389 
3390 /* Transaction based IO helpers */
3391 
3392 /*
3393  * An argresp is stored in an allocated page and holds the
3394  * size of the argument or response, along with its content
3395  */
3396 struct simple_transaction_argresp {
3397         ssize_t size;
3398         char data[0];
3399 };
3400 
3401 #define SIMPLE_TRANSACTION_LIMIT (PAGE_SIZE - sizeof(struct simple_transaction_argresp))
3402 
3403 char *simple_transaction_get(struct file *file, const char __user *buf,
3404                                 size_t size);
3405 ssize_t simple_transaction_read(struct file *file, char __user *buf,
3406                                 size_t size, loff_t *pos);
3407 int simple_transaction_release(struct inode *inode, struct file *file);
3408 
3409 void simple_transaction_set(struct file *file, size_t n);
3410 
3411 /*
3412  * simple attribute files
3413  *
3414  * These attributes behave similar to those in sysfs:
3415  *
3416  * Writing to an attribute immediately sets a value, an open file can be
3417  * written to multiple times.
3418  *
3419  * Reading from an attribute creates a buffer from the value that might get
3420  * read with multiple read calls. When the attribute has been read
3421  * completely, no further read calls are possible until the file is opened
3422  * again.
3423  *
3424  * All attributes contain a text representation of a numeric value
3425  * that are accessed with the get() and set() functions.
3426  */
3427 #define DEFINE_SIMPLE_ATTRIBUTE(__fops, __get, __set, __fmt)            \
3428 static int __fops ## _open(struct inode *inode, struct file *file)      \
3429 {                                                                       \
3430         __simple_attr_check_format(__fmt, 0ull);                        \
3431         return simple_attr_open(inode, file, __get, __set, __fmt);      \
3432 }                                                                       \
3433 static const struct file_operations __fops = {                          \
3434         .owner   = THIS_MODULE,                                         \
3435         .open    = __fops ## _open,                                     \
3436         .release = simple_attr_release,                                 \
3437         .read    = simple_attr_read,                                    \
3438         .write   = simple_attr_write,                                   \
3439         .llseek  = generic_file_llseek,                                 \
3440 }
3441 
3442 static inline __printf(1, 2)
3443 void __simple_attr_check_format(const char *fmt, ...)
3444 {
3445         /* don't do anything, just let the compiler check the arguments; */
3446 }
3447 
3448 int simple_attr_open(struct inode *inode, struct file *file,
3449                      int (*get)(void *, u64 *), int (*set)(void *, u64),
3450                      const char *fmt);
3451 int simple_attr_release(struct inode *inode, struct file *file);
3452 ssize_t simple_attr_read(struct file *file, char __user *buf,
3453                          size_t len, loff_t *ppos);
3454 ssize_t simple_attr_write(struct file *file, const char __user *buf,
3455                           size_t len, loff_t *ppos);
3456 
3457 struct ctl_table;
3458 int proc_nr_files(struct ctl_table *table, int write,
3459                   void __user *buffer, size_t *lenp, loff_t *ppos);
3460 int proc_nr_dentry(struct ctl_table *table, int write,
3461                   void __user *buffer, size_t *lenp, loff_t *ppos);
3462 int proc_nr_inodes(struct ctl_table *table, int write,
3463                    void __user *buffer, size_t *lenp, loff_t *ppos);
3464 int __init get_filesystem_list(char *buf);
3465 
3466 #define __FMODE_EXEC            ((__force int) FMODE_EXEC)
3467 #define __FMODE_NONOTIFY        ((__force int) FMODE_NONOTIFY)
3468 
3469 #define ACC_MODE(x) ("\004\002\006\006"[(x)&O_ACCMODE])
3470 #define OPEN_FMODE(flag) ((__force fmode_t)(((flag + 1) & O_ACCMODE) | \
3471                                             (flag & __FMODE_NONOTIFY)))
3472 
3473 static inline bool is_sxid(umode_t mode)
3474 {
3475         return (mode & S_ISUID) || ((mode & S_ISGID) && (mode & S_IXGRP));
3476 }
3477 
3478 static inline int check_sticky(struct inode *dir, struct inode *inode)
3479 {
3480         if (!(dir->i_mode & S_ISVTX))
3481                 return 0;
3482 
3483         return __check_sticky(dir, inode);
3484 }
3485 
3486 static inline void inode_has_no_xattr(struct inode *inode)
3487 {
3488         if (!is_sxid(inode->i_mode) && (inode->i_sb->s_flags & SB_NOSEC))
3489                 inode->i_flags |= S_NOSEC;
3490 }
3491 
3492 static inline bool is_root_inode(struct inode *inode)
3493 {
3494         return inode == inode->i_sb->s_root->d_inode;
3495 }
3496 
3497 static inline bool dir_emit(struct dir_context *ctx,
3498                             const char *name, int namelen,
3499                             u64 ino, unsigned type)
3500 {
3501         return ctx->actor(ctx, name, namelen, ctx->pos, ino, type) == 0;
3502 }
3503 static inline bool dir_emit_dot(struct file *file, struct dir_context *ctx)
3504 {
3505         return ctx->actor(ctx, ".", 1, ctx->pos,
3506                           file->f_path.dentry->d_inode->i_ino, DT_DIR) == 0;
3507 }
3508 static inline bool dir_emit_dotdot(struct file *file, struct dir_context *ctx)
3509 {
3510         return ctx->actor(ctx, "..", 2, ctx->pos,
3511                           parent_ino(file->f_path.dentry), DT_DIR) == 0;
3512 }
3513 static inline bool dir_emit_dots(struct file *file, struct dir_context *ctx)
3514 {
3515         if (ctx->pos == 0) {
3516                 if (!dir_emit_dot(file, ctx))
3517                         return false;
3518                 ctx->pos = 1;
3519         }
3520         if (ctx->pos == 1) {
3521                 if (!dir_emit_dotdot(file, ctx))
3522                         return false;
3523                 ctx->pos = 2;
3524         }
3525         return true;
3526 }
3527 static inline bool dir_relax(struct inode *inode)
3528 {
3529         inode_unlock(inode);
3530         inode_lock(inode);
3531         return !IS_DEADDIR(inode);
3532 }
3533 
3534 static inline bool dir_relax_shared(struct inode *inode)
3535 {
3536         inode_unlock_shared(inode);
3537         inode_lock_shared(inode);
3538         return !IS_DEADDIR(inode);
3539 }
3540 
3541 extern bool path_noexec(const struct path *path);
3542 extern void inode_nohighmem(struct inode *inode);
3543 
3544 /* mm/fadvise.c */
3545 extern int vfs_fadvise(struct file *file, loff_t offset, loff_t len,
3546                        int advice);
3547 extern int generic_fadvise(struct file *file, loff_t offset, loff_t len,
3548                            int advice);
3549 
3550 #if defined(CONFIG_IO_URING)
3551 extern struct sock *io_uring_get_socket(struct file *file);
3552 #else
3553 static inline struct sock *io_uring_get_socket(struct file *file)
3554 {
3555         return NULL;
3556 }
3557 #endif
3558 
3559 #endif /* _LINUX_FS_H */
3560 

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