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

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