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

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