Version:  2.0.40 2.2.26 2.4.37 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8

Linux/include/linux/fs.h

  1 #ifndef _LINUX_FS_H
  2 #define _LINUX_FS_H
  3 
  4 #include <linux/linkage.h>
  5 #include <linux/wait.h>
  6 #include <linux/kdev_t.h>
  7 #include <linux/dcache.h>
  8 #include <linux/path.h>
  9 #include <linux/stat.h>
 10 #include <linux/cache.h>
 11 #include <linux/list.h>
 12 #include <linux/list_lru.h>
 13 #include <linux/llist.h>
 14 #include <linux/radix-tree.h>
 15 #include <linux/rbtree.h>
 16 #include <linux/init.h>
 17 #include <linux/pid.h>
 18 #include <linux/bug.h>
 19 #include <linux/mutex.h>
 20 #include <linux/rwsem.h>
 21 #include <linux/capability.h>
 22 #include <linux/semaphore.h>
 23 #include <linux/fiemap.h>
 24 #include <linux/rculist_bl.h>
 25 #include <linux/atomic.h>
 26 #include <linux/shrinker.h>
 27 #include <linux/migrate_mode.h>
 28 #include <linux/uidgid.h>
 29 #include <linux/lockdep.h>
 30 #include <linux/percpu-rwsem.h>
 31 #include <linux/blk_types.h>
 32 #include <linux/workqueue.h>
 33 #include <linux/percpu-rwsem.h>
 34 #include <linux/delayed_call.h>
 35 
 36 #include <asm/byteorder.h>
 37 #include <uapi/linux/fs.h>
 38 
 39 struct backing_dev_info;
 40 struct bdi_writeback;
 41 struct export_operations;
 42 struct hd_geometry;
 43 struct iovec;
 44 struct kiocb;
 45 struct kobject;
 46 struct pipe_inode_info;
 47 struct poll_table_struct;
 48 struct kstatfs;
 49 struct vm_area_struct;
 50 struct vfsmount;
 51 struct cred;
 52 struct swap_info_struct;
 53 struct seq_file;
 54 struct workqueue_struct;
 55 struct iov_iter;
 56 struct fscrypt_info;
 57 struct fscrypt_operations;
 58 
 59 extern void __init inode_init(void);
 60 extern void __init inode_init_early(void);
 61 extern void __init files_init(void);
 62 extern void __init files_maxfiles_init(void);
 63 
 64 extern struct files_stat_struct files_stat;
 65 extern unsigned long get_max_files(void);
 66 extern int sysctl_nr_open;
 67 extern struct inodes_stat_t inodes_stat;
 68 extern int leases_enable, lease_break_time;
 69 extern int sysctl_protected_symlinks;
 70 extern int sysctl_protected_hardlinks;
 71 
 72 struct buffer_head;
 73 typedef int (get_block_t)(struct inode *inode, sector_t iblock,
 74                         struct buffer_head *bh_result, int create);
 75 typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset,
 76                         ssize_t bytes, void *private);
 77 
 78 #define MAY_EXEC                0x00000001
 79 #define MAY_WRITE               0x00000002
 80 #define MAY_READ                0x00000004
 81 #define MAY_APPEND              0x00000008
 82 #define MAY_ACCESS              0x00000010
 83 #define MAY_OPEN                0x00000020
 84 #define MAY_CHDIR               0x00000040
 85 /* called from RCU mode, don't block */
 86 #define MAY_NOT_BLOCK           0x00000080
 87 
 88 /*
 89  * flags in file.f_mode.  Note that FMODE_READ and FMODE_WRITE must correspond
 90  * to O_WRONLY and O_RDWR via the strange trick in __dentry_open()
 91  */
 92 
 93 /* file is open for reading */
 94 #define FMODE_READ              ((__force fmode_t)0x1)
 95 /* file is open for writing */
 96 #define FMODE_WRITE             ((__force fmode_t)0x2)
 97 /* file is seekable */
 98 #define FMODE_LSEEK             ((__force fmode_t)0x4)
 99 /* file can be accessed using pread */
100 #define FMODE_PREAD             ((__force fmode_t)0x8)
101 /* file can be accessed using pwrite */
102 #define FMODE_PWRITE            ((__force fmode_t)0x10)
103 /* File is opened for execution with sys_execve / sys_uselib */
104 #define FMODE_EXEC              ((__force fmode_t)0x20)
105 /* File is opened with O_NDELAY (only set for block devices) */
106 #define FMODE_NDELAY            ((__force fmode_t)0x40)
107 /* File is opened with O_EXCL (only set for block devices) */
108 #define FMODE_EXCL              ((__force fmode_t)0x80)
109 /* File is opened using open(.., 3, ..) and is writeable only for ioctls
110    (specialy hack for floppy.c) */
111 #define FMODE_WRITE_IOCTL       ((__force fmode_t)0x100)
112 /* 32bit hashes as llseek() offset (for directories) */
113 #define FMODE_32BITHASH         ((__force fmode_t)0x200)
114 /* 64bit hashes as llseek() offset (for directories) */
115 #define FMODE_64BITHASH         ((__force fmode_t)0x400)
116 
117 /*
118  * Don't update ctime and mtime.
119  *
120  * Currently a special hack for the XFS open_by_handle ioctl, but we'll
121  * hopefully graduate it to a proper O_CMTIME flag supported by open(2) soon.
122  */
123 #define FMODE_NOCMTIME          ((__force fmode_t)0x800)
124 
125 /* Expect random access pattern */
126 #define FMODE_RANDOM            ((__force fmode_t)0x1000)
127 
128 /* File is huge (eg. /dev/kmem): treat loff_t as unsigned */
129 #define FMODE_UNSIGNED_OFFSET   ((__force fmode_t)0x2000)
130 
131 /* File is opened with O_PATH; almost nothing can be done with it */
132 #define FMODE_PATH              ((__force fmode_t)0x4000)
133 
134 /* File needs atomic accesses to f_pos */
135 #define FMODE_ATOMIC_POS        ((__force fmode_t)0x8000)
136 /* Write access to underlying fs */
137 #define FMODE_WRITER            ((__force fmode_t)0x10000)
138 /* Has read method(s) */
139 #define FMODE_CAN_READ          ((__force fmode_t)0x20000)
140 /* Has write method(s) */
141 #define FMODE_CAN_WRITE         ((__force fmode_t)0x40000)
142 
143 /* File was opened by fanotify and shouldn't generate fanotify events */
144 #define FMODE_NONOTIFY          ((__force fmode_t)0x4000000)
145 
146 /*
147  * Flag for rw_copy_check_uvector and compat_rw_copy_check_uvector
148  * that indicates that they should check the contents of the iovec are
149  * valid, but not check the memory that the iovec elements
150  * points too.
151  */
152 #define CHECK_IOVEC_ONLY -1
153 
154 /*
155  * The below are the various read and write flags that we support. Some of
156  * them include behavioral modifiers that send information down to the
157  * block layer and IO scheduler. They should be used along with a req_op.
158  * Terminology:
159  *
160  *      The block layer uses device plugging to defer IO a little bit, in
161  *      the hope that we will see more IO very shortly. This increases
162  *      coalescing of adjacent IO and thus reduces the number of IOs we
163  *      have to send to the device. It also allows for better queuing,
164  *      if the IO isn't mergeable. If the caller is going to be waiting
165  *      for the IO, then he must ensure that the device is unplugged so
166  *      that the IO is dispatched to the driver.
167  *
168  *      All IO is handled async in Linux. This is fine for background
169  *      writes, but for reads or writes that someone waits for completion
170  *      on, we want to notify the block layer and IO scheduler so that they
171  *      know about it. That allows them to make better scheduling
172  *      decisions. So when the below references 'sync' and 'async', it
173  *      is referencing this priority hint.
174  *
175  * With that in mind, the available types are:
176  *
177  * READ                 A normal read operation. Device will be plugged.
178  * READ_SYNC            A synchronous read. Device is not plugged, caller can
179  *                      immediately wait on this read without caring about
180  *                      unplugging.
181  * WRITE                A normal async write. Device will be plugged.
182  * WRITE_SYNC           Synchronous write. Identical to WRITE, but passes down
183  *                      the hint that someone will be waiting on this IO
184  *                      shortly. The write equivalent of READ_SYNC.
185  * WRITE_ODIRECT        Special case write for O_DIRECT only.
186  * WRITE_FLUSH          Like WRITE_SYNC but with preceding cache flush.
187  * WRITE_FUA            Like WRITE_SYNC but data is guaranteed to be on
188  *                      non-volatile media on completion.
189  * WRITE_FLUSH_FUA      Combination of WRITE_FLUSH and FUA. The IO is preceded
190  *                      by a cache flush and data is guaranteed to be on
191  *                      non-volatile media on completion.
192  *
193  */
194 #define RW_MASK                 REQ_OP_WRITE
195 
196 #define READ                    REQ_OP_READ
197 #define WRITE                   REQ_OP_WRITE
198 
199 #define READ_SYNC               REQ_SYNC
200 #define WRITE_SYNC              (REQ_SYNC | REQ_NOIDLE)
201 #define WRITE_ODIRECT           REQ_SYNC
202 #define WRITE_FLUSH             (REQ_SYNC | REQ_NOIDLE | REQ_PREFLUSH)
203 #define WRITE_FUA               (REQ_SYNC | REQ_NOIDLE | REQ_FUA)
204 #define WRITE_FLUSH_FUA         (REQ_SYNC | REQ_NOIDLE | REQ_PREFLUSH | REQ_FUA)
205 
206 /*
207  * Attribute flags.  These should be or-ed together to figure out what
208  * has been changed!
209  */
210 #define ATTR_MODE       (1 << 0)
211 #define ATTR_UID        (1 << 1)
212 #define ATTR_GID        (1 << 2)
213 #define ATTR_SIZE       (1 << 3)
214 #define ATTR_ATIME      (1 << 4)
215 #define ATTR_MTIME      (1 << 5)
216 #define ATTR_CTIME      (1 << 6)
217 #define ATTR_ATIME_SET  (1 << 7)
218 #define ATTR_MTIME_SET  (1 << 8)
219 #define ATTR_FORCE      (1 << 9) /* Not a change, but a change it */
220 #define ATTR_ATTR_FLAG  (1 << 10)
221 #define ATTR_KILL_SUID  (1 << 11)
222 #define ATTR_KILL_SGID  (1 << 12)
223 #define ATTR_FILE       (1 << 13)
224 #define ATTR_KILL_PRIV  (1 << 14)
225 #define ATTR_OPEN       (1 << 15) /* Truncating from open(O_TRUNC) */
226 #define ATTR_TIMES_SET  (1 << 16)
227 
228 /*
229  * Whiteout is represented by a char device.  The following constants define the
230  * mode and device number to use.
231  */
232 #define WHITEOUT_MODE 0
233 #define WHITEOUT_DEV 0
234 
235 /*
236  * This is the Inode Attributes structure, used for notify_change().  It
237  * uses the above definitions as flags, to know which values have changed.
238  * Also, in this manner, a Filesystem can look at only the values it cares
239  * about.  Basically, these are the attributes that the VFS layer can
240  * request to change from the FS layer.
241  *
242  * Derek Atkins <warlord@MIT.EDU> 94-10-20
243  */
244 struct iattr {
245         unsigned int    ia_valid;
246         umode_t         ia_mode;
247         kuid_t          ia_uid;
248         kgid_t          ia_gid;
249         loff_t          ia_size;
250         struct timespec ia_atime;
251         struct timespec ia_mtime;
252         struct timespec ia_ctime;
253 
254         /*
255          * Not an attribute, but an auxiliary info for filesystems wanting to
256          * implement an ftruncate() like method.  NOTE: filesystem should
257          * check for (ia_valid & ATTR_FILE), and not for (ia_file != NULL).
258          */
259         struct file     *ia_file;
260 };
261 
262 /*
263  * Includes for diskquotas.
264  */
265 #include <linux/quota.h>
266 
267 /*
268  * Maximum number of layers of fs stack.  Needs to be limited to
269  * prevent kernel stack overflow
270  */
271 #define FILESYSTEM_MAX_STACK_DEPTH 2
272 
273 /** 
274  * enum positive_aop_returns - aop return codes with specific semantics
275  *
276  * @AOP_WRITEPAGE_ACTIVATE: Informs the caller that page writeback has
277  *                          completed, that the page is still locked, and
278  *                          should be considered active.  The VM uses this hint
279  *                          to return the page to the active list -- it won't
280  *                          be a candidate for writeback again in the near
281  *                          future.  Other callers must be careful to unlock
282  *                          the page if they get this return.  Returned by
283  *                          writepage(); 
284  *
285  * @AOP_TRUNCATED_PAGE: The AOP method that was handed a locked page has
286  *                      unlocked it and the page might have been truncated.
287  *                      The caller should back up to acquiring a new page and
288  *                      trying again.  The aop will be taking reasonable
289  *                      precautions not to livelock.  If the caller held a page
290  *                      reference, it should drop it before retrying.  Returned
291  *                      by readpage().
292  *
293  * address_space_operation functions return these large constants to indicate
294  * special semantics to the caller.  These are much larger than the bytes in a
295  * page to allow for functions that return the number of bytes operated on in a
296  * given page.
297  */
298 
299 enum positive_aop_returns {
300         AOP_WRITEPAGE_ACTIVATE  = 0x80000,
301         AOP_TRUNCATED_PAGE      = 0x80001,
302 };
303 
304 #define AOP_FLAG_UNINTERRUPTIBLE        0x0001 /* will not do a short write */
305 #define AOP_FLAG_CONT_EXPAND            0x0002 /* called from cont_expand */
306 #define AOP_FLAG_NOFS                   0x0004 /* used by filesystem to direct
307                                                 * helper code (eg buffer layer)
308                                                 * to clear GFP_FS from alloc */
309 
310 /*
311  * oh the beauties of C type declarations.
312  */
313 struct page;
314 struct address_space;
315 struct writeback_control;
316 
317 #define IOCB_EVENTFD            (1 << 0)
318 #define IOCB_APPEND             (1 << 1)
319 #define IOCB_DIRECT             (1 << 2)
320 #define IOCB_HIPRI              (1 << 3)
321 #define IOCB_DSYNC              (1 << 4)
322 #define IOCB_SYNC               (1 << 5)
323 
324 struct kiocb {
325         struct file             *ki_filp;
326         loff_t                  ki_pos;
327         void (*ki_complete)(struct kiocb *iocb, long ret, long ret2);
328         void                    *private;
329         int                     ki_flags;
330 };
331 
332 static inline bool is_sync_kiocb(struct kiocb *kiocb)
333 {
334         return kiocb->ki_complete == NULL;
335 }
336 
337 static inline int iocb_flags(struct file *file);
338 
339 static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp)
340 {
341         *kiocb = (struct kiocb) {
342                 .ki_filp = filp,
343                 .ki_flags = iocb_flags(filp),
344         };
345 }
346 
347 /*
348  * "descriptor" for what we're up to with a read.
349  * This allows us to use the same read code yet
350  * have multiple different users of the data that
351  * we read from a file.
352  *
353  * The simplest case just copies the data to user
354  * mode.
355  */
356 typedef struct {
357         size_t written;
358         size_t count;
359         union {
360                 char __user *buf;
361                 void *data;
362         } arg;
363         int error;
364 } read_descriptor_t;
365 
366 typedef int (*read_actor_t)(read_descriptor_t *, struct page *,
367                 unsigned long, unsigned long);
368 
369 struct address_space_operations {
370         int (*writepage)(struct page *page, struct writeback_control *wbc);
371         int (*readpage)(struct file *, struct page *);
372 
373         /* Write back some dirty pages from this mapping. */
374         int (*writepages)(struct address_space *, struct writeback_control *);
375 
376         /* Set a page dirty.  Return true if this dirtied it */
377         int (*set_page_dirty)(struct page *page);
378 
379         int (*readpages)(struct file *filp, struct address_space *mapping,
380                         struct list_head *pages, unsigned nr_pages);
381 
382         int (*write_begin)(struct file *, struct address_space *mapping,
383                                 loff_t pos, unsigned len, unsigned flags,
384                                 struct page **pagep, void **fsdata);
385         int (*write_end)(struct file *, struct address_space *mapping,
386                                 loff_t pos, unsigned len, unsigned copied,
387                                 struct page *page, void *fsdata);
388 
389         /* Unfortunately this kludge is needed for FIBMAP. Don't use it */
390         sector_t (*bmap)(struct address_space *, sector_t);
391         void (*invalidatepage) (struct page *, unsigned int, unsigned int);
392         int (*releasepage) (struct page *, gfp_t);
393         void (*freepage)(struct page *);
394         ssize_t (*direct_IO)(struct kiocb *, struct iov_iter *iter);
395         /*
396          * migrate the contents of a page to the specified target. If
397          * migrate_mode is MIGRATE_ASYNC, it must not block.
398          */
399         int (*migratepage) (struct address_space *,
400                         struct page *, struct page *, enum migrate_mode);
401         bool (*isolate_page)(struct page *, isolate_mode_t);
402         void (*putback_page)(struct page *);
403         int (*launder_page) (struct page *);
404         int (*is_partially_uptodate) (struct page *, unsigned long,
405                                         unsigned long);
406         void (*is_dirty_writeback) (struct page *, bool *, bool *);
407         int (*error_remove_page)(struct address_space *, struct page *);
408 
409         /* swapfile support */
410         int (*swap_activate)(struct swap_info_struct *sis, struct file *file,
411                                 sector_t *span);
412         void (*swap_deactivate)(struct file *file);
413 };
414 
415 extern const struct address_space_operations empty_aops;
416 
417 /*
418  * pagecache_write_begin/pagecache_write_end must be used by general code
419  * to write into the pagecache.
420  */
421 int pagecache_write_begin(struct file *, struct address_space *mapping,
422                                 loff_t pos, unsigned len, unsigned flags,
423                                 struct page **pagep, void **fsdata);
424 
425 int pagecache_write_end(struct file *, struct address_space *mapping,
426                                 loff_t pos, unsigned len, unsigned copied,
427                                 struct page *page, void *fsdata);
428 
429 struct address_space {
430         struct inode            *host;          /* owner: inode, block_device */
431         struct radix_tree_root  page_tree;      /* radix tree of all pages */
432         spinlock_t              tree_lock;      /* and lock protecting it */
433         atomic_t                i_mmap_writable;/* count VM_SHARED mappings */
434         struct rb_root          i_mmap;         /* tree of private and shared mappings */
435         struct rw_semaphore     i_mmap_rwsem;   /* protect tree, count, list */
436         /* Protected by tree_lock together with the radix tree */
437         unsigned long           nrpages;        /* number of total pages */
438         /* number of shadow or DAX exceptional entries */
439         unsigned long           nrexceptional;
440         pgoff_t                 writeback_index;/* writeback starts here */
441         const struct address_space_operations *a_ops;   /* methods */
442         unsigned long           flags;          /* error bits/gfp mask */
443         spinlock_t              private_lock;   /* for use by the address_space */
444         struct list_head        private_list;   /* ditto */
445         void                    *private_data;  /* ditto */
446 } __attribute__((aligned(sizeof(long))));
447         /*
448          * On most architectures that alignment is already the case; but
449          * must be enforced here for CRIS, to let the least significant bit
450          * of struct page's "mapping" pointer be used for PAGE_MAPPING_ANON.
451          */
452 struct request_queue;
453 
454 struct block_device {
455         dev_t                   bd_dev;  /* not a kdev_t - it's a search key */
456         int                     bd_openers;
457         struct inode *          bd_inode;       /* will die */
458         struct super_block *    bd_super;
459         struct mutex            bd_mutex;       /* open/close mutex */
460         void *                  bd_claiming;
461         void *                  bd_holder;
462         int                     bd_holders;
463         bool                    bd_write_holder;
464 #ifdef CONFIG_SYSFS
465         struct list_head        bd_holder_disks;
466 #endif
467         struct block_device *   bd_contains;
468         unsigned                bd_block_size;
469         struct hd_struct *      bd_part;
470         /* number of times partitions within this device have been opened. */
471         unsigned                bd_part_count;
472         int                     bd_invalidated;
473         struct gendisk *        bd_disk;
474         struct request_queue *  bd_queue;
475         struct list_head        bd_list;
476         /*
477          * Private data.  You must have bd_claim'ed the block_device
478          * to use this.  NOTE:  bd_claim allows an owner to claim
479          * the same device multiple times, the owner must take special
480          * care to not mess up bd_private for that case.
481          */
482         unsigned long           bd_private;
483 
484         /* The counter of freeze processes */
485         int                     bd_fsfreeze_count;
486         /* Mutex for freeze */
487         struct mutex            bd_fsfreeze_mutex;
488 };
489 
490 /*
491  * Radix-tree tags, for tagging dirty and writeback pages within the pagecache
492  * radix trees
493  */
494 #define PAGECACHE_TAG_DIRTY     0
495 #define PAGECACHE_TAG_WRITEBACK 1
496 #define PAGECACHE_TAG_TOWRITE   2
497 
498 int mapping_tagged(struct address_space *mapping, int tag);
499 
500 static inline void i_mmap_lock_write(struct address_space *mapping)
501 {
502         down_write(&mapping->i_mmap_rwsem);
503 }
504 
505 static inline void i_mmap_unlock_write(struct address_space *mapping)
506 {
507         up_write(&mapping->i_mmap_rwsem);
508 }
509 
510 static inline void i_mmap_lock_read(struct address_space *mapping)
511 {
512         down_read(&mapping->i_mmap_rwsem);
513 }
514 
515 static inline void i_mmap_unlock_read(struct address_space *mapping)
516 {
517         up_read(&mapping->i_mmap_rwsem);
518 }
519 
520 /*
521  * Might pages of this file be mapped into userspace?
522  */
523 static inline int mapping_mapped(struct address_space *mapping)
524 {
525         return  !RB_EMPTY_ROOT(&mapping->i_mmap);
526 }
527 
528 /*
529  * Might pages of this file have been modified in userspace?
530  * Note that i_mmap_writable counts all VM_SHARED vmas: do_mmap_pgoff
531  * marks vma as VM_SHARED if it is shared, and the file was opened for
532  * writing i.e. vma may be mprotected writable even if now readonly.
533  *
534  * If i_mmap_writable is negative, no new writable mappings are allowed. You
535  * can only deny writable mappings, if none exists right now.
536  */
537 static inline int mapping_writably_mapped(struct address_space *mapping)
538 {
539         return atomic_read(&mapping->i_mmap_writable) > 0;
540 }
541 
542 static inline int mapping_map_writable(struct address_space *mapping)
543 {
544         return atomic_inc_unless_negative(&mapping->i_mmap_writable) ?
545                 0 : -EPERM;
546 }
547 
548 static inline void mapping_unmap_writable(struct address_space *mapping)
549 {
550         atomic_dec(&mapping->i_mmap_writable);
551 }
552 
553 static inline int mapping_deny_writable(struct address_space *mapping)
554 {
555         return atomic_dec_unless_positive(&mapping->i_mmap_writable) ?
556                 0 : -EBUSY;
557 }
558 
559 static inline void mapping_allow_writable(struct address_space *mapping)
560 {
561         atomic_inc(&mapping->i_mmap_writable);
562 }
563 
564 /*
565  * Use sequence counter to get consistent i_size on 32-bit processors.
566  */
567 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
568 #include <linux/seqlock.h>
569 #define __NEED_I_SIZE_ORDERED
570 #define i_size_ordered_init(inode) seqcount_init(&inode->i_size_seqcount)
571 #else
572 #define i_size_ordered_init(inode) do { } while (0)
573 #endif
574 
575 struct posix_acl;
576 #define ACL_NOT_CACHED ((void *)(-1))
577 #define ACL_DONT_CACHE ((void *)(-3))
578 
579 static inline struct posix_acl *
580 uncached_acl_sentinel(struct task_struct *task)
581 {
582         return (void *)task + 1;
583 }
584 
585 static inline bool
586 is_uncached_acl(struct posix_acl *acl)
587 {
588         return (long)acl & 1;
589 }
590 
591 #define IOP_FASTPERM    0x0001
592 #define IOP_LOOKUP      0x0002
593 #define IOP_NOFOLLOW    0x0004
594 
595 /*
596  * Keep mostly read-only and often accessed (especially for
597  * the RCU path lookup and 'stat' data) fields at the beginning
598  * of the 'struct inode'
599  */
600 struct inode {
601         umode_t                 i_mode;
602         unsigned short          i_opflags;
603         kuid_t                  i_uid;
604         kgid_t                  i_gid;
605         unsigned int            i_flags;
606 
607 #ifdef CONFIG_FS_POSIX_ACL
608         struct posix_acl        *i_acl;
609         struct posix_acl        *i_default_acl;
610 #endif
611 
612         const struct inode_operations   *i_op;
613         struct super_block      *i_sb;
614         struct address_space    *i_mapping;
615 
616 #ifdef CONFIG_SECURITY
617         void                    *i_security;
618 #endif
619 
620         /* Stat data, not accessed from path walking */
621         unsigned long           i_ino;
622         /*
623          * Filesystems may only read i_nlink directly.  They shall use the
624          * following functions for modification:
625          *
626          *    (set|clear|inc|drop)_nlink
627          *    inode_(inc|dec)_link_count
628          */
629         union {
630                 const unsigned int i_nlink;
631                 unsigned int __i_nlink;
632         };
633         dev_t                   i_rdev;
634         loff_t                  i_size;
635         struct timespec         i_atime;
636         struct timespec         i_mtime;
637         struct timespec         i_ctime;
638         spinlock_t              i_lock; /* i_blocks, i_bytes, maybe i_size */
639         unsigned short          i_bytes;
640         unsigned int            i_blkbits;
641         blkcnt_t                i_blocks;
642 
643 #ifdef __NEED_I_SIZE_ORDERED
644         seqcount_t              i_size_seqcount;
645 #endif
646 
647         /* Misc */
648         unsigned long           i_state;
649         struct rw_semaphore     i_rwsem;
650 
651         unsigned long           dirtied_when;   /* jiffies of first dirtying */
652         unsigned long           dirtied_time_when;
653 
654         struct hlist_node       i_hash;
655         struct list_head        i_io_list;      /* backing dev IO list */
656 #ifdef CONFIG_CGROUP_WRITEBACK
657         struct bdi_writeback    *i_wb;          /* the associated cgroup wb */
658 
659         /* foreign inode detection, see wbc_detach_inode() */
660         int                     i_wb_frn_winner;
661         u16                     i_wb_frn_avg_time;
662         u16                     i_wb_frn_history;
663 #endif
664         struct list_head        i_lru;          /* inode LRU list */
665         struct list_head        i_sb_list;
666         struct list_head        i_wb_list;      /* backing dev writeback list */
667         union {
668                 struct hlist_head       i_dentry;
669                 struct rcu_head         i_rcu;
670         };
671         u64                     i_version;
672         atomic_t                i_count;
673         atomic_t                i_dio_count;
674         atomic_t                i_writecount;
675 #ifdef CONFIG_IMA
676         atomic_t                i_readcount; /* struct files open RO */
677 #endif
678         const struct file_operations    *i_fop; /* former ->i_op->default_file_ops */
679         struct file_lock_context        *i_flctx;
680         struct address_space    i_data;
681         struct list_head        i_devices;
682         union {
683                 struct pipe_inode_info  *i_pipe;
684                 struct block_device     *i_bdev;
685                 struct cdev             *i_cdev;
686                 char                    *i_link;
687                 unsigned                i_dir_seq;
688         };
689 
690         __u32                   i_generation;
691 
692 #ifdef CONFIG_FSNOTIFY
693         __u32                   i_fsnotify_mask; /* all events this inode cares about */
694         struct hlist_head       i_fsnotify_marks;
695 #endif
696 
697 #if IS_ENABLED(CONFIG_FS_ENCRYPTION)
698         struct fscrypt_info     *i_crypt_info;
699 #endif
700 
701         void                    *i_private; /* fs or device private pointer */
702 };
703 
704 static inline int inode_unhashed(struct inode *inode)
705 {
706         return hlist_unhashed(&inode->i_hash);
707 }
708 
709 /*
710  * inode->i_mutex nesting subclasses for the lock validator:
711  *
712  * 0: the object of the current VFS operation
713  * 1: parent
714  * 2: child/target
715  * 3: xattr
716  * 4: second non-directory
717  * 5: second parent (when locking independent directories in rename)
718  *
719  * I_MUTEX_NONDIR2 is for certain operations (such as rename) which lock two
720  * non-directories at once.
721  *
722  * The locking order between these classes is
723  * parent[2] -> child -> grandchild -> normal -> xattr -> second non-directory
724  */
725 enum inode_i_mutex_lock_class
726 {
727         I_MUTEX_NORMAL,
728         I_MUTEX_PARENT,
729         I_MUTEX_CHILD,
730         I_MUTEX_XATTR,
731         I_MUTEX_NONDIR2,
732         I_MUTEX_PARENT2,
733 };
734 
735 static inline void inode_lock(struct inode *inode)
736 {
737         down_write(&inode->i_rwsem);
738 }
739 
740 static inline void inode_unlock(struct inode *inode)
741 {
742         up_write(&inode->i_rwsem);
743 }
744 
745 static inline void inode_lock_shared(struct inode *inode)
746 {
747         down_read(&inode->i_rwsem);
748 }
749 
750 static inline void inode_unlock_shared(struct inode *inode)
751 {
752         up_read(&inode->i_rwsem);
753 }
754 
755 static inline int inode_trylock(struct inode *inode)
756 {
757         return down_write_trylock(&inode->i_rwsem);
758 }
759 
760 static inline int inode_trylock_shared(struct inode *inode)
761 {
762         return down_read_trylock(&inode->i_rwsem);
763 }
764 
765 static inline int inode_is_locked(struct inode *inode)
766 {
767         return rwsem_is_locked(&inode->i_rwsem);
768 }
769 
770 static inline void inode_lock_nested(struct inode *inode, unsigned subclass)
771 {
772         down_write_nested(&inode->i_rwsem, subclass);
773 }
774 
775 void lock_two_nondirectories(struct inode *, struct inode*);
776 void unlock_two_nondirectories(struct inode *, struct inode*);
777 
778 /*
779  * NOTE: in a 32bit arch with a preemptable kernel and
780  * an UP compile the i_size_read/write must be atomic
781  * with respect to the local cpu (unlike with preempt disabled),
782  * but they don't need to be atomic with respect to other cpus like in
783  * true SMP (so they need either to either locally disable irq around
784  * the read or for example on x86 they can be still implemented as a
785  * cmpxchg8b without the need of the lock prefix). For SMP compiles
786  * and 64bit archs it makes no difference if preempt is enabled or not.
787  */
788 static inline loff_t i_size_read(const struct inode *inode)
789 {
790 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
791         loff_t i_size;
792         unsigned int seq;
793 
794         do {
795                 seq = read_seqcount_begin(&inode->i_size_seqcount);
796                 i_size = inode->i_size;
797         } while (read_seqcount_retry(&inode->i_size_seqcount, seq));
798         return i_size;
799 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
800         loff_t i_size;
801 
802         preempt_disable();
803         i_size = inode->i_size;
804         preempt_enable();
805         return i_size;
806 #else
807         return inode->i_size;
808 #endif
809 }
810 
811 /*
812  * NOTE: unlike i_size_read(), i_size_write() does need locking around it
813  * (normally i_mutex), otherwise on 32bit/SMP an update of i_size_seqcount
814  * can be lost, resulting in subsequent i_size_read() calls spinning forever.
815  */
816 static inline void i_size_write(struct inode *inode, loff_t i_size)
817 {
818 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
819         preempt_disable();
820         write_seqcount_begin(&inode->i_size_seqcount);
821         inode->i_size = i_size;
822         write_seqcount_end(&inode->i_size_seqcount);
823         preempt_enable();
824 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
825         preempt_disable();
826         inode->i_size = i_size;
827         preempt_enable();
828 #else
829         inode->i_size = i_size;
830 #endif
831 }
832 
833 static inline unsigned iminor(const struct inode *inode)
834 {
835         return MINOR(inode->i_rdev);
836 }
837 
838 static inline unsigned imajor(const struct inode *inode)
839 {
840         return MAJOR(inode->i_rdev);
841 }
842 
843 extern struct block_device *I_BDEV(struct inode *inode);
844 
845 struct fown_struct {
846         rwlock_t lock;          /* protects pid, uid, euid fields */
847         struct pid *pid;        /* pid or -pgrp where SIGIO should be sent */
848         enum pid_type pid_type; /* Kind of process group SIGIO should be sent to */
849         kuid_t uid, euid;       /* uid/euid of process setting the owner */
850         int signum;             /* posix.1b rt signal to be delivered on IO */
851 };
852 
853 /*
854  * Track a single file's readahead state
855  */
856 struct file_ra_state {
857         pgoff_t start;                  /* where readahead started */
858         unsigned int size;              /* # of readahead pages */
859         unsigned int async_size;        /* do asynchronous readahead when
860                                            there are only # of pages ahead */
861 
862         unsigned int ra_pages;          /* Maximum readahead window */
863         unsigned int mmap_miss;         /* Cache miss stat for mmap accesses */
864         loff_t prev_pos;                /* Cache last read() position */
865 };
866 
867 /*
868  * Check if @index falls in the readahead windows.
869  */
870 static inline int ra_has_index(struct file_ra_state *ra, pgoff_t index)
871 {
872         return (index >= ra->start &&
873                 index <  ra->start + ra->size);
874 }
875 
876 struct file {
877         union {
878                 struct llist_node       fu_llist;
879                 struct rcu_head         fu_rcuhead;
880         } f_u;
881         struct path             f_path;
882         struct inode            *f_inode;       /* cached value */
883         const struct file_operations    *f_op;
884 
885         /*
886          * Protects f_ep_links, f_flags.
887          * Must not be taken from IRQ context.
888          */
889         spinlock_t              f_lock;
890         atomic_long_t           f_count;
891         unsigned int            f_flags;
892         fmode_t                 f_mode;
893         struct mutex            f_pos_lock;
894         loff_t                  f_pos;
895         struct fown_struct      f_owner;
896         const struct cred       *f_cred;
897         struct file_ra_state    f_ra;
898 
899         u64                     f_version;
900 #ifdef CONFIG_SECURITY
901         void                    *f_security;
902 #endif
903         /* needed for tty driver, and maybe others */
904         void                    *private_data;
905 
906 #ifdef CONFIG_EPOLL
907         /* Used by fs/eventpoll.c to link all the hooks to this file */
908         struct list_head        f_ep_links;
909         struct list_head        f_tfile_llink;
910 #endif /* #ifdef CONFIG_EPOLL */
911         struct address_space    *f_mapping;
912 } __attribute__((aligned(4)));  /* lest something weird decides that 2 is OK */
913 
914 struct file_handle {
915         __u32 handle_bytes;
916         int handle_type;
917         /* file identifier */
918         unsigned char f_handle[0];
919 };
920 
921 static inline struct file *get_file(struct file *f)
922 {
923         atomic_long_inc(&f->f_count);
924         return f;
925 }
926 #define get_file_rcu(x) atomic_long_inc_not_zero(&(x)->f_count)
927 #define fput_atomic(x)  atomic_long_add_unless(&(x)->f_count, -1, 1)
928 #define file_count(x)   atomic_long_read(&(x)->f_count)
929 
930 #define MAX_NON_LFS     ((1UL<<31) - 1)
931 
932 /* Page cache limit. The filesystems should put that into their s_maxbytes 
933    limits, otherwise bad things can happen in VM. */ 
934 #if BITS_PER_LONG==32
935 #define MAX_LFS_FILESIZE        (((loff_t)PAGE_SIZE << (BITS_PER_LONG-1))-1)
936 #elif BITS_PER_LONG==64
937 #define MAX_LFS_FILESIZE        ((loff_t)0x7fffffffffffffffLL)
938 #endif
939 
940 #define FL_POSIX        1
941 #define FL_FLOCK        2
942 #define FL_DELEG        4       /* NFSv4 delegation */
943 #define FL_ACCESS       8       /* not trying to lock, just looking */
944 #define FL_EXISTS       16      /* when unlocking, test for existence */
945 #define FL_LEASE        32      /* lease held on this file */
946 #define FL_CLOSE        64      /* unlock on close */
947 #define FL_SLEEP        128     /* A blocking lock */
948 #define FL_DOWNGRADE_PENDING    256 /* Lease is being downgraded */
949 #define FL_UNLOCK_PENDING       512 /* Lease is being broken */
950 #define FL_OFDLCK       1024    /* lock is "owned" by struct file */
951 #define FL_LAYOUT       2048    /* outstanding pNFS layout */
952 
953 /*
954  * Special return value from posix_lock_file() and vfs_lock_file() for
955  * asynchronous locking.
956  */
957 #define FILE_LOCK_DEFERRED 1
958 
959 /* legacy typedef, should eventually be removed */
960 typedef void *fl_owner_t;
961 
962 struct file_lock;
963 
964 struct file_lock_operations {
965         void (*fl_copy_lock)(struct file_lock *, struct file_lock *);
966         void (*fl_release_private)(struct file_lock *);
967 };
968 
969 struct lock_manager_operations {
970         int (*lm_compare_owner)(struct file_lock *, struct file_lock *);
971         unsigned long (*lm_owner_key)(struct file_lock *);
972         fl_owner_t (*lm_get_owner)(fl_owner_t);
973         void (*lm_put_owner)(fl_owner_t);
974         void (*lm_notify)(struct file_lock *);  /* unblock callback */
975         int (*lm_grant)(struct file_lock *, int);
976         bool (*lm_break)(struct file_lock *);
977         int (*lm_change)(struct file_lock *, int, struct list_head *);
978         void (*lm_setup)(struct file_lock *, void **);
979 };
980 
981 struct lock_manager {
982         struct list_head list;
983         /*
984          * NFSv4 and up also want opens blocked during the grace period;
985          * NLM doesn't care:
986          */
987         bool block_opens;
988 };
989 
990 struct net;
991 void locks_start_grace(struct net *, struct lock_manager *);
992 void locks_end_grace(struct lock_manager *);
993 int locks_in_grace(struct net *);
994 int opens_in_grace(struct net *);
995 
996 /* that will die - we need it for nfs_lock_info */
997 #include <linux/nfs_fs_i.h>
998 
999 /*
1000  * struct file_lock represents a generic "file lock". It's used to represent
1001  * POSIX byte range locks, BSD (flock) locks, and leases. It's important to
1002  * note that the same struct is used to represent both a request for a lock and
1003  * the lock itself, but the same object is never used for both.
1004  *
1005  * FIXME: should we create a separate "struct lock_request" to help distinguish
1006  * these two uses?
1007  *
1008  * The varous i_flctx lists are ordered by:
1009  *
1010  * 1) lock owner
1011  * 2) lock range start
1012  * 3) lock range end
1013  *
1014  * Obviously, the last two criteria only matter for POSIX locks.
1015  */
1016 struct file_lock {
1017         struct file_lock *fl_next;      /* singly linked list for this inode  */
1018         struct list_head fl_list;       /* link into file_lock_context */
1019         struct hlist_node fl_link;      /* node in global lists */
1020         struct list_head fl_block;      /* circular list of blocked processes */
1021         fl_owner_t fl_owner;
1022         unsigned int fl_flags;
1023         unsigned char fl_type;
1024         unsigned int fl_pid;
1025         int fl_link_cpu;                /* what cpu's list is this on? */
1026         struct pid *fl_nspid;
1027         wait_queue_head_t fl_wait;
1028         struct file *fl_file;
1029         loff_t fl_start;
1030         loff_t fl_end;
1031 
1032         struct fasync_struct *  fl_fasync; /* for lease break notifications */
1033         /* for lease breaks: */
1034         unsigned long fl_break_time;
1035         unsigned long fl_downgrade_time;
1036 
1037         const struct file_lock_operations *fl_ops;      /* Callbacks for filesystems */
1038         const struct lock_manager_operations *fl_lmops; /* Callbacks for lockmanagers */
1039         union {
1040                 struct nfs_lock_info    nfs_fl;
1041                 struct nfs4_lock_info   nfs4_fl;
1042                 struct {
1043                         struct list_head link;  /* link in AFS vnode's pending_locks list */
1044                         int state;              /* state of grant or error if -ve */
1045                 } afs;
1046         } fl_u;
1047 };
1048 
1049 struct file_lock_context {
1050         spinlock_t              flc_lock;
1051         struct list_head        flc_flock;
1052         struct list_head        flc_posix;
1053         struct list_head        flc_lease;
1054 };
1055 
1056 /* The following constant reflects the upper bound of the file/locking space */
1057 #ifndef OFFSET_MAX
1058 #define INT_LIMIT(x)    (~((x)1 << (sizeof(x)*8 - 1)))
1059 #define OFFSET_MAX      INT_LIMIT(loff_t)
1060 #define OFFT_OFFSET_MAX INT_LIMIT(off_t)
1061 #endif
1062 
1063 #include <linux/fcntl.h>
1064 
1065 extern void send_sigio(struct fown_struct *fown, int fd, int band);
1066 
1067 #ifdef CONFIG_FILE_LOCKING
1068 extern int fcntl_getlk(struct file *, unsigned int, struct flock __user *);
1069 extern int fcntl_setlk(unsigned int, struct file *, unsigned int,
1070                         struct flock __user *);
1071 
1072 #if BITS_PER_LONG == 32
1073 extern int fcntl_getlk64(struct file *, unsigned int, struct flock64 __user *);
1074 extern int fcntl_setlk64(unsigned int, struct file *, unsigned int,
1075                         struct flock64 __user *);
1076 #endif
1077 
1078 extern int fcntl_setlease(unsigned int fd, struct file *filp, long arg);
1079 extern int fcntl_getlease(struct file *filp);
1080 
1081 /* fs/locks.c */
1082 void locks_free_lock_context(struct inode *inode);
1083 void locks_free_lock(struct file_lock *fl);
1084 extern void locks_init_lock(struct file_lock *);
1085 extern struct file_lock * locks_alloc_lock(void);
1086 extern void locks_copy_lock(struct file_lock *, struct file_lock *);
1087 extern void locks_copy_conflock(struct file_lock *, struct file_lock *);
1088 extern void locks_remove_posix(struct file *, fl_owner_t);
1089 extern void locks_remove_file(struct file *);
1090 extern void locks_release_private(struct file_lock *);
1091 extern void posix_test_lock(struct file *, struct file_lock *);
1092 extern int posix_lock_file(struct file *, struct file_lock *, struct file_lock *);
1093 extern int posix_unblock_lock(struct file_lock *);
1094 extern int vfs_test_lock(struct file *, struct file_lock *);
1095 extern int vfs_lock_file(struct file *, unsigned int, struct file_lock *, struct file_lock *);
1096 extern int vfs_cancel_lock(struct file *filp, struct file_lock *fl);
1097 extern int locks_lock_inode_wait(struct inode *inode, struct file_lock *fl);
1098 extern int __break_lease(struct inode *inode, unsigned int flags, unsigned int type);
1099 extern void lease_get_mtime(struct inode *, struct timespec *time);
1100 extern int generic_setlease(struct file *, long, struct file_lock **, void **priv);
1101 extern int vfs_setlease(struct file *, long, struct file_lock **, void **);
1102 extern int lease_modify(struct file_lock *, int, struct list_head *);
1103 struct files_struct;
1104 extern void show_fd_locks(struct seq_file *f,
1105                          struct file *filp, struct files_struct *files);
1106 #else /* !CONFIG_FILE_LOCKING */
1107 static inline int fcntl_getlk(struct file *file, unsigned int cmd,
1108                               struct flock __user *user)
1109 {
1110         return -EINVAL;
1111 }
1112 
1113 static inline int fcntl_setlk(unsigned int fd, struct file *file,
1114                               unsigned int cmd, struct flock __user *user)
1115 {
1116         return -EACCES;
1117 }
1118 
1119 #if BITS_PER_LONG == 32
1120 static inline int fcntl_getlk64(struct file *file, unsigned int cmd,
1121                                 struct flock64 __user *user)
1122 {
1123         return -EINVAL;
1124 }
1125 
1126 static inline int fcntl_setlk64(unsigned int fd, struct file *file,
1127                                 unsigned int cmd, struct flock64 __user *user)
1128 {
1129         return -EACCES;
1130 }
1131 #endif
1132 static inline int fcntl_setlease(unsigned int fd, struct file *filp, long arg)
1133 {
1134         return -EINVAL;
1135 }
1136 
1137 static inline int fcntl_getlease(struct file *filp)
1138 {
1139         return F_UNLCK;
1140 }
1141 
1142 static inline void
1143 locks_free_lock_context(struct inode *inode)
1144 {
1145 }
1146 
1147 static inline void locks_init_lock(struct file_lock *fl)
1148 {
1149         return;
1150 }
1151 
1152 static inline void locks_copy_conflock(struct file_lock *new, struct file_lock *fl)
1153 {
1154         return;
1155 }
1156 
1157 static inline void locks_copy_lock(struct file_lock *new, struct file_lock *fl)
1158 {
1159         return;
1160 }
1161 
1162 static inline void locks_remove_posix(struct file *filp, fl_owner_t owner)
1163 {
1164         return;
1165 }
1166 
1167 static inline void locks_remove_file(struct file *filp)
1168 {
1169         return;
1170 }
1171 
1172 static inline void posix_test_lock(struct file *filp, struct file_lock *fl)
1173 {
1174         return;
1175 }
1176 
1177 static inline int posix_lock_file(struct file *filp, struct file_lock *fl,
1178                                   struct file_lock *conflock)
1179 {
1180         return -ENOLCK;
1181 }
1182 
1183 static inline int posix_unblock_lock(struct file_lock *waiter)
1184 {
1185         return -ENOENT;
1186 }
1187 
1188 static inline int vfs_test_lock(struct file *filp, struct file_lock *fl)
1189 {
1190         return 0;
1191 }
1192 
1193 static inline int vfs_lock_file(struct file *filp, unsigned int cmd,
1194                                 struct file_lock *fl, struct file_lock *conf)
1195 {
1196         return -ENOLCK;
1197 }
1198 
1199 static inline int vfs_cancel_lock(struct file *filp, struct file_lock *fl)
1200 {
1201         return 0;
1202 }
1203 
1204 static inline int locks_lock_inode_wait(struct inode *inode, struct file_lock *fl)
1205 {
1206         return -ENOLCK;
1207 }
1208 
1209 static inline int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
1210 {
1211         return 0;
1212 }
1213 
1214 static inline void lease_get_mtime(struct inode *inode, struct timespec *time)
1215 {
1216         return;
1217 }
1218 
1219 static inline int generic_setlease(struct file *filp, long arg,
1220                                     struct file_lock **flp, void **priv)
1221 {
1222         return -EINVAL;
1223 }
1224 
1225 static inline int vfs_setlease(struct file *filp, long arg,
1226                                struct file_lock **lease, void **priv)
1227 {
1228         return -EINVAL;
1229 }
1230 
1231 static inline int lease_modify(struct file_lock *fl, int arg,
1232                                struct list_head *dispose)
1233 {
1234         return -EINVAL;
1235 }
1236 
1237 struct files_struct;
1238 static inline void show_fd_locks(struct seq_file *f,
1239                         struct file *filp, struct files_struct *files) {}
1240 #endif /* !CONFIG_FILE_LOCKING */
1241 
1242 static inline struct inode *file_inode(const struct file *f)
1243 {
1244         return f->f_inode;
1245 }
1246 
1247 static inline struct dentry *file_dentry(const struct file *file)
1248 {
1249         return d_real(file->f_path.dentry, file_inode(file), 0);
1250 }
1251 
1252 static inline int locks_lock_file_wait(struct file *filp, struct file_lock *fl)
1253 {
1254         return locks_lock_inode_wait(file_inode(filp), fl);
1255 }
1256 
1257 struct fasync_struct {
1258         spinlock_t              fa_lock;
1259         int                     magic;
1260         int                     fa_fd;
1261         struct fasync_struct    *fa_next; /* singly linked list */
1262         struct file             *fa_file;
1263         struct rcu_head         fa_rcu;
1264 };
1265 
1266 #define FASYNC_MAGIC 0x4601
1267 
1268 /* SMP safe fasync helpers: */
1269 extern int fasync_helper(int, struct file *, int, struct fasync_struct **);
1270 extern struct fasync_struct *fasync_insert_entry(int, struct file *, struct fasync_struct **, struct fasync_struct *);
1271 extern int fasync_remove_entry(struct file *, struct fasync_struct **);
1272 extern struct fasync_struct *fasync_alloc(void);
1273 extern void fasync_free(struct fasync_struct *);
1274 
1275 /* can be called from interrupts */
1276 extern void kill_fasync(struct fasync_struct **, int, int);
1277 
1278 extern void __f_setown(struct file *filp, struct pid *, enum pid_type, int force);
1279 extern void f_setown(struct file *filp, unsigned long arg, int force);
1280 extern void f_delown(struct file *filp);
1281 extern pid_t f_getown(struct file *filp);
1282 extern int send_sigurg(struct fown_struct *fown);
1283 
1284 struct mm_struct;
1285 
1286 /*
1287  *      Umount options
1288  */
1289 
1290 #define MNT_FORCE       0x00000001      /* Attempt to forcibily umount */
1291 #define MNT_DETACH      0x00000002      /* Just detach from the tree */
1292 #define MNT_EXPIRE      0x00000004      /* Mark for expiry */
1293 #define UMOUNT_NOFOLLOW 0x00000008      /* Don't follow symlink on umount */
1294 #define UMOUNT_UNUSED   0x80000000      /* Flag guaranteed to be unused */
1295 
1296 /* sb->s_iflags */
1297 #define SB_I_CGROUPWB   0x00000001      /* cgroup-aware writeback enabled */
1298 #define SB_I_NOEXEC     0x00000002      /* Ignore executables on this fs */
1299 #define SB_I_NODEV      0x00000004      /* Ignore devices on this fs */
1300 
1301 /* sb->s_iflags to limit user namespace mounts */
1302 #define SB_I_USERNS_VISIBLE             0x00000010 /* fstype already mounted */
1303 
1304 /* Possible states of 'frozen' field */
1305 enum {
1306         SB_UNFROZEN = 0,                /* FS is unfrozen */
1307         SB_FREEZE_WRITE = 1,            /* Writes, dir ops, ioctls frozen */
1308         SB_FREEZE_PAGEFAULT = 2,        /* Page faults stopped as well */
1309         SB_FREEZE_FS = 3,               /* For internal FS use (e.g. to stop
1310                                          * internal threads if needed) */
1311         SB_FREEZE_COMPLETE = 4,         /* ->freeze_fs finished successfully */
1312 };
1313 
1314 #define SB_FREEZE_LEVELS (SB_FREEZE_COMPLETE - 1)
1315 
1316 struct sb_writers {
1317         int                             frozen;         /* Is sb frozen? */
1318         wait_queue_head_t               wait_unfrozen;  /* for get_super_thawed() */
1319         struct percpu_rw_semaphore      rw_sem[SB_FREEZE_LEVELS];
1320 };
1321 
1322 struct super_block {
1323         struct list_head        s_list;         /* Keep this first */
1324         dev_t                   s_dev;          /* search index; _not_ kdev_t */
1325         unsigned char           s_blocksize_bits;
1326         unsigned long           s_blocksize;
1327         loff_t                  s_maxbytes;     /* Max file size */
1328         struct file_system_type *s_type;
1329         const struct super_operations   *s_op;
1330         const struct dquot_operations   *dq_op;
1331         const struct quotactl_ops       *s_qcop;
1332         const struct export_operations *s_export_op;
1333         unsigned long           s_flags;
1334         unsigned long           s_iflags;       /* internal SB_I_* flags */
1335         unsigned long           s_magic;
1336         struct dentry           *s_root;
1337         struct rw_semaphore     s_umount;
1338         int                     s_count;
1339         atomic_t                s_active;
1340 #ifdef CONFIG_SECURITY
1341         void                    *s_security;
1342 #endif
1343         const struct xattr_handler **s_xattr;
1344 
1345         const struct fscrypt_operations *s_cop;
1346 
1347         struct hlist_bl_head    s_anon;         /* anonymous dentries for (nfs) exporting */
1348         struct list_head        s_mounts;       /* list of mounts; _not_ for fs use */
1349         struct block_device     *s_bdev;
1350         struct backing_dev_info *s_bdi;
1351         struct mtd_info         *s_mtd;
1352         struct hlist_node       s_instances;
1353         unsigned int            s_quota_types;  /* Bitmask of supported quota types */
1354         struct quota_info       s_dquot;        /* Diskquota specific options */
1355 
1356         struct sb_writers       s_writers;
1357 
1358         char s_id[32];                          /* Informational name */
1359         u8 s_uuid[16];                          /* UUID */
1360 
1361         void                    *s_fs_info;     /* Filesystem private info */
1362         unsigned int            s_max_links;
1363         fmode_t                 s_mode;
1364 
1365         /* Granularity of c/m/atime in ns.
1366            Cannot be worse than a second */
1367         u32                s_time_gran;
1368 
1369         /*
1370          * The next field is for VFS *only*. No filesystems have any business
1371          * even looking at it. You had been warned.
1372          */
1373         struct mutex s_vfs_rename_mutex;        /* Kludge */
1374 
1375         /*
1376          * Filesystem subtype.  If non-empty the filesystem type field
1377          * in /proc/mounts will be "type.subtype"
1378          */
1379         char *s_subtype;
1380 
1381         /*
1382          * Saved mount options for lazy filesystems using
1383          * generic_show_options()
1384          */
1385         char __rcu *s_options;
1386         const struct dentry_operations *s_d_op; /* default d_op for dentries */
1387 
1388         /*
1389          * Saved pool identifier for cleancache (-1 means none)
1390          */
1391         int cleancache_poolid;
1392 
1393         struct shrinker s_shrink;       /* per-sb shrinker handle */
1394 
1395         /* Number of inodes with nlink == 0 but still referenced */
1396         atomic_long_t s_remove_count;
1397 
1398         /* Being remounted read-only */
1399         int s_readonly_remount;
1400 
1401         /* AIO completions deferred from interrupt context */
1402         struct workqueue_struct *s_dio_done_wq;
1403         struct hlist_head s_pins;
1404 
1405         /*
1406          * Owning user namespace and default context in which to
1407          * interpret filesystem uids, gids, quotas, device nodes,
1408          * xattrs and security labels.
1409          */
1410         struct user_namespace *s_user_ns;
1411 
1412         /*
1413          * Keep the lru lists last in the structure so they always sit on their
1414          * own individual cachelines.
1415          */
1416         struct list_lru         s_dentry_lru ____cacheline_aligned_in_smp;
1417         struct list_lru         s_inode_lru ____cacheline_aligned_in_smp;
1418         struct rcu_head         rcu;
1419         struct work_struct      destroy_work;
1420 
1421         struct mutex            s_sync_lock;    /* sync serialisation lock */
1422 
1423         /*
1424          * Indicates how deep in a filesystem stack this SB is
1425          */
1426         int s_stack_depth;
1427 
1428         /* s_inode_list_lock protects s_inodes */
1429         spinlock_t              s_inode_list_lock ____cacheline_aligned_in_smp;
1430         struct list_head        s_inodes;       /* all inodes */
1431 
1432         spinlock_t              s_inode_wblist_lock;
1433         struct list_head        s_inodes_wb;    /* writeback inodes */
1434 };
1435 
1436 /* Helper functions so that in most cases filesystems will
1437  * not need to deal directly with kuid_t and kgid_t and can
1438  * instead deal with the raw numeric values that are stored
1439  * in the filesystem.
1440  */
1441 static inline uid_t i_uid_read(const struct inode *inode)
1442 {
1443         return from_kuid(inode->i_sb->s_user_ns, inode->i_uid);
1444 }
1445 
1446 static inline gid_t i_gid_read(const struct inode *inode)
1447 {
1448         return from_kgid(inode->i_sb->s_user_ns, inode->i_gid);
1449 }
1450 
1451 static inline void i_uid_write(struct inode *inode, uid_t uid)
1452 {
1453         inode->i_uid = make_kuid(inode->i_sb->s_user_ns, uid);
1454 }
1455 
1456 static inline void i_gid_write(struct inode *inode, gid_t gid)
1457 {
1458         inode->i_gid = make_kgid(inode->i_sb->s_user_ns, gid);
1459 }
1460 
1461 extern struct timespec current_fs_time(struct super_block *sb);
1462 
1463 /*
1464  * Snapshotting support.
1465  */
1466 
1467 void __sb_end_write(struct super_block *sb, int level);
1468 int __sb_start_write(struct super_block *sb, int level, bool wait);
1469 
1470 #define __sb_writers_acquired(sb, lev)  \
1471         percpu_rwsem_acquire(&(sb)->s_writers.rw_sem[(lev)-1], 1, _THIS_IP_)
1472 #define __sb_writers_release(sb, lev)   \
1473         percpu_rwsem_release(&(sb)->s_writers.rw_sem[(lev)-1], 1, _THIS_IP_)
1474 
1475 /**
1476  * sb_end_write - drop write access to a superblock
1477  * @sb: the super we wrote to
1478  *
1479  * Decrement number of writers to the filesystem. Wake up possible waiters
1480  * wanting to freeze the filesystem.
1481  */
1482 static inline void sb_end_write(struct super_block *sb)
1483 {
1484         __sb_end_write(sb, SB_FREEZE_WRITE);
1485 }
1486 
1487 /**
1488  * sb_end_pagefault - drop write access to a superblock from a page fault
1489  * @sb: the super we wrote to
1490  *
1491  * Decrement number of processes handling write page fault to the filesystem.
1492  * Wake up possible waiters wanting to freeze the filesystem.
1493  */
1494 static inline void sb_end_pagefault(struct super_block *sb)
1495 {
1496         __sb_end_write(sb, SB_FREEZE_PAGEFAULT);
1497 }
1498 
1499 /**
1500  * sb_end_intwrite - drop write access to a superblock for internal fs purposes
1501  * @sb: the super we wrote to
1502  *
1503  * Decrement fs-internal number of writers to the filesystem.  Wake up possible
1504  * waiters wanting to freeze the filesystem.
1505  */
1506 static inline void sb_end_intwrite(struct super_block *sb)
1507 {
1508         __sb_end_write(sb, SB_FREEZE_FS);
1509 }
1510 
1511 /**
1512  * sb_start_write - get write access to a superblock
1513  * @sb: the super we write to
1514  *
1515  * When a process wants to write data or metadata to a file system (i.e. dirty
1516  * a page or an inode), it should embed the operation in a sb_start_write() -
1517  * sb_end_write() pair to get exclusion against file system freezing. This
1518  * function increments number of writers preventing freezing. If the file
1519  * system is already frozen, the function waits until the file system is
1520  * thawed.
1521  *
1522  * Since freeze protection behaves as a lock, users have to preserve
1523  * ordering of freeze protection and other filesystem locks. Generally,
1524  * freeze protection should be the outermost lock. In particular, we have:
1525  *
1526  * sb_start_write
1527  *   -> i_mutex                 (write path, truncate, directory ops, ...)
1528  *   -> s_umount                (freeze_super, thaw_super)
1529  */
1530 static inline void sb_start_write(struct super_block *sb)
1531 {
1532         __sb_start_write(sb, SB_FREEZE_WRITE, true);
1533 }
1534 
1535 static inline int sb_start_write_trylock(struct super_block *sb)
1536 {
1537         return __sb_start_write(sb, SB_FREEZE_WRITE, false);
1538 }
1539 
1540 /**
1541  * sb_start_pagefault - get write access to a superblock from a page fault
1542  * @sb: the super we write to
1543  *
1544  * When a process starts handling write page fault, it should embed the
1545  * operation into sb_start_pagefault() - sb_end_pagefault() pair to get
1546  * exclusion against file system freezing. This is needed since the page fault
1547  * is going to dirty a page. This function increments number of running page
1548  * faults preventing freezing. If the file system is already frozen, the
1549  * function waits until the file system is thawed.
1550  *
1551  * Since page fault freeze protection behaves as a lock, users have to preserve
1552  * ordering of freeze protection and other filesystem locks. It is advised to
1553  * put sb_start_pagefault() close to mmap_sem in lock ordering. Page fault
1554  * handling code implies lock dependency:
1555  *
1556  * mmap_sem
1557  *   -> sb_start_pagefault
1558  */
1559 static inline void sb_start_pagefault(struct super_block *sb)
1560 {
1561         __sb_start_write(sb, SB_FREEZE_PAGEFAULT, true);
1562 }
1563 
1564 /*
1565  * sb_start_intwrite - get write access to a superblock for internal fs purposes
1566  * @sb: the super we write to
1567  *
1568  * This is the third level of protection against filesystem freezing. It is
1569  * free for use by a filesystem. The only requirement is that it must rank
1570  * below sb_start_pagefault.
1571  *
1572  * For example filesystem can call sb_start_intwrite() when starting a
1573  * transaction which somewhat eases handling of freezing for internal sources
1574  * of filesystem changes (internal fs threads, discarding preallocation on file
1575  * close, etc.).
1576  */
1577 static inline void sb_start_intwrite(struct super_block *sb)
1578 {
1579         __sb_start_write(sb, SB_FREEZE_FS, true);
1580 }
1581 
1582 
1583 extern bool inode_owner_or_capable(const struct inode *inode);
1584 
1585 /*
1586  * VFS helper functions..
1587  */
1588 extern int vfs_create(struct inode *, struct dentry *, umode_t, bool);
1589 extern int vfs_mkdir(struct inode *, struct dentry *, umode_t);
1590 extern int vfs_mknod(struct inode *, struct dentry *, umode_t, dev_t);
1591 extern int vfs_symlink(struct inode *, struct dentry *, const char *);
1592 extern int vfs_link(struct dentry *, struct inode *, struct dentry *, struct inode **);
1593 extern int vfs_rmdir(struct inode *, struct dentry *);
1594 extern int vfs_unlink(struct inode *, struct dentry *, struct inode **);
1595 extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *, struct inode **, unsigned int);
1596 extern int vfs_whiteout(struct inode *, struct dentry *);
1597 
1598 /*
1599  * VFS file helper functions.
1600  */
1601 extern void inode_init_owner(struct inode *inode, const struct inode *dir,
1602                         umode_t mode);
1603 extern bool may_open_dev(const struct path *path);
1604 /*
1605  * VFS FS_IOC_FIEMAP helper definitions.
1606  */
1607 struct fiemap_extent_info {
1608         unsigned int fi_flags;          /* Flags as passed from user */
1609         unsigned int fi_extents_mapped; /* Number of mapped extents */
1610         unsigned int fi_extents_max;    /* Size of fiemap_extent array */
1611         struct fiemap_extent __user *fi_extents_start; /* Start of
1612                                                         fiemap_extent array */
1613 };
1614 int fiemap_fill_next_extent(struct fiemap_extent_info *info, u64 logical,
1615                             u64 phys, u64 len, u32 flags);
1616 int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags);
1617 
1618 /*
1619  * File types
1620  *
1621  * NOTE! These match bits 12..15 of stat.st_mode
1622  * (ie "(i_mode >> 12) & 15").
1623  */
1624 #define DT_UNKNOWN      0
1625 #define DT_FIFO         1
1626 #define DT_CHR          2
1627 #define DT_DIR          4
1628 #define DT_BLK          6
1629 #define DT_REG          8
1630 #define DT_LNK          10
1631 #define DT_SOCK         12
1632 #define DT_WHT          14
1633 
1634 /*
1635  * This is the "filldir" function type, used by readdir() to let
1636  * the kernel specify what kind of dirent layout it wants to have.
1637  * This allows the kernel to read directories into kernel space or
1638  * to have different dirent layouts depending on the binary type.
1639  */
1640 struct dir_context;
1641 typedef int (*filldir_t)(struct dir_context *, const char *, int, loff_t, u64,
1642                          unsigned);
1643 
1644 struct dir_context {
1645         const filldir_t actor;
1646         loff_t pos;
1647 };
1648 
1649 struct block_device_operations;
1650 
1651 /* These macros are for out of kernel modules to test that
1652  * the kernel supports the unlocked_ioctl and compat_ioctl
1653  * fields in struct file_operations. */
1654 #define HAVE_COMPAT_IOCTL 1
1655 #define HAVE_UNLOCKED_IOCTL 1
1656 
1657 /*
1658  * These flags let !MMU mmap() govern direct device mapping vs immediate
1659  * copying more easily for MAP_PRIVATE, especially for ROM filesystems.
1660  *
1661  * NOMMU_MAP_COPY:      Copy can be mapped (MAP_PRIVATE)
1662  * NOMMU_MAP_DIRECT:    Can be mapped directly (MAP_SHARED)
1663  * NOMMU_MAP_READ:      Can be mapped for reading
1664  * NOMMU_MAP_WRITE:     Can be mapped for writing
1665  * NOMMU_MAP_EXEC:      Can be mapped for execution
1666  */
1667 #define NOMMU_MAP_COPY          0x00000001
1668 #define NOMMU_MAP_DIRECT        0x00000008
1669 #define NOMMU_MAP_READ          VM_MAYREAD
1670 #define NOMMU_MAP_WRITE         VM_MAYWRITE
1671 #define NOMMU_MAP_EXEC          VM_MAYEXEC
1672 
1673 #define NOMMU_VMFLAGS \
1674         (NOMMU_MAP_READ | NOMMU_MAP_WRITE | NOMMU_MAP_EXEC)
1675 
1676 
1677 struct iov_iter;
1678 
1679 struct file_operations {
1680         struct module *owner;
1681         loff_t (*llseek) (struct file *, loff_t, int);
1682         ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
1683         ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
1684         ssize_t (*read_iter) (struct kiocb *, struct iov_iter *);
1685         ssize_t (*write_iter) (struct kiocb *, struct iov_iter *);
1686         int (*iterate) (struct file *, struct dir_context *);
1687         int (*iterate_shared) (struct file *, struct dir_context *);
1688         unsigned int (*poll) (struct file *, struct poll_table_struct *);
1689         long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
1690         long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
1691         int (*mmap) (struct file *, struct vm_area_struct *);
1692         int (*open) (struct inode *, struct file *);
1693         int (*flush) (struct file *, fl_owner_t id);
1694         int (*release) (struct inode *, struct file *);
1695         int (*fsync) (struct file *, loff_t, loff_t, int datasync);
1696         int (*aio_fsync) (struct kiocb *, int datasync);
1697         int (*fasync) (int, struct file *, int);
1698         int (*lock) (struct file *, int, struct file_lock *);
1699         ssize_t (*sendpage) (struct file *, struct page *, int, size_t, loff_t *, int);
1700         unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
1701         int (*check_flags)(int);
1702         int (*flock) (struct file *, int, struct file_lock *);
1703         ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int);
1704         ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int);
1705         int (*setlease)(struct file *, long, struct file_lock **, void **);
1706         long (*fallocate)(struct file *file, int mode, loff_t offset,
1707                           loff_t len);
1708         void (*show_fdinfo)(struct seq_file *m, struct file *f);
1709 #ifndef CONFIG_MMU
1710         unsigned (*mmap_capabilities)(struct file *);
1711 #endif
1712         ssize_t (*copy_file_range)(struct file *, loff_t, struct file *,
1713                         loff_t, size_t, unsigned int);
1714         int (*clone_file_range)(struct file *, loff_t, struct file *, loff_t,
1715                         u64);
1716         ssize_t (*dedupe_file_range)(struct file *, u64, u64, struct file *,
1717                         u64);
1718 };
1719 
1720 struct inode_operations {
1721         struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int);
1722         const char * (*get_link) (struct dentry *, struct inode *, struct delayed_call *);
1723         int (*permission) (struct inode *, int);
1724         struct posix_acl * (*get_acl)(struct inode *, int);
1725 
1726         int (*readlink) (struct dentry *, char __user *,int);
1727 
1728         int (*create) (struct inode *,struct dentry *, umode_t, bool);
1729         int (*link) (struct dentry *,struct inode *,struct dentry *);
1730         int (*unlink) (struct inode *,struct dentry *);
1731         int (*symlink) (struct inode *,struct dentry *,const char *);
1732         int (*mkdir) (struct inode *,struct dentry *,umode_t);
1733         int (*rmdir) (struct inode *,struct dentry *);
1734         int (*mknod) (struct inode *,struct dentry *,umode_t,dev_t);
1735         int (*rename) (struct inode *, struct dentry *,
1736                         struct inode *, struct dentry *);
1737         int (*rename2) (struct inode *, struct dentry *,
1738                         struct inode *, struct dentry *, unsigned int);
1739         int (*setattr) (struct dentry *, struct iattr *);
1740         int (*getattr) (struct vfsmount *mnt, struct dentry *, struct kstat *);
1741         int (*setxattr) (struct dentry *, struct inode *,
1742                          const char *, const void *, size_t, int);
1743         ssize_t (*getxattr) (struct dentry *, struct inode *,
1744                              const char *, void *, size_t);
1745         ssize_t (*listxattr) (struct dentry *, char *, size_t);
1746         int (*removexattr) (struct dentry *, const char *);
1747         int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start,
1748                       u64 len);
1749         int (*update_time)(struct inode *, struct timespec *, int);
1750         int (*atomic_open)(struct inode *, struct dentry *,
1751                            struct file *, unsigned open_flag,
1752                            umode_t create_mode, int *opened);
1753         int (*tmpfile) (struct inode *, struct dentry *, umode_t);
1754         int (*set_acl)(struct inode *, struct posix_acl *, int);
1755 } ____cacheline_aligned;
1756 
1757 ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
1758                               unsigned long nr_segs, unsigned long fast_segs,
1759                               struct iovec *fast_pointer,
1760                               struct iovec **ret_pointer);
1761 
1762 extern ssize_t __vfs_read(struct file *, char __user *, size_t, loff_t *);
1763 extern ssize_t __vfs_write(struct file *, const char __user *, size_t, loff_t *);
1764 extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *);
1765 extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *);
1766 extern ssize_t vfs_readv(struct file *, const struct iovec __user *,
1767                 unsigned long, loff_t *, int);
1768 extern ssize_t vfs_writev(struct file *, const struct iovec __user *,
1769                 unsigned long, loff_t *, int);
1770 extern ssize_t vfs_copy_file_range(struct file *, loff_t , struct file *,
1771                                    loff_t, size_t, unsigned int);
1772 extern int vfs_clone_file_range(struct file *file_in, loff_t pos_in,
1773                 struct file *file_out, loff_t pos_out, u64 len);
1774 extern int vfs_dedupe_file_range(struct file *file,
1775                                  struct file_dedupe_range *same);
1776 
1777 struct super_operations {
1778         struct inode *(*alloc_inode)(struct super_block *sb);
1779         void (*destroy_inode)(struct inode *);
1780 
1781         void (*dirty_inode) (struct inode *, int flags);
1782         int (*write_inode) (struct inode *, struct writeback_control *wbc);
1783         int (*drop_inode) (struct inode *);
1784         void (*evict_inode) (struct inode *);
1785         void (*put_super) (struct super_block *);
1786         int (*sync_fs)(struct super_block *sb, int wait);
1787         int (*freeze_super) (struct super_block *);
1788         int (*freeze_fs) (struct super_block *);
1789         int (*thaw_super) (struct super_block *);
1790         int (*unfreeze_fs) (struct super_block *);
1791         int (*statfs) (struct dentry *, struct kstatfs *);
1792         int (*remount_fs) (struct super_block *, int *, char *);
1793         void (*umount_begin) (struct super_block *);
1794 
1795         int (*show_options)(struct seq_file *, struct dentry *);
1796         int (*show_devname)(struct seq_file *, struct dentry *);
1797         int (*show_path)(struct seq_file *, struct dentry *);
1798         int (*show_stats)(struct seq_file *, struct dentry *);
1799 #ifdef CONFIG_QUOTA
1800         ssize_t (*quota_read)(struct super_block *, int, char *, size_t, loff_t);
1801         ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t);
1802         struct dquot **(*get_dquots)(struct inode *);
1803 #endif
1804         int (*bdev_try_to_free_page)(struct super_block*, struct page*, gfp_t);
1805         long (*nr_cached_objects)(struct super_block *,
1806                                   struct shrink_control *);
1807         long (*free_cached_objects)(struct super_block *,
1808                                     struct shrink_control *);
1809 };
1810 
1811 /*
1812  * Inode flags - they have no relation to superblock flags now
1813  */
1814 #define S_SYNC          1       /* Writes are synced at once */
1815 #define S_NOATIME       2       /* Do not update access times */
1816 #define S_APPEND        4       /* Append-only file */
1817 #define S_IMMUTABLE     8       /* Immutable file */
1818 #define S_DEAD          16      /* removed, but still open directory */
1819 #define S_NOQUOTA       32      /* Inode is not counted to quota */
1820 #define S_DIRSYNC       64      /* Directory modifications are synchronous */
1821 #define S_NOCMTIME      128     /* Do not update file c/mtime */
1822 #define S_SWAPFILE      256     /* Do not truncate: swapon got its bmaps */
1823 #define S_PRIVATE       512     /* Inode is fs-internal */
1824 #define S_IMA           1024    /* Inode has an associated IMA struct */
1825 #define S_AUTOMOUNT     2048    /* Automount/referral quasi-directory */
1826 #define S_NOSEC         4096    /* no suid or xattr security attributes */
1827 #ifdef CONFIG_FS_DAX
1828 #define S_DAX           8192    /* Direct Access, avoiding the page cache */
1829 #else
1830 #define S_DAX           0       /* Make all the DAX code disappear */
1831 #endif
1832 
1833 /*
1834  * Note that nosuid etc flags are inode-specific: setting some file-system
1835  * flags just means all the inodes inherit those flags by default. It might be
1836  * possible to override it selectively if you really wanted to with some
1837  * ioctl() that is not currently implemented.
1838  *
1839  * Exception: MS_RDONLY is always applied to the entire file system.
1840  *
1841  * Unfortunately, it is possible to change a filesystems flags with it mounted
1842  * with files in use.  This means that all of the inodes will not have their
1843  * i_flags updated.  Hence, i_flags no longer inherit the superblock mount
1844  * flags, so these have to be checked separately. -- rmk@arm.uk.linux.org
1845  */
1846 #define __IS_FLG(inode, flg)    ((inode)->i_sb->s_flags & (flg))
1847 
1848 #define IS_RDONLY(inode)        ((inode)->i_sb->s_flags & MS_RDONLY)
1849 #define IS_SYNC(inode)          (__IS_FLG(inode, MS_SYNCHRONOUS) || \
1850                                         ((inode)->i_flags & S_SYNC))
1851 #define IS_DIRSYNC(inode)       (__IS_FLG(inode, MS_SYNCHRONOUS|MS_DIRSYNC) || \
1852                                         ((inode)->i_flags & (S_SYNC|S_DIRSYNC)))
1853 #define IS_MANDLOCK(inode)      __IS_FLG(inode, MS_MANDLOCK)
1854 #define IS_NOATIME(inode)       __IS_FLG(inode, MS_RDONLY|MS_NOATIME)
1855 #define IS_I_VERSION(inode)     __IS_FLG(inode, MS_I_VERSION)
1856 
1857 #define IS_NOQUOTA(inode)       ((inode)->i_flags & S_NOQUOTA)
1858 #define IS_APPEND(inode)        ((inode)->i_flags & S_APPEND)
1859 #define IS_IMMUTABLE(inode)     ((inode)->i_flags & S_IMMUTABLE)
1860 #define IS_POSIXACL(inode)      __IS_FLG(inode, MS_POSIXACL)
1861 
1862 #define IS_DEADDIR(inode)       ((inode)->i_flags & S_DEAD)
1863 #define IS_NOCMTIME(inode)      ((inode)->i_flags & S_NOCMTIME)
1864 #define IS_SWAPFILE(inode)      ((inode)->i_flags & S_SWAPFILE)
1865 #define IS_PRIVATE(inode)       ((inode)->i_flags & S_PRIVATE)
1866 #define IS_IMA(inode)           ((inode)->i_flags & S_IMA)
1867 #define IS_AUTOMOUNT(inode)     ((inode)->i_flags & S_AUTOMOUNT)
1868 #define IS_NOSEC(inode)         ((inode)->i_flags & S_NOSEC)
1869 #define IS_DAX(inode)           ((inode)->i_flags & S_DAX)
1870 
1871 #define IS_WHITEOUT(inode)      (S_ISCHR(inode->i_mode) && \
1872                                  (inode)->i_rdev == WHITEOUT_DEV)
1873 
1874 static inline bool HAS_UNMAPPED_ID(struct inode *inode)
1875 {
1876         return !uid_valid(inode->i_uid) || !gid_valid(inode->i_gid);
1877 }
1878 
1879 /*
1880  * Inode state bits.  Protected by inode->i_lock
1881  *
1882  * Three bits determine the dirty state of the inode, I_DIRTY_SYNC,
1883  * I_DIRTY_DATASYNC and I_DIRTY_PAGES.
1884  *
1885  * Four bits define the lifetime of an inode.  Initially, inodes are I_NEW,
1886  * until that flag is cleared.  I_WILL_FREE, I_FREEING and I_CLEAR are set at
1887  * various stages of removing an inode.
1888  *
1889  * Two bits are used for locking and completion notification, I_NEW and I_SYNC.
1890  *
1891  * I_DIRTY_SYNC         Inode is dirty, but doesn't have to be written on
1892  *                      fdatasync().  i_atime is the usual cause.
1893  * I_DIRTY_DATASYNC     Data-related inode changes pending. We keep track of
1894  *                      these changes separately from I_DIRTY_SYNC so that we
1895  *                      don't have to write inode on fdatasync() when only
1896  *                      mtime has changed in it.
1897  * I_DIRTY_PAGES        Inode has dirty pages.  Inode itself may be clean.
1898  * I_NEW                Serves as both a mutex and completion notification.
1899  *                      New inodes set I_NEW.  If two processes both create
1900  *                      the same inode, one of them will release its inode and
1901  *                      wait for I_NEW to be released before returning.
1902  *                      Inodes in I_WILL_FREE, I_FREEING or I_CLEAR state can
1903  *                      also cause waiting on I_NEW, without I_NEW actually
1904  *                      being set.  find_inode() uses this to prevent returning
1905  *                      nearly-dead inodes.
1906  * I_WILL_FREE          Must be set when calling write_inode_now() if i_count
1907  *                      is zero.  I_FREEING must be set when I_WILL_FREE is
1908  *                      cleared.
1909  * I_FREEING            Set when inode is about to be freed but still has dirty
1910  *                      pages or buffers attached or the inode itself is still
1911  *                      dirty.
1912  * I_CLEAR              Added by clear_inode().  In this state the inode is
1913  *                      clean and can be destroyed.  Inode keeps I_FREEING.
1914  *
1915  *                      Inodes that are I_WILL_FREE, I_FREEING or I_CLEAR are
1916  *                      prohibited for many purposes.  iget() must wait for
1917  *                      the inode to be completely released, then create it
1918  *                      anew.  Other functions will just ignore such inodes,
1919  *                      if appropriate.  I_NEW is used for waiting.
1920  *
1921  * I_SYNC               Writeback of inode is running. The bit is set during
1922  *                      data writeback, and cleared with a wakeup on the bit
1923  *                      address once it is done. The bit is also used to pin
1924  *                      the inode in memory for flusher thread.
1925  *
1926  * I_REFERENCED         Marks the inode as recently references on the LRU list.
1927  *
1928  * I_DIO_WAKEUP         Never set.  Only used as a key for wait_on_bit().
1929  *
1930  * I_WB_SWITCH          Cgroup bdi_writeback switching in progress.  Used to
1931  *                      synchronize competing switching instances and to tell
1932  *                      wb stat updates to grab mapping->tree_lock.  See
1933  *                      inode_switch_wb_work_fn() for details.
1934  *
1935  * Q: What is the difference between I_WILL_FREE and I_FREEING?
1936  */
1937 #define I_DIRTY_SYNC            (1 << 0)
1938 #define I_DIRTY_DATASYNC        (1 << 1)
1939 #define I_DIRTY_PAGES           (1 << 2)
1940 #define __I_NEW                 3
1941 #define I_NEW                   (1 << __I_NEW)
1942 #define I_WILL_FREE             (1 << 4)
1943 #define I_FREEING               (1 << 5)
1944 #define I_CLEAR                 (1 << 6)
1945 #define __I_SYNC                7
1946 #define I_SYNC                  (1 << __I_SYNC)
1947 #define I_REFERENCED            (1 << 8)
1948 #define __I_DIO_WAKEUP          9
1949 #define I_DIO_WAKEUP            (1 << __I_DIO_WAKEUP)
1950 #define I_LINKABLE              (1 << 10)
1951 #define I_DIRTY_TIME            (1 << 11)
1952 #define __I_DIRTY_TIME_EXPIRED  12
1953 #define I_DIRTY_TIME_EXPIRED    (1 << __I_DIRTY_TIME_EXPIRED)
1954 #define I_WB_SWITCH             (1 << 13)
1955 
1956 #define I_DIRTY (I_DIRTY_SYNC | I_DIRTY_DATASYNC | I_DIRTY_PAGES)
1957 #define I_DIRTY_ALL (I_DIRTY | I_DIRTY_TIME)
1958 
1959 extern void __mark_inode_dirty(struct inode *, int);
1960 static inline void mark_inode_dirty(struct inode *inode)
1961 {
1962         __mark_inode_dirty(inode, I_DIRTY);
1963 }
1964 
1965 static inline void mark_inode_dirty_sync(struct inode *inode)
1966 {
1967         __mark_inode_dirty(inode, I_DIRTY_SYNC);
1968 }
1969 
1970 extern void inc_nlink(struct inode *inode);
1971 extern void drop_nlink(struct inode *inode);
1972 extern void clear_nlink(struct inode *inode);
1973 extern void set_nlink(struct inode *inode, unsigned int nlink);
1974 
1975 static inline void inode_inc_link_count(struct inode *inode)
1976 {
1977         inc_nlink(inode);
1978         mark_inode_dirty(inode);
1979 }
1980 
1981 static inline void inode_dec_link_count(struct inode *inode)
1982 {
1983         drop_nlink(inode);
1984         mark_inode_dirty(inode);
1985 }
1986 
1987 /**
1988  * inode_inc_iversion - increments i_version
1989  * @inode: inode that need to be updated
1990  *
1991  * Every time the inode is modified, the i_version field will be incremented.
1992  * The filesystem has to be mounted with i_version flag
1993  */
1994 
1995 static inline void inode_inc_iversion(struct inode *inode)
1996 {
1997        spin_lock(&inode->i_lock);
1998        inode->i_version++;
1999        spin_unlock(&inode->i_lock);
2000 }
2001 
2002 enum file_time_flags {
2003         S_ATIME = 1,
2004         S_MTIME = 2,
2005         S_CTIME = 4,
2006         S_VERSION = 8,
2007 };
2008 
2009 extern bool atime_needs_update(const struct path *, struct inode *);
2010 extern void touch_atime(const struct path *);
2011 static inline void file_accessed(struct file *file)
2012 {
2013         if (!(file->f_flags & O_NOATIME))
2014                 touch_atime(&file->f_path);
2015 }
2016 
2017 int sync_inode(struct inode *inode, struct writeback_control *wbc);
2018 int sync_inode_metadata(struct inode *inode, int wait);
2019 
2020 struct file_system_type {
2021         const char *name;
2022         int fs_flags;
2023 #define FS_REQUIRES_DEV         1 
2024 #define FS_BINARY_MOUNTDATA     2
2025 #define FS_HAS_SUBTYPE          4
2026 #define FS_USERNS_MOUNT         8       /* Can be mounted by userns root */
2027 #define FS_RENAME_DOES_D_MOVE   32768   /* FS will handle d_move() during rename() internally. */
2028         struct dentry *(*mount) (struct file_system_type *, int,
2029                        const char *, void *);
2030         void (*kill_sb) (struct super_block *);
2031         struct module *owner;
2032         struct file_system_type * next;
2033         struct hlist_head fs_supers;
2034 
2035         struct lock_class_key s_lock_key;
2036         struct lock_class_key s_umount_key;
2037         struct lock_class_key s_vfs_rename_key;
2038         struct lock_class_key s_writers_key[SB_FREEZE_LEVELS];
2039 
2040         struct lock_class_key i_lock_key;
2041         struct lock_class_key i_mutex_key;
2042         struct lock_class_key i_mutex_dir_key;
2043 };
2044 
2045 #define MODULE_ALIAS_FS(NAME) MODULE_ALIAS("fs-" NAME)
2046 
2047 extern struct dentry *mount_ns(struct file_system_type *fs_type,
2048         int flags, void *data, void *ns, struct user_namespace *user_ns,
2049         int (*fill_super)(struct super_block *, void *, int));
2050 extern struct dentry *mount_bdev(struct file_system_type *fs_type,
2051         int flags, const char *dev_name, void *data,
2052         int (*fill_super)(struct super_block *, void *, int));
2053 extern struct dentry *mount_single(struct file_system_type *fs_type,
2054         int flags, void *data,
2055         int (*fill_super)(struct super_block *, void *, int));
2056 extern struct dentry *mount_nodev(struct file_system_type *fs_type,
2057         int flags, void *data,
2058         int (*fill_super)(struct super_block *, void *, int));
2059 extern struct dentry *mount_subtree(struct vfsmount *mnt, const char *path);
2060 void generic_shutdown_super(struct super_block *sb);
2061 void kill_block_super(struct super_block *sb);
2062 void kill_anon_super(struct super_block *sb);
2063 void kill_litter_super(struct super_block *sb);
2064 void deactivate_super(struct super_block *sb);
2065 void deactivate_locked_super(struct super_block *sb);
2066 int set_anon_super(struct super_block *s, void *data);
2067 int get_anon_bdev(dev_t *);
2068 void free_anon_bdev(dev_t);
2069 struct super_block *sget_userns(struct file_system_type *type,
2070                         int (*test)(struct super_block *,void *),
2071                         int (*set)(struct super_block *,void *),
2072                         int flags, struct user_namespace *user_ns,
2073                         void *data);
2074 struct super_block *sget(struct file_system_type *type,
2075                         int (*test)(struct super_block *,void *),
2076                         int (*set)(struct super_block *,void *),
2077                         int flags, void *data);
2078 extern struct dentry *mount_pseudo(struct file_system_type *, char *,
2079         const struct super_operations *ops,
2080         const struct dentry_operations *dops,
2081         unsigned long);
2082 
2083 /* Alas, no aliases. Too much hassle with bringing module.h everywhere */
2084 #define fops_get(fops) \
2085         (((fops) && try_module_get((fops)->owner) ? (fops) : NULL))
2086 #define fops_put(fops) \
2087         do { if (fops) module_put((fops)->owner); } while(0)
2088 /*
2089  * This one is to be used *ONLY* from ->open() instances.
2090  * fops must be non-NULL, pinned down *and* module dependencies
2091  * should be sufficient to pin the caller down as well.
2092  */
2093 #define replace_fops(f, fops) \
2094         do {    \
2095                 struct file *__file = (f); \
2096                 fops_put(__file->f_op); \
2097                 BUG_ON(!(__file->f_op = (fops))); \
2098         } while(0)
2099 
2100 extern int register_filesystem(struct file_system_type *);
2101 extern int unregister_filesystem(struct file_system_type *);
2102 extern struct vfsmount *kern_mount_data(struct file_system_type *, void *data);
2103 #define kern_mount(type) kern_mount_data(type, NULL)
2104 extern void kern_unmount(struct vfsmount *mnt);
2105 extern int may_umount_tree(struct vfsmount *);
2106 extern int may_umount(struct vfsmount *);
2107 extern long do_mount(const char *, const char __user *,
2108                      const char *, unsigned long, void *);
2109 extern struct vfsmount *collect_mounts(struct path *);
2110 extern void drop_collected_mounts(struct vfsmount *);
2111 extern int iterate_mounts(int (*)(struct vfsmount *, void *), void *,
2112                           struct vfsmount *);
2113 extern int vfs_statfs(struct path *, struct kstatfs *);
2114 extern int user_statfs(const char __user *, struct kstatfs *);
2115 extern int fd_statfs(int, struct kstatfs *);
2116 extern int vfs_ustat(dev_t, struct kstatfs *);
2117 extern int freeze_super(struct super_block *super);
2118 extern int thaw_super(struct super_block *super);
2119 extern bool our_mnt(struct vfsmount *mnt);
2120 
2121 extern int current_umask(void);
2122 
2123 extern void ihold(struct inode * inode);
2124 extern void iput(struct inode *);
2125 extern int generic_update_time(struct inode *, struct timespec *, int);
2126 
2127 /* /sys/fs */
2128 extern struct kobject *fs_kobj;
2129 
2130 #define MAX_RW_COUNT (INT_MAX & PAGE_MASK)
2131 
2132 #ifdef CONFIG_MANDATORY_FILE_LOCKING
2133 extern int locks_mandatory_locked(struct file *);
2134 extern int locks_mandatory_area(struct inode *, struct file *, loff_t, loff_t, unsigned char);
2135 
2136 /*
2137  * Candidates for mandatory locking have the setgid bit set
2138  * but no group execute bit -  an otherwise meaningless combination.
2139  */
2140 
2141 static inline int __mandatory_lock(struct inode *ino)
2142 {
2143         return (ino->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID;
2144 }
2145 
2146 /*
2147  * ... and these candidates should be on MS_MANDLOCK mounted fs,
2148  * otherwise these will be advisory locks
2149  */
2150 
2151 static inline int mandatory_lock(struct inode *ino)
2152 {
2153         return IS_MANDLOCK(ino) && __mandatory_lock(ino);
2154 }
2155 
2156 static inline int locks_verify_locked(struct file *file)
2157 {
2158         if (mandatory_lock(file_inode(file)))
2159                 return locks_mandatory_locked(file);
2160         return 0;
2161 }
2162 
2163 static inline int locks_verify_truncate(struct inode *inode,
2164                                     struct file *f,
2165                                     loff_t size)
2166 {
2167         if (!inode->i_flctx || !mandatory_lock(inode))
2168                 return 0;
2169 
2170         if (size < inode->i_size) {
2171                 return locks_mandatory_area(inode, f, size, inode->i_size - 1,
2172                                 F_WRLCK);
2173         } else {
2174                 return locks_mandatory_area(inode, f, inode->i_size, size - 1,
2175                                 F_WRLCK);
2176         }
2177 }
2178 
2179 #else /* !CONFIG_MANDATORY_FILE_LOCKING */
2180 
2181 static inline int locks_mandatory_locked(struct file *file)
2182 {
2183         return 0;
2184 }
2185 
2186 static inline int locks_mandatory_area(struct inode *inode, struct file *filp,
2187                                        loff_t start, loff_t end, unsigned char type)
2188 {
2189         return 0;
2190 }
2191 
2192 static inline int __mandatory_lock(struct inode *inode)
2193 {
2194         return 0;
2195 }
2196 
2197 static inline int mandatory_lock(struct inode *inode)
2198 {
2199         return 0;
2200 }
2201 
2202 static inline int locks_verify_locked(struct file *file)
2203 {
2204         return 0;
2205 }
2206 
2207 static inline int locks_verify_truncate(struct inode *inode, struct file *filp,
2208                                         size_t size)
2209 {
2210         return 0;
2211 }
2212 
2213 #endif /* CONFIG_MANDATORY_FILE_LOCKING */
2214 
2215 
2216 #ifdef CONFIG_FILE_LOCKING
2217 static inline int break_lease(struct inode *inode, unsigned int mode)
2218 {
2219         /*
2220          * Since this check is lockless, we must ensure that any refcounts
2221          * taken are done before checking i_flctx->flc_lease. Otherwise, we
2222          * could end up racing with tasks trying to set a new lease on this
2223          * file.
2224          */
2225         smp_mb();
2226         if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease))
2227                 return __break_lease(inode, mode, FL_LEASE);
2228         return 0;
2229 }
2230 
2231 static inline int break_deleg(struct inode *inode, unsigned int mode)
2232 {
2233         /*
2234          * Since this check is lockless, we must ensure that any refcounts
2235          * taken are done before checking i_flctx->flc_lease. Otherwise, we
2236          * could end up racing with tasks trying to set a new lease on this
2237          * file.
2238          */
2239         smp_mb();
2240         if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease))
2241                 return __break_lease(inode, mode, FL_DELEG);
2242         return 0;
2243 }
2244 
2245 static inline int try_break_deleg(struct inode *inode, struct inode **delegated_inode)
2246 {
2247         int ret;
2248 
2249         ret = break_deleg(inode, O_WRONLY|O_NONBLOCK);
2250         if (ret == -EWOULDBLOCK && delegated_inode) {
2251                 *delegated_inode = inode;
2252                 ihold(inode);
2253         }
2254         return ret;
2255 }
2256 
2257 static inline int break_deleg_wait(struct inode **delegated_inode)
2258 {
2259         int ret;
2260 
2261         ret = break_deleg(*delegated_inode, O_WRONLY);
2262         iput(*delegated_inode);
2263         *delegated_inode = NULL;
2264         return ret;
2265 }
2266 
2267 static inline int break_layout(struct inode *inode, bool wait)
2268 {
2269         smp_mb();
2270         if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease))
2271                 return __break_lease(inode,
2272                                 wait ? O_WRONLY : O_WRONLY | O_NONBLOCK,
2273                                 FL_LAYOUT);
2274         return 0;
2275 }
2276 
2277 #else /* !CONFIG_FILE_LOCKING */
2278 static inline int break_lease(struct inode *inode, unsigned int mode)
2279 {
2280         return 0;
2281 }
2282 
2283 static inline int break_deleg(struct inode *inode, unsigned int mode)
2284 {
2285         return 0;
2286 }
2287 
2288 static inline int try_break_deleg(struct inode *inode, struct inode **delegated_inode)
2289 {
2290         return 0;
2291 }
2292 
2293 static inline int break_deleg_wait(struct inode **delegated_inode)
2294 {
2295         BUG();
2296         return 0;
2297 }
2298 
2299 static inline int break_layout(struct inode *inode, bool wait)
2300 {
2301         return 0;
2302 }
2303 
2304 #endif /* CONFIG_FILE_LOCKING */
2305 
2306 /* fs/open.c */
2307 struct audit_names;
2308 struct filename {
2309         const char              *name;  /* pointer to actual string */
2310         const __user char       *uptr;  /* original userland pointer */
2311         struct audit_names      *aname;
2312         int                     refcnt;
2313         const char              iname[];
2314 };
2315 
2316 extern long vfs_truncate(const struct path *, loff_t);
2317 extern int do_truncate(struct dentry *, loff_t start, unsigned int time_attrs,
2318                        struct file *filp);
2319 extern int vfs_fallocate(struct file *file, int mode, loff_t offset,
2320                         loff_t len);
2321 extern long do_sys_open(int dfd, const char __user *filename, int flags,
2322                         umode_t mode);
2323 extern struct file *file_open_name(struct filename *, int, umode_t);
2324 extern struct file *filp_open(const char *, int, umode_t);
2325 extern struct file *file_open_root(struct dentry *, struct vfsmount *,
2326                                    const char *, int, umode_t);
2327 extern struct file * dentry_open(const struct path *, int, const struct cred *);
2328 extern int filp_close(struct file *, fl_owner_t id);
2329 
2330 extern struct filename *getname_flags(const char __user *, int, int *);
2331 extern struct filename *getname(const char __user *);
2332 extern struct filename *getname_kernel(const char *);
2333 extern void putname(struct filename *name);
2334 
2335 enum {
2336         FILE_CREATED = 1,
2337         FILE_OPENED = 2
2338 };
2339 extern int finish_open(struct file *file, struct dentry *dentry,
2340                         int (*open)(struct inode *, struct file *),
2341                         int *opened);
2342 extern int finish_no_open(struct file *file, struct dentry *dentry);
2343 
2344 /* fs/ioctl.c */
2345 
2346 extern int ioctl_preallocate(struct file *filp, void __user *argp);
2347 
2348 /* fs/dcache.c */
2349 extern void __init vfs_caches_init_early(void);
2350 extern void __init vfs_caches_init(void);
2351 
2352 extern struct kmem_cache *names_cachep;
2353 
2354 #define __getname()             kmem_cache_alloc(names_cachep, GFP_KERNEL)
2355 #define __putname(name)         kmem_cache_free(names_cachep, (void *)(name))
2356 
2357 #ifdef CONFIG_BLOCK
2358 extern int register_blkdev(unsigned int, const char *);
2359 extern void unregister_blkdev(unsigned int, const char *);
2360 extern struct block_device *bdget(dev_t);
2361 extern struct block_device *bdgrab(struct block_device *bdev);
2362 extern void bd_set_size(struct block_device *, loff_t size);
2363 extern void bd_forget(struct inode *inode);
2364 extern void bdput(struct block_device *);
2365 extern void invalidate_bdev(struct block_device *);
2366 extern void iterate_bdevs(void (*)(struct block_device *, void *), void *);
2367 extern int sync_blockdev(struct block_device *bdev);
2368 extern void kill_bdev(struct block_device *);
2369 extern struct super_block *freeze_bdev(struct block_device *);
2370 extern void emergency_thaw_all(void);
2371 extern int thaw_bdev(struct block_device *bdev, struct super_block *sb);
2372 extern int fsync_bdev(struct block_device *);
2373 
2374 extern struct super_block *blockdev_superblock;
2375 
2376 static inline bool sb_is_blkdev_sb(struct super_block *sb)
2377 {
2378         return sb == blockdev_superblock;
2379 }
2380 #else
2381 static inline void bd_forget(struct inode *inode) {}
2382 static inline int sync_blockdev(struct block_device *bdev) { return 0; }
2383 static inline void kill_bdev(struct block_device *bdev) {}
2384 static inline void invalidate_bdev(struct block_device *bdev) {}
2385 
2386 static inline struct super_block *freeze_bdev(struct block_device *sb)
2387 {
2388         return NULL;
2389 }
2390 
2391 static inline int thaw_bdev(struct block_device *bdev, struct super_block *sb)
2392 {
2393         return 0;
2394 }
2395 
2396 static inline void iterate_bdevs(void (*f)(struct block_device *, void *), void *arg)
2397 {
2398 }
2399 
2400 static inline bool sb_is_blkdev_sb(struct super_block *sb)
2401 {
2402         return false;
2403 }
2404 #endif
2405 extern int sync_filesystem(struct super_block *);
2406 extern const struct file_operations def_blk_fops;
2407 extern const struct file_operations def_chr_fops;
2408 #ifdef CONFIG_BLOCK
2409 extern int ioctl_by_bdev(struct block_device *, unsigned, unsigned long);
2410 extern int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long);
2411 extern long compat_blkdev_ioctl(struct file *, unsigned, unsigned long);
2412 extern int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder);
2413 extern struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
2414                                                void *holder);
2415 extern struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode,
2416                                               void *holder);
2417 extern void blkdev_put(struct block_device *bdev, fmode_t mode);
2418 extern int __blkdev_reread_part(struct block_device *bdev);
2419 extern int blkdev_reread_part(struct block_device *bdev);
2420 
2421 #ifdef CONFIG_SYSFS
2422 extern int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);
2423 extern void bd_unlink_disk_holder(struct block_device *bdev,
2424                                   struct gendisk *disk);
2425 #else
2426 static inline int bd_link_disk_holder(struct block_device *bdev,
2427                                       struct gendisk *disk)
2428 {
2429         return 0;
2430 }
2431 static inline void bd_unlink_disk_holder(struct block_device *bdev,
2432                                          struct gendisk *disk)
2433 {
2434 }
2435 #endif
2436 #endif
2437 
2438 /* fs/char_dev.c */
2439 #define CHRDEV_MAJOR_HASH_SIZE  255
2440 /* Marks the bottom of the first segment of free char majors */
2441 #define CHRDEV_MAJOR_DYN_END 234
2442 extern int alloc_chrdev_region(dev_t *, unsigned, unsigned, const char *);
2443 extern int register_chrdev_region(dev_t, unsigned, const char *);
2444 extern int __register_chrdev(unsigned int major, unsigned int baseminor,
2445                              unsigned int count, const char *name,
2446                              const struct file_operations *fops);
2447 extern void __unregister_chrdev(unsigned int major, unsigned int baseminor,
2448                                 unsigned int count, const char *name);
2449 extern void unregister_chrdev_region(dev_t, unsigned);
2450 extern void chrdev_show(struct seq_file *,off_t);
2451 
2452 static inline int register_chrdev(unsigned int major, const char *name,
2453                                   const struct file_operations *fops)
2454 {
2455         return __register_chrdev(major, 0, 256, name, fops);
2456 }
2457 
2458 static inline void unregister_chrdev(unsigned int major, const char *name)
2459 {
2460         __unregister_chrdev(major, 0, 256, name);
2461 }
2462 
2463 /* fs/block_dev.c */
2464 #define BDEVNAME_SIZE   32      /* Largest string for a blockdev identifier */
2465 #define BDEVT_SIZE      10      /* Largest string for MAJ:MIN for blkdev */
2466 
2467 #ifdef CONFIG_BLOCK
2468 #define BLKDEV_MAJOR_HASH_SIZE  255
2469 extern const char *__bdevname(dev_t, char *buffer);
2470 extern const char *bdevname(struct block_device *bdev, char *buffer);
2471 extern struct block_device *lookup_bdev(const char *);
2472 extern void blkdev_show(struct seq_file *,off_t);
2473 
2474 #else
2475 #define BLKDEV_MAJOR_HASH_SIZE  0
2476 #endif
2477 
2478 extern void init_special_inode(struct inode *, umode_t, dev_t);
2479 
2480 /* Invalid inode operations -- fs/bad_inode.c */
2481 extern void make_bad_inode(struct inode *);
2482 extern bool is_bad_inode(struct inode *);
2483 
2484 #ifdef CONFIG_BLOCK
2485 static inline bool op_is_write(unsigned int op)
2486 {
2487         return op == REQ_OP_READ ? false : true;
2488 }
2489 
2490 /*
2491  * return data direction, READ or WRITE
2492  */
2493 static inline int bio_data_dir(struct bio *bio)
2494 {
2495         return op_is_write(bio_op(bio)) ? WRITE : READ;
2496 }
2497 
2498 extern void check_disk_size_change(struct gendisk *disk,
2499                                    struct block_device *bdev);
2500 extern int revalidate_disk(struct gendisk *);
2501 extern int check_disk_change(struct block_device *);
2502 extern int __invalidate_device(struct block_device *, bool);
2503 extern int invalidate_partition(struct gendisk *, int);
2504 #endif
2505 unsigned long invalidate_mapping_pages(struct address_space *mapping,
2506                                         pgoff_t start, pgoff_t end);
2507 
2508 static inline void invalidate_remote_inode(struct inode *inode)
2509 {
2510         if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2511             S_ISLNK(inode->i_mode))
2512                 invalidate_mapping_pages(inode->i_mapping, 0, -1);
2513 }
2514 extern int invalidate_inode_pages2(struct address_space *mapping);
2515 extern int invalidate_inode_pages2_range(struct address_space *mapping,
2516                                          pgoff_t start, pgoff_t end);
2517 extern int write_inode_now(struct inode *, int);
2518 extern int filemap_fdatawrite(struct address_space *);
2519 extern int filemap_flush(struct address_space *);
2520 extern int filemap_fdatawait(struct address_space *);
2521 extern void filemap_fdatawait_keep_errors(struct address_space *);
2522 extern int filemap_fdatawait_range(struct address_space *, loff_t lstart,
2523                                    loff_t lend);
2524 extern int filemap_write_and_wait(struct address_space *mapping);
2525 extern int filemap_write_and_wait_range(struct address_space *mapping,
2526                                         loff_t lstart, loff_t lend);
2527 extern int __filemap_fdatawrite_range(struct address_space *mapping,
2528                                 loff_t start, loff_t end, int sync_mode);
2529 extern int filemap_fdatawrite_range(struct address_space *mapping,
2530                                 loff_t start, loff_t end);
2531 extern int filemap_check_errors(struct address_space *mapping);
2532 
2533 extern int vfs_fsync_range(struct file *file, loff_t start, loff_t end,
2534                            int datasync);
2535 extern int vfs_fsync(struct file *file, int datasync);
2536 
2537 /*
2538  * Sync the bytes written if this was a synchronous write.  Expect ki_pos
2539  * to already be updated for the write, and will return either the amount
2540  * of bytes passed in, or an error if syncing the file failed.
2541  */
2542 static inline ssize_t generic_write_sync(struct kiocb *iocb, ssize_t count)
2543 {
2544         if (iocb->ki_flags & IOCB_DSYNC) {
2545                 int ret = vfs_fsync_range(iocb->ki_filp,
2546                                 iocb->ki_pos - count, iocb->ki_pos - 1,
2547                                 (iocb->ki_flags & IOCB_SYNC) ? 0 : 1);
2548                 if (ret)
2549                         return ret;
2550         }
2551 
2552         return count;
2553 }
2554 
2555 extern void emergency_sync(void);
2556 extern void emergency_remount(void);
2557 #ifdef CONFIG_BLOCK
2558 extern sector_t bmap(struct inode *, sector_t);
2559 #endif
2560 extern int notify_change(struct dentry *, struct iattr *, struct inode **);
2561 extern int inode_permission(struct inode *, int);
2562 extern int __inode_permission(struct inode *, int);
2563 extern int generic_permission(struct inode *, int);
2564 extern int __check_sticky(struct inode *dir, struct inode *inode);
2565 
2566 static inline bool execute_ok(struct inode *inode)
2567 {
2568         return (inode->i_mode & S_IXUGO) || S_ISDIR(inode->i_mode);
2569 }
2570 
2571 static inline void file_start_write(struct file *file)
2572 {
2573         if (!S_ISREG(file_inode(file)->i_mode))
2574                 return;
2575         __sb_start_write(file_inode(file)->i_sb, SB_FREEZE_WRITE, true);
2576 }
2577 
2578 static inline bool file_start_write_trylock(struct file *file)
2579 {
2580         if (!S_ISREG(file_inode(file)->i_mode))
2581                 return true;
2582         return __sb_start_write(file_inode(file)->i_sb, SB_FREEZE_WRITE, false);
2583 }
2584 
2585 static inline void file_end_write(struct file *file)
2586 {
2587         if (!S_ISREG(file_inode(file)->i_mode))
2588                 return;
2589         __sb_end_write(file_inode(file)->i_sb, SB_FREEZE_WRITE);
2590 }
2591 
2592 /*
2593  * get_write_access() gets write permission for a file.
2594  * put_write_access() releases this write permission.
2595  * This is used for regular files.
2596  * We cannot support write (and maybe mmap read-write shared) accesses and
2597  * MAP_DENYWRITE mmappings simultaneously. The i_writecount field of an inode
2598  * can have the following values:
2599  * 0: no writers, no VM_DENYWRITE mappings
2600  * < 0: (-i_writecount) vm_area_structs with VM_DENYWRITE set exist
2601  * > 0: (i_writecount) users are writing to the file.
2602  *
2603  * Normally we operate on that counter with atomic_{inc,dec} and it's safe
2604  * except for the cases where we don't hold i_writecount yet. Then we need to
2605  * use {get,deny}_write_access() - these functions check the sign and refuse
2606  * to do the change if sign is wrong.
2607  */
2608 static inline int get_write_access(struct inode *inode)
2609 {
2610         return atomic_inc_unless_negative(&inode->i_writecount) ? 0 : -ETXTBSY;
2611 }
2612 static inline int deny_write_access(struct file *file)
2613 {
2614         struct inode *inode = file_inode(file);
2615         return atomic_dec_unless_positive(&inode->i_writecount) ? 0 : -ETXTBSY;
2616 }
2617 static inline void put_write_access(struct inode * inode)
2618 {
2619         atomic_dec(&inode->i_writecount);
2620 }
2621 static inline void allow_write_access(struct file *file)
2622 {
2623         if (file)
2624                 atomic_inc(&file_inode(file)->i_writecount);
2625 }
2626 static inline bool inode_is_open_for_write(const struct inode *inode)
2627 {
2628         return atomic_read(&inode->i_writecount) > 0;
2629 }
2630 
2631 #ifdef CONFIG_IMA
2632 static inline void i_readcount_dec(struct inode *inode)
2633 {
2634         BUG_ON(!atomic_read(&inode->i_readcount));
2635         atomic_dec(&inode->i_readcount);
2636 }
2637 static inline void i_readcount_inc(struct inode *inode)
2638 {
2639         atomic_inc(&inode->i_readcount);
2640 }
2641 #else
2642 static inline void i_readcount_dec(struct inode *inode)
2643 {
2644         return;
2645 }
2646 static inline void i_readcount_inc(struct inode *inode)
2647 {
2648         return;
2649 }
2650 #endif
2651 extern int do_pipe_flags(int *, int);
2652 
2653 #define __kernel_read_file_id(id) \
2654         id(UNKNOWN, unknown)            \
2655         id(FIRMWARE, firmware)          \
2656         id(FIRMWARE_PREALLOC_BUFFER, firmware)  \
2657         id(MODULE, kernel-module)               \
2658         id(KEXEC_IMAGE, kexec-image)            \
2659         id(KEXEC_INITRAMFS, kexec-initramfs)    \
2660         id(POLICY, security-policy)             \
2661         id(MAX_ID, )
2662 
2663 #define __fid_enumify(ENUM, dummy) READING_ ## ENUM,
2664 #define __fid_stringify(dummy, str) #str,
2665 
2666 enum kernel_read_file_id {
2667         __kernel_read_file_id(__fid_enumify)
2668 };
2669 
2670 static const char * const kernel_read_file_str[] = {
2671         __kernel_read_file_id(__fid_stringify)
2672 };
2673 
2674 static inline const char *kernel_read_file_id_str(enum kernel_read_file_id id)
2675 {
2676         if (id < 0 || id >= READING_MAX_ID)
2677                 return kernel_read_file_str[READING_UNKNOWN];
2678 
2679         return kernel_read_file_str[id];
2680 }
2681 
2682 extern int kernel_read(struct file *, loff_t, char *, unsigned long);
2683 extern int kernel_read_file(struct file *, void **, loff_t *, loff_t,
2684                             enum kernel_read_file_id);
2685 extern int kernel_read_file_from_path(char *, void **, loff_t *, loff_t,
2686                                       enum kernel_read_file_id);
2687 extern int kernel_read_file_from_fd(int, void **, loff_t *, loff_t,
2688                                     enum kernel_read_file_id);
2689 extern ssize_t kernel_write(struct file *, const char *, size_t, loff_t);
2690 extern ssize_t __kernel_write(struct file *, const char *, size_t, loff_t *);
2691 extern struct file * open_exec(const char *);
2692  
2693 /* fs/dcache.c -- generic fs support functions */
2694 extern bool is_subdir(struct dentry *, struct dentry *);
2695 extern bool path_is_under(struct path *, struct path *);
2696 
2697 extern char *file_path(struct file *, char *, int);
2698 
2699 #include <linux/err.h>
2700 
2701 /* needed for stackable file system support */
2702 extern loff_t default_llseek(struct file *file, loff_t offset, int whence);
2703 
2704 extern loff_t vfs_llseek(struct file *file, loff_t offset, int whence);
2705 
2706 extern int inode_init_always(struct super_block *, struct inode *);
2707 extern void inode_init_once(struct inode *);
2708 extern void address_space_init_once(struct address_space *mapping);
2709 extern struct inode * igrab(struct inode *);
2710 extern ino_t iunique(struct super_block *, ino_t);
2711 extern int inode_needs_sync(struct inode *inode);
2712 extern int generic_delete_inode(struct inode *inode);
2713 static inline int generic_drop_inode(struct inode *inode)
2714 {
2715         return !inode->i_nlink || inode_unhashed(inode);
2716 }
2717 
2718 extern struct inode *ilookup5_nowait(struct super_block *sb,
2719                 unsigned long hashval, int (*test)(struct inode *, void *),
2720                 void *data);
2721 extern struct inode *ilookup5(struct super_block *sb, unsigned long hashval,
2722                 int (*test)(struct inode *, void *), void *data);
2723 extern struct inode *ilookup(struct super_block *sb, unsigned long ino);
2724 
2725 extern struct inode * iget5_locked(struct super_block *, unsigned long, int (*test)(struct inode *, void *), int (*set)(struct inode *, void *), void *);
2726 extern struct inode * iget_locked(struct super_block *, unsigned long);
2727 extern struct inode *find_inode_nowait(struct super_block *,
2728                                        unsigned long,
2729                                        int (*match)(struct inode *,
2730                                                     unsigned long, void *),
2731                                        void *data);
2732 extern int insert_inode_locked4(struct inode *, unsigned long, int (*test)(struct inode *, void *), void *);
2733 extern int insert_inode_locked(struct inode *);
2734 #ifdef CONFIG_DEBUG_LOCK_ALLOC
2735 extern void lockdep_annotate_inode_mutex_key(struct inode *inode);
2736 #else
2737 static inline void lockdep_annotate_inode_mutex_key(struct inode *inode) { };
2738 #endif
2739 extern void unlock_new_inode(struct inode *);
2740 extern unsigned int get_next_ino(void);
2741 
2742 extern void __iget(struct inode * inode);
2743 extern void iget_failed(struct inode *);
2744 extern void clear_inode(struct inode *);
2745 extern void __destroy_inode(struct inode *);
2746 extern struct inode *new_inode_pseudo(struct super_block *sb);
2747 extern struct inode *new_inode(struct super_block *sb);
2748 extern void free_inode_nonrcu(struct inode *inode);
2749 extern int should_remove_suid(struct dentry *);
2750 extern int file_remove_privs(struct file *);
2751 
2752 extern void __insert_inode_hash(struct inode *, unsigned long hashval);
2753 static inline void insert_inode_hash(struct inode *inode)
2754 {
2755         __insert_inode_hash(inode, inode->i_ino);
2756 }
2757 
2758 extern void __remove_inode_hash(struct inode *);
2759 static inline void remove_inode_hash(struct inode *inode)
2760 {
2761         if (!inode_unhashed(inode) && !hlist_fake(&inode->i_hash))
2762                 __remove_inode_hash(inode);
2763 }
2764 
2765 extern void inode_sb_list_add(struct inode *inode);
2766 
2767 #ifdef CONFIG_BLOCK
2768 extern blk_qc_t submit_bio(struct bio *);
2769 extern int bdev_read_only(struct block_device *);
2770 #endif
2771 extern int set_blocksize(struct block_device *, int);
2772 extern int sb_set_blocksize(struct super_block *, int);
2773 extern int sb_min_blocksize(struct super_block *, int);
2774 
2775 extern int generic_file_mmap(struct file *, struct vm_area_struct *);
2776 extern int generic_file_readonly_mmap(struct file *, struct vm_area_struct *);
2777 extern ssize_t generic_write_checks(struct kiocb *, struct iov_iter *);
2778 extern ssize_t generic_file_read_iter(struct kiocb *, struct iov_iter *);
2779 extern ssize_t __generic_file_write_iter(struct kiocb *, struct iov_iter *);
2780 extern ssize_t generic_file_write_iter(struct kiocb *, struct iov_iter *);
2781 extern ssize_t generic_file_direct_write(struct kiocb *, struct iov_iter *);
2782 extern ssize_t generic_perform_write(struct file *, struct iov_iter *, loff_t);
2783 
2784 ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos);
2785 ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos);
2786 
2787 /* fs/block_dev.c */
2788 extern ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to);
2789 extern ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from);
2790 extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
2791                         int datasync);
2792 extern void block_sync_page(struct page *page);
2793 
2794 /* fs/splice.c */
2795 extern ssize_t generic_file_splice_read(struct file *, loff_t *,
2796                 struct pipe_inode_info *, size_t, unsigned int);
2797 extern ssize_t default_file_splice_read(struct file *, loff_t *,
2798                 struct pipe_inode_info *, size_t, unsigned int);
2799 extern ssize_t iter_file_splice_write(struct pipe_inode_info *,
2800                 struct file *, loff_t *, size_t, unsigned int);
2801 extern ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe,
2802                 struct file *out, loff_t *, size_t len, unsigned int flags);
2803 extern long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
2804                 loff_t *opos, size_t len, unsigned int flags);
2805 
2806 
2807 extern void
2808 file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping);
2809 extern loff_t noop_llseek(struct file *file, loff_t offset, int whence);
2810 extern loff_t no_llseek(struct file *file, loff_t offset, int whence);
2811 extern loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize);
2812 extern loff_t generic_file_llseek(struct file *file, loff_t offset, int whence);
2813 extern loff_t generic_file_llseek_size(struct file *file, loff_t offset,
2814                 int whence, loff_t maxsize, loff_t eof);
2815 extern loff_t fixed_size_llseek(struct file *file, loff_t offset,
2816                 int whence, loff_t size);
2817 extern loff_t no_seek_end_llseek_size(struct file *, loff_t, int, loff_t);
2818 extern loff_t no_seek_end_llseek(struct file *, loff_t, int);
2819 extern int generic_file_open(struct inode * inode, struct file * filp);
2820 extern int nonseekable_open(struct inode * inode, struct file * filp);
2821 
2822 #ifdef CONFIG_BLOCK
2823 typedef void (dio_submit_t)(struct bio *bio, struct inode *inode,
2824                             loff_t file_offset);
2825 
2826 enum {
2827         /* need locking between buffered and direct access */
2828         DIO_LOCKING     = 0x01,
2829 
2830         /* filesystem does not support filling holes */
2831         DIO_SKIP_HOLES  = 0x02,
2832 
2833         /* filesystem can handle aio writes beyond i_size */
2834         DIO_ASYNC_EXTEND = 0x04,
2835 
2836         /* inode/fs/bdev does not need truncate protection */
2837         DIO_SKIP_DIO_COUNT = 0x08,
2838 };
2839 
2840 void dio_end_io(struct bio *bio, int error);
2841 
2842 ssize_t __blockdev_direct_IO(struct kiocb *iocb, struct inode *inode,
2843                              struct block_device *bdev, struct iov_iter *iter,
2844                              get_block_t get_block,
2845                              dio_iodone_t end_io, dio_submit_t submit_io,
2846                              int flags);
2847 
2848 static inline ssize_t blockdev_direct_IO(struct kiocb *iocb,
2849                                          struct inode *inode,
2850                                          struct iov_iter *iter,
2851                                          get_block_t get_block)
2852 {
2853         return __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev, iter,
2854                         get_block, NULL, NULL, DIO_LOCKING | DIO_SKIP_HOLES);
2855 }
2856 #endif
2857 
2858 void inode_dio_wait(struct inode *inode);
2859 
2860 /*
2861  * inode_dio_begin - signal start of a direct I/O requests
2862  * @inode: inode the direct I/O happens on
2863  *
2864  * This is called once we've finished processing a direct I/O request,
2865  * and is used to wake up callers waiting for direct I/O to be quiesced.
2866  */
2867 static inline void inode_dio_begin(struct inode *inode)
2868 {
2869         atomic_inc(&inode->i_dio_count);
2870 }
2871 
2872 /*
2873  * inode_dio_end - signal finish of a direct I/O requests
2874  * @inode: inode the direct I/O happens on
2875  *
2876  * This is called once we've finished processing a direct I/O request,
2877  * and is used to wake up callers waiting for direct I/O to be quiesced.
2878  */
2879 static inline void inode_dio_end(struct inode *inode)
2880 {
2881         if (atomic_dec_and_test(&inode->i_dio_count))
2882                 wake_up_bit(&inode->i_state, __I_DIO_WAKEUP);
2883 }
2884 
2885 extern void inode_set_flags(struct inode *inode, unsigned int flags,
2886                             unsigned int mask);
2887 
2888 extern const struct file_operations generic_ro_fops;
2889 
2890 #define special_file(m) (S_ISCHR(m)||S_ISBLK(m)||S_ISFIFO(m)||S_ISSOCK(m))
2891 
2892 extern int readlink_copy(char __user *, int, const char *);
2893 extern int page_readlink(struct dentry *, char __user *, int);
2894 extern const char *page_get_link(struct dentry *, struct inode *,
2895                                  struct delayed_call *);
2896 extern void page_put_link(void *);
2897 extern int __page_symlink(struct inode *inode, const char *symname, int len,
2898                 int nofs);
2899 extern int page_symlink(struct inode *inode, const char *symname, int len);
2900 extern const struct inode_operations page_symlink_inode_operations;
2901 extern void kfree_link(void *);
2902 extern int generic_readlink(struct dentry *, char __user *, int);
2903 extern void generic_fillattr(struct inode *, struct kstat *);
2904 int vfs_getattr_nosec(struct path *path, struct kstat *stat);
2905 extern int vfs_getattr(struct path *, struct kstat *);
2906 void __inode_add_bytes(struct inode *inode, loff_t bytes);
2907 void inode_add_bytes(struct inode *inode, loff_t bytes);
2908 void __inode_sub_bytes(struct inode *inode, loff_t bytes);
2909 void inode_sub_bytes(struct inode *inode, loff_t bytes);
2910 loff_t inode_get_bytes(struct inode *inode);
2911 void inode_set_bytes(struct inode *inode, loff_t bytes);
2912 const char *simple_get_link(struct dentry *, struct inode *,
2913                             struct delayed_call *);
2914 extern const struct inode_operations simple_symlink_inode_operations;
2915 
2916 extern int iterate_dir(struct file *, struct dir_context *);
2917 
2918 extern int vfs_stat(const char __user *, struct kstat *);
2919 extern int vfs_lstat(const char __user *, struct kstat *);
2920 extern int vfs_fstat(unsigned int, struct kstat *);
2921 extern int vfs_fstatat(int , const char __user *, struct kstat *, int);
2922 
2923 extern int __generic_block_fiemap(struct inode *inode,
2924                                   struct fiemap_extent_info *fieinfo,
2925                                   loff_t start, loff_t len,
2926                                   get_block_t *get_block);
2927 extern int generic_block_fiemap(struct inode *inode,
2928                                 struct fiemap_extent_info *fieinfo, u64 start,
2929                                 u64 len, get_block_t *get_block);
2930 
2931 extern void get_filesystem(struct file_system_type *fs);
2932 extern void put_filesystem(struct file_system_type *fs);
2933 extern struct file_system_type *get_fs_type(const char *name);
2934 extern struct super_block *get_super(struct block_device *);
2935 extern struct super_block *get_super_thawed(struct block_device *);
2936 extern struct super_block *get_active_super(struct block_device *bdev);
2937 extern void drop_super(struct super_block *sb);
2938 extern void iterate_supers(void (*)(struct super_block *, void *), void *);
2939 extern void iterate_supers_type(struct file_system_type *,
2940                                 void (*)(struct super_block *, void *), void *);
2941 
2942 extern int dcache_dir_open(struct inode *, struct file *);
2943 extern int dcache_dir_close(struct inode *, struct file *);
2944 extern loff_t dcache_dir_lseek(struct file *, loff_t, int);
2945 extern int dcache_readdir(struct file *, struct dir_context *);
2946 extern int simple_setattr(struct dentry *, struct iattr *);
2947 extern int simple_getattr(struct vfsmount *, struct dentry *, struct kstat *);
2948 extern int simple_statfs(struct dentry *, struct kstatfs *);
2949 extern int simple_open(struct inode *inode, struct file *file);
2950 extern int simple_link(struct dentry *, struct inode *, struct dentry *);
2951 extern int simple_unlink(struct inode *, struct dentry *);
2952 extern int simple_rmdir(struct inode *, struct dentry *);
2953 extern int simple_rename(struct inode *, struct dentry *, struct inode *, struct dentry *);
2954 extern int noop_fsync(struct file *, loff_t, loff_t, int);
2955 extern int simple_empty(struct dentry *);
2956 extern int simple_readpage(struct file *file, struct page *page);
2957 extern int simple_write_begin(struct file *file, struct address_space *mapping,
2958                         loff_t pos, unsigned len, unsigned flags,
2959                         struct page **pagep, void **fsdata);
2960 extern int simple_write_end(struct file *file, struct address_space *mapping,
2961                         loff_t pos, unsigned len, unsigned copied,
2962                         struct page *page, void *fsdata);
2963 extern int always_delete_dentry(const struct dentry *);
2964 extern struct inode *alloc_anon_inode(struct super_block *);
2965 extern int simple_nosetlease(struct file *, long, struct file_lock **, void **);
2966 extern const struct dentry_operations simple_dentry_operations;
2967 
2968 extern struct dentry *simple_lookup(struct inode *, struct dentry *, unsigned int flags);
2969 extern ssize_t generic_read_dir(struct file *, char __user *, size_t, loff_t *);
2970 extern const struct file_operations simple_dir_operations;
2971 extern const struct inode_operations simple_dir_inode_operations;
2972 extern void make_empty_dir_inode(struct inode *inode);
2973 extern bool is_empty_dir_inode(struct inode *inode);
2974 struct tree_descr { char *name; const struct file_operations *ops; int mode; };
2975 struct dentry *d_alloc_name(struct dentry *, const char *);
2976 extern int simple_fill_super(struct super_block *, unsigned long, struct tree_descr *);
2977 extern int simple_pin_fs(struct file_system_type *, struct vfsmount **mount, int *count);
2978 extern void simple_release_fs(struct vfsmount **mount, int *count);
2979 
2980 extern ssize_t simple_read_from_buffer(void __user *to, size_t count,
2981                         loff_t *ppos, const void *from, size_t available);
2982 extern ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos,
2983                 const void __user *from, size_t count);
2984 
2985 extern int __generic_file_fsync(struct file *, loff_t, loff_t, int);
2986 extern int generic_file_fsync(struct file *, loff_t, loff_t, int);
2987 
2988 extern int generic_check_addressable(unsigned, u64);
2989 
2990 #ifdef CONFIG_MIGRATION
2991 extern int buffer_migrate_page(struct address_space *,
2992                                 struct page *, struct page *,
2993                                 enum migrate_mode);
2994 #else
2995 #define buffer_migrate_page NULL
2996 #endif
2997 
2998 extern int inode_change_ok(const struct inode *, struct iattr *);
2999 extern int inode_newsize_ok(const struct inode *, loff_t offset);
3000 extern void setattr_copy(struct inode *inode, const struct iattr *attr);
3001 
3002 extern int file_update_time(struct file *file);
3003 
3004 extern int generic_show_options(struct seq_file *m, struct dentry *root);
3005 extern void save_mount_options(struct super_block *sb, char *options);
3006 extern void replace_mount_options(struct super_block *sb, char *options);
3007 
3008 static inline bool io_is_direct(struct file *filp)
3009 {
3010         return (filp->f_flags & O_DIRECT) || IS_DAX(filp->f_mapping->host);
3011 }
3012 
3013 static inline int iocb_flags(struct file *file)
3014 {
3015         int res = 0;
3016         if (file->f_flags & O_APPEND)
3017                 res |= IOCB_APPEND;
3018         if (io_is_direct(file))
3019                 res |= IOCB_DIRECT;
3020         if ((file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host))
3021                 res |= IOCB_DSYNC;
3022         if (file->f_flags & __O_SYNC)
3023                 res |= IOCB_SYNC;
3024         return res;
3025 }
3026 
3027 static inline ino_t parent_ino(struct dentry *dentry)
3028 {
3029         ino_t res;
3030 
3031         /*
3032          * Don't strictly need d_lock here? If the parent ino could change
3033          * then surely we'd have a deeper race in the caller?
3034          */
3035         spin_lock(&dentry->d_lock);
3036         res = dentry->d_parent->d_inode->i_ino;
3037         spin_unlock(&dentry->d_lock);
3038         return res;
3039 }
3040 
3041 /* Transaction based IO helpers */
3042 
3043 /*
3044  * An argresp is stored in an allocated page and holds the
3045  * size of the argument or response, along with its content
3046  */
3047 struct simple_transaction_argresp {
3048         ssize_t size;
3049         char data[0];
3050 };
3051 
3052 #define SIMPLE_TRANSACTION_LIMIT (PAGE_SIZE - sizeof(struct simple_transaction_argresp))
3053 
3054 char *simple_transaction_get(struct file *file, const char __user *buf,
3055                                 size_t size);
3056 ssize_t simple_transaction_read(struct file *file, char __user *buf,
3057                                 size_t size, loff_t *pos);
3058 int simple_transaction_release(struct inode *inode, struct file *file);
3059 
3060 void simple_transaction_set(struct file *file, size_t n);
3061 
3062 /*
3063  * simple attribute files
3064  *
3065  * These attributes behave similar to those in sysfs:
3066  *
3067  * Writing to an attribute immediately sets a value, an open file can be
3068  * written to multiple times.
3069  *
3070  * Reading from an attribute creates a buffer from the value that might get
3071  * read with multiple read calls. When the attribute has been read
3072  * completely, no further read calls are possible until the file is opened
3073  * again.
3074  *
3075  * All attributes contain a text representation of a numeric value
3076  * that are accessed with the get() and set() functions.
3077  */
3078 #define DEFINE_SIMPLE_ATTRIBUTE(__fops, __get, __set, __fmt)            \
3079 static int __fops ## _open(struct inode *inode, struct file *file)      \
3080 {                                                                       \
3081         __simple_attr_check_format(__fmt, 0ull);                        \
3082         return simple_attr_open(inode, file, __get, __set, __fmt);      \
3083 }                                                                       \
3084 static const struct file_operations __fops = {                          \
3085         .owner   = THIS_MODULE,                                         \
3086         .open    = __fops ## _open,                                     \
3087         .release = simple_attr_release,                                 \
3088         .read    = simple_attr_read,                                    \
3089         .write   = simple_attr_write,                                   \
3090         .llseek  = generic_file_llseek,                                 \
3091 }
3092 
3093 static inline __printf(1, 2)
3094 void __simple_attr_check_format(const char *fmt, ...)
3095 {
3096         /* don't do anything, just let the compiler check the arguments; */
3097 }
3098 
3099 int simple_attr_open(struct inode *inode, struct file *file,
3100                      int (*get)(void *, u64 *), int (*set)(void *, u64),
3101                      const char *fmt);
3102 int simple_attr_release(struct inode *inode, struct file *file);
3103 ssize_t simple_attr_read(struct file *file, char __user *buf,
3104                          size_t len, loff_t *ppos);
3105 ssize_t simple_attr_write(struct file *file, const char __user *buf,
3106                           size_t len, loff_t *ppos);
3107 
3108 struct ctl_table;
3109 int proc_nr_files(struct ctl_table *table, int write,
3110                   void __user *buffer, size_t *lenp, loff_t *ppos);
3111 int proc_nr_dentry(struct ctl_table *table, int write,
3112                   void __user *buffer, size_t *lenp, loff_t *ppos);
3113 int proc_nr_inodes(struct ctl_table *table, int write,
3114                    void __user *buffer, size_t *lenp, loff_t *ppos);
3115 int __init get_filesystem_list(char *buf);
3116 
3117 #define __FMODE_EXEC            ((__force int) FMODE_EXEC)
3118 #define __FMODE_NONOTIFY        ((__force int) FMODE_NONOTIFY)
3119 
3120 #define ACC_MODE(x) ("\004\002\006\006"[(x)&O_ACCMODE])
3121 #define OPEN_FMODE(flag) ((__force fmode_t)(((flag + 1) & O_ACCMODE) | \
3122                                             (flag & __FMODE_NONOTIFY)))
3123 
3124 static inline bool is_sxid(umode_t mode)
3125 {
3126         return (mode & S_ISUID) || ((mode & S_ISGID) && (mode & S_IXGRP));
3127 }
3128 
3129 static inline int check_sticky(struct inode *dir, struct inode *inode)
3130 {
3131         if (!(dir->i_mode & S_ISVTX))
3132                 return 0;
3133 
3134         return __check_sticky(dir, inode);
3135 }
3136 
3137 static inline void inode_has_no_xattr(struct inode *inode)
3138 {
3139         if (!is_sxid(inode->i_mode) && (inode->i_sb->s_flags & MS_NOSEC))
3140                 inode->i_flags |= S_NOSEC;
3141 }
3142 
3143 static inline bool is_root_inode(struct inode *inode)
3144 {
3145         return inode == inode->i_sb->s_root->d_inode;
3146 }
3147 
3148 static inline bool dir_emit(struct dir_context *ctx,
3149                             const char *name, int namelen,
3150                             u64 ino, unsigned type)
3151 {
3152         return ctx->actor(ctx, name, namelen, ctx->pos, ino, type) == 0;
3153 }
3154 static inline bool dir_emit_dot(struct file *file, struct dir_context *ctx)
3155 {
3156         return ctx->actor(ctx, ".", 1, ctx->pos,
3157                           file->f_path.dentry->d_inode->i_ino, DT_DIR) == 0;
3158 }
3159 static inline bool dir_emit_dotdot(struct file *file, struct dir_context *ctx)
3160 {
3161         return ctx->actor(ctx, "..", 2, ctx->pos,
3162                           parent_ino(file->f_path.dentry), DT_DIR) == 0;
3163 }
3164 static inline bool dir_emit_dots(struct file *file, struct dir_context *ctx)
3165 {
3166         if (ctx->pos == 0) {
3167                 if (!dir_emit_dot(file, ctx))
3168                         return false;
3169                 ctx->pos = 1;
3170         }
3171         if (ctx->pos == 1) {
3172                 if (!dir_emit_dotdot(file, ctx))
3173                         return false;
3174                 ctx->pos = 2;
3175         }
3176         return true;
3177 }
3178 static inline bool dir_relax(struct inode *inode)
3179 {
3180         inode_unlock(inode);
3181         inode_lock(inode);
3182         return !IS_DEADDIR(inode);
3183 }
3184 
3185 static inline bool dir_relax_shared(struct inode *inode)
3186 {
3187         inode_unlock_shared(inode);
3188         inode_lock_shared(inode);
3189         return !IS_DEADDIR(inode);
3190 }
3191 
3192 extern bool path_noexec(const struct path *path);
3193 extern void inode_nohighmem(struct inode *inode);
3194 
3195 #endif /* _LINUX_FS_H */
3196 

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