~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

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

Version: ~ [ linux-5.18 ] ~ [ linux-5.17.9 ] ~ [ linux-5.16.20 ] ~ [ linux-5.15.41 ] ~ [ linux-5.14.21 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.117 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.195 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.244 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.280 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.315 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.302 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.9 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /* SPDX-License-Identifier: GPL-2.0 */
  2 #ifndef _LINUX_FS_H
  3 #define _LINUX_FS_H
  4 
  5 #include <linux/linkage.h>
  6 #include <linux/wait_bit.h>
  7 #include <linux/kdev_t.h>
  8 #include <linux/dcache.h>
  9 #include <linux/path.h>
 10 #include <linux/stat.h>
 11 #include <linux/cache.h>
 12 #include <linux/list.h>
 13 #include <linux/list_lru.h>
 14 #include <linux/llist.h>
 15 #include <linux/radix-tree.h>
 16 #include <linux/xarray.h>
 17 #include <linux/rbtree.h>
 18 #include <linux/init.h>
 19 #include <linux/pid.h>
 20 #include <linux/bug.h>
 21 #include <linux/mutex.h>
 22 #include <linux/rwsem.h>
 23 #include <linux/mm_types.h>
 24 #include <linux/capability.h>
 25 #include <linux/semaphore.h>
 26 #include <linux/fcntl.h>
 27 #include <linux/rculist_bl.h>
 28 #include <linux/atomic.h>
 29 #include <linux/shrinker.h>
 30 #include <linux/migrate_mode.h>
 31 #include <linux/uidgid.h>
 32 #include <linux/lockdep.h>
 33 #include <linux/percpu-rwsem.h>
 34 #include <linux/workqueue.h>
 35 #include <linux/delayed_call.h>
 36 #include <linux/uuid.h>
 37 #include <linux/errseq.h>
 38 #include <linux/ioprio.h>
 39 #include <linux/fs_types.h>
 40 #include <linux/build_bug.h>
 41 #include <linux/stddef.h>
 42 #include <linux/mount.h>
 43 #include <linux/cred.h>
 44 
 45 #include <asm/byteorder.h>
 46 #include <uapi/linux/fs.h>
 47 
 48 struct backing_dev_info;
 49 struct bdi_writeback;
 50 struct bio;
 51 struct export_operations;
 52 struct fiemap_extent_info;
 53 struct hd_geometry;
 54 struct iovec;
 55 struct kiocb;
 56 struct kobject;
 57 struct pipe_inode_info;
 58 struct poll_table_struct;
 59 struct kstatfs;
 60 struct vm_area_struct;
 61 struct vfsmount;
 62 struct cred;
 63 struct swap_info_struct;
 64 struct seq_file;
 65 struct workqueue_struct;
 66 struct iov_iter;
 67 struct fscrypt_info;
 68 struct fscrypt_operations;
 69 struct fsverity_info;
 70 struct fsverity_operations;
 71 struct fs_context;
 72 struct fs_parameter_spec;
 73 
 74 extern void __init inode_init(void);
 75 extern void __init inode_init_early(void);
 76 extern void __init files_init(void);
 77 extern void __init files_maxfiles_init(void);
 78 
 79 extern struct files_stat_struct files_stat;
 80 extern unsigned long get_max_files(void);
 81 extern unsigned int sysctl_nr_open;
 82 extern struct inodes_stat_t inodes_stat;
 83 extern int leases_enable, lease_break_time;
 84 extern int sysctl_protected_symlinks;
 85 extern int sysctl_protected_hardlinks;
 86 extern int sysctl_protected_fifos;
 87 extern int sysctl_protected_regular;
 88 
 89 typedef __kernel_rwf_t rwf_t;
 90 
 91 struct buffer_head;
 92 typedef int (get_block_t)(struct inode *inode, sector_t iblock,
 93                         struct buffer_head *bh_result, int create);
 94 typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset,
 95                         ssize_t bytes, void *private);
 96 
 97 #define MAY_EXEC                0x00000001
 98 #define MAY_WRITE               0x00000002
 99 #define MAY_READ                0x00000004
100 #define MAY_APPEND              0x00000008
101 #define MAY_ACCESS              0x00000010
102 #define MAY_OPEN                0x00000020
103 #define MAY_CHDIR               0x00000040
104 /* called from RCU mode, don't block */
105 #define MAY_NOT_BLOCK           0x00000080
106 
107 /*
108  * flags in file.f_mode.  Note that FMODE_READ and FMODE_WRITE must correspond
109  * to O_WRONLY and O_RDWR via the strange trick in do_dentry_open()
110  */
111 
112 /* file is open for reading */
113 #define FMODE_READ              ((__force fmode_t)0x1)
114 /* file is open for writing */
115 #define FMODE_WRITE             ((__force fmode_t)0x2)
116 /* file is seekable */
117 #define FMODE_LSEEK             ((__force fmode_t)0x4)
118 /* file can be accessed using pread */
119 #define FMODE_PREAD             ((__force fmode_t)0x8)
120 /* file can be accessed using pwrite */
121 #define FMODE_PWRITE            ((__force fmode_t)0x10)
122 /* File is opened for execution with sys_execve / sys_uselib */
123 #define FMODE_EXEC              ((__force fmode_t)0x20)
124 /* File is opened with O_NDELAY (only set for block devices) */
125 #define FMODE_NDELAY            ((__force fmode_t)0x40)
126 /* File is opened with O_EXCL (only set for block devices) */
127 #define FMODE_EXCL              ((__force fmode_t)0x80)
128 /* File is opened using open(.., 3, ..) and is writeable only for ioctls
129    (specialy hack for floppy.c) */
130 #define FMODE_WRITE_IOCTL       ((__force fmode_t)0x100)
131 /* 32bit hashes as llseek() offset (for directories) */
132 #define FMODE_32BITHASH         ((__force fmode_t)0x200)
133 /* 64bit hashes as llseek() offset (for directories) */
134 #define FMODE_64BITHASH         ((__force fmode_t)0x400)
135 
136 /*
137  * Don't update ctime and mtime.
138  *
139  * Currently a special hack for the XFS open_by_handle ioctl, but we'll
140  * hopefully graduate it to a proper O_CMTIME flag supported by open(2) soon.
141  */
142 #define FMODE_NOCMTIME          ((__force fmode_t)0x800)
143 
144 /* Expect random access pattern */
145 #define FMODE_RANDOM            ((__force fmode_t)0x1000)
146 
147 /* File is huge (eg. /dev/kmem): treat loff_t as unsigned */
148 #define FMODE_UNSIGNED_OFFSET   ((__force fmode_t)0x2000)
149 
150 /* File is opened with O_PATH; almost nothing can be done with it */
151 #define FMODE_PATH              ((__force fmode_t)0x4000)
152 
153 /* File needs atomic accesses to f_pos */
154 #define FMODE_ATOMIC_POS        ((__force fmode_t)0x8000)
155 /* Write access to underlying fs */
156 #define FMODE_WRITER            ((__force fmode_t)0x10000)
157 /* Has read method(s) */
158 #define FMODE_CAN_READ          ((__force fmode_t)0x20000)
159 /* Has write method(s) */
160 #define FMODE_CAN_WRITE         ((__force fmode_t)0x40000)
161 
162 #define FMODE_OPENED            ((__force fmode_t)0x80000)
163 #define FMODE_CREATED           ((__force fmode_t)0x100000)
164 
165 /* File is stream-like */
166 #define FMODE_STREAM            ((__force fmode_t)0x200000)
167 
168 /* File was opened by fanotify and shouldn't generate fanotify events */
169 #define FMODE_NONOTIFY          ((__force fmode_t)0x4000000)
170 
171 /* File is capable of returning -EAGAIN if I/O will block */
172 #define FMODE_NOWAIT            ((__force fmode_t)0x8000000)
173 
174 /* File represents mount that needs unmounting */
175 #define FMODE_NEED_UNMOUNT      ((__force fmode_t)0x10000000)
176 
177 /* File does not contribute to nr_files count */
178 #define FMODE_NOACCOUNT         ((__force fmode_t)0x20000000)
179 
180 /* File supports async buffered reads */
181 #define FMODE_BUF_RASYNC        ((__force fmode_t)0x40000000)
182 
183 /*
184  * Attribute flags.  These should be or-ed together to figure out what
185  * has been changed!
186  */
187 #define ATTR_MODE       (1 << 0)
188 #define ATTR_UID        (1 << 1)
189 #define ATTR_GID        (1 << 2)
190 #define ATTR_SIZE       (1 << 3)
191 #define ATTR_ATIME      (1 << 4)
192 #define ATTR_MTIME      (1 << 5)
193 #define ATTR_CTIME      (1 << 6)
194 #define ATTR_ATIME_SET  (1 << 7)
195 #define ATTR_MTIME_SET  (1 << 8)
196 #define ATTR_FORCE      (1 << 9) /* Not a change, but a change it */
197 #define ATTR_KILL_SUID  (1 << 11)
198 #define ATTR_KILL_SGID  (1 << 12)
199 #define ATTR_FILE       (1 << 13)
200 #define ATTR_KILL_PRIV  (1 << 14)
201 #define ATTR_OPEN       (1 << 15) /* Truncating from open(O_TRUNC) */
202 #define ATTR_TIMES_SET  (1 << 16)
203 #define ATTR_TOUCH      (1 << 17)
204 
205 /*
206  * Whiteout is represented by a char device.  The following constants define the
207  * mode and device number to use.
208  */
209 #define WHITEOUT_MODE 0
210 #define WHITEOUT_DEV 0
211 
212 /*
213  * This is the Inode Attributes structure, used for notify_change().  It
214  * uses the above definitions as flags, to know which values have changed.
215  * Also, in this manner, a Filesystem can look at only the values it cares
216  * about.  Basically, these are the attributes that the VFS layer can
217  * request to change from the FS layer.
218  *
219  * Derek Atkins <warlord@MIT.EDU> 94-10-20
220  */
221 struct iattr {
222         unsigned int    ia_valid;
223         umode_t         ia_mode;
224         kuid_t          ia_uid;
225         kgid_t          ia_gid;
226         loff_t          ia_size;
227         struct timespec64 ia_atime;
228         struct timespec64 ia_mtime;
229         struct timespec64 ia_ctime;
230 
231         /*
232          * Not an attribute, but an auxiliary info for filesystems wanting to
233          * implement an ftruncate() like method.  NOTE: filesystem should
234          * check for (ia_valid & ATTR_FILE), and not for (ia_file != NULL).
235          */
236         struct file     *ia_file;
237 };
238 
239 /*
240  * Includes for diskquotas.
241  */
242 #include <linux/quota.h>
243 
244 /*
245  * Maximum number of layers of fs stack.  Needs to be limited to
246  * prevent kernel stack overflow
247  */
248 #define FILESYSTEM_MAX_STACK_DEPTH 2
249 
250 /** 
251  * enum positive_aop_returns - aop return codes with specific semantics
252  *
253  * @AOP_WRITEPAGE_ACTIVATE: Informs the caller that page writeback has
254  *                          completed, that the page is still locked, and
255  *                          should be considered active.  The VM uses this hint
256  *                          to return the page to the active list -- it won't
257  *                          be a candidate for writeback again in the near
258  *                          future.  Other callers must be careful to unlock
259  *                          the page if they get this return.  Returned by
260  *                          writepage(); 
261  *
262  * @AOP_TRUNCATED_PAGE: The AOP method that was handed a locked page has
263  *                      unlocked it and the page might have been truncated.
264  *                      The caller should back up to acquiring a new page and
265  *                      trying again.  The aop will be taking reasonable
266  *                      precautions not to livelock.  If the caller held a page
267  *                      reference, it should drop it before retrying.  Returned
268  *                      by readpage().
269  *
270  * address_space_operation functions return these large constants to indicate
271  * special semantics to the caller.  These are much larger than the bytes in a
272  * page to allow for functions that return the number of bytes operated on in a
273  * given page.
274  */
275 
276 enum positive_aop_returns {
277         AOP_WRITEPAGE_ACTIVATE  = 0x80000,
278         AOP_TRUNCATED_PAGE      = 0x80001,
279 };
280 
281 #define AOP_FLAG_CONT_EXPAND            0x0001 /* called from cont_expand */
282 #define AOP_FLAG_NOFS                   0x0002 /* used by filesystem to direct
283                                                 * helper code (eg buffer layer)
284                                                 * to clear GFP_FS from alloc */
285 
286 /*
287  * oh the beauties of C type declarations.
288  */
289 struct page;
290 struct address_space;
291 struct writeback_control;
292 struct readahead_control;
293 
294 /*
295  * Write life time hint values.
296  * Stored in struct inode as u8.
297  */
298 enum rw_hint {
299         WRITE_LIFE_NOT_SET      = 0,
300         WRITE_LIFE_NONE         = RWH_WRITE_LIFE_NONE,
301         WRITE_LIFE_SHORT        = RWH_WRITE_LIFE_SHORT,
302         WRITE_LIFE_MEDIUM       = RWH_WRITE_LIFE_MEDIUM,
303         WRITE_LIFE_LONG         = RWH_WRITE_LIFE_LONG,
304         WRITE_LIFE_EXTREME      = RWH_WRITE_LIFE_EXTREME,
305 };
306 
307 /* Match RWF_* bits to IOCB bits */
308 #define IOCB_HIPRI              (__force int) RWF_HIPRI
309 #define IOCB_DSYNC              (__force int) RWF_DSYNC
310 #define IOCB_SYNC               (__force int) RWF_SYNC
311 #define IOCB_NOWAIT             (__force int) RWF_NOWAIT
312 #define IOCB_APPEND             (__force int) RWF_APPEND
313 
314 /* non-RWF related bits - start at 16 */
315 #define IOCB_EVENTFD            (1 << 16)
316 #define IOCB_DIRECT             (1 << 17)
317 #define IOCB_WRITE              (1 << 18)
318 /* iocb->ki_waitq is valid */
319 #define IOCB_WAITQ              (1 << 19)
320 #define IOCB_NOIO               (1 << 20)
321 
322 struct kiocb {
323         struct file             *ki_filp;
324 
325         /* The 'ki_filp' pointer is shared in a union for aio */
326         randomized_struct_fields_start
327 
328         loff_t                  ki_pos;
329         void (*ki_complete)(struct kiocb *iocb, long ret, long ret2);
330         void                    *private;
331         int                     ki_flags;
332         u16                     ki_hint;
333         u16                     ki_ioprio; /* See linux/ioprio.h */
334         union {
335                 unsigned int            ki_cookie; /* for ->iopoll */
336                 struct wait_page_queue  *ki_waitq; /* for async buffered IO */
337         };
338 
339         randomized_struct_fields_end
340 };
341 
342 static inline bool is_sync_kiocb(struct kiocb *kiocb)
343 {
344         return kiocb->ki_complete == NULL;
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         /*
380          * Reads in the requested pages. Unlike ->readpage(), this is
381          * PURELY used for read-ahead!.
382          */
383         int (*readpages)(struct file *filp, struct address_space *mapping,
384                         struct list_head *pages, unsigned nr_pages);
385         void (*readahead)(struct readahead_control *);
386 
387         int (*write_begin)(struct file *, struct address_space *mapping,
388                                 loff_t pos, unsigned len, unsigned flags,
389                                 struct page **pagep, void **fsdata);
390         int (*write_end)(struct file *, struct address_space *mapping,
391                                 loff_t pos, unsigned len, unsigned copied,
392                                 struct page *page, void *fsdata);
393 
394         /* Unfortunately this kludge is needed for FIBMAP. Don't use it */
395         sector_t (*bmap)(struct address_space *, sector_t);
396         void (*invalidatepage) (struct page *, unsigned int, unsigned int);
397         int (*releasepage) (struct page *, gfp_t);
398         void (*freepage)(struct page *);
399         ssize_t (*direct_IO)(struct kiocb *, struct iov_iter *iter);
400         /*
401          * migrate the contents of a page to the specified target. If
402          * migrate_mode is MIGRATE_ASYNC, it must not block.
403          */
404         int (*migratepage) (struct address_space *,
405                         struct page *, struct page *, enum migrate_mode);
406         bool (*isolate_page)(struct page *, isolate_mode_t);
407         void (*putback_page)(struct page *);
408         int (*launder_page) (struct page *);
409         int (*is_partially_uptodate) (struct page *, unsigned long,
410                                         unsigned long);
411         void (*is_dirty_writeback) (struct page *, bool *, bool *);
412         int (*error_remove_page)(struct address_space *, struct page *);
413 
414         /* swapfile support */
415         int (*swap_activate)(struct swap_info_struct *sis, struct file *file,
416                                 sector_t *span);
417         void (*swap_deactivate)(struct file *file);
418 };
419 
420 extern const struct address_space_operations empty_aops;
421 
422 /*
423  * pagecache_write_begin/pagecache_write_end must be used by general code
424  * to write into the pagecache.
425  */
426 int pagecache_write_begin(struct file *, struct address_space *mapping,
427                                 loff_t pos, unsigned len, unsigned flags,
428                                 struct page **pagep, void **fsdata);
429 
430 int pagecache_write_end(struct file *, struct address_space *mapping,
431                                 loff_t pos, unsigned len, unsigned copied,
432                                 struct page *page, void *fsdata);
433 
434 /**
435  * struct address_space - Contents of a cacheable, mappable object.
436  * @host: Owner, either the inode or the block_device.
437  * @i_pages: Cached pages.
438  * @gfp_mask: Memory allocation flags to use for allocating pages.
439  * @i_mmap_writable: Number of VM_SHARED mappings.
440  * @nr_thps: Number of THPs in the pagecache (non-shmem only).
441  * @i_mmap: Tree of private and shared mappings.
442  * @i_mmap_rwsem: Protects @i_mmap and @i_mmap_writable.
443  * @nrpages: Number of page entries, protected by the i_pages lock.
444  * @nrexceptional: Shadow or DAX entries, protected by the i_pages lock.
445  * @writeback_index: Writeback starts here.
446  * @a_ops: Methods.
447  * @flags: Error bits and flags (AS_*).
448  * @wb_err: The most recent error which has occurred.
449  * @private_lock: For use by the owner of the address_space.
450  * @private_list: For use by the owner of the address_space.
451  * @private_data: For use by the owner of the address_space.
452  */
453 struct address_space {
454         struct inode            *host;
455         struct xarray           i_pages;
456         gfp_t                   gfp_mask;
457         atomic_t                i_mmap_writable;
458 #ifdef CONFIG_READ_ONLY_THP_FOR_FS
459         /* number of thp, only for non-shmem files */
460         atomic_t                nr_thps;
461 #endif
462         struct rb_root_cached   i_mmap;
463         struct rw_semaphore     i_mmap_rwsem;
464         unsigned long           nrpages;
465         unsigned long           nrexceptional;
466         pgoff_t                 writeback_index;
467         const struct address_space_operations *a_ops;
468         unsigned long           flags;
469         errseq_t                wb_err;
470         spinlock_t              private_lock;
471         struct list_head        private_list;
472         void                    *private_data;
473 } __attribute__((aligned(sizeof(long)))) __randomize_layout;
474         /*
475          * On most architectures that alignment is already the case; but
476          * must be enforced here for CRIS, to let the least significant bit
477          * of struct page's "mapping" pointer be used for PAGE_MAPPING_ANON.
478          */
479 
480 /* XArray tags, for tagging dirty and writeback pages in the pagecache. */
481 #define PAGECACHE_TAG_DIRTY     XA_MARK_0
482 #define PAGECACHE_TAG_WRITEBACK XA_MARK_1
483 #define PAGECACHE_TAG_TOWRITE   XA_MARK_2
484 
485 /*
486  * Returns true if any of the pages in the mapping are marked with the tag.
487  */
488 static inline bool mapping_tagged(struct address_space *mapping, xa_mark_t tag)
489 {
490         return xa_marked(&mapping->i_pages, tag);
491 }
492 
493 static inline void i_mmap_lock_write(struct address_space *mapping)
494 {
495         down_write(&mapping->i_mmap_rwsem);
496 }
497 
498 static inline int i_mmap_trylock_write(struct address_space *mapping)
499 {
500         return down_write_trylock(&mapping->i_mmap_rwsem);
501 }
502 
503 static inline void i_mmap_unlock_write(struct address_space *mapping)
504 {
505         up_write(&mapping->i_mmap_rwsem);
506 }
507 
508 static inline void i_mmap_lock_read(struct address_space *mapping)
509 {
510         down_read(&mapping->i_mmap_rwsem);
511 }
512 
513 static inline void i_mmap_unlock_read(struct address_space *mapping)
514 {
515         up_read(&mapping->i_mmap_rwsem);
516 }
517 
518 static inline void i_mmap_assert_locked(struct address_space *mapping)
519 {
520         lockdep_assert_held(&mapping->i_mmap_rwsem);
521 }
522 
523 static inline void i_mmap_assert_write_locked(struct address_space *mapping)
524 {
525         lockdep_assert_held_write(&mapping->i_mmap_rwsem);
526 }
527 
528 /*
529  * Might pages of this file be mapped into userspace?
530  */
531 static inline int mapping_mapped(struct address_space *mapping)
532 {
533         return  !RB_EMPTY_ROOT(&mapping->i_mmap.rb_root);
534 }
535 
536 /*
537  * Might pages of this file have been modified in userspace?
538  * Note that i_mmap_writable counts all VM_SHARED vmas: do_mmap
539  * marks vma as VM_SHARED if it is shared, and the file was opened for
540  * writing i.e. vma may be mprotected writable even if now readonly.
541  *
542  * If i_mmap_writable is negative, no new writable mappings are allowed. You
543  * can only deny writable mappings, if none exists right now.
544  */
545 static inline int mapping_writably_mapped(struct address_space *mapping)
546 {
547         return atomic_read(&mapping->i_mmap_writable) > 0;
548 }
549 
550 static inline int mapping_map_writable(struct address_space *mapping)
551 {
552         return atomic_inc_unless_negative(&mapping->i_mmap_writable) ?
553                 0 : -EPERM;
554 }
555 
556 static inline void mapping_unmap_writable(struct address_space *mapping)
557 {
558         atomic_dec(&mapping->i_mmap_writable);
559 }
560 
561 static inline int mapping_deny_writable(struct address_space *mapping)
562 {
563         return atomic_dec_unless_positive(&mapping->i_mmap_writable) ?
564                 0 : -EBUSY;
565 }
566 
567 static inline void mapping_allow_writable(struct address_space *mapping)
568 {
569         atomic_inc(&mapping->i_mmap_writable);
570 }
571 
572 /*
573  * Use sequence counter to get consistent i_size on 32-bit processors.
574  */
575 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
576 #include <linux/seqlock.h>
577 #define __NEED_I_SIZE_ORDERED
578 #define i_size_ordered_init(inode) seqcount_init(&inode->i_size_seqcount)
579 #else
580 #define i_size_ordered_init(inode) do { } while (0)
581 #endif
582 
583 struct posix_acl;
584 #define ACL_NOT_CACHED ((void *)(-1))
585 #define ACL_DONT_CACHE ((void *)(-3))
586 
587 static inline struct posix_acl *
588 uncached_acl_sentinel(struct task_struct *task)
589 {
590         return (void *)task + 1;
591 }
592 
593 static inline bool
594 is_uncached_acl(struct posix_acl *acl)
595 {
596         return (long)acl & 1;
597 }
598 
599 #define IOP_FASTPERM    0x0001
600 #define IOP_LOOKUP      0x0002
601 #define IOP_NOFOLLOW    0x0004
602 #define IOP_XATTR       0x0008
603 #define IOP_DEFAULT_READLINK    0x0010
604 
605 struct fsnotify_mark_connector;
606 
607 /*
608  * Keep mostly read-only and often accessed (especially for
609  * the RCU path lookup and 'stat' data) fields at the beginning
610  * of the 'struct inode'
611  */
612 struct inode {
613         umode_t                 i_mode;
614         unsigned short          i_opflags;
615         kuid_t                  i_uid;
616         kgid_t                  i_gid;
617         unsigned int            i_flags;
618 
619 #ifdef CONFIG_FS_POSIX_ACL
620         struct posix_acl        *i_acl;
621         struct posix_acl        *i_default_acl;
622 #endif
623 
624         const struct inode_operations   *i_op;
625         struct super_block      *i_sb;
626         struct address_space    *i_mapping;
627 
628 #ifdef CONFIG_SECURITY
629         void                    *i_security;
630 #endif
631 
632         /* Stat data, not accessed from path walking */
633         unsigned long           i_ino;
634         /*
635          * Filesystems may only read i_nlink directly.  They shall use the
636          * following functions for modification:
637          *
638          *    (set|clear|inc|drop)_nlink
639          *    inode_(inc|dec)_link_count
640          */
641         union {
642                 const unsigned int i_nlink;
643                 unsigned int __i_nlink;
644         };
645         dev_t                   i_rdev;
646         loff_t                  i_size;
647         struct timespec64       i_atime;
648         struct timespec64       i_mtime;
649         struct timespec64       i_ctime;
650         spinlock_t              i_lock; /* i_blocks, i_bytes, maybe i_size */
651         unsigned short          i_bytes;
652         u8                      i_blkbits;
653         u8                      i_write_hint;
654         blkcnt_t                i_blocks;
655 
656 #ifdef __NEED_I_SIZE_ORDERED
657         seqcount_t              i_size_seqcount;
658 #endif
659 
660         /* Misc */
661         unsigned long           i_state;
662         struct rw_semaphore     i_rwsem;
663 
664         unsigned long           dirtied_when;   /* jiffies of first dirtying */
665         unsigned long           dirtied_time_when;
666 
667         struct hlist_node       i_hash;
668         struct list_head        i_io_list;      /* backing dev IO list */
669 #ifdef CONFIG_CGROUP_WRITEBACK
670         struct bdi_writeback    *i_wb;          /* the associated cgroup wb */
671 
672         /* foreign inode detection, see wbc_detach_inode() */
673         int                     i_wb_frn_winner;
674         u16                     i_wb_frn_avg_time;
675         u16                     i_wb_frn_history;
676 #endif
677         struct list_head        i_lru;          /* inode LRU list */
678         struct list_head        i_sb_list;
679         struct list_head        i_wb_list;      /* backing dev writeback list */
680         union {
681                 struct hlist_head       i_dentry;
682                 struct rcu_head         i_rcu;
683         };
684         atomic64_t              i_version;
685         atomic64_t              i_sequence; /* see futex */
686         atomic_t                i_count;
687         atomic_t                i_dio_count;
688         atomic_t                i_writecount;
689 #if defined(CONFIG_IMA) || defined(CONFIG_FILE_LOCKING)
690         atomic_t                i_readcount; /* struct files open RO */
691 #endif
692         union {
693                 const struct file_operations    *i_fop; /* former ->i_op->default_file_ops */
694                 void (*free_inode)(struct inode *);
695         };
696         struct file_lock_context        *i_flctx;
697         struct address_space    i_data;
698         struct list_head        i_devices;
699         union {
700                 struct pipe_inode_info  *i_pipe;
701                 struct cdev             *i_cdev;
702                 char                    *i_link;
703                 unsigned                i_dir_seq;
704         };
705 
706         __u32                   i_generation;
707 
708 #ifdef CONFIG_FSNOTIFY
709         __u32                   i_fsnotify_mask; /* all events this inode cares about */
710         struct fsnotify_mark_connector __rcu    *i_fsnotify_marks;
711 #endif
712 
713 #ifdef CONFIG_FS_ENCRYPTION
714         struct fscrypt_info     *i_crypt_info;
715 #endif
716 
717 #ifdef CONFIG_FS_VERITY
718         struct fsverity_info    *i_verity_info;
719 #endif
720 
721         void                    *i_private; /* fs or device private pointer */
722 } __randomize_layout;
723 
724 struct timespec64 timestamp_truncate(struct timespec64 t, struct inode *inode);
725 
726 static inline unsigned int i_blocksize(const struct inode *node)
727 {
728         return (1 << node->i_blkbits);
729 }
730 
731 static inline int inode_unhashed(struct inode *inode)
732 {
733         return hlist_unhashed(&inode->i_hash);
734 }
735 
736 /*
737  * __mark_inode_dirty expects inodes to be hashed.  Since we don't
738  * want special inodes in the fileset inode space, we make them
739  * appear hashed, but do not put on any lists.  hlist_del()
740  * will work fine and require no locking.
741  */
742 static inline void inode_fake_hash(struct inode *inode)
743 {
744         hlist_add_fake(&inode->i_hash);
745 }
746 
747 /*
748  * inode->i_mutex nesting subclasses for the lock validator:
749  *
750  * 0: the object of the current VFS operation
751  * 1: parent
752  * 2: child/target
753  * 3: xattr
754  * 4: second non-directory
755  * 5: second parent (when locking independent directories in rename)
756  *
757  * I_MUTEX_NONDIR2 is for certain operations (such as rename) which lock two
758  * non-directories at once.
759  *
760  * The locking order between these classes is
761  * parent[2] -> child -> grandchild -> normal -> xattr -> second non-directory
762  */
763 enum inode_i_mutex_lock_class
764 {
765         I_MUTEX_NORMAL,
766         I_MUTEX_PARENT,
767         I_MUTEX_CHILD,
768         I_MUTEX_XATTR,
769         I_MUTEX_NONDIR2,
770         I_MUTEX_PARENT2,
771 };
772 
773 static inline void inode_lock(struct inode *inode)
774 {
775         down_write(&inode->i_rwsem);
776 }
777 
778 static inline void inode_unlock(struct inode *inode)
779 {
780         up_write(&inode->i_rwsem);
781 }
782 
783 static inline void inode_lock_shared(struct inode *inode)
784 {
785         down_read(&inode->i_rwsem);
786 }
787 
788 static inline void inode_unlock_shared(struct inode *inode)
789 {
790         up_read(&inode->i_rwsem);
791 }
792 
793 static inline int inode_trylock(struct inode *inode)
794 {
795         return down_write_trylock(&inode->i_rwsem);
796 }
797 
798 static inline int inode_trylock_shared(struct inode *inode)
799 {
800         return down_read_trylock(&inode->i_rwsem);
801 }
802 
803 static inline int inode_is_locked(struct inode *inode)
804 {
805         return rwsem_is_locked(&inode->i_rwsem);
806 }
807 
808 static inline void inode_lock_nested(struct inode *inode, unsigned subclass)
809 {
810         down_write_nested(&inode->i_rwsem, subclass);
811 }
812 
813 static inline void inode_lock_shared_nested(struct inode *inode, unsigned subclass)
814 {
815         down_read_nested(&inode->i_rwsem, subclass);
816 }
817 
818 void lock_two_nondirectories(struct inode *, struct inode*);
819 void unlock_two_nondirectories(struct inode *, struct inode*);
820 
821 /*
822  * NOTE: in a 32bit arch with a preemptable kernel and
823  * an UP compile the i_size_read/write must be atomic
824  * with respect to the local cpu (unlike with preempt disabled),
825  * but they don't need to be atomic with respect to other cpus like in
826  * true SMP (so they need either to either locally disable irq around
827  * the read or for example on x86 they can be still implemented as a
828  * cmpxchg8b without the need of the lock prefix). For SMP compiles
829  * and 64bit archs it makes no difference if preempt is enabled or not.
830  */
831 static inline loff_t i_size_read(const struct inode *inode)
832 {
833 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
834         loff_t i_size;
835         unsigned int seq;
836 
837         do {
838                 seq = read_seqcount_begin(&inode->i_size_seqcount);
839                 i_size = inode->i_size;
840         } while (read_seqcount_retry(&inode->i_size_seqcount, seq));
841         return i_size;
842 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION)
843         loff_t i_size;
844 
845         preempt_disable();
846         i_size = inode->i_size;
847         preempt_enable();
848         return i_size;
849 #else
850         return inode->i_size;
851 #endif
852 }
853 
854 /*
855  * NOTE: unlike i_size_read(), i_size_write() does need locking around it
856  * (normally i_mutex), otherwise on 32bit/SMP an update of i_size_seqcount
857  * can be lost, resulting in subsequent i_size_read() calls spinning forever.
858  */
859 static inline void i_size_write(struct inode *inode, loff_t i_size)
860 {
861 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
862         preempt_disable();
863         write_seqcount_begin(&inode->i_size_seqcount);
864         inode->i_size = i_size;
865         write_seqcount_end(&inode->i_size_seqcount);
866         preempt_enable();
867 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION)
868         preempt_disable();
869         inode->i_size = i_size;
870         preempt_enable();
871 #else
872         inode->i_size = i_size;
873 #endif
874 }
875 
876 static inline unsigned iminor(const struct inode *inode)
877 {
878         return MINOR(inode->i_rdev);
879 }
880 
881 static inline unsigned imajor(const struct inode *inode)
882 {
883         return MAJOR(inode->i_rdev);
884 }
885 
886 struct fown_struct {
887         rwlock_t lock;          /* protects pid, uid, euid fields */
888         struct pid *pid;        /* pid or -pgrp where SIGIO should be sent */
889         enum pid_type pid_type; /* Kind of process group SIGIO should be sent to */
890         kuid_t uid, euid;       /* uid/euid of process setting the owner */
891         int signum;             /* posix.1b rt signal to be delivered on IO */
892 };
893 
894 /*
895  * Track a single file's readahead state
896  */
897 struct file_ra_state {
898         pgoff_t start;                  /* where readahead started */
899         unsigned int size;              /* # of readahead pages */
900         unsigned int async_size;        /* do asynchronous readahead when
901                                            there are only # of pages ahead */
902 
903         unsigned int ra_pages;          /* Maximum readahead window */
904         unsigned int mmap_miss;         /* Cache miss stat for mmap accesses */
905         loff_t prev_pos;                /* Cache last read() position */
906 };
907 
908 /*
909  * Check if @index falls in the readahead windows.
910  */
911 static inline int ra_has_index(struct file_ra_state *ra, pgoff_t index)
912 {
913         return (index >= ra->start &&
914                 index <  ra->start + ra->size);
915 }
916 
917 struct file {
918         union {
919                 struct llist_node       fu_llist;
920                 struct rcu_head         fu_rcuhead;
921         } f_u;
922         struct path             f_path;
923         struct inode            *f_inode;       /* cached value */
924         const struct file_operations    *f_op;
925 
926         /*
927          * Protects f_ep, f_flags.
928          * Must not be taken from IRQ context.
929          */
930         spinlock_t              f_lock;
931         enum rw_hint            f_write_hint;
932         atomic_long_t           f_count;
933         unsigned int            f_flags;
934         fmode_t                 f_mode;
935         struct mutex            f_pos_lock;
936         loff_t                  f_pos;
937         struct fown_struct      f_owner;
938         const struct cred       *f_cred;
939         struct file_ra_state    f_ra;
940 
941         u64                     f_version;
942 #ifdef CONFIG_SECURITY
943         void                    *f_security;
944 #endif
945         /* needed for tty driver, and maybe others */
946         void                    *private_data;
947 
948 #ifdef CONFIG_EPOLL
949         /* Used by fs/eventpoll.c to link all the hooks to this file */
950         struct hlist_head       *f_ep;
951 #endif /* #ifdef CONFIG_EPOLL */
952         struct address_space    *f_mapping;
953         errseq_t                f_wb_err;
954         errseq_t                f_sb_err; /* for syncfs */
955 } __randomize_layout
956   __attribute__((aligned(4)));  /* lest something weird decides that 2 is OK */
957 
958 struct file_handle {
959         __u32 handle_bytes;
960         int handle_type;
961         /* file identifier */
962         unsigned char f_handle[];
963 };
964 
965 static inline struct file *get_file(struct file *f)
966 {
967         atomic_long_inc(&f->f_count);
968         return f;
969 }
970 #define get_file_rcu_many(x, cnt)       \
971         atomic_long_add_unless(&(x)->f_count, (cnt), 0)
972 #define get_file_rcu(x) get_file_rcu_many((x), 1)
973 #define file_count(x)   atomic_long_read(&(x)->f_count)
974 
975 #define MAX_NON_LFS     ((1UL<<31) - 1)
976 
977 /* Page cache limit. The filesystems should put that into their s_maxbytes 
978    limits, otherwise bad things can happen in VM. */ 
979 #if BITS_PER_LONG==32
980 #define MAX_LFS_FILESIZE        ((loff_t)ULONG_MAX << PAGE_SHIFT)
981 #elif BITS_PER_LONG==64
982 #define MAX_LFS_FILESIZE        ((loff_t)LLONG_MAX)
983 #endif
984 
985 #define FL_POSIX        1
986 #define FL_FLOCK        2
987 #define FL_DELEG        4       /* NFSv4 delegation */
988 #define FL_ACCESS       8       /* not trying to lock, just looking */
989 #define FL_EXISTS       16      /* when unlocking, test for existence */
990 #define FL_LEASE        32      /* lease held on this file */
991 #define FL_CLOSE        64      /* unlock on close */
992 #define FL_SLEEP        128     /* A blocking lock */
993 #define FL_DOWNGRADE_PENDING    256 /* Lease is being downgraded */
994 #define FL_UNLOCK_PENDING       512 /* Lease is being broken */
995 #define FL_OFDLCK       1024    /* lock is "owned" by struct file */
996 #define FL_LAYOUT       2048    /* outstanding pNFS layout */
997 
998 #define FL_CLOSE_POSIX (FL_POSIX | FL_CLOSE)
999 
1000 /*
1001  * Special return value from posix_lock_file() and vfs_lock_file() for
1002  * asynchronous locking.
1003  */
1004 #define FILE_LOCK_DEFERRED 1
1005 
1006 /* legacy typedef, should eventually be removed */
1007 typedef void *fl_owner_t;
1008 
1009 struct file_lock;
1010 
1011 struct file_lock_operations {
1012         void (*fl_copy_lock)(struct file_lock *, struct file_lock *);
1013         void (*fl_release_private)(struct file_lock *);
1014 };
1015 
1016 struct lock_manager_operations {
1017         fl_owner_t (*lm_get_owner)(fl_owner_t);
1018         void (*lm_put_owner)(fl_owner_t);
1019         void (*lm_notify)(struct file_lock *);  /* unblock callback */
1020         int (*lm_grant)(struct file_lock *, int);
1021         bool (*lm_break)(struct file_lock *);
1022         int (*lm_change)(struct file_lock *, int, struct list_head *);
1023         void (*lm_setup)(struct file_lock *, void **);
1024         bool (*lm_breaker_owns_lease)(struct file_lock *);
1025 };
1026 
1027 struct lock_manager {
1028         struct list_head list;
1029         /*
1030          * NFSv4 and up also want opens blocked during the grace period;
1031          * NLM doesn't care:
1032          */
1033         bool block_opens;
1034 };
1035 
1036 struct net;
1037 void locks_start_grace(struct net *, struct lock_manager *);
1038 void locks_end_grace(struct lock_manager *);
1039 bool locks_in_grace(struct net *);
1040 bool opens_in_grace(struct net *);
1041 
1042 /* that will die - we need it for nfs_lock_info */
1043 #include <linux/nfs_fs_i.h>
1044 
1045 /*
1046  * struct file_lock represents a generic "file lock". It's used to represent
1047  * POSIX byte range locks, BSD (flock) locks, and leases. It's important to
1048  * note that the same struct is used to represent both a request for a lock and
1049  * the lock itself, but the same object is never used for both.
1050  *
1051  * FIXME: should we create a separate "struct lock_request" to help distinguish
1052  * these two uses?
1053  *
1054  * The varous i_flctx lists are ordered by:
1055  *
1056  * 1) lock owner
1057  * 2) lock range start
1058  * 3) lock range end
1059  *
1060  * Obviously, the last two criteria only matter for POSIX locks.
1061  */
1062 struct file_lock {
1063         struct file_lock *fl_blocker;   /* The lock, that is blocking us */
1064         struct list_head fl_list;       /* link into file_lock_context */
1065         struct hlist_node fl_link;      /* node in global lists */
1066         struct list_head fl_blocked_requests;   /* list of requests with
1067                                                  * ->fl_blocker pointing here
1068                                                  */
1069         struct list_head fl_blocked_member;     /* node in
1070                                                  * ->fl_blocker->fl_blocked_requests
1071                                                  */
1072         fl_owner_t fl_owner;
1073         unsigned int fl_flags;
1074         unsigned char fl_type;
1075         unsigned int fl_pid;
1076         int fl_link_cpu;                /* what cpu's list is this on? */
1077         wait_queue_head_t fl_wait;
1078         struct file *fl_file;
1079         loff_t fl_start;
1080         loff_t fl_end;
1081 
1082         struct fasync_struct *  fl_fasync; /* for lease break notifications */
1083         /* for lease breaks: */
1084         unsigned long fl_break_time;
1085         unsigned long fl_downgrade_time;
1086 
1087         const struct file_lock_operations *fl_ops;      /* Callbacks for filesystems */
1088         const struct lock_manager_operations *fl_lmops; /* Callbacks for lockmanagers */
1089         union {
1090                 struct nfs_lock_info    nfs_fl;
1091                 struct nfs4_lock_info   nfs4_fl;
1092                 struct {
1093                         struct list_head link;  /* link in AFS vnode's pending_locks list */
1094                         int state;              /* state of grant or error if -ve */
1095                         unsigned int    debug_id;
1096                 } afs;
1097         } fl_u;
1098 } __randomize_layout;
1099 
1100 struct file_lock_context {
1101         spinlock_t              flc_lock;
1102         struct list_head        flc_flock;
1103         struct list_head        flc_posix;
1104         struct list_head        flc_lease;
1105 };
1106 
1107 /* The following constant reflects the upper bound of the file/locking space */
1108 #ifndef OFFSET_MAX
1109 #define INT_LIMIT(x)    (~((x)1 << (sizeof(x)*8 - 1)))
1110 #define OFFSET_MAX      INT_LIMIT(loff_t)
1111 #define OFFT_OFFSET_MAX INT_LIMIT(off_t)
1112 #endif
1113 
1114 extern void send_sigio(struct fown_struct *fown, int fd, int band);
1115 
1116 #define locks_inode(f) file_inode(f)
1117 
1118 #ifdef CONFIG_FILE_LOCKING
1119 extern int fcntl_getlk(struct file *, unsigned int, struct flock *);
1120 extern int fcntl_setlk(unsigned int, struct file *, unsigned int,
1121                         struct flock *);
1122 
1123 #if BITS_PER_LONG == 32
1124 extern int fcntl_getlk64(struct file *, unsigned int, struct flock64 *);
1125 extern int fcntl_setlk64(unsigned int, struct file *, unsigned int,
1126                         struct flock64 *);
1127 #endif
1128 
1129 extern int fcntl_setlease(unsigned int fd, struct file *filp, long arg);
1130 extern int fcntl_getlease(struct file *filp);
1131 
1132 /* fs/locks.c */
1133 void locks_free_lock_context(struct inode *inode);
1134 void locks_free_lock(struct file_lock *fl);
1135 extern void locks_init_lock(struct file_lock *);
1136 extern struct file_lock * locks_alloc_lock(void);
1137 extern void locks_copy_lock(struct file_lock *, struct file_lock *);
1138 extern void locks_copy_conflock(struct file_lock *, struct file_lock *);
1139 extern void locks_remove_posix(struct file *, fl_owner_t);
1140 extern void locks_remove_file(struct file *);
1141 extern void locks_release_private(struct file_lock *);
1142 extern void posix_test_lock(struct file *, struct file_lock *);
1143 extern int posix_lock_file(struct file *, struct file_lock *, struct file_lock *);
1144 extern int locks_delete_block(struct file_lock *);
1145 extern int vfs_test_lock(struct file *, struct file_lock *);
1146 extern int vfs_lock_file(struct file *, unsigned int, struct file_lock *, struct file_lock *);
1147 extern int vfs_cancel_lock(struct file *filp, struct file_lock *fl);
1148 extern int locks_lock_inode_wait(struct inode *inode, struct file_lock *fl);
1149 extern int __break_lease(struct inode *inode, unsigned int flags, unsigned int type);
1150 extern void lease_get_mtime(struct inode *, struct timespec64 *time);
1151 extern int generic_setlease(struct file *, long, struct file_lock **, void **priv);
1152 extern int vfs_setlease(struct file *, long, struct file_lock **, void **);
1153 extern int lease_modify(struct file_lock *, int, struct list_head *);
1154 
1155 struct notifier_block;
1156 extern int lease_register_notifier(struct notifier_block *);
1157 extern void lease_unregister_notifier(struct notifier_block *);
1158 
1159 struct files_struct;
1160 extern void show_fd_locks(struct seq_file *f,
1161                          struct file *filp, struct files_struct *files);
1162 #else /* !CONFIG_FILE_LOCKING */
1163 static inline int fcntl_getlk(struct file *file, unsigned int cmd,
1164                               struct flock __user *user)
1165 {
1166         return -EINVAL;
1167 }
1168 
1169 static inline int fcntl_setlk(unsigned int fd, struct file *file,
1170                               unsigned int cmd, struct flock __user *user)
1171 {
1172         return -EACCES;
1173 }
1174 
1175 #if BITS_PER_LONG == 32
1176 static inline int fcntl_getlk64(struct file *file, unsigned int cmd,
1177                                 struct flock64 __user *user)
1178 {
1179         return -EINVAL;
1180 }
1181 
1182 static inline int fcntl_setlk64(unsigned int fd, struct file *file,
1183                                 unsigned int cmd, struct flock64 __user *user)
1184 {
1185         return -EACCES;
1186 }
1187 #endif
1188 static inline int fcntl_setlease(unsigned int fd, struct file *filp, long arg)
1189 {
1190         return -EINVAL;
1191 }
1192 
1193 static inline int fcntl_getlease(struct file *filp)
1194 {
1195         return F_UNLCK;
1196 }
1197 
1198 static inline void
1199 locks_free_lock_context(struct inode *inode)
1200 {
1201 }
1202 
1203 static inline void locks_init_lock(struct file_lock *fl)
1204 {
1205         return;
1206 }
1207 
1208 static inline void locks_copy_conflock(struct file_lock *new, struct file_lock *fl)
1209 {
1210         return;
1211 }
1212 
1213 static inline void locks_copy_lock(struct file_lock *new, struct file_lock *fl)
1214 {
1215         return;
1216 }
1217 
1218 static inline void locks_remove_posix(struct file *filp, fl_owner_t owner)
1219 {
1220         return;
1221 }
1222 
1223 static inline void locks_remove_file(struct file *filp)
1224 {
1225         return;
1226 }
1227 
1228 static inline void posix_test_lock(struct file *filp, struct file_lock *fl)
1229 {
1230         return;
1231 }
1232 
1233 static inline int posix_lock_file(struct file *filp, struct file_lock *fl,
1234                                   struct file_lock *conflock)
1235 {
1236         return -ENOLCK;
1237 }
1238 
1239 static inline int locks_delete_block(struct file_lock *waiter)
1240 {
1241         return -ENOENT;
1242 }
1243 
1244 static inline int vfs_test_lock(struct file *filp, struct file_lock *fl)
1245 {
1246         return 0;
1247 }
1248 
1249 static inline int vfs_lock_file(struct file *filp, unsigned int cmd,
1250                                 struct file_lock *fl, struct file_lock *conf)
1251 {
1252         return -ENOLCK;
1253 }
1254 
1255 static inline int vfs_cancel_lock(struct file *filp, struct file_lock *fl)
1256 {
1257         return 0;
1258 }
1259 
1260 static inline int locks_lock_inode_wait(struct inode *inode, struct file_lock *fl)
1261 {
1262         return -ENOLCK;
1263 }
1264 
1265 static inline int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
1266 {
1267         return 0;
1268 }
1269 
1270 static inline void lease_get_mtime(struct inode *inode,
1271                                    struct timespec64 *time)
1272 {
1273         return;
1274 }
1275 
1276 static inline int generic_setlease(struct file *filp, long arg,
1277                                     struct file_lock **flp, void **priv)
1278 {
1279         return -EINVAL;
1280 }
1281 
1282 static inline int vfs_setlease(struct file *filp, long arg,
1283                                struct file_lock **lease, void **priv)
1284 {
1285         return -EINVAL;
1286 }
1287 
1288 static inline int lease_modify(struct file_lock *fl, int arg,
1289                                struct list_head *dispose)
1290 {
1291         return -EINVAL;
1292 }
1293 
1294 struct files_struct;
1295 static inline void show_fd_locks(struct seq_file *f,
1296                         struct file *filp, struct files_struct *files) {}
1297 #endif /* !CONFIG_FILE_LOCKING */
1298 
1299 static inline struct inode *file_inode(const struct file *f)
1300 {
1301         return f->f_inode;
1302 }
1303 
1304 static inline struct dentry *file_dentry(const struct file *file)
1305 {
1306         return d_real(file->f_path.dentry, file_inode(file));
1307 }
1308 
1309 static inline int locks_lock_file_wait(struct file *filp, struct file_lock *fl)
1310 {
1311         return locks_lock_inode_wait(locks_inode(filp), fl);
1312 }
1313 
1314 struct fasync_struct {
1315         rwlock_t                fa_lock;
1316         int                     magic;
1317         int                     fa_fd;
1318         struct fasync_struct    *fa_next; /* singly linked list */
1319         struct file             *fa_file;
1320         struct rcu_head         fa_rcu;
1321 };
1322 
1323 #define FASYNC_MAGIC 0x4601
1324 
1325 /* SMP safe fasync helpers: */
1326 extern int fasync_helper(int, struct file *, int, struct fasync_struct **);
1327 extern struct fasync_struct *fasync_insert_entry(int, struct file *, struct fasync_struct **, struct fasync_struct *);
1328 extern int fasync_remove_entry(struct file *, struct fasync_struct **);
1329 extern struct fasync_struct *fasync_alloc(void);
1330 extern void fasync_free(struct fasync_struct *);
1331 
1332 /* can be called from interrupts */
1333 extern void kill_fasync(struct fasync_struct **, int, int);
1334 
1335 extern void __f_setown(struct file *filp, struct pid *, enum pid_type, int force);
1336 extern int f_setown(struct file *filp, unsigned long arg, int force);
1337 extern void f_delown(struct file *filp);
1338 extern pid_t f_getown(struct file *filp);
1339 extern int send_sigurg(struct fown_struct *fown);
1340 
1341 /*
1342  * sb->s_flags.  Note that these mirror the equivalent MS_* flags where
1343  * represented in both.
1344  */
1345 #define SB_RDONLY        1      /* Mount read-only */
1346 #define SB_NOSUID        2      /* Ignore suid and sgid bits */
1347 #define SB_NODEV         4      /* Disallow access to device special files */
1348 #define SB_NOEXEC        8      /* Disallow program execution */
1349 #define SB_SYNCHRONOUS  16      /* Writes are synced at once */
1350 #define SB_MANDLOCK     64      /* Allow mandatory locks on an FS */
1351 #define SB_DIRSYNC      128     /* Directory modifications are synchronous */
1352 #define SB_NOATIME      1024    /* Do not update access times. */
1353 #define SB_NODIRATIME   2048    /* Do not update directory access times */
1354 #define SB_SILENT       32768
1355 #define SB_POSIXACL     (1<<16) /* VFS does not apply the umask */
1356 #define SB_INLINECRYPT  (1<<17) /* Use blk-crypto for encrypted files */
1357 #define SB_KERNMOUNT    (1<<22) /* this is a kern_mount call */
1358 #define SB_I_VERSION    (1<<23) /* Update inode I_version field */
1359 #define SB_LAZYTIME     (1<<25) /* Update the on-disk [acm]times lazily */
1360 
1361 /* These sb flags are internal to the kernel */
1362 #define SB_SUBMOUNT     (1<<26)
1363 #define SB_FORCE        (1<<27)
1364 #define SB_NOSEC        (1<<28)
1365 #define SB_BORN         (1<<29)
1366 #define SB_ACTIVE       (1<<30)
1367 #define SB_NOUSER       (1<<31)
1368 
1369 /* These flags relate to encoding and casefolding */
1370 #define SB_ENC_STRICT_MODE_FL   (1 << 0)
1371 
1372 #define sb_has_strict_encoding(sb) \
1373         (sb->s_encoding_flags & SB_ENC_STRICT_MODE_FL)
1374 
1375 /*
1376  *      Umount options
1377  */
1378 
1379 #define MNT_FORCE       0x00000001      /* Attempt to forcibily umount */
1380 #define MNT_DETACH      0x00000002      /* Just detach from the tree */
1381 #define MNT_EXPIRE      0x00000004      /* Mark for expiry */
1382 #define UMOUNT_NOFOLLOW 0x00000008      /* Don't follow symlink on umount */
1383 #define UMOUNT_UNUSED   0x80000000      /* Flag guaranteed to be unused */
1384 
1385 /* sb->s_iflags */
1386 #define SB_I_CGROUPWB   0x00000001      /* cgroup-aware writeback enabled */
1387 #define SB_I_NOEXEC     0x00000002      /* Ignore executables on this fs */
1388 #define SB_I_NODEV      0x00000004      /* Ignore devices on this fs */
1389 #define SB_I_STABLE_WRITES 0x00000008   /* don't modify blks until WB is done */
1390 
1391 /* sb->s_iflags to limit user namespace mounts */
1392 #define SB_I_USERNS_VISIBLE             0x00000010 /* fstype already mounted */
1393 #define SB_I_IMA_UNVERIFIABLE_SIGNATURE 0x00000020
1394 #define SB_I_UNTRUSTED_MOUNTER          0x00000040
1395 
1396 #define SB_I_SKIP_SYNC  0x00000100      /* Skip superblock at global sync */
1397 
1398 /* Possible states of 'frozen' field */
1399 enum {
1400         SB_UNFROZEN = 0,                /* FS is unfrozen */
1401         SB_FREEZE_WRITE = 1,            /* Writes, dir ops, ioctls frozen */
1402         SB_FREEZE_PAGEFAULT = 2,        /* Page faults stopped as well */
1403         SB_FREEZE_FS = 3,               /* For internal FS use (e.g. to stop
1404                                          * internal threads if needed) */
1405         SB_FREEZE_COMPLETE = 4,         /* ->freeze_fs finished successfully */
1406 };
1407 
1408 #define SB_FREEZE_LEVELS (SB_FREEZE_COMPLETE - 1)
1409 
1410 struct sb_writers {
1411         int                             frozen;         /* Is sb frozen? */
1412         wait_queue_head_t               wait_unfrozen;  /* wait for thaw */
1413         struct percpu_rw_semaphore      rw_sem[SB_FREEZE_LEVELS];
1414 };
1415 
1416 struct super_block {
1417         struct list_head        s_list;         /* Keep this first */
1418         dev_t                   s_dev;          /* search index; _not_ kdev_t */
1419         unsigned char           s_blocksize_bits;
1420         unsigned long           s_blocksize;
1421         loff_t                  s_maxbytes;     /* Max file size */
1422         struct file_system_type *s_type;
1423         const struct super_operations   *s_op;
1424         const struct dquot_operations   *dq_op;
1425         const struct quotactl_ops       *s_qcop;
1426         const struct export_operations *s_export_op;
1427         unsigned long           s_flags;
1428         unsigned long           s_iflags;       /* internal SB_I_* flags */
1429         unsigned long           s_magic;
1430         struct dentry           *s_root;
1431         struct rw_semaphore     s_umount;
1432         int                     s_count;
1433         atomic_t                s_active;
1434 #ifdef CONFIG_SECURITY
1435         void                    *s_security;
1436 #endif
1437         const struct xattr_handler **s_xattr;
1438 #ifdef CONFIG_FS_ENCRYPTION
1439         const struct fscrypt_operations *s_cop;
1440         struct key              *s_master_keys; /* master crypto keys in use */
1441 #endif
1442 #ifdef CONFIG_FS_VERITY
1443         const struct fsverity_operations *s_vop;
1444 #endif
1445 #ifdef CONFIG_UNICODE
1446         struct unicode_map *s_encoding;
1447         __u16 s_encoding_flags;
1448 #endif
1449         struct hlist_bl_head    s_roots;        /* alternate root dentries for NFS */
1450         struct list_head        s_mounts;       /* list of mounts; _not_ for fs use */
1451         struct block_device     *s_bdev;
1452         struct backing_dev_info *s_bdi;
1453         struct mtd_info         *s_mtd;
1454         struct hlist_node       s_instances;
1455         unsigned int            s_quota_types;  /* Bitmask of supported quota types */
1456         struct quota_info       s_dquot;        /* Diskquota specific options */
1457 
1458         struct sb_writers       s_writers;
1459 
1460         /*
1461          * Keep s_fs_info, s_time_gran, s_fsnotify_mask, and
1462          * s_fsnotify_marks together for cache efficiency. They are frequently
1463          * accessed and rarely modified.
1464          */
1465         void                    *s_fs_info;     /* Filesystem private info */
1466 
1467         /* Granularity of c/m/atime in ns (cannot be worse than a second) */
1468         u32                     s_time_gran;
1469         /* Time limits for c/m/atime in seconds */
1470         time64_t                   s_time_min;
1471         time64_t                   s_time_max;
1472 #ifdef CONFIG_FSNOTIFY
1473         __u32                   s_fsnotify_mask;
1474         struct fsnotify_mark_connector __rcu    *s_fsnotify_marks;
1475 #endif
1476 
1477         char                    s_id[32];       /* Informational name */
1478         uuid_t                  s_uuid;         /* UUID */
1479 
1480         unsigned int            s_max_links;
1481         fmode_t                 s_mode;
1482 
1483         /*
1484          * The next field is for VFS *only*. No filesystems have any business
1485          * even looking at it. You had been warned.
1486          */
1487         struct mutex s_vfs_rename_mutex;        /* Kludge */
1488 
1489         /*
1490          * Filesystem subtype.  If non-empty the filesystem type field
1491          * in /proc/mounts will be "type.subtype"
1492          */
1493         const char *s_subtype;
1494 
1495         const struct dentry_operations *s_d_op; /* default d_op for dentries */
1496 
1497         /*
1498          * Saved pool identifier for cleancache (-1 means none)
1499          */
1500         int cleancache_poolid;
1501 
1502         struct shrinker s_shrink;       /* per-sb shrinker handle */
1503 
1504         /* Number of inodes with nlink == 0 but still referenced */
1505         atomic_long_t s_remove_count;
1506 
1507         /* Pending fsnotify inode refs */
1508         atomic_long_t s_fsnotify_inode_refs;
1509 
1510         /* Being remounted read-only */
1511         int s_readonly_remount;
1512 
1513         /* per-sb errseq_t for reporting writeback errors via syncfs */
1514         errseq_t s_wb_err;
1515 
1516         /* AIO completions deferred from interrupt context */
1517         struct workqueue_struct *s_dio_done_wq;
1518         struct hlist_head s_pins;
1519 
1520         /*
1521          * Owning user namespace and default context in which to
1522          * interpret filesystem uids, gids, quotas, device nodes,
1523          * xattrs and security labels.
1524          */
1525         struct user_namespace *s_user_ns;
1526 
1527         /*
1528          * The list_lru structure is essentially just a pointer to a table
1529          * of per-node lru lists, each of which has its own spinlock.
1530          * There is no need to put them into separate cachelines.
1531          */
1532         struct list_lru         s_dentry_lru;
1533         struct list_lru         s_inode_lru;
1534         struct rcu_head         rcu;
1535         struct work_struct      destroy_work;
1536 
1537         struct mutex            s_sync_lock;    /* sync serialisation lock */
1538 
1539         /*
1540          * Indicates how deep in a filesystem stack this SB is
1541          */
1542         int s_stack_depth;
1543 
1544         /* s_inode_list_lock protects s_inodes */
1545         spinlock_t              s_inode_list_lock ____cacheline_aligned_in_smp;
1546         struct list_head        s_inodes;       /* all inodes */
1547 
1548         spinlock_t              s_inode_wblist_lock;
1549         struct list_head        s_inodes_wb;    /* writeback inodes */
1550 } __randomize_layout;
1551 
1552 /* Helper functions so that in most cases filesystems will
1553  * not need to deal directly with kuid_t and kgid_t and can
1554  * instead deal with the raw numeric values that are stored
1555  * in the filesystem.
1556  */
1557 static inline uid_t i_uid_read(const struct inode *inode)
1558 {
1559         return from_kuid(inode->i_sb->s_user_ns, inode->i_uid);
1560 }
1561 
1562 static inline gid_t i_gid_read(const struct inode *inode)
1563 {
1564         return from_kgid(inode->i_sb->s_user_ns, inode->i_gid);
1565 }
1566 
1567 static inline void i_uid_write(struct inode *inode, uid_t uid)
1568 {
1569         inode->i_uid = make_kuid(inode->i_sb->s_user_ns, uid);
1570 }
1571 
1572 static inline void i_gid_write(struct inode *inode, gid_t gid)
1573 {
1574         inode->i_gid = make_kgid(inode->i_sb->s_user_ns, gid);
1575 }
1576 
1577 static inline kuid_t kuid_into_mnt(struct user_namespace *mnt_userns,
1578                                    kuid_t kuid)
1579 {
1580         return make_kuid(mnt_userns, __kuid_val(kuid));
1581 }
1582 
1583 static inline kgid_t kgid_into_mnt(struct user_namespace *mnt_userns,
1584                                    kgid_t kgid)
1585 {
1586         return make_kgid(mnt_userns, __kgid_val(kgid));
1587 }
1588 
1589 static inline kuid_t i_uid_into_mnt(struct user_namespace *mnt_userns,
1590                                     const struct inode *inode)
1591 {
1592         return kuid_into_mnt(mnt_userns, inode->i_uid);
1593 }
1594 
1595 static inline kgid_t i_gid_into_mnt(struct user_namespace *mnt_userns,
1596                                     const struct inode *inode)
1597 {
1598         return kgid_into_mnt(mnt_userns, inode->i_gid);
1599 }
1600 
1601 static inline kuid_t kuid_from_mnt(struct user_namespace *mnt_userns,
1602                                    kuid_t kuid)
1603 {
1604         return KUIDT_INIT(from_kuid(mnt_userns, kuid));
1605 }
1606 
1607 static inline kgid_t kgid_from_mnt(struct user_namespace *mnt_userns,
1608                                    kgid_t kgid)
1609 {
1610         return KGIDT_INIT(from_kgid(mnt_userns, kgid));
1611 }
1612 
1613 static inline kuid_t fsuid_into_mnt(struct user_namespace *mnt_userns)
1614 {
1615         return kuid_from_mnt(mnt_userns, current_fsuid());
1616 }
1617 
1618 static inline kgid_t fsgid_into_mnt(struct user_namespace *mnt_userns)
1619 {
1620         return kgid_from_mnt(mnt_userns, current_fsgid());
1621 }
1622 
1623 extern struct timespec64 current_time(struct inode *inode);
1624 
1625 /*
1626  * Snapshotting support.
1627  */
1628 
1629 /*
1630  * These are internal functions, please use sb_start_{write,pagefault,intwrite}
1631  * instead.
1632  */
1633 static inline void __sb_end_write(struct super_block *sb, int level)
1634 {
1635         percpu_up_read(sb->s_writers.rw_sem + level-1);
1636 }
1637 
1638 static inline void __sb_start_write(struct super_block *sb, int level)
1639 {
1640         percpu_down_read(sb->s_writers.rw_sem + level - 1);
1641 }
1642 
1643 static inline bool __sb_start_write_trylock(struct super_block *sb, int level)
1644 {
1645         return percpu_down_read_trylock(sb->s_writers.rw_sem + level - 1);
1646 }
1647 
1648 #define __sb_writers_acquired(sb, lev)  \
1649         percpu_rwsem_acquire(&(sb)->s_writers.rw_sem[(lev)-1], 1, _THIS_IP_)
1650 #define __sb_writers_release(sb, lev)   \
1651         percpu_rwsem_release(&(sb)->s_writers.rw_sem[(lev)-1], 1, _THIS_IP_)
1652 
1653 /**
1654  * sb_end_write - drop write access to a superblock
1655  * @sb: the super we wrote to
1656  *
1657  * Decrement number of writers to the filesystem. Wake up possible waiters
1658  * wanting to freeze the filesystem.
1659  */
1660 static inline void sb_end_write(struct super_block *sb)
1661 {
1662         __sb_end_write(sb, SB_FREEZE_WRITE);
1663 }
1664 
1665 /**
1666  * sb_end_pagefault - drop write access to a superblock from a page fault
1667  * @sb: the super we wrote to
1668  *
1669  * Decrement number of processes handling write page fault to the filesystem.
1670  * Wake up possible waiters wanting to freeze the filesystem.
1671  */
1672 static inline void sb_end_pagefault(struct super_block *sb)
1673 {
1674         __sb_end_write(sb, SB_FREEZE_PAGEFAULT);
1675 }
1676 
1677 /**
1678  * sb_end_intwrite - drop write access to a superblock for internal fs purposes
1679  * @sb: the super we wrote to
1680  *
1681  * Decrement fs-internal number of writers to the filesystem.  Wake up possible
1682  * waiters wanting to freeze the filesystem.
1683  */
1684 static inline void sb_end_intwrite(struct super_block *sb)
1685 {
1686         __sb_end_write(sb, SB_FREEZE_FS);
1687 }
1688 
1689 /**
1690  * sb_start_write - get write access to a superblock
1691  * @sb: the super we write to
1692  *
1693  * When a process wants to write data or metadata to a file system (i.e. dirty
1694  * a page or an inode), it should embed the operation in a sb_start_write() -
1695  * sb_end_write() pair to get exclusion against file system freezing. This
1696  * function increments number of writers preventing freezing. If the file
1697  * system is already frozen, the function waits until the file system is
1698  * thawed.
1699  *
1700  * Since freeze protection behaves as a lock, users have to preserve
1701  * ordering of freeze protection and other filesystem locks. Generally,
1702  * freeze protection should be the outermost lock. In particular, we have:
1703  *
1704  * sb_start_write
1705  *   -> i_mutex                 (write path, truncate, directory ops, ...)
1706  *   -> s_umount                (freeze_super, thaw_super)
1707  */
1708 static inline void sb_start_write(struct super_block *sb)
1709 {
1710         __sb_start_write(sb, SB_FREEZE_WRITE);
1711 }
1712 
1713 static inline bool sb_start_write_trylock(struct super_block *sb)
1714 {
1715         return __sb_start_write_trylock(sb, SB_FREEZE_WRITE);
1716 }
1717 
1718 /**
1719  * sb_start_pagefault - get write access to a superblock from a page fault
1720  * @sb: the super we write to
1721  *
1722  * When a process starts handling write page fault, it should embed the
1723  * operation into sb_start_pagefault() - sb_end_pagefault() pair to get
1724  * exclusion against file system freezing. This is needed since the page fault
1725  * is going to dirty a page. This function increments number of running page
1726  * faults preventing freezing. If the file system is already frozen, the
1727  * function waits until the file system is thawed.
1728  *
1729  * Since page fault freeze protection behaves as a lock, users have to preserve
1730  * ordering of freeze protection and other filesystem locks. It is advised to
1731  * put sb_start_pagefault() close to mmap_lock in lock ordering. Page fault
1732  * handling code implies lock dependency:
1733  *
1734  * mmap_lock
1735  *   -> sb_start_pagefault
1736  */
1737 static inline void sb_start_pagefault(struct super_block *sb)
1738 {
1739         __sb_start_write(sb, SB_FREEZE_PAGEFAULT);
1740 }
1741 
1742 /*
1743  * sb_start_intwrite - get write access to a superblock for internal fs purposes
1744  * @sb: the super we write to
1745  *
1746  * This is the third level of protection against filesystem freezing. It is
1747  * free for use by a filesystem. The only requirement is that it must rank
1748  * below sb_start_pagefault.
1749  *
1750  * For example filesystem can call sb_start_intwrite() when starting a
1751  * transaction which somewhat eases handling of freezing for internal sources
1752  * of filesystem changes (internal fs threads, discarding preallocation on file
1753  * close, etc.).
1754  */
1755 static inline void sb_start_intwrite(struct super_block *sb)
1756 {
1757         __sb_start_write(sb, SB_FREEZE_FS);
1758 }
1759 
1760 static inline bool sb_start_intwrite_trylock(struct super_block *sb)
1761 {
1762         return __sb_start_write_trylock(sb, SB_FREEZE_FS);
1763 }
1764 
1765 bool inode_owner_or_capable(struct user_namespace *mnt_userns,
1766                             const struct inode *inode);
1767 
1768 /*
1769  * VFS helper functions..
1770  */
1771 int vfs_create(struct user_namespace *, struct inode *,
1772                struct dentry *, umode_t, bool);
1773 int vfs_mkdir(struct user_namespace *, struct inode *,
1774               struct dentry *, umode_t);
1775 int vfs_mknod(struct user_namespace *, struct inode *, struct dentry *,
1776               umode_t, dev_t);
1777 int vfs_symlink(struct user_namespace *, struct inode *,
1778                 struct dentry *, const char *);
1779 int vfs_link(struct dentry *, struct user_namespace *, struct inode *,
1780              struct dentry *, struct inode **);
1781 int vfs_rmdir(struct user_namespace *, struct inode *, struct dentry *);
1782 int vfs_unlink(struct user_namespace *, struct inode *, struct dentry *,
1783                struct inode **);
1784 
1785 struct renamedata {
1786         struct user_namespace *old_mnt_userns;
1787         struct inode *old_dir;
1788         struct dentry *old_dentry;
1789         struct user_namespace *new_mnt_userns;
1790         struct inode *new_dir;
1791         struct dentry *new_dentry;
1792         struct inode **delegated_inode;
1793         unsigned int flags;
1794 } __randomize_layout;
1795 
1796 int vfs_rename(struct renamedata *);
1797 
1798 static inline int vfs_whiteout(struct user_namespace *mnt_userns,
1799                                struct inode *dir, struct dentry *dentry)
1800 {
1801         return vfs_mknod(mnt_userns, dir, dentry, S_IFCHR | WHITEOUT_MODE,
1802                          WHITEOUT_DEV);
1803 }
1804 
1805 struct dentry *vfs_tmpfile(struct user_namespace *mnt_userns,
1806                            struct dentry *dentry, umode_t mode, int open_flag);
1807 
1808 int vfs_mkobj(struct dentry *, umode_t,
1809                 int (*f)(struct dentry *, umode_t, void *),
1810                 void *);
1811 
1812 int vfs_fchown(struct file *file, uid_t user, gid_t group);
1813 int vfs_fchmod(struct file *file, umode_t mode);
1814 int vfs_utimes(const struct path *path, struct timespec64 *times);
1815 
1816 extern long vfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
1817 
1818 #ifdef CONFIG_COMPAT
1819 extern long compat_ptr_ioctl(struct file *file, unsigned int cmd,
1820                                         unsigned long arg);
1821 #else
1822 #define compat_ptr_ioctl NULL
1823 #endif
1824 
1825 /*
1826  * VFS file helper functions.
1827  */
1828 void inode_init_owner(struct user_namespace *mnt_userns, struct inode *inode,
1829                       const struct inode *dir, umode_t mode);
1830 extern bool may_open_dev(const struct path *path);
1831 
1832 /*
1833  * This is the "filldir" function type, used by readdir() to let
1834  * the kernel specify what kind of dirent layout it wants to have.
1835  * This allows the kernel to read directories into kernel space or
1836  * to have different dirent layouts depending on the binary type.
1837  */
1838 struct dir_context;
1839 typedef int (*filldir_t)(struct dir_context *, const char *, int, loff_t, u64,
1840                          unsigned);
1841 
1842 struct dir_context {
1843         filldir_t actor;
1844         loff_t pos;
1845 };
1846 
1847 /*
1848  * These flags let !MMU mmap() govern direct device mapping vs immediate
1849  * copying more easily for MAP_PRIVATE, especially for ROM filesystems.
1850  *
1851  * NOMMU_MAP_COPY:      Copy can be mapped (MAP_PRIVATE)
1852  * NOMMU_MAP_DIRECT:    Can be mapped directly (MAP_SHARED)
1853  * NOMMU_MAP_READ:      Can be mapped for reading
1854  * NOMMU_MAP_WRITE:     Can be mapped for writing
1855  * NOMMU_MAP_EXEC:      Can be mapped for execution
1856  */
1857 #define NOMMU_MAP_COPY          0x00000001
1858 #define NOMMU_MAP_DIRECT        0x00000008
1859 #define NOMMU_MAP_READ          VM_MAYREAD
1860 #define NOMMU_MAP_WRITE         VM_MAYWRITE
1861 #define NOMMU_MAP_EXEC          VM_MAYEXEC
1862 
1863 #define NOMMU_VMFLAGS \
1864         (NOMMU_MAP_READ | NOMMU_MAP_WRITE | NOMMU_MAP_EXEC)
1865 
1866 /*
1867  * These flags control the behavior of the remap_file_range function pointer.
1868  * If it is called with len == 0 that means "remap to end of source file".
1869  * See Documentation/filesystems/vfs.rst for more details about this call.
1870  *
1871  * REMAP_FILE_DEDUP: only remap if contents identical (i.e. deduplicate)
1872  * REMAP_FILE_CAN_SHORTEN: caller can handle a shortened request
1873  */
1874 #define REMAP_FILE_DEDUP                (1 << 0)
1875 #define REMAP_FILE_CAN_SHORTEN          (1 << 1)
1876 
1877 /*
1878  * These flags signal that the caller is ok with altering various aspects of
1879  * the behavior of the remap operation.  The changes must be made by the
1880  * implementation; the vfs remap helper functions can take advantage of them.
1881  * Flags in this category exist to preserve the quirky behavior of the hoisted
1882  * btrfs clone/dedupe ioctls.
1883  */
1884 #define REMAP_FILE_ADVISORY             (REMAP_FILE_CAN_SHORTEN)
1885 
1886 struct iov_iter;
1887 
1888 struct file_operations {
1889         struct module *owner;
1890         loff_t (*llseek) (struct file *, loff_t, int);
1891         ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
1892         ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
1893         ssize_t (*read_iter) (struct kiocb *, struct iov_iter *);
1894         ssize_t (*write_iter) (struct kiocb *, struct iov_iter *);
1895         int (*iopoll)(struct kiocb *kiocb, bool spin);
1896         int (*iterate) (struct file *, struct dir_context *);
1897         int (*iterate_shared) (struct file *, struct dir_context *);
1898         __poll_t (*poll) (struct file *, struct poll_table_struct *);
1899         long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
1900         long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
1901         int (*mmap) (struct file *, struct vm_area_struct *);
1902         unsigned long mmap_supported_flags;
1903         int (*open) (struct inode *, struct file *);
1904         int (*flush) (struct file *, fl_owner_t id);
1905         int (*release) (struct inode *, struct file *);
1906         int (*fsync) (struct file *, loff_t, loff_t, int datasync);
1907         int (*fasync) (int, struct file *, int);
1908         int (*lock) (struct file *, int, struct file_lock *);
1909         ssize_t (*sendpage) (struct file *, struct page *, int, size_t, loff_t *, int);
1910         unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
1911         int (*check_flags)(int);
1912         int (*flock) (struct file *, int, struct file_lock *);
1913         ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int);
1914         ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int);
1915         int (*setlease)(struct file *, long, struct file_lock **, void **);
1916         long (*fallocate)(struct file *file, int mode, loff_t offset,
1917                           loff_t len);
1918         void (*show_fdinfo)(struct seq_file *m, struct file *f);
1919 #ifndef CONFIG_MMU
1920         unsigned (*mmap_capabilities)(struct file *);
1921 #endif
1922         ssize_t (*copy_file_range)(struct file *, loff_t, struct file *,
1923                         loff_t, size_t, unsigned int);
1924         loff_t (*remap_file_range)(struct file *file_in, loff_t pos_in,
1925                                    struct file *file_out, loff_t pos_out,
1926                                    loff_t len, unsigned int remap_flags);
1927         int (*fadvise)(struct file *, loff_t, loff_t, int);
1928 } __randomize_layout;
1929 
1930 struct inode_operations {
1931         struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int);
1932         const char * (*get_link) (struct dentry *, struct inode *, struct delayed_call *);
1933         int (*permission) (struct user_namespace *, struct inode *, int);
1934         struct posix_acl * (*get_acl)(struct inode *, int);
1935 
1936         int (*readlink) (struct dentry *, char __user *,int);
1937 
1938         int (*create) (struct user_namespace *, struct inode *,struct dentry *,
1939                        umode_t, bool);
1940         int (*link) (struct dentry *,struct inode *,struct dentry *);
1941         int (*unlink) (struct inode *,struct dentry *);
1942         int (*symlink) (struct user_namespace *, struct inode *,struct dentry *,
1943                         const char *);
1944         int (*mkdir) (struct user_namespace *, struct inode *,struct dentry *,
1945                       umode_t);
1946         int (*rmdir) (struct inode *,struct dentry *);
1947         int (*mknod) (struct user_namespace *, struct inode *,struct dentry *,
1948                       umode_t,dev_t);
1949         int (*rename) (struct user_namespace *, struct inode *, struct dentry *,
1950                         struct inode *, struct dentry *, unsigned int);
1951         int (*setattr) (struct user_namespace *, struct dentry *,
1952                         struct iattr *);
1953         int (*getattr) (struct user_namespace *, const struct path *,
1954                         struct kstat *, u32, unsigned int);
1955         ssize_t (*listxattr) (struct dentry *, char *, size_t);
1956         int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start,
1957                       u64 len);
1958         int (*update_time)(struct inode *, struct timespec64 *, int);
1959         int (*atomic_open)(struct inode *, struct dentry *,
1960                            struct file *, unsigned open_flag,
1961                            umode_t create_mode);
1962         int (*tmpfile) (struct user_namespace *, struct inode *,
1963                         struct dentry *, umode_t);
1964         int (*set_acl)(struct user_namespace *, struct inode *,
1965                        struct posix_acl *, int);
1966 } ____cacheline_aligned;
1967 
1968 static inline ssize_t call_read_iter(struct file *file, struct kiocb *kio,
1969                                      struct iov_iter *iter)
1970 {
1971         return file->f_op->read_iter(kio, iter);
1972 }
1973 
1974 static inline ssize_t call_write_iter(struct file *file, struct kiocb *kio,
1975                                       struct iov_iter *iter)
1976 {
1977         return file->f_op->write_iter(kio, iter);
1978 }
1979 
1980 static inline int call_mmap(struct file *file, struct vm_area_struct *vma)
1981 {
1982         return file->f_op->mmap(file, vma);
1983 }
1984 
1985 extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *);
1986 extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *);
1987 extern ssize_t vfs_copy_file_range(struct file *, loff_t , struct file *,
1988                                    loff_t, size_t, unsigned int);
1989 extern ssize_t generic_copy_file_range(struct file *file_in, loff_t pos_in,
1990                                        struct file *file_out, loff_t pos_out,
1991                                        size_t len, unsigned int flags);
1992 extern int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in,
1993                                          struct file *file_out, loff_t pos_out,
1994                                          loff_t *count,
1995                                          unsigned int remap_flags);
1996 extern loff_t do_clone_file_range(struct file *file_in, loff_t pos_in,
1997                                   struct file *file_out, loff_t pos_out,
1998                                   loff_t len, unsigned int remap_flags);
1999 extern loff_t vfs_clone_file_range(struct file *file_in, loff_t pos_in,
2000                                    struct file *file_out, loff_t pos_out,
2001                                    loff_t len, unsigned int remap_flags);
2002 extern int vfs_dedupe_file_range(struct file *file,
2003                                  struct file_dedupe_range *same);
2004 extern loff_t vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos,
2005                                         struct file *dst_file, loff_t dst_pos,
2006                                         loff_t len, unsigned int remap_flags);
2007 
2008 
2009 struct super_operations {
2010         struct inode *(*alloc_inode)(struct super_block *sb);
2011         void (*destroy_inode)(struct inode *);
2012         void (*free_inode)(struct inode *);
2013 
2014         void (*dirty_inode) (struct inode *, int flags);
2015         int (*write_inode) (struct inode *, struct writeback_control *wbc);
2016         int (*drop_inode) (struct inode *);
2017         void (*evict_inode) (struct inode *);
2018         void (*put_super) (struct super_block *);
2019         int (*sync_fs)(struct super_block *sb, int wait);
2020         int (*freeze_super) (struct super_block *);
2021         int (*freeze_fs) (struct super_block *);
2022         int (*thaw_super) (struct super_block *);
2023         int (*unfreeze_fs) (struct super_block *);
2024         int (*statfs) (struct dentry *, struct kstatfs *);
2025         int (*remount_fs) (struct super_block *, int *, char *);
2026         void (*umount_begin) (struct super_block *);
2027 
2028         int (*show_options)(struct seq_file *, struct dentry *);
2029         int (*show_devname)(struct seq_file *, struct dentry *);
2030         int (*show_path)(struct seq_file *, struct dentry *);
2031         int (*show_stats)(struct seq_file *, struct dentry *);
2032 #ifdef CONFIG_QUOTA
2033         ssize_t (*quota_read)(struct super_block *, int, char *, size_t, loff_t);
2034         ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t);
2035         struct dquot **(*get_dquots)(struct inode *);
2036 #endif
2037         int (*bdev_try_to_free_page)(struct super_block*, struct page*, gfp_t);
2038         long (*nr_cached_objects)(struct super_block *,
2039                                   struct shrink_control *);
2040         long (*free_cached_objects)(struct super_block *,
2041                                     struct shrink_control *);
2042 };
2043 
2044 /*
2045  * Inode flags - they have no relation to superblock flags now
2046  */
2047 #define S_SYNC          (1 << 0)  /* Writes are synced at once */
2048 #define S_NOATIME       (1 << 1)  /* Do not update access times */
2049 #define S_APPEND        (1 << 2)  /* Append-only file */
2050 #define S_IMMUTABLE     (1 << 3)  /* Immutable file */
2051 #define S_DEAD          (1 << 4)  /* removed, but still open directory */
2052 #define S_NOQUOTA       (1 << 5)  /* Inode is not counted to quota */
2053 #define S_DIRSYNC       (1 << 6)  /* Directory modifications are synchronous */
2054 #define S_NOCMTIME      (1 << 7)  /* Do not update file c/mtime */
2055 #define S_SWAPFILE      (1 << 8)  /* Do not truncate: swapon got its bmaps */
2056 #define S_PRIVATE       (1 << 9)  /* Inode is fs-internal */
2057 #define S_IMA           (1 << 10) /* Inode has an associated IMA struct */
2058 #define S_AUTOMOUNT     (1 << 11) /* Automount/referral quasi-directory */
2059 #define S_NOSEC         (1 << 12) /* no suid or xattr security attributes */
2060 #ifdef CONFIG_FS_DAX
2061 #define S_DAX           (1 << 13) /* Direct Access, avoiding the page cache */
2062 #else
2063 #define S_DAX           0         /* Make all the DAX code disappear */
2064 #endif
2065 #define S_ENCRYPTED     (1 << 14) /* Encrypted file (using fs/crypto/) */
2066 #define S_CASEFOLD      (1 << 15) /* Casefolded file */
2067 #define S_VERITY        (1 << 16) /* Verity file (using fs/verity/) */
2068 
2069 /*
2070  * Note that nosuid etc flags are inode-specific: setting some file-system
2071  * flags just means all the inodes inherit those flags by default. It might be
2072  * possible to override it selectively if you really wanted to with some
2073  * ioctl() that is not currently implemented.
2074  *
2075  * Exception: SB_RDONLY is always applied to the entire file system.
2076  *
2077  * Unfortunately, it is possible to change a filesystems flags with it mounted
2078  * with files in use.  This means that all of the inodes will not have their
2079  * i_flags updated.  Hence, i_flags no longer inherit the superblock mount
2080  * flags, so these have to be checked separately. -- rmk@arm.uk.linux.org
2081  */
2082 #define __IS_FLG(inode, flg)    ((inode)->i_sb->s_flags & (flg))
2083 
2084 static inline bool sb_rdonly(const struct super_block *sb) { return sb->s_flags & SB_RDONLY; }
2085 #define IS_RDONLY(inode)        sb_rdonly((inode)->i_sb)
2086 #define IS_SYNC(inode)          (__IS_FLG(inode, SB_SYNCHRONOUS) || \
2087                                         ((inode)->i_flags & S_SYNC))
2088 #define IS_DIRSYNC(inode)       (__IS_FLG(inode, SB_SYNCHRONOUS|SB_DIRSYNC) || \
2089                                         ((inode)->i_flags & (S_SYNC|S_DIRSYNC)))
2090 #define IS_MANDLOCK(inode)      __IS_FLG(inode, SB_MANDLOCK)
2091 #define IS_NOATIME(inode)       __IS_FLG(inode, SB_RDONLY|SB_NOATIME)
2092 #define IS_I_VERSION(inode)     __IS_FLG(inode, SB_I_VERSION)
2093 
2094 #define IS_NOQUOTA(inode)       ((inode)->i_flags & S_NOQUOTA)
2095 #define IS_APPEND(inode)        ((inode)->i_flags & S_APPEND)
2096 #define IS_IMMUTABLE(inode)     ((inode)->i_flags & S_IMMUTABLE)
2097 #define IS_POSIXACL(inode)      __IS_FLG(inode, SB_POSIXACL)
2098 
2099 #define IS_DEADDIR(inode)       ((inode)->i_flags & S_DEAD)
2100 #define IS_NOCMTIME(inode)      ((inode)->i_flags & S_NOCMTIME)
2101 #define IS_SWAPFILE(inode)      ((inode)->i_flags & S_SWAPFILE)
2102 #define IS_PRIVATE(inode)       ((inode)->i_flags & S_PRIVATE)
2103 #define IS_IMA(inode)           ((inode)->i_flags & S_IMA)
2104 #define IS_AUTOMOUNT(inode)     ((inode)->i_flags & S_AUTOMOUNT)
2105 #define IS_NOSEC(inode)         ((inode)->i_flags & S_NOSEC)
2106 #define IS_DAX(inode)           ((inode)->i_flags & S_DAX)
2107 #define IS_ENCRYPTED(inode)     ((inode)->i_flags & S_ENCRYPTED)
2108 #define IS_CASEFOLDED(inode)    ((inode)->i_flags & S_CASEFOLD)
2109 #define IS_VERITY(inode)        ((inode)->i_flags & S_VERITY)
2110 
2111 #define IS_WHITEOUT(inode)      (S_ISCHR(inode->i_mode) && \
2112                                  (inode)->i_rdev == WHITEOUT_DEV)
2113 
2114 static inline bool HAS_UNMAPPED_ID(struct user_namespace *mnt_userns,
2115                                    struct inode *inode)
2116 {
2117         return !uid_valid(i_uid_into_mnt(mnt_userns, inode)) ||
2118                !gid_valid(i_gid_into_mnt(mnt_userns, inode));
2119 }
2120 
2121 static inline enum rw_hint file_write_hint(struct file *file)
2122 {
2123         if (file->f_write_hint != WRITE_LIFE_NOT_SET)
2124                 return file->f_write_hint;
2125 
2126         return file_inode(file)->i_write_hint;
2127 }
2128 
2129 static inline int iocb_flags(struct file *file);
2130 
2131 static inline u16 ki_hint_validate(enum rw_hint hint)
2132 {
2133         typeof(((struct kiocb *)0)->ki_hint) max_hint = -1;
2134 
2135         if (hint <= max_hint)
2136                 return hint;
2137         return 0;
2138 }
2139 
2140 static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp)
2141 {
2142         *kiocb = (struct kiocb) {
2143                 .ki_filp = filp,
2144                 .ki_flags = iocb_flags(filp),
2145                 .ki_hint = ki_hint_validate(file_write_hint(filp)),
2146                 .ki_ioprio = get_current_ioprio(),
2147         };
2148 }
2149 
2150 static inline void kiocb_clone(struct kiocb *kiocb, struct kiocb *kiocb_src,
2151                                struct file *filp)
2152 {
2153         *kiocb = (struct kiocb) {
2154                 .ki_filp = filp,
2155                 .ki_flags = kiocb_src->ki_flags,
2156                 .ki_hint = kiocb_src->ki_hint,
2157                 .ki_ioprio = kiocb_src->ki_ioprio,
2158                 .ki_pos = kiocb_src->ki_pos,
2159         };
2160 }
2161 
2162 /*
2163  * Inode state bits.  Protected by inode->i_lock
2164  *
2165  * Four bits determine the dirty state of the inode: I_DIRTY_SYNC,
2166  * I_DIRTY_DATASYNC, I_DIRTY_PAGES, and I_DIRTY_TIME.
2167  *
2168  * Four bits define the lifetime of an inode.  Initially, inodes are I_NEW,
2169  * until that flag is cleared.  I_WILL_FREE, I_FREEING and I_CLEAR are set at
2170  * various stages of removing an inode.
2171  *
2172  * Two bits are used for locking and completion notification, I_NEW and I_SYNC.
2173  *
2174  * I_DIRTY_SYNC         Inode is dirty, but doesn't have to be written on
2175  *                      fdatasync() (unless I_DIRTY_DATASYNC is also set).
2176  *                      Timestamp updates are the usual cause.
2177  * I_DIRTY_DATASYNC     Data-related inode changes pending.  We keep track of
2178  *                      these changes separately from I_DIRTY_SYNC so that we
2179  *                      don't have to write inode on fdatasync() when only
2180  *                      e.g. the timestamps have changed.
2181  * I_DIRTY_PAGES        Inode has dirty pages.  Inode itself may be clean.
2182  * I_DIRTY_TIME         The inode itself only has dirty timestamps, and the
2183  *                      lazytime mount option is enabled.  We keep track of this
2184  *                      separately from I_DIRTY_SYNC in order to implement
2185  *                      lazytime.  This gets cleared if I_DIRTY_INODE
2186  *                      (I_DIRTY_SYNC and/or I_DIRTY_DATASYNC) gets set.  I.e.
2187  *                      either I_DIRTY_TIME *or* I_DIRTY_INODE can be set in
2188  *                      i_state, but not both.  I_DIRTY_PAGES may still be set.
2189  * I_NEW                Serves as both a mutex and completion notification.
2190  *                      New inodes set I_NEW.  If two processes both create
2191  *                      the same inode, one of them will release its inode and
2192  *                      wait for I_NEW to be released before returning.
2193  *                      Inodes in I_WILL_FREE, I_FREEING or I_CLEAR state can
2194  *                      also cause waiting on I_NEW, without I_NEW actually
2195  *                      being set.  find_inode() uses this to prevent returning
2196  *                      nearly-dead inodes.
2197  * I_WILL_FREE          Must be set when calling write_inode_now() if i_count
2198  *                      is zero.  I_FREEING must be set when I_WILL_FREE is
2199  *                      cleared.
2200  * I_FREEING            Set when inode is about to be freed but still has dirty
2201  *                      pages or buffers attached or the inode itself is still
2202  *                      dirty.
2203  * I_CLEAR              Added by clear_inode().  In this state the inode is
2204  *                      clean and can be destroyed.  Inode keeps I_FREEING.
2205  *
2206  *                      Inodes that are I_WILL_FREE, I_FREEING or I_CLEAR are
2207  *                      prohibited for many purposes.  iget() must wait for
2208  *                      the inode to be completely released, then create it
2209  *                      anew.  Other functions will just ignore such inodes,
2210  *                      if appropriate.  I_NEW is used for waiting.
2211  *
2212  * I_SYNC               Writeback of inode is running. The bit is set during
2213  *                      data writeback, and cleared with a wakeup on the bit
2214  *                      address once it is done. The bit is also used to pin
2215  *                      the inode in memory for flusher thread.
2216  *
2217  * I_REFERENCED         Marks the inode as recently references on the LRU list.
2218  *
2219  * I_DIO_WAKEUP         Never set.  Only used as a key for wait_on_bit().
2220  *
2221  * I_WB_SWITCH          Cgroup bdi_writeback switching in progress.  Used to
2222  *                      synchronize competing switching instances and to tell
2223  *                      wb stat updates to grab the i_pages lock.  See
2224  *                      inode_switch_wbs_work_fn() for details.
2225  *
2226  * I_OVL_INUSE          Used by overlayfs to get exclusive ownership on upper
2227  *                      and work dirs among overlayfs mounts.
2228  *
2229  * I_CREATING           New object's inode in the middle of setting up.
2230  *
2231  * I_DONTCACHE          Evict inode as soon as it is not used anymore.
2232  *
2233  * I_SYNC_QUEUED        Inode is queued in b_io or b_more_io writeback lists.
2234  *                      Used to detect that mark_inode_dirty() should not move
2235  *                      inode between dirty lists.
2236  *
2237  * Q: What is the difference between I_WILL_FREE and I_FREEING?
2238  */
2239 #define I_DIRTY_SYNC            (1 << 0)
2240 #define I_DIRTY_DATASYNC        (1 << 1)
2241 #define I_DIRTY_PAGES           (1 << 2)
2242 #define __I_NEW                 3
2243 #define I_NEW                   (1 << __I_NEW)
2244 #define I_WILL_FREE             (1 << 4)
2245 #define I_FREEING               (1 << 5)
2246 #define I_CLEAR                 (1 << 6)
2247 #define __I_SYNC                7
2248 #define I_SYNC                  (1 << __I_SYNC)
2249 #define I_REFERENCED            (1 << 8)
2250 #define __I_DIO_WAKEUP          9
2251 #define I_DIO_WAKEUP            (1 << __I_DIO_WAKEUP)
2252 #define I_LINKABLE              (1 << 10)
2253 #define I_DIRTY_TIME            (1 << 11)
2254 #define I_WB_SWITCH             (1 << 13)
2255 #define I_OVL_INUSE             (1 << 14)
2256 #define I_CREATING              (1 << 15)
2257 #define I_DONTCACHE             (1 << 16)
2258 #define I_SYNC_QUEUED           (1 << 17)
2259 
2260 #define I_DIRTY_INODE (I_DIRTY_SYNC | I_DIRTY_DATASYNC)
2261 #define I_DIRTY (I_DIRTY_INODE | I_DIRTY_PAGES)
2262 #define I_DIRTY_ALL (I_DIRTY | I_DIRTY_TIME)
2263 
2264 extern void __mark_inode_dirty(struct inode *, int);
2265 static inline void mark_inode_dirty(struct inode *inode)
2266 {
2267         __mark_inode_dirty(inode, I_DIRTY);
2268 }
2269 
2270 static inline void mark_inode_dirty_sync(struct inode *inode)
2271 {
2272         __mark_inode_dirty(inode, I_DIRTY_SYNC);
2273 }
2274 
2275 /*
2276  * Returns true if the given inode itself only has dirty timestamps (its pages
2277  * may still be dirty) and isn't currently being allocated or freed.
2278  * Filesystems should call this if when writing an inode when lazytime is
2279  * enabled, they want to opportunistically write the timestamps of other inodes
2280  * located very nearby on-disk, e.g. in the same inode block.  This returns true
2281  * if the given inode is in need of such an opportunistic update.  Requires
2282  * i_lock, or at least later re-checking under i_lock.
2283  */
2284 static inline bool inode_is_dirtytime_only(struct inode *inode)
2285 {
2286         return (inode->i_state & (I_DIRTY_TIME | I_NEW |
2287                                   I_FREEING | I_WILL_FREE)) == I_DIRTY_TIME;
2288 }
2289 
2290 extern void inc_nlink(struct inode *inode);
2291 extern void drop_nlink(struct inode *inode);
2292 extern void clear_nlink(struct inode *inode);
2293 extern void set_nlink(struct inode *inode, unsigned int nlink);
2294 
2295 static inline void inode_inc_link_count(struct inode *inode)
2296 {
2297         inc_nlink(inode);
2298         mark_inode_dirty(inode);
2299 }
2300 
2301 static inline void inode_dec_link_count(struct inode *inode)
2302 {
2303         drop_nlink(inode);
2304         mark_inode_dirty(inode);
2305 }
2306 
2307 enum file_time_flags {
2308         S_ATIME = 1,
2309         S_MTIME = 2,
2310         S_CTIME = 4,
2311         S_VERSION = 8,
2312 };
2313 
2314 extern bool atime_needs_update(const struct path *, struct inode *);
2315 extern void touch_atime(const struct path *);
2316 static inline void file_accessed(struct file *file)
2317 {
2318         if (!(file->f_flags & O_NOATIME))
2319                 touch_atime(&file->f_path);
2320 }
2321 
2322 extern int file_modified(struct file *file);
2323 
2324 int sync_inode(struct inode *inode, struct writeback_control *wbc);
2325 int sync_inode_metadata(struct inode *inode, int wait);
2326 
2327 struct file_system_type {
2328         const char *name;
2329         int fs_flags;
2330 #define FS_REQUIRES_DEV         1 
2331 #define FS_BINARY_MOUNTDATA     2
2332 #define FS_HAS_SUBTYPE          4
2333 #define FS_USERNS_MOUNT         8       /* Can be mounted by userns root */
2334 #define FS_DISALLOW_NOTIFY_PERM 16      /* Disable fanotify permission events */
2335 #define FS_ALLOW_IDMAP         32      /* FS has been updated to handle vfs idmappings. */
2336 #define FS_THP_SUPPORT          8192    /* Remove once all fs converted */
2337 #define FS_RENAME_DOES_D_MOVE   32768   /* FS will handle d_move() during rename() internally. */
2338         int (*init_fs_context)(struct fs_context *);
2339         const struct fs_parameter_spec *parameters;
2340         struct dentry *(*mount) (struct file_system_type *, int,
2341                        const char *, void *);
2342         void (*kill_sb) (struct super_block *);
2343         struct module *owner;
2344         struct file_system_type * next;
2345         struct hlist_head fs_supers;
2346 
2347         struct lock_class_key s_lock_key;
2348         struct lock_class_key s_umount_key;
2349         struct lock_class_key s_vfs_rename_key;
2350         struct lock_class_key s_writers_key[SB_FREEZE_LEVELS];
2351 
2352         struct lock_class_key i_lock_key;
2353         struct lock_class_key i_mutex_key;
2354         struct lock_class_key i_mutex_dir_key;
2355 };
2356 
2357 #define MODULE_ALIAS_FS(NAME) MODULE_ALIAS("fs-" NAME)
2358 
2359 extern struct dentry *mount_bdev(struct file_system_type *fs_type,
2360         int flags, const char *dev_name, void *data,
2361         int (*fill_super)(struct super_block *, void *, int));
2362 extern struct dentry *mount_single(struct file_system_type *fs_type,
2363         int flags, void *data,
2364         int (*fill_super)(struct super_block *, void *, int));
2365 extern struct dentry *mount_nodev(struct file_system_type *fs_type,
2366         int flags, void *data,
2367         int (*fill_super)(struct super_block *, void *, int));
2368 extern struct dentry *mount_subtree(struct vfsmount *mnt, const char *path);
2369 void generic_shutdown_super(struct super_block *sb);
2370 void kill_block_super(struct super_block *sb);
2371 void kill_anon_super(struct super_block *sb);
2372 void kill_litter_super(struct super_block *sb);
2373 void deactivate_super(struct super_block *sb);
2374 void deactivate_locked_super(struct super_block *sb);
2375 int set_anon_super(struct super_block *s, void *data);
2376 int set_anon_super_fc(struct super_block *s, struct fs_context *fc);
2377 int get_anon_bdev(dev_t *);
2378 void free_anon_bdev(dev_t);
2379 struct super_block *sget_fc(struct fs_context *fc,
2380                             int (*test)(struct super_block *, struct fs_context *),
2381                             int (*set)(struct super_block *, struct fs_context *));
2382 struct super_block *sget(struct file_system_type *type,
2383                         int (*test)(struct super_block *,void *),
2384                         int (*set)(struct super_block *,void *),
2385                         int flags, void *data);
2386 
2387 /* Alas, no aliases. Too much hassle with bringing module.h everywhere */
2388 #define fops_get(fops) \
2389         (((fops) && try_module_get((fops)->owner) ? (fops) : NULL))
2390 #define fops_put(fops) \
2391         do { if (fops) module_put((fops)->owner); } while(0)
2392 /*
2393  * This one is to be used *ONLY* from ->open() instances.
2394  * fops must be non-NULL, pinned down *and* module dependencies
2395  * should be sufficient to pin the caller down as well.
2396  */
2397 #define replace_fops(f, fops) \
2398         do {    \
2399                 struct file *__file = (f); \
2400                 fops_put(__file->f_op); \
2401                 BUG_ON(!(__file->f_op = (fops))); \
2402         } while(0)
2403 
2404 extern int register_filesystem(struct file_system_type *);
2405 extern int unregister_filesystem(struct file_system_type *);
2406 extern struct vfsmount *kern_mount(struct file_system_type *);
2407 extern void kern_unmount(struct vfsmount *mnt);
2408 extern int may_umount_tree(struct vfsmount *);
2409 extern int may_umount(struct vfsmount *);
2410 extern long do_mount(const char *, const char __user *,
2411                      const char *, unsigned long, void *);
2412 extern struct vfsmount *collect_mounts(const struct path *);
2413 extern void drop_collected_mounts(struct vfsmount *);
2414 extern int iterate_mounts(int (*)(struct vfsmount *, void *), void *,
2415                           struct vfsmount *);
2416 extern int vfs_statfs(const struct path *, struct kstatfs *);
2417 extern int user_statfs(const char __user *, struct kstatfs *);
2418 extern int fd_statfs(int, struct kstatfs *);
2419 extern int freeze_super(struct super_block *super);
2420 extern int thaw_super(struct super_block *super);
2421 extern bool our_mnt(struct vfsmount *mnt);
2422 extern __printf(2, 3)
2423 int super_setup_bdi_name(struct super_block *sb, char *fmt, ...);
2424 extern int super_setup_bdi(struct super_block *sb);
2425 
2426 extern int current_umask(void);
2427 
2428 extern void ihold(struct inode * inode);
2429 extern void iput(struct inode *);
2430 extern int generic_update_time(struct inode *, struct timespec64 *, int);
2431 
2432 /* /sys/fs */
2433 extern struct kobject *fs_kobj;
2434 
2435 #define MAX_RW_COUNT (INT_MAX & PAGE_MASK)
2436 
2437 #ifdef CONFIG_MANDATORY_FILE_LOCKING
2438 extern int locks_mandatory_locked(struct file *);
2439 extern int locks_mandatory_area(struct inode *, struct file *, loff_t, loff_t, unsigned char);
2440 
2441 /*
2442  * Candidates for mandatory locking have the setgid bit set
2443  * but no group execute bit -  an otherwise meaningless combination.
2444  */
2445 
2446 static inline int __mandatory_lock(struct inode *ino)
2447 {
2448         return (ino->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID;
2449 }
2450 
2451 /*
2452  * ... and these candidates should be on SB_MANDLOCK mounted fs,
2453  * otherwise these will be advisory locks
2454  */
2455 
2456 static inline int mandatory_lock(struct inode *ino)
2457 {
2458         return IS_MANDLOCK(ino) && __mandatory_lock(ino);
2459 }
2460 
2461 static inline int locks_verify_locked(struct file *file)
2462 {
2463         if (mandatory_lock(locks_inode(file)))
2464                 return locks_mandatory_locked(file);
2465         return 0;
2466 }
2467 
2468 static inline int locks_verify_truncate(struct inode *inode,
2469                                     struct file *f,
2470                                     loff_t size)
2471 {
2472         if (!inode->i_flctx || !mandatory_lock(inode))
2473                 return 0;
2474 
2475         if (size < inode->i_size) {
2476                 return locks_mandatory_area(inode, f, size, inode->i_size - 1,
2477                                 F_WRLCK);
2478         } else {
2479                 return locks_mandatory_area(inode, f, inode->i_size, size - 1,
2480                                 F_WRLCK);
2481         }
2482 }
2483 
2484 #else /* !CONFIG_MANDATORY_FILE_LOCKING */
2485 
2486 static inline int locks_mandatory_locked(struct file *file)
2487 {
2488         return 0;
2489 }
2490 
2491 static inline int locks_mandatory_area(struct inode *inode, struct file *filp,
2492                                        loff_t start, loff_t end, unsigned char type)
2493 {
2494         return 0;
2495 }
2496 
2497 static inline int __mandatory_lock(struct inode *inode)
2498 {
2499         return 0;
2500 }
2501 
2502 static inline int mandatory_lock(struct inode *inode)
2503 {
2504         return 0;
2505 }
2506 
2507 static inline int locks_verify_locked(struct file *file)
2508 {
2509         return 0;
2510 }
2511 
2512 static inline int locks_verify_truncate(struct inode *inode, struct file *filp,
2513                                         size_t size)
2514 {
2515         return 0;
2516 }
2517 
2518 #endif /* CONFIG_MANDATORY_FILE_LOCKING */
2519 
2520 
2521 #ifdef CONFIG_FILE_LOCKING
2522 static inline int break_lease(struct inode *inode, unsigned int mode)
2523 {
2524         /*
2525          * Since this check is lockless, we must ensure that any refcounts
2526          * taken are done before checking i_flctx->flc_lease. Otherwise, we
2527          * could end up racing with tasks trying to set a new lease on this
2528          * file.
2529          */
2530         smp_mb();
2531         if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease))
2532                 return __break_lease(inode, mode, FL_LEASE);
2533         return 0;
2534 }
2535 
2536 static inline int break_deleg(struct inode *inode, unsigned int mode)
2537 {
2538         /*
2539          * Since this check is lockless, we must ensure that any refcounts
2540          * taken are done before checking i_flctx->flc_lease. Otherwise, we
2541          * could end up racing with tasks trying to set a new lease on this
2542          * file.
2543          */
2544         smp_mb();
2545         if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease))
2546                 return __break_lease(inode, mode, FL_DELEG);
2547         return 0;
2548 }
2549 
2550 static inline int try_break_deleg(struct inode *inode, struct inode **delegated_inode)
2551 {
2552         int ret;
2553 
2554         ret = break_deleg(inode, O_WRONLY|O_NONBLOCK);
2555         if (ret == -EWOULDBLOCK && delegated_inode) {
2556                 *delegated_inode = inode;
2557                 ihold(inode);
2558         }
2559         return ret;
2560 }
2561 
2562 static inline int break_deleg_wait(struct inode **delegated_inode)
2563 {
2564         int ret;
2565 
2566         ret = break_deleg(*delegated_inode, O_WRONLY);
2567         iput(*delegated_inode);
2568         *delegated_inode = NULL;
2569         return ret;
2570 }
2571 
2572 static inline int break_layout(struct inode *inode, bool wait)
2573 {
2574         smp_mb();
2575         if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease))
2576                 return __break_lease(inode,
2577                                 wait ? O_WRONLY : O_WRONLY | O_NONBLOCK,
2578                                 FL_LAYOUT);
2579         return 0;
2580 }
2581 
2582 #else /* !CONFIG_FILE_LOCKING */
2583 static inline int break_lease(struct inode *inode, unsigned int mode)
2584 {
2585         return 0;
2586 }
2587 
2588 static inline int break_deleg(struct inode *inode, unsigned int mode)
2589 {
2590         return 0;
2591 }
2592 
2593 static inline int try_break_deleg(struct inode *inode, struct inode **delegated_inode)
2594 {
2595         return 0;
2596 }
2597 
2598 static inline int break_deleg_wait(struct inode **delegated_inode)
2599 {
2600         BUG();
2601         return 0;
2602 }
2603 
2604 static inline int break_layout(struct inode *inode, bool wait)
2605 {
2606         return 0;
2607 }
2608 
2609 #endif /* CONFIG_FILE_LOCKING */
2610 
2611 /* fs/open.c */
2612 struct audit_names;
2613 struct filename {
2614         const char              *name;  /* pointer to actual string */
2615         const __user char       *uptr;  /* original userland pointer */
2616         int                     refcnt;
2617         struct audit_names      *aname;
2618         const char              iname[];
2619 };
2620 static_assert(offsetof(struct filename, iname) % sizeof(long) == 0);
2621 
2622 static inline struct user_namespace *file_mnt_user_ns(struct file *file)
2623 {
2624         return mnt_user_ns(file->f_path.mnt);
2625 }
2626 extern long vfs_truncate(const struct path *, loff_t);
2627 int do_truncate(struct user_namespace *, struct dentry *, loff_t start,
2628                 unsigned int time_attrs, struct file *filp);
2629 extern int vfs_fallocate(struct file *file, int mode, loff_t offset,
2630                         loff_t len);
2631 extern long do_sys_open(int dfd, const char __user *filename, int flags,
2632                         umode_t mode);
2633 extern struct file *file_open_name(struct filename *, int, umode_t);
2634 extern struct file *filp_open(const char *, int, umode_t);
2635 extern struct file *file_open_root(struct dentry *, struct vfsmount *,
2636                                    const char *, int, umode_t);
2637 extern struct file * dentry_open(const struct path *, int, const struct cred *);
2638 extern struct file * open_with_fake_path(const struct path *, int,
2639                                          struct inode*, const struct cred *);
2640 static inline struct file *file_clone_open(struct file *file)
2641 {
2642         return dentry_open(&file->f_path, file->f_flags, file->f_cred);
2643 }
2644 extern int filp_close(struct file *, fl_owner_t id);
2645 
2646 extern struct filename *getname_flags(const char __user *, int, int *);
2647 extern struct filename *getname(const char __user *);
2648 extern struct filename *getname_kernel(const char *);
2649 extern void putname(struct filename *name);
2650 
2651 extern int finish_open(struct file *file, struct dentry *dentry,
2652                         int (*open)(struct inode *, struct file *));
2653 extern int finish_no_open(struct file *file, struct dentry *dentry);
2654 
2655 /* fs/dcache.c */
2656 extern void __init vfs_caches_init_early(void);
2657 extern void __init vfs_caches_init(void);
2658 
2659 extern struct kmem_cache *names_cachep;
2660 
2661 #define __getname()             kmem_cache_alloc(names_cachep, GFP_KERNEL)
2662 #define __putname(name)         kmem_cache_free(names_cachep, (void *)(name))
2663 
2664 extern struct super_block *blockdev_superblock;
2665 static inline bool sb_is_blkdev_sb(struct super_block *sb)
2666 {
2667         return IS_ENABLED(CONFIG_BLOCK) && sb == blockdev_superblock;
2668 }
2669 
2670 void emergency_thaw_all(void);
2671 extern int sync_filesystem(struct super_block *);
2672 extern const struct file_operations def_blk_fops;
2673 extern const struct file_operations def_chr_fops;
2674 
2675 /* fs/char_dev.c */
2676 #define CHRDEV_MAJOR_MAX 512
2677 /* Marks the bottom of the first segment of free char majors */
2678 #define CHRDEV_MAJOR_DYN_END 234
2679 /* Marks the top and bottom of the second segment of free char majors */
2680 #define CHRDEV_MAJOR_DYN_EXT_START 511
2681 #define CHRDEV_MAJOR_DYN_EXT_END 384
2682 
2683 extern int alloc_chrdev_region(dev_t *, unsigned, unsigned, const char *);
2684 extern int register_chrdev_region(dev_t, unsigned, const char *);
2685 extern int __register_chrdev(unsigned int major, unsigned int baseminor,
2686                              unsigned int count, const char *name,
2687                              const struct file_operations *fops);
2688 extern void __unregister_chrdev(unsigned int major, unsigned int baseminor,
2689                                 unsigned int count, const char *name);
2690 extern void unregister_chrdev_region(dev_t, unsigned);
2691 extern void chrdev_show(struct seq_file *,off_t);
2692 
2693 static inline int register_chrdev(unsigned int major, const char *name,
2694                                   const struct file_operations *fops)
2695 {
2696         return __register_chrdev(major, 0, 256, name, fops);
2697 }
2698 
2699 static inline void unregister_chrdev(unsigned int major, const char *name)
2700 {
2701         __unregister_chrdev(major, 0, 256, name);
2702 }
2703 
2704 extern void init_special_inode(struct inode *, umode_t, dev_t);
2705 
2706 /* Invalid inode operations -- fs/bad_inode.c */
2707 extern void make_bad_inode(struct inode *);
2708 extern bool is_bad_inode(struct inode *);
2709 
2710 unsigned long invalidate_mapping_pages(struct address_space *mapping,
2711                                         pgoff_t start, pgoff_t end);
2712 
2713 void invalidate_mapping_pagevec(struct address_space *mapping,
2714                                 pgoff_t start, pgoff_t end,
2715                                 unsigned long *nr_pagevec);
2716 
2717 static inline void invalidate_remote_inode(struct inode *inode)
2718 {
2719         if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2720             S_ISLNK(inode->i_mode))
2721                 invalidate_mapping_pages(inode->i_mapping, 0, -1);
2722 }
2723 extern int invalidate_inode_pages2(struct address_space *mapping);
2724 extern int invalidate_inode_pages2_range(struct address_space *mapping,
2725                                          pgoff_t start, pgoff_t end);
2726 extern int write_inode_now(struct inode *, int);
2727 extern int filemap_fdatawrite(struct address_space *);
2728 extern int filemap_flush(struct address_space *);
2729 extern int filemap_fdatawait_keep_errors(struct address_space *mapping);
2730 extern int filemap_fdatawait_range(struct address_space *, loff_t lstart,
2731                                    loff_t lend);
2732 extern int filemap_fdatawait_range_keep_errors(struct address_space *mapping,
2733                 loff_t start_byte, loff_t end_byte);
2734 
2735 static inline int filemap_fdatawait(struct address_space *mapping)
2736 {
2737         return filemap_fdatawait_range(mapping, 0, LLONG_MAX);
2738 }
2739 
2740 extern bool filemap_range_has_page(struct address_space *, loff_t lstart,
2741                                   loff_t lend);
2742 extern int filemap_write_and_wait_range(struct address_space *mapping,
2743                                         loff_t lstart, loff_t lend);
2744 extern int __filemap_fdatawrite_range(struct address_space *mapping,
2745                                 loff_t start, loff_t end, int sync_mode);
2746 extern int filemap_fdatawrite_range(struct address_space *mapping,
2747                                 loff_t start, loff_t end);
2748 extern int filemap_check_errors(struct address_space *mapping);
2749 extern void __filemap_set_wb_err(struct address_space *mapping, int err);
2750 
2751 static inline int filemap_write_and_wait(struct address_space *mapping)
2752 {
2753         return filemap_write_and_wait_range(mapping, 0, LLONG_MAX);
2754 }
2755 
2756 extern int __must_check file_fdatawait_range(struct file *file, loff_t lstart,
2757                                                 loff_t lend);
2758 extern int __must_check file_check_and_advance_wb_err(struct file *file);
2759 extern int __must_check file_write_and_wait_range(struct file *file,
2760                                                 loff_t start, loff_t end);
2761 
2762 static inline int file_write_and_wait(struct file *file)
2763 {
2764         return file_write_and_wait_range(file, 0, LLONG_MAX);
2765 }
2766 
2767 /**
2768  * filemap_set_wb_err - set a writeback error on an address_space
2769  * @mapping: mapping in which to set writeback error
2770  * @err: error to be set in mapping
2771  *
2772  * When writeback fails in some way, we must record that error so that
2773  * userspace can be informed when fsync and the like are called.  We endeavor
2774  * to report errors on any file that was open at the time of the error.  Some
2775  * internal callers also need to know when writeback errors have occurred.
2776  *
2777  * When a writeback error occurs, most filesystems will want to call
2778  * filemap_set_wb_err to record the error in the mapping so that it will be
2779  * automatically reported whenever fsync is called on the file.
2780  */
2781 static inline void filemap_set_wb_err(struct address_space *mapping, int err)
2782 {
2783         /* Fastpath for common case of no error */
2784         if (unlikely(err))
2785                 __filemap_set_wb_err(mapping, err);
2786 }
2787 
2788 /**
2789  * filemap_check_wb_err - has an error occurred since the mark was sampled?
2790  * @mapping: mapping to check for writeback errors
2791  * @since: previously-sampled errseq_t
2792  *
2793  * Grab the errseq_t value from the mapping, and see if it has changed "since"
2794  * the given value was sampled.
2795  *
2796  * If it has then report the latest error set, otherwise return 0.
2797  */
2798 static inline int filemap_check_wb_err(struct address_space *mapping,
2799                                         errseq_t since)
2800 {
2801         return errseq_check(&mapping->wb_err, since);
2802 }
2803 
2804 /**
2805  * filemap_sample_wb_err - sample the current errseq_t to test for later errors
2806  * @mapping: mapping to be sampled
2807  *
2808  * Writeback errors are always reported relative to a particular sample point
2809  * in the past. This function provides those sample points.
2810  */
2811 static inline errseq_t filemap_sample_wb_err(struct address_space *mapping)
2812 {
2813         return errseq_sample(&mapping->wb_err);
2814 }
2815 
2816 /**
2817  * file_sample_sb_err - sample the current errseq_t to test for later errors
2818  * @file: file pointer to be sampled
2819  *
2820  * Grab the most current superblock-level errseq_t value for the given
2821  * struct file.
2822  */
2823 static inline errseq_t file_sample_sb_err(struct file *file)
2824 {
2825         return errseq_sample(&file->f_path.dentry->d_sb->s_wb_err);
2826 }
2827 
2828 extern int vfs_fsync_range(struct file *file, loff_t start, loff_t end,
2829                            int datasync);
2830 extern int vfs_fsync(struct file *file, int datasync);
2831 
2832 extern int sync_file_range(struct file *file, loff_t offset, loff_t nbytes,
2833                                 unsigned int flags);
2834 
2835 /*
2836  * Sync the bytes written if this was a synchronous write.  Expect ki_pos
2837  * to already be updated for the write, and will return either the amount
2838  * of bytes passed in, or an error if syncing the file failed.
2839  */
2840 static inline ssize_t generic_write_sync(struct kiocb *iocb, ssize_t count)
2841 {
2842         if (iocb->ki_flags & IOCB_DSYNC) {
2843                 int ret = vfs_fsync_range(iocb->ki_filp,
2844                                 iocb->ki_pos - count, iocb->ki_pos - 1,
2845                                 (iocb->ki_flags & IOCB_SYNC) ? 0 : 1);
2846                 if (ret)
2847                         return ret;
2848         }
2849 
2850         return count;
2851 }
2852 
2853 extern void emergency_sync(void);
2854 extern void emergency_remount(void);
2855 
2856 #ifdef CONFIG_BLOCK
2857 extern int bmap(struct inode *inode, sector_t *block);
2858 #else
2859 static inline int bmap(struct inode *inode,  sector_t *block)
2860 {
2861         return -EINVAL;
2862 }
2863 #endif
2864 
2865 int notify_change(struct user_namespace *, struct dentry *,
2866                   struct iattr *, struct inode **);
2867 int inode_permission(struct user_namespace *, struct inode *, int);
2868 int generic_permission(struct user_namespace *, struct inode *, int);
2869 static inline int file_permission(struct file *file, int mask)
2870 {
2871         return inode_permission(file_mnt_user_ns(file),
2872                                 file_inode(file), mask);
2873 }
2874 static inline int path_permission(const struct path *path, int mask)
2875 {
2876         return inode_permission(mnt_user_ns(path->mnt),
2877                                 d_inode(path->dentry), mask);
2878 }
2879 int __check_sticky(struct user_namespace *mnt_userns, struct inode *dir,
2880                    struct inode *inode);
2881 
2882 static inline bool execute_ok(struct inode *inode)
2883 {
2884         return (inode->i_mode & S_IXUGO) || S_ISDIR(inode->i_mode);
2885 }
2886 
2887 static inline void file_start_write(struct file *file)
2888 {
2889         if (!S_ISREG(file_inode(file)->i_mode))
2890                 return;
2891         sb_start_write(file_inode(file)->i_sb);
2892 }
2893 
2894 static inline bool file_start_write_trylock(struct file *file)
2895 {
2896         if (!S_ISREG(file_inode(file)->i_mode))
2897                 return true;
2898         return sb_start_write_trylock(file_inode(file)->i_sb);
2899 }
2900 
2901 static inline void file_end_write(struct file *file)
2902 {
2903         if (!S_ISREG(file_inode(file)->i_mode))
2904                 return;
2905         __sb_end_write(file_inode(file)->i_sb, SB_FREEZE_WRITE);
2906 }
2907 
2908 /*
2909  * get_write_access() gets write permission for a file.
2910  * put_write_access() releases this write permission.
2911  * This is used for regular files.
2912  * We cannot support write (and maybe mmap read-write shared) accesses and
2913  * MAP_DENYWRITE mmappings simultaneously. The i_writecount field of an inode
2914  * can have the following values:
2915  * 0: no writers, no VM_DENYWRITE mappings
2916  * < 0: (-i_writecount) vm_area_structs with VM_DENYWRITE set exist
2917  * > 0: (i_writecount) users are writing to the file.
2918  *
2919  * Normally we operate on that counter with atomic_{inc,dec} and it's safe
2920  * except for the cases where we don't hold i_writecount yet. Then we need to
2921  * use {get,deny}_write_access() - these functions check the sign and refuse
2922  * to do the change if sign is wrong.
2923  */
2924 static inline int get_write_access(struct inode *inode)
2925 {
2926         return atomic_inc_unless_negative(&inode->i_writecount) ? 0 : -ETXTBSY;
2927 }
2928 static inline int deny_write_access(struct file *file)
2929 {
2930         struct inode *inode = file_inode(file);
2931         return atomic_dec_unless_positive(&inode->i_writecount) ? 0 : -ETXTBSY;
2932 }
2933 static inline void put_write_access(struct inode * inode)
2934 {
2935         atomic_dec(&inode->i_writecount);
2936 }
2937 static inline void allow_write_access(struct file *file)
2938 {
2939         if (file)
2940                 atomic_inc(&file_inode(file)->i_writecount);
2941 }
2942 static inline bool inode_is_open_for_write(const struct inode *inode)
2943 {
2944         return atomic_read(&inode->i_writecount) > 0;
2945 }
2946 
2947 #if defined(CONFIG_IMA) || defined(CONFIG_FILE_LOCKING)
2948 static inline void i_readcount_dec(struct inode *inode)
2949 {
2950         BUG_ON(!atomic_read(&inode->i_readcount));
2951         atomic_dec(&inode->i_readcount);
2952 }
2953 static inline void i_readcount_inc(struct inode *inode)
2954 {
2955         atomic_inc(&inode->i_readcount);
2956 }
2957 #else
2958 static inline void i_readcount_dec(struct inode *inode)
2959 {
2960         return;
2961 }
2962 static inline void i_readcount_inc(struct inode *inode)
2963 {
2964         return;
2965 }
2966 #endif
2967 extern int do_pipe_flags(int *, int);
2968 
2969 extern ssize_t kernel_read(struct file *, void *, size_t, loff_t *);
2970 ssize_t __kernel_read(struct file *file, void *buf, size_t count, loff_t *pos);
2971 extern ssize_t kernel_write(struct file *, const void *, size_t, loff_t *);
2972 extern ssize_t __kernel_write(struct file *, const void *, size_t, loff_t *);
2973 extern struct file * open_exec(const char *);
2974  
2975 /* fs/dcache.c -- generic fs support functions */
2976 extern bool is_subdir(struct dentry *, struct dentry *);
2977 extern bool path_is_under(const struct path *, const struct path *);
2978 
2979 extern char *file_path(struct file *, char *, int);
2980 
2981 #include <linux/err.h>
2982 
2983 /* needed for stackable file system support */
2984 extern loff_t default_llseek(struct file *file, loff_t offset, int whence);
2985 
2986 extern loff_t vfs_llseek(struct file *file, loff_t offset, int whence);
2987 
2988 extern int inode_init_always(struct super_block *, struct inode *);
2989 extern void inode_init_once(struct inode *);
2990 extern void address_space_init_once(struct address_space *mapping);
2991 extern struct inode * igrab(struct inode *);
2992 extern ino_t iunique(struct super_block *, ino_t);
2993 extern int inode_needs_sync(struct inode *inode);
2994 extern int generic_delete_inode(struct inode *inode);
2995 static inline int generic_drop_inode(struct inode *inode)
2996 {
2997         return !inode->i_nlink || inode_unhashed(inode);
2998 }
2999 extern void d_mark_dontcache(struct inode *inode);
3000 
3001 extern struct inode *ilookup5_nowait(struct super_block *sb,
3002                 unsigned long hashval, int (*test)(struct inode *, void *),
3003                 void *data);
3004 extern struct inode *ilookup5(struct super_block *sb, unsigned long hashval,
3005                 int (*test)(struct inode *, void *), void *data);
3006 extern struct inode *ilookup(struct super_block *sb, unsigned long ino);
3007 
3008 extern struct inode *inode_insert5(struct inode *inode, unsigned long hashval,
3009                 int (*test)(struct inode *, void *),
3010                 int (*set)(struct inode *, void *),
3011                 void *data);
3012 extern struct inode * iget5_locked(struct super_block *, unsigned long, int (*test)(struct inode *, void *), int (*set)(struct inode *, void *), void *);
3013 extern struct inode * iget_locked(struct super_block *, unsigned long);
3014 extern struct inode *find_inode_nowait(struct super_block *,
3015                                        unsigned long,
3016                                        int (*match)(struct inode *,
3017                                                     unsigned long, void *),
3018                                        void *data);
3019 extern struct inode *find_inode_rcu(struct super_block *, unsigned long,
3020                                     int (*)(struct inode *, void *), void *);
3021 extern struct inode *find_inode_by_ino_rcu(struct super_block *, unsigned long);
3022 extern int insert_inode_locked4(struct inode *, unsigned long, int (*test)(struct inode *, void *), void *);
3023 extern int insert_inode_locked(struct inode *);
3024 #ifdef CONFIG_DEBUG_LOCK_ALLOC
3025 extern void lockdep_annotate_inode_mutex_key(struct inode *inode);
3026 #else
3027 static inline void lockdep_annotate_inode_mutex_key(struct inode *inode) { };
3028 #endif
3029 extern void unlock_new_inode(struct inode *);
3030 extern void discard_new_inode(struct inode *);
3031 extern unsigned int get_next_ino(void);
3032 extern void evict_inodes(struct super_block *sb);
3033 
3034 /*
3035  * Userspace may rely on the the inode number being non-zero. For example, glibc
3036  * simply ignores files with zero i_ino in unlink() and other places.
3037  *
3038  * As an additional complication, if userspace was compiled with
3039  * _FILE_OFFSET_BITS=32 on a 64-bit kernel we'll only end up reading out the
3040  * lower 32 bits, so we need to check that those aren't zero explicitly. With
3041  * _FILE_OFFSET_BITS=64, this may cause some harmless false-negatives, but
3042  * better safe than sorry.
3043  */
3044 static inline bool is_zero_ino(ino_t ino)
3045 {
3046         return (u32)ino == 0;
3047 }
3048 
3049 extern void __iget(struct inode * inode);
3050 extern void iget_failed(struct inode *);
3051 extern void clear_inode(struct inode *);
3052 extern void __destroy_inode(struct inode *);
3053 extern struct inode *new_inode_pseudo(struct super_block *sb);
3054 extern struct inode *new_inode(struct super_block *sb);
3055 extern void free_inode_nonrcu(struct inode *inode);
3056 extern int should_remove_suid(struct dentry *);
3057 extern int file_remove_privs(struct file *);
3058 
3059 extern void __insert_inode_hash(struct inode *, unsigned long hashval);
3060 static inline void insert_inode_hash(struct inode *inode)
3061 {
3062         __insert_inode_hash(inode, inode->i_ino);
3063 }
3064 
3065 extern void __remove_inode_hash(struct inode *);
3066 static inline void remove_inode_hash(struct inode *inode)
3067 {
3068         if (!inode_unhashed(inode) && !hlist_fake(&inode->i_hash))
3069                 __remove_inode_hash(inode);
3070 }
3071 
3072 extern void inode_sb_list_add(struct inode *inode);
3073 
3074 extern int sb_set_blocksize(struct super_block *, int);
3075 extern int sb_min_blocksize(struct super_block *, int);
3076 
3077 extern int generic_file_mmap(struct file *, struct vm_area_struct *);
3078 extern int generic_file_readonly_mmap(struct file *, struct vm_area_struct *);
3079 extern ssize_t generic_write_checks(struct kiocb *, struct iov_iter *);
3080 extern int generic_write_check_limits(struct file *file, loff_t pos,
3081                 loff_t *count);
3082 extern int generic_file_rw_checks(struct file *file_in, struct file *file_out);
3083 ssize_t filemap_read(struct kiocb *iocb, struct iov_iter *to,
3084                 ssize_t already_read);
3085 extern ssize_t generic_file_read_iter(struct kiocb *, struct iov_iter *);
3086 extern ssize_t __generic_file_write_iter(struct kiocb *, struct iov_iter *);
3087 extern ssize_t generic_file_write_iter(struct kiocb *, struct iov_iter *);
3088 extern ssize_t generic_file_direct_write(struct kiocb *, struct iov_iter *);
3089 extern ssize_t generic_perform_write(struct file *, struct iov_iter *, loff_t);
3090 
3091 ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos,
3092                 rwf_t flags);
3093 ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos,
3094                 rwf_t flags);
3095 ssize_t vfs_iocb_iter_read(struct file *file, struct kiocb *iocb,
3096                            struct iov_iter *iter);
3097 ssize_t vfs_iocb_iter_write(struct file *file, struct kiocb *iocb,
3098                             struct iov_iter *iter);
3099 
3100 /* fs/block_dev.c */
3101 extern ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to);
3102 extern ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from);
3103 extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
3104                         int datasync);
3105 extern void block_sync_page(struct page *page);
3106 
3107 /* fs/splice.c */
3108 extern ssize_t generic_file_splice_read(struct file *, loff_t *,
3109                 struct pipe_inode_info *, size_t, unsigned int);
3110 extern ssize_t iter_file_splice_write(struct pipe_inode_info *,
3111                 struct file *, loff_t *, size_t, unsigned int);
3112 extern ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe,
3113                 struct file *out, loff_t *, size_t len, unsigned int flags);
3114 extern long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
3115                 loff_t *opos, size_t len, unsigned int flags);
3116 
3117 
3118 extern void
3119 file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping);
3120 extern loff_t noop_llseek(struct file *file, loff_t offset, int whence);
3121 extern loff_t no_llseek(struct file *file, loff_t offset, int whence);
3122 extern loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize);
3123 extern loff_t generic_file_llseek(struct file *file, loff_t offset, int whence);
3124 extern loff_t generic_file_llseek_size(struct file *file, loff_t offset,
3125                 int whence, loff_t maxsize, loff_t eof);
3126 extern loff_t fixed_size_llseek(struct file *file, loff_t offset,
3127                 int whence, loff_t size);
3128 extern loff_t no_seek_end_llseek_size(struct file *, loff_t, int, loff_t);
3129 extern loff_t no_seek_end_llseek(struct file *, loff_t, int);
3130 extern int generic_file_open(struct inode * inode, struct file * filp);
3131 extern int nonseekable_open(struct inode * inode, struct file * filp);
3132 extern int stream_open(struct inode * inode, struct file * filp);
3133 
3134 #ifdef CONFIG_BLOCK
3135 typedef void (dio_submit_t)(struct bio *bio, struct inode *inode,
3136                             loff_t file_offset);
3137 
3138 enum {
3139         /* need locking between buffered and direct access */
3140         DIO_LOCKING     = 0x01,
3141 
3142         /* filesystem does not support filling holes */
3143         DIO_SKIP_HOLES  = 0x02,
3144 };
3145 
3146 ssize_t __blockdev_direct_IO(struct kiocb *iocb, struct inode *inode,
3147                              struct block_device *bdev, struct iov_iter *iter,
3148                              get_block_t get_block,
3149                              dio_iodone_t end_io, dio_submit_t submit_io,
3150                              int flags);
3151 
3152 static inline ssize_t blockdev_direct_IO(struct kiocb *iocb,
3153                                          struct inode *inode,
3154                                          struct iov_iter *iter,
3155                                          get_block_t get_block)
3156 {
3157         return __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev, iter,
3158                         get_block, NULL, NULL, DIO_LOCKING | DIO_SKIP_HOLES);
3159 }
3160 #endif
3161 
3162 void inode_dio_wait(struct inode *inode);
3163 
3164 /*
3165  * inode_dio_begin - signal start of a direct I/O requests
3166  * @inode: inode the direct I/O happens on
3167  *
3168  * This is called once we've finished processing a direct I/O request,
3169  * and is used to wake up callers waiting for direct I/O to be quiesced.
3170  */
3171 static inline void inode_dio_begin(struct inode *inode)
3172 {
3173         atomic_inc(&inode->i_dio_count);
3174 }
3175 
3176 /*
3177  * inode_dio_end - signal finish of a direct I/O requests
3178  * @inode: inode the direct I/O happens on
3179  *
3180  * This is called once we've finished processing a direct I/O request,
3181  * and is used to wake up callers waiting for direct I/O to be quiesced.
3182  */
3183 static inline void inode_dio_end(struct inode *inode)
3184 {
3185         if (atomic_dec_and_test(&inode->i_dio_count))
3186                 wake_up_bit(&inode->i_state, __I_DIO_WAKEUP);
3187 }
3188 
3189 /*
3190  * Warn about a page cache invalidation failure diring a direct I/O write.
3191  */
3192 void dio_warn_stale_pagecache(struct file *filp);
3193 
3194 extern void inode_set_flags(struct inode *inode, unsigned int flags,
3195                             unsigned int mask);
3196 
3197 extern const struct file_operations generic_ro_fops;
3198 
3199 #define special_file(m) (S_ISCHR(m)||S_ISBLK(m)||S_ISFIFO(m)||S_ISSOCK(m))
3200 
3201 extern int readlink_copy(char __user *, int, const char *);
3202 extern int page_readlink(struct dentry *, char __user *, int);
3203 extern const char *page_get_link(struct dentry *, struct inode *,
3204                                  struct delayed_call *);
3205 extern void page_put_link(void *);
3206 extern int __page_symlink(struct inode *inode, const char *symname, int len,
3207                 int nofs);
3208 extern int page_symlink(struct inode *inode, const char *symname, int len);
3209 extern const struct inode_operations page_symlink_inode_operations;
3210 extern void kfree_link(void *);
3211 void generic_fillattr(struct user_namespace *, struct inode *, struct kstat *);
3212 extern int vfs_getattr_nosec(const struct path *, struct kstat *, u32, unsigned int);
3213 extern int vfs_getattr(const struct path *, struct kstat *, u32, unsigned int);
3214 void __inode_add_bytes(struct inode *inode, loff_t bytes);
3215 void inode_add_bytes(struct inode *inode, loff_t bytes);
3216 void __inode_sub_bytes(struct inode *inode, loff_t bytes);
3217 void inode_sub_bytes(struct inode *inode, loff_t bytes);
3218 static inline loff_t __inode_get_bytes(struct inode *inode)
3219 {
3220         return (((loff_t)inode->i_blocks) << 9) + inode->i_bytes;
3221 }
3222 loff_t inode_get_bytes(struct inode *inode);
3223 void inode_set_bytes(struct inode *inode, loff_t bytes);
3224 const char *simple_get_link(struct dentry *, struct inode *,
3225                             struct delayed_call *);
3226 extern const struct inode_operations simple_symlink_inode_operations;
3227 
3228 extern int iterate_dir(struct file *, struct dir_context *);
3229 
3230 int vfs_fstatat(int dfd, const char __user *filename, struct kstat *stat,
3231                 int flags);
3232 int vfs_fstat(int fd, struct kstat *stat);
3233 
3234 static inline int vfs_stat(const char __user *filename, struct kstat *stat)
3235 {
3236         return vfs_fstatat(AT_FDCWD, filename, stat, 0);
3237 }
3238 static inline int vfs_lstat(const char __user *name, struct kstat *stat)
3239 {
3240         return vfs_fstatat(AT_FDCWD, name, stat, AT_SYMLINK_NOFOLLOW);
3241 }
3242 
3243 extern const char *vfs_get_link(struct dentry *, struct delayed_call *);
3244 extern int vfs_readlink(struct dentry *, char __user *, int);
3245 
3246 extern struct file_system_type *get_filesystem(struct file_system_type *fs);
3247 extern void put_filesystem(struct file_system_type *fs);
3248 extern struct file_system_type *get_fs_type(const char *name);
3249 extern struct super_block *get_super(struct block_device *);
3250 extern struct super_block *get_active_super(struct block_device *bdev);
3251 extern void drop_super(struct super_block *sb);
3252 extern void drop_super_exclusive(struct super_block *sb);
3253 extern void iterate_supers(void (*)(struct super_block *, void *), void *);
3254 extern void iterate_supers_type(struct file_system_type *,
3255                                 void (*)(struct super_block *, void *), void *);
3256 
3257 extern int dcache_dir_open(struct inode *, struct file *);
3258 extern int dcache_dir_close(struct inode *, struct file *);
3259 extern loff_t dcache_dir_lseek(struct file *, loff_t, int);
3260 extern int dcache_readdir(struct file *, struct dir_context *);
3261 extern int simple_setattr(struct user_namespace *, struct dentry *,
3262                           struct iattr *);
3263 extern int simple_getattr(struct user_namespace *, const struct path *,
3264                           struct kstat *, u32, unsigned int);
3265 extern int simple_statfs(struct dentry *, struct kstatfs *);
3266 extern int simple_open(struct inode *inode, struct file *file);
3267 extern int simple_link(struct dentry *, struct inode *, struct dentry *);
3268 extern int simple_unlink(struct inode *, struct dentry *);
3269 extern int simple_rmdir(struct inode *, struct dentry *);
3270 extern int simple_rename(struct user_namespace *, struct inode *,
3271                          struct dentry *, struct inode *, struct dentry *,
3272                          unsigned int);
3273 extern void simple_recursive_removal(struct dentry *,
3274                               void (*callback)(struct dentry *));
3275 extern int noop_fsync(struct file *, loff_t, loff_t, int);
3276 extern int noop_set_page_dirty(struct page *page);
3277 extern void noop_invalidatepage(struct page *page, unsigned int offset,
3278                 unsigned int length);
3279 extern ssize_t noop_direct_IO(struct kiocb *iocb, struct iov_iter *iter);
3280 extern int simple_empty(struct dentry *);
3281 extern int simple_readpage(struct file *file, struct page *page);
3282 extern int simple_write_begin(struct file *file, struct address_space *mapping,
3283                         loff_t pos, unsigned len, unsigned flags,
3284                         struct page **pagep, void **fsdata);
3285 extern int simple_write_end(struct file *file, struct address_space *mapping,
3286                         loff_t pos, unsigned len, unsigned copied,
3287                         struct page *page, void *fsdata);
3288 extern int always_delete_dentry(const struct dentry *);
3289 extern struct inode *alloc_anon_inode(struct super_block *);
3290 extern int simple_nosetlease(struct file *, long, struct file_lock **, void **);
3291 extern const struct dentry_operations simple_dentry_operations;
3292 
3293 extern struct dentry *simple_lookup(struct inode *, struct dentry *, unsigned int flags);
3294 extern ssize_t generic_read_dir(struct file *, char __user *, size_t, loff_t *);
3295 extern const struct file_operations simple_dir_operations;
3296 extern const struct inode_operations simple_dir_inode_operations;
3297 extern void make_empty_dir_inode(struct inode *inode);
3298 extern bool is_empty_dir_inode(struct inode *inode);
3299 struct tree_descr { const char *name; const struct file_operations *ops; int mode; };
3300 struct dentry *d_alloc_name(struct dentry *, const char *);
3301 extern int simple_fill_super(struct super_block *, unsigned long,
3302                              const struct tree_descr *);
3303 extern int simple_pin_fs(struct file_system_type *, struct vfsmount **mount, int *count);
3304 extern void simple_release_fs(struct vfsmount **mount, int *count);
3305 
3306 extern ssize_t simple_read_from_buffer(void __user *to, size_t count,
3307                         loff_t *ppos, const void *from, size_t available);
3308 extern ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos,
3309                 const void __user *from, size_t count);
3310 
3311 extern int __generic_file_fsync(struct file *, loff_t, loff_t, int);
3312 extern int generic_file_fsync(struct file *, loff_t, loff_t, int);
3313 
3314 extern int generic_check_addressable(unsigned, u64);
3315 
3316 extern void generic_set_encrypted_ci_d_ops(struct dentry *dentry);
3317 
3318 #ifdef CONFIG_MIGRATION
3319 extern int buffer_migrate_page(struct address_space *,
3320                                 struct page *, struct page *,
3321                                 enum migrate_mode);
3322 extern int buffer_migrate_page_norefs(struct address_space *,
3323                                 struct page *, struct page *,
3324                                 enum migrate_mode);
3325 #else
3326 #define buffer_migrate_page NULL
3327 #define buffer_migrate_page_norefs NULL
3328 #endif
3329 
3330 int setattr_prepare(struct user_namespace *, struct dentry *, struct iattr *);
3331 extern int inode_newsize_ok(const struct inode *, loff_t offset);
3332 void setattr_copy(struct user_namespace *, struct inode *inode,
3333                   const struct iattr *attr);
3334 
3335 extern int file_update_time(struct file *file);
3336 
3337 static inline bool vma_is_dax(const struct vm_area_struct *vma)
3338 {
3339         return vma->vm_file && IS_DAX(vma->vm_file->f_mapping->host);
3340 }
3341 
3342 static inline bool vma_is_fsdax(struct vm_area_struct *vma)
3343 {
3344         struct inode *inode;
3345 
3346         if (!IS_ENABLED(CONFIG_FS_DAX) || !vma->vm_file)
3347                 return false;
3348         if (!vma_is_dax(vma))
3349                 return false;
3350         inode = file_inode(vma->vm_file);
3351         if (S_ISCHR(inode->i_mode))
3352                 return false; /* device-dax */
3353         return true;
3354 }
3355 
3356 static inline int iocb_flags(struct file *file)
3357 {
3358         int res = 0;
3359         if (file->f_flags & O_APPEND)
3360                 res |= IOCB_APPEND;
3361         if (file->f_flags & O_DIRECT)
3362                 res |= IOCB_DIRECT;
3363         if ((file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host))
3364                 res |= IOCB_DSYNC;
3365         if (file->f_flags & __O_SYNC)
3366                 res |= IOCB_SYNC;
3367         return res;
3368 }
3369 
3370 static inline int kiocb_set_rw_flags(struct kiocb *ki, rwf_t flags)
3371 {
3372         int kiocb_flags = 0;
3373 
3374         /* make sure there's no overlap between RWF and private IOCB flags */
3375         BUILD_BUG_ON((__force int) RWF_SUPPORTED & IOCB_EVENTFD);
3376 
3377         if (!flags)
3378                 return 0;
3379         if (unlikely(flags & ~RWF_SUPPORTED))
3380                 return -EOPNOTSUPP;
3381 
3382         if (flags & RWF_NOWAIT) {
3383                 if (!(ki->ki_filp->f_mode & FMODE_NOWAIT))
3384                         return -EOPNOTSUPP;
3385                 kiocb_flags |= IOCB_NOIO;
3386         }
3387         kiocb_flags |= (__force int) (flags & RWF_SUPPORTED);
3388         if (flags & RWF_SYNC)
3389                 kiocb_flags |= IOCB_DSYNC;
3390 
3391         ki->ki_flags |= kiocb_flags;
3392         return 0;
3393 }
3394 
3395 static inline ino_t parent_ino(struct dentry *dentry)
3396 {
3397         ino_t res;
3398 
3399         /*
3400          * Don't strictly need d_lock here? If the parent ino could change
3401          * then surely we'd have a deeper race in the caller?
3402          */
3403         spin_lock(&dentry->d_lock);
3404         res = dentry->d_parent->d_inode->i_ino;
3405         spin_unlock(&dentry->d_lock);
3406         return res;
3407 }
3408 
3409 /* Transaction based IO helpers */
3410 
3411 /*
3412  * An argresp is stored in an allocated page and holds the
3413  * size of the argument or response, along with its content
3414  */
3415 struct simple_transaction_argresp {
3416         ssize_t size;
3417         char data[];
3418 };
3419 
3420 #define SIMPLE_TRANSACTION_LIMIT (PAGE_SIZE - sizeof(struct simple_transaction_argresp))
3421 
3422 char *simple_transaction_get(struct file *file, const char __user *buf,
3423                                 size_t size);
3424 ssize_t simple_transaction_read(struct file *file, char __user *buf,
3425                                 size_t size, loff_t *pos);
3426 int simple_transaction_release(struct inode *inode, struct file *file);
3427 
3428 void simple_transaction_set(struct file *file, size_t n);
3429 
3430 /*
3431  * simple attribute files
3432  *
3433  * These attributes behave similar to those in sysfs:
3434  *
3435  * Writing to an attribute immediately sets a value, an open file can be
3436  * written to multiple times.
3437  *
3438  * Reading from an attribute creates a buffer from the value that might get
3439  * read with multiple read calls. When the attribute has been read
3440  * completely, no further read calls are possible until the file is opened
3441  * again.
3442  *
3443  * All attributes contain a text representation of a numeric value
3444  * that are accessed with the get() and set() functions.
3445  */
3446 #define DEFINE_SIMPLE_ATTRIBUTE(__fops, __get, __set, __fmt)            \
3447 static int __fops ## _open(struct inode *inode, struct file *file)      \
3448 {                                                                       \
3449         __simple_attr_check_format(__fmt, 0ull);                        \
3450         return simple_attr_open(inode, file, __get, __set, __fmt);      \
3451 }                                                                       \
3452 static const struct file_operations __fops = {                          \
3453         .owner   = THIS_MODULE,                                         \
3454         .open    = __fops ## _open,                                     \
3455         .release = simple_attr_release,                                 \
3456         .read    = simple_attr_read,                                    \
3457         .write   = simple_attr_write,                                   \
3458         .llseek  = generic_file_llseek,                                 \
3459 }
3460 
3461 static inline __printf(1, 2)
3462 void __simple_attr_check_format(const char *fmt, ...)
3463 {
3464         /* don't do anything, just let the compiler check the arguments; */
3465 }
3466 
3467 int simple_attr_open(struct inode *inode, struct file *file,
3468                      int (*get)(void *, u64 *), int (*set)(void *, u64),
3469                      const char *fmt);
3470 int simple_attr_release(struct inode *inode, struct file *file);
3471 ssize_t simple_attr_read(struct file *file, char __user *buf,
3472                          size_t len, loff_t *ppos);
3473 ssize_t simple_attr_write(struct file *file, const char __user *buf,
3474                           size_t len, loff_t *ppos);
3475 
3476 struct ctl_table;
3477 int proc_nr_files(struct ctl_table *table, int write,
3478                   void *buffer, size_t *lenp, loff_t *ppos);
3479 int proc_nr_dentry(struct ctl_table *table, int write,
3480                   void *buffer, size_t *lenp, loff_t *ppos);
3481 int proc_nr_inodes(struct ctl_table *table, int write,
3482                    void *buffer, size_t *lenp, loff_t *ppos);
3483 int __init get_filesystem_list(char *buf);
3484 
3485 #define __FMODE_EXEC            ((__force int) FMODE_EXEC)
3486 #define __FMODE_NONOTIFY        ((__force int) FMODE_NONOTIFY)
3487 
3488 #define ACC_MODE(x) ("\004\002\006\006"[(x)&O_ACCMODE])
3489 #define OPEN_FMODE(flag) ((__force fmode_t)(((flag + 1) & O_ACCMODE) | \
3490                                             (flag & __FMODE_NONOTIFY)))
3491 
3492 static inline bool is_sxid(umode_t mode)
3493 {
3494         return (mode & S_ISUID) || ((mode & S_ISGID) && (mode & S_IXGRP));
3495 }
3496 
3497 static inline int check_sticky(struct user_namespace *mnt_userns,
3498                                struct inode *dir, struct inode *inode)
3499 {
3500         if (!(dir->i_mode & S_ISVTX))
3501                 return 0;
3502 
3503         return __check_sticky(mnt_userns, dir, inode);
3504 }
3505 
3506 static inline void inode_has_no_xattr(struct inode *inode)
3507 {
3508         if (!is_sxid(inode->i_mode) && (inode->i_sb->s_flags & SB_NOSEC))
3509                 inode->i_flags |= S_NOSEC;
3510 }
3511 
3512 static inline bool is_root_inode(struct inode *inode)
3513 {
3514         return inode == inode->i_sb->s_root->d_inode;
3515 }
3516 
3517 static inline bool dir_emit(struct dir_context *ctx,
3518                             const char *name, int namelen,
3519                             u64 ino, unsigned type)
3520 {
3521         return ctx->actor(ctx, name, namelen, ctx->pos, ino, type) == 0;
3522 }
3523 static inline bool dir_emit_dot(struct file *file, struct dir_context *ctx)
3524 {
3525         return ctx->actor(ctx, ".", 1, ctx->pos,
3526                           file->f_path.dentry->d_inode->i_ino, DT_DIR) == 0;
3527 }
3528 static inline bool dir_emit_dotdot(struct file *file, struct dir_context *ctx)
3529 {
3530         return ctx->actor(ctx, "..", 2, ctx->pos,
3531                           parent_ino(file->f_path.dentry), DT_DIR) == 0;
3532 }
3533 static inline bool dir_emit_dots(struct file *file, struct dir_context *ctx)
3534 {
3535         if (ctx->pos == 0) {
3536                 if (!dir_emit_dot(file, ctx))
3537                         return false;
3538                 ctx->pos = 1;
3539         }
3540         if (ctx->pos == 1) {
3541                 if (!dir_emit_dotdot(file, ctx))
3542                         return false;
3543                 ctx->pos = 2;
3544         }
3545         return true;
3546 }
3547 static inline bool dir_relax(struct inode *inode)
3548 {
3549         inode_unlock(inode);
3550         inode_lock(inode);
3551         return !IS_DEADDIR(inode);
3552 }
3553 
3554 static inline bool dir_relax_shared(struct inode *inode)
3555 {
3556         inode_unlock_shared(inode);
3557         inode_lock_shared(inode);
3558         return !IS_DEADDIR(inode);
3559 }
3560 
3561 extern bool path_noexec(const struct path *path);
3562 extern void inode_nohighmem(struct inode *inode);
3563 
3564 /* mm/fadvise.c */
3565 extern int vfs_fadvise(struct file *file, loff_t offset, loff_t len,
3566                        int advice);
3567 extern int generic_fadvise(struct file *file, loff_t offset, loff_t len,
3568                            int advice);
3569 
3570 int vfs_ioc_setflags_prepare(struct inode *inode, unsigned int oldflags,
3571                              unsigned int flags);
3572 
3573 int vfs_ioc_fssetxattr_check(struct inode *inode, const struct fsxattr *old_fa,
3574                              struct fsxattr *fa);
3575 
3576 static inline void simple_fill_fsxattr(struct fsxattr *fa, __u32 xflags)
3577 {
3578         memset(fa, 0, sizeof(*fa));
3579         fa->fsx_xflags = xflags;
3580 }
3581 
3582 /*
3583  * Flush file data before changing attributes.  Caller must hold any locks
3584  * required to prevent further writes to this file until we're done setting
3585  * flags.
3586  */
3587 static inline int inode_drain_writes(struct inode *inode)
3588 {
3589         inode_dio_wait(inode);
3590         return filemap_write_and_wait(inode->i_mapping);
3591 }
3592 
3593 #endif /* _LINUX_FS_H */
3594 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp