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 #include <linux/mnt_idmapping.h> 45 #include <linux/slab.h> 46 47 #include <asm/byteorder.h> 48 #include <uapi/linux/fs.h> 49 50 struct backing_dev_info; 51 struct bdi_writeback; 52 struct bio; 53 struct io_comp_batch; 54 struct export_operations; 55 struct fiemap_extent_info; 56 struct hd_geometry; 57 struct iovec; 58 struct kiocb; 59 struct kobject; 60 struct pipe_inode_info; 61 struct poll_table_struct; 62 struct kstatfs; 63 struct vm_area_struct; 64 struct vfsmount; 65 struct cred; 66 struct swap_info_struct; 67 struct seq_file; 68 struct workqueue_struct; 69 struct iov_iter; 70 struct fscrypt_info; 71 struct fscrypt_operations; 72 struct fsverity_info; 73 struct fsverity_operations; 74 struct fs_context; 75 struct fs_parameter_spec; 76 struct fileattr; 77 struct iomap_ops; 78 79 extern void __init inode_init(void); 80 extern void __init inode_init_early(void); 81 extern void __init files_init(void); 82 extern void __init files_maxfiles_init(void); 83 84 extern unsigned long get_max_files(void); 85 extern unsigned int sysctl_nr_open; 86 87 typedef __kernel_rwf_t rwf_t; 88 89 struct buffer_head; 90 typedef int (get_block_t)(struct inode *inode, sector_t iblock, 91 struct buffer_head *bh_result, int create); 92 typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset, 93 ssize_t bytes, void *private); 94 95 #define MAY_EXEC 0x00000001 96 #define MAY_WRITE 0x00000002 97 #define MAY_READ 0x00000004 98 #define MAY_APPEND 0x00000008 99 #define MAY_ACCESS 0x00000010 100 #define MAY_OPEN 0x00000020 101 #define MAY_CHDIR 0x00000040 102 /* called from RCU mode, don't block */ 103 #define MAY_NOT_BLOCK 0x00000080 104 105 /* 106 * flags in file.f_mode. Note that FMODE_READ and FMODE_WRITE must correspond 107 * to O_WRONLY and O_RDWR via the strange trick in do_dentry_open() 108 */ 109 110 /* file is open for reading */ 111 #define FMODE_READ ((__force fmode_t)0x1) 112 /* file is open for writing */ 113 #define FMODE_WRITE ((__force fmode_t)0x2) 114 /* file is seekable */ 115 #define FMODE_LSEEK ((__force fmode_t)0x4) 116 /* file can be accessed using pread */ 117 #define FMODE_PREAD ((__force fmode_t)0x8) 118 /* file can be accessed using pwrite */ 119 #define FMODE_PWRITE ((__force fmode_t)0x10) 120 /* File is opened for execution with sys_execve / sys_uselib */ 121 #define FMODE_EXEC ((__force fmode_t)0x20) 122 /* File is opened with O_NDELAY (only set for block devices) */ 123 #define FMODE_NDELAY ((__force fmode_t)0x40) 124 /* File is opened with O_EXCL (only set for block devices) */ 125 #define FMODE_EXCL ((__force fmode_t)0x80) 126 /* File is opened using open(.., 3, ..) and is writeable only for ioctls 127 (specialy hack for floppy.c) */ 128 #define FMODE_WRITE_IOCTL ((__force fmode_t)0x100) 129 /* 32bit hashes as llseek() offset (for directories) */ 130 #define FMODE_32BITHASH ((__force fmode_t)0x200) 131 /* 64bit hashes as llseek() offset (for directories) */ 132 #define FMODE_64BITHASH ((__force fmode_t)0x400) 133 134 /* 135 * Don't update ctime and mtime. 136 * 137 * Currently a special hack for the XFS open_by_handle ioctl, but we'll 138 * hopefully graduate it to a proper O_CMTIME flag supported by open(2) soon. 139 */ 140 #define FMODE_NOCMTIME ((__force fmode_t)0x800) 141 142 /* Expect random access pattern */ 143 #define FMODE_RANDOM ((__force fmode_t)0x1000) 144 145 /* File is huge (eg. /dev/mem): treat loff_t as unsigned */ 146 #define FMODE_UNSIGNED_OFFSET ((__force fmode_t)0x2000) 147 148 /* File is opened with O_PATH; almost nothing can be done with it */ 149 #define FMODE_PATH ((__force fmode_t)0x4000) 150 151 /* File needs atomic accesses to f_pos */ 152 #define FMODE_ATOMIC_POS ((__force fmode_t)0x8000) 153 /* Write access to underlying fs */ 154 #define FMODE_WRITER ((__force fmode_t)0x10000) 155 /* Has read method(s) */ 156 #define FMODE_CAN_READ ((__force fmode_t)0x20000) 157 /* Has write method(s) */ 158 #define FMODE_CAN_WRITE ((__force fmode_t)0x40000) 159 160 #define FMODE_OPENED ((__force fmode_t)0x80000) 161 #define FMODE_CREATED ((__force fmode_t)0x100000) 162 163 /* File is stream-like */ 164 #define FMODE_STREAM ((__force fmode_t)0x200000) 165 166 /* File supports DIRECT IO */ 167 #define FMODE_CAN_ODIRECT ((__force fmode_t)0x400000) 168 169 /* File was opened by fanotify and shouldn't generate fanotify events */ 170 #define FMODE_NONOTIFY ((__force fmode_t)0x4000000) 171 172 /* File is capable of returning -EAGAIN if I/O will block */ 173 #define FMODE_NOWAIT ((__force fmode_t)0x8000000) 174 175 /* File represents mount that needs unmounting */ 176 #define FMODE_NEED_UNMOUNT ((__force fmode_t)0x10000000) 177 178 /* File does not contribute to nr_files count */ 179 #define FMODE_NOACCOUNT ((__force fmode_t)0x20000000) 180 181 /* File supports async buffered reads */ 182 #define FMODE_BUF_RASYNC ((__force fmode_t)0x40000000) 183 184 /* File supports async nowait buffered writes */ 185 #define FMODE_BUF_WASYNC ((__force fmode_t)0x80000000) 186 187 /* 188 * Attribute flags. These should be or-ed together to figure out what 189 * has been changed! 190 */ 191 #define ATTR_MODE (1 << 0) 192 #define ATTR_UID (1 << 1) 193 #define ATTR_GID (1 << 2) 194 #define ATTR_SIZE (1 << 3) 195 #define ATTR_ATIME (1 << 4) 196 #define ATTR_MTIME (1 << 5) 197 #define ATTR_CTIME (1 << 6) 198 #define ATTR_ATIME_SET (1 << 7) 199 #define ATTR_MTIME_SET (1 << 8) 200 #define ATTR_FORCE (1 << 9) /* Not a change, but a change it */ 201 #define ATTR_KILL_SUID (1 << 11) 202 #define ATTR_KILL_SGID (1 << 12) 203 #define ATTR_FILE (1 << 13) 204 #define ATTR_KILL_PRIV (1 << 14) 205 #define ATTR_OPEN (1 << 15) /* Truncating from open(O_TRUNC) */ 206 #define ATTR_TIMES_SET (1 << 16) 207 #define ATTR_TOUCH (1 << 17) 208 209 /* 210 * Whiteout is represented by a char device. The following constants define the 211 * mode and device number to use. 212 */ 213 #define WHITEOUT_MODE 0 214 #define WHITEOUT_DEV 0 215 216 /* 217 * This is the Inode Attributes structure, used for notify_change(). It 218 * uses the above definitions as flags, to know which values have changed. 219 * Also, in this manner, a Filesystem can look at only the values it cares 220 * about. Basically, these are the attributes that the VFS layer can 221 * request to change from the FS layer. 222 * 223 * Derek Atkins <warlord@MIT.EDU> 94-10-20 224 */ 225 struct iattr { 226 unsigned int ia_valid; 227 umode_t ia_mode; 228 /* 229 * The two anonymous unions wrap structures with the same member. 230 * 231 * Filesystems raising FS_ALLOW_IDMAP need to use ia_vfs{g,u}id which 232 * are a dedicated type requiring the filesystem to use the dedicated 233 * helpers. Other filesystem can continue to use ia_{g,u}id until they 234 * have been ported. 235 * 236 * They always contain the same value. In other words FS_ALLOW_IDMAP 237 * pass down the same value on idmapped mounts as they would on regular 238 * mounts. 239 */ 240 union { 241 kuid_t ia_uid; 242 vfsuid_t ia_vfsuid; 243 }; 244 union { 245 kgid_t ia_gid; 246 vfsgid_t ia_vfsgid; 247 }; 248 loff_t ia_size; 249 struct timespec64 ia_atime; 250 struct timespec64 ia_mtime; 251 struct timespec64 ia_ctime; 252 253 /* 254 * Not an attribute, but an auxiliary info for filesystems wanting to 255 * implement an ftruncate() like method. NOTE: filesystem should 256 * check for (ia_valid & ATTR_FILE), and not for (ia_file != NULL). 257 */ 258 struct file *ia_file; 259 }; 260 261 /* 262 * Includes for diskquotas. 263 */ 264 #include <linux/quota.h> 265 266 /* 267 * Maximum number of layers of fs stack. Needs to be limited to 268 * prevent kernel stack overflow 269 */ 270 #define FILESYSTEM_MAX_STACK_DEPTH 2 271 272 /** 273 * enum positive_aop_returns - aop return codes with specific semantics 274 * 275 * @AOP_WRITEPAGE_ACTIVATE: Informs the caller that page writeback has 276 * completed, that the page is still locked, and 277 * should be considered active. The VM uses this hint 278 * to return the page to the active list -- it won't 279 * be a candidate for writeback again in the near 280 * future. Other callers must be careful to unlock 281 * the page if they get this return. Returned by 282 * writepage(); 283 * 284 * @AOP_TRUNCATED_PAGE: The AOP method that was handed a locked page has 285 * unlocked it and the page might have been truncated. 286 * The caller should back up to acquiring a new page and 287 * trying again. The aop will be taking reasonable 288 * precautions not to livelock. If the caller held a page 289 * reference, it should drop it before retrying. Returned 290 * by read_folio(). 291 * 292 * address_space_operation functions return these large constants to indicate 293 * special semantics to the caller. These are much larger than the bytes in a 294 * page to allow for functions that return the number of bytes operated on in a 295 * given page. 296 */ 297 298 enum positive_aop_returns { 299 AOP_WRITEPAGE_ACTIVATE = 0x80000, 300 AOP_TRUNCATED_PAGE = 0x80001, 301 }; 302 303 /* 304 * oh the beauties of C type declarations. 305 */ 306 struct page; 307 struct address_space; 308 struct writeback_control; 309 struct readahead_control; 310 311 /* 312 * Write life time hint values. 313 * Stored in struct inode as u8. 314 */ 315 enum rw_hint { 316 WRITE_LIFE_NOT_SET = 0, 317 WRITE_LIFE_NONE = RWH_WRITE_LIFE_NONE, 318 WRITE_LIFE_SHORT = RWH_WRITE_LIFE_SHORT, 319 WRITE_LIFE_MEDIUM = RWH_WRITE_LIFE_MEDIUM, 320 WRITE_LIFE_LONG = RWH_WRITE_LIFE_LONG, 321 WRITE_LIFE_EXTREME = RWH_WRITE_LIFE_EXTREME, 322 }; 323 324 /* Match RWF_* bits to IOCB bits */ 325 #define IOCB_HIPRI (__force int) RWF_HIPRI 326 #define IOCB_DSYNC (__force int) RWF_DSYNC 327 #define IOCB_SYNC (__force int) RWF_SYNC 328 #define IOCB_NOWAIT (__force int) RWF_NOWAIT 329 #define IOCB_APPEND (__force int) RWF_APPEND 330 331 /* non-RWF related bits - start at 16 */ 332 #define IOCB_EVENTFD (1 << 16) 333 #define IOCB_DIRECT (1 << 17) 334 #define IOCB_WRITE (1 << 18) 335 /* iocb->ki_waitq is valid */ 336 #define IOCB_WAITQ (1 << 19) 337 #define IOCB_NOIO (1 << 20) 338 /* can use bio alloc cache */ 339 #define IOCB_ALLOC_CACHE (1 << 21) 340 341 struct kiocb { 342 struct file *ki_filp; 343 loff_t ki_pos; 344 void (*ki_complete)(struct kiocb *iocb, long ret); 345 void *private; 346 int ki_flags; 347 u16 ki_ioprio; /* See linux/ioprio.h */ 348 struct wait_page_queue *ki_waitq; /* for async buffered IO */ 349 }; 350 351 static inline bool is_sync_kiocb(struct kiocb *kiocb) 352 { 353 return kiocb->ki_complete == NULL; 354 } 355 356 struct address_space_operations { 357 int (*writepage)(struct page *page, struct writeback_control *wbc); 358 int (*read_folio)(struct file *, struct folio *); 359 360 /* Write back some dirty pages from this mapping. */ 361 int (*writepages)(struct address_space *, struct writeback_control *); 362 363 /* Mark a folio dirty. Return true if this dirtied it */ 364 bool (*dirty_folio)(struct address_space *, struct folio *); 365 366 void (*readahead)(struct readahead_control *); 367 368 int (*write_begin)(struct file *, struct address_space *mapping, 369 loff_t pos, unsigned len, 370 struct page **pagep, void **fsdata); 371 int (*write_end)(struct file *, struct address_space *mapping, 372 loff_t pos, unsigned len, unsigned copied, 373 struct page *page, void *fsdata); 374 375 /* Unfortunately this kludge is needed for FIBMAP. Don't use it */ 376 sector_t (*bmap)(struct address_space *, sector_t); 377 void (*invalidate_folio) (struct folio *, size_t offset, size_t len); 378 bool (*release_folio)(struct folio *, gfp_t); 379 void (*free_folio)(struct folio *folio); 380 ssize_t (*direct_IO)(struct kiocb *, struct iov_iter *iter); 381 /* 382 * migrate the contents of a folio to the specified target. If 383 * migrate_mode is MIGRATE_ASYNC, it must not block. 384 */ 385 int (*migrate_folio)(struct address_space *, struct folio *dst, 386 struct folio *src, enum migrate_mode); 387 int (*launder_folio)(struct folio *); 388 bool (*is_partially_uptodate) (struct folio *, size_t from, 389 size_t count); 390 void (*is_dirty_writeback) (struct folio *, bool *dirty, bool *wb); 391 int (*error_remove_page)(struct address_space *, struct page *); 392 393 /* swapfile support */ 394 int (*swap_activate)(struct swap_info_struct *sis, struct file *file, 395 sector_t *span); 396 void (*swap_deactivate)(struct file *file); 397 int (*swap_rw)(struct kiocb *iocb, struct iov_iter *iter); 398 }; 399 400 extern const struct address_space_operations empty_aops; 401 402 /** 403 * struct address_space - Contents of a cacheable, mappable object. 404 * @host: Owner, either the inode or the block_device. 405 * @i_pages: Cached pages. 406 * @invalidate_lock: Guards coherency between page cache contents and 407 * file offset->disk block mappings in the filesystem during invalidates. 408 * It is also used to block modification of page cache contents through 409 * memory mappings. 410 * @gfp_mask: Memory allocation flags to use for allocating pages. 411 * @i_mmap_writable: Number of VM_SHARED mappings. 412 * @nr_thps: Number of THPs in the pagecache (non-shmem only). 413 * @i_mmap: Tree of private and shared mappings. 414 * @i_mmap_rwsem: Protects @i_mmap and @i_mmap_writable. 415 * @nrpages: Number of page entries, protected by the i_pages lock. 416 * @writeback_index: Writeback starts here. 417 * @a_ops: Methods. 418 * @flags: Error bits and flags (AS_*). 419 * @wb_err: The most recent error which has occurred. 420 * @private_lock: For use by the owner of the address_space. 421 * @private_list: For use by the owner of the address_space. 422 * @private_data: For use by the owner of the address_space. 423 */ 424 struct address_space { 425 struct inode *host; 426 struct xarray i_pages; 427 struct rw_semaphore invalidate_lock; 428 gfp_t gfp_mask; 429 atomic_t i_mmap_writable; 430 #ifdef CONFIG_READ_ONLY_THP_FOR_FS 431 /* number of thp, only for non-shmem files */ 432 atomic_t nr_thps; 433 #endif 434 struct rb_root_cached i_mmap; 435 struct rw_semaphore i_mmap_rwsem; 436 unsigned long nrpages; 437 pgoff_t writeback_index; 438 const struct address_space_operations *a_ops; 439 unsigned long flags; 440 errseq_t wb_err; 441 spinlock_t private_lock; 442 struct list_head private_list; 443 void *private_data; 444 } __attribute__((aligned(sizeof(long)))) __randomize_layout; 445 /* 446 * On most architectures that alignment is already the case; but 447 * must be enforced here for CRIS, to let the least significant bit 448 * of struct page's "mapping" pointer be used for PAGE_MAPPING_ANON. 449 */ 450 451 /* XArray tags, for tagging dirty and writeback pages in the pagecache. */ 452 #define PAGECACHE_TAG_DIRTY XA_MARK_0 453 #define PAGECACHE_TAG_WRITEBACK XA_MARK_1 454 #define PAGECACHE_TAG_TOWRITE XA_MARK_2 455 456 /* 457 * Returns true if any of the pages in the mapping are marked with the tag. 458 */ 459 static inline bool mapping_tagged(struct address_space *mapping, xa_mark_t tag) 460 { 461 return xa_marked(&mapping->i_pages, tag); 462 } 463 464 static inline void i_mmap_lock_write(struct address_space *mapping) 465 { 466 down_write(&mapping->i_mmap_rwsem); 467 } 468 469 static inline int i_mmap_trylock_write(struct address_space *mapping) 470 { 471 return down_write_trylock(&mapping->i_mmap_rwsem); 472 } 473 474 static inline void i_mmap_unlock_write(struct address_space *mapping) 475 { 476 up_write(&mapping->i_mmap_rwsem); 477 } 478 479 static inline int i_mmap_trylock_read(struct address_space *mapping) 480 { 481 return down_read_trylock(&mapping->i_mmap_rwsem); 482 } 483 484 static inline void i_mmap_lock_read(struct address_space *mapping) 485 { 486 down_read(&mapping->i_mmap_rwsem); 487 } 488 489 static inline void i_mmap_unlock_read(struct address_space *mapping) 490 { 491 up_read(&mapping->i_mmap_rwsem); 492 } 493 494 static inline void i_mmap_assert_locked(struct address_space *mapping) 495 { 496 lockdep_assert_held(&mapping->i_mmap_rwsem); 497 } 498 499 static inline void i_mmap_assert_write_locked(struct address_space *mapping) 500 { 501 lockdep_assert_held_write(&mapping->i_mmap_rwsem); 502 } 503 504 /* 505 * Might pages of this file be mapped into userspace? 506 */ 507 static inline int mapping_mapped(struct address_space *mapping) 508 { 509 return !RB_EMPTY_ROOT(&mapping->i_mmap.rb_root); 510 } 511 512 /* 513 * Might pages of this file have been modified in userspace? 514 * Note that i_mmap_writable counts all VM_SHARED vmas: do_mmap 515 * marks vma as VM_SHARED if it is shared, and the file was opened for 516 * writing i.e. vma may be mprotected writable even if now readonly. 517 * 518 * If i_mmap_writable is negative, no new writable mappings are allowed. You 519 * can only deny writable mappings, if none exists right now. 520 */ 521 static inline int mapping_writably_mapped(struct address_space *mapping) 522 { 523 return atomic_read(&mapping->i_mmap_writable) > 0; 524 } 525 526 static inline int mapping_map_writable(struct address_space *mapping) 527 { 528 return atomic_inc_unless_negative(&mapping->i_mmap_writable) ? 529 0 : -EPERM; 530 } 531 532 static inline void mapping_unmap_writable(struct address_space *mapping) 533 { 534 atomic_dec(&mapping->i_mmap_writable); 535 } 536 537 static inline int mapping_deny_writable(struct address_space *mapping) 538 { 539 return atomic_dec_unless_positive(&mapping->i_mmap_writable) ? 540 0 : -EBUSY; 541 } 542 543 static inline void mapping_allow_writable(struct address_space *mapping) 544 { 545 atomic_inc(&mapping->i_mmap_writable); 546 } 547 548 /* 549 * Use sequence counter to get consistent i_size on 32-bit processors. 550 */ 551 #if BITS_PER_LONG==32 && defined(CONFIG_SMP) 552 #include <linux/seqlock.h> 553 #define __NEED_I_SIZE_ORDERED 554 #define i_size_ordered_init(inode) seqcount_init(&inode->i_size_seqcount) 555 #else 556 #define i_size_ordered_init(inode) do { } while (0) 557 #endif 558 559 struct posix_acl; 560 #define ACL_NOT_CACHED ((void *)(-1)) 561 /* 562 * ACL_DONT_CACHE is for stacked filesystems, that rely on underlying fs to 563 * cache the ACL. This also means that ->get_acl() can be called in RCU mode 564 * with the LOOKUP_RCU flag. 565 */ 566 #define ACL_DONT_CACHE ((void *)(-3)) 567 568 static inline struct posix_acl * 569 uncached_acl_sentinel(struct task_struct *task) 570 { 571 return (void *)task + 1; 572 } 573 574 static inline bool 575 is_uncached_acl(struct posix_acl *acl) 576 { 577 return (long)acl & 1; 578 } 579 580 #define IOP_FASTPERM 0x0001 581 #define IOP_LOOKUP 0x0002 582 #define IOP_NOFOLLOW 0x0004 583 #define IOP_XATTR 0x0008 584 #define IOP_DEFAULT_READLINK 0x0010 585 586 struct fsnotify_mark_connector; 587 588 /* 589 * Keep mostly read-only and often accessed (especially for 590 * the RCU path lookup and 'stat' data) fields at the beginning 591 * of the 'struct inode' 592 */ 593 struct inode { 594 umode_t i_mode; 595 unsigned short i_opflags; 596 kuid_t i_uid; 597 kgid_t i_gid; 598 unsigned int i_flags; 599 600 #ifdef CONFIG_FS_POSIX_ACL 601 struct posix_acl *i_acl; 602 struct posix_acl *i_default_acl; 603 #endif 604 605 const struct inode_operations *i_op; 606 struct super_block *i_sb; 607 struct address_space *i_mapping; 608 609 #ifdef CONFIG_SECURITY 610 void *i_security; 611 #endif 612 613 /* Stat data, not accessed from path walking */ 614 unsigned long i_ino; 615 /* 616 * Filesystems may only read i_nlink directly. They shall use the 617 * following functions for modification: 618 * 619 * (set|clear|inc|drop)_nlink 620 * inode_(inc|dec)_link_count 621 */ 622 union { 623 const unsigned int i_nlink; 624 unsigned int __i_nlink; 625 }; 626 dev_t i_rdev; 627 loff_t i_size; 628 struct timespec64 i_atime; 629 struct timespec64 i_mtime; 630 struct timespec64 i_ctime; 631 spinlock_t i_lock; /* i_blocks, i_bytes, maybe i_size */ 632 unsigned short i_bytes; 633 u8 i_blkbits; 634 u8 i_write_hint; 635 blkcnt_t i_blocks; 636 637 #ifdef __NEED_I_SIZE_ORDERED 638 seqcount_t i_size_seqcount; 639 #endif 640 641 /* Misc */ 642 unsigned long i_state; 643 struct rw_semaphore i_rwsem; 644 645 unsigned long dirtied_when; /* jiffies of first dirtying */ 646 unsigned long dirtied_time_when; 647 648 struct hlist_node i_hash; 649 struct list_head i_io_list; /* backing dev IO list */ 650 #ifdef CONFIG_CGROUP_WRITEBACK 651 struct bdi_writeback *i_wb; /* the associated cgroup wb */ 652 653 /* foreign inode detection, see wbc_detach_inode() */ 654 int i_wb_frn_winner; 655 u16 i_wb_frn_avg_time; 656 u16 i_wb_frn_history; 657 #endif 658 struct list_head i_lru; /* inode LRU list */ 659 struct list_head i_sb_list; 660 struct list_head i_wb_list; /* backing dev writeback list */ 661 union { 662 struct hlist_head i_dentry; 663 struct rcu_head i_rcu; 664 }; 665 atomic64_t i_version; 666 atomic64_t i_sequence; /* see futex */ 667 atomic_t i_count; 668 atomic_t i_dio_count; 669 atomic_t i_writecount; 670 #if defined(CONFIG_IMA) || defined(CONFIG_FILE_LOCKING) 671 atomic_t i_readcount; /* struct files open RO */ 672 #endif 673 union { 674 const struct file_operations *i_fop; /* former ->i_op->default_file_ops */ 675 void (*free_inode)(struct inode *); 676 }; 677 struct file_lock_context *i_flctx; 678 struct address_space i_data; 679 struct list_head i_devices; 680 union { 681 struct pipe_inode_info *i_pipe; 682 struct cdev *i_cdev; 683 char *i_link; 684 unsigned i_dir_seq; 685 }; 686 687 __u32 i_generation; 688 689 #ifdef CONFIG_FSNOTIFY 690 __u32 i_fsnotify_mask; /* all events this inode cares about */ 691 struct fsnotify_mark_connector __rcu *i_fsnotify_marks; 692 #endif 693 694 #ifdef CONFIG_FS_ENCRYPTION 695 struct fscrypt_info *i_crypt_info; 696 #endif 697 698 #ifdef CONFIG_FS_VERITY 699 struct fsverity_info *i_verity_info; 700 #endif 701 702 void *i_private; /* fs or device private pointer */ 703 } __randomize_layout; 704 705 struct timespec64 timestamp_truncate(struct timespec64 t, struct inode *inode); 706 707 static inline unsigned int i_blocksize(const struct inode *node) 708 { 709 return (1 << node->i_blkbits); 710 } 711 712 static inline int inode_unhashed(struct inode *inode) 713 { 714 return hlist_unhashed(&inode->i_hash); 715 } 716 717 /* 718 * __mark_inode_dirty expects inodes to be hashed. Since we don't 719 * want special inodes in the fileset inode space, we make them 720 * appear hashed, but do not put on any lists. hlist_del() 721 * will work fine and require no locking. 722 */ 723 static inline void inode_fake_hash(struct inode *inode) 724 { 725 hlist_add_fake(&inode->i_hash); 726 } 727 728 /* 729 * inode->i_mutex nesting subclasses for the lock validator: 730 * 731 * 0: the object of the current VFS operation 732 * 1: parent 733 * 2: child/target 734 * 3: xattr 735 * 4: second non-directory 736 * 5: second parent (when locking independent directories in rename) 737 * 738 * I_MUTEX_NONDIR2 is for certain operations (such as rename) which lock two 739 * non-directories at once. 740 * 741 * The locking order between these classes is 742 * parent[2] -> child -> grandchild -> normal -> xattr -> second non-directory 743 */ 744 enum inode_i_mutex_lock_class 745 { 746 I_MUTEX_NORMAL, 747 I_MUTEX_PARENT, 748 I_MUTEX_CHILD, 749 I_MUTEX_XATTR, 750 I_MUTEX_NONDIR2, 751 I_MUTEX_PARENT2, 752 }; 753 754 static inline void inode_lock(struct inode *inode) 755 { 756 down_write(&inode->i_rwsem); 757 } 758 759 static inline void inode_unlock(struct inode *inode) 760 { 761 up_write(&inode->i_rwsem); 762 } 763 764 static inline void inode_lock_shared(struct inode *inode) 765 { 766 down_read(&inode->i_rwsem); 767 } 768 769 static inline void inode_unlock_shared(struct inode *inode) 770 { 771 up_read(&inode->i_rwsem); 772 } 773 774 static inline int inode_trylock(struct inode *inode) 775 { 776 return down_write_trylock(&inode->i_rwsem); 777 } 778 779 static inline int inode_trylock_shared(struct inode *inode) 780 { 781 return down_read_trylock(&inode->i_rwsem); 782 } 783 784 static inline int inode_is_locked(struct inode *inode) 785 { 786 return rwsem_is_locked(&inode->i_rwsem); 787 } 788 789 static inline void inode_lock_nested(struct inode *inode, unsigned subclass) 790 { 791 down_write_nested(&inode->i_rwsem, subclass); 792 } 793 794 static inline void inode_lock_shared_nested(struct inode *inode, unsigned subclass) 795 { 796 down_read_nested(&inode->i_rwsem, subclass); 797 } 798 799 static inline void filemap_invalidate_lock(struct address_space *mapping) 800 { 801 down_write(&mapping->invalidate_lock); 802 } 803 804 static inline void filemap_invalidate_unlock(struct address_space *mapping) 805 { 806 up_write(&mapping->invalidate_lock); 807 } 808 809 static inline void filemap_invalidate_lock_shared(struct address_space *mapping) 810 { 811 down_read(&mapping->invalidate_lock); 812 } 813 814 static inline int filemap_invalidate_trylock_shared( 815 struct address_space *mapping) 816 { 817 return down_read_trylock(&mapping->invalidate_lock); 818 } 819 820 static inline void filemap_invalidate_unlock_shared( 821 struct address_space *mapping) 822 { 823 up_read(&mapping->invalidate_lock); 824 } 825 826 void lock_two_nondirectories(struct inode *, struct inode*); 827 void unlock_two_nondirectories(struct inode *, struct inode*); 828 829 void filemap_invalidate_lock_two(struct address_space *mapping1, 830 struct address_space *mapping2); 831 void filemap_invalidate_unlock_two(struct address_space *mapping1, 832 struct address_space *mapping2); 833 834 835 /* 836 * NOTE: in a 32bit arch with a preemptable kernel and 837 * an UP compile the i_size_read/write must be atomic 838 * with respect to the local cpu (unlike with preempt disabled), 839 * but they don't need to be atomic with respect to other cpus like in 840 * true SMP (so they need either to either locally disable irq around 841 * the read or for example on x86 they can be still implemented as a 842 * cmpxchg8b without the need of the lock prefix). For SMP compiles 843 * and 64bit archs it makes no difference if preempt is enabled or not. 844 */ 845 static inline loff_t i_size_read(const struct inode *inode) 846 { 847 #if BITS_PER_LONG==32 && defined(CONFIG_SMP) 848 loff_t i_size; 849 unsigned int seq; 850 851 do { 852 seq = read_seqcount_begin(&inode->i_size_seqcount); 853 i_size = inode->i_size; 854 } while (read_seqcount_retry(&inode->i_size_seqcount, seq)); 855 return i_size; 856 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION) 857 loff_t i_size; 858 859 preempt_disable(); 860 i_size = inode->i_size; 861 preempt_enable(); 862 return i_size; 863 #else 864 return inode->i_size; 865 #endif 866 } 867 868 /* 869 * NOTE: unlike i_size_read(), i_size_write() does need locking around it 870 * (normally i_mutex), otherwise on 32bit/SMP an update of i_size_seqcount 871 * can be lost, resulting in subsequent i_size_read() calls spinning forever. 872 */ 873 static inline void i_size_write(struct inode *inode, loff_t i_size) 874 { 875 #if BITS_PER_LONG==32 && defined(CONFIG_SMP) 876 preempt_disable(); 877 write_seqcount_begin(&inode->i_size_seqcount); 878 inode->i_size = i_size; 879 write_seqcount_end(&inode->i_size_seqcount); 880 preempt_enable(); 881 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPTION) 882 preempt_disable(); 883 inode->i_size = i_size; 884 preempt_enable(); 885 #else 886 inode->i_size = i_size; 887 #endif 888 } 889 890 static inline unsigned iminor(const struct inode *inode) 891 { 892 return MINOR(inode->i_rdev); 893 } 894 895 static inline unsigned imajor(const struct inode *inode) 896 { 897 return MAJOR(inode->i_rdev); 898 } 899 900 struct fown_struct { 901 rwlock_t lock; /* protects pid, uid, euid fields */ 902 struct pid *pid; /* pid or -pgrp where SIGIO should be sent */ 903 enum pid_type pid_type; /* Kind of process group SIGIO should be sent to */ 904 kuid_t uid, euid; /* uid/euid of process setting the owner */ 905 int signum; /* posix.1b rt signal to be delivered on IO */ 906 }; 907 908 /** 909 * struct file_ra_state - Track a file's readahead state. 910 * @start: Where the most recent readahead started. 911 * @size: Number of pages read in the most recent readahead. 912 * @async_size: Numer of pages that were/are not needed immediately 913 * and so were/are genuinely "ahead". Start next readahead when 914 * the first of these pages is accessed. 915 * @ra_pages: Maximum size of a readahead request, copied from the bdi. 916 * @mmap_miss: How many mmap accesses missed in the page cache. 917 * @prev_pos: The last byte in the most recent read request. 918 * 919 * When this structure is passed to ->readahead(), the "most recent" 920 * readahead means the current readahead. 921 */ 922 struct file_ra_state { 923 pgoff_t start; 924 unsigned int size; 925 unsigned int async_size; 926 unsigned int ra_pages; 927 unsigned int mmap_miss; 928 loff_t prev_pos; 929 }; 930 931 /* 932 * Check if @index falls in the readahead windows. 933 */ 934 static inline int ra_has_index(struct file_ra_state *ra, pgoff_t index) 935 { 936 return (index >= ra->start && 937 index < ra->start + ra->size); 938 } 939 940 struct file { 941 union { 942 struct llist_node f_llist; 943 struct rcu_head f_rcuhead; 944 unsigned int f_iocb_flags; 945 }; 946 struct path f_path; 947 struct inode *f_inode; /* cached value */ 948 const struct file_operations *f_op; 949 950 /* 951 * Protects f_ep, f_flags. 952 * Must not be taken from IRQ context. 953 */ 954 spinlock_t f_lock; 955 atomic_long_t f_count; 956 unsigned int f_flags; 957 fmode_t f_mode; 958 struct mutex f_pos_lock; 959 loff_t f_pos; 960 struct fown_struct f_owner; 961 const struct cred *f_cred; 962 struct file_ra_state f_ra; 963 964 u64 f_version; 965 #ifdef CONFIG_SECURITY 966 void *f_security; 967 #endif 968 /* needed for tty driver, and maybe others */ 969 void *private_data; 970 971 #ifdef CONFIG_EPOLL 972 /* Used by fs/eventpoll.c to link all the hooks to this file */ 973 struct hlist_head *f_ep; 974 #endif /* #ifdef CONFIG_EPOLL */ 975 struct address_space *f_mapping; 976 errseq_t f_wb_err; 977 errseq_t f_sb_err; /* for syncfs */ 978 } __randomize_layout 979 __attribute__((aligned(4))); /* lest something weird decides that 2 is OK */ 980 981 struct file_handle { 982 __u32 handle_bytes; 983 int handle_type; 984 /* file identifier */ 985 unsigned char f_handle[]; 986 }; 987 988 static inline struct file *get_file(struct file *f) 989 { 990 atomic_long_inc(&f->f_count); 991 return f; 992 } 993 #define get_file_rcu(x) atomic_long_inc_not_zero(&(x)->f_count) 994 #define file_count(x) atomic_long_read(&(x)->f_count) 995 996 #define MAX_NON_LFS ((1UL<<31) - 1) 997 998 /* Page cache limit. The filesystems should put that into their s_maxbytes 999 limits, otherwise bad things can happen in VM. */ 1000 #if BITS_PER_LONG==32 1001 #define MAX_LFS_FILESIZE ((loff_t)ULONG_MAX << PAGE_SHIFT) 1002 #elif BITS_PER_LONG==64 1003 #define MAX_LFS_FILESIZE ((loff_t)LLONG_MAX) 1004 #endif 1005 1006 #define FL_POSIX 1 1007 #define FL_FLOCK 2 1008 #define FL_DELEG 4 /* NFSv4 delegation */ 1009 #define FL_ACCESS 8 /* not trying to lock, just looking */ 1010 #define FL_EXISTS 16 /* when unlocking, test for existence */ 1011 #define FL_LEASE 32 /* lease held on this file */ 1012 #define FL_CLOSE 64 /* unlock on close */ 1013 #define FL_SLEEP 128 /* A blocking lock */ 1014 #define FL_DOWNGRADE_PENDING 256 /* Lease is being downgraded */ 1015 #define FL_UNLOCK_PENDING 512 /* Lease is being broken */ 1016 #define FL_OFDLCK 1024 /* lock is "owned" by struct file */ 1017 #define FL_LAYOUT 2048 /* outstanding pNFS layout */ 1018 #define FL_RECLAIM 4096 /* reclaiming from a reboot server */ 1019 1020 #define FL_CLOSE_POSIX (FL_POSIX | FL_CLOSE) 1021 1022 /* 1023 * Special return value from posix_lock_file() and vfs_lock_file() for 1024 * asynchronous locking. 1025 */ 1026 #define FILE_LOCK_DEFERRED 1 1027 1028 /* legacy typedef, should eventually be removed */ 1029 typedef void *fl_owner_t; 1030 1031 struct file_lock; 1032 1033 struct file_lock_operations { 1034 void (*fl_copy_lock)(struct file_lock *, struct file_lock *); 1035 void (*fl_release_private)(struct file_lock *); 1036 }; 1037 1038 struct lock_manager_operations { 1039 void *lm_mod_owner; 1040 fl_owner_t (*lm_get_owner)(fl_owner_t); 1041 void (*lm_put_owner)(fl_owner_t); 1042 void (*lm_notify)(struct file_lock *); /* unblock callback */ 1043 int (*lm_grant)(struct file_lock *, int); 1044 bool (*lm_break)(struct file_lock *); 1045 int (*lm_change)(struct file_lock *, int, struct list_head *); 1046 void (*lm_setup)(struct file_lock *, void **); 1047 bool (*lm_breaker_owns_lease)(struct file_lock *); 1048 bool (*lm_lock_expirable)(struct file_lock *cfl); 1049 void (*lm_expire_lock)(void); 1050 }; 1051 1052 struct lock_manager { 1053 struct list_head list; 1054 /* 1055 * NFSv4 and up also want opens blocked during the grace period; 1056 * NLM doesn't care: 1057 */ 1058 bool block_opens; 1059 }; 1060 1061 struct net; 1062 void locks_start_grace(struct net *, struct lock_manager *); 1063 void locks_end_grace(struct lock_manager *); 1064 bool locks_in_grace(struct net *); 1065 bool opens_in_grace(struct net *); 1066 1067 /* that will die - we need it for nfs_lock_info */ 1068 #include <linux/nfs_fs_i.h> 1069 1070 /* 1071 * struct file_lock represents a generic "file lock". It's used to represent 1072 * POSIX byte range locks, BSD (flock) locks, and leases. It's important to 1073 * note that the same struct is used to represent both a request for a lock and 1074 * the lock itself, but the same object is never used for both. 1075 * 1076 * FIXME: should we create a separate "struct lock_request" to help distinguish 1077 * these two uses? 1078 * 1079 * The varous i_flctx lists are ordered by: 1080 * 1081 * 1) lock owner 1082 * 2) lock range start 1083 * 3) lock range end 1084 * 1085 * Obviously, the last two criteria only matter for POSIX locks. 1086 */ 1087 struct file_lock { 1088 struct file_lock *fl_blocker; /* The lock, that is blocking us */ 1089 struct list_head fl_list; /* link into file_lock_context */ 1090 struct hlist_node fl_link; /* node in global lists */ 1091 struct list_head fl_blocked_requests; /* list of requests with 1092 * ->fl_blocker pointing here 1093 */ 1094 struct list_head fl_blocked_member; /* node in 1095 * ->fl_blocker->fl_blocked_requests 1096 */ 1097 fl_owner_t fl_owner; 1098 unsigned int fl_flags; 1099 unsigned char fl_type; 1100 unsigned int fl_pid; 1101 int fl_link_cpu; /* what cpu's list is this on? */ 1102 wait_queue_head_t fl_wait; 1103 struct file *fl_file; 1104 loff_t fl_start; 1105 loff_t fl_end; 1106 1107 struct fasync_struct * fl_fasync; /* for lease break notifications */ 1108 /* for lease breaks: */ 1109 unsigned long fl_break_time; 1110 unsigned long fl_downgrade_time; 1111 1112 const struct file_lock_operations *fl_ops; /* Callbacks for filesystems */ 1113 const struct lock_manager_operations *fl_lmops; /* Callbacks for lockmanagers */ 1114 union { 1115 struct nfs_lock_info nfs_fl; 1116 struct nfs4_lock_info nfs4_fl; 1117 struct { 1118 struct list_head link; /* link in AFS vnode's pending_locks list */ 1119 int state; /* state of grant or error if -ve */ 1120 unsigned int debug_id; 1121 } afs; 1122 } fl_u; 1123 } __randomize_layout; 1124 1125 struct file_lock_context { 1126 spinlock_t flc_lock; 1127 struct list_head flc_flock; 1128 struct list_head flc_posix; 1129 struct list_head flc_lease; 1130 }; 1131 1132 /* The following constant reflects the upper bound of the file/locking space */ 1133 #ifndef OFFSET_MAX 1134 #define INT_LIMIT(x) (~((x)1 << (sizeof(x)*8 - 1))) 1135 #define OFFSET_MAX INT_LIMIT(loff_t) 1136 #define OFFT_OFFSET_MAX INT_LIMIT(off_t) 1137 #endif 1138 1139 extern void send_sigio(struct fown_struct *fown, int fd, int band); 1140 1141 #define locks_inode(f) file_inode(f) 1142 1143 #ifdef CONFIG_FILE_LOCKING 1144 extern int fcntl_getlk(struct file *, unsigned int, struct flock *); 1145 extern int fcntl_setlk(unsigned int, struct file *, unsigned int, 1146 struct flock *); 1147 1148 #if BITS_PER_LONG == 32 1149 extern int fcntl_getlk64(struct file *, unsigned int, struct flock64 *); 1150 extern int fcntl_setlk64(unsigned int, struct file *, unsigned int, 1151 struct flock64 *); 1152 #endif 1153 1154 extern int fcntl_setlease(unsigned int fd, struct file *filp, long arg); 1155 extern int fcntl_getlease(struct file *filp); 1156 1157 /* fs/locks.c */ 1158 void locks_free_lock_context(struct inode *inode); 1159 void locks_free_lock(struct file_lock *fl); 1160 extern void locks_init_lock(struct file_lock *); 1161 extern struct file_lock * locks_alloc_lock(void); 1162 extern void locks_copy_lock(struct file_lock *, struct file_lock *); 1163 extern void locks_copy_conflock(struct file_lock *, struct file_lock *); 1164 extern void locks_remove_posix(struct file *, fl_owner_t); 1165 extern void locks_remove_file(struct file *); 1166 extern void locks_release_private(struct file_lock *); 1167 extern void posix_test_lock(struct file *, struct file_lock *); 1168 extern int posix_lock_file(struct file *, struct file_lock *, struct file_lock *); 1169 extern int locks_delete_block(struct file_lock *); 1170 extern int vfs_test_lock(struct file *, struct file_lock *); 1171 extern int vfs_lock_file(struct file *, unsigned int, struct file_lock *, struct file_lock *); 1172 extern int vfs_cancel_lock(struct file *filp, struct file_lock *fl); 1173 extern int locks_lock_inode_wait(struct inode *inode, struct file_lock *fl); 1174 extern int __break_lease(struct inode *inode, unsigned int flags, unsigned int type); 1175 extern void lease_get_mtime(struct inode *, struct timespec64 *time); 1176 extern int generic_setlease(struct file *, long, struct file_lock **, void **priv); 1177 extern int vfs_setlease(struct file *, long, struct file_lock **, void **); 1178 extern int lease_modify(struct file_lock *, int, struct list_head *); 1179 1180 struct notifier_block; 1181 extern int lease_register_notifier(struct notifier_block *); 1182 extern void lease_unregister_notifier(struct notifier_block *); 1183 1184 struct files_struct; 1185 extern void show_fd_locks(struct seq_file *f, 1186 struct file *filp, struct files_struct *files); 1187 extern bool locks_owner_has_blockers(struct file_lock_context *flctx, 1188 fl_owner_t owner); 1189 #else /* !CONFIG_FILE_LOCKING */ 1190 static inline int fcntl_getlk(struct file *file, unsigned int cmd, 1191 struct flock __user *user) 1192 { 1193 return -EINVAL; 1194 } 1195 1196 static inline int fcntl_setlk(unsigned int fd, struct file *file, 1197 unsigned int cmd, struct flock __user *user) 1198 { 1199 return -EACCES; 1200 } 1201 1202 #if BITS_PER_LONG == 32 1203 static inline int fcntl_getlk64(struct file *file, unsigned int cmd, 1204 struct flock64 *user) 1205 { 1206 return -EINVAL; 1207 } 1208 1209 static inline int fcntl_setlk64(unsigned int fd, struct file *file, 1210 unsigned int cmd, struct flock64 *user) 1211 { 1212 return -EACCES; 1213 } 1214 #endif 1215 static inline int fcntl_setlease(unsigned int fd, struct file *filp, long arg) 1216 { 1217 return -EINVAL; 1218 } 1219 1220 static inline int fcntl_getlease(struct file *filp) 1221 { 1222 return F_UNLCK; 1223 } 1224 1225 static inline void 1226 locks_free_lock_context(struct inode *inode) 1227 { 1228 } 1229 1230 static inline void locks_init_lock(struct file_lock *fl) 1231 { 1232 return; 1233 } 1234 1235 static inline void locks_copy_conflock(struct file_lock *new, struct file_lock *fl) 1236 { 1237 return; 1238 } 1239 1240 static inline void locks_copy_lock(struct file_lock *new, struct file_lock *fl) 1241 { 1242 return; 1243 } 1244 1245 static inline void locks_remove_posix(struct file *filp, fl_owner_t owner) 1246 { 1247 return; 1248 } 1249 1250 static inline void locks_remove_file(struct file *filp) 1251 { 1252 return; 1253 } 1254 1255 static inline void posix_test_lock(struct file *filp, struct file_lock *fl) 1256 { 1257 return; 1258 } 1259 1260 static inline int posix_lock_file(struct file *filp, struct file_lock *fl, 1261 struct file_lock *conflock) 1262 { 1263 return -ENOLCK; 1264 } 1265 1266 static inline int locks_delete_block(struct file_lock *waiter) 1267 { 1268 return -ENOENT; 1269 } 1270 1271 static inline int vfs_test_lock(struct file *filp, struct file_lock *fl) 1272 { 1273 return 0; 1274 } 1275 1276 static inline int vfs_lock_file(struct file *filp, unsigned int cmd, 1277 struct file_lock *fl, struct file_lock *conf) 1278 { 1279 return -ENOLCK; 1280 } 1281 1282 static inline int vfs_cancel_lock(struct file *filp, struct file_lock *fl) 1283 { 1284 return 0; 1285 } 1286 1287 static inline int locks_lock_inode_wait(struct inode *inode, struct file_lock *fl) 1288 { 1289 return -ENOLCK; 1290 } 1291 1292 static inline int __break_lease(struct inode *inode, unsigned int mode, unsigned int type) 1293 { 1294 return 0; 1295 } 1296 1297 static inline void lease_get_mtime(struct inode *inode, 1298 struct timespec64 *time) 1299 { 1300 return; 1301 } 1302 1303 static inline int generic_setlease(struct file *filp, long arg, 1304 struct file_lock **flp, void **priv) 1305 { 1306 return -EINVAL; 1307 } 1308 1309 static inline int vfs_setlease(struct file *filp, long arg, 1310 struct file_lock **lease, void **priv) 1311 { 1312 return -EINVAL; 1313 } 1314 1315 static inline int lease_modify(struct file_lock *fl, int arg, 1316 struct list_head *dispose) 1317 { 1318 return -EINVAL; 1319 } 1320 1321 struct files_struct; 1322 static inline void show_fd_locks(struct seq_file *f, 1323 struct file *filp, struct files_struct *files) {} 1324 static inline bool locks_owner_has_blockers(struct file_lock_context *flctx, 1325 fl_owner_t owner) 1326 { 1327 return false; 1328 } 1329 #endif /* !CONFIG_FILE_LOCKING */ 1330 1331 static inline struct inode *file_inode(const struct file *f) 1332 { 1333 return f->f_inode; 1334 } 1335 1336 static inline struct dentry *file_dentry(const struct file *file) 1337 { 1338 return d_real(file->f_path.dentry, file_inode(file)); 1339 } 1340 1341 static inline int locks_lock_file_wait(struct file *filp, struct file_lock *fl) 1342 { 1343 return locks_lock_inode_wait(locks_inode(filp), fl); 1344 } 1345 1346 struct fasync_struct { 1347 rwlock_t fa_lock; 1348 int magic; 1349 int fa_fd; 1350 struct fasync_struct *fa_next; /* singly linked list */ 1351 struct file *fa_file; 1352 struct rcu_head fa_rcu; 1353 }; 1354 1355 #define FASYNC_MAGIC 0x4601 1356 1357 /* SMP safe fasync helpers: */ 1358 extern int fasync_helper(int, struct file *, int, struct fasync_struct **); 1359 extern struct fasync_struct *fasync_insert_entry(int, struct file *, struct fasync_struct **, struct fasync_struct *); 1360 extern int fasync_remove_entry(struct file *, struct fasync_struct **); 1361 extern struct fasync_struct *fasync_alloc(void); 1362 extern void fasync_free(struct fasync_struct *); 1363 1364 /* can be called from interrupts */ 1365 extern void kill_fasync(struct fasync_struct **, int, int); 1366 1367 extern void __f_setown(struct file *filp, struct pid *, enum pid_type, int force); 1368 extern int f_setown(struct file *filp, unsigned long arg, int force); 1369 extern void f_delown(struct file *filp); 1370 extern pid_t f_getown(struct file *filp); 1371 extern int send_sigurg(struct fown_struct *fown); 1372 1373 /* 1374 * sb->s_flags. Note that these mirror the equivalent MS_* flags where 1375 * represented in both. 1376 */ 1377 #define SB_RDONLY 1 /* Mount read-only */ 1378 #define SB_NOSUID 2 /* Ignore suid and sgid bits */ 1379 #define SB_NODEV 4 /* Disallow access to device special files */ 1380 #define SB_NOEXEC 8 /* Disallow program execution */ 1381 #define SB_SYNCHRONOUS 16 /* Writes are synced at once */ 1382 #define SB_MANDLOCK 64 /* Allow mandatory locks on an FS */ 1383 #define SB_DIRSYNC 128 /* Directory modifications are synchronous */ 1384 #define SB_NOATIME 1024 /* Do not update access times. */ 1385 #define SB_NODIRATIME 2048 /* Do not update directory access times */ 1386 #define SB_SILENT 32768 1387 #define SB_POSIXACL (1<<16) /* VFS does not apply the umask */ 1388 #define SB_INLINECRYPT (1<<17) /* Use blk-crypto for encrypted files */ 1389 #define SB_KERNMOUNT (1<<22) /* this is a kern_mount call */ 1390 #define SB_I_VERSION (1<<23) /* Update inode I_version field */ 1391 #define SB_LAZYTIME (1<<25) /* Update the on-disk [acm]times lazily */ 1392 1393 /* These sb flags are internal to the kernel */ 1394 #define SB_SUBMOUNT (1<<26) 1395 #define SB_FORCE (1<<27) 1396 #define SB_NOSEC (1<<28) 1397 #define SB_BORN (1<<29) 1398 #define SB_ACTIVE (1<<30) 1399 #define SB_NOUSER (1<<31) 1400 1401 /* These flags relate to encoding and casefolding */ 1402 #define SB_ENC_STRICT_MODE_FL (1 << 0) 1403 1404 #define sb_has_strict_encoding(sb) \ 1405 (sb->s_encoding_flags & SB_ENC_STRICT_MODE_FL) 1406 1407 /* 1408 * Umount options 1409 */ 1410 1411 #define MNT_FORCE 0x00000001 /* Attempt to forcibily umount */ 1412 #define MNT_DETACH 0x00000002 /* Just detach from the tree */ 1413 #define MNT_EXPIRE 0x00000004 /* Mark for expiry */ 1414 #define UMOUNT_NOFOLLOW 0x00000008 /* Don't follow symlink on umount */ 1415 #define UMOUNT_UNUSED 0x80000000 /* Flag guaranteed to be unused */ 1416 1417 /* sb->s_iflags */ 1418 #define SB_I_CGROUPWB 0x00000001 /* cgroup-aware writeback enabled */ 1419 #define SB_I_NOEXEC 0x00000002 /* Ignore executables on this fs */ 1420 #define SB_I_NODEV 0x00000004 /* Ignore devices on this fs */ 1421 #define SB_I_STABLE_WRITES 0x00000008 /* don't modify blks until WB is done */ 1422 1423 /* sb->s_iflags to limit user namespace mounts */ 1424 #define SB_I_USERNS_VISIBLE 0x00000010 /* fstype already mounted */ 1425 #define SB_I_IMA_UNVERIFIABLE_SIGNATURE 0x00000020 1426 #define SB_I_UNTRUSTED_MOUNTER 0x00000040 1427 1428 #define SB_I_SKIP_SYNC 0x00000100 /* Skip superblock at global sync */ 1429 #define SB_I_PERSB_BDI 0x00000200 /* has a per-sb bdi */ 1430 #define SB_I_TS_EXPIRY_WARNED 0x00000400 /* warned about timestamp range expiry */ 1431 #define SB_I_RETIRED 0x00000800 /* superblock shouldn't be reused */ 1432 1433 /* Possible states of 'frozen' field */ 1434 enum { 1435 SB_UNFROZEN = 0, /* FS is unfrozen */ 1436 SB_FREEZE_WRITE = 1, /* Writes, dir ops, ioctls frozen */ 1437 SB_FREEZE_PAGEFAULT = 2, /* Page faults stopped as well */ 1438 SB_FREEZE_FS = 3, /* For internal FS use (e.g. to stop 1439 * internal threads if needed) */ 1440 SB_FREEZE_COMPLETE = 4, /* ->freeze_fs finished successfully */ 1441 }; 1442 1443 #define SB_FREEZE_LEVELS (SB_FREEZE_COMPLETE - 1) 1444 1445 struct sb_writers { 1446 int frozen; /* Is sb frozen? */ 1447 wait_queue_head_t wait_unfrozen; /* wait for thaw */ 1448 struct percpu_rw_semaphore rw_sem[SB_FREEZE_LEVELS]; 1449 }; 1450 1451 struct super_block { 1452 struct list_head s_list; /* Keep this first */ 1453 dev_t s_dev; /* search index; _not_ kdev_t */ 1454 unsigned char s_blocksize_bits; 1455 unsigned long s_blocksize; 1456 loff_t s_maxbytes; /* Max file size */ 1457 struct file_system_type *s_type; 1458 const struct super_operations *s_op; 1459 const struct dquot_operations *dq_op; 1460 const struct quotactl_ops *s_qcop; 1461 const struct export_operations *s_export_op; 1462 unsigned long s_flags; 1463 unsigned long s_iflags; /* internal SB_I_* flags */ 1464 unsigned long s_magic; 1465 struct dentry *s_root; 1466 struct rw_semaphore s_umount; 1467 int s_count; 1468 atomic_t s_active; 1469 #ifdef CONFIG_SECURITY 1470 void *s_security; 1471 #endif 1472 const struct xattr_handler **s_xattr; 1473 #ifdef CONFIG_FS_ENCRYPTION 1474 const struct fscrypt_operations *s_cop; 1475 struct key *s_master_keys; /* master crypto keys in use */ 1476 #endif 1477 #ifdef CONFIG_FS_VERITY 1478 const struct fsverity_operations *s_vop; 1479 #endif 1480 #if IS_ENABLED(CONFIG_UNICODE) 1481 struct unicode_map *s_encoding; 1482 __u16 s_encoding_flags; 1483 #endif 1484 struct hlist_bl_head s_roots; /* alternate root dentries for NFS */ 1485 struct list_head s_mounts; /* list of mounts; _not_ for fs use */ 1486 struct block_device *s_bdev; 1487 struct backing_dev_info *s_bdi; 1488 struct mtd_info *s_mtd; 1489 struct hlist_node s_instances; 1490 unsigned int s_quota_types; /* Bitmask of supported quota types */ 1491 struct quota_info s_dquot; /* Diskquota specific options */ 1492 1493 struct sb_writers s_writers; 1494 1495 /* 1496 * Keep s_fs_info, s_time_gran, s_fsnotify_mask, and 1497 * s_fsnotify_marks together for cache efficiency. They are frequently 1498 * accessed and rarely modified. 1499 */ 1500 void *s_fs_info; /* Filesystem private info */ 1501 1502 /* Granularity of c/m/atime in ns (cannot be worse than a second) */ 1503 u32 s_time_gran; 1504 /* Time limits for c/m/atime in seconds */ 1505 time64_t s_time_min; 1506 time64_t s_time_max; 1507 #ifdef CONFIG_FSNOTIFY 1508 __u32 s_fsnotify_mask; 1509 struct fsnotify_mark_connector __rcu *s_fsnotify_marks; 1510 #endif 1511 1512 char s_id[32]; /* Informational name */ 1513 uuid_t s_uuid; /* UUID */ 1514 1515 unsigned int s_max_links; 1516 fmode_t s_mode; 1517 1518 /* 1519 * The next field is for VFS *only*. No filesystems have any business 1520 * even looking at it. You had been warned. 1521 */ 1522 struct mutex s_vfs_rename_mutex; /* Kludge */ 1523 1524 /* 1525 * Filesystem subtype. If non-empty the filesystem type field 1526 * in /proc/mounts will be "type.subtype" 1527 */ 1528 const char *s_subtype; 1529 1530 const struct dentry_operations *s_d_op; /* default d_op for dentries */ 1531 1532 struct shrinker s_shrink; /* per-sb shrinker handle */ 1533 1534 /* Number of inodes with nlink == 0 but still referenced */ 1535 atomic_long_t s_remove_count; 1536 1537 /* 1538 * Number of inode/mount/sb objects that are being watched, note that 1539 * inodes objects are currently double-accounted. 1540 */ 1541 atomic_long_t s_fsnotify_connectors; 1542 1543 /* Being remounted read-only */ 1544 int s_readonly_remount; 1545 1546 /* per-sb errseq_t for reporting writeback errors via syncfs */ 1547 errseq_t s_wb_err; 1548 1549 /* AIO completions deferred from interrupt context */ 1550 struct workqueue_struct *s_dio_done_wq; 1551 struct hlist_head s_pins; 1552 1553 /* 1554 * Owning user namespace and default context in which to 1555 * interpret filesystem uids, gids, quotas, device nodes, 1556 * xattrs and security labels. 1557 */ 1558 struct user_namespace *s_user_ns; 1559 1560 /* 1561 * The list_lru structure is essentially just a pointer to a table 1562 * of per-node lru lists, each of which has its own spinlock. 1563 * There is no need to put them into separate cachelines. 1564 */ 1565 struct list_lru s_dentry_lru; 1566 struct list_lru s_inode_lru; 1567 struct rcu_head rcu; 1568 struct work_struct destroy_work; 1569 1570 struct mutex s_sync_lock; /* sync serialisation lock */ 1571 1572 /* 1573 * Indicates how deep in a filesystem stack this SB is 1574 */ 1575 int s_stack_depth; 1576 1577 /* s_inode_list_lock protects s_inodes */ 1578 spinlock_t s_inode_list_lock ____cacheline_aligned_in_smp; 1579 struct list_head s_inodes; /* all inodes */ 1580 1581 spinlock_t s_inode_wblist_lock; 1582 struct list_head s_inodes_wb; /* writeback inodes */ 1583 } __randomize_layout; 1584 1585 static inline struct user_namespace *i_user_ns(const struct inode *inode) 1586 { 1587 return inode->i_sb->s_user_ns; 1588 } 1589 1590 /* Helper functions so that in most cases filesystems will 1591 * not need to deal directly with kuid_t and kgid_t and can 1592 * instead deal with the raw numeric values that are stored 1593 * in the filesystem. 1594 */ 1595 static inline uid_t i_uid_read(const struct inode *inode) 1596 { 1597 return from_kuid(i_user_ns(inode), inode->i_uid); 1598 } 1599 1600 static inline gid_t i_gid_read(const struct inode *inode) 1601 { 1602 return from_kgid(i_user_ns(inode), inode->i_gid); 1603 } 1604 1605 static inline void i_uid_write(struct inode *inode, uid_t uid) 1606 { 1607 inode->i_uid = make_kuid(i_user_ns(inode), uid); 1608 } 1609 1610 static inline void i_gid_write(struct inode *inode, gid_t gid) 1611 { 1612 inode->i_gid = make_kgid(i_user_ns(inode), gid); 1613 } 1614 1615 /** 1616 * i_uid_into_mnt - map an inode's i_uid down into a mnt_userns 1617 * @mnt_userns: user namespace of the mount the inode was found from 1618 * @inode: inode to map 1619 * 1620 * Note, this will eventually be removed completely in favor of the type-safe 1621 * i_uid_into_vfsuid(). 1622 * 1623 * Return: the inode's i_uid mapped down according to @mnt_userns. 1624 * If the inode's i_uid has no mapping INVALID_UID is returned. 1625 */ 1626 static inline kuid_t i_uid_into_mnt(struct user_namespace *mnt_userns, 1627 const struct inode *inode) 1628 { 1629 return AS_KUIDT(make_vfsuid(mnt_userns, i_user_ns(inode), inode->i_uid)); 1630 } 1631 1632 /** 1633 * i_uid_into_vfsuid - map an inode's i_uid down into a mnt_userns 1634 * @mnt_userns: user namespace of the mount the inode was found from 1635 * @inode: inode to map 1636 * 1637 * Return: whe inode's i_uid mapped down according to @mnt_userns. 1638 * If the inode's i_uid has no mapping INVALID_VFSUID is returned. 1639 */ 1640 static inline vfsuid_t i_uid_into_vfsuid(struct user_namespace *mnt_userns, 1641 const struct inode *inode) 1642 { 1643 return make_vfsuid(mnt_userns, i_user_ns(inode), inode->i_uid); 1644 } 1645 1646 /** 1647 * i_uid_needs_update - check whether inode's i_uid needs to be updated 1648 * @mnt_userns: user namespace of the mount the inode was found from 1649 * @attr: the new attributes of @inode 1650 * @inode: the inode to update 1651 * 1652 * Check whether the $inode's i_uid field needs to be updated taking idmapped 1653 * mounts into account if the filesystem supports it. 1654 * 1655 * Return: true if @inode's i_uid field needs to be updated, false if not. 1656 */ 1657 static inline bool i_uid_needs_update(struct user_namespace *mnt_userns, 1658 const struct iattr *attr, 1659 const struct inode *inode) 1660 { 1661 return ((attr->ia_valid & ATTR_UID) && 1662 !vfsuid_eq(attr->ia_vfsuid, 1663 i_uid_into_vfsuid(mnt_userns, inode))); 1664 } 1665 1666 /** 1667 * i_uid_update - update @inode's i_uid field 1668 * @mnt_userns: user namespace of the mount the inode was found from 1669 * @attr: the new attributes of @inode 1670 * @inode: the inode to update 1671 * 1672 * Safely update @inode's i_uid field translating the vfsuid of any idmapped 1673 * mount into the filesystem kuid. 1674 */ 1675 static inline void i_uid_update(struct user_namespace *mnt_userns, 1676 const struct iattr *attr, 1677 struct inode *inode) 1678 { 1679 if (attr->ia_valid & ATTR_UID) 1680 inode->i_uid = from_vfsuid(mnt_userns, i_user_ns(inode), 1681 attr->ia_vfsuid); 1682 } 1683 1684 /** 1685 * i_gid_into_mnt - map an inode's i_gid down into a mnt_userns 1686 * @mnt_userns: user namespace of the mount the inode was found from 1687 * @inode: inode to map 1688 * 1689 * Note, this will eventually be removed completely in favor of the type-safe 1690 * i_gid_into_vfsgid(). 1691 * 1692 * Return: the inode's i_gid mapped down according to @mnt_userns. 1693 * If the inode's i_gid has no mapping INVALID_GID is returned. 1694 */ 1695 static inline kgid_t i_gid_into_mnt(struct user_namespace *mnt_userns, 1696 const struct inode *inode) 1697 { 1698 return AS_KGIDT(make_vfsgid(mnt_userns, i_user_ns(inode), inode->i_gid)); 1699 } 1700 1701 /** 1702 * i_gid_into_vfsgid - map an inode's i_gid down into a mnt_userns 1703 * @mnt_userns: user namespace of the mount the inode was found from 1704 * @inode: inode to map 1705 * 1706 * Return: the inode's i_gid mapped down according to @mnt_userns. 1707 * If the inode's i_gid has no mapping INVALID_VFSGID is returned. 1708 */ 1709 static inline vfsgid_t i_gid_into_vfsgid(struct user_namespace *mnt_userns, 1710 const struct inode *inode) 1711 { 1712 return make_vfsgid(mnt_userns, i_user_ns(inode), inode->i_gid); 1713 } 1714 1715 /** 1716 * i_gid_needs_update - check whether inode's i_gid needs to be updated 1717 * @mnt_userns: user namespace of the mount the inode was found from 1718 * @attr: the new attributes of @inode 1719 * @inode: the inode to update 1720 * 1721 * Check whether the $inode's i_gid field needs to be updated taking idmapped 1722 * mounts into account if the filesystem supports it. 1723 * 1724 * Return: true if @inode's i_gid field needs to be updated, false if not. 1725 */ 1726 static inline bool i_gid_needs_update(struct user_namespace *mnt_userns, 1727 const struct iattr *attr, 1728 const struct inode *inode) 1729 { 1730 return ((attr->ia_valid & ATTR_GID) && 1731 !vfsgid_eq(attr->ia_vfsgid, 1732 i_gid_into_vfsgid(mnt_userns, inode))); 1733 } 1734 1735 /** 1736 * i_gid_update - update @inode's i_gid field 1737 * @mnt_userns: user namespace of the mount the inode was found from 1738 * @attr: the new attributes of @inode 1739 * @inode: the inode to update 1740 * 1741 * Safely update @inode's i_gid field translating the vfsgid of any idmapped 1742 * mount into the filesystem kgid. 1743 */ 1744 static inline void i_gid_update(struct user_namespace *mnt_userns, 1745 const struct iattr *attr, 1746 struct inode *inode) 1747 { 1748 if (attr->ia_valid & ATTR_GID) 1749 inode->i_gid = from_vfsgid(mnt_userns, i_user_ns(inode), 1750 attr->ia_vfsgid); 1751 } 1752 1753 /** 1754 * inode_fsuid_set - initialize inode's i_uid field with callers fsuid 1755 * @inode: inode to initialize 1756 * @mnt_userns: user namespace of the mount the inode was found from 1757 * 1758 * Initialize the i_uid field of @inode. If the inode was found/created via 1759 * an idmapped mount map the caller's fsuid according to @mnt_users. 1760 */ 1761 static inline void inode_fsuid_set(struct inode *inode, 1762 struct user_namespace *mnt_userns) 1763 { 1764 inode->i_uid = mapped_fsuid(mnt_userns, i_user_ns(inode)); 1765 } 1766 1767 /** 1768 * inode_fsgid_set - initialize inode's i_gid field with callers fsgid 1769 * @inode: inode to initialize 1770 * @mnt_userns: user namespace of the mount the inode was found from 1771 * 1772 * Initialize the i_gid field of @inode. If the inode was found/created via 1773 * an idmapped mount map the caller's fsgid according to @mnt_users. 1774 */ 1775 static inline void inode_fsgid_set(struct inode *inode, 1776 struct user_namespace *mnt_userns) 1777 { 1778 inode->i_gid = mapped_fsgid(mnt_userns, i_user_ns(inode)); 1779 } 1780 1781 /** 1782 * fsuidgid_has_mapping() - check whether caller's fsuid/fsgid is mapped 1783 * @sb: the superblock we want a mapping in 1784 * @mnt_userns: user namespace of the relevant mount 1785 * 1786 * Check whether the caller's fsuid and fsgid have a valid mapping in the 1787 * s_user_ns of the superblock @sb. If the caller is on an idmapped mount map 1788 * the caller's fsuid and fsgid according to the @mnt_userns first. 1789 * 1790 * Return: true if fsuid and fsgid is mapped, false if not. 1791 */ 1792 static inline bool fsuidgid_has_mapping(struct super_block *sb, 1793 struct user_namespace *mnt_userns) 1794 { 1795 struct user_namespace *fs_userns = sb->s_user_ns; 1796 kuid_t kuid; 1797 kgid_t kgid; 1798 1799 kuid = mapped_fsuid(mnt_userns, fs_userns); 1800 if (!uid_valid(kuid)) 1801 return false; 1802 kgid = mapped_fsgid(mnt_userns, fs_userns); 1803 if (!gid_valid(kgid)) 1804 return false; 1805 return kuid_has_mapping(fs_userns, kuid) && 1806 kgid_has_mapping(fs_userns, kgid); 1807 } 1808 1809 extern struct timespec64 current_time(struct inode *inode); 1810 1811 /* 1812 * Snapshotting support. 1813 */ 1814 1815 /* 1816 * These are internal functions, please use sb_start_{write,pagefault,intwrite} 1817 * instead. 1818 */ 1819 static inline void __sb_end_write(struct super_block *sb, int level) 1820 { 1821 percpu_up_read(sb->s_writers.rw_sem + level-1); 1822 } 1823 1824 static inline void __sb_start_write(struct super_block *sb, int level) 1825 { 1826 percpu_down_read(sb->s_writers.rw_sem + level - 1); 1827 } 1828 1829 static inline bool __sb_start_write_trylock(struct super_block *sb, int level) 1830 { 1831 return percpu_down_read_trylock(sb->s_writers.rw_sem + level - 1); 1832 } 1833 1834 #define __sb_writers_acquired(sb, lev) \ 1835 percpu_rwsem_acquire(&(sb)->s_writers.rw_sem[(lev)-1], 1, _THIS_IP_) 1836 #define __sb_writers_release(sb, lev) \ 1837 percpu_rwsem_release(&(sb)->s_writers.rw_sem[(lev)-1], 1, _THIS_IP_) 1838 1839 static inline bool sb_write_started(const struct super_block *sb) 1840 { 1841 return lockdep_is_held_type(sb->s_writers.rw_sem + SB_FREEZE_WRITE - 1, 1); 1842 } 1843 1844 /** 1845 * sb_end_write - drop write access to a superblock 1846 * @sb: the super we wrote to 1847 * 1848 * Decrement number of writers to the filesystem. Wake up possible waiters 1849 * wanting to freeze the filesystem. 1850 */ 1851 static inline void sb_end_write(struct super_block *sb) 1852 { 1853 __sb_end_write(sb, SB_FREEZE_WRITE); 1854 } 1855 1856 /** 1857 * sb_end_pagefault - drop write access to a superblock from a page fault 1858 * @sb: the super we wrote to 1859 * 1860 * Decrement number of processes handling write page fault to the filesystem. 1861 * Wake up possible waiters wanting to freeze the filesystem. 1862 */ 1863 static inline void sb_end_pagefault(struct super_block *sb) 1864 { 1865 __sb_end_write(sb, SB_FREEZE_PAGEFAULT); 1866 } 1867 1868 /** 1869 * sb_end_intwrite - drop write access to a superblock for internal fs purposes 1870 * @sb: the super we wrote to 1871 * 1872 * Decrement fs-internal number of writers to the filesystem. Wake up possible 1873 * waiters wanting to freeze the filesystem. 1874 */ 1875 static inline void sb_end_intwrite(struct super_block *sb) 1876 { 1877 __sb_end_write(sb, SB_FREEZE_FS); 1878 } 1879 1880 /** 1881 * sb_start_write - get write access to a superblock 1882 * @sb: the super we write to 1883 * 1884 * When a process wants to write data or metadata to a file system (i.e. dirty 1885 * a page or an inode), it should embed the operation in a sb_start_write() - 1886 * sb_end_write() pair to get exclusion against file system freezing. This 1887 * function increments number of writers preventing freezing. If the file 1888 * system is already frozen, the function waits until the file system is 1889 * thawed. 1890 * 1891 * Since freeze protection behaves as a lock, users have to preserve 1892 * ordering of freeze protection and other filesystem locks. Generally, 1893 * freeze protection should be the outermost lock. In particular, we have: 1894 * 1895 * sb_start_write 1896 * -> i_mutex (write path, truncate, directory ops, ...) 1897 * -> s_umount (freeze_super, thaw_super) 1898 */ 1899 static inline void sb_start_write(struct super_block *sb) 1900 { 1901 __sb_start_write(sb, SB_FREEZE_WRITE); 1902 } 1903 1904 static inline bool sb_start_write_trylock(struct super_block *sb) 1905 { 1906 return __sb_start_write_trylock(sb, SB_FREEZE_WRITE); 1907 } 1908 1909 /** 1910 * sb_start_pagefault - get write access to a superblock from a page fault 1911 * @sb: the super we write to 1912 * 1913 * When a process starts handling write page fault, it should embed the 1914 * operation into sb_start_pagefault() - sb_end_pagefault() pair to get 1915 * exclusion against file system freezing. This is needed since the page fault 1916 * is going to dirty a page. This function increments number of running page 1917 * faults preventing freezing. If the file system is already frozen, the 1918 * function waits until the file system is thawed. 1919 * 1920 * Since page fault freeze protection behaves as a lock, users have to preserve 1921 * ordering of freeze protection and other filesystem locks. It is advised to 1922 * put sb_start_pagefault() close to mmap_lock in lock ordering. Page fault 1923 * handling code implies lock dependency: 1924 * 1925 * mmap_lock 1926 * -> sb_start_pagefault 1927 */ 1928 static inline void sb_start_pagefault(struct super_block *sb) 1929 { 1930 __sb_start_write(sb, SB_FREEZE_PAGEFAULT); 1931 } 1932 1933 /** 1934 * sb_start_intwrite - get write access to a superblock for internal fs purposes 1935 * @sb: the super we write to 1936 * 1937 * This is the third level of protection against filesystem freezing. It is 1938 * free for use by a filesystem. The only requirement is that it must rank 1939 * below sb_start_pagefault. 1940 * 1941 * For example filesystem can call sb_start_intwrite() when starting a 1942 * transaction which somewhat eases handling of freezing for internal sources 1943 * of filesystem changes (internal fs threads, discarding preallocation on file 1944 * close, etc.). 1945 */ 1946 static inline void sb_start_intwrite(struct super_block *sb) 1947 { 1948 __sb_start_write(sb, SB_FREEZE_FS); 1949 } 1950 1951 static inline bool sb_start_intwrite_trylock(struct super_block *sb) 1952 { 1953 return __sb_start_write_trylock(sb, SB_FREEZE_FS); 1954 } 1955 1956 bool inode_owner_or_capable(struct user_namespace *mnt_userns, 1957 const struct inode *inode); 1958 1959 /* 1960 * VFS helper functions.. 1961 */ 1962 int vfs_create(struct user_namespace *, struct inode *, 1963 struct dentry *, umode_t, bool); 1964 int vfs_mkdir(struct user_namespace *, struct inode *, 1965 struct dentry *, umode_t); 1966 int vfs_mknod(struct user_namespace *, struct inode *, struct dentry *, 1967 umode_t, dev_t); 1968 int vfs_symlink(struct user_namespace *, struct inode *, 1969 struct dentry *, const char *); 1970 int vfs_link(struct dentry *, struct user_namespace *, struct inode *, 1971 struct dentry *, struct inode **); 1972 int vfs_rmdir(struct user_namespace *, struct inode *, struct dentry *); 1973 int vfs_unlink(struct user_namespace *, struct inode *, struct dentry *, 1974 struct inode **); 1975 1976 /** 1977 * struct renamedata - contains all information required for renaming 1978 * @old_mnt_userns: old user namespace of the mount the inode was found from 1979 * @old_dir: parent of source 1980 * @old_dentry: source 1981 * @new_mnt_userns: new user namespace of the mount the inode was found from 1982 * @new_dir: parent of destination 1983 * @new_dentry: destination 1984 * @delegated_inode: returns an inode needing a delegation break 1985 * @flags: rename flags 1986 */ 1987 struct renamedata { 1988 struct user_namespace *old_mnt_userns; 1989 struct inode *old_dir; 1990 struct dentry *old_dentry; 1991 struct user_namespace *new_mnt_userns; 1992 struct inode *new_dir; 1993 struct dentry *new_dentry; 1994 struct inode **delegated_inode; 1995 unsigned int flags; 1996 } __randomize_layout; 1997 1998 int vfs_rename(struct renamedata *); 1999 2000 static inline int vfs_whiteout(struct user_namespace *mnt_userns, 2001 struct inode *dir, struct dentry *dentry) 2002 { 2003 return vfs_mknod(mnt_userns, dir, dentry, S_IFCHR | WHITEOUT_MODE, 2004 WHITEOUT_DEV); 2005 } 2006 2007 struct dentry *vfs_tmpfile(struct user_namespace *mnt_userns, 2008 struct dentry *dentry, umode_t mode, int open_flag); 2009 2010 int vfs_mkobj(struct dentry *, umode_t, 2011 int (*f)(struct dentry *, umode_t, void *), 2012 void *); 2013 2014 int vfs_fchown(struct file *file, uid_t user, gid_t group); 2015 int vfs_fchmod(struct file *file, umode_t mode); 2016 int vfs_utimes(const struct path *path, struct timespec64 *times); 2017 2018 extern long vfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg); 2019 2020 #ifdef CONFIG_COMPAT 2021 extern long compat_ptr_ioctl(struct file *file, unsigned int cmd, 2022 unsigned long arg); 2023 #else 2024 #define compat_ptr_ioctl NULL 2025 #endif 2026 2027 /* 2028 * VFS file helper functions. 2029 */ 2030 void inode_init_owner(struct user_namespace *mnt_userns, struct inode *inode, 2031 const struct inode *dir, umode_t mode); 2032 extern bool may_open_dev(const struct path *path); 2033 umode_t mode_strip_sgid(struct user_namespace *mnt_userns, 2034 const struct inode *dir, umode_t mode); 2035 2036 /* 2037 * This is the "filldir" function type, used by readdir() to let 2038 * the kernel specify what kind of dirent layout it wants to have. 2039 * This allows the kernel to read directories into kernel space or 2040 * to have different dirent layouts depending on the binary type. 2041 */ 2042 struct dir_context; 2043 typedef int (*filldir_t)(struct dir_context *, const char *, int, loff_t, u64, 2044 unsigned); 2045 2046 struct dir_context { 2047 filldir_t actor; 2048 loff_t pos; 2049 }; 2050 2051 /* 2052 * These flags let !MMU mmap() govern direct device mapping vs immediate 2053 * copying more easily for MAP_PRIVATE, especially for ROM filesystems. 2054 * 2055 * NOMMU_MAP_COPY: Copy can be mapped (MAP_PRIVATE) 2056 * NOMMU_MAP_DIRECT: Can be mapped directly (MAP_SHARED) 2057 * NOMMU_MAP_READ: Can be mapped for reading 2058 * NOMMU_MAP_WRITE: Can be mapped for writing 2059 * NOMMU_MAP_EXEC: Can be mapped for execution 2060 */ 2061 #define NOMMU_MAP_COPY 0x00000001 2062 #define NOMMU_MAP_DIRECT 0x00000008 2063 #define NOMMU_MAP_READ VM_MAYREAD 2064 #define NOMMU_MAP_WRITE VM_MAYWRITE 2065 #define NOMMU_MAP_EXEC VM_MAYEXEC 2066 2067 #define NOMMU_VMFLAGS \ 2068 (NOMMU_MAP_READ | NOMMU_MAP_WRITE | NOMMU_MAP_EXEC) 2069 2070 /* 2071 * These flags control the behavior of the remap_file_range function pointer. 2072 * If it is called with len == 0 that means "remap to end of source file". 2073 * See Documentation/filesystems/vfs.rst for more details about this call. 2074 * 2075 * REMAP_FILE_DEDUP: only remap if contents identical (i.e. deduplicate) 2076 * REMAP_FILE_CAN_SHORTEN: caller can handle a shortened request 2077 */ 2078 #define REMAP_FILE_DEDUP (1 << 0) 2079 #define REMAP_FILE_CAN_SHORTEN (1 << 1) 2080 2081 /* 2082 * These flags signal that the caller is ok with altering various aspects of 2083 * the behavior of the remap operation. The changes must be made by the 2084 * implementation; the vfs remap helper functions can take advantage of them. 2085 * Flags in this category exist to preserve the quirky behavior of the hoisted 2086 * btrfs clone/dedupe ioctls. 2087 */ 2088 #define REMAP_FILE_ADVISORY (REMAP_FILE_CAN_SHORTEN) 2089 2090 struct iov_iter; 2091 struct io_uring_cmd; 2092 2093 struct file_operations { 2094 struct module *owner; 2095 loff_t (*llseek) (struct file *, loff_t, int); 2096 ssize_t (*read) (struct file *, char __user *, size_t, loff_t *); 2097 ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *); 2098 ssize_t (*read_iter) (struct kiocb *, struct iov_iter *); 2099 ssize_t (*write_iter) (struct kiocb *, struct iov_iter *); 2100 int (*iopoll)(struct kiocb *kiocb, struct io_comp_batch *, 2101 unsigned int flags); 2102 int (*iterate) (struct file *, struct dir_context *); 2103 int (*iterate_shared) (struct file *, struct dir_context *); 2104 __poll_t (*poll) (struct file *, struct poll_table_struct *); 2105 long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long); 2106 long (*compat_ioctl) (struct file *, unsigned int, unsigned long); 2107 int (*mmap) (struct file *, struct vm_area_struct *); 2108 unsigned long mmap_supported_flags; 2109 int (*open) (struct inode *, struct file *); 2110 int (*flush) (struct file *, fl_owner_t id); 2111 int (*release) (struct inode *, struct file *); 2112 int (*fsync) (struct file *, loff_t, loff_t, int datasync); 2113 int (*fasync) (int, struct file *, int); 2114 int (*lock) (struct file *, int, struct file_lock *); 2115 ssize_t (*sendpage) (struct file *, struct page *, int, size_t, loff_t *, int); 2116 unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long); 2117 int (*check_flags)(int); 2118 int (*flock) (struct file *, int, struct file_lock *); 2119 ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int); 2120 ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int); 2121 int (*setlease)(struct file *, long, struct file_lock **, void **); 2122 long (*fallocate)(struct file *file, int mode, loff_t offset, 2123 loff_t len); 2124 void (*show_fdinfo)(struct seq_file *m, struct file *f); 2125 #ifndef CONFIG_MMU 2126 unsigned (*mmap_capabilities)(struct file *); 2127 #endif 2128 ssize_t (*copy_file_range)(struct file *, loff_t, struct file *, 2129 loff_t, size_t, unsigned int); 2130 loff_t (*remap_file_range)(struct file *file_in, loff_t pos_in, 2131 struct file *file_out, loff_t pos_out, 2132 loff_t len, unsigned int remap_flags); 2133 int (*fadvise)(struct file *, loff_t, loff_t, int); 2134 int (*uring_cmd)(struct io_uring_cmd *ioucmd, unsigned int issue_flags); 2135 } __randomize_layout; 2136 2137 struct inode_operations { 2138 struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int); 2139 const char * (*get_link) (struct dentry *, struct inode *, struct delayed_call *); 2140 int (*permission) (struct user_namespace *, struct inode *, int); 2141 struct posix_acl * (*get_acl)(struct inode *, int, bool); 2142 2143 int (*readlink) (struct dentry *, char __user *,int); 2144 2145 int (*create) (struct user_namespace *, struct inode *,struct dentry *, 2146 umode_t, bool); 2147 int (*link) (struct dentry *,struct inode *,struct dentry *); 2148 int (*unlink) (struct inode *,struct dentry *); 2149 int (*symlink) (struct user_namespace *, struct inode *,struct dentry *, 2150 const char *); 2151 int (*mkdir) (struct user_namespace *, struct inode *,struct dentry *, 2152 umode_t); 2153 int (*rmdir) (struct inode *,struct dentry *); 2154 int (*mknod) (struct user_namespace *, struct inode *,struct dentry *, 2155 umode_t,dev_t); 2156 int (*rename) (struct user_namespace *, struct inode *, struct dentry *, 2157 struct inode *, struct dentry *, unsigned int); 2158 int (*setattr) (struct user_namespace *, struct dentry *, 2159 struct iattr *); 2160 int (*getattr) (struct user_namespace *, const struct path *, 2161 struct kstat *, u32, unsigned int); 2162 ssize_t (*listxattr) (struct dentry *, char *, size_t); 2163 int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start, 2164 u64 len); 2165 int (*update_time)(struct inode *, struct timespec64 *, int); 2166 int (*atomic_open)(struct inode *, struct dentry *, 2167 struct file *, unsigned open_flag, 2168 umode_t create_mode); 2169 int (*tmpfile) (struct user_namespace *, struct inode *, 2170 struct dentry *, umode_t); 2171 int (*set_acl)(struct user_namespace *, struct inode *, 2172 struct posix_acl *, int); 2173 int (*fileattr_set)(struct user_namespace *mnt_userns, 2174 struct dentry *dentry, struct fileattr *fa); 2175 int (*fileattr_get)(struct dentry *dentry, struct fileattr *fa); 2176 } ____cacheline_aligned; 2177 2178 static inline ssize_t call_read_iter(struct file *file, struct kiocb *kio, 2179 struct iov_iter *iter) 2180 { 2181 return file->f_op->read_iter(kio, iter); 2182 } 2183 2184 static inline ssize_t call_write_iter(struct file *file, struct kiocb *kio, 2185 struct iov_iter *iter) 2186 { 2187 return file->f_op->write_iter(kio, iter); 2188 } 2189 2190 static inline int call_mmap(struct file *file, struct vm_area_struct *vma) 2191 { 2192 return file->f_op->mmap(file, vma); 2193 } 2194 2195 extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *); 2196 extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *); 2197 extern ssize_t vfs_copy_file_range(struct file *, loff_t , struct file *, 2198 loff_t, size_t, unsigned int); 2199 extern ssize_t generic_copy_file_range(struct file *file_in, loff_t pos_in, 2200 struct file *file_out, loff_t pos_out, 2201 size_t len, unsigned int flags); 2202 int __generic_remap_file_range_prep(struct file *file_in, loff_t pos_in, 2203 struct file *file_out, loff_t pos_out, 2204 loff_t *len, unsigned int remap_flags, 2205 const struct iomap_ops *dax_read_ops); 2206 int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in, 2207 struct file *file_out, loff_t pos_out, 2208 loff_t *count, unsigned int remap_flags); 2209 extern loff_t do_clone_file_range(struct file *file_in, loff_t pos_in, 2210 struct file *file_out, loff_t pos_out, 2211 loff_t len, unsigned int remap_flags); 2212 extern loff_t vfs_clone_file_range(struct file *file_in, loff_t pos_in, 2213 struct file *file_out, loff_t pos_out, 2214 loff_t len, unsigned int remap_flags); 2215 extern int vfs_dedupe_file_range(struct file *file, 2216 struct file_dedupe_range *same); 2217 extern loff_t vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos, 2218 struct file *dst_file, loff_t dst_pos, 2219 loff_t len, unsigned int remap_flags); 2220 2221 2222 struct super_operations { 2223 struct inode *(*alloc_inode)(struct super_block *sb); 2224 void (*destroy_inode)(struct inode *); 2225 void (*free_inode)(struct inode *); 2226 2227 void (*dirty_inode) (struct inode *, int flags); 2228 int (*write_inode) (struct inode *, struct writeback_control *wbc); 2229 int (*drop_inode) (struct inode *); 2230 void (*evict_inode) (struct inode *); 2231 void (*put_super) (struct super_block *); 2232 int (*sync_fs)(struct super_block *sb, int wait); 2233 int (*freeze_super) (struct super_block *); 2234 int (*freeze_fs) (struct super_block *); 2235 int (*thaw_super) (struct super_block *); 2236 int (*unfreeze_fs) (struct super_block *); 2237 int (*statfs) (struct dentry *, struct kstatfs *); 2238 int (*remount_fs) (struct super_block *, int *, char *); 2239 void (*umount_begin) (struct super_block *); 2240 2241 int (*show_options)(struct seq_file *, struct dentry *); 2242 int (*show_devname)(struct seq_file *, struct dentry *); 2243 int (*show_path)(struct seq_file *, struct dentry *); 2244 int (*show_stats)(struct seq_file *, struct dentry *); 2245 #ifdef CONFIG_QUOTA 2246 ssize_t (*quota_read)(struct super_block *, int, char *, size_t, loff_t); 2247 ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t); 2248 struct dquot **(*get_dquots)(struct inode *); 2249 #endif 2250 long (*nr_cached_objects)(struct super_block *, 2251 struct shrink_control *); 2252 long (*free_cached_objects)(struct super_block *, 2253 struct shrink_control *); 2254 }; 2255 2256 /* 2257 * Inode flags - they have no relation to superblock flags now 2258 */ 2259 #define S_SYNC (1 << 0) /* Writes are synced at once */ 2260 #define S_NOATIME (1 << 1) /* Do not update access times */ 2261 #define S_APPEND (1 << 2) /* Append-only file */ 2262 #define S_IMMUTABLE (1 << 3) /* Immutable file */ 2263 #define S_DEAD (1 << 4) /* removed, but still open directory */ 2264 #define S_NOQUOTA (1 << 5) /* Inode is not counted to quota */ 2265 #define S_DIRSYNC (1 << 6) /* Directory modifications are synchronous */ 2266 #define S_NOCMTIME (1 << 7) /* Do not update file c/mtime */ 2267 #define S_SWAPFILE (1 << 8) /* Do not truncate: swapon got its bmaps */ 2268 #define S_PRIVATE (1 << 9) /* Inode is fs-internal */ 2269 #define S_IMA (1 << 10) /* Inode has an associated IMA struct */ 2270 #define S_AUTOMOUNT (1 << 11) /* Automount/referral quasi-directory */ 2271 #define S_NOSEC (1 << 12) /* no suid or xattr security attributes */ 2272 #ifdef CONFIG_FS_DAX 2273 #define S_DAX (1 << 13) /* Direct Access, avoiding the page cache */ 2274 #else 2275 #define S_DAX 0 /* Make all the DAX code disappear */ 2276 #endif 2277 #define S_ENCRYPTED (1 << 14) /* Encrypted file (using fs/crypto/) */ 2278 #define S_CASEFOLD (1 << 15) /* Casefolded file */ 2279 #define S_VERITY (1 << 16) /* Verity file (using fs/verity/) */ 2280 #define S_KERNEL_FILE (1 << 17) /* File is in use by the kernel (eg. fs/cachefiles) */ 2281 2282 /* 2283 * Note that nosuid etc flags are inode-specific: setting some file-system 2284 * flags just means all the inodes inherit those flags by default. It might be 2285 * possible to override it selectively if you really wanted to with some 2286 * ioctl() that is not currently implemented. 2287 * 2288 * Exception: SB_RDONLY is always applied to the entire file system. 2289 * 2290 * Unfortunately, it is possible to change a filesystems flags with it mounted 2291 * with files in use. This means that all of the inodes will not have their 2292 * i_flags updated. Hence, i_flags no longer inherit the superblock mount 2293 * flags, so these have to be checked separately. -- rmk@arm.uk.linux.org 2294 */ 2295 #define __IS_FLG(inode, flg) ((inode)->i_sb->s_flags & (flg)) 2296 2297 static inline bool sb_rdonly(const struct super_block *sb) { return sb->s_flags & SB_RDONLY; } 2298 #define IS_RDONLY(inode) sb_rdonly((inode)->i_sb) 2299 #define IS_SYNC(inode) (__IS_FLG(inode, SB_SYNCHRONOUS) || \ 2300 ((inode)->i_flags & S_SYNC)) 2301 #define IS_DIRSYNC(inode) (__IS_FLG(inode, SB_SYNCHRONOUS|SB_DIRSYNC) || \ 2302 ((inode)->i_flags & (S_SYNC|S_DIRSYNC))) 2303 #define IS_MANDLOCK(inode) __IS_FLG(inode, SB_MANDLOCK) 2304 #define IS_NOATIME(inode) __IS_FLG(inode, SB_RDONLY|SB_NOATIME) 2305 #define IS_I_VERSION(inode) __IS_FLG(inode, SB_I_VERSION) 2306 2307 #define IS_NOQUOTA(inode) ((inode)->i_flags & S_NOQUOTA) 2308 #define IS_APPEND(inode) ((inode)->i_flags & S_APPEND) 2309 #define IS_IMMUTABLE(inode) ((inode)->i_flags & S_IMMUTABLE) 2310 #define IS_POSIXACL(inode) __IS_FLG(inode, SB_POSIXACL) 2311 2312 #define IS_DEADDIR(inode) ((inode)->i_flags & S_DEAD) 2313 #define IS_NOCMTIME(inode) ((inode)->i_flags & S_NOCMTIME) 2314 #define IS_SWAPFILE(inode) ((inode)->i_flags & S_SWAPFILE) 2315 #define IS_PRIVATE(inode) ((inode)->i_flags & S_PRIVATE) 2316 #define IS_IMA(inode) ((inode)->i_flags & S_IMA) 2317 #define IS_AUTOMOUNT(inode) ((inode)->i_flags & S_AUTOMOUNT) 2318 #define IS_NOSEC(inode) ((inode)->i_flags & S_NOSEC) 2319 #define IS_DAX(inode) ((inode)->i_flags & S_DAX) 2320 #define IS_ENCRYPTED(inode) ((inode)->i_flags & S_ENCRYPTED) 2321 #define IS_CASEFOLDED(inode) ((inode)->i_flags & S_CASEFOLD) 2322 #define IS_VERITY(inode) ((inode)->i_flags & S_VERITY) 2323 2324 #define IS_WHITEOUT(inode) (S_ISCHR(inode->i_mode) && \ 2325 (inode)->i_rdev == WHITEOUT_DEV) 2326 2327 static inline bool HAS_UNMAPPED_ID(struct user_namespace *mnt_userns, 2328 struct inode *inode) 2329 { 2330 return !vfsuid_valid(i_uid_into_vfsuid(mnt_userns, inode)) || 2331 !vfsgid_valid(i_gid_into_vfsgid(mnt_userns, inode)); 2332 } 2333 2334 static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp) 2335 { 2336 *kiocb = (struct kiocb) { 2337 .ki_filp = filp, 2338 .ki_flags = filp->f_iocb_flags, 2339 .ki_ioprio = get_current_ioprio(), 2340 }; 2341 } 2342 2343 static inline void kiocb_clone(struct kiocb *kiocb, struct kiocb *kiocb_src, 2344 struct file *filp) 2345 { 2346 *kiocb = (struct kiocb) { 2347 .ki_filp = filp, 2348 .ki_flags = kiocb_src->ki_flags, 2349 .ki_ioprio = kiocb_src->ki_ioprio, 2350 .ki_pos = kiocb_src->ki_pos, 2351 }; 2352 } 2353 2354 /* 2355 * Inode state bits. Protected by inode->i_lock 2356 * 2357 * Four bits determine the dirty state of the inode: I_DIRTY_SYNC, 2358 * I_DIRTY_DATASYNC, I_DIRTY_PAGES, and I_DIRTY_TIME. 2359 * 2360 * Four bits define the lifetime of an inode. Initially, inodes are I_NEW, 2361 * until that flag is cleared. I_WILL_FREE, I_FREEING and I_CLEAR are set at 2362 * various stages of removing an inode. 2363 * 2364 * Two bits are used for locking and completion notification, I_NEW and I_SYNC. 2365 * 2366 * I_DIRTY_SYNC Inode is dirty, but doesn't have to be written on 2367 * fdatasync() (unless I_DIRTY_DATASYNC is also set). 2368 * Timestamp updates are the usual cause. 2369 * I_DIRTY_DATASYNC Data-related inode changes pending. We keep track of 2370 * these changes separately from I_DIRTY_SYNC so that we 2371 * don't have to write inode on fdatasync() when only 2372 * e.g. the timestamps have changed. 2373 * I_DIRTY_PAGES Inode has dirty pages. Inode itself may be clean. 2374 * I_DIRTY_TIME The inode itself only has dirty timestamps, and the 2375 * lazytime mount option is enabled. We keep track of this 2376 * separately from I_DIRTY_SYNC in order to implement 2377 * lazytime. This gets cleared if I_DIRTY_INODE 2378 * (I_DIRTY_SYNC and/or I_DIRTY_DATASYNC) gets set. I.e. 2379 * either I_DIRTY_TIME *or* I_DIRTY_INODE can be set in 2380 * i_state, but not both. I_DIRTY_PAGES may still be set. 2381 * I_NEW Serves as both a mutex and completion notification. 2382 * New inodes set I_NEW. If two processes both create 2383 * the same inode, one of them will release its inode and 2384 * wait for I_NEW to be released before returning. 2385 * Inodes in I_WILL_FREE, I_FREEING or I_CLEAR state can 2386 * also cause waiting on I_NEW, without I_NEW actually 2387 * being set. find_inode() uses this to prevent returning 2388 * nearly-dead inodes. 2389 * I_WILL_FREE Must be set when calling write_inode_now() if i_count 2390 * is zero. I_FREEING must be set when I_WILL_FREE is 2391 * cleared. 2392 * I_FREEING Set when inode is about to be freed but still has dirty 2393 * pages or buffers attached or the inode itself is still 2394 * dirty. 2395 * I_CLEAR Added by clear_inode(). In this state the inode is 2396 * clean and can be destroyed. Inode keeps I_FREEING. 2397 * 2398 * Inodes that are I_WILL_FREE, I_FREEING or I_CLEAR are 2399 * prohibited for many purposes. iget() must wait for 2400 * the inode to be completely released, then create it 2401 * anew. Other functions will just ignore such inodes, 2402 * if appropriate. I_NEW is used for waiting. 2403 * 2404 * I_SYNC Writeback of inode is running. The bit is set during 2405 * data writeback, and cleared with a wakeup on the bit 2406 * address once it is done. The bit is also used to pin 2407 * the inode in memory for flusher thread. 2408 * 2409 * I_REFERENCED Marks the inode as recently references on the LRU list. 2410 * 2411 * I_DIO_WAKEUP Never set. Only used as a key for wait_on_bit(). 2412 * 2413 * I_WB_SWITCH Cgroup bdi_writeback switching in progress. Used to 2414 * synchronize competing switching instances and to tell 2415 * wb stat updates to grab the i_pages lock. See 2416 * inode_switch_wbs_work_fn() for details. 2417 * 2418 * I_OVL_INUSE Used by overlayfs to get exclusive ownership on upper 2419 * and work dirs among overlayfs mounts. 2420 * 2421 * I_CREATING New object's inode in the middle of setting up. 2422 * 2423 * I_DONTCACHE Evict inode as soon as it is not used anymore. 2424 * 2425 * I_SYNC_QUEUED Inode is queued in b_io or b_more_io writeback lists. 2426 * Used to detect that mark_inode_dirty() should not move 2427 * inode between dirty lists. 2428 * 2429 * I_PINNING_FSCACHE_WB Inode is pinning an fscache object for writeback. 2430 * 2431 * Q: What is the difference between I_WILL_FREE and I_FREEING? 2432 */ 2433 #define I_DIRTY_SYNC (1 << 0) 2434 #define I_DIRTY_DATASYNC (1 << 1) 2435 #define I_DIRTY_PAGES (1 << 2) 2436 #define __I_NEW 3 2437 #define I_NEW (1 << __I_NEW) 2438 #define I_WILL_FREE (1 << 4) 2439 #define I_FREEING (1 << 5) 2440 #define I_CLEAR (1 << 6) 2441 #define __I_SYNC 7 2442 #define I_SYNC (1 << __I_SYNC) 2443 #define I_REFERENCED (1 << 8) 2444 #define __I_DIO_WAKEUP 9 2445 #define I_DIO_WAKEUP (1 << __I_DIO_WAKEUP) 2446 #define I_LINKABLE (1 << 10) 2447 #define I_DIRTY_TIME (1 << 11) 2448 #define I_WB_SWITCH (1 << 13) 2449 #define I_OVL_INUSE (1 << 14) 2450 #define I_CREATING (1 << 15) 2451 #define I_DONTCACHE (1 << 16) 2452 #define I_SYNC_QUEUED (1 << 17) 2453 #define I_PINNING_FSCACHE_WB (1 << 18) 2454 2455 #define I_DIRTY_INODE (I_DIRTY_SYNC | I_DIRTY_DATASYNC) 2456 #define I_DIRTY (I_DIRTY_INODE | I_DIRTY_PAGES) 2457 #define I_DIRTY_ALL (I_DIRTY | I_DIRTY_TIME) 2458 2459 extern void __mark_inode_dirty(struct inode *, int); 2460 static inline void mark_inode_dirty(struct inode *inode) 2461 { 2462 __mark_inode_dirty(inode, I_DIRTY); 2463 } 2464 2465 static inline void mark_inode_dirty_sync(struct inode *inode) 2466 { 2467 __mark_inode_dirty(inode, I_DIRTY_SYNC); 2468 } 2469 2470 /* 2471 * Returns true if the given inode itself only has dirty timestamps (its pages 2472 * may still be dirty) and isn't currently being allocated or freed. 2473 * Filesystems should call this if when writing an inode when lazytime is 2474 * enabled, they want to opportunistically write the timestamps of other inodes 2475 * located very nearby on-disk, e.g. in the same inode block. This returns true 2476 * if the given inode is in need of such an opportunistic update. Requires 2477 * i_lock, or at least later re-checking under i_lock. 2478 */ 2479 static inline bool inode_is_dirtytime_only(struct inode *inode) 2480 { 2481 return (inode->i_state & (I_DIRTY_TIME | I_NEW | 2482 I_FREEING | I_WILL_FREE)) == I_DIRTY_TIME; 2483 } 2484 2485 extern void inc_nlink(struct inode *inode); 2486 extern void drop_nlink(struct inode *inode); 2487 extern void clear_nlink(struct inode *inode); 2488 extern void set_nlink(struct inode *inode, unsigned int nlink); 2489 2490 static inline void inode_inc_link_count(struct inode *inode) 2491 { 2492 inc_nlink(inode); 2493 mark_inode_dirty(inode); 2494 } 2495 2496 static inline void inode_dec_link_count(struct inode *inode) 2497 { 2498 drop_nlink(inode); 2499 mark_inode_dirty(inode); 2500 } 2501 2502 enum file_time_flags { 2503 S_ATIME = 1, 2504 S_MTIME = 2, 2505 S_CTIME = 4, 2506 S_VERSION = 8, 2507 }; 2508 2509 extern bool atime_needs_update(const struct path *, struct inode *); 2510 extern void touch_atime(const struct path *); 2511 int inode_update_time(struct inode *inode, struct timespec64 *time, int flags); 2512 2513 static inline void file_accessed(struct file *file) 2514 { 2515 if (!(file->f_flags & O_NOATIME)) 2516 touch_atime(&file->f_path); 2517 } 2518 2519 extern int file_modified(struct file *file); 2520 int kiocb_modified(struct kiocb *iocb); 2521 2522 int sync_inode_metadata(struct inode *inode, int wait); 2523 2524 struct file_system_type { 2525 const char *name; 2526 int fs_flags; 2527 #define FS_REQUIRES_DEV 1 2528 #define FS_BINARY_MOUNTDATA 2 2529 #define FS_HAS_SUBTYPE 4 2530 #define FS_USERNS_MOUNT 8 /* Can be mounted by userns root */ 2531 #define FS_DISALLOW_NOTIFY_PERM 16 /* Disable fanotify permission events */ 2532 #define FS_ALLOW_IDMAP 32 /* FS has been updated to handle vfs idmappings. */ 2533 #define FS_RENAME_DOES_D_MOVE 32768 /* FS will handle d_move() during rename() internally. */ 2534 int (*init_fs_context)(struct fs_context *); 2535 const struct fs_parameter_spec *parameters; 2536 struct dentry *(*mount) (struct file_system_type *, int, 2537 const char *, void *); 2538 void (*kill_sb) (struct super_block *); 2539 struct module *owner; 2540 struct file_system_type * next; 2541 struct hlist_head fs_supers; 2542 2543 struct lock_class_key s_lock_key; 2544 struct lock_class_key s_umount_key; 2545 struct lock_class_key s_vfs_rename_key; 2546 struct lock_class_key s_writers_key[SB_FREEZE_LEVELS]; 2547 2548 struct lock_class_key i_lock_key; 2549 struct lock_class_key i_mutex_key; 2550 struct lock_class_key invalidate_lock_key; 2551 struct lock_class_key i_mutex_dir_key; 2552 }; 2553 2554 #define MODULE_ALIAS_FS(NAME) MODULE_ALIAS("fs-" NAME) 2555 2556 extern struct dentry *mount_bdev(struct file_system_type *fs_type, 2557 int flags, const char *dev_name, void *data, 2558 int (*fill_super)(struct super_block *, void *, int)); 2559 extern struct dentry *mount_single(struct file_system_type *fs_type, 2560 int flags, void *data, 2561 int (*fill_super)(struct super_block *, void *, int)); 2562 extern struct dentry *mount_nodev(struct file_system_type *fs_type, 2563 int flags, void *data, 2564 int (*fill_super)(struct super_block *, void *, int)); 2565 extern struct dentry *mount_subtree(struct vfsmount *mnt, const char *path); 2566 void retire_super(struct super_block *sb); 2567 void generic_shutdown_super(struct super_block *sb); 2568 void kill_block_super(struct super_block *sb); 2569 void kill_anon_super(struct super_block *sb); 2570 void kill_litter_super(struct super_block *sb); 2571 void deactivate_super(struct super_block *sb); 2572 void deactivate_locked_super(struct super_block *sb); 2573 int set_anon_super(struct super_block *s, void *data); 2574 int set_anon_super_fc(struct super_block *s, struct fs_context *fc); 2575 int get_anon_bdev(dev_t *); 2576 void free_anon_bdev(dev_t); 2577 struct super_block *sget_fc(struct fs_context *fc, 2578 int (*test)(struct super_block *, struct fs_context *), 2579 int (*set)(struct super_block *, struct fs_context *)); 2580 struct super_block *sget(struct file_system_type *type, 2581 int (*test)(struct super_block *,void *), 2582 int (*set)(struct super_block *,void *), 2583 int flags, void *data); 2584 2585 /* Alas, no aliases. Too much hassle with bringing module.h everywhere */ 2586 #define fops_get(fops) \ 2587 (((fops) && try_module_get((fops)->owner) ? (fops) : NULL)) 2588 #define fops_put(fops) \ 2589 do { if (fops) module_put((fops)->owner); } while(0) 2590 /* 2591 * This one is to be used *ONLY* from ->open() instances. 2592 * fops must be non-NULL, pinned down *and* module dependencies 2593 * should be sufficient to pin the caller down as well. 2594 */ 2595 #define replace_fops(f, fops) \ 2596 do { \ 2597 struct file *__file = (f); \ 2598 fops_put(__file->f_op); \ 2599 BUG_ON(!(__file->f_op = (fops))); \ 2600 } while(0) 2601 2602 extern int register_filesystem(struct file_system_type *); 2603 extern int unregister_filesystem(struct file_system_type *); 2604 extern int vfs_statfs(const struct path *, struct kstatfs *); 2605 extern int user_statfs(const char __user *, struct kstatfs *); 2606 extern int fd_statfs(int, struct kstatfs *); 2607 extern int freeze_super(struct super_block *super); 2608 extern int thaw_super(struct super_block *super); 2609 extern __printf(2, 3) 2610 int super_setup_bdi_name(struct super_block *sb, char *fmt, ...); 2611 extern int super_setup_bdi(struct super_block *sb); 2612 2613 extern int current_umask(void); 2614 2615 extern void ihold(struct inode * inode); 2616 extern void iput(struct inode *); 2617 extern int generic_update_time(struct inode *, struct timespec64 *, int); 2618 2619 /* /sys/fs */ 2620 extern struct kobject *fs_kobj; 2621 2622 #define MAX_RW_COUNT (INT_MAX & PAGE_MASK) 2623 2624 #ifdef CONFIG_FILE_LOCKING 2625 static inline int break_lease(struct inode *inode, unsigned int mode) 2626 { 2627 /* 2628 * Since this check is lockless, we must ensure that any refcounts 2629 * taken are done before checking i_flctx->flc_lease. Otherwise, we 2630 * could end up racing with tasks trying to set a new lease on this 2631 * file. 2632 */ 2633 smp_mb(); 2634 if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease)) 2635 return __break_lease(inode, mode, FL_LEASE); 2636 return 0; 2637 } 2638 2639 static inline int break_deleg(struct inode *inode, unsigned int mode) 2640 { 2641 /* 2642 * Since this check is lockless, we must ensure that any refcounts 2643 * taken are done before checking i_flctx->flc_lease. Otherwise, we 2644 * could end up racing with tasks trying to set a new lease on this 2645 * file. 2646 */ 2647 smp_mb(); 2648 if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease)) 2649 return __break_lease(inode, mode, FL_DELEG); 2650 return 0; 2651 } 2652 2653 static inline int try_break_deleg(struct inode *inode, struct inode **delegated_inode) 2654 { 2655 int ret; 2656 2657 ret = break_deleg(inode, O_WRONLY|O_NONBLOCK); 2658 if (ret == -EWOULDBLOCK && delegated_inode) { 2659 *delegated_inode = inode; 2660 ihold(inode); 2661 } 2662 return ret; 2663 } 2664 2665 static inline int break_deleg_wait(struct inode **delegated_inode) 2666 { 2667 int ret; 2668 2669 ret = break_deleg(*delegated_inode, O_WRONLY); 2670 iput(*delegated_inode); 2671 *delegated_inode = NULL; 2672 return ret; 2673 } 2674 2675 static inline int break_layout(struct inode *inode, bool wait) 2676 { 2677 smp_mb(); 2678 if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease)) 2679 return __break_lease(inode, 2680 wait ? O_WRONLY : O_WRONLY | O_NONBLOCK, 2681 FL_LAYOUT); 2682 return 0; 2683 } 2684 2685 #else /* !CONFIG_FILE_LOCKING */ 2686 static inline int break_lease(struct inode *inode, unsigned int mode) 2687 { 2688 return 0; 2689 } 2690 2691 static inline int break_deleg(struct inode *inode, unsigned int mode) 2692 { 2693 return 0; 2694 } 2695 2696 static inline int try_break_deleg(struct inode *inode, struct inode **delegated_inode) 2697 { 2698 return 0; 2699 } 2700 2701 static inline int break_deleg_wait(struct inode **delegated_inode) 2702 { 2703 BUG(); 2704 return 0; 2705 } 2706 2707 static inline int break_layout(struct inode *inode, bool wait) 2708 { 2709 return 0; 2710 } 2711 2712 #endif /* CONFIG_FILE_LOCKING */ 2713 2714 /* fs/open.c */ 2715 struct audit_names; 2716 struct filename { 2717 const char *name; /* pointer to actual string */ 2718 const __user char *uptr; /* original userland pointer */ 2719 int refcnt; 2720 struct audit_names *aname; 2721 const char iname[]; 2722 }; 2723 static_assert(offsetof(struct filename, iname) % sizeof(long) == 0); 2724 2725 static inline struct user_namespace *file_mnt_user_ns(struct file *file) 2726 { 2727 return mnt_user_ns(file->f_path.mnt); 2728 } 2729 2730 /** 2731 * is_idmapped_mnt - check whether a mount is mapped 2732 * @mnt: the mount to check 2733 * 2734 * If @mnt has an idmapping attached different from the 2735 * filesystem's idmapping then @mnt is mapped. 2736 * 2737 * Return: true if mount is mapped, false if not. 2738 */ 2739 static inline bool is_idmapped_mnt(const struct vfsmount *mnt) 2740 { 2741 return mnt_user_ns(mnt) != mnt->mnt_sb->s_user_ns; 2742 } 2743 2744 extern long vfs_truncate(const struct path *, loff_t); 2745 int do_truncate(struct user_namespace *, struct dentry *, loff_t start, 2746 unsigned int time_attrs, struct file *filp); 2747 extern int vfs_fallocate(struct file *file, int mode, loff_t offset, 2748 loff_t len); 2749 extern long do_sys_open(int dfd, const char __user *filename, int flags, 2750 umode_t mode); 2751 extern struct file *file_open_name(struct filename *, int, umode_t); 2752 extern struct file *filp_open(const char *, int, umode_t); 2753 extern struct file *file_open_root(const struct path *, 2754 const char *, int, umode_t); 2755 static inline struct file *file_open_root_mnt(struct vfsmount *mnt, 2756 const char *name, int flags, umode_t mode) 2757 { 2758 return file_open_root(&(struct path){.mnt = mnt, .dentry = mnt->mnt_root}, 2759 name, flags, mode); 2760 } 2761 extern struct file * dentry_open(const struct path *, int, const struct cred *); 2762 extern struct file *dentry_create(const struct path *path, int flags, 2763 umode_t mode, const struct cred *cred); 2764 extern struct file * open_with_fake_path(const struct path *, int, 2765 struct inode*, const struct cred *); 2766 static inline struct file *file_clone_open(struct file *file) 2767 { 2768 return dentry_open(&file->f_path, file->f_flags, file->f_cred); 2769 } 2770 extern int filp_close(struct file *, fl_owner_t id); 2771 2772 extern struct filename *getname_flags(const char __user *, int, int *); 2773 extern struct filename *getname_uflags(const char __user *, int); 2774 extern struct filename *getname(const char __user *); 2775 extern struct filename *getname_kernel(const char *); 2776 extern void putname(struct filename *name); 2777 2778 extern int finish_open(struct file *file, struct dentry *dentry, 2779 int (*open)(struct inode *, struct file *)); 2780 extern int finish_no_open(struct file *file, struct dentry *dentry); 2781 2782 /* fs/dcache.c */ 2783 extern void __init vfs_caches_init_early(void); 2784 extern void __init vfs_caches_init(void); 2785 2786 extern struct kmem_cache *names_cachep; 2787 2788 #define __getname() kmem_cache_alloc(names_cachep, GFP_KERNEL) 2789 #define __putname(name) kmem_cache_free(names_cachep, (void *)(name)) 2790 2791 extern struct super_block *blockdev_superblock; 2792 static inline bool sb_is_blkdev_sb(struct super_block *sb) 2793 { 2794 return IS_ENABLED(CONFIG_BLOCK) && sb == blockdev_superblock; 2795 } 2796 2797 void emergency_thaw_all(void); 2798 extern int sync_filesystem(struct super_block *); 2799 extern const struct file_operations def_blk_fops; 2800 extern const struct file_operations def_chr_fops; 2801 2802 /* fs/char_dev.c */ 2803 #define CHRDEV_MAJOR_MAX 512 2804 /* Marks the bottom of the first segment of free char majors */ 2805 #define CHRDEV_MAJOR_DYN_END 234 2806 /* Marks the top and bottom of the second segment of free char majors */ 2807 #define CHRDEV_MAJOR_DYN_EXT_START 511 2808 #define CHRDEV_MAJOR_DYN_EXT_END 384 2809 2810 extern int alloc_chrdev_region(dev_t *, unsigned, unsigned, const char *); 2811 extern int register_chrdev_region(dev_t, unsigned, const char *); 2812 extern int __register_chrdev(unsigned int major, unsigned int baseminor, 2813 unsigned int count, const char *name, 2814 const struct file_operations *fops); 2815 extern void __unregister_chrdev(unsigned int major, unsigned int baseminor, 2816 unsigned int count, const char *name); 2817 extern void unregister_chrdev_region(dev_t, unsigned); 2818 extern void chrdev_show(struct seq_file *,off_t); 2819 2820 static inline int register_chrdev(unsigned int major, const char *name, 2821 const struct file_operations *fops) 2822 { 2823 return __register_chrdev(major, 0, 256, name, fops); 2824 } 2825 2826 static inline void unregister_chrdev(unsigned int major, const char *name) 2827 { 2828 __unregister_chrdev(major, 0, 256, name); 2829 } 2830 2831 extern void init_special_inode(struct inode *, umode_t, dev_t); 2832 2833 /* Invalid inode operations -- fs/bad_inode.c */ 2834 extern void make_bad_inode(struct inode *); 2835 extern bool is_bad_inode(struct inode *); 2836 2837 extern int __must_check file_fdatawait_range(struct file *file, loff_t lstart, 2838 loff_t lend); 2839 extern int __must_check file_check_and_advance_wb_err(struct file *file); 2840 extern int __must_check file_write_and_wait_range(struct file *file, 2841 loff_t start, loff_t end); 2842 2843 static inline int file_write_and_wait(struct file *file) 2844 { 2845 return file_write_and_wait_range(file, 0, LLONG_MAX); 2846 } 2847 2848 extern int vfs_fsync_range(struct file *file, loff_t start, loff_t end, 2849 int datasync); 2850 extern int vfs_fsync(struct file *file, int datasync); 2851 2852 extern int sync_file_range(struct file *file, loff_t offset, loff_t nbytes, 2853 unsigned int flags); 2854 2855 static inline bool iocb_is_dsync(const struct kiocb *iocb) 2856 { 2857 return (iocb->ki_flags & IOCB_DSYNC) || 2858 IS_SYNC(iocb->ki_filp->f_mapping->host); 2859 } 2860 2861 /* 2862 * Sync the bytes written if this was a synchronous write. Expect ki_pos 2863 * to already be updated for the write, and will return either the amount 2864 * of bytes passed in, or an error if syncing the file failed. 2865 */ 2866 static inline ssize_t generic_write_sync(struct kiocb *iocb, ssize_t count) 2867 { 2868 if (iocb_is_dsync(iocb)) { 2869 int ret = vfs_fsync_range(iocb->ki_filp, 2870 iocb->ki_pos - count, iocb->ki_pos - 1, 2871 (iocb->ki_flags & IOCB_SYNC) ? 0 : 1); 2872 if (ret) 2873 return ret; 2874 } 2875 2876 return count; 2877 } 2878 2879 extern void emergency_sync(void); 2880 extern void emergency_remount(void); 2881 2882 #ifdef CONFIG_BLOCK 2883 extern int bmap(struct inode *inode, sector_t *block); 2884 #else 2885 static inline int bmap(struct inode *inode, sector_t *block) 2886 { 2887 return -EINVAL; 2888 } 2889 #endif 2890 2891 int notify_change(struct user_namespace *, struct dentry *, 2892 struct iattr *, struct inode **); 2893 int inode_permission(struct user_namespace *, struct inode *, int); 2894 int generic_permission(struct user_namespace *, struct inode *, int); 2895 static inline int file_permission(struct file *file, int mask) 2896 { 2897 return inode_permission(file_mnt_user_ns(file), 2898 file_inode(file), mask); 2899 } 2900 static inline int path_permission(const struct path *path, int mask) 2901 { 2902 return inode_permission(mnt_user_ns(path->mnt), 2903 d_inode(path->dentry), mask); 2904 } 2905 int __check_sticky(struct user_namespace *mnt_userns, struct inode *dir, 2906 struct inode *inode); 2907 2908 static inline bool execute_ok(struct inode *inode) 2909 { 2910 return (inode->i_mode & S_IXUGO) || S_ISDIR(inode->i_mode); 2911 } 2912 2913 static inline bool inode_wrong_type(const struct inode *inode, umode_t mode) 2914 { 2915 return (inode->i_mode ^ mode) & S_IFMT; 2916 } 2917 2918 static inline void file_start_write(struct file *file) 2919 { 2920 if (!S_ISREG(file_inode(file)->i_mode)) 2921 return; 2922 sb_start_write(file_inode(file)->i_sb); 2923 } 2924 2925 static inline bool file_start_write_trylock(struct file *file) 2926 { 2927 if (!S_ISREG(file_inode(file)->i_mode)) 2928 return true; 2929 return sb_start_write_trylock(file_inode(file)->i_sb); 2930 } 2931 2932 static inline void file_end_write(struct file *file) 2933 { 2934 if (!S_ISREG(file_inode(file)->i_mode)) 2935 return; 2936 __sb_end_write(file_inode(file)->i_sb, SB_FREEZE_WRITE); 2937 } 2938 2939 /* 2940 * This is used for regular files where some users -- especially the 2941 * currently executed binary in a process, previously handled via 2942 * VM_DENYWRITE -- cannot handle concurrent write (and maybe mmap 2943 * read-write shared) accesses. 2944 * 2945 * get_write_access() gets write permission for a file. 2946 * put_write_access() releases this write permission. 2947 * deny_write_access() denies write access to a file. 2948 * allow_write_access() re-enables write access to a file. 2949 * 2950 * The i_writecount field of an inode can have the following values: 2951 * 0: no write access, no denied write access 2952 * < 0: (-i_writecount) users that denied write access to the file. 2953 * > 0: (i_writecount) users that have write access to the file. 2954 * 2955 * Normally we operate on that counter with atomic_{inc,dec} and it's safe 2956 * except for the cases where we don't hold i_writecount yet. Then we need to 2957 * use {get,deny}_write_access() - these functions check the sign and refuse 2958 * to do the change if sign is wrong. 2959 */ 2960 static inline int get_write_access(struct inode *inode) 2961 { 2962 return atomic_inc_unless_negative(&inode->i_writecount) ? 0 : -ETXTBSY; 2963 } 2964 static inline int deny_write_access(struct file *file) 2965 { 2966 struct inode *inode = file_inode(file); 2967 return atomic_dec_unless_positive(&inode->i_writecount) ? 0 : -ETXTBSY; 2968 } 2969 static inline void put_write_access(struct inode * inode) 2970 { 2971 atomic_dec(&inode->i_writecount); 2972 } 2973 static inline void allow_write_access(struct file *file) 2974 { 2975 if (file) 2976 atomic_inc(&file_inode(file)->i_writecount); 2977 } 2978 static inline bool inode_is_open_for_write(const struct inode *inode) 2979 { 2980 return atomic_read(&inode->i_writecount) > 0; 2981 } 2982 2983 #if defined(CONFIG_IMA) || defined(CONFIG_FILE_LOCKING) 2984 static inline void i_readcount_dec(struct inode *inode) 2985 { 2986 BUG_ON(!atomic_read(&inode->i_readcount)); 2987 atomic_dec(&inode->i_readcount); 2988 } 2989 static inline void i_readcount_inc(struct inode *inode) 2990 { 2991 atomic_inc(&inode->i_readcount); 2992 } 2993 #else 2994 static inline void i_readcount_dec(struct inode *inode) 2995 { 2996 return; 2997 } 2998 static inline void i_readcount_inc(struct inode *inode) 2999 { 3000 return; 3001 } 3002 #endif 3003 extern int do_pipe_flags(int *, int); 3004 3005 extern ssize_t kernel_read(struct file *, void *, size_t, loff_t *); 3006 ssize_t __kernel_read(struct file *file, void *buf, size_t count, loff_t *pos); 3007 extern ssize_t kernel_write(struct file *, const void *, size_t, loff_t *); 3008 extern ssize_t __kernel_write(struct file *, const void *, size_t, loff_t *); 3009 extern struct file * open_exec(const char *); 3010 3011 /* fs/dcache.c -- generic fs support functions */ 3012 extern bool is_subdir(struct dentry *, struct dentry *); 3013 extern bool path_is_under(const struct path *, const struct path *); 3014 3015 extern char *file_path(struct file *, char *, int); 3016 3017 #include <linux/err.h> 3018 3019 /* needed for stackable file system support */ 3020 extern loff_t default_llseek(struct file *file, loff_t offset, int whence); 3021 3022 extern loff_t vfs_llseek(struct file *file, loff_t offset, int whence); 3023 3024 extern int inode_init_always(struct super_block *, struct inode *); 3025 extern void inode_init_once(struct inode *); 3026 extern void address_space_init_once(struct address_space *mapping); 3027 extern struct inode * igrab(struct inode *); 3028 extern ino_t iunique(struct super_block *, ino_t); 3029 extern int inode_needs_sync(struct inode *inode); 3030 extern int generic_delete_inode(struct inode *inode); 3031 static inline int generic_drop_inode(struct inode *inode) 3032 { 3033 return !inode->i_nlink || inode_unhashed(inode); 3034 } 3035 extern void d_mark_dontcache(struct inode *inode); 3036 3037 extern struct inode *ilookup5_nowait(struct super_block *sb, 3038 unsigned long hashval, int (*test)(struct inode *, void *), 3039 void *data); 3040 extern struct inode *ilookup5(struct super_block *sb, unsigned long hashval, 3041 int (*test)(struct inode *, void *), void *data); 3042 extern struct inode *ilookup(struct super_block *sb, unsigned long ino); 3043 3044 extern struct inode *inode_insert5(struct inode *inode, unsigned long hashval, 3045 int (*test)(struct inode *, void *), 3046 int (*set)(struct inode *, void *), 3047 void *data); 3048 extern struct inode * iget5_locked(struct super_block *, unsigned long, int (*test)(struct inode *, void *), int (*set)(struct inode *, void *), void *); 3049 extern struct inode * iget_locked(struct super_block *, unsigned long); 3050 extern struct inode *find_inode_nowait(struct super_block *, 3051 unsigned long, 3052 int (*match)(struct inode *, 3053 unsigned long, void *), 3054 void *data); 3055 extern struct inode *find_inode_rcu(struct super_block *, unsigned long, 3056 int (*)(struct inode *, void *), void *); 3057 extern struct inode *find_inode_by_ino_rcu(struct super_block *, unsigned long); 3058 extern int insert_inode_locked4(struct inode *, unsigned long, int (*test)(struct inode *, void *), void *); 3059 extern int insert_inode_locked(struct inode *); 3060 #ifdef CONFIG_DEBUG_LOCK_ALLOC 3061 extern void lockdep_annotate_inode_mutex_key(struct inode *inode); 3062 #else 3063 static inline void lockdep_annotate_inode_mutex_key(struct inode *inode) { }; 3064 #endif 3065 extern void unlock_new_inode(struct inode *); 3066 extern void discard_new_inode(struct inode *); 3067 extern unsigned int get_next_ino(void); 3068 extern void evict_inodes(struct super_block *sb); 3069 void dump_mapping(const struct address_space *); 3070 3071 /* 3072 * Userspace may rely on the the inode number being non-zero. For example, glibc 3073 * simply ignores files with zero i_ino in unlink() and other places. 3074 * 3075 * As an additional complication, if userspace was compiled with 3076 * _FILE_OFFSET_BITS=32 on a 64-bit kernel we'll only end up reading out the 3077 * lower 32 bits, so we need to check that those aren't zero explicitly. With 3078 * _FILE_OFFSET_BITS=64, this may cause some harmless false-negatives, but 3079 * better safe than sorry. 3080 */ 3081 static inline bool is_zero_ino(ino_t ino) 3082 { 3083 return (u32)ino == 0; 3084 } 3085 3086 extern void __iget(struct inode * inode); 3087 extern void iget_failed(struct inode *); 3088 extern void clear_inode(struct inode *); 3089 extern void __destroy_inode(struct inode *); 3090 extern struct inode *new_inode_pseudo(struct super_block *sb); 3091 extern struct inode *new_inode(struct super_block *sb); 3092 extern void free_inode_nonrcu(struct inode *inode); 3093 extern int should_remove_suid(struct dentry *); 3094 extern int file_remove_privs(struct file *); 3095 3096 /* 3097 * This must be used for allocating filesystems specific inodes to set 3098 * up the inode reclaim context correctly. 3099 */ 3100 static inline void * 3101 alloc_inode_sb(struct super_block *sb, struct kmem_cache *cache, gfp_t gfp) 3102 { 3103 return kmem_cache_alloc_lru(cache, &sb->s_inode_lru, gfp); 3104 } 3105 3106 extern void __insert_inode_hash(struct inode *, unsigned long hashval); 3107 static inline void insert_inode_hash(struct inode *inode) 3108 { 3109 __insert_inode_hash(inode, inode->i_ino); 3110 } 3111 3112 extern void __remove_inode_hash(struct inode *); 3113 static inline void remove_inode_hash(struct inode *inode) 3114 { 3115 if (!inode_unhashed(inode) && !hlist_fake(&inode->i_hash)) 3116 __remove_inode_hash(inode); 3117 } 3118 3119 extern void inode_sb_list_add(struct inode *inode); 3120 extern void inode_add_lru(struct inode *inode); 3121 3122 extern int sb_set_blocksize(struct super_block *, int); 3123 extern int sb_min_blocksize(struct super_block *, int); 3124 3125 extern int generic_file_mmap(struct file *, struct vm_area_struct *); 3126 extern int generic_file_readonly_mmap(struct file *, struct vm_area_struct *); 3127 extern ssize_t generic_write_checks(struct kiocb *, struct iov_iter *); 3128 int generic_write_checks_count(struct kiocb *iocb, loff_t *count); 3129 extern int generic_write_check_limits(struct file *file, loff_t pos, 3130 loff_t *count); 3131 extern int generic_file_rw_checks(struct file *file_in, struct file *file_out); 3132 ssize_t filemap_read(struct kiocb *iocb, struct iov_iter *to, 3133 ssize_t already_read); 3134 extern ssize_t generic_file_read_iter(struct kiocb *, struct iov_iter *); 3135 extern ssize_t __generic_file_write_iter(struct kiocb *, struct iov_iter *); 3136 extern ssize_t generic_file_write_iter(struct kiocb *, struct iov_iter *); 3137 extern ssize_t generic_file_direct_write(struct kiocb *, struct iov_iter *); 3138 ssize_t generic_perform_write(struct kiocb *, struct iov_iter *); 3139 3140 ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos, 3141 rwf_t flags); 3142 ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos, 3143 rwf_t flags); 3144 ssize_t vfs_iocb_iter_read(struct file *file, struct kiocb *iocb, 3145 struct iov_iter *iter); 3146 ssize_t vfs_iocb_iter_write(struct file *file, struct kiocb *iocb, 3147 struct iov_iter *iter); 3148 3149 /* fs/splice.c */ 3150 extern ssize_t generic_file_splice_read(struct file *, loff_t *, 3151 struct pipe_inode_info *, size_t, unsigned int); 3152 extern ssize_t iter_file_splice_write(struct pipe_inode_info *, 3153 struct file *, loff_t *, size_t, unsigned int); 3154 extern ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe, 3155 struct file *out, loff_t *, size_t len, unsigned int flags); 3156 extern long do_splice_direct(struct file *in, loff_t *ppos, struct file *out, 3157 loff_t *opos, size_t len, unsigned int flags); 3158 3159 3160 extern void 3161 file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping); 3162 extern loff_t noop_llseek(struct file *file, loff_t offset, int whence); 3163 #define no_llseek NULL 3164 extern loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize); 3165 extern loff_t generic_file_llseek(struct file *file, loff_t offset, int whence); 3166 extern loff_t generic_file_llseek_size(struct file *file, loff_t offset, 3167 int whence, loff_t maxsize, loff_t eof); 3168 extern loff_t fixed_size_llseek(struct file *file, loff_t offset, 3169 int whence, loff_t size); 3170 extern loff_t no_seek_end_llseek_size(struct file *, loff_t, int, loff_t); 3171 extern loff_t no_seek_end_llseek(struct file *, loff_t, int); 3172 int rw_verify_area(int, struct file *, const loff_t *, size_t); 3173 extern int generic_file_open(struct inode * inode, struct file * filp); 3174 extern int nonseekable_open(struct inode * inode, struct file * filp); 3175 extern int stream_open(struct inode * inode, struct file * filp); 3176 3177 #ifdef CONFIG_BLOCK 3178 typedef void (dio_submit_t)(struct bio *bio, struct inode *inode, 3179 loff_t file_offset); 3180 3181 enum { 3182 /* need locking between buffered and direct access */ 3183 DIO_LOCKING = 0x01, 3184 3185 /* filesystem does not support filling holes */ 3186 DIO_SKIP_HOLES = 0x02, 3187 }; 3188 3189 ssize_t __blockdev_direct_IO(struct kiocb *iocb, struct inode *inode, 3190 struct block_device *bdev, struct iov_iter *iter, 3191 get_block_t get_block, 3192 dio_iodone_t end_io, dio_submit_t submit_io, 3193 int flags); 3194 3195 static inline ssize_t blockdev_direct_IO(struct kiocb *iocb, 3196 struct inode *inode, 3197 struct iov_iter *iter, 3198 get_block_t get_block) 3199 { 3200 return __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev, iter, 3201 get_block, NULL, NULL, DIO_LOCKING | DIO_SKIP_HOLES); 3202 } 3203 #endif 3204 3205 void inode_dio_wait(struct inode *inode); 3206 3207 /** 3208 * inode_dio_begin - signal start of a direct I/O requests 3209 * @inode: inode the direct I/O happens on 3210 * 3211 * This is called once we've finished processing a direct I/O request, 3212 * and is used to wake up callers waiting for direct I/O to be quiesced. 3213 */ 3214 static inline void inode_dio_begin(struct inode *inode) 3215 { 3216 atomic_inc(&inode->i_dio_count); 3217 } 3218 3219 /** 3220 * inode_dio_end - signal finish of a direct I/O requests 3221 * @inode: inode the direct I/O happens on 3222 * 3223 * This is called once we've finished processing a direct I/O request, 3224 * and is used to wake up callers waiting for direct I/O to be quiesced. 3225 */ 3226 static inline void inode_dio_end(struct inode *inode) 3227 { 3228 if (atomic_dec_and_test(&inode->i_dio_count)) 3229 wake_up_bit(&inode->i_state, __I_DIO_WAKEUP); 3230 } 3231 3232 /* 3233 * Warn about a page cache invalidation failure diring a direct I/O write. 3234 */ 3235 void dio_warn_stale_pagecache(struct file *filp); 3236 3237 extern void inode_set_flags(struct inode *inode, unsigned int flags, 3238 unsigned int mask); 3239 3240 extern const struct file_operations generic_ro_fops; 3241 3242 #define special_file(m) (S_ISCHR(m)||S_ISBLK(m)||S_ISFIFO(m)||S_ISSOCK(m)) 3243 3244 extern int readlink_copy(char __user *, int, const char *); 3245 extern int page_readlink(struct dentry *, char __user *, int); 3246 extern const char *page_get_link(struct dentry *, struct inode *, 3247 struct delayed_call *); 3248 extern void page_put_link(void *); 3249 extern int page_symlink(struct inode *inode, const char *symname, int len); 3250 extern const struct inode_operations page_symlink_inode_operations; 3251 extern void kfree_link(void *); 3252 void generic_fillattr(struct user_namespace *, struct inode *, struct kstat *); 3253 void generic_fill_statx_attr(struct inode *inode, struct kstat *stat); 3254 extern int vfs_getattr_nosec(const struct path *, struct kstat *, u32, unsigned int); 3255 extern int vfs_getattr(const struct path *, struct kstat *, u32, unsigned int); 3256 void __inode_add_bytes(struct inode *inode, loff_t bytes); 3257 void inode_add_bytes(struct inode *inode, loff_t bytes); 3258 void __inode_sub_bytes(struct inode *inode, loff_t bytes); 3259 void inode_sub_bytes(struct inode *inode, loff_t bytes); 3260 static inline loff_t __inode_get_bytes(struct inode *inode) 3261 { 3262 return (((loff_t)inode->i_blocks) << 9) + inode->i_bytes; 3263 } 3264 loff_t inode_get_bytes(struct inode *inode); 3265 void inode_set_bytes(struct inode *inode, loff_t bytes); 3266 const char *simple_get_link(struct dentry *, struct inode *, 3267 struct delayed_call *); 3268 extern const struct inode_operations simple_symlink_inode_operations; 3269 3270 extern int iterate_dir(struct file *, struct dir_context *); 3271 3272 int vfs_fstatat(int dfd, const char __user *filename, struct kstat *stat, 3273 int flags); 3274 int vfs_fstat(int fd, struct kstat *stat); 3275 3276 static inline int vfs_stat(const char __user *filename, struct kstat *stat) 3277 { 3278 return vfs_fstatat(AT_FDCWD, filename, stat, 0); 3279 } 3280 static inline int vfs_lstat(const char __user *name, struct kstat *stat) 3281 { 3282 return vfs_fstatat(AT_FDCWD, name, stat, AT_SYMLINK_NOFOLLOW); 3283 } 3284 3285 extern const char *vfs_get_link(struct dentry *, struct delayed_call *); 3286 extern int vfs_readlink(struct dentry *, char __user *, int); 3287 3288 extern struct file_system_type *get_filesystem(struct file_system_type *fs); 3289 extern void put_filesystem(struct file_system_type *fs); 3290 extern struct file_system_type *get_fs_type(const char *name); 3291 extern struct super_block *get_super(struct block_device *); 3292 extern struct super_block *get_active_super(struct block_device *bdev); 3293 extern void drop_super(struct super_block *sb); 3294 extern void drop_super_exclusive(struct super_block *sb); 3295 extern void iterate_supers(void (*)(struct super_block *, void *), void *); 3296 extern void iterate_supers_type(struct file_system_type *, 3297 void (*)(struct super_block *, void *), void *); 3298 3299 extern int dcache_dir_open(struct inode *, struct file *); 3300 extern int dcache_dir_close(struct inode *, struct file *); 3301 extern loff_t dcache_dir_lseek(struct file *, loff_t, int); 3302 extern int dcache_readdir(struct file *, struct dir_context *); 3303 extern int simple_setattr(struct user_namespace *, struct dentry *, 3304 struct iattr *); 3305 extern int simple_getattr(struct user_namespace *, const struct path *, 3306 struct kstat *, u32, unsigned int); 3307 extern int simple_statfs(struct dentry *, struct kstatfs *); 3308 extern int simple_open(struct inode *inode, struct file *file); 3309 extern int simple_link(struct dentry *, struct inode *, struct dentry *); 3310 extern int simple_unlink(struct inode *, struct dentry *); 3311 extern int simple_rmdir(struct inode *, struct dentry *); 3312 extern int simple_rename_exchange(struct inode *old_dir, struct dentry *old_dentry, 3313 struct inode *new_dir, struct dentry *new_dentry); 3314 extern int simple_rename(struct user_namespace *, struct inode *, 3315 struct dentry *, struct inode *, struct dentry *, 3316 unsigned int); 3317 extern void simple_recursive_removal(struct dentry *, 3318 void (*callback)(struct dentry *)); 3319 extern int noop_fsync(struct file *, loff_t, loff_t, int); 3320 extern ssize_t noop_direct_IO(struct kiocb *iocb, struct iov_iter *iter); 3321 extern int simple_empty(struct dentry *); 3322 extern int simple_write_begin(struct file *file, struct address_space *mapping, 3323 loff_t pos, unsigned len, 3324 struct page **pagep, void **fsdata); 3325 extern const struct address_space_operations ram_aops; 3326 extern int always_delete_dentry(const struct dentry *); 3327 extern struct inode *alloc_anon_inode(struct super_block *); 3328 extern int simple_nosetlease(struct file *, long, struct file_lock **, void **); 3329 extern const struct dentry_operations simple_dentry_operations; 3330 3331 extern struct dentry *simple_lookup(struct inode *, struct dentry *, unsigned int flags); 3332 extern ssize_t generic_read_dir(struct file *, char __user *, size_t, loff_t *); 3333 extern const struct file_operations simple_dir_operations; 3334 extern const struct inode_operations simple_dir_inode_operations; 3335 extern void make_empty_dir_inode(struct inode *inode); 3336 extern bool is_empty_dir_inode(struct inode *inode); 3337 struct tree_descr { const char *name; const struct file_operations *ops; int mode; }; 3338 struct dentry *d_alloc_name(struct dentry *, const char *); 3339 extern int simple_fill_super(struct super_block *, unsigned long, 3340 const struct tree_descr *); 3341 extern int simple_pin_fs(struct file_system_type *, struct vfsmount **mount, int *count); 3342 extern void simple_release_fs(struct vfsmount **mount, int *count); 3343 3344 extern ssize_t simple_read_from_buffer(void __user *to, size_t count, 3345 loff_t *ppos, const void *from, size_t available); 3346 extern ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos, 3347 const void __user *from, size_t count); 3348 3349 extern int __generic_file_fsync(struct file *, loff_t, loff_t, int); 3350 extern int generic_file_fsync(struct file *, loff_t, loff_t, int); 3351 3352 extern int generic_check_addressable(unsigned, u64); 3353 3354 extern void generic_set_encrypted_ci_d_ops(struct dentry *dentry); 3355 3356 int may_setattr(struct user_namespace *mnt_userns, struct inode *inode, 3357 unsigned int ia_valid); 3358 int setattr_prepare(struct user_namespace *, struct dentry *, struct iattr *); 3359 extern int inode_newsize_ok(const struct inode *, loff_t offset); 3360 void setattr_copy(struct user_namespace *, struct inode *inode, 3361 const struct iattr *attr); 3362 3363 extern int file_update_time(struct file *file); 3364 3365 static inline bool vma_is_dax(const struct vm_area_struct *vma) 3366 { 3367 return vma->vm_file && IS_DAX(vma->vm_file->f_mapping->host); 3368 } 3369 3370 static inline bool vma_is_fsdax(struct vm_area_struct *vma) 3371 { 3372 struct inode *inode; 3373 3374 if (!IS_ENABLED(CONFIG_FS_DAX) || !vma->vm_file) 3375 return false; 3376 if (!vma_is_dax(vma)) 3377 return false; 3378 inode = file_inode(vma->vm_file); 3379 if (S_ISCHR(inode->i_mode)) 3380 return false; /* device-dax */ 3381 return true; 3382 } 3383 3384 static inline int iocb_flags(struct file *file) 3385 { 3386 int res = 0; 3387 if (file->f_flags & O_APPEND) 3388 res |= IOCB_APPEND; 3389 if (file->f_flags & O_DIRECT) 3390 res |= IOCB_DIRECT; 3391 if (file->f_flags & O_DSYNC) 3392 res |= IOCB_DSYNC; 3393 if (file->f_flags & __O_SYNC) 3394 res |= IOCB_SYNC; 3395 return res; 3396 } 3397 3398 static inline int kiocb_set_rw_flags(struct kiocb *ki, rwf_t flags) 3399 { 3400 int kiocb_flags = 0; 3401 3402 /* make sure there's no overlap between RWF and private IOCB flags */ 3403 BUILD_BUG_ON((__force int) RWF_SUPPORTED & IOCB_EVENTFD); 3404 3405 if (!flags) 3406 return 0; 3407 if (unlikely(flags & ~RWF_SUPPORTED)) 3408 return -EOPNOTSUPP; 3409 3410 if (flags & RWF_NOWAIT) { 3411 if (!(ki->ki_filp->f_mode & FMODE_NOWAIT)) 3412 return -EOPNOTSUPP; 3413 kiocb_flags |= IOCB_NOIO; 3414 } 3415 kiocb_flags |= (__force int) (flags & RWF_SUPPORTED); 3416 if (flags & RWF_SYNC) 3417 kiocb_flags |= IOCB_DSYNC; 3418 3419 ki->ki_flags |= kiocb_flags; 3420 return 0; 3421 } 3422 3423 static inline ino_t parent_ino(struct dentry *dentry) 3424 { 3425 ino_t res; 3426 3427 /* 3428 * Don't strictly need d_lock here? If the parent ino could change 3429 * then surely we'd have a deeper race in the caller? 3430 */ 3431 spin_lock(&dentry->d_lock); 3432 res = dentry->d_parent->d_inode->i_ino; 3433 spin_unlock(&dentry->d_lock); 3434 return res; 3435 } 3436 3437 /* Transaction based IO helpers */ 3438 3439 /* 3440 * An argresp is stored in an allocated page and holds the 3441 * size of the argument or response, along with its content 3442 */ 3443 struct simple_transaction_argresp { 3444 ssize_t size; 3445 char data[]; 3446 }; 3447 3448 #define SIMPLE_TRANSACTION_LIMIT (PAGE_SIZE - sizeof(struct simple_transaction_argresp)) 3449 3450 char *simple_transaction_get(struct file *file, const char __user *buf, 3451 size_t size); 3452 ssize_t simple_transaction_read(struct file *file, char __user *buf, 3453 size_t size, loff_t *pos); 3454 int simple_transaction_release(struct inode *inode, struct file *file); 3455 3456 void simple_transaction_set(struct file *file, size_t n); 3457 3458 /* 3459 * simple attribute files 3460 * 3461 * These attributes behave similar to those in sysfs: 3462 * 3463 * Writing to an attribute immediately sets a value, an open file can be 3464 * written to multiple times. 3465 * 3466 * Reading from an attribute creates a buffer from the value that might get 3467 * read with multiple read calls. When the attribute has been read 3468 * completely, no further read calls are possible until the file is opened 3469 * again. 3470 * 3471 * All attributes contain a text representation of a numeric value 3472 * that are accessed with the get() and set() functions. 3473 */ 3474 #define DEFINE_SIMPLE_ATTRIBUTE(__fops, __get, __set, __fmt) \ 3475 static int __fops ## _open(struct inode *inode, struct file *file) \ 3476 { \ 3477 __simple_attr_check_format(__fmt, 0ull); \ 3478 return simple_attr_open(inode, file, __get, __set, __fmt); \ 3479 } \ 3480 static const struct file_operations __fops = { \ 3481 .owner = THIS_MODULE, \ 3482 .open = __fops ## _open, \ 3483 .release = simple_attr_release, \ 3484 .read = simple_attr_read, \ 3485 .write = simple_attr_write, \ 3486 .llseek = generic_file_llseek, \ 3487 } 3488 3489 static inline __printf(1, 2) 3490 void __simple_attr_check_format(const char *fmt, ...) 3491 { 3492 /* don't do anything, just let the compiler check the arguments; */ 3493 } 3494 3495 int simple_attr_open(struct inode *inode, struct file *file, 3496 int (*get)(void *, u64 *), int (*set)(void *, u64), 3497 const char *fmt); 3498 int simple_attr_release(struct inode *inode, struct file *file); 3499 ssize_t simple_attr_read(struct file *file, char __user *buf, 3500 size_t len, loff_t *ppos); 3501 ssize_t simple_attr_write(struct file *file, const char __user *buf, 3502 size_t len, loff_t *ppos); 3503 3504 struct ctl_table; 3505 int __init list_bdev_fs_names(char *buf, size_t size); 3506 3507 #define __FMODE_EXEC ((__force int) FMODE_EXEC) 3508 #define __FMODE_NONOTIFY ((__force int) FMODE_NONOTIFY) 3509 3510 #define ACC_MODE(x) ("\004\002\006\006"[(x)&O_ACCMODE]) 3511 #define OPEN_FMODE(flag) ((__force fmode_t)(((flag + 1) & O_ACCMODE) | \ 3512 (flag & __FMODE_NONOTIFY))) 3513 3514 static inline bool is_sxid(umode_t mode) 3515 { 3516 return (mode & S_ISUID) || ((mode & S_ISGID) && (mode & S_IXGRP)); 3517 } 3518 3519 static inline int check_sticky(struct user_namespace *mnt_userns, 3520 struct inode *dir, struct inode *inode) 3521 { 3522 if (!(dir->i_mode & S_ISVTX)) 3523 return 0; 3524 3525 return __check_sticky(mnt_userns, dir, inode); 3526 } 3527 3528 static inline void inode_has_no_xattr(struct inode *inode) 3529 { 3530 if (!is_sxid(inode->i_mode) && (inode->i_sb->s_flags & SB_NOSEC)) 3531 inode->i_flags |= S_NOSEC; 3532 } 3533 3534 static inline bool is_root_inode(struct inode *inode) 3535 { 3536 return inode == inode->i_sb->s_root->d_inode; 3537 } 3538 3539 static inline bool dir_emit(struct dir_context *ctx, 3540 const char *name, int namelen, 3541 u64 ino, unsigned type) 3542 { 3543 return ctx->actor(ctx, name, namelen, ctx->pos, ino, type) == 0; 3544 } 3545 static inline bool dir_emit_dot(struct file *file, struct dir_context *ctx) 3546 { 3547 return ctx->actor(ctx, ".", 1, ctx->pos, 3548 file->f_path.dentry->d_inode->i_ino, DT_DIR) == 0; 3549 } 3550 static inline bool dir_emit_dotdot(struct file *file, struct dir_context *ctx) 3551 { 3552 return ctx->actor(ctx, "..", 2, ctx->pos, 3553 parent_ino(file->f_path.dentry), DT_DIR) == 0; 3554 } 3555 static inline bool dir_emit_dots(struct file *file, struct dir_context *ctx) 3556 { 3557 if (ctx->pos == 0) { 3558 if (!dir_emit_dot(file, ctx)) 3559 return false; 3560 ctx->pos = 1; 3561 } 3562 if (ctx->pos == 1) { 3563 if (!dir_emit_dotdot(file, ctx)) 3564 return false; 3565 ctx->pos = 2; 3566 } 3567 return true; 3568 } 3569 static inline bool dir_relax(struct inode *inode) 3570 { 3571 inode_unlock(inode); 3572 inode_lock(inode); 3573 return !IS_DEADDIR(inode); 3574 } 3575 3576 static inline bool dir_relax_shared(struct inode *inode) 3577 { 3578 inode_unlock_shared(inode); 3579 inode_lock_shared(inode); 3580 return !IS_DEADDIR(inode); 3581 } 3582 3583 extern bool path_noexec(const struct path *path); 3584 extern void inode_nohighmem(struct inode *inode); 3585 3586 /* mm/fadvise.c */ 3587 extern int vfs_fadvise(struct file *file, loff_t offset, loff_t len, 3588 int advice); 3589 extern int generic_fadvise(struct file *file, loff_t offset, loff_t len, 3590 int advice); 3591 3592 #endif /* _LINUX_FS_H */ 3593