1 #ifndef _LINUX_FS_H 2 #define _LINUX_FS_H 3 4 5 #include <linux/linkage.h> 6 #include <linux/wait.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/radix-tree.h> 14 #include <linux/rbtree.h> 15 #include <linux/init.h> 16 #include <linux/pid.h> 17 #include <linux/bug.h> 18 #include <linux/mutex.h> 19 #include <linux/capability.h> 20 #include <linux/semaphore.h> 21 #include <linux/fiemap.h> 22 #include <linux/rculist_bl.h> 23 #include <linux/atomic.h> 24 #include <linux/shrinker.h> 25 #include <linux/migrate_mode.h> 26 #include <linux/uidgid.h> 27 #include <linux/lockdep.h> 28 #include <linux/percpu-rwsem.h> 29 #include <linux/blk_types.h> 30 31 #include <asm/byteorder.h> 32 #include <uapi/linux/fs.h> 33 34 struct export_operations; 35 struct hd_geometry; 36 struct iovec; 37 struct nameidata; 38 struct kiocb; 39 struct kobject; 40 struct pipe_inode_info; 41 struct poll_table_struct; 42 struct kstatfs; 43 struct vm_area_struct; 44 struct vfsmount; 45 struct cred; 46 struct swap_info_struct; 47 48 extern void __init inode_init(void); 49 extern void __init inode_init_early(void); 50 extern void __init files_init(unsigned long); 51 52 extern struct files_stat_struct files_stat; 53 extern unsigned long get_max_files(void); 54 extern int sysctl_nr_open; 55 extern struct inodes_stat_t inodes_stat; 56 extern int leases_enable, lease_break_time; 57 extern int sysctl_protected_symlinks; 58 extern int sysctl_protected_hardlinks; 59 60 struct buffer_head; 61 typedef int (get_block_t)(struct inode *inode, sector_t iblock, 62 struct buffer_head *bh_result, int create); 63 typedef void (dio_iodone_t)(struct kiocb *iocb, loff_t offset, 64 ssize_t bytes, void *private, int ret, 65 bool is_async); 66 67 /* 68 * The below are the various read and write types that we support. Some of 69 * them include behavioral modifiers that send information down to the 70 * block layer and IO scheduler. Terminology: 71 * 72 * The block layer uses device plugging to defer IO a little bit, in 73 * the hope that we will see more IO very shortly. This increases 74 * coalescing of adjacent IO and thus reduces the number of IOs we 75 * have to send to the device. It also allows for better queuing, 76 * if the IO isn't mergeable. If the caller is going to be waiting 77 * for the IO, then he must ensure that the device is unplugged so 78 * that the IO is dispatched to the driver. 79 * 80 * All IO is handled async in Linux. This is fine for background 81 * writes, but for reads or writes that someone waits for completion 82 * on, we want to notify the block layer and IO scheduler so that they 83 * know about it. That allows them to make better scheduling 84 * decisions. So when the below references 'sync' and 'async', it 85 * is referencing this priority hint. 86 * 87 * With that in mind, the available types are: 88 * 89 * READ A normal read operation. Device will be plugged. 90 * READ_SYNC A synchronous read. Device is not plugged, caller can 91 * immediately wait on this read without caring about 92 * unplugging. 93 * READA Used for read-ahead operations. Lower priority, and the 94 * block layer could (in theory) choose to ignore this 95 * request if it runs into resource problems. 96 * WRITE A normal async write. Device will be plugged. 97 * WRITE_SYNC Synchronous write. Identical to WRITE, but passes down 98 * the hint that someone will be waiting on this IO 99 * shortly. The write equivalent of READ_SYNC. 100 * WRITE_ODIRECT Special case write for O_DIRECT only. 101 * WRITE_FLUSH Like WRITE_SYNC but with preceding cache flush. 102 * WRITE_FUA Like WRITE_SYNC but data is guaranteed to be on 103 * non-volatile media on completion. 104 * WRITE_FLUSH_FUA Combination of WRITE_FLUSH and FUA. The IO is preceded 105 * by a cache flush and data is guaranteed to be on 106 * non-volatile media on completion. 107 * 108 */ 109 #define RW_MASK REQ_WRITE 110 #define RWA_MASK REQ_RAHEAD 111 112 #define READ 0 113 #define WRITE RW_MASK 114 #define READA RWA_MASK 115 #define KERNEL_READ (READ|REQ_KERNEL) 116 #define KERNEL_WRITE (WRITE|REQ_KERNEL) 117 118 #define READ_SYNC (READ | REQ_SYNC) 119 #define WRITE_SYNC (WRITE | REQ_SYNC | REQ_NOIDLE) 120 #define WRITE_ODIRECT (WRITE | REQ_SYNC) 121 #define WRITE_FLUSH (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_FLUSH) 122 #define WRITE_FUA (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_FUA) 123 #define WRITE_FLUSH_FUA (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_FLUSH | REQ_FUA) 124 125 /* 126 * Attribute flags. These should be or-ed together to figure out what 127 * has been changed! 128 */ 129 #define ATTR_MODE (1 << 0) 130 #define ATTR_UID (1 << 1) 131 #define ATTR_GID (1 << 2) 132 #define ATTR_SIZE (1 << 3) 133 #define ATTR_ATIME (1 << 4) 134 #define ATTR_MTIME (1 << 5) 135 #define ATTR_CTIME (1 << 6) 136 #define ATTR_ATIME_SET (1 << 7) 137 #define ATTR_MTIME_SET (1 << 8) 138 #define ATTR_FORCE (1 << 9) /* Not a change, but a change it */ 139 #define ATTR_ATTR_FLAG (1 << 10) 140 #define ATTR_KILL_SUID (1 << 11) 141 #define ATTR_KILL_SGID (1 << 12) 142 #define ATTR_FILE (1 << 13) 143 #define ATTR_KILL_PRIV (1 << 14) 144 #define ATTR_OPEN (1 << 15) /* Truncating from open(O_TRUNC) */ 145 #define ATTR_TIMES_SET (1 << 16) 146 147 /* 148 * This is the Inode Attributes structure, used for notify_change(). It 149 * uses the above definitions as flags, to know which values have changed. 150 * Also, in this manner, a Filesystem can look at only the values it cares 151 * about. Basically, these are the attributes that the VFS layer can 152 * request to change from the FS layer. 153 * 154 * Derek Atkins <[email protected]> 94-10-20 155 */ 156 struct iattr { 157 unsigned int ia_valid; 158 umode_t ia_mode; 159 kuid_t ia_uid; 160 kgid_t ia_gid; 161 loff_t ia_size; 162 struct timespec ia_atime; 163 struct timespec ia_mtime; 164 struct timespec ia_ctime; 165 166 /* 167 * Not an attribute, but an auxiliary info for filesystems wanting to 168 * implement an ftruncate() like method. NOTE: filesystem should 169 * check for (ia_valid & ATTR_FILE), and not for (ia_file != NULL). 170 */ 171 struct file *ia_file; 172 }; 173 174 /* 175 * Includes for diskquotas. 176 */ 177 #include <linux/quota.h> 178 179 /** 180 * enum positive_aop_returns - aop return codes with specific semantics 181 * 182 * @AOP_WRITEPAGE_ACTIVATE: Informs the caller that page writeback has 183 * completed, that the page is still locked, and 184 * should be considered active. The VM uses this hint 185 * to return the page to the active list -- it won't 186 * be a candidate for writeback again in the near 187 * future. Other callers must be careful to unlock 188 * the page if they get this return. Returned by 189 * writepage(); 190 * 191 * @AOP_TRUNCATED_PAGE: The AOP method that was handed a locked page has 192 * unlocked it and the page might have been truncated. 193 * The caller should back up to acquiring a new page and 194 * trying again. The aop will be taking reasonable 195 * precautions not to livelock. If the caller held a page 196 * reference, it should drop it before retrying. Returned 197 * by readpage(). 198 * 199 * address_space_operation functions return these large constants to indicate 200 * special semantics to the caller. These are much larger than the bytes in a 201 * page to allow for functions that return the number of bytes operated on in a 202 * given page. 203 */ 204 205 enum positive_aop_returns { 206 AOP_WRITEPAGE_ACTIVATE = 0x80000, 207 AOP_TRUNCATED_PAGE = 0x80001, 208 }; 209 210 #define AOP_FLAG_UNINTERRUPTIBLE 0x0001 /* will not do a short write */ 211 #define AOP_FLAG_CONT_EXPAND 0x0002 /* called from cont_expand */ 212 #define AOP_FLAG_NOFS 0x0004 /* used by filesystem to direct 213 * helper code (eg buffer layer) 214 * to clear GFP_FS from alloc */ 215 216 /* 217 * oh the beauties of C type declarations. 218 */ 219 struct page; 220 struct address_space; 221 struct writeback_control; 222 223 struct iov_iter { 224 const struct iovec *iov; 225 unsigned long nr_segs; 226 size_t iov_offset; 227 size_t count; 228 }; 229 230 size_t iov_iter_copy_from_user_atomic(struct page *page, 231 struct iov_iter *i, unsigned long offset, size_t bytes); 232 size_t iov_iter_copy_from_user(struct page *page, 233 struct iov_iter *i, unsigned long offset, size_t bytes); 234 void iov_iter_advance(struct iov_iter *i, size_t bytes); 235 int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes); 236 size_t iov_iter_single_seg_count(struct iov_iter *i); 237 238 static inline void iov_iter_init(struct iov_iter *i, 239 const struct iovec *iov, unsigned long nr_segs, 240 size_t count, size_t written) 241 { 242 i->iov = iov; 243 i->nr_segs = nr_segs; 244 i->iov_offset = 0; 245 i->count = count + written; 246 247 iov_iter_advance(i, written); 248 } 249 250 static inline size_t iov_iter_count(struct iov_iter *i) 251 { 252 return i->count; 253 } 254 255 /* 256 * "descriptor" for what we're up to with a read. 257 * This allows us to use the same read code yet 258 * have multiple different users of the data that 259 * we read from a file. 260 * 261 * The simplest case just copies the data to user 262 * mode. 263 */ 264 typedef struct { 265 size_t written; 266 size_t count; 267 union { 268 char __user *buf; 269 void *data; 270 } arg; 271 int error; 272 } read_descriptor_t; 273 274 typedef int (*read_actor_t)(read_descriptor_t *, struct page *, 275 unsigned long, unsigned long); 276 277 struct address_space_operations { 278 int (*writepage)(struct page *page, struct writeback_control *wbc); 279 int (*readpage)(struct file *, struct page *); 280 281 /* Write back some dirty pages from this mapping. */ 282 int (*writepages)(struct address_space *, struct writeback_control *); 283 284 /* Set a page dirty. Return true if this dirtied it */ 285 int (*set_page_dirty)(struct page *page); 286 287 int (*readpages)(struct file *filp, struct address_space *mapping, 288 struct list_head *pages, unsigned nr_pages); 289 290 int (*write_begin)(struct file *, struct address_space *mapping, 291 loff_t pos, unsigned len, unsigned flags, 292 struct page **pagep, void **fsdata); 293 int (*write_end)(struct file *, struct address_space *mapping, 294 loff_t pos, unsigned len, unsigned copied, 295 struct page *page, void *fsdata); 296 297 /* Unfortunately this kludge is needed for FIBMAP. Don't use it */ 298 sector_t (*bmap)(struct address_space *, sector_t); 299 void (*invalidatepage) (struct page *, unsigned long); 300 int (*releasepage) (struct page *, gfp_t); 301 void (*freepage)(struct page *); 302 ssize_t (*direct_IO)(int, struct kiocb *, const struct iovec *iov, 303 loff_t offset, unsigned long nr_segs); 304 int (*get_xip_mem)(struct address_space *, pgoff_t, int, 305 void **, unsigned long *); 306 /* 307 * migrate the contents of a page to the specified target. If sync 308 * is false, it must not block. 309 */ 310 int (*migratepage) (struct address_space *, 311 struct page *, struct page *, enum migrate_mode); 312 int (*launder_page) (struct page *); 313 int (*is_partially_uptodate) (struct page *, read_descriptor_t *, 314 unsigned long); 315 int (*error_remove_page)(struct address_space *, struct page *); 316 317 /* swapfile support */ 318 int (*swap_activate)(struct swap_info_struct *sis, struct file *file, 319 sector_t *span); 320 void (*swap_deactivate)(struct file *file); 321 }; 322 323 extern const struct address_space_operations empty_aops; 324 325 /* 326 * pagecache_write_begin/pagecache_write_end must be used by general code 327 * to write into the pagecache. 328 */ 329 int pagecache_write_begin(struct file *, struct address_space *mapping, 330 loff_t pos, unsigned len, unsigned flags, 331 struct page **pagep, void **fsdata); 332 333 int pagecache_write_end(struct file *, struct address_space *mapping, 334 loff_t pos, unsigned len, unsigned copied, 335 struct page *page, void *fsdata); 336 337 struct backing_dev_info; 338 struct address_space { 339 struct inode *host; /* owner: inode, block_device */ 340 struct radix_tree_root page_tree; /* radix tree of all pages */ 341 spinlock_t tree_lock; /* and lock protecting it */ 342 unsigned int i_mmap_writable;/* count VM_SHARED mappings */ 343 struct rb_root i_mmap; /* tree of private and shared mappings */ 344 struct list_head i_mmap_nonlinear;/*list VM_NONLINEAR mappings */ 345 struct mutex i_mmap_mutex; /* protect tree, count, list */ 346 /* Protected by tree_lock together with the radix tree */ 347 unsigned long nrpages; /* number of total pages */ 348 pgoff_t writeback_index;/* writeback starts here */ 349 const struct address_space_operations *a_ops; /* methods */ 350 unsigned long flags; /* error bits/gfp mask */ 351 struct backing_dev_info *backing_dev_info; /* device readahead, etc */ 352 spinlock_t private_lock; /* for use by the address_space */ 353 struct list_head private_list; /* ditto */ 354 struct address_space *assoc_mapping; /* ditto */ 355 } __attribute__((aligned(sizeof(long)))); 356 /* 357 * On most architectures that alignment is already the case; but 358 * must be enforced here for CRIS, to let the least significant bit 359 * of struct page's "mapping" pointer be used for PAGE_MAPPING_ANON. 360 */ 361 struct request_queue; 362 363 struct block_device { 364 dev_t bd_dev; /* not a kdev_t - it's a search key */ 365 int bd_openers; 366 struct inode * bd_inode; /* will die */ 367 struct super_block * bd_super; 368 struct mutex bd_mutex; /* open/close mutex */ 369 struct list_head bd_inodes; 370 void * bd_claiming; 371 void * bd_holder; 372 int bd_holders; 373 bool bd_write_holder; 374 #ifdef CONFIG_SYSFS 375 struct list_head bd_holder_disks; 376 #endif 377 struct block_device * bd_contains; 378 unsigned bd_block_size; 379 struct hd_struct * bd_part; 380 /* number of times partitions within this device have been opened. */ 381 unsigned bd_part_count; 382 int bd_invalidated; 383 struct gendisk * bd_disk; 384 struct request_queue * bd_queue; 385 struct list_head bd_list; 386 /* 387 * Private data. You must have bd_claim'ed the block_device 388 * to use this. NOTE: bd_claim allows an owner to claim 389 * the same device multiple times, the owner must take special 390 * care to not mess up bd_private for that case. 391 */ 392 unsigned long bd_private; 393 394 /* The counter of freeze processes */ 395 int bd_fsfreeze_count; 396 /* Mutex for freeze */ 397 struct mutex bd_fsfreeze_mutex; 398 /* A semaphore that prevents I/O while block size is being changed */ 399 struct percpu_rw_semaphore bd_block_size_semaphore; 400 }; 401 402 /* 403 * Radix-tree tags, for tagging dirty and writeback pages within the pagecache 404 * radix trees 405 */ 406 #define PAGECACHE_TAG_DIRTY 0 407 #define PAGECACHE_TAG_WRITEBACK 1 408 #define PAGECACHE_TAG_TOWRITE 2 409 410 int mapping_tagged(struct address_space *mapping, int tag); 411 412 /* 413 * Might pages of this file be mapped into userspace? 414 */ 415 static inline int mapping_mapped(struct address_space *mapping) 416 { 417 return !RB_EMPTY_ROOT(&mapping->i_mmap) || 418 !list_empty(&mapping->i_mmap_nonlinear); 419 } 420 421 /* 422 * Might pages of this file have been modified in userspace? 423 * Note that i_mmap_writable counts all VM_SHARED vmas: do_mmap_pgoff 424 * marks vma as VM_SHARED if it is shared, and the file was opened for 425 * writing i.e. vma may be mprotected writable even if now readonly. 426 */ 427 static inline int mapping_writably_mapped(struct address_space *mapping) 428 { 429 return mapping->i_mmap_writable != 0; 430 } 431 432 /* 433 * Use sequence counter to get consistent i_size on 32-bit processors. 434 */ 435 #if BITS_PER_LONG==32 && defined(CONFIG_SMP) 436 #include <linux/seqlock.h> 437 #define __NEED_I_SIZE_ORDERED 438 #define i_size_ordered_init(inode) seqcount_init(&inode->i_size_seqcount) 439 #else 440 #define i_size_ordered_init(inode) do { } while (0) 441 #endif 442 443 struct posix_acl; 444 #define ACL_NOT_CACHED ((void *)(-1)) 445 446 #define IOP_FASTPERM 0x0001 447 #define IOP_LOOKUP 0x0002 448 #define IOP_NOFOLLOW 0x0004 449 450 /* 451 * Keep mostly read-only and often accessed (especially for 452 * the RCU path lookup and 'stat' data) fields at the beginning 453 * of the 'struct inode' 454 */ 455 struct inode { 456 umode_t i_mode; 457 unsigned short i_opflags; 458 kuid_t i_uid; 459 kgid_t i_gid; 460 unsigned int i_flags; 461 462 #ifdef CONFIG_FS_POSIX_ACL 463 struct posix_acl *i_acl; 464 struct posix_acl *i_default_acl; 465 #endif 466 467 const struct inode_operations *i_op; 468 struct super_block *i_sb; 469 struct address_space *i_mapping; 470 471 #ifdef CONFIG_SECURITY 472 void *i_security; 473 #endif 474 475 /* Stat data, not accessed from path walking */ 476 unsigned long i_ino; 477 /* 478 * Filesystems may only read i_nlink directly. They shall use the 479 * following functions for modification: 480 * 481 * (set|clear|inc|drop)_nlink 482 * inode_(inc|dec)_link_count 483 */ 484 union { 485 const unsigned int i_nlink; 486 unsigned int __i_nlink; 487 }; 488 dev_t i_rdev; 489 loff_t i_size; 490 struct timespec i_atime; 491 struct timespec i_mtime; 492 struct timespec i_ctime; 493 spinlock_t i_lock; /* i_blocks, i_bytes, maybe i_size */ 494 unsigned short i_bytes; 495 unsigned int i_blkbits; 496 blkcnt_t i_blocks; 497 498 #ifdef __NEED_I_SIZE_ORDERED 499 seqcount_t i_size_seqcount; 500 #endif 501 502 /* Misc */ 503 unsigned long i_state; 504 struct mutex i_mutex; 505 506 unsigned long dirtied_when; /* jiffies of first dirtying */ 507 508 struct hlist_node i_hash; 509 struct list_head i_wb_list; /* backing dev IO list */ 510 struct list_head i_lru; /* inode LRU list */ 511 struct list_head i_sb_list; 512 union { 513 struct hlist_head i_dentry; 514 struct rcu_head i_rcu; 515 }; 516 u64 i_version; 517 atomic_t i_count; 518 atomic_t i_dio_count; 519 atomic_t i_writecount; 520 const struct file_operations *i_fop; /* former ->i_op->default_file_ops */ 521 struct file_lock *i_flock; 522 struct address_space i_data; 523 #ifdef CONFIG_QUOTA 524 struct dquot *i_dquot[MAXQUOTAS]; 525 #endif 526 struct list_head i_devices; 527 union { 528 struct pipe_inode_info *i_pipe; 529 struct block_device *i_bdev; 530 struct cdev *i_cdev; 531 }; 532 533 __u32 i_generation; 534 535 #ifdef CONFIG_FSNOTIFY 536 __u32 i_fsnotify_mask; /* all events this inode cares about */ 537 struct hlist_head i_fsnotify_marks; 538 #endif 539 540 #ifdef CONFIG_IMA 541 atomic_t i_readcount; /* struct files open RO */ 542 #endif 543 void *i_private; /* fs or device private pointer */ 544 }; 545 546 static inline int inode_unhashed(struct inode *inode) 547 { 548 return hlist_unhashed(&inode->i_hash); 549 } 550 551 /* 552 * inode->i_mutex nesting subclasses for the lock validator: 553 * 554 * 0: the object of the current VFS operation 555 * 1: parent 556 * 2: child/target 557 * 3: quota file 558 * 559 * The locking order between these classes is 560 * parent -> child -> normal -> xattr -> quota 561 */ 562 enum inode_i_mutex_lock_class 563 { 564 I_MUTEX_NORMAL, 565 I_MUTEX_PARENT, 566 I_MUTEX_CHILD, 567 I_MUTEX_XATTR, 568 I_MUTEX_QUOTA 569 }; 570 571 /* 572 * NOTE: in a 32bit arch with a preemptable kernel and 573 * an UP compile the i_size_read/write must be atomic 574 * with respect to the local cpu (unlike with preempt disabled), 575 * but they don't need to be atomic with respect to other cpus like in 576 * true SMP (so they need either to either locally disable irq around 577 * the read or for example on x86 they can be still implemented as a 578 * cmpxchg8b without the need of the lock prefix). For SMP compiles 579 * and 64bit archs it makes no difference if preempt is enabled or not. 580 */ 581 static inline loff_t i_size_read(const struct inode *inode) 582 { 583 #if BITS_PER_LONG==32 && defined(CONFIG_SMP) 584 loff_t i_size; 585 unsigned int seq; 586 587 do { 588 seq = read_seqcount_begin(&inode->i_size_seqcount); 589 i_size = inode->i_size; 590 } while (read_seqcount_retry(&inode->i_size_seqcount, seq)); 591 return i_size; 592 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT) 593 loff_t i_size; 594 595 preempt_disable(); 596 i_size = inode->i_size; 597 preempt_enable(); 598 return i_size; 599 #else 600 return inode->i_size; 601 #endif 602 } 603 604 /* 605 * NOTE: unlike i_size_read(), i_size_write() does need locking around it 606 * (normally i_mutex), otherwise on 32bit/SMP an update of i_size_seqcount 607 * can be lost, resulting in subsequent i_size_read() calls spinning forever. 608 */ 609 static inline void i_size_write(struct inode *inode, loff_t i_size) 610 { 611 #if BITS_PER_LONG==32 && defined(CONFIG_SMP) 612 write_seqcount_begin(&inode->i_size_seqcount); 613 inode->i_size = i_size; 614 write_seqcount_end(&inode->i_size_seqcount); 615 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT) 616 preempt_disable(); 617 inode->i_size = i_size; 618 preempt_enable(); 619 #else 620 inode->i_size = i_size; 621 #endif 622 } 623 624 /* Helper functions so that in most cases filesystems will 625 * not need to deal directly with kuid_t and kgid_t and can 626 * instead deal with the raw numeric values that are stored 627 * in the filesystem. 628 */ 629 static inline uid_t i_uid_read(const struct inode *inode) 630 { 631 return from_kuid(&init_user_ns, inode->i_uid); 632 } 633 634 static inline gid_t i_gid_read(const struct inode *inode) 635 { 636 return from_kgid(&init_user_ns, inode->i_gid); 637 } 638 639 static inline void i_uid_write(struct inode *inode, uid_t uid) 640 { 641 inode->i_uid = make_kuid(&init_user_ns, uid); 642 } 643 644 static inline void i_gid_write(struct inode *inode, gid_t gid) 645 { 646 inode->i_gid = make_kgid(&init_user_ns, gid); 647 } 648 649 static inline unsigned iminor(const struct inode *inode) 650 { 651 return MINOR(inode->i_rdev); 652 } 653 654 static inline unsigned imajor(const struct inode *inode) 655 { 656 return MAJOR(inode->i_rdev); 657 } 658 659 extern struct block_device *I_BDEV(struct inode *inode); 660 661 struct fown_struct { 662 rwlock_t lock; /* protects pid, uid, euid fields */ 663 struct pid *pid; /* pid or -pgrp where SIGIO should be sent */ 664 enum pid_type pid_type; /* Kind of process group SIGIO should be sent to */ 665 kuid_t uid, euid; /* uid/euid of process setting the owner */ 666 int signum; /* posix.1b rt signal to be delivered on IO */ 667 }; 668 669 /* 670 * Track a single file's readahead state 671 */ 672 struct file_ra_state { 673 pgoff_t start; /* where readahead started */ 674 unsigned int size; /* # of readahead pages */ 675 unsigned int async_size; /* do asynchronous readahead when 676 there are only # of pages ahead */ 677 678 unsigned int ra_pages; /* Maximum readahead window */ 679 unsigned int mmap_miss; /* Cache miss stat for mmap accesses */ 680 loff_t prev_pos; /* Cache last read() position */ 681 }; 682 683 /* 684 * Check if @index falls in the readahead windows. 685 */ 686 static inline int ra_has_index(struct file_ra_state *ra, pgoff_t index) 687 { 688 return (index >= ra->start && 689 index < ra->start + ra->size); 690 } 691 692 #define FILE_MNT_WRITE_TAKEN 1 693 #define FILE_MNT_WRITE_RELEASED 2 694 695 struct file { 696 /* 697 * fu_list becomes invalid after file_free is called and queued via 698 * fu_rcuhead for RCU freeing 699 */ 700 union { 701 struct list_head fu_list; 702 struct rcu_head fu_rcuhead; 703 } f_u; 704 struct path f_path; 705 #define f_dentry f_path.dentry 706 #define f_vfsmnt f_path.mnt 707 const struct file_operations *f_op; 708 709 /* 710 * Protects f_ep_links, f_flags, f_pos vs i_size in lseek SEEK_CUR. 711 * Must not be taken from IRQ context. 712 */ 713 spinlock_t f_lock; 714 #ifdef CONFIG_SMP 715 int f_sb_list_cpu; 716 #endif 717 atomic_long_t f_count; 718 unsigned int f_flags; 719 fmode_t f_mode; 720 loff_t f_pos; 721 struct fown_struct f_owner; 722 const struct cred *f_cred; 723 struct file_ra_state f_ra; 724 725 u64 f_version; 726 #ifdef CONFIG_SECURITY 727 void *f_security; 728 #endif 729 /* needed for tty driver, and maybe others */ 730 void *private_data; 731 732 #ifdef CONFIG_EPOLL 733 /* Used by fs/eventpoll.c to link all the hooks to this file */ 734 struct list_head f_ep_links; 735 struct list_head f_tfile_llink; 736 #endif /* #ifdef CONFIG_EPOLL */ 737 struct address_space *f_mapping; 738 #ifdef CONFIG_DEBUG_WRITECOUNT 739 unsigned long f_mnt_write_state; 740 #endif 741 }; 742 743 struct file_handle { 744 __u32 handle_bytes; 745 int handle_type; 746 /* file identifier */ 747 unsigned char f_handle[0]; 748 }; 749 750 static inline struct file *get_file(struct file *f) 751 { 752 atomic_long_inc(&f->f_count); 753 return f; 754 } 755 #define fput_atomic(x) atomic_long_add_unless(&(x)->f_count, -1, 1) 756 #define file_count(x) atomic_long_read(&(x)->f_count) 757 758 #ifdef CONFIG_DEBUG_WRITECOUNT 759 static inline void file_take_write(struct file *f) 760 { 761 WARN_ON(f->f_mnt_write_state != 0); 762 f->f_mnt_write_state = FILE_MNT_WRITE_TAKEN; 763 } 764 static inline void file_release_write(struct file *f) 765 { 766 f->f_mnt_write_state |= FILE_MNT_WRITE_RELEASED; 767 } 768 static inline void file_reset_write(struct file *f) 769 { 770 f->f_mnt_write_state = 0; 771 } 772 static inline void file_check_state(struct file *f) 773 { 774 /* 775 * At this point, either both or neither of these bits 776 * should be set. 777 */ 778 WARN_ON(f->f_mnt_write_state == FILE_MNT_WRITE_TAKEN); 779 WARN_ON(f->f_mnt_write_state == FILE_MNT_WRITE_RELEASED); 780 } 781 static inline int file_check_writeable(struct file *f) 782 { 783 if (f->f_mnt_write_state == FILE_MNT_WRITE_TAKEN) 784 return 0; 785 printk(KERN_WARNING "writeable file with no " 786 "mnt_want_write()\n"); 787 WARN_ON(1); 788 return -EINVAL; 789 } 790 #else /* !CONFIG_DEBUG_WRITECOUNT */ 791 static inline void file_take_write(struct file *filp) {} 792 static inline void file_release_write(struct file *filp) {} 793 static inline void file_reset_write(struct file *filp) {} 794 static inline void file_check_state(struct file *filp) {} 795 static inline int file_check_writeable(struct file *filp) 796 { 797 return 0; 798 } 799 #endif /* CONFIG_DEBUG_WRITECOUNT */ 800 801 #define MAX_NON_LFS ((1UL<<31) - 1) 802 803 /* Page cache limit. The filesystems should put that into their s_maxbytes 804 limits, otherwise bad things can happen in VM. */ 805 #if BITS_PER_LONG==32 806 #define MAX_LFS_FILESIZE (((loff_t)PAGE_CACHE_SIZE << (BITS_PER_LONG-1))-1) 807 #elif BITS_PER_LONG==64 808 #define MAX_LFS_FILESIZE ((loff_t)0x7fffffffffffffffLL) 809 #endif 810 811 #define FL_POSIX 1 812 #define FL_FLOCK 2 813 #define FL_ACCESS 8 /* not trying to lock, just looking */ 814 #define FL_EXISTS 16 /* when unlocking, test for existence */ 815 #define FL_LEASE 32 /* lease held on this file */ 816 #define FL_CLOSE 64 /* unlock on close */ 817 #define FL_SLEEP 128 /* A blocking lock */ 818 #define FL_DOWNGRADE_PENDING 256 /* Lease is being downgraded */ 819 #define FL_UNLOCK_PENDING 512 /* Lease is being broken */ 820 821 /* 822 * Special return value from posix_lock_file() and vfs_lock_file() for 823 * asynchronous locking. 824 */ 825 #define FILE_LOCK_DEFERRED 1 826 827 /* 828 * The POSIX file lock owner is determined by 829 * the "struct files_struct" in the thread group 830 * (or NULL for no owner - BSD locks). 831 * 832 * Lockd stuffs a "host" pointer into this. 833 */ 834 typedef struct files_struct *fl_owner_t; 835 836 struct file_lock_operations { 837 void (*fl_copy_lock)(struct file_lock *, struct file_lock *); 838 void (*fl_release_private)(struct file_lock *); 839 }; 840 841 struct lock_manager_operations { 842 int (*lm_compare_owner)(struct file_lock *, struct file_lock *); 843 void (*lm_notify)(struct file_lock *); /* unblock callback */ 844 int (*lm_grant)(struct file_lock *, struct file_lock *, int); 845 void (*lm_break)(struct file_lock *); 846 int (*lm_change)(struct file_lock **, int); 847 }; 848 849 struct lock_manager { 850 struct list_head list; 851 }; 852 853 struct net; 854 void locks_start_grace(struct net *, struct lock_manager *); 855 void locks_end_grace(struct lock_manager *); 856 int locks_in_grace(struct net *); 857 858 /* that will die - we need it for nfs_lock_info */ 859 #include <linux/nfs_fs_i.h> 860 861 struct file_lock { 862 struct file_lock *fl_next; /* singly linked list for this inode */ 863 struct list_head fl_link; /* doubly linked list of all locks */ 864 struct list_head fl_block; /* circular list of blocked processes */ 865 fl_owner_t fl_owner; 866 unsigned int fl_flags; 867 unsigned char fl_type; 868 unsigned int fl_pid; 869 struct pid *fl_nspid; 870 wait_queue_head_t fl_wait; 871 struct file *fl_file; 872 loff_t fl_start; 873 loff_t fl_end; 874 875 struct fasync_struct * fl_fasync; /* for lease break notifications */ 876 /* for lease breaks: */ 877 unsigned long fl_break_time; 878 unsigned long fl_downgrade_time; 879 880 const struct file_lock_operations *fl_ops; /* Callbacks for filesystems */ 881 const struct lock_manager_operations *fl_lmops; /* Callbacks for lockmanagers */ 882 union { 883 struct nfs_lock_info nfs_fl; 884 struct nfs4_lock_info nfs4_fl; 885 struct { 886 struct list_head link; /* link in AFS vnode's pending_locks list */ 887 int state; /* state of grant or error if -ve */ 888 } afs; 889 } fl_u; 890 }; 891 892 /* The following constant reflects the upper bound of the file/locking space */ 893 #ifndef OFFSET_MAX 894 #define INT_LIMIT(x) (~((x)1 << (sizeof(x)*8 - 1))) 895 #define OFFSET_MAX INT_LIMIT(loff_t) 896 #define OFFT_OFFSET_MAX INT_LIMIT(off_t) 897 #endif 898 899 #include <linux/fcntl.h> 900 901 extern void send_sigio(struct fown_struct *fown, int fd, int band); 902 903 #ifdef CONFIG_FILE_LOCKING 904 extern int fcntl_getlk(struct file *, struct flock __user *); 905 extern int fcntl_setlk(unsigned int, struct file *, unsigned int, 906 struct flock __user *); 907 908 #if BITS_PER_LONG == 32 909 extern int fcntl_getlk64(struct file *, struct flock64 __user *); 910 extern int fcntl_setlk64(unsigned int, struct file *, unsigned int, 911 struct flock64 __user *); 912 #endif 913 914 extern int fcntl_setlease(unsigned int fd, struct file *filp, long arg); 915 extern int fcntl_getlease(struct file *filp); 916 917 /* fs/locks.c */ 918 void locks_free_lock(struct file_lock *fl); 919 extern void locks_init_lock(struct file_lock *); 920 extern struct file_lock * locks_alloc_lock(void); 921 extern void locks_copy_lock(struct file_lock *, struct file_lock *); 922 extern void __locks_copy_lock(struct file_lock *, const struct file_lock *); 923 extern void locks_remove_posix(struct file *, fl_owner_t); 924 extern void locks_remove_flock(struct file *); 925 extern void locks_release_private(struct file_lock *); 926 extern void posix_test_lock(struct file *, struct file_lock *); 927 extern int posix_lock_file(struct file *, struct file_lock *, struct file_lock *); 928 extern int posix_lock_file_wait(struct file *, struct file_lock *); 929 extern int posix_unblock_lock(struct file *, struct file_lock *); 930 extern int vfs_test_lock(struct file *, struct file_lock *); 931 extern int vfs_lock_file(struct file *, unsigned int, struct file_lock *, struct file_lock *); 932 extern int vfs_cancel_lock(struct file *filp, struct file_lock *fl); 933 extern int flock_lock_file_wait(struct file *filp, struct file_lock *fl); 934 extern int __break_lease(struct inode *inode, unsigned int flags); 935 extern void lease_get_mtime(struct inode *, struct timespec *time); 936 extern int generic_setlease(struct file *, long, struct file_lock **); 937 extern int vfs_setlease(struct file *, long, struct file_lock **); 938 extern int lease_modify(struct file_lock **, int); 939 extern int lock_may_read(struct inode *, loff_t start, unsigned long count); 940 extern int lock_may_write(struct inode *, loff_t start, unsigned long count); 941 extern void locks_delete_block(struct file_lock *waiter); 942 extern void lock_flocks(void); 943 extern void unlock_flocks(void); 944 #else /* !CONFIG_FILE_LOCKING */ 945 static inline int fcntl_getlk(struct file *file, struct flock __user *user) 946 { 947 return -EINVAL; 948 } 949 950 static inline int fcntl_setlk(unsigned int fd, struct file *file, 951 unsigned int cmd, struct flock __user *user) 952 { 953 return -EACCES; 954 } 955 956 #if BITS_PER_LONG == 32 957 static inline int fcntl_getlk64(struct file *file, struct flock64 __user *user) 958 { 959 return -EINVAL; 960 } 961 962 static inline int fcntl_setlk64(unsigned int fd, struct file *file, 963 unsigned int cmd, struct flock64 __user *user) 964 { 965 return -EACCES; 966 } 967 #endif 968 static inline int fcntl_setlease(unsigned int fd, struct file *filp, long arg) 969 { 970 return 0; 971 } 972 973 static inline int fcntl_getlease(struct file *filp) 974 { 975 return 0; 976 } 977 978 static inline void locks_init_lock(struct file_lock *fl) 979 { 980 return; 981 } 982 983 static inline void __locks_copy_lock(struct file_lock *new, struct file_lock *fl) 984 { 985 return; 986 } 987 988 static inline void locks_copy_lock(struct file_lock *new, struct file_lock *fl) 989 { 990 return; 991 } 992 993 static inline void locks_remove_posix(struct file *filp, fl_owner_t owner) 994 { 995 return; 996 } 997 998 static inline void locks_remove_flock(struct file *filp) 999 { 1000 return; 1001 } 1002 1003 static inline void posix_test_lock(struct file *filp, struct file_lock *fl) 1004 { 1005 return; 1006 } 1007 1008 static inline int posix_lock_file(struct file *filp, struct file_lock *fl, 1009 struct file_lock *conflock) 1010 { 1011 return -ENOLCK; 1012 } 1013 1014 static inline int posix_lock_file_wait(struct file *filp, struct file_lock *fl) 1015 { 1016 return -ENOLCK; 1017 } 1018 1019 static inline int posix_unblock_lock(struct file *filp, 1020 struct file_lock *waiter) 1021 { 1022 return -ENOENT; 1023 } 1024 1025 static inline int vfs_test_lock(struct file *filp, struct file_lock *fl) 1026 { 1027 return 0; 1028 } 1029 1030 static inline int vfs_lock_file(struct file *filp, unsigned int cmd, 1031 struct file_lock *fl, struct file_lock *conf) 1032 { 1033 return -ENOLCK; 1034 } 1035 1036 static inline int vfs_cancel_lock(struct file *filp, struct file_lock *fl) 1037 { 1038 return 0; 1039 } 1040 1041 static inline int flock_lock_file_wait(struct file *filp, 1042 struct file_lock *request) 1043 { 1044 return -ENOLCK; 1045 } 1046 1047 static inline int __break_lease(struct inode *inode, unsigned int mode) 1048 { 1049 return 0; 1050 } 1051 1052 static inline void lease_get_mtime(struct inode *inode, struct timespec *time) 1053 { 1054 return; 1055 } 1056 1057 static inline int generic_setlease(struct file *filp, long arg, 1058 struct file_lock **flp) 1059 { 1060 return -EINVAL; 1061 } 1062 1063 static inline int vfs_setlease(struct file *filp, long arg, 1064 struct file_lock **lease) 1065 { 1066 return -EINVAL; 1067 } 1068 1069 static inline int lease_modify(struct file_lock **before, int arg) 1070 { 1071 return -EINVAL; 1072 } 1073 1074 static inline int lock_may_read(struct inode *inode, loff_t start, 1075 unsigned long len) 1076 { 1077 return 1; 1078 } 1079 1080 static inline int lock_may_write(struct inode *inode, loff_t start, 1081 unsigned long len) 1082 { 1083 return 1; 1084 } 1085 1086 static inline void locks_delete_block(struct file_lock *waiter) 1087 { 1088 } 1089 1090 static inline void lock_flocks(void) 1091 { 1092 } 1093 1094 static inline void unlock_flocks(void) 1095 { 1096 } 1097 1098 #endif /* !CONFIG_FILE_LOCKING */ 1099 1100 1101 struct fasync_struct { 1102 spinlock_t fa_lock; 1103 int magic; 1104 int fa_fd; 1105 struct fasync_struct *fa_next; /* singly linked list */ 1106 struct file *fa_file; 1107 struct rcu_head fa_rcu; 1108 }; 1109 1110 #define FASYNC_MAGIC 0x4601 1111 1112 /* SMP safe fasync helpers: */ 1113 extern int fasync_helper(int, struct file *, int, struct fasync_struct **); 1114 extern struct fasync_struct *fasync_insert_entry(int, struct file *, struct fasync_struct **, struct fasync_struct *); 1115 extern int fasync_remove_entry(struct file *, struct fasync_struct **); 1116 extern struct fasync_struct *fasync_alloc(void); 1117 extern void fasync_free(struct fasync_struct *); 1118 1119 /* can be called from interrupts */ 1120 extern void kill_fasync(struct fasync_struct **, int, int); 1121 1122 extern int __f_setown(struct file *filp, struct pid *, enum pid_type, int force); 1123 extern int f_setown(struct file *filp, unsigned long arg, int force); 1124 extern void f_delown(struct file *filp); 1125 extern pid_t f_getown(struct file *filp); 1126 extern int send_sigurg(struct fown_struct *fown); 1127 1128 struct mm_struct; 1129 1130 /* 1131 * Umount options 1132 */ 1133 1134 #define MNT_FORCE 0x00000001 /* Attempt to forcibily umount */ 1135 #define MNT_DETACH 0x00000002 /* Just detach from the tree */ 1136 #define MNT_EXPIRE 0x00000004 /* Mark for expiry */ 1137 #define UMOUNT_NOFOLLOW 0x00000008 /* Don't follow symlink on umount */ 1138 #define UMOUNT_UNUSED 0x80000000 /* Flag guaranteed to be unused */ 1139 1140 extern struct list_head super_blocks; 1141 extern spinlock_t sb_lock; 1142 1143 /* Possible states of 'frozen' field */ 1144 enum { 1145 SB_UNFROZEN = 0, /* FS is unfrozen */ 1146 SB_FREEZE_WRITE = 1, /* Writes, dir ops, ioctls frozen */ 1147 SB_FREEZE_PAGEFAULT = 2, /* Page faults stopped as well */ 1148 SB_FREEZE_FS = 3, /* For internal FS use (e.g. to stop 1149 * internal threads if needed) */ 1150 SB_FREEZE_COMPLETE = 4, /* ->freeze_fs finished successfully */ 1151 }; 1152 1153 #define SB_FREEZE_LEVELS (SB_FREEZE_COMPLETE - 1) 1154 1155 struct sb_writers { 1156 /* Counters for counting writers at each level */ 1157 struct percpu_counter counter[SB_FREEZE_LEVELS]; 1158 wait_queue_head_t wait; /* queue for waiting for 1159 writers / faults to finish */ 1160 int frozen; /* Is sb frozen? */ 1161 wait_queue_head_t wait_unfrozen; /* queue for waiting for 1162 sb to be thawed */ 1163 #ifdef CONFIG_DEBUG_LOCK_ALLOC 1164 struct lockdep_map lock_map[SB_FREEZE_LEVELS]; 1165 #endif 1166 }; 1167 1168 struct super_block { 1169 struct list_head s_list; /* Keep this first */ 1170 dev_t s_dev; /* search index; _not_ kdev_t */ 1171 unsigned char s_blocksize_bits; 1172 unsigned long s_blocksize; 1173 loff_t s_maxbytes; /* Max file size */ 1174 struct file_system_type *s_type; 1175 const struct super_operations *s_op; 1176 const struct dquot_operations *dq_op; 1177 const struct quotactl_ops *s_qcop; 1178 const struct export_operations *s_export_op; 1179 unsigned long s_flags; 1180 unsigned long s_magic; 1181 struct dentry *s_root; 1182 struct rw_semaphore s_umount; 1183 int s_count; 1184 atomic_t s_active; 1185 #ifdef CONFIG_SECURITY 1186 void *s_security; 1187 #endif 1188 const struct xattr_handler **s_xattr; 1189 1190 struct list_head s_inodes; /* all inodes */ 1191 struct hlist_bl_head s_anon; /* anonymous dentries for (nfs) exporting */ 1192 #ifdef CONFIG_SMP 1193 struct list_head __percpu *s_files; 1194 #else 1195 struct list_head s_files; 1196 #endif 1197 struct list_head s_mounts; /* list of mounts; _not_ for fs use */ 1198 /* s_dentry_lru, s_nr_dentry_unused protected by dcache.c lru locks */ 1199 struct list_head s_dentry_lru; /* unused dentry lru */ 1200 int s_nr_dentry_unused; /* # of dentry on lru */ 1201 1202 /* s_inode_lru_lock protects s_inode_lru and s_nr_inodes_unused */ 1203 spinlock_t s_inode_lru_lock ____cacheline_aligned_in_smp; 1204 struct list_head s_inode_lru; /* unused inode lru */ 1205 int s_nr_inodes_unused; /* # of inodes on lru */ 1206 1207 struct block_device *s_bdev; 1208 struct backing_dev_info *s_bdi; 1209 struct mtd_info *s_mtd; 1210 struct hlist_node s_instances; 1211 struct quota_info s_dquot; /* Diskquota specific options */ 1212 1213 struct sb_writers s_writers; 1214 1215 char s_id[32]; /* Informational name */ 1216 u8 s_uuid[16]; /* UUID */ 1217 1218 void *s_fs_info; /* Filesystem private info */ 1219 unsigned int s_max_links; 1220 fmode_t s_mode; 1221 1222 /* Granularity of c/m/atime in ns. 1223 Cannot be worse than a second */ 1224 u32 s_time_gran; 1225 1226 /* 1227 * The next field is for VFS *only*. No filesystems have any business 1228 * even looking at it. You had been warned. 1229 */ 1230 struct mutex s_vfs_rename_mutex; /* Kludge */ 1231 1232 /* 1233 * Filesystem subtype. If non-empty the filesystem type field 1234 * in /proc/mounts will be "type.subtype" 1235 */ 1236 char *s_subtype; 1237 1238 /* 1239 * Saved mount options for lazy filesystems using 1240 * generic_show_options() 1241 */ 1242 char __rcu *s_options; 1243 const struct dentry_operations *s_d_op; /* default d_op for dentries */ 1244 1245 /* 1246 * Saved pool identifier for cleancache (-1 means none) 1247 */ 1248 int cleancache_poolid; 1249 1250 struct shrinker s_shrink; /* per-sb shrinker handle */ 1251 1252 /* Number of inodes with nlink == 0 but still referenced */ 1253 atomic_long_t s_remove_count; 1254 1255 /* Being remounted read-only */ 1256 int s_readonly_remount; 1257 }; 1258 1259 /* superblock cache pruning functions */ 1260 extern void prune_icache_sb(struct super_block *sb, int nr_to_scan); 1261 extern void prune_dcache_sb(struct super_block *sb, int nr_to_scan); 1262 1263 extern struct timespec current_fs_time(struct super_block *sb); 1264 1265 /* 1266 * Snapshotting support. 1267 */ 1268 1269 void __sb_end_write(struct super_block *sb, int level); 1270 int __sb_start_write(struct super_block *sb, int level, bool wait); 1271 1272 /** 1273 * sb_end_write - drop write access to a superblock 1274 * @sb: the super we wrote to 1275 * 1276 * Decrement number of writers to the filesystem. Wake up possible waiters 1277 * wanting to freeze the filesystem. 1278 */ 1279 static inline void sb_end_write(struct super_block *sb) 1280 { 1281 __sb_end_write(sb, SB_FREEZE_WRITE); 1282 } 1283 1284 /** 1285 * sb_end_pagefault - drop write access to a superblock from a page fault 1286 * @sb: the super we wrote to 1287 * 1288 * Decrement number of processes handling write page fault to the filesystem. 1289 * Wake up possible waiters wanting to freeze the filesystem. 1290 */ 1291 static inline void sb_end_pagefault(struct super_block *sb) 1292 { 1293 __sb_end_write(sb, SB_FREEZE_PAGEFAULT); 1294 } 1295 1296 /** 1297 * sb_end_intwrite - drop write access to a superblock for internal fs purposes 1298 * @sb: the super we wrote to 1299 * 1300 * Decrement fs-internal number of writers to the filesystem. Wake up possible 1301 * waiters wanting to freeze the filesystem. 1302 */ 1303 static inline void sb_end_intwrite(struct super_block *sb) 1304 { 1305 __sb_end_write(sb, SB_FREEZE_FS); 1306 } 1307 1308 /** 1309 * sb_start_write - get write access to a superblock 1310 * @sb: the super we write to 1311 * 1312 * When a process wants to write data or metadata to a file system (i.e. dirty 1313 * a page or an inode), it should embed the operation in a sb_start_write() - 1314 * sb_end_write() pair to get exclusion against file system freezing. This 1315 * function increments number of writers preventing freezing. If the file 1316 * system is already frozen, the function waits until the file system is 1317 * thawed. 1318 * 1319 * Since freeze protection behaves as a lock, users have to preserve 1320 * ordering of freeze protection and other filesystem locks. Generally, 1321 * freeze protection should be the outermost lock. In particular, we have: 1322 * 1323 * sb_start_write 1324 * -> i_mutex (write path, truncate, directory ops, ...) 1325 * -> s_umount (freeze_super, thaw_super) 1326 */ 1327 static inline void sb_start_write(struct super_block *sb) 1328 { 1329 __sb_start_write(sb, SB_FREEZE_WRITE, true); 1330 } 1331 1332 static inline int sb_start_write_trylock(struct super_block *sb) 1333 { 1334 return __sb_start_write(sb, SB_FREEZE_WRITE, false); 1335 } 1336 1337 /** 1338 * sb_start_pagefault - get write access to a superblock from a page fault 1339 * @sb: the super we write to 1340 * 1341 * When a process starts handling write page fault, it should embed the 1342 * operation into sb_start_pagefault() - sb_end_pagefault() pair to get 1343 * exclusion against file system freezing. This is needed since the page fault 1344 * is going to dirty a page. This function increments number of running page 1345 * faults preventing freezing. If the file system is already frozen, the 1346 * function waits until the file system is thawed. 1347 * 1348 * Since page fault freeze protection behaves as a lock, users have to preserve 1349 * ordering of freeze protection and other filesystem locks. It is advised to 1350 * put sb_start_pagefault() close to mmap_sem in lock ordering. Page fault 1351 * handling code implies lock dependency: 1352 * 1353 * mmap_sem 1354 * -> sb_start_pagefault 1355 */ 1356 static inline void sb_start_pagefault(struct super_block *sb) 1357 { 1358 __sb_start_write(sb, SB_FREEZE_PAGEFAULT, true); 1359 } 1360 1361 /* 1362 * sb_start_intwrite - get write access to a superblock for internal fs purposes 1363 * @sb: the super we write to 1364 * 1365 * This is the third level of protection against filesystem freezing. It is 1366 * free for use by a filesystem. The only requirement is that it must rank 1367 * below sb_start_pagefault. 1368 * 1369 * For example filesystem can call sb_start_intwrite() when starting a 1370 * transaction which somewhat eases handling of freezing for internal sources 1371 * of filesystem changes (internal fs threads, discarding preallocation on file 1372 * close, etc.). 1373 */ 1374 static inline void sb_start_intwrite(struct super_block *sb) 1375 { 1376 __sb_start_write(sb, SB_FREEZE_FS, true); 1377 } 1378 1379 1380 extern bool inode_owner_or_capable(const struct inode *inode); 1381 1382 /* not quite ready to be deprecated, but... */ 1383 extern void lock_super(struct super_block *); 1384 extern void unlock_super(struct super_block *); 1385 1386 /* 1387 * VFS helper functions.. 1388 */ 1389 extern int vfs_create(struct inode *, struct dentry *, umode_t, bool); 1390 extern int vfs_mkdir(struct inode *, struct dentry *, umode_t); 1391 extern int vfs_mknod(struct inode *, struct dentry *, umode_t, dev_t); 1392 extern int vfs_symlink(struct inode *, struct dentry *, const char *); 1393 extern int vfs_link(struct dentry *, struct inode *, struct dentry *); 1394 extern int vfs_rmdir(struct inode *, struct dentry *); 1395 extern int vfs_unlink(struct inode *, struct dentry *); 1396 extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *); 1397 1398 /* 1399 * VFS dentry helper functions. 1400 */ 1401 extern void dentry_unhash(struct dentry *dentry); 1402 1403 /* 1404 * VFS file helper functions. 1405 */ 1406 extern void inode_init_owner(struct inode *inode, const struct inode *dir, 1407 umode_t mode); 1408 /* 1409 * VFS FS_IOC_FIEMAP helper definitions. 1410 */ 1411 struct fiemap_extent_info { 1412 unsigned int fi_flags; /* Flags as passed from user */ 1413 unsigned int fi_extents_mapped; /* Number of mapped extents */ 1414 unsigned int fi_extents_max; /* Size of fiemap_extent array */ 1415 struct fiemap_extent __user *fi_extents_start; /* Start of 1416 fiemap_extent array */ 1417 }; 1418 int fiemap_fill_next_extent(struct fiemap_extent_info *info, u64 logical, 1419 u64 phys, u64 len, u32 flags); 1420 int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags); 1421 1422 /* 1423 * File types 1424 * 1425 * NOTE! These match bits 12..15 of stat.st_mode 1426 * (ie "(i_mode >> 12) & 15"). 1427 */ 1428 #define DT_UNKNOWN 0 1429 #define DT_FIFO 1 1430 #define DT_CHR 2 1431 #define DT_DIR 4 1432 #define DT_BLK 6 1433 #define DT_REG 8 1434 #define DT_LNK 10 1435 #define DT_SOCK 12 1436 #define DT_WHT 14 1437 1438 /* 1439 * This is the "filldir" function type, used by readdir() to let 1440 * the kernel specify what kind of dirent layout it wants to have. 1441 * This allows the kernel to read directories into kernel space or 1442 * to have different dirent layouts depending on the binary type. 1443 */ 1444 typedef int (*filldir_t)(void *, const char *, int, loff_t, u64, unsigned); 1445 struct block_device_operations; 1446 1447 /* These macros are for out of kernel modules to test that 1448 * the kernel supports the unlocked_ioctl and compat_ioctl 1449 * fields in struct file_operations. */ 1450 #define HAVE_COMPAT_IOCTL 1 1451 #define HAVE_UNLOCKED_IOCTL 1 1452 1453 struct file_operations { 1454 struct module *owner; 1455 loff_t (*llseek) (struct file *, loff_t, int); 1456 ssize_t (*read) (struct file *, char __user *, size_t, loff_t *); 1457 ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *); 1458 ssize_t (*aio_read) (struct kiocb *, const struct iovec *, unsigned long, loff_t); 1459 ssize_t (*aio_write) (struct kiocb *, const struct iovec *, unsigned long, loff_t); 1460 int (*readdir) (struct file *, void *, filldir_t); 1461 unsigned int (*poll) (struct file *, struct poll_table_struct *); 1462 long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long); 1463 long (*compat_ioctl) (struct file *, unsigned int, unsigned long); 1464 int (*mmap) (struct file *, struct vm_area_struct *); 1465 int (*open) (struct inode *, struct file *); 1466 int (*flush) (struct file *, fl_owner_t id); 1467 int (*release) (struct inode *, struct file *); 1468 int (*fsync) (struct file *, loff_t, loff_t, int datasync); 1469 int (*aio_fsync) (struct kiocb *, int datasync); 1470 int (*fasync) (int, struct file *, int); 1471 int (*lock) (struct file *, int, struct file_lock *); 1472 ssize_t (*sendpage) (struct file *, struct page *, int, size_t, loff_t *, int); 1473 unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long); 1474 int (*check_flags)(int); 1475 int (*flock) (struct file *, int, struct file_lock *); 1476 ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int); 1477 ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int); 1478 int (*setlease)(struct file *, long, struct file_lock **); 1479 long (*fallocate)(struct file *file, int mode, loff_t offset, 1480 loff_t len); 1481 }; 1482 1483 struct inode_operations { 1484 struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int); 1485 void * (*follow_link) (struct dentry *, struct nameidata *); 1486 int (*permission) (struct inode *, int); 1487 struct posix_acl * (*get_acl)(struct inode *, int); 1488 1489 int (*readlink) (struct dentry *, char __user *,int); 1490 void (*put_link) (struct dentry *, struct nameidata *, void *); 1491 1492 int (*create) (struct inode *,struct dentry *, umode_t, bool); 1493 int (*link) (struct dentry *,struct inode *,struct dentry *); 1494 int (*unlink) (struct inode *,struct dentry *); 1495 int (*symlink) (struct inode *,struct dentry *,const char *); 1496 int (*mkdir) (struct inode *,struct dentry *,umode_t); 1497 int (*rmdir) (struct inode *,struct dentry *); 1498 int (*mknod) (struct inode *,struct dentry *,umode_t,dev_t); 1499 int (*rename) (struct inode *, struct dentry *, 1500 struct inode *, struct dentry *); 1501 void (*truncate) (struct inode *); 1502 int (*setattr) (struct dentry *, struct iattr *); 1503 int (*getattr) (struct vfsmount *mnt, struct dentry *, struct kstat *); 1504 int (*setxattr) (struct dentry *, const char *,const void *,size_t,int); 1505 ssize_t (*getxattr) (struct dentry *, const char *, void *, size_t); 1506 ssize_t (*listxattr) (struct dentry *, char *, size_t); 1507 int (*removexattr) (struct dentry *, const char *); 1508 int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start, 1509 u64 len); 1510 int (*update_time)(struct inode *, struct timespec *, int); 1511 int (*atomic_open)(struct inode *, struct dentry *, 1512 struct file *, unsigned open_flag, 1513 umode_t create_mode, int *opened); 1514 } ____cacheline_aligned; 1515 1516 struct seq_file; 1517 1518 ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector, 1519 unsigned long nr_segs, unsigned long fast_segs, 1520 struct iovec *fast_pointer, 1521 struct iovec **ret_pointer); 1522 1523 extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *); 1524 extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *); 1525 extern ssize_t vfs_readv(struct file *, const struct iovec __user *, 1526 unsigned long, loff_t *); 1527 extern ssize_t vfs_writev(struct file *, const struct iovec __user *, 1528 unsigned long, loff_t *); 1529 1530 struct super_operations { 1531 struct inode *(*alloc_inode)(struct super_block *sb); 1532 void (*destroy_inode)(struct inode *); 1533 1534 void (*dirty_inode) (struct inode *, int flags); 1535 int (*write_inode) (struct inode *, struct writeback_control *wbc); 1536 int (*drop_inode) (struct inode *); 1537 void (*evict_inode) (struct inode *); 1538 void (*put_super) (struct super_block *); 1539 int (*sync_fs)(struct super_block *sb, int wait); 1540 int (*freeze_fs) (struct super_block *); 1541 int (*unfreeze_fs) (struct super_block *); 1542 int (*statfs) (struct dentry *, struct kstatfs *); 1543 int (*remount_fs) (struct super_block *, int *, char *); 1544 void (*umount_begin) (struct super_block *); 1545 1546 int (*show_options)(struct seq_file *, struct dentry *); 1547 int (*show_devname)(struct seq_file *, struct dentry *); 1548 int (*show_path)(struct seq_file *, struct dentry *); 1549 int (*show_stats)(struct seq_file *, struct dentry *); 1550 #ifdef CONFIG_QUOTA 1551 ssize_t (*quota_read)(struct super_block *, int, char *, size_t, loff_t); 1552 ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t); 1553 #endif 1554 int (*bdev_try_to_free_page)(struct super_block*, struct page*, gfp_t); 1555 int (*nr_cached_objects)(struct super_block *); 1556 void (*free_cached_objects)(struct super_block *, int); 1557 }; 1558 1559 /* 1560 * Inode state bits. Protected by inode->i_lock 1561 * 1562 * Three bits determine the dirty state of the inode, I_DIRTY_SYNC, 1563 * I_DIRTY_DATASYNC and I_DIRTY_PAGES. 1564 * 1565 * Four bits define the lifetime of an inode. Initially, inodes are I_NEW, 1566 * until that flag is cleared. I_WILL_FREE, I_FREEING and I_CLEAR are set at 1567 * various stages of removing an inode. 1568 * 1569 * Two bits are used for locking and completion notification, I_NEW and I_SYNC. 1570 * 1571 * I_DIRTY_SYNC Inode is dirty, but doesn't have to be written on 1572 * fdatasync(). i_atime is the usual cause. 1573 * I_DIRTY_DATASYNC Data-related inode changes pending. We keep track of 1574 * these changes separately from I_DIRTY_SYNC so that we 1575 * don't have to write inode on fdatasync() when only 1576 * mtime has changed in it. 1577 * I_DIRTY_PAGES Inode has dirty pages. Inode itself may be clean. 1578 * I_NEW Serves as both a mutex and completion notification. 1579 * New inodes set I_NEW. If two processes both create 1580 * the same inode, one of them will release its inode and 1581 * wait for I_NEW to be released before returning. 1582 * Inodes in I_WILL_FREE, I_FREEING or I_CLEAR state can 1583 * also cause waiting on I_NEW, without I_NEW actually 1584 * being set. find_inode() uses this to prevent returning 1585 * nearly-dead inodes. 1586 * I_WILL_FREE Must be set when calling write_inode_now() if i_count 1587 * is zero. I_FREEING must be set when I_WILL_FREE is 1588 * cleared. 1589 * I_FREEING Set when inode is about to be freed but still has dirty 1590 * pages or buffers attached or the inode itself is still 1591 * dirty. 1592 * I_CLEAR Added by clear_inode(). In this state the inode is 1593 * clean and can be destroyed. Inode keeps I_FREEING. 1594 * 1595 * Inodes that are I_WILL_FREE, I_FREEING or I_CLEAR are 1596 * prohibited for many purposes. iget() must wait for 1597 * the inode to be completely released, then create it 1598 * anew. Other functions will just ignore such inodes, 1599 * if appropriate. I_NEW is used for waiting. 1600 * 1601 * I_SYNC Writeback of inode is running. The bit is set during 1602 * data writeback, and cleared with a wakeup on the bit 1603 * address once it is done. The bit is also used to pin 1604 * the inode in memory for flusher thread. 1605 * 1606 * I_REFERENCED Marks the inode as recently references on the LRU list. 1607 * 1608 * I_DIO_WAKEUP Never set. Only used as a key for wait_on_bit(). 1609 * 1610 * Q: What is the difference between I_WILL_FREE and I_FREEING? 1611 */ 1612 #define I_DIRTY_SYNC (1 << 0) 1613 #define I_DIRTY_DATASYNC (1 << 1) 1614 #define I_DIRTY_PAGES (1 << 2) 1615 #define __I_NEW 3 1616 #define I_NEW (1 << __I_NEW) 1617 #define I_WILL_FREE (1 << 4) 1618 #define I_FREEING (1 << 5) 1619 #define I_CLEAR (1 << 6) 1620 #define __I_SYNC 7 1621 #define I_SYNC (1 << __I_SYNC) 1622 #define I_REFERENCED (1 << 8) 1623 #define __I_DIO_WAKEUP 9 1624 #define I_DIO_WAKEUP (1 << I_DIO_WAKEUP) 1625 1626 #define I_DIRTY (I_DIRTY_SYNC | I_DIRTY_DATASYNC | I_DIRTY_PAGES) 1627 1628 extern void __mark_inode_dirty(struct inode *, int); 1629 static inline void mark_inode_dirty(struct inode *inode) 1630 { 1631 __mark_inode_dirty(inode, I_DIRTY); 1632 } 1633 1634 static inline void mark_inode_dirty_sync(struct inode *inode) 1635 { 1636 __mark_inode_dirty(inode, I_DIRTY_SYNC); 1637 } 1638 1639 extern void inc_nlink(struct inode *inode); 1640 extern void drop_nlink(struct inode *inode); 1641 extern void clear_nlink(struct inode *inode); 1642 extern void set_nlink(struct inode *inode, unsigned int nlink); 1643 1644 static inline void inode_inc_link_count(struct inode *inode) 1645 { 1646 inc_nlink(inode); 1647 mark_inode_dirty(inode); 1648 } 1649 1650 static inline void inode_dec_link_count(struct inode *inode) 1651 { 1652 drop_nlink(inode); 1653 mark_inode_dirty(inode); 1654 } 1655 1656 /** 1657 * inode_inc_iversion - increments i_version 1658 * @inode: inode that need to be updated 1659 * 1660 * Every time the inode is modified, the i_version field will be incremented. 1661 * The filesystem has to be mounted with i_version flag 1662 */ 1663 1664 static inline void inode_inc_iversion(struct inode *inode) 1665 { 1666 spin_lock(&inode->i_lock); 1667 inode->i_version++; 1668 spin_unlock(&inode->i_lock); 1669 } 1670 1671 enum file_time_flags { 1672 S_ATIME = 1, 1673 S_MTIME = 2, 1674 S_CTIME = 4, 1675 S_VERSION = 8, 1676 }; 1677 1678 extern void touch_atime(struct path *); 1679 static inline void file_accessed(struct file *file) 1680 { 1681 if (!(file->f_flags & O_NOATIME)) 1682 touch_atime(&file->f_path); 1683 } 1684 1685 int sync_inode(struct inode *inode, struct writeback_control *wbc); 1686 int sync_inode_metadata(struct inode *inode, int wait); 1687 1688 struct file_system_type { 1689 const char *name; 1690 int fs_flags; 1691 struct dentry *(*mount) (struct file_system_type *, int, 1692 const char *, void *); 1693 void (*kill_sb) (struct super_block *); 1694 struct module *owner; 1695 struct file_system_type * next; 1696 struct hlist_head fs_supers; 1697 1698 struct lock_class_key s_lock_key; 1699 struct lock_class_key s_umount_key; 1700 struct lock_class_key s_vfs_rename_key; 1701 struct lock_class_key s_writers_key[SB_FREEZE_LEVELS]; 1702 1703 struct lock_class_key i_lock_key; 1704 struct lock_class_key i_mutex_key; 1705 struct lock_class_key i_mutex_dir_key; 1706 }; 1707 1708 extern struct dentry *mount_ns(struct file_system_type *fs_type, int flags, 1709 void *data, int (*fill_super)(struct super_block *, void *, int)); 1710 extern struct dentry *mount_bdev(struct file_system_type *fs_type, 1711 int flags, const char *dev_name, void *data, 1712 int (*fill_super)(struct super_block *, void *, int)); 1713 extern struct dentry *mount_single(struct file_system_type *fs_type, 1714 int flags, void *data, 1715 int (*fill_super)(struct super_block *, void *, int)); 1716 extern struct dentry *mount_nodev(struct file_system_type *fs_type, 1717 int flags, void *data, 1718 int (*fill_super)(struct super_block *, void *, int)); 1719 extern struct dentry *mount_subtree(struct vfsmount *mnt, const char *path); 1720 void generic_shutdown_super(struct super_block *sb); 1721 void kill_block_super(struct super_block *sb); 1722 void kill_anon_super(struct super_block *sb); 1723 void kill_litter_super(struct super_block *sb); 1724 void deactivate_super(struct super_block *sb); 1725 void deactivate_locked_super(struct super_block *sb); 1726 int set_anon_super(struct super_block *s, void *data); 1727 int get_anon_bdev(dev_t *); 1728 void free_anon_bdev(dev_t); 1729 struct super_block *sget(struct file_system_type *type, 1730 int (*test)(struct super_block *,void *), 1731 int (*set)(struct super_block *,void *), 1732 int flags, void *data); 1733 extern struct dentry *mount_pseudo(struct file_system_type *, char *, 1734 const struct super_operations *ops, 1735 const struct dentry_operations *dops, 1736 unsigned long); 1737 1738 /* Alas, no aliases. Too much hassle with bringing module.h everywhere */ 1739 #define fops_get(fops) \ 1740 (((fops) && try_module_get((fops)->owner) ? (fops) : NULL)) 1741 #define fops_put(fops) \ 1742 do { if (fops) module_put((fops)->owner); } while(0) 1743 1744 extern int register_filesystem(struct file_system_type *); 1745 extern int unregister_filesystem(struct file_system_type *); 1746 extern struct vfsmount *kern_mount_data(struct file_system_type *, void *data); 1747 #define kern_mount(type) kern_mount_data(type, NULL) 1748 extern void kern_unmount(struct vfsmount *mnt); 1749 extern int may_umount_tree(struct vfsmount *); 1750 extern int may_umount(struct vfsmount *); 1751 extern long do_mount(const char *, const char *, const char *, unsigned long, void *); 1752 extern struct vfsmount *collect_mounts(struct path *); 1753 extern void drop_collected_mounts(struct vfsmount *); 1754 extern int iterate_mounts(int (*)(struct vfsmount *, void *), void *, 1755 struct vfsmount *); 1756 extern int vfs_statfs(struct path *, struct kstatfs *); 1757 extern int user_statfs(const char __user *, struct kstatfs *); 1758 extern int fd_statfs(int, struct kstatfs *); 1759 extern int vfs_ustat(dev_t, struct kstatfs *); 1760 extern int freeze_super(struct super_block *super); 1761 extern int thaw_super(struct super_block *super); 1762 extern bool our_mnt(struct vfsmount *mnt); 1763 1764 extern int current_umask(void); 1765 1766 /* /sys/fs */ 1767 extern struct kobject *fs_kobj; 1768 1769 #define MAX_RW_COUNT (INT_MAX & PAGE_CACHE_MASK) 1770 extern int rw_verify_area(int, struct file *, loff_t *, size_t); 1771 1772 #define FLOCK_VERIFY_READ 1 1773 #define FLOCK_VERIFY_WRITE 2 1774 1775 #ifdef CONFIG_FILE_LOCKING 1776 extern int locks_mandatory_locked(struct inode *); 1777 extern int locks_mandatory_area(int, struct inode *, struct file *, loff_t, size_t); 1778 1779 /* 1780 * Candidates for mandatory locking have the setgid bit set 1781 * but no group execute bit - an otherwise meaningless combination. 1782 */ 1783 1784 static inline int __mandatory_lock(struct inode *ino) 1785 { 1786 return (ino->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID; 1787 } 1788 1789 /* 1790 * ... and these candidates should be on MS_MANDLOCK mounted fs, 1791 * otherwise these will be advisory locks 1792 */ 1793 1794 static inline int mandatory_lock(struct inode *ino) 1795 { 1796 return IS_MANDLOCK(ino) && __mandatory_lock(ino); 1797 } 1798 1799 static inline int locks_verify_locked(struct inode *inode) 1800 { 1801 if (mandatory_lock(inode)) 1802 return locks_mandatory_locked(inode); 1803 return 0; 1804 } 1805 1806 static inline int locks_verify_truncate(struct inode *inode, 1807 struct file *filp, 1808 loff_t size) 1809 { 1810 if (inode->i_flock && mandatory_lock(inode)) 1811 return locks_mandatory_area( 1812 FLOCK_VERIFY_WRITE, inode, filp, 1813 size < inode->i_size ? size : inode->i_size, 1814 (size < inode->i_size ? inode->i_size - size 1815 : size - inode->i_size) 1816 ); 1817 return 0; 1818 } 1819 1820 static inline int break_lease(struct inode *inode, unsigned int mode) 1821 { 1822 if (inode->i_flock) 1823 return __break_lease(inode, mode); 1824 return 0; 1825 } 1826 #else /* !CONFIG_FILE_LOCKING */ 1827 static inline int locks_mandatory_locked(struct inode *inode) 1828 { 1829 return 0; 1830 } 1831 1832 static inline int locks_mandatory_area(int rw, struct inode *inode, 1833 struct file *filp, loff_t offset, 1834 size_t count) 1835 { 1836 return 0; 1837 } 1838 1839 static inline int __mandatory_lock(struct inode *inode) 1840 { 1841 return 0; 1842 } 1843 1844 static inline int mandatory_lock(struct inode *inode) 1845 { 1846 return 0; 1847 } 1848 1849 static inline int locks_verify_locked(struct inode *inode) 1850 { 1851 return 0; 1852 } 1853 1854 static inline int locks_verify_truncate(struct inode *inode, struct file *filp, 1855 size_t size) 1856 { 1857 return 0; 1858 } 1859 1860 static inline int break_lease(struct inode *inode, unsigned int mode) 1861 { 1862 return 0; 1863 } 1864 1865 #endif /* CONFIG_FILE_LOCKING */ 1866 1867 /* fs/open.c */ 1868 struct audit_names; 1869 struct filename { 1870 const char *name; /* pointer to actual string */ 1871 const __user char *uptr; /* original userland pointer */ 1872 struct audit_names *aname; 1873 bool separate; /* should "name" be freed? */ 1874 }; 1875 1876 extern int do_truncate(struct dentry *, loff_t start, unsigned int time_attrs, 1877 struct file *filp); 1878 extern int do_fallocate(struct file *file, int mode, loff_t offset, 1879 loff_t len); 1880 extern long do_sys_open(int dfd, const char __user *filename, int flags, 1881 umode_t mode); 1882 extern struct file *file_open_name(struct filename *, int, umode_t); 1883 extern struct file *filp_open(const char *, int, umode_t); 1884 extern struct file *file_open_root(struct dentry *, struct vfsmount *, 1885 const char *, int); 1886 extern struct file * dentry_open(const struct path *, int, const struct cred *); 1887 extern int filp_close(struct file *, fl_owner_t id); 1888 1889 extern struct filename *getname(const char __user *); 1890 1891 enum { 1892 FILE_CREATED = 1, 1893 FILE_OPENED = 2 1894 }; 1895 extern int finish_open(struct file *file, struct dentry *dentry, 1896 int (*open)(struct inode *, struct file *), 1897 int *opened); 1898 extern int finish_no_open(struct file *file, struct dentry *dentry); 1899 1900 /* fs/ioctl.c */ 1901 1902 extern int ioctl_preallocate(struct file *filp, void __user *argp); 1903 1904 /* fs/dcache.c */ 1905 extern void __init vfs_caches_init_early(void); 1906 extern void __init vfs_caches_init(unsigned long); 1907 1908 extern struct kmem_cache *names_cachep; 1909 1910 extern void final_putname(struct filename *name); 1911 1912 #define __getname() kmem_cache_alloc(names_cachep, GFP_KERNEL) 1913 #define __putname(name) kmem_cache_free(names_cachep, (void *)(name)) 1914 #ifndef CONFIG_AUDITSYSCALL 1915 #define putname(name) final_putname(name) 1916 #else 1917 extern void putname(struct filename *name); 1918 #endif 1919 1920 #ifdef CONFIG_BLOCK 1921 extern int register_blkdev(unsigned int, const char *); 1922 extern void unregister_blkdev(unsigned int, const char *); 1923 extern struct block_device *bdget(dev_t); 1924 extern struct block_device *bdgrab(struct block_device *bdev); 1925 extern void bd_set_size(struct block_device *, loff_t size); 1926 extern sector_t blkdev_max_block(struct block_device *bdev); 1927 extern void bd_forget(struct inode *inode); 1928 extern void bdput(struct block_device *); 1929 extern void invalidate_bdev(struct block_device *); 1930 extern void iterate_bdevs(void (*)(struct block_device *, void *), void *); 1931 extern int sync_blockdev(struct block_device *bdev); 1932 extern void kill_bdev(struct block_device *); 1933 extern struct super_block *freeze_bdev(struct block_device *); 1934 extern void emergency_thaw_all(void); 1935 extern int thaw_bdev(struct block_device *bdev, struct super_block *sb); 1936 extern int fsync_bdev(struct block_device *); 1937 #else 1938 static inline void bd_forget(struct inode *inode) {} 1939 static inline int sync_blockdev(struct block_device *bdev) { return 0; } 1940 static inline void kill_bdev(struct block_device *bdev) {} 1941 static inline void invalidate_bdev(struct block_device *bdev) {} 1942 1943 static inline struct super_block *freeze_bdev(struct block_device *sb) 1944 { 1945 return NULL; 1946 } 1947 1948 static inline int thaw_bdev(struct block_device *bdev, struct super_block *sb) 1949 { 1950 return 0; 1951 } 1952 1953 static inline void iterate_bdevs(void (*f)(struct block_device *, void *), void *arg) 1954 { 1955 } 1956 #endif 1957 extern int sync_filesystem(struct super_block *); 1958 extern const struct file_operations def_blk_fops; 1959 extern const struct file_operations def_chr_fops; 1960 extern const struct file_operations bad_sock_fops; 1961 extern const struct file_operations def_fifo_fops; 1962 #ifdef CONFIG_BLOCK 1963 extern int ioctl_by_bdev(struct block_device *, unsigned, unsigned long); 1964 extern int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long); 1965 extern long compat_blkdev_ioctl(struct file *, unsigned, unsigned long); 1966 extern int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder); 1967 extern struct block_device *blkdev_get_by_path(const char *path, fmode_t mode, 1968 void *holder); 1969 extern struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, 1970 void *holder); 1971 extern int blkdev_put(struct block_device *bdev, fmode_t mode); 1972 #ifdef CONFIG_SYSFS 1973 extern int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk); 1974 extern void bd_unlink_disk_holder(struct block_device *bdev, 1975 struct gendisk *disk); 1976 #else 1977 static inline int bd_link_disk_holder(struct block_device *bdev, 1978 struct gendisk *disk) 1979 { 1980 return 0; 1981 } 1982 static inline void bd_unlink_disk_holder(struct block_device *bdev, 1983 struct gendisk *disk) 1984 { 1985 } 1986 #endif 1987 #endif 1988 1989 /* fs/char_dev.c */ 1990 #define CHRDEV_MAJOR_HASH_SIZE 255 1991 extern int alloc_chrdev_region(dev_t *, unsigned, unsigned, const char *); 1992 extern int register_chrdev_region(dev_t, unsigned, const char *); 1993 extern int __register_chrdev(unsigned int major, unsigned int baseminor, 1994 unsigned int count, const char *name, 1995 const struct file_operations *fops); 1996 extern void __unregister_chrdev(unsigned int major, unsigned int baseminor, 1997 unsigned int count, const char *name); 1998 extern void unregister_chrdev_region(dev_t, unsigned); 1999 extern void chrdev_show(struct seq_file *,off_t); 2000 2001 static inline int register_chrdev(unsigned int major, const char *name, 2002 const struct file_operations *fops) 2003 { 2004 return __register_chrdev(major, 0, 256, name, fops); 2005 } 2006 2007 static inline void unregister_chrdev(unsigned int major, const char *name) 2008 { 2009 __unregister_chrdev(major, 0, 256, name); 2010 } 2011 2012 /* fs/block_dev.c */ 2013 #define BDEVNAME_SIZE 32 /* Largest string for a blockdev identifier */ 2014 #define BDEVT_SIZE 10 /* Largest string for MAJ:MIN for blkdev */ 2015 2016 #ifdef CONFIG_BLOCK 2017 #define BLKDEV_MAJOR_HASH_SIZE 255 2018 extern const char *__bdevname(dev_t, char *buffer); 2019 extern const char *bdevname(struct block_device *bdev, char *buffer); 2020 extern struct block_device *lookup_bdev(const char *); 2021 extern void blkdev_show(struct seq_file *,off_t); 2022 2023 #else 2024 #define BLKDEV_MAJOR_HASH_SIZE 0 2025 #endif 2026 2027 extern void init_special_inode(struct inode *, umode_t, dev_t); 2028 2029 /* Invalid inode operations -- fs/bad_inode.c */ 2030 extern void make_bad_inode(struct inode *); 2031 extern int is_bad_inode(struct inode *); 2032 2033 extern const struct file_operations read_pipefifo_fops; 2034 extern const struct file_operations write_pipefifo_fops; 2035 extern const struct file_operations rdwr_pipefifo_fops; 2036 2037 #ifdef CONFIG_BLOCK 2038 /* 2039 * return READ, READA, or WRITE 2040 */ 2041 #define bio_rw(bio) ((bio)->bi_rw & (RW_MASK | RWA_MASK)) 2042 2043 /* 2044 * return data direction, READ or WRITE 2045 */ 2046 #define bio_data_dir(bio) ((bio)->bi_rw & 1) 2047 2048 extern void check_disk_size_change(struct gendisk *disk, 2049 struct block_device *bdev); 2050 extern int revalidate_disk(struct gendisk *); 2051 extern int check_disk_change(struct block_device *); 2052 extern int __invalidate_device(struct block_device *, bool); 2053 extern int invalidate_partition(struct gendisk *, int); 2054 #endif 2055 unsigned long invalidate_mapping_pages(struct address_space *mapping, 2056 pgoff_t start, pgoff_t end); 2057 2058 static inline void invalidate_remote_inode(struct inode *inode) 2059 { 2060 if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 2061 S_ISLNK(inode->i_mode)) 2062 invalidate_mapping_pages(inode->i_mapping, 0, -1); 2063 } 2064 extern int invalidate_inode_pages2(struct address_space *mapping); 2065 extern int invalidate_inode_pages2_range(struct address_space *mapping, 2066 pgoff_t start, pgoff_t end); 2067 extern int write_inode_now(struct inode *, int); 2068 extern int filemap_fdatawrite(struct address_space *); 2069 extern int filemap_flush(struct address_space *); 2070 extern int filemap_fdatawait(struct address_space *); 2071 extern int filemap_fdatawait_range(struct address_space *, loff_t lstart, 2072 loff_t lend); 2073 extern int filemap_write_and_wait(struct address_space *mapping); 2074 extern int filemap_write_and_wait_range(struct address_space *mapping, 2075 loff_t lstart, loff_t lend); 2076 extern int __filemap_fdatawrite_range(struct address_space *mapping, 2077 loff_t start, loff_t end, int sync_mode); 2078 extern int filemap_fdatawrite_range(struct address_space *mapping, 2079 loff_t start, loff_t end); 2080 2081 extern int vfs_fsync_range(struct file *file, loff_t start, loff_t end, 2082 int datasync); 2083 extern int vfs_fsync(struct file *file, int datasync); 2084 extern int generic_write_sync(struct file *file, loff_t pos, loff_t count); 2085 extern void emergency_sync(void); 2086 extern void emergency_remount(void); 2087 #ifdef CONFIG_BLOCK 2088 extern sector_t bmap(struct inode *, sector_t); 2089 #endif 2090 extern int notify_change(struct dentry *, struct iattr *); 2091 extern int inode_permission(struct inode *, int); 2092 extern int generic_permission(struct inode *, int); 2093 2094 static inline bool execute_ok(struct inode *inode) 2095 { 2096 return (inode->i_mode & S_IXUGO) || S_ISDIR(inode->i_mode); 2097 } 2098 2099 /* 2100 * get_write_access() gets write permission for a file. 2101 * put_write_access() releases this write permission. 2102 * This is used for regular files. 2103 * We cannot support write (and maybe mmap read-write shared) accesses and 2104 * MAP_DENYWRITE mmappings simultaneously. The i_writecount field of an inode 2105 * can have the following values: 2106 * 0: no writers, no VM_DENYWRITE mappings 2107 * < 0: (-i_writecount) vm_area_structs with VM_DENYWRITE set exist 2108 * > 0: (i_writecount) users are writing to the file. 2109 * 2110 * Normally we operate on that counter with atomic_{inc,dec} and it's safe 2111 * except for the cases where we don't hold i_writecount yet. Then we need to 2112 * use {get,deny}_write_access() - these functions check the sign and refuse 2113 * to do the change if sign is wrong. 2114 */ 2115 static inline int get_write_access(struct inode *inode) 2116 { 2117 return atomic_inc_unless_negative(&inode->i_writecount) ? 0 : -ETXTBSY; 2118 } 2119 static inline int deny_write_access(struct file *file) 2120 { 2121 struct inode *inode = file->f_path.dentry->d_inode; 2122 return atomic_dec_unless_positive(&inode->i_writecount) ? 0 : -ETXTBSY; 2123 } 2124 static inline void put_write_access(struct inode * inode) 2125 { 2126 atomic_dec(&inode->i_writecount); 2127 } 2128 static inline void allow_write_access(struct file *file) 2129 { 2130 if (file) 2131 atomic_inc(&file->f_path.dentry->d_inode->i_writecount); 2132 } 2133 #ifdef CONFIG_IMA 2134 static inline void i_readcount_dec(struct inode *inode) 2135 { 2136 BUG_ON(!atomic_read(&inode->i_readcount)); 2137 atomic_dec(&inode->i_readcount); 2138 } 2139 static inline void i_readcount_inc(struct inode *inode) 2140 { 2141 atomic_inc(&inode->i_readcount); 2142 } 2143 #else 2144 static inline void i_readcount_dec(struct inode *inode) 2145 { 2146 return; 2147 } 2148 static inline void i_readcount_inc(struct inode *inode) 2149 { 2150 return; 2151 } 2152 #endif 2153 extern int do_pipe_flags(int *, int); 2154 2155 extern int kernel_read(struct file *, loff_t, char *, unsigned long); 2156 extern struct file * open_exec(const char *); 2157 2158 /* fs/dcache.c -- generic fs support functions */ 2159 extern int is_subdir(struct dentry *, struct dentry *); 2160 extern int path_is_under(struct path *, struct path *); 2161 extern ino_t find_inode_number(struct dentry *, struct qstr *); 2162 2163 #include <linux/err.h> 2164 2165 /* needed for stackable file system support */ 2166 extern loff_t default_llseek(struct file *file, loff_t offset, int origin); 2167 2168 extern loff_t vfs_llseek(struct file *file, loff_t offset, int origin); 2169 2170 extern int inode_init_always(struct super_block *, struct inode *); 2171 extern void inode_init_once(struct inode *); 2172 extern void address_space_init_once(struct address_space *mapping); 2173 extern void ihold(struct inode * inode); 2174 extern void iput(struct inode *); 2175 extern struct inode * igrab(struct inode *); 2176 extern ino_t iunique(struct super_block *, ino_t); 2177 extern int inode_needs_sync(struct inode *inode); 2178 extern int generic_delete_inode(struct inode *inode); 2179 static inline int generic_drop_inode(struct inode *inode) 2180 { 2181 return !inode->i_nlink || inode_unhashed(inode); 2182 } 2183 2184 extern struct inode *ilookup5_nowait(struct super_block *sb, 2185 unsigned long hashval, int (*test)(struct inode *, void *), 2186 void *data); 2187 extern struct inode *ilookup5(struct super_block *sb, unsigned long hashval, 2188 int (*test)(struct inode *, void *), void *data); 2189 extern struct inode *ilookup(struct super_block *sb, unsigned long ino); 2190 2191 extern struct inode * iget5_locked(struct super_block *, unsigned long, int (*test)(struct inode *, void *), int (*set)(struct inode *, void *), void *); 2192 extern struct inode * iget_locked(struct super_block *, unsigned long); 2193 extern int insert_inode_locked4(struct inode *, unsigned long, int (*test)(struct inode *, void *), void *); 2194 extern int insert_inode_locked(struct inode *); 2195 #ifdef CONFIG_DEBUG_LOCK_ALLOC 2196 extern void lockdep_annotate_inode_mutex_key(struct inode *inode); 2197 #else 2198 static inline void lockdep_annotate_inode_mutex_key(struct inode *inode) { }; 2199 #endif 2200 extern void unlock_new_inode(struct inode *); 2201 extern unsigned int get_next_ino(void); 2202 2203 extern void __iget(struct inode * inode); 2204 extern void iget_failed(struct inode *); 2205 extern void clear_inode(struct inode *); 2206 extern void __destroy_inode(struct inode *); 2207 extern struct inode *new_inode_pseudo(struct super_block *sb); 2208 extern struct inode *new_inode(struct super_block *sb); 2209 extern void free_inode_nonrcu(struct inode *inode); 2210 extern int should_remove_suid(struct dentry *); 2211 extern int file_remove_suid(struct file *); 2212 2213 extern void __insert_inode_hash(struct inode *, unsigned long hashval); 2214 static inline void insert_inode_hash(struct inode *inode) 2215 { 2216 __insert_inode_hash(inode, inode->i_ino); 2217 } 2218 2219 extern void __remove_inode_hash(struct inode *); 2220 static inline void remove_inode_hash(struct inode *inode) 2221 { 2222 if (!inode_unhashed(inode)) 2223 __remove_inode_hash(inode); 2224 } 2225 2226 extern void inode_sb_list_add(struct inode *inode); 2227 2228 #ifdef CONFIG_BLOCK 2229 extern void submit_bio(int, struct bio *); 2230 extern int bdev_read_only(struct block_device *); 2231 #endif 2232 extern int set_blocksize(struct block_device *, int); 2233 extern int sb_set_blocksize(struct super_block *, int); 2234 extern int sb_min_blocksize(struct super_block *, int); 2235 2236 extern int generic_file_mmap(struct file *, struct vm_area_struct *); 2237 extern int generic_file_readonly_mmap(struct file *, struct vm_area_struct *); 2238 extern int generic_file_remap_pages(struct vm_area_struct *, unsigned long addr, 2239 unsigned long size, pgoff_t pgoff); 2240 extern int file_read_actor(read_descriptor_t * desc, struct page *page, unsigned long offset, unsigned long size); 2241 int generic_write_checks(struct file *file, loff_t *pos, size_t *count, int isblk); 2242 extern ssize_t generic_file_aio_read(struct kiocb *, const struct iovec *, unsigned long, loff_t); 2243 extern ssize_t __generic_file_aio_write(struct kiocb *, const struct iovec *, unsigned long, 2244 loff_t *); 2245 extern ssize_t generic_file_aio_write(struct kiocb *, const struct iovec *, unsigned long, loff_t); 2246 extern ssize_t generic_file_direct_write(struct kiocb *, const struct iovec *, 2247 unsigned long *, loff_t, loff_t *, size_t, size_t); 2248 extern ssize_t generic_file_buffered_write(struct kiocb *, const struct iovec *, 2249 unsigned long, loff_t, loff_t *, size_t, ssize_t); 2250 extern ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos); 2251 extern ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos); 2252 extern int generic_segment_checks(const struct iovec *iov, 2253 unsigned long *nr_segs, size_t *count, int access_flags); 2254 2255 /* fs/block_dev.c */ 2256 extern ssize_t blkdev_aio_read(struct kiocb *iocb, const struct iovec *iov, 2257 unsigned long nr_segs, loff_t pos); 2258 extern ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov, 2259 unsigned long nr_segs, loff_t pos); 2260 extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end, 2261 int datasync); 2262 extern void block_sync_page(struct page *page); 2263 2264 /* fs/splice.c */ 2265 extern ssize_t generic_file_splice_read(struct file *, loff_t *, 2266 struct pipe_inode_info *, size_t, unsigned int); 2267 extern ssize_t default_file_splice_read(struct file *, loff_t *, 2268 struct pipe_inode_info *, size_t, unsigned int); 2269 extern ssize_t generic_file_splice_write(struct pipe_inode_info *, 2270 struct file *, loff_t *, size_t, unsigned int); 2271 extern ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe, 2272 struct file *out, loff_t *, size_t len, unsigned int flags); 2273 extern long do_splice_direct(struct file *in, loff_t *ppos, struct file *out, 2274 size_t len, unsigned int flags); 2275 2276 extern void 2277 file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping); 2278 extern loff_t noop_llseek(struct file *file, loff_t offset, int origin); 2279 extern loff_t no_llseek(struct file *file, loff_t offset, int origin); 2280 extern loff_t generic_file_llseek(struct file *file, loff_t offset, int origin); 2281 extern loff_t generic_file_llseek_size(struct file *file, loff_t offset, 2282 int origin, loff_t maxsize, loff_t eof); 2283 extern int generic_file_open(struct inode * inode, struct file * filp); 2284 extern int nonseekable_open(struct inode * inode, struct file * filp); 2285 2286 #ifdef CONFIG_FS_XIP 2287 extern ssize_t xip_file_read(struct file *filp, char __user *buf, size_t len, 2288 loff_t *ppos); 2289 extern int xip_file_mmap(struct file * file, struct vm_area_struct * vma); 2290 extern ssize_t xip_file_write(struct file *filp, const char __user *buf, 2291 size_t len, loff_t *ppos); 2292 extern int xip_truncate_page(struct address_space *mapping, loff_t from); 2293 #else 2294 static inline int xip_truncate_page(struct address_space *mapping, loff_t from) 2295 { 2296 return 0; 2297 } 2298 #endif 2299 2300 #ifdef CONFIG_BLOCK 2301 typedef void (dio_submit_t)(int rw, struct bio *bio, struct inode *inode, 2302 loff_t file_offset); 2303 2304 enum { 2305 /* need locking between buffered and direct access */ 2306 DIO_LOCKING = 0x01, 2307 2308 /* filesystem does not support filling holes */ 2309 DIO_SKIP_HOLES = 0x02, 2310 }; 2311 2312 void dio_end_io(struct bio *bio, int error); 2313 2314 ssize_t __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode, 2315 struct block_device *bdev, const struct iovec *iov, loff_t offset, 2316 unsigned long nr_segs, get_block_t get_block, dio_iodone_t end_io, 2317 dio_submit_t submit_io, int flags); 2318 2319 static inline ssize_t blockdev_direct_IO(int rw, struct kiocb *iocb, 2320 struct inode *inode, const struct iovec *iov, loff_t offset, 2321 unsigned long nr_segs, get_block_t get_block) 2322 { 2323 return __blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov, 2324 offset, nr_segs, get_block, NULL, NULL, 2325 DIO_LOCKING | DIO_SKIP_HOLES); 2326 } 2327 #endif 2328 2329 void inode_dio_wait(struct inode *inode); 2330 void inode_dio_done(struct inode *inode); 2331 2332 extern const struct file_operations generic_ro_fops; 2333 2334 #define special_file(m) (S_ISCHR(m)||S_ISBLK(m)||S_ISFIFO(m)||S_ISSOCK(m)) 2335 2336 extern int vfs_readlink(struct dentry *, char __user *, int, const char *); 2337 extern int vfs_follow_link(struct nameidata *, const char *); 2338 extern int page_readlink(struct dentry *, char __user *, int); 2339 extern void *page_follow_link_light(struct dentry *, struct nameidata *); 2340 extern void page_put_link(struct dentry *, struct nameidata *, void *); 2341 extern int __page_symlink(struct inode *inode, const char *symname, int len, 2342 int nofs); 2343 extern int page_symlink(struct inode *inode, const char *symname, int len); 2344 extern const struct inode_operations page_symlink_inode_operations; 2345 extern int generic_readlink(struct dentry *, char __user *, int); 2346 extern void generic_fillattr(struct inode *, struct kstat *); 2347 extern int vfs_getattr(struct vfsmount *, struct dentry *, struct kstat *); 2348 void __inode_add_bytes(struct inode *inode, loff_t bytes); 2349 void inode_add_bytes(struct inode *inode, loff_t bytes); 2350 void inode_sub_bytes(struct inode *inode, loff_t bytes); 2351 loff_t inode_get_bytes(struct inode *inode); 2352 void inode_set_bytes(struct inode *inode, loff_t bytes); 2353 2354 extern int vfs_readdir(struct file *, filldir_t, void *); 2355 2356 extern int vfs_stat(const char __user *, struct kstat *); 2357 extern int vfs_lstat(const char __user *, struct kstat *); 2358 extern int vfs_fstat(unsigned int, struct kstat *); 2359 extern int vfs_fstatat(int , const char __user *, struct kstat *, int); 2360 2361 extern int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd, 2362 unsigned long arg); 2363 extern int __generic_block_fiemap(struct inode *inode, 2364 struct fiemap_extent_info *fieinfo, 2365 loff_t start, loff_t len, 2366 get_block_t *get_block); 2367 extern int generic_block_fiemap(struct inode *inode, 2368 struct fiemap_extent_info *fieinfo, u64 start, 2369 u64 len, get_block_t *get_block); 2370 2371 extern void get_filesystem(struct file_system_type *fs); 2372 extern void put_filesystem(struct file_system_type *fs); 2373 extern struct file_system_type *get_fs_type(const char *name); 2374 extern struct super_block *get_super(struct block_device *); 2375 extern struct super_block *get_super_thawed(struct block_device *); 2376 extern struct super_block *get_active_super(struct block_device *bdev); 2377 extern void drop_super(struct super_block *sb); 2378 extern void iterate_supers(void (*)(struct super_block *, void *), void *); 2379 extern void iterate_supers_type(struct file_system_type *, 2380 void (*)(struct super_block *, void *), void *); 2381 2382 extern int dcache_dir_open(struct inode *, struct file *); 2383 extern int dcache_dir_close(struct inode *, struct file *); 2384 extern loff_t dcache_dir_lseek(struct file *, loff_t, int); 2385 extern int dcache_readdir(struct file *, void *, filldir_t); 2386 extern int simple_setattr(struct dentry *, struct iattr *); 2387 extern int simple_getattr(struct vfsmount *, struct dentry *, struct kstat *); 2388 extern int simple_statfs(struct dentry *, struct kstatfs *); 2389 extern int simple_open(struct inode *inode, struct file *file); 2390 extern int simple_link(struct dentry *, struct inode *, struct dentry *); 2391 extern int simple_unlink(struct inode *, struct dentry *); 2392 extern int simple_rmdir(struct inode *, struct dentry *); 2393 extern int simple_rename(struct inode *, struct dentry *, struct inode *, struct dentry *); 2394 extern int noop_fsync(struct file *, loff_t, loff_t, int); 2395 extern int simple_empty(struct dentry *); 2396 extern int simple_readpage(struct file *file, struct page *page); 2397 extern int simple_write_begin(struct file *file, struct address_space *mapping, 2398 loff_t pos, unsigned len, unsigned flags, 2399 struct page **pagep, void **fsdata); 2400 extern int simple_write_end(struct file *file, struct address_space *mapping, 2401 loff_t pos, unsigned len, unsigned copied, 2402 struct page *page, void *fsdata); 2403 2404 extern struct dentry *simple_lookup(struct inode *, struct dentry *, unsigned int flags); 2405 extern ssize_t generic_read_dir(struct file *, char __user *, size_t, loff_t *); 2406 extern const struct file_operations simple_dir_operations; 2407 extern const struct inode_operations simple_dir_inode_operations; 2408 struct tree_descr { char *name; const struct file_operations *ops; int mode; }; 2409 struct dentry *d_alloc_name(struct dentry *, const char *); 2410 extern int simple_fill_super(struct super_block *, unsigned long, struct tree_descr *); 2411 extern int simple_pin_fs(struct file_system_type *, struct vfsmount **mount, int *count); 2412 extern void simple_release_fs(struct vfsmount **mount, int *count); 2413 2414 extern ssize_t simple_read_from_buffer(void __user *to, size_t count, 2415 loff_t *ppos, const void *from, size_t available); 2416 extern ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos, 2417 const void __user *from, size_t count); 2418 2419 extern int generic_file_fsync(struct file *, loff_t, loff_t, int); 2420 2421 extern int generic_check_addressable(unsigned, u64); 2422 2423 #ifdef CONFIG_MIGRATION 2424 extern int buffer_migrate_page(struct address_space *, 2425 struct page *, struct page *, 2426 enum migrate_mode); 2427 #else 2428 #define buffer_migrate_page NULL 2429 #endif 2430 2431 extern int inode_change_ok(const struct inode *, struct iattr *); 2432 extern int inode_newsize_ok(const struct inode *, loff_t offset); 2433 extern void setattr_copy(struct inode *inode, const struct iattr *attr); 2434 2435 extern int file_update_time(struct file *file); 2436 2437 extern int generic_show_options(struct seq_file *m, struct dentry *root); 2438 extern void save_mount_options(struct super_block *sb, char *options); 2439 extern void replace_mount_options(struct super_block *sb, char *options); 2440 2441 static inline ino_t parent_ino(struct dentry *dentry) 2442 { 2443 ino_t res; 2444 2445 /* 2446 * Don't strictly need d_lock here? If the parent ino could change 2447 * then surely we'd have a deeper race in the caller? 2448 */ 2449 spin_lock(&dentry->d_lock); 2450 res = dentry->d_parent->d_inode->i_ino; 2451 spin_unlock(&dentry->d_lock); 2452 return res; 2453 } 2454 2455 /* Transaction based IO helpers */ 2456 2457 /* 2458 * An argresp is stored in an allocated page and holds the 2459 * size of the argument or response, along with its content 2460 */ 2461 struct simple_transaction_argresp { 2462 ssize_t size; 2463 char data[0]; 2464 }; 2465 2466 #define SIMPLE_TRANSACTION_LIMIT (PAGE_SIZE - sizeof(struct simple_transaction_argresp)) 2467 2468 char *simple_transaction_get(struct file *file, const char __user *buf, 2469 size_t size); 2470 ssize_t simple_transaction_read(struct file *file, char __user *buf, 2471 size_t size, loff_t *pos); 2472 int simple_transaction_release(struct inode *inode, struct file *file); 2473 2474 void simple_transaction_set(struct file *file, size_t n); 2475 2476 /* 2477 * simple attribute files 2478 * 2479 * These attributes behave similar to those in sysfs: 2480 * 2481 * Writing to an attribute immediately sets a value, an open file can be 2482 * written to multiple times. 2483 * 2484 * Reading from an attribute creates a buffer from the value that might get 2485 * read with multiple read calls. When the attribute has been read 2486 * completely, no further read calls are possible until the file is opened 2487 * again. 2488 * 2489 * All attributes contain a text representation of a numeric value 2490 * that are accessed with the get() and set() functions. 2491 */ 2492 #define DEFINE_SIMPLE_ATTRIBUTE(__fops, __get, __set, __fmt) \ 2493 static int __fops ## _open(struct inode *inode, struct file *file) \ 2494 { \ 2495 __simple_attr_check_format(__fmt, 0ull); \ 2496 return simple_attr_open(inode, file, __get, __set, __fmt); \ 2497 } \ 2498 static const struct file_operations __fops = { \ 2499 .owner = THIS_MODULE, \ 2500 .open = __fops ## _open, \ 2501 .release = simple_attr_release, \ 2502 .read = simple_attr_read, \ 2503 .write = simple_attr_write, \ 2504 .llseek = generic_file_llseek, \ 2505 }; 2506 2507 static inline __printf(1, 2) 2508 void __simple_attr_check_format(const char *fmt, ...) 2509 { 2510 /* don't do anything, just let the compiler check the arguments; */ 2511 } 2512 2513 int simple_attr_open(struct inode *inode, struct file *file, 2514 int (*get)(void *, u64 *), int (*set)(void *, u64), 2515 const char *fmt); 2516 int simple_attr_release(struct inode *inode, struct file *file); 2517 ssize_t simple_attr_read(struct file *file, char __user *buf, 2518 size_t len, loff_t *ppos); 2519 ssize_t simple_attr_write(struct file *file, const char __user *buf, 2520 size_t len, loff_t *ppos); 2521 2522 struct ctl_table; 2523 int proc_nr_files(struct ctl_table *table, int write, 2524 void __user *buffer, size_t *lenp, loff_t *ppos); 2525 int proc_nr_dentry(struct ctl_table *table, int write, 2526 void __user *buffer, size_t *lenp, loff_t *ppos); 2527 int proc_nr_inodes(struct ctl_table *table, int write, 2528 void __user *buffer, size_t *lenp, loff_t *ppos); 2529 int __init get_filesystem_list(char *buf); 2530 2531 #define __FMODE_EXEC ((__force int) FMODE_EXEC) 2532 #define __FMODE_NONOTIFY ((__force int) FMODE_NONOTIFY) 2533 2534 #define ACC_MODE(x) ("\004\002\006\006"[(x)&O_ACCMODE]) 2535 #define OPEN_FMODE(flag) ((__force fmode_t)(((flag + 1) & O_ACCMODE) | \ 2536 (flag & __FMODE_NONOTIFY))) 2537 2538 static inline int is_sxid(umode_t mode) 2539 { 2540 return (mode & S_ISUID) || ((mode & S_ISGID) && (mode & S_IXGRP)); 2541 } 2542 2543 static inline void inode_has_no_xattr(struct inode *inode) 2544 { 2545 if (!is_sxid(inode->i_mode) && (inode->i_sb->s_flags & MS_NOSEC)) 2546 inode->i_flags |= S_NOSEC; 2547 } 2548 2549 #endif /* _LINUX_FS_H */ 2550