1 #ifndef _LINUX_FS_H 2 #define _LINUX_FS_H 3 4 /* 5 * This file has definitions for some important file table 6 * structures etc. 7 */ 8 9 #include <linux/config.h> 10 #include <linux/limits.h> 11 #include <linux/ioctl.h> 12 13 /* 14 * It's silly to have NR_OPEN bigger than NR_FILE, but you can change 15 * the file limit at runtime and only root can increase the per-process 16 * nr_file rlimit, so it's safe to set up a ridiculously high absolute 17 * upper limit on files-per-process. 18 * 19 * Some programs (notably those using select()) may have to be 20 * recompiled to take full advantage of the new limits.. 21 */ 22 23 /* Fixed constants first: */ 24 #undef NR_OPEN 25 #define NR_OPEN (1024*1024) /* Absolute upper limit on fd num */ 26 #define INR_OPEN 1024 /* Initial setting for nfile rlimits */ 27 28 #define BLOCK_SIZE_BITS 10 29 #define BLOCK_SIZE (1<<BLOCK_SIZE_BITS) 30 31 /* And dynamically-tunable limits and defaults: */ 32 struct files_stat_struct { 33 int nr_files; /* read only */ 34 int nr_free_files; /* read only */ 35 int max_files; /* tunable */ 36 }; 37 extern struct files_stat_struct files_stat; 38 39 struct inodes_stat_t { 40 int nr_inodes; 41 int nr_unused; 42 int dummy[5]; 43 }; 44 extern struct inodes_stat_t inodes_stat; 45 46 extern int leases_enable, lease_break_time; 47 48 #ifdef CONFIG_DNOTIFY 49 extern int dir_notify_enable; 50 #endif 51 52 #define NR_FILE 8192 /* this can well be larger on a larger system */ 53 54 #define MAY_EXEC 1 55 #define MAY_WRITE 2 56 #define MAY_READ 4 57 #define MAY_APPEND 8 58 59 #define FMODE_READ 1 60 #define FMODE_WRITE 2 61 62 /* Internal kernel extensions */ 63 #define FMODE_LSEEK 4 64 #define FMODE_PREAD 8 65 #define FMODE_PWRITE FMODE_PREAD /* These go hand in hand */ 66 67 #define RW_MASK 1 68 #define RWA_MASK 2 69 #define READ 0 70 #define WRITE 1 71 #define READA 2 /* read-ahead - don't block if no resources */ 72 #define SPECIAL 4 /* For non-blockdevice requests in request queue */ 73 #define READ_SYNC (READ | (1 << BIO_RW_SYNC)) 74 #define WRITE_SYNC (WRITE | (1 << BIO_RW_SYNC)) 75 #define WRITE_BARRIER ((1 << BIO_RW) | (1 << BIO_RW_BARRIER)) 76 77 #define SEL_IN 1 78 #define SEL_OUT 2 79 #define SEL_EX 4 80 81 /* public flags for file_system_type */ 82 #define FS_REQUIRES_DEV 1 83 #define FS_BINARY_MOUNTDATA 2 84 #define FS_REVAL_DOT 16384 /* Check the paths ".", ".." for staleness */ 85 #define FS_ODD_RENAME 32768 /* Temporary stuff; will go away as soon 86 * as nfs_rename() will be cleaned up 87 */ 88 /* 89 * These are the fs-independent mount-flags: up to 32 flags are supported 90 */ 91 #define MS_RDONLY 1 /* Mount read-only */ 92 #define MS_NOSUID 2 /* Ignore suid and sgid bits */ 93 #define MS_NODEV 4 /* Disallow access to device special files */ 94 #define MS_NOEXEC 8 /* Disallow program execution */ 95 #define MS_SYNCHRONOUS 16 /* Writes are synced at once */ 96 #define MS_REMOUNT 32 /* Alter flags of a mounted FS */ 97 #define MS_MANDLOCK 64 /* Allow mandatory locks on an FS */ 98 #define MS_DIRSYNC 128 /* Directory modifications are synchronous */ 99 #define MS_NOATIME 1024 /* Do not update access times. */ 100 #define MS_NODIRATIME 2048 /* Do not update directory access times */ 101 #define MS_BIND 4096 102 #define MS_MOVE 8192 103 #define MS_REC 16384 104 #define MS_VERBOSE 32768 105 #define MS_POSIXACL (1<<16) /* VFS does not apply the umask */ 106 #define MS_ACTIVE (1<<30) 107 #define MS_NOUSER (1<<31) 108 109 /* 110 * Superblock flags that can be altered by MS_REMOUNT 111 */ 112 #define MS_RMT_MASK (MS_RDONLY|MS_SYNCHRONOUS|MS_MANDLOCK|MS_NOATIME|\ 113 MS_NODIRATIME) 114 115 /* 116 * Old magic mount flag and mask 117 */ 118 #define MS_MGC_VAL 0xC0ED0000 119 #define MS_MGC_MSK 0xffff0000 120 121 /* Inode flags - they have nothing to superblock flags now */ 122 123 #define S_SYNC 1 /* Writes are synced at once */ 124 #define S_NOATIME 2 /* Do not update access times */ 125 #define S_APPEND 4 /* Append-only file */ 126 #define S_IMMUTABLE 8 /* Immutable file */ 127 #define S_DEAD 16 /* removed, but still open directory */ 128 #define S_NOQUOTA 32 /* Inode is not counted to quota */ 129 #define S_DIRSYNC 64 /* Directory modifications are synchronous */ 130 #define S_NOCMTIME 128 /* Do not update file c/mtime */ 131 #define S_SWAPFILE 256 /* Do not truncate: swapon got its bmaps */ 132 #define S_PRIVATE 512 /* Inode is fs-internal */ 133 134 /* 135 * Note that nosuid etc flags are inode-specific: setting some file-system 136 * flags just means all the inodes inherit those flags by default. It might be 137 * possible to override it selectively if you really wanted to with some 138 * ioctl() that is not currently implemented. 139 * 140 * Exception: MS_RDONLY is always applied to the entire file system. 141 * 142 * Unfortunately, it is possible to change a filesystems flags with it mounted 143 * with files in use. This means that all of the inodes will not have their 144 * i_flags updated. Hence, i_flags no longer inherit the superblock mount 145 * flags, so these have to be checked separately. -- [email protected] 146 */ 147 #define __IS_FLG(inode,flg) ((inode)->i_sb->s_flags & (flg)) 148 149 #define IS_RDONLY(inode) ((inode)->i_sb->s_flags & MS_RDONLY) 150 #define IS_SYNC(inode) (__IS_FLG(inode, MS_SYNCHRONOUS) || \ 151 ((inode)->i_flags & S_SYNC)) 152 #define IS_DIRSYNC(inode) (__IS_FLG(inode, MS_SYNCHRONOUS|MS_DIRSYNC) || \ 153 ((inode)->i_flags & (S_SYNC|S_DIRSYNC))) 154 #define IS_MANDLOCK(inode) __IS_FLG(inode, MS_MANDLOCK) 155 156 #define IS_NOQUOTA(inode) ((inode)->i_flags & S_NOQUOTA) 157 #define IS_APPEND(inode) ((inode)->i_flags & S_APPEND) 158 #define IS_IMMUTABLE(inode) ((inode)->i_flags & S_IMMUTABLE) 159 #define IS_NOATIME(inode) (__IS_FLG(inode, MS_NOATIME) || ((inode)->i_flags & S_NOATIME)) 160 #define IS_NODIRATIME(inode) __IS_FLG(inode, MS_NODIRATIME) 161 #define IS_POSIXACL(inode) __IS_FLG(inode, MS_POSIXACL) 162 163 #define IS_DEADDIR(inode) ((inode)->i_flags & S_DEAD) 164 #define IS_NOCMTIME(inode) ((inode)->i_flags & S_NOCMTIME) 165 #define IS_SWAPFILE(inode) ((inode)->i_flags & S_SWAPFILE) 166 #define IS_PRIVATE(inode) ((inode)->i_flags & S_PRIVATE) 167 168 /* the read-only stuff doesn't really belong here, but any other place is 169 probably as bad and I don't want to create yet another include file. */ 170 171 #define BLKROSET _IO(0x12,93) /* set device read-only (0 = read-write) */ 172 #define BLKROGET _IO(0x12,94) /* get read-only status (0 = read_write) */ 173 #define BLKRRPART _IO(0x12,95) /* re-read partition table */ 174 #define BLKGETSIZE _IO(0x12,96) /* return device size /512 (long *arg) */ 175 #define BLKFLSBUF _IO(0x12,97) /* flush buffer cache */ 176 #define BLKRASET _IO(0x12,98) /* set read ahead for block device */ 177 #define BLKRAGET _IO(0x12,99) /* get current read ahead setting */ 178 #define BLKFRASET _IO(0x12,100)/* set filesystem (mm/filemap.c) read-ahead */ 179 #define BLKFRAGET _IO(0x12,101)/* get filesystem (mm/filemap.c) read-ahead */ 180 #define BLKSECTSET _IO(0x12,102)/* set max sectors per request (ll_rw_blk.c) */ 181 #define BLKSECTGET _IO(0x12,103)/* get max sectors per request (ll_rw_blk.c) */ 182 #define BLKSSZGET _IO(0x12,104)/* get block device sector size */ 183 #if 0 184 #define BLKPG _IO(0x12,105)/* See blkpg.h */ 185 186 /* Some people are morons. Do not use sizeof! */ 187 188 #define BLKELVGET _IOR(0x12,106,size_t)/* elevator get */ 189 #define BLKELVSET _IOW(0x12,107,size_t)/* elevator set */ 190 /* This was here just to show that the number is taken - 191 probably all these _IO(0x12,*) ioctls should be moved to blkpg.h. */ 192 #endif 193 /* A jump here: 108-111 have been used for various private purposes. */ 194 #define BLKBSZGET _IOR(0x12,112,size_t) 195 #define BLKBSZSET _IOW(0x12,113,size_t) 196 #define BLKGETSIZE64 _IOR(0x12,114,size_t) /* return device size in bytes (u64 *arg) */ 197 198 #define BMAP_IOCTL 1 /* obsolete - kept for compatibility */ 199 #define FIBMAP _IO(0x00,1) /* bmap access */ 200 #define FIGETBSZ _IO(0x00,2) /* get the block size used for bmap */ 201 202 #ifdef __KERNEL__ 203 204 #include <linux/linkage.h> 205 #include <linux/wait.h> 206 #include <linux/types.h> 207 #include <linux/kdev_t.h> 208 #include <linux/dcache.h> 209 #include <linux/stat.h> 210 #include <linux/cache.h> 211 #include <linux/kobject.h> 212 #include <linux/list.h> 213 #include <linux/radix-tree.h> 214 #include <linux/prio_tree.h> 215 #include <linux/init.h> 216 217 #include <asm/atomic.h> 218 #include <asm/semaphore.h> 219 #include <asm/byteorder.h> 220 221 struct iovec; 222 struct nameidata; 223 struct kiocb; 224 struct pipe_inode_info; 225 struct poll_table_struct; 226 struct kstatfs; 227 struct vm_area_struct; 228 struct vfsmount; 229 230 /* Used to be a macro which just called the function, now just a function */ 231 extern void update_atime (struct inode *); 232 233 extern void __init inode_init(unsigned long); 234 extern void __init inode_init_early(void); 235 extern void __init mnt_init(unsigned long); 236 extern void __init files_init(unsigned long); 237 238 struct buffer_head; 239 typedef int (get_block_t)(struct inode *inode, sector_t iblock, 240 struct buffer_head *bh_result, int create); 241 typedef int (get_blocks_t)(struct inode *inode, sector_t iblock, 242 unsigned long max_blocks, 243 struct buffer_head *bh_result, int create); 244 typedef void (dio_iodone_t)(struct kiocb *iocb, loff_t offset, 245 ssize_t bytes, void *private); 246 247 /* 248 * Attribute flags. These should be or-ed together to figure out what 249 * has been changed! 250 */ 251 #define ATTR_MODE 1 252 #define ATTR_UID 2 253 #define ATTR_GID 4 254 #define ATTR_SIZE 8 255 #define ATTR_ATIME 16 256 #define ATTR_MTIME 32 257 #define ATTR_CTIME 64 258 #define ATTR_ATIME_SET 128 259 #define ATTR_MTIME_SET 256 260 #define ATTR_FORCE 512 /* Not a change, but a change it */ 261 #define ATTR_ATTR_FLAG 1024 262 #define ATTR_KILL_SUID 2048 263 #define ATTR_KILL_SGID 4096 264 265 /* 266 * This is the Inode Attributes structure, used for notify_change(). It 267 * uses the above definitions as flags, to know which values have changed. 268 * Also, in this manner, a Filesystem can look at only the values it cares 269 * about. Basically, these are the attributes that the VFS layer can 270 * request to change from the FS layer. 271 * 272 * Derek Atkins <[email protected]> 94-10-20 273 */ 274 struct iattr { 275 unsigned int ia_valid; 276 umode_t ia_mode; 277 uid_t ia_uid; 278 gid_t ia_gid; 279 loff_t ia_size; 280 struct timespec ia_atime; 281 struct timespec ia_mtime; 282 struct timespec ia_ctime; 283 unsigned int ia_attr_flags; 284 }; 285 286 /* 287 * This is the inode attributes flag definitions 288 */ 289 #define ATTR_FLAG_SYNCRONOUS 1 /* Syncronous write */ 290 #define ATTR_FLAG_NOATIME 2 /* Don't update atime */ 291 #define ATTR_FLAG_APPEND 4 /* Append-only file */ 292 #define ATTR_FLAG_IMMUTABLE 8 /* Immutable file */ 293 #define ATTR_FLAG_NODIRATIME 16 /* Don't update atime for directory */ 294 295 /* 296 * Includes for diskquotas. 297 */ 298 #include <linux/quota.h> 299 300 /* 301 * oh the beauties of C type declarations. 302 */ 303 struct page; 304 struct address_space; 305 struct writeback_control; 306 307 struct address_space_operations { 308 int (*writepage)(struct page *page, struct writeback_control *wbc); 309 int (*readpage)(struct file *, struct page *); 310 int (*sync_page)(struct page *); 311 312 /* Write back some dirty pages from this mapping. */ 313 int (*writepages)(struct address_space *, struct writeback_control *); 314 315 /* Set a page dirty */ 316 int (*set_page_dirty)(struct page *page); 317 318 int (*readpages)(struct file *filp, struct address_space *mapping, 319 struct list_head *pages, unsigned nr_pages); 320 321 /* 322 * ext3 requires that a successful prepare_write() call be followed 323 * by a commit_write() call - they must be balanced 324 */ 325 int (*prepare_write)(struct file *, struct page *, unsigned, unsigned); 326 int (*commit_write)(struct file *, struct page *, unsigned, unsigned); 327 /* Unfortunately this kludge is needed for FIBMAP. Don't use it */ 328 sector_t (*bmap)(struct address_space *, sector_t); 329 int (*invalidatepage) (struct page *, unsigned long); 330 int (*releasepage) (struct page *, int); 331 ssize_t (*direct_IO)(int, struct kiocb *, const struct iovec *iov, 332 loff_t offset, unsigned long nr_segs); 333 }; 334 335 struct backing_dev_info; 336 struct address_space { 337 struct inode *host; /* owner: inode, block_device */ 338 struct radix_tree_root page_tree; /* radix tree of all pages */ 339 rwlock_t tree_lock; /* and rwlock protecting it */ 340 unsigned int i_mmap_writable;/* count VM_SHARED mappings */ 341 struct prio_tree_root i_mmap; /* tree of private and shared mappings */ 342 struct list_head i_mmap_nonlinear;/*list VM_NONLINEAR mappings */ 343 spinlock_t i_mmap_lock; /* protect tree, count, list */ 344 unsigned int truncate_count; /* Cover race condition with truncate */ 345 unsigned long nrpages; /* number of total pages */ 346 pgoff_t writeback_index;/* writeback starts here */ 347 struct address_space_operations *a_ops; /* methods */ 348 unsigned long flags; /* error bits/gfp mask */ 349 struct backing_dev_info *backing_dev_info; /* device readahead, etc */ 350 spinlock_t private_lock; /* for use by the address_space */ 351 struct list_head private_list; /* ditto */ 352 struct address_space *assoc_mapping; /* ditto */ 353 } __attribute__((aligned(sizeof(long)))); 354 /* 355 * On most architectures that alignment is already the case; but 356 * must be enforced here for CRIS, to let the least signficant bit 357 * of struct page's "mapping" pointer be used for PAGE_MAPPING_ANON. 358 */ 359 360 struct block_device { 361 dev_t bd_dev; /* not a kdev_t - it's a search key */ 362 struct inode * bd_inode; /* will die */ 363 int bd_openers; 364 struct semaphore bd_sem; /* open/close mutex */ 365 struct semaphore bd_mount_sem; /* mount mutex */ 366 struct list_head bd_inodes; 367 void * bd_holder; 368 int bd_holders; 369 struct block_device * bd_contains; 370 unsigned bd_block_size; 371 struct hd_struct * bd_part; 372 /* number of times partitions within this device have been opened. */ 373 unsigned bd_part_count; 374 int bd_invalidated; 375 struct gendisk * bd_disk; 376 struct list_head bd_list; 377 struct backing_dev_info *bd_inode_backing_dev_info; 378 /* 379 * Private data. You must have bd_claim'ed the block_device 380 * to use this. NOTE: bd_claim allows an owner to claim 381 * the same device multiple times, the owner must take special 382 * care to not mess up bd_private for that case. 383 */ 384 unsigned long bd_private; 385 }; 386 387 /* 388 * Radix-tree tags, for tagging dirty and writeback pages within the pagecache 389 * radix trees 390 */ 391 #define PAGECACHE_TAG_DIRTY 0 392 #define PAGECACHE_TAG_WRITEBACK 1 393 394 int mapping_tagged(struct address_space *mapping, int tag); 395 396 /* 397 * Might pages of this file be mapped into userspace? 398 */ 399 static inline int mapping_mapped(struct address_space *mapping) 400 { 401 return !prio_tree_empty(&mapping->i_mmap) || 402 !list_empty(&mapping->i_mmap_nonlinear); 403 } 404 405 /* 406 * Might pages of this file have been modified in userspace? 407 * Note that i_mmap_writable counts all VM_SHARED vmas: do_mmap_pgoff 408 * marks vma as VM_SHARED if it is shared, and the file was opened for 409 * writing i.e. vma may be mprotected writable even if now readonly. 410 */ 411 static inline int mapping_writably_mapped(struct address_space *mapping) 412 { 413 return mapping->i_mmap_writable != 0; 414 } 415 416 /* 417 * Use sequence counter to get consistent i_size on 32-bit processors. 418 */ 419 #if BITS_PER_LONG==32 && defined(CONFIG_SMP) 420 #include <linux/seqlock.h> 421 #define __NEED_I_SIZE_ORDERED 422 #define i_size_ordered_init(inode) seqcount_init(&inode->i_size_seqcount) 423 #else 424 #define i_size_ordered_init(inode) do { } while (0) 425 #endif 426 427 struct inode { 428 struct hlist_node i_hash; 429 struct list_head i_list; 430 struct list_head i_sb_list; 431 struct list_head i_dentry; 432 unsigned long i_ino; 433 atomic_t i_count; 434 umode_t i_mode; 435 unsigned int i_nlink; 436 uid_t i_uid; 437 gid_t i_gid; 438 dev_t i_rdev; 439 loff_t i_size; 440 struct timespec i_atime; 441 struct timespec i_mtime; 442 struct timespec i_ctime; 443 unsigned int i_blkbits; 444 unsigned long i_blksize; 445 unsigned long i_version; 446 unsigned long i_blocks; 447 unsigned short i_bytes; 448 spinlock_t i_lock; /* i_blocks, i_bytes, maybe i_size */ 449 struct semaphore i_sem; 450 struct rw_semaphore i_alloc_sem; 451 struct inode_operations *i_op; 452 struct file_operations *i_fop; /* former ->i_op->default_file_ops */ 453 struct super_block *i_sb; 454 struct file_lock *i_flock; 455 struct address_space *i_mapping; 456 struct address_space i_data; 457 #ifdef CONFIG_QUOTA 458 struct dquot *i_dquot[MAXQUOTAS]; 459 #endif 460 /* These three should probably be a union */ 461 struct list_head i_devices; 462 struct pipe_inode_info *i_pipe; 463 struct block_device *i_bdev; 464 struct cdev *i_cdev; 465 int i_cindex; 466 467 __u32 i_generation; 468 469 #ifdef CONFIG_DNOTIFY 470 unsigned long i_dnotify_mask; /* Directory notify events */ 471 struct dnotify_struct *i_dnotify; /* for directory notifications */ 472 #endif 473 474 unsigned long i_state; 475 unsigned long dirtied_when; /* jiffies of first dirtying */ 476 477 unsigned int i_flags; 478 479 atomic_t i_writecount; 480 void *i_security; 481 union { 482 void *generic_ip; 483 } u; 484 #ifdef __NEED_I_SIZE_ORDERED 485 seqcount_t i_size_seqcount; 486 #endif 487 }; 488 489 /* 490 * NOTE: in a 32bit arch with a preemptable kernel and 491 * an UP compile the i_size_read/write must be atomic 492 * with respect to the local cpu (unlike with preempt disabled), 493 * but they don't need to be atomic with respect to other cpus like in 494 * true SMP (so they need either to either locally disable irq around 495 * the read or for example on x86 they can be still implemented as a 496 * cmpxchg8b without the need of the lock prefix). For SMP compiles 497 * and 64bit archs it makes no difference if preempt is enabled or not. 498 */ 499 static inline loff_t i_size_read(struct inode *inode) 500 { 501 #if BITS_PER_LONG==32 && defined(CONFIG_SMP) 502 loff_t i_size; 503 unsigned int seq; 504 505 do { 506 seq = read_seqcount_begin(&inode->i_size_seqcount); 507 i_size = inode->i_size; 508 } while (read_seqcount_retry(&inode->i_size_seqcount, seq)); 509 return i_size; 510 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT) 511 loff_t i_size; 512 513 preempt_disable(); 514 i_size = inode->i_size; 515 preempt_enable(); 516 return i_size; 517 #else 518 return inode->i_size; 519 #endif 520 } 521 522 523 static inline void i_size_write(struct inode *inode, loff_t i_size) 524 { 525 #if BITS_PER_LONG==32 && defined(CONFIG_SMP) 526 write_seqcount_begin(&inode->i_size_seqcount); 527 inode->i_size = i_size; 528 write_seqcount_end(&inode->i_size_seqcount); 529 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT) 530 preempt_disable(); 531 inode->i_size = i_size; 532 preempt_enable(); 533 #else 534 inode->i_size = i_size; 535 #endif 536 } 537 538 static inline unsigned iminor(struct inode *inode) 539 { 540 return MINOR(inode->i_rdev); 541 } 542 543 static inline unsigned imajor(struct inode *inode) 544 { 545 return MAJOR(inode->i_rdev); 546 } 547 548 extern struct block_device *I_BDEV(struct inode *inode); 549 550 struct fown_struct { 551 rwlock_t lock; /* protects pid, uid, euid fields */ 552 int pid; /* pid or -pgrp where SIGIO should be sent */ 553 uid_t uid, euid; /* uid/euid of process setting the owner */ 554 void *security; 555 int signum; /* posix.1b rt signal to be delivered on IO */ 556 }; 557 558 /* 559 * Track a single file's readahead state 560 */ 561 struct file_ra_state { 562 unsigned long start; /* Current window */ 563 unsigned long size; 564 unsigned long flags; /* ra flags RA_FLAG_xxx*/ 565 unsigned long cache_hit; /* cache hit count*/ 566 unsigned long prev_page; /* Cache last read() position */ 567 unsigned long ahead_start; /* Ahead window */ 568 unsigned long ahead_size; 569 unsigned long ra_pages; /* Maximum readahead window */ 570 unsigned long mmap_hit; /* Cache hit stat for mmap accesses */ 571 unsigned long mmap_miss; /* Cache miss stat for mmap accesses */ 572 }; 573 #define RA_FLAG_MISS 0x01 /* a cache miss occured against this file */ 574 #define RA_FLAG_INCACHE 0x02 /* file is already in cache */ 575 576 struct file { 577 struct list_head f_list; 578 struct dentry *f_dentry; 579 struct vfsmount *f_vfsmnt; 580 struct file_operations *f_op; 581 atomic_t f_count; 582 unsigned int f_flags; 583 mode_t f_mode; 584 loff_t f_pos; 585 struct fown_struct f_owner; 586 unsigned int f_uid, f_gid; 587 struct file_ra_state f_ra; 588 589 size_t f_maxcount; 590 unsigned long f_version; 591 void *f_security; 592 593 /* needed for tty driver, and maybe others */ 594 void *private_data; 595 596 #ifdef CONFIG_EPOLL 597 /* Used by fs/eventpoll.c to link all the hooks to this file */ 598 struct list_head f_ep_links; 599 spinlock_t f_ep_lock; 600 #endif /* #ifdef CONFIG_EPOLL */ 601 struct address_space *f_mapping; 602 }; 603 extern spinlock_t files_lock; 604 #define file_list_lock() spin_lock(&files_lock); 605 #define file_list_unlock() spin_unlock(&files_lock); 606 607 #define get_file(x) atomic_inc(&(x)->f_count) 608 #define file_count(x) atomic_read(&(x)->f_count) 609 610 #define MAX_NON_LFS ((1UL<<31) - 1) 611 612 /* Page cache limit. The filesystems should put that into their s_maxbytes 613 limits, otherwise bad things can happen in VM. */ 614 #if BITS_PER_LONG==32 615 #define MAX_LFS_FILESIZE (((u64)PAGE_CACHE_SIZE << (BITS_PER_LONG-1))-1) 616 #elif BITS_PER_LONG==64 617 #define MAX_LFS_FILESIZE 0x7fffffffffffffffUL 618 #endif 619 620 #define FL_POSIX 1 621 #define FL_FLOCK 2 622 #define FL_ACCESS 8 /* not trying to lock, just looking */ 623 #define FL_LOCKD 16 /* lock held by rpc.lockd */ 624 #define FL_LEASE 32 /* lease held on this file */ 625 #define FL_SLEEP 128 /* A blocking lock */ 626 627 /* 628 * The POSIX file lock owner is determined by 629 * the "struct files_struct" in the thread group 630 * (or NULL for no owner - BSD locks). 631 * 632 * Lockd stuffs a "host" pointer into this. 633 */ 634 typedef struct files_struct *fl_owner_t; 635 636 struct file_lock_operations { 637 void (*fl_insert)(struct file_lock *); /* lock insertion callback */ 638 void (*fl_remove)(struct file_lock *); /* lock removal callback */ 639 void (*fl_copy_lock)(struct file_lock *, struct file_lock *); 640 void (*fl_release_private)(struct file_lock *); 641 }; 642 643 struct lock_manager_operations { 644 int (*fl_compare_owner)(struct file_lock *, struct file_lock *); 645 void (*fl_notify)(struct file_lock *); /* unblock callback */ 646 void (*fl_copy_lock)(struct file_lock *, struct file_lock *); 647 void (*fl_release_private)(struct file_lock *); 648 void (*fl_break)(struct file_lock *); 649 int (*fl_mylease)(struct file_lock *, struct file_lock *); 650 int (*fl_change)(struct file_lock **, int); 651 }; 652 653 /* that will die - we need it for nfs_lock_info */ 654 #include <linux/nfs_fs_i.h> 655 656 struct file_lock { 657 struct file_lock *fl_next; /* singly linked list for this inode */ 658 struct list_head fl_link; /* doubly linked list of all locks */ 659 struct list_head fl_block; /* circular list of blocked processes */ 660 fl_owner_t fl_owner; 661 unsigned int fl_pid; 662 wait_queue_head_t fl_wait; 663 struct file *fl_file; 664 unsigned char fl_flags; 665 unsigned char fl_type; 666 loff_t fl_start; 667 loff_t fl_end; 668 669 struct fasync_struct * fl_fasync; /* for lease break notifications */ 670 unsigned long fl_break_time; /* for nonblocking lease breaks */ 671 672 struct file_lock_operations *fl_ops; /* Callbacks for filesystems */ 673 struct lock_manager_operations *fl_lmops; /* Callbacks for lockmanagers */ 674 union { 675 struct nfs_lock_info nfs_fl; 676 struct nfs4_lock_info nfs4_fl; 677 } fl_u; 678 }; 679 680 /* The following constant reflects the upper bound of the file/locking space */ 681 #ifndef OFFSET_MAX 682 #define INT_LIMIT(x) (~((x)1 << (sizeof(x)*8 - 1))) 683 #define OFFSET_MAX INT_LIMIT(loff_t) 684 #define OFFT_OFFSET_MAX INT_LIMIT(off_t) 685 #endif 686 687 extern struct list_head file_lock_list; 688 689 #include <linux/fcntl.h> 690 691 extern int fcntl_getlk(struct file *, struct flock __user *); 692 extern int fcntl_setlk(struct file *, unsigned int, struct flock __user *); 693 694 #if BITS_PER_LONG == 32 695 extern int fcntl_getlk64(struct file *, struct flock64 __user *); 696 extern int fcntl_setlk64(struct file *, unsigned int, struct flock64 __user *); 697 #endif 698 699 extern void send_sigio(struct fown_struct *fown, int fd, int band); 700 extern int fcntl_setlease(unsigned int fd, struct file *filp, long arg); 701 extern int fcntl_getlease(struct file *filp); 702 703 /* fs/locks.c */ 704 extern void locks_init_lock(struct file_lock *); 705 extern void locks_copy_lock(struct file_lock *, struct file_lock *); 706 extern void locks_remove_posix(struct file *, fl_owner_t); 707 extern void locks_remove_flock(struct file *); 708 extern struct file_lock *posix_test_lock(struct file *, struct file_lock *); 709 extern int posix_lock_file(struct file *, struct file_lock *); 710 extern int posix_lock_file_wait(struct file *, struct file_lock *); 711 extern void posix_block_lock(struct file_lock *, struct file_lock *); 712 extern void posix_unblock_lock(struct file *, struct file_lock *); 713 extern int posix_locks_deadlock(struct file_lock *, struct file_lock *); 714 extern int flock_lock_file_wait(struct file *filp, struct file_lock *fl); 715 extern int __break_lease(struct inode *inode, unsigned int flags); 716 extern void lease_get_mtime(struct inode *, struct timespec *time); 717 extern int setlease(struct file *, long, struct file_lock **); 718 extern int lease_modify(struct file_lock **, int); 719 extern int lock_may_read(struct inode *, loff_t start, unsigned long count); 720 extern int lock_may_write(struct inode *, loff_t start, unsigned long count); 721 extern void steal_locks(fl_owner_t from); 722 723 struct fasync_struct { 724 int magic; 725 int fa_fd; 726 struct fasync_struct *fa_next; /* singly linked list */ 727 struct file *fa_file; 728 }; 729 730 #define FASYNC_MAGIC 0x4601 731 732 /* SMP safe fasync helpers: */ 733 extern int fasync_helper(int, struct file *, int, struct fasync_struct **); 734 /* can be called from interrupts */ 735 extern void kill_fasync(struct fasync_struct **, int, int); 736 /* only for net: no internal synchronization */ 737 extern void __kill_fasync(struct fasync_struct *, int, int); 738 739 extern int f_setown(struct file *filp, unsigned long arg, int force); 740 extern void f_delown(struct file *filp); 741 extern int send_sigurg(struct fown_struct *fown); 742 743 /* 744 * Umount options 745 */ 746 747 #define MNT_FORCE 0x00000001 /* Attempt to forcibily umount */ 748 #define MNT_DETACH 0x00000002 /* Just detach from the tree */ 749 #define MNT_EXPIRE 0x00000004 /* Mark for expiry */ 750 751 extern struct list_head super_blocks; 752 extern spinlock_t sb_lock; 753 754 #define sb_entry(list) list_entry((list), struct super_block, s_list) 755 #define S_BIAS (1<<30) 756 struct super_block { 757 struct list_head s_list; /* Keep this first */ 758 dev_t s_dev; /* search index; _not_ kdev_t */ 759 unsigned long s_blocksize; 760 unsigned long s_old_blocksize; 761 unsigned char s_blocksize_bits; 762 unsigned char s_dirt; 763 unsigned long long s_maxbytes; /* Max file size */ 764 struct file_system_type *s_type; 765 struct super_operations *s_op; 766 struct dquot_operations *dq_op; 767 struct quotactl_ops *s_qcop; 768 struct export_operations *s_export_op; 769 unsigned long s_flags; 770 unsigned long s_magic; 771 struct dentry *s_root; 772 struct rw_semaphore s_umount; 773 struct semaphore s_lock; 774 int s_count; 775 int s_syncing; 776 int s_need_sync_fs; 777 atomic_t s_active; 778 void *s_security; 779 struct xattr_handler **s_xattr; 780 781 struct list_head s_inodes; /* all inodes */ 782 struct list_head s_dirty; /* dirty inodes */ 783 struct list_head s_io; /* parked for writeback */ 784 struct hlist_head s_anon; /* anonymous dentries for (nfs) exporting */ 785 struct list_head s_files; 786 787 struct block_device *s_bdev; 788 struct list_head s_instances; 789 struct quota_info s_dquot; /* Diskquota specific options */ 790 791 int s_frozen; 792 wait_queue_head_t s_wait_unfrozen; 793 794 char s_id[32]; /* Informational name */ 795 796 void *s_fs_info; /* Filesystem private info */ 797 798 /* 799 * The next field is for VFS *only*. No filesystems have any business 800 * even looking at it. You had been warned. 801 */ 802 struct semaphore s_vfs_rename_sem; /* Kludge */ 803 804 /* Granuality of c/m/atime in ns. 805 Cannot be worse than a second */ 806 u32 s_time_gran; 807 }; 808 809 extern struct timespec current_fs_time(struct super_block *sb); 810 811 /* 812 * Snapshotting support. 813 */ 814 enum { 815 SB_UNFROZEN = 0, 816 SB_FREEZE_WRITE = 1, 817 SB_FREEZE_TRANS = 2, 818 }; 819 820 #define vfs_check_frozen(sb, level) \ 821 wait_event((sb)->s_wait_unfrozen, ((sb)->s_frozen < (level))) 822 823 /* 824 * Superblock locking. 825 */ 826 static inline void lock_super(struct super_block * sb) 827 { 828 down(&sb->s_lock); 829 } 830 831 static inline void unlock_super(struct super_block * sb) 832 { 833 up(&sb->s_lock); 834 } 835 836 /* 837 * VFS helper functions.. 838 */ 839 extern int vfs_create(struct inode *, struct dentry *, int, struct nameidata *); 840 extern int vfs_mkdir(struct inode *, struct dentry *, int); 841 extern int vfs_mknod(struct inode *, struct dentry *, int, dev_t); 842 extern int vfs_symlink(struct inode *, struct dentry *, const char *, int); 843 extern int vfs_link(struct dentry *, struct inode *, struct dentry *); 844 extern int vfs_rmdir(struct inode *, struct dentry *); 845 extern int vfs_unlink(struct inode *, struct dentry *); 846 extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *); 847 848 /* 849 * VFS dentry helper functions. 850 */ 851 extern void dentry_unhash(struct dentry *dentry); 852 853 /* 854 * File types 855 * 856 * NOTE! These match bits 12..15 of stat.st_mode 857 * (ie "(i_mode >> 12) & 15"). 858 */ 859 #define DT_UNKNOWN 0 860 #define DT_FIFO 1 861 #define DT_CHR 2 862 #define DT_DIR 4 863 #define DT_BLK 6 864 #define DT_REG 8 865 #define DT_LNK 10 866 #define DT_SOCK 12 867 #define DT_WHT 14 868 869 #define OSYNC_METADATA (1<<0) 870 #define OSYNC_DATA (1<<1) 871 #define OSYNC_INODE (1<<2) 872 int generic_osync_inode(struct inode *, struct address_space *, int); 873 874 /* 875 * This is the "filldir" function type, used by readdir() to let 876 * the kernel specify what kind of dirent layout it wants to have. 877 * This allows the kernel to read directories into kernel space or 878 * to have different dirent layouts depending on the binary type. 879 */ 880 typedef int (*filldir_t)(void *, const char *, int, loff_t, ino_t, unsigned); 881 882 struct block_device_operations { 883 int (*open) (struct inode *, struct file *); 884 int (*release) (struct inode *, struct file *); 885 int (*ioctl) (struct inode *, struct file *, unsigned, unsigned long); 886 long (*unlocked_ioctl) (struct file *, unsigned, unsigned long); 887 long (*compat_ioctl) (struct file *, unsigned, unsigned long); 888 int (*media_changed) (struct gendisk *); 889 int (*revalidate_disk) (struct gendisk *); 890 struct module *owner; 891 }; 892 893 /* 894 * "descriptor" for what we're up to with a read for sendfile(). 895 * This allows us to use the same read code yet 896 * have multiple different users of the data that 897 * we read from a file. 898 * 899 * The simplest case just copies the data to user 900 * mode. 901 */ 902 typedef struct { 903 size_t written; 904 size_t count; 905 union { 906 char __user * buf; 907 void *data; 908 } arg; 909 int error; 910 } read_descriptor_t; 911 912 typedef int (*read_actor_t)(read_descriptor_t *, struct page *, unsigned long, unsigned long); 913 914 /* These macros are for out of kernel modules to test that 915 * the kernel supports the unlocked_ioctl and compat_ioctl 916 * fields in struct file_operations. */ 917 #define HAVE_COMPAT_IOCTL 1 918 #define HAVE_UNLOCKED_IOCTL 1 919 920 /* 921 * NOTE: 922 * read, write, poll, fsync, readv, writev, unlocked_ioctl and compat_ioctl 923 * can be called without the big kernel lock held in all filesystems. 924 */ 925 struct file_operations { 926 struct module *owner; 927 loff_t (*llseek) (struct file *, loff_t, int); 928 ssize_t (*read) (struct file *, char __user *, size_t, loff_t *); 929 ssize_t (*aio_read) (struct kiocb *, char __user *, size_t, loff_t); 930 ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *); 931 ssize_t (*aio_write) (struct kiocb *, const char __user *, size_t, loff_t); 932 int (*readdir) (struct file *, void *, filldir_t); 933 unsigned int (*poll) (struct file *, struct poll_table_struct *); 934 int (*ioctl) (struct inode *, struct file *, unsigned int, unsigned long); 935 long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long); 936 long (*compat_ioctl) (struct file *, unsigned int, unsigned long); 937 int (*mmap) (struct file *, struct vm_area_struct *); 938 int (*open) (struct inode *, struct file *); 939 int (*flush) (struct file *); 940 int (*release) (struct inode *, struct file *); 941 int (*fsync) (struct file *, struct dentry *, int datasync); 942 int (*aio_fsync) (struct kiocb *, int datasync); 943 int (*fasync) (int, struct file *, int); 944 int (*lock) (struct file *, int, struct file_lock *); 945 ssize_t (*readv) (struct file *, const struct iovec *, unsigned long, loff_t *); 946 ssize_t (*writev) (struct file *, const struct iovec *, unsigned long, loff_t *); 947 ssize_t (*sendfile) (struct file *, loff_t *, size_t, read_actor_t, void *); 948 ssize_t (*sendpage) (struct file *, struct page *, int, size_t, loff_t *, int); 949 unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long); 950 int (*check_flags)(int); 951 int (*dir_notify)(struct file *filp, unsigned long arg); 952 int (*flock) (struct file *, int, struct file_lock *); 953 }; 954 955 struct inode_operations { 956 int (*create) (struct inode *,struct dentry *,int, struct nameidata *); 957 struct dentry * (*lookup) (struct inode *,struct dentry *, struct nameidata *); 958 int (*link) (struct dentry *,struct inode *,struct dentry *); 959 int (*unlink) (struct inode *,struct dentry *); 960 int (*symlink) (struct inode *,struct dentry *,const char *); 961 int (*mkdir) (struct inode *,struct dentry *,int); 962 int (*rmdir) (struct inode *,struct dentry *); 963 int (*mknod) (struct inode *,struct dentry *,int,dev_t); 964 int (*rename) (struct inode *, struct dentry *, 965 struct inode *, struct dentry *); 966 int (*readlink) (struct dentry *, char __user *,int); 967 int (*follow_link) (struct dentry *, struct nameidata *); 968 void (*put_link) (struct dentry *, struct nameidata *); 969 void (*truncate) (struct inode *); 970 int (*permission) (struct inode *, int, struct nameidata *); 971 int (*setattr) (struct dentry *, struct iattr *); 972 int (*getattr) (struct vfsmount *mnt, struct dentry *, struct kstat *); 973 int (*setxattr) (struct dentry *, const char *,const void *,size_t,int); 974 ssize_t (*getxattr) (struct dentry *, const char *, void *, size_t); 975 ssize_t (*listxattr) (struct dentry *, char *, size_t); 976 int (*removexattr) (struct dentry *, const char *); 977 }; 978 979 struct seq_file; 980 981 extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *); 982 extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *); 983 extern ssize_t vfs_readv(struct file *, const struct iovec __user *, 984 unsigned long, loff_t *); 985 extern ssize_t vfs_writev(struct file *, const struct iovec __user *, 986 unsigned long, loff_t *); 987 988 /* 989 * NOTE: write_inode, delete_inode, clear_inode, put_inode can be called 990 * without the big kernel lock held in all filesystems. 991 */ 992 struct super_operations { 993 struct inode *(*alloc_inode)(struct super_block *sb); 994 void (*destroy_inode)(struct inode *); 995 996 void (*read_inode) (struct inode *); 997 998 void (*dirty_inode) (struct inode *); 999 int (*write_inode) (struct inode *, int); 1000 void (*put_inode) (struct inode *); 1001 void (*drop_inode) (struct inode *); 1002 void (*delete_inode) (struct inode *); 1003 void (*put_super) (struct super_block *); 1004 void (*write_super) (struct super_block *); 1005 int (*sync_fs)(struct super_block *sb, int wait); 1006 void (*write_super_lockfs) (struct super_block *); 1007 void (*unlockfs) (struct super_block *); 1008 int (*statfs) (struct super_block *, struct kstatfs *); 1009 int (*remount_fs) (struct super_block *, int *, char *); 1010 void (*clear_inode) (struct inode *); 1011 void (*umount_begin) (struct super_block *); 1012 1013 int (*show_options)(struct seq_file *, struct vfsmount *); 1014 1015 ssize_t (*quota_read)(struct super_block *, int, char *, size_t, loff_t); 1016 ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t); 1017 }; 1018 1019 /* Inode state bits. Protected by inode_lock. */ 1020 #define I_DIRTY_SYNC 1 /* Not dirty enough for O_DATASYNC */ 1021 #define I_DIRTY_DATASYNC 2 /* Data-related inode changes pending */ 1022 #define I_DIRTY_PAGES 4 /* Data-related inode changes pending */ 1023 #define __I_LOCK 3 1024 #define I_LOCK (1 << __I_LOCK) 1025 #define I_FREEING 16 1026 #define I_CLEAR 32 1027 #define I_NEW 64 1028 #define I_WILL_FREE 128 1029 1030 #define I_DIRTY (I_DIRTY_SYNC | I_DIRTY_DATASYNC | I_DIRTY_PAGES) 1031 1032 extern void __mark_inode_dirty(struct inode *, int); 1033 static inline void mark_inode_dirty(struct inode *inode) 1034 { 1035 __mark_inode_dirty(inode, I_DIRTY); 1036 } 1037 1038 static inline void mark_inode_dirty_sync(struct inode *inode) 1039 { 1040 __mark_inode_dirty(inode, I_DIRTY_SYNC); 1041 } 1042 1043 static inline void touch_atime(struct vfsmount *mnt, struct dentry *dentry) 1044 { 1045 /* per-mountpoint checks will go here */ 1046 update_atime(dentry->d_inode); 1047 } 1048 1049 static inline void file_accessed(struct file *file) 1050 { 1051 if (!(file->f_flags & O_NOATIME)) 1052 touch_atime(file->f_vfsmnt, file->f_dentry); 1053 } 1054 1055 int sync_inode(struct inode *inode, struct writeback_control *wbc); 1056 1057 /** 1058 * struct export_operations - for nfsd to communicate with file systems 1059 * @decode_fh: decode a file handle fragment and return a &struct dentry 1060 * @encode_fh: encode a file handle fragment from a dentry 1061 * @get_name: find the name for a given inode in a given directory 1062 * @get_parent: find the parent of a given directory 1063 * @get_dentry: find a dentry for the inode given a file handle sub-fragment 1064 * 1065 * Description: 1066 * The export_operations structure provides a means for nfsd to communicate 1067 * with a particular exported file system - particularly enabling nfsd and 1068 * the filesystem to co-operate when dealing with file handles. 1069 * 1070 * export_operations contains two basic operation for dealing with file 1071 * handles, decode_fh() and encode_fh(), and allows for some other 1072 * operations to be defined which standard helper routines use to get 1073 * specific information from the filesystem. 1074 * 1075 * nfsd encodes information use to determine which filesystem a filehandle 1076 * applies to in the initial part of the file handle. The remainder, termed 1077 * a file handle fragment, is controlled completely by the filesystem. The 1078 * standard helper routines assume that this fragment will contain one or 1079 * two sub-fragments, one which identifies the file, and one which may be 1080 * used to identify the (a) directory containing the file. 1081 * 1082 * In some situations, nfsd needs to get a dentry which is connected into a 1083 * specific part of the file tree. To allow for this, it passes the 1084 * function acceptable() together with a @context which can be used to see 1085 * if the dentry is acceptable. As there can be multiple dentrys for a 1086 * given file, the filesystem should check each one for acceptability before 1087 * looking for the next. As soon as an acceptable one is found, it should 1088 * be returned. 1089 * 1090 * decode_fh: 1091 * @decode_fh is given a &struct super_block (@sb), a file handle fragment 1092 * (@fh, @fh_len) and an acceptability testing function (@acceptable, 1093 * @context). It should return a &struct dentry which refers to the same 1094 * file that the file handle fragment refers to, and which passes the 1095 * acceptability test. If it cannot, it should return a %NULL pointer if 1096 * the file was found but no acceptable &dentries were available, or a 1097 * %ERR_PTR error code indicating why it couldn't be found (e.g. %ENOENT or 1098 * %ENOMEM). 1099 * 1100 * encode_fh: 1101 * @encode_fh should store in the file handle fragment @fh (using at most 1102 * @max_len bytes) information that can be used by @decode_fh to recover the 1103 * file refered to by the &struct dentry @de. If the @connectable flag is 1104 * set, the encode_fh() should store sufficient information so that a good 1105 * attempt can be made to find not only the file but also it's place in the 1106 * filesystem. This typically means storing a reference to de->d_parent in 1107 * the filehandle fragment. encode_fh() should return the number of bytes 1108 * stored or a negative error code such as %-ENOSPC 1109 * 1110 * get_name: 1111 * @get_name should find a name for the given @child in the given @parent 1112 * directory. The name should be stored in the @name (with the 1113 * understanding that it is already pointing to a a %NAME_MAX+1 sized 1114 * buffer. get_name() should return %0 on success, a negative error code 1115 * or error. @get_name will be called without @parent->i_sem held. 1116 * 1117 * get_parent: 1118 * @get_parent should find the parent directory for the given @child which 1119 * is also a directory. In the event that it cannot be found, or storage 1120 * space cannot be allocated, a %ERR_PTR should be returned. 1121 * 1122 * get_dentry: 1123 * Given a &super_block (@sb) and a pointer to a file-system specific inode 1124 * identifier, possibly an inode number, (@inump) get_dentry() should find 1125 * the identified inode and return a dentry for that inode. Any suitable 1126 * dentry can be returned including, if necessary, a new dentry created with 1127 * d_alloc_root. The caller can then find any other extant dentrys by 1128 * following the d_alias links. If a new dentry was created using 1129 * d_alloc_root, DCACHE_NFSD_DISCONNECTED should be set, and the dentry 1130 * should be d_rehash()ed. 1131 * 1132 * If the inode cannot be found, either a %NULL pointer or an %ERR_PTR code 1133 * can be returned. The @inump will be whatever was passed to 1134 * nfsd_find_fh_dentry() in either the @obj or @parent parameters. 1135 * 1136 * Locking rules: 1137 * get_parent is called with child->d_inode->i_sem down 1138 * get_name is not (which is possibly inconsistent) 1139 */ 1140 1141 struct export_operations { 1142 struct dentry *(*decode_fh)(struct super_block *sb, __u32 *fh, int fh_len, int fh_type, 1143 int (*acceptable)(void *context, struct dentry *de), 1144 void *context); 1145 int (*encode_fh)(struct dentry *de, __u32 *fh, int *max_len, 1146 int connectable); 1147 1148 /* the following are only called from the filesystem itself */ 1149 int (*get_name)(struct dentry *parent, char *name, 1150 struct dentry *child); 1151 struct dentry * (*get_parent)(struct dentry *child); 1152 struct dentry * (*get_dentry)(struct super_block *sb, void *inump); 1153 1154 /* This is set by the exporting module to a standard helper */ 1155 struct dentry * (*find_exported_dentry)( 1156 struct super_block *sb, void *obj, void *parent, 1157 int (*acceptable)(void *context, struct dentry *de), 1158 void *context); 1159 1160 1161 }; 1162 1163 extern struct dentry * 1164 find_exported_dentry(struct super_block *sb, void *obj, void *parent, 1165 int (*acceptable)(void *context, struct dentry *de), 1166 void *context); 1167 1168 struct file_system_type { 1169 const char *name; 1170 int fs_flags; 1171 struct super_block *(*get_sb) (struct file_system_type *, int, 1172 const char *, void *); 1173 void (*kill_sb) (struct super_block *); 1174 struct module *owner; 1175 struct file_system_type * next; 1176 struct list_head fs_supers; 1177 }; 1178 1179 struct super_block *get_sb_bdev(struct file_system_type *fs_type, 1180 int flags, const char *dev_name, void *data, 1181 int (*fill_super)(struct super_block *, void *, int)); 1182 struct super_block *get_sb_single(struct file_system_type *fs_type, 1183 int flags, void *data, 1184 int (*fill_super)(struct super_block *, void *, int)); 1185 struct super_block *get_sb_nodev(struct file_system_type *fs_type, 1186 int flags, void *data, 1187 int (*fill_super)(struct super_block *, void *, int)); 1188 void generic_shutdown_super(struct super_block *sb); 1189 void kill_block_super(struct super_block *sb); 1190 void kill_anon_super(struct super_block *sb); 1191 void kill_litter_super(struct super_block *sb); 1192 void deactivate_super(struct super_block *sb); 1193 int set_anon_super(struct super_block *s, void *data); 1194 struct super_block *sget(struct file_system_type *type, 1195 int (*test)(struct super_block *,void *), 1196 int (*set)(struct super_block *,void *), 1197 void *data); 1198 struct super_block *get_sb_pseudo(struct file_system_type *, char *, 1199 struct super_operations *ops, unsigned long); 1200 int __put_super(struct super_block *sb); 1201 int __put_super_and_need_restart(struct super_block *sb); 1202 void unnamed_dev_init(void); 1203 1204 /* Alas, no aliases. Too much hassle with bringing module.h everywhere */ 1205 #define fops_get(fops) \ 1206 (((fops) && try_module_get((fops)->owner) ? (fops) : NULL)) 1207 #define fops_put(fops) \ 1208 do { if (fops) module_put((fops)->owner); } while(0) 1209 1210 extern int register_filesystem(struct file_system_type *); 1211 extern int unregister_filesystem(struct file_system_type *); 1212 extern struct vfsmount *kern_mount(struct file_system_type *); 1213 extern int may_umount_tree(struct vfsmount *); 1214 extern int may_umount(struct vfsmount *); 1215 extern long do_mount(char *, char *, char *, unsigned long, void *); 1216 1217 extern int vfs_statfs(struct super_block *, struct kstatfs *); 1218 1219 #define FLOCK_VERIFY_READ 1 1220 #define FLOCK_VERIFY_WRITE 2 1221 1222 extern int locks_mandatory_locked(struct inode *); 1223 extern int locks_mandatory_area(int, struct inode *, struct file *, loff_t, size_t); 1224 1225 /* 1226 * Candidates for mandatory locking have the setgid bit set 1227 * but no group execute bit - an otherwise meaningless combination. 1228 */ 1229 #define MANDATORY_LOCK(inode) \ 1230 (IS_MANDLOCK(inode) && ((inode)->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID) 1231 1232 static inline int locks_verify_locked(struct inode *inode) 1233 { 1234 if (MANDATORY_LOCK(inode)) 1235 return locks_mandatory_locked(inode); 1236 return 0; 1237 } 1238 1239 extern int rw_verify_area(int, struct file *, loff_t *, size_t); 1240 1241 static inline int locks_verify_truncate(struct inode *inode, 1242 struct file *filp, 1243 loff_t size) 1244 { 1245 if (inode->i_flock && MANDATORY_LOCK(inode)) 1246 return locks_mandatory_area( 1247 FLOCK_VERIFY_WRITE, inode, filp, 1248 size < inode->i_size ? size : inode->i_size, 1249 (size < inode->i_size ? inode->i_size - size 1250 : size - inode->i_size) 1251 ); 1252 return 0; 1253 } 1254 1255 static inline int break_lease(struct inode *inode, unsigned int mode) 1256 { 1257 if (inode->i_flock) 1258 return __break_lease(inode, mode); 1259 return 0; 1260 } 1261 1262 /* fs/open.c */ 1263 1264 extern int do_truncate(struct dentry *, loff_t start); 1265 extern struct file *filp_open(const char *, int, int); 1266 extern struct file * dentry_open(struct dentry *, struct vfsmount *, int); 1267 extern int filp_close(struct file *, fl_owner_t id); 1268 extern char * getname(const char __user *); 1269 1270 /* fs/dcache.c */ 1271 extern void __init vfs_caches_init_early(void); 1272 extern void __init vfs_caches_init(unsigned long); 1273 1274 #define __getname() kmem_cache_alloc(names_cachep, SLAB_KERNEL) 1275 #define __putname(name) kmem_cache_free(names_cachep, (void *)(name)) 1276 #ifndef CONFIG_AUDITSYSCALL 1277 #define putname(name) __putname(name) 1278 #else 1279 extern void putname(const char *name); 1280 #endif 1281 1282 extern int register_blkdev(unsigned int, const char *); 1283 extern int unregister_blkdev(unsigned int, const char *); 1284 extern struct block_device *bdget(dev_t); 1285 extern void bd_set_size(struct block_device *, loff_t size); 1286 extern void bd_forget(struct inode *inode); 1287 extern void bdput(struct block_device *); 1288 extern struct block_device *open_by_devnum(dev_t, unsigned); 1289 extern struct file_operations def_blk_fops; 1290 extern struct address_space_operations def_blk_aops; 1291 extern struct file_operations def_chr_fops; 1292 extern struct file_operations bad_sock_fops; 1293 extern struct file_operations def_fifo_fops; 1294 extern int ioctl_by_bdev(struct block_device *, unsigned, unsigned long); 1295 extern int blkdev_ioctl(struct inode *, struct file *, unsigned, unsigned long); 1296 extern long compat_blkdev_ioctl(struct file *, unsigned, unsigned long); 1297 extern int blkdev_get(struct block_device *, mode_t, unsigned); 1298 extern int blkdev_put(struct block_device *); 1299 extern int bd_claim(struct block_device *, void *); 1300 extern void bd_release(struct block_device *); 1301 1302 /* fs/char_dev.c */ 1303 extern int alloc_chrdev_region(dev_t *, unsigned, unsigned, const char *); 1304 extern int register_chrdev_region(dev_t, unsigned, const char *); 1305 extern int register_chrdev(unsigned int, const char *, 1306 struct file_operations *); 1307 extern int unregister_chrdev(unsigned int, const char *); 1308 extern void unregister_chrdev_region(dev_t, unsigned); 1309 extern int chrdev_open(struct inode *, struct file *); 1310 1311 /* fs/block_dev.c */ 1312 #define BDEVNAME_SIZE 32 /* Largest string for a blockdev identifier */ 1313 extern const char *__bdevname(dev_t, char *buffer); 1314 extern const char *bdevname(struct block_device *bdev, char *buffer); 1315 extern struct block_device *lookup_bdev(const char *); 1316 extern struct block_device *open_bdev_excl(const char *, int, void *); 1317 extern void close_bdev_excl(struct block_device *); 1318 1319 extern void init_special_inode(struct inode *, umode_t, dev_t); 1320 1321 /* Invalid inode operations -- fs/bad_inode.c */ 1322 extern void make_bad_inode(struct inode *); 1323 extern int is_bad_inode(struct inode *); 1324 1325 extern struct file_operations read_fifo_fops; 1326 extern struct file_operations write_fifo_fops; 1327 extern struct file_operations rdwr_fifo_fops; 1328 extern struct file_operations read_pipe_fops; 1329 extern struct file_operations write_pipe_fops; 1330 extern struct file_operations rdwr_pipe_fops; 1331 1332 extern int fs_may_remount_ro(struct super_block *); 1333 1334 /* 1335 * return READ, READA, or WRITE 1336 */ 1337 #define bio_rw(bio) ((bio)->bi_rw & (RW_MASK | RWA_MASK)) 1338 1339 /* 1340 * return data direction, READ or WRITE 1341 */ 1342 #define bio_data_dir(bio) ((bio)->bi_rw & 1) 1343 1344 extern int check_disk_change(struct block_device *); 1345 extern int invalidate_inodes(struct super_block *); 1346 extern int __invalidate_device(struct block_device *); 1347 extern int invalidate_partition(struct gendisk *, int); 1348 unsigned long invalidate_mapping_pages(struct address_space *mapping, 1349 pgoff_t start, pgoff_t end); 1350 unsigned long invalidate_inode_pages(struct address_space *mapping); 1351 static inline void invalidate_remote_inode(struct inode *inode) 1352 { 1353 if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || 1354 S_ISLNK(inode->i_mode)) 1355 invalidate_inode_pages(inode->i_mapping); 1356 } 1357 extern int invalidate_inode_pages2(struct address_space *mapping); 1358 extern int invalidate_inode_pages2_range(struct address_space *mapping, 1359 pgoff_t start, pgoff_t end); 1360 extern int write_inode_now(struct inode *, int); 1361 extern int filemap_fdatawrite(struct address_space *); 1362 extern int filemap_flush(struct address_space *); 1363 extern int filemap_fdatawait(struct address_space *); 1364 extern int filemap_write_and_wait(struct address_space *mapping); 1365 extern int filemap_write_and_wait_range(struct address_space *mapping, 1366 loff_t lstart, loff_t lend); 1367 extern void sync_supers(void); 1368 extern void sync_filesystems(int wait); 1369 extern void emergency_sync(void); 1370 extern void emergency_remount(void); 1371 extern int do_remount_sb(struct super_block *sb, int flags, 1372 void *data, int force); 1373 extern sector_t bmap(struct inode *, sector_t); 1374 extern int setattr_mask(unsigned int); 1375 extern int notify_change(struct dentry *, struct iattr *); 1376 extern int permission(struct inode *, int, struct nameidata *); 1377 extern int generic_permission(struct inode *, int, 1378 int (*check_acl)(struct inode *, int)); 1379 1380 extern int get_write_access(struct inode *); 1381 extern int deny_write_access(struct file *); 1382 static inline void put_write_access(struct inode * inode) 1383 { 1384 atomic_dec(&inode->i_writecount); 1385 } 1386 static inline void allow_write_access(struct file *file) 1387 { 1388 if (file) 1389 atomic_inc(&file->f_dentry->d_inode->i_writecount); 1390 } 1391 extern int do_pipe(int *); 1392 1393 extern int open_namei(const char *, int, int, struct nameidata *); 1394 extern int may_open(struct nameidata *, int, int); 1395 1396 extern int kernel_read(struct file *, unsigned long, char *, unsigned long); 1397 extern struct file * open_exec(const char *); 1398 1399 /* fs/dcache.c -- generic fs support functions */ 1400 extern int is_subdir(struct dentry *, struct dentry *); 1401 extern ino_t find_inode_number(struct dentry *, struct qstr *); 1402 1403 #include <linux/err.h> 1404 1405 /* needed for stackable file system support */ 1406 extern loff_t default_llseek(struct file *file, loff_t offset, int origin); 1407 1408 extern loff_t vfs_llseek(struct file *file, loff_t offset, int origin); 1409 1410 extern void inode_init_once(struct inode *); 1411 extern void iput(struct inode *); 1412 extern struct inode * igrab(struct inode *); 1413 extern ino_t iunique(struct super_block *, ino_t); 1414 extern int inode_needs_sync(struct inode *inode); 1415 extern void generic_delete_inode(struct inode *inode); 1416 1417 extern struct inode *ilookup5(struct super_block *sb, unsigned long hashval, 1418 int (*test)(struct inode *, void *), void *data); 1419 extern struct inode *ilookup(struct super_block *sb, unsigned long ino); 1420 1421 extern struct inode * iget5_locked(struct super_block *, unsigned long, int (*test)(struct inode *, void *), int (*set)(struct inode *, void *), void *); 1422 extern struct inode * iget_locked(struct super_block *, unsigned long); 1423 extern void unlock_new_inode(struct inode *); 1424 1425 static inline struct inode *iget(struct super_block *sb, unsigned long ino) 1426 { 1427 struct inode *inode = iget_locked(sb, ino); 1428 1429 if (inode && (inode->i_state & I_NEW)) { 1430 sb->s_op->read_inode(inode); 1431 unlock_new_inode(inode); 1432 } 1433 1434 return inode; 1435 } 1436 1437 extern void __iget(struct inode * inode); 1438 extern void clear_inode(struct inode *); 1439 extern void destroy_inode(struct inode *); 1440 extern struct inode *new_inode(struct super_block *); 1441 extern int remove_suid(struct dentry *); 1442 extern void remove_dquot_ref(struct super_block *, int, struct list_head *); 1443 extern struct semaphore iprune_sem; 1444 1445 extern void __insert_inode_hash(struct inode *, unsigned long hashval); 1446 extern void remove_inode_hash(struct inode *); 1447 static inline void insert_inode_hash(struct inode *inode) { 1448 __insert_inode_hash(inode, inode->i_ino); 1449 } 1450 1451 extern struct file * get_empty_filp(void); 1452 extern void file_move(struct file *f, struct list_head *list); 1453 extern void file_kill(struct file *f); 1454 struct bio; 1455 extern void submit_bio(int, struct bio *); 1456 extern int bdev_read_only(struct block_device *); 1457 extern int set_blocksize(struct block_device *, int); 1458 extern int sb_set_blocksize(struct super_block *, int); 1459 extern int sb_min_blocksize(struct super_block *, int); 1460 1461 extern int generic_file_mmap(struct file *, struct vm_area_struct *); 1462 extern int generic_file_readonly_mmap(struct file *, struct vm_area_struct *); 1463 extern int file_read_actor(read_descriptor_t * desc, struct page *page, unsigned long offset, unsigned long size); 1464 extern int file_send_actor(read_descriptor_t * desc, struct page *page, unsigned long offset, unsigned long size); 1465 extern ssize_t generic_file_read(struct file *, char __user *, size_t, loff_t *); 1466 int generic_write_checks(struct file *file, loff_t *pos, size_t *count, int isblk); 1467 extern ssize_t generic_file_write(struct file *, const char __user *, size_t, loff_t *); 1468 extern ssize_t generic_file_aio_read(struct kiocb *, char __user *, size_t, loff_t); 1469 extern ssize_t __generic_file_aio_read(struct kiocb *, const struct iovec *, unsigned long, loff_t *); 1470 extern ssize_t generic_file_aio_write(struct kiocb *, const char __user *, size_t, loff_t); 1471 extern ssize_t generic_file_aio_write_nolock(struct kiocb *, const struct iovec *, 1472 unsigned long, loff_t *); 1473 extern ssize_t generic_file_direct_write(struct kiocb *, const struct iovec *, 1474 unsigned long *, loff_t, loff_t *, size_t, size_t); 1475 extern ssize_t generic_file_buffered_write(struct kiocb *, const struct iovec *, 1476 unsigned long, loff_t, loff_t *, size_t, ssize_t); 1477 extern ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos); 1478 extern ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos); 1479 ssize_t generic_file_write_nolock(struct file *file, const struct iovec *iov, 1480 unsigned long nr_segs, loff_t *ppos); 1481 extern ssize_t generic_file_sendfile(struct file *, loff_t *, size_t, read_actor_t, void *); 1482 extern void do_generic_mapping_read(struct address_space *mapping, 1483 struct file_ra_state *, struct file *, 1484 loff_t *, read_descriptor_t *, read_actor_t); 1485 extern void 1486 file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping); 1487 extern ssize_t generic_file_direct_IO(int rw, struct kiocb *iocb, 1488 const struct iovec *iov, loff_t offset, unsigned long nr_segs); 1489 extern ssize_t generic_file_readv(struct file *filp, const struct iovec *iov, 1490 unsigned long nr_segs, loff_t *ppos); 1491 ssize_t generic_file_writev(struct file *filp, const struct iovec *iov, 1492 unsigned long nr_segs, loff_t *ppos); 1493 extern loff_t no_llseek(struct file *file, loff_t offset, int origin); 1494 extern loff_t generic_file_llseek(struct file *file, loff_t offset, int origin); 1495 extern loff_t remote_llseek(struct file *file, loff_t offset, int origin); 1496 extern int generic_file_open(struct inode * inode, struct file * filp); 1497 extern int nonseekable_open(struct inode * inode, struct file * filp); 1498 1499 static inline void do_generic_file_read(struct file * filp, loff_t *ppos, 1500 read_descriptor_t * desc, 1501 read_actor_t actor) 1502 { 1503 do_generic_mapping_read(filp->f_mapping, 1504 &filp->f_ra, 1505 filp, 1506 ppos, 1507 desc, 1508 actor); 1509 } 1510 1511 ssize_t __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode, 1512 struct block_device *bdev, const struct iovec *iov, loff_t offset, 1513 unsigned long nr_segs, get_blocks_t get_blocks, dio_iodone_t end_io, 1514 int lock_type); 1515 1516 enum { 1517 DIO_LOCKING = 1, /* need locking between buffered and direct access */ 1518 DIO_NO_LOCKING, /* bdev; no locking at all between buffered/direct */ 1519 DIO_OWN_LOCKING, /* filesystem locks buffered and direct internally */ 1520 }; 1521 1522 static inline ssize_t blockdev_direct_IO(int rw, struct kiocb *iocb, 1523 struct inode *inode, struct block_device *bdev, const struct iovec *iov, 1524 loff_t offset, unsigned long nr_segs, get_blocks_t get_blocks, 1525 dio_iodone_t end_io) 1526 { 1527 return __blockdev_direct_IO(rw, iocb, inode, bdev, iov, offset, 1528 nr_segs, get_blocks, end_io, DIO_LOCKING); 1529 } 1530 1531 static inline ssize_t blockdev_direct_IO_no_locking(int rw, struct kiocb *iocb, 1532 struct inode *inode, struct block_device *bdev, const struct iovec *iov, 1533 loff_t offset, unsigned long nr_segs, get_blocks_t get_blocks, 1534 dio_iodone_t end_io) 1535 { 1536 return __blockdev_direct_IO(rw, iocb, inode, bdev, iov, offset, 1537 nr_segs, get_blocks, end_io, DIO_NO_LOCKING); 1538 } 1539 1540 static inline ssize_t blockdev_direct_IO_own_locking(int rw, struct kiocb *iocb, 1541 struct inode *inode, struct block_device *bdev, const struct iovec *iov, 1542 loff_t offset, unsigned long nr_segs, get_blocks_t get_blocks, 1543 dio_iodone_t end_io) 1544 { 1545 return __blockdev_direct_IO(rw, iocb, inode, bdev, iov, offset, 1546 nr_segs, get_blocks, end_io, DIO_OWN_LOCKING); 1547 } 1548 1549 extern struct file_operations generic_ro_fops; 1550 1551 #define special_file(m) (S_ISCHR(m)||S_ISBLK(m)||S_ISFIFO(m)||S_ISSOCK(m)) 1552 1553 extern int vfs_readlink(struct dentry *, char __user *, int, const char *); 1554 extern int vfs_follow_link(struct nameidata *, const char *); 1555 extern int page_readlink(struct dentry *, char __user *, int); 1556 extern int page_follow_link_light(struct dentry *, struct nameidata *); 1557 extern void page_put_link(struct dentry *, struct nameidata *); 1558 extern int page_symlink(struct inode *inode, const char *symname, int len); 1559 extern struct inode_operations page_symlink_inode_operations; 1560 extern int generic_readlink(struct dentry *, char __user *, int); 1561 extern void generic_fillattr(struct inode *, struct kstat *); 1562 extern int vfs_getattr(struct vfsmount *, struct dentry *, struct kstat *); 1563 void inode_add_bytes(struct inode *inode, loff_t bytes); 1564 void inode_sub_bytes(struct inode *inode, loff_t bytes); 1565 loff_t inode_get_bytes(struct inode *inode); 1566 void inode_set_bytes(struct inode *inode, loff_t bytes); 1567 1568 extern int vfs_readdir(struct file *, filldir_t, void *); 1569 1570 extern int vfs_stat(char __user *, struct kstat *); 1571 extern int vfs_lstat(char __user *, struct kstat *); 1572 extern int vfs_fstat(unsigned int, struct kstat *); 1573 1574 extern int vfs_ioctl(struct file *, unsigned int, unsigned int, unsigned long); 1575 1576 extern struct file_system_type *get_fs_type(const char *name); 1577 extern struct super_block *get_super(struct block_device *); 1578 extern struct super_block *user_get_super(dev_t); 1579 extern void drop_super(struct super_block *sb); 1580 1581 extern int dcache_dir_open(struct inode *, struct file *); 1582 extern int dcache_dir_close(struct inode *, struct file *); 1583 extern loff_t dcache_dir_lseek(struct file *, loff_t, int); 1584 extern int dcache_readdir(struct file *, void *, filldir_t); 1585 extern int simple_getattr(struct vfsmount *, struct dentry *, struct kstat *); 1586 extern int simple_statfs(struct super_block *, struct kstatfs *); 1587 extern int simple_link(struct dentry *, struct inode *, struct dentry *); 1588 extern int simple_unlink(struct inode *, struct dentry *); 1589 extern int simple_rmdir(struct inode *, struct dentry *); 1590 extern int simple_rename(struct inode *, struct dentry *, struct inode *, struct dentry *); 1591 extern int simple_sync_file(struct file *, struct dentry *, int); 1592 extern int simple_empty(struct dentry *); 1593 extern int simple_readpage(struct file *file, struct page *page); 1594 extern int simple_prepare_write(struct file *file, struct page *page, 1595 unsigned offset, unsigned to); 1596 extern int simple_commit_write(struct file *file, struct page *page, 1597 unsigned offset, unsigned to); 1598 1599 extern struct dentry *simple_lookup(struct inode *, struct dentry *, struct nameidata *); 1600 extern ssize_t generic_read_dir(struct file *, char __user *, size_t, loff_t *); 1601 extern struct file_operations simple_dir_operations; 1602 extern struct inode_operations simple_dir_inode_operations; 1603 struct tree_descr { char *name; struct file_operations *ops; int mode; }; 1604 struct dentry *d_alloc_name(struct dentry *, const char *); 1605 extern int simple_fill_super(struct super_block *, int, struct tree_descr *); 1606 extern int simple_pin_fs(char *name, struct vfsmount **mount, int *count); 1607 extern void simple_release_fs(struct vfsmount **mount, int *count); 1608 1609 extern ssize_t simple_read_from_buffer(void __user *, size_t, loff_t *, const void *, size_t); 1610 1611 extern int inode_change_ok(struct inode *, struct iattr *); 1612 extern int __must_check inode_setattr(struct inode *, struct iattr *); 1613 1614 extern void inode_update_time(struct inode *inode, int ctime_too); 1615 1616 static inline ino_t parent_ino(struct dentry *dentry) 1617 { 1618 ino_t res; 1619 1620 spin_lock(&dentry->d_lock); 1621 res = dentry->d_parent->d_inode->i_ino; 1622 spin_unlock(&dentry->d_lock); 1623 return res; 1624 } 1625 1626 /* kernel/fork.c */ 1627 extern int unshare_files(void); 1628 1629 /* Transaction based IO helpers */ 1630 1631 /* 1632 * An argresp is stored in an allocated page and holds the 1633 * size of the argument or response, along with its content 1634 */ 1635 struct simple_transaction_argresp { 1636 ssize_t size; 1637 char data[0]; 1638 }; 1639 1640 #define SIMPLE_TRANSACTION_LIMIT (PAGE_SIZE - sizeof(struct simple_transaction_argresp)) 1641 1642 char *simple_transaction_get(struct file *file, const char __user *buf, 1643 size_t size); 1644 ssize_t simple_transaction_read(struct file *file, char __user *buf, 1645 size_t size, loff_t *pos); 1646 int simple_transaction_release(struct inode *inode, struct file *file); 1647 1648 static inline void simple_transaction_set(struct file *file, size_t n) 1649 { 1650 struct simple_transaction_argresp *ar = file->private_data; 1651 1652 BUG_ON(n > SIMPLE_TRANSACTION_LIMIT); 1653 1654 /* 1655 * The barrier ensures that ar->size will really remain zero until 1656 * ar->data is ready for reading. 1657 */ 1658 smp_mb(); 1659 ar->size = n; 1660 } 1661 1662 /* 1663 * simple attribute files 1664 * 1665 * These attributes behave similar to those in sysfs: 1666 * 1667 * Writing to an attribute immediately sets a value, an open file can be 1668 * written to multiple times. 1669 * 1670 * Reading from an attribute creates a buffer from the value that might get 1671 * read with multiple read calls. When the attribute has been read 1672 * completely, no further read calls are possible until the file is opened 1673 * again. 1674 * 1675 * All attributes contain a text representation of a numeric value 1676 * that are accessed with the get() and set() functions. 1677 */ 1678 #define DEFINE_SIMPLE_ATTRIBUTE(__fops, __get, __set, __fmt) \ 1679 static int __fops ## _open(struct inode *inode, struct file *file) \ 1680 { \ 1681 __simple_attr_check_format(__fmt, 0ull); \ 1682 return simple_attr_open(inode, file, __get, __set, __fmt); \ 1683 } \ 1684 static struct file_operations __fops = { \ 1685 .owner = THIS_MODULE, \ 1686 .open = __fops ## _open, \ 1687 .release = simple_attr_close, \ 1688 .read = simple_attr_read, \ 1689 .write = simple_attr_write, \ 1690 }; 1691 1692 static inline void __attribute__((format(printf, 1, 2))) 1693 __simple_attr_check_format(const char *fmt, ...) 1694 { 1695 /* don't do anything, just let the compiler check the arguments; */ 1696 } 1697 1698 int simple_attr_open(struct inode *inode, struct file *file, 1699 u64 (*get)(void *), void (*set)(void *, u64), 1700 const char *fmt); 1701 int simple_attr_close(struct inode *inode, struct file *file); 1702 ssize_t simple_attr_read(struct file *file, char __user *buf, 1703 size_t len, loff_t *ppos); 1704 ssize_t simple_attr_write(struct file *file, const char __user *buf, 1705 size_t len, loff_t *ppos); 1706 1707 1708 #ifdef CONFIG_SECURITY 1709 static inline char *alloc_secdata(void) 1710 { 1711 return (char *)get_zeroed_page(GFP_KERNEL); 1712 } 1713 1714 static inline void free_secdata(void *secdata) 1715 { 1716 free_page((unsigned long)secdata); 1717 } 1718 #else 1719 static inline char *alloc_secdata(void) 1720 { 1721 return (char *)1; 1722 } 1723 1724 static inline void free_secdata(void *secdata) 1725 { } 1726 #endif /* CONFIG_SECURITY */ 1727 1728 #endif /* __KERNEL__ */ 1729 #endif /* _LINUX_FS_H */ 1730