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