linux/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/limits.h>
  10#include <linux/ioctl.h>
  11#include <linux/blk_types.h>
  12#include <linux/types.h>
  13
  14/*
  15 * It's silly to have NR_OPEN bigger than NR_FILE, but you can change
  16 * the file limit at runtime and only root can increase the per-process
  17 * nr_file rlimit, so it's safe to set up a ridiculously high absolute
  18 * upper limit on files-per-process.
  19 *
  20 * Some programs (notably those using select()) may have to be 
  21 * recompiled to take full advantage of the new limits..  
  22 */
  23
  24/* Fixed constants first: */
  25#undef NR_OPEN
  26#define INR_OPEN_CUR 1024       /* Initial setting for nfile rlimits */
  27#define INR_OPEN_MAX 4096       /* Hard limit for nfile rlimits */
  28
  29#define BLOCK_SIZE_BITS 10
  30#define BLOCK_SIZE (1<<BLOCK_SIZE_BITS)
  31
  32#define SEEK_SET        0       /* seek relative to beginning of file */
  33#define SEEK_CUR        1       /* seek relative to current file position */
  34#define SEEK_END        2       /* seek relative to end of file */
  35#define SEEK_DATA       3       /* seek to the next data */
  36#define SEEK_HOLE       4       /* seek to the next hole */
  37#define SEEK_MAX        SEEK_HOLE
  38
  39struct fstrim_range {
  40        __u64 start;
  41        __u64 len;
  42        __u64 minlen;
  43};
  44
  45/* And dynamically-tunable limits and defaults: */
  46struct files_stat_struct {
  47        unsigned long nr_files;         /* read only */
  48        unsigned long nr_free_files;    /* read only */
  49        unsigned long max_files;                /* tunable */
  50};
  51
  52struct inodes_stat_t {
  53        int nr_inodes;
  54        int nr_unused;
  55        int dummy[5];           /* padding for sysctl ABI compatibility */
  56};
  57
  58
  59#define NR_FILE  8192   /* this can well be larger on a larger system */
  60
  61#define MAY_EXEC                0x00000001
  62#define MAY_WRITE               0x00000002
  63#define MAY_READ                0x00000004
  64#define MAY_APPEND              0x00000008
  65#define MAY_ACCESS              0x00000010
  66#define MAY_OPEN                0x00000020
  67#define MAY_CHDIR               0x00000040
  68/* called from RCU mode, don't block */
  69#define MAY_NOT_BLOCK           0x00000080
  70
  71/*
  72 * flags in file.f_mode.  Note that FMODE_READ and FMODE_WRITE must correspond
  73 * to O_WRONLY and O_RDWR via the strange trick in __dentry_open()
  74 */
  75
  76/* file is open for reading */
  77#define FMODE_READ              ((__force fmode_t)0x1)
  78/* file is open for writing */
  79#define FMODE_WRITE             ((__force fmode_t)0x2)
  80/* file is seekable */
  81#define FMODE_LSEEK             ((__force fmode_t)0x4)
  82/* file can be accessed using pread */
  83#define FMODE_PREAD             ((__force fmode_t)0x8)
  84/* file can be accessed using pwrite */
  85#define FMODE_PWRITE            ((__force fmode_t)0x10)
  86/* File is opened for execution with sys_execve / sys_uselib */
  87#define FMODE_EXEC              ((__force fmode_t)0x20)
  88/* File is opened with O_NDELAY (only set for block devices) */
  89#define FMODE_NDELAY            ((__force fmode_t)0x40)
  90/* File is opened with O_EXCL (only set for block devices) */
  91#define FMODE_EXCL              ((__force fmode_t)0x80)
  92/* File is opened using open(.., 3, ..) and is writeable only for ioctls
  93   (specialy hack for floppy.c) */
  94#define FMODE_WRITE_IOCTL       ((__force fmode_t)0x100)
  95/* 32bit hashes as llseek() offset (for directories) */
  96#define FMODE_32BITHASH         ((__force fmode_t)0x200)
  97/* 64bit hashes as llseek() offset (for directories) */
  98#define FMODE_64BITHASH         ((__force fmode_t)0x400)
  99
 100/*
 101 * Don't update ctime and mtime.
 102 *
 103 * Currently a special hack for the XFS open_by_handle ioctl, but we'll
 104 * hopefully graduate it to a proper O_CMTIME flag supported by open(2) soon.
 105 */
 106#define FMODE_NOCMTIME          ((__force fmode_t)0x800)
 107
 108/* Expect random access pattern */
 109#define FMODE_RANDOM            ((__force fmode_t)0x1000)
 110
 111/* File is huge (eg. /dev/kmem): treat loff_t as unsigned */
 112#define FMODE_UNSIGNED_OFFSET   ((__force fmode_t)0x2000)
 113
 114/* File is opened with O_PATH; almost nothing can be done with it */
 115#define FMODE_PATH              ((__force fmode_t)0x4000)
 116
 117/* File was opened by fanotify and shouldn't generate fanotify events */
 118#define FMODE_NONOTIFY          ((__force fmode_t)0x1000000)
 119
 120/*
 121 * The below are the various read and write types that we support. Some of
 122 * them include behavioral modifiers that send information down to the
 123 * block layer and IO scheduler. Terminology:
 124 *
 125 *      The block layer uses device plugging to defer IO a little bit, in
 126 *      the hope that we will see more IO very shortly. This increases
 127 *      coalescing of adjacent IO and thus reduces the number of IOs we
 128 *      have to send to the device. It also allows for better queuing,
 129 *      if the IO isn't mergeable. If the caller is going to be waiting
 130 *      for the IO, then he must ensure that the device is unplugged so
 131 *      that the IO is dispatched to the driver.
 132 *
 133 *      All IO is handled async in Linux. This is fine for background
 134 *      writes, but for reads or writes that someone waits for completion
 135 *      on, we want to notify the block layer and IO scheduler so that they
 136 *      know about it. That allows them to make better scheduling
 137 *      decisions. So when the below references 'sync' and 'async', it
 138 *      is referencing this priority hint.
 139 *
 140 * With that in mind, the available types are:
 141 *
 142 * READ                 A normal read operation. Device will be plugged.
 143 * READ_SYNC            A synchronous read. Device is not plugged, caller can
 144 *                      immediately wait on this read without caring about
 145 *                      unplugging.
 146 * READA                Used for read-ahead operations. Lower priority, and the
 147 *                      block layer could (in theory) choose to ignore this
 148 *                      request if it runs into resource problems.
 149 * WRITE                A normal async write. Device will be plugged.
 150 * WRITE_SYNC           Synchronous write. Identical to WRITE, but passes down
 151 *                      the hint that someone will be waiting on this IO
 152 *                      shortly. The write equivalent of READ_SYNC.
 153 * WRITE_ODIRECT        Special case write for O_DIRECT only.
 154 * WRITE_FLUSH          Like WRITE_SYNC but with preceding cache flush.
 155 * WRITE_FUA            Like WRITE_SYNC but data is guaranteed to be on
 156 *                      non-volatile media on completion.
 157 * WRITE_FLUSH_FUA      Combination of WRITE_FLUSH and FUA. The IO is preceded
 158 *                      by a cache flush and data is guaranteed to be on
 159 *                      non-volatile media on completion.
 160 *
 161 */
 162#define RW_MASK                 REQ_WRITE
 163#define RWA_MASK                REQ_RAHEAD
 164
 165#define READ                    0
 166#define WRITE                   RW_MASK
 167#define READA                   RWA_MASK
 168#define KERNEL_READ             (READ|REQ_KERNEL)
 169#define KERNEL_WRITE            (WRITE|REQ_KERNEL)
 170
 171#define READ_SYNC               (READ | REQ_SYNC)
 172#define WRITE_SYNC              (WRITE | REQ_SYNC | REQ_NOIDLE)
 173#define WRITE_ODIRECT           (WRITE | REQ_SYNC)
 174#define WRITE_FLUSH             (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_FLUSH)
 175#define WRITE_FUA               (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_FUA)
 176#define WRITE_FLUSH_FUA         (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_FLUSH | REQ_FUA)
 177
 178
 179/*
 180 * Flag for rw_copy_check_uvector and compat_rw_copy_check_uvector
 181 * that indicates that they should check the contents of the iovec are
 182 * valid, but not check the memory that the iovec elements
 183 * points too.
 184 */
 185#define CHECK_IOVEC_ONLY -1
 186
 187#define SEL_IN          1
 188#define SEL_OUT         2
 189#define SEL_EX          4
 190
 191/* public flags for file_system_type */
 192#define FS_REQUIRES_DEV 1 
 193#define FS_BINARY_MOUNTDATA 2
 194#define FS_HAS_SUBTYPE 4
 195#define FS_REVAL_DOT    16384   /* Check the paths ".", ".." for staleness */
 196#define FS_RENAME_DOES_D_MOVE   32768   /* FS will handle d_move()
 197                                         * during rename() internally.
 198                                         */
 199
 200/*
 201 * These are the fs-independent mount-flags: up to 32 flags are supported
 202 */
 203#define MS_RDONLY        1      /* Mount read-only */
 204#define MS_NOSUID        2      /* Ignore suid and sgid bits */
 205#define MS_NODEV         4      /* Disallow access to device special files */
 206#define MS_NOEXEC        8      /* Disallow program execution */
 207#define MS_SYNCHRONOUS  16      /* Writes are synced at once */
 208#define MS_REMOUNT      32      /* Alter flags of a mounted FS */
 209#define MS_MANDLOCK     64      /* Allow mandatory locks on an FS */
 210#define MS_DIRSYNC      128     /* Directory modifications are synchronous */
 211#define MS_NOATIME      1024    /* Do not update access times. */
 212#define MS_NODIRATIME   2048    /* Do not update directory access times */
 213#define MS_BIND         4096
 214#define MS_MOVE         8192
 215#define MS_REC          16384
 216#define MS_VERBOSE      32768   /* War is peace. Verbosity is silence.
 217                                   MS_VERBOSE is deprecated. */
 218#define MS_SILENT       32768
 219#define MS_POSIXACL     (1<<16) /* VFS does not apply the umask */
 220#define MS_UNBINDABLE   (1<<17) /* change to unbindable */
 221#define MS_PRIVATE      (1<<18) /* change to private */
 222#define MS_SLAVE        (1<<19) /* change to slave */
 223#define MS_SHARED       (1<<20) /* change to shared */
 224#define MS_RELATIME     (1<<21) /* Update atime relative to mtime/ctime. */
 225#define MS_KERNMOUNT    (1<<22) /* this is a kern_mount call */
 226#define MS_I_VERSION    (1<<23) /* Update inode I_version field */
 227#define MS_STRICTATIME  (1<<24) /* Always perform atime updates */
 228#define MS_NOSEC        (1<<28)
 229#define MS_BORN         (1<<29)
 230#define MS_ACTIVE       (1<<30)
 231#define MS_NOUSER       (1<<31)
 232
 233/*
 234 * Superblock flags that can be altered by MS_REMOUNT
 235 */
 236#define MS_RMT_MASK     (MS_RDONLY|MS_SYNCHRONOUS|MS_MANDLOCK|MS_I_VERSION)
 237
 238/*
 239 * Old magic mount flag and mask
 240 */
 241#define MS_MGC_VAL 0xC0ED0000
 242#define MS_MGC_MSK 0xffff0000
 243
 244/* Inode flags - they have nothing to superblock flags now */
 245
 246#define S_SYNC          1       /* Writes are synced at once */
 247#define S_NOATIME       2       /* Do not update access times */
 248#define S_APPEND        4       /* Append-only file */
 249#define S_IMMUTABLE     8       /* Immutable file */
 250#define S_DEAD          16      /* removed, but still open directory */
 251#define S_NOQUOTA       32      /* Inode is not counted to quota */
 252#define S_DIRSYNC       64      /* Directory modifications are synchronous */
 253#define S_NOCMTIME      128     /* Do not update file c/mtime */
 254#define S_SWAPFILE      256     /* Do not truncate: swapon got its bmaps */
 255#define S_PRIVATE       512     /* Inode is fs-internal */
 256#define S_IMA           1024    /* Inode has an associated IMA struct */
 257#define S_AUTOMOUNT     2048    /* Automount/referral quasi-directory */
 258#define S_NOSEC         4096    /* no suid or xattr security attributes */
 259
 260/*
 261 * Note that nosuid etc flags are inode-specific: setting some file-system
 262 * flags just means all the inodes inherit those flags by default. It might be
 263 * possible to override it selectively if you really wanted to with some
 264 * ioctl() that is not currently implemented.
 265 *
 266 * Exception: MS_RDONLY is always applied to the entire file system.
 267 *
 268 * Unfortunately, it is possible to change a filesystems flags with it mounted
 269 * with files in use.  This means that all of the inodes will not have their
 270 * i_flags updated.  Hence, i_flags no longer inherit the superblock mount
 271 * flags, so these have to be checked separately. -- rmk@arm.uk.linux.org
 272 */
 273#define __IS_FLG(inode,flg) ((inode)->i_sb->s_flags & (flg))
 274
 275#define IS_RDONLY(inode) ((inode)->i_sb->s_flags & MS_RDONLY)
 276#define IS_SYNC(inode)          (__IS_FLG(inode, MS_SYNCHRONOUS) || \
 277                                        ((inode)->i_flags & S_SYNC))
 278#define IS_DIRSYNC(inode)       (__IS_FLG(inode, MS_SYNCHRONOUS|MS_DIRSYNC) || \
 279                                        ((inode)->i_flags & (S_SYNC|S_DIRSYNC)))
 280#define IS_MANDLOCK(inode)      __IS_FLG(inode, MS_MANDLOCK)
 281#define IS_NOATIME(inode)   __IS_FLG(inode, MS_RDONLY|MS_NOATIME)
 282#define IS_I_VERSION(inode)   __IS_FLG(inode, MS_I_VERSION)
 283
 284#define IS_NOQUOTA(inode)       ((inode)->i_flags & S_NOQUOTA)
 285#define IS_APPEND(inode)        ((inode)->i_flags & S_APPEND)
 286#define IS_IMMUTABLE(inode)     ((inode)->i_flags & S_IMMUTABLE)
 287#define IS_POSIXACL(inode)      __IS_FLG(inode, MS_POSIXACL)
 288
 289#define IS_DEADDIR(inode)       ((inode)->i_flags & S_DEAD)
 290#define IS_NOCMTIME(inode)      ((inode)->i_flags & S_NOCMTIME)
 291#define IS_SWAPFILE(inode)      ((inode)->i_flags & S_SWAPFILE)
 292#define IS_PRIVATE(inode)       ((inode)->i_flags & S_PRIVATE)
 293#define IS_IMA(inode)           ((inode)->i_flags & S_IMA)
 294#define IS_AUTOMOUNT(inode)     ((inode)->i_flags & S_AUTOMOUNT)
 295#define IS_NOSEC(inode)         ((inode)->i_flags & S_NOSEC)
 296
 297/* the read-only stuff doesn't really belong here, but any other place is
 298   probably as bad and I don't want to create yet another include file. */
 299
 300#define BLKROSET   _IO(0x12,93) /* set device read-only (0 = read-write) */
 301#define BLKROGET   _IO(0x12,94) /* get read-only status (0 = read_write) */
 302#define BLKRRPART  _IO(0x12,95) /* re-read partition table */
 303#define BLKGETSIZE _IO(0x12,96) /* return device size /512 (long *arg) */
 304#define BLKFLSBUF  _IO(0x12,97) /* flush buffer cache */
 305#define BLKRASET   _IO(0x12,98) /* set read ahead for block device */
 306#define BLKRAGET   _IO(0x12,99) /* get current read ahead setting */
 307#define BLKFRASET  _IO(0x12,100)/* set filesystem (mm/filemap.c) read-ahead */
 308#define BLKFRAGET  _IO(0x12,101)/* get filesystem (mm/filemap.c) read-ahead */
 309#define BLKSECTSET _IO(0x12,102)/* set max sectors per request (ll_rw_blk.c) */
 310#define BLKSECTGET _IO(0x12,103)/* get max sectors per request (ll_rw_blk.c) */
 311#define BLKSSZGET  _IO(0x12,104)/* get block device sector size */
 312#if 0
 313#define BLKPG      _IO(0x12,105)/* See blkpg.h */
 314
 315/* Some people are morons.  Do not use sizeof! */
 316
 317#define BLKELVGET  _IOR(0x12,106,size_t)/* elevator get */
 318#define BLKELVSET  _IOW(0x12,107,size_t)/* elevator set */
 319/* This was here just to show that the number is taken -
 320   probably all these _IO(0x12,*) ioctls should be moved to blkpg.h. */
 321#endif
 322/* A jump here: 108-111 have been used for various private purposes. */
 323#define BLKBSZGET  _IOR(0x12,112,size_t)
 324#define BLKBSZSET  _IOW(0x12,113,size_t)
 325#define BLKGETSIZE64 _IOR(0x12,114,size_t)      /* return device size in bytes (u64 *arg) */
 326#define BLKTRACESETUP _IOWR(0x12,115,struct blk_user_trace_setup)
 327#define BLKTRACESTART _IO(0x12,116)
 328#define BLKTRACESTOP _IO(0x12,117)
 329#define BLKTRACETEARDOWN _IO(0x12,118)
 330#define BLKDISCARD _IO(0x12,119)
 331#define BLKIOMIN _IO(0x12,120)
 332#define BLKIOOPT _IO(0x12,121)
 333#define BLKALIGNOFF _IO(0x12,122)
 334#define BLKPBSZGET _IO(0x12,123)
 335#define BLKDISCARDZEROES _IO(0x12,124)
 336#define BLKSECDISCARD _IO(0x12,125)
 337#define BLKROTATIONAL _IO(0x12,126)
 338
 339#define BMAP_IOCTL 1            /* obsolete - kept for compatibility */
 340#define FIBMAP     _IO(0x00,1)  /* bmap access */
 341#define FIGETBSZ   _IO(0x00,2)  /* get the block size used for bmap */
 342#define FIFREEZE        _IOWR('X', 119, int)    /* Freeze */
 343#define FITHAW          _IOWR('X', 120, int)    /* Thaw */
 344#define FITRIM          _IOWR('X', 121, struct fstrim_range)    /* Trim */
 345
 346#define FS_IOC_GETFLAGS                 _IOR('f', 1, long)
 347#define FS_IOC_SETFLAGS                 _IOW('f', 2, long)
 348#define FS_IOC_GETVERSION               _IOR('v', 1, long)
 349#define FS_IOC_SETVERSION               _IOW('v', 2, long)
 350#define FS_IOC_FIEMAP                   _IOWR('f', 11, struct fiemap)
 351#define FS_IOC32_GETFLAGS               _IOR('f', 1, int)
 352#define FS_IOC32_SETFLAGS               _IOW('f', 2, int)
 353#define FS_IOC32_GETVERSION             _IOR('v', 1, int)
 354#define FS_IOC32_SETVERSION             _IOW('v', 2, int)
 355
 356/*
 357 * Inode flags (FS_IOC_GETFLAGS / FS_IOC_SETFLAGS)
 358 */
 359#define FS_SECRM_FL                     0x00000001 /* Secure deletion */
 360#define FS_UNRM_FL                      0x00000002 /* Undelete */
 361#define FS_COMPR_FL                     0x00000004 /* Compress file */
 362#define FS_SYNC_FL                      0x00000008 /* Synchronous updates */
 363#define FS_IMMUTABLE_FL                 0x00000010 /* Immutable file */
 364#define FS_APPEND_FL                    0x00000020 /* writes to file may only append */
 365#define FS_NODUMP_FL                    0x00000040 /* do not dump file */
 366#define FS_NOATIME_FL                   0x00000080 /* do not update atime */
 367/* Reserved for compression usage... */
 368#define FS_DIRTY_FL                     0x00000100
 369#define FS_COMPRBLK_FL                  0x00000200 /* One or more compressed clusters */
 370#define FS_NOCOMP_FL                    0x00000400 /* Don't compress */
 371#define FS_ECOMPR_FL                    0x00000800 /* Compression error */
 372/* End compression flags --- maybe not all used */
 373#define FS_BTREE_FL                     0x00001000 /* btree format dir */
 374#define FS_INDEX_FL                     0x00001000 /* hash-indexed directory */
 375#define FS_IMAGIC_FL                    0x00002000 /* AFS directory */
 376#define FS_JOURNAL_DATA_FL              0x00004000 /* Reserved for ext3 */
 377#define FS_NOTAIL_FL                    0x00008000 /* file tail should not be merged */
 378#define FS_DIRSYNC_FL                   0x00010000 /* dirsync behaviour (directories only) */
 379#define FS_TOPDIR_FL                    0x00020000 /* Top of directory hierarchies*/
 380#define FS_EXTENT_FL                    0x00080000 /* Extents */
 381#define FS_DIRECTIO_FL                  0x00100000 /* Use direct i/o */
 382#define FS_NOCOW_FL                     0x00800000 /* Do not cow file */
 383#define FS_RESERVED_FL                  0x80000000 /* reserved for ext2 lib */
 384
 385#define FS_FL_USER_VISIBLE              0x0003DFFF /* User visible flags */
 386#define FS_FL_USER_MODIFIABLE           0x000380FF /* User modifiable flags */
 387
 388
 389#define SYNC_FILE_RANGE_WAIT_BEFORE     1
 390#define SYNC_FILE_RANGE_WRITE           2
 391#define SYNC_FILE_RANGE_WAIT_AFTER      4
 392
 393#ifdef __KERNEL__
 394
 395#include <linux/linkage.h>
 396#include <linux/wait.h>
 397#include <linux/kdev_t.h>
 398#include <linux/dcache.h>
 399#include <linux/path.h>
 400#include <linux/stat.h>
 401#include <linux/cache.h>
 402#include <linux/list.h>
 403#include <linux/radix-tree.h>
 404#include <linux/prio_tree.h>
 405#include <linux/init.h>
 406#include <linux/pid.h>
 407#include <linux/bug.h>
 408#include <linux/mutex.h>
 409#include <linux/capability.h>
 410#include <linux/semaphore.h>
 411#include <linux/fiemap.h>
 412#include <linux/rculist_bl.h>
 413#include <linux/atomic.h>
 414#include <linux/shrinker.h>
 415#include <linux/migrate_mode.h>
 416#include <linux/uidgid.h>
 417#include <linux/lockdep.h>
 418
 419#include <asm/byteorder.h>
 420
 421struct export_operations;
 422struct hd_geometry;
 423struct iovec;
 424struct nameidata;
 425struct kiocb;
 426struct kobject;
 427struct pipe_inode_info;
 428struct poll_table_struct;
 429struct kstatfs;
 430struct vm_area_struct;
 431struct vfsmount;
 432struct cred;
 433struct swap_info_struct;
 434
 435extern void __init inode_init(void);
 436extern void __init inode_init_early(void);
 437extern void __init files_init(unsigned long);
 438
 439extern struct files_stat_struct files_stat;
 440extern unsigned long get_max_files(void);
 441extern int sysctl_nr_open;
 442extern struct inodes_stat_t inodes_stat;
 443extern int leases_enable, lease_break_time;
 444extern int sysctl_protected_symlinks;
 445extern int sysctl_protected_hardlinks;
 446
 447struct buffer_head;
 448typedef int (get_block_t)(struct inode *inode, sector_t iblock,
 449                        struct buffer_head *bh_result, int create);
 450typedef void (dio_iodone_t)(struct kiocb *iocb, loff_t offset,
 451                        ssize_t bytes, void *private, int ret,
 452                        bool is_async);
 453
 454/*
 455 * Attribute flags.  These should be or-ed together to figure out what
 456 * has been changed!
 457 */
 458#define ATTR_MODE       (1 << 0)
 459#define ATTR_UID        (1 << 1)
 460#define ATTR_GID        (1 << 2)
 461#define ATTR_SIZE       (1 << 3)
 462#define ATTR_ATIME      (1 << 4)
 463#define ATTR_MTIME      (1 << 5)
 464#define ATTR_CTIME      (1 << 6)
 465#define ATTR_ATIME_SET  (1 << 7)
 466#define ATTR_MTIME_SET  (1 << 8)
 467#define ATTR_FORCE      (1 << 9) /* Not a change, but a change it */
 468#define ATTR_ATTR_FLAG  (1 << 10)
 469#define ATTR_KILL_SUID  (1 << 11)
 470#define ATTR_KILL_SGID  (1 << 12)
 471#define ATTR_FILE       (1 << 13)
 472#define ATTR_KILL_PRIV  (1 << 14)
 473#define ATTR_OPEN       (1 << 15) /* Truncating from open(O_TRUNC) */
 474#define ATTR_TIMES_SET  (1 << 16)
 475
 476/*
 477 * This is the Inode Attributes structure, used for notify_change().  It
 478 * uses the above definitions as flags, to know which values have changed.
 479 * Also, in this manner, a Filesystem can look at only the values it cares
 480 * about.  Basically, these are the attributes that the VFS layer can
 481 * request to change from the FS layer.
 482 *
 483 * Derek Atkins <warlord@MIT.EDU> 94-10-20
 484 */
 485struct iattr {
 486        unsigned int    ia_valid;
 487        umode_t         ia_mode;
 488        kuid_t          ia_uid;
 489        kgid_t          ia_gid;
 490        loff_t          ia_size;
 491        struct timespec ia_atime;
 492        struct timespec ia_mtime;
 493        struct timespec ia_ctime;
 494
 495        /*
 496         * Not an attribute, but an auxiliary info for filesystems wanting to
 497         * implement an ftruncate() like method.  NOTE: filesystem should
 498         * check for (ia_valid & ATTR_FILE), and not for (ia_file != NULL).
 499         */
 500        struct file     *ia_file;
 501};
 502
 503/*
 504 * Includes for diskquotas.
 505 */
 506#include <linux/quota.h>
 507
 508/** 
 509 * enum positive_aop_returns - aop return codes with specific semantics
 510 *
 511 * @AOP_WRITEPAGE_ACTIVATE: Informs the caller that page writeback has
 512 *                          completed, that the page is still locked, and
 513 *                          should be considered active.  The VM uses this hint
 514 *                          to return the page to the active list -- it won't
 515 *                          be a candidate for writeback again in the near
 516 *                          future.  Other callers must be careful to unlock
 517 *                          the page if they get this return.  Returned by
 518 *                          writepage(); 
 519 *
 520 * @AOP_TRUNCATED_PAGE: The AOP method that was handed a locked page has
 521 *                      unlocked it and the page might have been truncated.
 522 *                      The caller should back up to acquiring a new page and
 523 *                      trying again.  The aop will be taking reasonable
 524 *                      precautions not to livelock.  If the caller held a page
 525 *                      reference, it should drop it before retrying.  Returned
 526 *                      by readpage().
 527 *
 528 * address_space_operation functions return these large constants to indicate
 529 * special semantics to the caller.  These are much larger than the bytes in a
 530 * page to allow for functions that return the number of bytes operated on in a
 531 * given page.
 532 */
 533
 534enum positive_aop_returns {
 535        AOP_WRITEPAGE_ACTIVATE  = 0x80000,
 536        AOP_TRUNCATED_PAGE      = 0x80001,
 537};
 538
 539#define AOP_FLAG_UNINTERRUPTIBLE        0x0001 /* will not do a short write */
 540#define AOP_FLAG_CONT_EXPAND            0x0002 /* called from cont_expand */
 541#define AOP_FLAG_NOFS                   0x0004 /* used by filesystem to direct
 542                                                * helper code (eg buffer layer)
 543                                                * to clear GFP_FS from alloc */
 544
 545/*
 546 * oh the beauties of C type declarations.
 547 */
 548struct page;
 549struct address_space;
 550struct writeback_control;
 551
 552struct iov_iter {
 553        const struct iovec *iov;
 554        unsigned long nr_segs;
 555        size_t iov_offset;
 556        size_t count;
 557};
 558
 559size_t iov_iter_copy_from_user_atomic(struct page *page,
 560                struct iov_iter *i, unsigned long offset, size_t bytes);
 561size_t iov_iter_copy_from_user(struct page *page,
 562                struct iov_iter *i, unsigned long offset, size_t bytes);
 563void iov_iter_advance(struct iov_iter *i, size_t bytes);
 564int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes);
 565size_t iov_iter_single_seg_count(struct iov_iter *i);
 566
 567static inline void iov_iter_init(struct iov_iter *i,
 568                        const struct iovec *iov, unsigned long nr_segs,
 569                        size_t count, size_t written)
 570{
 571        i->iov = iov;
 572        i->nr_segs = nr_segs;
 573        i->iov_offset = 0;
 574        i->count = count + written;
 575
 576        iov_iter_advance(i, written);
 577}
 578
 579static inline size_t iov_iter_count(struct iov_iter *i)
 580{
 581        return i->count;
 582}
 583
 584/*
 585 * "descriptor" for what we're up to with a read.
 586 * This allows us to use the same read code yet
 587 * have multiple different users of the data that
 588 * we read from a file.
 589 *
 590 * The simplest case just copies the data to user
 591 * mode.
 592 */
 593typedef struct {
 594        size_t written;
 595        size_t count;
 596        union {
 597                char __user *buf;
 598                void *data;
 599        } arg;
 600        int error;
 601} read_descriptor_t;
 602
 603typedef int (*read_actor_t)(read_descriptor_t *, struct page *,
 604                unsigned long, unsigned long);
 605
 606struct address_space_operations {
 607        int (*writepage)(struct page *page, struct writeback_control *wbc);
 608        int (*readpage)(struct file *, struct page *);
 609
 610        /* Write back some dirty pages from this mapping. */
 611        int (*writepages)(struct address_space *, struct writeback_control *);
 612
 613        /* Set a page dirty.  Return true if this dirtied it */
 614        int (*set_page_dirty)(struct page *page);
 615
 616        int (*readpages)(struct file *filp, struct address_space *mapping,
 617                        struct list_head *pages, unsigned nr_pages);
 618
 619        int (*write_begin)(struct file *, struct address_space *mapping,
 620                                loff_t pos, unsigned len, unsigned flags,
 621                                struct page **pagep, void **fsdata);
 622        int (*write_end)(struct file *, struct address_space *mapping,
 623                                loff_t pos, unsigned len, unsigned copied,
 624                                struct page *page, void *fsdata);
 625
 626        /* Unfortunately this kludge is needed for FIBMAP. Don't use it */
 627        sector_t (*bmap)(struct address_space *, sector_t);
 628        void (*invalidatepage) (struct page *, unsigned long);
 629        int (*releasepage) (struct page *, gfp_t);
 630        void (*freepage)(struct page *);
 631        ssize_t (*direct_IO)(int, struct kiocb *, const struct iovec *iov,
 632                        loff_t offset, unsigned long nr_segs);
 633        int (*get_xip_mem)(struct address_space *, pgoff_t, int,
 634                                                void **, unsigned long *);
 635        /*
 636         * migrate the contents of a page to the specified target. If sync
 637         * is false, it must not block.
 638         */
 639        int (*migratepage) (struct address_space *,
 640                        struct page *, struct page *, enum migrate_mode);
 641        int (*launder_page) (struct page *);
 642        int (*is_partially_uptodate) (struct page *, read_descriptor_t *,
 643                                        unsigned long);
 644        int (*error_remove_page)(struct address_space *, struct page *);
 645
 646        /* swapfile support */
 647        int (*swap_activate)(struct swap_info_struct *sis, struct file *file,
 648                                sector_t *span);
 649        void (*swap_deactivate)(struct file *file);
 650};
 651
 652extern const struct address_space_operations empty_aops;
 653
 654/*
 655 * pagecache_write_begin/pagecache_write_end must be used by general code
 656 * to write into the pagecache.
 657 */
 658int pagecache_write_begin(struct file *, struct address_space *mapping,
 659                                loff_t pos, unsigned len, unsigned flags,
 660                                struct page **pagep, void **fsdata);
 661
 662int pagecache_write_end(struct file *, struct address_space *mapping,
 663                                loff_t pos, unsigned len, unsigned copied,
 664                                struct page *page, void *fsdata);
 665
 666struct backing_dev_info;
 667struct address_space {
 668        struct inode            *host;          /* owner: inode, block_device */
 669        struct radix_tree_root  page_tree;      /* radix tree of all pages */
 670        spinlock_t              tree_lock;      /* and lock protecting it */
 671        unsigned int            i_mmap_writable;/* count VM_SHARED mappings */
 672        struct prio_tree_root   i_mmap;         /* tree of private and shared mappings */
 673        struct list_head        i_mmap_nonlinear;/*list VM_NONLINEAR mappings */
 674        struct mutex            i_mmap_mutex;   /* protect tree, count, list */
 675        /* Protected by tree_lock together with the radix tree */
 676        unsigned long           nrpages;        /* number of total pages */
 677        pgoff_t                 writeback_index;/* writeback starts here */
 678        const struct address_space_operations *a_ops;   /* methods */
 679        unsigned long           flags;          /* error bits/gfp mask */
 680        struct backing_dev_info *backing_dev_info; /* device readahead, etc */
 681        spinlock_t              private_lock;   /* for use by the address_space */
 682        struct list_head        private_list;   /* ditto */
 683        struct address_space    *assoc_mapping; /* ditto */
 684} __attribute__((aligned(sizeof(long))));
 685        /*
 686         * On most architectures that alignment is already the case; but
 687         * must be enforced here for CRIS, to let the least significant bit
 688         * of struct page's "mapping" pointer be used for PAGE_MAPPING_ANON.
 689         */
 690struct request_queue;
 691
 692struct block_device {
 693        dev_t                   bd_dev;  /* not a kdev_t - it's a search key */
 694        int                     bd_openers;
 695        struct inode *          bd_inode;       /* will die */
 696        struct super_block *    bd_super;
 697        struct mutex            bd_mutex;       /* open/close mutex */
 698        struct list_head        bd_inodes;
 699        void *                  bd_claiming;
 700        void *                  bd_holder;
 701        int                     bd_holders;
 702        bool                    bd_write_holder;
 703#ifdef CONFIG_SYSFS
 704        struct list_head        bd_holder_disks;
 705#endif
 706        struct block_device *   bd_contains;
 707        unsigned                bd_block_size;
 708        struct hd_struct *      bd_part;
 709        /* number of times partitions within this device have been opened. */
 710        unsigned                bd_part_count;
 711        int                     bd_invalidated;
 712        struct gendisk *        bd_disk;
 713        struct request_queue *  bd_queue;
 714        struct list_head        bd_list;
 715        /*
 716         * Private data.  You must have bd_claim'ed the block_device
 717         * to use this.  NOTE:  bd_claim allows an owner to claim
 718         * the same device multiple times, the owner must take special
 719         * care to not mess up bd_private for that case.
 720         */
 721        unsigned long           bd_private;
 722
 723        /* The counter of freeze processes */
 724        int                     bd_fsfreeze_count;
 725        /* Mutex for freeze */
 726        struct mutex            bd_fsfreeze_mutex;
 727};
 728
 729/*
 730 * Radix-tree tags, for tagging dirty and writeback pages within the pagecache
 731 * radix trees
 732 */
 733#define PAGECACHE_TAG_DIRTY     0
 734#define PAGECACHE_TAG_WRITEBACK 1
 735#define PAGECACHE_TAG_TOWRITE   2
 736
 737int mapping_tagged(struct address_space *mapping, int tag);
 738
 739/*
 740 * Might pages of this file be mapped into userspace?
 741 */
 742static inline int mapping_mapped(struct address_space *mapping)
 743{
 744        return  !prio_tree_empty(&mapping->i_mmap) ||
 745                !list_empty(&mapping->i_mmap_nonlinear);
 746}
 747
 748/*
 749 * Might pages of this file have been modified in userspace?
 750 * Note that i_mmap_writable counts all VM_SHARED vmas: do_mmap_pgoff
 751 * marks vma as VM_SHARED if it is shared, and the file was opened for
 752 * writing i.e. vma may be mprotected writable even if now readonly.
 753 */
 754static inline int mapping_writably_mapped(struct address_space *mapping)
 755{
 756        return mapping->i_mmap_writable != 0;
 757}
 758
 759/*
 760 * Use sequence counter to get consistent i_size on 32-bit processors.
 761 */
 762#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
 763#include <linux/seqlock.h>
 764#define __NEED_I_SIZE_ORDERED
 765#define i_size_ordered_init(inode) seqcount_init(&inode->i_size_seqcount)
 766#else
 767#define i_size_ordered_init(inode) do { } while (0)
 768#endif
 769
 770struct posix_acl;
 771#define ACL_NOT_CACHED ((void *)(-1))
 772
 773#define IOP_FASTPERM    0x0001
 774#define IOP_LOOKUP      0x0002
 775#define IOP_NOFOLLOW    0x0004
 776
 777/*
 778 * Keep mostly read-only and often accessed (especially for
 779 * the RCU path lookup and 'stat' data) fields at the beginning
 780 * of the 'struct inode'
 781 */
 782struct inode {
 783        umode_t                 i_mode;
 784        unsigned short          i_opflags;
 785        kuid_t                  i_uid;
 786        kgid_t                  i_gid;
 787        unsigned int            i_flags;
 788
 789#ifdef CONFIG_FS_POSIX_ACL
 790        struct posix_acl        *i_acl;
 791        struct posix_acl        *i_default_acl;
 792#endif
 793
 794        const struct inode_operations   *i_op;
 795        struct super_block      *i_sb;
 796        struct address_space    *i_mapping;
 797
 798#ifdef CONFIG_SECURITY
 799        void                    *i_security;
 800#endif
 801
 802        /* Stat data, not accessed from path walking */
 803        unsigned long           i_ino;
 804        /*
 805         * Filesystems may only read i_nlink directly.  They shall use the
 806         * following functions for modification:
 807         *
 808         *    (set|clear|inc|drop)_nlink
 809         *    inode_(inc|dec)_link_count
 810         */
 811        union {
 812                const unsigned int i_nlink;
 813                unsigned int __i_nlink;
 814        };
 815        dev_t                   i_rdev;
 816        loff_t                  i_size;
 817        struct timespec         i_atime;
 818        struct timespec         i_mtime;
 819        struct timespec         i_ctime;
 820        spinlock_t              i_lock; /* i_blocks, i_bytes, maybe i_size */
 821        unsigned short          i_bytes;
 822        unsigned int            i_blkbits;
 823        blkcnt_t                i_blocks;
 824
 825#ifdef __NEED_I_SIZE_ORDERED
 826        seqcount_t              i_size_seqcount;
 827#endif
 828
 829        /* Misc */
 830        unsigned long           i_state;
 831        struct mutex            i_mutex;
 832
 833        unsigned long           dirtied_when;   /* jiffies of first dirtying */
 834
 835        struct hlist_node       i_hash;
 836        struct list_head        i_wb_list;      /* backing dev IO list */
 837        struct list_head        i_lru;          /* inode LRU list */
 838        struct list_head        i_sb_list;
 839        union {
 840                struct hlist_head       i_dentry;
 841                struct rcu_head         i_rcu;
 842        };
 843        u64                     i_version;
 844        atomic_t                i_count;
 845        atomic_t                i_dio_count;
 846        atomic_t                i_writecount;
 847        const struct file_operations    *i_fop; /* former ->i_op->default_file_ops */
 848        struct file_lock        *i_flock;
 849        struct address_space    i_data;
 850#ifdef CONFIG_QUOTA
 851        struct dquot            *i_dquot[MAXQUOTAS];
 852#endif
 853        struct list_head        i_devices;
 854        union {
 855                struct pipe_inode_info  *i_pipe;
 856                struct block_device     *i_bdev;
 857                struct cdev             *i_cdev;
 858        };
 859
 860        __u32                   i_generation;
 861
 862#ifdef CONFIG_FSNOTIFY
 863        __u32                   i_fsnotify_mask; /* all events this inode cares about */
 864        struct hlist_head       i_fsnotify_marks;
 865#endif
 866
 867#ifdef CONFIG_IMA
 868        atomic_t                i_readcount; /* struct files open RO */
 869#endif
 870        void                    *i_private; /* fs or device private pointer */
 871};
 872
 873static inline int inode_unhashed(struct inode *inode)
 874{
 875        return hlist_unhashed(&inode->i_hash);
 876}
 877
 878/*
 879 * inode->i_mutex nesting subclasses for the lock validator:
 880 *
 881 * 0: the object of the current VFS operation
 882 * 1: parent
 883 * 2: child/target
 884 * 3: quota file
 885 *
 886 * The locking order between these classes is
 887 * parent -> child -> normal -> xattr -> quota
 888 */
 889enum inode_i_mutex_lock_class
 890{
 891        I_MUTEX_NORMAL,
 892        I_MUTEX_PARENT,
 893        I_MUTEX_CHILD,
 894        I_MUTEX_XATTR,
 895        I_MUTEX_QUOTA
 896};
 897
 898/*
 899 * NOTE: in a 32bit arch with a preemptable kernel and
 900 * an UP compile the i_size_read/write must be atomic
 901 * with respect to the local cpu (unlike with preempt disabled),
 902 * but they don't need to be atomic with respect to other cpus like in
 903 * true SMP (so they need either to either locally disable irq around
 904 * the read or for example on x86 they can be still implemented as a
 905 * cmpxchg8b without the need of the lock prefix). For SMP compiles
 906 * and 64bit archs it makes no difference if preempt is enabled or not.
 907 */
 908static inline loff_t i_size_read(const struct inode *inode)
 909{
 910#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
 911        loff_t i_size;
 912        unsigned int seq;
 913
 914        do {
 915                seq = read_seqcount_begin(&inode->i_size_seqcount);
 916                i_size = inode->i_size;
 917        } while (read_seqcount_retry(&inode->i_size_seqcount, seq));
 918        return i_size;
 919#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
 920        loff_t i_size;
 921
 922        preempt_disable();
 923        i_size = inode->i_size;
 924        preempt_enable();
 925        return i_size;
 926#else
 927        return inode->i_size;
 928#endif
 929}
 930
 931/*
 932 * NOTE: unlike i_size_read(), i_size_write() does need locking around it
 933 * (normally i_mutex), otherwise on 32bit/SMP an update of i_size_seqcount
 934 * can be lost, resulting in subsequent i_size_read() calls spinning forever.
 935 */
 936static inline void i_size_write(struct inode *inode, loff_t i_size)
 937{
 938#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
 939        write_seqcount_begin(&inode->i_size_seqcount);
 940        inode->i_size = i_size;
 941        write_seqcount_end(&inode->i_size_seqcount);
 942#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
 943        preempt_disable();
 944        inode->i_size = i_size;
 945        preempt_enable();
 946#else
 947        inode->i_size = i_size;
 948#endif
 949}
 950
 951/* Helper functions so that in most cases filesystems will
 952 * not need to deal directly with kuid_t and kgid_t and can
 953 * instead deal with the raw numeric values that are stored
 954 * in the filesystem.
 955 */
 956static inline uid_t i_uid_read(const struct inode *inode)
 957{
 958        return from_kuid(&init_user_ns, inode->i_uid);
 959}
 960
 961static inline gid_t i_gid_read(const struct inode *inode)
 962{
 963        return from_kgid(&init_user_ns, inode->i_gid);
 964}
 965
 966static inline void i_uid_write(struct inode *inode, uid_t uid)
 967{
 968        inode->i_uid = make_kuid(&init_user_ns, uid);
 969}
 970
 971static inline void i_gid_write(struct inode *inode, gid_t gid)
 972{
 973        inode->i_gid = make_kgid(&init_user_ns, gid);
 974}
 975
 976static inline unsigned iminor(const struct inode *inode)
 977{
 978        return MINOR(inode->i_rdev);
 979}
 980
 981static inline unsigned imajor(const struct inode *inode)
 982{
 983        return MAJOR(inode->i_rdev);
 984}
 985
 986extern struct block_device *I_BDEV(struct inode *inode);
 987
 988struct fown_struct {
 989        rwlock_t lock;          /* protects pid, uid, euid fields */
 990        struct pid *pid;        /* pid or -pgrp where SIGIO should be sent */
 991        enum pid_type pid_type; /* Kind of process group SIGIO should be sent to */
 992        kuid_t uid, euid;       /* uid/euid of process setting the owner */
 993        int signum;             /* posix.1b rt signal to be delivered on IO */
 994};
 995
 996/*
 997 * Track a single file's readahead state
 998 */
 999struct file_ra_state {
1000        pgoff_t start;                  /* where readahead started */
1001        unsigned int size;              /* # of readahead pages */
1002        unsigned int async_size;        /* do asynchronous readahead when
1003                                           there are only # of pages ahead */
1004
1005        unsigned int ra_pages;          /* Maximum readahead window */
1006        unsigned int mmap_miss;         /* Cache miss stat for mmap accesses */
1007        loff_t prev_pos;                /* Cache last read() position */
1008};
1009
1010/*
1011 * Check if @index falls in the readahead windows.
1012 */
1013static inline int ra_has_index(struct file_ra_state *ra, pgoff_t index)
1014{
1015        return (index >= ra->start &&
1016                index <  ra->start + ra->size);
1017}
1018
1019#define FILE_MNT_WRITE_TAKEN    1
1020#define FILE_MNT_WRITE_RELEASED 2
1021
1022struct file {
1023        /*
1024         * fu_list becomes invalid after file_free is called and queued via
1025         * fu_rcuhead for RCU freeing
1026         */
1027        union {
1028                struct list_head        fu_list;
1029                struct rcu_head         fu_rcuhead;
1030        } f_u;
1031        struct path             f_path;
1032#define f_dentry        f_path.dentry
1033#define f_vfsmnt        f_path.mnt
1034        const struct file_operations    *f_op;
1035
1036        /*
1037         * Protects f_ep_links, f_flags, f_pos vs i_size in lseek SEEK_CUR.
1038         * Must not be taken from IRQ context.
1039         */
1040        spinlock_t              f_lock;
1041#ifdef CONFIG_SMP
1042        int                     f_sb_list_cpu;
1043#endif
1044        atomic_long_t           f_count;
1045        unsigned int            f_flags;
1046        fmode_t                 f_mode;
1047        loff_t                  f_pos;
1048        struct fown_struct      f_owner;
1049        const struct cred       *f_cred;
1050        struct file_ra_state    f_ra;
1051
1052        u64                     f_version;
1053#ifdef CONFIG_SECURITY
1054        void                    *f_security;
1055#endif
1056        /* needed for tty driver, and maybe others */
1057        void                    *private_data;
1058
1059#ifdef CONFIG_EPOLL
1060        /* Used by fs/eventpoll.c to link all the hooks to this file */
1061        struct list_head        f_ep_links;
1062        struct list_head        f_tfile_llink;
1063#endif /* #ifdef CONFIG_EPOLL */
1064        struct address_space    *f_mapping;
1065#ifdef CONFIG_DEBUG_WRITECOUNT
1066        unsigned long f_mnt_write_state;
1067#endif
1068};
1069
1070struct file_handle {
1071        __u32 handle_bytes;
1072        int handle_type;
1073        /* file identifier */
1074        unsigned char f_handle[0];
1075};
1076
1077#define get_file(x)     atomic_long_inc(&(x)->f_count)
1078#define fput_atomic(x)  atomic_long_add_unless(&(x)->f_count, -1, 1)
1079#define file_count(x)   atomic_long_read(&(x)->f_count)
1080
1081#ifdef CONFIG_DEBUG_WRITECOUNT
1082static inline void file_take_write(struct file *f)
1083{
1084        WARN_ON(f->f_mnt_write_state != 0);
1085        f->f_mnt_write_state = FILE_MNT_WRITE_TAKEN;
1086}
1087static inline void file_release_write(struct file *f)
1088{
1089        f->f_mnt_write_state |= FILE_MNT_WRITE_RELEASED;
1090}
1091static inline void file_reset_write(struct file *f)
1092{
1093        f->f_mnt_write_state = 0;
1094}
1095static inline void file_check_state(struct file *f)
1096{
1097        /*
1098         * At this point, either both or neither of these bits
1099         * should be set.
1100         */
1101        WARN_ON(f->f_mnt_write_state == FILE_MNT_WRITE_TAKEN);
1102        WARN_ON(f->f_mnt_write_state == FILE_MNT_WRITE_RELEASED);
1103}
1104static inline int file_check_writeable(struct file *f)
1105{
1106        if (f->f_mnt_write_state == FILE_MNT_WRITE_TAKEN)
1107                return 0;
1108        printk(KERN_WARNING "writeable file with no "
1109                            "mnt_want_write()\n");
1110        WARN_ON(1);
1111        return -EINVAL;
1112}
1113#else /* !CONFIG_DEBUG_WRITECOUNT */
1114static inline void file_take_write(struct file *filp) {}
1115static inline void file_release_write(struct file *filp) {}
1116static inline void file_reset_write(struct file *filp) {}
1117static inline void file_check_state(struct file *filp) {}
1118static inline int file_check_writeable(struct file *filp)
1119{
1120        return 0;
1121}
1122#endif /* CONFIG_DEBUG_WRITECOUNT */
1123
1124#define MAX_NON_LFS     ((1UL<<31) - 1)
1125
1126/* Page cache limit. The filesystems should put that into their s_maxbytes 
1127   limits, otherwise bad things can happen in VM. */ 
1128#if BITS_PER_LONG==32
1129#define MAX_LFS_FILESIZE        (((u64)PAGE_CACHE_SIZE << (BITS_PER_LONG-1))-1) 
1130#elif BITS_PER_LONG==64
1131#define MAX_LFS_FILESIZE        0x7fffffffffffffffUL
1132#endif
1133
1134#define FL_POSIX        1
1135#define FL_FLOCK        2
1136#define FL_ACCESS       8       /* not trying to lock, just looking */
1137#define FL_EXISTS       16      /* when unlocking, test for existence */
1138#define FL_LEASE        32      /* lease held on this file */
1139#define FL_CLOSE        64      /* unlock on close */
1140#define FL_SLEEP        128     /* A blocking lock */
1141#define FL_DOWNGRADE_PENDING    256 /* Lease is being downgraded */
1142#define FL_UNLOCK_PENDING       512 /* Lease is being broken */
1143
1144/*
1145 * Special return value from posix_lock_file() and vfs_lock_file() for
1146 * asynchronous locking.
1147 */
1148#define FILE_LOCK_DEFERRED 1
1149
1150/*
1151 * The POSIX file lock owner is determined by
1152 * the "struct files_struct" in the thread group
1153 * (or NULL for no owner - BSD locks).
1154 *
1155 * Lockd stuffs a "host" pointer into this.
1156 */
1157typedef struct files_struct *fl_owner_t;
1158
1159struct file_lock_operations {
1160        void (*fl_copy_lock)(struct file_lock *, struct file_lock *);
1161        void (*fl_release_private)(struct file_lock *);
1162};
1163
1164struct lock_manager_operations {
1165        int (*lm_compare_owner)(struct file_lock *, struct file_lock *);
1166        void (*lm_notify)(struct file_lock *);  /* unblock callback */
1167        int (*lm_grant)(struct file_lock *, struct file_lock *, int);
1168        void (*lm_break)(struct file_lock *);
1169        int (*lm_change)(struct file_lock **, int);
1170};
1171
1172struct lock_manager {
1173        struct list_head list;
1174};
1175
1176struct net;
1177void locks_start_grace(struct net *, struct lock_manager *);
1178void locks_end_grace(struct lock_manager *);
1179int locks_in_grace(struct net *);
1180
1181/* that will die - we need it for nfs_lock_info */
1182#include <linux/nfs_fs_i.h>
1183
1184struct file_lock {
1185        struct file_lock *fl_next;      /* singly linked list for this inode  */
1186        struct list_head fl_link;       /* doubly linked list of all locks */
1187        struct list_head fl_block;      /* circular list of blocked processes */
1188        fl_owner_t fl_owner;
1189        unsigned int fl_flags;
1190        unsigned char fl_type;
1191        unsigned int fl_pid;
1192        struct pid *fl_nspid;
1193        wait_queue_head_t fl_wait;
1194        struct file *fl_file;
1195        loff_t fl_start;
1196        loff_t fl_end;
1197
1198        struct fasync_struct *  fl_fasync; /* for lease break notifications */
1199        /* for lease breaks: */
1200        unsigned long fl_break_time;
1201        unsigned long fl_downgrade_time;
1202
1203        const struct file_lock_operations *fl_ops;      /* Callbacks for filesystems */
1204        const struct lock_manager_operations *fl_lmops; /* Callbacks for lockmanagers */
1205        union {
1206                struct nfs_lock_info    nfs_fl;
1207                struct nfs4_lock_info   nfs4_fl;
1208                struct {
1209                        struct list_head link;  /* link in AFS vnode's pending_locks list */
1210                        int state;              /* state of grant or error if -ve */
1211                } afs;
1212        } fl_u;
1213};
1214
1215/* The following constant reflects the upper bound of the file/locking space */
1216#ifndef OFFSET_MAX
1217#define INT_LIMIT(x)    (~((x)1 << (sizeof(x)*8 - 1)))
1218#define OFFSET_MAX      INT_LIMIT(loff_t)
1219#define OFFT_OFFSET_MAX INT_LIMIT(off_t)
1220#endif
1221
1222#include <linux/fcntl.h>
1223
1224extern void send_sigio(struct fown_struct *fown, int fd, int band);
1225
1226#ifdef CONFIG_FILE_LOCKING
1227extern int fcntl_getlk(struct file *, struct flock __user *);
1228extern int fcntl_setlk(unsigned int, struct file *, unsigned int,
1229                        struct flock __user *);
1230
1231#if BITS_PER_LONG == 32
1232extern int fcntl_getlk64(struct file *, struct flock64 __user *);
1233extern int fcntl_setlk64(unsigned int, struct file *, unsigned int,
1234                        struct flock64 __user *);
1235#endif
1236
1237extern int fcntl_setlease(unsigned int fd, struct file *filp, long arg);
1238extern int fcntl_getlease(struct file *filp);
1239
1240/* fs/locks.c */
1241void locks_free_lock(struct file_lock *fl);
1242extern void locks_init_lock(struct file_lock *);
1243extern struct file_lock * locks_alloc_lock(void);
1244extern void locks_copy_lock(struct file_lock *, struct file_lock *);
1245extern void __locks_copy_lock(struct file_lock *, const struct file_lock *);
1246extern void locks_remove_posix(struct file *, fl_owner_t);
1247extern void locks_remove_flock(struct file *);
1248extern void locks_release_private(struct file_lock *);
1249extern void posix_test_lock(struct file *, struct file_lock *);
1250extern int posix_lock_file(struct file *, struct file_lock *, struct file_lock *);
1251extern int posix_lock_file_wait(struct file *, struct file_lock *);
1252extern int posix_unblock_lock(struct file *, struct file_lock *);
1253extern int vfs_test_lock(struct file *, struct file_lock *);
1254extern int vfs_lock_file(struct file *, unsigned int, struct file_lock *, struct file_lock *);
1255extern int vfs_cancel_lock(struct file *filp, struct file_lock *fl);
1256extern int flock_lock_file_wait(struct file *filp, struct file_lock *fl);
1257extern int __break_lease(struct inode *inode, unsigned int flags);
1258extern void lease_get_mtime(struct inode *, struct timespec *time);
1259extern int generic_setlease(struct file *, long, struct file_lock **);
1260extern int vfs_setlease(struct file *, long, struct file_lock **);
1261extern int lease_modify(struct file_lock **, int);
1262extern int lock_may_read(struct inode *, loff_t start, unsigned long count);
1263extern int lock_may_write(struct inode *, loff_t start, unsigned long count);
1264extern void locks_delete_block(struct file_lock *waiter);
1265extern void lock_flocks(void);
1266extern void unlock_flocks(void);
1267#else /* !CONFIG_FILE_LOCKING */
1268static inline int fcntl_getlk(struct file *file, struct flock __user *user)
1269{
1270        return -EINVAL;
1271}
1272
1273static inline int fcntl_setlk(unsigned int fd, struct file *file,
1274                              unsigned int cmd, struct flock __user *user)
1275{
1276        return -EACCES;
1277}
1278
1279#if BITS_PER_LONG == 32
1280static inline int fcntl_getlk64(struct file *file, struct flock64 __user *user)
1281{
1282        return -EINVAL;
1283}
1284
1285static inline int fcntl_setlk64(unsigned int fd, struct file *file,
1286                                unsigned int cmd, struct flock64 __user *user)
1287{
1288        return -EACCES;
1289}
1290#endif
1291static inline int fcntl_setlease(unsigned int fd, struct file *filp, long arg)
1292{
1293        return 0;
1294}
1295
1296static inline int fcntl_getlease(struct file *filp)
1297{
1298        return 0;
1299}
1300
1301static inline void locks_init_lock(struct file_lock *fl)
1302{
1303        return;
1304}
1305
1306static inline void __locks_copy_lock(struct file_lock *new, struct file_lock *fl)
1307{
1308        return;
1309}
1310
1311static inline void locks_copy_lock(struct file_lock *new, struct file_lock *fl)
1312{
1313        return;
1314}
1315
1316static inline void locks_remove_posix(struct file *filp, fl_owner_t owner)
1317{
1318        return;
1319}
1320
1321static inline void locks_remove_flock(struct file *filp)
1322{
1323        return;
1324}
1325
1326static inline void posix_test_lock(struct file *filp, struct file_lock *fl)
1327{
1328        return;
1329}
1330
1331static inline int posix_lock_file(struct file *filp, struct file_lock *fl,
1332                                  struct file_lock *conflock)
1333{
1334        return -ENOLCK;
1335}
1336
1337static inline int posix_lock_file_wait(struct file *filp, struct file_lock *fl)
1338{
1339        return -ENOLCK;
1340}
1341
1342static inline int posix_unblock_lock(struct file *filp,
1343                                     struct file_lock *waiter)
1344{
1345        return -ENOENT;
1346}
1347
1348static inline int vfs_test_lock(struct file *filp, struct file_lock *fl)
1349{
1350        return 0;
1351}
1352
1353static inline int vfs_lock_file(struct file *filp, unsigned int cmd,
1354                                struct file_lock *fl, struct file_lock *conf)
1355{
1356        return -ENOLCK;
1357}
1358
1359static inline int vfs_cancel_lock(struct file *filp, struct file_lock *fl)
1360{
1361        return 0;
1362}
1363
1364static inline int flock_lock_file_wait(struct file *filp,
1365                                       struct file_lock *request)
1366{
1367        return -ENOLCK;
1368}
1369
1370static inline int __break_lease(struct inode *inode, unsigned int mode)
1371{
1372        return 0;
1373}
1374
1375static inline void lease_get_mtime(struct inode *inode, struct timespec *time)
1376{
1377        return;
1378}
1379
1380static inline int generic_setlease(struct file *filp, long arg,
1381                                    struct file_lock **flp)
1382{
1383        return -EINVAL;
1384}
1385
1386static inline int vfs_setlease(struct file *filp, long arg,
1387                               struct file_lock **lease)
1388{
1389        return -EINVAL;
1390}
1391
1392static inline int lease_modify(struct file_lock **before, int arg)
1393{
1394        return -EINVAL;
1395}
1396
1397static inline int lock_may_read(struct inode *inode, loff_t start,
1398                                unsigned long len)
1399{
1400        return 1;
1401}
1402
1403static inline int lock_may_write(struct inode *inode, loff_t start,
1404                                 unsigned long len)
1405{
1406        return 1;
1407}
1408
1409static inline void locks_delete_block(struct file_lock *waiter)
1410{
1411}
1412
1413static inline void lock_flocks(void)
1414{
1415}
1416
1417static inline void unlock_flocks(void)
1418{
1419}
1420
1421#endif /* !CONFIG_FILE_LOCKING */
1422
1423
1424struct fasync_struct {
1425        spinlock_t              fa_lock;
1426        int                     magic;
1427        int                     fa_fd;
1428        struct fasync_struct    *fa_next; /* singly linked list */
1429        struct file             *fa_file;
1430        struct rcu_head         fa_rcu;
1431};
1432
1433#define FASYNC_MAGIC 0x4601
1434
1435/* SMP safe fasync helpers: */
1436extern int fasync_helper(int, struct file *, int, struct fasync_struct **);
1437extern struct fasync_struct *fasync_insert_entry(int, struct file *, struct fasync_struct **, struct fasync_struct *);
1438extern int fasync_remove_entry(struct file *, struct fasync_struct **);
1439extern struct fasync_struct *fasync_alloc(void);
1440extern void fasync_free(struct fasync_struct *);
1441
1442/* can be called from interrupts */
1443extern void kill_fasync(struct fasync_struct **, int, int);
1444
1445extern int __f_setown(struct file *filp, struct pid *, enum pid_type, int force);
1446extern int f_setown(struct file *filp, unsigned long arg, int force);
1447extern void f_delown(struct file *filp);
1448extern pid_t f_getown(struct file *filp);
1449extern int send_sigurg(struct fown_struct *fown);
1450
1451struct mm_struct;
1452
1453/*
1454 *      Umount options
1455 */
1456
1457#define MNT_FORCE       0x00000001      /* Attempt to forcibily umount */
1458#define MNT_DETACH      0x00000002      /* Just detach from the tree */
1459#define MNT_EXPIRE      0x00000004      /* Mark for expiry */
1460#define UMOUNT_NOFOLLOW 0x00000008      /* Don't follow symlink on umount */
1461#define UMOUNT_UNUSED   0x80000000      /* Flag guaranteed to be unused */
1462
1463extern struct list_head super_blocks;
1464extern spinlock_t sb_lock;
1465
1466/* Possible states of 'frozen' field */
1467enum {
1468        SB_UNFROZEN = 0,                /* FS is unfrozen */
1469        SB_FREEZE_WRITE = 1,            /* Writes, dir ops, ioctls frozen */
1470        SB_FREEZE_PAGEFAULT = 2,        /* Page faults stopped as well */
1471        SB_FREEZE_FS = 3,               /* For internal FS use (e.g. to stop
1472                                         * internal threads if needed) */
1473        SB_FREEZE_COMPLETE = 4,         /* ->freeze_fs finished successfully */
1474};
1475
1476#define SB_FREEZE_LEVELS (SB_FREEZE_COMPLETE - 1)
1477
1478struct sb_writers {
1479        /* Counters for counting writers at each level */
1480        struct percpu_counter   counter[SB_FREEZE_LEVELS];
1481        wait_queue_head_t       wait;           /* queue for waiting for
1482                                                   writers / faults to finish */
1483        int                     frozen;         /* Is sb frozen? */
1484        wait_queue_head_t       wait_unfrozen;  /* queue for waiting for
1485                                                   sb to be thawed */
1486#ifdef CONFIG_DEBUG_LOCK_ALLOC
1487        struct lockdep_map      lock_map[SB_FREEZE_LEVELS];
1488#endif
1489};
1490
1491struct super_block {
1492        struct list_head        s_list;         /* Keep this first */
1493        dev_t                   s_dev;          /* search index; _not_ kdev_t */
1494        unsigned char           s_blocksize_bits;
1495        unsigned long           s_blocksize;
1496        loff_t                  s_maxbytes;     /* Max file size */
1497        struct file_system_type *s_type;
1498        const struct super_operations   *s_op;
1499        const struct dquot_operations   *dq_op;
1500        const struct quotactl_ops       *s_qcop;
1501        const struct export_operations *s_export_op;
1502        unsigned long           s_flags;
1503        unsigned long           s_magic;
1504        struct dentry           *s_root;
1505        struct rw_semaphore     s_umount;
1506        struct mutex            s_lock;
1507        int                     s_count;
1508        atomic_t                s_active;
1509#ifdef CONFIG_SECURITY
1510        void                    *s_security;
1511#endif
1512        const struct xattr_handler **s_xattr;
1513
1514        struct list_head        s_inodes;       /* all inodes */
1515        struct hlist_bl_head    s_anon;         /* anonymous dentries for (nfs) exporting */
1516#ifdef CONFIG_SMP
1517        struct list_head __percpu *s_files;
1518#else
1519        struct list_head        s_files;
1520#endif
1521        struct list_head        s_mounts;       /* list of mounts; _not_ for fs use */
1522        /* s_dentry_lru, s_nr_dentry_unused protected by dcache.c lru locks */
1523        struct list_head        s_dentry_lru;   /* unused dentry lru */
1524        int                     s_nr_dentry_unused;     /* # of dentry on lru */
1525
1526        /* s_inode_lru_lock protects s_inode_lru and s_nr_inodes_unused */
1527        spinlock_t              s_inode_lru_lock ____cacheline_aligned_in_smp;
1528        struct list_head        s_inode_lru;            /* unused inode lru */
1529        int                     s_nr_inodes_unused;     /* # of inodes on lru */
1530
1531        struct block_device     *s_bdev;
1532        struct backing_dev_info *s_bdi;
1533        struct mtd_info         *s_mtd;
1534        struct hlist_node       s_instances;
1535        struct quota_info       s_dquot;        /* Diskquota specific options */
1536
1537        struct sb_writers       s_writers;
1538
1539        char s_id[32];                          /* Informational name */
1540        u8 s_uuid[16];                          /* UUID */
1541
1542        void                    *s_fs_info;     /* Filesystem private info */
1543        unsigned int            s_max_links;
1544        fmode_t                 s_mode;
1545
1546        /* Granularity of c/m/atime in ns.
1547           Cannot be worse than a second */
1548        u32                s_time_gran;
1549
1550        /*
1551         * The next field is for VFS *only*. No filesystems have any business
1552         * even looking at it. You had been warned.
1553         */
1554        struct mutex s_vfs_rename_mutex;        /* Kludge */
1555
1556        /*
1557         * Filesystem subtype.  If non-empty the filesystem type field
1558         * in /proc/mounts will be "type.subtype"
1559         */
1560        char *s_subtype;
1561
1562        /*
1563         * Saved mount options for lazy filesystems using
1564         * generic_show_options()
1565         */
1566        char __rcu *s_options;
1567        const struct dentry_operations *s_d_op; /* default d_op for dentries */
1568
1569        /*
1570         * Saved pool identifier for cleancache (-1 means none)
1571         */
1572        int cleancache_poolid;
1573
1574        struct shrinker s_shrink;       /* per-sb shrinker handle */
1575
1576        /* Number of inodes with nlink == 0 but still referenced */
1577        atomic_long_t s_remove_count;
1578
1579        /* Being remounted read-only */
1580        int s_readonly_remount;
1581};
1582
1583/* superblock cache pruning functions */
1584extern void prune_icache_sb(struct super_block *sb, int nr_to_scan);
1585extern void prune_dcache_sb(struct super_block *sb, int nr_to_scan);
1586
1587extern struct timespec current_fs_time(struct super_block *sb);
1588
1589/*
1590 * Snapshotting support.
1591 */
1592
1593void __sb_end_write(struct super_block *sb, int level);
1594int __sb_start_write(struct super_block *sb, int level, bool wait);
1595
1596/**
1597 * sb_end_write - drop write access to a superblock
1598 * @sb: the super we wrote to
1599 *
1600 * Decrement number of writers to the filesystem. Wake up possible waiters
1601 * wanting to freeze the filesystem.
1602 */
1603static inline void sb_end_write(struct super_block *sb)
1604{
1605        __sb_end_write(sb, SB_FREEZE_WRITE);
1606}
1607
1608/**
1609 * sb_end_pagefault - drop write access to a superblock from a page fault
1610 * @sb: the super we wrote to
1611 *
1612 * Decrement number of processes handling write page fault to the filesystem.
1613 * Wake up possible waiters wanting to freeze the filesystem.
1614 */
1615static inline void sb_end_pagefault(struct super_block *sb)
1616{
1617        __sb_end_write(sb, SB_FREEZE_PAGEFAULT);
1618}
1619
1620/**
1621 * sb_end_intwrite - drop write access to a superblock for internal fs purposes
1622 * @sb: the super we wrote to
1623 *
1624 * Decrement fs-internal number of writers to the filesystem.  Wake up possible
1625 * waiters wanting to freeze the filesystem.
1626 */
1627static inline void sb_end_intwrite(struct super_block *sb)
1628{
1629        __sb_end_write(sb, SB_FREEZE_FS);
1630}
1631
1632/**
1633 * sb_start_write - get write access to a superblock
1634 * @sb: the super we write to
1635 *
1636 * When a process wants to write data or metadata to a file system (i.e. dirty
1637 * a page or an inode), it should embed the operation in a sb_start_write() -
1638 * sb_end_write() pair to get exclusion against file system freezing. This
1639 * function increments number of writers preventing freezing. If the file
1640 * system is already frozen, the function waits until the file system is
1641 * thawed.
1642 *
1643 * Since freeze protection behaves as a lock, users have to preserve
1644 * ordering of freeze protection and other filesystem locks. Generally,
1645 * freeze protection should be the outermost lock. In particular, we have:
1646 *
1647 * sb_start_write
1648 *   -> i_mutex                 (write path, truncate, directory ops, ...)
1649 *   -> s_umount                (freeze_super, thaw_super)
1650 */
1651static inline void sb_start_write(struct super_block *sb)
1652{
1653        __sb_start_write(sb, SB_FREEZE_WRITE, true);
1654}
1655
1656static inline int sb_start_write_trylock(struct super_block *sb)
1657{
1658        return __sb_start_write(sb, SB_FREEZE_WRITE, false);
1659}
1660
1661/**
1662 * sb_start_pagefault - get write access to a superblock from a page fault
1663 * @sb: the super we write to
1664 *
1665 * When a process starts handling write page fault, it should embed the
1666 * operation into sb_start_pagefault() - sb_end_pagefault() pair to get
1667 * exclusion against file system freezing. This is needed since the page fault
1668 * is going to dirty a page. This function increments number of running page
1669 * faults preventing freezing. If the file system is already frozen, the
1670 * function waits until the file system is thawed.
1671 *
1672 * Since page fault freeze protection behaves as a lock, users have to preserve
1673 * ordering of freeze protection and other filesystem locks. It is advised to
1674 * put sb_start_pagefault() close to mmap_sem in lock ordering. Page fault
1675 * handling code implies lock dependency:
1676 *
1677 * mmap_sem
1678 *   -> sb_start_pagefault
1679 */
1680static inline void sb_start_pagefault(struct super_block *sb)
1681{
1682        __sb_start_write(sb, SB_FREEZE_PAGEFAULT, true);
1683}
1684
1685/*
1686 * sb_start_intwrite - get write access to a superblock for internal fs purposes
1687 * @sb: the super we write to
1688 *
1689 * This is the third level of protection against filesystem freezing. It is
1690 * free for use by a filesystem. The only requirement is that it must rank
1691 * below sb_start_pagefault.
1692 *
1693 * For example filesystem can call sb_start_intwrite() when starting a
1694 * transaction which somewhat eases handling of freezing for internal sources
1695 * of filesystem changes (internal fs threads, discarding preallocation on file
1696 * close, etc.).
1697 */
1698static inline void sb_start_intwrite(struct super_block *sb)
1699{
1700        __sb_start_write(sb, SB_FREEZE_FS, true);
1701}
1702
1703
1704extern bool inode_owner_or_capable(const struct inode *inode);
1705
1706/* not quite ready to be deprecated, but... */
1707extern void lock_super(struct super_block *);
1708extern void unlock_super(struct super_block *);
1709
1710/*
1711 * VFS helper functions..
1712 */
1713extern int vfs_create(struct inode *, struct dentry *, umode_t, bool);
1714extern int vfs_mkdir(struct inode *, struct dentry *, umode_t);
1715extern int vfs_mknod(struct inode *, struct dentry *, umode_t, dev_t);
1716extern int vfs_symlink(struct inode *, struct dentry *, const char *);
1717extern int vfs_link(struct dentry *, struct inode *, struct dentry *);
1718extern int vfs_rmdir(struct inode *, struct dentry *);
1719extern int vfs_unlink(struct inode *, struct dentry *);
1720extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *);
1721
1722/*
1723 * VFS dentry helper functions.
1724 */
1725extern void dentry_unhash(struct dentry *dentry);
1726
1727/*
1728 * VFS file helper functions.
1729 */
1730extern void inode_init_owner(struct inode *inode, const struct inode *dir,
1731                        umode_t mode);
1732/*
1733 * VFS FS_IOC_FIEMAP helper definitions.
1734 */
1735struct fiemap_extent_info {
1736        unsigned int fi_flags;          /* Flags as passed from user */
1737        unsigned int fi_extents_mapped; /* Number of mapped extents */
1738        unsigned int fi_extents_max;    /* Size of fiemap_extent array */
1739        struct fiemap_extent __user *fi_extents_start; /* Start of
1740                                                        fiemap_extent array */
1741};
1742int fiemap_fill_next_extent(struct fiemap_extent_info *info, u64 logical,
1743                            u64 phys, u64 len, u32 flags);
1744int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags);
1745
1746/*
1747 * File types
1748 *
1749 * NOTE! These match bits 12..15 of stat.st_mode
1750 * (ie "(i_mode >> 12) & 15").
1751 */
1752#define DT_UNKNOWN      0
1753#define DT_FIFO         1
1754#define DT_CHR          2
1755#define DT_DIR          4
1756#define DT_BLK          6
1757#define DT_REG          8
1758#define DT_LNK          10
1759#define DT_SOCK         12
1760#define DT_WHT          14
1761
1762/*
1763 * This is the "filldir" function type, used by readdir() to let
1764 * the kernel specify what kind of dirent layout it wants to have.
1765 * This allows the kernel to read directories into kernel space or
1766 * to have different dirent layouts depending on the binary type.
1767 */
1768typedef int (*filldir_t)(void *, const char *, int, loff_t, u64, unsigned);
1769struct block_device_operations;
1770
1771/* These macros are for out of kernel modules to test that
1772 * the kernel supports the unlocked_ioctl and compat_ioctl
1773 * fields in struct file_operations. */
1774#define HAVE_COMPAT_IOCTL 1
1775#define HAVE_UNLOCKED_IOCTL 1
1776
1777struct file_operations {
1778        struct module *owner;
1779        loff_t (*llseek) (struct file *, loff_t, int);
1780        ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
1781        ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
1782        ssize_t (*aio_read) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
1783        ssize_t (*aio_write) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
1784        int (*readdir) (struct file *, void *, filldir_t);
1785        unsigned int (*poll) (struct file *, struct poll_table_struct *);
1786        long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
1787        long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
1788        int (*mmap) (struct file *, struct vm_area_struct *);
1789        int (*open) (struct inode *, struct file *);
1790        int (*flush) (struct file *, fl_owner_t id);
1791        int (*release) (struct inode *, struct file *);
1792        int (*fsync) (struct file *, loff_t, loff_t, int datasync);
1793        int (*aio_fsync) (struct kiocb *, int datasync);
1794        int (*fasync) (int, struct file *, int);
1795        int (*lock) (struct file *, int, struct file_lock *);
1796        ssize_t (*sendpage) (struct file *, struct page *, int, size_t, loff_t *, int);
1797        unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
1798        int (*check_flags)(int);
1799        int (*flock) (struct file *, int, struct file_lock *);
1800        ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int);
1801        ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int);
1802        int (*setlease)(struct file *, long, struct file_lock **);
1803        long (*fallocate)(struct file *file, int mode, loff_t offset,
1804                          loff_t len);
1805};
1806
1807struct inode_operations {
1808        struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int);
1809        void * (*follow_link) (struct dentry *, struct nameidata *);
1810        int (*permission) (struct inode *, int);
1811        struct posix_acl * (*get_acl)(struct inode *, int);
1812
1813        int (*readlink) (struct dentry *, char __user *,int);
1814        void (*put_link) (struct dentry *, struct nameidata *, void *);
1815
1816        int (*create) (struct inode *,struct dentry *, umode_t, bool);
1817        int (*link) (struct dentry *,struct inode *,struct dentry *);
1818        int (*unlink) (struct inode *,struct dentry *);
1819        int (*symlink) (struct inode *,struct dentry *,const char *);
1820        int (*mkdir) (struct inode *,struct dentry *,umode_t);
1821        int (*rmdir) (struct inode *,struct dentry *);
1822        int (*mknod) (struct inode *,struct dentry *,umode_t,dev_t);
1823        int (*rename) (struct inode *, struct dentry *,
1824                        struct inode *, struct dentry *);
1825        void (*truncate) (struct inode *);
1826        int (*setattr) (struct dentry *, struct iattr *);
1827        int (*getattr) (struct vfsmount *mnt, struct dentry *, struct kstat *);
1828        int (*setxattr) (struct dentry *, const char *,const void *,size_t,int);
1829        ssize_t (*getxattr) (struct dentry *, const char *, void *, size_t);
1830        ssize_t (*listxattr) (struct dentry *, char *, size_t);
1831        int (*removexattr) (struct dentry *, const char *);
1832        int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start,
1833                      u64 len);
1834        int (*update_time)(struct inode *, struct timespec *, int);
1835        int (*atomic_open)(struct inode *, struct dentry *,
1836                           struct file *, unsigned open_flag,
1837                           umode_t create_mode, int *opened);
1838} ____cacheline_aligned;
1839
1840struct seq_file;
1841
1842ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
1843                              unsigned long nr_segs, unsigned long fast_segs,
1844                              struct iovec *fast_pointer,
1845                              struct iovec **ret_pointer);
1846
1847extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *);
1848extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *);
1849extern ssize_t vfs_readv(struct file *, const struct iovec __user *,
1850                unsigned long, loff_t *);
1851extern ssize_t vfs_writev(struct file *, const struct iovec __user *,
1852                unsigned long, loff_t *);
1853
1854struct super_operations {
1855        struct inode *(*alloc_inode)(struct super_block *sb);
1856        void (*destroy_inode)(struct inode *);
1857
1858        void (*dirty_inode) (struct inode *, int flags);
1859        int (*write_inode) (struct inode *, struct writeback_control *wbc);
1860        int (*drop_inode) (struct inode *);
1861        void (*evict_inode) (struct inode *);
1862        void (*put_super) (struct super_block *);
1863        int (*sync_fs)(struct super_block *sb, int wait);
1864        int (*freeze_fs) (struct super_block *);
1865        int (*unfreeze_fs) (struct super_block *);
1866        int (*statfs) (struct dentry *, struct kstatfs *);
1867        int (*remount_fs) (struct super_block *, int *, char *);
1868        void (*umount_begin) (struct super_block *);
1869
1870        int (*show_options)(struct seq_file *, struct dentry *);
1871        int (*show_devname)(struct seq_file *, struct dentry *);
1872        int (*show_path)(struct seq_file *, struct dentry *);
1873        int (*show_stats)(struct seq_file *, struct dentry *);
1874#ifdef CONFIG_QUOTA
1875        ssize_t (*quota_read)(struct super_block *, int, char *, size_t, loff_t);
1876        ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t);
1877#endif
1878        int (*bdev_try_to_free_page)(struct super_block*, struct page*, gfp_t);
1879        int (*nr_cached_objects)(struct super_block *);
1880        void (*free_cached_objects)(struct super_block *, int);
1881};
1882
1883/*
1884 * Inode state bits.  Protected by inode->i_lock
1885 *
1886 * Three bits determine the dirty state of the inode, I_DIRTY_SYNC,
1887 * I_DIRTY_DATASYNC and I_DIRTY_PAGES.
1888 *
1889 * Four bits define the lifetime of an inode.  Initially, inodes are I_NEW,
1890 * until that flag is cleared.  I_WILL_FREE, I_FREEING and I_CLEAR are set at
1891 * various stages of removing an inode.
1892 *
1893 * Two bits are used for locking and completion notification, I_NEW and I_SYNC.
1894 *
1895 * I_DIRTY_SYNC         Inode is dirty, but doesn't have to be written on
1896 *                      fdatasync().  i_atime is the usual cause.
1897 * I_DIRTY_DATASYNC     Data-related inode changes pending. We keep track of
1898 *                      these changes separately from I_DIRTY_SYNC so that we
1899 *                      don't have to write inode on fdatasync() when only
1900 *                      mtime has changed in it.
1901 * I_DIRTY_PAGES        Inode has dirty pages.  Inode itself may be clean.
1902 * I_NEW                Serves as both a mutex and completion notification.
1903 *                      New inodes set I_NEW.  If two processes both create
1904 *                      the same inode, one of them will release its inode and
1905 *                      wait for I_NEW to be released before returning.
1906 *                      Inodes in I_WILL_FREE, I_FREEING or I_CLEAR state can
1907 *                      also cause waiting on I_NEW, without I_NEW actually
1908 *                      being set.  find_inode() uses this to prevent returning
1909 *                      nearly-dead inodes.
1910 * I_WILL_FREE          Must be set when calling write_inode_now() if i_count
1911 *                      is zero.  I_FREEING must be set when I_WILL_FREE is
1912 *                      cleared.
1913 * I_FREEING            Set when inode is about to be freed but still has dirty
1914 *                      pages or buffers attached or the inode itself is still
1915 *                      dirty.
1916 * I_CLEAR              Added by clear_inode().  In this state the inode is
1917 *                      clean and can be destroyed.  Inode keeps I_FREEING.
1918 *
1919 *                      Inodes that are I_WILL_FREE, I_FREEING or I_CLEAR are
1920 *                      prohibited for many purposes.  iget() must wait for
1921 *                      the inode to be completely released, then create it
1922 *                      anew.  Other functions will just ignore such inodes,
1923 *                      if appropriate.  I_NEW is used for waiting.
1924 *
1925 * I_SYNC               Writeback of inode is running. The bit is set during
1926 *                      data writeback, and cleared with a wakeup on the bit
1927 *                      address once it is done. The bit is also used to pin
1928 *                      the inode in memory for flusher thread.
1929 *
1930 * I_REFERENCED         Marks the inode as recently references on the LRU list.
1931 *
1932 * I_DIO_WAKEUP         Never set.  Only used as a key for wait_on_bit().
1933 *
1934 * Q: What is the difference between I_WILL_FREE and I_FREEING?
1935 */
1936#define I_DIRTY_SYNC            (1 << 0)
1937#define I_DIRTY_DATASYNC        (1 << 1)
1938#define I_DIRTY_PAGES           (1 << 2)
1939#define __I_NEW                 3
1940#define I_NEW                   (1 << __I_NEW)
1941#define I_WILL_FREE             (1 << 4)
1942#define I_FREEING               (1 << 5)
1943#define I_CLEAR                 (1 << 6)
1944#define __I_SYNC                7
1945#define I_SYNC                  (1 << __I_SYNC)
1946#define I_REFERENCED            (1 << 8)
1947#define __I_DIO_WAKEUP          9
1948#define I_DIO_WAKEUP            (1 << I_DIO_WAKEUP)
1949
1950#define I_DIRTY (I_DIRTY_SYNC | I_DIRTY_DATASYNC | I_DIRTY_PAGES)
1951
1952extern void __mark_inode_dirty(struct inode *, int);
1953static inline void mark_inode_dirty(struct inode *inode)
1954{
1955        __mark_inode_dirty(inode, I_DIRTY);
1956}
1957
1958static inline void mark_inode_dirty_sync(struct inode *inode)
1959{
1960        __mark_inode_dirty(inode, I_DIRTY_SYNC);
1961}
1962
1963extern void inc_nlink(struct inode *inode);
1964extern void drop_nlink(struct inode *inode);
1965extern void clear_nlink(struct inode *inode);
1966extern void set_nlink(struct inode *inode, unsigned int nlink);
1967
1968static inline void inode_inc_link_count(struct inode *inode)
1969{
1970        inc_nlink(inode);
1971        mark_inode_dirty(inode);
1972}
1973
1974static inline void inode_dec_link_count(struct inode *inode)
1975{
1976        drop_nlink(inode);
1977        mark_inode_dirty(inode);
1978}
1979
1980/**
1981 * inode_inc_iversion - increments i_version
1982 * @inode: inode that need to be updated
1983 *
1984 * Every time the inode is modified, the i_version field will be incremented.
1985 * The filesystem has to be mounted with i_version flag
1986 */
1987
1988static inline void inode_inc_iversion(struct inode *inode)
1989{
1990       spin_lock(&inode->i_lock);
1991       inode->i_version++;
1992       spin_unlock(&inode->i_lock);
1993}
1994
1995enum file_time_flags {
1996        S_ATIME = 1,
1997        S_MTIME = 2,
1998        S_CTIME = 4,
1999        S_VERSION = 8,
2000};
2001
2002extern void touch_atime(struct path *);
2003static inline void file_accessed(struct file *file)
2004{
2005        if (!(file->f_flags & O_NOATIME))
2006                touch_atime(&file->f_path);
2007}
2008
2009int sync_inode(struct inode *inode, struct writeback_control *wbc);
2010int sync_inode_metadata(struct inode *inode, int wait);
2011
2012struct file_system_type {
2013        const char *name;
2014        int fs_flags;
2015        struct dentry *(*mount) (struct file_system_type *, int,
2016                       const char *, void *);
2017        void (*kill_sb) (struct super_block *);
2018        struct module *owner;
2019        struct file_system_type * next;
2020        struct hlist_head fs_supers;
2021
2022        struct lock_class_key s_lock_key;
2023        struct lock_class_key s_umount_key;
2024        struct lock_class_key s_vfs_rename_key;
2025        struct lock_class_key s_writers_key[SB_FREEZE_LEVELS];
2026
2027        struct lock_class_key i_lock_key;
2028        struct lock_class_key i_mutex_key;
2029        struct lock_class_key i_mutex_dir_key;
2030};
2031
2032extern struct dentry *mount_ns(struct file_system_type *fs_type, int flags,
2033        void *data, int (*fill_super)(struct super_block *, void *, int));
2034extern struct dentry *mount_bdev(struct file_system_type *fs_type,
2035        int flags, const char *dev_name, void *data,
2036        int (*fill_super)(struct super_block *, void *, int));
2037extern struct dentry *mount_single(struct file_system_type *fs_type,
2038        int flags, void *data,
2039        int (*fill_super)(struct super_block *, void *, int));
2040extern struct dentry *mount_nodev(struct file_system_type *fs_type,
2041        int flags, void *data,
2042        int (*fill_super)(struct super_block *, void *, int));
2043extern struct dentry *mount_subtree(struct vfsmount *mnt, const char *path);
2044void generic_shutdown_super(struct super_block *sb);
2045void kill_block_super(struct super_block *sb);
2046void kill_anon_super(struct super_block *sb);
2047void kill_litter_super(struct super_block *sb);
2048void deactivate_super(struct super_block *sb);
2049void deactivate_locked_super(struct super_block *sb);
2050int set_anon_super(struct super_block *s, void *data);
2051int get_anon_bdev(dev_t *);
2052void free_anon_bdev(dev_t);
2053struct super_block *sget(struct file_system_type *type,
2054                        int (*test)(struct super_block *,void *),
2055                        int (*set)(struct super_block *,void *),
2056                        int flags, void *data);
2057extern struct dentry *mount_pseudo(struct file_system_type *, char *,
2058        const struct super_operations *ops,
2059        const struct dentry_operations *dops,
2060        unsigned long);
2061
2062/* Alas, no aliases. Too much hassle with bringing module.h everywhere */
2063#define fops_get(fops) \
2064        (((fops) && try_module_get((fops)->owner) ? (fops) : NULL))
2065#define fops_put(fops) \
2066        do { if (fops) module_put((fops)->owner); } while(0)
2067
2068extern int register_filesystem(struct file_system_type *);
2069extern int unregister_filesystem(struct file_system_type *);
2070extern struct vfsmount *kern_mount_data(struct file_system_type *, void *data);
2071#define kern_mount(type) kern_mount_data(type, NULL)
2072extern void kern_unmount(struct vfsmount *mnt);
2073extern int may_umount_tree(struct vfsmount *);
2074extern int may_umount(struct vfsmount *);
2075extern long do_mount(char *, char *, char *, unsigned long, void *);
2076extern struct vfsmount *collect_mounts(struct path *);
2077extern void drop_collected_mounts(struct vfsmount *);
2078extern int iterate_mounts(int (*)(struct vfsmount *, void *), void *,
2079                          struct vfsmount *);
2080extern int vfs_statfs(struct path *, struct kstatfs *);
2081extern int user_statfs(const char __user *, struct kstatfs *);
2082extern int fd_statfs(int, struct kstatfs *);
2083extern int vfs_ustat(dev_t, struct kstatfs *);
2084extern int freeze_super(struct super_block *super);
2085extern int thaw_super(struct super_block *super);
2086extern bool our_mnt(struct vfsmount *mnt);
2087
2088extern int current_umask(void);
2089
2090/* /sys/fs */
2091extern struct kobject *fs_kobj;
2092
2093#define MAX_RW_COUNT (INT_MAX & PAGE_CACHE_MASK)
2094extern int rw_verify_area(int, struct file *, loff_t *, size_t);
2095
2096#define FLOCK_VERIFY_READ  1
2097#define FLOCK_VERIFY_WRITE 2
2098
2099#ifdef CONFIG_FILE_LOCKING
2100extern int locks_mandatory_locked(struct inode *);
2101extern int locks_mandatory_area(int, struct inode *, struct file *, loff_t, size_t);
2102
2103/*
2104 * Candidates for mandatory locking have the setgid bit set
2105 * but no group execute bit -  an otherwise meaningless combination.
2106 */
2107
2108static inline int __mandatory_lock(struct inode *ino)
2109{
2110        return (ino->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID;
2111}
2112
2113/*
2114 * ... and these candidates should be on MS_MANDLOCK mounted fs,
2115 * otherwise these will be advisory locks
2116 */
2117
2118static inline int mandatory_lock(struct inode *ino)
2119{
2120        return IS_MANDLOCK(ino) && __mandatory_lock(ino);
2121}
2122
2123static inline int locks_verify_locked(struct inode *inode)
2124{
2125        if (mandatory_lock(inode))
2126                return locks_mandatory_locked(inode);
2127        return 0;
2128}
2129
2130static inline int locks_verify_truncate(struct inode *inode,
2131                                    struct file *filp,
2132                                    loff_t size)
2133{
2134        if (inode->i_flock && mandatory_lock(inode))
2135                return locks_mandatory_area(
2136                        FLOCK_VERIFY_WRITE, inode, filp,
2137                        size < inode->i_size ? size : inode->i_size,
2138                        (size < inode->i_size ? inode->i_size - size
2139                         : size - inode->i_size)
2140                );
2141        return 0;
2142}
2143
2144static inline int break_lease(struct inode *inode, unsigned int mode)
2145{
2146        if (inode->i_flock)
2147                return __break_lease(inode, mode);
2148        return 0;
2149}
2150#else /* !CONFIG_FILE_LOCKING */
2151static inline int locks_mandatory_locked(struct inode *inode)
2152{
2153        return 0;
2154}
2155
2156static inline int locks_mandatory_area(int rw, struct inode *inode,
2157                                       struct file *filp, loff_t offset,
2158                                       size_t count)
2159{
2160        return 0;
2161}
2162
2163static inline int __mandatory_lock(struct inode *inode)
2164{
2165        return 0;
2166}
2167
2168static inline int mandatory_lock(struct inode *inode)
2169{
2170        return 0;
2171}
2172
2173static inline int locks_verify_locked(struct inode *inode)
2174{
2175        return 0;
2176}
2177
2178static inline int locks_verify_truncate(struct inode *inode, struct file *filp,
2179                                        size_t size)
2180{
2181        return 0;
2182}
2183
2184static inline int break_lease(struct inode *inode, unsigned int mode)
2185{
2186        return 0;
2187}
2188
2189#endif /* CONFIG_FILE_LOCKING */
2190
2191/* fs/open.c */
2192
2193extern int do_truncate(struct dentry *, loff_t start, unsigned int time_attrs,
2194                       struct file *filp);
2195extern int do_fallocate(struct file *file, int mode, loff_t offset,
2196                        loff_t len);
2197extern long do_sys_open(int dfd, const char __user *filename, int flags,
2198                        umode_t mode);
2199extern struct file *filp_open(const char *, int, umode_t);
2200extern struct file *file_open_root(struct dentry *, struct vfsmount *,
2201                                   const char *, int);
2202extern struct file * dentry_open(const struct path *, int, const struct cred *);
2203extern int filp_close(struct file *, fl_owner_t id);
2204extern char * getname(const char __user *);
2205enum {
2206        FILE_CREATED = 1,
2207        FILE_OPENED = 2
2208};
2209extern int finish_open(struct file *file, struct dentry *dentry,
2210                        int (*open)(struct inode *, struct file *),
2211                        int *opened);
2212extern int finish_no_open(struct file *file, struct dentry *dentry);
2213
2214/* fs/ioctl.c */
2215
2216extern int ioctl_preallocate(struct file *filp, void __user *argp);
2217
2218/* fs/dcache.c */
2219extern void __init vfs_caches_init_early(void);
2220extern void __init vfs_caches_init(unsigned long);
2221
2222extern struct kmem_cache *names_cachep;
2223
2224#define __getname_gfp(gfp)      kmem_cache_alloc(names_cachep, (gfp))
2225#define __getname()             __getname_gfp(GFP_KERNEL)
2226#define __putname(name)         kmem_cache_free(names_cachep, (void *)(name))
2227#ifndef CONFIG_AUDITSYSCALL
2228#define putname(name)   __putname(name)
2229#else
2230extern void putname(const char *name);
2231#endif
2232
2233#ifdef CONFIG_BLOCK
2234extern int register_blkdev(unsigned int, const char *);
2235extern void unregister_blkdev(unsigned int, const char *);
2236extern struct block_device *bdget(dev_t);
2237extern struct block_device *bdgrab(struct block_device *bdev);
2238extern void bd_set_size(struct block_device *, loff_t size);
2239extern sector_t blkdev_max_block(struct block_device *bdev);
2240extern void bd_forget(struct inode *inode);
2241extern void bdput(struct block_device *);
2242extern void invalidate_bdev(struct block_device *);
2243extern void iterate_bdevs(void (*)(struct block_device *, void *), void *);
2244extern int sync_blockdev(struct block_device *bdev);
2245extern void kill_bdev(struct block_device *);
2246extern struct super_block *freeze_bdev(struct block_device *);
2247extern void emergency_thaw_all(void);
2248extern int thaw_bdev(struct block_device *bdev, struct super_block *sb);
2249extern int fsync_bdev(struct block_device *);
2250#else
2251static inline void bd_forget(struct inode *inode) {}
2252static inline int sync_blockdev(struct block_device *bdev) { return 0; }
2253static inline void kill_bdev(struct block_device *bdev) {}
2254static inline void invalidate_bdev(struct block_device *bdev) {}
2255
2256static inline struct super_block *freeze_bdev(struct block_device *sb)
2257{
2258        return NULL;
2259}
2260
2261static inline int thaw_bdev(struct block_device *bdev, struct super_block *sb)
2262{
2263        return 0;
2264}
2265
2266static inline void iterate_bdevs(void (*f)(struct block_device *, void *), void *arg)
2267{
2268}
2269#endif
2270extern int sync_filesystem(struct super_block *);
2271extern const struct file_operations def_blk_fops;
2272extern const struct file_operations def_chr_fops;
2273extern const struct file_operations bad_sock_fops;
2274extern const struct file_operations def_fifo_fops;
2275#ifdef CONFIG_BLOCK
2276extern int ioctl_by_bdev(struct block_device *, unsigned, unsigned long);
2277extern int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long);
2278extern long compat_blkdev_ioctl(struct file *, unsigned, unsigned long);
2279extern int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder);
2280extern struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
2281                                               void *holder);
2282extern struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode,
2283                                              void *holder);
2284extern int blkdev_put(struct block_device *bdev, fmode_t mode);
2285#ifdef CONFIG_SYSFS
2286extern int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);
2287extern void bd_unlink_disk_holder(struct block_device *bdev,
2288                                  struct gendisk *disk);
2289#else
2290static inline int bd_link_disk_holder(struct block_device *bdev,
2291                                      struct gendisk *disk)
2292{
2293        return 0;
2294}
2295static inline void bd_unlink_disk_holder(struct block_device *bdev,
2296                                         struct gendisk *disk)
2297{
2298}
2299#endif
2300#endif
2301
2302/* fs/char_dev.c */
2303#define CHRDEV_MAJOR_HASH_SIZE  255
2304extern int alloc_chrdev_region(dev_t *, unsigned, unsigned, const char *);
2305extern int register_chrdev_region(dev_t, unsigned, const char *);
2306extern int __register_chrdev(unsigned int major, unsigned int baseminor,
2307                             unsigned int count, const char *name,
2308                             const struct file_operations *fops);
2309extern void __unregister_chrdev(unsigned int major, unsigned int baseminor,
2310                                unsigned int count, const char *name);
2311extern void unregister_chrdev_region(dev_t, unsigned);
2312extern void chrdev_show(struct seq_file *,off_t);
2313
2314static inline int register_chrdev(unsigned int major, const char *name,
2315                                  const struct file_operations *fops)
2316{
2317        return __register_chrdev(major, 0, 256, name, fops);
2318}
2319
2320static inline void unregister_chrdev(unsigned int major, const char *name)
2321{
2322        __unregister_chrdev(major, 0, 256, name);
2323}
2324
2325/* fs/block_dev.c */
2326#define BDEVNAME_SIZE   32      /* Largest string for a blockdev identifier */
2327#define BDEVT_SIZE      10      /* Largest string for MAJ:MIN for blkdev */
2328
2329#ifdef CONFIG_BLOCK
2330#define BLKDEV_MAJOR_HASH_SIZE  255
2331extern const char *__bdevname(dev_t, char *buffer);
2332extern const char *bdevname(struct block_device *bdev, char *buffer);
2333extern struct block_device *lookup_bdev(const char *);
2334extern void blkdev_show(struct seq_file *,off_t);
2335
2336#else
2337#define BLKDEV_MAJOR_HASH_SIZE  0
2338#endif
2339
2340extern void init_special_inode(struct inode *, umode_t, dev_t);
2341
2342/* Invalid inode operations -- fs/bad_inode.c */
2343extern void make_bad_inode(struct inode *);
2344extern int is_bad_inode(struct inode *);
2345
2346extern const struct file_operations read_pipefifo_fops;
2347extern const struct file_operations write_pipefifo_fops;
2348extern const struct file_operations rdwr_pipefifo_fops;
2349
2350#ifdef CONFIG_BLOCK
2351/*
2352 * return READ, READA, or WRITE
2353 */
2354#define bio_rw(bio)             ((bio)->bi_rw & (RW_MASK | RWA_MASK))
2355
2356/*
2357 * return data direction, READ or WRITE
2358 */
2359#define bio_data_dir(bio)       ((bio)->bi_rw & 1)
2360
2361extern void check_disk_size_change(struct gendisk *disk,
2362                                   struct block_device *bdev);
2363extern int revalidate_disk(struct gendisk *);
2364extern int check_disk_change(struct block_device *);
2365extern int __invalidate_device(struct block_device *, bool);
2366extern int invalidate_partition(struct gendisk *, int);
2367#endif
2368unsigned long invalidate_mapping_pages(struct address_space *mapping,
2369                                        pgoff_t start, pgoff_t end);
2370
2371static inline void invalidate_remote_inode(struct inode *inode)
2372{
2373        if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2374            S_ISLNK(inode->i_mode))
2375                invalidate_mapping_pages(inode->i_mapping, 0, -1);
2376}
2377extern int invalidate_inode_pages2(struct address_space *mapping);
2378extern int invalidate_inode_pages2_range(struct address_space *mapping,
2379                                         pgoff_t start, pgoff_t end);
2380extern int write_inode_now(struct inode *, int);
2381extern int filemap_fdatawrite(struct address_space *);
2382extern int filemap_flush(struct address_space *);
2383extern int filemap_fdatawait(struct address_space *);
2384extern int filemap_fdatawait_range(struct address_space *, loff_t lstart,
2385                                   loff_t lend);
2386extern int filemap_write_and_wait(struct address_space *mapping);
2387extern int filemap_write_and_wait_range(struct address_space *mapping,
2388                                        loff_t lstart, loff_t lend);
2389extern int __filemap_fdatawrite_range(struct address_space *mapping,
2390                                loff_t start, loff_t end, int sync_mode);
2391extern int filemap_fdatawrite_range(struct address_space *mapping,
2392                                loff_t start, loff_t end);
2393
2394extern int vfs_fsync_range(struct file *file, loff_t start, loff_t end,
2395                           int datasync);
2396extern int vfs_fsync(struct file *file, int datasync);
2397extern int generic_write_sync(struct file *file, loff_t pos, loff_t count);
2398extern void emergency_sync(void);
2399extern void emergency_remount(void);
2400#ifdef CONFIG_BLOCK
2401extern sector_t bmap(struct inode *, sector_t);
2402#endif
2403extern int notify_change(struct dentry *, struct iattr *);
2404extern int inode_permission(struct inode *, int);
2405extern int generic_permission(struct inode *, int);
2406
2407static inline bool execute_ok(struct inode *inode)
2408{
2409        return (inode->i_mode & S_IXUGO) || S_ISDIR(inode->i_mode);
2410}
2411
2412/*
2413 * get_write_access() gets write permission for a file.
2414 * put_write_access() releases this write permission.
2415 * This is used for regular files.
2416 * We cannot support write (and maybe mmap read-write shared) accesses and
2417 * MAP_DENYWRITE mmappings simultaneously. The i_writecount field of an inode
2418 * can have the following values:
2419 * 0: no writers, no VM_DENYWRITE mappings
2420 * < 0: (-i_writecount) vm_area_structs with VM_DENYWRITE set exist
2421 * > 0: (i_writecount) users are writing to the file.
2422 *
2423 * Normally we operate on that counter with atomic_{inc,dec} and it's safe
2424 * except for the cases where we don't hold i_writecount yet. Then we need to
2425 * use {get,deny}_write_access() - these functions check the sign and refuse
2426 * to do the change if sign is wrong.
2427 */
2428static inline int get_write_access(struct inode *inode)
2429{
2430        return atomic_inc_unless_negative(&inode->i_writecount) ? 0 : -ETXTBSY;
2431}
2432static inline int deny_write_access(struct file *file)
2433{
2434        struct inode *inode = file->f_path.dentry->d_inode;
2435        return atomic_dec_unless_positive(&inode->i_writecount) ? 0 : -ETXTBSY;
2436}
2437static inline void put_write_access(struct inode * inode)
2438{
2439        atomic_dec(&inode->i_writecount);
2440}
2441static inline void allow_write_access(struct file *file)
2442{
2443        if (file)
2444                atomic_inc(&file->f_path.dentry->d_inode->i_writecount);
2445}
2446#ifdef CONFIG_IMA
2447static inline void i_readcount_dec(struct inode *inode)
2448{
2449        BUG_ON(!atomic_read(&inode->i_readcount));
2450        atomic_dec(&inode->i_readcount);
2451}
2452static inline void i_readcount_inc(struct inode *inode)
2453{
2454        atomic_inc(&inode->i_readcount);
2455}
2456#else
2457static inline void i_readcount_dec(struct inode *inode)
2458{
2459        return;
2460}
2461static inline void i_readcount_inc(struct inode *inode)
2462{
2463        return;
2464}
2465#endif
2466extern int do_pipe_flags(int *, int);
2467
2468extern int kernel_read(struct file *, loff_t, char *, unsigned long);
2469extern struct file * open_exec(const char *);
2470 
2471/* fs/dcache.c -- generic fs support functions */
2472extern int is_subdir(struct dentry *, struct dentry *);
2473extern int path_is_under(struct path *, struct path *);
2474extern ino_t find_inode_number(struct dentry *, struct qstr *);
2475
2476#include <linux/err.h>
2477
2478/* needed for stackable file system support */
2479extern loff_t default_llseek(struct file *file, loff_t offset, int origin);
2480
2481extern loff_t vfs_llseek(struct file *file, loff_t offset, int origin);
2482
2483extern int inode_init_always(struct super_block *, struct inode *);
2484extern void inode_init_once(struct inode *);
2485extern void address_space_init_once(struct address_space *mapping);
2486extern void ihold(struct inode * inode);
2487extern void iput(struct inode *);
2488extern struct inode * igrab(struct inode *);
2489extern ino_t iunique(struct super_block *, ino_t);
2490extern int inode_needs_sync(struct inode *inode);
2491extern int generic_delete_inode(struct inode *inode);
2492static inline int generic_drop_inode(struct inode *inode)
2493{
2494        return !inode->i_nlink || inode_unhashed(inode);
2495}
2496
2497extern struct inode *ilookup5_nowait(struct super_block *sb,
2498                unsigned long hashval, int (*test)(struct inode *, void *),
2499                void *data);
2500extern struct inode *ilookup5(struct super_block *sb, unsigned long hashval,
2501                int (*test)(struct inode *, void *), void *data);
2502extern struct inode *ilookup(struct super_block *sb, unsigned long ino);
2503
2504extern struct inode * iget5_locked(struct super_block *, unsigned long, int (*test)(struct inode *, void *), int (*set)(struct inode *, void *), void *);
2505extern struct inode * iget_locked(struct super_block *, unsigned long);
2506extern int insert_inode_locked4(struct inode *, unsigned long, int (*test)(struct inode *, void *), void *);
2507extern int insert_inode_locked(struct inode *);
2508#ifdef CONFIG_DEBUG_LOCK_ALLOC
2509extern void lockdep_annotate_inode_mutex_key(struct inode *inode);
2510#else
2511static inline void lockdep_annotate_inode_mutex_key(struct inode *inode) { };
2512#endif
2513extern void unlock_new_inode(struct inode *);
2514extern unsigned int get_next_ino(void);
2515
2516extern void __iget(struct inode * inode);
2517extern void iget_failed(struct inode *);
2518extern void clear_inode(struct inode *);
2519extern void __destroy_inode(struct inode *);
2520extern struct inode *new_inode_pseudo(struct super_block *sb);
2521extern struct inode *new_inode(struct super_block *sb);
2522extern void free_inode_nonrcu(struct inode *inode);
2523extern int should_remove_suid(struct dentry *);
2524extern int file_remove_suid(struct file *);
2525
2526extern void __insert_inode_hash(struct inode *, unsigned long hashval);
2527static inline void insert_inode_hash(struct inode *inode)
2528{
2529        __insert_inode_hash(inode, inode->i_ino);
2530}
2531
2532extern void __remove_inode_hash(struct inode *);
2533static inline void remove_inode_hash(struct inode *inode)
2534{
2535        if (!inode_unhashed(inode))
2536                __remove_inode_hash(inode);
2537}
2538
2539extern void inode_sb_list_add(struct inode *inode);
2540
2541#ifdef CONFIG_BLOCK
2542extern void submit_bio(int, struct bio *);
2543extern int bdev_read_only(struct block_device *);
2544#endif
2545extern int set_blocksize(struct block_device *, int);
2546extern int sb_set_blocksize(struct super_block *, int);
2547extern int sb_min_blocksize(struct super_block *, int);
2548
2549extern int generic_file_mmap(struct file *, struct vm_area_struct *);
2550extern int generic_file_readonly_mmap(struct file *, struct vm_area_struct *);
2551extern int file_read_actor(read_descriptor_t * desc, struct page *page, unsigned long offset, unsigned long size);
2552int generic_write_checks(struct file *file, loff_t *pos, size_t *count, int isblk);
2553extern ssize_t generic_file_aio_read(struct kiocb *, const struct iovec *, unsigned long, loff_t);
2554extern ssize_t __generic_file_aio_write(struct kiocb *, const struct iovec *, unsigned long,
2555                loff_t *);
2556extern ssize_t generic_file_aio_write(struct kiocb *, const struct iovec *, unsigned long, loff_t);
2557extern ssize_t generic_file_direct_write(struct kiocb *, const struct iovec *,
2558                unsigned long *, loff_t, loff_t *, size_t, size_t);
2559extern ssize_t generic_file_buffered_write(struct kiocb *, const struct iovec *,
2560                unsigned long, loff_t, loff_t *, size_t, ssize_t);
2561extern ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos);
2562extern ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos);
2563extern int generic_segment_checks(const struct iovec *iov,
2564                unsigned long *nr_segs, size_t *count, int access_flags);
2565
2566/* fs/block_dev.c */
2567extern ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov,
2568                                unsigned long nr_segs, loff_t pos);
2569extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
2570                        int datasync);
2571extern void block_sync_page(struct page *page);
2572
2573/* fs/splice.c */
2574extern ssize_t generic_file_splice_read(struct file *, loff_t *,
2575                struct pipe_inode_info *, size_t, unsigned int);
2576extern ssize_t default_file_splice_read(struct file *, loff_t *,
2577                struct pipe_inode_info *, size_t, unsigned int);
2578extern ssize_t generic_file_splice_write(struct pipe_inode_info *,
2579                struct file *, loff_t *, size_t, unsigned int);
2580extern ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe,
2581                struct file *out, loff_t *, size_t len, unsigned int flags);
2582extern long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
2583                size_t len, unsigned int flags);
2584
2585extern void
2586file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping);
2587extern loff_t noop_llseek(struct file *file, loff_t offset, int origin);
2588extern loff_t no_llseek(struct file *file, loff_t offset, int origin);
2589extern loff_t generic_file_llseek(struct file *file, loff_t offset, int origin);
2590extern loff_t generic_file_llseek_size(struct file *file, loff_t offset,
2591                int origin, loff_t maxsize, loff_t eof);
2592extern int generic_file_open(struct inode * inode, struct file * filp);
2593extern int nonseekable_open(struct inode * inode, struct file * filp);
2594
2595#ifdef CONFIG_FS_XIP
2596extern ssize_t xip_file_read(struct file *filp, char __user *buf, size_t len,
2597                             loff_t *ppos);
2598extern int xip_file_mmap(struct file * file, struct vm_area_struct * vma);
2599extern ssize_t xip_file_write(struct file *filp, const char __user *buf,
2600                              size_t len, loff_t *ppos);
2601extern int xip_truncate_page(struct address_space *mapping, loff_t from);
2602#else
2603static inline int xip_truncate_page(struct address_space *mapping, loff_t from)
2604{
2605        return 0;
2606}
2607#endif
2608
2609#ifdef CONFIG_BLOCK
2610typedef void (dio_submit_t)(int rw, struct bio *bio, struct inode *inode,
2611                            loff_t file_offset);
2612
2613enum {
2614        /* need locking between buffered and direct access */
2615        DIO_LOCKING     = 0x01,
2616
2617        /* filesystem does not support filling holes */
2618        DIO_SKIP_HOLES  = 0x02,
2619};
2620
2621void dio_end_io(struct bio *bio, int error);
2622
2623ssize_t __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
2624        struct block_device *bdev, const struct iovec *iov, loff_t offset,
2625        unsigned long nr_segs, get_block_t get_block, dio_iodone_t end_io,
2626        dio_submit_t submit_io, int flags);
2627
2628static inline ssize_t blockdev_direct_IO(int rw, struct kiocb *iocb,
2629                struct inode *inode, const struct iovec *iov, loff_t offset,
2630                unsigned long nr_segs, get_block_t get_block)
2631{
2632        return __blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
2633                                    offset, nr_segs, get_block, NULL, NULL,
2634                                    DIO_LOCKING | DIO_SKIP_HOLES);
2635}
2636#endif
2637
2638void inode_dio_wait(struct inode *inode);
2639void inode_dio_done(struct inode *inode);
2640
2641extern const struct file_operations generic_ro_fops;
2642
2643#define special_file(m) (S_ISCHR(m)||S_ISBLK(m)||S_ISFIFO(m)||S_ISSOCK(m))
2644
2645extern int vfs_readlink(struct dentry *, char __user *, int, const char *);
2646extern int vfs_follow_link(struct nameidata *, const char *);
2647extern int page_readlink(struct dentry *, char __user *, int);
2648extern void *page_follow_link_light(struct dentry *, struct nameidata *);
2649extern void page_put_link(struct dentry *, struct nameidata *, void *);
2650extern int __page_symlink(struct inode *inode, const char *symname, int len,
2651                int nofs);
2652extern int page_symlink(struct inode *inode, const char *symname, int len);
2653extern const struct inode_operations page_symlink_inode_operations;
2654extern int generic_readlink(struct dentry *, char __user *, int);
2655extern void generic_fillattr(struct inode *, struct kstat *);
2656extern int vfs_getattr(struct vfsmount *, struct dentry *, struct kstat *);
2657void __inode_add_bytes(struct inode *inode, loff_t bytes);
2658void inode_add_bytes(struct inode *inode, loff_t bytes);
2659void inode_sub_bytes(struct inode *inode, loff_t bytes);
2660loff_t inode_get_bytes(struct inode *inode);
2661void inode_set_bytes(struct inode *inode, loff_t bytes);
2662
2663extern int vfs_readdir(struct file *, filldir_t, void *);
2664
2665extern int vfs_stat(const char __user *, struct kstat *);
2666extern int vfs_lstat(const char __user *, struct kstat *);
2667extern int vfs_fstat(unsigned int, struct kstat *);
2668extern int vfs_fstatat(int , const char __user *, struct kstat *, int);
2669
2670extern int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd,
2671                    unsigned long arg);
2672extern int __generic_block_fiemap(struct inode *inode,
2673                                  struct fiemap_extent_info *fieinfo,
2674                                  loff_t start, loff_t len,
2675                                  get_block_t *get_block);
2676extern int generic_block_fiemap(struct inode *inode,
2677                                struct fiemap_extent_info *fieinfo, u64 start,
2678                                u64 len, get_block_t *get_block);
2679
2680extern void get_filesystem(struct file_system_type *fs);
2681extern void put_filesystem(struct file_system_type *fs);
2682extern struct file_system_type *get_fs_type(const char *name);
2683extern struct super_block *get_super(struct block_device *);
2684extern struct super_block *get_super_thawed(struct block_device *);
2685extern struct super_block *get_active_super(struct block_device *bdev);
2686extern void drop_super(struct super_block *sb);
2687extern void iterate_supers(void (*)(struct super_block *, void *), void *);
2688extern void iterate_supers_type(struct file_system_type *,
2689                                void (*)(struct super_block *, void *), void *);
2690
2691extern int dcache_dir_open(struct inode *, struct file *);
2692extern int dcache_dir_close(struct inode *, struct file *);
2693extern loff_t dcache_dir_lseek(struct file *, loff_t, int);
2694extern int dcache_readdir(struct file *, void *, filldir_t);
2695extern int simple_setattr(struct dentry *, struct iattr *);
2696extern int simple_getattr(struct vfsmount *, struct dentry *, struct kstat *);
2697extern int simple_statfs(struct dentry *, struct kstatfs *);
2698extern int simple_open(struct inode *inode, struct file *file);
2699extern int simple_link(struct dentry *, struct inode *, struct dentry *);
2700extern int simple_unlink(struct inode *, struct dentry *);
2701extern int simple_rmdir(struct inode *, struct dentry *);
2702extern int simple_rename(struct inode *, struct dentry *, struct inode *, struct dentry *);
2703extern int noop_fsync(struct file *, loff_t, loff_t, int);
2704extern int simple_empty(struct dentry *);
2705extern int simple_readpage(struct file *file, struct page *page);
2706extern int simple_write_begin(struct file *file, struct address_space *mapping,
2707                        loff_t pos, unsigned len, unsigned flags,
2708                        struct page **pagep, void **fsdata);
2709extern int simple_write_end(struct file *file, struct address_space *mapping,
2710                        loff_t pos, unsigned len, unsigned copied,
2711                        struct page *page, void *fsdata);
2712
2713extern struct dentry *simple_lookup(struct inode *, struct dentry *, unsigned int flags);
2714extern ssize_t generic_read_dir(struct file *, char __user *, size_t, loff_t *);
2715extern const struct file_operations simple_dir_operations;
2716extern const struct inode_operations simple_dir_inode_operations;
2717struct tree_descr { char *name; const struct file_operations *ops; int mode; };
2718struct dentry *d_alloc_name(struct dentry *, const char *);
2719extern int simple_fill_super(struct super_block *, unsigned long, struct tree_descr *);
2720extern int simple_pin_fs(struct file_system_type *, struct vfsmount **mount, int *count);
2721extern void simple_release_fs(struct vfsmount **mount, int *count);
2722
2723extern ssize_t simple_read_from_buffer(void __user *to, size_t count,
2724                        loff_t *ppos, const void *from, size_t available);
2725extern ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos,
2726                const void __user *from, size_t count);
2727
2728extern int generic_file_fsync(struct file *, loff_t, loff_t, int);
2729
2730extern int generic_check_addressable(unsigned, u64);
2731
2732#ifdef CONFIG_MIGRATION
2733extern int buffer_migrate_page(struct address_space *,
2734                                struct page *, struct page *,
2735                                enum migrate_mode);
2736#else
2737#define buffer_migrate_page NULL
2738#endif
2739
2740extern int inode_change_ok(const struct inode *, struct iattr *);
2741extern int inode_newsize_ok(const struct inode *, loff_t offset);
2742extern void setattr_copy(struct inode *inode, const struct iattr *attr);
2743
2744extern int file_update_time(struct file *file);
2745
2746extern int generic_show_options(struct seq_file *m, struct dentry *root);
2747extern void save_mount_options(struct super_block *sb, char *options);
2748extern void replace_mount_options(struct super_block *sb, char *options);
2749
2750static inline ino_t parent_ino(struct dentry *dentry)
2751{
2752        ino_t res;
2753
2754        /*
2755         * Don't strictly need d_lock here? If the parent ino could change
2756         * then surely we'd have a deeper race in the caller?
2757         */
2758        spin_lock(&dentry->d_lock);
2759        res = dentry->d_parent->d_inode->i_ino;
2760        spin_unlock(&dentry->d_lock);
2761        return res;
2762}
2763
2764/* Transaction based IO helpers */
2765
2766/*
2767 * An argresp is stored in an allocated page and holds the
2768 * size of the argument or response, along with its content
2769 */
2770struct simple_transaction_argresp {
2771        ssize_t size;
2772        char data[0];
2773};
2774
2775#define SIMPLE_TRANSACTION_LIMIT (PAGE_SIZE - sizeof(struct simple_transaction_argresp))
2776
2777char *simple_transaction_get(struct file *file, const char __user *buf,
2778                                size_t size);
2779ssize_t simple_transaction_read(struct file *file, char __user *buf,
2780                                size_t size, loff_t *pos);
2781int simple_transaction_release(struct inode *inode, struct file *file);
2782
2783void simple_transaction_set(struct file *file, size_t n);
2784
2785/*
2786 * simple attribute files
2787 *
2788 * These attributes behave similar to those in sysfs:
2789 *
2790 * Writing to an attribute immediately sets a value, an open file can be
2791 * written to multiple times.
2792 *
2793 * Reading from an attribute creates a buffer from the value that might get
2794 * read with multiple read calls. When the attribute has been read
2795 * completely, no further read calls are possible until the file is opened
2796 * again.
2797 *
2798 * All attributes contain a text representation of a numeric value
2799 * that are accessed with the get() and set() functions.
2800 */
2801#define DEFINE_SIMPLE_ATTRIBUTE(__fops, __get, __set, __fmt)            \
2802static int __fops ## _open(struct inode *inode, struct file *file)      \
2803{                                                                       \
2804        __simple_attr_check_format(__fmt, 0ull);                        \
2805        return simple_attr_open(inode, file, __get, __set, __fmt);      \
2806}                                                                       \
2807static const struct file_operations __fops = {                          \
2808        .owner   = THIS_MODULE,                                         \
2809        .open    = __fops ## _open,                                     \
2810        .release = simple_attr_release,                                 \
2811        .read    = simple_attr_read,                                    \
2812        .write   = simple_attr_write,                                   \
2813        .llseek  = generic_file_llseek,                                 \
2814};
2815
2816static inline __printf(1, 2)
2817void __simple_attr_check_format(const char *fmt, ...)
2818{
2819        /* don't do anything, just let the compiler check the arguments; */
2820}
2821
2822int simple_attr_open(struct inode *inode, struct file *file,
2823                     int (*get)(void *, u64 *), int (*set)(void *, u64),
2824                     const char *fmt);
2825int simple_attr_release(struct inode *inode, struct file *file);
2826ssize_t simple_attr_read(struct file *file, char __user *buf,
2827                         size_t len, loff_t *ppos);
2828ssize_t simple_attr_write(struct file *file, const char __user *buf,
2829                          size_t len, loff_t *ppos);
2830
2831struct ctl_table;
2832int proc_nr_files(struct ctl_table *table, int write,
2833                  void __user *buffer, size_t *lenp, loff_t *ppos);
2834int proc_nr_dentry(struct ctl_table *table, int write,
2835                  void __user *buffer, size_t *lenp, loff_t *ppos);
2836int proc_nr_inodes(struct ctl_table *table, int write,
2837                   void __user *buffer, size_t *lenp, loff_t *ppos);
2838int __init get_filesystem_list(char *buf);
2839
2840#define __FMODE_EXEC            ((__force int) FMODE_EXEC)
2841#define __FMODE_NONOTIFY        ((__force int) FMODE_NONOTIFY)
2842
2843#define ACC_MODE(x) ("\004\002\006\006"[(x)&O_ACCMODE])
2844#define OPEN_FMODE(flag) ((__force fmode_t)(((flag + 1) & O_ACCMODE) | \
2845                                            (flag & __FMODE_NONOTIFY)))
2846
2847static inline int is_sxid(umode_t mode)
2848{
2849        return (mode & S_ISUID) || ((mode & S_ISGID) && (mode & S_IXGRP));
2850}
2851
2852static inline void inode_has_no_xattr(struct inode *inode)
2853{
2854        if (!is_sxid(inode->i_mode) && (inode->i_sb->s_flags & MS_NOSEC))
2855                inode->i_flags |= S_NOSEC;
2856}
2857
2858#endif /* __KERNEL__ */
2859#endif /* _LINUX_FS_H */
2860
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