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