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fs.h
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fs.h
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#ifndef _LINUX_FS_H
#define _LINUX_FS_H
/*
* This file has definitions for some important file table
* structures etc.
*/
#include <linux/limits.h>
#include <linux/ioctl.h>
/*
* It's silly to have NR_OPEN bigger than NR_FILE, but you can change
* the file limit at runtime and only root can increase the per-process
* nr_file rlimit, so it's safe to set up a ridiculously high absolute
* upper limit on files-per-process.
*
* Some programs (notably those using select()) may have to be
* recompiled to take full advantage of the new limits..
*/
/* Fixed constants first: */
#undef NR_OPEN
#define INR_OPEN 1024 /* Initial setting for nfile rlimits */
#define BLOCK_SIZE_BITS 10
#define BLOCK_SIZE (1<<BLOCK_SIZE_BITS)
#define SEEK_SET 0 /* seek relative to beginning of file */
#define SEEK_CUR 1 /* seek relative to current file position */
#define SEEK_END 2 /* seek relative to end of file */
#define SEEK_MAX SEEK_END
/* And dynamically-tunable limits and defaults: */
struct files_stat_struct {
int nr_files; /* read only */
int nr_free_files; /* read only */
int max_files; /* tunable */
};
struct inodes_stat_t {
int nr_inodes;
int nr_unused;
int dummy[5]; /* padding for sysctl ABI compatibility */
};
#define NR_FILE 8192 /* this can well be larger on a larger system */
#define MAY_EXEC 1
#define MAY_WRITE 2
#define MAY_READ 4
#define MAY_APPEND 8
#define MAY_ACCESS 16
#define MAY_OPEN 32
/*
* flags in file.f_mode. Note that FMODE_READ and FMODE_WRITE must correspond
* to O_WRONLY and O_RDWR via the strange trick in __dentry_open()
*/
/* file is open for reading */
#define FMODE_READ ((__force fmode_t)0x1)
/* file is open for writing */
#define FMODE_WRITE ((__force fmode_t)0x2)
/* file is seekable */
#define FMODE_LSEEK ((__force fmode_t)0x4)
/* file can be accessed using pread */
#define FMODE_PREAD ((__force fmode_t)0x8)
/* file can be accessed using pwrite */
#define FMODE_PWRITE ((__force fmode_t)0x10)
/* File is opened for execution with sys_execve / sys_uselib */
#define FMODE_EXEC ((__force fmode_t)0x20)
/* File is opened with O_NDELAY (only set for block devices) */
#define FMODE_NDELAY ((__force fmode_t)0x40)
/* File is opened with O_EXCL (only set for block devices) */
#define FMODE_EXCL ((__force fmode_t)0x80)
/* File is opened using open(.., 3, ..) and is writeable only for ioctls
(specialy hack for floppy.c) */
#define FMODE_WRITE_IOCTL ((__force fmode_t)0x100)
/*
* Don't update ctime and mtime.
*
* Currently a special hack for the XFS open_by_handle ioctl, but we'll
* hopefully graduate it to a proper O_CMTIME flag supported by open(2) soon.
*/
#define FMODE_NOCMTIME ((__force fmode_t)0x800)
/* Expect random access pattern */
#define FMODE_RANDOM ((__force fmode_t)0x1000)
/*
* The below are the various read and write types that we support. Some of
* them include behavioral modifiers that send information down to the
* block layer and IO scheduler. Terminology:
*
* The block layer uses device plugging to defer IO a little bit, in
* the hope that we will see more IO very shortly. This increases
* coalescing of adjacent IO and thus reduces the number of IOs we
* have to send to the device. It also allows for better queuing,
* if the IO isn't mergeable. If the caller is going to be waiting
* for the IO, then he must ensure that the device is unplugged so
* that the IO is dispatched to the driver.
*
* All IO is handled async in Linux. This is fine for background
* writes, but for reads or writes that someone waits for completion
* on, we want to notify the block layer and IO scheduler so that they
* know about it. That allows them to make better scheduling
* decisions. So when the below references 'sync' and 'async', it
* is referencing this priority hint.
*
* With that in mind, the available types are:
*
* READ A normal read operation. Device will be plugged.
* READ_SYNC A synchronous read. Device is not plugged, caller can
* immediately wait on this read without caring about
* unplugging.
* READA Used for read-ahead operations. Lower priority, and the
* block layer could (in theory) choose to ignore this
* request if it runs into resource problems.
* WRITE A normal async write. Device will be plugged.
* SWRITE Like WRITE, but a special case for ll_rw_block() that
* tells it to lock the buffer first. Normally a buffer
* must be locked before doing IO.
* WRITE_SYNC_PLUG Synchronous write. Identical to WRITE, but passes down
* the hint that someone will be waiting on this IO
* shortly. The device must still be unplugged explicitly,
* WRITE_SYNC_PLUG does not do this as we could be
* submitting more writes before we actually wait on any
* of them.
* WRITE_SYNC Like WRITE_SYNC_PLUG, but also unplugs the device
* immediately after submission. The write equivalent
* of READ_SYNC.
* WRITE_ODIRECT_PLUG Special case write for O_DIRECT only.
* SWRITE_SYNC
* SWRITE_SYNC_PLUG Like WRITE_SYNC/WRITE_SYNC_PLUG, but locks the buffer.
* See SWRITE.
* WRITE_BARRIER Like WRITE, but tells the block layer that all
* previously submitted writes must be safely on storage
* before this one is started. Also guarantees that when
* this write is complete, it itself is also safely on
* storage. Prevents reordering of writes on both sides
* of this IO.
*
*/
#define RW_MASK 1
#define RWA_MASK 2
#define READ 0
#define WRITE 1
#define READA 2 /* read-ahead - don't block if no resources */
#define SWRITE 3 /* for ll_rw_block() - wait for buffer lock */
#define READ_SYNC (READ | (1 << BIO_RW_SYNCIO) | (1 << BIO_RW_UNPLUG))
#define READ_META (READ | (1 << BIO_RW_META))
#define WRITE_SYNC_PLUG (WRITE | (1 << BIO_RW_SYNCIO) | (1 << BIO_RW_NOIDLE))
#define WRITE_SYNC (WRITE_SYNC_PLUG | (1 << BIO_RW_UNPLUG))
#define WRITE_ODIRECT_PLUG (WRITE | (1 << BIO_RW_SYNCIO))
#define WRITE_META (WRITE | (1 << BIO_RW_META))
#define SWRITE_SYNC_PLUG \
(SWRITE | (1 << BIO_RW_SYNCIO) | (1 << BIO_RW_NOIDLE))
#define SWRITE_SYNC (SWRITE_SYNC_PLUG | (1 << BIO_RW_UNPLUG))
#define WRITE_BARRIER (WRITE | (1 << BIO_RW_BARRIER))
/*
* These aren't really reads or writes, they pass down information about
* parts of device that are now unused by the file system.
*/
#define DISCARD_NOBARRIER (WRITE | (1 << BIO_RW_DISCARD))
#define DISCARD_BARRIER (DISCARD_NOBARRIER | (1 << BIO_RW_BARRIER))
#define SEL_IN 1
#define SEL_OUT 2
#define SEL_EX 4
/* public flags for file_system_type */
#define FS_REQUIRES_DEV 1
#define FS_BINARY_MOUNTDATA 2
#define FS_HAS_SUBTYPE 4
#define FS_REVAL_DOT 16384 /* Check the paths ".", ".." for staleness */
#define FS_RENAME_DOES_D_MOVE 32768 /* FS will handle d_move()
* during rename() internally.
*/
/*
* These are the fs-independent mount-flags: up to 32 flags are supported
*/
#define MS_RDONLY 1 /* Mount read-only */
#define MS_NOSUID 2 /* Ignore suid and sgid bits */
#define MS_NODEV 4 /* Disallow access to device special files */
#define MS_NOEXEC 8 /* Disallow program execution */
#define MS_SYNCHRONOUS 16 /* Writes are synced at once */
#define MS_REMOUNT 32 /* Alter flags of a mounted FS */
#define MS_MANDLOCK 64 /* Allow mandatory locks on an FS */
#define MS_DIRSYNC 128 /* Directory modifications are synchronous */
#define MS_NOATIME 1024 /* Do not update access times. */
#define MS_NODIRATIME 2048 /* Do not update directory access times */
#define MS_BIND 4096
#define MS_MOVE 8192
#define MS_REC 16384
#define MS_VERBOSE 32768 /* War is peace. Verbosity is silence.
MS_VERBOSE is deprecated. */
#define MS_SILENT 32768
#define MS_POSIXACL (1<<16) /* VFS does not apply the umask */
#define MS_UNBINDABLE (1<<17) /* change to unbindable */
#define MS_PRIVATE (1<<18) /* change to private */
#define MS_SLAVE (1<<19) /* change to slave */
#define MS_SHARED (1<<20) /* change to shared */
#define MS_RELATIME (1<<21) /* Update atime relative to mtime/ctime. */
#define MS_KERNMOUNT (1<<22) /* this is a kern_mount call */
#define MS_I_VERSION (1<<23) /* Update inode I_version field */
#define MS_STRICTATIME (1<<24) /* Always perform atime updates */
#define MS_ACTIVE (1<<30)
#define MS_NOUSER (1<<31)
/*
* Superblock flags that can be altered by MS_REMOUNT
*/
#define MS_RMT_MASK (MS_RDONLY|MS_SYNCHRONOUS|MS_MANDLOCK|MS_I_VERSION)
/*
* Old magic mount flag and mask
*/
#define MS_MGC_VAL 0xC0ED0000
#define MS_MGC_MSK 0xffff0000
/* Inode flags - they have nothing to superblock flags now */
#define S_SYNC 1 /* Writes are synced at once */
#define S_NOATIME 2 /* Do not update access times */
#define S_APPEND 4 /* Append-only file */
#define S_IMMUTABLE 8 /* Immutable file */
#define S_DEAD 16 /* removed, but still open directory */
#define S_NOQUOTA 32 /* Inode is not counted to quota */
#define S_DIRSYNC 64 /* Directory modifications are synchronous */
#define S_NOCMTIME 128 /* Do not update file c/mtime */
#define S_SWAPFILE 256 /* Do not truncate: swapon got its bmaps */
#define S_PRIVATE 512 /* Inode is fs-internal */
/*
* Note that nosuid etc flags are inode-specific: setting some file-system
* flags just means all the inodes inherit those flags by default. It might be
* possible to override it selectively if you really wanted to with some
* ioctl() that is not currently implemented.
*
* Exception: MS_RDONLY is always applied to the entire file system.
*
* Unfortunately, it is possible to change a filesystems flags with it mounted
* with files in use. This means that all of the inodes will not have their
* i_flags updated. Hence, i_flags no longer inherit the superblock mount
* flags, so these have to be checked separately. -- rmk@arm.uk.linux.org
*/
#define __IS_FLG(inode,flg) ((inode)->i_sb->s_flags & (flg))
#define IS_RDONLY(inode) ((inode)->i_sb->s_flags & MS_RDONLY)
#define IS_SYNC(inode) (__IS_FLG(inode, MS_SYNCHRONOUS) || \
((inode)->i_flags & S_SYNC))
#define IS_DIRSYNC(inode) (__IS_FLG(inode, MS_SYNCHRONOUS|MS_DIRSYNC) || \
((inode)->i_flags & (S_SYNC|S_DIRSYNC)))
#define IS_MANDLOCK(inode) __IS_FLG(inode, MS_MANDLOCK)
#define IS_NOATIME(inode) __IS_FLG(inode, MS_RDONLY|MS_NOATIME)
#define IS_I_VERSION(inode) __IS_FLG(inode, MS_I_VERSION)
#define IS_NOQUOTA(inode) ((inode)->i_flags & S_NOQUOTA)
#define IS_APPEND(inode) ((inode)->i_flags & S_APPEND)
#define IS_IMMUTABLE(inode) ((inode)->i_flags & S_IMMUTABLE)
#define IS_POSIXACL(inode) __IS_FLG(inode, MS_POSIXACL)
#define IS_DEADDIR(inode) ((inode)->i_flags & S_DEAD)
#define IS_NOCMTIME(inode) ((inode)->i_flags & S_NOCMTIME)
#define IS_SWAPFILE(inode) ((inode)->i_flags & S_SWAPFILE)
#define IS_PRIVATE(inode) ((inode)->i_flags & S_PRIVATE)
/* the read-only stuff doesn't really belong here, but any other place is
probably as bad and I don't want to create yet another include file. */
#define BLKROSET _IO(0x12,93) /* set device read-only (0 = read-write) */
#define BLKROGET _IO(0x12,94) /* get read-only status (0 = read_write) */
#define BLKRRPART _IO(0x12,95) /* re-read partition table */
#define BLKGETSIZE _IO(0x12,96) /* return device size /512 (long *arg) */
#define BLKFLSBUF _IO(0x12,97) /* flush buffer cache */
#define BLKRASET _IO(0x12,98) /* set read ahead for block device */
#define BLKRAGET _IO(0x12,99) /* get current read ahead setting */
#define BLKFRASET _IO(0x12,100)/* set filesystem (mm/filemap.c) read-ahead */
#define BLKFRAGET _IO(0x12,101)/* get filesystem (mm/filemap.c) read-ahead */
#define BLKSECTSET _IO(0x12,102)/* set max sectors per request (ll_rw_blk.c) */
#define BLKSECTGET _IO(0x12,103)/* get max sectors per request (ll_rw_blk.c) */
#define BLKSSZGET _IO(0x12,104)/* get block device sector size */
#if 0
#define BLKPG _IO(0x12,105)/* See blkpg.h */
/* Some people are morons. Do not use sizeof! */
#define BLKELVGET _IOR(0x12,106,size_t)/* elevator get */
#define BLKELVSET _IOW(0x12,107,size_t)/* elevator set */
/* This was here just to show that the number is taken -
probably all these _IO(0x12,*) ioctls should be moved to blkpg.h. */
#endif
/* A jump here: 108-111 have been used for various private purposes. */
#define BLKBSZGET _IOR(0x12,112,size_t)
#define BLKBSZSET _IOW(0x12,113,size_t)
#define BLKGETSIZE64 _IOR(0x12,114,size_t) /* return device size in bytes (u64 *arg) */
#define BLKTRACESETUP _IOWR(0x12,115,struct blk_user_trace_setup)
#define BLKTRACESTART _IO(0x12,116)
#define BLKTRACESTOP _IO(0x12,117)
#define BLKTRACETEARDOWN _IO(0x12,118)
#define BLKDISCARD _IO(0x12,119)
#define BLKIOMIN _IO(0x12,120)
#define BLKIOOPT _IO(0x12,121)
#define BLKALIGNOFF _IO(0x12,122)
#define BLKPBSZGET _IO(0x12,123)
#define BLKDISCARDZEROES _IO(0x12,124)
#define BMAP_IOCTL 1 /* obsolete - kept for compatibility */
#define FIBMAP _IO(0x00,1) /* bmap access */
#define FIGETBSZ _IO(0x00,2) /* get the block size used for bmap */
#define FIFREEZE _IOWR('X', 119, int) /* Freeze */
#define FITHAW _IOWR('X', 120, int) /* Thaw */
#define FS_IOC_GETFLAGS _IOR('f', 1, long)
#define FS_IOC_SETFLAGS _IOW('f', 2, long)
#define FS_IOC_GETVERSION _IOR('v', 1, long)
#define FS_IOC_SETVERSION _IOW('v', 2, long)
#define FS_IOC_FIEMAP _IOWR('f', 11, struct fiemap)
#define FS_IOC32_GETFLAGS _IOR('f', 1, int)
#define FS_IOC32_SETFLAGS _IOW('f', 2, int)
#define FS_IOC32_GETVERSION _IOR('v', 1, int)
#define FS_IOC32_SETVERSION _IOW('v', 2, int)
/*
* Inode flags (FS_IOC_GETFLAGS / FS_IOC_SETFLAGS)
*/
#define FS_SECRM_FL 0x00000001 /* Secure deletion */
#define FS_UNRM_FL 0x00000002 /* Undelete */
#define FS_COMPR_FL 0x00000004 /* Compress file */
#define FS_SYNC_FL 0x00000008 /* Synchronous updates */
#define FS_IMMUTABLE_FL 0x00000010 /* Immutable file */
#define FS_APPEND_FL 0x00000020 /* writes to file may only append */
#define FS_NODUMP_FL 0x00000040 /* do not dump file */
#define FS_NOATIME_FL 0x00000080 /* do not update atime */
/* Reserved for compression usage... */
#define FS_DIRTY_FL 0x00000100
#define FS_COMPRBLK_FL 0x00000200 /* One or more compressed clusters */
#define FS_NOCOMP_FL 0x00000400 /* Don't compress */
#define FS_ECOMPR_FL 0x00000800 /* Compression error */
/* End compression flags --- maybe not all used */
#define FS_BTREE_FL 0x00001000 /* btree format dir */
#define FS_INDEX_FL 0x00001000 /* hash-indexed directory */
#define FS_IMAGIC_FL 0x00002000 /* AFS directory */
#define FS_JOURNAL_DATA_FL 0x00004000 /* Reserved for ext3 */
#define FS_NOTAIL_FL 0x00008000 /* file tail should not be merged */
#define FS_DIRSYNC_FL 0x00010000 /* dirsync behaviour (directories only) */
#define FS_TOPDIR_FL 0x00020000 /* Top of directory hierarchies*/
#define FS_EXTENT_FL 0x00080000 /* Extents */
#define FS_DIRECTIO_FL 0x00100000 /* Use direct i/o */
#define FS_RESERVED_FL 0x80000000 /* reserved for ext2 lib */
#define FS_FL_USER_VISIBLE 0x0003DFFF /* User visible flags */
#define FS_FL_USER_MODIFIABLE 0x000380FF /* User modifiable flags */
#define SYNC_FILE_RANGE_WAIT_BEFORE 1
#define SYNC_FILE_RANGE_WRITE 2
#define SYNC_FILE_RANGE_WAIT_AFTER 4
#ifdef __KERNEL__
#include <linux/linkage.h>
#include <linux/wait.h>
#include <linux/types.h>
#include <linux/kdev_t.h>
#include <linux/dcache.h>
#include <linux/path.h>
#include <linux/stat.h>
#include <linux/cache.h>
#include <linux/kobject.h>
#include <linux/list.h>
#include <linux/radix-tree.h>
#include <linux/prio_tree.h>
#include <linux/init.h>
#include <linux/pid.h>
#include <linux/mutex.h>
#include <linux/capability.h>
#include <linux/semaphore.h>
#include <linux/fiemap.h>
#include <asm/atomic.h>
#include <asm/byteorder.h>
struct export_operations;
struct hd_geometry;
struct iovec;
struct nameidata;
struct kiocb;
struct pipe_inode_info;
struct poll_table_struct;
struct kstatfs;
struct vm_area_struct;
struct vfsmount;
struct cred;
extern void __init inode_init(void);
extern void __init inode_init_early(void);
extern void __init files_init(unsigned long);
extern struct files_stat_struct files_stat;
extern int get_max_files(void);
extern int sysctl_nr_open;
extern struct inodes_stat_t inodes_stat;
extern int leases_enable, lease_break_time;
#ifdef CONFIG_DNOTIFY
extern int dir_notify_enable;
#endif
struct buffer_head;
typedef int (get_block_t)(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create);
typedef void (dio_iodone_t)(struct kiocb *iocb, loff_t offset,
ssize_t bytes, void *private);
/*
* Attribute flags. These should be or-ed together to figure out what
* has been changed!
*/
#define ATTR_MODE (1 << 0)
#define ATTR_UID (1 << 1)
#define ATTR_GID (1 << 2)
#define ATTR_SIZE (1 << 3)
#define ATTR_ATIME (1 << 4)
#define ATTR_MTIME (1 << 5)
#define ATTR_CTIME (1 << 6)
#define ATTR_ATIME_SET (1 << 7)
#define ATTR_MTIME_SET (1 << 8)
#define ATTR_FORCE (1 << 9) /* Not a change, but a change it */
#define ATTR_ATTR_FLAG (1 << 10)
#define ATTR_KILL_SUID (1 << 11)
#define ATTR_KILL_SGID (1 << 12)
#define ATTR_FILE (1 << 13)
#define ATTR_KILL_PRIV (1 << 14)
#define ATTR_OPEN (1 << 15) /* Truncating from open(O_TRUNC) */
#define ATTR_TIMES_SET (1 << 16)
/*
* This is the Inode Attributes structure, used for notify_change(). It
* uses the above definitions as flags, to know which values have changed.
* Also, in this manner, a Filesystem can look at only the values it cares
* about. Basically, these are the attributes that the VFS layer can
* request to change from the FS layer.
*
* Derek Atkins <warlord@MIT.EDU> 94-10-20
*/
struct iattr {
unsigned int ia_valid;
umode_t ia_mode;
uid_t ia_uid;
gid_t ia_gid;
loff_t ia_size;
struct timespec ia_atime;
struct timespec ia_mtime;
struct timespec ia_ctime;
/*
* Not an attribute, but an auxilary info for filesystems wanting to
* implement an ftruncate() like method. NOTE: filesystem should
* check for (ia_valid & ATTR_FILE), and not for (ia_file != NULL).
*/
struct file *ia_file;
};
/*
* Includes for diskquotas.
*/
#include <linux/quota.h>
/**
* enum positive_aop_returns - aop return codes with specific semantics
*
* @AOP_WRITEPAGE_ACTIVATE: Informs the caller that page writeback has
* completed, that the page is still locked, and
* should be considered active. The VM uses this hint
* to return the page to the active list -- it won't
* be a candidate for writeback again in the near
* future. Other callers must be careful to unlock
* the page if they get this return. Returned by
* writepage();
*
* @AOP_TRUNCATED_PAGE: The AOP method that was handed a locked page has
* unlocked it and the page might have been truncated.
* The caller should back up to acquiring a new page and
* trying again. The aop will be taking reasonable
* precautions not to livelock. If the caller held a page
* reference, it should drop it before retrying. Returned
* by readpage().
*
* address_space_operation functions return these large constants to indicate
* special semantics to the caller. These are much larger than the bytes in a
* page to allow for functions that return the number of bytes operated on in a
* given page.
*/
enum positive_aop_returns {
AOP_WRITEPAGE_ACTIVATE = 0x80000,
AOP_TRUNCATED_PAGE = 0x80001,
};
#define AOP_FLAG_UNINTERRUPTIBLE 0x0001 /* will not do a short write */
#define AOP_FLAG_CONT_EXPAND 0x0002 /* called from cont_expand */
#define AOP_FLAG_NOFS 0x0004 /* used by filesystem to direct
* helper code (eg buffer layer)
* to clear GFP_FS from alloc */
/*
* oh the beauties of C type declarations.
*/
struct page;
struct address_space;
struct writeback_control;
struct iov_iter {
const struct iovec *iov;
unsigned long nr_segs;
size_t iov_offset;
size_t count;
};
size_t iov_iter_copy_from_user_atomic(struct page *page,
struct iov_iter *i, unsigned long offset, size_t bytes);
size_t iov_iter_copy_from_user(struct page *page,
struct iov_iter *i, unsigned long offset, size_t bytes);
void iov_iter_advance(struct iov_iter *i, size_t bytes);
int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes);
size_t iov_iter_single_seg_count(struct iov_iter *i);
static inline void iov_iter_init(struct iov_iter *i,
const struct iovec *iov, unsigned long nr_segs,
size_t count, size_t written)
{
i->iov = iov;
i->nr_segs = nr_segs;
i->iov_offset = 0;
i->count = count + written;
iov_iter_advance(i, written);
}
static inline size_t iov_iter_count(struct iov_iter *i)
{
return i->count;
}
/*
* "descriptor" for what we're up to with a read.
* This allows us to use the same read code yet
* have multiple different users of the data that
* we read from a file.
*
* The simplest case just copies the data to user
* mode.
*/
typedef struct {
size_t written;
size_t count;
union {
char __user *buf;
void *data;
} arg;
int error;
} read_descriptor_t;
typedef int (*read_actor_t)(read_descriptor_t *, struct page *,
unsigned long, unsigned long);
struct address_space_operations {
int (*writepage)(struct page *page, struct writeback_control *wbc);
int (*readpage)(struct file *, struct page *);
void (*sync_page)(struct page *);
/* Write back some dirty pages from this mapping. */
int (*writepages)(struct address_space *, struct writeback_control *);
/* Set a page dirty. Return true if this dirtied it */
int (*set_page_dirty)(struct page *page);
int (*readpages)(struct file *filp, struct address_space *mapping,
struct list_head *pages, unsigned nr_pages);
int (*write_begin)(struct file *, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata);
int (*write_end)(struct file *, struct address_space *mapping,
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata);
/* Unfortunately this kludge is needed for FIBMAP. Don't use it */
sector_t (*bmap)(struct address_space *, sector_t);
void (*invalidatepage) (struct page *, unsigned long);
int (*releasepage) (struct page *, gfp_t);
ssize_t (*direct_IO)(int, struct kiocb *, const struct iovec *iov,
loff_t offset, unsigned long nr_segs);
int (*get_xip_mem)(struct address_space *, pgoff_t, int,
void **, unsigned long *);
/* migrate the contents of a page to the specified target */
int (*migratepage) (struct address_space *,
struct page *, struct page *);
int (*launder_page) (struct page *);
int (*is_partially_uptodate) (struct page *, read_descriptor_t *,
unsigned long);
int (*error_remove_page)(struct address_space *, struct page *);
};
/*
* pagecache_write_begin/pagecache_write_end must be used by general code
* to write into the pagecache.
*/
int pagecache_write_begin(struct file *, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata);
int pagecache_write_end(struct file *, struct address_space *mapping,
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata);
struct backing_dev_info;
struct address_space {
struct inode *host; /* owner: inode, block_device */
struct radix_tree_root page_tree; /* radix tree of all pages */
spinlock_t tree_lock; /* and lock protecting it */
unsigned int i_mmap_writable;/* count VM_SHARED mappings */
struct prio_tree_root i_mmap; /* tree of private and shared mappings */
struct list_head i_mmap_nonlinear;/*list VM_NONLINEAR mappings */
spinlock_t i_mmap_lock; /* protect tree, count, list */
unsigned int truncate_count; /* Cover race condition with truncate */
unsigned long nrpages; /* number of total pages */
pgoff_t writeback_index;/* writeback starts here */
const struct address_space_operations *a_ops; /* methods */
unsigned long flags; /* error bits/gfp mask */
struct backing_dev_info *backing_dev_info; /* device readahead, etc */
spinlock_t private_lock; /* for use by the address_space */
struct list_head private_list; /* ditto */
struct address_space *assoc_mapping; /* ditto */
} __attribute__((aligned(sizeof(long))));
/*
* On most architectures that alignment is already the case; but
* must be enforced here for CRIS, to let the least signficant bit
* of struct page's "mapping" pointer be used for PAGE_MAPPING_ANON.
*/
struct block_device {
dev_t bd_dev; /* not a kdev_t - it's a search key */
struct inode * bd_inode; /* will die */
struct super_block * bd_super;
int bd_openers;
struct mutex bd_mutex; /* open/close mutex */
struct list_head bd_inodes;
void * bd_holder;
int bd_holders;
#ifdef CONFIG_SYSFS
struct list_head bd_holder_list;
#endif
struct block_device * bd_contains;
unsigned bd_block_size;
struct hd_struct * bd_part;
/* number of times partitions within this device have been opened. */
unsigned bd_part_count;
int bd_invalidated;
struct gendisk * bd_disk;
struct list_head bd_list;
/*
* Private data. You must have bd_claim'ed the block_device
* to use this. NOTE: bd_claim allows an owner to claim
* the same device multiple times, the owner must take special
* care to not mess up bd_private for that case.
*/
unsigned long bd_private;
/* The counter of freeze processes */
int bd_fsfreeze_count;
/* Mutex for freeze */
struct mutex bd_fsfreeze_mutex;
};
/*
* Radix-tree tags, for tagging dirty and writeback pages within the pagecache
* radix trees
*/
#define PAGECACHE_TAG_DIRTY 0
#define PAGECACHE_TAG_WRITEBACK 1
int mapping_tagged(struct address_space *mapping, int tag);
/*
* Might pages of this file be mapped into userspace?
*/
static inline int mapping_mapped(struct address_space *mapping)
{
return !prio_tree_empty(&mapping->i_mmap) ||
!list_empty(&mapping->i_mmap_nonlinear);
}
/*
* Might pages of this file have been modified in userspace?
* Note that i_mmap_writable counts all VM_SHARED vmas: do_mmap_pgoff
* marks vma as VM_SHARED if it is shared, and the file was opened for
* writing i.e. vma may be mprotected writable even if now readonly.
*/
static inline int mapping_writably_mapped(struct address_space *mapping)
{
return mapping->i_mmap_writable != 0;
}
/*
* Use sequence counter to get consistent i_size on 32-bit processors.
*/
#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
#include <linux/seqlock.h>
#define __NEED_I_SIZE_ORDERED
#define i_size_ordered_init(inode) seqcount_init(&inode->i_size_seqcount)
#else
#define i_size_ordered_init(inode) do { } while (0)
#endif
struct posix_acl;
#define ACL_NOT_CACHED ((void *)(-1))
struct inode {
struct hlist_node i_hash;
struct list_head i_list; /* backing dev IO list */
struct list_head i_sb_list;
struct list_head i_dentry;
unsigned long i_ino;
atomic_t i_count;
unsigned int i_nlink;
uid_t i_uid;
gid_t i_gid;
dev_t i_rdev;
unsigned int i_blkbits;
u64 i_version;
loff_t i_size;
#ifdef __NEED_I_SIZE_ORDERED
seqcount_t i_size_seqcount;
#endif
struct timespec i_atime;
struct timespec i_mtime;
struct timespec i_ctime;
blkcnt_t i_blocks;
unsigned short i_bytes;
umode_t i_mode;
spinlock_t i_lock; /* i_blocks, i_bytes, maybe i_size */
struct mutex i_mutex;
struct rw_semaphore i_alloc_sem;
const struct inode_operations *i_op;
const struct file_operations *i_fop; /* former ->i_op->default_file_ops */
struct super_block *i_sb;
struct file_lock *i_flock;
struct address_space *i_mapping;
struct address_space i_data;
#ifdef CONFIG_QUOTA
struct dquot *i_dquot[MAXQUOTAS];
#endif
struct list_head i_devices;
union {
struct pipe_inode_info *i_pipe;
struct block_device *i_bdev;
struct cdev *i_cdev;
};
__u32 i_generation;
#ifdef CONFIG_FSNOTIFY
__u32 i_fsnotify_mask; /* all events this inode cares about */
struct hlist_head i_fsnotify_mark_entries; /* fsnotify mark entries */
#endif
#ifdef CONFIG_INOTIFY
struct list_head inotify_watches; /* watches on this inode */
struct mutex inotify_mutex; /* protects the watches list */
#endif
unsigned long i_state;
unsigned long dirtied_when; /* jiffies of first dirtying */
unsigned int i_flags;
atomic_t i_writecount;
#ifdef CONFIG_SECURITY
void *i_security;
#endif
#ifdef CONFIG_FS_POSIX_ACL
struct posix_acl *i_acl;
struct posix_acl *i_default_acl;
#endif
void *i_private; /* fs or device private pointer */
};
/*
* inode->i_mutex nesting subclasses for the lock validator:
*
* 0: the object of the current VFS operation
* 1: parent
* 2: child/target
* 3: quota file
*
* The locking order between these classes is
* parent -> child -> normal -> xattr -> quota
*/
enum inode_i_mutex_lock_class
{
I_MUTEX_NORMAL,
I_MUTEX_PARENT,
I_MUTEX_CHILD,
I_MUTEX_XATTR,
I_MUTEX_QUOTA
};
/*
* NOTE: in a 32bit arch with a preemptable kernel and
* an UP compile the i_size_read/write must be atomic
* with respect to the local cpu (unlike with preempt disabled),
* but they don't need to be atomic with respect to other cpus like in
* true SMP (so they need either to either locally disable irq around
* the read or for example on x86 they can be still implemented as a
* cmpxchg8b without the need of the lock prefix). For SMP compiles
* and 64bit archs it makes no difference if preempt is enabled or not.
*/
static inline loff_t i_size_read(const struct inode *inode)
{
#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
loff_t i_size;
unsigned int seq;
do {
seq = read_seqcount_begin(&inode->i_size_seqcount);
i_size = inode->i_size;
} while (read_seqcount_retry(&inode->i_size_seqcount, seq));
return i_size;
#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
loff_t i_size;
preempt_disable();
i_size = inode->i_size;
preempt_enable();
return i_size;
#else
return inode->i_size;
#endif
}
/*
* NOTE: unlike i_size_read(), i_size_write() does need locking around it
* (normally i_mutex), otherwise on 32bit/SMP an update of i_size_seqcount
* can be lost, resulting in subsequent i_size_read() calls spinning forever.
*/
static inline void i_size_write(struct inode *inode, loff_t i_size)
{
#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
write_seqcount_begin(&inode->i_size_seqcount);
inode->i_size = i_size;
write_seqcount_end(&inode->i_size_seqcount);
#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
preempt_disable();
inode->i_size = i_size;
preempt_enable();
#else
inode->i_size = i_size;
#endif
}
static inline unsigned iminor(const struct inode *inode)
{
return MINOR(inode->i_rdev);
}
static inline unsigned imajor(const struct inode *inode)
{
return MAJOR(inode->i_rdev);
}
extern struct block_device *I_BDEV(struct inode *inode);
struct fown_struct {
rwlock_t lock; /* protects pid, uid, euid fields */
struct pid *pid; /* pid or -pgrp where SIGIO should be sent */
enum pid_type pid_type; /* Kind of process group SIGIO should be sent to */
uid_t uid, euid; /* uid/euid of process setting the owner */
int signum; /* posix.1b rt signal to be delivered on IO */
};
/*
* Track a single file's readahead state
*/
struct file_ra_state {
pgoff_t start; /* where readahead started */
unsigned int size; /* # of readahead pages */
unsigned int async_size; /* do asynchronous readahead when
there are only # of pages ahead */
unsigned int ra_pages; /* Maximum readahead window */
unsigned int mmap_miss; /* Cache miss stat for mmap accesses */
loff_t prev_pos; /* Cache last read() position */
};
/*
* Check if @index falls in the readahead windows.
*/
static inline int ra_has_index(struct file_ra_state *ra, pgoff_t index)
{
return (index >= ra->start &&
index < ra->start + ra->size);
}
#define FILE_MNT_WRITE_TAKEN 1
#define FILE_MNT_WRITE_RELEASED 2
struct file {
/*
* fu_list becomes invalid after file_free is called and queued via
* fu_rcuhead for RCU freeing
*/
union {
struct list_head fu_list;
struct rcu_head fu_rcuhead;
} f_u;
struct path f_path;
#define f_dentry f_path.dentry
#define f_vfsmnt f_path.mnt
const struct file_operations *f_op;
spinlock_t f_lock; /* f_ep_links, f_flags, no IRQ */
atomic_long_t f_count;
unsigned int f_flags;
fmode_t f_mode;
loff_t f_pos;
struct fown_struct f_owner;
const struct cred *f_cred;
struct file_ra_state f_ra;
u64 f_version;
#ifdef CONFIG_SECURITY
void *f_security;
#endif
/* needed for tty driver, and maybe others */
void *private_data;
#ifdef CONFIG_EPOLL
/* Used by fs/eventpoll.c to link all the hooks to this file */
struct list_head f_ep_links;
#endif /* #ifdef CONFIG_EPOLL */
struct address_space *f_mapping;
#ifdef CONFIG_DEBUG_WRITECOUNT
unsigned long f_mnt_write_state;
#endif
};
extern spinlock_t files_lock;
#define file_list_lock() spin_lock(&files_lock);
#define file_list_unlock() spin_unlock(&files_lock);
#define get_file(x) atomic_long_inc(&(x)->f_count)
#define file_count(x) atomic_long_read(&(x)->f_count)
#ifdef CONFIG_DEBUG_WRITECOUNT
static inline void file_take_write(struct file *f)
{
WARN_ON(f->f_mnt_write_state != 0);
f->f_mnt_write_state = FILE_MNT_WRITE_TAKEN;
}
static inline void file_release_write(struct file *f)
{
f->f_mnt_write_state |= FILE_MNT_WRITE_RELEASED;
}
static inline void file_reset_write(struct file *f)
{
f->f_mnt_write_state = 0;
}
static inline void file_check_state(struct file *f)
{
/*
* At this point, either both or neither of these bits
* should be set.
*/
WARN_ON(f->f_mnt_write_state == FILE_MNT_WRITE_TAKEN);
WARN_ON(f->f_mnt_write_state == FILE_MNT_WRITE_RELEASED);
}
static inline int file_check_writeable(struct file *f)
{
if (f->f_mnt_write_state == FILE_MNT_WRITE_TAKEN)
return 0;
printk(KERN_WARNING "writeable file with no "
"mnt_want_write()\n");
WARN_ON(1);
return -EINVAL;
}
#else /* !CONFIG_DEBUG_WRITECOUNT */
static inline void file_take_write(struct file *filp) {}
static inline void file_release_write(struct file *filp) {}
static inline void file_reset_write(struct file *filp) {}
static inline void file_check_state(struct file *filp) {}
static inline int file_check_writeable(struct file *filp)
{
return 0;
}
#endif /* CONFIG_DEBUG_WRITECOUNT */