fs.h 91.3 KB
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#ifndef _LINUX_FS_H
#define _LINUX_FS_H


#include <linux/linkage.h>
#include <linux/wait.h>
#include <linux/kdev_t.h>
#include <linux/dcache.h>
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#include <linux/path.h>
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#include <linux/stat.h>
#include <linux/cache.h>
#include <linux/list.h>
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#include <linux/list_lru.h>
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#include <linux/llist.h>
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#include <linux/radix-tree.h>
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#include <linux/rbtree.h>
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#include <linux/init.h>
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#include <linux/pid.h>
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#include <linux/bug.h>
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#include <linux/mutex.h>
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#include <linux/capability.h>
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#include <linux/semaphore.h>
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#include <linux/fiemap.h>
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#include <linux/rculist_bl.h>
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#include <linux/atomic.h>
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#include <linux/shrinker.h>
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#include <linux/migrate_mode.h>
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#include <linux/uidgid.h>
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#include <linux/lockdep.h>
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#include <linux/percpu-rwsem.h>
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#include <linux/blk_types.h>
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#include <asm/byteorder.h>
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#include <uapi/linux/fs.h>
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struct export_operations;
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struct hd_geometry;
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struct iovec;
struct nameidata;
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struct kiocb;
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struct kobject;
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struct pipe_inode_info;
struct poll_table_struct;
struct kstatfs;
struct vm_area_struct;
struct vfsmount;
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struct cred;
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struct swap_info_struct;
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struct seq_file;
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struct workqueue_struct;
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extern void __init inode_init(void);
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extern void __init inode_init_early(void);
extern void __init files_init(unsigned long);

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extern struct files_stat_struct files_stat;
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extern unsigned long get_max_files(void);
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extern int sysctl_nr_open;
extern struct inodes_stat_t inodes_stat;
extern int leases_enable, lease_break_time;
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extern int sysctl_protected_symlinks;
extern int sysctl_protected_hardlinks;
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struct buffer_head;
typedef int (get_block_t)(struct inode *inode, sector_t iblock,
			struct buffer_head *bh_result, int create);
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typedef void (dio_iodone_t)(struct kiocb *iocb, loff_t offset,
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			ssize_t bytes, void *private);
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#define MAY_EXEC		0x00000001
#define MAY_WRITE		0x00000002
#define MAY_READ		0x00000004
#define MAY_APPEND		0x00000008
#define MAY_ACCESS		0x00000010
#define MAY_OPEN		0x00000020
#define MAY_CHDIR		0x00000040
/* called from RCU mode, don't block */
#define MAY_NOT_BLOCK		0x00000080

/*
 * 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)
/* 32bit hashes as llseek() offset (for directories) */
#define FMODE_32BITHASH         ((__force fmode_t)0x200)
/* 64bit hashes as llseek() offset (for directories) */
#define FMODE_64BITHASH         ((__force fmode_t)0x400)

/*
 * 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)

/* File is huge (eg. /dev/kmem): treat loff_t as unsigned */
#define FMODE_UNSIGNED_OFFSET	((__force fmode_t)0x2000)

/* File is opened with O_PATH; almost nothing can be done with it */
#define FMODE_PATH		((__force fmode_t)0x4000)

/* File was opened by fanotify and shouldn't generate fanotify events */
#define FMODE_NONOTIFY		((__force fmode_t)0x1000000)

/*
 * Flag for rw_copy_check_uvector and compat_rw_copy_check_uvector
 * that indicates that they should check the contents of the iovec are
 * valid, but not check the memory that the iovec elements
 * points too.
 */
#define CHECK_IOVEC_ONLY -1

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/*
 * 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.
 * WRITE_SYNC		Synchronous write. Identical to WRITE, but passes down
 *			the hint that someone will be waiting on this IO
 *			shortly. The write equivalent of READ_SYNC.
 * WRITE_ODIRECT	Special case write for O_DIRECT only.
 * WRITE_FLUSH		Like WRITE_SYNC but with preceding cache flush.
 * WRITE_FUA		Like WRITE_SYNC but data is guaranteed to be on
 *			non-volatile media on completion.
 * WRITE_FLUSH_FUA	Combination of WRITE_FLUSH and FUA. The IO is preceded
 *			by a cache flush and data is guaranteed to be on
 *			non-volatile media on completion.
 *
 */
#define RW_MASK			REQ_WRITE
#define RWA_MASK		REQ_RAHEAD

#define READ			0
#define WRITE			RW_MASK
#define READA			RWA_MASK
#define KERNEL_READ		(READ|REQ_KERNEL)
#define KERNEL_WRITE		(WRITE|REQ_KERNEL)

#define READ_SYNC		(READ | REQ_SYNC)
#define WRITE_SYNC		(WRITE | REQ_SYNC | REQ_NOIDLE)
#define WRITE_ODIRECT		(WRITE | REQ_SYNC)
#define WRITE_FLUSH		(WRITE | REQ_SYNC | REQ_NOIDLE | REQ_FLUSH)
#define WRITE_FUA		(WRITE | REQ_SYNC | REQ_NOIDLE | REQ_FUA)
#define WRITE_FLUSH_FUA		(WRITE | REQ_SYNC | REQ_NOIDLE | REQ_FLUSH | REQ_FUA)

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/*
 * Attribute flags.  These should be or-ed together to figure out what
 * has been changed!
 */
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#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)
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/*
 * 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;
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	kuid_t		ia_uid;
	kgid_t		ia_gid;
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	loff_t		ia_size;
	struct timespec	ia_atime;
	struct timespec	ia_mtime;
	struct timespec	ia_ctime;
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	/*
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	 * Not an attribute, but an auxiliary info for filesystems wanting to
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	 * implement an ftruncate() like method.  NOTE: filesystem should
	 * check for (ia_valid & ATTR_FILE), and not for (ia_file != NULL).
	 */
	struct file	*ia_file;
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};

/*
 * Includes for diskquotas.
 */
#include <linux/quota.h>

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/** 
 * 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
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 *  			by readpage().
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 *
 * 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,
};

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#define AOP_FLAG_UNINTERRUPTIBLE	0x0001 /* will not do a short write */
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#define AOP_FLAG_CONT_EXPAND		0x0002 /* called from cont_expand */
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#define AOP_FLAG_NOFS			0x0004 /* used by filesystem to direct
						* helper code (eg buffer layer)
						* to clear GFP_FS from alloc */
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/*
 * oh the beauties of C type declarations.
 */
struct page;
struct address_space;
struct writeback_control;

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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);
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int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes);
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size_t iov_iter_single_seg_count(const struct iov_iter *i);
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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;
}

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/*
 * "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);
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struct address_space_operations {
	int (*writepage)(struct page *page, struct writeback_control *wbc);
	int (*readpage)(struct file *, struct page *);

	/* Write back some dirty pages from this mapping. */
	int (*writepages)(struct address_space *, struct writeback_control *);

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	/* Set a page dirty.  Return true if this dirtied it */
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	int (*set_page_dirty)(struct page *page);

	int (*readpages)(struct file *filp, struct address_space *mapping,
			struct list_head *pages, unsigned nr_pages);

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	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);

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	/* Unfortunately this kludge is needed for FIBMAP. Don't use it */
	sector_t (*bmap)(struct address_space *, sector_t);
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	void (*invalidatepage) (struct page *, unsigned int, unsigned int);
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	int (*releasepage) (struct page *, gfp_t);
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	void (*freepage)(struct page *);
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	ssize_t (*direct_IO)(int, struct kiocb *, const struct iovec *iov,
			loff_t offset, unsigned long nr_segs);
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	int (*get_xip_mem)(struct address_space *, pgoff_t, int,
						void **, unsigned long *);
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	/*
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	 * migrate the contents of a page to the specified target. If
	 * migrate_mode is MIGRATE_ASYNC, it must not block.
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	 */
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	int (*migratepage) (struct address_space *,
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			struct page *, struct page *, enum migrate_mode);
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	int (*launder_page) (struct page *);
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	int (*is_partially_uptodate) (struct page *, read_descriptor_t *,
					unsigned long);
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	void (*is_dirty_writeback) (struct page *, bool *, bool *);
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	int (*error_remove_page)(struct address_space *, struct page *);
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	/* swapfile support */
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	int (*swap_activate)(struct swap_info_struct *sis, struct file *file,
				sector_t *span);
	void (*swap_deactivate)(struct file *file);
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};

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extern const struct address_space_operations empty_aops;

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/*
 * 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);

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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 */
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	spinlock_t		tree_lock;	/* and lock protecting it */
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	unsigned int		i_mmap_writable;/* count VM_SHARED mappings */
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	struct rb_root		i_mmap;		/* tree of private and shared mappings */
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	struct list_head	i_mmap_nonlinear;/*list VM_NONLINEAR mappings */
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	struct mutex		i_mmap_mutex;	/* protect tree, count, list */
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	/* Protected by tree_lock together with the radix tree */
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	unsigned long		nrpages;	/* number of total pages */
	pgoff_t			writeback_index;/* writeback starts here */
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	const struct address_space_operations *a_ops;	/* methods */
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	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 */
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	void			*private_data;	/* ditto */
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} __attribute__((aligned(sizeof(long))));
	/*
	 * On most architectures that alignment is already the case; but
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	 * must be enforced here for CRIS, to let the least significant bit
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	 * of struct page's "mapping" pointer be used for PAGE_MAPPING_ANON.
	 */
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struct request_queue;
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struct block_device {
	dev_t			bd_dev;  /* not a kdev_t - it's a search key */
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	int			bd_openers;
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	struct inode *		bd_inode;	/* will die */
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	struct super_block *	bd_super;
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	struct mutex		bd_mutex;	/* open/close mutex */
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	struct list_head	bd_inodes;
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	void *			bd_claiming;
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	void *			bd_holder;
	int			bd_holders;
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	bool			bd_write_holder;
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#ifdef CONFIG_SYSFS
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	struct list_head	bd_holder_disks;
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#endif
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	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;
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	struct request_queue *  bd_queue;
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	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;
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	/* The counter of freeze processes */
	int			bd_fsfreeze_count;
	/* Mutex for freeze */
	struct mutex		bd_fsfreeze_mutex;
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};

/*
 * Radix-tree tags, for tagging dirty and writeback pages within the pagecache
 * radix trees
 */
#define PAGECACHE_TAG_DIRTY	0
#define PAGECACHE_TAG_WRITEBACK	1
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#define PAGECACHE_TAG_TOWRITE	2
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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)
{
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	return	!RB_EMPTY_ROOT(&mapping->i_mmap) ||
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		!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

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struct posix_acl;
#define ACL_NOT_CACHED ((void *)(-1))

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#define IOP_FASTPERM	0x0001
#define IOP_LOOKUP	0x0002
#define IOP_NOFOLLOW	0x0004

/*
 * Keep mostly read-only and often accessed (especially for
 * the RCU path lookup and 'stat' data) fields at the beginning
 * of the 'struct inode'
 */
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struct inode {
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	umode_t			i_mode;
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	unsigned short		i_opflags;
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	kuid_t			i_uid;
	kgid_t			i_gid;
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	unsigned int		i_flags;

#ifdef CONFIG_FS_POSIX_ACL
	struct posix_acl	*i_acl;
	struct posix_acl	*i_default_acl;
#endif

536 537
	const struct inode_operations	*i_op;
	struct super_block	*i_sb;
538
	struct address_space	*i_mapping;
539

540 541 542
#ifdef CONFIG_SECURITY
	void			*i_security;
#endif
543

544 545
	/* Stat data, not accessed from path walking */
	unsigned long		i_ino;
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	/*
	 * Filesystems may only read i_nlink directly.  They shall use the
	 * following functions for modification:
	 *
	 *    (set|clear|inc|drop)_nlink
	 *    inode_(inc|dec)_link_count
	 */
	union {
		const unsigned int i_nlink;
		unsigned int __i_nlink;
	};
557
	dev_t			i_rdev;
558
	loff_t			i_size;
559 560 561
	struct timespec		i_atime;
	struct timespec		i_mtime;
	struct timespec		i_ctime;
562 563
	spinlock_t		i_lock;	/* i_blocks, i_bytes, maybe i_size */
	unsigned short          i_bytes;
564
	unsigned int		i_blkbits;
565 566 567 568 569 570 571 572 573
	blkcnt_t		i_blocks;

#ifdef __NEED_I_SIZE_ORDERED
	seqcount_t		i_size_seqcount;
#endif

	/* Misc */
	unsigned long		i_state;
	struct mutex		i_mutex;
574

575 576
	unsigned long		dirtied_when;	/* jiffies of first dirtying */

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	struct hlist_node	i_hash;
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	struct list_head	i_wb_list;	/* backing dev IO list */
	struct list_head	i_lru;		/* inode LRU list */
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	struct list_head	i_sb_list;
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	union {
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		struct hlist_head	i_dentry;
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		struct rcu_head		i_rcu;
	};
585
	u64			i_version;
586
	atomic_t		i_count;
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	atomic_t		i_dio_count;
588
	atomic_t		i_writecount;
589
	const struct file_operations	*i_fop;	/* former ->i_op->default_file_ops */
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	struct file_lock	*i_flock;
	struct address_space	i_data;
#ifdef CONFIG_QUOTA
	struct dquot		*i_dquot[MAXQUOTAS];
#endif
	struct list_head	i_devices;
596 597
	union {
		struct pipe_inode_info	*i_pipe;
598
		struct block_device	*i_bdev;
599
		struct cdev		*i_cdev;
600
	};
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	__u32			i_generation;

604 605
#ifdef CONFIG_FSNOTIFY
	__u32			i_fsnotify_mask; /* all events this inode cares about */
606
	struct hlist_head	i_fsnotify_marks;
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#endif

609
#ifdef CONFIG_IMA
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	atomic_t		i_readcount; /* struct files open RO */
611
#endif
612
	void			*i_private; /* fs or device private pointer */
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};

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static inline int inode_unhashed(struct inode *inode)
{
	return hlist_unhashed(&inode->i_hash);
}

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/*
 * inode->i_mutex nesting subclasses for the lock validator:
 *
 * 0: the object of the current VFS operation
 * 1: parent
 * 2: child/target
626 627 628 629
 * 3: xattr
 * 4: second non-directory
 * The last is for certain operations (such as rename) which lock two
 * non-directories at once.
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 *
 * The locking order between these classes is
632
 * parent -> child -> normal -> xattr -> second non-directory
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 */
enum inode_i_mutex_lock_class
{
	I_MUTEX_NORMAL,
	I_MUTEX_PARENT,
	I_MUTEX_CHILD,
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	I_MUTEX_XATTR,
640
	I_MUTEX_NONDIR2
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};

643 644 645
void lock_two_nondirectories(struct inode *, struct inode*);
void unlock_two_nondirectories(struct inode *, struct inode*);

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/*
 * 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.
 */
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static inline loff_t i_size_read(const struct inode *inode)
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{
#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
}

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/*
 * 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.
 */
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static inline void i_size_write(struct inode *inode, loff_t i_size)
{
#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
687
	preempt_disable();
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	write_seqcount_begin(&inode->i_size_seqcount);
	inode->i_size = i_size;
	write_seqcount_end(&inode->i_size_seqcount);
691
	preempt_enable();
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#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
	preempt_disable();
	inode->i_size = i_size;
	preempt_enable();
#else
	inode->i_size = i_size;
#endif
}

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/* Helper functions so that in most cases filesystems will
 * not need to deal directly with kuid_t and kgid_t and can
 * instead deal with the raw numeric values that are stored
 * in the filesystem.
 */
static inline uid_t i_uid_read(const struct inode *inode)
{
	return from_kuid(&init_user_ns, inode->i_uid);
}

static inline gid_t i_gid_read(const struct inode *inode)
{
	return from_kgid(&init_user_ns, inode->i_gid);
}

static inline void i_uid_write(struct inode *inode, uid_t uid)
{
	inode->i_uid = make_kuid(&init_user_ns, uid);
}

static inline void i_gid_write(struct inode *inode, gid_t gid)
{
	inode->i_gid = make_kgid(&init_user_ns, gid);
}

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static inline unsigned iminor(const struct inode *inode)
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{
	return MINOR(inode->i_rdev);
}

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static inline unsigned imajor(const struct inode *inode)
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{
	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 */
740 741
	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 */
742
	kuid_t uid, euid;	/* uid/euid of process setting the owner */
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	int signum;		/* posix.1b rt signal to be delivered on IO */
};

/*
 * Track a single file's readahead state
 */
struct file_ra_state {
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	pgoff_t start;			/* where readahead started */
	unsigned int size;		/* # of readahead pages */
	unsigned int async_size;	/* do asynchronous readahead when
753
					   there are only # of pages ahead */
754

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	unsigned int ra_pages;		/* Maximum readahead window */
756
	unsigned int mmap_miss;		/* Cache miss stat for mmap accesses */
757
	loff_t prev_pos;		/* Cache last read() position */
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};

760 761 762 763 764
/*
 * Check if @index falls in the readahead windows.
 */
static inline int ra_has_index(struct file_ra_state *ra, pgoff_t index)
{
765 766
	return (index >= ra->start &&
		index <  ra->start + ra->size);
767 768
}

769 770 771
#define FILE_MNT_WRITE_TAKEN	1
#define FILE_MNT_WRITE_RELEASED	2

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struct file {
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	union {
774
		struct llist_node	fu_llist;
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		struct rcu_head 	fu_rcuhead;
	} f_u;
777 778
	struct path		f_path;
#define f_dentry	f_path.dentry
779
	struct inode		*f_inode;	/* cached value */
780
	const struct file_operations	*f_op;
781 782 783 784 785 786

	/*
	 * Protects f_ep_links, f_flags, f_pos vs i_size in lseek SEEK_CUR.
	 * Must not be taken from IRQ context.
	 */
	spinlock_t		f_lock;
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	atomic_long_t		f_count;
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	unsigned int 		f_flags;
789
	fmode_t			f_mode;
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	loff_t			f_pos;
	struct fown_struct	f_owner;
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	const struct cred	*f_cred;
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	struct file_ra_state	f_ra;

795
	u64			f_version;
796
#ifdef CONFIG_SECURITY
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	void			*f_security;
798
#endif
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	/* 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;
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	struct list_head	f_tfile_llink;
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#endif /* #ifdef CONFIG_EPOLL */
	struct address_space	*f_mapping;
808 809 810
#ifdef CONFIG_DEBUG_WRITECOUNT
	unsigned long f_mnt_write_state;
#endif
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};

813 814 815 816 817 818 819
struct file_handle {
	__u32 handle_bytes;
	int handle_type;
	/* file identifier */
	unsigned char f_handle[0];
};

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static inline struct file *get_file(struct file *f)
{
	atomic_long_inc(&f->f_count);
	return f;
}
825
#define fput_atomic(x)	atomic_long_add_unless(&(x)->f_count, -1, 1)
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#define file_count(x)	atomic_long_read(&(x)->f_count)
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#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 */

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#define	MAX_NON_LFS	((1UL<<31) - 1)

/* Page cache limit. The filesystems should put that into their s_maxbytes 
   limits, otherwise bad things can happen in VM. */ 
#if BITS_PER_LONG==32
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#define MAX_LFS_FILESIZE	(((loff_t)PAGE_CACHE_SIZE << (BITS_PER_LONG-1))-1) 
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#elif BITS_PER_LONG==64
878
#define MAX_LFS_FILESIZE 	((loff_t)0x7fffffffffffffffLL)
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#endif

#define FL_POSIX	1
#define FL_FLOCK	2
883
#define FL_DELEG	4	/* NFSv4 delegation */
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#define FL_ACCESS	8	/* not trying to lock, just looking */
885
#define FL_EXISTS	16	/* when unlocking, test for existence */
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#define FL_LEASE	32	/* lease held on this file */
887
#define FL_CLOSE	64	/* unlock on close */
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#define FL_SLEEP	128	/* A blocking lock */
889 890
#define FL_DOWNGRADE_PENDING	256 /* Lease is being downgraded */
#define FL_UNLOCK_PENDING	512 /* Lease is being broken */
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892 893 894 895 896 897
/*
 * Special return value from posix_lock_file() and vfs_lock_file() for
 * asynchronous locking.
 */
#define FILE_LOCK_DEFERRED 1

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/*
 * The POSIX file lock owner is determined by
 * the "struct files_struct" in the thread group
 * (or NULL for no owner - BSD locks).
 *
 * Lockd stuffs a "host" pointer into this.
 */
typedef struct files_struct *fl_owner_t;

struct file_lock_operations {
	void (*fl_copy_lock)(struct file_lock *, struct file_lock *);
	void (*fl_release_private)(struct file_lock *);
};

struct lock_manager_operations {
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	int (*lm_compare_owner)(struct file_lock *, struct file_lock *);
914
	unsigned long (*lm_owner_key)(struct file_lock *);
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	void (*lm_notify)(struct file_lock *);	/* unblock callback */
	int (*lm_grant)(struct file_lock *, struct file_lock *, int);
	void (*lm_break)(struct file_lock *);
	int (*lm_change)(struct file_lock **, int);
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};

921 922 923 924
struct lock_manager {
	struct list_head list;
};

925 926
struct net;
void locks_start_grace(struct net *, struct lock_manager *);
927
void locks_end_grace(struct lock_manager *);
928
int locks_in_grace(struct net *);
929

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/* that will die - we need it for nfs_lock_info */
#include <linux/nfs_fs_i.h>

933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950
/*
 * struct file_lock represents a generic "file lock". It's used to represent
 * POSIX byte range locks, BSD (flock) locks, and leases. It's important to
 * note that the same struct is used to represent both a request for a lock and
 * the lock itself, but the same object is never used for both.
 *
 * FIXME: should we create a separate "struct lock_request" to help distinguish
 * these two uses?
 *
 * The i_flock list is ordered by:
 *
 * 1) lock type -- FL_LEASEs first, then FL_FLOCK, and finally FL_POSIX
 * 2) lock owner
 * 3) lock range start
 * 4) lock range end
 *
 * Obviously, the last two criteria only matter for POSIX locks.
 */
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struct file_lock {
	struct file_lock *fl_next;	/* singly linked list for this inode  */
953
	struct hlist_node fl_link;	/* node in global lists */
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	struct list_head fl_block;	/* circular list of blocked processes */
	fl_owner_t fl_owner;
956
	unsigned int fl_flags;
957
	unsigned char fl_type;
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	unsigned int fl_pid;
959
	int fl_link_cpu;		/* what cpu's list is this on? */
960
	struct pid *fl_nspid;
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	wait_queue_head_t fl_wait;
	struct file *fl_file;
	loff_t fl_start;
	loff_t fl_end;

	struct fasync_struct *	fl_fasync; /* for lease break notifications */
967 968 969
	/* for lease breaks: */
	unsigned long fl_break_time;
	unsigned long fl_downgrade_time;
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971
	const struct file_lock_operations *fl_ops;	/* Callbacks for filesystems */
972
	const struct lock_manager_operations *fl_lmops;	/* Callbacks for lockmanagers */
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	union {
		struct nfs_lock_info	nfs_fl;
975
		struct nfs4_lock_info	nfs4_fl;
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		struct {
			struct list_head link;	/* link in AFS vnode's pending_locks list */
			int state;		/* state of grant or error if -ve */
		} afs;
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	} fl_u;
};

/* The following constant reflects the upper bound of the file/locking space */
#ifndef OFFSET_MAX
#define INT_LIMIT(x)	(~((x)1 << (sizeof(x)*8 - 1)))
#define OFFSET_MAX	INT_LIMIT(loff_t)
#define OFFT_OFFSET_MAX	INT_LIMIT(off_t)
#endif

#include <linux/fcntl.h>

992 993 994
extern void send_sigio(struct fown_struct *fown, int fd, int band);

#ifdef CONFIG_FILE_LOCKING
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extern int fcntl_getlk(struct file *, struct flock __user *);
996 997
extern int fcntl_setlk(unsigned int, struct file *, unsigned int,
			struct flock __user *);
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#if BITS_PER_LONG == 32
extern int fcntl_getlk64(struct file *, struct flock64 __user *);
1001 1002
extern int fcntl_setlk64(unsigned int, struct file *, unsigned int,
			struct flock64 __user *);
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#endif

extern int fcntl_setlease(unsigned int fd, struct file *filp, long arg);
extern int fcntl_getlease(struct file *filp);

/* fs/locks.c */
1009
void locks_free_lock(struct file_lock *fl);
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extern void locks_init_lock(struct file_lock *);
1011
extern struct file_lock * locks_alloc_lock(void);
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extern void locks_copy_lock(struct file_lock *, struct file_lock *);
1013
extern void __locks_copy_lock(struct file_lock *, const struct file_lock *);
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extern void locks_remove_posix(struct file *, fl_owner_t);
extern void locks_remove_flock(struct file *);
1016
extern void locks_release_private(struct file_lock *);
1017
extern void posix_test_lock(struct file *, struct file_lock *);
1018
extern int posix_lock_file(struct file *, struct file_lock *, struct file_lock *);
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extern int posix_lock_file_wait(struct file *, struct file_lock *);
1020
extern int posix_unblock_lock(struct file_lock *);
1021
extern int vfs_test_lock(struct file *, struct file_lock *);
1022
extern int vfs_lock_file(struct file *, unsigned int, struct file_lock *, struct file_lock *);
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extern int vfs_cancel_lock(struct file *filp, struct file_lock *fl);
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extern int flock_lock_file_wait(struct file *filp, struct file_lock *fl);
extern int __break_lease(struct inode *inode, unsigned int flags);
extern void lease_get_mtime(struct inode *, struct timespec *time);
1027
extern int generic_setlease(struct file *, long, struct file_lock **);
1028
extern int vfs_setlease(struct file *, long, struct file_lock **);
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extern int lease_modify(struct file_lock **, int);
extern int lock_may_read(struct inode *, loff_t start, unsigned long count);
extern int lock_may_write(struct inode *, loff_t start, unsigned long count);
1032
#else /* !CONFIG_FILE_LOCKING */
1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043
static inline int fcntl_getlk(struct file *file, struct flock __user *user)
{
	return -EINVAL;
}

static inline int fcntl_setlk(unsigned int fd, struct file *file,
			      unsigned int cmd, struct flock __user *user)
{
	return -EACCES;
}

1044
#if BITS_PER_LONG == 32
1045 1046 1047 1048 1049 1050 1051 1052 1053 1054
static inline int fcntl_getlk64(struct file *file, struct flock64 __user *user)
{
	return -EINVAL;
}

static inline int fcntl_setlk64(unsigned int fd, struct file *file,
				unsigned int cmd, struct flock64 __user *user)
{
	return -EACCES;
}
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#endif
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static inline int fcntl_setlease(unsigned int fd, struct file *filp, long arg)
{
	return 0;
}

static inline int fcntl_getlease(struct file *filp)
{
	return 0;
}

static inline void locks_init_lock(struct file_lock *fl)
{
	return;
}

static inline void __locks_copy_lock(struct file_lock *new, struct file_lock *fl)
{
	return;
}

static inline void locks_copy_lock(struct file_lock *new, struct file_lock *fl)
{
	return;
}

static inline void locks_remove_posix(struct file *filp, fl_owner_t owner)
{
	return;
}

static inline void locks_remove_flock(struct file *filp)
{
	return;
}

static inline void posix_test_lock(struct file *filp, struct file_lock *fl)
{
	return;
}

static inline int posix_lock_file(struct file *filp, struct file_lock *fl,
				  struct file_lock *conflock)
{
	return -ENOLCK;
}

static inline int posix_lock_file_wait(struct file *filp, struct file_lock *fl)
{
	return -ENOLCK;
}

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static inline int posix_unblock_lock(struct file_lock *waiter)
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{
	return -ENOENT;
}

static inline int vfs_test_lock(struct file *filp, struct file_lock *fl)
{
	return 0;
}

static inline int vfs_lock_file(struct file *filp, unsigned int cmd,
				struct file_lock *fl, struct file_lock *conf)
{
	return -ENOLCK;
}

static inline int vfs_cancel_lock(struct file *filp, struct file_lock *fl)
{
	return 0;
}

static inline int flock_lock_file_wait(struct file *filp,
				       struct file_lock *request)
{
	return -ENOLCK;
}

static inline int __break_lease(struct inode *inode, unsigned int mode)
{
	return 0;
}

static inline void lease_get_mtime(struct inode *inode, struct timespec *time)
{
	return;
}

static inline int generic_setlease(struct file *filp, long arg,
				    struct file_lock **flp)
{
	return -EINVAL;
}

static inline int vfs_setlease(struct file *filp, long arg,
			       struct file_lock **lease)
{
	return -EINVAL;
}

static inline int lease_modify(struct file_lock **before, int arg)
{
	return -EINVAL;
}

static inline int lock_may_read(struct inode *inode, loff_t start,
				unsigned long len)
{
	return 1;
}

static inline int lock_may_write(struct inode *inode, loff_t start,
				 unsigned long len)
{
	return 1;
}
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#endif /* !CONFIG_FILE_LOCKING */

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struct fasync_struct {
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	spinlock_t		fa_lock;
	int			magic;
	int			fa_fd;
	struct fasync_struct	*fa_next; /* singly linked list */
	struct file		*fa_file;
	struct rcu_head		fa_rcu;
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};

#define FASYNC_MAGIC 0x4601

/* SMP safe fasync helpers: */
extern int fasync_helper(int, struct file *, int, struct fasync_struct **);
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extern struct fasync_struct *fasync_insert_entry(int, struct file *, struct fasync_struct **, struct fasync_struct *);
extern int fasync_remove_entry(struct file *, struct fasync_struct **);
extern struct fasync_struct *fasync_alloc(void);
extern void fasync_free(struct fasync_struct *);

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/* can be called from interrupts */
extern void kill_fasync(struct fasync_struct **, int, int);

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extern int __f_setown(struct file *filp, struct pid *, enum pid_type, int force);
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extern int f_setown(struct file *filp, unsigned long arg, int force);
extern void f_delown(struct file *filp);
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extern pid_t f_getown(struct file *filp);
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extern int send_sigurg(struct fown_struct *fown);

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struct mm_struct;

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/*
 *	Umount options
 */

#define MNT_FORCE	0x00000001	/* Attempt to forcibily umount */
#define MNT_DETACH	0x00000002	/* Just detach from the tree */
#define MNT_EXPIRE	0x00000004	/* Mark for expiry */
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#define UMOUNT_NOFOLLOW	0x00000008	/* Don't follow symlink on umount */
#define UMOUNT_UNUSED	0x80000000	/* Flag guaranteed to be unused */
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extern struct list_head super_blocks;
extern spinlock_t sb_lock;

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/* Possible states of 'frozen' field */
enum {
	SB_UNFROZEN = 0,		/* FS is unfrozen */
	SB_FREEZE_WRITE	= 1,		/* Writes, dir ops, ioctls frozen */
	SB_FREEZE_PAGEFAULT = 2,	/* Page faults stopped as well */
	SB_FREEZE_FS = 3,		/* For internal FS use (e.g. to stop
					 * internal threads if needed) */
	SB_FREEZE_COMPLETE = 4,		/* ->freeze_fs finished successfully */
};

#define SB_FREEZE_LEVELS (SB_FREEZE_COMPLETE - 1)

struct sb_writers {
	/* Counters for counting writers at each level */
	struct percpu_counter	counter[SB_FREEZE_LEVELS];
	wait_queue_head_t	wait;		/* queue for waiting for
						   writers / faults to finish */
	int			frozen;		/* Is sb frozen? */
	wait_queue_head_t	wait_unfrozen;	/* queue for waiting for
						   sb to be thawed */
#ifdef CONFIG_DEBUG_LOCK_ALLOC
	struct lockdep_map	lock_map[SB_FREEZE_LEVELS];
#endif
};

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struct super_block {
	struct list_head	s_list;		/* Keep this first */
	dev_t			s_dev;		/* search index; _not_ kdev_t */
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	unsigned char		s_blocksize_bits;
	unsigned long		s_blocksize;
1247
	loff_t			s_maxbytes;	/* Max file size */
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	struct file_system_type	*s_type;
1249
	const struct super_operations	*s_op;
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	const struct dquot_operations	*dq_op;
1251
	const struct quotactl_ops	*s_qcop;
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	const struct export_operations *s_export_op;
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	unsigned long		s_flags;
	unsigned long		s_magic;
	struct dentry		*s_root;
	struct rw_semaphore	s_umount;
	int			s_count;
	atomic_t		s_active;
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#ifdef CONFIG_SECURITY
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	void                    *s_security;
1261
#endif
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	const struct xattr_handler **s_xattr;
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	struct list_head	s_inodes;	/* all inodes */
1265
	struct hlist_bl_head	s_anon;		/* anonymous dentries for (nfs) exporting */
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	struct list_head	s_mounts;	/* list of mounts; _not_ for fs use */
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	struct block_device	*s_bdev;
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	struct backing_dev_info *s_bdi;
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	struct mtd_info		*s_mtd;
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	struct hlist_node	s_instances;
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	struct quota_info	s_dquot;	/* Diskquota specific options */

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	struct sb_writers	s_writers;
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	char s_id[32];				/* Informational name */
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	u8 s_uuid[16];				/* UUID */
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	void 			*s_fs_info;	/* Filesystem private info */
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	unsigned int		s_max_links;
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	fmode_t			s_mode;
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	/* Granularity of c/m/atime in ns.
	   Cannot be worse than a second */
	u32		   s_time_gran;

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	/*
	 * The next field is for VFS *only*. No filesystems have any business
	 * even looking at it. You had been warned.
	 */
1290
	struct mutex s_vfs_rename_mutex;	/* Kludge */
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	/*
	 * Filesystem subtype.  If non-empty the filesystem type field
	 * in /proc/mounts will be "type.subtype"
	 */
	char *s_subtype;
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	/*
	 * Saved mount options for lazy filesystems using
	 * generic_show_options()
	 */
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	char __rcu *s_options;
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	const struct dentry_operations *s_d_op; /* default d_op for dentries */
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	/*
	 * Saved pool identifier for cleancache (-1 means none)
	 */
	int cleancache_poolid;
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	struct shrinker s_shrink;	/* per-sb shrinker handle */
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	/* Number of inodes with nlink == 0 but still referenced */
	atomic_long_t s_remove_count;

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	/* Being remounted read-only */
	int s_readonly_remount;
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	/* AIO completions deferred from interrupt context */
	struct workqueue_struct *s_dio_done_wq;
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	/*
	 * Keep the lru lists last in the structure so they always sit on their
	 * own individual cachelines.
	 */
	struct list_lru		s_dentry_lru ____cacheline_aligned_in_smp;
	struct list_lru		s_inode_lru ____cacheline_aligned_in_smp;
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	struct rcu_head		rcu;
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};

extern struct timespec current_fs_time(struct super_block *sb);

/*
 * Snapshotting support.
 */

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void __sb_end_write(struct super_block *sb, int level);
int __sb_start_write(struct super_block *sb, int level, bool wait);

/**
 * sb_end_write - drop write access to a superblock
 * @sb: the super we wrote to
 *
 * Decrement number of writers to the filesystem. Wake up possible waiters
 * wanting to freeze the filesystem.
 */
static inline void sb_end_write(struct super_block *sb)
{
	__sb_end_write(sb, SB_FREEZE_WRITE);
}

/**
 * sb_end_pagefault - drop write access to a superblock from a page fault
 * @sb: the super we wrote to
 *
 * Decrement number of processes handling write page fault to the filesystem.
 * Wake up possible waiters wanting to freeze the filesystem.
 */
static inline void sb_end_pagefault(struct super_block *sb)
{
	__sb_end_write(sb, SB_FREEZE_PAGEFAULT);
}

/**
 * sb_end_intwrite - drop write access to a superblock for internal fs purposes
 * @sb: the super we wrote to
 *
 * Decrement fs-internal number of writers to the filesystem.  Wake up possible
 * waiters wanting to freeze the filesystem.
 */
static inline void sb_end_intwrite(struct super_block *sb)
{
	__sb_end_write(sb, SB_FREEZE_FS);
}

/**
 * sb_start_write - get write access to a superblock
 * @sb: the super we write to
 *
 * When a process wants to write data or metadata to a file system (i.e. dirty
 * a page or an inode), it should embed the operation in a sb_start_write() -
 * sb_end_write() pair to get exclusion against file system freezing. This
 * function increments number of writers preventing freezing. If the file
 * system is already frozen, the function waits until the file system is
 * thawed.
 *
 * Since freeze protection behaves as a lock, users have to preserve
 * ordering of freeze protection and other filesystem locks. Generally,
 * freeze protection should be the outermost lock. In particular, we have:
 *
 * sb_start_write
 *   -> i_mutex			(write path, truncate, directory ops, ...)
 *   -> s_umount		(freeze_super, thaw_super)
 */
static inline void sb_start_write(struct super_block *sb)
{
	__sb_start_write(sb, SB_FREEZE_WRITE, true);
}

static inline int sb_start_write_trylock(struct super_block *sb)
{
	return __sb_start_write(sb, SB_FREEZE_WRITE, false);
}

/**
 * sb_start_pagefault - get write access to a superblock from a page fault
 * @sb: the super we write to
 *
 * When a process starts handling write page fault, it should embed the
 * operation into sb_start_pagefault() - sb_end_pagefault() pair to get
 * exclusion against file system freezing. This is needed since the page fault
 * is going to dirty a page. This function increments number of running page
 * faults preventing freezing. If the file system is already frozen, the
 * function waits until the file system is thawed.
 *
 * Since page fault freeze protection behaves as a lock, users have to preserve
 * ordering of freeze protection and other filesystem locks. It is advised to
 * put sb_start_pagefault() close to mmap_sem in lock ordering. Page fault
 * handling code implies lock dependency:
 *
 * mmap_sem
 *   -> sb_start_pagefault
 */
static inline void sb_start_pagefault(struct super_block *sb)
{
	__sb_start_write(sb, SB_FREEZE_PAGEFAULT, true);
}

/*
 * sb_start_intwrite - get write access to a superblock for internal fs purposes
 * @sb: the super we write to
 *
 * This is the third level of protection against filesystem freezing. It is
 * free for use by a filesystem. The only requirement is that it must rank
 * below sb_start_pagefault.
 *
 * For example filesystem can call sb_start_intwrite() when starting a
 * transaction which somewhat eases handling of freezing for internal sources
 * of filesystem changes (internal fs threads, discarding preallocation on file
 * close, etc.).
 */
static inline void sb_start_intwrite(struct super_block *sb)
{
	__sb_start_write(sb, SB_FREEZE_FS, true);
}
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extern bool inode_owner_or_capable(const struct inode *inode);
1448

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/*
 * VFS helper functions..
 */
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extern int vfs_create(struct inode *, struct dentry *, umode_t, bool);
1453
extern int vfs_mkdir(struct inode *, struct dentry *, umode_t);
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extern int vfs_mknod(struct inode *, struct dentry *, umode_t, dev_t);
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extern int vfs_symlink(struct inode *, struct dentry *, const char *);
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extern int vfs_link(struct dentry *, struct inode *, struct dentry *);
extern int vfs_rmdir(struct inode *, struct dentry *);
extern int vfs_unlink(struct inode *, struct dentry *);
extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *);

/*
 * VFS dentry helper functions.
 */
extern void dentry_unhash(struct dentry *dentry);

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/*
 * VFS file helper functions.
 */
1469
extern void inode_init_owner(struct inode *inode, const struct inode *dir,
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			umode_t mode);
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/*
 * VFS FS_IOC_FIEMAP helper definitions.
 */
struct fiemap_extent_info {
	unsigned int fi_flags;		/* Flags as passed from user */
	unsigned int fi_extents_mapped;	/* Number of mapped extents */
	unsigned int fi_extents_max;	/* Size of fiemap_extent array */
1478 1479
	struct fiemap_extent __user *fi_extents_start; /* Start of
							fiemap_extent array */
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};
int fiemap_fill_next_extent(struct fiemap_extent_info *info, u64 logical,
			    u64 phys, u64 len, u32 flags);
int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags);

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/*
 * File types
 *
 * NOTE! These match bits 12..15 of stat.st_mode
 * (ie "(i_mode >> 12) & 15").
 */
#define DT_UNKNOWN	0
#define DT_FIFO		1
#define DT_CHR		2
#define DT_DIR		4
#define DT_BLK		6
#define DT_REG		8
#define DT_LNK		10
#define DT_SOCK		12
#define DT_WHT		14

/*
 * This is the "filldir" function type, used by readdir() to let
 * the kernel specify what kind of dirent layout it wants to have.
 * This allows the kernel to read directories into kernel space or
 * to have different dirent layouts depending on the binary type.
 */
1507
typedef int (*filldir_t)(void *, const char *, int, loff_t, u64, unsigned);
1508
struct dir_context {
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	const filldir_t actor;
1510
	loff_t pos;
1511
};
1512

1513
struct block_device_operations;
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/* These macros are for out of kernel modules to test that
 * the kernel supports the unlocked_ioctl and compat_ioctl
 * fields in struct file_operations. */
#define HAVE_COMPAT_IOCTL 1
#define HAVE_UNLOCKED_IOCTL 1

struct file_operations {
	struct module *owner;
	loff_t (*llseek) (struct file *, loff_t, int);
	ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
	ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
1526 1527
	ssize_t (*aio_read) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
	ssize_t (*aio_write) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
1528
	int (*iterate) (struct file *, struct dir_context *);
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	unsigned int (*poll) (struct file *, struct poll_table_struct *);
	long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
	long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
	int (*mmap) (struct file *, struct vm_area_struct *);
	int (*open) (struct inode *, struct file *);
1534
	int (*flush) (struct file *, fl_owner_t id);
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	int (*release) (struct inode *, struct file *);
1536
	int (*fsync) (struct file *, loff_t, loff_t, int datasync);
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	int (*aio_fsync) (struct kiocb *, int datasync);
	int (*fasync) (int, struct file *, int);
	int (*lock) (struct file *, int, struct file_lock *);
	ssize_t (*sendpage) (struct file *, struct page *, int, size_t, loff_t *, int);
	unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
	int (*check_flags)(int);
	int (*flock) (struct file *, int, struct file_lock *);
1544 1545
	ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int);
	ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int);
1546
	int (*setlease)(struct file *, long, struct file_lock **);
1547 1548
	long (*fallocate)(struct file *file, int mode, loff_t offset,
			  loff_t len);
1549
	int (*show_fdinfo)(struct seq_file *m, struct file *f);
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};

struct inode_operations {
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	struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int);
1554
	void * (*follow_link) (struct dentry *, struct nameidata *);
1555
	int (*permission) (struct inode *, int);
1556
	struct posix_acl * (*get_acl)(struct inode *, int);
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	int (*readlink) (struct dentry *, char __user *,int);
	void (*put_link) (struct dentry *, struct nameidata *, void *);

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	int (*create) (struct inode *,struct dentry *, umode_t, bool);
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	int (*link) (struct dentry *,struct inode *,struct dentry *);
	int (*unlink) (struct inode *,struct dentry *);
	int (*symlink) (struct inode *,struct dentry *,const char *);
1565
	int (*mkdir) (struct inode *,struct dentry *,umode_t);
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	int (*rmdir) (struct inode *,struct dentry *);
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	int (*mknod) (struct inode *,struct dentry *,umode_t,dev_t);
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	int (*rename) (struct inode *, struct dentry *,
			struct inode *, struct dentry *);
	int (*setattr) (struct dentry *, struct iattr *);
	int (*getattr) (struct vfsmount *mnt, struct dentry *, struct kstat *);
	int (*setxattr) (struct dentry *, const char *,const void *,size_t,int);
	ssize_t (*getxattr) (struct dentry *, const char *, void *, size_t);
	ssize_t (*listxattr) (struct dentry *, char *, size_t);
	int (*removexattr) (struct dentry *, const char *);
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	int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start,
		      u64 len);
1578
	int (*update_time)(struct inode *, struct timespec *, int);
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	int (*atomic_open)(struct inode *, struct dentry *,
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			   struct file *, unsigned open_flag,
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			   umode_t create_mode, int *opened);
1582
	int (*tmpfile) (struct inode *, struct dentry *, umode_t);
1583
} ____cacheline_aligned;
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ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
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			      unsigned long nr_segs, unsigned long fast_segs,
			      struct iovec *fast_pointer,
1588
			      struct iovec **ret_pointer);
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extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *);
extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *);
extern ssize_t vfs_readv(struct file *, const struct iovec __user *,
		unsigned long, loff_t *);
extern ssize_t vfs_writev(struct file *, const struct iovec __user *,
		unsigned long, loff_t *);

struct super_operations {
   	struct inode *(*alloc_inode)(struct super_block *sb);
	void (*destroy_inode)(struct inode *);

1601
   	void (*dirty_inode) (struct inode *, int flags);
1602
	int (*write_inode) (struct inode *, struct writeback_control *wbc);
1603
	int (*drop_inode) (struct inode *);
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	void (*evict_inode) (struct inode *);
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	void (*put_super) (struct super_block *);
	int (*sync_fs)(struct super_block *sb, int wait);
1607 1608
	int (*freeze_fs) (struct super_block *);
	int (*unfreeze_fs) (struct super_block *);
1609
	int (*statfs) (struct dentry *, struct kstatfs *);
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1610
	int (*remount_fs) (struct super_block *, int *, char *);
1611
	void (*umount_begin) (struct super_block *);
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1612

1613
	int (*show_options)(struct seq_file *, struct dentry *);
1614
	int (*show_devname)(struct seq_file *, struct dentry *);
1615
	int (*show_path)(struct seq_file *, struct dentry *);
1616
	int (*show_stats)(struct seq_file *, struct dentry *);
1617
#ifdef CONFIG_QUOTA
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	ssize_t (*quota_read)(struct super_block *, int, char *, size_t, loff_t);
	ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t);
1620
#endif
1621
	int (*bdev_try_to_free_page)(struct super_block*, struct page*, gfp_t);
1622 1623
	long (*nr_cached_objects)(struct super_block *, int);
	long (*free_cached_objects)(struct super_block *, long, int);
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};

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/*
 * Inode flags - they have no relation 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 */
#define S_IMA		1024	/* Inode has an associated IMA struct */
#define S_AUTOMOUNT	2048	/* Automount/referral quasi-directory */
#define S_NOSEC		4096	/* no suid or xattr security attributes */

/*
 * 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)
#define IS_IMA(inode)		((inode)->i_flags & S_IMA)
#define IS_AUTOMOUNT(inode)	((inode)->i_flags & S_AUTOMOUNT)
#define IS_NOSEC(inode)		((inode)->i_flags & S_NOSEC)

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/*
1681
 * Inode state bits.  Protected by inode->i_lock
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 *
 * Three bits determine the dirty state of the inode, I_DIRTY_SYNC,
 * I_DIRTY_DATASYNC and I_DIRTY_PAGES.
 *
 * Four bits define the lifetime of an inode.  Initially, inodes are I_NEW,
 * until that flag is cleared.  I_WILL_FREE, I_FREEING and I_CLEAR are set at
 * various stages of removing an inode.
 *
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 * Two bits are used for locking and completion notification, I_NEW and I_SYNC.
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 *
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 * I_DIRTY_SYNC		Inode is dirty, but doesn't have to be written on
 *			fdatasync().  i_atime is the usual cause.
1694 1695 1696 1697
 * I_DIRTY_DATASYNC	Data-related inode changes pending. We keep track of
 *			these changes separately from I_DIRTY_SYNC so that we
 *			don't have to write inode on fdatasync() when only
 *			mtime has changed in it.
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 * I_DIRTY_PAGES	Inode has dirty pages.  Inode itself may be clean.
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 * I_NEW		Serves as both a mutex and completion notification.
 *			New inodes set I_NEW.  If two processes both create
 *			the same inode, one of them will release its inode and
 *			wait for I_NEW to be released before returning.
 *			Inodes in I_WILL_FREE, I_FREEING or I_CLEAR state can
 *			also cause waiting on I_NEW, without I_NEW actually
 *			being set.  find_inode() uses this to prevent returning
 *			nearly-dead inodes.
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 * I_WILL_FREE		Must be set when calling write_inode_now() if i_count
 *			is zero.  I_FREEING must be set when I_WILL_FREE is
 *			cleared.
 * I_FREEING		Set when inode is about to be freed but still has dirty
 *			pages or buffers attached or the inode itself is still
 *			dirty.
1713 1714
 * I_CLEAR		Added by clear_inode().  In this state the inode is
 *			clean and can be destroyed.  Inode keeps I_FREEING.
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 *
 *			Inodes that are I_WILL_FREE, I_FREEING or I_CLEAR are
 *			prohibited for many purposes.  iget() must wait for
 *			the inode to be completely released, then create it
 *			anew.  Other functions will just ignore such inodes,
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 *			if appropriate.  I_NEW is used for waiting.
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 *
1722 1723 1724 1725
 * I_SYNC		Writeback of inode is running. The bit is set during
 *			data writeback, and cleared with a wakeup on the bit
 *			address once it is done. The bit is also used to pin
 *			the inode in memory for flusher thread.
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 *
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 * I_REFERENCED		Marks the inode as recently references on the LRU list.
 *
 * I_DIO_WAKEUP		Never set.  Only used as a key for wait_on_bit().
 *
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 * Q: What is the difference between I_WILL_FREE and I_FREEING?
 */
1733 1734 1735
#define I_DIRTY_SYNC		(1 << 0)
#define I_DIRTY_DATASYNC	(1 << 1)
#define I_DIRTY_PAGES		(1 << 2)
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#define __I_NEW			3
#define I_NEW			(1 << __I_NEW)
1738 1739 1740
#define I_WILL_FREE		(1 << 4)
#define I_FREEING		(1 << 5)
#define I_CLEAR			(1 << 6)
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#define __I_SYNC		7
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#define I_SYNC			(1 << __I_SYNC)
1743
#define I_REFERENCED		(1 << 8)
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#define __I_DIO_WAKEUP		9
#define I_DIO_WAKEUP		(1 << I_DIO_WAKEUP)
1746
#define I_LINKABLE		(1 << 10)
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#define I_DIRTY (I_DIRTY_SYNC | I_DIRTY_DATASYNC | I_DIRTY_PAGES)

extern void __mark_inode_dirty(struct inode *, int);
static inline void mark_inode_dirty(struct inode *inode)
{
	__mark_inode_dirty(inode, I_DIRTY);
}

static inline void mark_inode_dirty_sync(struct inode *inode)
{
	__mark_inode_dirty(inode, I_DIRTY_SYNC);
}

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Miklos Szeredi 已提交
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extern void inc_nlink(struct inode *inode);
extern void drop_nlink(struct inode *inode);
extern void clear_nlink(struct inode *inode);
extern void set_nlink(struct inode *inode, unsigned int nlink);
1765 1766 1767 1768

static inline void inode_inc_link_count(struct inode *inode)
{
	inc_nlink(inode);
1769 1770 1771
	mark_inode_dirty(inode);
}

1772 1773 1774
static inline void inode_dec_link_count(struct inode *inode)
{
	drop_nlink(inode);
1775 1776 1777
	mark_inode_dirty(inode);
}

1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792
/**
 * inode_inc_iversion - increments i_version
 * @inode: inode that need to be updated
 *
 * Every time the inode is modified, the i_version field will be incremented.
 * The filesystem has to be mounted with i_version flag
 */

static inline void inode_inc_iversion(struct inode *inode)
{
       spin_lock(&inode->i_lock);
       inode->i_version++;
       spin_unlock(&inode->i_lock);
}

1793 1794 1795 1796 1797 1798 1799
enum file_time_flags {
	S_ATIME = 1,
	S_MTIME = 2,
	S_CTIME = 4,
	S_VERSION = 8,
};

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extern void touch_atime(const struct path *);
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static inline void file_accessed(struct file *file)
{
	if (!(file->f_flags & O_NOATIME))
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		touch_atime(&file->f_path);
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}

int sync_inode(struct inode *inode, struct writeback_control *wbc);
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int sync_inode_metadata(struct inode *inode, int wait);
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struct file_system_type {
	const char *name;
	int fs_flags;
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#define FS_REQUIRES_DEV		1 
#define FS_BINARY_MOUNTDATA	2
#define FS_HAS_SUBTYPE		4
1816 1817
#define FS_USERNS_MOUNT		8	/* Can be mounted by userns root */
#define FS_USERNS_DEV_MOUNT	16 /* A userns mount does not imply MNT_NODEV */
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#define FS_RENAME_DOES_D_MOVE	32768	/* FS will handle d_move() during rename() internally. */
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	struct dentry *(*mount) (struct file_system_type *, int,
		       const char *, void *);
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	void (*kill_sb) (struct super_block *);
	struct module *owner;
	struct file_system_type * next;
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	struct hlist_head fs_supers;
1825

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	struct lock_class_key s_lock_key;
1827
	struct lock_class_key s_umount_key;
1828
	struct lock_class_key s_vfs_rename_key;
1829
	struct lock_class_key s_writers_key[SB_FREEZE_LEVELS];
1830 1831 1832

	struct lock_class_key i_lock_key;
	struct lock_class_key i_mutex_key;
1833
	struct lock_class_key i_mutex_dir_key;
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};

1836 1837
#define MODULE_ALIAS_FS(NAME) MODULE_ALIAS("fs-" NAME)

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extern struct dentry *mount_ns(struct file_system_type *fs_type, int flags,
	void *data, int (*fill_super)(struct super_block *, void *, int));
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extern struct dentry *mount_bdev(struct file_system_type *fs_type,
	int flags, const char *dev_name, void *data,
	int (*fill_super)(struct super_block *, void *, int));
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extern struct dentry *mount_single(struct file_system_type *fs_type,
	int flags, void *data,
	int (*fill_super)(struct super_block *, void *, int));
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extern struct dentry *mount_nodev(struct file_system_type *fs_type,
	int flags, void *data,
	int (*fill_super)(struct super_block *, void *, int));
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extern struct dentry *mount_subtree(struct vfsmount *mnt, const char *path);
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void generic_shutdown_super(struct super_block *sb);
void kill_block_super(struct super_block *sb);
void kill_anon_super(struct super_block *sb);
void kill_litter_super(struct super_block *sb);
void deactivate_super(struct super_block *sb);
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1855
void deactivate_locked_super(struct super_block *sb);
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int set_anon_super(struct super_block *s, void *data);
1857 1858
int get_anon_bdev(dev_t *);
void free_anon_bdev(dev_t);
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struct super_block *sget(struct file_system_type *type,
			int (*test)(struct super_block *,void *),
			int (*set)(struct super_block *,void *),
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			int flags, void *data);
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extern struct dentry *mount_pseudo(struct file_system_type *, char *,
1864 1865 1866
	const struct super_operations *ops,
	const struct dentry_operations *dops,
	unsigned long);
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/* Alas, no aliases. Too much hassle with bringing module.h everywhere */
#define fops_get(fops) \
	(((fops) && try_module_get((fops)->owner) ? (fops) : NULL))
#define fops_put(fops) \
	do { if (fops) module_put((fops)->owner); } while(0)
1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883
/*
 * This one is to be used *ONLY* from ->open() instances.
 * fops must be non-NULL, pinned down *and* module dependencies
 * should be sufficient to pin the caller down as well.
 */
#define replace_fops(f, fops) \
	do {	\
		struct file *__file = (f); \
		fops_put(__file->f_op); \
		BUG_ON(!(__file->f_op = (fops))); \
	} while(0)
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Linus Torvalds 已提交
1884 1885 1886

extern int register_filesystem(struct file_system_type *);
extern int unregister_filesystem(struct file_system_type *);
1887 1888
extern struct vfsmount *kern_mount_data(struct file_system_type *, void *data);
#define kern_mount(type) kern_mount_data(type, NULL)
1889
extern void kern_unmount(struct vfsmount *mnt);
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extern int may_umount_tree(struct vfsmount *);
extern int may_umount(struct vfsmount *);
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extern long do_mount(const char *, const char *, const char *, unsigned long, void *);
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1893
extern struct vfsmount *collect_mounts(struct path *);
1894
extern void drop_collected_mounts(struct vfsmount *);
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extern int iterate_mounts(int (*)(struct vfsmount *, void *), void *,
			  struct vfsmount *);
1897
extern int vfs_statfs(struct path *, struct kstatfs *);
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extern int user_statfs(const char __user *, struct kstatfs *);
extern int fd_statfs(int, struct kstatfs *);
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1900
extern int vfs_ustat(dev_t, struct kstatfs *);
1901 1902
extern int freeze_super(struct super_block *super);
extern int thaw_super(struct super_block *super);
1903
extern bool our_mnt(struct vfsmount *mnt);
1904
extern bool fs_fully_visible(struct file_system_type *);
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1905

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1906 1907
extern int current_umask(void);

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1908
/* /sys/fs */
1909
extern struct kobject *fs_kobj;
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1911
#define MAX_RW_COUNT (INT_MAX & PAGE_CACHE_MASK)
1912

L
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#define FLOCK_VERIFY_READ  1
#define FLOCK_VERIFY_WRITE 2

1916
#ifdef CONFIG_FILE_LOCKING
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extern int locks_mandatory_locked(struct inode *);
extern int locks_mandatory_area(int, struct inode *, struct file *, loff_t, size_t);

/*
 * Candidates for mandatory locking have the setgid bit set
 * but no group execute bit -  an otherwise meaningless combination.
 */
1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938

static inline int __mandatory_lock(struct inode *ino)
{
	return (ino->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID;
}

/*
 * ... and these candidates should be on MS_MANDLOCK mounted fs,
 * otherwise these will be advisory locks
 */

static inline int mandatory_lock(struct inode *ino)
{
	return IS_MANDLOCK(ino) && __mandatory_lock(ino);
}
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static inline int locks_verify_locked(struct inode *inode)
{
1942
	if (mandatory_lock(inode))
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		return locks_mandatory_locked(inode);
	return 0;
}

static inline int locks_verify_truncate(struct inode *inode,
				    struct file *filp,
				    loff_t size)
{
1951
	if (inode->i_flock && mandatory_lock(inode))
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		return locks_mandatory_area(
			FLOCK_VERIFY_WRITE, inode, filp,
			size < inode->i_size ? size : inode->i_size,
			(size < inode->i_size ? inode->i_size - size
			 : size - inode->i_size)
		);
	return 0;
}

static inline int break_lease(struct inode *inode, unsigned int mode)
{
	if (inode->i_flock)
		return __break_lease(inode, mode);
	return 0;
}
1967
#else /* !CONFIG_FILE_LOCKING */
1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
static inline int locks_mandatory_locked(struct inode *inode)
{
	return 0;
}

static inline int locks_mandatory_area(int rw, struct inode *inode,
				       struct file *filp, loff_t offset,
				       size_t count)
{
	return 0;
}

static inline int __mandatory_lock(struct inode *inode)
{
	return 0;
}

static inline int mandatory_lock(struct inode *inode)
{
	return 0;
}

static inline int locks_verify_locked(struct inode *inode)
{
	return 0;
}

static inline int locks_verify_truncate(struct inode *inode, struct file *filp,
					size_t size)
{
	return 0;
}

static inline int break_lease(struct inode *inode, unsigned int mode)
{
	return 0;
}

2006
#endif /* CONFIG_FILE_LOCKING */
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2007 2008

/* fs/open.c */
2009
struct audit_names;
2010
struct filename {
2011 2012 2013
	const char		*name;	/* pointer to actual string */
	const __user char	*uptr;	/* original userland pointer */
	struct audit_names	*aname;
2014
	bool			separate; /* should "name" be freed? */
2015
};
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2016

2017
extern long vfs_truncate(struct path *, loff_t);
2018 2019
extern int do_truncate(struct dentry *, loff_t start, unsigned int time_attrs,
		       struct file *filp);
2020 2021
extern int do_fallocate(struct file *file, int mode, loff_t offset,
			loff_t len);
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Jason Uhlenkott 已提交
2022
extern long do_sys_open(int dfd, const char __user *filename, int flags,
2023
			umode_t mode);
2024
extern struct file *file_open_name(struct filename *, int, umode_t);
2025
extern struct file *filp_open(const char *, int, umode_t);
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Al Viro 已提交
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extern struct file *file_open_root(struct dentry *, struct vfsmount *,
				   const char *, int);
2028
extern struct file * dentry_open(const struct path *, int, const struct cred *);
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2029
extern int filp_close(struct file *, fl_owner_t id);
2030 2031 2032

extern struct filename *getname(const char __user *);

2033 2034 2035 2036
enum {
	FILE_CREATED = 1,
	FILE_OPENED = 2
};
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extern int finish_open(struct file *file, struct dentry *dentry,
			int (*open)(struct inode *, struct file *),
			int *opened);
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2040
extern int finish_no_open(struct file *file, struct dentry *dentry);
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2041

2042 2043 2044 2045
/* fs/ioctl.c */

extern int ioctl_preallocate(struct file *filp, void __user *argp);

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2046 2047 2048 2049
/* fs/dcache.c */
extern void __init vfs_caches_init_early(void);
extern void __init vfs_caches_init(unsigned long);

2050 2051
extern struct kmem_cache *names_cachep;

2052 2053
extern void final_putname(struct filename *name);

2054
#define __getname()		kmem_cache_alloc(names_cachep, GFP_KERNEL)
V
Vegard Nossum 已提交
2055
#define __putname(name)		kmem_cache_free(names_cachep, (void *)(name))
L
Linus Torvalds 已提交
2056
#ifndef CONFIG_AUDITSYSCALL
2057
#define putname(name)		final_putname(name)
L
Linus Torvalds 已提交
2058
#else
2059
extern void putname(struct filename *name);
L
Linus Torvalds 已提交
2060 2061
#endif

2062
#ifdef CONFIG_BLOCK
L
Linus Torvalds 已提交
2063
extern int register_blkdev(unsigned int, const char *);
A
Akinobu Mita 已提交
2064
extern void unregister_blkdev(unsigned int, const char *);
L
Linus Torvalds 已提交
2065
extern struct block_device *bdget(dev_t);
2066
extern struct block_device *bdgrab(struct block_device *bdev);
L
Linus Torvalds 已提交
2067 2068 2069
extern void bd_set_size(struct block_device *, loff_t size);
extern void bd_forget(struct inode *inode);
extern void bdput(struct block_device *);
N
Nick Piggin 已提交
2070
extern void invalidate_bdev(struct block_device *);
2071
extern void iterate_bdevs(void (*)(struct block_device *, void *), void *);
N
Nick Piggin 已提交
2072
extern int sync_blockdev(struct block_device *bdev);
A
Al Viro 已提交
2073
extern void kill_bdev(struct block_device *);
N
Nick Piggin 已提交
2074
extern struct super_block *freeze_bdev(struct block_device *);
2075
extern void emergency_thaw_all(void);
N
Nick Piggin 已提交
2076 2077
extern int thaw_bdev(struct block_device *bdev, struct super_block *sb);
extern int fsync_bdev(struct block_device *);
2078
extern int sb_is_blkdev_sb(struct super_block *sb);
2079 2080
#else
static inline void bd_forget(struct inode *inode) {}
2081
static inline int sync_blockdev(struct block_device *bdev) { return 0; }
A
Al Viro 已提交
2082
static inline void kill_bdev(struct block_device *bdev) {}
2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093
static inline void invalidate_bdev(struct block_device *bdev) {}

static inline struct super_block *freeze_bdev(struct block_device *sb)
{
	return NULL;
}

static inline int thaw_bdev(struct block_device *bdev, struct super_block *sb)
{
	return 0;
}
2094 2095 2096 2097

static inline void iterate_bdevs(void (*f)(struct block_device *, void *), void *arg)
{
}
2098 2099 2100 2101 2102

static inline int sb_is_blkdev_sb(struct super_block *sb)
{
	return 0;
}
2103
#endif
2104
extern int sync_filesystem(struct super_block *);
2105
extern const struct file_operations def_blk_fops;
2106 2107
extern const struct file_operations def_chr_fops;
extern const struct file_operations bad_sock_fops;
2108
#ifdef CONFIG_BLOCK
L
Linus Torvalds 已提交
2109
extern int ioctl_by_bdev(struct block_device *, unsigned, unsigned long);
2110
extern int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long);
L
Linus Torvalds 已提交
2111
extern long compat_blkdev_ioctl(struct file *, unsigned, unsigned long);
2112
extern int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder);
2113 2114 2115 2116
extern struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
					       void *holder);
extern struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode,
					      void *holder);
A
Al Viro 已提交
2117
extern void blkdev_put(struct block_device *bdev, fmode_t mode);
2118
#ifdef CONFIG_SYSFS
2119
extern int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);
2120 2121
extern void bd_unlink_disk_holder(struct block_device *bdev,
				  struct gendisk *disk);
2122
#else
2123 2124 2125 2126 2127
static inline int bd_link_disk_holder(struct block_device *bdev,
				      struct gendisk *disk)
{
	return 0;
}
2128 2129 2130 2131
static inline void bd_unlink_disk_holder(struct block_device *bdev,
					 struct gendisk *disk)
{
}
2132
#endif
2133
#endif
L
Linus Torvalds 已提交
2134 2135

/* fs/char_dev.c */
2136
#define CHRDEV_MAJOR_HASH_SIZE	255
L
Linus Torvalds 已提交
2137 2138
extern int alloc_chrdev_region(dev_t *, unsigned, unsigned, const char *);
extern int register_chrdev_region(dev_t, unsigned, const char *);
2139 2140 2141 2142 2143
extern int __register_chrdev(unsigned int major, unsigned int baseminor,
			     unsigned int count, const char *name,
			     const struct file_operations *fops);
extern void __unregister_chrdev(unsigned int major, unsigned int baseminor,
				unsigned int count, const char *name);
L
Linus Torvalds 已提交
2144
extern void unregister_chrdev_region(dev_t, unsigned);
2145
extern void chrdev_show(struct seq_file *,off_t);
L
Linus Torvalds 已提交
2146

2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157
static inline int register_chrdev(unsigned int major, const char *name,
				  const struct file_operations *fops)
{
	return __register_chrdev(major, 0, 256, name, fops);
}

static inline void unregister_chrdev(unsigned int major, const char *name)
{
	__unregister_chrdev(major, 0, 256, name);
}

L
Linus Torvalds 已提交
2158 2159
/* fs/block_dev.c */
#define BDEVNAME_SIZE	32	/* Largest string for a blockdev identifier */
2160
#define BDEVT_SIZE	10	/* Largest string for MAJ:MIN for blkdev */
2161 2162 2163

#ifdef CONFIG_BLOCK
#define BLKDEV_MAJOR_HASH_SIZE	255
L
Linus Torvalds 已提交
2164 2165 2166
extern const char *__bdevname(dev_t, char *buffer);
extern const char *bdevname(struct block_device *bdev, char *buffer);
extern struct block_device *lookup_bdev(const char *);
2167
extern void blkdev_show(struct seq_file *,off_t);
2168

2169 2170 2171
#else
#define BLKDEV_MAJOR_HASH_SIZE	0
#endif
L
Linus Torvalds 已提交
2172 2173 2174 2175 2176 2177 2178

extern void init_special_inode(struct inode *, umode_t, dev_t);

/* Invalid inode operations -- fs/bad_inode.c */
extern void make_bad_inode(struct inode *);
extern int is_bad_inode(struct inode *);

2179
#ifdef CONFIG_BLOCK
L
Linus Torvalds 已提交
2180 2181 2182 2183 2184 2185 2186 2187 2188 2189
/*
 * return READ, READA, or WRITE
 */
#define bio_rw(bio)		((bio)->bi_rw & (RW_MASK | RWA_MASK))

/*
 * return data direction, READ or WRITE
 */
#define bio_data_dir(bio)	((bio)->bi_rw & 1)

2190 2191
extern void check_disk_size_change(struct gendisk *disk,
				   struct block_device *bdev);
2192
extern int revalidate_disk(struct gendisk *);
L
Linus Torvalds 已提交
2193
extern int check_disk_change(struct block_device *);
2194
extern int __invalidate_device(struct block_device *, bool);
L
Linus Torvalds 已提交
2195
extern int invalidate_partition(struct gendisk *, int);
2196
#endif
L
Linus Torvalds 已提交
2197 2198
unsigned long invalidate_mapping_pages(struct address_space *mapping,
					pgoff_t start, pgoff_t end);
2199

L
Linus Torvalds 已提交
2200 2201 2202 2203
static inline void invalidate_remote_inode(struct inode *inode)
{
	if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
	    S_ISLNK(inode->i_mode))
2204
		invalidate_mapping_pages(inode->i_mapping, 0, -1);
L
Linus Torvalds 已提交
2205 2206 2207 2208 2209 2210 2211 2212
}
extern int invalidate_inode_pages2(struct address_space *mapping);
extern int invalidate_inode_pages2_range(struct address_space *mapping,
					 pgoff_t start, pgoff_t end);
extern int write_inode_now(struct inode *, int);
extern int filemap_fdatawrite(struct address_space *);
extern int filemap_flush(struct address_space *);
extern int filemap_fdatawait(struct address_space *);
2213 2214
extern int filemap_fdatawait_range(struct address_space *, loff_t lstart,
				   loff_t lend);
L
Linus Torvalds 已提交
2215 2216 2217
extern int filemap_write_and_wait(struct address_space *mapping);
extern int filemap_write_and_wait_range(struct address_space *mapping,
				        loff_t lstart, loff_t lend);
2218 2219
extern int __filemap_fdatawrite_range(struct address_space *mapping,
				loff_t start, loff_t end, int sync_mode);
2220 2221
extern int filemap_fdatawrite_range(struct address_space *mapping,
				loff_t start, loff_t end);
2222

2223 2224 2225
extern int vfs_fsync_range(struct file *file, loff_t start, loff_t end,
			   int datasync);
extern int vfs_fsync(struct file *file, int datasync);
2226
extern int generic_write_sync(struct file *file, loff_t pos, loff_t count);
L
Linus Torvalds 已提交
2227 2228
extern void emergency_sync(void);
extern void emergency_remount(void);
2229
#ifdef CONFIG_BLOCK
L
Linus Torvalds 已提交
2230
extern sector_t bmap(struct inode *, sector_t);
2231
#endif
L
Linus Torvalds 已提交
2232
extern int notify_change(struct dentry *, struct iattr *);
2233
extern int inode_permission(struct inode *, int);
2234
extern int generic_permission(struct inode *, int);
L
Linus Torvalds 已提交
2235

2236 2237 2238 2239 2240
static inline bool execute_ok(struct inode *inode)
{
	return (inode->i_mode & S_IXUGO) || S_ISDIR(inode->i_mode);
}

A
Al Viro 已提交
2241 2242
static inline struct inode *file_inode(struct file *f)
{
2243
	return f->f_inode;
A
Al Viro 已提交
2244 2245
}

2246 2247 2248 2249 2250 2251 2252
static inline void file_start_write(struct file *file)
{
	if (!S_ISREG(file_inode(file)->i_mode))
		return;
	__sb_start_write(file_inode(file)->i_sb, SB_FREEZE_WRITE, true);
}

2253 2254 2255 2256 2257 2258 2259
static inline bool file_start_write_trylock(struct file *file)
{
	if (!S_ISREG(file_inode(file)->i_mode))
		return true;
	return __sb_start_write(file_inode(file)->i_sb, SB_FREEZE_WRITE, false);
}

2260 2261 2262 2263 2264 2265 2266
static inline void file_end_write(struct file *file)
{
	if (!S_ISREG(file_inode(file)->i_mode))
		return;
	__sb_end_write(file_inode(file)->i_sb, SB_FREEZE_WRITE);
}

2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288
/*
 * get_write_access() gets write permission for a file.
 * put_write_access() releases this write permission.
 * This is used for regular files.
 * We cannot support write (and maybe mmap read-write shared) accesses and
 * MAP_DENYWRITE mmappings simultaneously. The i_writecount field of an inode
 * can have the following values:
 * 0: no writers, no VM_DENYWRITE mappings
 * < 0: (-i_writecount) vm_area_structs with VM_DENYWRITE set exist
 * > 0: (i_writecount) users are writing to the file.
 *
 * Normally we operate on that counter with atomic_{inc,dec} and it's safe
 * except for the cases where we don't hold i_writecount yet. Then we need to
 * use {get,deny}_write_access() - these functions check the sign and refuse
 * to do the change if sign is wrong.
 */
static inline int get_write_access(struct inode *inode)
{
	return atomic_inc_unless_negative(&inode->i_writecount) ? 0 : -ETXTBSY;
}
static inline int deny_write_access(struct file *file)
{
A
Al Viro 已提交
2289
	struct inode *inode = file_inode(file);
2290 2291
	return atomic_dec_unless_positive(&inode->i_writecount) ? 0 : -ETXTBSY;
}
L
Linus Torvalds 已提交
2292 2293 2294 2295 2296 2297 2298
static inline void put_write_access(struct inode * inode)
{
	atomic_dec(&inode->i_writecount);
}
static inline void allow_write_access(struct file *file)
{
	if (file)
A
Al Viro 已提交
2299
		atomic_inc(&file_inode(file)->i_writecount);
L
Linus Torvalds 已提交
2300
}
M
Mimi Zohar 已提交
2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320
#ifdef CONFIG_IMA
static inline void i_readcount_dec(struct inode *inode)
{
	BUG_ON(!atomic_read(&inode->i_readcount));
	atomic_dec(&inode->i_readcount);
}
static inline void i_readcount_inc(struct inode *inode)
{
	atomic_inc(&inode->i_readcount);
}
#else
static inline void i_readcount_dec(struct inode *inode)
{
	return;
}
static inline void i_readcount_inc(struct inode *inode)
{
	return;
}
#endif
U
Ulrich Drepper 已提交
2321
extern int do_pipe_flags(int *, int);
L
Linus Torvalds 已提交
2322

M
Mimi Zohar 已提交
2323
extern int kernel_read(struct file *, loff_t, char *, unsigned long);
2324
extern ssize_t kernel_write(struct file *, const char *, size_t, loff_t);
L
Linus Torvalds 已提交
2325 2326 2327 2328
extern struct file * open_exec(const char *);
 
/* fs/dcache.c -- generic fs support functions */
extern int is_subdir(struct dentry *, struct dentry *);
2329
extern int path_is_under(struct path *, struct path *);
L
Linus Torvalds 已提交
2330 2331 2332 2333

#include <linux/err.h>

/* needed for stackable file system support */
2334
extern loff_t default_llseek(struct file *file, loff_t offset, int whence);
L
Linus Torvalds 已提交
2335

2336
extern loff_t vfs_llseek(struct file *file, loff_t offset, int whence);
L
Linus Torvalds 已提交
2337

2338
extern int inode_init_always(struct super_block *, struct inode *);
L
Linus Torvalds 已提交
2339
extern void inode_init_once(struct inode *);
2340
extern void address_space_init_once(struct address_space *mapping);
A
Al Viro 已提交
2341
extern void ihold(struct inode * inode);
L
Linus Torvalds 已提交
2342 2343 2344 2345
extern void iput(struct inode *);
extern struct inode * igrab(struct inode *);
extern ino_t iunique(struct super_block *, ino_t);
extern int inode_needs_sync(struct inode *inode);
2346
extern int generic_delete_inode(struct inode *inode);
2347 2348 2349 2350
static inline int generic_drop_inode(struct inode *inode)
{
	return !inode->i_nlink || inode_unhashed(inode);
}
L
Linus Torvalds 已提交
2351

2352 2353 2354
extern struct inode *ilookup5_nowait(struct super_block *sb,
		unsigned long hashval, int (*test)(struct inode *, void *),
		void *data);
L
Linus Torvalds 已提交
2355 2356 2357 2358 2359 2360
extern struct inode *ilookup5(struct super_block *sb, unsigned long hashval,
		int (*test)(struct inode *, void *), void *data);
extern struct inode *ilookup(struct super_block *sb, unsigned long ino);

extern struct inode * iget5_locked(struct super_block *, unsigned long, int (*test)(struct inode *, void *), int (*set)(struct inode *, void *), void *);
extern struct inode * iget_locked(struct super_block *, unsigned long);
A
Al Viro 已提交
2361 2362
extern int insert_inode_locked4(struct inode *, unsigned long, int (*test)(struct inode *, void *), void *);
extern int insert_inode_locked(struct inode *);
2363 2364 2365 2366 2367
#ifdef CONFIG_DEBUG_LOCK_ALLOC
extern void lockdep_annotate_inode_mutex_key(struct inode *inode);
#else
static inline void lockdep_annotate_inode_mutex_key(struct inode *inode) { };
#endif
L
Linus Torvalds 已提交
2368
extern void unlock_new_inode(struct inode *);
2369
extern unsigned int get_next_ino(void);
L
Linus Torvalds 已提交
2370 2371

extern void __iget(struct inode * inode);
2372
extern void iget_failed(struct inode *);
2373
extern void clear_inode(struct inode *);
C
Christoph Hellwig 已提交
2374
extern void __destroy_inode(struct inode *);
2375 2376
extern struct inode *new_inode_pseudo(struct super_block *sb);
extern struct inode *new_inode(struct super_block *sb);
2377
extern void free_inode_nonrcu(struct inode *inode);
2378
extern int should_remove_suid(struct dentry *);
2379
extern int file_remove_suid(struct file *);
L
Linus Torvalds 已提交
2380 2381

extern void __insert_inode_hash(struct inode *, unsigned long hashval);
2382 2383
static inline void insert_inode_hash(struct inode *inode)
{
L
Linus Torvalds 已提交
2384 2385
	__insert_inode_hash(inode, inode->i_ino);
}
2386 2387 2388 2389 2390 2391 2392 2393

extern void __remove_inode_hash(struct inode *);
static inline void remove_inode_hash(struct inode *inode)
{
	if (!inode_unhashed(inode))
		__remove_inode_hash(inode);
}

2394
extern void inode_sb_list_add(struct inode *inode);
L
Linus Torvalds 已提交
2395

2396
#ifdef CONFIG_BLOCK
L
Linus Torvalds 已提交
2397 2398
extern void submit_bio(int, struct bio *);
extern int bdev_read_only(struct block_device *);
2399
#endif
L
Linus Torvalds 已提交
2400 2401 2402 2403 2404 2405
extern int set_blocksize(struct block_device *, int);
extern int sb_set_blocksize(struct super_block *, int);
extern int sb_min_blocksize(struct super_block *, int);

extern int generic_file_mmap(struct file *, struct vm_area_struct *);
extern int generic_file_readonly_mmap(struct file *, struct vm_area_struct *);
2406 2407
extern int generic_file_remap_pages(struct vm_area_struct *, unsigned long addr,
		unsigned long size, pgoff_t pgoff);
L
Linus Torvalds 已提交
2408 2409
extern int file_read_actor(read_descriptor_t * desc, struct page *page, unsigned long offset, unsigned long size);
int generic_write_checks(struct file *file, loff_t *pos, size_t *count, int isblk);
2410
extern ssize_t generic_file_aio_read(struct kiocb *, const struct iovec *, unsigned long, loff_t);
2411 2412
extern ssize_t __generic_file_aio_write(struct kiocb *, const struct iovec *, unsigned long,
		loff_t *);
2413
extern ssize_t generic_file_aio_write(struct kiocb *, const struct iovec *, unsigned long, loff_t);
L
Linus Torvalds 已提交
2414 2415 2416 2417 2418 2419
extern ssize_t generic_file_direct_write(struct kiocb *, const struct iovec *,
		unsigned long *, loff_t, loff_t *, size_t, size_t);
extern ssize_t generic_file_buffered_write(struct kiocb *, const struct iovec *,
		unsigned long, loff_t, loff_t *, size_t, ssize_t);
extern ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos);
extern ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos);
2420 2421
extern int generic_segment_checks(const struct iovec *iov,
		unsigned long *nr_segs, size_t *count, int access_flags);
A
Andrew Morton 已提交
2422

2423 2424 2425
/* fs/block_dev.c */
extern ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov,
				unsigned long nr_segs, loff_t pos);
2426 2427
extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
			int datasync);
A
Al Viro 已提交
2428
extern void block_sync_page(struct page *page);
2429

A
Andrew Morton 已提交
2430
/* fs/splice.c */
2431
extern ssize_t generic_file_splice_read(struct file *, loff_t *,
A
Andrew Morton 已提交
2432
		struct pipe_inode_info *, size_t, unsigned int);
2433 2434
extern ssize_t default_file_splice_read(struct file *, loff_t *,
		struct pipe_inode_info *, size_t, unsigned int);
A
Andrew Morton 已提交
2435
extern ssize_t generic_file_splice_write(struct pipe_inode_info *,
2436
		struct file *, loff_t *, size_t, unsigned int);
A
Andrew Morton 已提交
2437
extern ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe,
2438
		struct file *out, loff_t *, size_t len, unsigned int flags);
A
Andrew Morton 已提交
2439

L
Linus Torvalds 已提交
2440 2441
extern void
file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping);
2442 2443
extern loff_t noop_llseek(struct file *file, loff_t offset, int whence);
extern loff_t no_llseek(struct file *file, loff_t offset, int whence);
J
Jie Liu 已提交
2444
extern loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize);
2445
extern loff_t generic_file_llseek(struct file *file, loff_t offset, int whence);
A
Andi Kleen 已提交
2446
extern loff_t generic_file_llseek_size(struct file *file, loff_t offset,
2447
		int whence, loff_t maxsize, loff_t eof);
A
Al Viro 已提交
2448 2449
extern loff_t fixed_size_llseek(struct file *file, loff_t offset,
		int whence, loff_t size);
L
Linus Torvalds 已提交
2450 2451 2452
extern int generic_file_open(struct inode * inode, struct file * filp);
extern int nonseekable_open(struct inode * inode, struct file * filp);

2453
#ifdef CONFIG_FS_XIP
2454 2455
extern ssize_t xip_file_read(struct file *filp, char __user *buf, size_t len,
			     loff_t *ppos);
2456
extern int xip_file_mmap(struct file * file, struct vm_area_struct * vma);
2457 2458
extern ssize_t xip_file_write(struct file *filp, const char __user *buf,
			      size_t len, loff_t *ppos);
2459
extern int xip_truncate_page(struct address_space *mapping, loff_t from);
2460 2461 2462 2463 2464
#else
static inline int xip_truncate_page(struct address_space *mapping, loff_t from)
{
	return 0;
}
2465 2466
#endif

2467
#ifdef CONFIG_BLOCK
2468 2469
typedef void (dio_submit_t)(int rw, struct bio *bio, struct inode *inode,
			    loff_t file_offset);
L
Linus Torvalds 已提交
2470 2471

enum {
2472 2473 2474 2475 2476
	/* need locking between buffered and direct access */
	DIO_LOCKING	= 0x01,

	/* filesystem does not support filling holes */
	DIO_SKIP_HOLES	= 0x02,
L
Linus Torvalds 已提交
2477 2478
};

2479 2480 2481 2482 2483 2484
void dio_end_io(struct bio *bio, int error);

ssize_t __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
	struct block_device *bdev, const struct iovec *iov, loff_t offset,
	unsigned long nr_segs, get_block_t get_block, dio_iodone_t end_io,
	dio_submit_t submit_io,	int flags);
2485

L
Linus Torvalds 已提交
2486
static inline ssize_t blockdev_direct_IO(int rw, struct kiocb *iocb,
2487 2488
		struct inode *inode, const struct iovec *iov, loff_t offset,
		unsigned long nr_segs, get_block_t get_block)
L
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{
2490 2491
	return __blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
				    offset, nr_segs, get_block, NULL, NULL,
2492
				    DIO_LOCKING | DIO_SKIP_HOLES);
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}
2494
#endif
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2496 2497 2498
void inode_dio_wait(struct inode *inode);
void inode_dio_done(struct inode *inode);

2499
extern const struct file_operations generic_ro_fops;
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#define special_file(m) (S_ISCHR(m)||S_ISBLK(m)||S_ISFIFO(m)||S_ISSOCK(m))

extern int vfs_readlink(struct dentry *, char __user *, int, const char *);
extern int page_readlink(struct dentry *, char __user *, int);
2505 2506
extern void *page_follow_link_light(struct dentry *, struct nameidata *);
extern void page_put_link(struct dentry *, struct nameidata *, void *);
2507
extern int __page_symlink(struct inode *inode, const char *symname, int len,
2508
		int nofs);
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extern int page_symlink(struct inode *inode, const char *symname, int len);
2510
extern const struct inode_operations page_symlink_inode_operations;
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extern void kfree_put_link(struct dentry *, struct nameidata *, void *);
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extern int generic_readlink(struct dentry *, char __user *, int);
extern void generic_fillattr(struct inode *, struct kstat *);
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J. Bruce Fields 已提交
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int vfs_getattr_nosec(struct path *path, struct kstat *stat);
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extern int vfs_getattr(struct path *, struct kstat *);
2516
void __inode_add_bytes(struct inode *inode, loff_t bytes);
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void inode_add_bytes(struct inode *inode, loff_t bytes);
2518
void __inode_sub_bytes(struct inode *inode, loff_t bytes);
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void inode_sub_bytes(struct inode *inode, loff_t bytes);
loff_t inode_get_bytes(struct inode *inode);
void inode_set_bytes(struct inode *inode, loff_t bytes);

extern int vfs_readdir(struct file *, filldir_t, void *);
2524
extern int iterate_dir(struct file *, struct dir_context *);
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2526 2527
extern int vfs_stat(const char __user *, struct kstat *);
extern int vfs_lstat(const char __user *, struct kstat *);
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extern int vfs_fstat(unsigned int, struct kstat *);
2529
extern int vfs_fstatat(int , const char __user *, struct kstat *, int);
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2531 2532
extern int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd,
		    unsigned long arg);
2533
extern int __generic_block_fiemap(struct inode *inode,
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Josef Bacik 已提交
2534 2535 2536
				  struct fiemap_extent_info *fieinfo,
				  loff_t start, loff_t len,
				  get_block_t *get_block);
2537 2538 2539
extern int generic_block_fiemap(struct inode *inode,
				struct fiemap_extent_info *fieinfo, u64 start,
				u64 len, get_block_t *get_block);
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2541 2542
extern void get_filesystem(struct file_system_type *fs);
extern void put_filesystem(struct file_system_type *fs);
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2543 2544
extern struct file_system_type *get_fs_type(const char *name);
extern struct super_block *get_super(struct block_device *);
2545
extern struct super_block *get_super_thawed(struct block_device *);
2546
extern struct super_block *get_active_super(struct block_device *bdev);
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extern void drop_super(struct super_block *sb);
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extern void iterate_supers(void (*)(struct super_block *, void *), void *);
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extern void iterate_supers_type(struct file_system_type *,
			        void (*)(struct super_block *, void *), void *);
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2551 2552 2553 2554

extern int dcache_dir_open(struct inode *, struct file *);
extern int dcache_dir_close(struct inode *, struct file *);
extern loff_t dcache_dir_lseek(struct file *, loff_t, int);
2555
extern int dcache_readdir(struct file *, struct dir_context *);
2556
extern int simple_setattr(struct dentry *, struct iattr *);
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extern int simple_getattr(struct vfsmount *, struct dentry *, struct kstat *);
2558
extern int simple_statfs(struct dentry *, struct kstatfs *);
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2559
extern int simple_open(struct inode *inode, struct file *file);
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2560 2561 2562 2563
extern int simple_link(struct dentry *, struct inode *, struct dentry *);
extern int simple_unlink(struct inode *, struct dentry *);
extern int simple_rmdir(struct inode *, struct dentry *);
extern int simple_rename(struct inode *, struct dentry *, struct inode *, struct dentry *);
2564
extern int noop_fsync(struct file *, loff_t, loff_t, int);
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extern int simple_empty(struct dentry *);
extern int simple_readpage(struct file *file, struct page *page);
2567 2568 2569 2570 2571 2572
extern int simple_write_begin(struct file *file, struct address_space *mapping,
			loff_t pos, unsigned len, unsigned flags,
			struct page **pagep, void **fsdata);
extern int simple_write_end(struct file *file, struct address_space *mapping,
			loff_t pos, unsigned len, unsigned copied,
			struct page *page, void *fsdata);
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Al Viro 已提交
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extern struct inode *alloc_anon_inode(struct super_block *);
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extern struct dentry *simple_lookup(struct inode *, struct dentry *, unsigned int flags);
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extern ssize_t generic_read_dir(struct file *, char __user *, size_t, loff_t *);
2577
extern const struct file_operations simple_dir_operations;
2578
extern const struct inode_operations simple_dir_inode_operations;
2579
struct tree_descr { char *name; const struct file_operations *ops; int mode; };
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struct dentry *d_alloc_name(struct dentry *, const char *);
2581
extern int simple_fill_super(struct super_block *, unsigned long, struct tree_descr *);
2582
extern int simple_pin_fs(struct file_system_type *, struct vfsmount **mount, int *count);
L
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2583 2584
extern void simple_release_fs(struct vfsmount **mount, int *count);

2585 2586
extern ssize_t simple_read_from_buffer(void __user *to, size_t count,
			loff_t *ppos, const void *from, size_t available);
2587 2588
extern ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos,
		const void __user *from, size_t count);
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2589

2590
extern int generic_file_fsync(struct file *, loff_t, loff_t, int);
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Al Viro 已提交
2591

2592 2593
extern int generic_check_addressable(unsigned, u64);

2594
#ifdef CONFIG_MIGRATION
2595
extern int buffer_migrate_page(struct address_space *,
2596 2597
				struct page *, struct page *,
				enum migrate_mode);
2598 2599 2600 2601
#else
#define buffer_migrate_page NULL
#endif

N
npiggin@suse.de 已提交
2602 2603
extern int inode_change_ok(const struct inode *, struct iattr *);
extern int inode_newsize_ok(const struct inode *, loff_t offset);
C
Christoph Hellwig 已提交
2604
extern void setattr_copy(struct inode *inode, const struct iattr *attr);
L
Linus Torvalds 已提交
2605

2606
extern int file_update_time(struct file *file);
L
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2607

2608
extern int generic_show_options(struct seq_file *m, struct dentry *root);
2609
extern void save_mount_options(struct super_block *sb, char *options);
2610
extern void replace_mount_options(struct super_block *sb, char *options);
2611

L
Linus Torvalds 已提交
2612 2613 2614 2615
static inline ino_t parent_ino(struct dentry *dentry)
{
	ino_t res;

N
Nick Piggin 已提交
2616 2617 2618 2619
	/*
	 * Don't strictly need d_lock here? If the parent ino could change
	 * then surely we'd have a deeper race in the caller?
	 */
L
Linus Torvalds 已提交
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	spin_lock(&dentry->d_lock);
	res = dentry->d_parent->d_inode->i_ino;
	spin_unlock(&dentry->d_lock);
	return res;
}

/* Transaction based IO helpers */

/*
 * An argresp is stored in an allocated page and holds the
 * size of the argument or response, along with its content
 */
struct simple_transaction_argresp {
	ssize_t size;
	char data[0];
};

#define SIMPLE_TRANSACTION_LIMIT (PAGE_SIZE - sizeof(struct simple_transaction_argresp))

char *simple_transaction_get(struct file *file, const char __user *buf,
				size_t size);
ssize_t simple_transaction_read(struct file *file, char __user *buf,
				size_t size, loff_t *pos);
int simple_transaction_release(struct inode *inode, struct file *file);

2645
void simple_transaction_set(struct file *file, size_t n);
L
Linus Torvalds 已提交
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2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668
/*
 * simple attribute files
 *
 * These attributes behave similar to those in sysfs:
 *
 * Writing to an attribute immediately sets a value, an open file can be
 * written to multiple times.
 *
 * Reading from an attribute creates a buffer from the value that might get
 * read with multiple read calls. When the attribute has been read
 * completely, no further read calls are possible until the file is opened
 * again.
 *
 * All attributes contain a text representation of a numeric value
 * that are accessed with the get() and set() functions.
 */
#define DEFINE_SIMPLE_ATTRIBUTE(__fops, __get, __set, __fmt)		\
static int __fops ## _open(struct inode *inode, struct file *file)	\
{									\
	__simple_attr_check_format(__fmt, 0ull);			\
	return simple_attr_open(inode, file, __get, __set, __fmt);	\
}									\
2669
static const struct file_operations __fops = {				\
2670 2671
	.owner	 = THIS_MODULE,						\
	.open	 = __fops ## _open,					\
2672
	.release = simple_attr_release,					\
2673 2674
	.read	 = simple_attr_read,					\
	.write	 = simple_attr_write,					\
2675
	.llseek	 = generic_file_llseek,					\
2676 2677
};

2678 2679
static inline __printf(1, 2)
void __simple_attr_check_format(const char *fmt, ...)
2680 2681 2682 2683 2684
{
	/* don't do anything, just let the compiler check the arguments; */
}

int simple_attr_open(struct inode *inode, struct file *file,
2685
		     int (*get)(void *, u64 *), int (*set)(void *, u64),
2686
		     const char *fmt);
2687
int simple_attr_release(struct inode *inode, struct file *file);
2688 2689 2690 2691 2692
ssize_t simple_attr_read(struct file *file, char __user *buf,
			 size_t len, loff_t *ppos);
ssize_t simple_attr_write(struct file *file, const char __user *buf,
			  size_t len, loff_t *ppos);

A
Alexey Dobriyan 已提交
2693
struct ctl_table;
2694
int proc_nr_files(struct ctl_table *table, int write,
2695
		  void __user *buffer, size_t *lenp, loff_t *ppos);
2696 2697
int proc_nr_dentry(struct ctl_table *table, int write,
		  void __user *buffer, size_t *lenp, loff_t *ppos);
2698 2699
int proc_nr_inodes(struct ctl_table *table, int write,
		   void __user *buffer, size_t *lenp, loff_t *ppos);
2700
int __init get_filesystem_list(char *buf);
2701

N
Namhyung Kim 已提交
2702
#define __FMODE_EXEC		((__force int) FMODE_EXEC)
2703 2704
#define __FMODE_NONOTIFY	((__force int) FMODE_NONOTIFY)

A
Al Viro 已提交
2705
#define ACC_MODE(x) ("\004\002\006\006"[(x)&O_ACCMODE])
E
Eric Paris 已提交
2706
#define OPEN_FMODE(flag) ((__force fmode_t)(((flag + 1) & O_ACCMODE) | \
2707
					    (flag & __FMODE_NONOTIFY)))
A
Al Viro 已提交
2708

A
Al Viro 已提交
2709
static inline int is_sxid(umode_t mode)
2710 2711 2712 2713 2714 2715
{
	return (mode & S_ISUID) || ((mode & S_ISGID) && (mode & S_IXGRP));
}

static inline void inode_has_no_xattr(struct inode *inode)
{
A
Al Viro 已提交
2716
	if (!is_sxid(inode->i_mode) && (inode->i_sb->s_flags & MS_NOSEC))
2717 2718 2719
		inode->i_flags |= S_NOSEC;
}

2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749
static inline bool dir_emit(struct dir_context *ctx,
			    const char *name, int namelen,
			    u64 ino, unsigned type)
{
	return ctx->actor(ctx, name, namelen, ctx->pos, ino, type) == 0;
}
static inline bool dir_emit_dot(struct file *file, struct dir_context *ctx)
{
	return ctx->actor(ctx, ".", 1, ctx->pos,
			  file->f_path.dentry->d_inode->i_ino, DT_DIR) == 0;
}
static inline bool dir_emit_dotdot(struct file *file, struct dir_context *ctx)
{
	return ctx->actor(ctx, "..", 2, ctx->pos,
			  parent_ino(file->f_path.dentry), DT_DIR) == 0;
}
static inline bool dir_emit_dots(struct file *file, struct dir_context *ctx)
{
	if (ctx->pos == 0) {
		if (!dir_emit_dot(file, ctx))
			return false;
		ctx->pos = 1;
	}
	if (ctx->pos == 1) {
		if (!dir_emit_dotdot(file, ctx))
			return false;
		ctx->pos = 2;
	}
	return true;
}
A
Al Viro 已提交
2750 2751 2752 2753 2754 2755
static inline bool dir_relax(struct inode *inode)
{
	mutex_unlock(&inode->i_mutex);
	mutex_lock(&inode->i_mutex);
	return !IS_DEADDIR(inode);
}
2756

L
Linus Torvalds 已提交
2757
#endif /* _LINUX_FS_H */