fs.h 92.8 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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struct iov_iter;
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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)

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/* File needs atomic accesses to f_pos */
#define FMODE_ATOMIC_POS	((__force fmode_t)0x8000)
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/* Write access to underlying fs */
#define FMODE_WRITER		((__force fmode_t)0x10000)
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/* Has read method(s) */
#define FMODE_CAN_READ          ((__force fmode_t)0x20000)
/* Has write method(s) */
#define FMODE_CAN_WRITE         ((__force fmode_t)0x40000)
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/* 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 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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/*
 * "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 *, struct iov_iter *iter, loff_t offset);
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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 *, unsigned long,
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					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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	atomic_t		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 */
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	unsigned long		nrshadows;	/* number of shadow entries */
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	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.
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 *
 * If i_mmap_writable is negative, no new writable mappings are allowed. You
 * can only deny writable mappings, if none exists right now.
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 */
static inline int mapping_writably_mapped(struct address_space *mapping)
{
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	return atomic_read(&mapping->i_mmap_writable) > 0;
}

static inline int mapping_map_writable(struct address_space *mapping)
{
	return atomic_inc_unless_negative(&mapping->i_mmap_writable) ?
		0 : -EPERM;
}

static inline void mapping_unmap_writable(struct address_space *mapping)
{
	atomic_dec(&mapping->i_mmap_writable);
}

static inline int mapping_deny_writable(struct address_space *mapping)
{
	return atomic_dec_unless_positive(&mapping->i_mmap_writable) ?
		0 : -EBUSY;
}

static inline void mapping_allow_writable(struct address_space *mapping)
{
	atomic_inc(&mapping->i_mmap_writable);
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}

/*
 * 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

537 538
	const struct inode_operations	*i_op;
	struct super_block	*i_sb;
539
	struct address_space	*i_mapping;
540

541 542 543
#ifdef CONFIG_SECURITY
	void			*i_security;
#endif
544

545 546
	/* 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;
	};
558
	dev_t			i_rdev;
559
	loff_t			i_size;
560 561 562
	struct timespec		i_atime;
	struct timespec		i_mtime;
	struct timespec		i_ctime;
563 564
	spinlock_t		i_lock;	/* i_blocks, i_bytes, maybe i_size */
	unsigned short          i_bytes;
565
	unsigned int		i_blkbits;
566 567 568 569 570 571 572 573 574
	blkcnt_t		i_blocks;

#ifdef __NEED_I_SIZE_ORDERED
	seqcount_t		i_size_seqcount;
#endif

	/* Misc */
	unsigned long		i_state;
	struct mutex		i_mutex;
575

576 577
	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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582
	union {
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		struct hlist_head	i_dentry;
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584 585
		struct rcu_head		i_rcu;
	};
586
	u64			i_version;
587
	atomic_t		i_count;
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	atomic_t		i_dio_count;
589
	atomic_t		i_writecount;
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#ifdef CONFIG_IMA
	atomic_t		i_readcount; /* struct files open RO */
#endif
593
	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;
600 601
	union {
		struct pipe_inode_info	*i_pipe;
602
		struct block_device	*i_bdev;
603
		struct cdev		*i_cdev;
604
	};
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	__u32			i_generation;

608 609
#ifdef CONFIG_FSNOTIFY
	__u32			i_fsnotify_mask; /* all events this inode cares about */
610
	struct hlist_head	i_fsnotify_marks;
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#endif

613
	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
627 628 629 630
 * 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
633
 * 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,
641
	I_MUTEX_NONDIR2
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};

644 645 646
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
}

680 681 682 683 684
/*
 * 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)
688
	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);
692
	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
}

702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726
/* 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 */
741 742
	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 */
743
	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
754
					   there are only # of pages ahead */
755

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	unsigned int ra_pages;		/* Maximum readahead window */
757
	unsigned int mmap_miss;		/* Cache miss stat for mmap accesses */
758
	loff_t prev_pos;		/* Cache last read() position */
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};

761 762 763 764 765
/*
 * Check if @index falls in the readahead windows.
 */
static inline int ra_has_index(struct file_ra_state *ra, pgoff_t index)
{
766 767
	return (index >= ra->start &&
		index <  ra->start + ra->size);
768 769
}

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struct file {
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	union {
772
		struct llist_node	fu_llist;
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		struct rcu_head 	fu_rcuhead;
	} f_u;
775 776
	struct path		f_path;
#define f_dentry	f_path.dentry
777
	struct inode		*f_inode;	/* cached value */
778
	const struct file_operations	*f_op;
779 780

	/*
781
	 * Protects f_ep_links, f_flags.
782 783 784
	 * 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;
787
	fmode_t			f_mode;
788
	struct mutex		f_pos_lock;
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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;

794
	u64			f_version;
795
#ifdef CONFIG_SECURITY
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	void			*f_security;
797
#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;
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} __attribute__((aligned(4)));	/* lest something weird decides that 2 is OK */
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809 810 811 812 813 814 815
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;
}
821
#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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#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
831
#define MAX_LFS_FILESIZE 	((loff_t)0x7fffffffffffffffLL)
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#endif

#define FL_POSIX	1
#define FL_FLOCK	2
836
#define FL_DELEG	4	/* NFSv4 delegation */
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#define FL_ACCESS	8	/* not trying to lock, just looking */
838
#define FL_EXISTS	16	/* when unlocking, test for existence */
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#define FL_LEASE	32	/* lease held on this file */
840
#define FL_CLOSE	64	/* unlock on close */
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#define FL_SLEEP	128	/* A blocking lock */
842 843
#define FL_DOWNGRADE_PENDING	256 /* Lease is being downgraded */
#define FL_UNLOCK_PENDING	512 /* Lease is being broken */
844
#define FL_OFDLCK	1024	/* lock is "owned" by struct file */
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846 847 848 849 850 851
/*
 * Special return value from posix_lock_file() and vfs_lock_file() for
 * asynchronous locking.
 */
#define FILE_LOCK_DEFERRED 1

852
/* legacy typedef, should eventually be removed */
853
typedef void *fl_owner_t;
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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 *);
862
	unsigned long (*lm_owner_key)(struct file_lock *);
863 864
	void (*lm_get_owner)(struct file_lock *, struct file_lock *);
	void (*lm_put_owner)(struct file_lock *);
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	void (*lm_notify)(struct file_lock *);	/* unblock callback */
866
	int (*lm_grant)(struct file_lock *, int);
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	bool (*lm_break)(struct file_lock *);
868
	int (*lm_change)(struct file_lock **, int, struct list_head *);
869
	void (*lm_setup)(struct file_lock *, void **);
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};

872 873 874 875
struct lock_manager {
	struct list_head list;
};

876 877
struct net;
void locks_start_grace(struct net *, struct lock_manager *);
878
void locks_end_grace(struct lock_manager *);
879
int locks_in_grace(struct net *);
880

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

884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901
/*
 * 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  */
904
	struct hlist_node fl_link;	/* node in global lists */
L
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	struct list_head fl_block;	/* circular list of blocked processes */
	fl_owner_t fl_owner;
907
	unsigned int fl_flags;
908
	unsigned char fl_type;
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	unsigned int fl_pid;
910
	int fl_link_cpu;		/* what cpu's list is this on? */
911
	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 */
918 919 920
	/* for lease breaks: */
	unsigned long fl_break_time;
	unsigned long fl_downgrade_time;
L
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921

922
	const struct file_lock_operations *fl_ops;	/* Callbacks for filesystems */
923
	const struct lock_manager_operations *fl_lmops;	/* Callbacks for lockmanagers */
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924 925
	union {
		struct nfs_lock_info	nfs_fl;
926
		struct nfs4_lock_info	nfs4_fl;
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927 928 929 930
		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>

943 944 945
extern void send_sigio(struct fown_struct *fown, int fd, int band);

#ifdef CONFIG_FILE_LOCKING
946
extern int fcntl_getlk(struct file *, unsigned int, struct flock __user *);
947 948
extern int fcntl_setlk(unsigned int, struct file *, unsigned int,
			struct flock __user *);
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949 950

#if BITS_PER_LONG == 32
951
extern int fcntl_getlk64(struct file *, unsigned int, struct flock64 __user *);
952 953
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 */
960
void locks_free_lock(struct file_lock *fl);
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961
extern void locks_init_lock(struct file_lock *);
962
extern struct file_lock * locks_alloc_lock(void);
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963
extern void locks_copy_lock(struct file_lock *, struct file_lock *);
964
extern void locks_copy_conflock(struct file_lock *, struct file_lock *);
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965
extern void locks_remove_posix(struct file *, fl_owner_t);
966
extern void locks_remove_file(struct file *);
967
extern void locks_release_private(struct file_lock *);
968
extern void posix_test_lock(struct file *, struct file_lock *);
969
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 *);
971
extern int posix_unblock_lock(struct file_lock *);
972
extern int vfs_test_lock(struct file *, struct file_lock *);
973
extern int vfs_lock_file(struct file *, unsigned int, struct file_lock *, struct file_lock *);
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974
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);
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976
extern int __break_lease(struct inode *inode, unsigned int flags, unsigned int type);
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extern void lease_get_mtime(struct inode *, struct timespec *time);
978 979
extern int generic_setlease(struct file *, long, struct file_lock **, void **priv);
extern int vfs_setlease(struct file *, long, struct file_lock **, void **);
980
extern int lease_modify(struct file_lock **, int, struct list_head *);
981
#else /* !CONFIG_FILE_LOCKING */
982 983
static inline int fcntl_getlk(struct file *file, unsigned int cmd,
			      struct flock __user *user)
984 985 986 987 988 989 990 991 992 993
{
	return -EINVAL;
}

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

994
#if BITS_PER_LONG == 32
995 996
static inline int fcntl_getlk64(struct file *file, unsigned int cmd,
				struct flock64 __user *user)
997 998 999 1000 1001 1002 1003 1004 1005
{
	return -EINVAL;
}

static inline int fcntl_setlk64(unsigned int fd, struct file *file,
				unsigned int cmd, struct flock64 __user *user)
{
	return -EACCES;
}
1006
#endif
1007 1008
static inline int fcntl_setlease(unsigned int fd, struct file *filp, long arg)
{
1009
	return -EINVAL;
1010 1011 1012 1013
}

static inline int fcntl_getlease(struct file *filp)
{
1014
	return F_UNLCK;
1015 1016 1017 1018 1019 1020 1021
}

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

1022
static inline void locks_copy_conflock(struct file_lock *new, struct file_lock *fl)
1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036
{
	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;
}

1037
static inline void locks_remove_file(struct file *filp)
1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057
{
	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;
}

1058
static inline int posix_unblock_lock(struct file_lock *waiter)
1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084
{
	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;
}

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static inline int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
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{
	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,
1096
				    struct file_lock **flp, void **priv)
1097 1098 1099 1100 1101
{
	return -EINVAL;
}

static inline int vfs_setlease(struct file *filp, long arg,
1102
			       struct file_lock **lease, void **priv)
1103 1104 1105 1106
{
	return -EINVAL;
}

1107 1108
static inline int lease_modify(struct file_lock **before, int arg,
			       struct list_head *dispose)
1109 1110 1111
{
	return -EINVAL;
}
1112 1113
#endif /* !CONFIG_FILE_LOCKING */

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struct fasync_struct {
1116 1117 1118 1119 1120 1121
	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 **);
1128 1129 1130 1131 1132
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);

1136 1137
extern void __f_setown(struct file *filp, struct pid *, enum pid_type, int force);
extern void f_setown(struct file *filp, unsigned long arg, int force);
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extern void f_delown(struct file *filp);
1139
extern pid_t f_getown(struct file *filp);
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extern int send_sigurg(struct fown_struct *fown);

1142 1143
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 */
1151 1152
#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 */
1185 1186
	unsigned char		s_blocksize_bits;
	unsigned long		s_blocksize;
1187
	loff_t			s_maxbytes;	/* Max file size */
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	struct file_system_type	*s_type;
1189
	const struct super_operations	*s_op;
1190
	const struct dquot_operations	*dq_op;
1191
	const struct quotactl_ops	*s_qcop;
1192
	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;
1199
#ifdef CONFIG_SECURITY
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	void                    *s_security;
1201
#endif
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	const struct xattr_handler **s_xattr;
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	struct list_head	s_inodes;	/* all inodes */
1205
	struct hlist_bl_head	s_anon;		/* anonymous dentries for (nfs) exporting */
1206
	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;
1209
	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 */

1213
	struct sb_writers	s_writers;
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	char s_id[32];				/* Informational name */
1216
	u8 s_uuid[16];				/* UUID */
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	void 			*s_fs_info;	/* Filesystem private info */
1219
	unsigned int		s_max_links;
1220
	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.
	 */
1230
	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;
1237 1238 1239 1240 1241

	/*
	 * 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 */
1244 1245 1246 1247 1248

	/*
	 * Saved pool identifier for cleancache (-1 means none)
	 */
	int cleancache_poolid;
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	struct shrinker s_shrink;	/* per-sb shrinker handle */
1251

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	/* Number of inodes with nlink == 0 but still referenced */
	atomic_long_t s_remove_count;

1255 1256
	/* Being remounted read-only */
	int s_readonly_remount;
1257 1258 1259

	/* AIO completions deferred from interrupt context */
	struct workqueue_struct *s_dio_done_wq;
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	struct hlist_head s_pins;
1261 1262 1263 1264 1265 1266 1267

	/*
	 * 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);
1389

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/*
 * VFS helper functions..
 */
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extern int vfs_create(struct inode *, struct dentry *, umode_t, bool);
1394
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);
1396
extern int vfs_symlink(struct inode *, struct dentry *, const char *);
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extern int vfs_link(struct dentry *, struct inode *, struct dentry *, struct inode **);
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extern int vfs_rmdir(struct inode *, struct dentry *);
1399
extern int vfs_unlink(struct inode *, struct dentry *, struct inode **);
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extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *, struct inode **, unsigned int);
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/*
 * VFS dentry helper functions.
 */
extern void dentry_unhash(struct dentry *dentry);

1407 1408 1409
/*
 * VFS file helper functions.
 */
1410
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 */
1419 1420
	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.
 */
1448
typedef int (*filldir_t)(void *, const char *, int, loff_t, u64, unsigned);
1449
struct dir_context {
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	const filldir_t actor;
1451
	loff_t pos;
1452
};
1453

1454
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

1462 1463
struct iov_iter;

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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 *);
1469 1470
	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);
1471 1472
	ssize_t (*read_iter) (struct kiocb *, struct iov_iter *);
	ssize_t (*write_iter) (struct kiocb *, struct iov_iter *);
1473
	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 *);
1479
	int (*flush) (struct file *, fl_owner_t id);
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	int (*release) (struct inode *, struct file *);
1481
	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 *);
1489 1490
	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);
1491
	int (*setlease)(struct file *, long, struct file_lock **, void **);
1492 1493
	long (*fallocate)(struct file *file, int mode, loff_t offset,
			  loff_t len);
1494
	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);
1499
	void * (*follow_link) (struct dentry *, struct nameidata *);
1500
	int (*permission) (struct inode *, int);
1501
	struct posix_acl * (*get_acl)(struct inode *, int);
1502 1503 1504 1505

	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 *);
1510
	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 *);
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	int (*rename2) (struct inode *, struct dentry *,
			struct inode *, struct dentry *, unsigned int);
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	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);
1525
	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);
1529
	int (*tmpfile) (struct inode *, struct dentry *, umode_t);
1530
	int (*set_acl)(struct inode *, struct posix_acl *, int);
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	/* WARNING: probably going away soon, do not use! */
	int (*dentry_open)(struct dentry *, struct file *, const struct cred *);
1534
} ____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,
1539
			      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 *);

1552
   	void (*dirty_inode) (struct inode *, int flags);
1553
	int (*write_inode) (struct inode *, struct writeback_control *wbc);
1554
	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);
1558 1559
	int (*freeze_fs) (struct super_block *);
	int (*unfreeze_fs) (struct super_block *);
1560
	int (*statfs) (struct dentry *, struct kstatfs *);
L
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1561
	int (*remount_fs) (struct super_block *, int *, char *);
1562
	void (*umount_begin) (struct super_block *);
L
Linus Torvalds 已提交
1563

1564
	int (*show_options)(struct seq_file *, struct dentry *);
1565
	int (*show_devname)(struct seq_file *, struct dentry *);
1566
	int (*show_path)(struct seq_file *, struct dentry *);
1567
	int (*show_stats)(struct seq_file *, struct dentry *);
1568
#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);
1571
#endif
1572
	int (*bdev_try_to_free_page)(struct super_block*, struct page*, gfp_t);
1573 1574
	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)

J
Joern Engel 已提交
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/*
1632
 * Inode state bits.  Protected by inode->i_lock
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1633 1634 1635 1636 1637 1638 1639 1640
 *
 * 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.
 *
C
Christoph Hellwig 已提交
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 * Two bits are used for locking and completion notification, I_NEW and I_SYNC.
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1642
 *
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1643 1644
 * I_DIRTY_SYNC		Inode is dirty, but doesn't have to be written on
 *			fdatasync().  i_atime is the usual cause.
1645 1646 1647 1648
 * 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.
1664 1665
 * I_CLEAR		Added by clear_inode().  In this state the inode is
 *			clean and can be destroyed.  Inode keeps I_FREEING.
J
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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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 *
1673 1674 1675 1676
 * 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?
 */
1684 1685 1686
#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)
1689 1690 1691
#define I_WILL_FREE		(1 << 4)
#define I_FREEING		(1 << 5)
#define I_CLEAR			(1 << 6)
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Christoph Hellwig 已提交
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#define __I_SYNC		7
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Joern Engel 已提交
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#define I_SYNC			(1 << __I_SYNC)
1694
#define I_REFERENCED		(1 << 8)
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Christoph Hellwig 已提交
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#define __I_DIO_WAKEUP		9
#define I_DIO_WAKEUP		(1 << I_DIO_WAKEUP)
1697
#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);
1716 1717 1718 1719

static inline void inode_inc_link_count(struct inode *inode)
{
	inc_nlink(inode);
1720 1721 1722
	mark_inode_dirty(inode);
}

1723 1724 1725
static inline void inode_dec_link_count(struct inode *inode)
{
	drop_nlink(inode);
1726 1727 1728
	mark_inode_dirty(inode);
}

1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743
/**
 * 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);
}

1744 1745 1746 1747 1748 1749 1750
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
1767 1768
#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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1769
#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;
1776

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Ingo Molnar 已提交
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	struct lock_class_key s_lock_key;
1778
	struct lock_class_key s_umount_key;
1779
	struct lock_class_key s_vfs_rename_key;
1780
	struct lock_class_key s_writers_key[SB_FREEZE_LEVELS];
1781 1782 1783

	struct lock_class_key i_lock_key;
	struct lock_class_key i_mutex_key;
1784
	struct lock_class_key i_mutex_dir_key;
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};

1787 1788
#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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1800
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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1806
void deactivate_locked_super(struct super_block *sb);
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int set_anon_super(struct super_block *s, void *data);
1808 1809
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 *),
D
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1813
			int flags, void *data);
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1814
extern struct dentry *mount_pseudo(struct file_system_type *, char *,
1815 1816 1817
	const struct super_operations *ops,
	const struct dentry_operations *dops,
	unsigned long);
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Linus Torvalds 已提交
1818 1819 1820 1821 1822 1823

/* 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)
1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834
/*
 * 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)
L
Linus Torvalds 已提交
1835 1836 1837

extern int register_filesystem(struct file_system_type *);
extern int unregister_filesystem(struct file_system_type *);
1838 1839
extern struct vfsmount *kern_mount_data(struct file_system_type *, void *data);
#define kern_mount(type) kern_mount_data(type, NULL)
1840
extern void kern_unmount(struct vfsmount *mnt);
L
Linus Torvalds 已提交
1841 1842
extern int may_umount_tree(struct vfsmount *);
extern int may_umount(struct vfsmount *);
1843 1844
extern long do_mount(const char *, const char __user *,
		     const char *, unsigned long, void *);
A
Al Viro 已提交
1845
extern struct vfsmount *collect_mounts(struct path *);
1846
extern void drop_collected_mounts(struct vfsmount *);
A
Al Viro 已提交
1847 1848
extern int iterate_mounts(int (*)(struct vfsmount *, void *), void *,
			  struct vfsmount *);
1849
extern int vfs_statfs(struct path *, struct kstatfs *);
A
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1850 1851
extern int user_statfs(const char __user *, struct kstatfs *);
extern int fd_statfs(int, struct kstatfs *);
A
Al Viro 已提交
1852
extern int vfs_ustat(dev_t, struct kstatfs *);
1853 1854
extern int freeze_super(struct super_block *super);
extern int thaw_super(struct super_block *super);
1855
extern bool our_mnt(struct vfsmount *mnt);
1856
extern bool fs_fully_visible(struct file_system_type *);
L
Linus Torvalds 已提交
1857

A
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1858 1859
extern int current_umask(void);

1860 1861 1862
extern void ihold(struct inode * inode);
extern void iput(struct inode *);

A
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1863
static inline struct inode *file_inode(const struct file *f)
1864 1865 1866 1867
{
	return f->f_inode;
}

M
Miklos Szeredi 已提交
1868
/* /sys/fs */
1869
extern struct kobject *fs_kobj;
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1870

1871
#define MAX_RW_COUNT (INT_MAX & PAGE_CACHE_MASK)
1872

L
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1873 1874 1875
#define FLOCK_VERIFY_READ  1
#define FLOCK_VERIFY_WRITE 2

1876
#ifdef CONFIG_FILE_LOCKING
1877
extern int locks_mandatory_locked(struct file *);
L
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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.
 */
1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898

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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1900
static inline int locks_verify_locked(struct file *file)
L
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1901
{
1902 1903
	if (mandatory_lock(file_inode(file)))
		return locks_mandatory_locked(file);
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1904 1905 1906 1907 1908 1909 1910
	return 0;
}

static inline int locks_verify_truncate(struct inode *inode,
				    struct file *filp,
				    loff_t size)
{
1911
	if (inode->i_flock && mandatory_lock(inode))
L
Linus Torvalds 已提交
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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)
{
1923 1924 1925 1926 1927 1928
	/*
	 * Since this check is lockless, we must ensure that any refcounts
	 * taken are done before checking inode->i_flock. Otherwise, we could
	 * end up racing with tasks trying to set a new lease on this file.
	 */
	smp_mb();
L
Linus Torvalds 已提交
1929
	if (inode->i_flock)
J
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1930
		return __break_lease(inode, mode, FL_LEASE);
L
Linus Torvalds 已提交
1931 1932
	return 0;
}
J
J. Bruce Fields 已提交
1933 1934 1935

static inline int break_deleg(struct inode *inode, unsigned int mode)
{
1936 1937 1938 1939 1940 1941
	/*
	 * Since this check is lockless, we must ensure that any refcounts
	 * taken are done before checking inode->i_flock. Otherwise, we could
	 * end up racing with tasks trying to set a new lease on this file.
	 */
	smp_mb();
J
J. Bruce Fields 已提交
1942 1943
	if (inode->i_flock)
		return __break_lease(inode, mode, FL_DELEG);
L
Linus Torvalds 已提交
1944 1945
	return 0;
}
J
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1946

1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968
static inline int try_break_deleg(struct inode *inode, struct inode **delegated_inode)
{
	int ret;

	ret = break_deleg(inode, O_WRONLY|O_NONBLOCK);
	if (ret == -EWOULDBLOCK && delegated_inode) {
		*delegated_inode = inode;
		ihold(inode);
	}
	return ret;
}

static inline int break_deleg_wait(struct inode **delegated_inode)
{
	int ret;

	ret = break_deleg(*delegated_inode, O_WRONLY);
	iput(*delegated_inode);
	*delegated_inode = NULL;
	return ret;
}

1969
#else /* !CONFIG_FILE_LOCKING */
1970
static inline int locks_mandatory_locked(struct file *file)
1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991
{
	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;
}

1992
static inline int locks_verify_locked(struct file *file)
1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
{
	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;
}

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J. Bruce Fields 已提交
2008 2009 2010 2011
static inline int break_deleg(struct inode *inode, unsigned int mode)
{
	return 0;
}
2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023

static inline int try_break_deleg(struct inode *inode, struct inode **delegated_inode)
{
	return 0;
}

static inline int break_deleg_wait(struct inode **delegated_inode)
{
	BUG();
	return 0;
}

2024
#endif /* CONFIG_FILE_LOCKING */
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Linus Torvalds 已提交
2025 2026

/* fs/open.c */
2027
struct audit_names;
2028
struct filename {
2029 2030 2031
	const char		*name;	/* pointer to actual string */
	const __user char	*uptr;	/* original userland pointer */
	struct audit_names	*aname;
2032
	bool			separate; /* should "name" be freed? */
2033
};
L
Linus Torvalds 已提交
2034

2035
extern long vfs_truncate(struct path *, loff_t);
2036 2037
extern int do_truncate(struct dentry *, loff_t start, unsigned int time_attrs,
		       struct file *filp);
2038 2039
extern int do_fallocate(struct file *file, int mode, loff_t offset,
			loff_t len);
J
Jason Uhlenkott 已提交
2040
extern long do_sys_open(int dfd, const char __user *filename, int flags,
2041
			umode_t mode);
2042
extern struct file *file_open_name(struct filename *, int, umode_t);
2043
extern struct file *filp_open(const char *, int, umode_t);
A
Al Viro 已提交
2044 2045
extern struct file *file_open_root(struct dentry *, struct vfsmount *,
				   const char *, int);
M
Miklos Szeredi 已提交
2046
extern int vfs_open(const struct path *, struct file *, const struct cred *);
2047
extern struct file * dentry_open(const struct path *, int, const struct cred *);
L
Linus Torvalds 已提交
2048
extern int filp_close(struct file *, fl_owner_t id);
2049 2050

extern struct filename *getname(const char __user *);
2051
extern struct filename *getname_kernel(const char *);
2052

2053 2054 2055 2056
enum {
	FILE_CREATED = 1,
	FILE_OPENED = 2
};
A
Al Viro 已提交
2057 2058 2059
extern int finish_open(struct file *file, struct dentry *dentry,
			int (*open)(struct inode *, struct file *),
			int *opened);
A
Al Viro 已提交
2060
extern int finish_no_open(struct file *file, struct dentry *dentry);
L
Linus Torvalds 已提交
2061

2062 2063 2064 2065
/* fs/ioctl.c */

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

L
Linus Torvalds 已提交
2066 2067 2068 2069
/* fs/dcache.c */
extern void __init vfs_caches_init_early(void);
extern void __init vfs_caches_init(unsigned long);

2070 2071
extern struct kmem_cache *names_cachep;

2072 2073
extern void final_putname(struct filename *name);

2074
#define __getname()		kmem_cache_alloc(names_cachep, GFP_KERNEL)
V
Vegard Nossum 已提交
2075
#define __putname(name)		kmem_cache_free(names_cachep, (void *)(name))
L
Linus Torvalds 已提交
2076
#ifndef CONFIG_AUDITSYSCALL
2077
#define putname(name)		final_putname(name)
L
Linus Torvalds 已提交
2078
#else
2079
extern void putname(struct filename *name);
L
Linus Torvalds 已提交
2080 2081
#endif

2082
#ifdef CONFIG_BLOCK
L
Linus Torvalds 已提交
2083
extern int register_blkdev(unsigned int, const char *);
A
Akinobu Mita 已提交
2084
extern void unregister_blkdev(unsigned int, const char *);
L
Linus Torvalds 已提交
2085
extern struct block_device *bdget(dev_t);
2086
extern struct block_device *bdgrab(struct block_device *bdev);
L
Linus Torvalds 已提交
2087 2088 2089
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
2090
extern void invalidate_bdev(struct block_device *);
2091
extern void iterate_bdevs(void (*)(struct block_device *, void *), void *);
N
Nick Piggin 已提交
2092
extern int sync_blockdev(struct block_device *bdev);
A
Al Viro 已提交
2093
extern void kill_bdev(struct block_device *);
N
Nick Piggin 已提交
2094
extern struct super_block *freeze_bdev(struct block_device *);
2095
extern void emergency_thaw_all(void);
N
Nick Piggin 已提交
2096 2097
extern int thaw_bdev(struct block_device *bdev, struct super_block *sb);
extern int fsync_bdev(struct block_device *);
2098
extern int sb_is_blkdev_sb(struct super_block *sb);
2099 2100
#else
static inline void bd_forget(struct inode *inode) {}
2101
static inline int sync_blockdev(struct block_device *bdev) { return 0; }
A
Al Viro 已提交
2102
static inline void kill_bdev(struct block_device *bdev) {}
2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113
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;
}
2114 2115 2116 2117

static inline void iterate_bdevs(void (*f)(struct block_device *, void *), void *arg)
{
}
2118 2119 2120 2121 2122

static inline int sb_is_blkdev_sb(struct super_block *sb)
{
	return 0;
}
2123
#endif
2124
extern int sync_filesystem(struct super_block *);
2125
extern const struct file_operations def_blk_fops;
2126 2127
extern const struct file_operations def_chr_fops;
extern const struct file_operations bad_sock_fops;
2128
#ifdef CONFIG_BLOCK
L
Linus Torvalds 已提交
2129
extern int ioctl_by_bdev(struct block_device *, unsigned, unsigned long);
2130
extern int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long);
L
Linus Torvalds 已提交
2131
extern long compat_blkdev_ioctl(struct file *, unsigned, unsigned long);
2132
extern int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder);
2133 2134 2135 2136
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
2137
extern void blkdev_put(struct block_device *bdev, fmode_t mode);
2138
#ifdef CONFIG_SYSFS
2139
extern int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);
2140 2141
extern void bd_unlink_disk_holder(struct block_device *bdev,
				  struct gendisk *disk);
2142
#else
2143 2144 2145 2146 2147
static inline int bd_link_disk_holder(struct block_device *bdev,
				      struct gendisk *disk)
{
	return 0;
}
2148 2149 2150 2151
static inline void bd_unlink_disk_holder(struct block_device *bdev,
					 struct gendisk *disk)
{
}
2152
#endif
2153
#endif
L
Linus Torvalds 已提交
2154 2155

/* fs/char_dev.c */
2156
#define CHRDEV_MAJOR_HASH_SIZE	255
L
Linus Torvalds 已提交
2157 2158
extern int alloc_chrdev_region(dev_t *, unsigned, unsigned, const char *);
extern int register_chrdev_region(dev_t, unsigned, const char *);
2159 2160 2161 2162 2163
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
2164
extern void unregister_chrdev_region(dev_t, unsigned);
2165
extern void chrdev_show(struct seq_file *,off_t);
L
Linus Torvalds 已提交
2166

2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177
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
2178 2179
/* fs/block_dev.c */
#define BDEVNAME_SIZE	32	/* Largest string for a blockdev identifier */
2180
#define BDEVT_SIZE	10	/* Largest string for MAJ:MIN for blkdev */
2181 2182 2183

#ifdef CONFIG_BLOCK
#define BLKDEV_MAJOR_HASH_SIZE	255
L
Linus Torvalds 已提交
2184 2185 2186
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 *);
2187
extern void blkdev_show(struct seq_file *,off_t);
2188

2189 2190 2191
#else
#define BLKDEV_MAJOR_HASH_SIZE	0
#endif
L
Linus Torvalds 已提交
2192 2193 2194 2195 2196 2197 2198

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 *);

2199
#ifdef CONFIG_BLOCK
L
Linus Torvalds 已提交
2200 2201 2202 2203 2204 2205 2206 2207 2208 2209
/*
 * 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)

2210 2211
extern void check_disk_size_change(struct gendisk *disk,
				   struct block_device *bdev);
2212
extern int revalidate_disk(struct gendisk *);
L
Linus Torvalds 已提交
2213
extern int check_disk_change(struct block_device *);
2214
extern int __invalidate_device(struct block_device *, bool);
L
Linus Torvalds 已提交
2215
extern int invalidate_partition(struct gendisk *, int);
2216
#endif
L
Linus Torvalds 已提交
2217 2218
unsigned long invalidate_mapping_pages(struct address_space *mapping,
					pgoff_t start, pgoff_t end);
2219

L
Linus Torvalds 已提交
2220 2221 2222 2223
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))
2224
		invalidate_mapping_pages(inode->i_mapping, 0, -1);
L
Linus Torvalds 已提交
2225 2226 2227 2228 2229 2230 2231 2232
}
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 *);
2233 2234
extern int filemap_fdatawait_range(struct address_space *, loff_t lstart,
				   loff_t lend);
L
Linus Torvalds 已提交
2235 2236 2237
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);
2238 2239
extern int __filemap_fdatawrite_range(struct address_space *mapping,
				loff_t start, loff_t end, int sync_mode);
2240 2241
extern int filemap_fdatawrite_range(struct address_space *mapping,
				loff_t start, loff_t end);
2242

2243 2244 2245
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);
2246 2247 2248 2249 2250 2251 2252
static inline int generic_write_sync(struct file *file, loff_t pos, loff_t count)
{
	if (!(file->f_flags & O_DSYNC) && !IS_SYNC(file->f_mapping->host))
		return 0;
	return vfs_fsync_range(file, pos, pos + count - 1,
			       (file->f_flags & __O_SYNC) ? 0 : 1);
}
L
Linus Torvalds 已提交
2253 2254
extern void emergency_sync(void);
extern void emergency_remount(void);
2255
#ifdef CONFIG_BLOCK
L
Linus Torvalds 已提交
2256
extern sector_t bmap(struct inode *, sector_t);
2257
#endif
2258
extern int notify_change(struct dentry *, struct iattr *, struct inode **);
2259
extern int inode_permission(struct inode *, int);
2260
extern int __inode_permission(struct inode *, int);
2261
extern int generic_permission(struct inode *, int);
L
Linus Torvalds 已提交
2262

2263 2264 2265 2266 2267
static inline bool execute_ok(struct inode *inode)
{
	return (inode->i_mode & S_IXUGO) || S_ISDIR(inode->i_mode);
}

2268 2269 2270 2271 2272 2273 2274
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);
}

2275 2276 2277 2278 2279 2280 2281
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);
}

2282 2283 2284 2285 2286 2287 2288
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);
}

2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310
/*
 * 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
2311
	struct inode *inode = file_inode(file);
2312 2313
	return atomic_dec_unless_positive(&inode->i_writecount) ? 0 : -ETXTBSY;
}
L
Linus Torvalds 已提交
2314 2315 2316 2317 2318 2319 2320
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
2321
		atomic_inc(&file_inode(file)->i_writecount);
L
Linus Torvalds 已提交
2322
}
2323 2324 2325 2326 2327
static inline bool inode_is_open_for_write(const struct inode *inode)
{
	return atomic_read(&inode->i_writecount) > 0;
}

M
Mimi Zohar 已提交
2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347
#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
2348
extern int do_pipe_flags(int *, int);
L
Linus Torvalds 已提交
2349

M
Mimi Zohar 已提交
2350
extern int kernel_read(struct file *, loff_t, char *, unsigned long);
2351
extern ssize_t kernel_write(struct file *, const char *, size_t, loff_t);
A
Al Viro 已提交
2352
extern ssize_t __kernel_write(struct file *, const char *, size_t, loff_t *);
L
Linus Torvalds 已提交
2353 2354 2355 2356
extern struct file * open_exec(const char *);
 
/* fs/dcache.c -- generic fs support functions */
extern int is_subdir(struct dentry *, struct dentry *);
2357
extern int path_is_under(struct path *, struct path *);
L
Linus Torvalds 已提交
2358 2359 2360 2361

#include <linux/err.h>

/* needed for stackable file system support */
2362
extern loff_t default_llseek(struct file *file, loff_t offset, int whence);
L
Linus Torvalds 已提交
2363

2364
extern loff_t vfs_llseek(struct file *file, loff_t offset, int whence);
L
Linus Torvalds 已提交
2365

2366
extern int inode_init_always(struct super_block *, struct inode *);
L
Linus Torvalds 已提交
2367
extern void inode_init_once(struct inode *);
2368
extern void address_space_init_once(struct address_space *mapping);
L
Linus Torvalds 已提交
2369 2370 2371
extern struct inode * igrab(struct inode *);
extern ino_t iunique(struct super_block *, ino_t);
extern int inode_needs_sync(struct inode *inode);
2372
extern int generic_delete_inode(struct inode *inode);
2373 2374 2375 2376
static inline int generic_drop_inode(struct inode *inode)
{
	return !inode->i_nlink || inode_unhashed(inode);
}
L
Linus Torvalds 已提交
2377

2378 2379 2380
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
2381 2382 2383 2384 2385 2386
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
2387 2388
extern int insert_inode_locked4(struct inode *, unsigned long, int (*test)(struct inode *, void *), void *);
extern int insert_inode_locked(struct inode *);
2389 2390 2391 2392 2393
#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
2394
extern void unlock_new_inode(struct inode *);
2395
extern unsigned int get_next_ino(void);
L
Linus Torvalds 已提交
2396 2397

extern void __iget(struct inode * inode);
2398
extern void iget_failed(struct inode *);
2399
extern void clear_inode(struct inode *);
C
Christoph Hellwig 已提交
2400
extern void __destroy_inode(struct inode *);
2401 2402
extern struct inode *new_inode_pseudo(struct super_block *sb);
extern struct inode *new_inode(struct super_block *sb);
2403
extern void free_inode_nonrcu(struct inode *inode);
2404
extern int should_remove_suid(struct dentry *);
2405
extern int file_remove_suid(struct file *);
L
Linus Torvalds 已提交
2406 2407

extern void __insert_inode_hash(struct inode *, unsigned long hashval);
2408 2409
static inline void insert_inode_hash(struct inode *inode)
{
L
Linus Torvalds 已提交
2410 2411
	__insert_inode_hash(inode, inode->i_ino);
}
2412 2413 2414 2415 2416 2417 2418 2419

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

2420
extern void inode_sb_list_add(struct inode *inode);
L
Linus Torvalds 已提交
2421

2422
#ifdef CONFIG_BLOCK
L
Linus Torvalds 已提交
2423 2424
extern void submit_bio(int, struct bio *);
extern int bdev_read_only(struct block_device *);
2425
#endif
L
Linus Torvalds 已提交
2426 2427 2428 2429 2430 2431
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 *);
2432 2433
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
2434
int generic_write_checks(struct file *file, loff_t *pos, size_t *count, int isblk);
A
Al Viro 已提交
2435
extern ssize_t generic_file_read_iter(struct kiocb *, struct iov_iter *);
2436 2437
extern ssize_t __generic_file_write_iter(struct kiocb *, struct iov_iter *);
extern ssize_t generic_file_write_iter(struct kiocb *, struct iov_iter *);
A
Al Viro 已提交
2438
extern ssize_t generic_file_direct_write(struct kiocb *, struct iov_iter *, loff_t);
2439
extern ssize_t generic_perform_write(struct file *, struct iov_iter *, loff_t);
L
Linus Torvalds 已提交
2440 2441
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);
2442 2443
extern ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos);
extern ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos);
A
Andrew Morton 已提交
2444

2445
/* fs/block_dev.c */
2446
extern ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from);
2447 2448
extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
			int datasync);
A
Al Viro 已提交
2449
extern void block_sync_page(struct page *page);
2450

A
Andrew Morton 已提交
2451
/* fs/splice.c */
2452
extern ssize_t generic_file_splice_read(struct file *, loff_t *,
A
Andrew Morton 已提交
2453
		struct pipe_inode_info *, size_t, unsigned int);
2454 2455
extern ssize_t default_file_splice_read(struct file *, loff_t *,
		struct pipe_inode_info *, size_t, unsigned int);
A
Al Viro 已提交
2456
extern ssize_t iter_file_splice_write(struct pipe_inode_info *,
2457
		struct file *, loff_t *, size_t, unsigned int);
A
Andrew Morton 已提交
2458
extern ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe,
2459
		struct file *out, loff_t *, size_t len, unsigned int flags);
2460 2461 2462
extern long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
		loff_t *opos, size_t len, unsigned int flags);

A
Andrew Morton 已提交
2463

L
Linus Torvalds 已提交
2464 2465
extern void
file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping);
2466 2467
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
2468
extern loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize);
2469
extern loff_t generic_file_llseek(struct file *file, loff_t offset, int whence);
A
Andi Kleen 已提交
2470
extern loff_t generic_file_llseek_size(struct file *file, loff_t offset,
2471
		int whence, loff_t maxsize, loff_t eof);
A
Al Viro 已提交
2472 2473
extern loff_t fixed_size_llseek(struct file *file, loff_t offset,
		int whence, loff_t size);
L
Linus Torvalds 已提交
2474 2475 2476
extern int generic_file_open(struct inode * inode, struct file * filp);
extern int nonseekable_open(struct inode * inode, struct file * filp);

2477
#ifdef CONFIG_FS_XIP
2478 2479
extern ssize_t xip_file_read(struct file *filp, char __user *buf, size_t len,
			     loff_t *ppos);
2480
extern int xip_file_mmap(struct file * file, struct vm_area_struct * vma);
2481 2482
extern ssize_t xip_file_write(struct file *filp, const char __user *buf,
			      size_t len, loff_t *ppos);
2483
extern int xip_truncate_page(struct address_space *mapping, loff_t from);
2484 2485 2486 2487 2488
#else
static inline int xip_truncate_page(struct address_space *mapping, loff_t from)
{
	return 0;
}
2489 2490
#endif

2491
#ifdef CONFIG_BLOCK
2492 2493
typedef void (dio_submit_t)(int rw, struct bio *bio, struct inode *inode,
			    loff_t file_offset);
L
Linus Torvalds 已提交
2494 2495

enum {
2496 2497 2498 2499 2500
	/* need locking between buffered and direct access */
	DIO_LOCKING	= 0x01,

	/* filesystem does not support filling holes */
	DIO_SKIP_HOLES	= 0x02,
2501 2502 2503

	/* filesystem can handle aio writes beyond i_size */
	DIO_ASYNC_EXTEND = 0x04,
L
Linus Torvalds 已提交
2504 2505
};

2506 2507 2508
void dio_end_io(struct bio *bio, int error);

ssize_t __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
2509 2510
	struct block_device *bdev, struct iov_iter *iter, loff_t offset,
	get_block_t get_block, dio_iodone_t end_io,
2511
	dio_submit_t submit_io,	int flags);
2512

L
Linus Torvalds 已提交
2513
static inline ssize_t blockdev_direct_IO(int rw, struct kiocb *iocb,
2514 2515
		struct inode *inode, struct iov_iter *iter, loff_t offset,
		get_block_t get_block)
L
Linus Torvalds 已提交
2516
{
2517 2518
	return __blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iter,
				    offset, get_block, NULL, NULL,
2519
				    DIO_LOCKING | DIO_SKIP_HOLES);
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2520
}
2521
#endif
L
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2522

2523 2524 2525
void inode_dio_wait(struct inode *inode);
void inode_dio_done(struct inode *inode);

2526 2527 2528
extern void inode_set_flags(struct inode *inode, unsigned int flags,
			    unsigned int mask);

2529
extern const struct file_operations generic_ro_fops;
L
Linus Torvalds 已提交
2530 2531 2532

#define special_file(m) (S_ISCHR(m)||S_ISBLK(m)||S_ISFIFO(m)||S_ISSOCK(m))

A
Al Viro 已提交
2533
extern int readlink_copy(char __user *, int, const char *);
L
Linus Torvalds 已提交
2534
extern int page_readlink(struct dentry *, char __user *, int);
2535 2536
extern void *page_follow_link_light(struct dentry *, struct nameidata *);
extern void page_put_link(struct dentry *, struct nameidata *, void *);
2537
extern int __page_symlink(struct inode *inode, const char *symname, int len,
2538
		int nofs);
L
Linus Torvalds 已提交
2539
extern int page_symlink(struct inode *inode, const char *symname, int len);
2540
extern const struct inode_operations page_symlink_inode_operations;
A
Al Viro 已提交
2541
extern void kfree_put_link(struct dentry *, struct nameidata *, void *);
L
Linus Torvalds 已提交
2542 2543
extern int generic_readlink(struct dentry *, char __user *, int);
extern void generic_fillattr(struct inode *, struct kstat *);
J
J. Bruce Fields 已提交
2544
int vfs_getattr_nosec(struct path *path, struct kstat *stat);
A
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2545
extern int vfs_getattr(struct path *, struct kstat *);
2546
void __inode_add_bytes(struct inode *inode, loff_t bytes);
L
Linus Torvalds 已提交
2547
void inode_add_bytes(struct inode *inode, loff_t bytes);
2548
void __inode_sub_bytes(struct inode *inode, loff_t bytes);
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2549 2550 2551 2552 2553
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 *);
2554
extern int iterate_dir(struct file *, struct dir_context *);
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Linus Torvalds 已提交
2555

2556 2557
extern int vfs_stat(const char __user *, struct kstat *);
extern int vfs_lstat(const char __user *, struct kstat *);
L
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2558
extern int vfs_fstat(unsigned int, struct kstat *);
2559
extern int vfs_fstatat(int , const char __user *, struct kstat *, int);
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2560

2561 2562
extern int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd,
		    unsigned long arg);
2563
extern int __generic_block_fiemap(struct inode *inode,
J
Josef Bacik 已提交
2564 2565 2566
				  struct fiemap_extent_info *fieinfo,
				  loff_t start, loff_t len,
				  get_block_t *get_block);
2567 2568 2569
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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2570

2571 2572
extern void get_filesystem(struct file_system_type *fs);
extern void put_filesystem(struct file_system_type *fs);
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2573 2574
extern struct file_system_type *get_fs_type(const char *name);
extern struct super_block *get_super(struct block_device *);
2575
extern struct super_block *get_super_thawed(struct block_device *);
2576
extern struct super_block *get_active_super(struct block_device *bdev);
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2577
extern void drop_super(struct super_block *sb);
A
Al Viro 已提交
2578
extern void iterate_supers(void (*)(struct super_block *, void *), void *);
A
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2579 2580
extern void iterate_supers_type(struct file_system_type *,
			        void (*)(struct super_block *, void *), void *);
L
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2581 2582 2583 2584

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);
2585
extern int dcache_readdir(struct file *, struct dir_context *);
2586
extern int simple_setattr(struct dentry *, struct iattr *);
L
Linus Torvalds 已提交
2587
extern int simple_getattr(struct vfsmount *, struct dentry *, struct kstat *);
2588
extern int simple_statfs(struct dentry *, struct kstatfs *);
S
Stephen Boyd 已提交
2589
extern int simple_open(struct inode *inode, struct file *file);
L
Linus Torvalds 已提交
2590 2591 2592 2593
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 *);
2594
extern int noop_fsync(struct file *, loff_t, loff_t, int);
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Linus Torvalds 已提交
2595 2596
extern int simple_empty(struct dentry *);
extern int simple_readpage(struct file *file, struct page *page);
2597 2598 2599 2600 2601 2602
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);
2603
extern int always_delete_dentry(const struct dentry *);
A
Al Viro 已提交
2604
extern struct inode *alloc_anon_inode(struct super_block *);
2605
extern int simple_nosetlease(struct file *, long, struct file_lock **, void **);
2606
extern const struct dentry_operations simple_dentry_operations;
L
Linus Torvalds 已提交
2607

A
Al Viro 已提交
2608
extern struct dentry *simple_lookup(struct inode *, struct dentry *, unsigned int flags);
L
Linus Torvalds 已提交
2609
extern ssize_t generic_read_dir(struct file *, char __user *, size_t, loff_t *);
2610
extern const struct file_operations simple_dir_operations;
2611
extern const struct inode_operations simple_dir_inode_operations;
2612
struct tree_descr { char *name; const struct file_operations *ops; int mode; };
L
Linus Torvalds 已提交
2613
struct dentry *d_alloc_name(struct dentry *, const char *);
2614
extern int simple_fill_super(struct super_block *, unsigned long, struct tree_descr *);
2615
extern int simple_pin_fs(struct file_system_type *, struct vfsmount **mount, int *count);
L
Linus Torvalds 已提交
2616 2617
extern void simple_release_fs(struct vfsmount **mount, int *count);

2618 2619
extern ssize_t simple_read_from_buffer(void __user *to, size_t count,
			loff_t *ppos, const void *from, size_t available);
2620 2621
extern ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos,
		const void __user *from, size_t count);
L
Linus Torvalds 已提交
2622

2623
extern int __generic_file_fsync(struct file *, loff_t, loff_t, int);
2624
extern int generic_file_fsync(struct file *, loff_t, loff_t, int);
A
Al Viro 已提交
2625

2626 2627
extern int generic_check_addressable(unsigned, u64);

2628
#ifdef CONFIG_MIGRATION
2629
extern int buffer_migrate_page(struct address_space *,
2630 2631
				struct page *, struct page *,
				enum migrate_mode);
2632 2633 2634 2635
#else
#define buffer_migrate_page NULL
#endif

N
npiggin@suse.de 已提交
2636 2637
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
2638
extern void setattr_copy(struct inode *inode, const struct iattr *attr);
L
Linus Torvalds 已提交
2639

2640
extern int file_update_time(struct file *file);
L
Linus Torvalds 已提交
2641

2642
extern int generic_show_options(struct seq_file *m, struct dentry *root);
2643
extern void save_mount_options(struct super_block *sb, char *options);
2644
extern void replace_mount_options(struct super_block *sb, char *options);
2645

L
Linus Torvalds 已提交
2646 2647 2648 2649
static inline ino_t parent_ino(struct dentry *dentry)
{
	ino_t res;

N
Nick Piggin 已提交
2650 2651 2652 2653
	/*
	 * 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
2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668 2669 2670 2671 2672 2673 2674 2675 2676 2677 2678
	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);

2679
void simple_transaction_set(struct file *file, size_t n);
L
Linus Torvalds 已提交
2680

2681 2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702
/*
 * 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);	\
}									\
2703
static const struct file_operations __fops = {				\
2704 2705
	.owner	 = THIS_MODULE,						\
	.open	 = __fops ## _open,					\
2706
	.release = simple_attr_release,					\
2707 2708
	.read	 = simple_attr_read,					\
	.write	 = simple_attr_write,					\
2709
	.llseek	 = generic_file_llseek,					\
2710
}
2711

2712 2713
static inline __printf(1, 2)
void __simple_attr_check_format(const char *fmt, ...)
2714 2715 2716 2717 2718
{
	/* don't do anything, just let the compiler check the arguments; */
}

int simple_attr_open(struct inode *inode, struct file *file,
2719
		     int (*get)(void *, u64 *), int (*set)(void *, u64),
2720
		     const char *fmt);
2721
int simple_attr_release(struct inode *inode, struct file *file);
2722 2723 2724 2725 2726
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
2727
struct ctl_table;
2728
int proc_nr_files(struct ctl_table *table, int write,
2729
		  void __user *buffer, size_t *lenp, loff_t *ppos);
2730 2731
int proc_nr_dentry(struct ctl_table *table, int write,
		  void __user *buffer, size_t *lenp, loff_t *ppos);
2732 2733
int proc_nr_inodes(struct ctl_table *table, int write,
		   void __user *buffer, size_t *lenp, loff_t *ppos);
2734
int __init get_filesystem_list(char *buf);
2735

N
Namhyung Kim 已提交
2736
#define __FMODE_EXEC		((__force int) FMODE_EXEC)
2737 2738
#define __FMODE_NONOTIFY	((__force int) FMODE_NONOTIFY)

A
Al Viro 已提交
2739
#define ACC_MODE(x) ("\004\002\006\006"[(x)&O_ACCMODE])
E
Eric Paris 已提交
2740
#define OPEN_FMODE(flag) ((__force fmode_t)(((flag + 1) & O_ACCMODE) | \
2741
					    (flag & __FMODE_NONOTIFY)))
A
Al Viro 已提交
2742

A
Al Viro 已提交
2743
static inline int is_sxid(umode_t mode)
2744 2745 2746 2747 2748 2749
{
	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
2750
	if (!is_sxid(inode->i_mode) && (inode->i_sb->s_flags & MS_NOSEC))
2751 2752 2753
		inode->i_flags |= S_NOSEC;
}

2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780 2781 2782 2783
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
2784 2785 2786 2787 2788 2789
static inline bool dir_relax(struct inode *inode)
{
	mutex_unlock(&inode->i_mutex);
	mutex_lock(&inode->i_mutex);
	return !IS_DEADDIR(inode);
}
2790

L
Linus Torvalds 已提交
2791
#endif /* _LINUX_FS_H */