fs.h 103.3 KB
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#ifndef _LINUX_FS_H
#define _LINUX_FS_H

#include <linux/linkage.h>
#include <linux/wait.h>
#include <linux/kdev_t.h>
#include <linux/dcache.h>
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#include <linux/path.h>
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#include <linux/stat.h>
#include <linux/cache.h>
#include <linux/list.h>
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#include <linux/list_lru.h>
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#include <linux/llist.h>
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#include <linux/radix-tree.h>
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#include <linux/rbtree.h>
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#include <linux/init.h>
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#include <linux/pid.h>
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#include <linux/bug.h>
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#include <linux/mutex.h>
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#include <linux/rwsem.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 <linux/workqueue.h>
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#include <linux/percpu-rwsem.h>
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#include <linux/delayed_call.h>
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#include <asm/byteorder.h>
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#include <uapi/linux/fs.h>
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struct backing_dev_info;
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struct bdi_writeback;
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struct export_operations;
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struct hd_geometry;
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struct iovec;
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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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struct fscrypt_info;
struct fscrypt_operations;
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extern void __init inode_init(void);
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extern void __init inode_init_early(void);
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extern void __init files_init(void);
extern void __init files_maxfiles_init(void);
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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 int (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 */
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#define FMODE_NONOTIFY		((__force fmode_t)0x4000000)
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/*
 * 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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/*
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 * The below are the various read and write flags that we support. Some of
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 * them include behavioral modifiers that send information down to the
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 * block layer and IO scheduler. They should be used along with a req_op.
 * Terminology:
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 *
 *	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.
 * 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.
 *
 */
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#define RW_MASK			REQ_OP_WRITE
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#define READ			REQ_OP_READ
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#define WRITE			REQ_OP_WRITE
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#define READ_SYNC		REQ_SYNC
#define WRITE_SYNC		(REQ_SYNC | REQ_NOIDLE)
#define WRITE_ODIRECT		REQ_SYNC
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#define WRITE_FLUSH		(REQ_SYNC | REQ_NOIDLE | REQ_PREFLUSH)
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#define WRITE_FUA		(REQ_SYNC | REQ_NOIDLE | REQ_FUA)
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#define WRITE_FLUSH_FUA		(REQ_SYNC | REQ_NOIDLE | REQ_PREFLUSH | 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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/*
 * Whiteout is represented by a char device.  The following constants define the
 * mode and device number to use.
 */
#define WHITEOUT_MODE 0
#define WHITEOUT_DEV 0

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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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/*
 * Maximum number of layers of fs stack.  Needs to be limited to
 * prevent kernel stack overflow
 */
#define FILESYSTEM_MAX_STACK_DEPTH 2

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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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#define IOCB_EVENTFD		(1 << 0)
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#define IOCB_APPEND		(1 << 1)
#define IOCB_DIRECT		(1 << 2)
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#define IOCB_HIPRI		(1 << 3)
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#define IOCB_DSYNC		(1 << 4)
#define IOCB_SYNC		(1 << 5)
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struct kiocb {
	struct file		*ki_filp;
	loff_t			ki_pos;
	void (*ki_complete)(struct kiocb *iocb, long ret, long ret2);
	void			*private;
	int			ki_flags;
};

static inline bool is_sync_kiocb(struct kiocb *kiocb)
{
	return kiocb->ki_complete == NULL;
}

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static inline int iocb_flags(struct file *file);

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static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp)
{
	*kiocb = (struct kiocb) {
		.ki_filp = filp,
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		.ki_flags = iocb_flags(filp),
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	};
}

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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)(struct kiocb *, struct iov_iter *iter);
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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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	bool (*isolate_page)(struct page *, isolate_mode_t);
	void (*putback_page)(struct page *);
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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 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 rw_semaphore	i_mmap_rwsem;	/* 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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	/* number of shadow or DAX exceptional entries */
	unsigned long		nrexceptional;
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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 */
	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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	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);

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static inline void i_mmap_lock_write(struct address_space *mapping)
{
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	down_write(&mapping->i_mmap_rwsem);
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}

static inline void i_mmap_unlock_write(struct address_space *mapping)
{
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	up_write(&mapping->i_mmap_rwsem);
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}

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static inline void i_mmap_lock_read(struct address_space *mapping)
{
	down_read(&mapping->i_mmap_rwsem);
}

static inline void i_mmap_unlock_read(struct address_space *mapping)
{
	up_read(&mapping->i_mmap_rwsem);
}

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/*
 * 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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}

/*
 * 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.
533 534 535
 *
 * 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)
{
539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561
	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))
577
#define ACL_DONT_CACHE ((void *)(-3))
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579 580 581 582 583 584 585 586 587 588 589 590
static inline struct posix_acl *
uncached_acl_sentinel(struct task_struct *task)
{
	return (void *)task + 1;
}

static inline bool
is_uncached_acl(struct posix_acl *acl)
{
	return (long)acl & 1;
}

591 592 593 594 595 596 597 598 599
#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 {
601
	umode_t			i_mode;
602
	unsigned short		i_opflags;
603 604
	kuid_t			i_uid;
	kgid_t			i_gid;
605 606 607 608 609 610 611
	unsigned int		i_flags;

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

612 613
	const struct inode_operations	*i_op;
	struct super_block	*i_sb;
614
	struct address_space	*i_mapping;
615

616 617 618
#ifdef CONFIG_SECURITY
	void			*i_security;
#endif
619

620 621
	/* 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;
	};
633
	dev_t			i_rdev;
634
	loff_t			i_size;
635 636 637
	struct timespec		i_atime;
	struct timespec		i_mtime;
	struct timespec		i_ctime;
638 639
	spinlock_t		i_lock;	/* i_blocks, i_bytes, maybe i_size */
	unsigned short          i_bytes;
640
	unsigned int		i_blkbits;
641 642 643 644 645 646 647 648
	blkcnt_t		i_blocks;

#ifdef __NEED_I_SIZE_ORDERED
	seqcount_t		i_size_seqcount;
#endif

	/* Misc */
	unsigned long		i_state;
649
	struct rw_semaphore	i_rwsem;
650

651
	unsigned long		dirtied_when;	/* jiffies of first dirtying */
652
	unsigned long		dirtied_time_when;
653

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	struct hlist_node	i_hash;
655
	struct list_head	i_io_list;	/* backing dev IO list */
656 657
#ifdef CONFIG_CGROUP_WRITEBACK
	struct bdi_writeback	*i_wb;		/* the associated cgroup wb */
658 659 660 661 662

	/* foreign inode detection, see wbc_detach_inode() */
	int			i_wb_frn_winner;
	u16			i_wb_frn_avg_time;
	u16			i_wb_frn_history;
663
#endif
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	struct list_head	i_lru;		/* inode LRU list */
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	struct list_head	i_sb_list;
666
	struct list_head	i_wb_list;	/* backing dev writeback list */
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	union {
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		struct hlist_head	i_dentry;
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		struct rcu_head		i_rcu;
	};
671
	u64			i_version;
672
	atomic_t		i_count;
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	atomic_t		i_dio_count;
674
	atomic_t		i_writecount;
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#ifdef CONFIG_IMA
	atomic_t		i_readcount; /* struct files open RO */
#endif
678
	const struct file_operations	*i_fop;	/* former ->i_op->default_file_ops */
679
	struct file_lock_context	*i_flctx;
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	struct address_space	i_data;
	struct list_head	i_devices;
682 683
	union {
		struct pipe_inode_info	*i_pipe;
684
		struct block_device	*i_bdev;
685
		struct cdev		*i_cdev;
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		char			*i_link;
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		unsigned		i_dir_seq;
688
	};
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	__u32			i_generation;

692 693
#ifdef CONFIG_FSNOTIFY
	__u32			i_fsnotify_mask; /* all events this inode cares about */
694
	struct hlist_head	i_fsnotify_marks;
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#endif

697 698 699 700
#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
	struct fscrypt_info	*i_crypt_info;
#endif

701
	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
715 716
 * 3: xattr
 * 4: second non-directory
717 718 719
 * 5: second parent (when locking independent directories in rename)
 *
 * I_MUTEX_NONDIR2 is for certain operations (such as rename) which lock two
720
 * non-directories at once.
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 *
 * The locking order between these classes is
723
 * parent[2] -> child -> grandchild -> 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,
731 732
	I_MUTEX_NONDIR2,
	I_MUTEX_PARENT2,
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};

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static inline void inode_lock(struct inode *inode)
{
737
	down_write(&inode->i_rwsem);
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}

static inline void inode_unlock(struct inode *inode)
{
742 743 744 745 746 747 748 749 750 751 752
	up_write(&inode->i_rwsem);
}

static inline void inode_lock_shared(struct inode *inode)
{
	down_read(&inode->i_rwsem);
}

static inline void inode_unlock_shared(struct inode *inode)
{
	up_read(&inode->i_rwsem);
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}

static inline int inode_trylock(struct inode *inode)
{
757 758 759 760 761 762
	return down_write_trylock(&inode->i_rwsem);
}

static inline int inode_trylock_shared(struct inode *inode)
{
	return down_read_trylock(&inode->i_rwsem);
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}

static inline int inode_is_locked(struct inode *inode)
{
767
	return rwsem_is_locked(&inode->i_rwsem);
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}

static inline void inode_lock_nested(struct inode *inode, unsigned subclass)
{
772
	down_write_nested(&inode->i_rwsem, subclass);
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}

775 776 777
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
}

811 812 813 814 815
/*
 * 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)
819
	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);
823
	preempt_enable();
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#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
	preempt_disable();
	inode->i_size = i_size;
	preempt_enable();
#else
	inode->i_size = i_size;
#endif
}

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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 */
847 848
	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 */
849
	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
860
					   there are only # of pages ahead */
861

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	unsigned int ra_pages;		/* Maximum readahead window */
863
	unsigned int mmap_miss;		/* Cache miss stat for mmap accesses */
864
	loff_t prev_pos;		/* Cache last read() position */
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};

867 868 869 870 871
/*
 * Check if @index falls in the readahead windows.
 */
static inline int ra_has_index(struct file_ra_state *ra, pgoff_t index)
{
872 873
	return (index >= ra->start &&
		index <  ra->start + ra->size);
874 875
}

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struct file {
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877
	union {
878
		struct llist_node	fu_llist;
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879 880
		struct rcu_head 	fu_rcuhead;
	} f_u;
881
	struct path		f_path;
882
	struct inode		*f_inode;	/* cached value */
883
	const struct file_operations	*f_op;
884 885

	/*
886
	 * Protects f_ep_links, f_flags.
887 888 889
	 * Must not be taken from IRQ context.
	 */
	spinlock_t		f_lock;
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	atomic_long_t		f_count;
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891
	unsigned int 		f_flags;
892
	fmode_t			f_mode;
893
	struct mutex		f_pos_lock;
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	loff_t			f_pos;
	struct fown_struct	f_owner;
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896
	const struct cred	*f_cred;
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	struct file_ra_state	f_ra;

899
	u64			f_version;
900
#ifdef CONFIG_SECURITY
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901
	void			*f_security;
902
#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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914 915 916 917 918 919 920
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;
}
926
#define get_file_rcu(x) atomic_long_inc_not_zero(&(x)->f_count)
927
#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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929 930 931 932 933 934

#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
935
#define MAX_LFS_FILESIZE	(((loff_t)PAGE_SIZE << (BITS_PER_LONG-1))-1)
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#elif BITS_PER_LONG==64
937
#define MAX_LFS_FILESIZE 	((loff_t)0x7fffffffffffffffLL)
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938 939 940 941
#endif

#define FL_POSIX	1
#define FL_FLOCK	2
942
#define FL_DELEG	4	/* NFSv4 delegation */
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943
#define FL_ACCESS	8	/* not trying to lock, just looking */
944
#define FL_EXISTS	16	/* when unlocking, test for existence */
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945
#define FL_LEASE	32	/* lease held on this file */
946
#define FL_CLOSE	64	/* unlock on close */
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947
#define FL_SLEEP	128	/* A blocking lock */
948 949
#define FL_DOWNGRADE_PENDING	256 /* Lease is being downgraded */
#define FL_UNLOCK_PENDING	512 /* Lease is being broken */
950
#define FL_OFDLCK	1024	/* lock is "owned" by struct file */
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#define FL_LAYOUT	2048	/* outstanding pNFS layout */
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953 954 955 956 957 958
/*
 * Special return value from posix_lock_file() and vfs_lock_file() for
 * asynchronous locking.
 */
#define FILE_LOCK_DEFERRED 1

959
/* legacy typedef, should eventually be removed */
960
typedef void *fl_owner_t;
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961

962 963
struct file_lock;

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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 {
J
J. Bruce Fields 已提交
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	int (*lm_compare_owner)(struct file_lock *, struct file_lock *);
971
	unsigned long (*lm_owner_key)(struct file_lock *);
972 973
	fl_owner_t (*lm_get_owner)(fl_owner_t);
	void (*lm_put_owner)(fl_owner_t);
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974
	void (*lm_notify)(struct file_lock *);	/* unblock callback */
975
	int (*lm_grant)(struct file_lock *, int);
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976
	bool (*lm_break)(struct file_lock *);
977
	int (*lm_change)(struct file_lock *, int, struct list_head *);
978
	void (*lm_setup)(struct file_lock *, void **);
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};

981 982
struct lock_manager {
	struct list_head list;
983 984 985 986 987
	/*
	 * NFSv4 and up also want opens blocked during the grace period;
	 * NLM doesn't care:
	 */
	bool block_opens;
988 989
};

990 991
struct net;
void locks_start_grace(struct net *, struct lock_manager *);
992
void locks_end_grace(struct lock_manager *);
993
int locks_in_grace(struct net *);
994
int opens_in_grace(struct net *);
995

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

999 1000 1001 1002 1003 1004 1005 1006 1007
/*
 * 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?
 *
1008
 * The varous i_flctx lists are ordered by:
1009
 *
1010 1011 1012
 * 1) lock owner
 * 2) lock range start
 * 3) lock range end
1013 1014 1015
 *
 * 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  */
1018
	struct list_head fl_list;	/* link into file_lock_context */
1019
	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;
1022
	unsigned int fl_flags;
1023
	unsigned char fl_type;
L
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	unsigned int fl_pid;
1025
	int fl_link_cpu;		/* what cpu's list is this on? */
1026
	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 */
1033 1034 1035
	/* for lease breaks: */
	unsigned long fl_break_time;
	unsigned long fl_downgrade_time;
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1037
	const struct file_lock_operations *fl_ops;	/* Callbacks for filesystems */
1038
	const struct lock_manager_operations *fl_lmops;	/* Callbacks for lockmanagers */
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1039 1040
	union {
		struct nfs_lock_info	nfs_fl;
1041
		struct nfs4_lock_info	nfs4_fl;
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1042 1043 1044 1045
		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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1046 1047 1048
	} fl_u;
};

1049
struct file_lock_context {
1050
	spinlock_t		flc_lock;
1051
	struct list_head	flc_flock;
1052
	struct list_head	flc_posix;
1053
	struct list_head	flc_lease;
1054 1055
};

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/* 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>

1065 1066 1067
extern void send_sigio(struct fown_struct *fown, int fd, int band);

#ifdef CONFIG_FILE_LOCKING
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extern int fcntl_getlk(struct file *, unsigned int, struct flock __user *);
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extern int fcntl_setlk(unsigned int, struct file *, unsigned int,
			struct flock __user *);
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#if BITS_PER_LONG == 32
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extern int fcntl_getlk64(struct file *, unsigned int, struct flock64 __user *);
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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 */
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void locks_free_lock_context(struct inode *inode);
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void locks_free_lock(struct file_lock *fl);
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extern void locks_init_lock(struct file_lock *);
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extern struct file_lock * locks_alloc_lock(void);
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extern void locks_copy_lock(struct file_lock *, struct file_lock *);
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extern void locks_copy_conflock(struct file_lock *, struct file_lock *);
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extern void locks_remove_posix(struct file *, fl_owner_t);
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extern void locks_remove_file(struct file *);
1090
extern void locks_release_private(struct file_lock *);
1091
extern void posix_test_lock(struct file *, struct file_lock *);
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extern int posix_lock_file(struct file *, struct file_lock *, struct file_lock *);
1093
extern int posix_unblock_lock(struct file_lock *);
1094
extern int vfs_test_lock(struct file *, struct file_lock *);
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extern int vfs_lock_file(struct file *, unsigned int, struct file_lock *, struct file_lock *);
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extern int vfs_cancel_lock(struct file *filp, struct file_lock *fl);
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extern int locks_lock_inode_wait(struct inode *inode, struct file_lock *fl);
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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);
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extern int generic_setlease(struct file *, long, struct file_lock **, void **priv);
extern int vfs_setlease(struct file *, long, struct file_lock **, void **);
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extern int lease_modify(struct file_lock *, int, struct list_head *);
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struct files_struct;
extern void show_fd_locks(struct seq_file *f,
			 struct file *filp, struct files_struct *files);
1106
#else /* !CONFIG_FILE_LOCKING */
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static inline int fcntl_getlk(struct file *file, unsigned int cmd,
			      struct flock __user *user)
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{
	return -EINVAL;
}

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

1119
#if BITS_PER_LONG == 32
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static inline int fcntl_getlk64(struct file *file, unsigned int cmd,
				struct flock64 __user *user)
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{
	return -EINVAL;
}

static inline int fcntl_setlk64(unsigned int fd, struct file *file,
				unsigned int cmd, struct flock64 __user *user)
{
	return -EACCES;
}
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#endif
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static inline int fcntl_setlease(unsigned int fd, struct file *filp, long arg)
{
1134
	return -EINVAL;
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}

static inline int fcntl_getlease(struct file *filp)
{
1139
	return F_UNLCK;
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}

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static inline void
1143
locks_free_lock_context(struct inode *inode)
1144 1145 1146
{
}

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

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

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

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

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

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

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

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static inline int locks_lock_inode_wait(struct inode *inode, struct file_lock *fl)
{
	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,
1220
				    struct file_lock **flp, void **priv)
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{
	return -EINVAL;
}

static inline int vfs_setlease(struct file *filp, long arg,
1226
			       struct file_lock **lease, void **priv)
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{
	return -EINVAL;
}

1231
static inline int lease_modify(struct file_lock *fl, int arg,
1232
			       struct list_head *dispose)
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{
	return -EINVAL;
}
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struct files_struct;
static inline void show_fd_locks(struct seq_file *f,
			struct file *filp, struct files_struct *files) {}
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#endif /* !CONFIG_FILE_LOCKING */

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static inline struct inode *file_inode(const struct file *f)
{
	return f->f_inode;
}

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static inline struct dentry *file_dentry(const struct file *file)
{
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	return d_real(file->f_path.dentry, file_inode(file), 0);
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}

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static inline int locks_lock_file_wait(struct file *filp, struct file_lock *fl)
{
	return locks_lock_inode_wait(file_inode(filp), fl);
}

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

#define FASYNC_MAGIC 0x4601

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

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

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extern 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);
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extern pid_t f_getown(struct file *filp);
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extern int send_sigurg(struct fown_struct *fown);

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struct mm_struct;

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/*
 *	Umount options
 */

#define MNT_FORCE	0x00000001	/* Attempt to forcibily umount */
#define MNT_DETACH	0x00000002	/* Just detach from the tree */
#define MNT_EXPIRE	0x00000004	/* Mark for expiry */
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#define UMOUNT_NOFOLLOW	0x00000008	/* Don't follow symlink on umount */
#define UMOUNT_UNUSED	0x80000000	/* Flag guaranteed to be unused */
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/* sb->s_iflags */
#define SB_I_CGROUPWB	0x00000001	/* cgroup-aware writeback enabled */
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#define SB_I_NOEXEC	0x00000002	/* Ignore executables on this fs */
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#define SB_I_NODEV	0x00000004	/* Ignore devices on this fs */
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/* sb->s_iflags to limit user namespace mounts */
#define SB_I_USERNS_VISIBLE		0x00000010 /* fstype already mounted */
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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 {
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	int				frozen;		/* Is sb frozen? */
	wait_queue_head_t		wait_unfrozen;	/* for get_super_thawed() */
	struct percpu_rw_semaphore	rw_sem[SB_FREEZE_LEVELS];
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};

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struct super_block {
	struct list_head	s_list;		/* Keep this first */
	dev_t			s_dev;		/* search index; _not_ kdev_t */
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	unsigned char		s_blocksize_bits;
	unsigned long		s_blocksize;
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	loff_t			s_maxbytes;	/* Max file size */
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	struct file_system_type	*s_type;
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	const struct super_operations	*s_op;
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	const struct dquot_operations	*dq_op;
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	const struct quotactl_ops	*s_qcop;
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	const struct export_operations *s_export_op;
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	unsigned long		s_flags;
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	unsigned long		s_iflags;	/* internal SB_I_* flags */
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	unsigned long		s_magic;
	struct dentry		*s_root;
	struct rw_semaphore	s_umount;
	int			s_count;
	atomic_t		s_active;
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#ifdef CONFIG_SECURITY
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	void                    *s_security;
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#endif
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	const struct xattr_handler **s_xattr;
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	const struct fscrypt_operations	*s_cop;

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	struct hlist_bl_head	s_anon;		/* anonymous dentries for (nfs) exporting */
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	struct list_head	s_mounts;	/* list of mounts; _not_ for fs use */
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	struct block_device	*s_bdev;
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	struct backing_dev_info *s_bdi;
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	struct mtd_info		*s_mtd;
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	struct hlist_node	s_instances;
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	unsigned int		s_quota_types;	/* Bitmask of supported quota types */
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	struct quota_info	s_dquot;	/* Diskquota specific options */

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

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

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	/* Being remounted read-only */
	int s_readonly_remount;
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	/* AIO completions deferred from interrupt context */
	struct workqueue_struct *s_dio_done_wq;
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	struct hlist_head s_pins;
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	/*
	 * Owning user namespace and default context in which to
	 * interpret filesystem uids, gids, quotas, device nodes,
	 * xattrs and security labels.
	 */
	struct user_namespace *s_user_ns;

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	/*
	 * Keep the lru lists last in the structure so they always sit on their
	 * own individual cachelines.
	 */
	struct list_lru		s_dentry_lru ____cacheline_aligned_in_smp;
	struct list_lru		s_inode_lru ____cacheline_aligned_in_smp;
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	struct rcu_head		rcu;
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	struct work_struct	destroy_work;
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1421
	struct mutex		s_sync_lock;	/* sync serialisation lock */
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	/*
	 * Indicates how deep in a filesystem stack this SB is
	 */
	int s_stack_depth;
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	/* s_inode_list_lock protects s_inodes */
	spinlock_t		s_inode_list_lock ____cacheline_aligned_in_smp;
	struct list_head	s_inodes;	/* all inodes */
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	spinlock_t		s_inode_wblist_lock;
	struct list_head	s_inodes_wb;	/* writeback inodes */
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};

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

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

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

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

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extern struct timespec current_fs_time(struct super_block *sb);

/*
 * Snapshotting support.
 */

1467 1468 1469
void __sb_end_write(struct super_block *sb, int level);
int __sb_start_write(struct super_block *sb, int level, bool wait);

1470
#define __sb_writers_acquired(sb, lev)	\
1471
	percpu_rwsem_acquire(&(sb)->s_writers.rw_sem[(lev)-1], 1, _THIS_IP_)
1472
#define __sb_writers_release(sb, lev)	\
1473
	percpu_rwsem_release(&(sb)->s_writers.rw_sem[(lev)-1], 1, _THIS_IP_)
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/**
 * 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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1583
extern bool inode_owner_or_capable(const struct inode *inode);
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/*
 * VFS helper functions..
 */
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extern int vfs_create(struct inode *, struct dentry *, umode_t, bool);
1589
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);
1591
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 *);
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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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extern int vfs_whiteout(struct inode *, struct dentry *);
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/*
 * VFS file helper functions.
 */
1601
extern void inode_init_owner(struct inode *inode, const struct inode *dir,
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			umode_t mode);
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extern bool may_open_dev(const struct path *path);
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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 */
1611 1612
	struct fiemap_extent __user *fi_extents_start; /* Start of
							fiemap_extent array */
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Mark Fasheh 已提交
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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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1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639
/*
 * 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.
 */
1640 1641 1642 1643
struct dir_context;
typedef int (*filldir_t)(struct dir_context *, const char *, int, loff_t, u64,
			 unsigned);

1644
struct dir_context {
A
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1645
	const filldir_t actor;
1646
	loff_t pos;
1647
};
1648

1649
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

1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676
/*
 * These flags let !MMU mmap() govern direct device mapping vs immediate
 * copying more easily for MAP_PRIVATE, especially for ROM filesystems.
 *
 * NOMMU_MAP_COPY:	Copy can be mapped (MAP_PRIVATE)
 * NOMMU_MAP_DIRECT:	Can be mapped directly (MAP_SHARED)
 * NOMMU_MAP_READ:	Can be mapped for reading
 * NOMMU_MAP_WRITE:	Can be mapped for writing
 * NOMMU_MAP_EXEC:	Can be mapped for execution
 */
#define NOMMU_MAP_COPY		0x00000001
#define NOMMU_MAP_DIRECT	0x00000008
#define NOMMU_MAP_READ		VM_MAYREAD
#define NOMMU_MAP_WRITE		VM_MAYWRITE
#define NOMMU_MAP_EXEC		VM_MAYEXEC

#define NOMMU_VMFLAGS \
	(NOMMU_MAP_READ | NOMMU_MAP_WRITE | NOMMU_MAP_EXEC)


1677 1678
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 *);
1684 1685
	ssize_t (*read_iter) (struct kiocb *, struct iov_iter *);
	ssize_t (*write_iter) (struct kiocb *, struct iov_iter *);
1686
	int (*iterate) (struct file *, struct dir_context *);
1687
	int (*iterate_shared) (struct file *, struct dir_context *);
L
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1688 1689 1690 1691 1692
	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 *);
1693
	int (*flush) (struct file *, fl_owner_t id);
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1694
	int (*release) (struct inode *, struct file *);
1695
	int (*fsync) (struct file *, loff_t, loff_t, int datasync);
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1696 1697 1698 1699 1700 1701 1702
	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 *);
1703 1704
	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);
1705
	int (*setlease)(struct file *, long, struct file_lock **, void **);
1706 1707
	long (*fallocate)(struct file *file, int mode, loff_t offset,
			  loff_t len);
1708
	void (*show_fdinfo)(struct seq_file *m, struct file *f);
1709 1710 1711
#ifndef CONFIG_MMU
	unsigned (*mmap_capabilities)(struct file *);
#endif
1712 1713 1714 1715
	ssize_t (*copy_file_range)(struct file *, loff_t, struct file *,
			loff_t, size_t, unsigned int);
	int (*clone_file_range)(struct file *, loff_t, struct file *, loff_t,
			u64);
1716 1717
	ssize_t (*dedupe_file_range)(struct file *, u64, u64, struct file *,
			u64);
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};

struct inode_operations {
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	struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int);
1722
	const char * (*get_link) (struct dentry *, struct inode *, struct delayed_call *);
1723
	int (*permission) (struct inode *, int);
1724
	struct posix_acl * (*get_acl)(struct inode *, int);
1725 1726 1727

	int (*readlink) (struct dentry *, char __user *,int);

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	int (*create) (struct inode *,struct dentry *, umode_t, bool);
L
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1729 1730 1731
	int (*link) (struct dentry *,struct inode *,struct dentry *);
	int (*unlink) (struct inode *,struct dentry *);
	int (*symlink) (struct inode *,struct dentry *,const char *);
1732
	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);
L
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1735 1736
	int (*rename) (struct inode *, struct dentry *,
			struct inode *, struct dentry *);
M
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1737 1738
	int (*rename2) (struct inode *, struct dentry *,
			struct inode *, struct dentry *, unsigned int);
L
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1739 1740
	int (*setattr) (struct dentry *, struct iattr *);
	int (*getattr) (struct vfsmount *mnt, struct dentry *, struct kstat *);
1741 1742
	int (*setxattr) (struct dentry *, struct inode *,
			 const char *, const void *, size_t, int);
1743 1744
	ssize_t (*getxattr) (struct dentry *, struct inode *,
			     const char *, void *, size_t);
L
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1745 1746
	ssize_t (*listxattr) (struct dentry *, char *, size_t);
	int (*removexattr) (struct dentry *, const char *);
M
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1747 1748
	int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start,
		      u64 len);
1749
	int (*update_time)(struct inode *, struct timespec *, int);
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	int (*atomic_open)(struct inode *, struct dentry *,
A
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1751
			   struct file *, unsigned open_flag,
A
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1752
			   umode_t create_mode, int *opened);
1753
	int (*tmpfile) (struct inode *, struct dentry *, umode_t);
1754
	int (*set_acl)(struct inode *, struct posix_acl *, int);
1755
} ____cacheline_aligned;
L
Linus Torvalds 已提交
1756

B
Badari Pulavarty 已提交
1757
ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
C
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1758 1759
			      unsigned long nr_segs, unsigned long fast_segs,
			      struct iovec *fast_pointer,
1760
			      struct iovec **ret_pointer);
B
Badari Pulavarty 已提交
1761

D
Dmitry Kasatkin 已提交
1762
extern ssize_t __vfs_read(struct file *, char __user *, size_t, loff_t *);
A
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1763
extern ssize_t __vfs_write(struct file *, const char __user *, size_t, loff_t *);
L
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1764 1765 1766
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 *,
1767
		unsigned long, loff_t *, int);
L
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1768
extern ssize_t vfs_writev(struct file *, const struct iovec __user *,
1769
		unsigned long, loff_t *, int);
1770 1771
extern ssize_t vfs_copy_file_range(struct file *, loff_t , struct file *,
				   loff_t, size_t, unsigned int);
1772 1773
extern int vfs_clone_file_range(struct file *file_in, loff_t pos_in,
		struct file *file_out, loff_t pos_out, u64 len);
1774 1775
extern int vfs_dedupe_file_range(struct file *file,
				 struct file_dedupe_range *same);
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1776 1777 1778 1779 1780

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

1781
   	void (*dirty_inode) (struct inode *, int flags);
1782
	int (*write_inode) (struct inode *, struct writeback_control *wbc);
1783
	int (*drop_inode) (struct inode *);
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1784
	void (*evict_inode) (struct inode *);
L
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1785 1786
	void (*put_super) (struct super_block *);
	int (*sync_fs)(struct super_block *sb, int wait);
1787
	int (*freeze_super) (struct super_block *);
1788
	int (*freeze_fs) (struct super_block *);
1789
	int (*thaw_super) (struct super_block *);
1790
	int (*unfreeze_fs) (struct super_block *);
1791
	int (*statfs) (struct dentry *, struct kstatfs *);
L
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1792
	int (*remount_fs) (struct super_block *, int *, char *);
1793
	void (*umount_begin) (struct super_block *);
L
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1794

1795
	int (*show_options)(struct seq_file *, struct dentry *);
1796
	int (*show_devname)(struct seq_file *, struct dentry *);
1797
	int (*show_path)(struct seq_file *, struct dentry *);
1798
	int (*show_stats)(struct seq_file *, struct dentry *);
1799
#ifdef CONFIG_QUOTA
L
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1800 1801
	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);
1802
	struct dquot **(*get_dquots)(struct inode *);
1803
#endif
1804
	int (*bdev_try_to_free_page)(struct super_block*, struct page*, gfp_t);
1805 1806 1807 1808
	long (*nr_cached_objects)(struct super_block *,
				  struct shrink_control *);
	long (*free_cached_objects)(struct super_block *,
				    struct shrink_control *);
L
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1809 1810
};

D
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1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826
/*
 * 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 */
1827
#ifdef CONFIG_FS_DAX
1828 1829 1830 1831
#define S_DAX		8192	/* Direct Access, avoiding the page cache */
#else
#define S_DAX		0	/* Make all the DAX code disappear */
#endif
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David Howells 已提交
1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868

/*
 * 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)
1869
#define IS_DAX(inode)		((inode)->i_flags & S_DAX)
D
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1870

M
Miklos Szeredi 已提交
1871 1872 1873
#define IS_WHITEOUT(inode)	(S_ISCHR(inode->i_mode) && \
				 (inode)->i_rdev == WHITEOUT_DEV)

1874 1875 1876 1877 1878
static inline bool HAS_UNMAPPED_ID(struct inode *inode)
{
	return !uid_valid(inode->i_uid) || !gid_valid(inode->i_gid);
}

J
Joern Engel 已提交
1879
/*
1880
 * Inode state bits.  Protected by inode->i_lock
J
Joern Engel 已提交
1881 1882 1883 1884 1885 1886 1887 1888
 *
 * 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
1889
 * Two bits are used for locking and completion notification, I_NEW and I_SYNC.
J
Joern Engel 已提交
1890
 *
J
Joern Engel 已提交
1891 1892
 * I_DIRTY_SYNC		Inode is dirty, but doesn't have to be written on
 *			fdatasync().  i_atime is the usual cause.
1893 1894 1895 1896
 * 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.
J
Joern Engel 已提交
1897
 * I_DIRTY_PAGES	Inode has dirty pages.  Inode itself may be clean.
C
Christoph Hellwig 已提交
1898 1899 1900 1901 1902 1903 1904 1905
 * 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.
J
Joern Engel 已提交
1906 1907 1908 1909 1910 1911
 * 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.
1912 1913
 * I_CLEAR		Added by clear_inode().  In this state the inode is
 *			clean and can be destroyed.  Inode keeps I_FREEING.
J
Joern Engel 已提交
1914 1915 1916 1917 1918
 *
 *			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,
C
Christoph Hellwig 已提交
1919
 *			if appropriate.  I_NEW is used for waiting.
J
Joern Engel 已提交
1920
 *
1921 1922 1923 1924
 * 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.
J
Joern Engel 已提交
1925
 *
C
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1926 1927 1928 1929
 * 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().
 *
1930 1931 1932 1933 1934
 * I_WB_SWITCH		Cgroup bdi_writeback switching in progress.  Used to
 *			synchronize competing switching instances and to tell
 *			wb stat updates to grab mapping->tree_lock.  See
 *			inode_switch_wb_work_fn() for details.
 *
J
Joern Engel 已提交
1935 1936
 * Q: What is the difference between I_WILL_FREE and I_FREEING?
 */
1937 1938 1939
#define I_DIRTY_SYNC		(1 << 0)
#define I_DIRTY_DATASYNC	(1 << 1)
#define I_DIRTY_PAGES		(1 << 2)
C
Christoph Hellwig 已提交
1940 1941
#define __I_NEW			3
#define I_NEW			(1 << __I_NEW)
1942 1943 1944
#define I_WILL_FREE		(1 << 4)
#define I_FREEING		(1 << 5)
#define I_CLEAR			(1 << 6)
C
Christoph Hellwig 已提交
1945
#define __I_SYNC		7
J
Joern Engel 已提交
1946
#define I_SYNC			(1 << __I_SYNC)
1947
#define I_REFERENCED		(1 << 8)
C
Christoph Hellwig 已提交
1948
#define __I_DIO_WAKEUP		9
E
Eric Sandeen 已提交
1949
#define I_DIO_WAKEUP		(1 << __I_DIO_WAKEUP)
1950
#define I_LINKABLE		(1 << 10)
1951 1952 1953
#define I_DIRTY_TIME		(1 << 11)
#define __I_DIRTY_TIME_EXPIRED	12
#define I_DIRTY_TIME_EXPIRED	(1 << __I_DIRTY_TIME_EXPIRED)
1954
#define I_WB_SWITCH		(1 << 13)
L
Linus Torvalds 已提交
1955 1956

#define I_DIRTY (I_DIRTY_SYNC | I_DIRTY_DATASYNC | I_DIRTY_PAGES)
1957
#define I_DIRTY_ALL (I_DIRTY | I_DIRTY_TIME)
L
Linus Torvalds 已提交
1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969

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);
}

M
Miklos Szeredi 已提交
1970 1971 1972 1973
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);
1974 1975 1976 1977

static inline void inode_inc_link_count(struct inode *inode)
{
	inc_nlink(inode);
1978 1979 1980
	mark_inode_dirty(inode);
}

1981 1982 1983
static inline void inode_dec_link_count(struct inode *inode)
{
	drop_nlink(inode);
1984 1985 1986
	mark_inode_dirty(inode);
}

1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001
/**
 * 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);
}

2002 2003 2004 2005 2006 2007 2008
enum file_time_flags {
	S_ATIME = 1,
	S_MTIME = 2,
	S_CTIME = 4,
	S_VERSION = 8,
};

2009
extern bool atime_needs_update(const struct path *, struct inode *);
A
Al Viro 已提交
2010
extern void touch_atime(const struct path *);
L
Linus Torvalds 已提交
2011 2012 2013
static inline void file_accessed(struct file *file)
{
	if (!(file->f_flags & O_NOATIME))
A
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2014
		touch_atime(&file->f_path);
L
Linus Torvalds 已提交
2015 2016 2017
}

int sync_inode(struct inode *inode, struct writeback_control *wbc);
C
Christoph Hellwig 已提交
2018
int sync_inode_metadata(struct inode *inode, int wait);
L
Linus Torvalds 已提交
2019 2020 2021 2022

struct file_system_type {
	const char *name;
	int fs_flags;
D
David Howells 已提交
2023 2024 2025
#define FS_REQUIRES_DEV		1 
#define FS_BINARY_MOUNTDATA	2
#define FS_HAS_SUBTYPE		4
2026
#define FS_USERNS_MOUNT		8	/* Can be mounted by userns root */
D
David Howells 已提交
2027
#define FS_RENAME_DOES_D_MOVE	32768	/* FS will handle d_move() during rename() internally. */
A
Al Viro 已提交
2028 2029
	struct dentry *(*mount) (struct file_system_type *, int,
		       const char *, void *);
L
Linus Torvalds 已提交
2030 2031 2032
	void (*kill_sb) (struct super_block *);
	struct module *owner;
	struct file_system_type * next;
A
Al Viro 已提交
2033
	struct hlist_head fs_supers;
2034

I
Ingo Molnar 已提交
2035
	struct lock_class_key s_lock_key;
2036
	struct lock_class_key s_umount_key;
2037
	struct lock_class_key s_vfs_rename_key;
2038
	struct lock_class_key s_writers_key[SB_FREEZE_LEVELS];
2039 2040 2041

	struct lock_class_key i_lock_key;
	struct lock_class_key i_mutex_key;
2042
	struct lock_class_key i_mutex_dir_key;
L
Linus Torvalds 已提交
2043 2044
};

2045 2046
#define MODULE_ALIAS_FS(NAME) MODULE_ALIAS("fs-" NAME)

2047 2048 2049
extern struct dentry *mount_ns(struct file_system_type *fs_type,
	int flags, void *data, void *ns, struct user_namespace *user_ns,
	int (*fill_super)(struct super_block *, void *, int));
A
Al Viro 已提交
2050 2051 2052
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));
A
Al Viro 已提交
2053 2054 2055
extern struct dentry *mount_single(struct file_system_type *fs_type,
	int flags, void *data,
	int (*fill_super)(struct super_block *, void *, int));
A
Al Viro 已提交
2056 2057 2058
extern struct dentry *mount_nodev(struct file_system_type *fs_type,
	int flags, void *data,
	int (*fill_super)(struct super_block *, void *, int));
A
Al Viro 已提交
2059
extern struct dentry *mount_subtree(struct vfsmount *mnt, const char *path);
L
Linus Torvalds 已提交
2060 2061 2062 2063 2064
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);
A
Al Viro 已提交
2065
void deactivate_locked_super(struct super_block *sb);
L
Linus Torvalds 已提交
2066
int set_anon_super(struct super_block *s, void *data);
2067 2068
int get_anon_bdev(dev_t *);
void free_anon_bdev(dev_t);
2069 2070 2071 2072 2073
struct super_block *sget_userns(struct file_system_type *type,
			int (*test)(struct super_block *,void *),
			int (*set)(struct super_block *,void *),
			int flags, struct user_namespace *user_ns,
			void *data);
L
Linus Torvalds 已提交
2074 2075 2076
struct super_block *sget(struct file_system_type *type,
			int (*test)(struct super_block *,void *),
			int (*set)(struct super_block *,void *),
D
David Howells 已提交
2077
			int flags, void *data);
A
Al Viro 已提交
2078
extern struct dentry *mount_pseudo(struct file_system_type *, char *,
2079 2080 2081
	const struct super_operations *ops,
	const struct dentry_operations *dops,
	unsigned long);
L
Linus Torvalds 已提交
2082 2083 2084 2085 2086 2087

/* 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)
2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098
/*
 * 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
2099 2100 2101

extern int register_filesystem(struct file_system_type *);
extern int unregister_filesystem(struct file_system_type *);
2102 2103
extern struct vfsmount *kern_mount_data(struct file_system_type *, void *data);
#define kern_mount(type) kern_mount_data(type, NULL)
2104
extern void kern_unmount(struct vfsmount *mnt);
L
Linus Torvalds 已提交
2105 2106
extern int may_umount_tree(struct vfsmount *);
extern int may_umount(struct vfsmount *);
2107 2108
extern long do_mount(const char *, const char __user *,
		     const char *, unsigned long, void *);
A
Al Viro 已提交
2109
extern struct vfsmount *collect_mounts(struct path *);
2110
extern void drop_collected_mounts(struct vfsmount *);
A
Al Viro 已提交
2111 2112
extern int iterate_mounts(int (*)(struct vfsmount *, void *), void *,
			  struct vfsmount *);
2113
extern int vfs_statfs(struct path *, struct kstatfs *);
A
Al Viro 已提交
2114 2115
extern int user_statfs(const char __user *, struct kstatfs *);
extern int fd_statfs(int, struct kstatfs *);
A
Al Viro 已提交
2116
extern int vfs_ustat(dev_t, struct kstatfs *);
2117 2118
extern int freeze_super(struct super_block *super);
extern int thaw_super(struct super_block *super);
2119
extern bool our_mnt(struct vfsmount *mnt);
L
Linus Torvalds 已提交
2120

A
Al Viro 已提交
2121 2122
extern int current_umask(void);

2123 2124
extern void ihold(struct inode * inode);
extern void iput(struct inode *);
2125
extern int generic_update_time(struct inode *, struct timespec *, int);
2126

M
Miklos Szeredi 已提交
2127
/* /sys/fs */
2128
extern struct kobject *fs_kobj;
M
Miklos Szeredi 已提交
2129

2130
#define MAX_RW_COUNT (INT_MAX & PAGE_MASK)
2131

2132
#ifdef CONFIG_MANDATORY_FILE_LOCKING
2133
extern int locks_mandatory_locked(struct file *);
2134
extern int locks_mandatory_area(struct inode *, struct file *, loff_t, loff_t, unsigned char);
L
Linus Torvalds 已提交
2135 2136 2137 2138 2139

/*
 * Candidates for mandatory locking have the setgid bit set
 * but no group execute bit -  an otherwise meaningless combination.
 */
2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154

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);
}
L
Linus Torvalds 已提交
2155

2156
static inline int locks_verify_locked(struct file *file)
L
Linus Torvalds 已提交
2157
{
2158 2159
	if (mandatory_lock(file_inode(file)))
		return locks_mandatory_locked(file);
L
Linus Torvalds 已提交
2160 2161 2162 2163
	return 0;
}

static inline int locks_verify_truncate(struct inode *inode,
2164
				    struct file *f,
L
Linus Torvalds 已提交
2165 2166
				    loff_t size)
{
2167 2168 2169 2170 2171 2172 2173 2174 2175 2176
	if (!inode->i_flctx || !mandatory_lock(inode))
		return 0;

	if (size < inode->i_size) {
		return locks_mandatory_area(inode, f, size, inode->i_size - 1,
				F_WRLCK);
	} else {
		return locks_mandatory_area(inode, f, inode->i_size, size - 1,
				F_WRLCK);
	}
L
Linus Torvalds 已提交
2177 2178
}

2179 2180 2181 2182 2183 2184 2185
#else /* !CONFIG_MANDATORY_FILE_LOCKING */

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

2186 2187
static inline int locks_mandatory_area(struct inode *inode, struct file *filp,
                                       loff_t start, loff_t end, unsigned char type)
2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216
{
	return 0;
}

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

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

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

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

#endif /* CONFIG_MANDATORY_FILE_LOCKING */


#ifdef CONFIG_FILE_LOCKING
L
Linus Torvalds 已提交
2217 2218
static inline int break_lease(struct inode *inode, unsigned int mode)
{
2219 2220
	/*
	 * Since this check is lockless, we must ensure that any refcounts
2221 2222 2223
	 * taken are done before checking i_flctx->flc_lease. Otherwise, we
	 * could end up racing with tasks trying to set a new lease on this
	 * file.
2224 2225
	 */
	smp_mb();
2226
	if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease))
J
J. Bruce Fields 已提交
2227
		return __break_lease(inode, mode, FL_LEASE);
L
Linus Torvalds 已提交
2228 2229
	return 0;
}
J
J. Bruce Fields 已提交
2230 2231 2232

static inline int break_deleg(struct inode *inode, unsigned int mode)
{
2233 2234
	/*
	 * Since this check is lockless, we must ensure that any refcounts
2235 2236 2237
	 * taken are done before checking i_flctx->flc_lease. Otherwise, we
	 * could end up racing with tasks trying to set a new lease on this
	 * file.
2238 2239
	 */
	smp_mb();
2240
	if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease))
J
J. Bruce Fields 已提交
2241
		return __break_lease(inode, mode, FL_DELEG);
L
Linus Torvalds 已提交
2242 2243
	return 0;
}
J
J. Bruce Fields 已提交
2244

2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266
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;
}

C
Christoph Hellwig 已提交
2267 2268 2269 2270 2271 2272 2273 2274 2275 2276
static inline int break_layout(struct inode *inode, bool wait)
{
	smp_mb();
	if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease))
		return __break_lease(inode,
				wait ? O_WRONLY : O_WRONLY | O_NONBLOCK,
				FL_LAYOUT);
	return 0;
}

2277
#else /* !CONFIG_FILE_LOCKING */
2278 2279 2280 2281 2282
static inline int break_lease(struct inode *inode, unsigned int mode)
{
	return 0;
}

J
J. Bruce Fields 已提交
2283 2284 2285 2286
static inline int break_deleg(struct inode *inode, unsigned int mode)
{
	return 0;
}
2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298

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;
}

C
Christoph Hellwig 已提交
2299 2300 2301 2302 2303
static inline int break_layout(struct inode *inode, bool wait)
{
	return 0;
}

2304
#endif /* CONFIG_FILE_LOCKING */
L
Linus Torvalds 已提交
2305 2306

/* fs/open.c */
2307
struct audit_names;
2308
struct filename {
2309 2310 2311
	const char		*name;	/* pointer to actual string */
	const __user char	*uptr;	/* original userland pointer */
	struct audit_names	*aname;
2312
	int			refcnt;
A
Al Viro 已提交
2313
	const char		iname[];
2314
};
L
Linus Torvalds 已提交
2315

A
Al Viro 已提交
2316
extern long vfs_truncate(const struct path *, loff_t);
2317 2318
extern int do_truncate(struct dentry *, loff_t start, unsigned int time_attrs,
		       struct file *filp);
2319
extern int vfs_fallocate(struct file *file, int mode, loff_t offset,
2320
			loff_t len);
J
Jason Uhlenkott 已提交
2321
extern long do_sys_open(int dfd, const char __user *filename, int flags,
2322
			umode_t mode);
2323
extern struct file *file_open_name(struct filename *, int, umode_t);
2324
extern struct file *filp_open(const char *, int, umode_t);
A
Al Viro 已提交
2325
extern struct file *file_open_root(struct dentry *, struct vfsmount *,
2326
				   const char *, int, umode_t);
2327
extern struct file * dentry_open(const struct path *, int, const struct cred *);
L
Linus Torvalds 已提交
2328
extern int filp_close(struct file *, fl_owner_t id);
2329

2330
extern struct filename *getname_flags(const char __user *, int, int *);
2331
extern struct filename *getname(const char __user *);
2332
extern struct filename *getname_kernel(const char *);
2333
extern void putname(struct filename *name);
2334

2335 2336 2337 2338
enum {
	FILE_CREATED = 1,
	FILE_OPENED = 2
};
A
Al Viro 已提交
2339 2340 2341
extern int finish_open(struct file *file, struct dentry *dentry,
			int (*open)(struct inode *, struct file *),
			int *opened);
A
Al Viro 已提交
2342
extern int finish_no_open(struct file *file, struct dentry *dentry);
L
Linus Torvalds 已提交
2343

2344 2345 2346 2347
/* fs/ioctl.c */

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

L
Linus Torvalds 已提交
2348 2349
/* fs/dcache.c */
extern void __init vfs_caches_init_early(void);
2350
extern void __init vfs_caches_init(void);
L
Linus Torvalds 已提交
2351

2352 2353
extern struct kmem_cache *names_cachep;

2354
#define __getname()		kmem_cache_alloc(names_cachep, GFP_KERNEL)
V
Vegard Nossum 已提交
2355
#define __putname(name)		kmem_cache_free(names_cachep, (void *)(name))
L
Linus Torvalds 已提交
2356

2357
#ifdef CONFIG_BLOCK
L
Linus Torvalds 已提交
2358
extern int register_blkdev(unsigned int, const char *);
A
Akinobu Mita 已提交
2359
extern void unregister_blkdev(unsigned int, const char *);
L
Linus Torvalds 已提交
2360
extern struct block_device *bdget(dev_t);
2361
extern struct block_device *bdgrab(struct block_device *bdev);
L
Linus Torvalds 已提交
2362 2363 2364
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
2365
extern void invalidate_bdev(struct block_device *);
2366
extern void iterate_bdevs(void (*)(struct block_device *, void *), void *);
N
Nick Piggin 已提交
2367
extern int sync_blockdev(struct block_device *bdev);
A
Al Viro 已提交
2368
extern void kill_bdev(struct block_device *);
N
Nick Piggin 已提交
2369
extern struct super_block *freeze_bdev(struct block_device *);
2370
extern void emergency_thaw_all(void);
N
Nick Piggin 已提交
2371 2372
extern int thaw_bdev(struct block_device *bdev, struct super_block *sb);
extern int fsync_bdev(struct block_device *);
T
Tejun Heo 已提交
2373 2374 2375 2376 2377 2378 2379

extern struct super_block *blockdev_superblock;

static inline bool sb_is_blkdev_sb(struct super_block *sb)
{
	return sb == blockdev_superblock;
}
2380 2381
#else
static inline void bd_forget(struct inode *inode) {}
2382
static inline int sync_blockdev(struct block_device *bdev) { return 0; }
A
Al Viro 已提交
2383
static inline void kill_bdev(struct block_device *bdev) {}
2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394
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;
}
2395 2396 2397 2398

static inline void iterate_bdevs(void (*f)(struct block_device *, void *), void *arg)
{
}
2399

2400
static inline bool sb_is_blkdev_sb(struct super_block *sb)
2401
{
2402
	return false;
2403
}
2404
#endif
2405
extern int sync_filesystem(struct super_block *);
2406
extern const struct file_operations def_blk_fops;
2407
extern const struct file_operations def_chr_fops;
2408
#ifdef CONFIG_BLOCK
L
Linus Torvalds 已提交
2409
extern int ioctl_by_bdev(struct block_device *, unsigned, unsigned long);
2410
extern int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long);
L
Linus Torvalds 已提交
2411
extern long compat_blkdev_ioctl(struct file *, unsigned, unsigned long);
2412
extern int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder);
2413 2414 2415 2416
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
2417
extern void blkdev_put(struct block_device *bdev, fmode_t mode);
2418 2419 2420
extern int __blkdev_reread_part(struct block_device *bdev);
extern int blkdev_reread_part(struct block_device *bdev);

2421
#ifdef CONFIG_SYSFS
2422
extern int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);
2423 2424
extern void bd_unlink_disk_holder(struct block_device *bdev,
				  struct gendisk *disk);
2425
#else
2426 2427 2428 2429 2430
static inline int bd_link_disk_holder(struct block_device *bdev,
				      struct gendisk *disk)
{
	return 0;
}
2431 2432 2433 2434
static inline void bd_unlink_disk_holder(struct block_device *bdev,
					 struct gendisk *disk)
{
}
2435
#endif
2436
#endif
L
Linus Torvalds 已提交
2437 2438

/* fs/char_dev.c */
2439
#define CHRDEV_MAJOR_HASH_SIZE	255
2440 2441
/* Marks the bottom of the first segment of free char majors */
#define CHRDEV_MAJOR_DYN_END 234
L
Linus Torvalds 已提交
2442 2443
extern int alloc_chrdev_region(dev_t *, unsigned, unsigned, const char *);
extern int register_chrdev_region(dev_t, unsigned, const char *);
2444 2445 2446 2447 2448
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
2449
extern void unregister_chrdev_region(dev_t, unsigned);
2450
extern void chrdev_show(struct seq_file *,off_t);
L
Linus Torvalds 已提交
2451

2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462
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
2463 2464
/* fs/block_dev.c */
#define BDEVNAME_SIZE	32	/* Largest string for a blockdev identifier */
2465
#define BDEVT_SIZE	10	/* Largest string for MAJ:MIN for blkdev */
2466 2467 2468

#ifdef CONFIG_BLOCK
#define BLKDEV_MAJOR_HASH_SIZE	255
L
Linus Torvalds 已提交
2469 2470 2471
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 *);
2472
extern void blkdev_show(struct seq_file *,off_t);
2473

2474 2475 2476
#else
#define BLKDEV_MAJOR_HASH_SIZE	0
#endif
L
Linus Torvalds 已提交
2477 2478 2479 2480 2481

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 *);
2482
extern bool is_bad_inode(struct inode *);
L
Linus Torvalds 已提交
2483

2484
#ifdef CONFIG_BLOCK
2485
static inline bool op_is_write(unsigned int op)
2486
{
2487
	return op == REQ_OP_READ ? false : true;
2488 2489
}

L
Linus Torvalds 已提交
2490 2491 2492
/*
 * return data direction, READ or WRITE
 */
2493 2494
static inline int bio_data_dir(struct bio *bio)
{
2495
	return op_is_write(bio_op(bio)) ? WRITE : READ;
2496
}
L
Linus Torvalds 已提交
2497

2498 2499
extern void check_disk_size_change(struct gendisk *disk,
				   struct block_device *bdev);
2500
extern int revalidate_disk(struct gendisk *);
L
Linus Torvalds 已提交
2501
extern int check_disk_change(struct block_device *);
2502
extern int __invalidate_device(struct block_device *, bool);
L
Linus Torvalds 已提交
2503
extern int invalidate_partition(struct gendisk *, int);
2504
#endif
L
Linus Torvalds 已提交
2505 2506
unsigned long invalidate_mapping_pages(struct address_space *mapping,
					pgoff_t start, pgoff_t end);
2507

L
Linus Torvalds 已提交
2508 2509 2510 2511
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))
2512
		invalidate_mapping_pages(inode->i_mapping, 0, -1);
L
Linus Torvalds 已提交
2513 2514 2515 2516 2517 2518 2519 2520
}
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 *);
2521
extern void filemap_fdatawait_keep_errors(struct address_space *);
2522 2523
extern int filemap_fdatawait_range(struct address_space *, loff_t lstart,
				   loff_t lend);
L
Linus Torvalds 已提交
2524 2525 2526
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);
2527 2528
extern int __filemap_fdatawrite_range(struct address_space *mapping,
				loff_t start, loff_t end, int sync_mode);
2529 2530
extern int filemap_fdatawrite_range(struct address_space *mapping,
				loff_t start, loff_t end);
2531
extern int filemap_check_errors(struct address_space *mapping);
2532

2533 2534 2535
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);
2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551 2552

/*
 * Sync the bytes written if this was a synchronous write.  Expect ki_pos
 * to already be updated for the write, and will return either the amount
 * of bytes passed in, or an error if syncing the file failed.
 */
static inline ssize_t generic_write_sync(struct kiocb *iocb, ssize_t count)
{
	if (iocb->ki_flags & IOCB_DSYNC) {
		int ret = vfs_fsync_range(iocb->ki_filp,
				iocb->ki_pos - count, iocb->ki_pos - 1,
				(iocb->ki_flags & IOCB_SYNC) ? 0 : 1);
		if (ret)
			return ret;
	}

	return count;
2553
}
2554

L
Linus Torvalds 已提交
2555 2556
extern void emergency_sync(void);
extern void emergency_remount(void);
2557
#ifdef CONFIG_BLOCK
L
Linus Torvalds 已提交
2558
extern sector_t bmap(struct inode *, sector_t);
2559
#endif
2560
extern int notify_change(struct dentry *, struct iattr *, struct inode **);
2561
extern int inode_permission(struct inode *, int);
2562
extern int __inode_permission(struct inode *, int);
2563
extern int generic_permission(struct inode *, int);
M
Miklos Szeredi 已提交
2564
extern int __check_sticky(struct inode *dir, struct inode *inode);
L
Linus Torvalds 已提交
2565

2566 2567 2568 2569 2570
static inline bool execute_ok(struct inode *inode)
{
	return (inode->i_mode & S_IXUGO) || S_ISDIR(inode->i_mode);
}

2571 2572 2573 2574 2575 2576 2577
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);
}

2578 2579 2580 2581 2582 2583 2584
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);
}

2585 2586 2587 2588 2589 2590 2591
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);
}

2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613
/*
 * 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
2614
	struct inode *inode = file_inode(file);
2615 2616
	return atomic_dec_unless_positive(&inode->i_writecount) ? 0 : -ETXTBSY;
}
L
Linus Torvalds 已提交
2617 2618 2619 2620 2621 2622 2623
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
2624
		atomic_inc(&file_inode(file)->i_writecount);
L
Linus Torvalds 已提交
2625
}
2626 2627 2628 2629 2630
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
2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650
#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
2651
extern int do_pipe_flags(int *, int);
L
Linus Torvalds 已提交
2652

2653 2654 2655
#define __kernel_read_file_id(id) \
	id(UNKNOWN, unknown)		\
	id(FIRMWARE, firmware)		\
2656
	id(FIRMWARE_PREALLOC_BUFFER, firmware)	\
2657 2658 2659 2660 2661 2662 2663 2664 2665
	id(MODULE, kernel-module)		\
	id(KEXEC_IMAGE, kexec-image)		\
	id(KEXEC_INITRAMFS, kexec-initramfs)	\
	id(POLICY, security-policy)		\
	id(MAX_ID, )

#define __fid_enumify(ENUM, dummy) READING_ ## ENUM,
#define __fid_stringify(dummy, str) #str,

2666
enum kernel_read_file_id {
2667 2668 2669 2670 2671
	__kernel_read_file_id(__fid_enumify)
};

static const char * const kernel_read_file_str[] = {
	__kernel_read_file_id(__fid_stringify)
2672 2673
};

K
Kees Cook 已提交
2674
static inline const char *kernel_read_file_id_str(enum kernel_read_file_id id)
2675 2676 2677 2678 2679 2680 2681
{
	if (id < 0 || id >= READING_MAX_ID)
		return kernel_read_file_str[READING_UNKNOWN];

	return kernel_read_file_str[id];
}

M
Mimi Zohar 已提交
2682
extern int kernel_read(struct file *, loff_t, char *, unsigned long);
2683 2684
extern int kernel_read_file(struct file *, void **, loff_t *, loff_t,
			    enum kernel_read_file_id);
2685 2686
extern int kernel_read_file_from_path(char *, void **, loff_t *, loff_t,
				      enum kernel_read_file_id);
2687 2688
extern int kernel_read_file_from_fd(int, void **, loff_t *, loff_t,
				    enum kernel_read_file_id);
2689
extern ssize_t kernel_write(struct file *, const char *, size_t, loff_t);
A
Al Viro 已提交
2690
extern ssize_t __kernel_write(struct file *, const char *, size_t, loff_t *);
L
Linus Torvalds 已提交
2691 2692 2693
extern struct file * open_exec(const char *);
 
/* fs/dcache.c -- generic fs support functions */
Y
Yaowei Bai 已提交
2694
extern bool is_subdir(struct dentry *, struct dentry *);
2695
extern bool path_is_under(struct path *, struct path *);
L
Linus Torvalds 已提交
2696

M
Miklos Szeredi 已提交
2697 2698
extern char *file_path(struct file *, char *, int);

L
Linus Torvalds 已提交
2699 2700 2701
#include <linux/err.h>

/* needed for stackable file system support */
2702
extern loff_t default_llseek(struct file *file, loff_t offset, int whence);
L
Linus Torvalds 已提交
2703

2704
extern loff_t vfs_llseek(struct file *file, loff_t offset, int whence);
L
Linus Torvalds 已提交
2705

2706
extern int inode_init_always(struct super_block *, struct inode *);
L
Linus Torvalds 已提交
2707
extern void inode_init_once(struct inode *);
2708
extern void address_space_init_once(struct address_space *mapping);
L
Linus Torvalds 已提交
2709 2710 2711
extern struct inode * igrab(struct inode *);
extern ino_t iunique(struct super_block *, ino_t);
extern int inode_needs_sync(struct inode *inode);
2712
extern int generic_delete_inode(struct inode *inode);
2713 2714 2715 2716
static inline int generic_drop_inode(struct inode *inode)
{
	return !inode->i_nlink || inode_unhashed(inode);
}
L
Linus Torvalds 已提交
2717

2718 2719 2720
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
2721 2722 2723 2724 2725 2726
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);
2727 2728 2729 2730 2731
extern struct inode *find_inode_nowait(struct super_block *,
				       unsigned long,
				       int (*match)(struct inode *,
						    unsigned long, void *),
				       void *data);
A
Al Viro 已提交
2732 2733
extern int insert_inode_locked4(struct inode *, unsigned long, int (*test)(struct inode *, void *), void *);
extern int insert_inode_locked(struct inode *);
2734 2735 2736 2737 2738
#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
2739
extern void unlock_new_inode(struct inode *);
2740
extern unsigned int get_next_ino(void);
L
Linus Torvalds 已提交
2741 2742

extern void __iget(struct inode * inode);
2743
extern void iget_failed(struct inode *);
2744
extern void clear_inode(struct inode *);
C
Christoph Hellwig 已提交
2745
extern void __destroy_inode(struct inode *);
2746 2747
extern struct inode *new_inode_pseudo(struct super_block *sb);
extern struct inode *new_inode(struct super_block *sb);
2748
extern void free_inode_nonrcu(struct inode *inode);
2749
extern int should_remove_suid(struct dentry *);
2750
extern int file_remove_privs(struct file *);
L
Linus Torvalds 已提交
2751 2752

extern void __insert_inode_hash(struct inode *, unsigned long hashval);
2753 2754
static inline void insert_inode_hash(struct inode *inode)
{
L
Linus Torvalds 已提交
2755 2756
	__insert_inode_hash(inode, inode->i_ino);
}
2757 2758 2759 2760

extern void __remove_inode_hash(struct inode *);
static inline void remove_inode_hash(struct inode *inode)
{
2761
	if (!inode_unhashed(inode) && !hlist_fake(&inode->i_hash))
2762 2763 2764
		__remove_inode_hash(inode);
}

2765
extern void inode_sb_list_add(struct inode *inode);
L
Linus Torvalds 已提交
2766

2767
#ifdef CONFIG_BLOCK
2768
extern blk_qc_t submit_bio(struct bio *);
L
Linus Torvalds 已提交
2769
extern int bdev_read_only(struct block_device *);
2770
#endif
L
Linus Torvalds 已提交
2771 2772 2773 2774 2775 2776
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 *);
2777
extern ssize_t generic_write_checks(struct kiocb *, struct iov_iter *);
A
Al Viro 已提交
2778
extern ssize_t generic_file_read_iter(struct kiocb *, struct iov_iter *);
2779 2780
extern ssize_t __generic_file_write_iter(struct kiocb *, struct iov_iter *);
extern ssize_t generic_file_write_iter(struct kiocb *, struct iov_iter *);
2781
extern ssize_t generic_file_direct_write(struct kiocb *, struct iov_iter *);
2782
extern ssize_t generic_perform_write(struct file *, struct iov_iter *, loff_t);
A
Andrew Morton 已提交
2783

2784 2785 2786
ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos);
ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos);

2787
/* fs/block_dev.c */
2788
extern ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to);
2789
extern ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from);
2790 2791
extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
			int datasync);
A
Al Viro 已提交
2792
extern void block_sync_page(struct page *page);
2793

A
Andrew Morton 已提交
2794
/* fs/splice.c */
2795
extern ssize_t generic_file_splice_read(struct file *, loff_t *,
A
Andrew Morton 已提交
2796
		struct pipe_inode_info *, size_t, unsigned int);
2797 2798
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
2799
extern ssize_t iter_file_splice_write(struct pipe_inode_info *,
2800
		struct file *, loff_t *, size_t, unsigned int);
A
Andrew Morton 已提交
2801
extern ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe,
2802
		struct file *out, loff_t *, size_t len, unsigned int flags);
2803 2804 2805
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
2806

L
Linus Torvalds 已提交
2807 2808
extern void
file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping);
2809 2810
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
2811
extern loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize);
2812
extern loff_t generic_file_llseek(struct file *file, loff_t offset, int whence);
A
Andi Kleen 已提交
2813
extern loff_t generic_file_llseek_size(struct file *file, loff_t offset,
2814
		int whence, loff_t maxsize, loff_t eof);
A
Al Viro 已提交
2815 2816
extern loff_t fixed_size_llseek(struct file *file, loff_t offset,
		int whence, loff_t size);
2817 2818
extern loff_t no_seek_end_llseek_size(struct file *, loff_t, int, loff_t);
extern loff_t no_seek_end_llseek(struct file *, loff_t, int);
L
Linus Torvalds 已提交
2819 2820 2821
extern int generic_file_open(struct inode * inode, struct file * filp);
extern int nonseekable_open(struct inode * inode, struct file * filp);

2822
#ifdef CONFIG_BLOCK
2823
typedef void (dio_submit_t)(struct bio *bio, struct inode *inode,
2824
			    loff_t file_offset);
L
Linus Torvalds 已提交
2825 2826

enum {
2827 2828 2829 2830 2831
	/* need locking between buffered and direct access */
	DIO_LOCKING	= 0x01,

	/* filesystem does not support filling holes */
	DIO_SKIP_HOLES	= 0x02,
2832 2833 2834

	/* filesystem can handle aio writes beyond i_size */
	DIO_ASYNC_EXTEND = 0x04,
2835 2836 2837

	/* inode/fs/bdev does not need truncate protection */
	DIO_SKIP_DIO_COUNT = 0x08,
L
Linus Torvalds 已提交
2838 2839
};

2840 2841
void dio_end_io(struct bio *bio, int error);

2842 2843
ssize_t __blockdev_direct_IO(struct kiocb *iocb, struct inode *inode,
			     struct block_device *bdev, struct iov_iter *iter,
2844
			     get_block_t get_block,
2845 2846
			     dio_iodone_t end_io, dio_submit_t submit_io,
			     int flags);
2847

2848 2849
static inline ssize_t blockdev_direct_IO(struct kiocb *iocb,
					 struct inode *inode,
2850
					 struct iov_iter *iter,
2851
					 get_block_t get_block)
L
Linus Torvalds 已提交
2852
{
2853
	return __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev, iter,
2854
			get_block, NULL, NULL, DIO_LOCKING | DIO_SKIP_HOLES);
L
Linus Torvalds 已提交
2855
}
2856
#endif
L
Linus Torvalds 已提交
2857

2858
void inode_dio_wait(struct inode *inode);
2859 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883

/*
 * inode_dio_begin - signal start of a direct I/O requests
 * @inode: inode the direct I/O happens on
 *
 * This is called once we've finished processing a direct I/O request,
 * and is used to wake up callers waiting for direct I/O to be quiesced.
 */
static inline void inode_dio_begin(struct inode *inode)
{
	atomic_inc(&inode->i_dio_count);
}

/*
 * inode_dio_end - signal finish of a direct I/O requests
 * @inode: inode the direct I/O happens on
 *
 * This is called once we've finished processing a direct I/O request,
 * and is used to wake up callers waiting for direct I/O to be quiesced.
 */
static inline void inode_dio_end(struct inode *inode)
{
	if (atomic_dec_and_test(&inode->i_dio_count))
		wake_up_bit(&inode->i_state, __I_DIO_WAKEUP);
}
2884

2885 2886 2887
extern void inode_set_flags(struct inode *inode, unsigned int flags,
			    unsigned int mask);

2888
extern const struct file_operations generic_ro_fops;
L
Linus Torvalds 已提交
2889 2890 2891

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

A
Al Viro 已提交
2892
extern int readlink_copy(char __user *, int, const char *);
L
Linus Torvalds 已提交
2893
extern int page_readlink(struct dentry *, char __user *, int);
2894 2895 2896
extern const char *page_get_link(struct dentry *, struct inode *,
				 struct delayed_call *);
extern void page_put_link(void *);
2897
extern int __page_symlink(struct inode *inode, const char *symname, int len,
2898
		int nofs);
L
Linus Torvalds 已提交
2899
extern int page_symlink(struct inode *inode, const char *symname, int len);
2900
extern const struct inode_operations page_symlink_inode_operations;
2901
extern void kfree_link(void *);
L
Linus Torvalds 已提交
2902 2903
extern int generic_readlink(struct dentry *, char __user *, int);
extern void generic_fillattr(struct inode *, struct kstat *);
J
J. Bruce Fields 已提交
2904
int vfs_getattr_nosec(struct path *path, struct kstat *stat);
A
Al Viro 已提交
2905
extern int vfs_getattr(struct path *, struct kstat *);
2906
void __inode_add_bytes(struct inode *inode, loff_t bytes);
L
Linus Torvalds 已提交
2907
void inode_add_bytes(struct inode *inode, loff_t bytes);
2908
void __inode_sub_bytes(struct inode *inode, loff_t bytes);
L
Linus Torvalds 已提交
2909 2910 2911
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);
2912 2913
const char *simple_get_link(struct dentry *, struct inode *,
			    struct delayed_call *);
A
Al Viro 已提交
2914
extern const struct inode_operations simple_symlink_inode_operations;
L
Linus Torvalds 已提交
2915

2916
extern int iterate_dir(struct file *, struct dir_context *);
L
Linus Torvalds 已提交
2917

2918 2919
extern int vfs_stat(const char __user *, struct kstat *);
extern int vfs_lstat(const char __user *, struct kstat *);
L
Linus Torvalds 已提交
2920
extern int vfs_fstat(unsigned int, struct kstat *);
2921
extern int vfs_fstatat(int , const char __user *, struct kstat *, int);
L
Linus Torvalds 已提交
2922

2923
extern int __generic_block_fiemap(struct inode *inode,
J
Josef Bacik 已提交
2924 2925 2926
				  struct fiemap_extent_info *fieinfo,
				  loff_t start, loff_t len,
				  get_block_t *get_block);
2927 2928 2929
extern int generic_block_fiemap(struct inode *inode,
				struct fiemap_extent_info *fieinfo, u64 start,
				u64 len, get_block_t *get_block);
L
Linus Torvalds 已提交
2930

2931 2932
extern void get_filesystem(struct file_system_type *fs);
extern void put_filesystem(struct file_system_type *fs);
L
Linus Torvalds 已提交
2933 2934
extern struct file_system_type *get_fs_type(const char *name);
extern struct super_block *get_super(struct block_device *);
2935
extern struct super_block *get_super_thawed(struct block_device *);
2936
extern struct super_block *get_active_super(struct block_device *bdev);
L
Linus Torvalds 已提交
2937
extern void drop_super(struct super_block *sb);
A
Al Viro 已提交
2938
extern void iterate_supers(void (*)(struct super_block *, void *), void *);
A
Al Viro 已提交
2939 2940
extern void iterate_supers_type(struct file_system_type *,
			        void (*)(struct super_block *, void *), void *);
L
Linus Torvalds 已提交
2941 2942 2943 2944

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);
2945
extern int dcache_readdir(struct file *, struct dir_context *);
2946
extern int simple_setattr(struct dentry *, struct iattr *);
L
Linus Torvalds 已提交
2947
extern int simple_getattr(struct vfsmount *, struct dentry *, struct kstat *);
2948
extern int simple_statfs(struct dentry *, struct kstatfs *);
S
Stephen Boyd 已提交
2949
extern int simple_open(struct inode *inode, struct file *file);
L
Linus Torvalds 已提交
2950 2951 2952
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 *);
2953 2954
extern int simple_rename(struct inode *, struct dentry *,
			 struct inode *, struct dentry *, unsigned int);
2955
extern int noop_fsync(struct file *, loff_t, loff_t, int);
L
Linus Torvalds 已提交
2956 2957
extern int simple_empty(struct dentry *);
extern int simple_readpage(struct file *file, struct page *page);
2958 2959 2960 2961 2962 2963
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);
2964
extern int always_delete_dentry(const struct dentry *);
A
Al Viro 已提交
2965
extern struct inode *alloc_anon_inode(struct super_block *);
2966
extern int simple_nosetlease(struct file *, long, struct file_lock **, void **);
2967
extern const struct dentry_operations simple_dentry_operations;
L
Linus Torvalds 已提交
2968

A
Al Viro 已提交
2969
extern struct dentry *simple_lookup(struct inode *, struct dentry *, unsigned int flags);
L
Linus Torvalds 已提交
2970
extern ssize_t generic_read_dir(struct file *, char __user *, size_t, loff_t *);
2971
extern const struct file_operations simple_dir_operations;
2972
extern const struct inode_operations simple_dir_inode_operations;
2973 2974
extern void make_empty_dir_inode(struct inode *inode);
extern bool is_empty_dir_inode(struct inode *inode);
2975
struct tree_descr { char *name; const struct file_operations *ops; int mode; };
L
Linus Torvalds 已提交
2976
struct dentry *d_alloc_name(struct dentry *, const char *);
2977
extern int simple_fill_super(struct super_block *, unsigned long, struct tree_descr *);
2978
extern int simple_pin_fs(struct file_system_type *, struct vfsmount **mount, int *count);
L
Linus Torvalds 已提交
2979 2980
extern void simple_release_fs(struct vfsmount **mount, int *count);

2981 2982
extern ssize_t simple_read_from_buffer(void __user *to, size_t count,
			loff_t *ppos, const void *from, size_t available);
2983 2984
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
2985

2986
extern int __generic_file_fsync(struct file *, loff_t, loff_t, int);
2987
extern int generic_file_fsync(struct file *, loff_t, loff_t, int);
A
Al Viro 已提交
2988

2989 2990
extern int generic_check_addressable(unsigned, u64);

2991
#ifdef CONFIG_MIGRATION
2992
extern int buffer_migrate_page(struct address_space *,
2993 2994
				struct page *, struct page *,
				enum migrate_mode);
2995 2996 2997 2998
#else
#define buffer_migrate_page NULL
#endif

N
npiggin@suse.de 已提交
2999 3000
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
3001
extern void setattr_copy(struct inode *inode, const struct iattr *attr);
L
Linus Torvalds 已提交
3002

3003
extern int file_update_time(struct file *file);
L
Linus Torvalds 已提交
3004

3005
extern int generic_show_options(struct seq_file *m, struct dentry *root);
3006
extern void save_mount_options(struct super_block *sb, char *options);
3007
extern void replace_mount_options(struct super_block *sb, char *options);
3008

3009 3010
static inline bool io_is_direct(struct file *filp)
{
3011
	return (filp->f_flags & O_DIRECT) || IS_DAX(filp->f_mapping->host);
3012 3013
}

3014 3015 3016 3017 3018 3019 3020
static inline int iocb_flags(struct file *file)
{
	int res = 0;
	if (file->f_flags & O_APPEND)
		res |= IOCB_APPEND;
	if (io_is_direct(file))
		res |= IOCB_DIRECT;
3021 3022 3023 3024
	if ((file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host))
		res |= IOCB_DSYNC;
	if (file->f_flags & __O_SYNC)
		res |= IOCB_SYNC;
3025 3026 3027
	return res;
}

L
Linus Torvalds 已提交
3028 3029 3030 3031
static inline ino_t parent_ino(struct dentry *dentry)
{
	ino_t res;

N
Nick Piggin 已提交
3032 3033 3034 3035
	/*
	 * 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
3036 3037 3038 3039 3040 3041 3042 3043 3044 3045 3046 3047 3048 3049 3050 3051 3052 3053 3054 3055 3056 3057 3058 3059 3060
	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);

3061
void simple_transaction_set(struct file *file, size_t n);
L
Linus Torvalds 已提交
3062

3063 3064 3065 3066 3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080 3081 3082 3083 3084
/*
 * 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);	\
}									\
3085
static const struct file_operations __fops = {				\
3086 3087
	.owner	 = THIS_MODULE,						\
	.open	 = __fops ## _open,					\
3088
	.release = simple_attr_release,					\
3089 3090
	.read	 = simple_attr_read,					\
	.write	 = simple_attr_write,					\
3091
	.llseek	 = generic_file_llseek,					\
3092
}
3093

3094 3095
static inline __printf(1, 2)
void __simple_attr_check_format(const char *fmt, ...)
3096 3097 3098 3099 3100
{
	/* don't do anything, just let the compiler check the arguments; */
}

int simple_attr_open(struct inode *inode, struct file *file,
3101
		     int (*get)(void *, u64 *), int (*set)(void *, u64),
3102
		     const char *fmt);
3103
int simple_attr_release(struct inode *inode, struct file *file);
3104 3105 3106 3107 3108
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
3109
struct ctl_table;
3110
int proc_nr_files(struct ctl_table *table, int write,
3111
		  void __user *buffer, size_t *lenp, loff_t *ppos);
3112 3113
int proc_nr_dentry(struct ctl_table *table, int write,
		  void __user *buffer, size_t *lenp, loff_t *ppos);
3114 3115
int proc_nr_inodes(struct ctl_table *table, int write,
		   void __user *buffer, size_t *lenp, loff_t *ppos);
3116
int __init get_filesystem_list(char *buf);
3117

N
Namhyung Kim 已提交
3118
#define __FMODE_EXEC		((__force int) FMODE_EXEC)
3119 3120
#define __FMODE_NONOTIFY	((__force int) FMODE_NONOTIFY)

A
Al Viro 已提交
3121
#define ACC_MODE(x) ("\004\002\006\006"[(x)&O_ACCMODE])
E
Eric Paris 已提交
3122
#define OPEN_FMODE(flag) ((__force fmode_t)(((flag + 1) & O_ACCMODE) | \
3123
					    (flag & __FMODE_NONOTIFY)))
A
Al Viro 已提交
3124

Y
Yaowei Bai 已提交
3125
static inline bool is_sxid(umode_t mode)
3126 3127 3128 3129
{
	return (mode & S_ISUID) || ((mode & S_ISGID) && (mode & S_IXGRP));
}

M
Miklos Szeredi 已提交
3130 3131 3132 3133 3134 3135 3136 3137
static inline int check_sticky(struct inode *dir, struct inode *inode)
{
	if (!(dir->i_mode & S_ISVTX))
		return 0;

	return __check_sticky(dir, inode);
}

3138 3139
static inline void inode_has_no_xattr(struct inode *inode)
{
A
Al Viro 已提交
3140
	if (!is_sxid(inode->i_mode) && (inode->i_sb->s_flags & MS_NOSEC))
3141 3142 3143
		inode->i_flags |= S_NOSEC;
}

A
Al Viro 已提交
3144 3145 3146 3147 3148
static inline bool is_root_inode(struct inode *inode)
{
	return inode == inode->i_sb->s_root->d_inode;
}

3149 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159 3160 3161 3162 3163 3164 3165 3166 3167 3168 3169 3170 3171 3172 3173 3174 3175 3176 3177 3178
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
3179 3180
static inline bool dir_relax(struct inode *inode)
{
A
Al Viro 已提交
3181 3182
	inode_unlock(inode);
	inode_lock(inode);
A
Al Viro 已提交
3183 3184
	return !IS_DEADDIR(inode);
}
3185

A
Al Viro 已提交
3186 3187 3188 3189 3190 3191 3192
static inline bool dir_relax_shared(struct inode *inode)
{
	inode_unlock_shared(inode);
	inode_lock_shared(inode);
	return !IS_DEADDIR(inode);
}

3193
extern bool path_noexec(const struct path *path);
3194
extern void inode_nohighmem(struct inode *inode);
3195

L
Linus Torvalds 已提交
3196
#endif /* _LINUX_FS_H */