xref: /linux-6.15/include/linux/fs.h (revision 77d1c8eb)
1 #ifndef _LINUX_FS_H
2 #define _LINUX_FS_H
3 
4 /*
5  * This file has definitions for some important file table
6  * structures etc.
7  */
8 
9 #include <linux/limits.h>
10 #include <linux/ioctl.h>
11 #include <linux/blk_types.h>
12 #include <linux/types.h>
13 
14 /*
15  * It's silly to have NR_OPEN bigger than NR_FILE, but you can change
16  * the file limit at runtime and only root can increase the per-process
17  * nr_file rlimit, so it's safe to set up a ridiculously high absolute
18  * upper limit on files-per-process.
19  *
20  * Some programs (notably those using select()) may have to be
21  * recompiled to take full advantage of the new limits..
22  */
23 
24 /* Fixed constants first: */
25 #undef NR_OPEN
26 #define INR_OPEN 1024		/* Initial setting for nfile rlimits */
27 
28 #define BLOCK_SIZE_BITS 10
29 #define BLOCK_SIZE (1<<BLOCK_SIZE_BITS)
30 
31 #define SEEK_SET	0	/* seek relative to beginning of file */
32 #define SEEK_CUR	1	/* seek relative to current file position */
33 #define SEEK_END	2	/* seek relative to end of file */
34 #define SEEK_MAX	SEEK_END
35 
36 struct fstrim_range {
37 	__u64 start;
38 	__u64 len;
39 	__u64 minlen;
40 };
41 
42 /* And dynamically-tunable limits and defaults: */
43 struct files_stat_struct {
44 	unsigned long nr_files;		/* read only */
45 	unsigned long nr_free_files;	/* read only */
46 	unsigned long max_files;		/* tunable */
47 };
48 
49 struct inodes_stat_t {
50 	int nr_inodes;
51 	int nr_unused;
52 	int dummy[5];		/* padding for sysctl ABI compatibility */
53 };
54 
55 
56 #define NR_FILE  8192	/* this can well be larger on a larger system */
57 
58 #define MAY_EXEC 1
59 #define MAY_WRITE 2
60 #define MAY_READ 4
61 #define MAY_APPEND 8
62 #define MAY_ACCESS 16
63 #define MAY_OPEN 32
64 #define MAY_CHDIR 64
65 
66 /*
67  * flags in file.f_mode.  Note that FMODE_READ and FMODE_WRITE must correspond
68  * to O_WRONLY and O_RDWR via the strange trick in __dentry_open()
69  */
70 
71 /* file is open for reading */
72 #define FMODE_READ		((__force fmode_t)0x1)
73 /* file is open for writing */
74 #define FMODE_WRITE		((__force fmode_t)0x2)
75 /* file is seekable */
76 #define FMODE_LSEEK		((__force fmode_t)0x4)
77 /* file can be accessed using pread */
78 #define FMODE_PREAD		((__force fmode_t)0x8)
79 /* file can be accessed using pwrite */
80 #define FMODE_PWRITE		((__force fmode_t)0x10)
81 /* File is opened for execution with sys_execve / sys_uselib */
82 #define FMODE_EXEC		((__force fmode_t)0x20)
83 /* File is opened with O_NDELAY (only set for block devices) */
84 #define FMODE_NDELAY		((__force fmode_t)0x40)
85 /* File is opened with O_EXCL (only set for block devices) */
86 #define FMODE_EXCL		((__force fmode_t)0x80)
87 /* File is opened using open(.., 3, ..) and is writeable only for ioctls
88    (specialy hack for floppy.c) */
89 #define FMODE_WRITE_IOCTL	((__force fmode_t)0x100)
90 
91 /*
92  * Don't update ctime and mtime.
93  *
94  * Currently a special hack for the XFS open_by_handle ioctl, but we'll
95  * hopefully graduate it to a proper O_CMTIME flag supported by open(2) soon.
96  */
97 #define FMODE_NOCMTIME		((__force fmode_t)0x800)
98 
99 /* Expect random access pattern */
100 #define FMODE_RANDOM		((__force fmode_t)0x1000)
101 
102 /* File is huge (eg. /dev/kmem): treat loff_t as unsigned */
103 #define FMODE_UNSIGNED_OFFSET	((__force fmode_t)0x2000)
104 
105 /* File is opened with O_PATH; almost nothing can be done with it */
106 #define FMODE_PATH		((__force fmode_t)0x4000)
107 
108 /* File was opened by fanotify and shouldn't generate fanotify events */
109 #define FMODE_NONOTIFY		((__force fmode_t)0x1000000)
110 
111 /*
112  * The below are the various read and write types that we support. Some of
113  * them include behavioral modifiers that send information down to the
114  * block layer and IO scheduler. Terminology:
115  *
116  *	The block layer uses device plugging to defer IO a little bit, in
117  *	the hope that we will see more IO very shortly. This increases
118  *	coalescing of adjacent IO and thus reduces the number of IOs we
119  *	have to send to the device. It also allows for better queuing,
120  *	if the IO isn't mergeable. If the caller is going to be waiting
121  *	for the IO, then he must ensure that the device is unplugged so
122  *	that the IO is dispatched to the driver.
123  *
124  *	All IO is handled async in Linux. This is fine for background
125  *	writes, but for reads or writes that someone waits for completion
126  *	on, we want to notify the block layer and IO scheduler so that they
127  *	know about it. That allows them to make better scheduling
128  *	decisions. So when the below references 'sync' and 'async', it
129  *	is referencing this priority hint.
130  *
131  * With that in mind, the available types are:
132  *
133  * READ			A normal read operation. Device will be plugged.
134  * READ_SYNC		A synchronous read. Device is not plugged, caller can
135  *			immediately wait on this read without caring about
136  *			unplugging.
137  * READA		Used for read-ahead operations. Lower priority, and the
138  *			block layer could (in theory) choose to ignore this
139  *			request if it runs into resource problems.
140  * WRITE		A normal async write. Device will be plugged.
141  * WRITE_SYNC_PLUG	Synchronous write. Identical to WRITE, but passes down
142  *			the hint that someone will be waiting on this IO
143  *			shortly. The device must still be unplugged explicitly,
144  *			WRITE_SYNC_PLUG does not do this as we could be
145  *			submitting more writes before we actually wait on any
146  *			of them.
147  * WRITE_SYNC		Like WRITE_SYNC_PLUG, but also unplugs the device
148  *			immediately after submission. The write equivalent
149  *			of READ_SYNC.
150  * WRITE_ODIRECT_PLUG	Special case write for O_DIRECT only.
151  * WRITE_FLUSH		Like WRITE_SYNC but with preceding cache flush.
152  * WRITE_FUA		Like WRITE_SYNC but data is guaranteed to be on
153  *			non-volatile media on completion.
154  * WRITE_FLUSH_FUA	Combination of WRITE_FLUSH and FUA. The IO is preceded
155  *			by a cache flush and data is guaranteed to be on
156  *			non-volatile media on completion.
157  *
158  */
159 #define RW_MASK			REQ_WRITE
160 #define RWA_MASK		REQ_RAHEAD
161 
162 #define READ			0
163 #define WRITE			RW_MASK
164 #define READA			RWA_MASK
165 
166 #define READ_SYNC		(READ | REQ_SYNC | REQ_UNPLUG)
167 #define READ_META		(READ | REQ_META)
168 #define WRITE_SYNC_PLUG		(WRITE | REQ_SYNC | REQ_NOIDLE)
169 #define WRITE_SYNC		(WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG)
170 #define WRITE_ODIRECT_PLUG	(WRITE | REQ_SYNC)
171 #define WRITE_META		(WRITE | REQ_META)
172 #define WRITE_FLUSH		(WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
173 				 REQ_FLUSH)
174 #define WRITE_FUA		(WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
175 				 REQ_FUA)
176 #define WRITE_FLUSH_FUA		(WRITE | REQ_SYNC | REQ_NOIDLE | REQ_UNPLUG | \
177 				 REQ_FLUSH | REQ_FUA)
178 
179 #define SEL_IN		1
180 #define SEL_OUT		2
181 #define SEL_EX		4
182 
183 /* public flags for file_system_type */
184 #define FS_REQUIRES_DEV 1
185 #define FS_BINARY_MOUNTDATA 2
186 #define FS_HAS_SUBTYPE 4
187 #define FS_REVAL_DOT	16384	/* Check the paths ".", ".." for staleness */
188 #define FS_RENAME_DOES_D_MOVE	32768	/* FS will handle d_move()
189 					 * during rename() internally.
190 					 */
191 
192 /*
193  * These are the fs-independent mount-flags: up to 32 flags are supported
194  */
195 #define MS_RDONLY	 1	/* Mount read-only */
196 #define MS_NOSUID	 2	/* Ignore suid and sgid bits */
197 #define MS_NODEV	 4	/* Disallow access to device special files */
198 #define MS_NOEXEC	 8	/* Disallow program execution */
199 #define MS_SYNCHRONOUS	16	/* Writes are synced at once */
200 #define MS_REMOUNT	32	/* Alter flags of a mounted FS */
201 #define MS_MANDLOCK	64	/* Allow mandatory locks on an FS */
202 #define MS_DIRSYNC	128	/* Directory modifications are synchronous */
203 #define MS_NOATIME	1024	/* Do not update access times. */
204 #define MS_NODIRATIME	2048	/* Do not update directory access times */
205 #define MS_BIND		4096
206 #define MS_MOVE		8192
207 #define MS_REC		16384
208 #define MS_VERBOSE	32768	/* War is peace. Verbosity is silence.
209 				   MS_VERBOSE is deprecated. */
210 #define MS_SILENT	32768
211 #define MS_POSIXACL	(1<<16)	/* VFS does not apply the umask */
212 #define MS_UNBINDABLE	(1<<17)	/* change to unbindable */
213 #define MS_PRIVATE	(1<<18)	/* change to private */
214 #define MS_SLAVE	(1<<19)	/* change to slave */
215 #define MS_SHARED	(1<<20)	/* change to shared */
216 #define MS_RELATIME	(1<<21)	/* Update atime relative to mtime/ctime. */
217 #define MS_KERNMOUNT	(1<<22) /* this is a kern_mount call */
218 #define MS_I_VERSION	(1<<23) /* Update inode I_version field */
219 #define MS_STRICTATIME	(1<<24) /* Always perform atime updates */
220 #define MS_BORN		(1<<29)
221 #define MS_ACTIVE	(1<<30)
222 #define MS_NOUSER	(1<<31)
223 
224 /*
225  * Superblock flags that can be altered by MS_REMOUNT
226  */
227 #define MS_RMT_MASK	(MS_RDONLY|MS_SYNCHRONOUS|MS_MANDLOCK|MS_I_VERSION)
228 
229 /*
230  * Old magic mount flag and mask
231  */
232 #define MS_MGC_VAL 0xC0ED0000
233 #define MS_MGC_MSK 0xffff0000
234 
235 /* Inode flags - they have nothing to superblock flags now */
236 
237 #define S_SYNC		1	/* Writes are synced at once */
238 #define S_NOATIME	2	/* Do not update access times */
239 #define S_APPEND	4	/* Append-only file */
240 #define S_IMMUTABLE	8	/* Immutable file */
241 #define S_DEAD		16	/* removed, but still open directory */
242 #define S_NOQUOTA	32	/* Inode is not counted to quota */
243 #define S_DIRSYNC	64	/* Directory modifications are synchronous */
244 #define S_NOCMTIME	128	/* Do not update file c/mtime */
245 #define S_SWAPFILE	256	/* Do not truncate: swapon got its bmaps */
246 #define S_PRIVATE	512	/* Inode is fs-internal */
247 #define S_IMA		1024	/* Inode has an associated IMA struct */
248 #define S_AUTOMOUNT	2048	/* Automount/referral quasi-directory */
249 
250 /*
251  * Note that nosuid etc flags are inode-specific: setting some file-system
252  * flags just means all the inodes inherit those flags by default. It might be
253  * possible to override it selectively if you really wanted to with some
254  * ioctl() that is not currently implemented.
255  *
256  * Exception: MS_RDONLY is always applied to the entire file system.
257  *
258  * Unfortunately, it is possible to change a filesystems flags with it mounted
259  * with files in use.  This means that all of the inodes will not have their
260  * i_flags updated.  Hence, i_flags no longer inherit the superblock mount
261  * flags, so these have to be checked separately. -- [email protected]
262  */
263 #define __IS_FLG(inode,flg) ((inode)->i_sb->s_flags & (flg))
264 
265 #define IS_RDONLY(inode) ((inode)->i_sb->s_flags & MS_RDONLY)
266 #define IS_SYNC(inode)		(__IS_FLG(inode, MS_SYNCHRONOUS) || \
267 					((inode)->i_flags & S_SYNC))
268 #define IS_DIRSYNC(inode)	(__IS_FLG(inode, MS_SYNCHRONOUS|MS_DIRSYNC) || \
269 					((inode)->i_flags & (S_SYNC|S_DIRSYNC)))
270 #define IS_MANDLOCK(inode)	__IS_FLG(inode, MS_MANDLOCK)
271 #define IS_NOATIME(inode)   __IS_FLG(inode, MS_RDONLY|MS_NOATIME)
272 #define IS_I_VERSION(inode)   __IS_FLG(inode, MS_I_VERSION)
273 
274 #define IS_NOQUOTA(inode)	((inode)->i_flags & S_NOQUOTA)
275 #define IS_APPEND(inode)	((inode)->i_flags & S_APPEND)
276 #define IS_IMMUTABLE(inode)	((inode)->i_flags & S_IMMUTABLE)
277 #define IS_POSIXACL(inode)	__IS_FLG(inode, MS_POSIXACL)
278 
279 #define IS_DEADDIR(inode)	((inode)->i_flags & S_DEAD)
280 #define IS_NOCMTIME(inode)	((inode)->i_flags & S_NOCMTIME)
281 #define IS_SWAPFILE(inode)	((inode)->i_flags & S_SWAPFILE)
282 #define IS_PRIVATE(inode)	((inode)->i_flags & S_PRIVATE)
283 #define IS_IMA(inode)		((inode)->i_flags & S_IMA)
284 #define IS_AUTOMOUNT(inode)	((inode)->i_flags & S_AUTOMOUNT)
285 
286 /* the read-only stuff doesn't really belong here, but any other place is
287    probably as bad and I don't want to create yet another include file. */
288 
289 #define BLKROSET   _IO(0x12,93)	/* set device read-only (0 = read-write) */
290 #define BLKROGET   _IO(0x12,94)	/* get read-only status (0 = read_write) */
291 #define BLKRRPART  _IO(0x12,95)	/* re-read partition table */
292 #define BLKGETSIZE _IO(0x12,96)	/* return device size /512 (long *arg) */
293 #define BLKFLSBUF  _IO(0x12,97)	/* flush buffer cache */
294 #define BLKRASET   _IO(0x12,98)	/* set read ahead for block device */
295 #define BLKRAGET   _IO(0x12,99)	/* get current read ahead setting */
296 #define BLKFRASET  _IO(0x12,100)/* set filesystem (mm/filemap.c) read-ahead */
297 #define BLKFRAGET  _IO(0x12,101)/* get filesystem (mm/filemap.c) read-ahead */
298 #define BLKSECTSET _IO(0x12,102)/* set max sectors per request (ll_rw_blk.c) */
299 #define BLKSECTGET _IO(0x12,103)/* get max sectors per request (ll_rw_blk.c) */
300 #define BLKSSZGET  _IO(0x12,104)/* get block device sector size */
301 #if 0
302 #define BLKPG      _IO(0x12,105)/* See blkpg.h */
303 
304 /* Some people are morons.  Do not use sizeof! */
305 
306 #define BLKELVGET  _IOR(0x12,106,size_t)/* elevator get */
307 #define BLKELVSET  _IOW(0x12,107,size_t)/* elevator set */
308 /* This was here just to show that the number is taken -
309    probably all these _IO(0x12,*) ioctls should be moved to blkpg.h. */
310 #endif
311 /* A jump here: 108-111 have been used for various private purposes. */
312 #define BLKBSZGET  _IOR(0x12,112,size_t)
313 #define BLKBSZSET  _IOW(0x12,113,size_t)
314 #define BLKGETSIZE64 _IOR(0x12,114,size_t)	/* return device size in bytes (u64 *arg) */
315 #define BLKTRACESETUP _IOWR(0x12,115,struct blk_user_trace_setup)
316 #define BLKTRACESTART _IO(0x12,116)
317 #define BLKTRACESTOP _IO(0x12,117)
318 #define BLKTRACETEARDOWN _IO(0x12,118)
319 #define BLKDISCARD _IO(0x12,119)
320 #define BLKIOMIN _IO(0x12,120)
321 #define BLKIOOPT _IO(0x12,121)
322 #define BLKALIGNOFF _IO(0x12,122)
323 #define BLKPBSZGET _IO(0x12,123)
324 #define BLKDISCARDZEROES _IO(0x12,124)
325 #define BLKSECDISCARD _IO(0x12,125)
326 
327 #define BMAP_IOCTL 1		/* obsolete - kept for compatibility */
328 #define FIBMAP	   _IO(0x00,1)	/* bmap access */
329 #define FIGETBSZ   _IO(0x00,2)	/* get the block size used for bmap */
330 #define FIFREEZE	_IOWR('X', 119, int)	/* Freeze */
331 #define FITHAW		_IOWR('X', 120, int)	/* Thaw */
332 #define FITRIM		_IOWR('X', 121, struct fstrim_range)	/* Trim */
333 
334 #define	FS_IOC_GETFLAGS			_IOR('f', 1, long)
335 #define	FS_IOC_SETFLAGS			_IOW('f', 2, long)
336 #define	FS_IOC_GETVERSION		_IOR('v', 1, long)
337 #define	FS_IOC_SETVERSION		_IOW('v', 2, long)
338 #define FS_IOC_FIEMAP			_IOWR('f', 11, struct fiemap)
339 #define FS_IOC32_GETFLAGS		_IOR('f', 1, int)
340 #define FS_IOC32_SETFLAGS		_IOW('f', 2, int)
341 #define FS_IOC32_GETVERSION		_IOR('v', 1, int)
342 #define FS_IOC32_SETVERSION		_IOW('v', 2, int)
343 
344 /*
345  * Inode flags (FS_IOC_GETFLAGS / FS_IOC_SETFLAGS)
346  */
347 #define	FS_SECRM_FL			0x00000001 /* Secure deletion */
348 #define	FS_UNRM_FL			0x00000002 /* Undelete */
349 #define	FS_COMPR_FL			0x00000004 /* Compress file */
350 #define FS_SYNC_FL			0x00000008 /* Synchronous updates */
351 #define FS_IMMUTABLE_FL			0x00000010 /* Immutable file */
352 #define FS_APPEND_FL			0x00000020 /* writes to file may only append */
353 #define FS_NODUMP_FL			0x00000040 /* do not dump file */
354 #define FS_NOATIME_FL			0x00000080 /* do not update atime */
355 /* Reserved for compression usage... */
356 #define FS_DIRTY_FL			0x00000100
357 #define FS_COMPRBLK_FL			0x00000200 /* One or more compressed clusters */
358 #define FS_NOCOMP_FL			0x00000400 /* Don't compress */
359 #define FS_ECOMPR_FL			0x00000800 /* Compression error */
360 /* End compression flags --- maybe not all used */
361 #define FS_BTREE_FL			0x00001000 /* btree format dir */
362 #define FS_INDEX_FL			0x00001000 /* hash-indexed directory */
363 #define FS_IMAGIC_FL			0x00002000 /* AFS directory */
364 #define FS_JOURNAL_DATA_FL		0x00004000 /* Reserved for ext3 */
365 #define FS_NOTAIL_FL			0x00008000 /* file tail should not be merged */
366 #define FS_DIRSYNC_FL			0x00010000 /* dirsync behaviour (directories only) */
367 #define FS_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/
368 #define FS_EXTENT_FL			0x00080000 /* Extents */
369 #define FS_DIRECTIO_FL			0x00100000 /* Use direct i/o */
370 #define FS_RESERVED_FL			0x80000000 /* reserved for ext2 lib */
371 
372 #define FS_FL_USER_VISIBLE		0x0003DFFF /* User visible flags */
373 #define FS_FL_USER_MODIFIABLE		0x000380FF /* User modifiable flags */
374 
375 
376 #define SYNC_FILE_RANGE_WAIT_BEFORE	1
377 #define SYNC_FILE_RANGE_WRITE		2
378 #define SYNC_FILE_RANGE_WAIT_AFTER	4
379 
380 #ifdef __KERNEL__
381 
382 #include <linux/linkage.h>
383 #include <linux/wait.h>
384 #include <linux/types.h>
385 #include <linux/kdev_t.h>
386 #include <linux/dcache.h>
387 #include <linux/path.h>
388 #include <linux/stat.h>
389 #include <linux/cache.h>
390 #include <linux/list.h>
391 #include <linux/radix-tree.h>
392 #include <linux/prio_tree.h>
393 #include <linux/init.h>
394 #include <linux/pid.h>
395 #include <linux/mutex.h>
396 #include <linux/capability.h>
397 #include <linux/semaphore.h>
398 #include <linux/fiemap.h>
399 #include <linux/rculist_bl.h>
400 
401 #include <asm/atomic.h>
402 #include <asm/byteorder.h>
403 
404 struct export_operations;
405 struct hd_geometry;
406 struct iovec;
407 struct nameidata;
408 struct kiocb;
409 struct kobject;
410 struct pipe_inode_info;
411 struct poll_table_struct;
412 struct kstatfs;
413 struct vm_area_struct;
414 struct vfsmount;
415 struct cred;
416 
417 extern void __init inode_init(void);
418 extern void __init inode_init_early(void);
419 extern void __init files_init(unsigned long);
420 
421 extern struct files_stat_struct files_stat;
422 extern unsigned long get_max_files(void);
423 extern int sysctl_nr_open;
424 extern struct inodes_stat_t inodes_stat;
425 extern int leases_enable, lease_break_time;
426 
427 struct buffer_head;
428 typedef int (get_block_t)(struct inode *inode, sector_t iblock,
429 			struct buffer_head *bh_result, int create);
430 typedef void (dio_iodone_t)(struct kiocb *iocb, loff_t offset,
431 			ssize_t bytes, void *private, int ret,
432 			bool is_async);
433 
434 /*
435  * Attribute flags.  These should be or-ed together to figure out what
436  * has been changed!
437  */
438 #define ATTR_MODE	(1 << 0)
439 #define ATTR_UID	(1 << 1)
440 #define ATTR_GID	(1 << 2)
441 #define ATTR_SIZE	(1 << 3)
442 #define ATTR_ATIME	(1 << 4)
443 #define ATTR_MTIME	(1 << 5)
444 #define ATTR_CTIME	(1 << 6)
445 #define ATTR_ATIME_SET	(1 << 7)
446 #define ATTR_MTIME_SET	(1 << 8)
447 #define ATTR_FORCE	(1 << 9) /* Not a change, but a change it */
448 #define ATTR_ATTR_FLAG	(1 << 10)
449 #define ATTR_KILL_SUID	(1 << 11)
450 #define ATTR_KILL_SGID	(1 << 12)
451 #define ATTR_FILE	(1 << 13)
452 #define ATTR_KILL_PRIV	(1 << 14)
453 #define ATTR_OPEN	(1 << 15) /* Truncating from open(O_TRUNC) */
454 #define ATTR_TIMES_SET	(1 << 16)
455 
456 /*
457  * This is the Inode Attributes structure, used for notify_change().  It
458  * uses the above definitions as flags, to know which values have changed.
459  * Also, in this manner, a Filesystem can look at only the values it cares
460  * about.  Basically, these are the attributes that the VFS layer can
461  * request to change from the FS layer.
462  *
463  * Derek Atkins <[email protected]> 94-10-20
464  */
465 struct iattr {
466 	unsigned int	ia_valid;
467 	umode_t		ia_mode;
468 	uid_t		ia_uid;
469 	gid_t		ia_gid;
470 	loff_t		ia_size;
471 	struct timespec	ia_atime;
472 	struct timespec	ia_mtime;
473 	struct timespec	ia_ctime;
474 
475 	/*
476 	 * Not an attribute, but an auxilary info for filesystems wanting to
477 	 * implement an ftruncate() like method.  NOTE: filesystem should
478 	 * check for (ia_valid & ATTR_FILE), and not for (ia_file != NULL).
479 	 */
480 	struct file	*ia_file;
481 };
482 
483 /*
484  * Includes for diskquotas.
485  */
486 #include <linux/quota.h>
487 
488 /**
489  * enum positive_aop_returns - aop return codes with specific semantics
490  *
491  * @AOP_WRITEPAGE_ACTIVATE: Informs the caller that page writeback has
492  * 			    completed, that the page is still locked, and
493  * 			    should be considered active.  The VM uses this hint
494  * 			    to return the page to the active list -- it won't
495  * 			    be a candidate for writeback again in the near
496  * 			    future.  Other callers must be careful to unlock
497  * 			    the page if they get this return.  Returned by
498  * 			    writepage();
499  *
500  * @AOP_TRUNCATED_PAGE: The AOP method that was handed a locked page has
501  *  			unlocked it and the page might have been truncated.
502  *  			The caller should back up to acquiring a new page and
503  *  			trying again.  The aop will be taking reasonable
504  *  			precautions not to livelock.  If the caller held a page
505  *  			reference, it should drop it before retrying.  Returned
506  *  			by readpage().
507  *
508  * address_space_operation functions return these large constants to indicate
509  * special semantics to the caller.  These are much larger than the bytes in a
510  * page to allow for functions that return the number of bytes operated on in a
511  * given page.
512  */
513 
514 enum positive_aop_returns {
515 	AOP_WRITEPAGE_ACTIVATE	= 0x80000,
516 	AOP_TRUNCATED_PAGE	= 0x80001,
517 };
518 
519 #define AOP_FLAG_UNINTERRUPTIBLE	0x0001 /* will not do a short write */
520 #define AOP_FLAG_CONT_EXPAND		0x0002 /* called from cont_expand */
521 #define AOP_FLAG_NOFS			0x0004 /* used by filesystem to direct
522 						* helper code (eg buffer layer)
523 						* to clear GFP_FS from alloc */
524 
525 /*
526  * oh the beauties of C type declarations.
527  */
528 struct page;
529 struct address_space;
530 struct writeback_control;
531 
532 struct iov_iter {
533 	const struct iovec *iov;
534 	unsigned long nr_segs;
535 	size_t iov_offset;
536 	size_t count;
537 };
538 
539 size_t iov_iter_copy_from_user_atomic(struct page *page,
540 		struct iov_iter *i, unsigned long offset, size_t bytes);
541 size_t iov_iter_copy_from_user(struct page *page,
542 		struct iov_iter *i, unsigned long offset, size_t bytes);
543 void iov_iter_advance(struct iov_iter *i, size_t bytes);
544 int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes);
545 size_t iov_iter_single_seg_count(struct iov_iter *i);
546 
547 static inline void iov_iter_init(struct iov_iter *i,
548 			const struct iovec *iov, unsigned long nr_segs,
549 			size_t count, size_t written)
550 {
551 	i->iov = iov;
552 	i->nr_segs = nr_segs;
553 	i->iov_offset = 0;
554 	i->count = count + written;
555 
556 	iov_iter_advance(i, written);
557 }
558 
559 static inline size_t iov_iter_count(struct iov_iter *i)
560 {
561 	return i->count;
562 }
563 
564 /*
565  * "descriptor" for what we're up to with a read.
566  * This allows us to use the same read code yet
567  * have multiple different users of the data that
568  * we read from a file.
569  *
570  * The simplest case just copies the data to user
571  * mode.
572  */
573 typedef struct {
574 	size_t written;
575 	size_t count;
576 	union {
577 		char __user *buf;
578 		void *data;
579 	} arg;
580 	int error;
581 } read_descriptor_t;
582 
583 typedef int (*read_actor_t)(read_descriptor_t *, struct page *,
584 		unsigned long, unsigned long);
585 
586 struct address_space_operations {
587 	int (*writepage)(struct page *page, struct writeback_control *wbc);
588 	int (*readpage)(struct file *, struct page *);
589 	void (*sync_page)(struct page *);
590 
591 	/* Write back some dirty pages from this mapping. */
592 	int (*writepages)(struct address_space *, struct writeback_control *);
593 
594 	/* Set a page dirty.  Return true if this dirtied it */
595 	int (*set_page_dirty)(struct page *page);
596 
597 	int (*readpages)(struct file *filp, struct address_space *mapping,
598 			struct list_head *pages, unsigned nr_pages);
599 
600 	int (*write_begin)(struct file *, struct address_space *mapping,
601 				loff_t pos, unsigned len, unsigned flags,
602 				struct page **pagep, void **fsdata);
603 	int (*write_end)(struct file *, struct address_space *mapping,
604 				loff_t pos, unsigned len, unsigned copied,
605 				struct page *page, void *fsdata);
606 
607 	/* Unfortunately this kludge is needed for FIBMAP. Don't use it */
608 	sector_t (*bmap)(struct address_space *, sector_t);
609 	void (*invalidatepage) (struct page *, unsigned long);
610 	int (*releasepage) (struct page *, gfp_t);
611 	void (*freepage)(struct page *);
612 	ssize_t (*direct_IO)(int, struct kiocb *, const struct iovec *iov,
613 			loff_t offset, unsigned long nr_segs);
614 	int (*get_xip_mem)(struct address_space *, pgoff_t, int,
615 						void **, unsigned long *);
616 	/* migrate the contents of a page to the specified target */
617 	int (*migratepage) (struct address_space *,
618 			struct page *, struct page *);
619 	int (*launder_page) (struct page *);
620 	int (*is_partially_uptodate) (struct page *, read_descriptor_t *,
621 					unsigned long);
622 	int (*error_remove_page)(struct address_space *, struct page *);
623 };
624 
625 /*
626  * pagecache_write_begin/pagecache_write_end must be used by general code
627  * to write into the pagecache.
628  */
629 int pagecache_write_begin(struct file *, struct address_space *mapping,
630 				loff_t pos, unsigned len, unsigned flags,
631 				struct page **pagep, void **fsdata);
632 
633 int pagecache_write_end(struct file *, struct address_space *mapping,
634 				loff_t pos, unsigned len, unsigned copied,
635 				struct page *page, void *fsdata);
636 
637 struct backing_dev_info;
638 struct address_space {
639 	struct inode		*host;		/* owner: inode, block_device */
640 	struct radix_tree_root	page_tree;	/* radix tree of all pages */
641 	spinlock_t		tree_lock;	/* and lock protecting it */
642 	unsigned int		i_mmap_writable;/* count VM_SHARED mappings */
643 	struct prio_tree_root	i_mmap;		/* tree of private and shared mappings */
644 	struct list_head	i_mmap_nonlinear;/*list VM_NONLINEAR mappings */
645 	spinlock_t		i_mmap_lock;	/* protect tree, count, list */
646 	unsigned int		truncate_count;	/* Cover race condition with truncate */
647 	unsigned long		nrpages;	/* number of total pages */
648 	pgoff_t			writeback_index;/* writeback starts here */
649 	const struct address_space_operations *a_ops;	/* methods */
650 	unsigned long		flags;		/* error bits/gfp mask */
651 	struct backing_dev_info *backing_dev_info; /* device readahead, etc */
652 	spinlock_t		private_lock;	/* for use by the address_space */
653 	struct list_head	private_list;	/* ditto */
654 	struct address_space	*assoc_mapping;	/* ditto */
655 	struct mutex		unmap_mutex;    /* to protect unmapping */
656 } __attribute__((aligned(sizeof(long))));
657 	/*
658 	 * On most architectures that alignment is already the case; but
659 	 * must be enforced here for CRIS, to let the least signficant bit
660 	 * of struct page's "mapping" pointer be used for PAGE_MAPPING_ANON.
661 	 */
662 
663 struct block_device {
664 	dev_t			bd_dev;  /* not a kdev_t - it's a search key */
665 	int			bd_openers;
666 	struct inode *		bd_inode;	/* will die */
667 	struct super_block *	bd_super;
668 	struct mutex		bd_mutex;	/* open/close mutex */
669 	struct list_head	bd_inodes;
670 	void *			bd_claiming;
671 	void *			bd_holder;
672 	int			bd_holders;
673 	bool			bd_write_holder;
674 #ifdef CONFIG_SYSFS
675 	struct list_head	bd_holder_disks;
676 #endif
677 	struct block_device *	bd_contains;
678 	unsigned		bd_block_size;
679 	struct hd_struct *	bd_part;
680 	/* number of times partitions within this device have been opened. */
681 	unsigned		bd_part_count;
682 	int			bd_invalidated;
683 	struct gendisk *	bd_disk;
684 	struct list_head	bd_list;
685 	/*
686 	 * Private data.  You must have bd_claim'ed the block_device
687 	 * to use this.  NOTE:  bd_claim allows an owner to claim
688 	 * the same device multiple times, the owner must take special
689 	 * care to not mess up bd_private for that case.
690 	 */
691 	unsigned long		bd_private;
692 
693 	/* The counter of freeze processes */
694 	int			bd_fsfreeze_count;
695 	/* Mutex for freeze */
696 	struct mutex		bd_fsfreeze_mutex;
697 };
698 
699 /*
700  * Radix-tree tags, for tagging dirty and writeback pages within the pagecache
701  * radix trees
702  */
703 #define PAGECACHE_TAG_DIRTY	0
704 #define PAGECACHE_TAG_WRITEBACK	1
705 #define PAGECACHE_TAG_TOWRITE	2
706 
707 int mapping_tagged(struct address_space *mapping, int tag);
708 
709 /*
710  * Might pages of this file be mapped into userspace?
711  */
712 static inline int mapping_mapped(struct address_space *mapping)
713 {
714 	return	!prio_tree_empty(&mapping->i_mmap) ||
715 		!list_empty(&mapping->i_mmap_nonlinear);
716 }
717 
718 /*
719  * Might pages of this file have been modified in userspace?
720  * Note that i_mmap_writable counts all VM_SHARED vmas: do_mmap_pgoff
721  * marks vma as VM_SHARED if it is shared, and the file was opened for
722  * writing i.e. vma may be mprotected writable even if now readonly.
723  */
724 static inline int mapping_writably_mapped(struct address_space *mapping)
725 {
726 	return mapping->i_mmap_writable != 0;
727 }
728 
729 /*
730  * Use sequence counter to get consistent i_size on 32-bit processors.
731  */
732 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
733 #include <linux/seqlock.h>
734 #define __NEED_I_SIZE_ORDERED
735 #define i_size_ordered_init(inode) seqcount_init(&inode->i_size_seqcount)
736 #else
737 #define i_size_ordered_init(inode) do { } while (0)
738 #endif
739 
740 struct posix_acl;
741 #define ACL_NOT_CACHED ((void *)(-1))
742 
743 struct inode {
744 	/* RCU path lookup touches following: */
745 	umode_t			i_mode;
746 	uid_t			i_uid;
747 	gid_t			i_gid;
748 	const struct inode_operations	*i_op;
749 	struct super_block	*i_sb;
750 
751 	spinlock_t		i_lock;	/* i_blocks, i_bytes, maybe i_size */
752 	unsigned int		i_flags;
753 	struct mutex		i_mutex;
754 
755 	unsigned long		i_state;
756 	unsigned long		dirtied_when;	/* jiffies of first dirtying */
757 
758 	struct hlist_node	i_hash;
759 	struct list_head	i_wb_list;	/* backing dev IO list */
760 	struct list_head	i_lru;		/* inode LRU list */
761 	struct list_head	i_sb_list;
762 	union {
763 		struct list_head	i_dentry;
764 		struct rcu_head		i_rcu;
765 	};
766 	unsigned long		i_ino;
767 	atomic_t		i_count;
768 	unsigned int		i_nlink;
769 	dev_t			i_rdev;
770 	unsigned int		i_blkbits;
771 	u64			i_version;
772 	loff_t			i_size;
773 #ifdef __NEED_I_SIZE_ORDERED
774 	seqcount_t		i_size_seqcount;
775 #endif
776 	struct timespec		i_atime;
777 	struct timespec		i_mtime;
778 	struct timespec		i_ctime;
779 	blkcnt_t		i_blocks;
780 	unsigned short          i_bytes;
781 	struct rw_semaphore	i_alloc_sem;
782 	const struct file_operations	*i_fop;	/* former ->i_op->default_file_ops */
783 	struct file_lock	*i_flock;
784 	struct address_space	*i_mapping;
785 	struct address_space	i_data;
786 #ifdef CONFIG_QUOTA
787 	struct dquot		*i_dquot[MAXQUOTAS];
788 #endif
789 	struct list_head	i_devices;
790 	union {
791 		struct pipe_inode_info	*i_pipe;
792 		struct block_device	*i_bdev;
793 		struct cdev		*i_cdev;
794 	};
795 
796 	__u32			i_generation;
797 
798 #ifdef CONFIG_FSNOTIFY
799 	__u32			i_fsnotify_mask; /* all events this inode cares about */
800 	struct hlist_head	i_fsnotify_marks;
801 #endif
802 
803 #ifdef CONFIG_IMA
804 	atomic_t		i_readcount; /* struct files open RO */
805 #endif
806 	atomic_t		i_writecount;
807 #ifdef CONFIG_SECURITY
808 	void			*i_security;
809 #endif
810 #ifdef CONFIG_FS_POSIX_ACL
811 	struct posix_acl	*i_acl;
812 	struct posix_acl	*i_default_acl;
813 #endif
814 	void			*i_private; /* fs or device private pointer */
815 };
816 
817 static inline int inode_unhashed(struct inode *inode)
818 {
819 	return hlist_unhashed(&inode->i_hash);
820 }
821 
822 /*
823  * inode->i_mutex nesting subclasses for the lock validator:
824  *
825  * 0: the object of the current VFS operation
826  * 1: parent
827  * 2: child/target
828  * 3: quota file
829  *
830  * The locking order between these classes is
831  * parent -> child -> normal -> xattr -> quota
832  */
833 enum inode_i_mutex_lock_class
834 {
835 	I_MUTEX_NORMAL,
836 	I_MUTEX_PARENT,
837 	I_MUTEX_CHILD,
838 	I_MUTEX_XATTR,
839 	I_MUTEX_QUOTA
840 };
841 
842 /*
843  * NOTE: in a 32bit arch with a preemptable kernel and
844  * an UP compile the i_size_read/write must be atomic
845  * with respect to the local cpu (unlike with preempt disabled),
846  * but they don't need to be atomic with respect to other cpus like in
847  * true SMP (so they need either to either locally disable irq around
848  * the read or for example on x86 they can be still implemented as a
849  * cmpxchg8b without the need of the lock prefix). For SMP compiles
850  * and 64bit archs it makes no difference if preempt is enabled or not.
851  */
852 static inline loff_t i_size_read(const struct inode *inode)
853 {
854 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
855 	loff_t i_size;
856 	unsigned int seq;
857 
858 	do {
859 		seq = read_seqcount_begin(&inode->i_size_seqcount);
860 		i_size = inode->i_size;
861 	} while (read_seqcount_retry(&inode->i_size_seqcount, seq));
862 	return i_size;
863 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
864 	loff_t i_size;
865 
866 	preempt_disable();
867 	i_size = inode->i_size;
868 	preempt_enable();
869 	return i_size;
870 #else
871 	return inode->i_size;
872 #endif
873 }
874 
875 /*
876  * NOTE: unlike i_size_read(), i_size_write() does need locking around it
877  * (normally i_mutex), otherwise on 32bit/SMP an update of i_size_seqcount
878  * can be lost, resulting in subsequent i_size_read() calls spinning forever.
879  */
880 static inline void i_size_write(struct inode *inode, loff_t i_size)
881 {
882 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
883 	write_seqcount_begin(&inode->i_size_seqcount);
884 	inode->i_size = i_size;
885 	write_seqcount_end(&inode->i_size_seqcount);
886 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
887 	preempt_disable();
888 	inode->i_size = i_size;
889 	preempt_enable();
890 #else
891 	inode->i_size = i_size;
892 #endif
893 }
894 
895 static inline unsigned iminor(const struct inode *inode)
896 {
897 	return MINOR(inode->i_rdev);
898 }
899 
900 static inline unsigned imajor(const struct inode *inode)
901 {
902 	return MAJOR(inode->i_rdev);
903 }
904 
905 extern struct block_device *I_BDEV(struct inode *inode);
906 
907 struct fown_struct {
908 	rwlock_t lock;          /* protects pid, uid, euid fields */
909 	struct pid *pid;	/* pid or -pgrp where SIGIO should be sent */
910 	enum pid_type pid_type;	/* Kind of process group SIGIO should be sent to */
911 	uid_t uid, euid;	/* uid/euid of process setting the owner */
912 	int signum;		/* posix.1b rt signal to be delivered on IO */
913 };
914 
915 /*
916  * Track a single file's readahead state
917  */
918 struct file_ra_state {
919 	pgoff_t start;			/* where readahead started */
920 	unsigned int size;		/* # of readahead pages */
921 	unsigned int async_size;	/* do asynchronous readahead when
922 					   there are only # of pages ahead */
923 
924 	unsigned int ra_pages;		/* Maximum readahead window */
925 	unsigned int mmap_miss;		/* Cache miss stat for mmap accesses */
926 	loff_t prev_pos;		/* Cache last read() position */
927 };
928 
929 /*
930  * Check if @index falls in the readahead windows.
931  */
932 static inline int ra_has_index(struct file_ra_state *ra, pgoff_t index)
933 {
934 	return (index >= ra->start &&
935 		index <  ra->start + ra->size);
936 }
937 
938 #define FILE_MNT_WRITE_TAKEN	1
939 #define FILE_MNT_WRITE_RELEASED	2
940 
941 struct file {
942 	/*
943 	 * fu_list becomes invalid after file_free is called and queued via
944 	 * fu_rcuhead for RCU freeing
945 	 */
946 	union {
947 		struct list_head	fu_list;
948 		struct rcu_head 	fu_rcuhead;
949 	} f_u;
950 	struct path		f_path;
951 #define f_dentry	f_path.dentry
952 #define f_vfsmnt	f_path.mnt
953 	const struct file_operations	*f_op;
954 	spinlock_t		f_lock;  /* f_ep_links, f_flags, no IRQ */
955 #ifdef CONFIG_SMP
956 	int			f_sb_list_cpu;
957 #endif
958 	atomic_long_t		f_count;
959 	unsigned int 		f_flags;
960 	fmode_t			f_mode;
961 	loff_t			f_pos;
962 	struct fown_struct	f_owner;
963 	const struct cred	*f_cred;
964 	struct file_ra_state	f_ra;
965 
966 	u64			f_version;
967 #ifdef CONFIG_SECURITY
968 	void			*f_security;
969 #endif
970 	/* needed for tty driver, and maybe others */
971 	void			*private_data;
972 
973 #ifdef CONFIG_EPOLL
974 	/* Used by fs/eventpoll.c to link all the hooks to this file */
975 	struct list_head	f_ep_links;
976 #endif /* #ifdef CONFIG_EPOLL */
977 	struct address_space	*f_mapping;
978 #ifdef CONFIG_DEBUG_WRITECOUNT
979 	unsigned long f_mnt_write_state;
980 #endif
981 };
982 
983 struct file_handle {
984 	__u32 handle_bytes;
985 	int handle_type;
986 	/* file identifier */
987 	unsigned char f_handle[0];
988 };
989 
990 #define get_file(x)	atomic_long_inc(&(x)->f_count)
991 #define fput_atomic(x)	atomic_long_add_unless(&(x)->f_count, -1, 1)
992 #define file_count(x)	atomic_long_read(&(x)->f_count)
993 
994 #ifdef CONFIG_DEBUG_WRITECOUNT
995 static inline void file_take_write(struct file *f)
996 {
997 	WARN_ON(f->f_mnt_write_state != 0);
998 	f->f_mnt_write_state = FILE_MNT_WRITE_TAKEN;
999 }
1000 static inline void file_release_write(struct file *f)
1001 {
1002 	f->f_mnt_write_state |= FILE_MNT_WRITE_RELEASED;
1003 }
1004 static inline void file_reset_write(struct file *f)
1005 {
1006 	f->f_mnt_write_state = 0;
1007 }
1008 static inline void file_check_state(struct file *f)
1009 {
1010 	/*
1011 	 * At this point, either both or neither of these bits
1012 	 * should be set.
1013 	 */
1014 	WARN_ON(f->f_mnt_write_state == FILE_MNT_WRITE_TAKEN);
1015 	WARN_ON(f->f_mnt_write_state == FILE_MNT_WRITE_RELEASED);
1016 }
1017 static inline int file_check_writeable(struct file *f)
1018 {
1019 	if (f->f_mnt_write_state == FILE_MNT_WRITE_TAKEN)
1020 		return 0;
1021 	printk(KERN_WARNING "writeable file with no "
1022 			    "mnt_want_write()\n");
1023 	WARN_ON(1);
1024 	return -EINVAL;
1025 }
1026 #else /* !CONFIG_DEBUG_WRITECOUNT */
1027 static inline void file_take_write(struct file *filp) {}
1028 static inline void file_release_write(struct file *filp) {}
1029 static inline void file_reset_write(struct file *filp) {}
1030 static inline void file_check_state(struct file *filp) {}
1031 static inline int file_check_writeable(struct file *filp)
1032 {
1033 	return 0;
1034 }
1035 #endif /* CONFIG_DEBUG_WRITECOUNT */
1036 
1037 #define	MAX_NON_LFS	((1UL<<31) - 1)
1038 
1039 /* Page cache limit. The filesystems should put that into their s_maxbytes
1040    limits, otherwise bad things can happen in VM. */
1041 #if BITS_PER_LONG==32
1042 #define MAX_LFS_FILESIZE	(((u64)PAGE_CACHE_SIZE << (BITS_PER_LONG-1))-1)
1043 #elif BITS_PER_LONG==64
1044 #define MAX_LFS_FILESIZE 	0x7fffffffffffffffUL
1045 #endif
1046 
1047 #define FL_POSIX	1
1048 #define FL_FLOCK	2
1049 #define FL_ACCESS	8	/* not trying to lock, just looking */
1050 #define FL_EXISTS	16	/* when unlocking, test for existence */
1051 #define FL_LEASE	32	/* lease held on this file */
1052 #define FL_CLOSE	64	/* unlock on close */
1053 #define FL_SLEEP	128	/* A blocking lock */
1054 
1055 /*
1056  * Special return value from posix_lock_file() and vfs_lock_file() for
1057  * asynchronous locking.
1058  */
1059 #define FILE_LOCK_DEFERRED 1
1060 
1061 /*
1062  * The POSIX file lock owner is determined by
1063  * the "struct files_struct" in the thread group
1064  * (or NULL for no owner - BSD locks).
1065  *
1066  * Lockd stuffs a "host" pointer into this.
1067  */
1068 typedef struct files_struct *fl_owner_t;
1069 
1070 struct file_lock_operations {
1071 	void (*fl_copy_lock)(struct file_lock *, struct file_lock *);
1072 	void (*fl_release_private)(struct file_lock *);
1073 };
1074 
1075 struct lock_manager_operations {
1076 	int (*fl_compare_owner)(struct file_lock *, struct file_lock *);
1077 	void (*fl_notify)(struct file_lock *);	/* unblock callback */
1078 	int (*fl_grant)(struct file_lock *, struct file_lock *, int);
1079 	void (*fl_release_private)(struct file_lock *);
1080 	void (*fl_break)(struct file_lock *);
1081 	int (*fl_change)(struct file_lock **, int);
1082 };
1083 
1084 struct lock_manager {
1085 	struct list_head list;
1086 };
1087 
1088 void locks_start_grace(struct lock_manager *);
1089 void locks_end_grace(struct lock_manager *);
1090 int locks_in_grace(void);
1091 
1092 /* that will die - we need it for nfs_lock_info */
1093 #include <linux/nfs_fs_i.h>
1094 
1095 struct file_lock {
1096 	struct file_lock *fl_next;	/* singly linked list for this inode  */
1097 	struct list_head fl_link;	/* doubly linked list of all locks */
1098 	struct list_head fl_block;	/* circular list of blocked processes */
1099 	fl_owner_t fl_owner;
1100 	unsigned char fl_flags;
1101 	unsigned char fl_type;
1102 	unsigned int fl_pid;
1103 	struct pid *fl_nspid;
1104 	wait_queue_head_t fl_wait;
1105 	struct file *fl_file;
1106 	loff_t fl_start;
1107 	loff_t fl_end;
1108 
1109 	struct fasync_struct *	fl_fasync; /* for lease break notifications */
1110 	unsigned long fl_break_time;	/* for nonblocking lease breaks */
1111 
1112 	const struct file_lock_operations *fl_ops;	/* Callbacks for filesystems */
1113 	const struct lock_manager_operations *fl_lmops;	/* Callbacks for lockmanagers */
1114 	union {
1115 		struct nfs_lock_info	nfs_fl;
1116 		struct nfs4_lock_info	nfs4_fl;
1117 		struct {
1118 			struct list_head link;	/* link in AFS vnode's pending_locks list */
1119 			int state;		/* state of grant or error if -ve */
1120 		} afs;
1121 	} fl_u;
1122 };
1123 
1124 /* The following constant reflects the upper bound of the file/locking space */
1125 #ifndef OFFSET_MAX
1126 #define INT_LIMIT(x)	(~((x)1 << (sizeof(x)*8 - 1)))
1127 #define OFFSET_MAX	INT_LIMIT(loff_t)
1128 #define OFFT_OFFSET_MAX	INT_LIMIT(off_t)
1129 #endif
1130 
1131 #include <linux/fcntl.h>
1132 
1133 extern void send_sigio(struct fown_struct *fown, int fd, int band);
1134 
1135 #ifdef CONFIG_FILE_LOCKING
1136 extern int fcntl_getlk(struct file *, struct flock __user *);
1137 extern int fcntl_setlk(unsigned int, struct file *, unsigned int,
1138 			struct flock __user *);
1139 
1140 #if BITS_PER_LONG == 32
1141 extern int fcntl_getlk64(struct file *, struct flock64 __user *);
1142 extern int fcntl_setlk64(unsigned int, struct file *, unsigned int,
1143 			struct flock64 __user *);
1144 #endif
1145 
1146 extern int fcntl_setlease(unsigned int fd, struct file *filp, long arg);
1147 extern int fcntl_getlease(struct file *filp);
1148 
1149 /* fs/locks.c */
1150 void locks_free_lock(struct file_lock *fl);
1151 extern void locks_init_lock(struct file_lock *);
1152 extern struct file_lock * locks_alloc_lock(void);
1153 extern void locks_copy_lock(struct file_lock *, struct file_lock *);
1154 extern void __locks_copy_lock(struct file_lock *, const struct file_lock *);
1155 extern void locks_remove_posix(struct file *, fl_owner_t);
1156 extern void locks_remove_flock(struct file *);
1157 extern void locks_release_private(struct file_lock *);
1158 extern void posix_test_lock(struct file *, struct file_lock *);
1159 extern int posix_lock_file(struct file *, struct file_lock *, struct file_lock *);
1160 extern int posix_lock_file_wait(struct file *, struct file_lock *);
1161 extern int posix_unblock_lock(struct file *, struct file_lock *);
1162 extern int vfs_test_lock(struct file *, struct file_lock *);
1163 extern int vfs_lock_file(struct file *, unsigned int, struct file_lock *, struct file_lock *);
1164 extern int vfs_cancel_lock(struct file *filp, struct file_lock *fl);
1165 extern int flock_lock_file_wait(struct file *filp, struct file_lock *fl);
1166 extern int __break_lease(struct inode *inode, unsigned int flags);
1167 extern void lease_get_mtime(struct inode *, struct timespec *time);
1168 extern int generic_setlease(struct file *, long, struct file_lock **);
1169 extern int vfs_setlease(struct file *, long, struct file_lock **);
1170 extern int lease_modify(struct file_lock **, int);
1171 extern int lock_may_read(struct inode *, loff_t start, unsigned long count);
1172 extern int lock_may_write(struct inode *, loff_t start, unsigned long count);
1173 extern void lock_flocks(void);
1174 extern void unlock_flocks(void);
1175 #else /* !CONFIG_FILE_LOCKING */
1176 static inline int fcntl_getlk(struct file *file, struct flock __user *user)
1177 {
1178 	return -EINVAL;
1179 }
1180 
1181 static inline int fcntl_setlk(unsigned int fd, struct file *file,
1182 			      unsigned int cmd, struct flock __user *user)
1183 {
1184 	return -EACCES;
1185 }
1186 
1187 #if BITS_PER_LONG == 32
1188 static inline int fcntl_getlk64(struct file *file, struct flock64 __user *user)
1189 {
1190 	return -EINVAL;
1191 }
1192 
1193 static inline int fcntl_setlk64(unsigned int fd, struct file *file,
1194 				unsigned int cmd, struct flock64 __user *user)
1195 {
1196 	return -EACCES;
1197 }
1198 #endif
1199 static inline int fcntl_setlease(unsigned int fd, struct file *filp, long arg)
1200 {
1201 	return 0;
1202 }
1203 
1204 static inline int fcntl_getlease(struct file *filp)
1205 {
1206 	return 0;
1207 }
1208 
1209 static inline void locks_init_lock(struct file_lock *fl)
1210 {
1211 	return;
1212 }
1213 
1214 static inline void __locks_copy_lock(struct file_lock *new, struct file_lock *fl)
1215 {
1216 	return;
1217 }
1218 
1219 static inline void locks_copy_lock(struct file_lock *new, struct file_lock *fl)
1220 {
1221 	return;
1222 }
1223 
1224 static inline void locks_remove_posix(struct file *filp, fl_owner_t owner)
1225 {
1226 	return;
1227 }
1228 
1229 static inline void locks_remove_flock(struct file *filp)
1230 {
1231 	return;
1232 }
1233 
1234 static inline void posix_test_lock(struct file *filp, struct file_lock *fl)
1235 {
1236 	return;
1237 }
1238 
1239 static inline int posix_lock_file(struct file *filp, struct file_lock *fl,
1240 				  struct file_lock *conflock)
1241 {
1242 	return -ENOLCK;
1243 }
1244 
1245 static inline int posix_lock_file_wait(struct file *filp, struct file_lock *fl)
1246 {
1247 	return -ENOLCK;
1248 }
1249 
1250 static inline int posix_unblock_lock(struct file *filp,
1251 				     struct file_lock *waiter)
1252 {
1253 	return -ENOENT;
1254 }
1255 
1256 static inline int vfs_test_lock(struct file *filp, struct file_lock *fl)
1257 {
1258 	return 0;
1259 }
1260 
1261 static inline int vfs_lock_file(struct file *filp, unsigned int cmd,
1262 				struct file_lock *fl, struct file_lock *conf)
1263 {
1264 	return -ENOLCK;
1265 }
1266 
1267 static inline int vfs_cancel_lock(struct file *filp, struct file_lock *fl)
1268 {
1269 	return 0;
1270 }
1271 
1272 static inline int flock_lock_file_wait(struct file *filp,
1273 				       struct file_lock *request)
1274 {
1275 	return -ENOLCK;
1276 }
1277 
1278 static inline int __break_lease(struct inode *inode, unsigned int mode)
1279 {
1280 	return 0;
1281 }
1282 
1283 static inline void lease_get_mtime(struct inode *inode, struct timespec *time)
1284 {
1285 	return;
1286 }
1287 
1288 static inline int generic_setlease(struct file *filp, long arg,
1289 				    struct file_lock **flp)
1290 {
1291 	return -EINVAL;
1292 }
1293 
1294 static inline int vfs_setlease(struct file *filp, long arg,
1295 			       struct file_lock **lease)
1296 {
1297 	return -EINVAL;
1298 }
1299 
1300 static inline int lease_modify(struct file_lock **before, int arg)
1301 {
1302 	return -EINVAL;
1303 }
1304 
1305 static inline int lock_may_read(struct inode *inode, loff_t start,
1306 				unsigned long len)
1307 {
1308 	return 1;
1309 }
1310 
1311 static inline int lock_may_write(struct inode *inode, loff_t start,
1312 				 unsigned long len)
1313 {
1314 	return 1;
1315 }
1316 
1317 static inline void lock_flocks(void)
1318 {
1319 }
1320 
1321 static inline void unlock_flocks(void)
1322 {
1323 }
1324 
1325 #endif /* !CONFIG_FILE_LOCKING */
1326 
1327 
1328 struct fasync_struct {
1329 	spinlock_t		fa_lock;
1330 	int			magic;
1331 	int			fa_fd;
1332 	struct fasync_struct	*fa_next; /* singly linked list */
1333 	struct file		*fa_file;
1334 	struct rcu_head		fa_rcu;
1335 };
1336 
1337 #define FASYNC_MAGIC 0x4601
1338 
1339 /* SMP safe fasync helpers: */
1340 extern int fasync_helper(int, struct file *, int, struct fasync_struct **);
1341 extern struct fasync_struct *fasync_insert_entry(int, struct file *, struct fasync_struct **, struct fasync_struct *);
1342 extern int fasync_remove_entry(struct file *, struct fasync_struct **);
1343 extern struct fasync_struct *fasync_alloc(void);
1344 extern void fasync_free(struct fasync_struct *);
1345 
1346 /* can be called from interrupts */
1347 extern void kill_fasync(struct fasync_struct **, int, int);
1348 
1349 extern int __f_setown(struct file *filp, struct pid *, enum pid_type, int force);
1350 extern int f_setown(struct file *filp, unsigned long arg, int force);
1351 extern void f_delown(struct file *filp);
1352 extern pid_t f_getown(struct file *filp);
1353 extern int send_sigurg(struct fown_struct *fown);
1354 
1355 /*
1356  *	Umount options
1357  */
1358 
1359 #define MNT_FORCE	0x00000001	/* Attempt to forcibily umount */
1360 #define MNT_DETACH	0x00000002	/* Just detach from the tree */
1361 #define MNT_EXPIRE	0x00000004	/* Mark for expiry */
1362 #define UMOUNT_NOFOLLOW	0x00000008	/* Don't follow symlink on umount */
1363 #define UMOUNT_UNUSED	0x80000000	/* Flag guaranteed to be unused */
1364 
1365 extern struct list_head super_blocks;
1366 extern spinlock_t sb_lock;
1367 
1368 struct super_block {
1369 	struct list_head	s_list;		/* Keep this first */
1370 	dev_t			s_dev;		/* search index; _not_ kdev_t */
1371 	unsigned char		s_dirt;
1372 	unsigned char		s_blocksize_bits;
1373 	unsigned long		s_blocksize;
1374 	loff_t			s_maxbytes;	/* Max file size */
1375 	struct file_system_type	*s_type;
1376 	const struct super_operations	*s_op;
1377 	const struct dquot_operations	*dq_op;
1378 	const struct quotactl_ops	*s_qcop;
1379 	const struct export_operations *s_export_op;
1380 	unsigned long		s_flags;
1381 	unsigned long		s_magic;
1382 	struct dentry		*s_root;
1383 	struct rw_semaphore	s_umount;
1384 	struct mutex		s_lock;
1385 	int			s_count;
1386 	atomic_t		s_active;
1387 #ifdef CONFIG_SECURITY
1388 	void                    *s_security;
1389 #endif
1390 	const struct xattr_handler **s_xattr;
1391 
1392 	struct list_head	s_inodes;	/* all inodes */
1393 	struct hlist_bl_head	s_anon;		/* anonymous dentries for (nfs) exporting */
1394 #ifdef CONFIG_SMP
1395 	struct list_head __percpu *s_files;
1396 #else
1397 	struct list_head	s_files;
1398 #endif
1399 	/* s_dentry_lru, s_nr_dentry_unused protected by dcache.c lru locks */
1400 	struct list_head	s_dentry_lru;	/* unused dentry lru */
1401 	int			s_nr_dentry_unused;	/* # of dentry on lru */
1402 
1403 	struct block_device	*s_bdev;
1404 	struct backing_dev_info *s_bdi;
1405 	struct mtd_info		*s_mtd;
1406 	struct list_head	s_instances;
1407 	struct quota_info	s_dquot;	/* Diskquota specific options */
1408 
1409 	int			s_frozen;
1410 	wait_queue_head_t	s_wait_unfrozen;
1411 
1412 	char s_id[32];				/* Informational name */
1413 	u8 s_uuid[16];				/* UUID */
1414 
1415 	void 			*s_fs_info;	/* Filesystem private info */
1416 	fmode_t			s_mode;
1417 
1418 	/* Granularity of c/m/atime in ns.
1419 	   Cannot be worse than a second */
1420 	u32		   s_time_gran;
1421 
1422 	/*
1423 	 * The next field is for VFS *only*. No filesystems have any business
1424 	 * even looking at it. You had been warned.
1425 	 */
1426 	struct mutex s_vfs_rename_mutex;	/* Kludge */
1427 
1428 	/*
1429 	 * Filesystem subtype.  If non-empty the filesystem type field
1430 	 * in /proc/mounts will be "type.subtype"
1431 	 */
1432 	char *s_subtype;
1433 
1434 	/*
1435 	 * Saved mount options for lazy filesystems using
1436 	 * generic_show_options()
1437 	 */
1438 	char __rcu *s_options;
1439 	const struct dentry_operations *s_d_op; /* default d_op for dentries */
1440 };
1441 
1442 extern struct timespec current_fs_time(struct super_block *sb);
1443 
1444 /*
1445  * Snapshotting support.
1446  */
1447 enum {
1448 	SB_UNFROZEN = 0,
1449 	SB_FREEZE_WRITE	= 1,
1450 	SB_FREEZE_TRANS = 2,
1451 };
1452 
1453 #define vfs_check_frozen(sb, level) \
1454 	wait_event((sb)->s_wait_unfrozen, ((sb)->s_frozen < (level)))
1455 
1456 #define get_fs_excl() atomic_inc(&current->fs_excl)
1457 #define put_fs_excl() atomic_dec(&current->fs_excl)
1458 #define has_fs_excl() atomic_read(&current->fs_excl)
1459 
1460 #define is_owner_or_cap(inode)	\
1461 	((current_fsuid() == (inode)->i_uid) || capable(CAP_FOWNER))
1462 
1463 /* not quite ready to be deprecated, but... */
1464 extern void lock_super(struct super_block *);
1465 extern void unlock_super(struct super_block *);
1466 
1467 /*
1468  * VFS helper functions..
1469  */
1470 extern int vfs_create(struct inode *, struct dentry *, int, struct nameidata *);
1471 extern int vfs_mkdir(struct inode *, struct dentry *, int);
1472 extern int vfs_mknod(struct inode *, struct dentry *, int, dev_t);
1473 extern int vfs_symlink(struct inode *, struct dentry *, const char *);
1474 extern int vfs_link(struct dentry *, struct inode *, struct dentry *);
1475 extern int vfs_rmdir(struct inode *, struct dentry *);
1476 extern int vfs_unlink(struct inode *, struct dentry *);
1477 extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *);
1478 
1479 /*
1480  * VFS dentry helper functions.
1481  */
1482 extern void dentry_unhash(struct dentry *dentry);
1483 
1484 /*
1485  * VFS file helper functions.
1486  */
1487 extern int file_permission(struct file *, int);
1488 extern void inode_init_owner(struct inode *inode, const struct inode *dir,
1489 			mode_t mode);
1490 /*
1491  * VFS FS_IOC_FIEMAP helper definitions.
1492  */
1493 struct fiemap_extent_info {
1494 	unsigned int fi_flags;		/* Flags as passed from user */
1495 	unsigned int fi_extents_mapped;	/* Number of mapped extents */
1496 	unsigned int fi_extents_max;	/* Size of fiemap_extent array */
1497 	struct fiemap_extent __user *fi_extents_start; /* Start of
1498 							fiemap_extent array */
1499 };
1500 int fiemap_fill_next_extent(struct fiemap_extent_info *info, u64 logical,
1501 			    u64 phys, u64 len, u32 flags);
1502 int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags);
1503 
1504 /*
1505  * File types
1506  *
1507  * NOTE! These match bits 12..15 of stat.st_mode
1508  * (ie "(i_mode >> 12) & 15").
1509  */
1510 #define DT_UNKNOWN	0
1511 #define DT_FIFO		1
1512 #define DT_CHR		2
1513 #define DT_DIR		4
1514 #define DT_BLK		6
1515 #define DT_REG		8
1516 #define DT_LNK		10
1517 #define DT_SOCK		12
1518 #define DT_WHT		14
1519 
1520 /*
1521  * This is the "filldir" function type, used by readdir() to let
1522  * the kernel specify what kind of dirent layout it wants to have.
1523  * This allows the kernel to read directories into kernel space or
1524  * to have different dirent layouts depending on the binary type.
1525  */
1526 typedef int (*filldir_t)(void *, const char *, int, loff_t, u64, unsigned);
1527 struct block_device_operations;
1528 
1529 /* These macros are for out of kernel modules to test that
1530  * the kernel supports the unlocked_ioctl and compat_ioctl
1531  * fields in struct file_operations. */
1532 #define HAVE_COMPAT_IOCTL 1
1533 #define HAVE_UNLOCKED_IOCTL 1
1534 
1535 /*
1536  * NOTE:
1537  * all file operations except setlease can be called without
1538  * the big kernel lock held in all filesystems.
1539  */
1540 struct file_operations {
1541 	struct module *owner;
1542 	loff_t (*llseek) (struct file *, loff_t, int);
1543 	ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
1544 	ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
1545 	ssize_t (*aio_read) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
1546 	ssize_t (*aio_write) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
1547 	int (*readdir) (struct file *, void *, filldir_t);
1548 	unsigned int (*poll) (struct file *, struct poll_table_struct *);
1549 	long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
1550 	long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
1551 	int (*mmap) (struct file *, struct vm_area_struct *);
1552 	int (*open) (struct inode *, struct file *);
1553 	int (*flush) (struct file *, fl_owner_t id);
1554 	int (*release) (struct inode *, struct file *);
1555 	int (*fsync) (struct file *, int datasync);
1556 	int (*aio_fsync) (struct kiocb *, int datasync);
1557 	int (*fasync) (int, struct file *, int);
1558 	int (*lock) (struct file *, int, struct file_lock *);
1559 	ssize_t (*sendpage) (struct file *, struct page *, int, size_t, loff_t *, int);
1560 	unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
1561 	int (*check_flags)(int);
1562 	int (*flock) (struct file *, int, struct file_lock *);
1563 	ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int);
1564 	ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int);
1565 	int (*setlease)(struct file *, long, struct file_lock **);
1566 	long (*fallocate)(struct file *file, int mode, loff_t offset,
1567 			  loff_t len);
1568 };
1569 
1570 #define IPERM_FLAG_RCU	0x0001
1571 
1572 struct inode_operations {
1573 	struct dentry * (*lookup) (struct inode *,struct dentry *, struct nameidata *);
1574 	void * (*follow_link) (struct dentry *, struct nameidata *);
1575 	int (*permission) (struct inode *, int, unsigned int);
1576 	int (*check_acl)(struct inode *, int, unsigned int);
1577 
1578 	int (*readlink) (struct dentry *, char __user *,int);
1579 	void (*put_link) (struct dentry *, struct nameidata *, void *);
1580 
1581 	int (*create) (struct inode *,struct dentry *,int, struct nameidata *);
1582 	int (*link) (struct dentry *,struct inode *,struct dentry *);
1583 	int (*unlink) (struct inode *,struct dentry *);
1584 	int (*symlink) (struct inode *,struct dentry *,const char *);
1585 	int (*mkdir) (struct inode *,struct dentry *,int);
1586 	int (*rmdir) (struct inode *,struct dentry *);
1587 	int (*mknod) (struct inode *,struct dentry *,int,dev_t);
1588 	int (*rename) (struct inode *, struct dentry *,
1589 			struct inode *, struct dentry *);
1590 	void (*truncate) (struct inode *);
1591 	int (*setattr) (struct dentry *, struct iattr *);
1592 	int (*getattr) (struct vfsmount *mnt, struct dentry *, struct kstat *);
1593 	int (*setxattr) (struct dentry *, const char *,const void *,size_t,int);
1594 	ssize_t (*getxattr) (struct dentry *, const char *, void *, size_t);
1595 	ssize_t (*listxattr) (struct dentry *, char *, size_t);
1596 	int (*removexattr) (struct dentry *, const char *);
1597 	void (*truncate_range)(struct inode *, loff_t, loff_t);
1598 	int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start,
1599 		      u64 len);
1600 } ____cacheline_aligned;
1601 
1602 struct seq_file;
1603 
1604 ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
1605 				unsigned long nr_segs, unsigned long fast_segs,
1606 				struct iovec *fast_pointer,
1607 				struct iovec **ret_pointer);
1608 
1609 extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *);
1610 extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *);
1611 extern ssize_t vfs_readv(struct file *, const struct iovec __user *,
1612 		unsigned long, loff_t *);
1613 extern ssize_t vfs_writev(struct file *, const struct iovec __user *,
1614 		unsigned long, loff_t *);
1615 
1616 struct super_operations {
1617    	struct inode *(*alloc_inode)(struct super_block *sb);
1618 	void (*destroy_inode)(struct inode *);
1619 
1620    	void (*dirty_inode) (struct inode *);
1621 	int (*write_inode) (struct inode *, struct writeback_control *wbc);
1622 	int (*drop_inode) (struct inode *);
1623 	void (*evict_inode) (struct inode *);
1624 	void (*put_super) (struct super_block *);
1625 	void (*write_super) (struct super_block *);
1626 	int (*sync_fs)(struct super_block *sb, int wait);
1627 	int (*freeze_fs) (struct super_block *);
1628 	int (*unfreeze_fs) (struct super_block *);
1629 	int (*statfs) (struct dentry *, struct kstatfs *);
1630 	int (*remount_fs) (struct super_block *, int *, char *);
1631 	void (*umount_begin) (struct super_block *);
1632 
1633 	int (*show_options)(struct seq_file *, struct vfsmount *);
1634 	int (*show_devname)(struct seq_file *, struct vfsmount *);
1635 	int (*show_path)(struct seq_file *, struct vfsmount *);
1636 	int (*show_stats)(struct seq_file *, struct vfsmount *);
1637 #ifdef CONFIG_QUOTA
1638 	ssize_t (*quota_read)(struct super_block *, int, char *, size_t, loff_t);
1639 	ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t);
1640 #endif
1641 	int (*bdev_try_to_free_page)(struct super_block*, struct page*, gfp_t);
1642 };
1643 
1644 /*
1645  * Inode state bits.  Protected by inode_lock.
1646  *
1647  * Three bits determine the dirty state of the inode, I_DIRTY_SYNC,
1648  * I_DIRTY_DATASYNC and I_DIRTY_PAGES.
1649  *
1650  * Four bits define the lifetime of an inode.  Initially, inodes are I_NEW,
1651  * until that flag is cleared.  I_WILL_FREE, I_FREEING and I_CLEAR are set at
1652  * various stages of removing an inode.
1653  *
1654  * Two bits are used for locking and completion notification, I_NEW and I_SYNC.
1655  *
1656  * I_DIRTY_SYNC		Inode is dirty, but doesn't have to be written on
1657  *			fdatasync().  i_atime is the usual cause.
1658  * I_DIRTY_DATASYNC	Data-related inode changes pending. We keep track of
1659  *			these changes separately from I_DIRTY_SYNC so that we
1660  *			don't have to write inode on fdatasync() when only
1661  *			mtime has changed in it.
1662  * I_DIRTY_PAGES	Inode has dirty pages.  Inode itself may be clean.
1663  * I_NEW		Serves as both a mutex and completion notification.
1664  *			New inodes set I_NEW.  If two processes both create
1665  *			the same inode, one of them will release its inode and
1666  *			wait for I_NEW to be released before returning.
1667  *			Inodes in I_WILL_FREE, I_FREEING or I_CLEAR state can
1668  *			also cause waiting on I_NEW, without I_NEW actually
1669  *			being set.  find_inode() uses this to prevent returning
1670  *			nearly-dead inodes.
1671  * I_WILL_FREE		Must be set when calling write_inode_now() if i_count
1672  *			is zero.  I_FREEING must be set when I_WILL_FREE is
1673  *			cleared.
1674  * I_FREEING		Set when inode is about to be freed but still has dirty
1675  *			pages or buffers attached or the inode itself is still
1676  *			dirty.
1677  * I_CLEAR		Added by end_writeback().  In this state the inode is clean
1678  *			and can be destroyed.  Inode keeps I_FREEING.
1679  *
1680  *			Inodes that are I_WILL_FREE, I_FREEING or I_CLEAR are
1681  *			prohibited for many purposes.  iget() must wait for
1682  *			the inode to be completely released, then create it
1683  *			anew.  Other functions will just ignore such inodes,
1684  *			if appropriate.  I_NEW is used for waiting.
1685  *
1686  * I_SYNC		Synchonized write of dirty inode data.  The bits is
1687  *			set during data writeback, and cleared with a wakeup
1688  *			on the bit address once it is done.
1689  *
1690  * Q: What is the difference between I_WILL_FREE and I_FREEING?
1691  */
1692 #define I_DIRTY_SYNC		(1 << 0)
1693 #define I_DIRTY_DATASYNC	(1 << 1)
1694 #define I_DIRTY_PAGES		(1 << 2)
1695 #define __I_NEW			3
1696 #define I_NEW			(1 << __I_NEW)
1697 #define I_WILL_FREE		(1 << 4)
1698 #define I_FREEING		(1 << 5)
1699 #define I_CLEAR			(1 << 6)
1700 #define __I_SYNC		7
1701 #define I_SYNC			(1 << __I_SYNC)
1702 #define I_REFERENCED		(1 << 8)
1703 
1704 #define I_DIRTY (I_DIRTY_SYNC | I_DIRTY_DATASYNC | I_DIRTY_PAGES)
1705 
1706 extern void __mark_inode_dirty(struct inode *, int);
1707 static inline void mark_inode_dirty(struct inode *inode)
1708 {
1709 	__mark_inode_dirty(inode, I_DIRTY);
1710 }
1711 
1712 static inline void mark_inode_dirty_sync(struct inode *inode)
1713 {
1714 	__mark_inode_dirty(inode, I_DIRTY_SYNC);
1715 }
1716 
1717 /**
1718  * inc_nlink - directly increment an inode's link count
1719  * @inode: inode
1720  *
1721  * This is a low-level filesystem helper to replace any
1722  * direct filesystem manipulation of i_nlink.  Currently,
1723  * it is only here for parity with dec_nlink().
1724  */
1725 static inline void inc_nlink(struct inode *inode)
1726 {
1727 	inode->i_nlink++;
1728 }
1729 
1730 static inline void inode_inc_link_count(struct inode *inode)
1731 {
1732 	inc_nlink(inode);
1733 	mark_inode_dirty(inode);
1734 }
1735 
1736 /**
1737  * drop_nlink - directly drop an inode's link count
1738  * @inode: inode
1739  *
1740  * This is a low-level filesystem helper to replace any
1741  * direct filesystem manipulation of i_nlink.  In cases
1742  * where we are attempting to track writes to the
1743  * filesystem, a decrement to zero means an imminent
1744  * write when the file is truncated and actually unlinked
1745  * on the filesystem.
1746  */
1747 static inline void drop_nlink(struct inode *inode)
1748 {
1749 	inode->i_nlink--;
1750 }
1751 
1752 /**
1753  * clear_nlink - directly zero an inode's link count
1754  * @inode: inode
1755  *
1756  * This is a low-level filesystem helper to replace any
1757  * direct filesystem manipulation of i_nlink.  See
1758  * drop_nlink() for why we care about i_nlink hitting zero.
1759  */
1760 static inline void clear_nlink(struct inode *inode)
1761 {
1762 	inode->i_nlink = 0;
1763 }
1764 
1765 static inline void inode_dec_link_count(struct inode *inode)
1766 {
1767 	drop_nlink(inode);
1768 	mark_inode_dirty(inode);
1769 }
1770 
1771 /**
1772  * inode_inc_iversion - increments i_version
1773  * @inode: inode that need to be updated
1774  *
1775  * Every time the inode is modified, the i_version field will be incremented.
1776  * The filesystem has to be mounted with i_version flag
1777  */
1778 
1779 static inline void inode_inc_iversion(struct inode *inode)
1780 {
1781        spin_lock(&inode->i_lock);
1782        inode->i_version++;
1783        spin_unlock(&inode->i_lock);
1784 }
1785 
1786 extern void touch_atime(struct vfsmount *mnt, struct dentry *dentry);
1787 static inline void file_accessed(struct file *file)
1788 {
1789 	if (!(file->f_flags & O_NOATIME))
1790 		touch_atime(file->f_path.mnt, file->f_path.dentry);
1791 }
1792 
1793 int sync_inode(struct inode *inode, struct writeback_control *wbc);
1794 int sync_inode_metadata(struct inode *inode, int wait);
1795 
1796 struct file_system_type {
1797 	const char *name;
1798 	int fs_flags;
1799 	struct dentry *(*mount) (struct file_system_type *, int,
1800 		       const char *, void *);
1801 	void (*kill_sb) (struct super_block *);
1802 	struct module *owner;
1803 	struct file_system_type * next;
1804 	struct list_head fs_supers;
1805 
1806 	struct lock_class_key s_lock_key;
1807 	struct lock_class_key s_umount_key;
1808 	struct lock_class_key s_vfs_rename_key;
1809 
1810 	struct lock_class_key i_lock_key;
1811 	struct lock_class_key i_mutex_key;
1812 	struct lock_class_key i_mutex_dir_key;
1813 	struct lock_class_key i_alloc_sem_key;
1814 };
1815 
1816 extern struct dentry *mount_ns(struct file_system_type *fs_type, int flags,
1817 	void *data, int (*fill_super)(struct super_block *, void *, int));
1818 extern struct dentry *mount_bdev(struct file_system_type *fs_type,
1819 	int flags, const char *dev_name, void *data,
1820 	int (*fill_super)(struct super_block *, void *, int));
1821 extern struct dentry *mount_single(struct file_system_type *fs_type,
1822 	int flags, void *data,
1823 	int (*fill_super)(struct super_block *, void *, int));
1824 extern struct dentry *mount_nodev(struct file_system_type *fs_type,
1825 	int flags, void *data,
1826 	int (*fill_super)(struct super_block *, void *, int));
1827 void generic_shutdown_super(struct super_block *sb);
1828 void kill_block_super(struct super_block *sb);
1829 void kill_anon_super(struct super_block *sb);
1830 void kill_litter_super(struct super_block *sb);
1831 void deactivate_super(struct super_block *sb);
1832 void deactivate_locked_super(struct super_block *sb);
1833 int set_anon_super(struct super_block *s, void *data);
1834 struct super_block *sget(struct file_system_type *type,
1835 			int (*test)(struct super_block *,void *),
1836 			int (*set)(struct super_block *,void *),
1837 			void *data);
1838 extern struct dentry *mount_pseudo(struct file_system_type *, char *,
1839 	const struct super_operations *ops,
1840 	const struct dentry_operations *dops,
1841 	unsigned long);
1842 
1843 static inline void sb_mark_dirty(struct super_block *sb)
1844 {
1845 	sb->s_dirt = 1;
1846 }
1847 static inline void sb_mark_clean(struct super_block *sb)
1848 {
1849 	sb->s_dirt = 0;
1850 }
1851 static inline int sb_is_dirty(struct super_block *sb)
1852 {
1853 	return sb->s_dirt;
1854 }
1855 
1856 /* Alas, no aliases. Too much hassle with bringing module.h everywhere */
1857 #define fops_get(fops) \
1858 	(((fops) && try_module_get((fops)->owner) ? (fops) : NULL))
1859 #define fops_put(fops) \
1860 	do { if (fops) module_put((fops)->owner); } while(0)
1861 
1862 extern int register_filesystem(struct file_system_type *);
1863 extern int unregister_filesystem(struct file_system_type *);
1864 extern struct vfsmount *kern_mount_data(struct file_system_type *, void *data);
1865 #define kern_mount(type) kern_mount_data(type, NULL)
1866 extern int may_umount_tree(struct vfsmount *);
1867 extern int may_umount(struct vfsmount *);
1868 extern long do_mount(char *, char *, char *, unsigned long, void *);
1869 extern struct vfsmount *collect_mounts(struct path *);
1870 extern void drop_collected_mounts(struct vfsmount *);
1871 extern int iterate_mounts(int (*)(struct vfsmount *, void *), void *,
1872 			  struct vfsmount *);
1873 extern int vfs_statfs(struct path *, struct kstatfs *);
1874 extern int user_statfs(const char __user *, struct kstatfs *);
1875 extern int fd_statfs(int, struct kstatfs *);
1876 extern int statfs_by_dentry(struct dentry *, struct kstatfs *);
1877 extern int freeze_super(struct super_block *super);
1878 extern int thaw_super(struct super_block *super);
1879 
1880 extern int current_umask(void);
1881 
1882 /* /sys/fs */
1883 extern struct kobject *fs_kobj;
1884 
1885 #define MAX_RW_COUNT (INT_MAX & PAGE_CACHE_MASK)
1886 extern int rw_verify_area(int, struct file *, loff_t *, size_t);
1887 
1888 #define FLOCK_VERIFY_READ  1
1889 #define FLOCK_VERIFY_WRITE 2
1890 
1891 #ifdef CONFIG_FILE_LOCKING
1892 extern int locks_mandatory_locked(struct inode *);
1893 extern int locks_mandatory_area(int, struct inode *, struct file *, loff_t, size_t);
1894 
1895 /*
1896  * Candidates for mandatory locking have the setgid bit set
1897  * but no group execute bit -  an otherwise meaningless combination.
1898  */
1899 
1900 static inline int __mandatory_lock(struct inode *ino)
1901 {
1902 	return (ino->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID;
1903 }
1904 
1905 /*
1906  * ... and these candidates should be on MS_MANDLOCK mounted fs,
1907  * otherwise these will be advisory locks
1908  */
1909 
1910 static inline int mandatory_lock(struct inode *ino)
1911 {
1912 	return IS_MANDLOCK(ino) && __mandatory_lock(ino);
1913 }
1914 
1915 static inline int locks_verify_locked(struct inode *inode)
1916 {
1917 	if (mandatory_lock(inode))
1918 		return locks_mandatory_locked(inode);
1919 	return 0;
1920 }
1921 
1922 static inline int locks_verify_truncate(struct inode *inode,
1923 				    struct file *filp,
1924 				    loff_t size)
1925 {
1926 	if (inode->i_flock && mandatory_lock(inode))
1927 		return locks_mandatory_area(
1928 			FLOCK_VERIFY_WRITE, inode, filp,
1929 			size < inode->i_size ? size : inode->i_size,
1930 			(size < inode->i_size ? inode->i_size - size
1931 			 : size - inode->i_size)
1932 		);
1933 	return 0;
1934 }
1935 
1936 static inline int break_lease(struct inode *inode, unsigned int mode)
1937 {
1938 	if (inode->i_flock)
1939 		return __break_lease(inode, mode);
1940 	return 0;
1941 }
1942 #else /* !CONFIG_FILE_LOCKING */
1943 static inline int locks_mandatory_locked(struct inode *inode)
1944 {
1945 	return 0;
1946 }
1947 
1948 static inline int locks_mandatory_area(int rw, struct inode *inode,
1949 				       struct file *filp, loff_t offset,
1950 				       size_t count)
1951 {
1952 	return 0;
1953 }
1954 
1955 static inline int __mandatory_lock(struct inode *inode)
1956 {
1957 	return 0;
1958 }
1959 
1960 static inline int mandatory_lock(struct inode *inode)
1961 {
1962 	return 0;
1963 }
1964 
1965 static inline int locks_verify_locked(struct inode *inode)
1966 {
1967 	return 0;
1968 }
1969 
1970 static inline int locks_verify_truncate(struct inode *inode, struct file *filp,
1971 					size_t size)
1972 {
1973 	return 0;
1974 }
1975 
1976 static inline int break_lease(struct inode *inode, unsigned int mode)
1977 {
1978 	return 0;
1979 }
1980 
1981 #endif /* CONFIG_FILE_LOCKING */
1982 
1983 /* fs/open.c */
1984 
1985 extern int do_truncate(struct dentry *, loff_t start, unsigned int time_attrs,
1986 		       struct file *filp);
1987 extern int do_fallocate(struct file *file, int mode, loff_t offset,
1988 			loff_t len);
1989 extern long do_sys_open(int dfd, const char __user *filename, int flags,
1990 			int mode);
1991 extern struct file *filp_open(const char *, int, int);
1992 extern struct file *file_open_root(struct dentry *, struct vfsmount *,
1993 				   const char *, int);
1994 extern struct file * dentry_open(struct dentry *, struct vfsmount *, int,
1995 				 const struct cred *);
1996 extern int filp_close(struct file *, fl_owner_t id);
1997 extern char * getname(const char __user *);
1998 
1999 /* fs/ioctl.c */
2000 
2001 extern int ioctl_preallocate(struct file *filp, void __user *argp);
2002 
2003 /* fs/dcache.c */
2004 extern void __init vfs_caches_init_early(void);
2005 extern void __init vfs_caches_init(unsigned long);
2006 
2007 extern struct kmem_cache *names_cachep;
2008 
2009 #define __getname_gfp(gfp)	kmem_cache_alloc(names_cachep, (gfp))
2010 #define __getname()		__getname_gfp(GFP_KERNEL)
2011 #define __putname(name)		kmem_cache_free(names_cachep, (void *)(name))
2012 #ifndef CONFIG_AUDITSYSCALL
2013 #define putname(name)   __putname(name)
2014 #else
2015 extern void putname(const char *name);
2016 #endif
2017 
2018 #ifdef CONFIG_BLOCK
2019 extern int register_blkdev(unsigned int, const char *);
2020 extern void unregister_blkdev(unsigned int, const char *);
2021 extern struct block_device *bdget(dev_t);
2022 extern struct block_device *bdgrab(struct block_device *bdev);
2023 extern void bd_set_size(struct block_device *, loff_t size);
2024 extern void bd_forget(struct inode *inode);
2025 extern void bdput(struct block_device *);
2026 extern void invalidate_bdev(struct block_device *);
2027 extern int sync_blockdev(struct block_device *bdev);
2028 extern struct super_block *freeze_bdev(struct block_device *);
2029 extern void emergency_thaw_all(void);
2030 extern int thaw_bdev(struct block_device *bdev, struct super_block *sb);
2031 extern int fsync_bdev(struct block_device *);
2032 #else
2033 static inline void bd_forget(struct inode *inode) {}
2034 static inline int sync_blockdev(struct block_device *bdev) { return 0; }
2035 static inline void invalidate_bdev(struct block_device *bdev) {}
2036 
2037 static inline struct super_block *freeze_bdev(struct block_device *sb)
2038 {
2039 	return NULL;
2040 }
2041 
2042 static inline int thaw_bdev(struct block_device *bdev, struct super_block *sb)
2043 {
2044 	return 0;
2045 }
2046 #endif
2047 extern int sync_filesystem(struct super_block *);
2048 extern const struct file_operations def_blk_fops;
2049 extern const struct file_operations def_chr_fops;
2050 extern const struct file_operations bad_sock_fops;
2051 extern const struct file_operations def_fifo_fops;
2052 #ifdef CONFIG_BLOCK
2053 extern int ioctl_by_bdev(struct block_device *, unsigned, unsigned long);
2054 extern int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long);
2055 extern long compat_blkdev_ioctl(struct file *, unsigned, unsigned long);
2056 extern int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder);
2057 extern struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
2058 					       void *holder);
2059 extern struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode,
2060 					      void *holder);
2061 extern int blkdev_put(struct block_device *bdev, fmode_t mode);
2062 #ifdef CONFIG_SYSFS
2063 extern int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);
2064 extern void bd_unlink_disk_holder(struct block_device *bdev,
2065 				  struct gendisk *disk);
2066 #else
2067 static inline int bd_link_disk_holder(struct block_device *bdev,
2068 				      struct gendisk *disk)
2069 {
2070 	return 0;
2071 }
2072 static inline void bd_unlink_disk_holder(struct block_device *bdev,
2073 					 struct gendisk *disk)
2074 {
2075 }
2076 #endif
2077 #endif
2078 
2079 /* fs/char_dev.c */
2080 #define CHRDEV_MAJOR_HASH_SIZE	255
2081 extern int alloc_chrdev_region(dev_t *, unsigned, unsigned, const char *);
2082 extern int register_chrdev_region(dev_t, unsigned, const char *);
2083 extern int __register_chrdev(unsigned int major, unsigned int baseminor,
2084 			     unsigned int count, const char *name,
2085 			     const struct file_operations *fops);
2086 extern void __unregister_chrdev(unsigned int major, unsigned int baseminor,
2087 				unsigned int count, const char *name);
2088 extern void unregister_chrdev_region(dev_t, unsigned);
2089 extern void chrdev_show(struct seq_file *,off_t);
2090 
2091 static inline int register_chrdev(unsigned int major, const char *name,
2092 				  const struct file_operations *fops)
2093 {
2094 	return __register_chrdev(major, 0, 256, name, fops);
2095 }
2096 
2097 static inline void unregister_chrdev(unsigned int major, const char *name)
2098 {
2099 	__unregister_chrdev(major, 0, 256, name);
2100 }
2101 
2102 /* fs/block_dev.c */
2103 #define BDEVNAME_SIZE	32	/* Largest string for a blockdev identifier */
2104 #define BDEVT_SIZE	10	/* Largest string for MAJ:MIN for blkdev */
2105 
2106 #ifdef CONFIG_BLOCK
2107 #define BLKDEV_MAJOR_HASH_SIZE	255
2108 extern const char *__bdevname(dev_t, char *buffer);
2109 extern const char *bdevname(struct block_device *bdev, char *buffer);
2110 extern struct block_device *lookup_bdev(const char *);
2111 extern void blkdev_show(struct seq_file *,off_t);
2112 
2113 #else
2114 #define BLKDEV_MAJOR_HASH_SIZE	0
2115 #endif
2116 
2117 extern void init_special_inode(struct inode *, umode_t, dev_t);
2118 
2119 /* Invalid inode operations -- fs/bad_inode.c */
2120 extern void make_bad_inode(struct inode *);
2121 extern int is_bad_inode(struct inode *);
2122 
2123 extern const struct file_operations read_pipefifo_fops;
2124 extern const struct file_operations write_pipefifo_fops;
2125 extern const struct file_operations rdwr_pipefifo_fops;
2126 
2127 extern int fs_may_remount_ro(struct super_block *);
2128 
2129 #ifdef CONFIG_BLOCK
2130 /*
2131  * return READ, READA, or WRITE
2132  */
2133 #define bio_rw(bio)		((bio)->bi_rw & (RW_MASK | RWA_MASK))
2134 
2135 /*
2136  * return data direction, READ or WRITE
2137  */
2138 #define bio_data_dir(bio)	((bio)->bi_rw & 1)
2139 
2140 extern void check_disk_size_change(struct gendisk *disk,
2141 				   struct block_device *bdev);
2142 extern int revalidate_disk(struct gendisk *);
2143 extern int check_disk_change(struct block_device *);
2144 extern int __invalidate_device(struct block_device *, bool);
2145 extern int invalidate_partition(struct gendisk *, int);
2146 #endif
2147 unsigned long invalidate_mapping_pages(struct address_space *mapping,
2148 					pgoff_t start, pgoff_t end);
2149 
2150 static inline void invalidate_remote_inode(struct inode *inode)
2151 {
2152 	if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2153 	    S_ISLNK(inode->i_mode))
2154 		invalidate_mapping_pages(inode->i_mapping, 0, -1);
2155 }
2156 extern int invalidate_inode_pages2(struct address_space *mapping);
2157 extern int invalidate_inode_pages2_range(struct address_space *mapping,
2158 					 pgoff_t start, pgoff_t end);
2159 extern int write_inode_now(struct inode *, int);
2160 extern int filemap_fdatawrite(struct address_space *);
2161 extern int filemap_flush(struct address_space *);
2162 extern int filemap_fdatawait(struct address_space *);
2163 extern int filemap_fdatawait_range(struct address_space *, loff_t lstart,
2164 				   loff_t lend);
2165 extern int filemap_write_and_wait(struct address_space *mapping);
2166 extern int filemap_write_and_wait_range(struct address_space *mapping,
2167 				        loff_t lstart, loff_t lend);
2168 extern int __filemap_fdatawrite_range(struct address_space *mapping,
2169 				loff_t start, loff_t end, int sync_mode);
2170 extern int filemap_fdatawrite_range(struct address_space *mapping,
2171 				loff_t start, loff_t end);
2172 
2173 extern int vfs_fsync_range(struct file *file, loff_t start, loff_t end,
2174 			   int datasync);
2175 extern int vfs_fsync(struct file *file, int datasync);
2176 extern int generic_write_sync(struct file *file, loff_t pos, loff_t count);
2177 extern void sync_supers(void);
2178 extern void emergency_sync(void);
2179 extern void emergency_remount(void);
2180 #ifdef CONFIG_BLOCK
2181 extern sector_t bmap(struct inode *, sector_t);
2182 #endif
2183 extern int notify_change(struct dentry *, struct iattr *);
2184 extern int inode_permission(struct inode *, int);
2185 extern int generic_permission(struct inode *, int, unsigned int,
2186 		int (*check_acl)(struct inode *, int, unsigned int));
2187 
2188 static inline bool execute_ok(struct inode *inode)
2189 {
2190 	return (inode->i_mode & S_IXUGO) || S_ISDIR(inode->i_mode);
2191 }
2192 
2193 extern int get_write_access(struct inode *);
2194 extern int deny_write_access(struct file *);
2195 static inline void put_write_access(struct inode * inode)
2196 {
2197 	atomic_dec(&inode->i_writecount);
2198 }
2199 static inline void allow_write_access(struct file *file)
2200 {
2201 	if (file)
2202 		atomic_inc(&file->f_path.dentry->d_inode->i_writecount);
2203 }
2204 #ifdef CONFIG_IMA
2205 static inline void i_readcount_dec(struct inode *inode)
2206 {
2207 	BUG_ON(!atomic_read(&inode->i_readcount));
2208 	atomic_dec(&inode->i_readcount);
2209 }
2210 static inline void i_readcount_inc(struct inode *inode)
2211 {
2212 	atomic_inc(&inode->i_readcount);
2213 }
2214 #else
2215 static inline void i_readcount_dec(struct inode *inode)
2216 {
2217 	return;
2218 }
2219 static inline void i_readcount_inc(struct inode *inode)
2220 {
2221 	return;
2222 }
2223 #endif
2224 extern int do_pipe_flags(int *, int);
2225 extern struct file *create_read_pipe(struct file *f, int flags);
2226 extern struct file *create_write_pipe(int flags);
2227 extern void free_write_pipe(struct file *);
2228 
2229 extern int kernel_read(struct file *, loff_t, char *, unsigned long);
2230 extern struct file * open_exec(const char *);
2231 
2232 /* fs/dcache.c -- generic fs support functions */
2233 extern int is_subdir(struct dentry *, struct dentry *);
2234 extern int path_is_under(struct path *, struct path *);
2235 extern ino_t find_inode_number(struct dentry *, struct qstr *);
2236 
2237 #include <linux/err.h>
2238 
2239 /* needed for stackable file system support */
2240 extern loff_t default_llseek(struct file *file, loff_t offset, int origin);
2241 
2242 extern loff_t vfs_llseek(struct file *file, loff_t offset, int origin);
2243 
2244 extern int inode_init_always(struct super_block *, struct inode *);
2245 extern void inode_init_once(struct inode *);
2246 extern void address_space_init_once(struct address_space *mapping);
2247 extern void ihold(struct inode * inode);
2248 extern void iput(struct inode *);
2249 extern struct inode * igrab(struct inode *);
2250 extern ino_t iunique(struct super_block *, ino_t);
2251 extern int inode_needs_sync(struct inode *inode);
2252 extern int generic_delete_inode(struct inode *inode);
2253 extern int generic_drop_inode(struct inode *inode);
2254 
2255 extern struct inode *ilookup5_nowait(struct super_block *sb,
2256 		unsigned long hashval, int (*test)(struct inode *, void *),
2257 		void *data);
2258 extern struct inode *ilookup5(struct super_block *sb, unsigned long hashval,
2259 		int (*test)(struct inode *, void *), void *data);
2260 extern struct inode *ilookup(struct super_block *sb, unsigned long ino);
2261 
2262 extern struct inode * iget5_locked(struct super_block *, unsigned long, int (*test)(struct inode *, void *), int (*set)(struct inode *, void *), void *);
2263 extern struct inode * iget_locked(struct super_block *, unsigned long);
2264 extern int insert_inode_locked4(struct inode *, unsigned long, int (*test)(struct inode *, void *), void *);
2265 extern int insert_inode_locked(struct inode *);
2266 extern void unlock_new_inode(struct inode *);
2267 extern unsigned int get_next_ino(void);
2268 
2269 extern void __iget(struct inode * inode);
2270 extern void iget_failed(struct inode *);
2271 extern void end_writeback(struct inode *);
2272 extern void __destroy_inode(struct inode *);
2273 extern struct inode *new_inode(struct super_block *);
2274 extern void free_inode_nonrcu(struct inode *inode);
2275 extern int should_remove_suid(struct dentry *);
2276 extern int file_remove_suid(struct file *);
2277 
2278 extern void __insert_inode_hash(struct inode *, unsigned long hashval);
2279 extern void remove_inode_hash(struct inode *);
2280 static inline void insert_inode_hash(struct inode *inode)
2281 {
2282 	__insert_inode_hash(inode, inode->i_ino);
2283 }
2284 extern void inode_sb_list_add(struct inode *inode);
2285 
2286 #ifdef CONFIG_BLOCK
2287 extern void submit_bio(int, struct bio *);
2288 extern int bdev_read_only(struct block_device *);
2289 #endif
2290 extern int set_blocksize(struct block_device *, int);
2291 extern int sb_set_blocksize(struct super_block *, int);
2292 extern int sb_min_blocksize(struct super_block *, int);
2293 
2294 extern int generic_file_mmap(struct file *, struct vm_area_struct *);
2295 extern int generic_file_readonly_mmap(struct file *, struct vm_area_struct *);
2296 extern int file_read_actor(read_descriptor_t * desc, struct page *page, unsigned long offset, unsigned long size);
2297 int generic_write_checks(struct file *file, loff_t *pos, size_t *count, int isblk);
2298 extern ssize_t generic_file_aio_read(struct kiocb *, const struct iovec *, unsigned long, loff_t);
2299 extern ssize_t __generic_file_aio_write(struct kiocb *, const struct iovec *, unsigned long,
2300 		loff_t *);
2301 extern ssize_t generic_file_aio_write(struct kiocb *, const struct iovec *, unsigned long, loff_t);
2302 extern ssize_t generic_file_direct_write(struct kiocb *, const struct iovec *,
2303 		unsigned long *, loff_t, loff_t *, size_t, size_t);
2304 extern ssize_t generic_file_buffered_write(struct kiocb *, const struct iovec *,
2305 		unsigned long, loff_t, loff_t *, size_t, ssize_t);
2306 extern ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos);
2307 extern ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos);
2308 extern int generic_segment_checks(const struct iovec *iov,
2309 		unsigned long *nr_segs, size_t *count, int access_flags);
2310 
2311 /* fs/block_dev.c */
2312 extern ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov,
2313 				unsigned long nr_segs, loff_t pos);
2314 extern int blkdev_fsync(struct file *filp, int datasync);
2315 
2316 /* fs/splice.c */
2317 extern ssize_t generic_file_splice_read(struct file *, loff_t *,
2318 		struct pipe_inode_info *, size_t, unsigned int);
2319 extern ssize_t default_file_splice_read(struct file *, loff_t *,
2320 		struct pipe_inode_info *, size_t, unsigned int);
2321 extern ssize_t generic_file_splice_write(struct pipe_inode_info *,
2322 		struct file *, loff_t *, size_t, unsigned int);
2323 extern ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe,
2324 		struct file *out, loff_t *, size_t len, unsigned int flags);
2325 extern long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
2326 		size_t len, unsigned int flags);
2327 
2328 extern void
2329 file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping);
2330 extern loff_t noop_llseek(struct file *file, loff_t offset, int origin);
2331 extern loff_t no_llseek(struct file *file, loff_t offset, int origin);
2332 extern loff_t generic_file_llseek(struct file *file, loff_t offset, int origin);
2333 extern loff_t generic_file_llseek_unlocked(struct file *file, loff_t offset,
2334 			int origin);
2335 extern int generic_file_open(struct inode * inode, struct file * filp);
2336 extern int nonseekable_open(struct inode * inode, struct file * filp);
2337 
2338 #ifdef CONFIG_FS_XIP
2339 extern ssize_t xip_file_read(struct file *filp, char __user *buf, size_t len,
2340 			     loff_t *ppos);
2341 extern int xip_file_mmap(struct file * file, struct vm_area_struct * vma);
2342 extern ssize_t xip_file_write(struct file *filp, const char __user *buf,
2343 			      size_t len, loff_t *ppos);
2344 extern int xip_truncate_page(struct address_space *mapping, loff_t from);
2345 #else
2346 static inline int xip_truncate_page(struct address_space *mapping, loff_t from)
2347 {
2348 	return 0;
2349 }
2350 #endif
2351 
2352 #ifdef CONFIG_BLOCK
2353 typedef void (dio_submit_t)(int rw, struct bio *bio, struct inode *inode,
2354 			    loff_t file_offset);
2355 
2356 enum {
2357 	/* need locking between buffered and direct access */
2358 	DIO_LOCKING	= 0x01,
2359 
2360 	/* filesystem does not support filling holes */
2361 	DIO_SKIP_HOLES	= 0x02,
2362 };
2363 
2364 void dio_end_io(struct bio *bio, int error);
2365 
2366 ssize_t __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
2367 	struct block_device *bdev, const struct iovec *iov, loff_t offset,
2368 	unsigned long nr_segs, get_block_t get_block, dio_iodone_t end_io,
2369 	dio_submit_t submit_io,	int flags);
2370 
2371 static inline ssize_t blockdev_direct_IO(int rw, struct kiocb *iocb,
2372 	struct inode *inode, struct block_device *bdev, const struct iovec *iov,
2373 	loff_t offset, unsigned long nr_segs, get_block_t get_block,
2374 	dio_iodone_t end_io)
2375 {
2376 	return __blockdev_direct_IO(rw, iocb, inode, bdev, iov, offset,
2377 				    nr_segs, get_block, end_io, NULL,
2378 				    DIO_LOCKING | DIO_SKIP_HOLES);
2379 }
2380 #endif
2381 
2382 extern const struct file_operations generic_ro_fops;
2383 
2384 #define special_file(m) (S_ISCHR(m)||S_ISBLK(m)||S_ISFIFO(m)||S_ISSOCK(m))
2385 
2386 extern int vfs_readlink(struct dentry *, char __user *, int, const char *);
2387 extern int vfs_follow_link(struct nameidata *, const char *);
2388 extern int page_readlink(struct dentry *, char __user *, int);
2389 extern void *page_follow_link_light(struct dentry *, struct nameidata *);
2390 extern void page_put_link(struct dentry *, struct nameidata *, void *);
2391 extern int __page_symlink(struct inode *inode, const char *symname, int len,
2392 		int nofs);
2393 extern int page_symlink(struct inode *inode, const char *symname, int len);
2394 extern const struct inode_operations page_symlink_inode_operations;
2395 extern int generic_readlink(struct dentry *, char __user *, int);
2396 extern void generic_fillattr(struct inode *, struct kstat *);
2397 extern int vfs_getattr(struct vfsmount *, struct dentry *, struct kstat *);
2398 void __inode_add_bytes(struct inode *inode, loff_t bytes);
2399 void inode_add_bytes(struct inode *inode, loff_t bytes);
2400 void inode_sub_bytes(struct inode *inode, loff_t bytes);
2401 loff_t inode_get_bytes(struct inode *inode);
2402 void inode_set_bytes(struct inode *inode, loff_t bytes);
2403 
2404 extern int vfs_readdir(struct file *, filldir_t, void *);
2405 
2406 extern int vfs_stat(const char __user *, struct kstat *);
2407 extern int vfs_lstat(const char __user *, struct kstat *);
2408 extern int vfs_fstat(unsigned int, struct kstat *);
2409 extern int vfs_fstatat(int , const char __user *, struct kstat *, int);
2410 
2411 extern int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd,
2412 		    unsigned long arg);
2413 extern int __generic_block_fiemap(struct inode *inode,
2414 				  struct fiemap_extent_info *fieinfo,
2415 				  loff_t start, loff_t len,
2416 				  get_block_t *get_block);
2417 extern int generic_block_fiemap(struct inode *inode,
2418 				struct fiemap_extent_info *fieinfo, u64 start,
2419 				u64 len, get_block_t *get_block);
2420 
2421 extern void get_filesystem(struct file_system_type *fs);
2422 extern void put_filesystem(struct file_system_type *fs);
2423 extern struct file_system_type *get_fs_type(const char *name);
2424 extern struct super_block *get_super(struct block_device *);
2425 extern struct super_block *get_active_super(struct block_device *bdev);
2426 extern struct super_block *user_get_super(dev_t);
2427 extern void drop_super(struct super_block *sb);
2428 extern void iterate_supers(void (*)(struct super_block *, void *), void *);
2429 
2430 extern int dcache_dir_open(struct inode *, struct file *);
2431 extern int dcache_dir_close(struct inode *, struct file *);
2432 extern loff_t dcache_dir_lseek(struct file *, loff_t, int);
2433 extern int dcache_readdir(struct file *, void *, filldir_t);
2434 extern int simple_setattr(struct dentry *, struct iattr *);
2435 extern int simple_getattr(struct vfsmount *, struct dentry *, struct kstat *);
2436 extern int simple_statfs(struct dentry *, struct kstatfs *);
2437 extern int simple_link(struct dentry *, struct inode *, struct dentry *);
2438 extern int simple_unlink(struct inode *, struct dentry *);
2439 extern int simple_rmdir(struct inode *, struct dentry *);
2440 extern int simple_rename(struct inode *, struct dentry *, struct inode *, struct dentry *);
2441 extern int noop_fsync(struct file *, int);
2442 extern int simple_empty(struct dentry *);
2443 extern int simple_readpage(struct file *file, struct page *page);
2444 extern int simple_write_begin(struct file *file, struct address_space *mapping,
2445 			loff_t pos, unsigned len, unsigned flags,
2446 			struct page **pagep, void **fsdata);
2447 extern int simple_write_end(struct file *file, struct address_space *mapping,
2448 			loff_t pos, unsigned len, unsigned copied,
2449 			struct page *page, void *fsdata);
2450 
2451 extern struct dentry *simple_lookup(struct inode *, struct dentry *, struct nameidata *);
2452 extern ssize_t generic_read_dir(struct file *, char __user *, size_t, loff_t *);
2453 extern const struct file_operations simple_dir_operations;
2454 extern const struct inode_operations simple_dir_inode_operations;
2455 struct tree_descr { char *name; const struct file_operations *ops; int mode; };
2456 struct dentry *d_alloc_name(struct dentry *, const char *);
2457 extern int simple_fill_super(struct super_block *, unsigned long, struct tree_descr *);
2458 extern int simple_pin_fs(struct file_system_type *, struct vfsmount **mount, int *count);
2459 extern void simple_release_fs(struct vfsmount **mount, int *count);
2460 
2461 extern ssize_t simple_read_from_buffer(void __user *to, size_t count,
2462 			loff_t *ppos, const void *from, size_t available);
2463 extern ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos,
2464 		const void __user *from, size_t count);
2465 
2466 extern int generic_file_fsync(struct file *, int);
2467 
2468 extern int generic_check_addressable(unsigned, u64);
2469 
2470 #ifdef CONFIG_MIGRATION
2471 extern int buffer_migrate_page(struct address_space *,
2472 				struct page *, struct page *);
2473 #else
2474 #define buffer_migrate_page NULL
2475 #endif
2476 
2477 extern int inode_change_ok(const struct inode *, struct iattr *);
2478 extern int inode_newsize_ok(const struct inode *, loff_t offset);
2479 extern void setattr_copy(struct inode *inode, const struct iattr *attr);
2480 
2481 extern void file_update_time(struct file *file);
2482 
2483 extern int generic_show_options(struct seq_file *m, struct vfsmount *mnt);
2484 extern void save_mount_options(struct super_block *sb, char *options);
2485 extern void replace_mount_options(struct super_block *sb, char *options);
2486 
2487 static inline ino_t parent_ino(struct dentry *dentry)
2488 {
2489 	ino_t res;
2490 
2491 	/*
2492 	 * Don't strictly need d_lock here? If the parent ino could change
2493 	 * then surely we'd have a deeper race in the caller?
2494 	 */
2495 	spin_lock(&dentry->d_lock);
2496 	res = dentry->d_parent->d_inode->i_ino;
2497 	spin_unlock(&dentry->d_lock);
2498 	return res;
2499 }
2500 
2501 /* Transaction based IO helpers */
2502 
2503 /*
2504  * An argresp is stored in an allocated page and holds the
2505  * size of the argument or response, along with its content
2506  */
2507 struct simple_transaction_argresp {
2508 	ssize_t size;
2509 	char data[0];
2510 };
2511 
2512 #define SIMPLE_TRANSACTION_LIMIT (PAGE_SIZE - sizeof(struct simple_transaction_argresp))
2513 
2514 char *simple_transaction_get(struct file *file, const char __user *buf,
2515 				size_t size);
2516 ssize_t simple_transaction_read(struct file *file, char __user *buf,
2517 				size_t size, loff_t *pos);
2518 int simple_transaction_release(struct inode *inode, struct file *file);
2519 
2520 void simple_transaction_set(struct file *file, size_t n);
2521 
2522 /*
2523  * simple attribute files
2524  *
2525  * These attributes behave similar to those in sysfs:
2526  *
2527  * Writing to an attribute immediately sets a value, an open file can be
2528  * written to multiple times.
2529  *
2530  * Reading from an attribute creates a buffer from the value that might get
2531  * read with multiple read calls. When the attribute has been read
2532  * completely, no further read calls are possible until the file is opened
2533  * again.
2534  *
2535  * All attributes contain a text representation of a numeric value
2536  * that are accessed with the get() and set() functions.
2537  */
2538 #define DEFINE_SIMPLE_ATTRIBUTE(__fops, __get, __set, __fmt)		\
2539 static int __fops ## _open(struct inode *inode, struct file *file)	\
2540 {									\
2541 	__simple_attr_check_format(__fmt, 0ull);			\
2542 	return simple_attr_open(inode, file, __get, __set, __fmt);	\
2543 }									\
2544 static const struct file_operations __fops = {				\
2545 	.owner	 = THIS_MODULE,						\
2546 	.open	 = __fops ## _open,					\
2547 	.release = simple_attr_release,					\
2548 	.read	 = simple_attr_read,					\
2549 	.write	 = simple_attr_write,					\
2550 	.llseek	 = generic_file_llseek,					\
2551 };
2552 
2553 static inline void __attribute__((format(printf, 1, 2)))
2554 __simple_attr_check_format(const char *fmt, ...)
2555 {
2556 	/* don't do anything, just let the compiler check the arguments; */
2557 }
2558 
2559 int simple_attr_open(struct inode *inode, struct file *file,
2560 		     int (*get)(void *, u64 *), int (*set)(void *, u64),
2561 		     const char *fmt);
2562 int simple_attr_release(struct inode *inode, struct file *file);
2563 ssize_t simple_attr_read(struct file *file, char __user *buf,
2564 			 size_t len, loff_t *ppos);
2565 ssize_t simple_attr_write(struct file *file, const char __user *buf,
2566 			  size_t len, loff_t *ppos);
2567 
2568 struct ctl_table;
2569 int proc_nr_files(struct ctl_table *table, int write,
2570 		  void __user *buffer, size_t *lenp, loff_t *ppos);
2571 int proc_nr_dentry(struct ctl_table *table, int write,
2572 		  void __user *buffer, size_t *lenp, loff_t *ppos);
2573 int proc_nr_inodes(struct ctl_table *table, int write,
2574 		   void __user *buffer, size_t *lenp, loff_t *ppos);
2575 int __init get_filesystem_list(char *buf);
2576 
2577 #define __FMODE_EXEC		((__force int) FMODE_EXEC)
2578 #define __FMODE_NONOTIFY	((__force int) FMODE_NONOTIFY)
2579 
2580 #define ACC_MODE(x) ("\004\002\006\006"[(x)&O_ACCMODE])
2581 #define OPEN_FMODE(flag) ((__force fmode_t)(((flag + 1) & O_ACCMODE) | \
2582 					    (flag & __FMODE_NONOTIFY)))
2583 
2584 #endif /* __KERNEL__ */
2585 #endif /* _LINUX_FS_H */
2586